Update README.md (#431)

Updated tproxy.md location

.github/workflows/container-build.yaml

@@ -0,0 +1,63 @@
+name: Create and publish Container image
+
+on:
+  push:
+    branches:
+      - master
+    tags:
+      - 'v*'
+  pull_request:
+    branches:
+      - master
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  build-and-push-image:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v2
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v2
+
+      - name: Login to Container registry
+        uses: docker/login-action@v2
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v4
+        with:
+          images: |
+            ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          tags: |
+            type=ref,event=branch
+            type=ref,event=pr
+            type=edge
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}}
+
+      - name: Build and push
+        uses: docker/build-push-action@v4
+        with:
+          platforms: linux/amd64,linux/386,linux/arm64,linux/arm/v6,linux/arm/v7
+          context: .
+          file: Dockerfile
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

.gitignore

@@ -3,8 +3,10 @@
 *.o
 cscope.*
 echosrv
+libsslh.a
 sslh-fork
 sslh-select
+sslh-ev
 sslh.8.gz
 tags
 version.h

ChangeLog

@@ -1,3 +1,48 @@
+v2.1.0:
+	Support for the Landlock LSM. After initial setup,
+	sslh gives up all local file access rights.
+
+	Reintroduced --ssl as an alias to --tls.
+
+	Introduce autoconf to adapt to landlock presence.
+
+	Close connexion without error message if remote
+	client forcefully closes connexion, for Windows.
+
+v2.0.1:	
+	Fix resolve_on_forward setting, which would crash
+	sslh reliably.
+
+v2.0.0:
+v2.0:
+	New sslh-ev: this is functionally equivalent to
+	sslh-select (mono-process, only forks for specified
+	protocols), but based on libev, which should make it
+	scalable to large numbers of connections.
+
+	New log system: instead of --verbose with arbitrary
+	levels, there are now several message classes. Each
+	message class can be set to go to stderr, syslog, or
+	both. Classes are documented in example.cfg.
+
+	UDP connections are now managed in a hash to avoid
+	linear searches. The downside is that the number of
+	UDP connections is a hard limit, configurable with
+	the 'udp_max_connections', which defaults to 1024.
+	Timeouts are managed with lists.
+
+	inetd merges stderr output to what is sent to the
+	client, which is a security issue as it might give
+	information to an attacker. When inetd is activated,
+	stderr is forcibly closed.
+
+	New protocol-level option `resolve_on_forward`,
+	requests that target names are resolved at each
+	connection instead of at startup. Useful for dynamic
+	DNS situations. (Paul Schroeder/milkpirate)
+
+	New probe for MSRDP (akappner).
+
 v1.22: 17AUG2021
 	sslh-select now supports UDP protocols.
 	Probes specified in the `protocols`
@@ -12,7 +57,7 @@ v1.22: 17AUG2021
 	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'.
+	means explicitly 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.
@@ -54,7 +99,7 @@ v1.21: 11JUL2020
 
 	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.
+	listening socket, if all client protocols support it.
 	(Craig Andrews)
 
 	Added 'minlength' option to skip a probe if less
@@ -80,8 +125,8 @@ v1.20: 20NOV2018
 	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 
+	requires a lot of data (i.e. return PROBE_AGAIN for
+	a long time) could prevent successful matches from 
 	subsequent probes. The configuration file needed to
 	take that into account.
 
@@ -142,7 +187,7 @@ v1.18:	29MAR2016
 v1.17: 	09MAR2015
 	Support RFC5952-style IPv6 addresses, e.g. [::]:443.
 
-	Transparant proxy support for FreeBSD.
+	Transparent proxy support for FreeBSD.
 	(Ruben van Staveren)
 
 	Using -F with no argument will try
@@ -171,7 +216,7 @@ v1.16:	11FEB2014
 
 	Libcap support: Keep only CAP_NET_ADMIN if started
 	as root with transparent proxying and dropping
-	priviledges (enable USELIBCAP in Makefile). This
+	privileges (enable USELIBCAP in Makefile). This
 	avoids having to mess with filesystem capabilities.
 	(Sebastian Schmidt/yath)
 
@@ -180,7 +225,7 @@ v1.16:	11FEB2014
 	actual errors if connections are dropped before
 	getting to getpeername).
 
-	Set IP_FREEDBIND if available to bind to addresses
+	Set IP_FREEBIND if available to bind to addresses
 	that don't yet exist.
 
 v1.15:	27JUL2013
@@ -265,7 +310,7 @@ v1.11: 21APR2012
 	--user isn't specified, just run as current user.
 
 	No longer create PID file by default, it should be
-	explicitely set with --pidfile.
+	explicitly set with --pidfile.
 
 	No longer log to syslog if in foreground. Logs are
 	instead output to stderr.
@@ -356,7 +401,7 @@ v1.8: 15JUL2011
 v1.7: 01FEB2010
 	Added CentOS init.d script (Andre Krajnik).
 
-	Fixed default ssl address inconsistancy, now
+	Fixed default ssl address inconsistency, now
 	defaults to "localhost:443" and fixed documentation
 	accordingly (pointed by Markus Schalke).
 

Dockerfile

@@ -1,23 +1,38 @@
-FROM alpine:latest as build
+ARG ALPINE_VERSION="latest"
+ARG TARGET_ARCH="library"
 
-ADD . /sslh
+FROM docker.io/${TARGET_ARCH}/alpine:${ALPINE_VERSION} AS build
 
-RUN \
-  apk add \
-    gcc \
-    libconfig-dev \
-    make \
-    musl-dev \
-    pcre-dev \
-    perl && \
-  cd /sslh && \
-  make sslh-select && \
-  strip sslh-select
+WORKDIR /sslh
 
-FROM alpine:latest
+RUN apk add --no-cache \
+        'gcc' \
+        'libconfig-dev' \
+        'make' \
+        'musl-dev' \
+        'pcre2-dev' \
+        'perl' \
+        ;
 
-COPY --from=build /sslh/sslh-select /sslh
+COPY . /sslh
 
-RUN apk --no-cache add libconfig pcre
+RUN ./configure && make sslh-select && strip sslh-select
 
-ENTRYPOINT [ "/sslh", "--foreground"]
+FROM docker.io/${TARGET_ARCH}/alpine:${ALPINE_VERSION}
+
+COPY --from=build "/sslh/sslh-select" "/usr/local/bin/sslh"
+RUN apk add --no-cache \
+        'libconfig' \
+        'pcre2' \
+        'iptables' \
+        'ip6tables' \
+        'libcap' \
+    && \
+    adduser -s '/bin/sh' -S -D sslh && \
+    setcap cap_net_bind_service,cap_net_raw+ep /usr/local/bin/sslh
+
+COPY "./container-entrypoint.sh" "/init"
+ENTRYPOINT [ "/init" ]
+
+# required for updating iptables
+USER root:root

Makefile.in

@@ -3,8 +3,11 @@ VERSION=$(shell ./genver.sh -r)
 
 # Configuration -- you probably need to `make clean` if you
 # change any of these
+# landlock is checked by `configure` and set in config.h
+ENABLE_SANITIZER= # Enable ASAN/LSAN/UBSAN
 ENABLE_REGEX=1  # Enable regex probes
 USELIBCONFIG=1	# Use libconfig? (necessary to use configuration files)
+USELIBEV=1	# Use libev?
 USELIBWRAP?=	# Use libwrap?
 USELIBCAP=	# Use libcap?
 USESYSTEMD=     # Make use of systemd socket activation
@@ -19,15 +22,25 @@ MAN=sslh.8.gz	# man page name
 # End of configuration -- the rest should take care of
 # itself
 
+ifneq ($(strip $(ENABLE_SANITIZER)),)
+    CFLAGS_SAN=-fsanitize=address -fsanitize=leak -fsanitize=undefined
+endif
+
 ifneq ($(strip $(COV_TEST)),)
     CFLAGS_COV=-fprofile-arcs -ftest-coverage
 endif
 
 CC ?= gcc
-CFLAGS ?=-Wall -DLIBPCRE -g $(CFLAGS_COV)
+AR ?= ar
+CFLAGS +=-Wall -O2 -DLIBPCRE -g $(CFLAGS_COV) $(CFLAGS_SAN)
+
 
 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
+OBJS=sslh-conf.o common.o log.o sslh-main.o probe.o tls.o argtable3.o collection.o gap.o tcp-probe.o landlock.o
+OBJS_A=libsslh.a
+FORK_OBJS=sslh-fork.o $(OBJS_A)
+SELECT_OBJS=processes.o udp-listener.o sslh-select.o hash.o tcp-listener.o $(OBJS_A)
+EV_OBJS=processes.o udp-listener.o sslh-ev.o hash.o tcp-listener.o $(OBJS_A)
 
 CONDITIONAL_TARGETS=
 
@@ -61,39 +74,52 @@ ifneq ($(strip $(USELIBBSD)),)
         CPPFLAGS+=-DLIBBSD
 endif
 
+ifneq ($(strip $(USELIBEV)),)
+        CONDITIONAL_TARGETS+=sslh-ev
+endif
 
-all: sslh $(MAN) echosrv $(CONDITIONAL_TARGETS)
+all: sslh-fork sslh-select $(MAN) echosrv $(CONDITIONAL_TARGETS)
 
-.c.o: *.h version.h
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c $<
+%.o: %.c %.h version.h
+	$(CC) $(CFLAGS) $(CPPFLAGS) -c $< -o $@
+
+$(OBJS_A): $(OBJS)
+	$(AR) rcs $(OBJS_A) $(OBJS)
 
 version.h:
 	./genver.sh >version.h
 
-sslh: sslh-fork sslh-select
+$(OBJS) $(FORK_OBJS) $(SELECT_OBJS) $(EV_OBJS): argtable3.h collection.h common.h gap.h hash.h log.h probe.h processes.h sslh-conf.h tcp-listener.h tcp-probe.h tls.h udp-listener.h version.h
 
-$(OBJS): version.h common.h collection.h sslh-conf.h gap.h
+
+c2s:
+	conf2struct sslhconf.cfg
+	conf2struct echosrv.cfg
 
 sslh-conf.c sslh-conf.h: sslhconf.cfg
-	conf2struct sslhconf.cfg
+	$(warning "sslhconf.cfg is more recent than sslh-conf.[ch]. Use `make c2s` to rebuild using `conf2struct`")
 
-sslh-fork: version.h $(OBJS) sslh-fork.o Makefile
-	$(CC) $(CFLAGS) $(LDFLAGS) -o sslh-fork sslh-fork.o $(OBJS) $(LIBS)
-	#strip sslh-fork
+sslh-fork: version.h Makefile $(FORK_OBJS)
+	$(CC) $(CFLAGS) $(LDFLAGS) -o sslh-fork $(FORK_OBJS) $(LIBS)
 
-sslh-select: version.h $(OBJS) sslh-select.o Makefile
-	$(CC) $(CFLAGS) $(LDFLAGS) -o sslh-select sslh-select.o $(OBJS) $(LIBS)
-	#strip sslh-select
+sslh-select: version.h $(SELECT_OBJS) Makefile
+	$(CC) $(CFLAGS) $(LDFLAGS) -o sslh-select $(SELECT_OBJS) $(LIBS)
+
+sslh-ev: version.h $(EV_OBJS) Makefile
+	$(CC) $(CFLAGS) $(LDFLAGS) -o sslh-ev $(EV_OBJS) $(LIBS) -lev
 
 systemd-sslh-generator: systemd-sslh-generator.o
 	$(CC) $(CFLAGS) $(LDFLAGS) -o systemd-sslh-generator systemd-sslh-generator.o -lconfig
 
 echosrv-conf.c echosrv-conf.h: echosrv.cfg
-	conf2struct echosrv.cfg
+	$(warning "echosrv.cfg is more recent than echosrv-conf.[ch]. Use `make c2s` to rebuild using `conf2struct`")
 
 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)
 
+
+landlock.o: config.h
+
 $(MAN): sslh.pod Makefile
 	pod2man --section=8 --release=$(VERSION) --center=" " sslh.pod | gzip -9 - > $(MAN)
 
@@ -113,7 +139,7 @@ docker-clean:
 	yes | docker image prune
 
 # generic install: install binary and man page
-install: sslh $(MAN)
+install: sslh-fork $(MAN)
 	mkdir -p $(DESTDIR)/$(BINDIR)
 	mkdir -p $(DESTDIR)/$(MANDIR)
 	install -p sslh-fork $(DESTDIR)/$(BINDIR)/sslh
@@ -133,7 +159,7 @@ distclean: clean
 	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
+	rm -f sslh-fork sslh-select $(CONDITIONAL_TARGETS) echosrv version.h $(MAN) systemd-sslh-generator *.o *.gcov *.gcno *.gcda *.png *.html *.css *.info
 
 tags:
 	ctags --globals -T *.[ch]

README.md

@@ -11,7 +11,7 @@ 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. 
+443) while still serving HTTPS on that port.
 
 Hence `sslh` acts as a protocol demultiplexer, or a
 switchboard. With the SNI and ALPN probe, it makes a good
@@ -20,9 +20,10 @@ address.
 
 `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.
+systemd support, transparent proxying, chroot, logging,
+IPv4 and IPv6, TCP and UDP, a fork-based, a select-based
+model, and yet another based on libev for larger
+installations.
 
 Install
 =======
@@ -35,6 +36,18 @@ Configuration
 
 Please refer to the [configuration guide](doc/config.md).
 
+Transparent proxying allows the target server to see the
+original client IP address, i.e. `sslh` becomes invisible.
+This makes it easier to use the server's logs, and potential
+IP-based banning ability.
+
+Configuration of transparent proxying is highly dependent on
+your network environment and infrastructure setup. There is
+no known generic approach, and if you do not find directions
+for your exact setup, you will probably need an extensive
+knowledge of network management and iptables setup".
+
+It is described in its own [document](doc/tproxy.md).
 
 
 Docker image
@@ -44,45 +57,120 @@ How to use
 
 ---
 
-Build docker image
-
-    make docker
-
 
 ```bash
-docker container run \
+docker run \
+  --cap-add CAP_NET_RAW \
+  --cap-add CAP_NET_BIND_SERVICE \
   --rm \
   -it \
+  ghcr.io/yrutschle/sslh:latest \
+  --foreground \
   --listen=0.0.0.0:443 \
   --ssh=hostname:22 \
-  --tlshostname:443 \
-  sslh:latest
+  --tls=hostname:443
 ```
 
 docker-compose example
 
-```
----
+```yaml
 version: "3"
 
 services:
   sslh:
-    image: sslh:latest
+    image: ghcr.io/yrutschle/sslh:latest
     hostname: sslh
     ports:
-      - 443:443/tcp
-    command: --listen=0.0.0.0:443 --tlshostname:443 --openvpn=openvpn:1194
+      - 443:443
+    command: --foreground --listen=0.0.0.0:443 --tls=nginx:443 --openvpn=openvpn:1194
     depends_on:
       - nginx
       - openvpn
 
   nginx:
     image: nginx
-    hostname: nginx
+
+  openvpn:
+    image: openvpn
+```
+
+Transparent mode 1: using sslh container for networking
+
+_Note: For transparent mode to work, the sslh container must be able to reach your services via **localhost**_
+```yaml
+version: "3"
+
+services:
+  sslh:
+    build: https://github.com/yrutschle/sslh.git
+    container_name: sslh
+    environment:
+      - TZ=${TZ}
+    cap_add:
+      - NET_ADMIN
+      - NET_RAW
+      - NET_BIND_SERVICE
+    sysctls:
+      - net.ipv4.conf.default.route_localnet=1
+      - net.ipv4.conf.all.route_localnet=1
+    command: --transparent --foreground --listen=0.0.0.0:443 --tls=localhost:8443 --openvpn=localhost:1194
+    ports:
+      - 443:443 #sslh
+
+      - 80:80 #nginx
+      - 8443:8443 #nginx
+
+      - 1194:1194 #openvpn
+    extra_hosts:
+      - localbox:host-gateway
+    restart: unless-stopped
+
+  nginx:
+    image: nginx:latest
+    .....
+    network_mode: service:sslh #set nginx container to use sslh networking.
+    # ^^^ This is required. This makes nginx reachable by sslh via localhost
+  
+  openvpn:
+    image: openvpn:latest
+    .....
+    network_mode: service:sslh #set openvpn container to use sslh networking
+```
+
+Transparent mode 2: using host networking
+
+```yaml
+version: "3"
+
+services:
+  sslh:
+    build: https://github.com/yrutschle/sslh.git
+    container_name: sslh
+    environment:
+      - TZ=${TZ}
+    cap_add:
+      - NET_ADMIN
+      - NET_RAW
+      - NET_BIND_SERVICE
+    # must be set manually
+    #sysctls:
+    #  - net.ipv4.conf.default.route_localnet=1
+    #  - net.ipv4.conf.all.route_localnet=1
+    command: --transparent --foreground --listen=0.0.0.0:443 --tls=localhost:8443 --openvpn=localhost:1194
+    network_mode: host
+    restart: unless-stopped
+  
+  nginx:
+    image: nginx:latest
+    .....
+    ports:
+      - 8443:8443 # bind to docker host on port 8443
 
   openvpn:
     image: openvpn:latest
-    hostname: openvpn
+    .....
+    ports:
+      - 1194:1194 # bind to docker host on port 1194
 ```
 
 Comments? Questions?

argtable3.c

@@ -2876,9 +2876,9 @@ static void arg_file_resetfn(struct arg_file* parent) {
 static const char* arg_basename(const char* filename) {
     const char *result = NULL, *result1, *result2;
 
-    /* Find the last occurrence of eother file separator character. */
-    /* Two alternative file separator chars are supported as legal  */
-    /* file separators but not both together in the same filename.  */
+    /* Find the last occurrence of other file separator character. */
+    /* Two alternative file separator chars are supported as legal */
+    /* file separators but not both together in the same filename. */
     result1 = (filename ? strrchr(filename, FILESEPARATOR1) : NULL);
     result2 = (filename ? strrchr(filename, FILESEPARATOR2) : NULL);
 
@@ -2927,7 +2927,7 @@ static int arg_file_scanfn(struct arg_file* parent, const char* argval) {
     } else if (!argval) {
         /* a valid argument with no argument value was given. */
         /* This happens when an optional argument value was invoked. */
-        /* leave parent arguiment value unaltered but still count the argument. */
+        /* leave parent argument value unaltered but still count the argument. */
         parent->count++;
     } else {
         parent->filename[parent->count] = argval;
@@ -3173,7 +3173,7 @@ static int arg_int_scanfn(struct arg_int* parent, const char* argval) {
     } else if (!argval) {
         /* a valid argument with no argument value was given. */
         /* This happens when an optional argument value was invoked. */
-        /* leave parent arguiment value unaltered but still count the argument. */
+        /* leave parent argument value unaltered but still count the argument. */
         parent->count++;
     } else {
         long int val;
@@ -3813,8 +3813,8 @@ static const TRexChar* g_nnames[] = {_SC("NONE"),    _SC("OP_GREEDY"), _SC("OP_O
 #endif
 #define OP_GREEDY (MAX_CHAR + 1)  /*  * + ? {n} */
 #define OP_OR (MAX_CHAR + 2)
-#define OP_EXPR (MAX_CHAR + 3)       /* parentesis () */
-#define OP_NOCAPEXPR (MAX_CHAR + 4)  /* parentesis (?:) */
+#define OP_EXPR (MAX_CHAR + 3)       /* parenthesis () */
+#define OP_NOCAPEXPR (MAX_CHAR + 4)  /* parenthesis (?:) */
 #define OP_DOT (MAX_CHAR + 5)
 #define OP_CLASS (MAX_CHAR + 6)
 #define OP_CCLASS (MAX_CHAR + 7)
@@ -5313,7 +5313,7 @@ static void arg_parse_untagged(int argc, char** argv, struct arg_hdr** table, st
         }
     }
 
-    /* if a tenative error still remains at this point then register it as a proper error */
+    /* if a tentative error still remains at this point then register it as a proper error */
     if (errorlast) {
         arg_register_error(endtable, parentlast, errorlast, optarglast);
         optind++;
@@ -5384,7 +5384,7 @@ int arg_parse(int argc, char** argv, void** argtable) {
     /*
         Fill in the local copy of argv[]. We need a local copy
         because getopt rearranges argv[] which adversely affects
-        susbsequent parsing attempts.
+        subsequent parsing attempts.
         */
     for (i = 0; i < argc; i++)
         argvcopy[i] = argv[i];
@@ -5451,7 +5451,7 @@ static void arg_cat_option(char* dest, size_t ndest, const char* shortopts, cons
     if (shortopts) {
         char option[3];
 
-        /* note: option array[] is initialiazed dynamically here to satisfy   */
+        /* note: option array[] is initialized dynamically here to satisfy   */
         /* a deficiency in the watcom compiler wrt static array initializers. */
         option[0] = '-';
         option[1] = shortopts[0];
@@ -5509,7 +5509,7 @@ static void arg_cat_optionv(char* dest, size_t ndest, const char* shortopts, con
             /* "-a|-b|-c" */
             char shortopt[3];
 
-            /* note: shortopt array[] is initialiazed dynamically here to satisfy */
+            /* note: shortopt array[] is initialized dynamically here to satisfy */
             /* a deficiency in the watcom compiler wrt static array initializers. */
             shortopt[0] = '-';
             shortopt[1] = *c;
@@ -5881,7 +5881,7 @@ static void arg_print_formatted_ds(arg_dstr_t ds, const unsigned lmargin, const
  * Prints the glossary in strict GNU format.
  * Differences to arg_print_glossary() are:
  *   - wraps lines after 80 chars
- *   - indents lines without shortops
+ *   - indents lines without shortopts
  *   - does not accept formatstrings
  *
  * Contributed by Uli Fouquet
@@ -5956,7 +5956,7 @@ int arg_nullcheck(void** argtable) {
  * that entry were still allocated ok. Those subsequent allocations will not be
  * deallocated by arg_free().
  * Despite the unlikeliness of the problem occurring, and the even unlikelier event
- * that it has any deliterious effect, it is fixed regardless by replacing arg_free()
+ * that it has any deleterious effect, it is fixed regardless by replacing arg_free()
  * with the newer arg_freetable() function.
  * We still keep arg_free() for backwards compatibility.
  */

argtable3.h

@@ -87,7 +87,7 @@ typedef int(arg_comparefn)(const void* k1, const void* k2);
  * 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
+ * and are the pointer to them are initialised 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.
@@ -95,7 +95,7 @@ typedef int(arg_comparefn)(const void* k1, const void* k2);
 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* longopts;  /* String defining 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 */

basic.cfg

@@ -1,23 +1,25 @@
 # This is a basic configuration file that should provide
 # sensible values for "standard" setup.
 
-verbose: 0;
-foreground: false;
-inetd: false;
-numeric: false;
-transparent: false;
+# You will find extensive examples with explanations in
+# example.cfg
+
 timeout: 2;
 user: "nobody";
 pidfile: "/var/run/sslh.pid";
-chroot: "/var/empty";
 
 
-# Change hostname with your external address name.
+# Change hostname with your external address name, or the IP
+# of the interface that receives connections
 listen:
 (
     { host: "thelonious"; port: "443"; }
 );
 
+
+# Change to the protocols you want to forward to. The
+# defaults here are sensible for services running on
+# localhost
 protocols:
 (
      { name: "ssh"; service: "ssh"; host: "localhost"; port: "22"; fork: true; },

collection.c

@@ -30,8 +30,9 @@ 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)
+/* Allocates and initialises a new collection of connections with at least
+ * `len` elements. */
+cnx_collection* collection_init(int len)
 {
     cnx_collection* collection;
 
@@ -40,7 +41,7 @@ cnx_collection* collection_init(void)
 
     memset(collection, 0, sizeof(*collection));
 
-    collection->fd2cnx = gap_init();
+    collection->fd2cnx = gap_init(len);
 
     return collection;
 }

collection.h

@@ -4,7 +4,7 @@
 typedef struct cnx_collection cnx_collection;
 
 
-cnx_collection* collection_init(void);
+cnx_collection* collection_init(int len);
 void collection_destroy(cnx_collection* collection);
 
 struct connection* collection_alloc_cnx_from_fd(cnx_collection* collection, int fd);

common.c

@@ -4,7 +4,6 @@
  * No code here should assume whether sockets are blocking or not.
  **/
 
-#define SYSLOG_NAMES
 #define _GNU_SOURCE
 #include <stddef.h>
 #include <stdarg.h>
@@ -16,6 +15,7 @@
 
 #include "common.h"
 #include "probe.h"
+#include "log.h"
 #include "sslh-conf.h"
 
 /* Added to make the code compilable under CYGWIN
@@ -42,8 +42,6 @@ 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;
@@ -60,7 +58,7 @@ void check_res_dump(CR_ACTION act, int res, struct addrinfo *addr, char* syscall
     char buf[NI_MAXHOST];
 
     if (res == -1) {
-        fprintf(stderr, "%s:%s: %s\n",
+        print_message(msg_system_error, "%s:%s: %s\n",
                 sprintaddr(buf, sizeof(buf), addr),
                 syscall,
                 strerror(errno));
@@ -77,7 +75,7 @@ int get_fd_sockets(struct listen_endpoint *sockfd[])
 #ifdef SYSTEMD
     sd = sd_listen_fds(0);
     if (sd < 0) {
-      fprintf(stderr, "sd_listen_fds(): %s\n", strerror(-sd));
+      print_message(msg_system_error, "sd_listen_fds(): %s\n", strerror(-sd));
       exit(1);
     }
     if (sd > 0) {
@@ -112,7 +110,7 @@ int make_listen_tfo(int s)
     return setsockopt(s, SOL_SOCKET, TCP_FASTOPEN, (char*)&qlen, sizeof(qlen));
 }
 
-/* Starts listening on a single address 
+/* 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)
 {
@@ -177,7 +175,7 @@ int start_listen_sockets(struct listen_endpoint *sockfd[])
 
     *sockfd = NULL;
 
-    if (cfg.verbose) fprintf(stderr, "Listening to:\n");
+    print_message(msg_config, "Listening to:\n");
 
     for (i = 0; i < cfg.listen_len; i++) {
         keepalive = cfg.listen[i].keepalive;
@@ -188,13 +186,12 @@ int start_listen_sockets(struct listen_endpoint *sockfd[])
 
         for (addr = start_addr; addr; addr = addr->ai_next) {
             num_addr++;
-            *sockfd = realloc(*sockfd, num_addr * sizeof(*sockfd));
+            *sockfd = realloc(*sockfd, num_addr * sizeof(*sockfd[0]));
             (*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" : "");
+            print_message(msg_config, "%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);
     }
@@ -265,7 +262,7 @@ int bind_peer(int fd, int fd_from)
     /* if the destination is the same machine, there's no need to do bind */
     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 IP_TRANSPARENT");
@@ -281,7 +278,26 @@ int bind_peer(int fd, int fd_from)
     }
 #endif /* IP_TRANSPARENT / IP_BINDANY */
     res = bind(fd, from.ai_addr, from.ai_addrlen);
-    CHECK_RES_RETURN(res, "bind", res);
+    if (res == -1) {
+        if (errno != EADDRINUSE) {
+            print_message(msg_system_error, "%s:%d:%s:%d:%s\n", __FILE__, __LINE__,
+                        "bind", errno, strerror(errno));
+            return res;
+        }
+
+        /*
+         * If there is more than one transparent mode proxy going on, such as
+         * using sslh as the target of stunnel also in transparent mode, then
+         * the (ip,port) combination will already be bound for the previous application.
+         * In that case, the best we can do is bind with a different port.
+         * This does mean the local server can't use the ident protocol as the port will
+         * have changed, but most people won't care.
+         * Also note that stunnel uses the same logic for the same situation.
+         */
+        ((struct sockaddr_in *)from.ai_addr)->sin_port = 0;
+        res = bind(fd, from.ai_addr, from.ai_addrlen);
+        CHECK_RES_RETURN(res, "bind", res);
+    }
 
     return 0;
 }
@@ -322,19 +338,23 @@ int connect_addr(struct connection *cnx, int fd_from, connect_blocking blocking)
     res = getpeername(fd_from, from.ai_addr, &from.ai_addrlen);
     CHECK_RES_RETURN(res, "getpeername", res);
 
+    if (cnx->proto->resolve_on_forward) {
+        resolve_split_name(&(cnx->proto->saddr), cnx->proto->host,
+                           cnx->proto->port);
+    }
+
     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 (cfg.verbose)
-            fprintf(stderr, "connecting to %s family %d len %d\n",
+        print_message(msg_connections_try, "trying to connect to %s family %d len %d\n",
                     sprintaddr(buf, sizeof(buf), a),
                     a->ai_addr->sa_family, a->ai_addrlen);
 
         /* XXX Needs to match ai_family from fd_from when being transparent! */
         fd = socket(a->ai_family, SOCK_STREAM, 0);
         if (fd == -1) {
-            log_message(LOG_ERR, "forward to %s failed:socket: %s\n",
+            print_message(msg_connections_error, "forward to %s failed:socket: %s\n",
                         cnx->proto->name, strerror(errno));
         } else {
             one = 1;
@@ -347,6 +367,7 @@ int connect_addr(struct connection *cnx, int fd_from, connect_blocking blocking)
 
             if (transparent) {
                 res = bind_peer(fd, fd_from);
+                if (res == -1) close(fd);
                 CHECK_RES_RETURN(res, "bind_peer", res);
             }
             res = connect(fd, a->ai_addr, a->ai_addrlen);
@@ -354,7 +375,7 @@ int connect_addr(struct connection *cnx, int fd_from, connect_blocking blocking)
             /* 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",
+                print_message(msg_connections_error, "forward to %s failed:connect: %s\n",
                                      cnx->proto->name, strerror(errno));
                 close(fd);
                 continue; /* Try the next address */
@@ -374,9 +395,8 @@ 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 (cfg.verbose)
-        fprintf(stderr, "**** writing deferred on fd %d\n", q->fd);
 
+    print_message(msg_fd, "writing deferred on fd %d\n", q->fd);
     p = realloc(q->begin_deferred_data, data_offset + q->deferred_data_size + data_size);
     CHECK_ALLOC(p, "realloc");
 
@@ -397,8 +417,7 @@ int flush_deferred(struct queue *q)
 {
     int n;
 
-    if (cfg.verbose)
-        fprintf(stderr, "flushing deferred data to fd %d\n", q->fd);
+    print_message(msg_fd, "flushing deferred data to fd %d\n", q->fd);
 
     n = write(q->fd, q->deferred_data, q->deferred_data_size);
     if (n == -1)
@@ -430,11 +449,12 @@ void init_cnx(struct connection *cnx)
 
 void dump_connection(struct connection *cnx)
 {
-    printf("state: %d\n", cnx->state);
-    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);
+    print_message(msg_int_error, "type: %s\n", cnx->type == SOCK_DGRAM ? "UDP" : "TCP");
+    print_message(msg_int_error, "state: %d\n", cnx->state);
+    print_message(msg_int_error, "0: fd %d, %d deferred\n", cnx->q[0].fd, cnx->q[0].deferred_data_size);
+    hexdump(msg_int_error, cnx->q[0].deferred_data, cnx->q[0].deferred_data_size);
+    print_message(msg_int_error, "1: fd %d, %d deferred\n", cnx->q[1].fd, cnx->q[1].deferred_data_size);
+    hexdump(msg_int_error, cnx->q[1].deferred_data, cnx->q[1].deferred_data_size);
 }
 
 
@@ -459,11 +479,10 @@ int fd2fd(struct queue *target_q, struct queue *from_q)
    if (size_r == -1) {
        switch (errno) {
        case EAGAIN:
-           if (cfg.verbose)
-               fprintf(stderr, "reading 0 from %d\n", from);
            return FD_NODATA;
 
        case ECONNRESET:
+       case ENOTSOCK:
        case EPIPE:
            return FD_CNXCLOSED;
        }
@@ -511,7 +530,7 @@ char* sprintaddr(char* buf, size_t size, struct addrinfo *a)
                cfg.numeric ? NI_NUMERICHOST | NI_NUMERICSERV : 0 );
 
    if (res) {
-       log_message(LOG_ERR, "sprintaddr:getnameinfo: %s\n", gai_strerror(res));
+       print_message(msg_system_error, "sprintaddr:getnameinfo: %s\n", gai_strerror(res));
        /* Name resolution failed: do it numerically instead */
        res = getnameinfo(a->ai_addr, a->ai_addrlen,
                          host, sizeof(host),
@@ -519,7 +538,7 @@ char* sprintaddr(char* buf, size_t size, struct addrinfo *a)
                          NI_NUMERICHOST | NI_NUMERICSERV);
        /* should not fail but... */
        if (res) {
-           log_message(LOG_ERR, "sprintaddr:getnameinfo(NUM): %s\n", gai_strerror(res));
+           print_message(msg_system_error, "sprintaddr:getnameinfo(NUM): %s\n", gai_strerror(res));
            strcpy(host, "?");
            strcpy(serv, "?");
        }
@@ -531,7 +550,8 @@ 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
+ * On success, returns 0 
+ * On failure, returns -1 or one of getaddrinfo() codes
  */
 int resolve_split_name(struct addrinfo **out, char* host, char* serv)
 {
@@ -548,7 +568,7 @@ int resolve_split_name(struct addrinfo **out, char* host, char* serv)
    if (host[0] == '[') {
        end = strrchr(host, ']');
        if (!end) {
-           fprintf(stderr, "%s: no closing bracket in IPv6 address?\n", host);
+           print_message(msg_config_error, "%s: no closing bracket in IPv6 address?\n", host);
            return -1;
        }
        host++; /* skip first bracket */
@@ -557,7 +577,7 @@ int resolve_split_name(struct addrinfo **out, char* host, char* serv)
 
    res = getaddrinfo(host, serv, &hint, out);
    if (res)
-      log_message(LOG_ERR, "%s `%s:%s'\n", gai_strerror(res), host, serv);
+      print_message(msg_system_error, "resolve_split_name: %s `%s:%s'\n", gai_strerror(res), host, serv);
    return res;
 }
 
@@ -573,7 +593,7 @@ void resolve_name(struct addrinfo **out, char* fullname)
    /* Find port */
    char *sep = strrchr(fullname, ':');
    if (!sep) { /* No separator: parameter is just a port */
-      fprintf(stderr, "%s: names must be fully specified as hostname:port\n", fullname);
+      print_message(msg_config_error, "%s: names must be fully specified as hostname:port\n", fullname);
       exit(1);
    }
    serv = sep+1;
@@ -583,30 +603,13 @@ void resolve_name(struct addrinfo **out, char* fullname)
 
    res = resolve_split_name(out, host, serv);
    if (res) {
-      fprintf(stderr, "%s `%s'\n", gai_strerror(res), fullname);
+      print_message(msg_config_error, "%s `%s'\n", gai_strerror(res), fullname);
       if (res == EAI_SERVICE)
-         fprintf(stderr, "(Check you have specified all ports)\n");
+         print_message(msg_config_error, "(Check you have specified all ports)\n");
       exit(4);
    }
 }
 
-/* Log to syslog or stderr if foreground */
-void log_message(int type, const char* msg, ...)
-{
-    va_list ap;
-
-    va_start(ap, msg);
-    if (cfg.foreground)
-        vfprintf(stderr, msg, ap);
-    va_end(ap);
-
-    if (do_syslog) {
-        va_start(ap, msg);
-        vsyslog(type, msg, ap);
-        va_end(ap);
-    }
-}
-
 
 /* Fills a connection description; returns 0 on failure */
 int get_connection_desc(struct connection_desc* desc, const struct connection *cnx)
@@ -641,30 +644,6 @@ int get_connection_desc(struct connection_desc* desc, const struct connection *c
     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->name,
-                desc->peer,
-                desc->service,
-                desc->local,
-                desc->target);
-}
 
 void set_proctitle_shovel(struct connection_desc* desc, const struct connection *cnx)
 {
@@ -708,8 +687,7 @@ int check_access_rights(int in_socket, const char* service)
     /* extract peer address */
     res = getnameinfo(&peer.saddr, size, addr_str, sizeof(addr_str), NULL, 0, NI_NUMERICHOST);
     if (res) {
-        if (cfg.verbose)
-            fprintf(stderr, "getnameinfo(NI_NUMERICHOST):%s\n", gai_strerror(res));
+        print_message(msg_system_error, "getnameinfo(NI_NUMERICHOST):%s\n", gai_strerror(res));
         strcpy(addr_str, STRING_UNKNOWN);
     }
     /* extract peer name */
@@ -717,15 +695,12 @@ int check_access_rights(int in_socket, const char* service)
     if (!cfg.numeric) {
         res = getnameinfo(&peer.saddr, size, host, sizeof(host), NULL, 0, NI_NAMEREQD);
         if (res) {
-            if (cfg.verbose)
-                fprintf(stderr, "getnameinfo(NI_NAMEREQD):%s\n", gai_strerror(res));
+            print_message(msg_system_error, "getnameinfo(NI_NAMEREQD):%s\n", gai_strerror(res));
         }
     }
 
     if (!hosts_ctl(service, host, addr_str, STRING_UNKNOWN)) {
-        if (cfg.verbose)
-            fprintf(stderr, "access denied\n");
-        log_message(LOG_INFO, "connection from %s(%s): access denied", host, addr_str);
+        print_message(msg_connections, "connection from %s(%s): access denied", host, addr_str);
         close(in_socket);
         return -1;
     }
@@ -760,35 +735,6 @@ void setup_signals(void)
 
 }
 
-/* Open syslog connection with appropriate banner;
- * banner is made up of basename(bin_name)+"[pid]" */
-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, cfg.syslog_facility) == 0)
-            break;
-    if (facilitynames[fn].c_val == -1) {
-        fprintf(stderr, "Unknown facility %s\n", cfg.syslog_facility);
-        exit(1);
-    }
-
-    openlog(name2, LOG_CONS, facilitynames[fn].c_val);
-    free(name1);
-    /* Don't free name2, as openlog(3) uses it (at least in glibc) */
-
-    log_message(LOG_INFO, "%s %s started\n", server_type, VERSION);
-}
 
 /* Ask OS to keep capabilities over a setuid(nonzero) */
 void set_keepcaps(int val) {
@@ -866,16 +812,14 @@ void drop_privileges(const char* user_name, const char* chroot_path)
     if (user_name) {
         pw = getpwnam(user_name);
         if (!pw) {
-            fprintf(stderr, "%s: not found\n", user_name);
+            print_message(msg_config_error, "%s: not found\n", user_name);
             exit(2);
         }
-        if (cfg.verbose)
-            fprintf(stderr, "turning into %s\n", user_name);
+        print_message(msg_config, "turning into %s\n", user_name);
     }
 
     if (chroot_path) {
-        if (cfg.verbose)
-            fprintf(stderr, "chrooting into %s\n", chroot_path);
+        print_message(msg_config, "chrooting into %s\n", chroot_path);
 
         res = chroot(chroot_path);
         CHECK_RES_DIE(res, "chroot");
@@ -905,14 +849,23 @@ void drop_privileges(const char* user_name, const char* chroot_path)
 void write_pid_file(const char* pidfile)
 {
     FILE *f;
+    int res;
 
     f = fopen(pidfile, "w");
     if (!f) {
-        perror(pidfile);
+        print_message(msg_system_error, "write_pid_file:%s:%s", pidfile, strerror(errno));
         exit(3);
     }
 
-    fprintf(f, "%d\n", getpid());
-    fclose(f);
-}
+    res = fprintf(f, "%d\n", getpid());
+    if (res < 0) {
+        print_message(msg_system_error, "write_pid_file:fprintf:%s", strerror(errno));
+        exit(3);
+    }
 
+    res = fclose(f);
+    if (res == EOF) {
+        print_message(msg_system_error, "write_pid_file:fclose:%s", strerror(errno));
+        exit(3);
+    }
+}

common.h

@@ -5,6 +5,7 @@
  * enough for the macros to adapt (http://support.microsoft.com/kb/111855)
  */
 #ifdef __CYGWIN__
+#undef FD_SETSIZE
 #define FD_SETSIZE 4096
 #endif
 
@@ -40,20 +41,20 @@
 
 #define CHECK_RES_DIE(res, str) \
     if (res == -1) {    \
-       fprintf(stderr, "%s:%d:", __FILE__, __LINE__); \
+       print_message(msg_system_error, "%s:%d:", __FILE__, __LINE__); \
        perror(str);     \
        exit(1);         \
     }
 
 #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));  \
+        print_message(msg_system_error, "%s:%d:%s:%d:%s\n", __FILE__, __LINE__, str, errno, strerror(errno));  \
         return ret;                                     \
     } 
 
 #define CHECK_ALLOC(a, str) \
     if (!a) { \
-        fprintf(stderr, "%s:%d:", __FILE__, __LINE__); \
+        print_message(msg_system_error, "%s:%d:", __FILE__, __LINE__); \
         perror(str); \
         exit(1); \
     }
@@ -83,9 +84,6 @@ enum connection_state {
     ST_SHOVELING   /* Connexion is established */
 };
 
-/* this is used to pass protocols through the command-line parameter parsing */
-#define PROT_SHIFT 1000  /* protocol options will be 1000, 1001, etc */
-
 /* A 'queue' is composed of a file descriptor (which can be read from or
  * written to), and a queue for deferred write data */
 struct queue {
@@ -95,6 +93,12 @@ struct queue {
     int deferred_data_size;
 };
 
+/* Double linked list for timeout management */
+typedef struct {
+    struct connection* head;
+    struct connection* tail;
+} dl_list;
+
 struct connection {
     int type;           /* SOCK_DGRAM | SOCK_STREAM */
     struct sslhcfg_protocols_item* proto; /* Where to connect to */
@@ -109,13 +113,16 @@ struct connection {
     struct queue q[2];
 
     /* SOCK_DGRAM */
-    struct sockaddr client_addr; /* Contains the remote client address */
+    struct sockaddr_storage client_addr; /* Contains the remote client address */
     socklen_t addrlen;
 
     int local_endpoint; /* Contains the local address */
 
     time_t last_active;
 
+    /* double linked list of timeouts */
+    struct connection *timeout_prev, *timeout_next;
+
     /* We need one local socket for each target server, so we know where to
      * forward server responses */
     int target_sock;  
@@ -160,7 +167,6 @@ 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, const char* msg, ...);
 void dump_connection(struct connection *cnx);
 int resolve_split_name(struct addrinfo **out, char* hostname, char* port);
 
@@ -171,7 +177,6 @@ int flush_deferred(struct queue *q);
 
 extern struct sslhcfg_item cfg;
 extern struct addrinfo *addr_listen;
-extern const char* USAGE_STRING;
 extern const char* server_type;
 
 /* sslh-fork.c */
@@ -179,4 +184,8 @@ void start_shoveler(int);
 
 void main_loop(struct listen_endpoint *listen_sockets, int num_addr_listen);
 
+/* landlock.c */
+void setup_landlock(void);
+
+
 #endif

config.h.in

@@ -0,0 +1,9 @@
+
+
+#ifndef CONFIG_H
+/* Template for config.h, filled by `configure`. */
+
+/* Landlock sandboxing Linux LSM */
+#undef HAVE_LANDLOCK
+
+#endif

configure.ac

@@ -0,0 +1,9 @@
+
+dnl Use autoconf to generate the `configure` script from this and Makefile.in
+
+AC_INIT
+AC_CONFIG_HEADERS(config.h)
+AC_CONFIG_FILES([Makefile])
+
+AC_CHECK_HEADERS(linux/landlock.h, AC_DEFINE(HAVE_LANDLOCK), [])
+AC_OUTPUT

container-entrypoint.sh

@@ -0,0 +1,97 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL2-or-later
+#
+# Copyright (C) 2023 Olliver Schinagl <oliver@schinagl.nl>
+#
+# A beginning user should be able to docker run image bash (or sh) without
+# needing to learn about --entrypoint
+# https://github.com/docker-library/official-images#consistency
+
+set -eu
+
+bin='sslh'
+
+# run command if it is not starting with a "-" and is an executable in PATH
+if [ "${#}" -le 0 ] || \
+   [ "${1#-}" != "${1}" ] || \
+   [ -d "${1}" ] || \
+   ! command -v "${1}" > '/dev/null' 2>&1; then
+	entrypoint='true'
+fi
+
+unconfigure_iptables() { 
+	echo "Received SIG TERM/INT/KILL. Removing iptables / routing changes"
+
+	set +e # Don't exit if got error
+	set -x
+
+	iptables -t raw -D PREROUTING ! -i lo -d 127.0.0.0/8 -j DROP
+	iptables -t mangle -D POSTROUTING ! -o lo -s 127.0.0.0/8 -j DROP
+
+	iptables -t nat -D OUTPUT -m owner --uid-owner sslh -p tcp --tcp-flags FIN,SYN,RST,ACK SYN -j CONNMARK --set-xmark 0x01/0x0f
+	iptables -t mangle -D OUTPUT ! -o lo -p tcp -m connmark --mark 0x01/0x0f -j CONNMARK --restore-mark --mask 0x0f
+
+	ip rule del fwmark 0x1 lookup 100
+	ip route del local 0.0.0.0/0 dev lo table 100
+
+
+	if [ $(cat /proc/sys/net/ipv6/conf/all/disable_ipv6) -eq 0 ]; then
+		ip6tables -t raw -D PREROUTING ! -i lo -d ::1/128 -j DROP
+		ip6tables -t mangle -D POSTROUTING ! -o lo -s ::1/128 -j DROP
+		ip6tables -t nat -D OUTPUT -m owner --uid-owner sslh -p tcp --tcp-flags FIN,SYN,RST,ACK SYN -j CONNMARK --set-xmark 0x01/0x0f
+		ip6tables -t mangle -D OUTPUT ! -o lo -p tcp -m connmark --mark 0x01/0x0f -j CONNMARK --restore-mark --mask 0x0f
+
+		ip -6 rule del fwmark 0x1 lookup 100
+		ip -6 route del local ::/0 dev lo table 100
+	fi
+		
+	set -e
+	set +x
+}
+
+configure_iptables() {
+	echo "Configuring iptables and routing..."
+
+	set +e # Don't exit if got error
+	set -x
+	
+	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
+
+	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
+	iptables -t mangle -A OUTPUT ! -o lo -p tcp -m connmark --mark 0x01/0x0f -j CONNMARK --restore-mark --mask 0x0f
+
+	ip rule add fwmark 0x1 lookup 100
+	ip route add local 0.0.0.0/0 dev lo table 100
+
+	if [ $(cat /proc/sys/net/ipv6/conf/all/disable_ipv6) -eq 0 ]; then
+		ip6tables -t raw -A PREROUTING ! -i lo -d ::1/128 -j DROP
+		ip6tables -t mangle -A POSTROUTING ! -o lo -s ::1/128 -j DROP
+		ip6tables -t nat -A OUTPUT -m owner --uid-owner sslh -p tcp --tcp-flags FIN,SYN,RST,ACK SYN -j CONNMARK --set-xmark 0x01/0x0f
+		ip6tables -t mangle -A OUTPUT ! -o lo -p tcp -m connmark --mark 0x01/0x0f -j CONNMARK --restore-mark --mask 0x0f
+
+		ip -6 rule add fwmark 0x1 lookup 100
+		ip -6 route add local ::/0 dev lo table 100
+	fi
+	
+	set -e
+	set +x
+}
+
+for _args in "${@}" ; do
+	if [ "${_args:-}" = '--transparent' ] ; then
+		echo '--transparent flag is set'
+		configure_iptables
+		trap unconfigure_iptables TERM INT KILL
+		break
+	fi
+done
+
+# Drop privileges and run as sslh user
+sslh_cmd="${entrypoint:+${bin}} ${@}"
+echo "Executing with user 'sslh': ${sslh_cmd}"
+
+exec su - sslh -c "${sslh_cmd}" &
+wait "${!}"
+
+exit 0

doc/FAQ.md

@@ -7,7 +7,7 @@ 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.
+GitHub.
 
 Getting more info
 =================

doc/INSTALL.md

@@ -1,3 +1,12 @@
+Pre-built binaries
+==================
+
+Docker images of `master` and of the tagged versions are
+available directly from [Github](https://github.com/yrutschle/sslh/pkgs/container/sslh).
+
+Windows binaries for Cygwin are graciouly produced by
+nono303 on his [repository](https://github.com/nono303/sslh).
+
 Compile and install
 ===================
 
@@ -7,7 +16,7 @@ Dependencies
 `sslh` uses:
 
 * [libconfig](http://www.hyperrealm.com/libconfig/). For
-  Debian this is contained in package `libconfig8-dev`. You
+  Debian this is contained in package `libconfig-dev`. You
 can compile with or without it using USELIBCONFIG in the
 Makefile.
 
@@ -29,6 +38,13 @@ Makefile.
 which requires `libbsd` at runtime, and `libbsd-dev` at
 compile-time.
 
+* libpcre2, in package `libpcre-dev`. You can compile
+  with or without it using ENABLE_REGEX in the Makefile.
+
+* libev-dev, in package `libev-dev`. If you build a binary
+  specifically and do not build `sslh-ev`, you don't need
+  this.
+
 
 For OpenSUSE, these are contained in packages libconfig9 and
 libconfig-dev in repository
@@ -44,6 +60,10 @@ distclean` for example), you will also need to add
 [conf2struct](https://www.rutschle.net/tech/conf2struct/README.html)
 (v1.5) to your path.
 
+
+The test scripts are written in Perl, and will require
+IO::Socket::INET6 (libio-socket-inet6-perl in Debian).
+
 Compilation
 -----------
 
@@ -68,11 +88,25 @@ of the Makefile:
 * `USELIBBSD` compiles support for updating the process name (as shown
   by `ps`).
 
+Generating the configuration parser
+-----------------------------------
+
+The configuration file and command line parser is generated
+by `conf2struct`, from `sslhconf.cfg`, which generates
+`sslh-conf.c` and `sslh-conf.h`. The resulting files are
+included in the source so `sslh` can be built without
+`conf2struct` installed.
+
+Further, to prevent build issues, `sslh-conf.[ch]` has no
+dependency to `sslhconf.cfg` in the Makefile.  In the event
+of adding configuration settings, they need to be
+regenerated using `make c2s`.
+
 Binaries
 --------
 
-The Makefile produces two different executables: `sslh-fork`
-and `sslh-select`:
+The Makefile produces three different executables: `sslh-fork`,
+`sslh-select` and `sslh-ev`:
 
 * `sslh-fork` forks a new process for each incoming connection.
 It is well-tested and very reliable, but incurs the overhead
@@ -81,18 +115,17 @@ 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.
+* `sslh-select` uses only one thread, which monitors all
+  connections at once. It 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 hundreds of
+connections), or if you are on a system where forking is
+expensive (e.g. Windows), `sslh-select` will be better.
 
+* `sslh-ev` is similar to `sslh-select`, but uses `libev` as
+  a backend. This allows using specific kernel APIs that
+allow to manage thousands of connections concurrently.
 
 Installation
 ------------

doc/README.MacOSX

@@ -33,7 +33,7 @@ with launchctl or simply reboot.
 		<string>0.0.0.0:443</string>
 		<string>--ssh</string>
 		<string>localhost:22</string>
-		<string>--ssl</string>
+		<string>--tls</string>
 		<string>localhost:443</string>
 	</array>
 	<key>QueueDirectories</key>

doc/README.Windows.md

@@ -0,0 +1,72 @@
+It is possible to run `sslh` on Windows. The `fork` model
+should be avoided as it is very inefficient on Windows, but
+`sslh-select` and `sslh-ev` both work with good performance
+(prefer the latter, however).
+
+
+The following script downloads the latest cygwin, the latest version of sslh, and then compiles and copies the binaries with dependancies to an output folder.
+
+It may be needed to correct it from time to time, but it works. I use it in a virtual machine.
+Just retrieve WGET.EXE from [https://eternallybored.org/misc/wget/](url) or git binaries.
+
+Copy the 3 files
+
+	GO.cmd
+	wget.exe
+	compile.sh
+	
+to C root folder, then execute **GO.cmd** with administrative rights.
+
+with **GO.cmd**
+
+	@ECHO OFF
+	CD /D "%~dp0"
+	
+	NET SESSION >NUL 2>&1
+	IF %ERRORLEVEL% NEQ 0 (
+	    ECHO Permission denied. This script must be run as an Administrator.
+	    ECHO:
+	    GOTO FIN
+	) ELSE (
+	    ECHO Running as Administrator.
+	    TIMEOUT /T 2 >NUL
+		wget --no-check-certificate https://www.cygwin.com/setup-x86_64.exe
+		IF NOT EXIST setup-x86_64.exe GOTO FIN
+		MKDIR C:\Z
+		setup-x86_64.exe -l C:\Z -s ftp://ftp.funet.fi/pub/mirrors/sourceware.org/pub/cygwin/ -q -P make -P git -P gcc-g++ -P autoconf -P automake -P libtool -P libpcre-devel -P libpcre2-devel -P bison -P libev-devel
+		MKDIR C:\cygwin64\home\user
+	COPY COMPILE.SH C:\cygwin64\home\user
+			START C:\cygwin64\bin\mintty.exe /bin/bash --login -i ~/compile.sh
+		START EXPLORER C:\zzSORTIE
+	)
+	:FIN
+	PAUSE
+	EXIT
+
+
+and **compile.sh**
+
+	# SAVE FILE TO UNIX FORMAT
+	# COPY IT IN C cygwin64 home user
+	git clone https://github.com/hyperrealm/libconfig.git
+	cd libconfig
+	autoreconf -fi
+	./configure
+	make
+	make install
+	cd ..
+	cp /usr/local/lib/libconfig.* /usr/lib
+	git clone https://github.com/yrutschle/sslh.git
+	cd sslh
+	make
+	cd ..
+	mkdir /cygdrive/c/zzSORTIE
+	cp ./sslh/sslh*.exe /cygdrive/c/zzSORTIE
+	cp /usr/local/bin/cygconfig-11.dll /cygdrive/c/zzSORTIE
+	cp /cygdrive/c/cygwin64/bin/cygwin1.dll /cygdrive/c/zzSORTIE
+	cp /cygdrive/c/cygwin64/bin/cygpcreposix-0.dll /cygdrive/c/zzSORTIE
+	cp /cygdrive/c/cygwin64/bin/cygpcre-1.dll /cygdrive/c/zzSORTIE
+	cp /cygdrive/c/cygwin64/bin/cygev-4.dll /cygdrive/c/zzSORTIE
+	cp /cygdrive/c/cygwin64/bin/cygpcre2-8-0.dll /cygdrive/c/zzSORTIE
+
+This method was contributed by lerenardo on [github](https://github.com/yrutschle/sslh/issues/196#issuecomment-1692805639).

doc/config.md

@@ -65,13 +65,13 @@ Configuration goes like this on the server side, using `stunnel3`:
   * `-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
+	we're listening to for incoming connections
   * `-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.
+  * `--http` to forward HTTP connections to port 80,
+	and SSH connections to port 22.
 
 Capabilities support
 --------------------
@@ -92,165 +92,15 @@ 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.:
+Then you can run sslh-select as an unprivileged 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.
+Transparent proxying is described in its own
+[document](tproxy.md).
 
 Systemd Socket Activation
 -------------------------
@@ -313,7 +163,7 @@ 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.
+overridden 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 
@@ -335,13 +185,15 @@ UDP
 ---
 
 `sslh` can perform demultiplexing on UDP packets as well.
-This only works with `sslh-select` (it is not possible to
+This does not work with `sslh-fork` (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
+which can be overridden with `udp_timeout`. This allows to
 process both single-datagram protocols such as DNS, and
 connection-based protocols such as QUIC.
+
+An example for supporting QUIC is shown in `example.cfg`.

doc/tproxy.md

@@ -1,17 +1,181 @@
-Transparent Proxy to Two Hosts
-==============================
+# Transparent proxy
+
+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).
+
+This document shows recipes that may help to do that.
+
+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. If in trouble,
+it might be worth trying to set up the network rules
+with a simpler server than `sslh`, such as
+[`socat`](http://www.dest-unreach.org/socat/)
+
+
+Users have tried to do at least the following:
+
+  * `sslh` and the target servers run on the same host (see [below](#transparent-proxy-to-one-host))
+  * `sslh` runs on a host, and the target servers run on LXC or dockers running on the same host. No known working setup.
+  * `sslh` runs on a host, and the target servers run on different hosts on the same local network(see [below](#transparent-proxy-to-two-hosts))
+  * `sslh` runs on a host, and the target servers run on a different host on a different network (there is a [usecase](https://github.com/yrutschle/sslh/issues/295) for this). No known working setup, and it's unclear it is possible.
+
+
+## Transparent proxy to one host
+
+### 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
+
+Transparent 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.
+
+
+## Transparent Proxy to Two Hosts
 
 Tutorial by Sean Warner.  19 June 2019 20:35
 
-Aim
----
+### 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
-----------------------
+### 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)
@@ -20,8 +184,7 @@ Two Raspberry Pis on my home LAN:
 
 ![Architecture](tproxy.svg)
 
-`sslh` build
-------------
+### `sslh` build
  
 `sslh` Version: sslh v1.19c-2-gf451cc8-dirty.
 
@@ -47,8 +210,7 @@ MAN=sslh.8.gz          # man page name
 # itself
 ```
  
-systemd setup
--------------
+### systemd setup
 
 Create an sslh systemd service file...
 ```
@@ -83,8 +245,7 @@ Start it again to test…
 # systemctl start sslh
 ```
  
-Configure `sslh`
-----------------
+### Configure `sslh`
 
 First stop `sslh` then open the config file and replace with below, save and start `sslh` again
 ```
@@ -123,8 +284,7 @@ protocols:
 );
 ```
  
-Configure `stunnel`
--------------------
+### Configure `stunnel`
 
 First stop `stunnel` then open the config file and replace with below, save and start `stunnel` again
 ```
@@ -151,8 +311,7 @@ connect = 192.168.1.124:1022
 TIMEOUTclose  = 0
 ```
  
-Configure iptables for Pi A
---------------------------
+### 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..
@@ -194,8 +353,7 @@ Now run the "add" script on Pi A!
 # piA_tproxy_rm.sh
 ```
  
-Configure iptables for Pi B
---------------------------
+## Configure iptables for Pi B
 
 ```
 # nano /usr/local/sbin/piB_tproxy_add.sh
@@ -235,8 +393,8 @@ Now run the "add" script on Pi B!
 # piB_tproxy_rm.sh
 ```
  
-Testing
--------
+### Testing
+
 * Getting to sshd on PiA
 
 I did this test using 4G from my phone (outside the LAN)

echo_test.cfg

@@ -0,0 +1,12 @@
+
+# TODO: c2s does not warn if udp: 1 (instead of 'true')
+
+udp: true;
+
+prefix: "hello";
+
+listen: "localhost:9000";
+
+listen-host: "localhost";
+listen-port: "9000";
+

echosrv-conf.c

@@ -1,5 +1,5 @@
 /* Generated by conf2struct (https://www.rutschle.net/tech/conf2struct/README)
- * on Fri Aug 13 18:03:20 2021. 
+ * on Sat Apr 30 09:55:03 2022. 
 
 # conf2struct: generate libconf parsers that read to structs
 # Copyright (C) 2018-2021  Yves Rutschle
@@ -365,7 +365,7 @@ static int clcpy(config_type type, void* target, const void* cl_arg)
     return 0;
 }
 
-/* Copy the value of a string argument to arbitary memory
+/* Copy the value of a string argument to arbitrary memory
 * location that must be large enough, converting on the way
 * (i.e. CFG_INT gets atoi() and so on) */
 /* 0: success
@@ -862,7 +862,7 @@ static int set_target_fields(void* target_addr, struct compound_cl_arg* arg, con
             if (pmatch[pmatch_cnt].rm_so == -1) {
                 /* This should not happen as regexec() did
                 * match before, unless there is a
-                * discrepency between the regex and the
+                * discrepancy between the regex and the
                 * number of backreferences */
                 return 0;
             }
@@ -1155,7 +1155,7 @@ static void scalar_to_string(char** strp, config_setting_t* s)
 
 /* Typesets all the settings in a configuration as a
 * newly-allocated string. The string management is caller's
-* responsability. 
+* responsibility. 
 * Returns the number of scalars in the configuration */
 static int cfg_as_string(config_setting_t* parent, const char* path, char** strp)
 {

echosrv-conf.h

@@ -1,5 +1,5 @@
 /* Generated by conf2struct (https://www.rutschle.net/tech/conf2struct/README)
- * on Fri Aug 13 18:03:20 2021. 
+ * on Sat Apr 30 09:55:03 2022. 
 
 # conf2struct: generate libconf parsers that read to structs
 # Copyright (C) 2018-2021  Yves Rutschle

echosrv.c

@@ -1,6 +1,6 @@
 /* echosrv: a simple line echo server with optional prefix adding.
  *
- * echsrv --listen localhost6:1234 --prefix "ssl: "
+ * echosrv --listen localhost6:1234 --prefix "ssl: "
  *
  * This will bind to 1234, and echo every line pre-pending "ssl: ". This is
  * used for testing: we create several such servers with different prefixes,
@@ -100,7 +100,10 @@ void tcp_echo(struct listen_endpoint* listen_socket)
 {
     while (1) {
         int in_socket = accept(listen_socket->socketfd, 0, 0);
-        CHECK_RES_DIE(in_socket, "accept");
+        if (in_socket == -1) {
+            perror("tcp_echo:accept");
+            exit(1);
+        }
 
         if (!fork())
         {
@@ -109,6 +112,7 @@ void tcp_echo(struct listen_endpoint* listen_socket)
             exit(0);
         }
         close(in_socket);
+        waitpid(-1, NULL, WNOHANG);
     }
 }
 

echoѕrv-conf.h

@@ -0,0 +1,109 @@
+/* Generated by conf2struct (https://www.rutschle.net/tech/conf2struct/README)
+ * on Sat Nov  7 09:19:26 2020. 
+
+# conf2struct: generate libconf parsers that read to structs
+# Copyright (C) 2018-2019  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	keepalive;
+};
+
+struct sslhcfg_protocols_item {
+	char*	name;
+	char*	host;
+	char*	port;
+	int	service_is_present;
+	char*	service;
+	int	fork;
+	int	tfo_ok;
+	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 {
+	char*	prefix;
+	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;
+	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

example.cfg

@@ -3,7 +3,6 @@
 # not be used as a starting point for a working
 # configuration. Instead use basic.cfg.
 
-verbose: 0;
 foreground: true;
 inetd: false;
 numeric: false;
@@ -13,6 +12,30 @@ user: "nobody";
 pidfile: "/var/run/sslh.pid";
 chroot: "/var/empty";
 
+# Logging configuration
+# Value: 1: stdout; 2: syslog; 3: stdout+syslog; 4: logfile; ...; 7: all
+# Defaults are indicated here, and should be sensible. Generally, you want *-error
+# to be always enabled, to know if something is going wrong.
+verbose-config: 0; #  print configuration at startup
+verbose-config-error: 3;  # print configuration errors
+verbose-connections: 3; # trace established incoming address to forward address
+verbose-connections-error: 3; # connection errors
+verbose-connections-try: 0; # connection attempts towards targets
+verbose-fd: 0; # file descriptor activity, open/close/whatnot
+verbose-packets: 0; # hexdump packets on which probing is done
+verbose-probe-info: 0; # what's happening during the probe process
+verbose-probe-error: 3; # failures and problems during probing
+verbose-system-error: 3; # system call problem, i.e.  malloc, fork, failing
+verbose-int-error: 3; # internal errors, the kind that should never happen
+
+
+# Specify a path to the logfile.
+#logfile: "/var/log/sslh.log"
+
+# Specify the number of concurrent UDP connection that can
+# be managed (default 1024)
+udp_max_connections: 16;
+
 # Specify which syslog facility to use (names for your
 # system are usually defined in /usr/include/*/sys/syslog.h
 # or equivalent)
@@ -44,6 +67,8 @@ listen:
 #   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
+#   resolve_on_forward: Set to true if server address should be resolved on
+#         (every) newly incoming connection (again)
 #   transparent: Set to true to proxy this protocol
 #         transparently (server sees the remote client IP
 #         address). Same as the global option, but per-protocol
@@ -98,7 +123,7 @@ protocols:
                       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" ]; },
+     { name: "teamspeak"; host: "localhost"; is_udp: true; port: "9987"; },
 # 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" ]; },

gap.c

@@ -31,19 +31,14 @@
 #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)
+/* Creates a new gap at least `len` big, all pointers are initialised at NULL */
+gap_array* gap_init(int len)
 {
     gap_array* gap = malloc(sizeof(*gap));
     if (!gap) return NULL;
@@ -51,8 +46,12 @@ gap_array* gap_init(void)
 
     int elem_size = sizeof(gap->array[0]);
     gap->len = gap_len_alloc(elem_size);
+    if (gap->len < len) gap->len = len;
     gap->array = malloc(gap->len * elem_size);
-    if (!gap->array) return NULL;
+    if (!gap->array) {
+        free(gap);
+        return NULL;
+    }
 
     for (int i = 0; i < gap->len; i++)
         gap->array[i] = NULL;
@@ -60,12 +59,7 @@ gap_array* gap_init(void)
     return gap;
 }
 
-void* gap_get(gap_array* gap, int index)
-{
-    return gap->array[index];
-}
-
-static int gap_extend(gap_array* gap)
+int gap_extend(gap_array* gap)
 {
     int elem_size = sizeof(gap->array[0]);
     int new_length = gap->len + gap_len_alloc(elem_size);
@@ -83,17 +77,6 @@ static int gap_extend(gap_array* gap)
     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);
@@ -119,7 +102,7 @@ int gap_remove_ptr(gap_array* gap, void* ptr, int len)
     else
         return -1;
 
-    for (i = start; i < len; i++) {
+    for (i = start; i < len - 1; i++) {
         gap->array[i] = gap->array[i+1];
     }
 

gap.h

@@ -3,11 +3,41 @@
 
 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);
+gap_array* gap_init(int len);
+static void* gap_get(gap_array* gap, int index);
+static 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);
 
+/* Private declarations to allow inlining.
+ * Don't assume my implementation. */
+typedef struct gap_array {
+    int len; /* Number of elements in array */
+    void** array;
+} gap_array;
+
+int gap_extend(gap_array* gap);
+
+static inline int __attribute__((unused)) gap_set(gap_array* gap, int index, void* ptr)
+{
+    while (index >= gap->len) {
+        int res = gap_extend(gap);
+        if (res == -1) return -1;
+    }
+
+    gap->array[index] = ptr;
+    return 0;
+}
+
+static inline void* __attribute__((unused)) gap_get(gap_array* gap, int index)
+{
+    /* sslh-ev routinely reads before it writes. It's not clear if it should be
+     * its job to check the length (and add a gap_getlen()), or if it should be
+     * gap_get()'s job. This will do for now */
+    if (index >= gap->len) return NULL;
+
+    return gap->array[index];
+}
+
 #endif

genver.sh

@@ -10,14 +10,14 @@ fi
 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. 
-        
+        # zip file.
+
         # If downloaded from the release page, the directory
         # has the version number.
         release=`pwd | sed s/.*sslh-// | grep "[[:digit:]]"`
-        
+
         if [ "x$release" = "x" ]; then
-            # If downloaded from the head, Github creates the
+            # If downloaded from the head, GitHub creates the
             # zip file with all files dated from the last
             # change: use the Makefile's modification time as a
             # release number
@@ -28,7 +28,7 @@ fi
 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'`
+		2>/dev/null | tr -s '/' '-' | tr -d '\n'`
 
 	# Are there uncommitted changes?
 	git update-index --refresh --unmerged > /dev/null

hash.c

@@ -0,0 +1,224 @@
+/* 
+ * a fixed-sized hash
+ *
+# Copyright (C) 2022  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
+#
+# */
+
+
+/*  * The hash is open-addressing, linear search, robin-hood insertion, with 
+ * backward shift deletion. References:
+ * https://codecapsule.com/2013/11/11/robin-hood-hashing/
+ * https://codecapsule.com/2013/11/17/robin-hood-hashing-backward-shift-deletion/
+ * This means items are reordered upon insertion and deletion, and the hash
+ * is well-ordered at all times with no tombstones.
+ *
+ * Each pointer is either:
+ * - to a connection struct
+ * - FREE (NULL) if not allocated
+ *
+ * */
+
+#include <stdlib.h>
+#include <stddef.h>
+
+#include "gap.h"
+
+typedef void* hash_item;
+#include "hash.h"
+
+static void* const FREE = NULL;
+
+struct hash {
+    int hash_size;      /* Max number of items in the hash */
+    int item_cnt;       /* Number of items in the hash */
+    gap_array* data;
+
+    hash_make_key_fn hash_make_key;
+    hash_cmp_item_fn cmp_item;
+};
+
+typedef struct hash hash;
+
+
+static int hash_make_key(hash* h, hash_item item)
+{
+    return h->hash_make_key(item) % h->hash_size;
+}
+
+
+hash* hash_init(int hash_size, hash_make_key_fn make_key, hash_cmp_item_fn cmp_item)
+{
+    hash* h = malloc(sizeof(*h));
+    if (!h) return NULL;
+
+    h->hash_size = hash_size;
+    h->item_cnt = 0;
+    h->data = gap_init(hash_size);
+    h->hash_make_key = make_key;
+    h->cmp_item = cmp_item;
+
+    return h;
+}
+
+/* Return the index following i in h */
+static int hash_next_index(hash* h, int i)
+{
+    return (i + 1) % h->hash_size;
+}
+
+/* Returns the index in h of specified address, -1 if not found 
+ * item is an item object that must return the target wanted index and for
+ * which comparison with the searched object will succeed.
+ * */
+static int hash_find_index(hash* h, hash_item item)
+{
+    hash_item cnx;
+    int index = hash_make_key(h, item);
+    int cnt = 0;
+
+    cnx = gap_get(h->data, index);
+#ifdef DEBUG
+    fprintf(stderr, "searching %d\n", index);
+#endif
+    while (cnx != FREE) {
+        if (cnt++ > h->hash_size) return -1;
+
+        if (!h->cmp_item(cnx, item))
+            break;
+
+        index = hash_next_index(h, index);
+        cnx = gap_get(h->data, index);
+#ifdef DEBUG
+        fprintf(stderr, "searching %d\n", index);
+#endif
+    } 
+    if (cnx == FREE) return -1;
+    return index;
+}
+
+hash_item hash_find(hash* h, hash_item item)
+{
+    int index = hash_find_index(h, item);
+    if (index == -1) return NULL;
+    hash_item out = gap_get(h->data, index);
+    return out;
+}
+
+
+/* Returns DIB: distance to initial bucket */
+static int distance(int current_index, hash* h, hash_item item)
+{
+    int wanted_index = hash_make_key(h, item);
+    if (wanted_index <= current_index)
+        return current_index - wanted_index;
+    else
+        return current_index - wanted_index + h->hash_size;
+}
+
+
+int hash_insert(hash* h, hash_item new)
+{
+    int bubble_wanted_index = hash_make_key(h, new);
+    int index = bubble_wanted_index;
+    gap_array* hash = h->data;
+
+    if (h->item_cnt == h->hash_size)
+        return -1;
+
+    hash_item curr_item = gap_get(hash, index);
+    while (curr_item) {
+        if (distance(index, h, curr_item) < distance(index, h, new)) {
+            gap_set(h->data, index, new);
+#if DEBUG
+            fprintf(stderr, "intermediate insert [%s] at %d\n", &new->client_addr, index);
+#endif
+            new = curr_item;
+        }
+
+        index = hash_next_index(h, index);
+        curr_item = gap_get(hash, index);
+    }
+
+#if DEBUG
+    fprintf(stderr, "final insert at %d\n", index);
+#endif
+    gap_set(hash, index, new);
+    h->item_cnt++;
+
+    return 0;
+}
+
+/* Remove cnx from the hash */
+int hash_remove(hash* h, hash_item item)
+{
+    gap_array* hash = h->data;
+
+    int index = hash_find_index(h, item);
+    if (index == -1) return -1; /* Tried to remove something that isn't there */
+
+    while (1) {
+        int next_index = hash_next_index(h, index);
+        hash_item next = gap_get(h->data, next_index);
+        if ((next == FREE) || (distance(next_index, h, next) == 0)) {
+            h->item_cnt--;
+            gap_set(hash, index, FREE);
+            return 0;
+        }
+
+        gap_set(hash, index, next);
+
+        index = hash_next_index(h, index);;
+    }
+    return 0;
+}
+
+#if HASH_TESTING
+#include <stdio.h>
+#include <string.h>
+#define STR_LENGTH 16
+struct hash_item {
+    int wanted_index;
+    char str[STR_LENGTH];
+};
+void hash_dump(hash* h, char* filename)
+{
+    char str[STR_LENGTH];
+    FILE* out = fopen(filename, "w");
+
+    if (!out) {
+        perror(filename);
+        exit(1);
+    }
+    
+    fprintf(out, "<hash elem=%d>\n", h->item_cnt);
+    for (int i = 0; i < h->hash_size; i++) {
+        hash_item item = gap_get(h->data, i);
+        int idx = 0;
+
+        memset(str, 0, STR_LENGTH);
+        if (item) {
+            idx = hash_make_key(h, item);
+            memcpy(str, ((struct hash_item*)item)->str, STR_LENGTH);
+        }
+        fprintf(out, "\t%d:%d:%s\n", i, idx, str);
+    }
+    fprintf(out, "</hash>\n");
+    fclose(out);
+}
+#endif

hash.h

@@ -0,0 +1,28 @@
+#ifndef HASH_H
+#define HASH_H
+
+/* You will need to typedef a pointer type to hash_item before including this
+ * .h */
+
+typedef struct hash hash;
+
+/* Function that returns a key (index) for a given item. The key must be always
+ * the same for an item. It doesn't need to be bounded (hash.c masks it for you) */
+typedef int (*hash_make_key_fn)(hash_item item);
+
+/* Function that compares two items: returns 0 if they are the same */
+typedef int (*hash_cmp_item_fn)(hash_item item1, hash_item item2);
+
+hash* hash_init(int hash_size, hash_make_key_fn make_key, hash_cmp_item_fn cmp_item);
+
+int hash_insert(hash* h, hash_item new);
+int hash_remove(hash* h, hash_item item);
+
+/* Returns the hash item that matches specification (meaning the
+ * comparison function returns true for cmp(x, item), or NULL if not found */
+hash_item hash_find(hash* h, hash_item item);
+
+
+void hash_dump(hash* h, char* filename); /* For development only */
+
+#endif

hashtest/Makefile

@@ -0,0 +1,7 @@
+
+CFLAGS=-DHASH_TESTING -O2 -Wall
+OBJ=../hash.o ../gap.o htest.o
+
+htest: $(OBJ)
+	$(CC) -o htest $(OBJ)
+

hashtest/delete.tst

@@ -0,0 +1,8 @@
+# Basic delete
+a 10 aa
+a 10 ab
+a 10 ac
+a 20 ba
+a 21 bb
+
+d 21 bb

hashtest/delete.tst.ref

@@ -0,0 +1,34 @@
+<hash elem=4>
+	0:0:
+	1:0:
+	2:0:
+	3:0:
+	4:0:
+	5:0:
+	6:0:
+	7:0:
+	8:0:
+	9:0:
+	10:10:aa
+	11:10:ab
+	12:10:ac
+	13:0:
+	14:0:
+	15:0:
+	16:0:
+	17:0:
+	18:0:
+	19:0:
+	20:20:ba
+	21:0:
+	22:0:
+	23:0:
+	24:0:
+	25:0:
+	26:0:
+	27:0:
+	28:0:
+	29:0:
+	30:0:
+	31:0:
+</hash>

hashtest/delete_at_end.tst

@@ -0,0 +1,9 @@
+# Delete inside a block with nothing after
+
+a 10 aa
+a 10 ab
+a 12 ac
+a 13 ad
+a 14 ae
+
+d 14 ae

hashtest/delete_at_end.tst.ref

@@ -0,0 +1,34 @@
+<hash elem=4>
+	0:0:
+	1:0:
+	2:0:
+	3:0:
+	4:0:
+	5:0:
+	6:0:
+	7:0:
+	8:0:
+	9:0:
+	10:10:aa
+	11:10:ab
+	12:12:ac
+	13:13:ad
+	14:0:
+	15:0:
+	16:0:
+	17:0:
+	18:0:
+	19:0:
+	20:0:
+	21:0:
+	22:0:
+	23:0:
+	24:0:
+	25:0:
+	26:0:
+	27:0:
+	28:0:
+	29:0:
+	30:0:
+	31:0:
+</hash>

hashtest/delete_below_floor.tst

@@ -0,0 +1,9 @@
+# wrap-around and delete below floor
+a 2 ba
+a 30 aa
+a 30 ab
+a 30 ac
+a 30 ad
+a 2 bb
+
+d 30 ab

hashtest/delete_below_floor.tst.ref

@@ -0,0 +1,34 @@
+<hash elem=5>
+	0:30:ad
+	1:0:
+	2:2:ba
+	3:2:bb
+	4:0:
+	5:0:
+	6:0:
+	7:0:
+	8:0:
+	9:0:
+	10:0:
+	11:0:
+	12:0:
+	13:0:
+	14:0:
+	15:0:
+	16:0:
+	17:0:
+	18:0:
+	19:0:
+	20:0:
+	21:0:
+	22:0:
+	23:0:
+	24:0:
+	25:0:
+	26:0:
+	27:0:
+	28:0:
+	29:0:
+	30:30:aa
+	31:30:ac
+</hash>

hashtest/delete_discont.tst

@@ -0,0 +1,10 @@
+# delete in a discontinuous block
+
+a 10 aa
+a 11 ab
+a 12 ac
+a 14 ad
+a 10 bc
+
+d 11 ab
+

hashtest/delete_discont.tst.ref

@@ -0,0 +1,34 @@
+<hash elem=4>
+	0:0:
+	1:0:
+	2:0:
+	3:0:
+	4:0:
+	5:0:
+	6:0:
+	7:0:
+	8:0:
+	9:0:
+	10:10:aa
+	11:10:bc
+	12:12:ac
+	13:0:
+	14:14:ad
+	15:0:
+	16:0:
+	17:0:
+	18:0:
+	19:0:
+	20:0:
+	21:0:
+	22:0:
+	23:0:
+	24:0:
+	25:0:
+	26:0:
+	27:0:
+	28:0:
+	29:0:
+	30:0:
+	31:0:
+</hash>

hashtest/delete_empty.tst

@@ -0,0 +1,11 @@
+# Delete an unexisting element. And on an empty hash
+
+a 10 aa
+
+d 10 ab
+d 12 bc
+
+# Empty for real
+d 10 aa
+
+d 10 aa

hashtest/delete_empty.tst.ref

@@ -0,0 +1,34 @@
+<hash elem=0>
+	0:0:
+	1:0:
+	2:0:
+	3:0:
+	4:0:
+	5:0:
+	6:0:
+	7:0:
+	8:0:
+	9:0:
+	10:0:
+	11:0:
+	12:0:
+	13:0:
+	14:0:
+	15:0:
+	16:0:
+	17:0:
+	18:0:
+	19:0:
+	20:0:
+	21:0:
+	22:0:
+	23:0:
+	24:0:
+	25:0:
+	26:0:
+	27:0:
+	28:0:
+	29:0:
+	30:0:
+	31:0:
+</hash>

hashtest/delete_full.tst

@@ -0,0 +1,39 @@
+# delete on a full hash
+
+# First, fill the hash :-)
+
+a 0 aa
+a 1 ab
+a 2 ac
+a 3 ad
+a 4 ae
+a 5 af
+a 6 ag 
+a 7 ah
+a 8 ai
+a 9 af
+a 10 ba
+a 11 bb
+a 12 bc
+a 13 bd
+a 14 be 
+a 15 bf
+a 16 bg
+a 17 bh
+a 18 bi
+a 19 bj
+a 20 ca
+a 21 cb
+a 22 cd
+a 23 ce
+a 24 cf
+a 25 cg
+a 26 ch
+a 27 ci
+a 28 cj
+a 29 ck
+a 30 da
+a 31 db
+
+
+d 21 cb

hashtest/delete_full.tst.ref

@@ -0,0 +1,34 @@
+<hash elem=31>
+	0:0:aa
+	1:1:ab
+	2:2:ac
+	3:3:ad
+	4:4:ae
+	5:5:af
+	6:6:ag
+	7:7:ah
+	8:8:ai
+	9:9:af
+	10:10:ba
+	11:11:bb
+	12:12:bc
+	13:13:bd
+	14:14:be
+	15:15:bf
+	16:16:bg
+	17:17:bh
+	18:18:bi
+	19:19:bj
+	20:20:ca
+	21:0:
+	22:22:cd
+	23:23:ce
+	24:24:cf
+	25:25:cg
+	26:26:ch
+	27:27:ci
+	28:28:cj
+	29:29:ck
+	30:30:da
+	31:31:db
+</hash>

hashtest/delete_middle.tst

@@ -0,0 +1,10 @@
+# Delete inside a block with something discontinuous
+
+a 10 aa
+a 10 ab
+a 12 ac
+a 13 ad
+a 14 ae
+
+# ab shifts, ac and next doesn't
+d 10 aa

hashtest/delete_middle.tst.ref

@@ -0,0 +1,34 @@
+<hash elem=4>
+	0:0:
+	1:0:
+	2:0:
+	3:0:
+	4:0:
+	5:0:
+	6:0:
+	7:0:
+	8:0:
+	9:0:
+	10:10:ab
+	11:0:
+	12:12:ac
+	13:13:ad
+	14:14:ae
+	15:0:
+	16:0:
+	17:0:
+	18:0:
+	19:0:
+	20:0:
+	21:0:
+	22:0:
+	23:0:
+	24:0:
+	25:0:
+	26:0:
+	27:0:
+	28:0:
+	29:0:
+	30:0:
+	31:0:
+</hash>

hashtest/delete_wrap.tst

@@ -0,0 +1,8 @@
+# Basic delete when wrapping, between wrap and floor
+a 30 aa
+a 30 ab
+a 30 ac
+a 30 ba
+a 30 bb
+
+d 30 ac

hashtest/delete_wrap.tst.ref

@@ -0,0 +1,34 @@
+<hash elem=4>
+	0:30:ba
+	1:30:bb
+	2:0:
+	3:0:
+	4:0:
+	5:0:
+	6:0:
+	7:0:
+	8:0:
+	9:0:
+	10:0:
+	11:0:
+	12:0:
+	13:0:
+	14:0:
+	15:0:
+	16:0:
+	17:0:
+	18:0:
+	19:0:
+	20:0:
+	21:0:
+	22:0:
+	23:0:
+	24:0:
+	25:0:
+	26:0:
+	27:0:
+	28:0:
+	29:0:
+	30:30:aa
+	31:30:ab
+</hash>

hashtest/delete_wrap_at_end.tst

@@ -0,0 +1,10 @@
+# Delete inside a block with wrapping, with something after
+
+a 30 aa
+a 30 ab
+a 30 ac
+a 1 ad
+a 3 ae
+
+# shift ad but not ae
+d 14 ae

hashtest/delete_wrap_at_end.tst.ref

@@ -0,0 +1,34 @@
+<hash elem=5>
+	0:30:ac
+	1:1:ad
+	2:0:
+	3:3:ae
+	4:0:
+	5:0:
+	6:0:
+	7:0:
+	8:0:
+	9:0:
+	10:0:
+	11:0:
+	12:0:
+	13:0:
+	14:0:
+	15:0:
+	16:0:
+	17:0:
+	18:0:
+	19:0:
+	20:0:
+	21:0:
+	22:0:
+	23:0:
+	24:0:
+	25:0:
+	26:0:
+	27:0:
+	28:0:
+	29:0:
+	30:30:aa
+	31:30:ab
+</hash>

hashtest/delete_wrap_below_floor.tst

@@ -0,0 +1,8 @@
+# delete before wrap
+a 30 aa
+a 30 ab
+a 30 ac
+a 30 ad
+
+# shift ac and ad
+d 30 ab

hashtest/delete_wrap_below_floor.tst.ref

@@ -0,0 +1,34 @@
+<hash elem=3>
+	0:30:ad
+	1:0:
+	2:0:
+	3:0:
+	4:0:
+	5:0:
+	6:0:
+	7:0:
+	8:0:
+	9:0:
+	10:0:
+	11:0:
+	12:0:
+	13:0:
+	14:0:
+	15:0:
+	16:0:
+	17:0:
+	18:0:
+	19:0:
+	20:0:
+	21:0:
+	22:0:
+	23:0:
+	24:0:
+	25:0:
+	26:0:
+	27:0:
+	28:0:
+	29:0:
+	30:30:aa
+	31:30:ac
+</hash>

hashtest/delete_wrap_discont.tst

@@ -0,0 +1,11 @@
+# Delete with wrapping in discontinuous group
+
+a 30 aa
+a 30 ab
+a 30 ac
+a 31 ad
+a 2 ba
+a 3 bb
+
+# shift ac and ad but not ba and bb
+d 30 ab

hashtest/delete_wrap_discont.tst.ref

@@ -0,0 +1,34 @@
+<hash elem=5>
+	0:31:ad
+	1:0:
+	2:2:ba
+	3:3:bb
+	4:0:
+	5:0:
+	6:0:
+	7:0:
+	8:0:
+	9:0:
+	10:0:
+	11:0:
+	12:0:
+	13:0:
+	14:0:
+	15:0:
+	16:0:
+	17:0:
+	18:0:
+	19:0:
+	20:0:
+	21:0:
+	22:0:
+	23:0:
+	24:0:
+	25:0:
+	26:0:
+	27:0:
+	28:0:
+	29:0:
+	30:30:aa
+	31:30:ac
+</hash>

hashtest/htest.c

@@ -0,0 +1,109 @@
+/* Wee testing program from the hash code:
+ * htest <script> <dump>
+ *
+ * scripts are a list of operations:
+ * a $index $string
+ * => add an element at specified index
+ * d $index $string
+ * => remove an element
+ * s $index $string
+ * => prints the actual element index, if it's there
+ *
+ * The hash is dumped to the dump file at each iteration.
+ */
+
+
+#include <stdlib.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+
+
+/* tests have been written for a hash that holds 32 items */
+#define HASH_SIZE 32
+
+#define STR_LENGTH 16
+struct hash_item {
+    int wanted_index;
+    char str[STR_LENGTH];
+};
+
+typedef struct hash_item* hash_item;
+
+#include "../hash.h"
+
+
+
+static int cmp_item(hash_item item1, hash_item item2)
+{
+    return strcmp(item1->str, item2->str);
+}
+
+
+static int hash_make_key(hash_item item)
+{
+    return item->wanted_index;
+}
+
+
+static void htest_next_key(FILE* f, char* action, int* key, char str[STR_LENGTH])
+{
+
+    int res = 0;
+    while ((res != 3) && (res != EOF))
+        res = fscanf(f, "%c %d %s\n", action, key, str);
+    if (res == EOF) exit(0);
+}
+
+int main(int argc, char* argv[])
+{
+    hash* h = hash_init(HASH_SIZE, &hash_make_key, &cmp_item);
+    char action;
+    hash_item item;
+    int line = 0;
+    FILE* f;
+
+    if (argc != 3) {
+        fprintf(stderr, "Usage: htest <script file> <dump file>\n");
+        exit(1);
+    }
+    char* script_file = argv[1];
+    char* dump_file = argv[2];
+    f = fopen(argv[1], "r");
+    if (!f) {
+        perror(script_file);
+        exit(1);
+    }
+
+    while (1) {
+        item= malloc(sizeof(*item));
+        action = ' ';
+
+        line++;
+        htest_next_key(f, &action, &item->wanted_index, item->str);
+        fprintf(stderr, "action %d: %c %d %s\n", line, action, item->wanted_index, item->str);
+
+        switch (action) {
+        case 'a': /* add */
+            fprintf(stderr, "inserting [%s] at %d\n", item->str, item->wanted_index);
+            hash_insert(h, item);
+            break;
+
+        case 'd': /* del */
+            fprintf(stderr, "removing [%s] at %d\n", item->str, item->wanted_index);
+            hash_remove(h, item);
+            break;
+
+        case 's': /* search */
+            fprintf(stderr, "searching\n");
+            struct hash_item* found = hash_find(h, item);
+            fprintf(stderr, "searching %d[%s]: %p\n", item->wanted_index, item->str, found);
+            break;
+
+        case 'q': /* quit */
+            exit(1);
+        }
+        hash_dump(h, dump_file);
+    }
+    return 0;
+}

hashtest/insert.tst

@@ -0,0 +1,6 @@
+# Basic insertions
+a 10 aa
+a 10 ab
+a 10 ac
+a 20 ba
+a 21 bb

hashtest/insert.tst.ref

@@ -0,0 +1,34 @@
+<hash elem=5>
+	0:0:
+	1:0:
+	2:0:
+	3:0:
+	4:0:
+	5:0:
+	6:0:
+	7:0:
+	8:0:
+	9:0:
+	10:10:aa
+	11:10:ab
+	12:10:ac
+	13:0:
+	14:0:
+	15:0:
+	16:0:
+	17:0:
+	18:0:
+	19:0:
+	20:20:ba
+	21:21:bb
+	22:0:
+	23:0:
+	24:0:
+	25:0:
+	26:0:
+	27:0:
+	28:0:
+	29:0:
+	30:0:
+	31:0:
+</hash>

hashtest/insert_discont.tst

@@ -0,0 +1,8 @@
+# insert and bubble with single empty space
+
+a 10 aa
+a 11 ab
+a 12 ac
+a 14 ad
+a 10 bc
+

hashtest/insert_discont.tst.ref

@@ -0,0 +1,34 @@
+<hash elem=5>
+	0:0:
+	1:0:
+	2:0:
+	3:0:
+	4:0:
+	5:0:
+	6:0:
+	7:0:
+	8:0:
+	9:0:
+	10:10:aa
+	11:10:bc
+	12:11:ab
+	13:12:ac
+	14:14:ad
+	15:0:
+	16:0:
+	17:0:
+	18:0:
+	19:0:
+	20:0:
+	21:0:
+	22:0:
+	23:0:
+	24:0:
+	25:0:
+	26:0:
+	27:0:
+	28:0:
+	29:0:
+	30:0:
+	31:0:
+</hash>

hashtest/insert_full.tst

@@ -0,0 +1,40 @@
+# Insert on a full hash
+
+# First, fill the hash :-)
+
+a 0 aa
+a 1 ab
+a 2 ac
+a 3 ad
+a 4 ae
+a 5 af
+a 6 ag 
+a 7 ah
+a 8 ai
+a 9 af
+a 10 ba
+a 11 bb
+a 12 bc
+a 13 bd
+a 14 be 
+a 15 bf
+a 16 bg
+a 17 bh
+a 18 bi
+a 19 bj
+a 20 ca
+a 21 cb
+a 22 cd
+a 23 ce
+a 24 cf
+a 25 cg
+a 26 ch
+a 27 ci
+a 28 cj
+a 29 ck
+a 30 da
+a 31 db
+
+# it's full!
+a 20 zz
+a 31 za

hashtest/insert_full.tst.ref

@@ -0,0 +1,34 @@
+<hash elem=32>
+	0:0:aa
+	1:1:ab
+	2:2:ac
+	3:3:ad
+	4:4:ae
+	5:5:af
+	6:6:ag
+	7:7:ah
+	8:8:ai
+	9:9:af
+	10:10:ba
+	11:11:bb
+	12:12:bc
+	13:13:bd
+	14:14:be
+	15:15:bf
+	16:16:bg
+	17:17:bh
+	18:18:bi
+	19:19:bj
+	20:20:ca
+	21:21:cb
+	22:22:cd
+	23:23:ce
+	24:24:cf
+	25:25:cg
+	26:26:ch
+	27:27:ci
+	28:28:cj
+	29:29:ck
+	30:30:da
+	31:31:db
+</hash>

hashtest/insert_full_floor.tst

@@ -0,0 +1,7 @@
+# wrap-around and insert at full floor
+a 2 ba
+a 30 aa
+a 30 ab
+a 30 ac
+a 30 ad
+a 2 bb

hashtest/insert_full_floor.tst.ref

@@ -0,0 +1,34 @@
+<hash elem=6>
+	0:30:ac
+	1:30:ad
+	2:2:ba
+	3:2:bb
+	4:0:
+	5:0:
+	6:0:
+	7:0:
+	8:0:
+	9:0:
+	10:0:
+	11:0:
+	12:0:
+	13:0:
+	14:0:
+	15:0:
+	16:0:
+	17:0:
+	18:0:
+	19:0:
+	20:0:
+	21:0:
+	22:0:
+	23:0:
+	24:0:
+	25:0:
+	26:0:
+	27:0:
+	28:0:
+	29:0:
+	30:30:aa
+	31:30:ab
+</hash>

hashtest/insert_wrap.tst

@@ -0,0 +1,7 @@
+# wrap-around and insert above floor
+a 30 aa
+a 30 ab
+a 30 ac
+a 30 ad
+a 0 ba
+a 0 bb

hashtest/insert_wrap.tst.ref

@@ -0,0 +1,34 @@
+<hash elem=6>
+	0:30:ac
+	1:30:ad
+	2:0:ba
+	3:0:bb
+	4:0:
+	5:0:
+	6:0:
+	7:0:
+	8:0:
+	9:0:
+	10:0:
+	11:0:
+	12:0:
+	13:0:
+	14:0:
+	15:0:
+	16:0:
+	17:0:
+	18:0:
+	19:0:
+	20:0:
+	21:0:
+	22:0:
+	23:0:
+	24:0:
+	25:0:
+	26:0:
+	27:0:
+	28:0:
+	29:0:
+	30:30:aa
+	31:30:ab
+</hash>

hashtest/mkrand.pl

@@ -0,0 +1,41 @@
+#! /usr/bin/perl
+
+# Creates a script of random accesses and deletes
+
+use strict;
+
+
+my $i = 0;
+sub mkstr {
+    $i++;
+    return chr(ord('a') + ($i / 26) % 26) . chr(ord('a') + $i % 26);
+}
+
+my @elems;
+
+
+sub add_elem {
+    my $val = int(rand(32));
+    my $str = mkstr($val);
+    push @elems, "$val $str";
+    print "a $val $str\n";
+}
+
+sub del_elem {
+    my $remove = splice(@elems, rand @elems, 1);
+    print "d $remove\n";
+}
+
+while (1) {
+    if (@elems < 5) {
+        add_elem;
+    } elsif (@elems > 28) {
+        del_elem;
+    } else {
+        if (rand() < .5) {
+            add_elem;
+        } else {
+            del_elem;
+        }
+    }
+}

hashtest/run

@@ -0,0 +1,30 @@
+#! /usr/bin/perl -w
+
+# This runs all the tests.
+
+# Tests scripts are in *.tst files.
+# Corresponding output is put in *.out.
+# Reference output is put in *.ref.
+# Any discrepancy will be reported!
+
+use strict;
+
+my @res;
+foreach my $fn (`ls *.tst`) {
+    chomp $fn;
+    my $cmd = "./htest $fn $fn.out";
+    print "$cmd\n";
+    `$cmd`;
+    my $res = system("diff -u $fn.ref $fn.out");
+    push @res, [$fn, ($res == 0 ? "OK" : "*KO*")];
+}
+
+format =
+@<<<<<<<<<<<<<<<<<<<<<<<<<< @>>>
+$_->[0], $_->[1]
+.
+
+
+#format_name STDOUT test_result;
+map { write; } @res;
+

landlock.c

@@ -0,0 +1,156 @@
+/*
+ * Setup a sandbox using the Landlock LSM, if available.
+
+# Copyright (C) 2023  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 "config.h"
+#include "log.h"
+
+#ifdef HAVE_LANDLOCK
+
+#define _GNU_SOURCE
+#include <linux/landlock.h>
+#include <sys/prctl.h>
+#include <sys/syscall.h>
+
+/* Ubuntu 22.04 does not have this symbol */
+#ifndef LANDLOCK_ACCESS_FS_REFER
+#define LANDLOCK_ACCESS_FS_REFER			(1ULL << 13)
+#endif
+
+#ifndef landlock_create_ruleset
+static inline int
+landlock_create_ruleset(const struct landlock_ruleset_attr *const attr,
+			const size_t size, const __u32 flags)
+{
+	return syscall(__NR_landlock_create_ruleset, attr, size, flags);
+}
+#endif
+
+#ifndef landlock_add_rule
+static inline int landlock_add_rule(const int ruleset_fd,
+				    const enum landlock_rule_type rule_type,
+				    const void *const rule_attr,
+				    const __u32 flags)
+{
+	return syscall(__NR_landlock_add_rule, ruleset_fd, rule_type, rule_attr,
+		       flags);
+}
+#endif
+
+#ifndef landlock_restrict_self
+static inline int landlock_restrict_self(const int ruleset_fd,
+					 const __u32 flags)
+{
+	return syscall(__NR_landlock_restrict_self, ruleset_fd, flags);
+}
+#endif
+
+typedef enum {
+    LL_TREE,
+    LL_FILE
+} ll_obj_type;
+
+static int add_path_ro(int ruleset_fd, ll_obj_type otype, const char* path)
+{
+    int fd = open(path, O_PATH | O_CLOEXEC);
+    if (fd < 0) {
+        print_message(msg_config_error, "Landlock: Failed to open %s: %s\n", path, strerror(errno));
+        return -1;
+    }
+
+    struct landlock_path_beneath_attr path_beneath = {
+        .allowed_access = (otype == LL_TREE ? LANDLOCK_ACCESS_FS_READ_DIR : 0 ) |
+                          LANDLOCK_ACCESS_FS_READ_FILE,
+        .parent_fd = fd,
+    };
+
+    int res = landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH, &path_beneath, 0);
+    if (res) {
+        print_message(msg_config_error, "Landlock: Failed to update the ruleset with \"%s\": %s\n",
+                path, strerror(errno));
+        close(path_beneath.parent_fd);
+        return -1;
+    }
+
+    return 0;
+}
+
+
+void setup_landlock(void)
+{
+    __u64 restrict_rules = 
+        LANDLOCK_ACCESS_FS_EXECUTE |
+        LANDLOCK_ACCESS_FS_READ_FILE |
+        LANDLOCK_ACCESS_FS_READ_DIR |
+        LANDLOCK_ACCESS_FS_WRITE_FILE |
+        LANDLOCK_ACCESS_FS_REMOVE_DIR |
+        LANDLOCK_ACCESS_FS_REMOVE_FILE |
+        LANDLOCK_ACCESS_FS_MAKE_CHAR |
+        LANDLOCK_ACCESS_FS_MAKE_DIR |
+        LANDLOCK_ACCESS_FS_MAKE_REG |
+        LANDLOCK_ACCESS_FS_MAKE_SOCK |
+        LANDLOCK_ACCESS_FS_MAKE_FIFO |
+        LANDLOCK_ACCESS_FS_MAKE_BLOCK |
+        LANDLOCK_ACCESS_FS_MAKE_SYM |
+        LANDLOCK_ACCESS_FS_REFER;
+
+    struct landlock_ruleset_attr ruleset_attr = {
+        .handled_access_fs = restrict_rules
+    };
+
+    /* ruleset_addr.handled_access_fs contains all rights that will be restricted
+     * unless explicitly added */
+    int ruleset_fd = landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
+    if (ruleset_fd < 0) {
+        print_message(msg_config_error, "Landlock: Failed to create a ruleset");
+        return;
+    }
+
+    /* Access to libraries, to be able to fork */
+    add_path_ro(ruleset_fd, LL_TREE, "/lib");
+    add_path_ro(ruleset_fd, LL_TREE, "/usr/lib");
+    add_path_ro(ruleset_fd, LL_FILE, "/etc/ld.so.cache");  /* To avoid searching all libs... */
+
+    /* Files to resolve names (required when dynamic resolution is used) */
+    add_path_ro(ruleset_fd, LL_FILE, "/etc/hosts");
+    add_path_ro(ruleset_fd, LL_FILE, "/etc/resolv.conf");
+    add_path_ro(ruleset_fd, LL_FILE, "/etc/nsswitch.conf");
+
+    if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
+        print_message(msg_config_error, "Landlock: Failed to restrict privileges");
+        return;
+    }
+    if (landlock_restrict_self(ruleset_fd, 0)) {
+        print_message(msg_config_error, "Landlock: Failed to enforce ruleset");
+        return;
+    }
+    close(ruleset_fd);
+
+    print_message(msg_config, "Landlock: all restricted\n");
+}
+
+#else /* HAVE_LANDLOCK */
+void setup_landlock(void)
+{
+    print_message(msg_config, "Landlock: not built in\n");
+    return;
+}
+#endif /* HAVE_LANDLOCK */

log.c

@@ -0,0 +1,211 @@
+/*
+# log: processing of all outgoing messages
+#
+# 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
+# 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
+
+*/
+
+
+#define SYSLOG_NAMES
+#define _GNU_SOURCE
+#include <errno.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include "sslh-conf.h"
+#include "common.h"
+#include "log.h"
+
+msg_info msg_config = {
+    LOG_INFO,
+    &cfg.verbose_config
+};
+
+msg_info msg_config_error = {
+    LOG_ERR,
+    &cfg.verbose_config_error
+};
+
+msg_info msg_fd = {
+    LOG_DEBUG,
+    &cfg.verbose_fd
+};
+
+/* Internal errors: inconsistent states, impossible values, things that should never happen, and are therefore the sign of memory corruption: hence the LOG_CRIT */
+msg_info msg_int_error = {
+    LOG_CRIT,
+    &cfg.verbose_system_error
+};
+
+/* System errors: when the system around us fails us: memory allocation, fork, ... */
+msg_info msg_system_error = {
+    LOG_ERR,
+    &cfg.verbose_system_error
+};
+
+msg_info msg_packets = {
+    LOG_INFO,
+    &cfg.verbose_packets
+};
+
+/* additional info when attempting outgoing connections */
+msg_info msg_connections_try = {
+    LOG_DEBUG,
+    &cfg.verbose_connections_try
+};
+
+/* Connection information and failures (e.g. forbidden by policy) */
+msg_info msg_connections = {
+    LOG_INFO,
+    &cfg.verbose_connections
+};
+
+/* Connection failures, e.g. target server not present */
+msg_info msg_connections_error = {
+    LOG_ERR,
+    &cfg.verbose_connections_error
+};
+
+
+/* comment the probing process */
+msg_info msg_probe_info = {
+    LOG_INFO,
+    &cfg.verbose_probe_info
+};
+
+/* probing errors, e.g. inconsistent data in connections */
+msg_info msg_probe_error = {
+    LOG_ERR,
+    &cfg.verbose_probe_error
+};
+
+
+
+/* Bitmasks in verbose-* values */
+#define MSG_STDOUT 1
+#define MSG_SYSLOG 2
+#define MSG_FILE   4
+
+static FILE* logfile_fp = NULL;
+
+/* Prints a message to stderr and/or syslog if appropriate */
+void print_message(msg_info info, const char* str, ...)
+{
+    va_list ap;
+
+    if ((*info.verbose & MSG_STDOUT) && ! cfg.inetd) {
+        va_start(ap, str);
+        vfprintf(stderr, str, ap);
+        va_end(ap);
+    }
+
+    if (*info.verbose & MSG_SYSLOG) {
+        va_start(ap, str);
+        vsyslog(info.log_level, str, ap);
+        va_end(ap);
+    }
+
+    if (*info.verbose & MSG_FILE && logfile_fp != NULL) {
+        va_start(ap, str);
+        vfprintf(logfile_fp, str, ap);
+        fflush(logfile_fp);
+        va_end(ap);
+    }
+}
+
+static int do_syslog = 1; /* Should we syslog? controled by syslog_facility = "none" */
+
+/* Open syslog connection with appropriate banner;
+ * banner is made up of basename(bin_name)+"[pid]" */
+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, cfg.syslog_facility) == 0)
+            break;
+    if (facilitynames[fn].c_val == -1) {
+        fprintf(stderr, "Unknown facility %s\n", cfg.syslog_facility);
+        exit(1);
+    }
+
+    openlog(name2, LOG_CONS, facilitynames[fn].c_val);
+    free(name1);
+    /* Don't free name2, as openlog(3) uses it (at least in glibc) */
+}
+
+void setup_logfile()
+{
+    if (cfg.logfile == NULL)
+    {
+        return;
+    }
+
+    logfile_fp = fopen(cfg.logfile, "a");
+    if (logfile_fp == NULL)
+    {
+        fprintf(stderr, "Could not open logfile %s for writing: %s\n", cfg.logfile, strerror(errno));
+        exit(1);
+    }
+}
+
+void close_logfile()
+{
+    if (logfile_fp != NULL)
+    {
+        fclose(logfile_fp);
+        logfile_fp = NULL;
+    }
+}
+
+/* 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;
+        if (!get_connection_desc(desc, cnx)) {
+            print_message(msg_connections, "%s: lost incoming connection\n",
+                          cnx->proto->name);
+            return;
+        }
+    }
+
+    print_message(msg_connections, "%s:connection from %s to %s forwarded from %s to %s\n",
+                cnx->proto->name,
+                desc->peer,
+                desc->service,
+                desc->local,
+                desc->target);
+}

log.h

@@ -0,0 +1,36 @@
+#ifndef LOG_H
+#define LOG_H
+
+#include "common.h"
+
+void setup_syslog(const char* bin_name);
+
+void setup_logfile();
+
+void close_logfile();
+
+void log_connection(struct connection_desc* desc, const struct connection *cnx);
+
+typedef struct s_msg_info{
+    int log_level;
+    int *verbose;
+} msg_info;
+
+void print_message(msg_info info, const char* str, ...);
+extern msg_info msg_config;
+extern msg_info msg_config_error;
+
+extern msg_info msg_fd;
+extern msg_info msg_packets;
+
+extern msg_info msg_int_error;
+extern msg_info msg_system_error;
+
+extern msg_info msg_connections_try;
+extern msg_info msg_connections_error;
+extern msg_info msg_connections;
+
+extern msg_info msg_probe_info;
+extern msg_info msg_probe_error;
+
+#endif /* LOG_H */

probe.c

@@ -1,7 +1,7 @@
 /*
 # probe.c: Code for probing protocols
 #
-# Copyright (C) 2007-2019  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
@@ -27,11 +27,13 @@
 #endif
 #include <ctype.h>
 #include "probe.h"
+#include "log.h"
 
 
 
 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_wireguard_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*);
@@ -39,6 +41,8 @@ static int is_tls_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_
 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_teamspeak_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_item*);
+static int is_msrdp_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
@@ -47,6 +51,7 @@ static struct protocol_probe_desc builtins[] = {
     /* description  probe  */
     { "ssh",        is_ssh_protocol},
     { "openvpn",    is_openvpn_protocol },
+    { "wireguard",  is_wireguard_protocol },
     { "tinc",       is_tinc_protocol },
     { "xmpp",       is_xmpp_protocol },
     { "http",       is_http_protocol },
@@ -54,6 +59,8 @@ static struct protocol_probe_desc builtins[] = {
     { "adb",        is_adb_protocol },
     { "socks5",     is_socks5_protocol },
     { "syslog",     is_syslog_protocol },
+    { "teamspeak",  is_teamspeak_protocol },
+    { "msrdp",      is_msrdp_protocol },
     { "anyprot",    is_true }
 };
 
@@ -81,33 +88,38 @@ struct sslhcfg_protocols_item* timeout_protocol(void)
 
 /* From http://grapsus.net/blog/post/Hexadecimal-dump-in-C */
 #define HEXDUMP_COLS 16
-void hexdump(const char *mem, unsigned int len)
+void hexdump(msg_info msg_info, const char *mem, unsigned int len)
 {
     unsigned int i, j;
+    char str[10 + HEXDUMP_COLS * 4 + 2];
+    int c = 0; /* index in str */
 
     for(i = 0; i < len + ((len % HEXDUMP_COLS) ? (HEXDUMP_COLS - len % HEXDUMP_COLS) : 0); i++)
     {
         /* print offset */
         if(i % HEXDUMP_COLS == 0)
-            fprintf(stderr, "0x%06x: ", i);
+            c += sprintf(&str[c], "0x%06x: ", i);
 
         /* print hex data */
         if(i < len)
-            fprintf(stderr, "%02x ", 0xFF & mem[i]);
+            c += sprintf(&str[c], "%02x ", 0xFF & mem[i]);
         else /* end of block, just aligning for ASCII dump */
-            fprintf(stderr, "   ");
+            c+= sprintf(&str[c], "   ");
 
         /* print ASCII dump */
         if(i % HEXDUMP_COLS == (HEXDUMP_COLS - 1)) {
             for(j = i - (HEXDUMP_COLS - 1); j <= i; j++) {
                 if(j >= len) /* end of block, not really printing */
-                    fputc(' ', stderr);
+                    str[c++] = ' ';
                 else if(isprint(mem[j])) /* printable char */
-                    fputc(0xFF & mem[j], stderr);
+                    str[c++] = 0xFF & mem[j];
                 else /* other char */
-                    fputc('.', stderr);
+                    str[c++] = '.';
             }
-            fputc('\n', stderr);
+            str[c++] = '\n';
+            str[c++] = 0;
+            print_message(msg_info, "%s", str);
+            c = 0;
         }
     }
 }
@@ -131,15 +143,66 @@ static int is_ssh_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_
  * http://www.fengnet.com/book/vpns%20illustrated%20tunnels%20%20vpnsand%20ipsec/ch08lev1sec5.html
  * and OpenVPN ssl.c, ssl.h and options.c
  */
+#define OVPN_OPCODE_MASK 0xF8
+#define OVPN_CONTROL_HARD_RESET_CLIENT_V1  (0x01 << 3)
+#define OVPN_CONTROL_HARD_RESET_CLIENT_V2  (0x07 << 3)
+#define OVPN_HMAC_128 16
+#define OVPN_HMAC_160 20
+#define OVPN_HARD_RESET_PACKET_ID_OFFSET(hmac_size) (9 + hmac_size)
 static int is_openvpn_protocol (const char*p,ssize_t len, struct sslhcfg_protocols_item* proto)
 {
     int packet_len;
 
-    if (len < 2)
-        return PROBE_AGAIN;
+    if (proto->is_udp == 0)
+    {
+        if (len < 2)
+            return PROBE_AGAIN;
 
-    packet_len = ntohs(*(uint16_t*)p);
-    return packet_len == len - 2;
+        packet_len = ntohs(*(uint16_t*)p);
+        return packet_len == len - 2;
+    } else {
+        if (len < 1)
+            return PROBE_NEXT;
+
+        if ((p[0] & OVPN_OPCODE_MASK) != OVPN_CONTROL_HARD_RESET_CLIENT_V1 &&
+            (p[0] & OVPN_OPCODE_MASK) != OVPN_CONTROL_HARD_RESET_CLIENT_V2)
+            return PROBE_NEXT;
+
+        /* The detection pattern above may not be reliable enough.
+         * Check the packet id: OpenVPN sents five initial packets
+         * whereas the packet id is increased with every transmitted datagram.
+         */
+
+        if (len <= OVPN_HARD_RESET_PACKET_ID_OFFSET(OVPN_HMAC_128) + sizeof(uint32_t))
+            return PROBE_NEXT;
+
+        if (ntohl(*(uint32_t*)(p + OVPN_HARD_RESET_PACKET_ID_OFFSET(OVPN_HMAC_128))) <= 5u)
+            return PROBE_MATCH;
+
+        if (len <= OVPN_HARD_RESET_PACKET_ID_OFFSET(OVPN_HMAC_160) + sizeof(uint32_t))
+            return PROBE_NEXT;
+
+        if (ntohl(*(uint32_t*)(p + OVPN_HARD_RESET_PACKET_ID_OFFSET(OVPN_HMAC_160))) <= 5u)
+            return PROBE_MATCH;
+
+        return PROBE_NEXT;
+    }
+}
+
+static int is_wireguard_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_item* proto)
+{
+    if (proto->is_udp == 0)
+        return PROBE_NEXT;
+
+    // Handshake Init: 148 bytes
+    if (len != 148)
+        return PROBE_NEXT;
+
+    // Handshake Init: p[0] = 0x01, p[1..3] = 0x000000 (reserved)
+    if (ntohl(*(uint32_t*)p) != 0x01000000)
+        return PROBE_NEXT;
+
+    return PROBE_MATCH;
 }
 
 /* Is the buffer the beginning of a tinc connections?
@@ -312,6 +375,27 @@ static int is_syslog_protocol(const char *p, ssize_t len, struct sslhcfg_protoco
     return 0;
 }
 
+static int is_teamspeak_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_item* proto)
+{
+    if (len < 8)
+        return PROBE_NEXT;
+
+    return !strncmp(p, "TS3INIT1", len);
+}
+
+static int is_msrdp_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_item* proto)
+{
+    char version;
+    char packet_len;
+    if (len < 7)
+        return PROBE_NEXT;
+    version=*p;
+    if (version!=0x03)
+        return 0;
+    packet_len = ntohs(*(uint16_t*)(p+2));
+    return packet_len == len;
+}
+
 static int regex_probe(const char *p, ssize_t len, struct sslhcfg_protocols_item* proto)
 {
 #ifdef ENABLE_REGEX
@@ -328,51 +412,58 @@ static int regex_probe(const char *p, ssize_t len, struct sslhcfg_protocols_item
     return 0;
 #else
     /* Should never happen as we check when loading config file */
-    fprintf(stderr, "FATAL: regex probe called but not built in\n");
+    print_message(msg_int_error, "FATAL: regex probe called but not built in\n");
     exit(5);
 #endif
 }
 
 /* Run all the probes on a buffer
+ * buf, len: buffer to test on
+ * proto_in, proto_len: array of protocols to try
+ * proto_out: protocol that matched
+ *
  * 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)
+int probe_buffer(char* buf, int len,
+                 struct sslhcfg_protocols_item** proto_in,
+                 int proto_len,
+                 struct sslhcfg_protocols_item** proto_out
+                 )
 {
     struct sslhcfg_protocols_item* p;
     int i, res, again = 0;
 
-    if (cfg.verbose > 1) {
-        fprintf(stderr, "hexdump of incoming packet:\n");
-        hexdump(buf, len);
-    }
+    print_message(msg_packets, "hexdump of incoming packet:\n");
+    hexdump(msg_packets, buf, len);
 
-    *proto = NULL;
-    for (i = 0; i < cfg.protocols_len; i++) {
+    *proto_out = NULL;
+    for (i = 0; i < proto_len; i++) {
         char* probe_str[3] = {"PROBE_NEXT", "PROBE_MATCH", "PROBE_AGAIN"};
-        p = &cfg.protocols[i];
+        p = proto_in[i];
 
         if (! p->probe) continue;
 
-        if (cfg.verbose) fprintf(stderr, "probing for %s\n", p->name);
+        print_message(msg_probe_info, "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")))
+        if ((i == proto_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);
+            print_message(msg_probe_info, "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]);
+        print_message(msg_probe_info, "probed for %s: %s\n", p->name, probe_str[res]);
 
         if (res == PROBE_MATCH) {
-            *proto = p;
+            *proto_out = p;
             return PROBE_MATCH;
         }
         if (res == PROBE_AGAIN)
@@ -382,37 +473,14 @@ int probe_buffer(char* buf, int len, struct sslhcfg_protocols_item** proto)
         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.
- * 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];
-    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
-     * disconnected between the previous call to select() and now. If that
-     * happens, we just connect to the default protocol so the caller of this
-     * function does not have to deal with a specific  failure condition (the
-     * connection will just fail later normally). */
-
-    if (n > 0) {
-        defer_write(&cnx->q[1], buffer, n);
-        return probe_buffer(cnx->q[1].begin_deferred_data,
-                            cnx->q[1].deferred_data_size,
-                            &cnx->proto);
+    if (proto_len == 0) {
+        /* This should be caught by configuration sanity checks, but just in
+         * case, die gracefully rather than segfaulting */
+        print_message(msg_int_error, "Received traffic on transport that has no target\n");
+        exit(0);
     }
-
-    /* read() returned an error, so just connect to the last protocol to die */
-    cnx->proto = &cfg.protocols[cfg.protocols_len-1];
+    *proto_out = proto_in[proto_len-1];
     return PROBE_MATCH;
 }
 

probe.h

@@ -5,6 +5,7 @@
 
 #include "common.h"
 #include "tls.h"
+#include "log.h"
 
 typedef enum {
     PROBE_NEXT,  /* Enough data, probe failed -- it's some other protocol */
@@ -47,8 +48,12 @@ void set_protocol_list(struct sslhcfg_protocols_item*);
  */
 int probe_client_protocol(struct connection *cnx);
 
-/* Probe, but on a buffer */
-int probe_buffer(char* buf, int len, struct sslhcfg_protocols_item** proto);
+/* Probe on a buffer */
+int probe_buffer(char* buf, int len,
+                 struct sslhcfg_protocols_item** proto_in,
+                 int proto_len,
+                 struct sslhcfg_protocols_item** proto_out
+                 );
 
 /* set the protocol to connect to in case of timeout */
 void set_ontimeout(const char* name);
@@ -59,6 +64,6 @@ void set_ontimeout(const char* name);
  */
 struct sslhcfg_protocols_item* timeout_protocol(void);
 
-void hexdump(const char*, unsigned int);
+void hexdump(msg_info, const char*, unsigned int);
 
 #endif

processes.c

@@ -0,0 +1,115 @@
+/* 
+  Processes that are common to sslh-ev and 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 "udp-listener.h"
+#include "tcp-listener.h"
+#include "processes.h"
+#include "probe.h"
+#include "log.h"
+
+
+int tidy_connection(struct connection *cnx, struct loop_info* fd_info)
+{
+    int i;
+
+    for (i = 0; i < 2; i++) {
+        if (cnx->q[i].fd != -1) {
+            print_message(msg_fd, "closing fd %d\n", cnx->q[i].fd);
+
+            watchers_del_read(fd_info->watchers, cnx->q[i].fd);
+            watchers_del_write(fd_info->watchers, cnx->q[i].fd);
+            close(cnx->q[i].fd);
+            if (cnx->q[i].deferred_data)
+                free(cnx->q[i].deferred_data);
+        }
+    }
+
+    if (cnx->type == SOCK_DGRAM)
+        udp_tidy(cnx, fd_info);
+
+    if (gap_remove_ptr(fd_info->probing_list, cnx, fd_info->num_probing) != -1)
+        fd_info->num_probing--;
+
+    collection_remove_cnx(fd_info->collection, cnx);
+    return 0;
+}
+
+
+
+/* Process a connection that is active in read */
+
+void cnx_read_process(struct loop_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:
+        print_message(msg_int_error, "cnx_read_process: Illegal connection type %d\n", cnx->type);
+        dump_connection(cnx);
+        exit(1);
+    }
+}
+
+
+/* Process a connection that accepts a socket
+ * (For UDP, this means all traffic coming from remote clients)
+ * Returns new connection object, or NULL
+ * */
+struct connection* cnx_accept_process(struct loop_info* fd_info, struct listen_endpoint* listen_socket)
+{
+    int fd = listen_socket->socketfd;
+    int type = listen_socket->type;
+    struct connection* cnx;
+
+    switch (type) {
+    case SOCK_STREAM:
+        cnx = accept_new_connection(fd, fd_info);
+        if (!cnx) return NULL;
+
+        break;
+
+    case SOCK_DGRAM:
+        cnx = udp_c2s_forward(fd, fd_info);
+        if (!cnx) return NULL;
+        break;
+
+    default:
+        print_message(msg_int_error, "Inconsistent cnx type: %d\n", type);
+        exit(1);
+    }
+
+    int new_fd = cnx->q[0].fd;
+    watchers_add_read(fd_info->watchers, new_fd);
+    return cnx;
+}
+
+
+
+

processes.h

@@ -0,0 +1,41 @@
+#ifndef PROCESSES_H
+#define PROCESSES_H
+
+#include "common.h"
+#include "collection.h"
+#include "gap.h"
+
+typedef struct connection* hash_item;
+#include "hash.h"
+
+/* Provided by event loop, sslh-ev or sslh-select, for implementation-dependant
+ * data */
+typedef struct watchers watchers; 
+
+/* Global state for a loop */
+struct loop_info {
+    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 */
+
+    hash* hash_sources; /* UDP remote sources previously encountered */
+
+    watchers* watchers;
+
+    cnx_collection* collection; /* Collection of connections linked to this loop */
+};
+
+void cnx_read_process(struct loop_info* fd_info, int fd);
+struct connection* cnx_accept_process(struct loop_info* fd_info, struct listen_endpoint* listen_socket);
+
+int tidy_connection(struct connection *cnx, struct loop_info* fd_info);
+
+
+/* These must be declared in the loop handler, sslh-ev or sslh-select */
+void watchers_add_read(watchers* w, int fd);
+void watchers_del_read(watchers* w, int fd);
+void watchers_add_write(watchers* w, int fd);
+void watchers_del_write(watchers* w, int fd);
+
+#endif

scripts/etc.sysconfig.sslh

@@ -18,7 +18,7 @@
 #CONFIG=/etc/sslh.cfg
 
 #
-# Extra option to pass on comand line
+# Extra option to pass on command line
 # Those can supersede configuration file settings
 # 
 #OPTIONS=

scripts/fail2ban/sslh-ssh.conf

@@ -8,7 +8,7 @@
 # but many connection attempts from the same
 # origin is reason enough to block.
 #
-# Verion: 2014-03-28
+# Version: 2014-03-28
 
 [INCLUDES]
 
@@ -16,7 +16,7 @@
 
 [Definition]
 
-failregex = ^.+ sslh\[.+\]: connection from <HOST>:.+ to .+ forwarded
+failregex = ^.+ sslh\[.+\]: ssh:connection from <HOST>:.+ to .+ forwarded
 from .+ to .+:ssh\s*$
 
 ignoreregex =

sslh-conf.c

@@ -1,5 +1,5 @@
 /* Generated by conf2struct (https://www.rutschle.net/tech/conf2struct/README)
- * on Fri Aug 13 18:03:18 2021. 
+ * on Tue Jan  2 21:25:47 2024. 
 
 # conf2struct: generate libconf parsers that read to structs
 # Copyright (C) 2018-2021  Yves Rutschle
@@ -443,32 +443,48 @@ struct compound_cl_arg {
 
 
 struct arg_file* sslhcfg_conffile;
- struct arg_int* sslhcfg_verbose;
+ struct arg_int* sslhcfg_verbose_config;
+ struct arg_int* sslhcfg_verbose_config_error;
+ struct arg_int* sslhcfg_verbose_connections;
+ struct arg_int* sslhcfg_verbose_connections_try;
+ struct arg_int* sslhcfg_verbose_connections_error;
+ struct arg_int* sslhcfg_verbose_fd;
+ struct arg_int* sslhcfg_verbose_packets;
+ struct arg_int* sslhcfg_verbose_probe_info;
+ struct arg_int* sslhcfg_verbose_probe_error;
+ struct arg_int* sslhcfg_verbose_system_error;
+ struct arg_int* sslhcfg_verbose_int_error;
+ struct arg_lit* sslhcfg_version;
  struct arg_lit* sslhcfg_foreground;
  struct arg_lit* sslhcfg_inetd;
  struct arg_lit* sslhcfg_numeric;
  struct arg_lit* sslhcfg_transparent;
  struct arg_int* sslhcfg_timeout;
+ struct arg_int* sslhcfg_udp_max_connections;
  struct arg_str* sslhcfg_user;
  struct arg_str* sslhcfg_pidfile;
  struct arg_str* sslhcfg_chroot;
  struct arg_str* sslhcfg_syslog_facility;
+ struct arg_str* sslhcfg_logfile;
  struct arg_str* sslhcfg_on_timeout;
  struct arg_str* sslhcfg_prefix;
  	struct arg_str* sslhcfg_listen;
  	struct arg_str* sslhcfg_ssh;
  	struct arg_str* sslhcfg_tls;
+ 	struct arg_str* sslhcfg_ssl;
  	struct arg_str* sslhcfg_openvpn;
  	struct arg_str* sslhcfg_tinc;
+ 	struct arg_str* sslhcfg_wireguard;
  	struct arg_str* sslhcfg_xmpp;
  	struct arg_str* sslhcfg_http;
  	struct arg_str* sslhcfg_adb;
  	struct arg_str* sslhcfg_socks5;
  	struct arg_str* sslhcfg_syslog;
+ 	struct arg_str* sslhcfg_msrdp;
  	struct arg_str* sslhcfg_anyprot;
  struct arg_end* sslhcfg_end;
 
-                                                                                                                                               
+                                                                                                                                                        
 static struct config_desc table_sslhcfg_protocols[] = {
 
 
@@ -616,6 +632,22 @@ static struct config_desc table_sslhcfg_protocols[] = {
             /* default_val*/    .default_val.def_bool = 0 
         },
 
+        { 
+            /* name */          "resolve_on_forward", 
+            /* type */          CFG_BOOL, 
+            /* sub_group*/      NULL,
+            /* arg_cl */        NULL,
+            /* base_addr */     NULL,
+            /* offset */        offsetof(struct sslhcfg_protocols_item, resolve_on_forward),
+            /* offset_len */    0,
+            /* offset_present */ 0,
+            /* size */          sizeof(int), 
+            /* array_type */    -1,
+            /* mandatory */     0, 
+            /* optional */      0, 
+            /* default_val*/    .default_val.def_bool = 0 
+        },
+
         { 
             /* name */          "log_level", 
             /* type */          CFG_INT, 
@@ -782,17 +814,17 @@ static struct config_desc table_sslhcfg_listen[] = {
         },
 	{ 0 }
 };
-                                                                                                             
+                                                                                                                                                                                                                                  
 static struct config_desc table_sslhcfg[] = {
 
 
         { 
-            /* name */          "verbose", 
+            /* name */          "verbose_config", 
             /* type */          CFG_INT, 
             /* sub_group*/      NULL,
-            /* arg_cl */        & sslhcfg_verbose,
+            /* arg_cl */        & sslhcfg_verbose_config,
             /* base_addr */     NULL,
-            /* offset */        offsetof(struct sslhcfg_item, verbose),
+            /* offset */        offsetof(struct sslhcfg_item, verbose_config),
             /* offset_len */    0,
             /* offset_present */ 0,
             /* size */          sizeof(int), 
@@ -802,6 +834,182 @@ static struct config_desc table_sslhcfg[] = {
             /* default_val*/    .default_val.def_int = 0 
         },
 
+        { 
+            /* name */          "verbose_config_error", 
+            /* type */          CFG_INT, 
+            /* sub_group*/      NULL,
+            /* arg_cl */        & sslhcfg_verbose_config_error,
+            /* base_addr */     NULL,
+            /* offset */        offsetof(struct sslhcfg_item, verbose_config_error),
+            /* offset_len */    0,
+            /* offset_present */ 0,
+            /* size */          sizeof(int), 
+            /* array_type */    -1,
+            /* mandatory */     0, 
+            /* optional */      0, 
+            /* default_val*/    .default_val.def_int = 3 
+        },
+
+        { 
+            /* name */          "verbose_connections", 
+            /* type */          CFG_INT, 
+            /* sub_group*/      NULL,
+            /* arg_cl */        & sslhcfg_verbose_connections,
+            /* base_addr */     NULL,
+            /* offset */        offsetof(struct sslhcfg_item, verbose_connections),
+            /* offset_len */    0,
+            /* offset_present */ 0,
+            /* size */          sizeof(int), 
+            /* array_type */    -1,
+            /* mandatory */     0, 
+            /* optional */      0, 
+            /* default_val*/    .default_val.def_int = 3 
+        },
+
+        { 
+            /* name */          "verbose_connections_try", 
+            /* type */          CFG_INT, 
+            /* sub_group*/      NULL,
+            /* arg_cl */        & sslhcfg_verbose_connections_try,
+            /* base_addr */     NULL,
+            /* offset */        offsetof(struct sslhcfg_item, verbose_connections_try),
+            /* offset_len */    0,
+            /* offset_present */ 0,
+            /* size */          sizeof(int), 
+            /* array_type */    -1,
+            /* mandatory */     0, 
+            /* optional */      0, 
+            /* default_val*/    .default_val.def_int = 0 
+        },
+
+        { 
+            /* name */          "verbose_connections_error", 
+            /* type */          CFG_INT, 
+            /* sub_group*/      NULL,
+            /* arg_cl */        & sslhcfg_verbose_connections_error,
+            /* base_addr */     NULL,
+            /* offset */        offsetof(struct sslhcfg_item, verbose_connections_error),
+            /* offset_len */    0,
+            /* offset_present */ 0,
+            /* size */          sizeof(int), 
+            /* array_type */    -1,
+            /* mandatory */     0, 
+            /* optional */      0, 
+            /* default_val*/    .default_val.def_int = 3 
+        },
+
+        { 
+            /* name */          "verbose_fd", 
+            /* type */          CFG_INT, 
+            /* sub_group*/      NULL,
+            /* arg_cl */        & sslhcfg_verbose_fd,
+            /* base_addr */     NULL,
+            /* offset */        offsetof(struct sslhcfg_item, verbose_fd),
+            /* offset_len */    0,
+            /* offset_present */ 0,
+            /* size */          sizeof(int), 
+            /* array_type */    -1,
+            /* mandatory */     0, 
+            /* optional */      0, 
+            /* default_val*/    .default_val.def_int = 0 
+        },
+
+        { 
+            /* name */          "verbose_packets", 
+            /* type */          CFG_INT, 
+            /* sub_group*/      NULL,
+            /* arg_cl */        & sslhcfg_verbose_packets,
+            /* base_addr */     NULL,
+            /* offset */        offsetof(struct sslhcfg_item, verbose_packets),
+            /* offset_len */    0,
+            /* offset_present */ 0,
+            /* size */          sizeof(int), 
+            /* array_type */    -1,
+            /* mandatory */     0, 
+            /* optional */      0, 
+            /* default_val*/    .default_val.def_int = 0 
+        },
+
+        { 
+            /* name */          "verbose_probe_info", 
+            /* type */          CFG_INT, 
+            /* sub_group*/      NULL,
+            /* arg_cl */        & sslhcfg_verbose_probe_info,
+            /* base_addr */     NULL,
+            /* offset */        offsetof(struct sslhcfg_item, verbose_probe_info),
+            /* offset_len */    0,
+            /* offset_present */ 0,
+            /* size */          sizeof(int), 
+            /* array_type */    -1,
+            /* mandatory */     0, 
+            /* optional */      0, 
+            /* default_val*/    .default_val.def_int = 0 
+        },
+
+        { 
+            /* name */          "verbose_probe_error", 
+            /* type */          CFG_INT, 
+            /* sub_group*/      NULL,
+            /* arg_cl */        & sslhcfg_verbose_probe_error,
+            /* base_addr */     NULL,
+            /* offset */        offsetof(struct sslhcfg_item, verbose_probe_error),
+            /* offset_len */    0,
+            /* offset_present */ 0,
+            /* size */          sizeof(int), 
+            /* array_type */    -1,
+            /* mandatory */     0, 
+            /* optional */      0, 
+            /* default_val*/    .default_val.def_int = 3 
+        },
+
+        { 
+            /* name */          "verbose_system_error", 
+            /* type */          CFG_INT, 
+            /* sub_group*/      NULL,
+            /* arg_cl */        & sslhcfg_verbose_system_error,
+            /* base_addr */     NULL,
+            /* offset */        offsetof(struct sslhcfg_item, verbose_system_error),
+            /* offset_len */    0,
+            /* offset_present */ 0,
+            /* size */          sizeof(int), 
+            /* array_type */    -1,
+            /* mandatory */     0, 
+            /* optional */      0, 
+            /* default_val*/    .default_val.def_int = 3 
+        },
+
+        { 
+            /* name */          "verbose_int_error", 
+            /* type */          CFG_INT, 
+            /* sub_group*/      NULL,
+            /* arg_cl */        & sslhcfg_verbose_int_error,
+            /* base_addr */     NULL,
+            /* offset */        offsetof(struct sslhcfg_item, verbose_int_error),
+            /* offset_len */    0,
+            /* offset_present */ 0,
+            /* size */          sizeof(int), 
+            /* array_type */    -1,
+            /* mandatory */     0, 
+            /* optional */      0, 
+            /* default_val*/    .default_val.def_int = 3 
+        },
+
+        { 
+            /* name */          "version", 
+            /* type */          CFG_BOOL, 
+            /* sub_group*/      NULL,
+            /* arg_cl */        & sslhcfg_version,
+            /* base_addr */     NULL,
+            /* offset */        offsetof(struct sslhcfg_item, version),
+            /* offset_len */    0,
+            /* offset_present */ 0,
+            /* size */          sizeof(int), 
+            /* array_type */    -1,
+            /* mandatory */     0, 
+            /* optional */      0, 
+            /* default_val*/    .default_val.def_bool = 0 
+        },
+
         { 
             /* name */          "foreground", 
             /* type */          CFG_BOOL, 
@@ -882,6 +1090,22 @@ static struct config_desc table_sslhcfg[] = {
             /* default_val*/    .default_val.def_int = 5 
         },
 
+        { 
+            /* name */          "udp_max_connections", 
+            /* type */          CFG_INT, 
+            /* sub_group*/      NULL,
+            /* arg_cl */        & sslhcfg_udp_max_connections,
+            /* base_addr */     NULL,
+            /* offset */        offsetof(struct sslhcfg_item, udp_max_connections),
+            /* offset_len */    0,
+            /* offset_present */ 0,
+            /* size */          sizeof(int), 
+            /* array_type */    -1,
+            /* mandatory */     0, 
+            /* optional */      0, 
+            /* default_val*/    .default_val.def_int = 1024 
+        },
+
         { 
             /* name */          "user", 
             /* type */          CFG_STRING, 
@@ -946,6 +1170,22 @@ static struct config_desc table_sslhcfg[] = {
             /* default_val*/    .default_val.def_string = "auth" 
         },
 
+        { 
+            /* name */          "logfile", 
+            /* type */          CFG_STRING, 
+            /* sub_group*/      NULL,
+            /* arg_cl */        & sslhcfg_logfile,
+            /* base_addr */     NULL,
+            /* offset */        offsetof(struct sslhcfg_item, logfile),
+            /* offset_len */    0,
+            /* offset_present */ offsetof(struct sslhcfg_item, logfile_is_present),
+            /* size */          sizeof(char*), 
+            /* array_type */    -1,
+            /* mandatory */     0, 
+            /* optional */      1, 
+            /* default_val*/    .default_val.def_string = NULL 
+        },
+
         { 
             /* name */          "on_timeout", 
             /* type */          CFG_STRING, 
@@ -1015,7 +1255,15 @@ static struct compound_cl_target sslhcfg_anyprot_targets [] = {
 	{ & table_sslhcfg_protocols[0], 0, .value.def_string = "anyprot" },
 	{ & table_sslhcfg_protocols[1], 1, .value.def_string = "0" },
 	{ & table_sslhcfg_protocols[2], 2, .value.def_string = "0" },
-	{ & table_sslhcfg_protocols[9], 0, .value.def_int = 1 },
+	{ & table_sslhcfg_protocols[10], 0, .value.def_int = 1 },
+	{ 0 }
+};
+
+static struct compound_cl_target sslhcfg_msrdp_targets [] = {
+	{ & table_sslhcfg_protocols[0], 0, .value.def_string = "msrdp" },
+	{ & table_sslhcfg_protocols[1], 1, .value.def_string = "0" },
+	{ & table_sslhcfg_protocols[2], 2, .value.def_string = "0" },
+	{ & table_sslhcfg_protocols[10], 0, .value.def_int = 1 },
 	{ 0 }
 };
 
@@ -1023,7 +1271,7 @@ static struct compound_cl_target sslhcfg_syslog_targets [] = {
 	{ & table_sslhcfg_protocols[0], 0, .value.def_string = "syslog" },
 	{ & table_sslhcfg_protocols[1], 1, .value.def_string = "0" },
 	{ & table_sslhcfg_protocols[2], 2, .value.def_string = "0" },
-	{ & table_sslhcfg_protocols[9], 0, .value.def_int = 1 },
+	{ & table_sslhcfg_protocols[10], 0, .value.def_int = 1 },
 	{ 0 }
 };
 
@@ -1031,7 +1279,7 @@ static struct compound_cl_target sslhcfg_socks5_targets [] = {
 	{ & table_sslhcfg_protocols[0], 0, .value.def_string = "socks5" },
 	{ & table_sslhcfg_protocols[1], 1, .value.def_string = "0" },
 	{ & table_sslhcfg_protocols[2], 2, .value.def_string = "0" },
-	{ & table_sslhcfg_protocols[9], 0, .value.def_int = 1 },
+	{ & table_sslhcfg_protocols[10], 0, .value.def_int = 1 },
 	{ 0 }
 };
 
@@ -1039,7 +1287,7 @@ static struct compound_cl_target sslhcfg_adb_targets [] = {
 	{ & table_sslhcfg_protocols[0], 0, .value.def_string = "adb" },
 	{ & table_sslhcfg_protocols[1], 1, .value.def_string = "0" },
 	{ & table_sslhcfg_protocols[2], 2, .value.def_string = "0" },
-	{ & table_sslhcfg_protocols[9], 0, .value.def_int = 1 },
+	{ & table_sslhcfg_protocols[10], 0, .value.def_int = 1 },
 	{ 0 }
 };
 
@@ -1047,7 +1295,7 @@ static struct compound_cl_target sslhcfg_http_targets [] = {
 	{ & table_sslhcfg_protocols[0], 0, .value.def_string = "http" },
 	{ & table_sslhcfg_protocols[1], 1, .value.def_string = "0" },
 	{ & table_sslhcfg_protocols[2], 2, .value.def_string = "0" },
-	{ & table_sslhcfg_protocols[9], 0, .value.def_int = 1 },
+	{ & table_sslhcfg_protocols[10], 0, .value.def_int = 1 },
 	{ 0 }
 };
 
@@ -1055,7 +1303,16 @@ static struct compound_cl_target sslhcfg_xmpp_targets [] = {
 	{ & table_sslhcfg_protocols[0], 0, .value.def_string = "xmpp" },
 	{ & table_sslhcfg_protocols[1], 1, .value.def_string = "0" },
 	{ & table_sslhcfg_protocols[2], 2, .value.def_string = "0" },
-	{ & table_sslhcfg_protocols[9], 0, .value.def_int = 1 },
+	{ & table_sslhcfg_protocols[10], 0, .value.def_int = 1 },
+	{ 0 }
+};
+
+static struct compound_cl_target sslhcfg_wireguard_targets [] = {
+	{ & table_sslhcfg_protocols[0], 0, .value.def_string = "wireguard" },
+	{ & table_sslhcfg_protocols[1], 1, .value.def_string = "0" },
+	{ & table_sslhcfg_protocols[2], 2, .value.def_string = "0" },
+	{ & table_sslhcfg_protocols[10], 0, .value.def_int = 1 },
+	{ & table_sslhcfg_protocols[7], 0, .value.def_bool = 1 },
 	{ 0 }
 };
 
@@ -1063,7 +1320,7 @@ static struct compound_cl_target sslhcfg_tinc_targets [] = {
 	{ & table_sslhcfg_protocols[0], 0, .value.def_string = "tinc" },
 	{ & table_sslhcfg_protocols[1], 1, .value.def_string = "0" },
 	{ & table_sslhcfg_protocols[2], 2, .value.def_string = "0" },
-	{ & table_sslhcfg_protocols[9], 0, .value.def_int = 1 },
+	{ & table_sslhcfg_protocols[10], 0, .value.def_int = 1 },
 	{ & table_sslhcfg_protocols[7], 0, .value.def_bool = 1 },
 	{ 0 }
 };
@@ -1072,7 +1329,16 @@ static struct compound_cl_target sslhcfg_openvpn_targets [] = {
 	{ & table_sslhcfg_protocols[0], 0, .value.def_string = "openvpn" },
 	{ & table_sslhcfg_protocols[1], 1, .value.def_string = "0" },
 	{ & table_sslhcfg_protocols[2], 2, .value.def_string = "0" },
-	{ & table_sslhcfg_protocols[9], 0, .value.def_int = 1 },
+	{ & table_sslhcfg_protocols[10], 0, .value.def_int = 1 },
+	{ & table_sslhcfg_protocols[7], 0, .value.def_bool = 1 },
+	{ 0 }
+};
+
+static struct compound_cl_target sslhcfg_ssl_targets [] = {
+	{ & table_sslhcfg_protocols[0], 0, .value.def_string = "tls" },
+	{ & table_sslhcfg_protocols[1], 1, .value.def_string = "0" },
+	{ & table_sslhcfg_protocols[2], 2, .value.def_string = "0" },
+	{ & table_sslhcfg_protocols[10], 0, .value.def_int = 1 },
 	{ & table_sslhcfg_protocols[7], 0, .value.def_bool = 1 },
 	{ 0 }
 };
@@ -1081,7 +1347,7 @@ static struct compound_cl_target sslhcfg_tls_targets [] = {
 	{ & table_sslhcfg_protocols[0], 0, .value.def_string = "tls" },
 	{ & table_sslhcfg_protocols[1], 1, .value.def_string = "0" },
 	{ & table_sslhcfg_protocols[2], 2, .value.def_string = "0" },
-	{ & table_sslhcfg_protocols[9], 0, .value.def_int = 1 },
+	{ & table_sslhcfg_protocols[10], 0, .value.def_int = 1 },
 	{ & table_sslhcfg_protocols[7], 0, .value.def_bool = 1 },
 	{ 0 }
 };
@@ -1091,7 +1357,7 @@ static struct compound_cl_target sslhcfg_ssh_targets [] = {
 	{ & table_sslhcfg_protocols[1], 1, .value.def_string = "0" },
 	{ & table_sslhcfg_protocols[2], 2, .value.def_string = "0" },
 	{ & table_sslhcfg_protocols[6], 0, .value.def_bool = 1 },
-	{ & table_sslhcfg_protocols[9], 0, .value.def_int = 1 },
+	{ & table_sslhcfg_protocols[10], 0, .value.def_int = 1 },
 	{ & table_sslhcfg_protocols[7], 0, .value.def_bool = 1 },
 	{ 0 }
 };
@@ -1106,7 +1372,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: listen */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_listen,
-            .base_entry =      & table_sslhcfg [12],
+            .base_entry =      & table_sslhcfg [25],
             .targets =         sslhcfg_listen_targets,
 
 
@@ -1118,7 +1384,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: ssh */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_ssh,
-            .base_entry =      & table_sslhcfg [13],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_ssh_targets,
 
 
@@ -1130,7 +1396,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: tls */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_tls,
-            .base_entry =      & table_sslhcfg [13],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_tls_targets,
 
 
@@ -1139,10 +1405,22 @@ static struct compound_cl_arg compound_cl_args[] = {
             .override_const = "tls",
         },
 
+        {   /* arg: ssl */
+            .regex =           "(.+):(\\w+)",
+            .arg_cl =          & sslhcfg_ssl,
+            .base_entry =      & table_sslhcfg [26],
+            .targets =         sslhcfg_ssl_targets,
+
+
+            .override_desc =   & table_sslhcfg_protocols [0],
+            .override_matchindex = 0,
+            .override_const = "tls",
+        },
+
         {   /* arg: openvpn */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_openvpn,
-            .base_entry =      & table_sslhcfg [13],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_openvpn_targets,
 
 
@@ -1154,7 +1432,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: tinc */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_tinc,
-            .base_entry =      & table_sslhcfg [13],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_tinc_targets,
 
 
@@ -1163,10 +1441,22 @@ static struct compound_cl_arg compound_cl_args[] = {
             .override_const = "tinc",
         },
 
+        {   /* arg: wireguard */
+            .regex =           "(.+):(\\w+)",
+            .arg_cl =          & sslhcfg_wireguard,
+            .base_entry =      & table_sslhcfg [26],
+            .targets =         sslhcfg_wireguard_targets,
+
+
+            .override_desc =   & table_sslhcfg_protocols [0],
+            .override_matchindex = 0,
+            .override_const = "wireguard",
+        },
+
         {   /* arg: xmpp */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_xmpp,
-            .base_entry =      & table_sslhcfg [13],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_xmpp_targets,
 
 
@@ -1178,7 +1468,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: http */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_http,
-            .base_entry =      & table_sslhcfg [13],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_http_targets,
 
 
@@ -1190,7 +1480,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: adb */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_adb,
-            .base_entry =      & table_sslhcfg [13],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_adb_targets,
 
 
@@ -1202,7 +1492,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: socks5 */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_socks5,
-            .base_entry =      & table_sslhcfg [13],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_socks5_targets,
 
 
@@ -1214,7 +1504,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: syslog */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_syslog,
-            .base_entry =      & table_sslhcfg [13],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_syslog_targets,
 
 
@@ -1223,10 +1513,22 @@ static struct compound_cl_arg compound_cl_args[] = {
             .override_const = "syslog",
         },
 
+        {   /* arg: msrdp */
+            .regex =           "(.+):(\\w+)",
+            .arg_cl =          & sslhcfg_msrdp,
+            .base_entry =      & table_sslhcfg [26],
+            .targets =         sslhcfg_msrdp_targets,
+
+
+            .override_desc =   & table_sslhcfg_protocols [0],
+            .override_matchindex = 0,
+            .override_const = "msrdp",
+        },
+
         {   /* arg: anyprot */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_anyprot,
-            .base_entry =      & table_sslhcfg [13],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_anyprot_targets,
 
 
@@ -1891,28 +2193,44 @@ int sslhcfg_cl_parse(int argc, char* argv[], struct sslhcfg_item* cfg)
             #ifdef LIBCONFIG
         sslhcfg_conffile = arg_filen("F", "config", "<file>", 0, 1, "Specify configuration file"),
     #endif
-         sslhcfg_verbose = arg_intn("v", "verbose", "<n>", 0, 1, ""),
+         sslhcfg_verbose_config = arg_intn(NULL, "verbose-config", "<n>", 0, 1, "Print configuration at startup"),
+         sslhcfg_verbose_config_error = arg_intn(NULL, "verbose-config-error", "<n>", 0, 1, "Print configuration errors"),
+         sslhcfg_verbose_connections = arg_intn(NULL, "verbose-connections", "<n>", 0, 1, "Trace established incoming address to forward address"),
+         sslhcfg_verbose_connections_try = arg_intn(NULL, "verbose-connections-try", "<n>", 0, 1, "Connection errors"),
+         sslhcfg_verbose_connections_error = arg_intn(NULL, "verbose-connections-error", "<n>", 0, 1, "Connection attempts towards targets"),
+         sslhcfg_verbose_fd = arg_intn(NULL, "verbose-fd", "<n>", 0, 1, "File descriptor activity, open/close/whatnot"),
+         sslhcfg_verbose_packets = arg_intn(NULL, "verbose-packets", "<n>", 0, 1, "Hexdump packets on which probing is done"),
+         sslhcfg_verbose_probe_info = arg_intn(NULL, "verbose-probe-info", "<n>", 0, 1, "Trace the probe process"),
+         sslhcfg_verbose_probe_error = arg_intn(NULL, "verbose-probe-error", "<n>", 0, 1, "Failures and problems during probing"),
+         sslhcfg_verbose_system_error = arg_intn(NULL, "verbose-system-error", "<n>", 0, 1, "System call failures"),
+         sslhcfg_verbose_int_error = arg_intn(NULL, "verbose-int-error", "<n>", 0, 1, "Internal errors that should never happen"),
+         sslhcfg_version = arg_litn("V", "version", 0, 1, "Print version information and exit"),
          sslhcfg_foreground = arg_litn("f", "foreground", 0, 1, "Run in foreground instead of as a daemon"),
          sslhcfg_inetd = arg_litn("i", "inetd", 0, 1, "Run in inetd mode: use stdin/stdout instead of network listen"),
          sslhcfg_numeric = arg_litn("n", "numeric", 0, 1, "Print IP addresses and ports as numbers"),
          sslhcfg_transparent = arg_litn(NULL, "transparent", 0, 1, "Set up as a transparent proxy"),
          sslhcfg_timeout = arg_intn("t", "timeout", "<n>", 0, 1, "Set up timeout before connecting to default target"),
+         sslhcfg_udp_max_connections = arg_intn(NULL, "udp-max-connections", "<n>", 0, 1, "Number of concurrent UDP connections"),
          sslhcfg_user = arg_strn("u", "user", "<str>", 0, 1, "Username to change to after set-up"),
          sslhcfg_pidfile = arg_strn("P", "pidfile", "<file>", 0, 1, "Path to file to store PID of current instance"),
          sslhcfg_chroot = arg_strn("C", "chroot", "<path>", 0, 1, "Root to change to after set-up"),
          sslhcfg_syslog_facility = arg_strn(NULL, "syslog-facility", "<str>", 0, 1, "Facility to syslog to"),
+         sslhcfg_logfile = arg_strn(NULL, "logfile", "<str>", 0, 1, "Log messages to a file"),
          sslhcfg_on_timeout = arg_strn(NULL, "on-timeout", "<str>", 0, 1, "Target to connect to when timing out"),
          sslhcfg_prefix = arg_strn(NULL, "prefix", "<str>", 0, 1, "Reserved for testing"),
  	sslhcfg_listen = arg_strn("p", "listen", "<host:port>", 0, 10, "Listen on host:port"),
  	sslhcfg_ssh = arg_strn(NULL, "ssh", "<host:port>", 0, 10, "Set up ssh target"),
  	sslhcfg_tls = arg_strn(NULL, "tls", "<host:port>", 0, 10, "Set up TLS/SSL target"),
+ 	sslhcfg_ssl = arg_strn(NULL, "ssl", "<host:port>", 0, 10, "Set up TLS/SSL target"),
  	sslhcfg_openvpn = arg_strn(NULL, "openvpn", "<host:port>", 0, 10, "Set up OpenVPN target"),
  	sslhcfg_tinc = arg_strn(NULL, "tinc", "<host:port>", 0, 10, "Set up tinc target"),
+ 	sslhcfg_wireguard = arg_strn(NULL, "wireguard", "<host:port>", 0, 10, "Set up WireGuard target"),
  	sslhcfg_xmpp = arg_strn(NULL, "xmpp", "<host:port>", 0, 10, "Set up XMPP target"),
  	sslhcfg_http = arg_strn(NULL, "http", "<host:port>", 0, 10, "Set up HTTP (plain) target"),
  	sslhcfg_adb = arg_strn(NULL, "adb", "<host:port>", 0, 10, "Set up ADB (Android Debug) target"),
  	sslhcfg_socks5 = arg_strn(NULL, "socks5", "<host:port>", 0, 10, "Set up socks5 target"),
  	sslhcfg_syslog = arg_strn(NULL, "syslog", "<host:port>", 0, 10, "Set up syslog target"),
+ 	sslhcfg_msrdp = arg_strn(NULL, "msrdp", "<host:port>", 0, 10, "Set up msrdp target"),
  	sslhcfg_anyprot = arg_strn(NULL, "anyprot", "<host:port>", 0, 10, "Set up default target"),
  	sslhcfg_end = arg_end(10)
 
@@ -2002,6 +2320,9 @@ static void sslhcfg_protocols_fprint(
         fprintf(out, "transparent: %d", sslhcfg_protocols->transparent);
         fprintf(out, "\n");
         indent(out, depth);
+        fprintf(out, "resolve_on_forward: %d", sslhcfg_protocols->resolve_on_forward);
+        fprintf(out, "\n");
+        indent(out, depth);
         fprintf(out, "log_level: %d", sslhcfg_protocols->log_level);
         fprintf(out, "\n");
         indent(out, depth);
@@ -2059,7 +2380,40 @@ void sslhcfg_fprint(
 {
     int i;
         indent(out, depth);
-        fprintf(out, "verbose: %d", sslhcfg->verbose);
+        fprintf(out, "verbose_config: %d", sslhcfg->verbose_config);
+        fprintf(out, "\n");
+        indent(out, depth);
+        fprintf(out, "verbose_config_error: %d", sslhcfg->verbose_config_error);
+        fprintf(out, "\n");
+        indent(out, depth);
+        fprintf(out, "verbose_connections: %d", sslhcfg->verbose_connections);
+        fprintf(out, "\n");
+        indent(out, depth);
+        fprintf(out, "verbose_connections_try: %d", sslhcfg->verbose_connections_try);
+        fprintf(out, "\n");
+        indent(out, depth);
+        fprintf(out, "verbose_connections_error: %d", sslhcfg->verbose_connections_error);
+        fprintf(out, "\n");
+        indent(out, depth);
+        fprintf(out, "verbose_fd: %d", sslhcfg->verbose_fd);
+        fprintf(out, "\n");
+        indent(out, depth);
+        fprintf(out, "verbose_packets: %d", sslhcfg->verbose_packets);
+        fprintf(out, "\n");
+        indent(out, depth);
+        fprintf(out, "verbose_probe_info: %d", sslhcfg->verbose_probe_info);
+        fprintf(out, "\n");
+        indent(out, depth);
+        fprintf(out, "verbose_probe_error: %d", sslhcfg->verbose_probe_error);
+        fprintf(out, "\n");
+        indent(out, depth);
+        fprintf(out, "verbose_system_error: %d", sslhcfg->verbose_system_error);
+        fprintf(out, "\n");
+        indent(out, depth);
+        fprintf(out, "verbose_int_error: %d", sslhcfg->verbose_int_error);
+        fprintf(out, "\n");
+        indent(out, depth);
+        fprintf(out, "version: %d", sslhcfg->version);
         fprintf(out, "\n");
         indent(out, depth);
         fprintf(out, "foreground: %d", sslhcfg->foreground);
@@ -2077,6 +2431,9 @@ void sslhcfg_fprint(
         fprintf(out, "timeout: %d", sslhcfg->timeout);
         fprintf(out, "\n");
         indent(out, depth);
+        fprintf(out, "udp_max_connections: %d", sslhcfg->udp_max_connections);
+        fprintf(out, "\n");
+        indent(out, depth);
         fprintf(out, "user: %s", sslhcfg->user);
         if (! sslhcfg->user_is_present)
             fprintf(out, " <unset>");
@@ -2095,6 +2452,11 @@ void sslhcfg_fprint(
         fprintf(out, "syslog_facility: %s", sslhcfg->syslog_facility);
         fprintf(out, "\n");
         indent(out, depth);
+        fprintf(out, "logfile: %s", sslhcfg->logfile);
+        if (! sslhcfg->logfile_is_present)
+            fprintf(out, " <unset>");
+        fprintf(out, "\n");
+        indent(out, depth);
         fprintf(out, "on_timeout: %s", sslhcfg->on_timeout);
         fprintf(out, "\n");
         indent(out, depth);

sslh-conf.h

@@ -1,5 +1,5 @@
 /* Generated by conf2struct (https://www.rutschle.net/tech/conf2struct/README)
- * on Fri Aug 13 18:03:18 2021. 
+ * on Tue Jan  2 21:25:47 2024. 
 
 # conf2struct: generate libconf parsers that read to structs
 # Copyright (C) 2018-2021  Yves Rutschle
@@ -58,6 +58,7 @@ struct sslhcfg_protocols_item {
 	int	fork;
 	int	tfo_ok;
 	int	transparent;
+	int	resolve_on_forward;
 	int	log_level;
 	int	keepalive;
 	size_t	sni_hostnames_len;
@@ -71,15 +72,28 @@ struct sslhcfg_protocols_item {
 	T_PROBE*	probe;
 	struct addrinfo*	saddr;
 	void*	data;
+	dl_list	timeouts;
 };
 
 struct sslhcfg_item {
-	int	verbose;
+	int	verbose_config;
+	int	verbose_config_error;
+	int	verbose_connections;
+	int	verbose_connections_try;
+	int	verbose_connections_error;
+	int	verbose_fd;
+	int	verbose_packets;
+	int	verbose_probe_info;
+	int	verbose_probe_error;
+	int	verbose_system_error;
+	int	verbose_int_error;
+	int	version;
 	int	foreground;
 	int	inetd;
 	int	numeric;
 	int	transparent;
 	int	timeout;
+	int	udp_max_connections;
 	int	user_is_present;
 	char*	user;
 	int	pidfile_is_present;
@@ -87,6 +101,8 @@ struct sslhcfg_item {
 	int	chroot_is_present;
 	char*	chroot;
 	char*	syslog_facility;
+	int	logfile_is_present;
+	char*	logfile;
 	char*	on_timeout;
 	char*	prefix;
 	size_t	listen_len;

sslh-ev.c

@@ -0,0 +1,153 @@
+/*
+   sslh-ev: mono-processus server based on libev
+
+# 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 <ev.h>
+#include "gap.h"
+#include "log.h"
+#include "udp-listener.h"
+#include "tcp-listener.h"
+
+
+const char* server_type = "sslh-ev";
+
+static struct ev_loop* loop;
+
+/* Libev watchers */
+struct watchers {
+    /* one set of ev_io for read, one for write, indexed by file descriptor */
+    gap_array *ev_ior, *ev_iow;
+
+    struct listen_endpoint* listen_sockets;
+    gap_array* fd2ls;  /* Array indexed by file descriptor, pointing to listen_sockets */
+};
+
+static void cnx_read_cb(EV_P_ ev_io *w, int revents);
+static void cnx_write_cb(EV_P_ ev_io *w, int wevents);
+static void cnx_accept_cb(EV_P_ ev_io *w, int revents);
+
+
+static void watchers_init(watchers** w, struct listen_endpoint* listen_sockets, 
+                          int num_addr_listen)
+{
+    *w = malloc(sizeof(**w));
+    (*w)->ev_ior = gap_init(num_addr_listen);
+    (*w)->ev_iow = gap_init(num_addr_listen);
+    (*w)->listen_sockets = listen_sockets;
+    (*w)->fd2ls = gap_init(0);
+
+    /* Create watchers for listen sockets */
+    for (int i = 0; i < num_addr_listen; i++) {
+        ev_io* io = malloc(sizeof(*io));
+
+        ev_io_init(io, &cnx_accept_cb, listen_sockets[i].socketfd, EV_READ);
+        ev_io_start(EV_A_  io);
+        gap_set((*w)->ev_ior, i, io);
+        gap_set((*w)->fd2ls, listen_sockets[i].socketfd, &listen_sockets[i]);
+        set_nonblock(listen_sockets[i].socketfd);
+    }
+}
+
+void watchers_add_read(watchers* w, int fd)
+{
+    ev_io* io = gap_get(w->ev_ior, fd);
+    if (!io) {
+        io = malloc(sizeof(*io));
+        ev_io_init(io, &cnx_read_cb, fd, EV_READ);
+        ev_io_set(io, fd, EV_READ);
+
+        gap_set(w->ev_ior, fd, io);
+    }
+    ev_io_start(loop, io);
+}
+
+void watchers_del_read(watchers* w, int fd)
+{
+    ev_io* io = gap_get(w->ev_ior, fd);
+    if (io) ev_io_stop(EV_A_ io);
+}
+
+void watchers_add_write(watchers* w, int fd)
+{
+    ev_io* io = gap_get(w->ev_iow, fd);
+    if (!io) {
+        io = malloc(sizeof(*io));
+        ev_io_init(io, &cnx_write_cb, fd, EV_WRITE);
+        ev_io_set(io, fd, EV_WRITE);
+
+        gap_set(w->ev_iow, fd, io);
+    }
+    ev_io_start(loop, io);
+}
+
+void watchers_del_write(watchers* w, int fd)
+{
+    ev_io* io = gap_get(w->ev_iow, fd);
+    if (io) ev_io_stop(EV_A_ io);
+}
+
+/* /watchers */
+
+#include "processes.h"
+
+/* Libev callbacks */
+static void cnx_read_cb(EV_P_ ev_io *w, int revents)
+{
+    struct loop_info* info = ev_userdata(EV_A);
+    cnx_read_process(info, w->fd);
+}
+
+static void cnx_write_cb(EV_P_ ev_io *w, int wevents)
+{
+    struct loop_info* info = ev_userdata(EV_A);
+    cnx_write_process(info, w->fd);
+}
+
+
+static void cnx_accept_cb(EV_P_ ev_io *w, int revents)
+{
+    struct loop_info* info = ev_userdata(EV_A);
+    cnx_accept_process(info, gap_get(info->watchers->fd2ls, w->fd));
+}
+
+void main_loop(struct listen_endpoint listen_sockets[], int num_addr_listen)
+{
+    struct loop_info ev_info = {0};
+    loop = EV_DEFAULT;
+
+    ev_info.collection = collection_init(0);
+    ev_info.probing_list = gap_init(0);
+    udp_init(&ev_info);
+    tcp_init();
+
+    watchers_init(&ev_info.watchers, listen_sockets, num_addr_listen);
+    ev_set_userdata(EV_A_ &ev_info);
+
+    ev_run(EV_A_ 0);
+}
+
+void start_shoveler(int listen_socket) {
+    print_message(msg_config_error, "inetd mode is not supported in libev mode\n");
+    exit(1);
+}
+
+

sslh-fork.c

@@ -23,7 +23,8 @@
 #include "common.h"
 #include "probe.h"
 #include "sslh-conf.h"
-#include "udp-listener.h"
+#include "tcp-probe.h"
+#include "log.h"
 
 #ifdef LIBBSD
 #include <bsd/unistd.h>
@@ -58,8 +59,7 @@ int shovel(struct connection *cnx)
           if (FD_ISSET(cnx->q[i].fd, &fds)) {
               res = fd2fd(&cnx->q[1-i], &cnx->q[i]);
               if (res == FD_CNXCLOSED) {
-                  if (cfg.verbose) 
-                      fprintf(stderr, "%s %s", i ? "client" : "server", "socket closed\n");
+                  print_message(msg_fd, "%s %s", i ? "client" : "server", "socket closed\n");
                   return res;
               }
           }
@@ -99,8 +99,7 @@ void start_shoveler(int in_socket)
        } else {
            /* Timed out: it's necessarily SSH */
            cnx.proto = timeout_protocol();
-           if (cfg.verbose) 
-               log_message(LOG_INFO, "timed out, connect to %s\n", cnx.proto->name);
+           print_message(msg_fd, "timed out, connect to %s\n", cnx.proto->name);
            break;
        }
    }
@@ -129,8 +128,7 @@ void start_shoveler(int in_socket)
    close(in_socket);
    close(out_socket);
    
-   if (cfg.verbose)
-      fprintf(stderr, "connection closed down\n");
+   print_message(msg_fd, "connection closed down\n");
 
    exit(0);
 }
@@ -166,6 +164,13 @@ void set_listen_procname(struct listen_endpoint *listen_socket)
 }
 
 
+/* At least MacOS does not know these two options, so define them to something
+ * equivalent for our use case */
+#ifndef ENONET
+#define ENONET EWOULDBLOCK
+#endif
+/* /MacOS kludge */
+
 /* TCP listener: connections, fork a child for each new connection 
  * IN: 
  *      endpoint: array of listening endpoint objects
@@ -179,10 +184,30 @@ void tcp_listener(struct listen_endpoint* endpoint, int num_endpoints, int activ
 
     while (1) {
         in_socket = accept(endpoint[active_endpoint].socketfd, 0, 0);
-        if (cfg.verbose) fprintf(stderr, "accepted fd %d\n", in_socket);
+        CHECK_RES_RETURN(in_socket, "accept", /*void*/ );
+        if (in_socket == -1) {
+            print_message(msg_system_error, "%s:%d:%s:%d:%s\n", 
+                          __FILE__, __LINE__, "accept", errno, strerror(errno));
+            switch(in_socket) {
+            case ENETDOWN:  /* accept(2) cites all these errnos as "you should retry" */
+            case EPROTO:
+            case ENOPROTOOPT:
+            case EHOSTDOWN:
+            case ENONET:
+            case EHOSTUNREACH:
+            case EOPNOTSUPP:
+            case ENETUNREACH:
+            case ECONNABORTED:
+                continue;
+
+            default:  /* Otherwise, it's something wrong in our parameters, we fail */
+                return;
+            }
+        }
+        print_message(msg_fd, "accepted fd %d\n", in_socket);
 
         switch(fork()) {
-        case -1: log_message(LOG_ERR, "fork failed: err %d: %s\n", errno, strerror(errno));
+        case -1: print_message(msg_system_error, "fork failed: err %d: %s\n", errno, strerror(errno));
                  break;
 
         case 0: /* In child process */
@@ -209,20 +234,24 @@ void main_loop(struct listen_endpoint listen_sockets[], int num_addr_listen)
     listener_pid = malloc(listener_pid_number * sizeof(listener_pid[0]));
     CHECK_ALLOC(listener_pid, "malloc");
 
+    tcp_init();
+
     /* 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 */
-        case -1: log_message(LOG_ERR, "fork failed: err %d: %s\n", errno, strerror(errno));
+        case -1: print_message(msg_system_error, "fork failed: err %d: %s\n", errno, strerror(errno));
                  break;
         /* We're in the child, we have work to do  */
         case 0:
             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");
+                print_message(msg_config_error, "UDP not (yet?) supported in sslh-fork\n");
             else
                 tcp_listener(listen_sockets, num_addr_listen, i);
+
+            exit(0);
 	    break;
 
 	/* We're in the parent, we don't need to do anything */

sslh-main.c

@@ -36,29 +36,7 @@
 
 #include "common.h"
 #include "probe.h"
-
-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 <addr> [-p <addr> ...] \n" \
-"%s\n\n" /* Dynamically built list of builtin protocols */  \
-"\t[--on-timeout <addr>]\n" \
-"-v: verbose\n" \
-"-V: version\n" \
-"-f: foreground\n" \
-"-n: numeric output\n" \
-"-u: specify under which user to run\n" \
-"-C: specify under which chroot path to run\n" \
-"--transparent: behave as a transparent proxy\n" \
-"-F: use configuration file (warning: no space between -F and file name!)\n" \
-"--on-timeout: connect to specified address upon timeout (default: ssh address)\n" \
-"-t: seconds to wait before connecting to --on-timeout address.\n" \
-"-p: address and port to listen on.\n    Can be used several times to bind to several addresses.\n" \
-"--[ssh,ssl,...]: where to connect connections from corresponding protocol.\n" \
-"-P: PID file.\n" \
-"-i: Run as a inetd service.\n" \
-"";
+#include "log.h"
 
 /* Constants for options that have no one-character shorthand */
 #define OPT_ONTIMEOUT   257
@@ -73,7 +51,7 @@ static void printcaps(void) {
 
     desc = cap_to_text(caps, &len);
 
-    fprintf(stderr, "capabilities: %s\n", desc);
+    print_message(msg_config, "capabilities: %s\n", desc);
 
     cap_free(caps);
     cap_free(desc);
@@ -82,27 +60,38 @@ static void printcaps(void) {
 
 static void printsettings(void)
 {
-    char buf[NI_MAXHOST];
+    char buf[NI_MAXHOST + 256]; /* 256 > " family %d %d" for reasonable ints */
     int i;
     struct sslhcfg_protocols_item *p;
     
     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] [%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->transparent ? "transparent" : ""
-                );
+        strcpy(buf, "resolve on forward");
+        if (!p->resolve_on_forward) {
+            sprintaddr(buf, sizeof(buf), p->saddr);
+            int len = strlen(buf);
+            sprintf(buf+len, " family %d %d", 
+                    p->saddr->ai_family,
+                    p->saddr->ai_addr->sa_family);
+        }
+        print_message(msg_config, 
+                      "%s addr: %s. libwrap service: %s log_level: %d [%s] [%s] [%s]\n",
+                      p->name, 
+                      buf,
+                      p->service,
+                      p->log_level,
+                      p->keepalive ? "keepalive" : "",
+                      p->fork ? "fork" : "",
+                      p->transparent ? "transparent" : ""
+                     );
     }
-    fprintf(stderr, "timeout: %d\non-timeout: %s\n", cfg.timeout,
-            timeout_protocol()->name);
+    print_message(msg_config, 
+                  "timeout: %d\n"
+                  "on-timeout: %s\n"
+                  "UDP hash size: %d\n", 
+                  cfg.timeout,
+                  timeout_protocol()->name,
+                  cfg.udp_max_connections);
 }
 
 
@@ -126,7 +115,7 @@ static void setup_regex_probe(struct sslhcfg_protocols_item *p)
                                         &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",
+            print_message(msg_config_error, "compiling pattern /%s/:%d:%s at offset %ld\n",
                     p->regex_patterns[i], error, err_str, error_offset);
             exit(1);
         }
@@ -146,14 +135,19 @@ static void config_protocols()
     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);
+
+        if (
+            !p->resolve_on_forward &&
+            resolve_split_name(&(p->saddr), p->host, p->port)
+        ) {
+            print_message(msg_config_error, "cannot resolve %s:%s\n",
+                          p->host, p->port);
             exit(4);
         }
 
         p->probe = get_probe(p->name);
         if (!p->probe) {
-            fprintf(stderr, "%s: probe unknown\n", p->name);
+            print_message(msg_config_error, "%s: probe unknown\n", p->name);
             exit(1);
         }
 
@@ -172,23 +166,55 @@ static void config_protocols()
                                   (const char**) cfg.protocols[i].alpn_protocols,
                                   cfg.protocols[i].alpn_protocols_len);
         }
+
+        p->timeouts.head = NULL;
+        p->timeouts.tail = NULL;
     }
 }
 
 
-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);
-    }
+void config_sanity_check(struct sslhcfg_item* cfg)
+{
+    size_t i;
 
 /* If compiling with systemd socket support no need to require listen address */
 #ifndef SYSTEMD
     if (!cfg->listen_len && !cfg->inetd) {
-        fprintf(stderr, "No listening address specified; use at least one -p option\n");
+        print_message(msg_config_error, "No listening address specified; use at least one -p option\n");
         exit(1);
     }
 #endif
+
+    for (i = 0; i < cfg->protocols_len; ++i) {
+        if (strcmp(cfg->protocols[i].name, "tls")) {
+            if (cfg->protocols[i].sni_hostnames_len) {
+                print_message(msg_config_error, "name: \"%s\"; host: \"%s\"; port: \"%s\": "
+                              "Config option sni_hostnames is only applicable for tls\n",
+                              cfg->protocols[i].name, cfg->protocols[i].host, cfg->protocols[i].port);
+                exit(1);
+            }
+            if (cfg->protocols[i].alpn_protocols_len) {
+                print_message(msg_config_error, "name: \"%s\"; host: \"%s\"; port: \"%s\": "
+                              "Config option alpn_protocols is only applicable for tls\n",
+                              cfg->protocols[i].name, cfg->protocols[i].host, cfg->protocols[i].port);
+                exit(1);
+            }
+        }
+
+        if (cfg->protocols[i].is_udp) {
+            if (cfg->protocols[i].tfo_ok) {
+                print_message(msg_config_error, "name: \"%s\"; host: \"%s\"; port: \"%s\": "
+                              "Config option tfo_ok is not applicable for udp connections\n",
+                              cfg->protocols[i].name, cfg->protocols[i].host, cfg->protocols[i].port);
+                exit(1);
+            }
+        } else {
+            if (!strcmp(cfg->protocols[i].name, "wireguard")) {
+                print_message(msg_config_error, "Wireguard works only with UDP\n");
+                exit(1);
+            }
+        }
+    }
 }
 
 
@@ -207,26 +233,29 @@ int main(int argc, char *argv[], char* envp[])
    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);
+
+   if (cfg.version) {
+       printf("%s %s\n", server_type, VERSION);
+       exit(0);
+   }
+
    config_protocols();
    config_sanity_check(&cfg);
 
    if (cfg.inetd)
    {
-       cfg.verbose = 0;
+       close(fileno(stderr)); /* Make sure no error will go to client */
        start_shoveler(0);
        exit(0);
    }
 
-   if (cfg.verbose)
-       printsettings();
+   printsettings();
 
    num_addr_listen = start_listen_sockets(&listen_sockets);
 
 #ifdef SYSTEMD
    if (num_addr_listen < 1) {
-     fprintf(stderr, "No listening sockets found, restart sockets or specify addresses in config\n");
+     print_message(msg_config_error, "No listening sockets found, restart sockets or specify addresses in config\n");
      exit(1);
     }
 #endif
@@ -249,13 +278,22 @@ int main(int argc, char *argv[], char* envp[])
    /* Open syslog connection before we drop privs/chroot */
    setup_syslog(argv[0]);
 
+   /* Open log file for writing */
+   setup_logfile();
+
    if (cfg.user || cfg.chroot)
        drop_privileges(cfg.user, cfg.chroot);
+   setup_landlock();
 
-   if (cfg.verbose)
-       printcaps();
+   printcaps();
+
+   print_message(msg_config, "%s %s started\n", server_type, VERSION);
 
    main_loop(listen_sockets, num_addr_listen);
 
+   close_logfile();
+
+   free(listen_sockets);
+
    return 0;
 }

sslh-select.c

@@ -25,482 +25,88 @@
  * 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. */
+ * on many Linux. To support large numbers of descriptors efficiently, either use sslh-fork
+ * or sslh-ev. */
 
 #define __LINUX__
 
-#include <limits.h>
-
 #include "common.h"
 #include "probe.h"
+#include "tcp-listener.h"
 #include "udp-listener.h"
 #include "collection.h"
+#include "processes.h"
 #include "gap.h"
-
-static int debug = 0;
+#include "log.h"
 
 const char* server_type = "sslh-select";
 
-/* Global state for a select() loop */
-struct select_info {
-    int max_fd;   /* Highest fd number to pass to select() */
-
-    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 */
-
+/* watcher type for a select() loop */
+struct watchers {
     fd_set fds_r, fds_w;  /* reference fd sets (used to init working copies) */
-    cnx_collection* collection; /* Collection of connections linked to this loop */
-
-    time_t next_timeout; /* time at which next UDP connection times out */
+    int max_fd;   /* Highest fd number to pass to select() */
 };
 
 
-
-static int tidy_connection(struct connection *cnx, struct select_info* fd_info)
+static void watchers_init(watchers** w, struct listen_endpoint* listen_sockets,
+                          int num_addr_listen)
 {
-    int i;
-    fd_set* fds = &fd_info->fds_r;
-    fd_set* fds2 = &fd_info->fds_w;
+    *w = malloc(sizeof(**w));
+    CHECK_ALLOC(*w, "malloc");
 
-    for (i = 0; i < 2; i++) {
-        if (cnx->q[i].fd != -1) {
-            if (cfg.verbose)
-                fprintf(stderr, "closing fd %d\n", cnx->q[i].fd);
+    memset(*w, 0, sizeof(**w));
+    FD_ZERO(&(*w)->fds_r);
+    FD_ZERO(&(*w)->fds_w);
 
-            FD_CLR(cnx->q[i].fd, fds);
-            FD_CLR(cnx->q[i].fd, fds2);
-            close(cnx->q[i].fd);
-            if (cnx->q[i].deferred_data)
-                free(cnx->q[i].deferred_data);
-        }
+    for (int i = 0; i < num_addr_listen; i++) {
+        watchers_add_read(*w, listen_sockets[i].socketfd);
+        set_nonblock(listen_sockets[i].socketfd);
     }
-    collection_remove_cnx(fd_info->collection, cnx);
-    return 0;
 }
 
+void watchers_add_read(watchers* w, int fd)
+{
+    FD_SET(fd, &w->fds_r); 
+    if (fd > w->max_fd)
+        w->max_fd = fd + 1;
+}
+
+void watchers_del_read(watchers* w, int fd)
+{
+    FD_CLR(fd, &w->fds_r);
+}
+
+void watchers_add_write(watchers* w, int fd)
+{
+    FD_SET(fd, &w->fds_w); 
+    if (fd > w->max_fd)
+        w->max_fd = fd + 1;
+}
+
+void watchers_del_write(watchers* w, int fd)
+{
+    FD_CLR(fd, &w->fds_w);
+}
+
+/* /end watchers */
+
+
+
+
 /* 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 */
-static int fd_is_in_range(int fd) {
+static int fd_out_of_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;
+        print_message(msg_system_error, "too many open file descriptor to monitor them all -- dropping connection\n");
+        return 1;
     }
-    return 1;
-}
-
-/* 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 */
-static struct connection* accept_new_connection(int listen_socket, struct cnx_collection *collection)
-{
-    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", NULL);
-
-    if (!fd_is_in_range(in_socket)) {
-        close(in_socket);
-        return NULL;
-    }
-
-    res = set_nonblock(in_socket);
-    if (res == -1) {
-        close(in_socket);
-        return NULL;
-    }
-
-    struct connection* cnx = collection_alloc_cnx_from_fd(collection, in_socket);
-    if (!cnx) {
-        close(in_socket);
-        return NULL;
-    }
-
-    return cnx;
+    return 0;
 }
 
 
-/* Connect queue 1 of connection to SSL; returns new file descriptor */
-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, NON_BLOCKING);
-    if ((q->fd != -1) && fd_is_in_range(q->fd)) {
-        log_connection(NULL, cnx);
-        flush_deferred(q);
-        if (q->deferred_data) {
-            FD_SET(q->fd, &fd_info->fds_w);
-            FD_CLR(cnx->q[0].fd, &fd_info->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, fd_info);
-        return -1;
-    }
-}
-
-/* shovels data from active fd to the other
-   returns after one socket closed or operation would block
- */
-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 (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, fd_info);
-        break;
-
-    case FD_STALLED:
-        FD_SET(write_q->fd, &fd_info->fds_w);
-        FD_CLR(read_q->fd, &fd_info->fds_r);
-        break;
-
-    default: /* Nothing */
-        break;
-    }
-}
-
-/* shovels data from one fd to the other and vice-versa
-   returns after one socket closed
- */
-static void shovel_single(struct connection *cnx)
-{
-   fd_set fds_r, fds_w;
-   int res, i;
-   int max_fd = MAX(cnx->q[0].fd, cnx->q[1].fd) + 1;
-
-   FD_ZERO(&fds_r);
-   FD_ZERO(&fds_w);
-   while (1) {
-      for (i = 0; i < 2; i++) {
-         if (cnx->q[i].deferred_data_size) {
-            FD_SET(cnx->q[i].fd, &fds_w);
-            FD_CLR(cnx->q[1-i].fd, &fds_r);
-         } else {
-            FD_CLR(cnx->q[i].fd, &fds_w);
-            FD_SET(cnx->q[1-i].fd, &fds_r);
-         }
-      }
-
-      res = select(
-                   max_fd,
-                   &fds_r,
-                   &fds_w,
-                   NULL,
-                   NULL
-                  );
-      CHECK_RES_DIE(res, "select");
-
-      for (i = 0; i < 2; i++) {
-          if (FD_ISSET(cnx->q[i].fd, &fds_w)) {
-              res = flush_deferred(&cnx->q[i]);
-              if ((res == -1) && ((errno == EPIPE) || (errno == ECONNRESET))) {
-                  if (cfg.verbose)
-                      fprintf(stderr, "%s socket closed\n", i ? "server" : "client");
-                  return;
-              }
-          }
-          if (FD_ISSET(cnx->q[i].fd, &fds_r)) {
-              res = fd2fd(&cnx->q[1-i], &cnx->q[i]);
-              if (!res) {
-                  if (cfg.verbose)
-                      fprintf(stderr, "socket closed\n");
-                  return;
-              }
-          }
-      }
-   }
-}
-
-/* Child process that makes internal connection and proxies
- */
-static void connect_proxy(struct connection *cnx)
-{
-    int in_socket;
-    int out_socket;
-
-    /* Minimize the file descriptor value to help select() */
-    in_socket = dup(cnx->q[0].fd);
-    if (in_socket == -1) {
-        in_socket = cnx->q[0].fd;
-    } else {
-        close(cnx->q[0].fd);
-        cnx->q[0].fd = in_socket;
-    }
-
-    /* Connect the target socket */
-    out_socket = connect_addr(cnx, in_socket, BLOCKING);
-    CHECK_RES_DIE(out_socket, "connect");
-
-    cnx->q[1].fd = out_socket;
-
-    log_connection(NULL, cnx);
-
-    shovel_single(cnx);
-
-    close(in_socket);
-    close(out_socket);
-
-    if (cfg.verbose)
-        fprintf(stderr, "connection closed down\n");
-
-    exit(0);
-}
-
-/* Removes cnx from probing list */
-static void remove_probing_cnx(struct select_info* fd_info, struct connection* cnx)
-{
-    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:
  * - fds_r and fds_w contain the file descriptors to monitor in read and write
@@ -518,48 +124,42 @@ static void udp_timeouts(struct select_info* fd_info)
  */
 void main_loop(struct listen_endpoint listen_sockets[], int num_addr_listen)
 {
-    struct select_info fd_info = {0};
+    struct loop_info fd_info = {0};
     fd_set readfds, writefds; /* working read and write fd sets */
     struct timeval tv;
     int i, res;
 
     fd_info.num_probing = 0; 
-    FD_ZERO(&fd_info.fds_r);
-    FD_ZERO(&fd_info.fds_w);
-    fd_info.probing_list = gap_init();
+    fd_info.probing_list = gap_init(0);
+    udp_init(&fd_info);
+    tcp_init();
 
-    for (i = 0; i < num_addr_listen; i++) {
-        FD_SET(listen_sockets[i].socketfd, &fd_info.fds_r); 
-        set_nonblock(listen_sockets[i].socketfd);
-    }
-    fd_info.max_fd = listen_sockets[num_addr_listen-1].socketfd + 1;
+    watchers_init(&fd_info.watchers, listen_sockets, num_addr_listen);
 
-    fd_info.collection = collection_init();
+    fd_info.collection = collection_init(fd_info.watchers->max_fd);
 
     while (1)
     {
         memset(&tv, 0, sizeof(tv));
         tv.tv_sec = cfg.timeout;
 
-        memcpy(&readfds, &fd_info.fds_r, sizeof(readfds));
-        memcpy(&writefds, &fd_info.fds_w, sizeof(writefds));
+        memcpy(&readfds, &fd_info.watchers->fds_r, sizeof(readfds));
+        memcpy(&writefds, &fd_info.watchers->fds_w, sizeof(writefds));
 
-        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, 
+        print_message(msg_fd, "selecting... max_fd=%d num_probing=%d\n",
+                                          fd_info.watchers->max_fd, fd_info.num_probing);
+        res = select(fd_info.watchers->max_fd + 1, &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].socketfd, &readfds)) {
-                cnx_accept_process(&fd_info, &listen_sockets[i]);
+                struct connection* new_cnx = cnx_accept_process(&fd_info, &listen_sockets[i]);
+
+                if (fd_out_of_range(new_cnx->q[0].fd))
+                    tidy_connection(new_cnx, &fd_info);
 
                 /* don't also process it as a read socket */
                 FD_CLR(listen_sockets[i].socketfd, &readfds);
@@ -567,8 +167,11 @@ void main_loop(struct listen_endpoint listen_sockets[], int num_addr_listen)
         }
 
         /* Check all sockets for write activity */
-        for (i = 0; i < fd_info.max_fd; i++) {
-            if (FD_ISSET(i, &writefds)) {
+        for (i = 0; i < fd_info.watchers->max_fd; i++) {
+            /* Check if it's active AND currently monitored (if a connection
+             * died, it gets tidied, which closes both sockets, but writefs does
+             * not know about that */
+            if (FD_ISSET(i, &writefds) && FD_ISSET(i, &fd_info.watchers->fds_w)) {
                 cnx_write_process(&fd_info, i);
             }
         }
@@ -577,24 +180,23 @@ void main_loop(struct listen_endpoint listen_sockets[], int num_addr_listen)
         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);
+                print_message(msg_int_error, "Inconsistent probing: cnx=0x%p\n", cnx);
                 if (cnx)
-                    log_message(LOG_ERR, "Inconsistent probing: state=%d\n", cnx);
+                    print_message(msg_int_error, "Inconsistent probing: state=%d\n", cnx->state);
                 exit(1);
             }
             if (cnx->probe_timeout < time(NULL)) {
-                if (cfg.verbose)
-                    fprintf(stderr, "timeout slot %d\n", i);
+                print_message(msg_fd, "timeout slot %d\n", i);
                 probing_read_process(cnx, &fd_info);
             }
         }
 
         /* Check all sockets for read activity */
-        for (i = 0; i < fd_info.max_fd; i++) {
+        for (i = 0; i < fd_info.watchers->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)) {
+            if (FD_ISSET(i, &readfds) && FD_ISSET(i, &fd_info.watchers->fds_r)) {
                 cnx_read_process(&fd_info, i);
             }
         }
@@ -603,7 +205,7 @@ void main_loop(struct listen_endpoint listen_sockets[], int num_addr_listen)
 
 
 void start_shoveler(int listen_socket) {
-    fprintf(stderr, "inetd mode is not supported in select mode\n");
+    print_message(msg_config_error, "inetd mode is not supported in select mode\n");
     exit(1);
 }
 

sslhconf.cfg

@@ -25,7 +25,34 @@ config: {
          name : "sslhcfg",
          type: "list",
          items: (
-            { name: "verbose"; type: "int"; default: 0; short: "v"; },
+            { name: "verbose-config"; type: "int"; default: 0; 
+                description: "Print configuration at startup" },
+            { name: "verbose-config-error"; type: "int"; default: 3; 
+                description: "Print configuration errors" },
+            { name: "verbose-connections"; type: "int"; default: 3; 
+                description: "Trace established incoming address to forward address" },
+            { name: "verbose-connections-try"; type: "int"; default: 0; 
+                description: "Connection errors" },
+            { name: "verbose-connections-error"; type: "int"; default: 3; 
+                description: "Connection attempts towards targets" },
+            { name: "verbose-fd"; type: "int"; default: 0; 
+                description: "File descriptor activity, open/close/whatnot" },
+            { name: "verbose-packets"; type: "int"; default: 0; 
+                description: "Hexdump packets on which probing is done" },
+
+            { name: "verbose-probe-info"; type: "int"; default: 0; 
+                description: "Trace the probe process" },
+            { name: "verbose-probe-error"; type: "int"; default: 3; 
+                description: "Failures and problems during probing" },
+
+            { name: "verbose-system-error"; type: "int"; default: 3; 
+                description: "System call failures" },
+            { name: "verbose-int-error"; type: "int"; default: 3; 
+                description: "Internal errors that should never happen" },
+
+            { name: "version"; type: "bool"; default: false;
+              short: "V";
+              description: "Print version information and exit"; },
             { name: "foreground"; type: "bool"; default: false;
               short: "f";
               description: "Run in foreground instead of as a daemon"; },
@@ -40,6 +67,8 @@ config: {
             { name: "timeout"; type: "int"; default: 5; 
               short: "t";
               description: "Set up timeout before connecting to default target"; },
+            { name: "udp_max_connections"; type: "int"; default: 1024;
+              description: "Number of concurrent UDP connections"; },
             { name: "user"; type: "string"; optional: true; 
               short: "u";
               description: "Username to change to after set-up"; },
@@ -51,6 +80,8 @@ config: {
               description: "Root to change to after set-up"; },
             { name: "syslog_facility"; type: "string"; default: "auth"; 
               description: "Facility to syslog to"; },
+            { name: "logfile"; type: "string"; optional: true;
+              description: "Log messages to a file" },
 
             { name: "on-timeout"; type: "string"; default: "ssh"; 
               description: "Target to connect to when timing out"; },
@@ -81,8 +112,10 @@ config: {
                     { 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; 
+                    { name: "transparent"; type: "bool"; default: false;
                         description: "Set to proxy this protocol transparently" },
+                    { name: "resolve_on_forward"; type: "bool"; default: false;
+                        description: "Set to true if server address should be resolved on (every) newly incoming connection (again)" },
                     { name: "log_level"; type: "int"; default: 1 },
                     { name: "keepalive"; type: "bool"; default: false },
                     { name: "sni_hostnames",
@@ -102,7 +135,8 @@ config: {
                     # 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*" }
+                    { name: "data"; type: "runtime"; c_type: "void*" },
+                    { name: "timeouts"; type: "runtime"; c_type: "dl_list" }
                 )
             }
         )
@@ -152,6 +186,19 @@ cl_groups: (
         { path: "tfo_ok"; value: 1 }
         );
     },
+    # Redundant with the --tls setting before, for backwards compatibility
+    { name: "ssl"; 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";
@@ -176,6 +223,18 @@ cl_groups: (
         { path: "tfo_ok"; value: 1 }
         );
     },
+    { name: "wireguard"; pattern: "(.+):(\w+)"; description: "Set up WireGuard target";
+        list: "protocols";
+        override: "name";
+        argdesc: "<host:port>";
+        targets: (
+        { path: "name"; value: "wireguard" },
+        { 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";
@@ -231,6 +290,17 @@ cl_groups: (
         { path: "log_level"; value: 1 }
         );
     },
+    { name: "msrdp"; pattern: "(.+):(\w+)"; description: "Set up msrdp target";
+        list: "protocols";
+        override: "name";
+        argdesc: "<host:port>";
+        targets: (
+        { path: "name"; value: "msrdp" },
+        { 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";

systemd-sslh-generator.c

@@ -5,6 +5,8 @@
 #include "common.h"
 
 
+#define print_message(sink, format, file, line) fprintf(stderr, format, file, line)
+
 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 */
@@ -53,9 +55,12 @@ static int get_listen_from_conf(const char *filename, char **listen[]) {
                             config_setting_source_line(addr));
                     return -1;
                 } else {
-                    (*listen)[i] = malloc(strlen(resolve_listen(hostname, port)));
+                    char *resolved_listen = resolve_listen(hostname, port);
+
+                    (*listen)[i] = malloc(strlen(resolved_listen));
                     CHECK_ALLOC((*listen)[i], "malloc");
-                    strcpy((*listen)[i], resolve_listen(hostname, port));
+                    strcpy((*listen)[i], resolved_listen);
+                    free(resolved_listen);
                 }
             }
         }
@@ -123,6 +128,7 @@ static int gen_sslh_config(char *runtime_unit_dir) {
         strcpy(runtime_conf, runtime_unit_dir);
         strcat(runtime_conf, unit_file);
         runtime_conf_fd = fopen(runtime_conf, "w");
+        free(runtime_conf);
     }
 
 

t

@@ -26,6 +26,7 @@ my $PROBES_NOFRAG =     1;
 my $PROBES_AGAIN =      1;
 my $SSL_MIX_SSH =       1;
 my $SSH_MIX_SSL =       1;
+my $DROP_CNX =          1;
 
 # Robustness tests. These are mostly to achieve full test
 # coverage, but do not necessarily result in an actual test
@@ -285,6 +286,19 @@ for my $binary (@binaries) {
         }
     }
 
+# Test: Drop connection without writing anything
+    if ($DROP_CNX) {
+        print "***Test: Connect but don't write anything\n";
+        my $cnx_h = new IO::Socket::INET(PeerHost => "localhost:$sslh_port");
+        warn "$!\n" unless $cnx_h;
+        if ($cnx_h) {
+            close $cnx_h;
+            my_is(1, "$binary: Connect and write nothing");
+            # The goal of the test is to check sslh doesn't
+            # crash
+        }
+    }
+
 
     if ($PROBES_NOFRAG) {
         test_probes(no_frag => 1, binary => $binary);
@@ -382,7 +396,7 @@ if ($RB_RESOLVE_ADDRESS) {
     my $sslh_pid;
     if (!($sslh_pid = fork)) {
         my $user = (getpwuid $<)[0]; # Run under current username
-        exec "./sslh-select -v 3 -f -u $user --listen blahblah.dontexist:9000 --ssh $ssh_address --tls $ssl_address -P $pidfile";
+        exec "./sslh-select -v 3 -f -u $user --listen blahblah.nonexistent:9000 --ssh $ssh_address --tls $ssl_address -P $pidfile";
     }
     warn "spawned $sslh_pid\n";
     waitpid $sslh_pid, 0;

t_load

@@ -14,13 +14,13 @@
 use strict;
 use IO::Socket::INET6;
 use Data::Dumper;
-use Conf::Libconfig;
+use Conf::Libconfig 1.0.3;
 
 ## BEGIN TEST CONFIG
 
 # How many total clients to we start? Each client will pick
 # a new protocol among what's in test.cfg.
-my $NUM_CNX = 50;
+my $NUM_CNX = 16;
 
 # Delay between starting new processes when starting up. If
 # you start 200 processes in under a second, things go wrong
@@ -35,7 +35,7 @@ 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;
+my $stop_client_probability = .0001;
 
 ##END CONFIG
 
@@ -44,7 +44,7 @@ $conf->read_file("test.cfg");
 
 
 # Pick one address for TCP and one for UDP
-my @listen = @{$conf->fetch_array("listen")};
+my @listen = @{$conf->value("listen")};
 my ($sslh_tcp_address, $sslh_udp_address);
 
 foreach my $l (@listen) {
@@ -65,7 +65,7 @@ my %connect_params = (
         test_data => "foo bar",
         resp_len => 12,
     },
-        ssh => {
+    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
@@ -73,7 +73,7 @@ my %connect_params = (
     tinc => {
         sleep => 0,
         test_data => "0 ",
-        resp_len => 8, # length "tinc: 0 " => 10 
+        resp_len => 8, # length "tinc: 0 " => 10
     },
     openvpn => {
         sleep => 0,
@@ -186,7 +186,7 @@ sub udp_client {
     }
 }
 
-foreach my $p (@{$conf->fetch_array("protocols")}) {
+foreach my $p (@{$conf->value("protocols")}) {
     if (!fork) {
         my $udp = $p->{is_udp} ? "--udp" : "";
         my $cmd = "./echosrv $udp -p $p->{host}:$p->{port} --prefix '$p->{name}: ' 2> /dev/null";
@@ -203,7 +203,7 @@ sleep 2; # Let echosrv's and sslh start
 my ($c_in, $c_out);
 pipe $c_in, $c_out;
 
-my @protocols = @{$conf->fetch_array("protocols")};
+my @protocols = @{$conf->value("protocols")};
 
 if (!fork) {
     # Process that starts all the clients

tcp-listener.c

@@ -0,0 +1,333 @@
+/*
+   tcp-listener.c: handles demultiplexing TCP protocols
+
+# Copyright (C) 2022  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 <errno.h>
+#include "tcp-listener.h"
+#include "probe.h"
+#include "log.h"
+
+/* Removes cnx from probing list */
+static void remove_probing_cnx(struct loop_info* fd_info, struct connection* cnx)
+{
+    gap_remove_ptr(fd_info->probing_list, cnx, fd_info->num_probing);
+    fd_info->num_probing--;
+}
+
+static void add_probing_cnx(struct loop_info* fd_info, struct connection* cnx)
+{
+    gap_set(fd_info->probing_list, fd_info->num_probing, cnx);
+    fd_info->num_probing++;
+}
+
+/* shovels data from active fd to the other
+   returns after one socket closed or operation would block
+ */
+static void shovel(struct connection *cnx, int active_fd, struct loop_info* fd_info)
+{
+    struct queue *read_q, *write_q;
+
+    read_q = &cnx->q[active_fd];
+    write_q = &cnx->q[1-active_fd];
+
+    print_message(msg_fd, "activity on fd%d\n", read_q->fd);
+
+    switch(fd2fd(write_q, read_q)) {
+    case -1:
+    case FD_CNXCLOSED:
+        tidy_connection(cnx, fd_info);
+        break;
+
+    case FD_STALLED:
+        watchers_add_write(fd_info->watchers, write_q->fd);
+        watchers_del_read(fd_info->watchers, read_q->fd);
+        break;
+
+    default: /* Nothing */
+        break;
+    }
+}
+
+
+/* Returns the queue index that contains the specified file descriptor.
+ * This is called by the *_process functions, which got cnx from the fd, so it
+ * is impossible for fd to not be cnx, hence we die if it happens */
+static int active_queue(struct connection* cnx, int fd)
+{
+    if (cnx->q[0].fd == fd) return 0;
+    if (cnx->q[1].fd == fd) return 1;
+
+    print_message(msg_int_error, "file descriptor %d not found in connection object\n", fd);
+    exit(1);
+}
+
+/* Process a TCP read event on the specified file descriptor */
+void tcp_read_process(struct loop_info* fd_info,
+                             int fd)
+{
+    cnx_collection* collection = fd_info->collection;
+    struct connection* cnx = collection_get_cnx_from_fd(collection, fd);
+
+    /* connection can get tidied if there is an error on the other file
+     * descriptor -- then cnx is NULL */
+    if (!cnx) return;
+
+    /* 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) {
+            print_message(msg_int_error, "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 */
+        print_message(msg_int_error, "Illegal connection state %d\n", cnx->state);
+        dump_connection(cnx);
+        exit(1);
+    }
+}
+
+/* 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 */
+struct connection* accept_new_connection(int listen_socket, struct loop_info* fd_info)
+{
+    int in_socket, res;
+
+    print_message(msg_fd, "accepting from %d\n", listen_socket);
+
+    in_socket = accept(listen_socket, 0, 0);
+    CHECK_RES_RETURN(in_socket, "accept", NULL);
+
+    res = set_nonblock(in_socket);
+    if (res == -1) {
+        close(in_socket);
+        return NULL;
+    }
+
+    struct connection* cnx = collection_alloc_cnx_from_fd(fd_info->collection, in_socket);
+    if (!cnx) {
+        close(in_socket);
+        return NULL;
+    }
+
+    add_probing_cnx(fd_info, cnx);
+    return cnx;
+}
+
+
+/* Connect queue 1 of connection to SSL; returns new file descriptor */
+static int connect_queue(struct connection* cnx,
+                         struct loop_info* fd_info)
+{
+    struct queue *q = &cnx->q[1];
+
+    q->fd = connect_addr(cnx, cnx->q[0].fd, NON_BLOCKING);
+    if (q->fd != -1) {
+        log_connection(NULL, cnx);
+        flush_deferred(q);
+        if (q->deferred_data) {
+            watchers_add_write(fd_info->watchers, q->fd);
+            watchers_del_read(fd_info->watchers, cnx->q[0].fd);
+        }
+        watchers_add_read(fd_info->watchers, q->fd);
+        collection_add_fd(fd_info->collection, cnx, q->fd);
+        return q->fd;
+    } else {
+        tidy_connection(cnx, fd_info);
+        return -1;
+    }
+}
+
+/* shovels data from one fd to the other and vice-versa
+   returns after one socket closed
+ */
+static void shovel_single(struct connection *cnx)
+{
+   fd_set fds_r, fds_w;
+   int res, i;
+   int max_fd = MAX(cnx->q[0].fd, cnx->q[1].fd) + 1;
+
+   FD_ZERO(&fds_r);
+   FD_ZERO(&fds_w);
+   while (1) {
+      for (i = 0; i < 2; i++) {
+         if (cnx->q[i].deferred_data_size) {
+            FD_SET(cnx->q[i].fd, &fds_w);
+            FD_CLR(cnx->q[1-i].fd, &fds_r);
+         } else {
+            FD_CLR(cnx->q[i].fd, &fds_w);
+            FD_SET(cnx->q[1-i].fd, &fds_r);
+         }
+      }
+
+      res = select(
+                   max_fd,
+                   &fds_r,
+                   &fds_w,
+                   NULL,
+                   NULL
+                  );
+      CHECK_RES_DIE(res, "select");
+
+      for (i = 0; i < 2; i++) {
+          if (FD_ISSET(cnx->q[i].fd, &fds_w)) {
+              res = flush_deferred(&cnx->q[i]);
+              if ((res == -1) && ((errno == EPIPE) || (errno == ECONNRESET))) {
+                  print_message(msg_fd, "%s socket closed\n", i ? "server" : "client");
+                  return;
+              }
+          }
+          if (FD_ISSET(cnx->q[i].fd, &fds_r)) {
+              res = fd2fd(&cnx->q[1-i], &cnx->q[i]);
+              if (!res) {
+                  print_message(msg_fd, "socket closed\n");
+                  return;
+              }
+          }
+      }
+   }
+}
+
+
+
+/* Child process that makes internal connection and proxies
+ */
+static void connect_proxy(struct connection *cnx)
+{
+    int in_socket;
+    int out_socket;
+
+    /* Minimize the file descriptor value to help select() */
+    in_socket = dup(cnx->q[0].fd);
+    if (in_socket == -1) {
+        in_socket = cnx->q[0].fd;
+    } else {
+        close(cnx->q[0].fd);
+        cnx->q[0].fd = in_socket;
+    }
+
+    /* Connect the target socket */
+    out_socket = connect_addr(cnx, in_socket, BLOCKING);
+    CHECK_RES_DIE(out_socket, "connect");
+
+    cnx->q[1].fd = out_socket;
+
+    log_connection(NULL, cnx);
+
+    shovel_single(cnx);
+
+    close(in_socket);
+    close(out_socket);
+
+    print_message(msg_fd, "connection closed down\n");
+
+    exit(0);
+}
+
+/* Process read activity on a socket in probe state 
+ * IN/OUT cnx: connection data, updated if connected
+ * IN/OUT info: updated if connected
+ * */
+void probing_read_process(struct connection* cnx,
+                                 struct loop_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();
+        print_message(msg_fd, "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: print_message(msg_system_error, "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);
+    }
+}
+
+
+/* Process a connection that is active in write (this is TCP only, as
+ * UDP sockets are never "full" or deferred or whatever) */
+void cnx_write_process(struct loop_info* fd_info, int fd)
+{
+    struct connection* cnx = collection_get_cnx_from_fd(fd_info->collection, fd);
+
+    /* connection can get tidied if there is an error on the other file
+     * descriptor -- then cnx is NULL */
+    if (!cnx) return;
+
+    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) {
+            watchers_del_write(fd_info->watchers, cnx->q[queue].fd);
+            watchers_add_read(fd_info->watchers, cnx->q[1-queue].fd);
+        }
+    }
+}
+

tcp-listener.h

@@ -0,0 +1,13 @@
+#ifndef TCP_LISTENER_H
+#define TCP_LISTENER_H
+
+#include "processes.h"
+#include "collection.h"
+#include "tcp-probe.h"
+
+void tcp_read_process(struct loop_info* fd_info, int fd);
+struct connection* accept_new_connection(int listen_socket, struct loop_info* fd_info);
+void probing_read_process(struct connection* cnx, struct loop_info* fd_info);
+void cnx_write_process(struct loop_info* fd_info, int fd);
+
+#endif

tcp-probe.c

@@ -0,0 +1,99 @@
+/*
+# tcp-probe.c: TCP code that is common to the sslh-fork and sslh-[ev|select] 
+#
+# Copyright (C) 2022  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 "probe.h"
+
+static struct sslhcfg_protocols_item** tcp_protocols;
+static int tcp_protocols_len = 0;
+
+/*
+ * Read the beginning of data coming from the client connection and check if
+ * 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];
+    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
+     * disconnected between the previous call to select() and now. If that
+     * happens, we just connect to the default protocol so the caller of this
+     * function does not have to deal with a specific  failure condition (the
+     * connection will just fail later normally). */
+
+    if (n > 0) {
+        defer_write(&cnx->q[1], buffer, n);
+        return probe_buffer(cnx->q[1].begin_deferred_data,
+                            cnx->q[1].deferred_data_size,
+                            tcp_protocols, tcp_protocols_len,
+                            &cnx->proto
+                            );
+    }
+
+    /* read() returned an error, so just connect to the last protocol to die */
+    cnx->proto = &cfg.protocols[cfg.protocols_len-1];
+    return PROBE_MATCH;
+}
+
+
+static void tcp_protocol_list_init(void)
+{
+    for (int i = 0; i < cfg.protocols_len; i++) {
+        struct sslhcfg_protocols_item* p = &cfg.protocols[i];
+        if (!p->is_udp) {
+            tcp_protocols_len++;
+            tcp_protocols = realloc(tcp_protocols, tcp_protocols_len * sizeof(*tcp_protocols));
+            CHECK_ALLOC(tcp_protocols, "realloc");
+            tcp_protocols[tcp_protocols_len-1] = p;
+        }
+    }
+}
+
+/* Configuration sanity check for TCP:
+ * - If there is a listening socket, there must be at least one target
+ */
+static void tcp_sanity_check(void)
+{
+    int tcp_present = 0;
+
+    for (int i = 0; i < cfg.listen_len; i++) {
+        struct sslhcfg_listen_item* p = &cfg.listen[i];
+        if (!p->is_udp) {
+            tcp_present = 1;
+            break;
+        }
+    }
+
+    if (tcp_present && !tcp_protocols_len) {
+        print_message(msg_config_error, "At least one TCP target protocol must be specified.\n");
+        exit(2);
+    }
+}
+
+void tcp_init(void)
+{
+    tcp_protocol_list_init();
+    tcp_sanity_check();
+}

tcp-probe.h

@@ -0,0 +1,6 @@
+#ifndef TCP_PROBE_H
+#define TCP_PROBE_H
+
+void tcp_init(void);
+
+#endif

test.cfg

@@ -1,7 +1,6 @@
 # Configuration file for testing (use both by sslh under
 # test and the test script `t`)
 
-verbose: 4;
 foreground: true;
 inetd: false;
 numeric: true;
@@ -11,6 +10,21 @@ pidfile: "/tmp/sslh_test.pid";
 
 syslog_facility: "auth"; 
 
+# Logging configuration
+# Value: 1: stdout; 2: syslog; 3: both
+# Defaults should be sensible. Generally, you want *-error
+# to be always enabled, to know if something is going wrong.
+verbose-config: 1; #  print configuration at startup
+verbose-config-error: 1;  # print configuration errors
+verbose-connections: 1; # trace established incoming address to forward address
+verbose-connections-error: 1; # connection errors
+verbose-connections-try: 1; # connection attempts towards targets
+verbose-fd: 0; # file descriptor activity, open/close/whatnot
+verbose-packets: 1; # hexdump packets on which probing is done
+verbose-probe-info: 0; # what's happening during the probe process
+verbose-probe-error: 1; # failures and problems during probing
+verbose-system-error: 1; # system call problem, i.e.  malloc, fork, failing
+verbose-int-error: 1; # internal errors, the kind that should never happen
 
 # List of interfaces on which we should listen
 # Options:
@@ -21,10 +35,14 @@ listen:
     { host: "ip4-localhost"; is_udp: true; port: "8086"; }
 );
 
+
+# Tester beware: when using fork, the forked process loses
+# track of buffers of other, concurrent connections. Memory
+# leak tools thus complain each time a forked process stops.
  
 protocols:
 (
-     { name: "ssh";  host: "localhost"; port: "9000"; fork: true; transparent: true; },
+     { name: "ssh";  host: "localhost"; port: "9000"; fork: true; transparent: true; resolve_on_forward: true; },
      { name: "socks5";  host: "localhost"; port: "9001";  },
      { name: "http";  host: "localhost"; port: "9002";  },
      { name: "tinc";  host: "localhost"; port: "9003"; },
@@ -35,6 +53,7 @@ protocols:
      { name: "regex"; host: "ip4-localhost"; is_udp: true; port: "9020";
          udp_timeout: 30;
          regex_patterns: [ "^foo" ];
+         resolve_on_forward: true;
      },
      { name: "regex"; host: "localhost"; port: "9011";
         regex_patterns: [ "^foo", "^bar" ];

tls.c

@@ -33,6 +33,7 @@
 #include <fnmatch.h> /* fnmatch() */
 #include "tls.h"
 #include "sslh-conf.h"
+#include "log.h"
 
 #define TLS_HEADER_LEN 5
 #define TLS_HANDSHAKE_CONTENT_TYPE 0x16
@@ -82,14 +83,14 @@ parse_tls_header(const struct TLSProtocol *tls_data, const char *data, size_t da
 
     tls_content_type = data[0];
     if (tls_content_type != TLS_HANDSHAKE_CONTENT_TYPE) {
-        if (cfg.verbose) fprintf(stderr, "Request did not begin with TLS handshake.\n");
+        print_message(msg_probe_info, "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 (cfg.verbose) fprintf(stderr, "Received SSL %d.%d handshake which cannot be parsed.\n",
+        print_message(msg_probe_error, "Received SSL %d.%d handshake which cannot be parsed.\n",
               tls_version_major, tls_version_minor);
 
         return TLS_EVERSION;
@@ -111,7 +112,7 @@ parse_tls_header(const struct TLSProtocol *tls_data, const char *data, size_t da
         return TLS_EPROTOCOL;
     }
     if (data[pos] != TLS_HANDSHAKE_TYPE_CLIENT_HELLO) {
-        if (cfg.verbose) fprintf(stderr, "Not a client hello\n");
+        print_message(msg_probe_error, "Not a client hello\n");
 
         return TLS_EPROTOCOL;
     }
@@ -144,7 +145,7 @@ parse_tls_header(const struct TLSProtocol *tls_data, const char *data, size_t da
     pos += 1 + len;
 
     if (pos == data_len && tls_version_major == 3 && tls_version_minor == 0) {
-        if (cfg.verbose) fprintf(stderr, "Received SSL 3.0 handshake without extensions\n");
+        print_message(msg_probe_error, "Received SSL 3.0 handshake without extensions\n");
         return TLS_EVERSION;
     }
 
@@ -228,7 +229,7 @@ parse_server_name_extension(const struct TLSProtocol *tls_data, const char *data
                     return TLS_ENOEXT;
                 }
             default:
-                if (cfg.verbose) fprintf(stderr, "Unknown server name extension name type: %d\n",
+                print_message(msg_probe_error, "Unknown server name extension name type: %d\n",
                       data[pos]);
         }
         pos += 3 + len;
@@ -254,7 +255,7 @@ parse_alpn_extension(const struct TLSProtocol *tls_data, const char *data, size_
         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 (cfg.verbose) fprintf(stderr, "Unknown ALPN name: %.*s\n", (int)len, data + pos + 1);
+            print_message(msg_probe_error, "Unknown ALPN name: %.*s\n", (int)len, data + pos + 1);
         }
         pos += 1 + len;
     }
@@ -276,7 +277,7 @@ has_match(const char** list, size_t list_len, const char* name, size_t name_len)
 
     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);
+        print_message(msg_probe_error, "matching [%.*s] with [%s]\n", (int)name_len, name, *item);
         if(!fnmatch(*item, name_nullterminated, 0)) {
             free(name_nullterminated);
             return 1;

udp-listener.c

@@ -1,7 +1,7 @@
 /*
-   udp-listener.c: handles demultplexing UDP protocols
+   udp-listener.c: handles demultiplexing UDP protocols
 
-# Copyright (C) 2020-2021  Yves Rutschle
+# Copyright (C) 2020-2022  Yves Rutschle
 # 
 # This program is free software; you can redistribute it
 # and/or modify it under the terms of the GNU General Public
@@ -20,78 +20,279 @@
 
 */
 
+#include <limits.h>
+
 #include "common.h"
 #include "probe.h"
 #include "sslh-conf.h"
 #include "udp-listener.h"
 
+/* Incoming connections are of course all received on a single socket. Create a
+ * hash that associates (incoming sockaddr) => struct connection*, so finding
+ * the connection related to an incoming packet is fast.
+ */
 
-/* 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)
+
+
+static int cnx_cmp(struct connection* cnx1, struct connection* cnx2)
 {
-    int i;
+    struct sockaddr_storage* addr1 = &cnx1->client_addr;
+    socklen_t addrlen1 = cnx1->addrlen;
 
-    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;
-            }
+    struct sockaddr_storage* addr2 = &cnx2->client_addr;
+    socklen_t addrlen2 = cnx2->addrlen;
+
+    if (addrlen1 != addrlen2) return -1;
+
+    return memcmp(addr1, addr2, addrlen1);
+}
+
+/* From an IP address, create something that's useable as a hash key.
+ * Currently:
+ * lowest bytes of remote port */
+static int hash_make_key(hash_item new)
+{
+    struct sockaddr_storage* addr = &new->client_addr;
+    //socklen_t addrlen = new->addrlen;
+    struct sockaddr_in* addr4;
+    struct sockaddr_in6* addr6;
+    int out;
+
+    switch (((struct sockaddr*)addr)->sa_family) {
+    case AF_INET:
+        addr4 = (struct sockaddr_in*)addr;
+        out = addr4->sin_port;
+        break;
+
+    case AF_INET6:
+        addr6 = (struct sockaddr_in6*)addr;
+        out = addr6->sin6_port;
+        break;
+
+    default: /* Just use the first bytes, skipping the address family */
+        out = ((char*)addr)[2];
+        break;
+    }
+    return out;
+}
+
+static struct sslhcfg_protocols_item** udp_protocols;
+static int udp_protocols_len = 0;
+
+static void udp_protocol_list_init(void)
+{
+    for (int i = 0; i < cfg.protocols_len; i++) {
+        struct sslhcfg_protocols_item* p = &cfg.protocols[i];
+        if (p->is_udp) {
+            udp_protocols_len++;
+            udp_protocols = realloc(udp_protocols, udp_protocols_len * sizeof(*udp_protocols));
+            CHECK_ALLOC(udp_protocols, "realloc");
+            udp_protocols[udp_protocols_len-1] = p;
         }
     }
-    return -1;
 }
 
+/* Configuration sanity check for UDP:
+ * - If there is a listening address, there must be at least one target
+ */
+static void udp_sanity_check(void)
+{
+    int udp_present = 0;
+
+    for (int i = 0; i < cfg.listen_len; i++) {
+        struct sslhcfg_listen_item* p = &cfg.listen[i];
+        if (p->is_udp) {
+            udp_present = 1;
+            break;
+        }
+    }
+
+    if (udp_present && !udp_protocols_len) {
+        print_message(msg_config_error, "At least one UDP target protocol must be specified.\n");
+        exit(2);
+    }
+}
+
+/* Init the UDP subsystem.
+ * - Initialise the hash
+ * - that's all, folks
+ * */
+void udp_init(struct loop_info* fd_info)
+{
+    fd_info->hash_sources = hash_init(cfg.udp_max_connections, &hash_make_key, &cnx_cmp);
+
+    udp_protocol_list_init();
+    udp_sanity_check();
+}
+
+
+/* Find if the specified source has been seen before.
+ * If yes, returns file descriptor of connection
+ * If not, returns -1
+ * */
+static int known_source(hash* h, struct sockaddr_storage* addr, socklen_t addrlen)
+{
+    struct connection search;
+    search.client_addr = *addr;
+    search.addrlen = addrlen;
+
+    struct connection* cnx = hash_find(h, &search);
+    if (!cnx) return -1;
+    return cnx->q[0].fd;
+}
+
+
+
+static int new_source(hash* h, struct connection* new)
+{
+    return hash_insert(h, new);
+}
+
+
+/* Double linked list utilities: push element at tail of list */
+static void list_push(dl_list* list, struct connection* cnx)
+{
+    cnx->timeout_next = NULL;
+
+    if (!list->head) {
+        cnx->timeout_prev = NULL;
+        list->head = cnx;
+    }
+
+    if (list->tail) {
+        list->tail->timeout_next = cnx;
+        cnx->timeout_prev = list->tail;
+    }
+
+    list->tail = cnx;
+}
+
+/* Double linked list utilities: remove element */
+static void list_remove(dl_list* list, struct connection* cnx)
+{
+    if (list->head == cnx) list->head = cnx->timeout_next;
+    if (list->tail == cnx) list->tail = cnx->timeout_prev;
+
+    if (cnx->timeout_prev)
+        cnx->timeout_prev->timeout_next = cnx->timeout_next;
+
+    if (cnx->timeout_next)
+        cnx->timeout_next->timeout_prev = cnx->timeout_prev;
+}
+
+/* Timeouts are managed with one list for each protocol. Whenever a connection
+ * is active, it gets moved to the end of the list. Each call will pop the
+ * first elements that have timed out and free their resources.
+ *
+ * This gets called every time a UDP packet is received from the outside, i.e.
+ * every time we might need to free up resources. If no packets come in, we
+ * don't time out anything, as we don't need the resources.
+ * */
+void udp_timeouts(struct loop_info* fd_info)
+{
+    time_t now = time(NULL);
+
+    for (int i = 0; i < cfg.protocols_len; i++) {
+        struct connection *cnx = cfg.protocols[i].timeouts.head;
+        while (cnx && (now - cnx->last_active > cfg.protocols[i].udp_timeout)) {
+            print_message(msg_fd, "timed out UDP %d\n", cnx->target_sock);
+            tidy_connection(cnx, fd_info);
+
+            cnx = cfg.protocols[i].timeouts.head;
+        }
+    }
+}
+
+void udp_tidy(struct connection* cnx, struct loop_info* fd_info)
+{
+    close(cnx->target_sock);
+    hash_remove(fd_info->hash_sources, cnx);
+    list_remove(&cnx->proto->timeouts, cnx);
+}
+
+/* Mark the connection was active */
+static void mark_active(struct connection* cnx)
+{
+    cnx->last_active = time(NULL);
+
+    dl_list* list = &cnx->proto->timeouts;
+
+    list_remove(list, cnx);
+    list_push(list, cnx);
+}
+
+
+/* Creates a new non-blocking socket */
+static int nonblocking_socket(struct sslhcfg_protocols_item* proto)
+{
+    int res;
+
+    if (proto->resolve_on_forward) {
+        res = resolve_split_name(&(proto->saddr), proto->host,
+                                 proto->port);
+        if (res) return -1;
+    }
+
+    int out = socket(proto->saddr->ai_family, SOCK_DGRAM, 0);
+    res = set_nonblock(out);
+    if (res == -1) {
+        print_message(msg_system_error, "%s:%d:%s:%d:%s\n", __FILE__, __LINE__, "udp:socket:nonblock", errno, strerror(errno));
+        close(out);
+        return -1;
+    }
+    return out;
+}
+
+
 /* 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
+ * Returns: newly allocate connections, for new connections
+ * NULL otherwise
  * */
-int udp_c2s_forward(int sockfd, cnx_collection* collection, int max_fd)
+struct connection* udp_c2s_forward(int sockfd, struct loop_info* fd_info)
 {
     char addr_str[NI_MAXHOST+1+NI_MAXSERV+1];
-    struct sockaddr src_addr;
+    struct sockaddr_storage src_addr;
     struct addrinfo addrinfo;
     struct sslhcfg_protocols_item* proto;
+    cnx_collection* collection = fd_info->collection;
     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).
+    char data[65536]; /* Theoretical 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 */
 
+
+    udp_timeouts(fd_info);
+
     addrlen = sizeof(src_addr);
-    len = recvfrom(sockfd, data, sizeof(data), 0, &src_addr, &addrlen);
+    len = recvfrom(sockfd, data, sizeof(data), 0, (struct sockaddr*) &src_addr, &addrlen);
     if (len < 0) {
         perror("recvfrom");
-        return -1;
+        return NULL;
     }
-    target = known_source(collection, max_fd, &src_addr, addrlen);
-    addrinfo.ai_addr = &src_addr;
+    target = known_source(fd_info->hash_sources, &src_addr, addrlen);
+    addrinfo.ai_addr = (struct sockaddr*) &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));
+    print_message(msg_probe_info, "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);
+        res = probe_buffer(data, len, udp_protocols, udp_protocols_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);
+        print_message(msg_probe_info, "UDP probed: %d\n", res);
         if (res != PROBE_MATCH) {
-            return -1;
+            return NULL;
         }
 
-        out = socket(proto->saddr->ai_family, SOCK_DGRAM, 0);
+        out = nonblocking_socket(proto);
+        if (out == -1) return NULL;
         struct connection* cnx = collection_alloc_cnx_from_fd(collection, out);
-        if (!cnx) return -1;
+        if (!cnx) return NULL;
         target = out;
         cnx->target_sock = out;
         cnx->proto = proto;
@@ -99,18 +300,25 @@ int udp_c2s_forward(int sockfd, cnx_collection* collection, int max_fd)
         cnx->client_addr = src_addr;
         cnx->addrlen = addrlen;
         cnx->local_endpoint = sockfd;
+
+        res = new_source(fd_info->hash_sources, cnx);
+        if (res == -1) {
+            print_message(msg_connections_error, "Out of hash space for new incoming UDP connection -- increase udp_max_connections");
+            collection_remove_cnx(collection, cnx);
+            return NULL;
+        }
     }
     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", 
+    mark_active(cnx);
+    print_message(msg_fd, "sending %d to %s\n", 
             res, sprintaddr(data, sizeof(data), cnx->proto->saddr));
-    return out;
-}
 
+    return cnx;
+}
 
 void udp_s2c_forward(struct connection* cnx)
 {
@@ -119,20 +327,10 @@ void udp_s2c_forward(struct connection* cnx)
     int res;
 
     res = recvfrom(sockfd, data, sizeof(data), 0, NULL, NULL);
-    fprintf(stderr, "recvfrom %d\n", res);
+    if ((res == -1) && ((errno == EAGAIN) || (errno == EWOULDBLOCK))) return;
     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;
+                 (struct sockaddr*)&cnx->client_addr, cnx->addrlen);
+    mark_active(cnx);
 }
 

udp-listener.h

@@ -1,7 +1,10 @@
 #ifndef UDPLISTENER_H
 #define UDPLISTENER_H
 
+
 #include "collection.h"
+#include "processes.h"
+#include "common.h"
 
 /* UDP listener: upon incoming packet, find where it should go
  * This is run in its own process and never returns.
@@ -11,18 +14,16 @@ void udp_listener(struct listen_endpoint* endpoint, int num_endpoints, int activ
 
 /* 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
+ * Returns: newly allocate connections, for new connections
  * -1 otherwise
  * */
-int udp_c2s_forward(int sockfd, cnx_collection* collection, int max_fd);
+struct connection* udp_c2s_forward(int sockfd, struct loop_info* fd_info);
 
 /* 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);
+void udp_init(struct loop_info* fd_info);
+void udp_tidy(struct connection* cnx, struct loop_info* fd_info);
 
 #endif /* UDPLISTENER_H */