updated version numbers for release

update doc CAP_NET_RAW, remove CAP_SETUID/SETGID

ChangeLog

@@ -1,3 +1,108 @@
+v1.22: 17AUG2021
+	sslh-select now supports UDP protocols.
+	Probes specified in the `protocols`
+	configuration entry are tried on incoming packets,
+	TCP or UDP, and forwarded based on the input
+	protocol (an incoming TCP connection will be
+	forwarded as TCP, and same with UDP).
+	This has been tested with DNS as shown in udp.cfg:
+	incoming packets that contain my domain name are
+	assumed to be a DNS request and forwarded
+	accordingly. Note this could cause problems if
+	combined with incoming TLS with SNI.  UDP clients
+	and servers need to agree on the IPv4/IPv6 they use:
+	use the same protocol on all sides! Often, this
+	means explicitely using 'ip4-localhost'.
+	UDP sender-receiver pairs (connections, so to speak)
+	are kept for 60s, which can be changed with
+	`udp_timeout` in the configuration.
+
+	Added probes for UDP protocols QUICK and Teamspeak.
+
+	Added probes for syslog protocol.
+
+	sslh-select refactored to change linear searches
+	through connections to linear searches through
+	fd_set.
+
+	Fixed a libconfig call to support libconfig 1.7.3.
+
+	Added symbol to support libconfig 1.4.9, still in
+	use in CentOS7.
+
+	Warn about unknown settings in the configuration
+	file.
+
+	Added per-protocol `transparent` option. sslh-fork
+	drops the capability after creating the server-side
+	transparent socket. Transparent now uses CAP_NET_RAW
+	instead of CAP_NET_ADMIN.
+
+	Removed compile-time option to use POSIX regex. Now
+	regex must be PCRE2 (Perl-Compatible). This was in
+	fact the case since v1.21, as PCRE are used to parse
+	the config file.
+
+v1.21: 11JUL2020
+	WARNING:
+	Moved configuration and command-line management to
+	use conf2struct. Changes are:
+	* `--ssl` and using `name: 'ssl'` in config file is no longer supported, use `tls` instead.
+	* command line option <-F|--config> no longer defaults to /etc/sslh.cfg, so you have to
+	specify it explicitly.
+	* command line option <-v|--verbose> takes a mandatory integer parameter
+
+	Added TCP_FASTOPEN support for client sockets (if
+	tfo_ok is specified in their configuration) and for
+	listenint socket, if all client protocols support it.
+	(Craig Andrews)
+
+	Added 'minlength' option to skip a probe if less
+	than that many bytes have been received (mostly for
+	regex)
+
+	Update Let's Encrypt entry in example.cfg for tls-alpn-01
+	challenges; tls-sni-* challenges are now deprecated.
+
+	Log to syslog even if in foreground (for people who
+	use fail2ban)
+
+	Use syslog_facility: "none" to disable syslog
+	output.
+
+	Changed exit code for illegal command line parameter
+	from 1 to 6 (for testing purposes)
+
+v1.20: 20NOV2018
+	Added support for socks5 protocol (Eugene Protozanov)
+
+	New probing method:
+	Before, probes were tried in order, repeating on the
+	same probe as long it returned PROBE_AGAIN before
+	moving to the next one. This means a probe which
+	requires a lot of data (i.e. returne PROBE_AGAIN for
+	a long time) could prevent sucessful matches from 
+	subsequent probes. The configuration file needed to
+	take that into account.
+
+	Now, all probes are tried each time new data is
+	found. If any probe matches, use it. If at least one
+	probe requires more data, wait for more. If all
+	probes failed, connect to the last one. So the only
+	thing to know when writing the configuration file is
+	that 'anyprot' needs to be last.
+
+	Test suite heavily refactored; `t` uses `test.cfg`
+	to decide which probes to test and all setup is
+	automatic; probes get tested with 'fast' (entire
+	first message in one packet) and 'slow' (one byte at
+	a time); when SNI/ALPN are defined, all combinations
+	are tested.
+
+	Old 'tls' probe removed, 'sni_alpn' probe renamed as 'tls'.
+	You'll need to change 'sni_alpn' to 'tls' in
+	your configuration file, if ever you used it.
+
 v1.19: 20JAN2018
 	Added 'syslog_facility' configuration option to
 	specify where to log.

Dockerfile

@@ -0,0 +1,23 @@
+FROM alpine:latest as build
+
+ADD . /sslh
+
+RUN \
+  apk add \
+    gcc \
+    libconfig-dev \
+    make \
+    musl-dev \
+    pcre-dev \
+    perl && \
+  cd /sslh && \
+  make sslh-select && \
+  strip sslh-select
+
+FROM alpine:latest
+
+COPY --from=build /sslh/sslh-select /sslh
+
+RUN apk --no-cache add libconfig pcre
+
+ENTRYPOINT [ "/sslh", "--foreground"]

Makefile

@@ -1,12 +1,14 @@
-# Configuration
 
 VERSION=$(shell ./genver.sh -r)
+
+# Configuration -- you probably need to `make clean` if you
+# change any of these
 ENABLE_REGEX=1  # Enable regex probes
 USELIBCONFIG=1	# Use libconfig? (necessary to use configuration files)
-USELIBPCRE=1	# Use libpcre? (needed for regex on musl)
 USELIBWRAP?=	# Use libwrap?
 USELIBCAP=	# Use libcap?
 USESYSTEMD=     # Make use of systemd socket activation
+USELIBBSD?=     # Use libbsd (needed to update process name in `ps`)
 COV_TEST= 	# Perform test coverage?
 PREFIX?=/usr
 BINDIR?=$(PREFIX)/sbin
@@ -22,10 +24,10 @@ ifneq ($(strip $(COV_TEST)),)
 endif
 
 CC ?= gcc
-CFLAGS ?=-Wall -g $(CFLAGS_COV)
+CFLAGS ?=-Wall -DLIBPCRE -g $(CFLAGS_COV)
 
-LIBS=
-OBJS=common.o sslh-main.o probe.o tls.o
+LIBS=-lm -lpcre2-8
+OBJS=sslh-conf.o common.o sslh-main.o probe.o tls.o argtable3.o udp-listener.o collection.o gap.o
 
 CONDITIONAL_TARGETS=
 
@@ -38,11 +40,6 @@ ifneq ($(strip $(ENABLE_REGEX)),)
 	CPPFLAGS+=-DENABLE_REGEX
 endif
 
-ifneq ($(strip $(USELIBPCRE)),)
-	CPPFLAGS+=-DLIBPCRE
-	LIBS:=$(LIBS) -lpcreposix
-endif
-
 ifneq ($(strip $(USELIBCONFIG)),)
 	LIBS:=$(LIBS) -lconfig
 	CPPFLAGS+=-DLIBCONFIG
@@ -59,6 +56,11 @@ ifneq ($(strip $(USESYSTEMD)),)
 	CONDITIONAL_TARGETS+=systemd-sslh-generator
 endif
 
+ifneq ($(strip $(USELIBBSD)),)
+        LIBS:=$(LIBS) -lbsd
+        CPPFLAGS+=-DLIBBSD
+endif
+
 
 all: sslh $(MAN) echosrv $(CONDITIONAL_TARGETS)
 
@@ -70,21 +72,27 @@ version.h:
 
 sslh: sslh-fork sslh-select
 
-$(OBJS): version.h
+$(OBJS): version.h common.h collection.h sslh-conf.h gap.h
 
-sslh-fork: version.h $(OBJS) sslh-fork.o Makefile common.h
+sslh-conf.c sslh-conf.h: sslhconf.cfg
+	conf2struct sslhconf.cfg
+
+sslh-fork: version.h $(OBJS) sslh-fork.o Makefile
 	$(CC) $(CFLAGS) $(LDFLAGS) -o sslh-fork sslh-fork.o $(OBJS) $(LIBS)
 	#strip sslh-fork
 
-sslh-select: version.h $(OBJS) sslh-select.o Makefile common.h
+sslh-select: version.h $(OBJS) sslh-select.o Makefile
 	$(CC) $(CFLAGS) $(LDFLAGS) -o sslh-select sslh-select.o $(OBJS) $(LIBS)
 	#strip sslh-select
 
 systemd-sslh-generator: systemd-sslh-generator.o
 	$(CC) $(CFLAGS) $(LDFLAGS) -o systemd-sslh-generator systemd-sslh-generator.o -lconfig
 
-echosrv: version.h $(OBJS) echosrv.o
-	$(CC) $(CFLAGS) $(LDFLAGS) -o echosrv echosrv.o probe.o common.o tls.o $(LIBS)
+echosrv-conf.c echosrv-conf.h: echosrv.cfg
+	conf2struct echosrv.cfg
+
+echosrv: version.h echosrv-conf.c echosrv.o echosrv-conf.o argtable3.o
+	$(CC) $(CFLAGS) $(LDFLAGS) -o echosrv echosrv.o echosrv-conf.o argtable3.o $(LIBS)
 
 $(MAN): sslh.pod Makefile
 	pod2man --section=8 --release=$(VERSION) --center=" " sslh.pod | gzip -9 - > $(MAN)
@@ -93,6 +101,16 @@ $(MAN): sslh.pod Makefile
 # configuration
 release:
 	git archive master --prefix="sslh-$(VERSION)/" | gzip > /tmp/sslh-$(VERSION).tar.gz
+	gpg --detach-sign --armor /tmp/sslh-$(VERSION).tar.gz
+
+# Build docker image
+docker:
+	docker image build -t "sslh:${VERSION}" .
+	docker image tag "sslh:${VERSION}" sslh:latest
+
+docker-clean:
+	yes | docker image rm "sslh:${VERSION}" sslh:latest
+	yes | docker image prune
 
 # generic install: install binary and man page
 install: sslh $(MAN)
@@ -112,7 +130,7 @@ uninstall:
 	update-rc.d sslh remove
 
 distclean: clean
-	rm -f tags cscope.*
+	rm -f tags sslh-conf.[ch] echosrv-conf.[ch] cscope.*
 
 clean:
 	rm -f sslh-fork sslh-select echosrv version.h $(MAN) systemd-sslh-generator *.o *.gcov *.gcno *.gcda *.png *.html *.css *.info

README.md

@@ -5,444 +5,94 @@ sslh -- A ssl/ssh multiplexer
 them further based on tests performed on the first data
 packet sent by the remote client.
 
-Probes for HTTP, SSL, SSH, OpenVPN, tinc, XMPP are
-implemented, and any other protocol that can be tested using
-a regular expression, can be recognised. A typical use case
-is to allow serving several services on port 443 (e.g. to
-connect to SSH from inside a corporate firewall, which
-almost never block port 443) while still serving HTTPS on
-that port. 
+Probes for HTTP, TLS/SSL (including SNI and ALPN), SSH,
+OpenVPN, tinc, XMPP, SOCKS5, are implemented, and any other
+protocol that can be tested using a regular expression, can
+be recognised. A typical use case is to allow serving
+several services on port 443 (e.g. to connect to SSH from
+inside a corporate firewall, which almost never block port
+443) while still serving HTTPS on that port. 
 
 Hence `sslh` acts as a protocol demultiplexer, or a
-switchboard. Its name comes from its original function to
-serve SSH and HTTPS on the same port.
+switchboard. With the SNI and ALPN probe, it makes a good
+front-end to a virtual host farm hosted behind a single IP
+address.
 
-Compile and install
-===================
+`sslh` has the bells and whistles expected from a mature
+daemon: privilege and capabilities dropping, inetd support,
+systemd support, transparent proxying, chroot, logging, 
+IPv4 and IPv6, TCP and UDP, a fork-based and a select-based 
+model, and more.
 
-Dependencies
-------------
+Install
+=======
 
-`sslh` uses [libconfig](http://www.hyperrealm.com/libconfig/)
-and [libwrap](http://packages.debian.org/source/unstable/tcp-wrappers).
-
-For Debian, these are contained in packages `libwrap0-dev` and
-`libconfig8-dev`.
-
-For OpenSUSE, these are contained in packages libconfig9 and
-libconfig-dev in repository
-<http://download.opensuse.org/repositories/multimedia:/libs/openSUSE_12.1/>
-
-For Fedora, you'll need packages `libconfig` and
-`libconfig-devel`:
-
-	yum install libconfig libconfig-devel
-
-If you can't find `libconfig`, or just don't want a
-configuration file, set `USELIBCONFIG=` in the Makefile.
-
-Compilation
------------
-
-After this, the Makefile should work:
-
-	make install
-
-There are a couple of configuration options at the beginning
-of the Makefile: 
-
-* `USELIBWRAP` compiles support for host access control (see
-  `hosts_access(3)`), you will need `libwrap` headers and
-  library to compile (`libwrap0-dev` in Debian).
-
-* `USELIBCONFIG` compiles support for the configuration
-  file. You will need `libconfig` headers to compile
-  (`libconfig8-dev` in Debian).
-
-*  `USESYSTEMD` compiles support for using systemd socket activation.
-   You will need `systemd` headers to compile (`systemd-devel` in Fedora).
-
-Binaries
---------
-
-The Makefile produces two different executables: `sslh-fork`
-and `sslh-select`:
-
-* `sslh-fork` forks a new process for each incoming connection.
-It is well-tested and very reliable, but incurs the overhead
-of many processes.  
-If you are going to use `sslh` for a "small" setup (less than
-a dozen ssh connections and a low-traffic https server) then
-`sslh-fork` is probably more suited for you. 
-
-* `sslh-select` uses only one thread, which monitors all connections
-at once. It is more recent and less tested, but only incurs a 16
-byte overhead per connection. Also, if it stops, you'll lose all
-connections, which means you can't upgrade it remotely.  
-If you are going to use `sslh` on a "medium" setup (a few thousand ssh
-connections, and another few thousand ssl connections),
-`sslh-select` will be better.
-
-If you have a very large site (tens of thousands of connections),
-you'll need a vapourware version that would use libevent or
-something like that.
-
-
-Installation
-------------
-
-* In general:
-
-		make
-		cp sslh-fork /usr/local/sbin/sslh
-		cp basic.cfg /etc/sslh.cfg
-                vi /etc/sslh.cfg
-
-* For Debian:
-
-		cp scripts/etc.init.d.sslh /etc/init.d/sslh
-	
-* For CentOS:
-
-		cp scripts/etc.rc.d.init.d.sslh.centos /etc/rc.d/init.d/sslh
-
-
-You might need to create links in /etc/rc<x>.d so that the server
-start automatically at boot-up, e.g. under Debian:
-
-	update-rc.d sslh defaults
+Please refer to the [install guide](doc/INSTALL.md).
 
 
 Configuration
 =============
 
-If you use the scripts provided, sslh will get its
-configuration from /etc/sslh.cfg. Please refer to
-example.cfg for an overview of all the settings.
+Please refer to the [configuration guide](doc/config.md).
 
-A good scheme is to use the external name of the machine in
-`listen`, and bind `httpd` to `localhost:443` (instead of all
-binding to all interfaces): that way, HTTPS connections
-coming from inside your network don't need to go through
-`sslh`, and `sslh` is only there as a frontal for connections
-coming from the internet.
 
-Note that 'external name' in this context refers to the
-actual IP address of the machine as seen from your network,
-i.e. that that is not `127.0.0.1` in the output of
-`ifconfig(8)`.
 
-Libwrap support
----------------
+Docker image
+------------
 
-Sslh can optionally perform `libwrap` checks for the sshd
-service: because the connection to `sshd` will be coming
-locally from `sslh`, `sshd` cannot determine the IP of the
-client.
+How to use
 
-OpenVPN support
----------------
+---
 
-OpenVPN clients connecting to OpenVPN running with
-`-port-share` reportedly take more than one second between
-the time the TCP connection is established and the time they
-send the first data packet. This results in `sslh` with
-default settings timing out and assuming an SSH connection.
-To support OpenVPN connections reliably, it is necessary to
-increase `sslh`'s timeout to 5 seconds.
+Build docker image
 
-Instead of using OpenVPN's port sharing, it is more reliable
-to use `sslh`'s `--openvpn` option to get `sslh` to do the
-port sharing.
+    make docker
 
-Using proxytunnel with sslh
----------------------------
 
-If you are connecting through a proxy that checks that the
-outgoing connection really is SSL and rejects SSH, you can
-encapsulate all your traffic in SSL using `proxytunnel` (this
-should work with `corkscrew` as well). On the server side you
-receive the traffic with `stunnel` to decapsulate SSL, then
-pipe through `sslh` to switch HTTP on one side and SSL on the
-other.
+```bash
+docker container run \
+  --rm \
+  -it \
+  --listen=0.0.0.0:443 \
+  --ssh=hostname:22 \
+  --tlshostname:443 \
+  sslh:latest
+```
 
-In that case, you end up with something like this:
+docker-compose example
 
-	ssh -> proxytunnel -e ----[ssh/ssl]---> stunnel ---[ssh]---> sslh --> sshd
-	Web browser -------------[http/ssl]---> stunnel ---[http]--> sslh --> httpd
+```
+---
+version: "3"
 
-Configuration goes like this on the server side, using `stunnel3`:
+services:
+  sslh:
+    image: sslh:latest
+    hostname: sslh
+    ports:
+      - 443:443/tcp
+    command: --listen=0.0.0.0:443 --tlshostname:443 --openvpn=openvpn:1194
+    depends_on:
+      - nginx
+      - openvpn
 
-	stunnel -f -p mycert.pem  -d thelonious:443 -l /usr/local/sbin/sslh -- \
-		sslh -i  --http localhost:80 --ssh localhost:22
+  nginx:
+    image: nginx
+    hostname: nginx
 
-* stunnel options:
-  * `-f` for foreground/debugging
-  * `-p` for specifying the key and certificate
-  * `-d` for specifying which interface and port
-	we're listening to for incoming connexions
-  * `-l` summons `sslh` in inetd mode.
-
-* sslh options:
-  * `-i` for inetd mode
-  * `--http` to forward HTTP connexions to port 80,
-	and SSH connexions to port 22.
-
-Capabilities support
---------------------
-
-On Linux (only?), you can compile sslh with `USELIBCAP=1` to
-make use of POSIX capabilities; this will save the required
-capabilities needed for transparent proxying for unprivileged
-processes.
-
-Alternatively, you may use filesystem capabilities instead
-of starting sslh as root and asking it to drop privileges.
-You will need `CAP_NET_BIND_SERVICE` for listening on port 443
-and `CAP_NET_ADMIN` for transparent proxying (see
-`capabilities(7)`).
-
-You can use the `setcap(8)` utility to give these capabilities
-to the executable:
-
-	# setcap cap_net_bind_service,cap_net_admin+pe sslh-select
-
-Then you can run sslh-select as an unpriviledged user, e.g.:
-
-	$ sslh-select -p myname:443 --ssh localhost:22 --ssl localhost:443
-
-Caveat: `CAP_NET_ADMIN` does give sslh too many rights, e.g.
-configuring the interface. If you're not going to use
-transparent proxying, just don't use it (or use the libcap method).
-
-Transparent proxy support
--------------------------
-
-On Linux and FreeBSD you can use the `--transparent` option to
-request transparent proxying. This means services behind `sslh`
-(Apache, `sshd` and so on) will see the external IP and ports
-as if the external world connected directly to them. This
-simplifies IP-based access control (or makes it possible at
-all).
-
-Linux:
-
-`sslh` needs extended rights to perform this: you'll need to
-give it `CAP_NET_ADMIN` capabilities (see appropriate chapter)
-or run it as root (but don't do that).
-
-The firewalling tables also need to be adjusted as follows.
-I don't think it is possible to have `httpd` and `sslh` both listen to 443 in
-this scheme -- let me know if you manage that:
-
-	$ # Set route_localnet = 1 on all interfaces so that ssl can use "localhost" as destination
-	$ sysctl -w net.ipv4.conf.default.route_localnet=1
-	$ sysctl -w net.ipv4.conf.all.route_localnet=1
-
-	$ # DROP martian packets as they would have been if route_localnet was zero
-	$ # Note: packets not leaving the server aren't affected by this, thus sslh will still work
-	$ iptables -t raw -A PREROUTING ! -i lo -d 127.0.0.0/8 -j DROP
-	$ iptables -t mangle -A POSTROUTING ! -o lo -s 127.0.0.0/8 -j DROP
-
-	$ # Mark all connections made by ssl for special treatment (here sslh is run as user "sslh")
-	$ iptables -t nat -A OUTPUT -m owner --uid-owner sslh -p tcp --tcp-flags FIN,SYN,RST,ACK SYN -j CONNMARK --set-xmark 0x01/0x0f
-
-	$ # Outgoing packets that should go to sslh instead have to be rerouted, so mark them accordingly (copying over the connection mark)
-	$ iptables -t mangle -A OUTPUT ! -o lo -p tcp -m connmark --mark 0x01/0x0f -j CONNMARK --restore-mark --mask 0x0f
-
-	$ # Configure routing for those marked packets
-	$ ip rule add fwmark 0x1 lookup 100
-	$ ip route add local 0.0.0.0/0 dev lo table 100
-
-Tranparent proxying with IPv6 is similarly set up as follows:
-
-	$ # Set route_localnet = 1 on all interfaces so that ssl can use "localhost" as destination
-	$ # Not sure if this is needed for ipv6 though
-	$ sysctl -w net.ipv4.conf.default.route_localnet=1
-	$ sysctl -w net.ipv4.conf.all.route_localnet=1
-
-	$ # DROP martian packets as they would have been if route_localnet was zero
-	$ # Note: packets not leaving the server aren't affected by this, thus sslh will still work
-	$ ip6tables -t raw -A PREROUTING ! -i lo -d ::1/128 -j DROP
-	$ ip6tables -t mangle -A POSTROUTING ! -o lo -s ::1/128 -j DROP
-
-	$ # Mark all connections made by ssl for special treatment (here sslh is run as user "sslh")
-	$ ip6tables -t nat -A OUTPUT -m owner --uid-owner sslh -p tcp --tcp-flags FIN,SYN,RST,ACK SYN -j CONNMARK --set-xmark 0x01/0x0f
-
-	$ # Outgoing packets that should go to sslh instead have to be rerouted, so mark them accordingly (copying over the connection mark)
-	$ ip6tables -t mangle -A OUTPUT ! -o lo -p tcp -m connmark --mark 0x01/0x0f -j CONNMARK --restore-mark --mask 0x0f
-
-	$ # Configure routing for those marked packets
-	$ ip -6 rule add fwmark 0x1 lookup 100
-	$ ip -6 route add local ::/0 dev lo table 100
-
-Explanation:
-To be able to use `localhost` as destination in your sslh config along with transparent proxying
-you have to allow routing of loopback addresses as done above.
-This is something you usually should not do (see [this stackoverflow post](https://serverfault.com/questions/656279/how-to-force-linux-to-accept-packet-with-loopback-ip/656484#656484))
-The two `DROP` iptables rules emulate the behaviour of `route_localnet` set to off (with one small difference:
-allowing the reroute-check to happen after the fwmark is set on packets destined for sslh).
-See [this diagram](https://upload.wikimedia.org/wikipedia/commons/3/37/Netfilter-packet-flow.svg) for a good visualisation
-showing how packets will traverse the iptables chains.
-
-Note:
-You have to run `sslh` as dedicated user (in this example the user is also named `sslh`), to not mess up with your normal networking.
-These rules will allow you to connect directly to ssh on port
-22 (or to any other service behind sslh) as well as through sslh on port 443.
-
-Also remember that iptables configuration and ip routes and 
-rules won't be necessarily persisted after you reboot. Make 
-sure to save them properly. For example in CentOS7, you would 
-do `iptables-save > /etc/sysconfig/iptables`, and add both 
-`ip` commands to your `/etc/rc.local`.
-
-FreeBSD:
-
-Given you have no firewall defined yet, you can use the following configuration
-to have ipfw properly redirect traffic back to sslh
-
-	/etc/rc.conf
-	firewall_enable="YES"
-	firewall_type="open"
-	firewall_logif="YES"
-	firewall_coscripts="/etc/ipfw/sslh.rules"
-
-
-/etc/ipfw/sslh.rules
-
-	#! /bin/sh
-
-	# ssl
-	ipfw add 20000 fwd 192.0.2.1,443 log tcp from 192.0.2.1 8443 to any out
-	ipfw add 20010 fwd 2001:db8::1,443 log tcp from 2001:db8::1 8443 to any out
-
-	# ssh
-	ipfw add 20100 fwd 192.0.2.1,443 log tcp from 192.0.2.1 8022 to any out
-	ipfw add 20110 fwd 2001:db8::1,443 log tcp from 2001:db8::1 8022 to any out
-
-	# xmpp
-	ipfw add 20200 fwd 192.0.2.1,443 log tcp from 192.0.2.1 5222 to any out
-	ipfw add 20210 fwd 2001:db8::1,443 log tcp from 2001:db8::1 5222 to any out
-
-	# openvpn (running on other internal system)
-	ipfw add 20300 fwd 192.0.2.1,443 log tcp from 198.51.100.7 1194 to any out
-	ipfw add 20310 fwd 2001:db8::1,443 log tcp from 2001:db8:1::7 1194 to any out
-
-General notes:
-
-
-This will only work if `sslh` does not use any loopback
-addresses (no `127.0.0.1` or `localhost`), you'll need to use
-explicit IP addresses (or names):
-
-	sslh --listen 192.168.0.1:443 --ssh 192.168.0.1:22 --ssl 192.168.0.1:4443
-
-This will not work:
-
-	sslh --listen 192.168.0.1:443 --ssh 127.0.0.1:22 --ssl 127.0.0.1:4443
-    
-Transparent proxying means the target server sees the real
-origin address, so it means if the client connects using
-IPv6, the server must also support IPv6. It is easy to
-support both IPv4 and IPv6 by configuring the server
-accordingly, and setting `sslh` to connect to a name that
-resolves to both IPv4 and IPv6, e.g.:
-
-        sslh --transparent --listen <extaddr>:443 --ssh insideaddr:22
-
-        /etc/hosts:
-        192.168.0.1  insideaddr
-        201::::2     insideaddr
-
-Upon incoming IPv6 connection, `sslh` will first try to
-connect to the IPv4 address (which will fail), then connect
-to the IPv6 address.
-
-Systemd Socket Activation
--------------------------
-If compiled with `USESYSTEMD` then it is possible to activate 
-the service on demand and avoid running any code as root.
-
-In this mode any listen configuration options are ignored and 
-the sockets are passed by systemd to the service.
-
-Example socket unit:
-
-	[Unit]
-	Before=sslh.service
-	
-	[Socket]
-	ListenStream=1.2.3.4:443
-	ListenStream=5.6.7.8:444
-	ListenStream=9.10.11.12:445
-	FreeBind=true
-
-	[Install]
-	WantedBy=sockets.target
-
-Example service unit:
-
-	[Unit]
-	PartOf=sslh.socket
-	
-	[Service]
-	ExecStart=/usr/sbin/sslh -v -f --ssh 127.0.0.1:22 --ssl 127.0.0.1:443
-	KillMode=process
-	CapabilityBoundingSet=CAP_NET_BIND_SERVICE CAP_NET_ADMIN CAP_SETGID CAP_SETUID
-	PrivateTmp=true
-	PrivateDevices=true
-	ProtectSystem=full
-	ProtectHome=true
-	User=sslh
-
-
-With this setup only the socket needs to be enabled. The sslh service 
-will be started on demand and does not need to run as root to bind the 
-sockets as systemd has already bound and passed them over. If the sslh
-service is started on its own without the sockets being passed by systemd
-then it will look to use those defined on the command line or config
-file as usual. Any number of ListenStreams can be defined in the socket
-file and systemd will pass them all over to sslh to use as usual.
-
-To avoid inconsistency between starting via socket and starting directly
-via the service Requires=sslh.socket can be added to the service unit to
-mandate the use of the socket configuration.
-
-Rather than overwriting the entire socket file drop in values can be placed
-in /etc/systemd/system/sslh.socket.d/<name>.conf with additional ListenStream
-values that will be merged.
-
-In addition to the above with manual .socket file configuration there is an
-optional systemd generator which can be compiled - systemd-sslh-generator 
-
-This parses the /etc/sslh.cfg (or /etc/sslh/sslh.cfg file if that exists 
-instead) configuration file and dynamically generates a socket file to use.
-
-This will also merge with any sslh.socket.d drop in configuration but will be 
-overriden by a /etc/systemd/system/sslh.socket file.
-
-To use the generator place it in /usr/lib/systemd/system-generators and then
-call systemctl daemon-reload after any changes to /etc/sslh.cfg to generate 
-the new dynamic socket unit.
-
-Fail2ban
---------
-
-If using transparent proxying, just use the standard ssh
-rules. If you can't or don't want to use transparent
-proxying, you can set `fail2ban` rules to block repeated ssh
-connections from an IP address (obviously this depends
-on the site, there might be legitimate reasons you would get
-many connections to ssh from the same IP address...)
-
-See example files in scripts/fail2ban.
+  openvpn:
+    image: openvpn:latest
+    hostname: openvpn
+```
 
 Comments? Questions?
 ====================
 
 You can subscribe to the `sslh` mailing list here:
-<http://rutschle.net/cgi-bin/mailman/listinfo/sslh>
+<https://lists.rutschle.net/mailman/listinfo/sslh>
 
 This mailing list should be used for discussion, feature
-requests, and will be the prefered channel for announcements.
+requests, and will be the preferred channel for announcements.
+
+Of course, check the [FAQ](doc/FAQ.md) first!
 

argtable3.h

@@ -0,0 +1,273 @@
+/*******************************************************************************
+ * argtable3: Declares the main interfaces of the library
+ *
+ * This file is part of the argtable3 library.
+ *
+ * Copyright (C) 1998-2001,2003-2011,2013 Stewart Heitmann
+ * <sheitmann@users.sourceforge.net>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of STEWART HEITMANN nor the  names of its contributors
+ *       may be used to endorse or promote products derived from this software
+ *       without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL STEWART HEITMANN BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ ******************************************************************************/
+
+#ifndef ARGTABLE3
+#define ARGTABLE3
+
+#include <stdio.h> /* FILE */
+#include <time.h>  /* struct tm */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define ARG_REX_ICASE 1
+#define ARG_DSTR_SIZE 200
+#define ARG_CMD_NAME_LEN 100
+#define ARG_CMD_DESCRIPTION_LEN 256
+
+#ifndef ARG_REPLACE_GETOPT
+#define ARG_REPLACE_GETOPT 1 /* use the embedded getopt as the system getopt(3) */
+#endif /* ARG_REPLACE_GETOPT */
+
+/* bit masks for arg_hdr.flag */
+enum { ARG_TERMINATOR = 0x1, ARG_HASVALUE = 0x2, ARG_HASOPTVALUE = 0x4 };
+
+#if defined(_WIN32)
+  #if defined(argtable3_EXPORTS)
+    #define ARG_EXTERN __declspec(dllexport)
+  #elif defined(argtable3_IMPORTS)
+    #define ARG_EXTERN __declspec(dllimport)
+  #else
+    #define ARG_EXTERN
+  #endif
+#else
+  #define ARG_EXTERN
+#endif
+
+typedef struct _internal_arg_dstr* arg_dstr_t;
+typedef void* arg_cmd_itr_t;
+
+typedef void(arg_resetfn)(void* parent);
+typedef int(arg_scanfn)(void* parent, const char* argval);
+typedef int(arg_checkfn)(void* parent);
+typedef void(arg_errorfn)(void* parent, arg_dstr_t ds, int error, const char* argval, const char* progname);
+typedef void(arg_dstr_freefn)(char* buf);
+typedef int(arg_cmdfn)(int argc, char* argv[], arg_dstr_t res);
+typedef int(arg_comparefn)(const void* k1, const void* k2);
+
+/*
+ * The arg_hdr struct defines properties that are common to all arg_xxx structs.
+ * The argtable library requires each arg_xxx struct to have an arg_hdr
+ * struct as its first data member.
+ * The argtable library functions then use this data to identify the
+ * properties of the command line option, such as its option tags,
+ * datatype string, and glossary strings, and so on.
+ * Moreover, the arg_hdr struct contains pointers to custom functions that
+ * are provided by each arg_xxx struct which perform the tasks of parsing
+ * that particular arg_xxx arguments, performing post-parse checks, and
+ * reporting errors.
+ * These functions are private to the individual arg_xxx source code
+ * and are the pointer to them are initiliased by that arg_xxx struct's
+ * constructor function. The user could alter them after construction
+ * if desired, but the original intention is for them to be set by the
+ * constructor and left unaltered.
+ */
+typedef struct arg_hdr {
+    char flag;             /* Modifier flags: ARG_TERMINATOR, ARG_HASVALUE. */
+    const char* shortopts; /* String defining the short options */
+    const char* longopts;  /* String defiing the long options */
+    const char* datatype;  /* Description of the argument data type */
+    const char* glossary;  /* Description of the option as shown by arg_print_glossary function */
+    int mincount;          /* Minimum number of occurences of this option accepted */
+    int maxcount;          /* Maximum number of occurences if this option accepted */
+    void* parent;          /* Pointer to parent arg_xxx struct */
+    arg_resetfn* resetfn;  /* Pointer to parent arg_xxx reset function */
+    arg_scanfn* scanfn;    /* Pointer to parent arg_xxx scan function */
+    arg_checkfn* checkfn;  /* Pointer to parent arg_xxx check function */
+    arg_errorfn* errorfn;  /* Pointer to parent arg_xxx error function */
+    void* priv;            /* Pointer to private header data for use by arg_xxx functions */
+} arg_hdr_t;
+
+typedef struct arg_rem {
+    struct arg_hdr hdr; /* The mandatory argtable header struct */
+} arg_rem_t;
+
+typedef struct arg_lit {
+    struct arg_hdr hdr; /* The mandatory argtable header struct */
+    int count;          /* Number of matching command line args */
+} arg_lit_t;
+
+typedef struct arg_int {
+    struct arg_hdr hdr; /* The mandatory argtable header struct */
+    int count;          /* Number of matching command line args */
+    int* ival;          /* Array of parsed argument values */
+} arg_int_t;
+
+typedef struct arg_dbl {
+    struct arg_hdr hdr; /* The mandatory argtable header struct */
+    int count;          /* Number of matching command line args */
+    double* dval;       /* Array of parsed argument values */
+} arg_dbl_t;
+
+typedef struct arg_str {
+    struct arg_hdr hdr; /* The mandatory argtable header struct */
+    int count;          /* Number of matching command line args */
+    const char** sval;  /* Array of parsed argument values */
+} arg_str_t;
+
+typedef struct arg_rex {
+    struct arg_hdr hdr; /* The mandatory argtable header struct */
+    int count;          /* Number of matching command line args */
+    const char** sval;  /* Array of parsed argument values */
+} arg_rex_t;
+
+typedef struct arg_file {
+    struct arg_hdr hdr;     /* The mandatory argtable header struct */
+    int count;              /* Number of matching command line args*/
+    const char** filename;  /* Array of parsed filenames  (eg: /home/foo.bar) */
+    const char** basename;  /* Array of parsed basenames  (eg: foo.bar) */
+    const char** extension; /* Array of parsed extensions (eg: .bar) */
+} arg_file_t;
+
+typedef struct arg_date {
+    struct arg_hdr hdr; /* The mandatory argtable header struct */
+    const char* format; /* strptime format string used to parse the date */
+    int count;          /* Number of matching command line args */
+    struct tm* tmval;   /* Array of parsed time values */
+} arg_date_t;
+
+enum { ARG_ELIMIT = 1, ARG_EMALLOC, ARG_ENOMATCH, ARG_ELONGOPT, ARG_EMISSARG };
+typedef struct arg_end {
+    struct arg_hdr hdr;  /* The mandatory argtable header struct */
+    int count;           /* Number of errors encountered */
+    int* error;          /* Array of error codes */
+    void** parent;       /* Array of pointers to offending arg_xxx struct */
+    const char** argval; /* Array of pointers to offending argv[] string */
+} arg_end_t;
+
+typedef struct arg_cmd_info {
+    char name[ARG_CMD_NAME_LEN];
+    char description[ARG_CMD_DESCRIPTION_LEN];
+    arg_cmdfn* proc;
+} arg_cmd_info_t;
+
+/**** arg_xxx constructor functions *********************************/
+
+ARG_EXTERN struct arg_rem* arg_rem(const char* datatype, const char* glossary);
+
+ARG_EXTERN struct arg_lit* arg_lit0(const char* shortopts, const char* longopts, const char* glossary);
+ARG_EXTERN struct arg_lit* arg_lit1(const char* shortopts, const char* longopts, const char* glossary);
+ARG_EXTERN struct arg_lit* arg_litn(const char* shortopts, const char* longopts, int mincount, int maxcount, const char* glossary);
+
+ARG_EXTERN struct arg_int* arg_int0(const char* shortopts, const char* longopts, const char* datatype, const char* glossary);
+ARG_EXTERN struct arg_int* arg_int1(const char* shortopts, const char* longopts, const char* datatype, const char* glossary);
+ARG_EXTERN struct arg_int* arg_intn(const char* shortopts, const char* longopts, const char* datatype, int mincount, int maxcount, const char* glossary);
+
+ARG_EXTERN struct arg_dbl* arg_dbl0(const char* shortopts, const char* longopts, const char* datatype, const char* glossary);
+ARG_EXTERN struct arg_dbl* arg_dbl1(const char* shortopts, const char* longopts, const char* datatype, const char* glossary);
+ARG_EXTERN struct arg_dbl* arg_dbln(const char* shortopts, const char* longopts, const char* datatype, int mincount, int maxcount, const char* glossary);
+
+ARG_EXTERN struct arg_str* arg_str0(const char* shortopts, const char* longopts, const char* datatype, const char* glossary);
+ARG_EXTERN struct arg_str* arg_str1(const char* shortopts, const char* longopts, const char* datatype, const char* glossary);
+ARG_EXTERN struct arg_str* arg_strn(const char* shortopts, const char* longopts, const char* datatype, int mincount, int maxcount, const char* glossary);
+
+ARG_EXTERN struct arg_rex* arg_rex0(const char* shortopts, const char* longopts, const char* pattern, const char* datatype, int flags, const char* glossary);
+ARG_EXTERN struct arg_rex* arg_rex1(const char* shortopts, const char* longopts, const char* pattern, const char* datatype, int flags, const char* glossary);
+ARG_EXTERN struct arg_rex* arg_rexn(const char* shortopts,
+                         const char* longopts,
+                         const char* pattern,
+                         const char* datatype,
+                         int mincount,
+                         int maxcount,
+                         int flags,
+                         const char* glossary);
+
+ARG_EXTERN struct arg_file* arg_file0(const char* shortopts, const char* longopts, const char* datatype, const char* glossary);
+ARG_EXTERN struct arg_file* arg_file1(const char* shortopts, const char* longopts, const char* datatype, const char* glossary);
+ARG_EXTERN struct arg_file* arg_filen(const char* shortopts, const char* longopts, const char* datatype, int mincount, int maxcount, const char* glossary);
+
+ARG_EXTERN struct arg_date* arg_date0(const char* shortopts, const char* longopts, const char* format, const char* datatype, const char* glossary);
+ARG_EXTERN struct arg_date* arg_date1(const char* shortopts, const char* longopts, const char* format, const char* datatype, const char* glossary);
+ARG_EXTERN struct arg_date* arg_daten(const char* shortopts, const char* longopts, const char* format, const char* datatype, int mincount, int maxcount, const char* glossary);
+
+ARG_EXTERN struct arg_end* arg_end(int maxerrors);
+
+#define ARG_DSTR_STATIC ((arg_dstr_freefn*)0)
+#define ARG_DSTR_VOLATILE ((arg_dstr_freefn*)1)
+#define ARG_DSTR_DYNAMIC ((arg_dstr_freefn*)3)
+
+/**** other functions *******************************************/
+ARG_EXTERN int arg_nullcheck(void** argtable);
+ARG_EXTERN int arg_parse(int argc, char** argv, void** argtable);
+ARG_EXTERN void arg_print_option(FILE* fp, const char* shortopts, const char* longopts, const char* datatype, const char* suffix);
+ARG_EXTERN void arg_print_syntax(FILE* fp, void** argtable, const char* suffix);
+ARG_EXTERN void arg_print_syntaxv(FILE* fp, void** argtable, const char* suffix);
+ARG_EXTERN void arg_print_glossary(FILE* fp, void** argtable, const char* format);
+ARG_EXTERN void arg_print_glossary_gnu(FILE* fp, void** argtable);
+ARG_EXTERN void arg_print_errors(FILE* fp, struct arg_end* end, const char* progname);
+ARG_EXTERN void arg_print_option_ds(arg_dstr_t ds, const char* shortopts, const char* longopts, const char* datatype, const char* suffix);
+ARG_EXTERN void arg_print_syntax_ds(arg_dstr_t ds, void** argtable, const char* suffix);
+ARG_EXTERN void arg_print_syntaxv_ds(arg_dstr_t ds, void** argtable, const char* suffix);
+ARG_EXTERN void arg_print_glossary_ds(arg_dstr_t ds, void** argtable, const char* format);
+ARG_EXTERN void arg_print_glossary_gnu_ds(arg_dstr_t ds, void** argtable);
+ARG_EXTERN void arg_print_errors_ds(arg_dstr_t ds, struct arg_end* end, const char* progname);
+ARG_EXTERN void arg_freetable(void** argtable, size_t n);
+
+ARG_EXTERN arg_dstr_t arg_dstr_create(void);
+ARG_EXTERN void arg_dstr_destroy(arg_dstr_t ds);
+ARG_EXTERN void arg_dstr_reset(arg_dstr_t ds);
+ARG_EXTERN void arg_dstr_free(arg_dstr_t ds);
+ARG_EXTERN void arg_dstr_set(arg_dstr_t ds, char* str, arg_dstr_freefn* free_proc);
+ARG_EXTERN void arg_dstr_cat(arg_dstr_t ds, const char* str);
+ARG_EXTERN void arg_dstr_catc(arg_dstr_t ds, char c);
+ARG_EXTERN void arg_dstr_catf(arg_dstr_t ds, const char* fmt, ...);
+ARG_EXTERN char* arg_dstr_cstr(arg_dstr_t ds);
+
+ARG_EXTERN void arg_cmd_init(void);
+ARG_EXTERN void arg_cmd_uninit(void);
+ARG_EXTERN void arg_cmd_register(const char* name, arg_cmdfn* proc, const char* description);
+ARG_EXTERN void arg_cmd_unregister(const char* name);
+ARG_EXTERN int arg_cmd_dispatch(const char* name, int argc, char* argv[], arg_dstr_t res);
+ARG_EXTERN unsigned int arg_cmd_count(void);
+ARG_EXTERN arg_cmd_info_t* arg_cmd_info(const char* name);
+ARG_EXTERN arg_cmd_itr_t arg_cmd_itr_create(void);
+ARG_EXTERN void arg_cmd_itr_destroy(arg_cmd_itr_t itr);
+ARG_EXTERN int arg_cmd_itr_advance(arg_cmd_itr_t itr);
+ARG_EXTERN char* arg_cmd_itr_key(arg_cmd_itr_t itr);
+ARG_EXTERN arg_cmd_info_t* arg_cmd_itr_value(arg_cmd_itr_t itr);
+ARG_EXTERN int arg_cmd_itr_search(arg_cmd_itr_t itr, void* k);
+ARG_EXTERN void arg_mgsort(void* data, int size, int esize, int i, int k, arg_comparefn* comparefn);
+ARG_EXTERN void arg_make_get_help_msg(arg_dstr_t res);
+ARG_EXTERN void arg_make_help_msg(arg_dstr_t ds, char* cmd_name, void** argtable);
+ARG_EXTERN void arg_make_syntax_err_msg(arg_dstr_t ds, void** argtable, struct arg_end* end);
+ARG_EXTERN int arg_make_syntax_err_help_msg(arg_dstr_t ds, char* name, int help, int nerrors, void** argtable, struct arg_end* end, int* exitcode);
+ARG_EXTERN void arg_set_module_name(const char* name);
+ARG_EXTERN void arg_set_module_version(int major, int minor, int patch, const char* tag);
+
+/**** deprecated functions, for back-compatibility only ********/
+ARG_EXTERN void arg_free(void** argtable);
+
+#ifdef __cplusplus
+}
+#endif
+#endif

basic.cfg

@@ -1,7 +1,7 @@
 # This is a basic configuration file that should provide
 # sensible values for "standard" setup.
 
-verbose: false;
+verbose: 0;
 foreground: false;
 inetd: false;
 numeric: false;
@@ -24,7 +24,7 @@ protocols:
      { name: "openvpn"; host: "localhost"; port: "1194"; },
      { name: "xmpp"; host: "localhost"; port: "5222"; },
      { name: "http"; host: "localhost"; port: "80"; },
-     { name: "ssl"; host: "localhost"; port: "443"; log_level: 0; },
+     { name: "tls"; host: "localhost"; port: "443"; log_level: 0; },
      { name: "anyprot"; host: "localhost"; port: "443"; }
 );
 

collection.c

@@ -0,0 +1,97 @@
+/*
+   collection.c: management of a collection of connections, for sslh-select
+
+# Copyright (C) 2021  Yves Rutschle
+# 
+# This program is free software; you can redistribute it
+# and/or modify it under the terms of the GNU General Public
+# License as published by the Free Software Foundation; either
+# version 2 of the License, or (at your option) any later
+# version.
+# 
+# This program is distributed in the hope that it will be
+# useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+# PURPOSE.  See the GNU General Public License for more
+# details.
+# 
+# The full text for the General Public License is here:
+# http://www.gnu.org/licenses/gpl.html
+
+*/
+
+#include "common.h"
+#include "collection.h"
+#include "sslh-conf.h"
+#include "gap.h"
+
+/* Info to keep track of all connections */
+struct cnx_collection {
+    gap_array* fd2cnx;  /* Array indexed by file descriptor to things in cnx[] */
+};
+
+/* Allocates and initialises a new collection of connections. */
+cnx_collection* collection_init(void)
+{
+    cnx_collection* collection;
+
+    collection = malloc(sizeof(*collection));
+    CHECK_ALLOC(collection, "collection_init(collection)");
+
+    memset(collection, 0, sizeof(*collection));
+
+    collection->fd2cnx = gap_init();
+
+    return collection;
+}
+
+/* Caveat: might not work, as has never been used */
+void collection_destroy(cnx_collection* collection)
+{
+    /* Caveat 2: no code to free connections yet */
+    gap_destroy(collection->fd2cnx);
+    free(collection);
+}
+
+/* Points the file descriptor to the specified connection index */
+int collection_add_fd(cnx_collection* collection, struct connection* cnx, int fd)
+{
+    gap_set(collection->fd2cnx, fd, cnx);
+    return 0;
+}
+
+/* Allocates a connection and inits it with specified file descriptor */
+struct connection* collection_alloc_cnx_from_fd(struct cnx_collection* collection, int fd)
+{
+    struct connection* cnx = malloc(sizeof(*cnx));
+
+    if (!cnx) return NULL;
+
+    init_cnx(cnx);
+    cnx->type = SOCK_STREAM;
+    cnx->q[0].fd = fd;
+    cnx->state = ST_PROBING;
+    cnx->probe_timeout = time(NULL) + cfg.timeout;
+
+    gap_set(collection->fd2cnx, fd, cnx);
+
+    return cnx;
+}
+
+/* Remove a connection from the collection */
+int collection_remove_cnx(cnx_collection* collection, struct connection *cnx)
+{
+    if (cnx->q[0].fd != -1)
+        gap_set(collection->fd2cnx, cnx->q[0].fd, NULL);
+    if (cnx->q[1].fd != -1)
+        gap_set(collection->fd2cnx, cnx->q[1].fd, NULL);
+    free(cnx);
+    return 0;
+}
+
+/* Returns the connection that contains the file descriptor */
+struct connection* collection_get_cnx_from_fd(struct cnx_collection* collection, int fd)
+{
+    return gap_get(collection->fd2cnx, fd);
+}
+

collection.h

@@ -0,0 +1,18 @@
+#ifndef COLLECTION_H
+#define COLLECTION_H
+
+typedef struct cnx_collection cnx_collection;
+
+
+cnx_collection* collection_init(void);
+void collection_destroy(cnx_collection* collection);
+
+struct connection* collection_alloc_cnx_from_fd(cnx_collection* collection, int fd);
+int collection_add_fd(cnx_collection* collection, struct connection* cnx, int fd);
+
+/* Remove a connection from the collection */
+int collection_remove_cnx(cnx_collection* collection, struct connection *cnx);
+
+struct connection* collection_get_cnx_from_fd(struct cnx_collection* collection, int fd);
+
+#endif

common.c

@@ -16,6 +16,7 @@
 
 #include "common.h"
 #include "probe.h"
+#include "sslh-conf.h"
 
 /* Added to make the code compilable under CYGWIN
  * */
@@ -29,22 +30,20 @@
 #include <systemd/sd-daemon.h>
 #endif
 
+#ifdef LIBBSD
+#include <bsd/unistd.h>
+#endif
+
 /*
- * Settings that depend on the command line.  They're set in main(), but also
- * used in other places in common.c, and it'd be heavy-handed to pass it all as
- * parameters
+ * Settings that depend on the command line or the config file
  */
-int verbose = 0;
-int probing_timeout = 2;
-int inetd = 0;
-int foreground = 0;
-int background = 0;
-int transparent = 0;
-int numeric = 0;
-const char *user_name, *pid_file, *chroot_path, *facility = "auth";
+struct sslhcfg_item cfg;
 
 struct addrinfo *addr_listen = NULL; /* what addresses do we listen to? */
 
+
+static int do_syslog = 1; /* Should we syslog? controled by syslog_facility = "none" */
+
 #ifdef LIBWRAP
 #include <tcpd.h>
 int allow_severity =0, deny_severity = 0;
@@ -71,7 +70,7 @@ void check_res_dump(CR_ACTION act, int res, struct addrinfo *addr, char* syscall
     }
 }
 
-int get_fd_sockets(int *sockfd[])
+int get_fd_sockets(struct listen_endpoint *sockfd[])
 {
     int sd = 0;
 
@@ -84,8 +83,10 @@ int get_fd_sockets(int *sockfd[])
     if (sd > 0) {
       int i;
       *sockfd = malloc(sd * sizeof(*sockfd[0]));
+      CHECK_ALLOC(*sockfd, "malloc");
       for (i = 0; i < sd; i++) {
-        (*sockfd)[i] = SD_LISTEN_FDS_START + i;
+        (*sockfd)[i].socketfd = SD_LISTEN_FDS_START + i;
+        (*sockfd)[i].type = SOCK_STREAM;
       }
     }
 #endif
@@ -93,74 +94,156 @@ int get_fd_sockets(int *sockfd[])
     return sd;
 }
 
-/* Starts listening sockets on specified addresses.
- * IN: addr[], num_addr
- * OUT: *sockfd[]  pointer to newly-allocated array of file descriptors
- * Returns number of addresses bound
- * Bound file descriptors are returned in newly-allocated *sockfd pointer
-   */
-int start_listen_sockets(int *sockfd[], struct addrinfo *addr_list)
+/* Set TCP_FASTOPEN on listening socket if all client protocols support it */
+int make_listen_tfo(int s)
 {
-   struct sockaddr_storage *saddr;
-   struct addrinfo *addr;
-   int i, res, one;
-   int num_addr = 0;
-   int sd_socks = 0;
+    int i, qlen = 5;
 
-   sd_socks = get_fd_sockets(sockfd);
+    /* Don't do it if not supported */
+    if (!TCP_FASTOPEN)
+        return 0;
 
-   if (sd_socks > 0) {
-       return sd_socks;
-   }
+    /* Don't do it if any protocol does not specify it */
+    for (i = 0; i < cfg.protocols_len; i++) {
+        if (! cfg.protocols[i].tfo_ok)
+            return 0;
+    }
 
-   for (addr = addr_list; addr; addr = addr->ai_next)
-       num_addr++;
-
-   if (verbose)
-       fprintf(stderr, "listening to %d addresses\n", num_addr);
-
-   *sockfd = malloc(num_addr * sizeof(*sockfd[0]));
-
-   for (i = 0, addr = addr_list; i < num_addr && addr; i++, addr = addr->ai_next) {
-       if (!addr) {
-           fprintf(stderr, "FATAL: Inconsistent listen number. This should not happen.\n");
-           exit(1);
-       }
-       saddr = (struct sockaddr_storage*)addr->ai_addr;
-
-       (*sockfd)[i] = socket(saddr->ss_family, SOCK_STREAM, 0);
-       check_res_dump(CR_DIE, (*sockfd)[i], addr, "socket");
-
-       one = 1;
-       res = setsockopt((*sockfd)[i], SOL_SOCKET, SO_REUSEADDR, (char*)&one, sizeof(one));
-       check_res_dump(CR_DIE, res, addr, "setsockopt(SO_REUSEADDR)");
-
-       if (addr->ai_flags & SO_KEEPALIVE) {
-           res = setsockopt((*sockfd)[i], SOL_SOCKET, SO_KEEPALIVE, (char*)&one, sizeof(one));
-           check_res_dump(CR_DIE, res, addr, "setsockopt(SO_KEEPALIVE)");
-       }
-
-       if (IP_FREEBIND) {
-           res = setsockopt((*sockfd)[i], IPPROTO_IP, IP_FREEBIND, (char*)&one, sizeof(one));
-           check_res_dump(CR_WARN, res, addr, "setsockopt(IP_FREEBIND)");
-           }
-
-       if (addr->ai_addr->sa_family == AF_INET6) {
-           res = setsockopt((*sockfd)[i], IPPROTO_IPV6, IPV6_V6ONLY, (char*)&one, sizeof(one));
-           check_res_dump(CR_WARN, res, addr, "setsockopt(IPV6_V6ONLY)");
-       }
-
-       res = bind((*sockfd)[i], addr->ai_addr, addr->ai_addrlen);
-       check_res_dump(CR_DIE, res, addr, "bind");
-
-       res = listen ((*sockfd)[i], 50);
-       check_res_dump(CR_DIE, res, addr, "listen");
-
-   }
-
-   return num_addr;
+    return setsockopt(s, SOL_SOCKET, TCP_FASTOPEN, (char*)&qlen, sizeof(qlen));
 }
 
+/* Starts listening on a single address 
+ * Returns a socket filehandle, or dies with message in case of major error */
+int listen_single_addr(struct addrinfo* addr, int keepalive, int udp)
+{
+    struct sockaddr_storage *saddr;
+    int sockfd, one, res;
+
+    saddr = (struct sockaddr_storage*)addr->ai_addr;
+
+    sockfd = socket(saddr->ss_family, udp ? SOCK_DGRAM : SOCK_STREAM, 0);
+    check_res_dump(CR_DIE, sockfd, addr, "socket");
+
+    one = 1;
+    res = setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, (char*)&one, sizeof(one));
+    check_res_dump(CR_DIE, res, addr, "setsockopt(SO_REUSEADDR)");
+
+    res = make_listen_tfo(sockfd);
+    check_res_dump(CR_WARN, res, addr, "setsockopt(TCP_FASTOPEN)");
+
+    if (keepalive) {
+        res = setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, (char*)&one, sizeof(one));
+        check_res_dump(CR_DIE, res, addr, "setsockopt(SO_KEEPALIVE)");
+    }
+
+    if (IP_FREEBIND) {
+        res = setsockopt(sockfd, IPPROTO_IP, IP_FREEBIND, (char*)&one, sizeof(one));
+        check_res_dump(CR_WARN, res, addr, "setsockopt(IP_FREEBIND)");
+    }
+
+    if (addr->ai_addr->sa_family == AF_INET6) {
+        res = setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY, (char*)&one, sizeof(one));
+        check_res_dump(CR_WARN, res, addr, "setsockopt(IPV6_V6ONLY)");
+    }
+
+    res = bind(sockfd, addr->ai_addr, addr->ai_addrlen);
+    check_res_dump(CR_DIE, res, addr, "bind");
+
+    if (!udp) {
+        res = listen (sockfd, 50);
+        check_res_dump(CR_DIE, res, addr, "listen");
+    }
+
+    return sockfd;
+}
+
+/* Starts listening sockets on specified addresses.
+ * OUT: *sockfd[]  pointer to newly-allocated array of listen_endpoint objects
+ * Returns number of addresses bound
+   */
+int start_listen_sockets(struct listen_endpoint *sockfd[])
+{
+    struct addrinfo *addr, *start_addr;
+    char buf[NI_MAXHOST];
+    int i, res;
+    int num_addr = 0, keepalive = 0, udp = 0;
+    int sd_socks = 0;
+
+    sd_socks = get_fd_sockets(sockfd);
+
+    if (sd_socks > 0) {
+        return sd_socks;
+    }
+
+    *sockfd = NULL;
+
+    if (cfg.verbose) fprintf(stderr, "Listening to:\n");
+
+    for (i = 0; i < cfg.listen_len; i++) {
+        keepalive = cfg.listen[i].keepalive;
+        udp = cfg.listen[i].is_udp;
+
+        res = resolve_split_name(&start_addr, cfg.listen[i].host, cfg.listen[i].port);
+        if (res) exit(4);
+
+        for (addr = start_addr; addr; addr = addr->ai_next) {
+            num_addr++;
+            *sockfd = realloc(*sockfd, num_addr * sizeof(*sockfd));
+            (*sockfd)[num_addr-1].socketfd = listen_single_addr(addr, keepalive, udp);
+            (*sockfd)[num_addr-1].type = udp ? SOCK_DGRAM : SOCK_STREAM;
+            if (cfg.verbose)
+                fprintf(stderr, "%d:\t%s\t[%s] [%s]\n", (*sockfd)[num_addr-1].socketfd, sprintaddr(buf, sizeof(buf), addr),
+                        cfg.listen[i].keepalive ? "keepalive" : "",
+                        cfg.listen[i].is_udp ? "udp" : "");
+        }
+        freeaddrinfo(start_addr);
+    }
+
+    return num_addr;
+}
+
+
+/* returns 1 if given address is on the local machine: iterate through all
+ * network interfaces and check their addresses */
+int is_same_machine(struct addrinfo* from)
+{
+    struct ifaddrs *ifaddrs_p = NULL, *ifa;
+    int match = 0;
+
+    getifaddrs(&ifaddrs_p);
+
+    for (ifa = ifaddrs_p; ifa != NULL; ifa = ifa->ifa_next)
+    {
+        if (!ifa->ifa_addr)
+            continue;
+        if (from->ai_addr->sa_family == ifa->ifa_addr->sa_family)
+        {
+            int family = ifa->ifa_addr->sa_family;
+            if (family == AF_INET)
+            {
+                struct sockaddr_in *from_addr = (struct sockaddr_in*)from->ai_addr;
+                struct sockaddr_in *ifa_addr = (struct sockaddr_in*)ifa->ifa_addr;
+                if (from_addr->sin_addr.s_addr == ifa_addr->sin_addr.s_addr) {
+                    match = 1;
+                    break;
+                }
+            }
+            else if (family == AF_INET6)
+            {
+                struct sockaddr_in6 *from_addr = (struct sockaddr_in6*)from->ai_addr;
+                struct sockaddr_in6 *ifa_addr = (struct sockaddr_in6*)ifa->ifa_addr;
+                if (!memcmp(from_addr->sin6_addr.s6_addr, ifa_addr->sin6_addr.s6_addr, 16)) {
+                    match = 1;
+                    break;
+                }
+            }
+        }
+    }
+    freeifaddrs(ifaddrs_p);
+    return match;
+}
+
+
 /* Transparent proxying: bind the peer address of fd to the peer address of
  * fd_from */
 #define IP_TRANSPARENT 19
@@ -177,83 +260,73 @@ int bind_peer(int fd, int fd_from)
     /* getpeername can fail with ENOTCONN if connection was dropped before we
      * got here */
     res = getpeername(fd_from, from.ai_addr, &from.ai_addrlen);
-    CHECK_RES_RETURN(res, "getpeername");
-    
+    CHECK_RES_RETURN(res, "getpeername", res);
+
     /* if the destination is the same machine, there's no need to do bind */
-    struct ifaddrs *ifaddrs_p = NULL, *ifa;
-
-    getifaddrs(&ifaddrs_p);
-
-    for (ifa = ifaddrs_p; ifa != NULL; ifa = ifa->ifa_next)
-    {
-        if (!ifa->ifa_addr)
-            continue;
-        int match = 0;
-        if (from.ai_addr->sa_family == ifa->ifa_addr->sa_family)
-        {
-            int family = ifa->ifa_addr->sa_family;
-            if (family == AF_INET)
-            {
-                struct sockaddr_in *from_addr = (struct sockaddr_in*)from.ai_addr;
-                struct sockaddr_in *ifa_addr = (struct sockaddr_in*)ifa->ifa_addr;
-                if (from_addr->sin_addr.s_addr == ifa_addr->sin_addr.s_addr)
-                    match = 1;
-            }
-            else if (family == AF_INET6)
-            {
-                struct sockaddr_in6 *from_addr = (struct sockaddr_in6*)from.ai_addr;
-                struct sockaddr_in6 *ifa_addr = (struct sockaddr_in6*)ifa->ifa_addr;
-                if (!memcmp(from_addr->sin6_addr.s6_addr, ifa_addr->sin6_addr.s6_addr, 16))
-                    match = 1;
-            }
-        }
-        if (match)  /* the destination is the same as the source, should not create a transparent bind */
-            return 0;
-    }
-
+    if (is_same_machine(&from))
+        return 0;
+    
 #ifndef IP_BINDANY /* use IP_TRANSPARENT */
     res = setsockopt(fd, IPPROTO_IP, IP_TRANSPARENT, &trans, sizeof(trans));
-    CHECK_RES_DIE(res, "setsockopt");
+    CHECK_RES_DIE(res, "setsockopt IP_TRANSPARENT");
 #else
     if (from.ai_addr->sa_family==AF_INET) { /* IPv4 */
         res = setsockopt(fd, IPPROTO_IP, IP_BINDANY, &trans, sizeof(trans));
-        CHECK_RES_RETURN(res, "setsockopt IP_BINDANY");
+        CHECK_RES_RETURN(res, "setsockopt IP_BINDANY", res);
 #ifdef IPV6_BINDANY
     } else { /* IPv6 */
         res = setsockopt(fd, IPPROTO_IPV6, IPV6_BINDANY, &trans, sizeof(trans));
-        CHECK_RES_RETURN(res, "setsockopt IPV6_BINDANY");
+        CHECK_RES_RETURN(res, "setsockopt IPV6_BINDANY", res);
 #endif /* IPV6_BINDANY */
     }
 #endif /* IP_TRANSPARENT / IP_BINDANY */
     res = bind(fd, from.ai_addr, from.ai_addrlen);
-    CHECK_RES_RETURN(res, "bind");
+    CHECK_RES_RETURN(res, "bind", res);
 
     return 0;
 }
 
+/* Make the file descriptor non-block  */
+int set_nonblock(int fd)
+{
+    int flags;
+
+    flags = fcntl(fd, F_GETFL);
+    CHECK_RES_RETURN(flags, "fcntl", -1);
+
+    flags |= O_NONBLOCK;
+
+    flags = fcntl(fd, F_SETFL, flags);
+    CHECK_RES_RETURN(flags, "fcntl", -1);
+
+    return flags;
+}
+
+
 /* Connect to first address that works and returns a file descriptor, or -1 if
  * none work.
  * If transparent proxying is on, use fd_from peer address on external address
  * of new file descriptor. */
-int connect_addr(struct connection *cnx, int fd_from)
+int connect_addr(struct connection *cnx, int fd_from, connect_blocking blocking)
 {
     struct addrinfo *a, from;
     struct sockaddr_storage ss;
     char buf[NI_MAXHOST];
     int fd, res, one;
+    int transparent = cnx->proto->transparent || cfg.transparent;
 
     memset(&from, 0, sizeof(from));
     from.ai_addr = (struct sockaddr*)&ss;
     from.ai_addrlen = sizeof(ss);
 
     res = getpeername(fd_from, from.ai_addr, &from.ai_addrlen);
-    CHECK_RES_RETURN(res, "getpeername");
+    CHECK_RES_RETURN(res, "getpeername", res);
 
     for (a = cnx->proto->saddr; a; a = a->ai_next) {
         /* When transparent, make sure both connections use the same address family */
         if (transparent && a->ai_family != from.ai_addr->sa_family)
             continue;
-        if (verbose)
+        if (cfg.verbose)
             fprintf(stderr, "connecting to %s family %d len %d\n",
                     sprintaddr(buf, sizeof(buf), a),
                     a->ai_addr->sa_family, a->ai_addrlen);
@@ -262,25 +335,35 @@ int connect_addr(struct connection *cnx, int fd_from)
         fd = socket(a->ai_family, SOCK_STREAM, 0);
         if (fd == -1) {
             log_message(LOG_ERR, "forward to %s failed:socket: %s\n",
-                        cnx->proto->description, strerror(errno));
+                        cnx->proto->name, strerror(errno));
         } else {
+            one = 1;
+            setsockopt(fd, IPPROTO_TCP, TCP_FASTOPEN_CONNECT, &one, sizeof(one));
+            /* no need to check return value; if it's not supported, that's okay */
+
+            if (blocking == NON_BLOCKING) {
+                set_nonblock(fd);
+            }
+
             if (transparent) {
                 res = bind_peer(fd, fd_from);
-                CHECK_RES_RETURN(res, "bind_peer");
+                CHECK_RES_RETURN(res, "bind_peer", res);
             }
             res = connect(fd, a->ai_addr, a->ai_addrlen);
-            if (res == -1) {
+
+            /* EINPROGRESS indicates it might take time. If it eventually
+             * fails, it'll be caught as a failed read */
+            if ((res == -1) && (errno != EINPROGRESS)) {
                 log_message(LOG_ERR, "forward to %s failed:connect: %s\n",
-                            cnx->proto->description, strerror(errno));
+                                     cnx->proto->name, strerror(errno));
                 close(fd);
-            } else {
-                if (cnx->proto->keepalive) {
-                    one = 1;
-                    res = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (char*)&one, sizeof(one));
-                    CHECK_RES_RETURN(res, "setsockopt(SO_KEEPALIVE)");
-                }
-                return fd;
+                continue; /* Try the next address */
             }
+            if (cnx->proto->keepalive) {
+                res = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (char*)&one, sizeof(one));
+                CHECK_RES_RETURN(res, "setsockopt(SO_KEEPALIVE)", res);
+            }
+            return fd;
         }
     }
     return -1;
@@ -291,14 +374,11 @@ int defer_write(struct queue *q, void* data, int data_size)
 {
     char *p;
     ptrdiff_t data_offset = q->deferred_data - q->begin_deferred_data;
-    if (verbose)
+    if (cfg.verbose)
         fprintf(stderr, "**** writing deferred on fd %d\n", q->fd);
 
     p = realloc(q->begin_deferred_data, data_offset + q->deferred_data_size + data_size);
-    if (!p) {
-        perror("realloc");
-        exit(1);
-    }
+    CHECK_ALLOC(p, "realloc");
 
     q->begin_deferred_data = p;
     q->deferred_data = p + data_offset;
@@ -317,7 +397,7 @@ int flush_deferred(struct queue *q)
 {
     int n;
 
-    if (verbose)
+    if (cfg.verbose)
         fprintf(stderr, "flushing deferred data to fd %d\n", q->fd);
 
     n = write(q->fd, q->deferred_data, q->deferred_data_size);
@@ -345,14 +425,16 @@ void init_cnx(struct connection *cnx)
     memset(cnx, 0, sizeof(*cnx));
     cnx->q[0].fd = -1;
     cnx->q[1].fd = -1;
-    cnx->proto = get_first_protocol();
+    cnx->proto = NULL;
 }
 
 void dump_connection(struct connection *cnx)
 {
     printf("state: %d\n", cnx->state);
-    printf("fd %d, %d deferred\n", cnx->q[0].fd, cnx->q[0].deferred_data_size);
-    printf("fd %d, %d deferred\n", cnx->q[1].fd, cnx->q[1].deferred_data_size);
+    printf("0: fd %d, %d deferred\n", cnx->q[0].fd, cnx->q[0].deferred_data_size);
+    hexdump(cnx->q[0].deferred_data, cnx->q[0].deferred_data_size);
+    printf("1: fd %d, %d deferred\n", cnx->q[1].fd, cnx->q[1].deferred_data_size);
+    hexdump(cnx->q[1].deferred_data, cnx->q[1].deferred_data_size);
 }
 
 
@@ -377,7 +459,7 @@ int fd2fd(struct queue *target_q, struct queue *from_q)
    if (size_r == -1) {
        switch (errno) {
        case EAGAIN:
-           if (verbose)
+           if (cfg.verbose)
                fprintf(stderr, "reading 0 from %d\n", from);
            return FD_NODATA;
 
@@ -387,7 +469,7 @@ int fd2fd(struct queue *target_q, struct queue *from_q)
        }
    }
 
-   CHECK_RES_RETURN(size_r, "read");
+   CHECK_RES_RETURN(size_r, "read",FD_CNXCLOSED);
 
    if (size_r == 0)
       return FD_CNXCLOSED;
@@ -403,7 +485,7 @@ int fd2fd(struct queue *target_q, struct queue *from_q)
 
        case ECONNRESET:
        case EPIPE:
-           /* remove end closed -- drop the connection */
+           /* remote end closed -- drop the connection */
            return FD_CNXCLOSED;
        }
    } else if (size_w < size_r) {
@@ -412,7 +494,7 @@ int fd2fd(struct queue *target_q, struct queue *from_q)
        return FD_STALLED;
    }
 
-   CHECK_RES_RETURN(size_w, "write");
+   CHECK_RES_RETURN(size_w, "write", FD_CNXCLOSED);
 
    return size_w;
 }
@@ -426,7 +508,7 @@ char* sprintaddr(char* buf, size_t size, struct addrinfo *a)
    res = getnameinfo(a->ai_addr, a->ai_addrlen,
                host, sizeof(host),
                serv, sizeof(serv),
-               numeric ? NI_NUMERICHOST | NI_NUMERICSERV : 0 );
+               cfg.numeric ? NI_NUMERICHOST | NI_NUMERICSERV : 0 );
 
    if (res) {
        log_message(LOG_ERR, "sprintaddr:getnameinfo: %s\n", gai_strerror(res));
@@ -451,32 +533,23 @@ char* sprintaddr(char* buf, size_t size, struct addrinfo *a)
 /* Turns a hostname and port (or service) into a list of struct addrinfo
  * returns 0 on success, -1 otherwise and logs error
  */
-int resolve_split_name(struct addrinfo **out, const char* ct_host, const char* serv)
+int resolve_split_name(struct addrinfo **out, char* host, char* serv)
 {
    struct addrinfo hint;
    char *end;
    int res;
-   char* host, *host_base;
 
    memset(&hint, 0, sizeof(hint));
    hint.ai_family = PF_UNSPEC;
    hint.ai_socktype = SOCK_STREAM;
 
-   /* Copy parameter so not to clobber data in libconfig */
-   res = asprintf(&host_base, "%s", ct_host);
-   if (res == -1) {
-       log_message(LOG_ERR, "asprintf: cannot allocate memory");
-       return -1;
-   }
-
-   host = host_base;
-
    /* If it is a RFC-Compliant IPv6 address ("[1234::12]:443"), remove brackets
     * around IP address */
    if (host[0] == '[') {
        end = strrchr(host, ']');
        if (!end) {
            fprintf(stderr, "%s: no closing bracket in IPv6 address?\n", host);
+           return -1;
        }
        host++; /* skip first bracket */
        *end = 0; /* remove last bracket */
@@ -485,7 +558,6 @@ int resolve_split_name(struct addrinfo **out, const char* ct_host, const char* s
    res = getaddrinfo(host, serv, &hint, out);
    if (res)
       log_message(LOG_ERR, "%s `%s:%s'\n", gai_strerror(res), host, serv);
-   free(host_base);
    return res;
 }
 
@@ -519,60 +591,97 @@ void resolve_name(struct addrinfo **out, char* fullname)
 }
 
 /* Log to syslog or stderr if foreground */
-void log_message(int type, char* msg, ...)
+void log_message(int type, const char* msg, ...)
 {
     va_list ap;
 
     va_start(ap, msg);
-    if (foreground)
+    if (cfg.foreground)
         vfprintf(stderr, msg, ap);
-    else
-        vsyslog(type, msg, ap);
     va_end(ap);
+
+    if (do_syslog) {
+        va_start(ap, msg);
+        vsyslog(type, msg, ap);
+        va_end(ap);
+    }
 }
 
-/* syslogs who connected to where */
-void log_connection(struct connection *cnx)
+
+/* Fills a connection description; returns 0 on failure */
+int get_connection_desc(struct connection_desc* desc, const struct connection *cnx)
 {
+    int res;
     struct addrinfo addr;
     struct sockaddr_storage ss;
-#define MAX_NAMELENGTH (NI_MAXHOST + NI_MAXSERV + 1)
-    char peer[MAX_NAMELENGTH], service[MAX_NAMELENGTH],
-        local[MAX_NAMELENGTH], target[MAX_NAMELENGTH];
-    int res;
-
-    if (cnx->proto->log_level < 1)
-        return;
 
     addr.ai_addr = (struct sockaddr*)&ss;
     addr.ai_addrlen = sizeof(ss);
 
     res = getpeername(cnx->q[0].fd, addr.ai_addr, &addr.ai_addrlen);
-    if (res == -1) return; /* Can happen if connection drops before we get here.
+    if (res == -1) return 0; /* Can happen if connection drops before we get here.
                                In that case, don't log anything (there is no connection) */
-    sprintaddr(peer, sizeof(peer), &addr);
+    sprintaddr(desc->peer, sizeof(desc->peer), &addr);
 
     addr.ai_addrlen = sizeof(ss);
     res = getsockname(cnx->q[0].fd, addr.ai_addr, &addr.ai_addrlen);
-    if (res == -1) return;
-    sprintaddr(service, sizeof(service), &addr);
+    if (res == -1) return 0;
+    sprintaddr(desc->service, sizeof(desc->service), &addr);
 
     addr.ai_addrlen = sizeof(ss);
     res = getpeername(cnx->q[1].fd, addr.ai_addr, &addr.ai_addrlen);
-    if (res == -1) return;
-    sprintaddr(target, sizeof(target), &addr);
+    if (res == -1) return 0;
+    sprintaddr(desc->target, sizeof(desc->target), &addr);
 
     addr.ai_addrlen = sizeof(ss);
     res = getsockname(cnx->q[1].fd, addr.ai_addr, &addr.ai_addrlen);
-    if (res == -1) return;
-    sprintaddr(local, sizeof(local), &addr);
+    if (res == -1) return 0;
+    sprintaddr(desc->local, sizeof(desc->local), &addr);
+
+    return 1;
+}
+
+/* syslogs who connected to where 
+ * desc: string description of the connection. if NULL, log_connection will
+ * manage on its own
+ * cnx: connection descriptor
+ * */
+void log_connection(struct connection_desc* desc, const struct connection *cnx)
+{
+    struct connection_desc d;
+
+    if (cnx->proto->log_level < 1)
+        return;
+
+    if (!desc) {
+        desc = &d;
+        get_connection_desc(desc, cnx);
+    }
 
     log_message(LOG_INFO, "%s:connection from %s to %s forwarded from %s to %s\n",
-                cnx->proto->description,
-                peer,
-                service,
-                local,
-                target);
+                cnx->proto->name,
+                desc->peer,
+                desc->service,
+                desc->local,
+                desc->target);
+}
+
+void set_proctitle_shovel(struct connection_desc* desc, const struct connection *cnx)
+{
+#ifdef LIBBSD
+    struct connection_desc d;
+
+    if (!desc) {
+        desc = &d;
+        get_connection_desc(desc, cnx);
+    }
+    setproctitle("shovel %s %s->%s => %s->%s",
+        cnx->proto->name,
+        desc->peer,
+        desc->service,
+        desc->local,
+        desc->target);
+#endif
 }
 
 
@@ -594,27 +703,27 @@ int check_access_rights(int in_socket, const char* service)
     int res;
 
     res = getpeername(in_socket, &peer.saddr, &size);
-    CHECK_RES_RETURN(res, "getpeername");
+    CHECK_RES_RETURN(res, "getpeername", res);
 
     /* extract peer address */
     res = getnameinfo(&peer.saddr, size, addr_str, sizeof(addr_str), NULL, 0, NI_NUMERICHOST);
     if (res) {
-        if (verbose)
+        if (cfg.verbose)
             fprintf(stderr, "getnameinfo(NI_NUMERICHOST):%s\n", gai_strerror(res));
         strcpy(addr_str, STRING_UNKNOWN);
     }
     /* extract peer name */
     strcpy(host, STRING_UNKNOWN);
-    if (!numeric) {
+    if (!cfg.numeric) {
         res = getnameinfo(&peer.saddr, size, host, sizeof(host), NULL, 0, NI_NAMEREQD);
         if (res) {
-            if (verbose)
+            if (cfg.verbose)
                 fprintf(stderr, "getnameinfo(NI_NAMEREQD):%s\n", gai_strerror(res));
         }
     }
 
     if (!hosts_ctl(service, host, addr_str, STRING_UNKNOWN)) {
-        if (verbose)
+        if (cfg.verbose)
             fprintf(stderr, "access denied\n");
         log_message(LOG_INFO, "connection from %s(%s): access denied", host, addr_str);
         close(in_socket);
@@ -657,15 +766,20 @@ void setup_syslog(const char* bin_name) {
     char *name1, *name2;
     int res, fn;
 
+    if (!strcmp(cfg.syslog_facility, "none")) {
+        do_syslog = 0;
+        return;
+    }
+
     name1 = strdup(bin_name);
     res = asprintf(&name2, "%s[%d]", basename(name1), getpid());
     CHECK_RES_DIE(res, "asprintf");
 
     for (fn = 0; facilitynames[fn].c_val != -1; fn++)
-        if (strcmp(facilitynames[fn].c_name, facility) == 0)
+        if (strcmp(facilitynames[fn].c_name, cfg.syslog_facility) == 0)
             break;
-    if (fn == -1) {
-        fprintf(stderr, "Unknown facility %s\n", facility);
+    if (facilitynames[fn].c_val == -1) {
+        fprintf(stderr, "Unknown facility %s\n", cfg.syslog_facility);
         exit(1);
     }
 
@@ -688,16 +802,33 @@ void set_keepcaps(int val) {
 #endif
 }
 
-/* set needed capabilities for effective and permitted, clear rest */
-void set_capabilities(void) {
+/* Returns true if anything requires transparent proxying. */
+static int use_transparent(void)
+{
+#ifdef LIBCAP
+    if (cfg.transparent)
+        return 1;
+
+    for (int i = 0; i < cfg.protocols_len; i++)
+        if (cfg.protocols[i].transparent)
+            return 1;
+
+#endif
+    return 0;
+}
+
+/* set needed capabilities for effective and permitted, clear rest
+ * IN: cap_net_admin: set to 1 to set CAP_NET_RAW
+ * */
+void set_capabilities(int cap_net_admin) {
 #ifdef LIBCAP
     int res;
     cap_t caps;
     cap_value_t cap_list[10];
     int ncap = 0;
 
-    if (transparent)
-        cap_list[ncap++] = CAP_NET_ADMIN;
+    if (cap_net_admin)
+        cap_list[ncap++] = CAP_NET_RAW;
 
     caps = cap_init();
 
@@ -738,12 +869,12 @@ void drop_privileges(const char* user_name, const char* chroot_path)
             fprintf(stderr, "%s: not found\n", user_name);
             exit(2);
         }
-        if (verbose)
+        if (cfg.verbose)
             fprintf(stderr, "turning into %s\n", user_name);
     }
 
     if (chroot_path) {
-        if (verbose)
+        if (cfg.verbose)
             fprintf(stderr, "chrooting into %s\n", chroot_path);
 
         res = chroot(chroot_path);
@@ -765,7 +896,7 @@ void drop_privileges(const char* user_name, const char* chroot_path)
         res = setuid(pw->pw_uid);
         CHECK_RES_DIE(res, "setuid");
 
-        set_capabilities();
+        set_capabilities(use_transparent());
         set_keepcaps(0);
     }
 }

common.h

@@ -35,6 +35,9 @@
 
 #include "version.h"
 
+#define MAX(a, b)  (((a) > (b)) ? (a) : (b))
+
+
 #define CHECK_RES_DIE(res, str) \
     if (res == -1) {    \
        fprintf(stderr, "%s:%d:", __FILE__, __LINE__); \
@@ -42,12 +45,19 @@
        exit(1);         \
     }
 
-#define CHECK_RES_RETURN(res, str) \
+#define CHECK_RES_RETURN(res, str, ret) \
     if (res == -1) {                                    \
         log_message(LOG_CRIT, "%s:%d:%s:%d:%s\n", __FILE__, __LINE__, str, errno, strerror(errno));  \
-        return res;                                     \
+        return ret;                                     \
     } 
 
+#define CHECK_ALLOC(a, str) \
+    if (!a) { \
+        fprintf(stderr, "%s:%d:", __FILE__, __LINE__); \
+        perror(str); \
+        exit(1); \
+    }
+
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0]))
 
 #if 1
@@ -60,6 +70,14 @@
 #define IP_FREEBIND 0
 #endif
 
+#ifndef TCP_FASTOPEN
+#define TCP_FASTOPEN 0
+#endif
+
+#ifndef TCP_FASTOPEN_CONNECT
+#define TCP_FASTOPEN_CONNECT 30 /* Attempt FastOpen with connect.  */
+#endif
+
 enum connection_state {
     ST_PROBING=1,    /* Waiting for timeout to find where to forward */
     ST_SHOVELING   /* Connexion is established */
@@ -78,53 +96,87 @@ struct queue {
 };
 
 struct connection {
+    int type;           /* SOCK_DGRAM | SOCK_STREAM */
+    struct sslhcfg_protocols_item* proto; /* Where to connect to */
+
+    /* SOCK_STREAM */
     enum connection_state state;
     time_t probe_timeout;
-    struct proto *proto;
 
     /* q[0]: queue for external connection (client);
      * q[1]: queue for internal connection (httpd or sshd);
      * */
     struct queue q[2];
+
+    /* SOCK_DGRAM */
+    struct sockaddr client_addr; /* Contains the remote client address */
+    socklen_t addrlen;
+
+    int local_endpoint; /* Contains the local address */
+
+    time_t last_active;
+
+    /* We need one local socket for each target server, so we know where to
+     * forward server responses */
+    int target_sock;  
+};
+
+
+struct listen_endpoint {
+    int socketfd;       /* file descriptor of listening socket */
+    int type;           /* SOCK_DGRAM | SOCK_STREAM */
 };
 
 #define FD_CNXCLOSED    0
 #define FD_NODATA       -1
 #define FD_STALLED      -2
 
+/* String description of a connection */
+#define MAX_NAMELENGTH (NI_MAXHOST + NI_MAXSERV + 1)
+struct connection_desc {
+    char peer[MAX_NAMELENGTH], service[MAX_NAMELENGTH],
+        local[MAX_NAMELENGTH], target[MAX_NAMELENGTH];
+};
+
+typedef enum {
+    NON_BLOCKING = 0,
+    BLOCKING = 1
+} connect_blocking;
+
 
 /* common.c */
 void init_cnx(struct connection *cnx);
-int connect_addr(struct connection *cnx, int fd_from);
+int set_nonblock(int fd);
+int connect_addr(struct connection *cnx, int fd_from, connect_blocking blocking);
 int fd2fd(struct queue *target, struct queue *from);
 char* sprintaddr(char* buf, size_t size, struct addrinfo *a);
 void resolve_name(struct addrinfo **out, char* fullname);
-void log_connection(struct connection *cnx);
+int get_connection_desc(struct connection_desc* desc, const struct connection *cnx);
+void log_connection(struct connection_desc* desc, const struct connection *cnx);
+void set_proctitle_shovel(struct connection_desc* desc, const struct connection *cnx);
 int check_access_rights(int in_socket, const char* service);
 void setup_signals(void);
 void setup_syslog(const char* bin_name);
 void drop_privileges(const char* user_name, const char* chroot_path);
+void set_capabilities(int cap_net_admin);
 void write_pid_file(const char* pidfile);
-void log_message(int type, char* msg, ...);
+void log_message(int type, const char* msg, ...);
 void dump_connection(struct connection *cnx);
-int resolve_split_name(struct addrinfo **out, const char* hostname, const char* port);
+int resolve_split_name(struct addrinfo **out, char* hostname, char* port);
 
-int start_listen_sockets(int *sockfd[], struct addrinfo *addr_list);
+int start_listen_sockets(struct listen_endpoint *sockfd[]);
 
 int defer_write(struct queue *q, void* data, int data_size);
 int flush_deferred(struct queue *q);
 
-extern int probing_timeout, verbose, inetd, foreground, 
-       background, transparent, numeric;
-extern struct sockaddr_storage addr_ssl, addr_ssh, addr_openvpn;
+extern struct sslhcfg_item cfg;
 extern struct addrinfo *addr_listen;
 extern const char* USAGE_STRING;
-extern const char* user_name, *pid_file, *chroot_path, *facility;
 extern const char* server_type;
 
 /* sslh-fork.c */
 void start_shoveler(int);
 
-void main_loop(int *listen_sockets, int num_addr_listen);
+void main_loop(struct listen_endpoint *listen_sockets, int num_addr_listen);
 
 #endif

doc/FAQ.md

@@ -0,0 +1,169 @@
+Frequently Asked Questions
+==========================
+
+When something doesn't work, look up here... and if it still
+doesn't work, report how what was suggested here went.
+
+It's also worth reading [how to ask
+questions](http://www.catb.org/~esr/faqs/smart-questions.html)
+before posting on the mailing list or opening an issue in
+Github.
+
+Getting more info
+=================
+
+In general, if something doesn't work, you'll want to run
+`sslh` with lots of logging, and the logging directly in
+the terminal (Otherwise, logs are sent to `syslog`, and
+usually end up in `/var/log/auth.log`). You will achieve
+this by running `sslh` in foreground with verbose:
+
+```
+sslh -v 1 -f -F myconfig.cfg
+```
+
+Higher values of `verbose` produce more information. 1 is
+usually sufficient. 2 will also print incoming packets used
+for probing.
+
+forward to [PROBE] failed:connect: Connection refused
+=====================================================
+
+Usually this means `sslh` is configured to forward a
+protocol somewhere, but no service is listening on the
+target address. Check your `sslh` configuration, check the
+corresponding server really is listening and running.
+Finally, check the server is listening where you expect it
+to:
+
+```
+netstat -lpt
+```
+
+I get a segmentation fault!
+===========================
+
+Well, it's not yours (fault): a segfault is always a bug in
+the programme. Usually standard use cases are well tested,
+so it may be related to something unusual in your
+configuration, or even something wrong, but it should still
+never result in a segfault.
+
+Thankfully, when they are deterministic, segfaults are
+usually fairly easy to fix if you're willing to run a few
+diagnostics to help the developer.
+
+First, make sure you have debug symbols:
+```
+$ file sslh-select
+sslh-select: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 3.2.0, BuildID[sha1]=a758ac75ff11f1ace577705b4d6627e301940b59, with debug_info, not stripped
+```
+
+Note `with debug_info, not stripped` at the end. If you
+don't have that, your distribution stripped the binary: you
+will need to get the source code and compile it yourself
+(that way, you will also get the latest version).
+
+Install `valgrind` and run `sslh` under it:
+
+```
+valgrind --leak-check=full ./sslh-fork -v 2 -f -F yourconfig.cfg
+```
+
+Report the full output to the mailing list or github.
+Valgrind is very powerful and gives precise hints of what is
+wrong and why. For example on `sslh` issue
+(#273)[https://github.com/yrutschle/sslh/issues/273]:
+
+```
+sudo valgrind --leak-check=full ./sslh-fork -v 2 -f -F /etc/sslh.cfg
+==20037== Memcheck, a memory error detector
+==20037== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
+==20037== Using Valgrind-3.15.0 and LibVEX; rerun with -h for copyright info
+==20037== Command: ./sslh-fork -v 2 -f -F /etc/sslh.cfg
+==20037==
+sslh-fork v1.21b-1-g2c93a01-dirty started
+--20037-- WARNING: unhandled arm-linux syscall: 403
+--20037-- You may be able to write your own handler.
+--20037-- Read the file README_MISSING_SYSCALL_OR_IOCTL.
+--20037-- Nevertheless we consider this a bug.  Please report
+--20037-- it at http://valgrind.org/support/bug_reports.html.
+==20040== Conditional jump or move depends on uninitialised value(s)
+==20040==    at 0x112A3C: parse_tls_header (tls.c:162)
+==20040==    by 0x111CEF: is_tls_protocol (probe.c:214)
+==20040==    by 0x11239F: probe_client_protocol (probe.c:366)
+==20040==    by 0x10A8F7: start_shoveler (sslh-fork.c:98)
+==20040==    by 0x10AE9B: main_loop (sslh-fork.c:200)
+==20040==    by 0x1114FB: main (sslh-main.c:322)
+==20040==
+```
+
+Here we see that something wrong is happening at `tls.c`
+line 162, and it's linked to an uninitialised value.
+
+Using sslh for virtual hosting
+==============================
+
+Virtual hosting refers to having several domain names behind
+a single IP address. All Web servers handle this, but
+sometimes it can be useful to do it with `sslh`.
+
+TLS virtual hosting with SNI
+----------------------------
+
+For TLS, this is done very simply using Server Name
+Indication, SNI for short, which is a TLS extension whereby
+the client indicates the name of the server it wishes to
+connect to. This can be a very powerful way to separate
+several TLS-based services hosted behind the same port:
+simply name each service with its own hostname. For example,
+we could define `mail.rutschle.net`, `im.rutschle.net`,
+`www.rutschle.net`, all of which point to the same IP
+address.  `sslh` uses the `sni_hostnames` setting of the
+TLS probe to do this, e.g.:
+
+```
+protocols: (
+    {   name: "tls";
+        host: "localhost";
+        port: "993";
+        sni_hostnames: [ "mail.rutschle.net" ];
+    },
+    {   name: "tls";
+        host: "localhost";
+        port: "xmpp-client";
+        sni_hostnames: [ "im.rutschle.net" ];
+    },
+    {   name: "tls";
+        host: "localhost";
+        port: "4443";
+        sni_hostnames: [ "www.rutschle.net" ];
+    }
+);
+```
+
+HTTP virtual hosting with regex
+-------------------------------
+
+If you wish to serve several Web domains over HTTP through
+`sslh`, you can do this simply by using regular expressions
+on the Host specification part of the HTTP query.
+
+The following example forwards connections to `host_A.acme`
+to 192.168.0.2, and connections to `host_B.acme` to
+192.168.0.3.
+
+```
+protocols: (
+    {   name: "regex";
+        host: "192.168.0.2";
+        port: "80";
+        regex_patterns:
+                ["^(GET|POST|PUT|OPTIONS|DELETE|HEADER) [^ ]* HTTP/[0-9.]*[\r\n]*Host: host_A.acme"] },
+    {   name: "regex";
+        host: "192.168.0.3";
+        port: "80";
+        regex_patterns:
+                ["^(GET|POST|PUT|OPTIONS|DELETE|HEADER) [^ ]* HTTP/[0-9.]*[\r\n]*Host: host_B.acme"] }
+);
+```

doc/INSTALL.md

@@ -0,0 +1,120 @@
+Compile and install
+===================
+
+Dependencies
+------------
+
+`sslh` uses:
+
+* [libconfig](http://www.hyperrealm.com/libconfig/). For
+  Debian this is contained in package `libconfig8-dev`. You
+can compile with or without it using USELIBCONFIG in the
+Makefile.
+
+* [libwrap](http://packages.debian.org/source/unstable/tcp-wrappers).
+    For Debian, this is contained in packages
+`libwrap0-dev`. You
+can compile with or without it using USELIBWRAP in the
+Makefile.
+
+* [libsystemd](http://packages.debian.org/source/unstable/libsystemd-dev), in package `libsystemd-dev`.  You
+can compile with or without it using USESYSTEMD in the
+Makefile.
+
+* [libcap](http://packages.debian.org/source/unstable/libcap-dev), in package `libcap-dev`. You can compile with or without it using USELIBCAP in the Makefile
+
+* libbsd, to enable to change the process name (as shown in
+  `ps`, so each forked process shows what protocol and what
+  connection it is serving),
+which requires `libbsd` at runtime, and `libbsd-dev` at
+compile-time.
+
+
+For OpenSUSE, these are contained in packages libconfig9 and
+libconfig-dev in repository
+<http://download.opensuse.org/repositories/multimedia:/libs/openSUSE_12.1/>
+
+For Fedora, you'll need packages `libconfig` and
+`libconfig-devel`:
+
+	yum install libconfig libconfig-devel
+
+If you want to rebuild `sslh-conf.c` (after a `make
+distclean` for example), you will also need to add
+[conf2struct](https://www.rutschle.net/tech/conf2struct/README.html)
+(v1.5) to your path.
+
+Compilation
+-----------
+
+After this, the Makefile should work:
+
+	make install
+
+There are a couple of configuration options at the beginning
+of the Makefile: 
+
+* `USELIBWRAP` compiles support for host access control (see
+  `hosts_access(3)`), you will need `libwrap` headers and
+  library to compile (`libwrap0-dev` in Debian).
+
+* `USELIBCONFIG` compiles support for the configuration
+  file. You will need `libconfig` headers to compile
+  (`libconfig8-dev` in Debian).
+
+*  `USESYSTEMD` compiles support for using systemd socket activation.
+   You will need `systemd` headers to compile (`systemd-devel` in Fedora).
+
+* `USELIBBSD` compiles support for updating the process name (as shown
+  by `ps`).
+
+Binaries
+--------
+
+The Makefile produces two different executables: `sslh-fork`
+and `sslh-select`:
+
+* `sslh-fork` forks a new process for each incoming connection.
+It is well-tested and very reliable, but incurs the overhead
+of many processes.  
+If you are going to use `sslh` for a "small" setup (less than
+a dozen ssh connections and a low-traffic https server) then
+`sslh-fork` is probably more suited for you. 
+
+* `sslh-select` uses only one thread, which monitors all connections
+at once. It is more recent and less tested, but only incurs a 16
+byte overhead per connection. Also, if it stops, you'll lose all
+connections, which means you can't upgrade it remotely.  
+If you are going to use `sslh` on a "medium" setup (a few thousand ssh
+connections, and another few thousand ssl connections),
+`sslh-select` will be better.
+
+If you have a very large site (tens of thousands of connections),
+you'll need a vapourware version that would use libevent or
+something like that.
+
+
+Installation
+------------
+
+* In general:
+
+		make
+		cp sslh-fork /usr/local/sbin/sslh
+		cp basic.cfg /etc/sslh.cfg
+                vi /etc/sslh.cfg
+
+* For Debian:
+
+		cp scripts/etc.init.d.sslh /etc/init.d/sslh
+	
+* For CentOS:
+
+		cp scripts/etc.rc.d.init.d.sslh.centos /etc/rc.d/init.d/sslh
+
+
+You might need to create links in /etc/rc<x>.d so that the server
+start automatically at boot-up, e.g. under Debian:
+
+	update-rc.d sslh defaults
+

doc/config.md

@@ -0,0 +1,347 @@
+Configuration
+=============
+
+If you use the scripts provided, sslh will get its
+configuration from /etc/sslh.cfg. Please refer to
+example.cfg for an overview of all the settings.
+
+A good scheme is to use the external name of the machine in
+`listen`, and bind `httpd` to `localhost:443` (instead of all
+binding to all interfaces): that way, HTTPS connections
+coming from inside your network don't need to go through
+`sslh`, and `sslh` is only there as a frontal for connections
+coming from the internet.
+
+Note that 'external name' in this context refers to the
+actual IP address of the machine as seen from your network,
+i.e. that that is not `127.0.0.1` in the output of
+`ifconfig(8)`.
+
+Libwrap support
+---------------
+
+Sslh can optionally perform `libwrap` checks for the sshd
+service: because the connection to `sshd` will be coming
+locally from `sslh`, `sshd` cannot determine the IP of the
+client.
+
+OpenVPN support
+---------------
+
+OpenVPN clients connecting to OpenVPN running with
+`-port-share` reportedly take more than one second between
+the time the TCP connection is established and the time they
+send the first data packet. This results in `sslh` with
+default settings timing out and assuming an SSH connection.
+To support OpenVPN connections reliably, it is necessary to
+increase `sslh`'s timeout to 5 seconds.
+
+Instead of using OpenVPN's port sharing, it is more reliable
+to use `sslh`'s `--openvpn` option to get `sslh` to do the
+port sharing.
+
+Using proxytunnel with sslh
+---------------------------
+
+If you are connecting through a proxy that checks that the
+outgoing connection really is SSL and rejects SSH, you can
+encapsulate all your traffic in SSL using `proxytunnel` (this
+should work with `corkscrew` as well). On the server side you
+receive the traffic with `stunnel` to decapsulate SSL, then
+pipe through `sslh` to switch HTTP on one side and SSL on the
+other.
+
+In that case, you end up with something like this:
+
+	ssh -> proxytunnel -e ----[ssh/ssl]---> stunnel ---[ssh]---> sslh --> sshd
+	Web browser -------------[http/ssl]---> stunnel ---[http]--> sslh --> httpd
+
+Configuration goes like this on the server side, using `stunnel3`:
+
+	stunnel -f -p mycert.pem  -d thelonious:443 -l /usr/local/sbin/sslh -- \
+		sslh -i  --http localhost:80 --ssh localhost:22
+
+* stunnel options:
+  * `-f` for foreground/debugging
+  * `-p` for specifying the key and certificate
+  * `-d` for specifying which interface and port
+	we're listening to for incoming connexions
+  * `-l` summons `sslh` in inetd mode.
+
+* sslh options:
+  * `-i` for inetd mode
+  * `--http` to forward HTTP connexions to port 80,
+	and SSH connexions to port 22.
+
+Capabilities support
+--------------------
+
+On Linux (only?), you can compile sslh with `USELIBCAP=1` to
+make use of POSIX capabilities; this will save the required
+capabilities needed for transparent proxying for unprivileged
+processes.
+
+Alternatively, you may use filesystem capabilities instead
+of starting sslh as root and asking it to drop privileges.
+You will need `CAP_NET_BIND_SERVICE` for listening on port 443
+and `CAP_NET_RAW` for transparent proxying (see
+`capabilities(7)`).
+
+You can use the `setcap(8)` utility to give these capabilities
+to the executable:
+
+	sudo setcap cap_net_bind_service,cap_net_raw+pe sslh-select
+
+Then you can run sslh-select as an unpriviledged user, e.g.:
+
+	sslh-select -p myname:443 --ssh localhost:22 --tls localhost:443
+
+Transparent proxy support
+-------------------------
+
+On Linux and FreeBSD you can use the `--transparent` option to
+request transparent proxying. This means services behind `sslh`
+(Apache, `sshd` and so on) will see the external IP and ports
+as if the external world connected directly to them. This
+simplifies IP-based access control (or makes it possible at
+all).
+
+You can refer to Sean Warn'ѕ [tutorial](tproxy.md) for a
+different set-up which enables transparent proxying between
+two different machines. The following may only work if
+`sslh` and the final servers are on the same machine.
+
+Note that getting this to work is very tricky and
+detail-dependant: depending on whether the target server and
+sslh are on the same machine, different machines, or
+different dockers, and tool versions, all seem to change the
+required network configuration somewhat. If it doesn't work,
+it's almost certain that the problem is not linked to `sslh`
+but to the network setup that surrounds it.
+
+Linux:
+
+`sslh` needs extended rights to perform this: you'll need to
+give it `CAP_NET_RAW` capabilities (see appropriate chapter)
+or run it as root (but don't do that).
+
+The firewalling tables also need to be adjusted as follows.
+I don't think it is possible to have `httpd` and `sslh` both listen to 443 in
+this scheme -- let me know if you manage that:
+
+	# Set route_localnet = 1 on all interfaces so that ssl can use "localhost" as destination
+	sysctl -w net.ipv4.conf.default.route_localnet=1
+	sysctl -w net.ipv4.conf.all.route_localnet=1
+
+	# DROP martian packets as they would have been if route_localnet was zero
+	# Note: packets not leaving the server aren't affected by this, thus sslh will still work
+	iptables -t raw -A PREROUTING ! -i lo -d 127.0.0.0/8 -j DROP
+	iptables -t mangle -A POSTROUTING ! -o lo -s 127.0.0.0/8 -j DROP
+
+	# Mark all connections made by ssl for special treatment (here sslh is run as user "sslh")
+	iptables -t nat -A OUTPUT -m owner --uid-owner sslh -p tcp --tcp-flags FIN,SYN,RST,ACK SYN -j CONNMARK --set-xmark 0x01/0x0f
+
+	# Outgoing packets that should go to sslh instead have to be rerouted, so mark them accordingly (copying over the connection mark)
+	iptables -t mangle -A OUTPUT ! -o lo -p tcp -m connmark --mark 0x01/0x0f -j CONNMARK --restore-mark --mask 0x0f
+
+	# Configure routing for those marked packets
+	ip rule add fwmark 0x1 lookup 100
+	ip route add local 0.0.0.0/0 dev lo table 100
+
+Tranparent proxying with IPv6 is similarly set up as follows:
+
+	# Set route_localnet = 1 on all interfaces so that ssl can use "localhost" as destination
+	# Not sure if this is needed for ipv6 though
+	sysctl -w net.ipv4.conf.default.route_localnet=1
+	sysctl -w net.ipv4.conf.all.route_localnet=1
+
+	# DROP martian packets as they would have been if route_localnet was zero
+	# Note: packets not leaving the server aren't affected by this, thus sslh will still work
+	ip6tables -t raw -A PREROUTING ! -i lo -d ::1/128 -j DROP
+	ip6tables -t mangle -A POSTROUTING ! -o lo -s ::1/128 -j DROP
+
+	# Mark all connections made by ssl for special treatment (here sslh is run as user "sslh")
+	ip6tables -t nat -A OUTPUT -m owner --uid-owner sslh -p tcp --tcp-flags FIN,SYN,RST,ACK SYN -j CONNMARK --set-xmark 0x01/0x0f
+
+	# Outgoing packets that should go to sslh instead have to be rerouted, so mark them accordingly (copying over the connection mark)
+	ip6tables -t mangle -A OUTPUT ! -o lo -p tcp -m connmark --mark 0x01/0x0f -j CONNMARK --restore-mark --mask 0x0f
+
+	# Configure routing for those marked packets
+	ip -6 rule add fwmark 0x1 lookup 100
+	ip -6 route add local ::/0 dev lo table 100
+
+Explanation:
+To be able to use `localhost` as destination in your sslh config along with transparent proxying
+you have to allow routing of loopback addresses as done above.
+This is something you usually should not do (see [this stackoverflow post](https://serverfault.com/questions/656279/how-to-force-linux-to-accept-packet-with-loopback-ip/656484#656484))
+The two `DROP` iptables rules emulate the behaviour of `route_localnet` set to off (with one small difference:
+allowing the reroute-check to happen after the fwmark is set on packets destined for sslh).
+See [this diagram](https://upload.wikimedia.org/wikipedia/commons/3/37/Netfilter-packet-flow.svg) for a good visualisation
+showing how packets will traverse the iptables chains.
+
+Note:
+You have to run `sslh` as dedicated user (in this example the user is also named `sslh`), to not mess up with your normal networking.
+These rules will allow you to connect directly to ssh on port
+22 (or to any other service behind sslh) as well as through sslh on port 443.
+
+Also remember that iptables configuration and ip routes and 
+rules won't be necessarily persisted after you reboot. Make 
+sure to save them properly. For example in CentOS7, you would 
+do `iptables-save > /etc/sysconfig/iptables`, and add both 
+`ip` commands to your `/etc/rc.local`.
+
+FreeBSD:
+
+Given you have no firewall defined yet, you can use the following configuration
+to have ipfw properly redirect traffic back to sslh
+
+	/etc/rc.conf
+	firewall_enable="YES"
+	firewall_type="open"
+	firewall_logif="YES"
+	firewall_coscripts="/etc/ipfw/sslh.rules"
+
+
+/etc/ipfw/sslh.rules
+
+	#! /bin/sh
+
+	# ssl
+	ipfw add 20000 fwd 192.0.2.1,443 log tcp from 192.0.2.1 8443 to any out
+	ipfw add 20010 fwd 2001:db8::1,443 log tcp from 2001:db8::1 8443 to any out
+
+	# ssh
+	ipfw add 20100 fwd 192.0.2.1,443 log tcp from 192.0.2.1 8022 to any out
+	ipfw add 20110 fwd 2001:db8::1,443 log tcp from 2001:db8::1 8022 to any out
+
+	# xmpp
+	ipfw add 20200 fwd 192.0.2.1,443 log tcp from 192.0.2.1 5222 to any out
+	ipfw add 20210 fwd 2001:db8::1,443 log tcp from 2001:db8::1 5222 to any out
+
+	# openvpn (running on other internal system)
+	ipfw add 20300 fwd 192.0.2.1,443 log tcp from 198.51.100.7 1194 to any out
+	ipfw add 20310 fwd 2001:db8::1,443 log tcp from 2001:db8:1::7 1194 to any out
+
+General notes:
+
+
+This will only work if `sslh` does not use any loopback
+addresses (no `127.0.0.1` or `localhost`), you'll need to use
+explicit IP addresses (or names):
+
+	sslh --listen 192.168.0.1:443 --ssh 192.168.0.1:22 --tls 192.168.0.1:4443
+
+This will not work:
+
+	sslh --listen 192.168.0.1:443 --ssh 127.0.0.1:22 --tls 127.0.0.1:4443
+    
+Transparent proxying means the target server sees the real
+origin address, so it means if the client connects using
+IPv6, the server must also support IPv6. It is easy to
+support both IPv4 and IPv6 by configuring the server
+accordingly, and setting `sslh` to connect to a name that
+resolves to both IPv4 and IPv6, e.g.:
+
+        sslh --transparent --listen <extaddr>:443 --ssh insideaddr:22
+
+        /etc/hosts:
+        192.168.0.1  insideaddr
+        201::::2     insideaddr
+
+Upon incoming IPv6 connection, `sslh` will first try to
+connect to the IPv4 address (which will fail), then connect
+to the IPv6 address.
+
+Systemd Socket Activation
+-------------------------
+If compiled with `USESYSTEMD` then it is possible to activate 
+the service on demand and avoid running any code as root.
+
+In this mode any listen configuration options are ignored and 
+the sockets are passed by systemd to the service.
+
+Example socket unit:
+
+	[Unit]
+	Before=sslh.service
+	
+	[Socket]
+	ListenStream=1.2.3.4:443
+	ListenStream=5.6.7.8:444
+	ListenStream=9.10.11.12:445
+	FreeBind=true
+
+	[Install]
+	WantedBy=sockets.target
+
+Example service unit:
+
+	[Unit]
+	PartOf=sslh.socket
+	
+	[Service]
+	ExecStart=/usr/sbin/sslh -v -f --ssh 127.0.0.1:22 --tls 127.0.0.1:443
+	KillMode=process
+	CapabilityBoundingSet=CAP_NET_BIND_SERVICE CAP_NET_RAW
+	PrivateTmp=true
+	PrivateDevices=true
+	ProtectSystem=full
+	ProtectHome=true
+	User=sslh
+
+
+With this setup only the socket needs to be enabled. The sslh service 
+will be started on demand and does not need to run as root to bind the 
+sockets as systemd has already bound and passed them over. If the sslh
+service is started on its own without the sockets being passed by systemd
+then it will look to use those defined on the command line or config
+file as usual. Any number of ListenStreams can be defined in the socket
+file and systemd will pass them all over to sslh to use as usual.
+
+To avoid inconsistency between starting via socket and starting directly
+via the service Requires=sslh.socket can be added to the service unit to
+mandate the use of the socket configuration.
+
+Rather than overwriting the entire socket file drop in values can be placed
+in /etc/systemd/system/sslh.socket.d/<name>.conf with additional ListenStream
+values that will be merged.
+
+In addition to the above with manual .socket file configuration there is an
+optional systemd generator which can be compiled - systemd-sslh-generator 
+
+This parses the /etc/sslh.cfg (or /etc/sslh/sslh.cfg file if that exists 
+instead) configuration file and dynamically generates a socket file to use.
+
+This will also merge with any sslh.socket.d drop in configuration but will be 
+overriden by a /etc/systemd/system/sslh.socket file.
+
+To use the generator place it in /usr/lib/systemd/system-generators and then
+call systemctl daemon-reload after any changes to /etc/sslh.cfg to generate 
+the new dynamic socket unit.
+
+Fail2ban
+--------
+
+If using transparent proxying, just use the standard ssh
+rules. If you can't or don't want to use transparent
+proxying, you can set `fail2ban` rules to block repeated ssh
+connections from an IP address (obviously this depends
+on the site, there might be legitimate reasons you would get
+many connections to ssh from the same IP address...)
+
+See example files in scripts/fail2ban.
+
+UDP
+---
+
+`sslh` can perform demultiplexing on UDP packets as well.
+This only works with `sslh-select` (it is not possible to
+support UDP with a forking model). Specify a listening
+address and target protocols with `is_udp: true`. `sslh`
+will wait for incoming UDP packets, run the probes in the
+usual fashion, and forward packets to the appropriate
+target. `sslh` will then remember the association between
+remote host to target server for 60 seconds by default,
+which can be overriden with `udp_timeout`. This allows to
+process both single-datagram protocols such as DNS, and
+connection-based protocols such as QUIC.

doc/tproxy.md

@@ -0,0 +1,272 @@
+Transparent Proxy to Two Hosts
+==============================
+
+Tutorial by Sean Warner.  19 June 2019 20:35
+
+Aim
+---
+
+* Show that `sslh` can transparently proxy requests from the internet to services on two separate hosts that are both on the same LAN.
+* The IP address of the client initiating the request is what the destination should see… and not the IP address of the host that `sslh` is running on, which is what happens when `sslh` is not running in transparent mode.
+* The solution here only works for my very specific use-case but hopefully others can adapt it to suits their needs.
+
+Overview of my Network
+----------------------
+
+Two Raspberry Pis on my home LAN:
+* Pi A: 192.168.1.124 – `sslh` (Port 4433), Apache2 web server for https (port 443), `stunnel` (port 4480) to decrypt ssh traffic and forward to SSH server (also on Pi A at Port 1022)
+* Pi B: 192.168.1.123 - HTTP server (port 8000), SSH server (port 1022 on PiB).
+* I send traffic from the internet to my router's external port 443 then use a port forward rule in my router to map that to internal port 4433 where sslh is listening.
+
+![Architecture](tproxy.svg)
+
+`sslh` build
+------------
+ 
+`sslh` Version: sslh v1.19c-2-gf451cc8-dirty.
+
+I compiled sslh from sources giving the binary pretty much all possible options such as Posix capabilities and systemd support.. here are the first few lines of the makefile:
+ 
+```
+# Configuration
+ 
+VERSION=$(shell ./genver.sh -r)
+ENABLE_REGEX=1         # Enable regex probes
+USELIBCONFIG=1         # Use libconfig? (necessary to use configuration files)
+USELIBPCRE=1           # Use libpcre? (needed for regex on musl)
+USELIBWRAP=1           # Use libwrap?
+USELIBCAP=1            # Use libcap?
+USESYSTEMD=1           # Make use of systemd socket activation
+COV_TEST=              # Perform test coverage?
+PREFIX=/usr/local
+BINDIR=$(PREFIX)/sbin
+MANDIR=$(PREFIX)/share/man/man8
+MAN=sslh.8.gz          # man page name
+ 
+# End of configuration -- the rest should take care of
+# itself
+```
+ 
+systemd setup
+-------------
+
+Create an sslh systemd service file...
+```
+# nano /lib/systemd/system/sslh.service
+```
+ 
+Paste in this contents…
+ 
+```
+[Unit]
+Description=SSL/SSH multiplexer
+After=network.target
+Documentation=man:sslh(8)
+ 
+[Service]
+#EnvironmentFile=/etc/default/sslh
+#ExecStart=/usr/local/sbin/sslh $DAEMON_OPTS
+ExecStart=/usr/local/sbin/sslh -F /etc/sslh/sslh.cfg
+KillMode=process
+ 
+[Install]
+WantedBy=multi-user.target
+```
+ 
+Save it and then…
+```
+# systemctl daemon-reload
+```
+ 
+Start it again to test…
+```
+# systemctl start sslh
+```
+ 
+Configure `sslh`
+----------------
+
+First stop `sslh` then open the config file and replace with below, save and start `sslh` again
+```
+# systemctl stop sslh
+# nano /etc/sslh/sslh.cfg
+# systemctl start sslh
+```
+ 
+```
+verbose: true;
+foreground: true;
+inetd: false;
+numeric: true;
+transparent: true;
+timeout: 2;
+user: "sslh";
+pidfile: "/var/run/sslh.pid";
+chroot: "/var/empty";
+ 
+# You must have a port forward rule in the router: external port 443 <-> internal port 4433
+# Local ip address of PiA is: 192.168.1.124, sslh and stunnel4 are running on this Pi
+# Local ip address of PiB is: 192.168.1.123, http server and ssh server on this Pi
+listen:
+(
+{ host: "192.168.1.124"; port: "4433"; }
+);
+ 
+# sslh demultiplexes based on the Protocol and Hostname
+protocols:
+(
+{ name: "tls"; sni_hostnames: [ "www.example.com" ]; host: "192.168.1.124"; port: "443"; log_level: 1; },
+# This probe is for tls encrypted ssh. SSLH forwards it to stunnel on port 4480 which decrypts it and sends it to the ssh server on PiA port 1022
+{ name: "tls"; sni_hostnames: [ "ssh.example.com" ]; host: "192.168.1.124"; port: "4480"; log_level: 1; },
+{ name: "http"; host: "192.168.1.123"; port: "8000"; log_level: 1; },
+{ name: "ssh"; host: "192.168.1.123"; port: "1022"; log_level: 1; }
+);
+```
+ 
+Configure `stunnel`
+-------------------
+
+First stop `stunnel` then open the config file and replace with below, save and start `stunnel` again
+```
+# systemctl stop stunnel4
+# nano /etc/stunnel/stunnel.conf
+# systemctl start stunnel4
+```
+ 
+```
+# Debugging stuff (may be useful for troubleshooting)
+foreground = yes
+#debug = 5 # this is the default
+debug = 7
+output = /var/log/stunnel4/stunnel.log
+pid = /var/run/stunnel4/stunnel.pid
+fips = no
+ 
+cert = /etc/letsencrypt/live/example.com/fullchain.pem
+key = /etc/letsencrypt/live/example.com/privkey.pem
+ 
+[ssh]
+accept = 192.168.1.124:4480
+connect = 192.168.1.124:1022
+TIMEOUTclose  = 0
+```
+ 
+Configure iptables for Pi A
+--------------------------
+
+The `_add.sh` script creates the rules, the `_rm.sh` script removes the rules.
+They will be lost if you reboot but there are ways to make them load again on start-up..
+```
+# nano /usr/local/sbin/piA_tproxy_add.sh
+```
+``` piA_tproxy_add.sh
+iptables -t mangle -N SSLH
+iptables -t mangle -A PREROUTING -p tcp -m socket --transparent -j SSLH
+iptables -t mangle -A OUTPUT --protocol tcp --out-interface eth0 -m multiport --sport 443,4480 --jump SSLH
+iptables -t mangle -A SSLH --jump MARK --set-mark 0x1
+iptables -t mangle -A SSLH --jump ACCEPT
+ip rule add fwmark 0x1 lookup 100
+ip route add local 0.0.0.0/0 dev lo table 100
+```
+ 
+```
+# nano /usr/local/sbin/piA_tproxy_rm.sh
+```
+``` piA_tproxy_rm.sh
+iptables -t mangle -D PREROUTING -p tcp -m socket --transparent -j SSLH
+iptables -t mangle -D OUTPUT --protocol tcp --out-interface eth0 -m multiport --sport 443,4480 --jump SSLH
+iptables -t mangle -D SSLH --jump MARK --set-mark 0x1
+iptables -t mangle -D SSLH --jump ACCEPT
+iptables -t mangle -X SSLH
+ip rule del fwmark 0x1 lookup 100
+ip route del local 0.0.0.0/0 dev lo table 100
+```
+ 
+Make them executable..
+```
+# chmod +rx piA_tproxy_add.sh
+# chmod +rx piA_tproxy_rm.sh
+```
+ 
+Now run the "add" script on Pi A!
+```
+# piA_tproxy_add.sh
+# piA_tproxy_rm.sh
+```
+ 
+Configure iptables for Pi B
+--------------------------
+
+```
+# nano /usr/local/sbin/piB_tproxy_add.sh
+```
+``` piB_tproxy_add.sh
+iptables -t mangle -N SSLHSSL
+iptables -t mangle -A OUTPUT -o eth0 -p tcp -m multiport --sport 1022,8000 -j SSLHSSL
+iptables -t mangle -A SSLHSSL --jump MARK --set-mark 0x1
+iptables -t mangle -A SSLHSSL --jump ACCEPT
+ip rule add fwmark 0x1 lookup 100
+ip route add default via 192.168.1.124 table 100
+ip route flush cache
+```
+ 
+```
+# nano /usr/local/sbin/piB_tproxy_rm.sh
+```
+```
+iptables -t mangle -D OUTPUT -o eth0 -p tcp -m multiport --sport 1022,8000 -j SSLHSSL
+iptables -t mangle -D SSLHSSL --jump MARK --set-mark 0x1
+iptables -t mangle -D SSLHSSL --jump ACCEPT
+iptables -t mangle -X SSLHSSL
+ip rule del fwmark 0x1 lookup 100
+ip route del default via 192.168.1.124 table 100
+ip route flush cache
+```
+ 
+Make them executable..
+```
+# chmod +rx piB_tproxy_add.sh
+# chmod +rx piB_tproxy_rm.sh
+```
+ 
+Now run the "add" script on Pi B!
+```
+# piB_tproxy_add.sh
+# piB_tproxy_rm.sh
+```
+ 
+Testing
+-------
+* Getting to sshd on PiA
+
+I did this test using 4G from my phone (outside the LAN)
+
+To simulate this I use `proxytunnel`. External port 443 is forwarded by my router to 4433. I need to arrive at `sslh` (port 4433) with ssh encrypted as TLS (hence I use the -e switch) and the `sni_hostname` set to ssh.example.com so that `sslh` will demultiplex to `stunnel` (port 4480) which will decrypt and forward to ssh server on PiA… see `sslh.cfg` and `stunnel.conf`.
+
+The first IP:port is just a free HTTPS proxy I found on https://free-proxy-list.net
+I execute this command from a terminal window..
+ 
+```
+# proxytunnel -v -e -C root.pem -p 78.141.192.198:8080 -d ssh.example.com:443
+```
+* Getting to sshd on PiB
+
+I did this test using 4G from my phone (outside the LAN)
+
+My smartphone telecom provider blocks ssh over port 443 so I need to use `proxytunnel` to encrypt.
+
+Use the Proxytunnel `-X` switch to encrypt from local proxy to destination only so by the time we get to the destination it is unencrypted and `sslh` will see the ssh protocol and demultiplex to PiB as per `sslh.cfg`.
+ 
+```
+# proxytunnel -v -X -C root.pem -p 78.141.192.198:8080 -d ssh.example.com:443
+```
+
+Now when you test it all look at the output in daemon.log like this:
+```
+# grep -i 'ssl' /var/log/daemon.log
+```
+You should see that the IP address and port from the “connection from” and “forwarded from” fields are the same.
+
+Special thanks and appreciation to Michael Yelsukov without whom I would never have got this working.
+
+Any feedback or corrections very welcome!

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+         y="229.97469"
+         id="tspan190"
+         style="stroke-width:0.26458332"><tspan
+           x="167.74596"
+           y="229.97469"
+           style="font-style:normal;font-variant:normal;font-weight:bold;font-stretch:normal;font-size:3.88055563px;font-family:'Courier New';-inkscape-font-specification:'Courier New Bold';fill:#fa9600;fill-opacity:1;stroke-width:0.26458332"
+           id="tspan188">8000</tspan></tspan></text>
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-weight:normal;font-size:3.52777767px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332"
+       x="255.3237"
+       y="190.91431"
+       id="text246"><tspan
+         sodipodi:role="line"
+         x="255.3237"
+         y="190.91431"
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+         style="stroke-width:0.26458332"><tspan
+           x="255.3237"
+           y="190.91431"
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+           id="tspan242">ssh</tspan></tspan></text>
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-weight:normal;font-size:3.52777767px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332"
+       x="254.88899"
+       y="158.20918"
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+         sodipodi:role="line"
+         x="254.88899"
+         y="158.20918"
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+         style="stroke-width:0.26458332"><tspan
+           x="254.88899"
+           y="158.20918"
+           style="font-style:normal;font-variant:normal;font-weight:bold;font-stretch:normal;font-size:3.88055563px;font-family:'Courier New';-inkscape-font-specification:'Courier New Bold';fill:#fa9600;fill-opacity:1;stroke-width:0.26458332"
+           id="tspan236">1022</tspan></tspan></text>
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-weight:normal;font-size:3.52777767px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332"
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+         sodipodi:role="line"
+         x="255.15096"
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+         id="tspan250"
+         style="stroke-width:0.26458332"><tspan
+           x="255.15096"
+           y="230.24921"
+           style="font-style:normal;font-variant:normal;font-weight:bold;font-stretch:normal;font-size:3.88055563px;font-family:'Courier New';-inkscape-font-specification:'Courier New Bold';fill:#fa9600;fill-opacity:1;stroke-width:0.26458332"
+           id="tspan248">1022</tspan></tspan></text>
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-weight:normal;font-size:3.52777767px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#009600;fill-opacity:1;stroke:none;stroke-width:0.26458332;stroke-opacity:1"
+       x="186.26637"
+       y="193.70544"
+       id="text156"><tspan
+         sodipodi:role="line"
+         x="186.26637"
+         y="193.70544"
+         id="tspan154"
+         style="stroke-width:0.26458332"><tspan
+           x="186.26637"
+           y="193.70544"
+           style="font-style:normal;font-variant:normal;font-weight:bold;font-stretch:normal;font-size:3.88055563px;font-family:'Courier New';-inkscape-font-specification:'Courier New Bold';fill:#009600;fill-opacity:1;stroke:none;stroke-width:0.26458332;stroke-opacity:1"
+           id="tspan152">Web Server</tspan></tspan></text>
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-weight:normal;font-size:3.52777767px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#009600;fill-opacity:1;stroke:none;stroke-width:0.26458332;stroke-opacity:1"
+       x="225.25404"
+       y="170.88316"
+       id="text150"><tspan
+         sodipodi:role="line"
+         x="225.25404"
+         y="170.88316"
+         id="tspan148"
+         style="stroke-width:0.26458332"><tspan
+           x="225.25404"
+           y="170.88316"
+           style="font-style:normal;font-variant:normal;font-weight:bold;font-stretch:normal;font-size:3.88055563px;font-family:'Courier New';-inkscape-font-specification:'Courier New Bold';fill:#009600;fill-opacity:1;stroke:none;stroke-width:0.26458332;stroke-opacity:1"
+           id="tspan146">STUNNEL</tspan></tspan></text>
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-weight:normal;font-size:3.52777767px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#009600;fill-opacity:1;stroke:none;stroke-width:0.26458332;stroke-opacity:1"
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+         sodipodi:role="line"
+         x="222.6344"
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+         id="tspan160"
+         style="stroke-width:0.26458332"><tspan
+           x="222.6344"
+           y="194.19792"
+           style="font-style:normal;font-variant:normal;font-weight:bold;font-stretch:normal;font-size:3.88055563px;font-family:'Courier New';-inkscape-font-specification:'Courier New Bold';fill:#009600;fill-opacity:1;stroke:none;stroke-width:0.26458332;stroke-opacity:1"
+           id="tspan158">SSH Server</tspan></tspan></text>
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-weight:normal;font-size:3.52777767px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#009600;fill-opacity:1;stroke:none;stroke-width:0.26458332"
+       x="199.15128"
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+         sodipodi:role="line"
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+         y="157.29231"
+         id="tspan196"
+         style="stroke-width:0.26458332"><tspan
+           x="199.15128"
+           y="157.29231"
+           style="font-style:normal;font-variant:normal;font-weight:bold;font-stretch:normal;font-size:3.88055563px;font-family:'Courier New';-inkscape-font-specification:'Courier New Bold';fill:#009600;fill-opacity:1;stroke-width:0.26458332"
+           id="tspan194">443</tspan></tspan></text>
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-weight:normal;font-size:3.52777767px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#009600;fill-opacity:1;stroke:none;stroke-width:0.26458332"
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+         style="stroke-width:0.26458332"><tspan
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+           id="tspan206">443</tspan></tspan></text>
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-weight:normal;font-size:3.52777767px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#009600;fill-opacity:1;stroke:none;stroke-width:0.26458332"
+       x="199.15128"
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+           id="tspan200">tls</tspan></tspan></text>
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-weight:normal;font-size:3.52777767px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#009600;fill-opacity:1;stroke:none;stroke-width:0.26458332"
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+           id="tspan212">4480</tspan></tspan></text>
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-weight:normal;font-size:3.52777767px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#009600;fill-opacity:1;stroke:none;stroke-width:0.26458332"
+       x="235.14638"
+       y="158.60213"
+       id="text222"><tspan
+         sodipodi:role="line"
+         x="235.14638"
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+         style="stroke-width:0.26458332"><tspan
+           x="235.14638"
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+           style="font-style:normal;font-variant:normal;font-weight:bold;font-stretch:normal;font-size:3.88055563px;font-family:'Courier New';-inkscape-font-specification:'Courier New Bold';fill:#009600;fill-opacity:1;stroke-width:0.26458332"
+           id="tspan218">tls</tspan></tspan></text>
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-weight:normal;font-size:3.52777767px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#009600;fill-opacity:1;stroke:none;stroke-width:0.26458332"
+       x="222.57213"
+       y="182.44083"
+       id="text228"><tspan
+         sodipodi:role="line"
+         x="222.57213"
+         y="182.44083"
+         id="tspan226"
+         style="stroke-width:0.26458332"><tspan
+           x="222.57213"
+           y="182.44083"
+           style="font-style:normal;font-variant:normal;font-weight:bold;font-stretch:normal;font-size:3.88055563px;font-family:'Courier New';-inkscape-font-specification:'Courier New Bold';fill:#009600;fill-opacity:1;stroke-width:0.26458332"
+           id="tspan224">1022</tspan></tspan></text>
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-weight:normal;font-size:3.52777767px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#009600;fill-opacity:1;stroke:none;stroke-width:0.26458332"
+       x="234.88441"
+       y="182.44083"
+       id="text234"><tspan
+         sodipodi:role="line"
+         x="234.88441"
+         y="182.44083"
+         id="tspan232"
+         style="stroke-width:0.26458332"><tspan
+           x="234.88441"
+           y="182.44083"
+           style="font-style:normal;font-variant:normal;font-weight:bold;font-stretch:normal;font-size:3.88055563px;font-family:'Courier New';-inkscape-font-specification:'Courier New Bold';fill:#009600;fill-opacity:1;stroke-width:0.26458332"
+           id="tspan230">ssh</tspan></tspan></text>
+  </g>
+</svg>

echosrv-conf.h

@@ -0,0 +1,66 @@
+/* Generated by conf2struct (https://www.rutschle.net/tech/conf2struct/README)
+ * on Fri Aug 13 18:03:20 2021. 
+
+# conf2struct: generate libconf parsers that read to structs
+# Copyright (C) 2018-2021  Yves Rutschle
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice,
+#    this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+
+*/
+ 
+#ifndef C2S_ECHOCFG_H
+#define C2S_ECHOCFG_H
+#ifdef LIBCONFIG
+#    include <libconfig.h>
+#endif
+
+
+
+struct echocfg_listen_item {
+	char*	host;
+	char*	port;
+};
+
+struct echocfg_item {
+	int	udp;
+	char*	prefix;
+	size_t	listen_len;
+	struct echocfg_listen_item* listen;
+};
+
+int echocfg_parse_file(
+        const char* filename,
+        struct echocfg_item* echocfg, 
+        const char** errmsg);
+
+void echocfg_fprint(
+    FILE* out,
+    struct echocfg_item *echocfg,
+    int depth);
+
+int echocfg_cl_parse(
+    int argc,
+    char* argv[],
+    struct echocfg_item *echocfg);
+
+#endif

echosrv.c

@@ -27,8 +27,13 @@
 #include <syslog.h>
 #include <libgen.h>
 #include <getopt.h>
+#include <errno.h>
 
+#define cfg sslhcfg
 #include "common.h"
+#undef cfg
+
+#include "echosrv-conf.h"
 
 /* Added to make the code compilable under CYGWIN 
  * */
@@ -36,58 +41,21 @@
 #define SA_NOCLDWAIT 0
 #endif
 
-const char* USAGE_STRING =
-"echosrv\n" \
-"usage:\n" \
-"\techosrv  [-v] --listen <address:port> [--prefix <prefix>]\n"
-"-v: verbose\n" \
-"--listen: address to listen on. Can be specified multiple times.\n" \
-"--prefix: add specified prefix before every line echoed.\n"
-"";
+struct echocfg_item cfg;
 
-const char* server_type = "echsrv"; /* keep setup_syslog happy */
-
-/* 
- * Settings that depend on the command line. 
- */
-char* prefix = "";
-int port;
-
-void parse_cmdline(int argc, char* argv[])
+void check_res_dump(int res, struct addrinfo *addr, char* syscall)
 {
-    int c;
-    struct option options[] = {
-        { "verbose",    no_argument,            &verbose,       1 },
-        { "numeric",    no_argument,            &numeric,       1 },
-        { "listen",     required_argument,      0,              'l' },
-        { "prefix",     required_argument,      0,              'p' },
-    };
-    struct addrinfo **a;
+    char buf[NI_MAXHOST];
 
-    while ((c = getopt_long_only(argc, argv, "l:p:", options, NULL)) != -1) {
-        if (c == 0) continue;
+    if (res == -1) {
+        if (addr)
+            fprintf(stderr, "error %s:%s: %s\n",
+                    sprintaddr(buf, sizeof(buf), addr),
+                    syscall,
+                    strerror(errno));
+        else 
+            fprintf(stderr, "Dying just because\n");
 
-        switch (c) {
-
-        case 'l':
-            /* find the end of the listen list */
-            for (a = &addr_listen; *a; a = &((*a)->ai_next));
-            /* append the specified addresses */
-            resolve_name(a, optarg);
-            break;
-
-        case 'p':
-            prefix = optarg;
-            break;
-
-        default:
-            fprintf(stderr, "%s", USAGE_STRING);
-            exit(2);
-        }
-    }
-
-    if (!addr_listen) {
-        fprintf(stderr, "No listening port specified\n");
         exit(1);
     }
 }
@@ -97,19 +65,28 @@ void start_echo(int fd)
     int res;
     char buffer[1 << 20];
     int ret, prefix_len;
+    int first = 1;
 
-    prefix_len = strlen(prefix);
+    prefix_len = strlen(cfg.prefix);
 
     memset(buffer, 0, sizeof(buffer));
-    strcpy(buffer, prefix);
+    strcpy(buffer, cfg.prefix);
 
     while (1) {
-        ret = read(fd, buffer + prefix_len, sizeof(buffer));
-        if (ret == -1) {
+        ret = read(fd, buffer + prefix_len, sizeof(buffer) - prefix_len);
+        if (ret <= 0) {
             fprintf(stderr, "%s", strerror(errno));
             return;
         }
-        res = write(fd, buffer, ret + prefix_len);
+        if (first) {
+            res = write(fd, buffer, ret + prefix_len);
+            first = 0;
+            if (write(1, buffer, ret + prefix_len) < 0) {
+                fprintf(stderr, "%s", strerror(errno));
+            }
+        } else {
+            res = write(fd, buffer + prefix_len, ret);
+        }
         if (res < 0) {
             fprintf(stderr, "%s", strerror(errno));
             return;
@@ -117,30 +94,228 @@ void start_echo(int fd)
     }
 }
 
-void main_loop(int listen_sockets[], int num_addr_listen)
+/* TCP echo server: accepts connections to an endpoint, forks an echo for each
+ * connection, forever. Prefix is added at start of response stream */
+void tcp_echo(struct listen_endpoint* listen_socket)
 {
-    int in_socket, i;
+    while (1) {
+        int in_socket = accept(listen_socket->socketfd, 0, 0);
+        CHECK_RES_DIE(in_socket, "accept");
+
+        if (!fork())
+        {
+            close(listen_socket->socketfd);
+            start_echo(in_socket);
+            exit(0);
+        }
+        close(in_socket);
+    }
+}
+
+void print_udp_xchange(int sockfd, struct sockaddr* addr, socklen_t addrlen)
+{
+    struct addrinfo src_addrinfo, to_addrinfo;
+    char str_addr[NI_MAXHOST+1+NI_MAXSERV+1];
+    char str_addr2[NI_MAXHOST+1+NI_MAXSERV+1];
+    struct sockaddr_storage ss;
+
+    src_addrinfo.ai_addr = (struct sockaddr*)&ss;
+    src_addrinfo.ai_addrlen = sizeof(ss);
+    getsockname(sockfd, src_addrinfo.ai_addr, &src_addrinfo.ai_addrlen);
+
+    to_addrinfo.ai_addr = addr;
+    to_addrinfo.ai_addrlen = sizeof(*addr);
+
+    fprintf(stderr, "UDP local %s remote %s\n", 
+            sprintaddr(str_addr, sizeof(str_addr), &src_addrinfo),
+            sprintaddr(str_addr2, sizeof(str_addr2), &to_addrinfo)
+           );
+}
+
+/* UDP echo server: receive packets, return them, forever.
+ * Prefix is added at each packet */
+void udp_echo(struct listen_endpoint* listen_socket)
+{
+    char data[65536];
+    struct sockaddr src_addr;
+    socklen_t addrlen;
+
+    memset(data, 0, sizeof(data));
+
+    size_t prefix_len = strlen(cfg.prefix);
+    memcpy(data, cfg.prefix, prefix_len);
+
+    while (1) {
+        addrlen = sizeof(src_addr);
+        size_t len = recvfrom(listen_socket->socketfd, 
+                           data + prefix_len,
+                           sizeof(data) - prefix_len,
+                           0,
+                           &src_addr,
+                           &addrlen);
+
+        if (len < 0) {
+            perror("recvfrom");
+        }
+        *(data + prefix_len + len) = 0;
+        fprintf(stderr, "%ld: %s\n", len, data + prefix_len);
+
+        print_udp_xchange(listen_socket->socketfd, &src_addr, addrlen);
+
+        int res = sendto(listen_socket->socketfd,
+                         data,
+                         len + prefix_len,
+                         0,
+                         &src_addr,
+                         addrlen);
+        if (res < 0) {
+            perror("sendto");
+        }
+    }
+}
+
+void main_loop(struct listen_endpoint listen_sockets[], int num_addr_listen)
+{
+    int i;
 
     for (i = 0; i < num_addr_listen; i++) {
         if (!fork()) {
-            while (1)
-            {
-                in_socket = accept(listen_sockets[i], 0, 0);
-                if (verbose) fprintf(stderr, "accepted fd %d\n", in_socket);
-
-                if (!fork())
-                {
-                    close(listen_sockets[i]);
-                    start_echo(in_socket);
-                    exit(0);
-                }
-                close(in_socket);
+            if (cfg.udp) {
+                udp_echo(&listen_sockets[i]);
+            } else {
+                tcp_echo(&listen_sockets[i]);
             }
         }
     }
     wait(NULL);
 }
 
+/* Following is a number of utility functions copied from common.c: linking
+ * against common.o directly means echosrv has to work with sslh config struct,
+ * which makes it all too awkward */
+
+/* simplified from common.c */
+char* sprintaddr(char* buf, size_t size, struct addrinfo *a)
+{
+   char host[NI_MAXHOST], serv[NI_MAXSERV];
+   int res;
+
+   res = getnameinfo(a->ai_addr, a->ai_addrlen,
+               host, sizeof(host),
+               serv, sizeof(serv),
+               0 );
+
+   if (res) {
+       /* Name resolution failed: do it numerically instead */
+       res = getnameinfo(a->ai_addr, a->ai_addrlen,
+                         host, sizeof(host),
+                         serv, sizeof(serv),
+                         NI_NUMERICHOST | NI_NUMERICSERV);
+       /* should not fail but... */
+       if (res) {
+           strcpy(host, "?");
+           strcpy(serv, "?");
+       }
+   }
+
+   snprintf(buf, size, "%s:%s", host, serv);
+
+   return buf;
+}
+
+
+/* simplified from common.c */
+int listen_single_addr(struct addrinfo* addr, int keepalive, int udp)
+{
+    struct sockaddr_storage *saddr;
+    int sockfd, one, res;
+
+    saddr = (struct sockaddr_storage*)addr->ai_addr;
+
+    sockfd = socket(saddr->ss_family, udp ? SOCK_DGRAM : SOCK_STREAM, 0);
+    check_res_dump(sockfd, addr, "socket");
+
+    one = 1;
+    res = setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, (char*)&one, sizeof(one));
+    check_res_dump(res, addr, "setsockopt(SO_REUSEADDR)");
+
+    if (addr->ai_addr->sa_family == AF_INET6) {
+        res = setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY, (char*)&one, sizeof(one));
+        check_res_dump(res, addr, "setsockopt(IPV6_V6ONLY)");
+    }
+
+    res = bind(sockfd, addr->ai_addr, addr->ai_addrlen);
+    check_res_dump(res, addr, "bind");
+
+    if (!udp) {
+        res = listen (sockfd, 50);
+        check_res_dump(res, addr, "listen");
+    }
+
+    return sockfd;
+}
+
+/* simplified from common.c */
+int resolve_split_name(struct addrinfo **out, char* host, char* serv)
+{
+   struct addrinfo hint;
+   char *end;
+   int res;
+
+   memset(&hint, 0, sizeof(hint));
+   hint.ai_family = PF_UNSPEC;
+   hint.ai_socktype = SOCK_STREAM;
+
+   /* If it is a RFC-Compliant IPv6 address ("[1234::12]:443"), remove brackets
+    * around IP address */
+   if (host[0] == '[') {
+       end = strrchr(host, ']');
+       if (!end) {
+           fprintf(stderr, "%s: no closing bracket in IPv6 address?\n", host);
+           return -1;
+       }
+       host++; /* skip first bracket */
+       *end = 0; /* remove last bracket */
+   }
+
+   res = getaddrinfo(host, serv, &hint, out);
+
+   if (res)
+      fprintf(stderr, "%s `%s:%s'\n", gai_strerror(res), host, serv);
+   return res;
+}
+
+int start_listen_sockets(struct listen_endpoint *sockfd[])
+{
+    struct addrinfo *addr, *start_addr;
+    char buf[NI_MAXHOST];
+    int i, res;
+    int num_addr = 0, keepalive = 0, udp = 0;
+
+    *sockfd = NULL;
+
+    fprintf(stderr, "Listening to:\n");
+
+    for (i = 0; i < cfg.listen_len; i++) {
+        udp = cfg.udp;
+
+
+        res = resolve_split_name(&start_addr, cfg.listen[i].host, cfg.listen[i].port);
+        if (res) exit(4);
+
+        for (addr = start_addr; addr; addr = addr->ai_next) {
+            num_addr++;
+            *sockfd = realloc(*sockfd, num_addr * sizeof(*sockfd));
+            (*sockfd)[num_addr-1].socketfd = listen_single_addr(addr, keepalive, udp);
+            (*sockfd)[num_addr-1].type = udp ? SOCK_DGRAM : SOCK_STREAM;
+            fprintf(stderr, "%d:\t%s\n", (*sockfd)[num_addr-1].socketfd, sprintaddr(buf, sizeof(buf), addr));
+        }
+        freeaddrinfo(start_addr);
+    }
+
+    return num_addr;
+}
+
 int main(int argc, char *argv[])
 {
 
@@ -148,11 +323,15 @@ int main(int argc, char *argv[])
    extern int optind;
    int num_addr_listen;
 
-   int *listen_sockets;
+   struct listen_endpoint *listen_sockets;
 
-   parse_cmdline(argc, argv);
+   memset(&cfg, 0, sizeof(cfg));
+   if (echocfg_cl_parse(argc, argv, &cfg))
+       exit(1);
 
-   num_addr_listen = start_listen_sockets(&listen_sockets, addr_listen);
+   echocfg_fprint(stdout, &cfg, 0);
+
+   num_addr_listen = start_listen_sockets(&listen_sockets);
 
    main_loop(listen_sockets, num_addr_listen);
 

echosrv.cfg

@@ -0,0 +1,37 @@
+# conf2struct for echosrv
+
+header: "echosrv-conf.h";
+parser: "echosrv-conf.c";
+
+printer: true;
+
+conffile_option: ("F", "config");
+
+config: {
+          name: "echocfg",
+          type: "list",
+          items: (
+                  {name: "udp", type: "bool"; default: false; },
+                  {name: "prefix", type: "string"; },
+              { name: "listen", 
+                type: "list", 
+                items: (
+                        { name: "host"; type: "string"; var: true; },
+                        { name: "port"; type: "string"; var: true; }
+                    )
+                }
+            )
+}
+
+
+cl_groups: (
+    { name: "listen"; pattern: "(.+):(\w+)"; description: "Listen on host:port";
+      short: "p"; argdesc: "<host:port>";
+        list: "listen";
+        # no override, this just adds to the list (and thus can be specified several times)
+        targets: (
+        { path: "host"; value: "$1" },
+        { path: "port"; value: "$2" }
+        );
+    }
+)

example.cfg

@@ -3,7 +3,7 @@
 # not be used as a starting point for a working
 # configuration. Instead use basic.cfg.
 
-verbose: true;
+verbose: 0;
 foreground: true;
 inetd: false;
 numeric: false;
@@ -17,6 +17,7 @@ chroot: "/var/empty";
 # system are usually defined in /usr/include/*/sys/syslog.h
 # or equivalent)
 # Default is "auth"
+# "none" disables use of syslog
 syslog_facility: "auth"; 
 
 # List of interfaces on which we should listen
@@ -24,7 +25,8 @@ syslog_facility: "auth";
 listen:
 (
     { host: "thelonious"; port: "443"; },
-    { host: "thelonious"; port: "8080"; keepalive: true; }
+    { host: "thelonious"; port: "8080"; keepalive: true; },
+    { host: "thelonious"; is_udp: true; port: "443" }
 );
 
 # List of protocols
@@ -41,53 +43,75 @@ listen:
 #               connection (default is off)
 #   fork: Should a new process be forked for this protocol?
 #         (only useful for sslh-select)
+#   tfo_ok: Set to true if the server supports TCP FAST OPEN
+#   transparent: Set to true to proxy this protocol
+#         transparently (server sees the remote client IP
+#         address). Same as the global option, but per-protocol
 #
 #  Probe-specific options:
+# (sslh will try each probe in order they are declared, and
+# connect to the first that matches.)
+#
 #       tls:
 #               sni_hostnames:  list of FQDN for that target
 #               alpn_protocols: list of ALPN protocols for that target, see:
 #               https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml#alpn-protocol-ids
 #
 #               if both sni_hostnames AND alpn_protocols are specified, both must match
+#
 #               if neither are set, it is just checked whether this is the TLS protocol or not
+#
+#               Obviously set the most specific probes
+#               first, and if you use TLS with no ALPN/SNI
+#               set it as the last TLS probe
 #       regex:
 #               regex_patterns: list of patterns to match for
 #               that target.
 #   
-# sslh will try each probe in order they are declared, and
-# connect to the first that matches.
-#
 # You can specify several of 'regex' and 'tls'.
  
 protocols:
 (
-     { name: "ssh"; service: "ssh"; host: "localhost"; port: "22"; keepalive: true; fork: true; },
+     { name: "ssh"; service: "ssh"; host: "localhost"; port: "22"; 
+       keepalive: true; fork: true; tfo_ok: true },
      { name: "http"; host: "localhost"; port: "80"; },
 
 # match BOTH ALPN/SNI
-     { name: "tls"; host: "localhost"; port: "5223"; alpn_protocols: [ "xmpp-client" ]; sni_hostnames: [ "im.somethingelse.net" ]; log_level: 0;},
+     { name: "tls"; host: "localhost"; port: "5223"; alpn_protocols: [ "xmpp-client" ]; sni_hostnames: [ "im.somethingelse.net" ]; log_level: 0; tfo_ok: true },
 
 # just match ALPN
-     { name: "tls"; host: "localhost"; port: "443"; alpn_protocols: [ "h2", "http/1.1", "spdy/1", "spdy/2", "spdy/3" ]; log_level: 0; },
-     { name: "tls"; host: "localhost"; port: "xmpp-client"; alpn_protocols: [ "xmpp-client" ];  log_level: 0;},
+     { name: "tls"; host: "localhost"; port: "443"; alpn_protocols: [ "h2", "http/1.1", "spdy/1", "spdy/2", "spdy/3" ]; log_level: 0;  tfo_ok: true },
+     { name: "tls"; host: "localhost"; port: "xmpp-client"; alpn_protocols: [ "xmpp-client" ];  log_level: 0; tfo_ok: true },
 
 # just match SNI
-     { name: "tls"; host: "localhost"; port: "993"; sni_hostnames: [ "mail.rutschle.net", "mail.englishintoulouse.com" ]; log_level: 0; },
-     { name: "tls"; host: "localhost"; port: "xmpp-client"; sni_hostnames: [ "im.rutschle.net", "im.englishintoulouse.com" ];  log_level: 0;},
+     { name: "tls"; host: "localhost"; port: "993"; sni_hostnames: [ "mail.rutschle.net", "mail.englishintoulouse.com" ]; log_level: 0;  tfo_ok: true },
+     { name: "tls"; host: "localhost"; port: "xmpp-client"; sni_hostnames: [ "im.rutschle.net", "im.englishintoulouse.com" ];  log_level: 0; tfo_ok: true },
 
-# Let's Encrypt (tls-sni-* challenges)
-     { name: "tls"; host: "localhost"; port: "letsencrypt-client"; sni_hostnames: [ "*.*.acme.invalid" ];  log_level: 0;},
+# Let's Encrypt (tls-alpn-* challenges)
+     { name: "tls"; host: "localhost"; port: "letsencrypt-client"; alpn_protocols: [ "acme-tls/1" ]; log_level: 0;},
 
 # catch anything else TLS
-     { name: "tls"; host: "localhost"; port: "443"; },
+     { name: "tls"; host: "localhost"; port: "443";  tfo_ok: true },
+
+# Forward UDP 
+     { name: "regex"; host: "localhost"; is_udp: true; port: "123";
+                      udp_timeout: 20;  # Time after which the "connection" is forgotten
+                      regex_patterns: [ "hello" ]; },
+# Forward Teamspeak3 (Voice only)
+     { name: "regex"; host: "localhost"; is_udp: true; port: "9987"; regex_patterns: [ "TS3INIT1" ]; },
+# Forward IETF QUIC-50 ("Q050" -> "\x51\x30\x35\x30")
+# Remember that the regex needs to be adjusted for every supported QUIC version.
+     { name: "regex"; host: "localhost"; is_udp: true; port: "4433"; regex_patterns: [ "\x51\x30\x35\x30" ]; },
 
 # Regex examples -- better use the built-in probes for real-world use!
 # OpenVPN
      { name: "regex"; host: "localhost"; port: "1194"; regex_patterns: [ "^\x00[\x0D-\xFF]$", "^\x00[\x0D-\xFF]\x38" ]; },
 # Jabber
-     { name: "regex"; host: "localhost"; port: "5222"; regex_patterns: [ "jabber" ]; },
+     { name: "regex"; host: "localhost"; port: "5222"; regex_patterns: [ "jabber" ];
+       minlength: 60;  # Won't even try to match the regex if we don't have that many bytes
+     },
     
-# Catch-all
+# Catch-all (but better use 'anyprot')
      { name: "regex"; host: "localhost"; port: "443"; regex_patterns: [ "" ]; },
 
 # Where to connect in case of timeout (defaults to ssh)

gap.c

@@ -0,0 +1,128 @@
+/*
+   gap.c: gap, a simple, dynamically-growing array
+   of pointers that never shrinks
+
+# Copyright (C) 2021  Yves Rutschle
+# 
+# This program is free software; you can redistribute it
+# and/or modify it under the terms of the GNU General Public
+# License as published by the Free Software Foundation; either
+# version 2 of the License, or (at your option) any later
+# version.
+# 
+# This program is distributed in the hope that it will be
+# useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+# PURPOSE.  See the GNU General Public License for more
+# details.
+# 
+# The full text for the General Public License is here:
+# http://www.gnu.org/licenses/gpl.html
+
+*/
+
+
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+
+#include "sslh-conf.h"
+#include "gap.h"
+
+
+typedef struct gap_array {
+    int len; /* Number of elements in array */
+    void** array;
+} gap_array;
+
+/* Allocate one page-worth of elements */
+static int gap_len_alloc(int elem_size)
+{
+    return getpagesize() / elem_size;
+}
+
+/* Creates a new gap, all pointers are initialised at NULL */
+gap_array* gap_init(void)
+{
+    gap_array* gap = malloc(sizeof(*gap));
+    if (!gap) return NULL;
+    memset(gap, 0, sizeof(*gap));
+
+    int elem_size = sizeof(gap->array[0]);
+    gap->len = gap_len_alloc(elem_size);
+    gap->array = malloc(gap->len * elem_size);
+    if (!gap->array) return NULL;
+
+    for (int i = 0; i < gap->len; i++)
+        gap->array[i] = NULL;
+
+    return gap;
+}
+
+void* gap_get(gap_array* gap, int index)
+{
+    return gap->array[index];
+}
+
+static int gap_extend(gap_array* gap)
+{
+    int elem_size = sizeof(gap->array[0]);
+    int new_length = gap->len + gap_len_alloc(elem_size);
+    void** new = realloc(gap->array, new_length * elem_size);
+    if (!new) return -1;
+
+    gap->array = new;
+
+    for (int i = gap->len; i < new_length; i++) {
+        gap->array[i] = NULL;
+    }
+
+    gap->len = new_length;
+
+    return 0;
+}
+
+int gap_set(gap_array* gap, int index, void* ptr)
+{
+    if (index >= gap->len) {
+        int res = gap_extend(gap);
+        if (res == -1) return -1;
+    }
+
+    gap->array[index] = ptr;
+    return 0;
+}
+
+void gap_destroy(gap_array* gap) 
+{
+    free(gap->array);
+    free(gap);
+}
+
+
+/* In gap, find element pointing to ptr, then shift the rest of the array that
+ * is considered len elements long.
+ * A poor man's list, if you will. Currently only used to remove probing
+ * connections, so it only copies a few pointers at most.
+ * Returns -1 if ptr was not found */
+int gap_remove_ptr(gap_array* gap, void* ptr, int len)
+{
+    int start, i;
+
+    for (i = 0; i < len; i++)
+        if (gap->array[i] == ptr)
+            break;
+
+    if (i < len)
+        start = i;
+    else
+        return -1;
+
+    for (i = start; i < len; i++) {
+        gap->array[i] = gap->array[i+1];
+    }
+
+    return 0;
+}
+

gap.h

@@ -0,0 +1,13 @@
+#ifndef GAP_H
+#define GAP_H
+
+typedef struct gap_array gap_array;
+
+gap_array* gap_init();
+void* gap_get(gap_array* gap, int index);
+int gap_set(gap_array* gap, int index, void* ptr);
+void gap_destroy(gap_array* gap);
+
+int gap_remove_ptr(gap_array* gap, void* ptr, int len);
+
+#endif

genver.sh

@@ -7,7 +7,7 @@ else
 	QUIET=0
 fi
 
-if ! `(git status | grep -q "On branch") 2> /dev/null`; then
+if [ ! -d .git ] || ! `(git status | grep -q "On branch") 2> /dev/null`; then
         # If we don't have git, we can't work out what
         # version this is. It must have been downloaded as a
         # zip file. 
@@ -25,7 +25,7 @@ if ! `(git status | grep -q "On branch") 2> /dev/null`; then
         fi
 fi
 
-if head=`git rev-parse --verify HEAD 2>/dev/null`; then
+if [ -d .git ] && head=`git rev-parse --verify HEAD 2>/dev/null`; then
 	# generate the version info based on the tag
 	release=`(git describe --tags || git --describe || git describe --all --long) \
 		2>/dev/null | tr -d '\n'`

probe.c

@@ -1,7 +1,7 @@
 /*
 # probe.c: Code for probing protocols
 #
-# Copyright (C) 2007-2015  Yves Rutschle
+# Copyright (C) 2007-2019  Yves Rutschle
 # 
 # This program is free software; you can redistribute it
 # and/or modify it under the terms of the GNU General Public
@@ -22,45 +22,43 @@
 #define _GNU_SOURCE
 #include <stdio.h>
 #ifdef ENABLE_REGEX
-#ifdef LIBPCRE
-#include <pcreposix.h>
-#else
-#include <regex.h>
-#endif
+#define PCRE2_CODE_UNIT_WIDTH 8
+#include <pcre2.h>
 #endif
 #include <ctype.h>
 #include "probe.h"
 
 
 
-static int is_ssh_protocol(const char *p, int len, struct proto*);
-static int is_openvpn_protocol(const char *p, int len, struct proto*);
-static int is_tinc_protocol(const char *p, int len, struct proto*);
-static int is_xmpp_protocol(const char *p, int len, struct proto*);
-static int is_http_protocol(const char *p, int len, struct proto*);
-static int is_tls_protocol(const char *p, int len, struct proto*);
-static int is_adb_protocol(const char *p, int len, struct proto*);
-static int is_true(const char *p, int len, struct proto* proto) { return 1; }
+static int is_ssh_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_item*);
+static int is_openvpn_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_item*);
+static int is_tinc_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_item*);
+static int is_xmpp_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_item*);
+static int is_http_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_item*);
+static int is_tls_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_item*);
+static int is_adb_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_item*);
+static int is_socks5_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_item*);
+static int is_syslog_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_item*);
+static int is_true(const char *p, ssize_t len, struct sslhcfg_protocols_item* proto) { return 1; }
 
 /* Table of protocols that have a built-in probe
  */
-static struct proto builtins[] = {
-    /* description   service  saddr  log_level  keepalive  fork  probe  */
-    { "ssh",         "sshd",   NULL,  1,        0,         1,    is_ssh_protocol},
-    { "openvpn",     NULL,     NULL,  1,        0,         1,    is_openvpn_protocol },
-    { "tinc",        NULL,     NULL,  1,        0,         1,    is_tinc_protocol },
-    { "xmpp",        NULL,     NULL,  1,        0,         0,    is_xmpp_protocol },
-    { "http",        NULL,     NULL,  1,        0,         0,    is_http_protocol },
-    { "ssl",         NULL,     NULL,  1,        0,         0,    is_tls_protocol },
-    { "tls",         NULL,     NULL,  1,        0,         0,    is_tls_protocol },
-    { "adb",         NULL,     NULL,  1,        0,         0,    is_adb_protocol },
-    { "anyprot",     NULL,     NULL,  1,        0,         0,    is_true }
+static struct protocol_probe_desc builtins[] = {
+    /* description  probe  */
+    { "ssh",        is_ssh_protocol},
+    { "openvpn",    is_openvpn_protocol },
+    { "tinc",       is_tinc_protocol },
+    { "xmpp",       is_xmpp_protocol },
+    { "http",       is_http_protocol },
+    { "tls",        is_tls_protocol },
+    { "adb",        is_adb_protocol },
+    { "socks5",     is_socks5_protocol },
+    { "syslog",     is_syslog_protocol },
+    { "anyprot",    is_true }
 };
 
-static struct proto *protocols;
-static char* on_timeout = "ssh";
-
-struct proto*  get_builtins(void) {
+/* TODO I think this has to go */
+struct protocol_probe_desc*  get_builtins(void) {
     return builtins;
 }
 
@@ -68,34 +66,18 @@ int get_num_builtins(void) {
     return ARRAY_SIZE(builtins);
 }
 
-/* Sets the protocol name to connect to in case of timeout */
-void set_ontimeout(const char* name)
-{
-    int res = asprintf(&on_timeout, "%s", name);
-    CHECK_RES_DIE(res, "asprintf");
-}
-
 /* Returns the protocol to connect to in case of timeout; 
  * if not found, return the first protocol specified 
  */
-struct proto* timeout_protocol(void) 
+struct sslhcfg_protocols_item* timeout_protocol(void) 
 {
-    struct proto* p = get_first_protocol();
-    for (; p && strcmp(p->description, on_timeout); p = p->next);
-    if (p) return p;
-    return get_first_protocol();
+    int i;
+    for (i = 0; i < cfg.protocols_len; i++) {
+        if (!strcmp(cfg.protocols[i].name, cfg.on_timeout)) return &cfg.protocols[i];
+    }
+    return &cfg.protocols[0];
 }
 
-/* returns the first protocol (caller can then follow the *next pointers) */
-struct proto* get_first_protocol(void)
-{
-    return protocols;
-}
-
-void set_protocol_list(struct proto* prots)
-{
-    protocols = prots;
-}
 
 /* From http://grapsus.net/blog/post/Hexadecimal-dump-in-C */
 #define HEXDUMP_COLS 16
@@ -131,7 +113,7 @@ void hexdump(const char *mem, unsigned int len)
 }
 
 /* Is the buffer the beginning of an SSH connection? */
-static int is_ssh_protocol(const char *p, int len, struct proto *proto)
+static int is_ssh_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_item* proto)
 {
     if (len < 4)
         return PROBE_AGAIN;
@@ -149,7 +131,7 @@ static int is_ssh_protocol(const char *p, int len, struct proto *proto)
  * http://www.fengnet.com/book/vpns%20illustrated%20tunnels%20%20vpnsand%20ipsec/ch08lev1sec5.html
  * and OpenVPN ssl.c, ssl.h and options.c
  */
-static int is_openvpn_protocol (const char*p,int len, struct proto *proto)
+static int is_openvpn_protocol (const char*p,ssize_t len, struct sslhcfg_protocols_item* proto)
 {
     int packet_len;
 
@@ -164,7 +146,7 @@ static int is_openvpn_protocol (const char*p,int len, struct proto *proto)
  * Protocol is documented here: http://www.tinc-vpn.org/documentation/tinc.pdf
  * First connection starts with "0 " in 1.0.15)
  * */
-static int is_tinc_protocol( const char *p, int len, struct proto *proto)
+static int is_tinc_protocol( const char *p, ssize_t len, struct sslhcfg_protocols_item* proto)
 {
     if (len < 2)
         return PROBE_AGAIN;
@@ -176,15 +158,18 @@ static int is_tinc_protocol( const char *p, int len, struct proto *proto)
  * (Protocol is documented (http://tools.ietf.org/html/rfc6120) but for lazy
  * clients, just checking first frame containing "jabber" in xml entity)
  * */
-static int is_xmpp_protocol( const char *p, int len, struct proto *proto)
+static int is_xmpp_protocol( const char *p, ssize_t len, struct sslhcfg_protocols_item* proto)
 {
+    if (memmem(p, len, "jabber", 6))
+        return PROBE_MATCH;
+
     /* sometimes the word 'jabber' shows up late in the initial string,
        sometimes after a newline. this makes sure we snarf the entire preamble
        and detect it. (fixed for adium/pidgin) */
     if (len < 50)
         return PROBE_AGAIN;
 
-    return memmem(p, len, "jabber", 6) ? 1 : 0;
+    return PROBE_NEXT;
 }
 
 static int probe_http_method(const char *p, int len, const char *opt)
@@ -192,11 +177,11 @@ static int probe_http_method(const char *p, int len, const char *opt)
     if (len < strlen(opt))
         return PROBE_AGAIN;
 
-    return !strncmp(p, opt, len);
+    return !strncmp(p, opt, strlen(opt));
 }
 
 /* Is the buffer the beginning of an HTTP connection?  */
-static int is_http_protocol(const char *p, int len, struct proto *proto)
+static int is_http_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_item* proto)
 {
     int res;
     /* If it's got HTTP in the request (HTTP/1.1) then it's HTTP */
@@ -221,45 +206,15 @@ static int is_http_protocol(const char *p, int len, struct proto *proto)
     return PROBE_NEXT;
 }
 
-static int is_sni_alpn_protocol(const char *p, int len, struct proto *proto)
+/* Says if it's TLS, optionally with SNI and ALPN lists in proto->data */
+static int is_tls_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_item* proto)
 {
-    int valid_tls;
-
-    valid_tls = parse_tls_header(proto->data, p, len);
-
-    if(valid_tls < 0)
-        return -1 == valid_tls ? PROBE_AGAIN : PROBE_NEXT;
-
-    /* There *was* a valid match */
-    return PROBE_MATCH;
-}
-
-static int is_tls_protocol(const char *p, int len, struct proto *proto)
-{
-    if (len < 6)
-        return PROBE_AGAIN;
-
-    /* TLS packet starts with a record "Hello" (0x16), followed by the number of
-     * the highest version of SSL/TLS supported.
-     *
-     * A SSLv2 record header contains a two or three byte length code. If the
-     * most significant bit is set in the first byte of the record length code
-     * then the record has no padding and the total header length will be 2
-     * bytes,  otherwise the record has padding and the total header length will
-     * be 3 bytes. Next, a 1 char sized client-hello (0x01) is expected,
-     * followed by a 2 char sized version that indicates the highest version of
-     * TLS/SSL supported by the sender. [SSL2] Hickman, Kipp, "The SSL Protocol"
-     *
-     * We're checking the highest version of TLS/SSL supported against
-     * (0x03 0x00-0x03) (RFC6101 A.1). This means we reject the usage of SSLv2
-     * and lower, which is actually a good thing (RFC6176).
-     */
-    if (p[0] == 0x16) // TLS client-hello
-        return p[1] == 0x03 && ( p[2] >= 0 && p[2] <= 0x03);
-    if ((p[0] & 0x80) != 0) // SSLv2 client-hello, no padding
-        return p[2] == 0x01 && p[3] == 0x03 && ( p[4] >= 0 && p[4] <= 0x03);
-    else // SSLv2 client-hello, padded
-        return p[3] == 0x01 && p[4] == 0x03 && ( p[5] >= 0 && p[5] <= 0x03);
+    switch (parse_tls_header(proto->data, p, len)) {
+    case TLS_MATCH: return PROBE_MATCH;
+    case TLS_NOMATCH: return PROBE_NEXT;
+    case TLS_ELENGTH: return PROBE_AGAIN;
+    default: return PROBE_NEXT;
+    }
 }
 
 static int probe_adb_cnxn_message(const char *p)
@@ -272,7 +227,7 @@ static int probe_adb_cnxn_message(const char *p)
     return !memcmp(&p[0], "CNXN", 4) && !memcmp(&p[24], "host:", 5);
 }
 
-static int is_adb_protocol(const char *p, int len, struct proto *proto)
+static int is_adb_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_item* proto)
 {
     /* amessage.data_length is not being checked, under the assumption that
      * a packet >= 30 bytes will have "something" in the payload field.
@@ -311,16 +266,66 @@ static int is_adb_protocol(const char *p, int len, struct proto *proto)
     return probe_adb_cnxn_message(&p[sizeof(empty_message)]);
 }
 
-static int regex_probe(const char *p, int len, struct proto *proto)
+static int is_socks5_protocol(const char *p_in, ssize_t len, struct sslhcfg_protocols_item* proto)
+{
+    unsigned char* p = (unsigned char*)p_in;
+    int i;
+
+    if (len < 2)
+        return PROBE_AGAIN;
+
+    /* First byte should be socks protocol version */
+    if (p[0] != 5)
+        return PROBE_NEXT;
+
+    /* Second byte should be number of supported 
+     * authentication methods, assuming maximum of 10,
+     * as defined in https://www.iana.org/assignments/socks-methods/socks-methods.xhtml
+     */
+    char m_count = p[1];
+    if (m_count < 1 || m_count > 10)
+        return PROBE_NEXT;
+
+    if (len < 2 + m_count)
+        return PROBE_AGAIN;
+
+    /* Each authentication method number should be in range 0..9 
+     * (https://www.iana.org/assignments/socks-methods/socks-methods.xhtml)
+     */
+    for (i = 0; i < m_count; i++) {
+        if (p[2 + i] > 9)
+            return PROBE_NEXT;
+    }
+    return PROBE_MATCH;
+}
+
+static int is_syslog_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_item* proto)
+{
+    int res, i, j;
+
+    res = sscanf(p, "<%d>", &i);
+    if (res == 1) return 1;
+
+    res = sscanf(p, "%d <%d>", &i, &j);
+    if (res == 2) return 1;
+
+    return 0;
+}
+
+static int regex_probe(const char *p, ssize_t len, struct sslhcfg_protocols_item* proto)
 {
 #ifdef ENABLE_REGEX
-    regex_t **probe = proto->data;
-    regmatch_t pos = { 0, len };
+    pcre2_code**probe = (pcre2_code**)proto->data;
+    pcre2_match_data* matches;
 
-    for (; *probe && regexec(*probe, p, 0, &pos, REG_STARTEND); probe++)
-        /* try them all */;
+    matches = pcre2_match_data_create(1, NULL);
 
-    return (*probe != NULL);
+    for (; *probe; probe++) {
+        int res = pcre2_match(*probe, (PCRE2_SPTR8)p, len, 0, 0, matches, NULL);
+        if (res >= 0) return 1;
+
+    }
+    return 0;
 #else
     /* Should never happen as we check when loading config file */
     fprintf(stderr, "FATAL: regex probe called but not built in\n");
@@ -328,17 +333,69 @@ static int regex_probe(const char *p, int len, struct proto *proto)
 #endif
 }
 
-/* 
+/* Run all the probes on a buffer
+ * Returns
+ *      PROBE_AGAIN if not enough data, and set *proto to NULL
+ *      PROBE_MATCH if protocol is identified, in which case *proto is set to
+ *      point to the appropriate protocol
+ * */
+int probe_buffer(char* buf, int len, struct sslhcfg_protocols_item** proto)
+{
+    struct sslhcfg_protocols_item* p;
+    int i, res, again = 0;
+
+    if (cfg.verbose > 1) {
+        fprintf(stderr, "hexdump of incoming packet:\n");
+        hexdump(buf, len);
+    }
+
+    *proto = NULL;
+    for (i = 0; i < cfg.protocols_len; i++) {
+        char* probe_str[3] = {"PROBE_NEXT", "PROBE_MATCH", "PROBE_AGAIN"};
+        p = &cfg.protocols[i];
+
+        if (! p->probe) continue;
+
+        if (cfg.verbose) fprintf(stderr, "probing for %s\n", p->name);
+
+        /* Don't probe last protocol if it is anyprot (and store last protocol) */
+        if ((i == cfg.protocols_len - 1) && (!strcmp(p->name, "anyprot")))
+            break;
+
+        if (p->minlength_is_present && (len < p->minlength )) {
+            fprintf(stderr, "input too short, %d bytes but need %d\n", len , p->minlength);
+            again++;
+            continue;
+        }
+
+        res = p->probe(buf, len, p);
+        if (cfg.verbose) fprintf(stderr, "probed for %s: %s\n", p->name, probe_str[res]);
+
+        if (res == PROBE_MATCH) {
+            *proto = p;
+            return PROBE_MATCH;
+        }
+        if (res == PROBE_AGAIN)
+            again++;
+    }
+    if (again)
+        return PROBE_AGAIN;
+
+    /* Everything failed: match the last one */
+    *proto = &cfg.protocols[cfg.protocols_len-1];
+    return PROBE_MATCH;
+}
+
+/*
  * Read the beginning of data coming from the client connection and check if
- * it's a known protocol. 
+ * it's a known protocol.
  * Return PROBE_AGAIN if not enough data, or PROBE_MATCH if it succeeded in
  * which case cnx->proto is set to the appropriate protocol.
  */
 int probe_client_protocol(struct connection *cnx)
 {
     char buffer[BUFSIZ];
-    struct proto *p;
-    int n;
+    ssize_t n;
 
     n = read(cnx->q[0].fd, buffer, sizeof(buffer));
     /* It's possible that read() returns an error, e.g. if the client
@@ -347,60 +404,29 @@ int probe_client_protocol(struct connection *cnx)
      * function does not have to deal with a specific  failure condition (the
      * connection will just fail later normally). */
 
-    /* Dump hex values of the packet */
-    if (verbose>1) {
-        fprintf(stderr, "hexdump of incoming packet:\n");
-        hexdump(buffer, n);
-    }
-
     if (n > 0) {
-        int res = PROBE_NEXT;
-
         defer_write(&cnx->q[1], buffer, n);
-
-        for (p = cnx->proto; p && res == PROBE_NEXT; p = p->next) {
-            if (! p->probe) continue;
-            if (verbose) fprintf(stderr, "probing for %s\n", p->description);
-
-            cnx->proto = p;
-            res = p->probe(cnx->q[1].begin_deferred_data, cnx->q[1].deferred_data_size, p);
-        }
-        if (res != PROBE_NEXT)
-            return res;
+        return probe_buffer(cnx->q[1].begin_deferred_data,
+                            cnx->q[1].deferred_data_size,
+                            &cnx->proto);
     }
 
-    if (verbose) 
-        fprintf(stderr, 
-                "all probes failed, connecting to first protocol: %s\n", 
-                protocols->description);
-
-    /* If none worked, return the first one affected (that's completely
-     * arbitrary) */
-    cnx->proto = protocols;
+    /* read() returned an error, so just connect to the last protocol to die */
+    cnx->proto = &cfg.protocols[cfg.protocols_len-1];
     return PROBE_MATCH;
 }
 
-/* Returns the structure for specified protocol or NULL if not found */
-static struct proto* get_protocol(const char* description)
-{
-    int i;
-
-    for (i = 0; i < ARRAY_SIZE(builtins); i++) {
-        if (!strcmp(builtins[i].description, description)) {
-            return &builtins[i];
-        }
-    }
-    return NULL;
-}
-
 /* Returns the probe for specified protocol:
  * parameter is the description in builtins[], or "regex" 
  * */
 T_PROBE* get_probe(const char* description) {
-    struct proto* p = get_protocol(description);
+    int i;
 
-    if (p)
-        return p->probe;
+    for (i = 0; i < ARRAY_SIZE(builtins); i++) {
+        if (!strcmp(builtins[i].name, description)) {
+            return builtins[i].probe;
+        }
+    }
 
     /* Special case of "regex" probe (we don't want to set it in builtins
      * because builtins is also used to build the command-line options and
@@ -408,10 +434,6 @@ T_PROBE* get_probe(const char* description) {
     if (!strcmp(description, "regex"))
         return regex_probe;
 
-    /* Special case of "sni/alpn" probe for same reason as above*/
-    if (!strcmp(description, "sni_alpn"))
-        return is_sni_alpn_protocol;
-
     /* Special case of "timeout" is allowed as a probe name in the
      * configuration file even though it's not really a probe */
     if (!strcmp(description, "timeout"))

probe.h

@@ -12,30 +12,19 @@ typedef enum {
     PROBE_AGAIN, /* Not enough data for this probe, try again with more data */
 } probe_result;
 
-struct proto;
-typedef int T_PROBE(const char*, int, struct proto*);
+struct sslhcfg_protocols_item;
+typedef int T_PROBE(const char*, ssize_t, struct sslhcfg_protocols_item*);
 
-/* For each protocol we need: */
-struct proto {
-    const char* description;  /* a string that says what it is (for logging and command-line parsing) */
-    const char* service;      /* service name to do libwrap checks */
-    struct addrinfo *saddr; /* list of addresses to try and switch that protocol */
-    int log_level;  /* 0: No logging of connection
-                     * 1: Log incoming connection
-                     */
-    int keepalive; /* 0: No keepalive ; 1: Set Keepalive for this connection */
-    int fork; /* 0: Connection can run within shared process ; 1: Separate process required for this connection */
-
-    /* function to probe that protocol; parameters are buffer and length
-     * containing the data to probe, and a pointer to the protocol structure */
+struct protocol_probe_desc {
+    const char* name;
     T_PROBE* probe;
-    /* opaque pointer ; used to pass list of regex to regex probe, or TLSProtocol struct to sni/alpn probe */
-    void* data;
-    struct proto *next; /* pointer to next protocol in list, NULL if last */
 };
 
+
+#include "sslh-conf.h"
+
 /* Returns a pointer to the array of builtin protocols */
-struct proto * get_builtins(void);
+struct protocol_probe_desc* get_builtins(void);
 
 /* Returns the number of builtin protocols */
 int get_num_builtins(void);
@@ -44,10 +33,10 @@ int get_num_builtins(void);
 T_PROBE* get_probe(const char* description);
 
 /* Returns the head of the configured protocols */
-struct proto* get_first_protocol(void);
+struct sslhcfg_protocols_item* get_first_protocol(void);
 
 /* Set the list of configured protocols */
-void set_protocol_list(struct proto*);
+void set_protocol_list(struct sslhcfg_protocols_item*);
 
 /* probe_client_protocol
  *
@@ -58,6 +47,9 @@ void set_protocol_list(struct proto*);
  */
 int probe_client_protocol(struct connection *cnx);
 
+/* Probe, but on a buffer */
+int probe_buffer(char* buf, int len, struct sslhcfg_protocols_item** proto);
+
 /* set the protocol to connect to in case of timeout */
 void set_ontimeout(const char* name);
 
@@ -65,7 +57,7 @@ void set_ontimeout(const char* name);
  *
  * Returns the protocol to connect to in case of timeout
  */
-struct proto* timeout_protocol(void);
+struct sslhcfg_protocols_item* timeout_protocol(void);
 
 void hexdump(const char*, unsigned int);
 

scripts/etc.sysconfig.sslh

@@ -9,7 +9,7 @@
 # is needed in order to run as sslh user
 #
 #SSLH_USER=sslh
-#setcap cap_net_bind_service,cap_net_admin=+ep $SSLH
+#setcap cap_net_bind_service,cap_net_raw=+ep $SSLH
 
 #
 # Configuration file for sslh

scripts/systemd.sslh.service

@@ -4,11 +4,11 @@ After=network.target
 
 [Service]
 EnvironmentFile=/etc/conf.d/sslh
-ExecStart=/usr/bin/sslh --foreground $DAEMON_OPTS
+ExecStart=/usr/sbin/sslh --foreground $DAEMON_OPTS
 KillMode=process
 #Hardening
 PrivateTmp=true
-CapabilityBoundingSet=CAP_SETGID CAP_SETUID CAP_NET_BIND_SERVICE
+CapabilityBoundingSet=CAP_NET_BIND_SERVICE
 AmbientCapabilities=CAP_NET_BIND_SERVICE
 SecureBits=noroot-locked
 ProtectSystem=strict

sslh-conf.h

@@ -0,0 +1,113 @@
+/* Generated by conf2struct (https://www.rutschle.net/tech/conf2struct/README)
+ * on Fri Aug 13 18:03:18 2021. 
+
+# conf2struct: generate libconf parsers that read to structs
+# Copyright (C) 2018-2021  Yves Rutschle
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice,
+#    this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+
+*/
+ 
+#ifndef C2S_SSLHCFG_H
+#define C2S_SSLHCFG_H
+#ifdef LIBCONFIG
+#    include <libconfig.h>
+#endif
+
+
+#include "probe.h"
+#include  <sys/types.h>
+#include  <sys/socket.h>
+#include  <netdb.h>
+
+struct sslhcfg_listen_item {
+	char*	host;
+	char*	port;
+	int	is_udp;
+	int	keepalive;
+};
+
+struct sslhcfg_protocols_item {
+	char*	name;
+	char*	host;
+	char*	port;
+	int	service_is_present;
+	char*	service;
+	int	is_udp;
+	int	udp_timeout;
+	int	fork;
+	int	tfo_ok;
+	int	transparent;
+	int	log_level;
+	int	keepalive;
+	size_t	sni_hostnames_len;
+	char** sni_hostnames;
+	size_t	alpn_protocols_len;
+	char** alpn_protocols;
+	size_t	regex_patterns_len;
+	char** regex_patterns;
+	int	minlength_is_present;
+	int	minlength;
+	T_PROBE*	probe;
+	struct addrinfo*	saddr;
+	void*	data;
+};
+
+struct sslhcfg_item {
+	int	verbose;
+	int	foreground;
+	int	inetd;
+	int	numeric;
+	int	transparent;
+	int	timeout;
+	int	user_is_present;
+	char*	user;
+	int	pidfile_is_present;
+	char*	pidfile;
+	int	chroot_is_present;
+	char*	chroot;
+	char*	syslog_facility;
+	char*	on_timeout;
+	char*	prefix;
+	size_t	listen_len;
+	struct sslhcfg_listen_item* listen;
+	size_t	protocols_len;
+	struct sslhcfg_protocols_item* protocols;
+};
+
+int sslhcfg_parse_file(
+        const char* filename,
+        struct sslhcfg_item* sslhcfg, 
+        const char** errmsg);
+
+void sslhcfg_fprint(
+    FILE* out,
+    struct sslhcfg_item *sslhcfg,
+    int depth);
+
+int sslhcfg_cl_parse(
+    int argc,
+    char* argv[],
+    struct sslhcfg_item *sslhcfg);
+
+#endif

sslh-fork.c

@@ -1,7 +1,7 @@
 /*
    sslh-fork: forking server
 
-# Copyright (C) 2007-2012  Yves Rutschle
+# Copyright (C) 2007-2021  Yves Rutschle
 # 
 # This program is free software; you can redistribute it
 # and/or modify it under the terms of the GNU General Public
@@ -22,11 +22,15 @@
 
 #include "common.h"
 #include "probe.h"
+#include "sslh-conf.h"
+#include "udp-listener.h"
+
+#ifdef LIBBSD
+#include <bsd/unistd.h>
+#endif
 
 const char* server_type = "sslh-fork";
 
-#define MAX(a, b)  (((a) > (b)) ? (a) : (b))
-
 /* shovels data from one fd to the other and vice-versa 
    returns after one socket closed
  */
@@ -53,8 +57,8 @@ int shovel(struct connection *cnx)
       for (i = 0; i < 2; i++) {
           if (FD_ISSET(cnx->q[i].fd, &fds)) {
               res = fd2fd(&cnx->q[1-i], &cnx->q[i]);
-              if (!res) {
-                  if (verbose) 
+              if (res == FD_CNXCLOSED) {
+                  if (cfg.verbose) 
                       fprintf(stderr, "%s %s", i ? "client" : "server", "socket closed\n");
                   return res;
               }
@@ -72,6 +76,7 @@ void start_shoveler(int in_socket)
    int res = PROBE_AGAIN;
    int out_socket;
    struct connection cnx;
+   struct connection_desc desc;
 
    init_cnx(&cnx);
    cnx.q[0].fd = in_socket;
@@ -79,7 +84,7 @@ void start_shoveler(int in_socket)
    FD_ZERO(&fds);
    FD_SET(in_socket, &fds);
    memset(&tv, 0, sizeof(tv));
-   tv.tv_sec = probing_timeout;
+   tv.tv_sec = cfg.timeout;
 
    while (res == PROBE_AGAIN) {
        /* POSIX does not guarantee that tv will be updated, but the client can
@@ -94,8 +99,8 @@ void start_shoveler(int in_socket)
        } else {
            /* Timed out: it's necessarily SSH */
            cnx.proto = timeout_protocol();
-           if (verbose) 
-               log_message(LOG_INFO, "timed out, connect to %s\n", cnx.proto->description);
+           if (cfg.verbose) 
+               log_message(LOG_INFO, "timed out, connect to %s\n", cnx.proto->name);
            break;
        }
    }
@@ -106,12 +111,16 @@ void start_shoveler(int in_socket)
    }
 
    /* Connect the target socket */
-   out_socket = connect_addr(&cnx, in_socket);
+   out_socket = connect_addr(&cnx, in_socket, BLOCKING);
    CHECK_RES_DIE(out_socket, "connect");
 
+   set_capabilities(0);
+
    cnx.q[1].fd = out_socket;
 
-   log_connection(&cnx);
+   get_connection_desc(&desc, &cnx);
+   log_connection(&desc, &cnx);
+   set_proctitle_shovel(&desc, &cnx);
 
    flush_deferred(&cnx.q[1]);
 
@@ -120,13 +129,13 @@ void start_shoveler(int in_socket)
    close(in_socket);
    close(out_socket);
    
-   if (verbose)
+   if (cfg.verbose)
       fprintf(stderr, "connection closed down\n");
 
    exit(0);
 }
 
-static int *listener_pid;
+static pid_t *listener_pid;
 static int listener_pid_number = 0;
 
 void stop_listeners(int sig)
@@ -138,48 +147,85 @@ void stop_listeners(int sig)
     }
 }
 
-void main_loop(int listen_sockets[], int num_addr_listen)
+void set_listen_procname(struct listen_endpoint *listen_socket)
 {
-    int in_socket, i, res;
+#ifdef LIBBSD
+    int res;
+    struct addrinfo addr;
+    struct sockaddr_storage ss;
+    char listen_addr[NI_MAXHOST+1+NI_MAXSERV+1];
+
+    addr.ai_addr = (struct sockaddr*)&ss;
+    addr.ai_addrlen = sizeof(ss);
+    res = getsockname(listen_socket->socketfd, addr.ai_addr, &addr.ai_addrlen);
+    if (res != -1) {
+        sprintaddr(listen_addr, sizeof(listen_addr), &addr);
+        setproctitle("listener %s", listen_addr);
+    }
+#endif
+}
+
+
+/* TCP listener: connections, fork a child for each new connection 
+ * IN: 
+ *      endpoint: array of listening endpoint objects
+ *      num_endpoints: size of endpoint array
+ *      active_endpoint: which endpoint is this listener working on
+ * Does not return
+ * */
+void tcp_listener(struct listen_endpoint* endpoint, int num_endpoints, int active_endpoint)
+{
+    int i, in_socket;
+
+    while (1) {
+        in_socket = accept(endpoint[active_endpoint].socketfd, 0, 0);
+        if (cfg.verbose) fprintf(stderr, "accepted fd %d\n", in_socket);
+
+        switch(fork()) {
+        case -1: log_message(LOG_ERR, "fork failed: err %d: %s\n", errno, strerror(errno));
+                 break;
+
+        case 0: /* In child process */
+                 /* Shoveler processes don't need to hog file descriptors */
+                 for (i = 0; i < num_endpoints; i++)
+                     close(endpoint[i].socketfd);
+                 start_shoveler(in_socket);
+                 exit(0);
+
+        default: /* In parent process */
+                 break;
+        }
+        close(in_socket);
+    }
+}
+
+
+void main_loop(struct listen_endpoint listen_sockets[], int num_addr_listen)
+{
+    int i, res;
     struct sigaction action;
 
     listener_pid_number = num_addr_listen;
     listener_pid = malloc(listener_pid_number * sizeof(listener_pid[0]));
+    CHECK_ALLOC(listener_pid, "malloc");
 
     /* Start one process for each listening address */
     for (i = 0; i < num_addr_listen; i++) {
         listener_pid[i] = fork();
         switch(listener_pid[i]) {
-        // Log if fork() fails for some reason
+        /* Log if fork() fails for some reason */
         case -1: log_message(LOG_ERR, "fork failed: err %d: %s\n", errno, strerror(errno));
                  break;
-        // We're in the child, we have work to do 
+        /* We're in the child, we have work to do  */
         case 0:
-            /* Listening process just accepts a connection, forks, and goes
-             * back to listening */
-            while (1)
-            {
-                in_socket = accept(listen_sockets[i], 0, 0);
-                if (verbose) fprintf(stderr, "accepted fd %d\n", in_socket);
-
-                switch(fork()) {
-                case -1: log_message(LOG_ERR, "fork failed: err %d: %s\n", errno, strerror(errno));
-                         break;
-
-                /* In child process */
-                case 0:
-                    for (i = 0; i < num_addr_listen; ++i)
-                        close(listen_sockets[i]);
-                    start_shoveler(in_socket);
-                    exit(0);
-
-                /* In parent process */
-                default: break;
-                }
-                close(in_socket);
-            }
+            set_listen_procname(&listen_sockets[i]);
+            if (listen_sockets[i].type == SOCK_DGRAM)
+                log_message(LOG_ERR, "UDP not (yet?) supported in sslh-fork\n");
+            else
+                tcp_listener(listen_sockets, num_addr_listen, i);
 	    break;
-	// We're in the parent, we don't need to do anything
+
+	/* We're in the parent, we don't need to do anything */
 	default:
 	    break;
         }
@@ -193,6 +239,7 @@ void main_loop(int listen_sockets[], int num_addr_listen)
     res = sigaction(SIGTERM, &action, NULL);
     CHECK_RES_DIE(res, "sigaction");
 
+
     wait(NULL);
 }
 

sslh-main.c

@@ -2,7 +2,7 @@
 # main: processing of config file, command line options and start the main
 # loop.
 #
-# Copyright (C) 2007-2016  Yves Rutschle
+# Copyright (C) 2007-2018  Yves Rutschle
 # 
 # This program is free software; you can redistribute it
 # and/or modify it under the terms of the GNU General Public
@@ -26,11 +26,12 @@
 #include <libconfig.h>
 #endif
 #ifdef ENABLE_REGEX
-#ifdef LIBPCRE
-#include <pcreposix.h>
-#else
-#include <regex.h>
+#define PCRE2_CODE_UNIT_WIDTH 8
+#include <pcre2.h>
 #endif
+
+#ifdef LIBBSD
+#include <bsd/unistd.h>
 #endif
 
 #include "common.h"
@@ -40,7 +41,7 @@ const char* USAGE_STRING =
 "sslh " VERSION "\n" \
 "usage:\n" \
 "\tsslh  [-v] [-i] [-V] [-f] [-n] [--transparent] [-F<file>]\n"
-"\t[-t <timeout>] [-P <pidfile>] [-u <username>] [-C <chroot>] -p <add> [-p <addr> ...] \n" \
+"\t[-t <timeout>] [-P <pidfile>] [-u <username>] [-C <chroot>] -p <addr> [-p <addr> ...] \n" \
 "%s\n\n" /* Dynamically built list of builtin protocols */  \
 "\t[--on-timeout <addr>]\n" \
 "-v: verbose\n" \
@@ -62,44 +63,6 @@ const char* USAGE_STRING =
 /* Constants for options that have no one-character shorthand */
 #define OPT_ONTIMEOUT   257
 
-static struct option const_options[] = {
-    { "inetd",      no_argument,            &inetd,         1 },
-    { "foreground", no_argument,            &foreground,    1 },
-    { "background", no_argument,            &background,    1 },
-    { "transparent", no_argument,           &transparent,   1 },
-    { "numeric",    no_argument,            &numeric,       1 },
-    { "verbose",    no_argument,            &verbose,       1 },
-    { "user",       required_argument,      0,              'u' },
-    { "config",     optional_argument,      0,              'F' },
-    { "pidfile",    required_argument,      0,              'P' },
-    { "chroot",     required_argument,      0,              'C' },
-    { "timeout",    required_argument,      0,              't' },
-    { "on-timeout", required_argument,      0,              OPT_ONTIMEOUT },
-    { "listen",     required_argument,      0,              'p' },
-    {}
-};
-static struct option* all_options;
-static struct proto* builtins;
-static const char *optstr = "vt:T:p:VP:C:F::";
-
-
-
-static void print_usage(void)
-{
-    struct proto *p;
-    int i;
-    int res;
-    char *prots = "";
-
-    p = get_builtins();
-    for (i = 0; i < get_num_builtins(); i++) {
-        res = asprintf(&prots, "%s\t[--%s <addr>]\n", prots, p[i].description);
-        CHECK_RES_DIE(res, "asprintf");
-    }
-
-    fprintf(stderr, USAGE_STRING, prots);
-}
-
 static void printcaps(void) {
 #ifdef LIBCAP
     cap_t caps;
@@ -120,514 +83,146 @@ static void printcaps(void) {
 static void printsettings(void)
 {
     char buf[NI_MAXHOST];
-    struct addrinfo *a;
-    struct proto *p;
+    int i;
+    struct sslhcfg_protocols_item *p;
     
-    for (p = get_first_protocol(); p; p = p->next) {
+    for (i = 0; i < cfg.protocols_len; i++ ) {
+        p = &cfg.protocols[i];
         fprintf(stderr,
-                "%s addr: %s. libwrap service: %s log_level: %d family %d %d [%s] [%s]\n",
-                p->description, 
+                "%s addr: %s. libwrap service: %s log_level: %d family %d %d [%s] [%s] [%s]\n",
+                p->name, 
                 sprintaddr(buf, sizeof(buf), p->saddr), 
                 p->service,
                 p->log_level,
                 p->saddr->ai_family,
                 p->saddr->ai_addr->sa_family,
                 p->keepalive ? "keepalive" : "",
-                p->fork ? "fork" : "");
+                p->fork ? "fork" : "",
+                p->transparent ? "transparent" : ""
+                );
     }
-    fprintf(stderr, "listening on:\n");
-    for (a = addr_listen; a; a = a->ai_next) {
-        fprintf(stderr, 
-                "\t%s\t[%s]\n", 
-                sprintaddr(buf, sizeof(buf), a), 
-                a->ai_flags & SO_KEEPALIVE ? "keepalive" : "");
-    }
-    fprintf(stderr, "timeout: %d\non-timeout: %s\n", probing_timeout,
-            timeout_protocol()->description);
+    fprintf(stderr, "timeout: %d\non-timeout: %s\n", cfg.timeout,
+            timeout_protocol()->name);
 }
 
 
-/* Extract configuration on addresses and ports on which to listen.
- * out: newly allocated list of addrinfo to listen to
- */
-#ifdef LIBCONFIG
-static int config_listen(config_t *config, struct addrinfo **listen) 
-{
-    config_setting_t *setting, *addr;
-    int len, i, keepalive;
-    const char *hostname, *port;
-
-    setting = config_lookup(config, "listen");
-    if (setting) {
-        len = config_setting_length(setting);
-        for (i = 0; i < len; i++) {
-            addr = config_setting_get_elem(setting, i);
-            if (! (config_setting_lookup_string(addr, "host", &hostname) &&
-                   config_setting_lookup_string(addr, "port", &port))) {
-                fprintf(stderr,
-                            "line %d:Incomplete specification (hostname and port required)\n",
-                            config_setting_source_line(addr));
-                return -1;
-            }
-
-            keepalive = 0;
-            config_setting_lookup_bool(addr, "keepalive", &keepalive);
-
-            resolve_split_name(listen, hostname, port);
-
-            /* getaddrinfo returned a list of addresses corresponding to the
-             * specification; move the pointer to the end of that list before
-             * processing the next specification, while setting flags for
-             * start_listen_sockets() through ai_flags (which is not meant for
-             * that, but is only used as hint in getaddrinfo, so it's OK) */
-            for (; *listen; listen = &((*listen)->ai_next)) {
-                if (keepalive)
-                    (*listen)->ai_flags = SO_KEEPALIVE;
-            }
-        }
-    }
-
-    return 0;
-}
-#endif
-
-
-
-#ifdef LIBCONFIG
-static void setup_regex_probe(struct proto *p, config_setting_t* probes)
-{
+static void setup_regex_probe(struct sslhcfg_protocols_item *p)
 #ifdef ENABLE_REGEX
-    int num_probes, errsize, i, res;
-    char *err;
-    const char * expr;
-    regex_t** probe_list;
+{
+    int num_patterns, i, error;
+    pcre2_code** pattern_list;
+    PCRE2_SIZE error_offset;
+    PCRE2_UCHAR8 err_str[120];
 
-    num_probes = config_setting_length(probes);
-    if (!num_probes) {
-        fprintf(stderr, "%s: no probes specified\n", p->description);
-        exit(1);
-    }
+    num_patterns = p->regex_patterns_len;
 
-    p->probe = get_probe("regex");
-    probe_list = calloc(num_probes + 1, sizeof(*probe_list));
-    p->data = (void*)probe_list;
+    pattern_list = calloc(num_patterns + 1, sizeof(*pattern_list));
+    CHECK_ALLOC(pattern_list, "calloc");
+    p->data = (void*)pattern_list;
 
-    for (i = 0; i < num_probes; i++) {
-        probe_list[i] = malloc(sizeof(*(probe_list[i])));
-        expr = config_setting_get_string_elem(probes, i);
-        res = regcomp(probe_list[i], expr, REG_EXTENDED);
-        if (res) {
-            err = malloc(errsize = regerror(res, probe_list[i], NULL, 0));
-            regerror(res, probe_list[i], err, errsize);
-            fprintf(stderr, "%s:%s\n", expr, err);
-            free(err);
+    for (i = 0; i < num_patterns; i++) {
+        pattern_list[i] = pcre2_compile((PCRE2_SPTR8)p->regex_patterns[i], 
+                                        PCRE2_ZERO_TERMINATED, 0,
+                                        &error, &error_offset, NULL);
+        if (!pattern_list[i]) {
+            pcre2_get_error_message(error, err_str, sizeof(err_str));
+            fprintf(stderr, "compiling pattern /%s/:%d:%s at offset %ld\n",
+                    p->regex_patterns[i], error, err_str, error_offset);
             exit(1);
         }
     }
+}
 #else
-    fprintf(stderr, "line %d: regex probe specified but not compiled in\n", config_setting_source_line(probes));
-    exit(5);
-#endif
-}
-#endif
-
-#ifdef LIBCONFIG
-static void setup_sni_alpn_list(struct proto *p, config_setting_t* config_items, const char* name, int alpn)
 {
-    int num_probes, i, max_server_name_len, server_name_len;
-    const char * config_item;
-    char** sni_hostname_list;
-
-    num_probes = config_setting_length(config_items);
-    if (!num_probes) {
-        fprintf(stderr, "%s: no %s specified\n", p->description, name);
-        return;
-    }
-
-    max_server_name_len = 0;
-    for (i = 0; i < num_probes; i++) {
-        server_name_len = strlen(config_setting_get_string_elem(config_items, i));
-        if(server_name_len > max_server_name_len)
-            max_server_name_len = server_name_len;
-    }
-
-    sni_hostname_list = calloc(num_probes + 1, ++max_server_name_len);
-
-    for (i = 0; i < num_probes; i++) {
-        config_item = config_setting_get_string_elem(config_items, i);
-        sni_hostname_list[i] = malloc(max_server_name_len);
-        strcpy (sni_hostname_list[i], config_item);
-        if(verbose) fprintf(stderr, "%s: %s[%d]: %s\n", p->description, name, i, sni_hostname_list[i]);
-    }
-
-    p->data = (void*)tls_data_set_list(p->data, alpn, sni_hostname_list);
-}
-
-static void setup_sni_alpn(struct proto *p, config_setting_t* prot)
-{
-    config_setting_t *sni_hostnames, *alpn_protocols;
-
-    p->data = (void*)new_tls_data();
-    sni_hostnames = config_setting_get_member(prot, "sni_hostnames");
-    alpn_protocols = config_setting_get_member(prot, "alpn_protocols");
-
-    if(sni_hostnames && config_setting_is_array(sni_hostnames)) {
-        p->probe = get_probe("sni_alpn");
-        setup_sni_alpn_list(p, sni_hostnames, "sni_hostnames", 0);
-    }
-    if(alpn_protocols && config_setting_is_array(alpn_protocols)) {
-        p->probe = get_probe("sni_alpn");
-        setup_sni_alpn_list(p, alpn_protocols, "alpn_protocols", 1);
-    }
+    return;
 }
 #endif
 
-/* Extract configuration for protocols to connect to.
- * out: newly-allocated list of protocols
+/* For each protocol in the configuration, resolve address and set up protocol
+ * options if required
  */
-#ifdef LIBCONFIG
-static int config_protocols(config_t *config, struct proto **prots)
+static void config_protocols()
 {
-    config_setting_t *setting, *prot, *patterns;
-    const char *hostname, *port, *name;
-    int i, num_prots;
-    struct proto *p, *prev = NULL;
-
-    setting = config_lookup(config, "protocols");
-    if (setting) {
-        num_prots = config_setting_length(setting);
-        for (i = 0; i < num_prots; i++) {
-            p = calloc(1, sizeof(*p));
-            if (i == 0) *prots = p;
-            if (prev) prev->next = p;
-            prev = p;
-
-            prot = config_setting_get_elem(setting, i);
-            if ((config_setting_lookup_string(prot, "name", &name) &&
-                 config_setting_lookup_string(prot, "host", &hostname) &&
-                 config_setting_lookup_string(prot, "port", &port)
-                )) {
-                p->description = name;
-                config_setting_lookup_string(prot, "service", &(p->service));
-                config_setting_lookup_bool(prot, "keepalive", &p->keepalive);
-                config_setting_lookup_bool(prot, "fork", &p->fork);
-
-                if (config_setting_lookup_int(prot, "log_level", &p->log_level) == CONFIG_FALSE) {
-                    p->log_level = 1;
-                }
-
-                if (resolve_split_name(&(p->saddr), hostname, port)) {
-                    fprintf(stderr, "line %d: cannot resolve %s:%s\n", config_setting_source_line(prot), hostname, port);
-                    exit(1);
-                }
-
-                p->probe = get_probe(name);
-                if (!p->probe || !strcmp(name, "sni_alpn")) {
-                    fprintf(stderr, "line %d: %s: probe unknown\n", config_setting_source_line(prot), name);
-                    exit(1);
-                }
-
-                /* Probe-specific options: regex patterns */
-                if (!strcmp(name, "regex")) {
-                    patterns = config_setting_get_member(prot, "regex_patterns");
-                    if (patterns && config_setting_is_array(patterns)) {
-                        setup_regex_probe(p, patterns);
-                    }
-                }
-
-                /* Probe-specific options: SNI/ALPN */
-                if (!strcmp(name, "tls")) {
-                    setup_sni_alpn(p, prot);
-                }
-
-            } else {
-                fprintf(stderr, "line %d: Illegal protocol description (missing name, host or port)\n", config_setting_source_line(prot));
-                exit(1);
-            }
+    int i;
+    for (i = 0; i < cfg.protocols_len; i++) {
+        struct sslhcfg_protocols_item* p = &(cfg.protocols[i]);
+        if (resolve_split_name(&(p->saddr), p->host, p->port)) {
+            fprintf(stderr, "cannot resolve %s:%s\n", p->host, p->port);
+            exit(4);
         }
-    }
 
-    return 0;
-}
-#endif
-
-/* Parses a config file
- * in: *filename
- * out: *listen, a newly-allocated linked list of listen addrinfo
- *      *prots, a newly-allocated linked list of protocols
- *      1 on error, 0 on success
- */
-#ifdef LIBCONFIG
-static int config_parse(char *filename, struct addrinfo **listen, struct proto **prots)
-{
-    config_t config;
-    int timeout;
-    const char* str;
-
-    config_init(&config);
-    if (config_read_file(&config, filename) == CONFIG_FALSE) {
-        /* If it's a parse error then there will be a line number for the failure
-         * an I/O error (such as non-existent file) will have the error line as 0
-         */
-        if (config_error_line(&config) != 0) {
-            fprintf(stderr, "%s:%d:%s\n", 
-                    filename,
-                    config_error_line(&config),
-                    config_error_text(&config));
+        p->probe = get_probe(p->name);
+        if (!p->probe) {
+            fprintf(stderr, "%s: probe unknown\n", p->name);
             exit(1);
         }
-        fprintf(stderr, "%s:%s\n", 
-                filename,
-                config_error_text(&config));
-        return 1;
-    }
 
-    if(config_lookup_bool(&config, "verbose", &verbose) == CONFIG_FALSE) {
-	config_lookup_int(&config, "verbose", &verbose);
-    }
+        if (!strcmp(cfg.protocols[i].name, "regex")) {
+            setup_regex_probe(&cfg.protocols[i]);
+        }
 
-    config_lookup_bool(&config, "inetd", &inetd);
-    config_lookup_bool(&config, "foreground", &foreground);
-    config_lookup_bool(&config, "numeric", &numeric);
-    config_lookup_bool(&config, "transparent", &transparent);
-
-    if (config_lookup_int(&config, "timeout", (int *)&timeout) == CONFIG_TRUE) {
-        probing_timeout = timeout;
-    }
-
-    if (config_lookup_string(&config, "on-timeout", &str)) {
-        set_ontimeout(str);
-    }
-
-    config_lookup_string(&config, "user", &user_name);
-    config_lookup_string(&config, "pidfile", &pid_file);
-    config_lookup_string(&config, "chroot", &chroot_path);
-
-    config_lookup_string(&config, "syslog_facility", &facility);
-
-    config_listen(&config, listen);
-    config_protocols(&config, prots);
-
-    return 0;
-}
-#endif
-
-/* Adds protocols to the list of options, so command-line parsing uses the
- * protocol definition array 
- * options: array of options to add to; must be big enough
- * n_opts: number of options in *options before calling (i.e. where to append)
- * prot: array of protocols
- * n_prots: number of protocols in *prot
- * */
-static void append_protocols(struct option *options, int n_opts, struct proto *prot , int n_prots)
-{
-    int o, p;
-
-    for (o = n_opts, p = 0; p < n_prots; o++, p++) {
-        options[o].name = prot[p].description;
-        options[o].has_arg = required_argument;
-        options[o].flag = 0;
-        options[o].val = p + PROT_SHIFT;
+        if (!strcmp(cfg.protocols[i].name, "tls")) {
+            cfg.protocols[i].data = (void*)new_tls_data();
+            if (cfg.protocols[i].sni_hostnames_len)
+                tls_data_set_list(cfg.protocols[i].data, 0,
+                                  (const char**) cfg.protocols[i].sni_hostnames,
+                                  cfg.protocols[i].sni_hostnames_len);
+            if (cfg.protocols[i].alpn_protocols_len)
+                tls_data_set_list(cfg.protocols[i].data, 1, 
+                                  (const char**) cfg.protocols[i].alpn_protocols,
+                                  cfg.protocols[i].alpn_protocols_len);
+        }
     }
 }
 
-static void make_alloptions(void)
-{
-    builtins = get_builtins();
 
-    /* Create all_options, composed of const_options followed by one option per
-     * known protocol */
-    all_options = calloc(ARRAY_SIZE(const_options) + get_num_builtins(), sizeof(struct option));
-    memcpy(all_options, const_options, sizeof(const_options));
-    append_protocols(all_options, ARRAY_SIZE(const_options) - 1, builtins, get_num_builtins());
-}
-
-/* Performs a first scan of command line options to see if a configuration file
- * is specified. If there is one, parse it now before all other options (so
- * configuration file settings can be overridden from the command line).
- *
- * prots: newly-allocated list of configured protocols, if any.
- */
-static void cmdline_config(int argc, char* argv[], struct proto** prots)
-{
-#ifdef LIBCONFIG
-    int c, res;
-    char *config_filename;
-#endif
-
-    make_alloptions();
-
-#ifdef LIBCONFIG
-    optind = 1;
-    opterr = 0; /* we're missing protocol options at this stage so don't output errors */
-    while ((c = getopt_long_only(argc, argv, optstr, all_options, NULL)) != -1) {
-        if (c == 'v') {
-            verbose++;
-        }
-        if (c == 'F') {
-            config_filename = optarg;
-            if (config_filename) {
-                res = config_parse(config_filename, &addr_listen, prots);
-            } else {
-                /* No configuration file specified -- try default file locations */
-                res = config_parse("/etc/sslh/sslh.cfg", &addr_listen, prots);
-                if (!res && verbose) fprintf(stderr, "Using /etc/sslh/sslh.cfg\n");
-                if (res) {
-                    res = config_parse("/etc/sslh.cfg", &addr_listen, prots);
-                    if (!res && verbose) fprintf(stderr, "Using /etc/sslh.cfg\n");
-                }
-            }
-            if (res)
-                exit(4);
-            break;
-        }
-    }
-#endif
-}
-
-
-/* Parse command-line options. prots points to a list of configured protocols,
- * potentially non-allocated */
-static void parse_cmdline(int argc, char* argv[], struct proto* prots)
-{
-    int c;
-    struct addrinfo **a;
-    struct proto *p;
-
-    optind = 1;
-    opterr = 1;
-next_arg:
-    while ((c = getopt_long_only(argc, argv, optstr, all_options, NULL)) != -1) {
-        if (c == 0) continue;
-
-        if (c >= PROT_SHIFT) {
-            if (prots)
-                for (p = prots; p && p->next; p = p->next) {
-                    /* override if protocol was already defined by config file 
-                     * (note it only overrides address and use builtin probe) */
-                    if (!strcmp(p->description, builtins[c-PROT_SHIFT].description)) {
-                        resolve_name(&(p->saddr), optarg);
-                        p->probe = builtins[c-PROT_SHIFT].probe;
-                        goto next_arg;
-                    }
-                }
-            /* At this stage, it's a new protocol: add it to the end of the
-             * list */
-            if (!prots) {
-                /* No protocols yet -- create the list */
-                p = prots = calloc(1, sizeof(*p));
-            } else {
-                p->next = calloc(1, sizeof(*p));
-                p = p->next;
-            }
-            memcpy(p, &builtins[c-PROT_SHIFT], sizeof(*p));
-            resolve_name(&(p->saddr), optarg);
-            continue;
-        }
-
-        switch (c) {
-
-        case 'F':
-            /* Legal option, but do nothing, it was already processed in
-             * cmdline_config() */
-#ifndef LIBCONFIG
-            fprintf(stderr, "Built without libconfig support: configuration file not available.\n");
-            exit(1);
-#endif
-            break;
-
-        case 't':
-             probing_timeout = atoi(optarg);
-            break;
-
-        case OPT_ONTIMEOUT:
-            set_ontimeout(optarg);
-            break;
-
-        case 'p':
-            /* find the end of the listen list */
-            for (a = &addr_listen; *a; a = &((*a)->ai_next));
-            /* append the specified addresses */
-            resolve_name(a, optarg);
-            
-            break;
-
-        case 'V':
-            printf("%s %s\n", server_type, VERSION);
-            exit(0);
-
-        case 'u':
-            user_name = optarg;
-            break;
-
-        case 'P':
-            pid_file = optarg;
-            break;
-
-        case 'C':
-            chroot_path = optarg;
-            break;
-
-        case 'v':
-            verbose++;
-            break;
-
-        default:
-            print_usage();
-            exit(2);
-        }
-    }
-
-    if (!prots) {
+void config_sanity_check(struct sslhcfg_item* cfg) {
+    if (!cfg->protocols_len) {
         fprintf(stderr, "At least one target protocol must be specified.\n");
         exit(2);
     }
 
-    set_protocol_list(prots);
-
 /* If compiling with systemd socket support no need to require listen address */
 #ifndef SYSTEMD
-    if (!addr_listen && !inetd) {
+    if (!cfg->listen_len && !cfg->inetd) {
         fprintf(stderr, "No listening address specified; use at least one -p option\n");
         exit(1);
     }
 #endif
-
-    /* Did command-line override foreground setting? */
-    if (background)
-        foreground = 0;
-
 }
 
-int main(int argc, char *argv[])
+
+int main(int argc, char *argv[], char* envp[])
 {
 
    extern char *optarg;
    extern int optind;
    int res, num_addr_listen;
-   struct proto* protocols = NULL;
+   struct listen_endpoint *listen_sockets;
 
-   int *listen_sockets;
+#ifdef LIBBSD
+   setproctitle_init(argc, argv, envp);
+#endif
 
-   /* Init defaults */
-   pid_file = NULL;
-   user_name = NULL;
-   chroot_path = NULL;
+   memset(&cfg, 0, sizeof(cfg));
+   res = sslhcfg_cl_parse(argc, argv, &cfg);
+   if (res) exit(6);
+   if (cfg.verbose > 3)
+       sslhcfg_fprint(stderr, &cfg, 0);
+   config_protocols();
+   config_sanity_check(&cfg);
 
-   cmdline_config(argc, argv, &protocols);
-   parse_cmdline(argc, argv, protocols);
-
-   if (inetd)
+   if (cfg.inetd)
    {
-       verbose = 0;
+       cfg.verbose = 0;
        start_shoveler(0);
        exit(0);
    }
 
-   if (verbose)
+   if (cfg.verbose)
        printsettings();
 
-   num_addr_listen = start_listen_sockets(&listen_sockets, addr_listen);
+   num_addr_listen = start_listen_sockets(&listen_sockets);
 
 #ifdef SYSTEMD
    if (num_addr_listen < 1) {
@@ -636,7 +231,7 @@ int main(int argc, char *argv[])
     }
 #endif
 
-   if (!foreground) {
+   if (!cfg.foreground) {
        if (fork() > 0) exit(0); /* Detach */
 
        /* New session -- become group leader */
@@ -648,16 +243,16 @@ int main(int argc, char *argv[])
 
    setup_signals();
 
-   if (pid_file)
-       write_pid_file(pid_file);
+   if (cfg.pidfile)
+       write_pid_file(cfg.pidfile);
 
    /* Open syslog connection before we drop privs/chroot */
    setup_syslog(argv[0]);
 
-   if (user_name || chroot_path)
-       drop_privileges(user_name, chroot_path);
+   if (cfg.user || cfg.chroot)
+       drop_privileges(cfg.user, cfg.chroot);
 
-   if (verbose)
+   if (cfg.verbose)
        printcaps();
 
    main_loop(listen_sockets, num_addr_listen);

sslh-select.c

@@ -1,7 +1,7 @@
 /*
    sslh-select: mono-processus server
 
-# Copyright (C) 2007-2010  Yves Rutschle
+# Copyright (C) 2007-2021  Yves Rutschle
 # 
 # This program is free software; you can redistribute it
 # and/or modify it under the terms of the GNU General Public
@@ -20,47 +20,54 @@
 
 */
 
+/* Why use select(2) rather than poll(2)?
+ * No real reason except that's how it was written at first. This article:
+ * https://daniel.haxx.se/docs/poll-vs-select.html suggests that over a few
+ * hundred file descriptors, both become very slow, so there is little
+ * incentive to move to poll() to support more than FD_SETSIZE (which is 1024
+ * on many Linux. To support large numbers of descriptors, either use the fork
+ * version, or we'll have to write a new version based on libev. */
+
 #define __LINUX__
 
+#include <limits.h>
+
 #include "common.h"
 #include "probe.h"
+#include "udp-listener.h"
+#include "collection.h"
+#include "gap.h"
+
+static int debug = 0;
 
 const char* server_type = "sslh-select";
 
-#define MAX(a, b) (((a) > (b)) ? (a) : (b))
+/* Global state for a select() loop */
+struct select_info {
+    int max_fd;   /* Highest fd number to pass to select() */
 
-/* cnx_num_alloc is the number of connection to allocate at once (at start-up,
- * and then every time we get too many simultaneous connections: e.g. start
- * with 100 slots, then if we get more than 100 connections allocate another
- * 100 slots, and so on). We never free up connection structures. We try to
- * allocate as many structures at once as will fit in one page (which is 102
- * in sslh 1.9 on Linux on x86)
- */
-static long cnx_num_alloc;
+    int num_probing;     /* Number of connections currently probing 
+                          * We use this to know if we need to time out of
+                          * select() */
+    gap_array* probing_list;  /* Pointers to cnx that are in probing mode */
 
-/* Make the file descriptor non-block  */
-int set_nonblock(int fd)
-{
-    int flags;
+    fd_set fds_r, fds_w;  /* reference fd sets (used to init working copies) */
+    cnx_collection* collection; /* Collection of connections linked to this loop */
 
-    flags = fcntl(fd, F_GETFL);
-    CHECK_RES_RETURN(flags, "fcntl");
+    time_t next_timeout; /* time at which next UDP connection times out */
+};
 
-    flags |= O_NONBLOCK;
 
-    flags = fcntl(fd, F_SETFL, flags);
-    CHECK_RES_RETURN(flags, "fcntl");
 
-    return flags;
-}
-
-int tidy_connection(struct connection *cnx, fd_set *fds, fd_set *fds2)
+static int tidy_connection(struct connection *cnx, struct select_info* fd_info)
 {
     int i;
+    fd_set* fds = &fd_info->fds_r;
+    fd_set* fds2 = &fd_info->fds_w;
 
     for (i = 0; i < 2; i++) {
         if (cnx->q[i].fd != -1) {
-            if (verbose)
+            if (cfg.verbose)
                 fprintf(stderr, "closing fd %d\n", cnx->q[i].fd);
 
             FD_CLR(cnx->q[i].fd, fds);
@@ -70,13 +77,13 @@ int tidy_connection(struct connection *cnx, fd_set *fds, fd_set *fds2)
                 free(cnx->q[i].deferred_data);
         }
     }
-    init_cnx(cnx);
+    collection_remove_cnx(fd_info->collection, cnx);
     return 0;
 }
 
 /* if fd becomes higher than FD_SETSIZE, things won't work so well with FD_SET
  * and FD_CLR. Need to drop connections if we go above that limit */
-int fd_is_in_range(int fd) {
+static int fd_is_in_range(int fd) {
     if (fd >= FD_SETSIZE) {
         log_message(LOG_ERR, "too many open file descriptor to monitor them all -- dropping connection\n");
         return 0;
@@ -87,73 +94,56 @@ int fd_is_in_range(int fd) {
 /* Accepts a connection from the main socket and assigns it to an empty slot.
  * If no slots are available, allocate another few. If that fails, drop the
  * connexion */
-int accept_new_connection(int listen_socket, struct connection *cnx[], int* cnx_size) 
+static struct connection* accept_new_connection(int listen_socket, struct cnx_collection *collection)
 {
-    int in_socket, free, i, res;
-    struct connection *new;
+    int in_socket, res;
+
+
+    if (cfg.verbose) fprintf(stderr, "accepting from %d\n", listen_socket);
 
     in_socket = accept(listen_socket, 0, 0);
-    CHECK_RES_RETURN(in_socket, "accept");
+    CHECK_RES_RETURN(in_socket, "accept", NULL);
 
     if (!fd_is_in_range(in_socket)) {
         close(in_socket);
-        return -1;
+        return NULL;
     }
 
     res = set_nonblock(in_socket);
     if (res == -1) {
         close(in_socket);
-        return -1;
+        return NULL;
     }
 
-    /* Find an empty slot */
-    for (free = 0; (free < *cnx_size) && ((*cnx)[free].q[0].fd != -1); free++) {
-        /* nothing */
+    struct connection* cnx = collection_alloc_cnx_from_fd(collection, in_socket);
+    if (!cnx) {
+        close(in_socket);
+        return NULL;
     }
-    if (free >= *cnx_size)  {
-        if (verbose)
-            fprintf(stderr, "buying more slots from the slot machine.\n");
-        new = realloc(*cnx, (*cnx_size + cnx_num_alloc) * sizeof((*cnx)[0]));
-        if (!new) {
-            log_message(LOG_ERR, "unable to realloc -- dropping connection\n");
-            close(in_socket);
-            return -1;
-        }
-        *cnx = new;
-        *cnx_size += cnx_num_alloc;
-        for (i = free; i < *cnx_size; i++) {
-            init_cnx(&(*cnx)[i]); 
-        }
-    }
-    (*cnx)[free].q[0].fd = in_socket;
-    (*cnx)[free].state = ST_PROBING;
-    (*cnx)[free].probe_timeout = time(NULL) + probing_timeout;
 
-    if (verbose) 
-        fprintf(stderr, "accepted fd %d on slot %d\n", in_socket, free);
-
-    return in_socket;
+    return cnx;
 }
 
 
 /* Connect queue 1 of connection to SSL; returns new file descriptor */
-int connect_queue(struct connection *cnx, fd_set *fds_r, fd_set *fds_w)
+static int connect_queue(struct connection* cnx,
+                         struct select_info* fd_info)
 {
     struct queue *q = &cnx->q[1];
 
-    q->fd = connect_addr(cnx, cnx->q[0].fd);
+    q->fd = connect_addr(cnx, cnx->q[0].fd, NON_BLOCKING);
     if ((q->fd != -1) && fd_is_in_range(q->fd)) {
-        log_connection(cnx);
-        set_nonblock(q->fd);
+        log_connection(NULL, cnx);
         flush_deferred(q);
         if (q->deferred_data) {
-            FD_SET(q->fd, fds_w);
-            FD_CLR(cnx->q[0].fd, fds_r);
+            FD_SET(q->fd, &fd_info->fds_w);
+            FD_CLR(cnx->q[0].fd, &fd_info->fds_r);
         }
-        FD_SET(q->fd, fds_r);
+        FD_SET(q->fd, &fd_info->fds_r);
+        collection_add_fd(fd_info->collection, cnx, q->fd);
         return q->fd;
     } else {
-        tidy_connection(cnx, fds_r, fds_w);
+        tidy_connection(cnx, fd_info);
         return -1;
     }
 }
@@ -161,26 +151,25 @@ int connect_queue(struct connection *cnx, fd_set *fds_r, fd_set *fds_w)
 /* shovels data from active fd to the other
    returns after one socket closed or operation would block
  */
-void shovel(struct connection *cnx, int active_fd, 
-            fd_set *fds_r, fd_set *fds_w)
+static void shovel(struct connection *cnx, int active_fd, struct select_info* fd_info)
 {
     struct queue *read_q, *write_q;
 
     read_q = &cnx->q[active_fd];
     write_q = &cnx->q[1-active_fd];
 
-    if (verbose)
+    if (cfg.verbose)
         fprintf(stderr, "activity on fd%d\n", read_q->fd);
 
     switch(fd2fd(write_q, read_q)) {
     case -1:
     case FD_CNXCLOSED:
-        tidy_connection(cnx, fds_r, fds_w);
+        tidy_connection(cnx, fd_info);
         break;
 
     case FD_STALLED:
-        FD_SET(write_q->fd, fds_w);
-        FD_CLR(read_q->fd, fds_r);
+        FD_SET(write_q->fd, &fd_info->fds_w);
+        FD_CLR(read_q->fd, &fd_info->fds_r);
         break;
 
     default: /* Nothing */
@@ -191,7 +180,7 @@ void shovel(struct connection *cnx, int active_fd,
 /* shovels data from one fd to the other and vice-versa
    returns after one socket closed
  */
-void shovel_single(struct connection *cnx)
+static void shovel_single(struct connection *cnx)
 {
    fd_set fds_r, fds_w;
    int res, i;
@@ -223,7 +212,7 @@ void shovel_single(struct connection *cnx)
           if (FD_ISSET(cnx->q[i].fd, &fds_w)) {
               res = flush_deferred(&cnx->q[i]);
               if ((res == -1) && ((errno == EPIPE) || (errno == ECONNRESET))) {
-                  if (verbose)
+                  if (cfg.verbose)
                       fprintf(stderr, "%s socket closed\n", i ? "server" : "client");
                   return;
               }
@@ -231,7 +220,7 @@ void shovel_single(struct connection *cnx)
           if (FD_ISSET(cnx->q[i].fd, &fds_r)) {
               res = fd2fd(&cnx->q[1-i], &cnx->q[i]);
               if (!res) {
-                  if (verbose)
+                  if (cfg.verbose)
                       fprintf(stderr, "socket closed\n");
                   return;
               }
@@ -242,7 +231,7 @@ void shovel_single(struct connection *cnx)
 
 /* Child process that makes internal connection and proxies
  */
-void connect_proxy(struct connection *cnx)
+static void connect_proxy(struct connection *cnx)
 {
     int in_socket;
     int out_socket;
@@ -257,29 +246,260 @@ void connect_proxy(struct connection *cnx)
     }
 
     /* Connect the target socket */
-    out_socket = connect_addr(cnx, in_socket);
+    out_socket = connect_addr(cnx, in_socket, BLOCKING);
     CHECK_RES_DIE(out_socket, "connect");
 
     cnx->q[1].fd = out_socket;
 
-    log_connection(cnx);
+    log_connection(NULL, cnx);
 
     shovel_single(cnx);
 
     close(in_socket);
     close(out_socket);
 
-    if (verbose)
+    if (cfg.verbose)
         fprintf(stderr, "connection closed down\n");
 
     exit(0);
 }
 
-/* returns true if specified fd is initialised and present in fd_set */
-int is_fd_active(int fd, fd_set* set)
+/* Removes cnx from probing list */
+static void remove_probing_cnx(struct select_info* fd_info, struct connection* cnx)
 {
-    if (fd == -1) return 0;
-    return FD_ISSET(fd, set);
+    gap_remove_ptr(fd_info->probing_list, cnx, fd_info->num_probing);
+    fd_info->num_probing--;
+}
+
+static void add_probing_cnx(struct select_info* fd_info, struct connection* cnx)
+{
+    gap_set(fd_info->probing_list, fd_info->num_probing, cnx);
+    fd_info->num_probing++;
+}
+
+
+/* Process read activity on a socket in probe state 
+ * IN/OUT cnx: connection data, updated if connected
+ * IN/OUT info: updated if connected
+ * */
+
+static void probing_read_process(struct connection* cnx,
+                                 struct select_info* fd_info)
+{
+    int res;
+
+    /* If timed out it's SSH, otherwise the client sent
+     * data so probe the protocol */
+    if ((cnx->probe_timeout < time(NULL))) {
+        cnx->proto = timeout_protocol();
+        if (cfg.verbose) 
+            log_message(LOG_INFO, 
+                        "timed out, connect to %s\n", 
+                        cnx->proto->name);
+    } else {
+        res = probe_client_protocol(cnx);
+        if (res == PROBE_AGAIN)
+            return;
+    }
+
+    remove_probing_cnx(fd_info, cnx);
+    cnx->state = ST_SHOVELING;
+
+    /* libwrap check if required for this protocol */
+    if (cnx->proto->service &&
+        check_access_rights(cnx->q[0].fd, cnx->proto->service)) {
+        tidy_connection(cnx, fd_info);
+        res = -1;
+    } else if (cnx->proto->fork) {
+        switch (fork()) {
+        case 0:  /* child */
+            /* TODO: close all file descriptors except 2 */
+            /* free(cnx); */
+            connect_proxy(cnx);
+            exit(0);
+        case -1: log_message(LOG_ERR, "fork failed: err %d: %s\n", errno, strerror(errno));
+                 break;
+        default: /* parent */
+                 break;
+        }
+        tidy_connection(cnx, fd_info);
+        res = -1;
+    } else {
+        res = connect_queue(cnx, fd_info);
+    }
+
+    if (res >= fd_info->max_fd)
+        fd_info->max_fd = res + 1;;
+}
+
+
+/* Returns the queue index that contains the specified file descriptor */
+int active_queue(struct connection* cnx, int fd)
+{
+    if (cnx->q[0].fd == fd) return 0;
+    if (cnx->q[1].fd == fd) return 1;
+
+    log_message(LOG_ERR, "file descriptor %d not found in connection object\n", fd);
+    return -1;
+}
+
+/* Process a connection that is active in read */
+static void tcp_read_process(struct select_info* fd_info,
+                             int fd)
+{
+    if (debug) fprintf(stderr, "cnx_read_process fd %d\n", fd);
+
+    cnx_collection* collection = fd_info->collection;
+    struct connection* cnx = collection_get_cnx_from_fd(collection, fd);
+    /* Determine active queue (0 or 1): if fd is that of q[1], active_q = 1,
+     * otherwise it's 0 */
+    int active_q = active_queue(cnx, fd);
+
+    switch (cnx->state) {
+
+    case ST_PROBING:
+        if (active_q == 1) {
+            fprintf(stderr, "Activity on fd2 while probing, impossible\n");
+            dump_connection(cnx);
+            exit(1);
+        }
+
+        probing_read_process(cnx, fd_info);
+
+        break;
+
+    case ST_SHOVELING:
+        shovel(cnx, active_q, fd_info);
+        break;
+
+    default: /* illegal */
+        log_message(LOG_ERR, "Illegal connection state %d\n", cnx->state);
+        dump_connection(cnx);
+        exit(1);
+    }
+}
+
+static void cnx_read_process(struct select_info* fd_info, int fd)
+{
+    cnx_collection* collection = fd_info->collection;
+    struct connection* cnx = collection_get_cnx_from_fd(collection, fd);
+    switch (cnx->type)  {
+    case SOCK_STREAM:
+        tcp_read_process(fd_info, fd);
+        break;
+
+    case SOCK_DGRAM:
+        udp_s2c_forward(cnx);
+        break;
+
+    default:
+        log_message(LOG_ERR, "cnx_read_process: Illegal connection type %d\n", cnx->type);
+        dump_connection(cnx);
+        exit(1);
+    }
+
+}
+
+/* Process a connection that is active in write */
+static void cnx_write_process(struct select_info* fd_info, int fd)
+{
+    if (debug) fprintf(stderr, "cnx_write_process fd %d\n", fd);
+
+    struct connection* cnx = collection_get_cnx_from_fd(fd_info->collection, fd);
+    int res;
+    int queue = active_queue(cnx, fd);
+
+    res = flush_deferred(&cnx->q[queue]);
+    if ((res == -1) && ((errno == EPIPE) || (errno == ECONNRESET))) {
+        if (cnx->state == ST_PROBING) remove_probing_cnx(fd_info, cnx);
+        tidy_connection(cnx, fd_info);
+    } else {
+        /* If no deferred data is left, stop monitoring the fd 
+         * for write, and restart monitoring the other one for reads*/
+        if (!cnx->q[queue].deferred_data_size) {
+            FD_CLR(cnx->q[queue].fd, &fd_info->fds_w);
+            FD_SET(cnx->q[1-queue].fd, &fd_info->fds_r);
+        }
+    }
+}
+
+/* Process a connection that accepts a socket
+ * (For UDP, this means all traffic coming from remote clients)
+ * */
+void cnx_accept_process(struct select_info* fd_info, struct listen_endpoint* listen_socket)
+{
+    int fd = listen_socket->socketfd;
+    int type = listen_socket->type;
+    struct connection* cnx;
+    int new_fd;
+
+    if (debug) fprintf(stderr, "cnx_accept_process fd %d\n", fd);
+
+    switch (type) {
+    case SOCK_STREAM:
+        cnx = accept_new_connection(fd, fd_info->collection);
+
+        if (cnx) {
+            add_probing_cnx(fd_info, cnx);
+            new_fd = cnx->q[0].fd;
+        }
+        break;
+
+    case SOCK_DGRAM:
+        new_fd = udp_c2s_forward(fd, fd_info->collection, fd_info->max_fd);
+        fprintf(stderr, "new_fd %d\n", new_fd);
+        if (new_fd == -1)
+            return;
+        break;
+
+    default:
+        log_message(LOG_ERR, "Inconsistent cnx type: %d\n", type);
+        exit(1);
+        return;
+    }
+
+    FD_SET(new_fd, &fd_info->fds_r);
+    if (new_fd >= fd_info->max_fd)
+        fd_info->max_fd = new_fd + 1;
+
+}
+
+/* Check all connections to see if a UDP connections has timed out, then free
+ * it. At the same time, keep track of the closest, next timeout. Only do the
+ * search through connections if that timeout actually happened. If the
+ * connection that would have timed out has had activity, it doesn't matter: we
+ * go through connections to find the next timeout, which was needed anyway. */
+static void udp_timeouts(struct select_info* fd_info)
+{
+    time_t now = time(NULL);
+
+    if (now < fd_info->next_timeout) return;
+
+    for (int i = 0; i < fd_info->max_fd; i++) {
+        time_t next_timeout = INT_MAX;
+
+        /* if it's either in read or write set, there is a connection
+         * behind that file descriptor */
+        if (FD_ISSET(i, &fd_info->fds_r) || FD_ISSET(i, &fd_info->fds_w)) {
+            struct connection* cnx = collection_get_cnx_from_fd(fd_info->collection, i);
+            if (cnx) {
+                time_t timeout = udp_timeout(cnx);
+                if (cnx && (timeout <= now)) {
+                    if (cfg.verbose > 3)
+                        fprintf(stderr, "timed out UDP %d\n", cnx->target_sock);
+                    close(cnx->target_sock);
+                    FD_CLR(i, &fd_info->fds_r);
+                    FD_CLR(i, &fd_info->fds_w);
+                    collection_remove_cnx(fd_info->collection, cnx);
+                } else {
+                    if (timeout < next_timeout) next_timeout = timeout;
+                }
+            }
+        }
+
+        if (next_timeout != INT_MAX)
+            fd_info->next_timeout = next_timeout;
+    }
 }
 
 /* Main loop: the idea is as follow:
@@ -287,7 +507,7 @@ int is_fd_active(int fd, fd_set* set)
  * - When a file descriptor goes off, process it: read from it, write the data
  * to its corresponding pair.
  * - When a file descriptor blocks when writing, remove the read fd from fds_r,
- * move the data to a deferred buffer, and add the write fd to fds_w. Defered
+ * move the data to a deferred buffer, and add the write fd to fds_w. Deferred
  * buffer is allocated dynamically.
  * - When we can write to a file descriptor that has deferred data, we try to
  * write as much as we can. Once all data is written, remove the fd from fds_w
@@ -296,164 +516,86 @@ int is_fd_active(int fd, fd_set* set)
  * That way, each pair of file descriptor (read from one, write to the other)
  * is monitored either for read or for write, but never for both.
  */
-void main_loop(int listen_sockets[], int num_addr_listen)
+void main_loop(struct listen_endpoint listen_sockets[], int num_addr_listen)
 {
-    fd_set fds_r, fds_w;  /* reference fd sets (used to init the next 2) */
+    struct select_info fd_info = {0};
     fd_set readfds, writefds; /* working read and write fd sets */
     struct timeval tv;
-    int max_fd, in_socket, i, j, res;
-    struct connection *cnx;
-    int num_cnx;  /* Number of connections in *cnx */
-    int num_probing = 0; /* Number of connections currently probing 
-                          * We use this to know if we need to time out of
-                          * select() */
+    int i, res;
 
-    FD_ZERO(&fds_r);
-    FD_ZERO(&fds_w);
+    fd_info.num_probing = 0; 
+    FD_ZERO(&fd_info.fds_r);
+    FD_ZERO(&fd_info.fds_w);
+    fd_info.probing_list = gap_init();
 
     for (i = 0; i < num_addr_listen; i++) {
-        FD_SET(listen_sockets[i], &fds_r); 
-        set_nonblock(listen_sockets[i]);
+        FD_SET(listen_sockets[i].socketfd, &fd_info.fds_r); 
+        set_nonblock(listen_sockets[i].socketfd);
     }
-    max_fd = listen_sockets[num_addr_listen-1] + 1;
+    fd_info.max_fd = listen_sockets[num_addr_listen-1].socketfd + 1;
 
-    cnx_num_alloc = getpagesize() / sizeof(struct connection);
-
-    num_cnx = cnx_num_alloc; /* Start with a set pool of slots */
-    cnx = malloc(num_cnx * sizeof(struct connection));
-    for (i = 0; i < num_cnx; i++)
-        init_cnx(&cnx[i]);
+    fd_info.collection = collection_init();
 
     while (1)
     {
         memset(&tv, 0, sizeof(tv));
-        tv.tv_sec = probing_timeout;
+        tv.tv_sec = cfg.timeout;
 
-        memcpy(&readfds, &fds_r, sizeof(readfds));
-        memcpy(&writefds, &fds_w, sizeof(writefds));
+        memcpy(&readfds, &fd_info.fds_r, sizeof(readfds));
+        memcpy(&writefds, &fd_info.fds_w, sizeof(writefds));
 
-        if (verbose)
-            fprintf(stderr, "selecting... max_fd=%d num_probing=%d\n", max_fd, num_probing);
-        res = select(max_fd, &readfds, &writefds, NULL, num_probing ? &tv : NULL);
+        if (cfg.verbose)
+            fprintf(stderr, "selecting... max_fd=%d num_probing=%d\n", 
+                                          fd_info.max_fd, fd_info.num_probing);
+        res = select(fd_info.max_fd, &readfds, &writefds, 
+                     NULL, fd_info.num_probing ? &tv : NULL);
         if (res < 0)
             perror("select");
 
 
+        /* UDP timeouts: clear out connections after some idle time */
+        udp_timeouts(&fd_info);
+
         /* Check main socket for new connections */
         for (i = 0; i < num_addr_listen; i++) {
-            if (FD_ISSET(listen_sockets[i], &readfds)) {
-                in_socket = accept_new_connection(listen_sockets[i], &cnx, &num_cnx);
-                if (in_socket > 0) {
-                    num_probing++;
-                    FD_SET(in_socket, &fds_r);
-                    if (in_socket >= max_fd)
-                        max_fd = in_socket + 1;;
-                }
+            if (FD_ISSET(listen_sockets[i].socketfd, &readfds)) {
+                cnx_accept_process(&fd_info, &listen_sockets[i]);
+
+                /* don't also process it as a read socket */
+                FD_CLR(listen_sockets[i].socketfd, &readfds);
             }
         }
 
         /* Check all sockets for write activity */
-        for (i = 0; i < num_cnx; i++) {
-            if (cnx[i].q[0].fd != -1) {
-                for (j = 0; j < 2; j++) {
-                    if (is_fd_active(cnx[i].q[j].fd, &writefds)) {
-                        res = flush_deferred(&cnx[i].q[j]);
-                        if ((res == -1) && ((errno == EPIPE) || (errno == ECONNRESET))) {
-                            if (cnx[i].state == ST_PROBING) num_probing--;
-                            tidy_connection(&cnx[i], &fds_r, &fds_w);
-                            if (verbose)
-                                fprintf(stderr, "closed slot %d\n", i);
-                        } else {
-                            /* If no deferred data is left, stop monitoring the fd 
-                             * for write, and restart monitoring the other one for reads*/
-                            if (!cnx[i].q[j].deferred_data_size) {
-                                FD_CLR(cnx[i].q[j].fd, &fds_w);
-                                FD_SET(cnx[i].q[1-j].fd, &fds_r);
-                            }
-                        }
-                    }
-                }
+        for (i = 0; i < fd_info.max_fd; i++) {
+            if (FD_ISSET(i, &writefds)) {
+                cnx_write_process(&fd_info, i);
+            }
+        }
+
+        /* Check sockets in probing state for timeouts */
+        for (i = 0; i < fd_info.num_probing; i++) {
+            struct connection* cnx = gap_get(fd_info.probing_list, i);
+            if (!cnx || cnx->state != ST_PROBING) {
+                log_message(LOG_ERR, "Inconsistent probing: cnx=%0xp\n", cnx);
+                if (cnx)
+                    log_message(LOG_ERR, "Inconsistent probing: state=%d\n", cnx);
+                exit(1);
+            }
+            if (cnx->probe_timeout < time(NULL)) {
+                if (cfg.verbose)
+                    fprintf(stderr, "timeout slot %d\n", i);
+                probing_read_process(cnx, &fd_info);
             }
         }
 
         /* Check all sockets for read activity */
-        for (i = 0; i < num_cnx; i++) {
-            for (j = 0; j < 2; j++) {
-                if (is_fd_active(cnx[i].q[j].fd, &readfds) || 
-                    ((cnx[i].state == ST_PROBING) && (cnx[i].probe_timeout < time(NULL)))) {
-                    if (verbose)
-                        fprintf(stderr, "processing fd%d slot %d\n", j, i);
-
-                    switch (cnx[i].state) {
-
-                    case ST_PROBING:
-                        if (j == 1) {
-                            fprintf(stderr, "Activity on fd2 while probing, impossible\n");
-                            dump_connection(&cnx[i]);
-                            exit(1);
-                        }
-
-                        /* If timed out it's SSH, otherwise the client sent
-                         * data so probe the protocol */
-                        if ((cnx[i].probe_timeout < time(NULL))) {
-                            cnx[i].proto = timeout_protocol();
-                            if (verbose) 
-                                log_message(LOG_INFO, 
-                                            "timed out, connect to %s\n", 
-                                            cnx[i].proto->description);
-                        } else {
-                            res = probe_client_protocol(&cnx[i]);
-                            if (res == PROBE_AGAIN)
-                                continue;
-                        }
-
-                        num_probing--;
-                        cnx[i].state = ST_SHOVELING;
-
-			/* libwrap check if required for this protocol */
-			if (cnx[i].proto->service &&
-			    check_access_rights(in_socket, cnx[i].proto->service)) {
-			    tidy_connection(&cnx[i], &fds_r, &fds_w);
-			    res = -1;
-			} else if (cnx[i].proto->fork) {
-			    struct connection *pcnx_i = &cnx[i];
-			    struct connection cnx_i = *pcnx_i;
-			    switch (fork()) {
-			    case 0:  /* child */
-				for (i = 0; i < num_addr_listen; i++)
-				    close(listen_sockets[i]);
-				for (i = 0; i < num_cnx; i++)
-				    if (&cnx[i] != pcnx_i)
-					for (j = 0; j < 2; j++)
-					    if (cnx[i].q[j].fd != -1)
-						close(cnx[i].q[j].fd);
-				free(cnx);
-				connect_proxy(&cnx_i);
-				exit(0);
-			    case -1: log_message(LOG_ERR, "fork failed: err %d: %s\n", errno, strerror(errno));
-				     break;
-			    default: /* parent */
-				     break;
-			    }
-			    tidy_connection(&cnx[i], &fds_r, &fds_w);
-			    res = -1;
-			} else {
-			    res = connect_queue(&cnx[i], &fds_r, &fds_w);
-			}
-
-                        if (res >= max_fd)
-                            max_fd = res + 1;;
-                        break;
-
-                    case ST_SHOVELING:
-                        shovel(&cnx[i], j, &fds_r, &fds_w);
-                        break;
-
-                    default: /* illegal */
-                        log_message(LOG_ERR, "Illegal connection state %d\n", cnx[i].state);
-                        exit(1);
-                    }
-                }
+        for (i = 0; i < fd_info.max_fd; i++) {
+            /* Check if it's active AND currently monitored (if a connection
+             * died, it gets tidied, which closes both sockets, but readfs does
+             * not know about that */
+            if (FD_ISSET(i, &readfds) && FD_ISSET(i, &fd_info.fds_r)) {
+                cnx_read_process(&fd_info, i);
             }
         }
     }

sslh.pod

@@ -6,7 +6,7 @@
 
 =head1 SYNOPSIS
 
-sslh [B<-F>I<config file>] [B<-t> I<num>] [B<--transparent>] [B<-p> I<listening address> [B<-p> I<listening address> ...] [B<--ssl> I<target address for SSL>] [B<--tls> I<target address for TLS>] [B<--ssh> I<target address for SSH>] [B<--openvpn> I<target address for OpenVPN>] [B<--http> I<target address for HTTP>] [B<--xmpp> I<target address for XMPP>] [B<--tinc> I<target address for TINC>] [B<--anyprot> I<default target address>] [B<--on-timeout> I<protocol name>] [B<-u> I<username>] [B<-C> I<chroot>] [B<-P> I<pidfile>] [-v] [-i] [-V] [-f] [-n]
+sslh [B<-F>I<config file>] [B<-t> I<num>] [B<--transparent>] [B<-p> I<listening address> [B<-p> I<listening address> ...]  [B<--tls> I<target address for TLS>] [B<--ssh> I<target address for SSH>] [B<--openvpn> I<target address for OpenVPN>] [B<--http> I<target address for HTTP>] [B<--xmpp> I<target address for XMPP>] [B<--tinc> I<target address for TINC>] [B<--anyprot> I<default target address>] [B<--on-timeout> I<protocol name>] [B<-u> I<username>] [B<-C> I<chroot>] [B<-P> I<pidfile>] [-v] [-i] [-V] [-f] [-n]
 
 =head1 DESCRIPTION
 
@@ -84,9 +84,6 @@ Uses I<filename> as configuration file. If other
 command-line options are specified, they will override the
 configuration file's settings.
 
-When using the shorthand version, make sure there should be
-no space between B<-F> and the I<filename>.
-
 =item B<-t> I<num>, B<--timeout> I<num>
 
 Timeout before forwarding the connection to the timeout
@@ -95,7 +92,11 @@ protocol (which should usually be SSH). Default is 2s.
 =item B<--on-timeout> I<protocol name>
 
 Name of the protocol to connect to after the timeout period
-is over. Default is 'ssh'.
+is over. Default is to forward to the first specified
+protocol. It usually makes sense to specify 'ssh' as the
+timeout protocol, as the SSH specification does not tell
+who is supposed to speak first and a large number of SSH
+clients wait for the server to send its banner.
 
 =item B<--transparent>
 
@@ -113,8 +114,6 @@ IP address on which the Internet connection ends up).
 This can be specified several times to bind B<sslh> to
 several addresses.
 
-=item B<--ssl> I<target address>
-
 =item B<--tls> I<target address>
 
 Interface and port on which to forward SSL connection,
@@ -127,7 +126,7 @@ inside your network to just connect directly to B<httpd>.
 Also, B<sslh> probes for SSLv3 (or TLSv1) handshake and will
 reject connections from clients requesting SSLv2. This is
 compliant with RFC6176 which prohibits the usage of SSLv2. If
-you wish to accept SSLv2, use B<--default> instead.
+you wish to accept SSLv2, use B<--anyprot> instead.
 
 =item B<--ssh> I<target address>
 

sslhconf.cfg

@@ -0,0 +1,245 @@
+# This is a configuration file for the configuration
+# generator: it is used by
+# conf2struct(http://www.rutschle.net/tech/conf2struct/README.html)
+# to generate the config file and command line parser in
+# sslh-conf.c
+
+header: "sslh-conf.h";
+parser: "sslh-conf.c";
+
+printer: true;
+
+conffile_option: ("F", "config");
+
+# List of includes to define runtime types
+# (bug in libconfig? if swallows the brackets if they start
+# the string)
+includes: (
+           "probe.h",
+           " <sys/types.h>",
+           " <sys/socket.h>",
+           " <netdb.h>"
+          );
+
+config: {
+         name : "sslhcfg",
+         type: "list",
+         items: (
+            { name: "verbose"; type: "int"; default: 0; short: "v"; },
+            { name: "foreground"; type: "bool"; default: false;
+              short: "f";
+              description: "Run in foreground instead of as a daemon"; },
+            { name: "inetd"; type: "bool"; default: false;
+              short: "i";
+              description: "Run in inetd mode: use stdin/stdout instead of network listen"; },
+            { name: "numeric"; type: "bool"; default: false;
+              short: "n";
+              description: "Print IP addresses and ports as numbers"; },
+            { name: "transparent"; type: "bool"; default: false;
+              description: "Set up as a transparent proxy"; },
+            { name: "timeout"; type: "int"; default: 5; 
+              short: "t";
+              description: "Set up timeout before connecting to default target"; },
+            { name: "user"; type: "string"; optional: true; 
+              short: "u";
+              description: "Username to change to after set-up"; },
+            { name: "pidfile"; type: "string"; optional: true; 
+              short: "P"; argdesc: "<file>";
+              description: "Path to file to store PID of current instance"; },
+            { name: "chroot"; type: "string"; optional: true;
+              short: "C"; argdesc: "<path>";
+              description: "Root to change to after set-up"; },
+            { name: "syslog_facility"; type: "string"; default: "auth"; 
+              description: "Facility to syslog to"; },
+
+            { name: "on-timeout"; type: "string"; default: "ssh"; 
+              description: "Target to connect to when timing out"; },
+
+            { name: "prefix"; type: "string"; default: ""; description: "Reserved for testing" }, # For echosrv only, not sslh
+
+            { name: "listen", 
+                no_cl_accessors: true;  # disable generation of individual cl options for each group element (we create a specific --listen option further below)
+                type: "list", 
+                items: (
+                    { name: "host"; type: "string"; var: true; },
+                    { name: "port"; type: "string"; var: true; },
+                    { name: "is_udp"; type: "bool"; default: false },
+                    { name: "keepalive"; type: "bool"; default: false; }
+                )
+            },
+
+            { name: "protocols",
+                no_cl_accessors: true;
+                type: "list",
+                items: (
+                    { name: "name"; type: "string"; },
+                    { name: "host"; type: "string"; var: true; },
+                    { name: "port"; type: "string"; var: true; },
+                    { name: "service"; type: "string"; optional: true; },
+                    { name: "is_udp"; type: "bool"; default: false },
+                    { name: "udp_timeout"; type: "int"; default: 60 },
+                    { name: "fork"; type: "bool"; default: false },
+                    { name: "tfo_ok"; type: "bool"; default: false;
+                        description: "Set to true if this protocol supports TCP FAST OPEN" },
+                    { name: "transparent"; type: "bool"; default: false; 
+                        description: "Set to proxy this protocol transparently" },
+                    { name: "log_level"; type: "int"; default: 1 },
+                    { name: "keepalive"; type: "bool"; default: false },
+                    { name: "sni_hostnames",
+                        type: "array", 
+                        element_type: "string"
+                    },
+                    { name: "alpn_protocols",
+                    type: "array",
+                    element_type: "string" 
+                    },
+                    { name: "regex_patterns",
+                    type: "array",
+                    element_type: "string"
+                    },
+                    { name: "minlength"; type: "int"; optional: true },
+
+                    # Runtime data
+                    { name: "probe"; type: "runtime"; c_type: "T_PROBE*" },
+                    { name: "saddr"; type: "runtime"; c_type: "struct addrinfo*" },
+                    { name: "data"; type: "runtime"; c_type: "void*" }
+                )
+            }
+        )
+}
+
+# Command line for list settings: additional options that
+# can set up several settings at once. Each option will
+# create a new group setting entry if required (with
+# defaults set up)
+# This only works with string targets
+# This may not be the right abstraction at all and way too
+# sslh-centric
+cl_groups: (
+    { name: "listen"; pattern: "(.+):(\w+)"; description: "Listen on host:port";
+      short: "p"; argdesc: "<host:port>";
+        list: "listen";
+        # no override, this just adds to the list (and thus can be specified several times)
+        targets: (
+        { path: "host"; value: "$1" },
+        { path: "port"; value: "$2" }
+        );
+    },
+    { name: "ssh"; pattern: "(.+):(\w+)";  description: "Set up ssh target";
+        list: "protocols"; # List name that we're defining with this command line option
+        override: "name";  # Field in the group to override.  If not found in list, add an item
+                           # (it's mandatory to have that field as one of the targets
+                           # below)
+        argdesc: "<host:port>";
+        targets: (
+        { path: "name"; value: "ssh" },
+        { path: "host"; value: "$1" },
+        { path: "port"; value: "$2" },
+        { path: "fork"; value: 1 },
+        { path: "log_level"; value: 1 },
+        { path: "tfo_ok"; value: 1 }
+        );
+    },
+    { name: "tls"; pattern: "(.+):(\w+)"; description: "Set up TLS/SSL target";
+        list: "protocols";
+        override: "name";
+        argdesc: "<host:port>";
+        targets: (
+        { path: "name"; value: "tls" },
+        { path: "host"; value: "$1" },
+        { path: "port"; value: "$2" },
+        { path: "log_level"; value: 1 },
+        { path: "tfo_ok"; value: 1 }
+        );
+    },
+    { name: "openvpn"; pattern: "(.+):(\w+)"; description: "Set up OpenVPN target";
+        list: "protocols";
+        override: "name";
+        argdesc: "<host:port>";
+        targets: (
+        { path: "name"; value: "openvpn" },
+        { path: "host"; value: "$1" },
+        { path: "port"; value: "$2" },
+        { path: "log_level"; value: 1 },
+        { path: "tfo_ok"; value: 1 }
+        );
+    },
+    { name: "tinc"; pattern: "(.+):(\w+)"; description: "Set up tinc target";
+        list: "protocols";
+        override: "name";
+        argdesc: "<host:port>";
+        targets: (
+        { path: "name"; value: "tinc" },
+        { path: "host"; value: "$1" },
+        { path: "port"; value: "$2" },
+        { path: "log_level"; value: 1 },
+        { path: "tfo_ok"; value: 1 }
+        );
+    },
+    { name: "xmpp"; pattern: "(.+):(\w+)"; description: "Set up XMPP target";
+        list: "protocols";
+        override: "name";
+        argdesc: "<host:port>";
+        targets: (
+        { path: "name"; value: "xmpp" },
+        { path: "host"; value: "$1" },
+        { path: "port"; value: "$2" },
+        { path: "log_level"; value: 1 }
+        );
+    },
+    { name: "http"; pattern: "(.+):(\w+)"; description: "Set up HTTP (plain) target";
+        list: "protocols";
+        override: "name";
+        argdesc: "<host:port>";
+        targets: (
+        { path: "name"; value: "http" },
+        { path: "host"; value: "$1" },
+        { path: "port"; value: "$2" },
+        { path: "log_level"; value: 1 }
+        );
+    },
+    { name: "adb"; pattern: "(.+):(\w+)"; description: "Set up ADB (Android Debug) target";
+        list: "protocols";
+        override: "name";
+        argdesc: "<host:port>";
+        targets: (
+        { path: "name"; value: "adb" },
+        { path: "host"; value: "$1" },
+        { path: "port"; value: "$2" },
+        { path: "log_level"; value: 1 }
+        );
+    },
+    { name: "socks5"; pattern: "(.+):(\w+)"; description: "Set up socks5 target";
+        list: "protocols";
+        override: "name";
+        argdesc: "<host:port>";
+        targets: (
+        { path: "name"; value: "socks5" },
+        { path: "host"; value: "$1" },
+        { path: "port"; value: "$2" },
+        { path: "log_level"; value: 1 }
+        );
+    },
+    { name: "syslog"; pattern: "(.+):(\w+)"; description: "Set up syslog target";
+        list: "protocols";
+        override: "name";
+        argdesc: "<host:port>";
+        targets: (
+        { path: "name"; value: "syslog" },
+        { path: "host"; value: "$1" },
+        { path: "port"; value: "$2" },
+        { path: "log_level"; value: 1 }
+        );
+    },
+    { name: "anyprot"; pattern: "(.+):(\w+)"; description: "Set up default target";
+        list: "protocols";
+        override: "name";
+        argdesc: "<host:port>";
+        targets: (
+        { path: "name"; value: "anyprot" },
+        { path: "host"; value: "$1" },
+        { path: "port"; value: "$2" },
+        { path: "log_level"; value: 1 }
+        );
+    }
+)

systemd-sslh-generator.c

@@ -2,12 +2,14 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
+#include "common.h"
 
 
 static char* resolve_listen(const char *hostname, const char *port) {
     /* Need room in the strcat for \0 and :
      * the format in the socket unit file is hostname:port */
-    char *conn = (char*)malloc(strlen(hostname)+strlen(port)+2);
+    char *conn = malloc(strlen(hostname)+strlen(port)+2);
+    CHECK_ALLOC(conn, "malloc");
     strcpy(conn, hostname);
     strcat(conn, ":");
     strcat(conn, port);
@@ -41,6 +43,7 @@ static int get_listen_from_conf(const char *filename, char **listen[]) {
 	    int i;
             len = config_setting_length(setting);
             *listen = malloc(len * sizeof(**listen));
+            CHECK_ALLOC(*listen, "malloc");
             for (i = 0; i < len; i++) {
                 addr = config_setting_get_elem(setting, i);
                 if (! (config_setting_lookup_string(addr, "host", &hostname) &&
@@ -51,6 +54,7 @@ static int get_listen_from_conf(const char *filename, char **listen[]) {
                     return -1;
                 } else {
                     (*listen)[i] = malloc(strlen(resolve_listen(hostname, port)));
+                    CHECK_ALLOC((*listen)[i], "malloc");
                     strcpy((*listen)[i], resolve_listen(hostname, port));
                 }
             }
@@ -115,6 +119,7 @@ static int gen_sslh_config(char *runtime_unit_dir) {
         size_t uf_len = strlen(unit_file);
         size_t runtime_len = strlen(runtime_unit_dir) + uf_len + 1;
         char *runtime_conf = malloc(runtime_len);
+        CHECK_ALLOC(runtime_conf, "malloc");
         strcpy(runtime_conf, runtime_unit_dir);
         strcat(runtime_conf, unit_file);
         runtime_conf_fd = fopen(runtime_conf, "w");

t

@@ -2,86 +2,233 @@
 
 # Test script for sslh
 
+# Uses Conf::Libconfig to read sslh config file: install
+# with:
+# cpan Conf::Libconfig
+
 use strict;
 use IO::Socket::INET6;
 use Test::More qw/no_plan/;
+use Conf::Libconfig;
 
-# We use ports 9000, 9001 and 9002 -- hope that won't clash
-# with anything...
-my $ssh_address = "ip6-localhost:9000";
-my $ssl_address = "ip6-localhost:9001";
-my $sslh_port = 9002;
-my $no_listen = 9003;  # Port on which no-one listens
-my $pidfile = "/tmp/sslh_test.pid";
+my $conf = new Conf::Libconfig;
+$conf->read_file("test.cfg");
+
+
+my $no_listen = 8083;  # Port on which no-one listens
+my $pidfile = $conf->lookup_value("pidfile");
+my $sslh_port = $conf->fetch_array("listen")->[0]->{port};
+my $user = (getpwuid $<)[0]; # Run under current username
 
 # Which tests do we run
-my $SSL_CNX =           1;
-my $SSH_SHY_CNX =       1;
-my $SSH_BOLD_CNX =      1;
-my $SSH_PROBE_AGAIN =   1;
+my $SSH_SHY_CNX =       0;
+my $PROBES_NOFRAG =     1;
+my $PROBES_AGAIN =      1;
 my $SSL_MIX_SSH =       1;
 my $SSH_MIX_SSL =       1;
-my $BIG_MSG =           0; # This test is unreliable
-my $STALL_CNX =         0; # This test needs fixing
 
 # Robustness tests. These are mostly to achieve full test
 # coverage, but do not necessarily result in an actual test
 # (e.g. some tests need to be run with valgrind to check all
 # memory management code).
-my $RB_CNX_NOSERVER =           1;
-my $RB_PARAM_NOHOST =           1;
-my $RB_WRONG_USERNAME =         1;
-my $RB_OPEN_PID_FILE =          1;
-my $RB_BIND_ADDRESS =           1;
-my $RB_RESOLVE_ADDRESS =        1;
+my $RB_CNX_NOSERVER =           0;
+my $RB_PARAM_NOHOST =           0;
+my $RB_WRONG_USERNAME =         0;
+my $RB_OPEN_PID_FILE =          0;
+my $RB_RESOLVE_ADDRESS =        0;
+my $RB_CL_PARAMS =              0;
 
 `lcov --directory . --zerocounters`;
 
+sub verbose_exec
+{
+    my ($cmd) = @_;
 
-my ($ssh_pid, $ssl_pid);
-
-if (!($ssh_pid = fork)) {
-    exec "./echosrv --listen $ssh_address --prefix 'ssh: '";
+    warn "$cmd\n";
+    if (!fork) {
+        exec $cmd;
+    }
 }
 
-if (!($ssl_pid = fork)) {
-    exec "./echosrv --listen $ssl_address --prefix 'ssl: '";
+# We want to keep track of tests to print a report at the
+# end, so we centralise all calls to Test::More::is here
+my $cnt = 1;   # test counter
+my @results;
+sub my_is {
+    my ($a, $b, $desc) = @_;
+
+    my $res =  is($a, $b, $desc);
+    push @results, [$cnt++, $desc, $res];
 }
 
-my @binaries = ('sslh-select', 'sslh-fork');
+
+
+# For SNI/ALPN, build a protocol name as such:
+# tls:sni1,sni2,...;alpn1,alpn2,...
+# input: a protocol entry from Libconfig
+sub make_sni_alpn_name {
+    my ($prot) = @_;
+
+   return "tls:" . (join ",", @{$prot->{sni_hostnames} // []})
+           . ";" . (join ",", @{$prot->{alpn_protocols} // [] });
+}
+
+
+# Tests one probe: given input data, connect, verify we get
+# the expected server, verify shoveling works
+# Named options:
+# data: what to write
+# expected: expected protocol prefix
+# no_frag: don't print byte-per-byte
+sub test_probe {
+    my (%opts) = @_;
+
+    my $cnx = new IO::Socket::INET(PeerHost => "localhost:$sslh_port");
+    warn "$!\n" unless $cnx;
+    return unless $cnx;
+
+    my $pattern = $opts{data};
+    if ($opts{no_frag}) {
+        syswrite $cnx, $pattern;
+    } else {
+        while (length $pattern) {
+            syswrite $cnx, (substr $pattern, 0, 1, '');
+            select undef, undef, undef, .01;
+        }
+    }
+
+    my $data;
+    my $n = sysread $cnx, $data, 1024;
+    $data =~ /^(.*?): /;
+    my $prefix = $1;
+    $data =~ s/$prefix: //g;
+    print "Received $n bytes: protocol $prefix data [$data]\n";
+    close $cnx;
+
+    $opts{expected} =~ s/^ssl/tls/; # to remove in 1.21
+    my_is($prefix, $opts{expected}, "$opts{binary}:$opts{expected}: probe connected correctly");
+    my_is($data, $opts{data}, "$opts{binary}:$opts{expected}: data shoveled correctly");
+}
+
+# Test all probes, with or without fragmentation
+# options:
+#     no_frag: write test patterns all at once (also
+#     available per-protocol as some probes don't support
+#     fragmentation)
+sub test_probes {
+    my (%in_opts) = @_;
+
+    my @probes = @{$conf->fetch_array("protocols")};
+    foreach my $p (@probes) {
+        my %protocols = (
+            'ssh' => { data => "SSH-2.0 tester" },
+            'socks5' => { data => "\x05\x04\x01\x02\x03\x04" },
+            'http' => { 
+                data => "GET index.html HTTP/1.1",
+                no_frag => 1 },
+            'tls' => { 
+                # Packet with SNI and ALPN (`openssl s_client -connect localhost:443 -alpn alpn1 -servername sni1`)
+                data_sni_alpn => "\x16\x03\x01\x00\xc4\x01\x00\x00\xc0\x03\x03\x03\x19\x01\x00\x40\x14\x13\xcc\x1b\x94\xad\x20\x5d\x13\x1a\x8d\xd2\x65\x23\x70\xde\xd1\x3c\x5d\x05\x19\xcb\x27\x0d\x7c\x2c\x89\x00\x00\x38\xc0\x2c\xc0\x30\x00\x9f\xcc\xa9\xcc\xa8\xcc\xaa\xc0\x2b\xc0\x2f\x00\x9e\xc0\x24\xc0\x28\x00\x6b\xc0\x23\xc0\x27\x00\x67\xc0\x0a\xc0\x14\x00\x39\xc0\x09\xc0\x13\x00\x33\x00\x9d\x00\x9c\x00\x3d\x00\x3c\x00\x35\x00\x2f\x00\xff\x01\x00\x00\x5f\x00\x00\x00\x09\x00\x07\x00\x00\x04\$sni\x00\x0b\x00\x04\x03\x00\x01\x02\x00\x0a\x00\x0a\x00\x08\x00\x1d\x00\x17\x00\x19\x00\x18\x00\x23\x00\x00\x00\x0d\x00\x20\x00\x1e\x06\x01\x06\x02\x06\x03\x05\x01\x05\x02\x05\x03\x04\x01\x04\x02\x04\x03\x03\x01\x03\x02\x03\x03\x02\x01\x02\x02\x02\x03\x00\x10\x00\x08\x00\x06\x05\$alpn\x00\x16\x00\x00\x00\x17\x00\x00hello sni/alpn",
+                # Packet with SNI alone
+                data_sni => "\x16\x03\x01\x00\xb8\x01\x00\x00\xb4\x03\x03\x97\xe4\xe9\xad\x86\xe1\x21\xfd\xc4\x5b\x27\x0e\xad\x4b\x55\xc2\x50\xe4\x1c\x86\x2f\x37\x25\xde\xe8\x9c\x59\xfc\x1b\xa9\x37\x32\x00\x00\x38\xc0\x2c\xc0\x30\x00\x9f\xcc\xa9\xcc\xa8\xcc\xaa\xc0\x2b\xc0\x2f\x00\x9e\xc0\x24\xc0\x28\x00\x6b\xc0\x23\xc0\x27\x00\x67\xc0\x0a\xc0\x14\x00\x39\xc0\x09\xc0\x13\x00\x33\x00\x9d\x00\x9c\x00\x3d\x00\x3c\x00\x35\x00\x2f\x00\xff\x01\x00\x00\x53\x00\x00\x00\x09\x00\x07\x00\x00\x04\$sni\x00\x0b\x00\x04\x03\x00\x01\x02\x00\x0a\x00\x0a\x00\x08\x00\x1d\x00\x17\x00\x19\x00\x18\x00\x23\x00\x00\x00\x0d\x00\x20\x00\x1e\x06\x01\x06\x02\x06\x03\x05\x01\x05\x02\x05\x03\x04\x01\x04\x02\x04\x03\x03\x01\x03\x02\x03\x03\x02\x01\x02\x02\x02\x03\x00\x16\x00\x00\x00\x17\x00\x00hello sni",
+                # packet with ALPN alone
+                data_alpn => "\x16\x03\x01\x00\xb7\x01\x00\x00\xb3\x03\x03\xe2\x90\xa2\x29\x03\x31\xad\x98\x44\x51\x54\x90\x5b\xd9\x51\x0e\x66\xb5\x3f\xe8\x8b\x09\xc9\xe4\x2b\x97\x24\xef\xad\x56\x06\xc9\x00\x00\x38\xc0\x2c\xc0\x30\x00\x9f\xcc\xa9\xcc\xa8\xcc\xaa\xc0\x2b\xc0\x2f\x00\x9e\xc0\x24\xc0\x28\x00\x6b\xc0\x23\xc0\x27\x00\x67\xc0\x0a\xc0\x14\x00\x39\xc0\x09\xc0\x13\x00\x33\x00\x9d\x00\x9c\x00\x3d\x00\x3c\x00\x35\x00\x2f\x00\xff\x01\x00\x00\x52\x00\x0b\x00\x04\x03\x00\x01\x02\x00\x0a\x00\x0a\x00\x08\x00\x1d\x00\x17\x00\x19\x00\x18\x00\x23\x00\x00\x00\x0d\x00\x20\x00\x1e\x06\x01\x06\x02\x06\x03\x05\x01\x05\x02\x05\x03\x04\x01\x04\x02\x04\x03\x03\x01\x03\x02\x03\x03\x02\x01\x02\x02\x02\x03\x00\x10\x00\x08\x00\x06\x05\$alpn\x00\x16\x00\x00\x00\x17\x00\x00hello alpn",
+                # packet with no SNI, no ALPN
+                data => "\x16\x03\x01\x00\xab\x01\x00\x00\xa7\x03\x03\x89\x22\x33\x95\x43\x7a\xc3\x89\x45\x51\x12\x3c\x28\x24\x1b\x6a\x78\xbf\xbe\x95\xd8\x90\x58\xd7\x65\xf7\xbb\x2d\xb2\x8d\xa0\x75\x00\x00\x38\xc0\x2c\xc0\x30\x00\x9f\xcc\xa9\xcc\xa8\xcc\xaa\xc0\x2b\xc0\x2f\x00\x9e\xc0\x24\xc0\x28\x00\x6b\xc0\x23\xc0\x27\x00\x67\xc0\x0a\xc0\x14\x00\x39\xc0\x09\xc0\x13\x00\x33\x00\x9d\x00\x9c\x00\x3d\x00\x3c\x00\x35\x00\x2f\x00\xff\x01\x00\x00\x46\x00\x0b\x00\x04\x03\x00\x01\x02\x00\x0a\x00\x0a\x00\x08\x00\x1d\x00\x17\x00\x19\x00\x18\x00\x23\x00\x00\x00\x0d\x00\x20\x00\x1e\x06\x01\x06\x02\x06\x03\x05\x01\x05\x02\x05\x03\x04\x01\x04\x02\x04\x03\x03\x01\x03\x02\x03\x03\x02\x01\x02\x02\x02\x03\x00\x16\x00\x00\x00\x17\x00\x00hello tls alone"
+            },
+            'openvpn' => { data => "\x00\x00" },
+            'syslog' => { data => "<42> My syslog message" },
+            'tinc' => { data => "0 hello" },
+            'xmpp' => {data => "I should get a real jabber connection initialisation here" },
+            'adb' => { data => "CNXN....................host:..." },
+            'anyprot' => {data => "hello anyprot this needs to be longer than xmpp and adb which expect about 50 characters, which I all have to write before the timeout!" },
+        );
+
+        my $pattern = $protocols{$p->{name}}->{data};
+
+        my %opts = %in_opts;
+        $opts{no_frag} = 1 if $protocols{$p->{name}}->{no_frag};
+
+        if ($p->{sni_hostnames} or $p->{alpn_protocols}) {
+            my $pname = make_sni_alpn_name($p);
+
+            my @sni = @{$p->{sni_hostnames} // [""] };
+            my @alpn = @{$p->{alpn_protocols} // [""] };
+
+            foreach my $sni ( @sni ) {
+                foreach my $alpn ( @alpn ) {
+                    print "sni: $sni\nalpn: $alpn\n";
+                    $pattern = $protocols{tls}->{
+                        "data". ($sni ?  "_sni" : "") . 
+                                ($alpn ?  "_alpn": "")
+                    };
+                    $pattern =~ s/(\$\w+)/$1/eeg;
+
+                    test_probe(
+                        data => $pattern,
+                        expected => $pname,
+                        %opts
+                    );
+                }
+            }
+        } elsif ($p->{name} eq 'regex') {
+            foreach my $test (@{$p->{test_patterns}}) {
+                test_probe(
+                    data => $test->{pattern},
+                    expected => $test->{result},
+                    %opts
+                );
+            }
+        } else {
+            test_probe(
+                data => $pattern,
+                expected => $p->{name},
+                %opts
+            );
+
+        }
+    }
+}
+
+
+
+# Start an echoserver for each service
+foreach my $s (@{$conf->fetch_array("protocols")}) {
+    my $prefix = $s->{name};
+
+    $prefix =~ s/^ssl/tls/; # To remove in 1.21
+
+    if ($s->{sni_hostnames} or $s->{alpn_protocols}) {
+        $prefix = make_sni_alpn_name($s);
+    }
+
+    verbose_exec "./echosrv --listen $s->{host}:$s->{port} --prefix '$prefix: '";
+}
+
+
+#my @binaries = ('sslh-select', 'sslh-fork');
+my @binaries = ('sslh-select');
+
 for my $binary (@binaries) {
     warn "Testing $binary\n";
 
 # Start sslh with the right plumbing
-    my $sslh_pid;
+    my ($sslh_pid, $valgrind);
     if (!($sslh_pid = fork)) {
         my $user = (getpwuid $<)[0]; # Run under current username
-        my $cmd = "./$binary -v -f -u $user --listen localhost:$sslh_port --ssh $ssh_address --ssl $ssl_address -P $pidfile";
-        warn "$cmd\n";
-        #exec $cmd;
-        exec "valgrind --leak-check=full ./$binary -v -f -u $user --listen localhost:$sslh_port --ssh $ssh_address -ssl $ssl_address -P $pidfile";
+        my $cmd = "./$binary -v 4 -f -u $user -F test.cfg";
+        #$valgrind = 1;
+        #$cmd = "valgrind --leak-check=full $cmd";
+        verbose_exec $cmd;
         exit 0;
     }
     warn "spawned $sslh_pid\n";
-    sleep 5;  # valgrind can be heavy -- wait 5 seconds
+    sleep 1; # Give everyone some time to start
+    sleep 5 if $valgrind;  # valgrind can be heavy -- wait 5 seconds
 
 
     my $test_data = "hello world\n";
-#    my $ssl_test_data = (pack 'n', ((length $test_data) + 2)) .  $test_data;
-    my $ssl_test_data = "\x16\x03\x03$test_data\n";
-
-# Test: SSL connection
-    if ($SSL_CNX) {
-        print "***Test: SSL connection\n";
-        my $cnx_l = new IO::Socket::INET(PeerHost => "localhost:$sslh_port");
-        warn "$!\n" unless $cnx_l;
-        if (defined $cnx_l) {
-            print $cnx_l $ssl_test_data;
-            my $data;
-            my $n = sysread $cnx_l, $data, 1024;
-            is($data, "ssl: $ssl_test_data", "SSL connection");
-        }
-    }
+    my $ssl_test_data =  "\x16\x03\x01\x00\xab\x01\x00\x00\xa7\x03\x03\x89\x22\x33\x95\x43\x7a\xc3\x89\x45\x51\x12\x3c\x28\x24\x1b\x6a\x78\xbf\xbe\x95\xd8\x90\x58\xd7\x65\xf7\xbb\x2d\xb2\x8d\xa0\x75\x00\x00\x38\xc0\x2c\xc0\x30\x00\x9f\xcc\xa9\xcc\xa8\xcc\xaa\xc0\x2b\xc0\x2f\x00\x9e\xc0\x24\xc0\x28\x00\x6b\xc0\x23\xc0\x27\x00\x67\xc0\x0a\xc0\x14\x00\x39\xc0\x09\xc0\x13\x00\x33\x00\x9d\x00\x9c\x00\x3d\x00\x3c\x00\x35\x00\x2f\x00\xff\x01\x00\x00\x46\x00\x0b\x00\x04\x03\x00\x01\x02\x00\x0a\x00\x0a\x00\x08\x00\x1d\x00\x17\x00\x19\x00\x18\x00\x23\x00\x00\x00\x0d\x00\x20\x00\x1e\x06\x01\x06\x02\x06\x03\x05\x01\x05\x02\x05\x03\x04\x01\x04\x02\x04\x03\x03\x01\x03\x02\x03\x03\x02\x01\x02\x02\x02\x03\x00\x16\x00\x00\x00\x17\x00\x00hello tls alone";
 
 # Test: Shy SSH connection
     if ($SSH_SHY_CNX) {
@@ -89,42 +236,13 @@ for my $binary (@binaries) {
         my $cnx_h = new IO::Socket::INET(PeerHost => "localhost:$sslh_port");
         warn "$!\n" unless $cnx_h;
         if (defined $cnx_h) {
-            sleep 3;
+            sleep 13;
             print $cnx_h $test_data;
             my $data = <$cnx_h>;
-            is($data, "ssh: $test_data", "Shy SSH connection");
+            my_is($data, "ssh: $test_data", "$binary: Shy SSH connection");
         }
     }
 
-# Test: Bold SSH connection
-    if ($SSH_BOLD_CNX) {
-        print "***Test: Bold SSH connection\n";
-        my $cnx_h = new IO::Socket::INET(PeerHost => "localhost:$sslh_port");
-        warn "$!\n" unless $cnx_h;
-        if (defined $cnx_h) {
-            my $td = "SSH-2.0 testsuite\t$test_data";
-            print $cnx_h $td;
-            my $data = <$cnx_h>;
-            is($data, "ssh: $td", "Bold SSH connection");
-        }
-    }
-
-# Test: PROBE_AGAIN, incomplete first frame
-    if ($SSH_PROBE_AGAIN) {
-        print "***Test: incomplete SSH first frame\n";
-        my $cnx_h = new IO::Socket::INET(PeerHost => "localhost:$sslh_port");
-        warn "$!\n" unless $cnx_h;
-        if (defined $cnx_h) {
-            my $td = "SSH-2.0 testsuite\t$test_data";
-            print $cnx_h substr $td, 0, 2;
-            sleep 1;
-            print $cnx_h substr $td, 2;
-            my $data = <$cnx_h>;
-            is($data, "ssh: $td", "Incomplete first SSH frame");
-        }
-    }
-
-
 # Test: One SSL half-started then one SSH
     if ($SSL_MIX_SSH) {
         print "***Test: One SSL half-started then one SSH\n";
@@ -138,11 +256,11 @@ for my $binary (@binaries) {
                 sleep 3;
                 print $cnx_h $test_data;
                 my $data_h = <$cnx_h>;
-                is($data_h, "ssh: $test_data", "SSH during SSL being established");
+                my_is($data_h, "ssh: $test_data", "$binary: SSH during SSL being established");
             }
             my $data;
             my $n = sysread $cnx_l, $data, 1024;
-            is($data, "ssl: $ssl_test_data", "SSL connection interrupted by SSH");
+            my_is($data, "tls: $ssl_test_data", "$binary: SSL connection interrupted by SSH");
         }
     }
 
@@ -159,62 +277,21 @@ for my $binary (@binaries) {
                 print $cnx_l $ssl_test_data;
                 my $data;
                 my $n = sysread $cnx_l, $data, 1024;
-                is($data, "ssl: $ssl_test_data", "SSL during SSH being established");
+                my_is($data, "tls: $ssl_test_data", "$binary: SSL during SSH being established");
             }
             print $cnx_h $test_data;
             my $data = <$cnx_h>;
-            is($data, "ssh: $test_data", "SSH connection interrupted by SSL");
+            my_is($data, "ssh: $test_data", "$binary: SSH connection interrupted by SSL");
         }
     }
 
 
-# Test: Big messages (careful: don't go over echosrv's buffer limit (1M))
-    if ($BIG_MSG) {
-        print "***Test: big message\n";
-        my $cnx_l = new IO::Socket::INET(PeerHost => "localhost:$sslh_port");
-        warn "$!\n" unless $cnx_l;
-        my $rept = 1000;
-        my $test_data2 = $ssl_test_data . ("helloworld"x$rept);
-        if (defined $cnx_l) {
-            my $n = syswrite $cnx_l, $test_data2;
-            my ($data);
-            $n = sysread $cnx_l, $data, 1 << 20;
-            is($data, "ssl: ". $test_data2, "Big message");
-        }
+    if ($PROBES_NOFRAG) {
+        test_probes(no_frag => 1, binary => $binary);
     }
 
-# Test: Stalled connection
-# Create two connections, stall one, check the other one
-# works, unstall first and check it works fine
-# This test needs fixing.
-# Now that echosrv no longer works on "lines" (finishing
-# with '\n'), it may cut blocks randomly with prefixes.
-# The whole thing needs to be re-thought as it'll only
-# work by chance.
-    if ($STALL_CNX) {
-        print "***Test: Stalled connection\n";
-        my $cnx_1 = new IO::Socket::INET(PeerHost => "localhost:$sslh_port");
-        warn "$!\n" unless defined $cnx_1;
-        my $cnx_2 = new IO::Socket::INET(PeerHost => "localhost:$sslh_port");
-        warn "$!\n" unless defined $cnx_2;
-        my $test_data2 = "helloworld";
-        sleep 4;
-        my $rept = 1000;
-        if (defined $cnx_1 and defined $cnx_2) {
-            print $cnx_1 ($test_data2 x $rept);
-            print $cnx_1 "\n";
-            print $cnx_2 ($test_data2 x $rept);
-            print $cnx_2 "\n";
-            my $data = <$cnx_2>;
-            is($data, "ssh: " . ($test_data2 x $rept) . "\n", "Stalled connection (1)");
-            print $cnx_2 ($test_data2 x $rept);
-            print $cnx_2 "\n";
-            $data = <$cnx_2>;
-            is($data, "ssh: " . ($test_data2 x $rept) . "\n", "Stalled connection (2)");
-            $data = <$cnx_1>;
-            is($data, "ssh: " . ($test_data2 x $rept) . "\n", "Stalled connection (3)");
-
-        }
+    if ($PROBES_AGAIN) {
+        test_probes(binary => $binary);
     }
 
     my $pid = `cat $pidfile`;
@@ -228,8 +305,7 @@ if ($RB_CNX_NOSERVER) {
     print "***Test: Connecting to non-existant server\n";
     my $sslh_pid;
     if (!($sslh_pid = fork)) {
-        my $user = (getpwuid $<)[0]; # Run under current username
-        exec "./sslh-select -v -f -u $user --listen localhost:$sslh_port --ssh localhost:$no_listen --ssl localhost:$no_listen -P $pidfile";
+        exec "./sslh-select -v 3 -f -u $user --listen localhost:$sslh_port --ssh localhost:$no_listen --tls localhost:$no_listen -P $pidfile";
     }
     warn "spawned $sslh_pid\n";
 
@@ -249,19 +325,26 @@ if ($RB_CNX_NOSERVER) {
 }
 
 
+my $ssh_conf = (grep { $_->{name} eq "ssh" } @{$conf->fetch_array("protocols")})[0];
+my $ssh_address = $ssh_conf->{host} . ":" .  $ssh_conf->{port};
+
+# Use the last TLS echoserv (no SNI/ALPN)
+my $ssl_conf = (grep { $_->{name} eq "tls" } @{$conf->fetch_array("protocols")})[-1];
+my $ssl_address = $ssl_conf->{host} . ":" .  $ssl_conf->{port};
+
+
 # Robustness: No hostname in address
 if ($RB_PARAM_NOHOST) {
     print "***Test: No hostname in address\n";
     my $sslh_pid;
     if (!($sslh_pid = fork)) {
-        my $user = (getpwuid $<)[0]; # Run under current username
-        exec "./sslh-select -v -f -u $user --listen $sslh_port --ssh $ssh_address --ssl $ssl_address -P $pidfile";
+        exec "./sslh-select -v 3 -f -u $user --listen $sslh_port --ssh $ssh_address --tls $ssl_address -P $pidfile";
     }
     warn "spawned $sslh_pid\n";
     waitpid $sslh_pid, 0;
     my $code = $? >> 8;
     warn "exited with $code\n";
-    is($code, 1, "Exit status on illegal option");
+    my_is($code, 6, "Exit status on illegal option");
 }
 
 # Robustness: User does not exist
@@ -269,14 +352,13 @@ if ($RB_WRONG_USERNAME) {
     print "***Test: Changing to non-existant username\n";
     my $sslh_pid;
     if (!($sslh_pid = fork)) {
-        my $user = (getpwuid $<)[0]; # Run under current username
-        exec "./sslh-select -v -f -u ${user}_doesnt_exist --listen localhost:$sslh_port --ssh $ssh_address --ssl $ssl_address -P $pidfile";
+        exec "./sslh-select -v 3 -f -u ${user}_doesnt_exist --listen localhost:$no_listen --ssh $ssh_address --tls $ssl_address -P $pidfile";
     }
     warn "spawned $sslh_pid\n";
     waitpid $sslh_pid, 0;
     my $code = $? >> 8;
     warn "exited with $code\n";
-    is($code, 2, "Exit status on non-existant username");
+    my_is($code, 2, "Exit status on non-existant username");
 }
 
 # Robustness: Can't open PID file
@@ -284,15 +366,14 @@ if ($RB_OPEN_PID_FILE) {
     print "***Test: Can't open PID file\n";
     my $sslh_pid;
     if (!($sslh_pid = fork)) {
-        my $user = (getpwuid $<)[0]; # Run under current username
-        exec "./sslh-select -v -f -u $user --listen localhost:$sslh_port --ssh $ssh_address --ssl $ssl_address -P /dont_exist/$pidfile";
+        exec "./sslh-select -v 3 -f -u $user --listen localhost:$no_listen --ssh $ssh_address --tls $ssl_address -P /dont_exist/$pidfile";
         # You don't have a /dont_exist/ directory, do you?!
     }
     warn "spawned $sslh_pid\n";
     waitpid $sslh_pid, 0;
     my $code = $? >> 8;
     warn "exited with $code\n";
-    is($code, 3, "Exit status if can't open PID file");
+    my_is($code, 3, "Exit status if can't open PID file");
 }
 
 # Robustness: Can't resolve address
@@ -301,13 +382,62 @@ if ($RB_RESOLVE_ADDRESS) {
     my $sslh_pid;
     if (!($sslh_pid = fork)) {
         my $user = (getpwuid $<)[0]; # Run under current username
-        exec "./sslh-select -v -f -u $user --listen blahblah.dontexist:9000 --ssh $ssh_address --ssl $ssl_address -P $pidfile";
+        exec "./sslh-select -v 3 -f -u $user --listen blahblah.dontexist:9000 --ssh $ssh_address --tls $ssl_address -P $pidfile";
     }
     warn "spawned $sslh_pid\n";
     waitpid $sslh_pid, 0;
     my $code = $? >> 8;
     warn "exited with $code\n";
-    is($code, 4, "Exit status if can't resolve address");
+    my_is($code, 4, "Exit status if can't resolve address");
+}
+
+# Robustness: verify all command line options work
+if ($RB_CL_PARAMS) {
+    print "***Test: Command line parameters\n";
+    my $sslh_pid;
+    if (!($sslh_pid = fork)) {
+        my $user = (getpwuid $<)[0]; # Run under current username
+        # This doesn't test --inetd
+        exec "./sslh-select -v 3 -f -u $user -P $pidfile".
+        " -n --transparent --timeout 10 -C /tmp".
+        " --syslog-facility auth --on-timeout ssh".
+        " --listen localhost:$no_listen --ssh $ssh_address --tls $ssl_address".
+        " --openvpn localhost:$no_listen".
+        " --tinc localhost:$no_listen".
+        " --xmpp localhost:$no_listen".
+        " --http localhost:$no_listen".
+        " --adb localhost:$no_listen".
+        " --socks5 localhost:$no_listen".
+        " --anyprot localhost:$no_listen";
+        exit 0;
+    }
+    warn "spawned $sslh_pid\n";
+    # It will die soon because $user cannot chroot (you
+    # don't test as root, do you?)
+
+    waitpid $sslh_pid, 0;
+    my $code = $? >> 8;
+    warn "exited with $code\n";
+    my_is($code, 1, "Command line arguments");
+
+
+    print "***Test: Bad command line parameters\n";
+    my $sslh_pid;
+    if (!($sslh_pid = fork)) {
+        my $user = (getpwuid $<)[0]; # Run under current username
+        # This doesn't test --inetd
+        exec "./sslh-select -v 3 -f -u $user -P $pidfile".
+        " -n --transparent --timeout 10 -C /tmp".
+        " --fakeoption".
+        " --anyprot localhost:$no_listen";
+        exit 0;
+    }
+    warn "spawned $sslh_pid\n";
+
+    waitpid $sslh_pid, 0;
+    my $code = $? >> 8;
+    warn "exited with $code\n";
+    my_is($code, 6, "Bad command line parameters");
 }
 
 `lcov --directory . --capture --output-file sslh_cov.info`;
@@ -315,3 +445,17 @@ if ($RB_RESOLVE_ADDRESS) {
 
 `killall echosrv`;
 
+
+format test_results_top =
+ID  | Description                                                       | Status
+----+-------------------------------------------------------------------+-------
+.
+
+format test_results = 
+@>> | @<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< |   @>>
+$_->[0], $_->[1], $_->[2] ? "OK" : "NOK"
+.
+
+format_name STDOUT "test_results";
+format_top_name STDOUT "test_results_top";
+map { write; } @results;

t_load

@@ -14,114 +14,264 @@
 use strict;
 use IO::Socket::INET6;
 use Data::Dumper;
+use Conf::Libconfig;
 
 ## BEGIN TEST CONFIG
 
-# Do we test sslh-select or sslh-fork?
-my $sslh_binary = "./sslh-select";
-
-# How many clients to we start for each protocol?
-my $NUM_CNX = 30;
+# How many total clients to we start? Each client will pick
+# a new protocol among what's in test.cfg.
+my $NUM_CNX = 50;
 
 # Delay between starting new processes when starting up. If
 # you start 200 processes in under a second, things go wrong
 # and it's not sslh's fault (typically the echosrv won't be
 # forking fast enough).
-my $start_time_delay = 1;
-
-# If you test 4 protocols, you'll start $NUM_CNX * 4 clients
-# (e.g. 40), starting one every $start_time_delay seconds.
+my $start_time_delay = .5;
 
 # Max times we repeat the test string: allows to test for
 # large messages.
-my $block_rpt = 4096;
+my $block_rpt = 5;
 
 # Probability to stop a client after a message (e.g. with
 # .01 a client will send an average of 100 messages before
 # disconnecting).
 my $stop_client_probability = .001;
 
-# What protocols we test, and on what ports
-# Just comment out protocols you don't want to use.
-my %protocols = (
-    "ssh" => { address => "localhost:9001", client => client("ssh") },
-    "ssl" => { address => "localhost:9002", client => client("ssl") },
-    "openvpn" => {address => "localhost:9003", client => client("openvpn") },
-    "tinc" => {address => "localhost:9004", client => client("tinc") },
-);
-
 ##END CONFIG
 
+my $conf = new Conf::Libconfig;
+$conf->read_file("test.cfg");
+
+
+# Pick one address for TCP and one for UDP
+my @listen = @{$conf->fetch_array("listen")};
+my ($sslh_tcp_address, $sslh_udp_address);
+
+foreach my $l (@listen) {
+    if ($l->{is_udp}) {
+        $sslh_udp_address //= "$l->{host}:$l->{port}";
+    } else {
+        $sslh_tcp_address //= "$l->{host}:$l->{port}";
+    }
+    last if defined $sslh_tcp_address and defined $sslh_udp_address;
+}
+
+
+# code snippets to connect to each protocol
+my %connect_params = (
+    regex => {
+        is_udp => 1,
+        sleep => 0,
+        test_data => "foo bar",
+        resp_len => 12,
+    },
+        ssh => {
+        sleep => 20,  # So it times out 50% of connections
+        test_data => "SSH-2.0 hello",
+        resp_len => 18,  # length "ssh: SSH-2.0 hello" => 18
+    },
+    tinc => {
+        sleep => 0,
+        test_data => "0 ",
+        resp_len => 8, # length "tinc: 0 " => 10 
+    },
+    openvpn => {
+        sleep => 0,
+        test_data => "\x00\x00",
+        resp_len => 11,  # length "openvpn: \x0\x0" => 11
+    },
+);
+
+sub connect_service {
+    my ($cnx, $service) = @_;
+
+    my $params = $connect_params{$service};
+
+    sleep rand $params->{sleep};
+    my $test_data = $params->{test_data};
+    syswrite $cnx, $test_data;
+    sleep 1;
+    sysread $cnx, my $r, $params->{resp_len}; 
+
+    my $expected = "$service: $test_data";
+    return ($r eq $expected);
+}
 
-# We use ports 9000, 9001 and 9002 -- hope that won't clash
-# with anything...
-my $sslh_address = "localhost:9000";
-my $pidfile = "/tmp/sslh_test.pid";
 
 sub client {
-    my ($service) = @_;
+    my ($protocol, $client_id, $fd_out) = @_;
 
-    return sub {
-        while (1) {
-            my $cnx = new IO::Socket::INET(PeerHost => $sslh_address);
-            my $test_data = "$service testing " x int(rand($block_rpt)+1) . "\n";
+    my $service = $protocol->{name};
 
-            sleep 5 if $service eq "ssh";
-            if ($service eq "openvpn") {
-                syswrite $cnx, "\x00\x0F\x38\n";
-                my $msg;
-                sysread $cnx, $msg, 14; # length "openvpn: \x0\xF\x38\n" => 14
-            }
-            if ($service eq "tinc") {
-                syswrite $cnx, "0 \n";
-                my $msg;
-                sysread $cnx, $msg, 10; # length "tinc: 0 \n" => 10 
-            }
-            while (1) {
-                print $cnx $test_data;
-                my $r = <$cnx>;
-                ($? = 1, die "$service got [$r]\n") if ($r ne "$service: $test_data");
-                last if rand(1) < $stop_client_probability;
-            }
-        }
-        exit 0;
-    }
-}
+    while (1) {
+        my $r;
+        #warn "$client_id: connect $sslh_tcp_address\n";
+        my $cnx = new IO::Socket::INET(PeerHost => $sslh_tcp_address);
+        die "$@\n" if (!$cnx);
 
-foreach my $p (keys %protocols) {
-    if (!fork) {
-        exec "./echosrv --listen $protocols{$p}->{address} --prefix '$p: '";
-    }
-}
+        my $cnt = 0;
 
-# Start sslh with the right plumbing
-my $sslh_pid;
-if (!($sslh_pid = fork)) {
-    my $user = (getpwuid $<)[0]; # Run under current username
-    my $prots = join " ", map "--$_ $protocols{$_}->{address}", keys %protocols;
-    my $cmd = "$sslh_binary -f -t 3 -u $user --listen $sslh_address $prots -P $pidfile";
-    print "$cmd\n";
-    exec $cmd;
-    exit 0;
-}
-warn "spawned $sslh_pid\n";
-sleep 2;  # valgrind can be heavy -- wait 5 seconds
+        #warn "$client_id: connecting $service\n";
 
-
-for (1 .. $NUM_CNX) {
-    foreach my $p (keys %protocols) {
-        if (!fork) {
-            warn "starting $p\n";
-            &{$protocols{$p}->{client}};
+        if (not connect_service($cnx, $service)) {
+            print $fd_out "$client_id\t0\tC\n";
+            warn "$client_id: connecting failed\n";
             exit;
         }
-        # Give a little time so we don't overrun the
-        # listen(2) backlog.
-        select undef, undef, undef, $start_time_delay;
+
+        #warn "$client_id: shoveling $service\n";
+
+        while (1) {
+            my $test_data = "$service $cnt" x int(rand($block_rpt)+1) . "\n";
+            print $cnx $test_data;
+            $r = <$cnx>;
+            my $expected= "$test_data";
+            my $r_l = length $r;
+            my $e_l = length $expected;
+            $fd_out->autoflush;
+            my $error = "";
+            $error = "E" if $r ne $expected;
+            print $fd_out ("$client_id\t$r_l\t$error\n");
+            ($? = 1, die "$service got [$r] expected [$expected]\n") if ($r ne $expected);
+            if (rand(1) < $stop_client_probability) {
+                print $fd_out ("$client_id\t$r_l\tD\n");
+                last;
+            }
+            $cnt++;
+        }
+    }
+    exit 0;
+}
+
+# For now, a simple regex client
+sub udp_client {
+    my ($protocol, $client_id, $fd_out) = @_;
+
+    warn "UDP client starts\n";
+
+    while (1) {
+        my $cnx = new IO::Socket::INET(Proto => 'udp', PeerHost => $sslh_udp_address);
+        #        my $cnx; socket $cnx, PF_INET, SOCK_DGRAM, 0 or die "socket: $!\n";
+        die "$@\n" if (!$cnx);
+        my $cnt = 0;
+
+        while (1) {
+            my $test_data = "foo udp $cnt"x int(rand($block_rpt)+1). "\n";
+
+            my $ipaddr   = inet_aton("localhost");
+            my $portaddr = sockaddr_in(8086, $ipaddr);
+            my $res = send($cnx, $test_data, 0, $portaddr);
+            if ($res != length($test_data)) {
+                die "cannot sendto: $!";
+            }
+
+            my $expected= "$protocol->{name}: $test_data";
+
+            my $r;
+            defined(recv($cnx, $r, length $expected, 0)) or die "recv: $!\n";
+
+            my $r_l = length $r;
+            my $e_l = length $expected;
+            $fd_out->autoflush;
+            my $error = "";
+            $error = "M" if $r ne $expected;
+            print $fd_out ("$client_id\t$r_l\t$error\n");
+            ($? = 1, die "udp got [$r] expected [$expected]\n") if ($r ne $expected);
+            if (rand(1) < $stop_client_probability) {
+                print $fd_out ("$client_id\t$r_l\tD\n");
+                last;
+            }
+            $cnt++;
+        }
     }
 }
 
+foreach my $p (@{$conf->fetch_array("protocols")}) {
+    if (!fork) {
+        my $udp = $p->{is_udp} ? "--udp" : "";
+        my $cmd = "./echosrv $udp -p $p->{host}:$p->{port} --prefix '$p->{name}: ' 2> /dev/null";
+        warn "$cmd\n";
+        exec $cmd;
+        exit;
+    }
+}
+
+warn "Don't forget to run sslh -F test.cfg!\n";
+
+sleep 2; # Let echosrv's and sslh start
+
+my ($c_in, $c_out);
+pipe $c_in, $c_out;
+
+my @protocols = @{$conf->fetch_array("protocols")};
+
+if (!fork) {
+    # Process that starts all the clients
+    for my $client_num (1 .. $NUM_CNX) {
+            if (!fork) {
+                my @supported_protocols = keys %connect_params;
+                my $p_name = $supported_protocols[rand @supported_protocols];
+                my @p = grep { $_->{name} eq $p_name } @protocols;
+                my $p = shift @p;
+                if ($p->{is_udp}) {
+                    udp_client($p, "$p->{name}$client_num", $c_out);
+                } else {
+                    client($p, "$p->{name}$client_num", $c_out);
+                }
+                exit;
+            }
+            # Give a little time so we don't overrun the
+            # listen(2) backlog.
+            select undef, undef, undef, $start_time_delay;
+    }
+    exit;
+} else {
+    my %data;
+
+    # The condition here selects between pretty output or
+    # raw output
+    if (1) {
+        my $CLEAR_LINE = "\033[2K";
+        my $CURSOR_HOME = "\033[1;1H";
+        my $CLEAR_SCREEN = "\033[2J";
+
+        # Process that retrieves client output to pretty print
+        print $CLEAR_SCREEN; # Clear screen
+        while (<$c_in>) {
+            chop;
+            my ($client_id, $r_l, $error, @rest) = split /\t/, $_;
+
+            $data{$client_id} = [ 0, ""] if not exists $data{$client_id};
+            my ($curr_rcv) = ${$data{$client_id}}[0] + $r_l;;
+            $error //= "";
+            my ($curr_error) = "${$data{$client_id}}[1]$error";
+            # Consolidate into... roman numerals!
+            $curr_error =~ s/D{10}/X/;
+            $curr_error =~ s/X{10}/C/;
+            $curr_error =~ s/C{10}/M/;
+
+            $data{$client_id} = [ $r_l + $curr_rcv, "$curr_error$error" ];
+
+
+            $client_id =~ /(\d+)/;
+            my $i = $1;
+            #            print $CURSOR_HOME;
+            print "\033[$i;1H$CLEAR_LINE$client_id\t$curr_rcv\t$curr_error\n";
+            #foreach my $i (sort keys %data) {
+            #    ($r_l, $error) = @{$data{$i}};
+            #    print "$CLEAR_LINE$i\t$r_l\t$error\n"; 
+        }
+    } else {
+        # Just print the client outputs
+        while (<$c_in>) {
+            print;
+        }
+    }
+}
+
+warn "waiting\n";
 wait;
+warn "finished waiting\n";
 
 
 `killall echosrv`;

test.cfg

@@ -0,0 +1,59 @@
+# Configuration file for testing (use both by sslh under
+# test and the test script `t`)
+
+verbose: 4;
+foreground: true;
+inetd: false;
+numeric: true;
+transparent: false;
+timeout: 10;   # Probe test writes slowly
+pidfile: "/tmp/sslh_test.pid";
+
+syslog_facility: "auth"; 
+
+
+# List of interfaces on which we should listen
+# Options:
+listen:
+(
+    { host: "localhost"; port: "8080"; keepalive: true; },
+    { host: "localhost"; port: "8081"; keepalive: true; },
+    { host: "ip4-localhost"; is_udp: true; port: "8086"; }
+);
+
+ 
+protocols:
+(
+     { name: "ssh";  host: "localhost"; port: "9000"; fork: true; transparent: true; },
+     { name: "socks5";  host: "localhost"; port: "9001";  },
+     { name: "http";  host: "localhost"; port: "9002";  },
+     { name: "tinc";  host: "localhost"; port: "9003"; },
+     { name: "openvpn";  host: "localhost"; port: "9004"; },
+     { name: "xmpp";  host: "localhost"; port: "9009"; },
+     { name: "adb";  host: "localhost"; port: "9010"; },
+     { name: "syslog"; host: "localhost"; port: "9013"; },
+     { name: "regex"; host: "ip4-localhost"; is_udp: true; port: "9020";
+         udp_timeout: 30;
+         regex_patterns: [ "^foo" ];
+     },
+     { name: "regex"; host: "localhost"; port: "9011";
+        regex_patterns: [ "^foo", "^bar" ];
+        minlength: 4; 
+        test_patterns: (    # this is used by the test script, not by sslh
+            { pattern: "foo"; result: "ssh"; },  # After timeout
+            { pattern: "fooo"; result: "regex"; },
+            { pattern: "bar"; result: "ssh"; },
+            { pattern: "barr"; result: "regex"; },
+            { pattern: "barrrr"; result: "regex"; }
+        );
+     },
+     { name: "tls"; host: "localhost"; port: "9021"; alpn_protocols: [ "alpn1", "alpn2" ]; sni_hostnames: [ "sni1" ]; },
+     { name: "tls"; host: "localhost"; port: "9022"; alpn_protocols: [ "alpn1", "alpn2" ]; sni_hostnames: [ "sni2", "sni3" ]; },
+     { name: "tls"; host: "localhost"; port: "9023"; alpn_protocols: [ "alpn3" ]; },
+     { name: "tls"; host: "localhost"; port: "9024"; sni_hostnames: [ "sni3" ]; },
+     { name: "tls"; host: "localhost"; port: "9025"; },
+     { name: "anyprot";  host: "localhost"; port: "9099";  }
+);
+
+on_timeout: "ssh";
+

tls.c

@@ -32,6 +32,7 @@
 #include <stdlib.h> /* malloc() */
 #include <fnmatch.h> /* fnmatch() */
 #include "tls.h"
+#include "sslh-conf.h"
 
 #define TLS_HEADER_LEN 5
 #define TLS_HANDSHAKE_CONTENT_TYPE 0x16
@@ -41,28 +42,31 @@
 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
 #endif
 
+typedef struct {
+    int tls_match_sni : 1;
+    int tls_match_alpn : 1;
+} TLS_MATCHMODE;
 
 struct TLSProtocol {
-    int use_alpn;
-    char** sni_hostname_list;
-    char** alpn_protocol_list;
+    TLS_MATCHMODE match_mode;
+    int sni_list_len;
+    const char** sni_hostname_list;
+    int alpn_list_len;
+    const char** alpn_protocol_list;
 };
 
 static int parse_extensions(const struct TLSProtocol *, const char *, size_t);
 static int parse_server_name_extension(const struct TLSProtocol *, const char *, size_t);
 static int parse_alpn_extension(const struct TLSProtocol *, const char *, size_t);
-static int has_match(char**, const char*, size_t);
+static int has_match(const char**, size_t, const char*, size_t);
 
 /* Parse a TLS packet for the Server Name Indication and ALPN extension in the client
  * hello handshake, returning a status code
  *
  * Returns:
- *  >=0  - length of the hostname and updates *hostname
- *         caller is responsible for freeing *hostname
- *  -1   - Incomplete request
- *  -2   - No Host header included in this request
- *  -3   - Invalid hostname pointer
- *  < -4 - Invalid TLS client hello
+ * 0: no match
+ * 1: match
+ *  < 0:  error code (see tls.h)
  */
 int
 parse_tls_header(const struct TLSProtocol *tls_data, const char *data, size_t data_len) {
@@ -74,21 +78,21 @@ parse_tls_header(const struct TLSProtocol *tls_data, const char *data, size_t da
 
     /* Check that our TCP payload is at least large enough for a TLS header */
     if (data_len < TLS_HEADER_LEN)
-        return -1;
+        return TLS_ELENGTH;
 
     tls_content_type = data[0];
     if (tls_content_type != TLS_HANDSHAKE_CONTENT_TYPE) {
-        if (verbose) fprintf(stderr, "Request did not begin with TLS handshake.\n");
-        return -5;
+        if (cfg.verbose) fprintf(stderr, "Request did not begin with TLS handshake.\n");
+        return TLS_EPROTOCOL;
     }
 
     tls_version_major = data[1];
     tls_version_minor = data[2];
     if (tls_version_major < 3) {
-        if (verbose) fprintf(stderr, "Received SSL %d.%d handshake which cannot be parsed.\n",
+        if (cfg.verbose) fprintf(stderr, "Received SSL %d.%d handshake which cannot be parsed.\n",
               tls_version_major, tls_version_minor);
 
-        return -2;
+        return TLS_EVERSION;
     }
 
     /* TLS record length */
@@ -98,18 +102,18 @@ parse_tls_header(const struct TLSProtocol *tls_data, const char *data, size_t da
 
     /* Check we received entire TLS record length */
     if (data_len < len)
-        return -1;
+        return TLS_ELENGTH;
 
     /*
      * Handshake
      */
     if (pos + 1 > data_len) {
-        return -5;
+        return TLS_EPROTOCOL;
     }
     if (data[pos] != TLS_HANDSHAKE_TYPE_CLIENT_HELLO) {
-        if (verbose) fprintf(stderr, "Not a client hello\n");
+        if (cfg.verbose) fprintf(stderr, "Not a client hello\n");
 
-        return -5;
+        return TLS_EPROTOCOL;
     }
 
     /* Skip past fixed length records:
@@ -123,46 +127,54 @@ parse_tls_header(const struct TLSProtocol *tls_data, const char *data, size_t da
 
     /* Session ID */
     if (pos + 1 > data_len)
-        return -5;
+        return TLS_EPROTOCOL;
     len = (unsigned char)data[pos];
     pos += 1 + len;
 
     /* Cipher Suites */
     if (pos + 2 > data_len)
-        return -5;
+        return TLS_EPROTOCOL;
     len = ((unsigned char)data[pos] << 8) + (unsigned char)data[pos + 1];
     pos += 2 + len;
 
     /* Compression Methods */
     if (pos + 1 > data_len)
-        return -5;
+        return TLS_EPROTOCOL;
     len = (unsigned char)data[pos];
     pos += 1 + len;
 
     if (pos == data_len && tls_version_major == 3 && tls_version_minor == 0) {
-        if (verbose) fprintf(stderr, "Received SSL 3.0 handshake without extensions\n");
-        return -2;
+        if (cfg.verbose) fprintf(stderr, "Received SSL 3.0 handshake without extensions\n");
+        return TLS_EVERSION;
     }
 
     /* Extensions */
     if (pos + 2 > data_len)
-        return -5;
+        return TLS_EPROTOCOL;
     len = ((unsigned char)data[pos] << 8) + (unsigned char)data[pos + 1];
     pos += 2;
 
     if (pos + len > data_len)
-        return -5;
-    return parse_extensions(tls_data, data + pos, len);
+        return TLS_EPROTOCOL;
+
+    /* By now we know it's TLS. if SNI or ALPN is set, parse extensions to see if
+     * they match. Otherwise, it's a match already */
+    if (tls_data && 
+        (tls_data->match_mode.tls_match_alpn || tls_data->match_mode.tls_match_sni)) {
+        return parse_extensions(tls_data, data + pos, len);
+    } else {
+        return TLS_MATCH;
+    }
 }
 
 static int
 parse_extensions(const struct TLSProtocol *tls_data, const char *data, size_t data_len) {
     size_t pos = 0;
     size_t len;
-    int last_matched = 0;
+    int sni_match = 0, alpn_match = 0;
 
     if (tls_data == NULL)
-        return -3;
+        return TLS_EINVAL;
 
     /* Parse each 4 bytes for the extension header */
     while (pos + 4 <= data_len) {
@@ -171,54 +183,17 @@ parse_extensions(const struct TLSProtocol *tls_data, const char *data, size_t da
               (unsigned char) data[pos + 3];
 
         if (pos + 4 + len > data_len)
-            return -5;
+            return TLS_EPROTOCOL;
 
         size_t extension_type = ((unsigned char) data[pos] << 8) +
                                 (unsigned char) data[pos + 1];
 
-
-        /* Check if it's a server name extension */
-        /* There can be only one extension of each type, so we break
-           our state and move pos to beginning of the extension here */
-        if (tls_data->use_alpn == 2) {
-            /* we want BOTH alpn and sni to match */
-            if (extension_type == 0x00) { /* Server Name */
-                if (parse_server_name_extension(tls_data, data + pos + 4, len)) {
-                    /* SNI matched */
-                    if(last_matched) {
-                        /* this is only true if ALPN matched, so return true */
-                        return last_matched;
-                    } else {
-                        /* otherwise store that SNI matched */
-                        last_matched = 1;
-                    }
-                } else {
-                    /* both can't match */
-                    return -2;
-                }
-            } else if (extension_type == 0x10) { /* ALPN */
-                if (parse_alpn_extension(tls_data, data + pos + 4, len)) {
-                    /* ALPN matched */
-                    if(last_matched) {
-                        /* this is only true if SNI matched, so return true */
-                        return last_matched;
-                    } else {
-                        /* otherwise store that ALPN matched */
-                        last_matched = 1;
-                    }
-                } else {
-                    /* both can't match */
-                    return -2;
-                }
-            }
-
-        } else if (extension_type == 0x00 && tls_data->use_alpn == 0) { /* Server Name */
-            return parse_server_name_extension(tls_data, data + pos + 4, len);
-        } else if (extension_type == 0x10 && tls_data->use_alpn == 1) { /* ALPN */
-            if (parse_alpn_extension(tls_data, data + pos + 4, len) > 0) {
-                return 1;
-            }
-            return parse_alpn_extension(tls_data, data + pos + 4, len);
+        if (extension_type == 0x00 && tls_data->match_mode.tls_match_sni) { /* Server Name */
+            sni_match = parse_server_name_extension(tls_data, data + pos + 4, len);
+            if (sni_match < 0) return sni_match;
+        } else if (extension_type == 0x10 && tls_data->match_mode.tls_match_alpn) { /* ALPN */
+            alpn_match = parse_alpn_extension(tls_data, data + pos + 4, len);
+            if (alpn_match < 0) return alpn_match;
         }
 
         pos += 4 + len; /* Advance to the next extension header */
@@ -226,9 +201,11 @@ parse_extensions(const struct TLSProtocol *tls_data, const char *data, size_t da
 
     /* Check we ended where we expected to */
     if (pos != data_len)
-        return -5;
+        return TLS_EPROTOCOL;
 
-    return -2;
+    return (sni_match && alpn_match) 
+        || (!tls_data->match_mode.tls_match_sni && alpn_match)
+        || (!tls_data->match_mode.tls_match_alpn && sni_match);
 }
 
 static int
@@ -241,26 +218,26 @@ parse_server_name_extension(const struct TLSProtocol *tls_data, const char *data
               (unsigned char)data[pos + 2];
 
         if (pos + 3 + len > data_len)
-            return -5;
+            return TLS_EPROTOCOL;
 
         switch (data[pos]) { /* name type */
             case 0x00: /* host_name */
-                if(has_match(tls_data->sni_hostname_list, data + pos + 3, len)) {
+                if(has_match(tls_data->sni_hostname_list, tls_data->sni_list_len, data + pos + 3, len)) {
                     return len;
                 } else {
-                    return -2;
+                    return TLS_ENOEXT;
                 }
             default:
-                if (verbose) fprintf(stderr, "Unknown server name extension name type: %d\n",
+                if (cfg.verbose) fprintf(stderr, "Unknown server name extension name type: %d\n",
                       data[pos]);
         }
         pos += 3 + len;
     }
     /* Check we ended where we expected to */
     if (pos != data_len)
-        return -5;
+        return TLS_EPROTOCOL;
 
-    return -2;
+    return TLS_ENOEXT;
 }
 
 static int
@@ -272,31 +249,34 @@ parse_alpn_extension(const struct TLSProtocol *tls_data, const char *data, size_
         len = (unsigned char)data[pos];
 
         if (pos + 1 + len > data_len)
-            return -5;
+            return TLS_EPROTOCOL;
 
-        if (len > 0 && has_match(tls_data->alpn_protocol_list, data + pos + 1, len)) {
+        if (len > 0 && has_match(tls_data->alpn_protocol_list, tls_data->alpn_list_len, data + pos + 1, len)) {
             return len;
         } else if (len > 0) {
-            if (verbose) fprintf(stderr, "Unknown ALPN name: %.*s\n", (int)len, data + pos + 1);
+            if (cfg.verbose) fprintf(stderr, "Unknown ALPN name: %.*s\n", (int)len, data + pos + 1);
         }
         pos += 1 + len;
     }
     /* Check we ended where we expected to */
     if (pos != data_len)
-        return -5;
+        return TLS_EPROTOCOL;
 
-    return -2;
+    return TLS_ENOEXT;
 }
 
 static int
-has_match(char** list, const char* name, size_t name_len) {
-    char **item;
+has_match(const char** list, size_t list_len, const char* name, size_t name_len) {
+    const char **item;
+    int i;
     char *name_nullterminated = malloc(name_len+1);
+    CHECK_ALLOC(name_nullterminated, "malloc");
     memcpy(name_nullterminated, name, name_len);
     name_nullterminated[name_len]='\0';
 
-    for (item = list; *item; item++) {
-        if (verbose) fprintf(stderr, "matching [%.*s] with [%s]\n", (int)name_len, name, *item);
+    for (i = 0; i < list_len; i++) {
+        item = &list[i];
+        if (cfg.verbose) fprintf(stderr, "matching [%.*s] with [%s]\n", (int)name_len, name, *item);
         if(!fnmatch(*item, name_nullterminated, 0)) {
             free(name_nullterminated);
             return 1;
@@ -309,27 +289,23 @@ has_match(char** list, const char* name, size_t name_len) {
 struct TLSProtocol *
 new_tls_data() {
     struct TLSProtocol *tls_data = malloc(sizeof(struct TLSProtocol));
-    if (tls_data != NULL) {
-        tls_data->use_alpn = -1;
-    }
+    CHECK_ALLOC(tls_data, "malloc");
+
+    memset(tls_data, 0, sizeof(*tls_data));
 
     return tls_data;
 }
 
 struct TLSProtocol *
-tls_data_set_list(struct TLSProtocol *tls_data, int alpn, char** list) {
+tls_data_set_list(struct TLSProtocol *tls_data, int alpn, const char** list, size_t list_len) {
     if (alpn) {
         tls_data->alpn_protocol_list = list;
-        if(tls_data->use_alpn == 0)
-            tls_data->use_alpn = 2;
-        else
-            tls_data->use_alpn = 1;
+        tls_data->alpn_list_len = list_len;
+        tls_data->match_mode.tls_match_alpn = 1;
     } else {
         tls_data->sni_hostname_list = list;
-        if(tls_data->use_alpn == 1)
-            tls_data->use_alpn = 2;
-        else
-            tls_data->use_alpn = 0;
+        tls_data->sni_list_len = list_len;
+        tls_data->match_mode.tls_match_sni = 1;
     }
 
     return tls_data;

tls.h

@@ -33,6 +33,16 @@ struct TLSProtocol;
 int parse_tls_header(const struct TLSProtocol *tls_data, const char *data, size_t data_len);
 
 struct TLSProtocol *new_tls_data();
-struct TLSProtocol *tls_data_set_list(struct TLSProtocol *, int, char**);
+struct TLSProtocol *tls_data_set_list(struct TLSProtocol *, int, const char**, size_t);
+
+#define TLS_MATCH       1
+#define TLS_NOMATCH     0
+
+#define TLS_EINVAL      -1 /* Invalid parameter (NULL data pointer) */
+#define TLS_ELENGTH     -2 /* Incomplete request */
+#define TLS_EVERSION    -3 /* TLS version that cannot be parsed */
+#define TLS_ENOEXT      -4 /* No ALPN or SNI extension found */
+#define TLS_EPROTOCOL   -5 /* Protocol error */
+
 
 #endif

udp-listener.c

@@ -0,0 +1,138 @@
+/*
+   udp-listener.c: handles demultplexing UDP protocols
+
+# Copyright (C) 2020-2021  Yves Rutschle
+# 
+# This program is free software; you can redistribute it
+# and/or modify it under the terms of the GNU General Public
+# License as published by the Free Software Foundation; either
+# version 2 of the License, or (at your option) any later
+# version.
+# 
+# This program is distributed in the hope that it will be
+# useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+# PURPOSE.  See the GNU General Public License for more
+# details.
+# 
+# The full text for the General Public License is here:
+# http://www.gnu.org/licenses/gpl.html
+
+*/
+
+#include "common.h"
+#include "probe.h"
+#include "sslh-conf.h"
+#include "udp-listener.h"
+
+
+/* Find if the specified source has been seen before. -1 if not found
+ *
+ * TODO This is linear search and needs to be changed to something better for
+ * production if we have more than a dozen sources
+ * Also, this assumes src_addr from recvfrom() are repeatable for a specific
+ * source...
+ * */
+static int known_source(cnx_collection* collection, int max_fd, struct sockaddr* addr, socklen_t addrlen)
+{
+    int i;
+
+    for (i = 0; i < max_fd; i++) {
+        struct connection* cnx = collection_get_cnx_from_fd(collection, i);
+        if (cnx && (cnx->type == SOCK_DGRAM) && cnx->target_sock) {
+            if (!memcmp(&cnx->client_addr, addr, addrlen)) {
+                return i;
+            }
+        }
+    }
+    return -1;
+}
+
+/* Process UDP coming from outside (client towards server)
+ * If it's a new source, probe; otherwise, forward to previous target 
+ * Returns: >= 0 sockfd of newly allocated socket, for new connections
+ * -1 otherwise
+ * */
+int udp_c2s_forward(int sockfd, cnx_collection* collection, int max_fd)
+{
+    char addr_str[NI_MAXHOST+1+NI_MAXSERV+1];
+    struct sockaddr src_addr;
+    struct addrinfo addrinfo;
+    struct sslhcfg_protocols_item* proto;
+    struct connection* cnx;
+    ssize_t len;
+    socklen_t addrlen;
+    int res, target, out = -1;
+    char data[65536]; /* Theoritical max is 65507 (https://en.wikipedia.org/wiki/User_Datagram_Protocol).
+                         This will do.  Dynamic allocation is possible with the MSG_PEEK flag in recvfrom(2), but that'd imply
+                         malloc/free overhead for each packet, when really 64K is not that much */
+
+    addrlen = sizeof(src_addr);
+    len = recvfrom(sockfd, data, sizeof(data), 0, &src_addr, &addrlen);
+    if (len < 0) {
+        perror("recvfrom");
+        return -1;
+    }
+    target = known_source(collection, max_fd, &src_addr, addrlen);
+    addrinfo.ai_addr = &src_addr;
+    addrinfo.ai_addrlen = addrlen;
+    if (cfg.verbose) 
+        fprintf(stderr, "received %ld UDP from %d:%s\n", len, target, sprintaddr(addr_str, sizeof(addr_str), &addrinfo));
+
+    if (target == -1) {
+        res = probe_buffer(data, len, &proto);
+        /* First version: if we can't work out the protocol from the first
+         * packet, drop it. Conceivably, we could store several packets to
+         * run probes on packet sets */
+        if (cfg.verbose) fprintf(stderr, "UDP probed: %d\n", res);
+        if (res != PROBE_MATCH) {
+            return -1;
+        }
+
+        out = socket(proto->saddr->ai_family, SOCK_DGRAM, 0);
+        struct connection* cnx = collection_alloc_cnx_from_fd(collection, out);
+        if (!cnx) return -1;
+        target = out;
+        cnx->target_sock = out;
+        cnx->proto = proto;
+        cnx->type = SOCK_DGRAM;
+        cnx->client_addr = src_addr;
+        cnx->addrlen = addrlen;
+        cnx->local_endpoint = sockfd;
+    }
+    cnx = collection_get_cnx_from_fd(collection, target);
+
+    /* at this point src is the UDP connection */
+    res = sendto(cnx->target_sock, data, len, 0,
+                 cnx->proto->saddr->ai_addr, cnx->proto->saddr->ai_addrlen);
+    cnx->last_active = time(NULL);
+    fprintf(stderr, "sending %d to %s\n", 
+            res, sprintaddr(data, sizeof(data), cnx->proto->saddr));
+    return out;
+}
+
+
+void udp_s2c_forward(struct connection* cnx)
+{
+    int sockfd = cnx->target_sock;
+    char data[65536];
+    int res;
+
+    res = recvfrom(sockfd, data, sizeof(data), 0, NULL, NULL);
+    fprintf(stderr, "recvfrom %d\n", res);
+    CHECK_RES_DIE(res, "udp_listener/recvfrom");
+    res = sendto(cnx->local_endpoint, data, res, 0,
+                 &cnx->client_addr, cnx->addrlen);
+    cnx->last_active = time(NULL);
+    fprintf(stderr, "sendto %d to\n", res);
+}
+
+
+/* returns date at which this socket times out. */
+int udp_timeout(struct connection* cnx)
+{
+    if (cnx->type != SOCK_DGRAM) return 0; /* Not a UDP connection */
+
+    return cnx->proto->udp_timeout + cnx->last_active;
+}
+

udp-listener.h

@@ -0,0 +1,28 @@
+#ifndef UDPLISTENER_H
+#define UDPLISTENER_H
+
+#include "collection.h"
+
+/* UDP listener: upon incoming packet, find where it should go
+ * This is run in its own process and never returns.
+ */
+void udp_listener(struct listen_endpoint* endpoint, int num_endpoints, int active_endpoint);
+
+
+/* Process UDP coming from outside (client towards server)
+ * If it's a new source, probe; otherwise, forward to previous target 
+ * Returns: >= 0 sockfd of newly allocated socket, for new connections
+ * -1 otherwise
+ * */
+int udp_c2s_forward(int sockfd, cnx_collection* collection, int max_fd);
+
+/* Process UDP coming from inside (server towards client) */
+void udp_s2c_forward(struct connection* cnx);
+
+
+/* returns how many seconds before socket times out. Negative if timed out
+ * already.
+ */
+int udp_timeout(struct connection* cnx);
+
+#endif /* UDPLISTENER_H */

udp.cfg

@@ -0,0 +1,31 @@
+# Example for UDP protocols
+
+# Listen sockets get a `is_udp : true` option
+# Protocol entries work exactly the same as TCP, there is no
+# difference. Currently, if mix up TCP and UDP probes, sslh will
+# try them in order and forward a UDP packet to a TCP probe
+# that matches (but using UDP; meaning, sslh will happily
+# forward a UDP packet to udp:localhost:80 if the HTTP
+# probe is specified, and matches)
+
+verbose: 3;
+foreground: true;
+inetd: false;
+numeric: false;
+transparent: false;
+timeout: 10;
+pidfile: "/tmp/sslh_test.pid";
+
+
+# List of interfaces on which we should listen
+# Options:
+listen: (
+    { host: "localhost"; is_udp: true; port: "4443"; }
+);
+
+ 
+protocols:
+(
+     { name: "regex"; regex_patterns: [ "rutschle.net" ]; host: "ns1.rutschle.net"; port: "53"; },
+     { name: "anyprot";  host: "localhost"; port: "9099";  }
+);