update history

Add ./configure step
Fix libpcre-dev to libpcre2-dev

.gitignore

@@ -3,8 +3,15 @@
 *.o
 cscope.*
 echosrv
+libsslh.a
 sslh-fork
 sslh-select
+sslh-ev
+systemd-sslh-generator
 sslh.8.gz
 tags
 version.h
+/config.status
+/config.log
+/config.h
+/Makefile

ChangeLog

@@ -1,3 +1,20 @@
+v2.1.2:
+	Fix inetd mode.
+
+v2.1.1:
+	Various minor fixes.
+
+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.

Dockerfile

@@ -16,7 +16,7 @@ RUN apk add --no-cache \
 
 COPY . /sslh
 
-RUN make sslh-select && strip sslh-select
+RUN ./configure && make sslh-select && strip sslh-select
 
 FROM docker.io/${TARGET_ARCH}/alpine:${ALPINE_VERSION}
 

Makefile.in

@@ -3,9 +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
@@ -34,7 +36,7 @@ CFLAGS +=-Wall -O2 -DLIBPCRE -g $(CFLAGS_COV) $(CFLAGS_SAN)
 
 
 LIBS=-lm -lpcre2-8
-OBJS=sslh-conf.o common.o log.o sslh-main.o probe.o tls.o argtable3.o collection.o gap.o tcp-probe.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 $(OBJS_A)
@@ -72,8 +74,11 @@ ifneq ($(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)
 
 %.o: %.c %.h version.h
 	$(CC) $(CFLAGS) $(CPPFLAGS) -c $< -o $@
@@ -84,8 +89,6 @@ $(OBJS_A): $(OBJS)
 version.h:
 	./genver.sh >version.h
 
-sslh: sslh-fork sslh-select sslh-ev
-
 $(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
 
 
@@ -114,6 +117,9 @@ echosrv-conf.c echosrv-conf.h: echosrv.cfg
 echosrv: version.h echosrv-conf.c echosrv.o echosrv-conf.o argtable3.o
 	$(CC) $(CFLAGS) $(LDFLAGS) -o echosrv echosrv.o echosrv-conf.o argtable3.o $(LIBS)
 
+
+landlock.o: config.h
+
 $(MAN): sslh.pod Makefile
 	pod2man --section=8 --release=$(VERSION) --center=" " sslh.pod | gzip -9 - > $(MAN)
 
@@ -133,7 +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
@@ -153,7 +159,7 @@ distclean: clean
 	rm -f tags sslh-conf.[ch] echosrv-conf.[ch] cscope.*
 
 clean:
-	rm -f sslh-fork sslh-select sslh-ev 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

@@ -21,8 +21,9 @@ 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.
+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
@@ -65,7 +78,7 @@ version: "3"
 
 services:
   sslh:
-    image: sslh:latest
+    image: ghcr.io/yrutschle/sslh:latest
     hostname: sslh
     ports:
       - 443:443

basic.cfg

@@ -11,9 +11,13 @@ pidfile: "/var/run/sslh.pid";
 
 # Change hostname with your external address name, or the IP
 # of the interface that receives connections
+# Default is to bind all interfaces. httpd can be started
+# first to bind on localhost, in which case sslh will bind
+# only other interfaces.
 listen:
 (
-    { host: "thelonious"; port: "443"; }
+    { host: "0.0.0.0"; port: "443"; },
+    { host: "[::]"; port: "443"; }
 );
 
 
@@ -24,8 +28,6 @@ protocols:
 (
      { name: "ssh"; service: "ssh"; host: "localhost"; port: "22"; fork: true; },
      { name: "openvpn"; host: "localhost"; port: "1194"; },
-     { name: "xmpp"; host: "localhost"; port: "5222"; },
-     { name: "http"; host: "localhost"; port: "80"; },
      { name: "tls"; host: "localhost"; port: "443"; log_level: 0; },
      { name: "anyprot"; host: "localhost"; port: "443"; }
 );

common.c

@@ -110,7 +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)
 {
@@ -262,7 +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");
@@ -278,7 +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;
 }
@@ -372,7 +391,7 @@ int connect_addr(struct connection *cnx, int fd_from, connect_blocking blocking)
 }
 
 /* Store some data to write to the queue later */
-int defer_write(struct queue *q, void* data, int data_size)
+int defer_write(struct queue *q, void* data, ssize_t data_size)
 {
     char *p;
     ptrdiff_t data_offset = q->deferred_data - q->begin_deferred_data;
@@ -384,7 +403,7 @@ int defer_write(struct queue *q, void* data, int data_size)
     q->begin_deferred_data = p;
     q->deferred_data = p + data_offset;
     p += data_offset + q->deferred_data_size;
-    q->deferred_data_size += data_size;
+    q->deferred_data_size += (int)data_size;
     memcpy(p, data, data_size);
 
     return 0;
@@ -396,13 +415,13 @@ int defer_write(struct queue *q, void* data, int data_size)
  * */
 int flush_deferred(struct queue *q)
 {
-    int n;
+    ssize_t n;
 
     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)
-        return n;
+        return (int)n;
 
     if (n == q->deferred_data_size) {
         /* All has been written -- release the memory */
@@ -413,10 +432,10 @@ int flush_deferred(struct queue *q)
     } else {
         /* There is data left */
         q->deferred_data += n;
-        q->deferred_data_size -= n;
+        q->deferred_data_size -= (int)n;
     }
 
-    return n;
+    return (int)n;
 }
 
 
@@ -451,7 +470,8 @@ void dump_connection(struct connection *cnx)
 int fd2fd(struct queue *target_q, struct queue *from_q)
 {
    char buffer[BUFSIZ];
-   int target, from, size_r, size_w;
+   int target, from;
+   ssize_t size_r, size_w;
 
    target = target_q->fd;
    from = from_q->fd;
@@ -463,6 +483,7 @@ int fd2fd(struct queue *target_q, struct queue *from_q)
            return FD_NODATA;
 
        case ECONNRESET:
+       case ENOTSOCK:
        case EPIPE:
            return FD_CNXCLOSED;
        }
@@ -495,7 +516,7 @@ int fd2fd(struct queue *target_q, struct queue *from_q)
 
    CHECK_RES_RETURN(size_w, "write", FD_CNXCLOSED);
 
-   return size_w;
+   return (int)size_w;
 }
 
 /* returns a string that prints the IP and port of the sockaddr */
@@ -530,7 +551,8 @@ 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)
 {
@@ -556,7 +578,7 @@ int resolve_split_name(struct addrinfo **out, char* host, char* serv)
 
    res = getaddrinfo(host, serv, &hint, out);
    if (res)
-      print_message(msg_system_error, "%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;
 }
 
@@ -832,20 +854,19 @@ void write_pid_file(const char* pidfile)
 
     f = fopen(pidfile, "w");
     if (!f) {
-        print_message(msg_system_error, "write_pid_file:%s:%s", pidfile, strerror(errno));
-        exit(3);
+        print_message(msg_system_error, "write_pid_file: %s: %s\n", pidfile, strerror(errno));
+        return;
     }
 
     res = fprintf(f, "%d\n", getpid());
     if (res < 0) {
-        print_message(msg_system_error, "write_pid_file:fprintf:%s", strerror(errno));
-        exit(3);
+        print_message(msg_system_error, "write_pid_file: fprintf: %s\n", strerror(errno));
+        return;
     }
 
     res = fclose(f);
     if (res == EOF) {
-        print_message(msg_system_error, "write_pid_file:fclose:%s", strerror(errno));
-        exit(3);
+        print_message(msg_system_error, "write_pid_file: fclose: %s\n", strerror(errno));
+        return;
     }
 }
-

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
 
@@ -171,7 +172,7 @@ int resolve_split_name(struct addrinfo **out, char* hostname, char* port);
 
 int start_listen_sockets(struct listen_endpoint *sockfd[]);
 
-int defer_write(struct queue *q, void* data, int data_size);
+int defer_write(struct queue *q, void* data, ssize_t data_size);
 int flush_deferred(struct queue *q);
 
 extern struct sslhcfg_item cfg;
@@ -183,4 +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

doc/INSTALL.md

@@ -1,3 +1,13 @@
+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 graciously produced by
+nono303 on his [repository](https://github.com/nono303/sslh).
+
+
 Compile and install
 ===================
 
@@ -6,139 +16,130 @@ Dependencies
 
 `sslh` uses:
 
-* [libconfig](http://www.hyperrealm.com/libconfig/). For
-  Debian this is contained in package `libconfig-dev`. You
-can compile with or without it using USELIBCONFIG in the
-Makefile.
+* [libconfig](http://www.hyperrealm.com/libconfig/).
+  For Debian this is contained in package `libconfig-dev`.
+  You can compile with or without it using USELIBCONFIG in the Makefile.
 
 * [libwrap](http://packages.debian.org/source/unstable/tcp-wrappers).
-    For Debian, this is contained in packages
-`libwrap0-dev`. You
-can compile with or without it using USELIBWRAP in the
-Makefile.
+  For Debian, this is contained in packages `libwrap0-dev`.
+  You can compile with or without it using USELIBWRAP in the Makefile.
 
-* [libsystemd](http://packages.debian.org/source/unstable/libsystemd-dev), in package `libsystemd-dev`.  You
-can compile with or without it using USESYSTEMD in the
-Makefile.
+* [libsystemd](http://packages.debian.org/source/unstable/libsystemd-dev), in package `libsystemd-dev`.
+  You can compile with or without it using USESYSTEMD in the Makefile.
 
-* [libcap](http://packages.debian.org/source/unstable/libcap-dev), in package `libcap-dev`. You can compile with or without it using USELIBCAP in the Makefile
+* [libcap](http://packages.debian.org/source/unstable/libcap-dev), in package `libcap-dev`.
+  You can compile with or without it using USELIBCAP in the Makefile
 
-* libbsd, to enable to change the process name (as shown in
-  `ps`, so each forked process shows what protocol and what
-  connection it is serving),
-which requires `libbsd` at runtime, and `libbsd-dev` at
-compile-time.
+* libbsd, to enable to change the process name (as shown in `ps`,
+  so each forked process shows what protocol and what connection it is serving),
+  which requires `libbsd` at runtime, and `libbsd-dev` at compile-time.
 
-* libpcre2, in package `libpcre-dev`. You can compile
-  with or without it using ENABLE_REGEX in the Makefile.
+* libpcre2, in package `libpcre2-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.
+* 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
 <http://download.opensuse.org/repositories/multimedia:/libs/openSUSE_12.1/>
 
-For Fedora, you'll need packages `libconfig` and
-`libconfig-devel`:
+For Fedora, you'll need packages `libconfig` and `libconfig-devel`:
 
-	yum install libconfig libconfig-devel
+    yum install libconfig libconfig-devel
 
-If you want to rebuild `sslh-conf.c` (after a `make
-distclean` for example), you will also need to add
-[conf2struct](https://www.rutschle.net/tech/conf2struct/README.html)
+If you want to rebuild `sslh-conf.c` (after a `make distclean` for example),
+you will also need to add [conf2struct](https://www.rutschle.net/tech/conf2struct/README.html)
 (v1.5) to your path.
 
-
 The test scripts are written in Perl, and will require
-IO::Socket::INET6 (libio-socket-inet6-perl in Debian).
+`IO::Socket::INET6` (`libio-socket-inet6-perl` in Debian).
+
 
 Compilation
 -----------
 
 After this, the Makefile should work:
 
-	make install
+    make install
 
-There are a couple of configuration options at the beginning
-of the Makefile: 
+There are a couple of configuration options at the beginning of the Makefile: 
 
-* `USELIBWRAP` compiles support for host access control (see
-  `hosts_access(3)`), you will need `libwrap` headers and
-  library to compile (`libwrap0-dev` in Debian).
+* `USELIBWRAP` compiles support for host access control (see `hosts_access(3)`),
+  you will need `libwrap` headers and library to compile (`libwrap0-dev` in Debian).
 
-* `USELIBCONFIG` compiles support for the configuration
-  file. You will need `libconfig` headers to compile
-  (`libconfig8-dev` in Debian).
+* `USELIBCONFIG` compiles support for the configuration file.
+  You will need `libconfig` headers to compile (`libconfig8-dev` in Debian).
 
-*  `USESYSTEMD` compiles support for using systemd socket activation.
-   You will need `systemd` headers to compile (`systemd-devel` in Fedora).
+* `USESYSTEMD` compiles support for using systemd socket activation.
+  You will need `systemd` headers to compile (`systemd-devel` in Fedora).
+
+* `USELIBBSD` compiles support for updating the process name (as shown by `ps`).
 
-* `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.
+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`.
 
-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 three different executables: `sslh-fork`,
-`sslh-select` and `sslh-ev`:
+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
-of many processes.  
-If you are going to use `sslh` for a "small" setup (less than
-a dozen ssh connections and a low-traffic https server) then
-`sslh-fork` is probably more suited for you. 
+  It is well-tested and very reliable, but incurs the overhead of many processes.  
+  If you are going to use `sslh` for a "small" setup
+  (less than a dozen ssh connections and a low-traffic https server)
+  then `sslh-fork` is probably more suited for you.
 
-* `sslh-select` uses only one thread, which monitors all
-  connections at once. It 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-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.
 
-* `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
 ------------
 
 * In general:
-
-		make
-		cp sslh-fork /usr/local/sbin/sslh
-		cp basic.cfg /etc/sslh.cfg
-                vi /etc/sslh.cfg
-
+  ```sh
+  ./configure
+  make
+  cp sslh-fork /usr/local/sbin/sslh
+  cp basic.cfg /etc/sslh.cfg
+  vi /etc/sslh.cfg
+  ```
 * For Debian:
-
-		cp scripts/etc.init.d.sslh /etc/init.d/sslh
-	
+  ```sh
+  cp scripts/etc.init.d.sslh /etc/init.d/sslh
+  ```
 * For CentOS:
-
-		cp scripts/etc.rc.d.init.d.sslh.centos /etc/rc.d/init.d/sslh
-
+  ```sh
+  cp scripts/etc.rc.d.init.d.sslh.centos /etc/rc.d/init.d/sslh
+  ```
 
 You might need to create links in /etc/rc<x>.d so that the server
 start automatically at boot-up, e.g. under Debian:
-
-	update-rc.d sslh defaults
+```sh
+update-rc.d sslh defaults
+```
 

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/ 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

@@ -99,12 +99,8 @@ Then you can run sslh-select as an unprivileged user, e.g.:
 Transparent proxy support
 -------------------------
 
-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.
-
-Set up can get complicated, so it has its own [document](tproxy.md).
+Transparent proxying is described in its own
+[document](tproxy.md).
 
 Systemd Socket Activation
 -------------------------

echosrv.c

@@ -62,9 +62,10 @@ void check_res_dump(int res, struct addrinfo *addr, char* syscall)
 
 void start_echo(int fd)
 {
-    int res;
+    ssize_t res;
     char buffer[1 << 20];
-    int ret, prefix_len;
+    ssize_t ret;
+    size_t prefix_len;
     int first = 1;
 
     prefix_len = strlen(cfg.prefix);
@@ -151,7 +152,7 @@ void udp_echo(struct listen_endpoint* listen_socket)
 
     while (1) {
         addrlen = sizeof(src_addr);
-        size_t len = recvfrom(listen_socket->socketfd, 
+        ssize_t len = recvfrom(listen_socket->socketfd,
                            data + prefix_len,
                            sizeof(data) - prefix_len,
                            0,
@@ -166,7 +167,7 @@ void udp_echo(struct listen_endpoint* listen_socket)
 
         print_udp_xchange(listen_socket->socketfd, &src_addr, addrlen);
 
-        int res = sendto(listen_socket->socketfd,
+        ssize_t res = sendto(listen_socket->socketfd,
                          data,
                          len + prefix_len,
                          0,

example.cfg

@@ -78,7 +78,9 @@ listen:
 # connect to the first that matches.)
 #
 #       tls:
-#               sni_hostnames:  list of FQDN for that target
+#               sni_hostnames:  list of FQDN for that target. Each name can
+#               include wildcard following glob(7) rules.
+
 #               alpn_protocols: list of ALPN protocols for that target, see:
 #               https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml#alpn-protocol-ids
 #

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 */

probe.c

@@ -323,7 +323,7 @@ static int is_adb_protocol(const char *p, ssize_t len, struct sslhcfg_protocols_
     if (len < min_data_packet_size + sizeof(empty_message))
         return PROBE_AGAIN;
 
-    if (memcmp(&p[0], empty_message, sizeof(empty_message)))
+    if (memcmp(&p[0], empty_message, sizeof(empty_message)) != 0)
         return PROBE_NEXT;
 
     return probe_adb_cnxn_message(&p[sizeof(empty_message)]);

scripts/systemd.sslh-select@.service

@@ -0,0 +1,27 @@
+[Unit]
+Description=SSL/SSH multiplexer (select mode) for %I
+After=network.target
+
+[Service]
+EnvironmentFile=/etc/default/sslh
+ExecStart=/usr/sbin/sslh-select -F/etc/sslh/%I.cfg -f $DAEMON_OPTS
+KillMode=process
+#Hardening
+PrivateTmp=true
+CapabilityBoundingSet=CAP_NET_BIND_SERVICE
+AmbientCapabilities=CAP_NET_BIND_SERVICE
+SecureBits=noroot-locked
+ProtectSystem=strict
+ProtectHome=true
+ProtectKernelModules=true
+ProtectKernelTunables=true
+ProtectControlGroups=true
+MountFlags=private
+NoNewPrivileges=true
+PrivateDevices=true
+RestrictAddressFamilies=AF_INET AF_INET6 AF_UNIX
+MemoryDenyWriteExecute=true
+DynamicUser=true
+
+[Install]
+WantedBy=multi-user.target

scripts/systemd.sslh@.service

@@ -1,10 +1,10 @@
 [Unit]
-Description=SSL/SSH multiplexer
+Description=SSL/SSH multiplexer (fork mode) for %I
 After=network.target
 
 [Service]
-EnvironmentFile=/etc/conf.d/sslh
-ExecStart=/usr/sbin/sslh --foreground $DAEMON_OPTS
+EnvironmentFile=/etc/default/sslh
+ExecStart=/usr/sbin/sslh -F/etc/sslh/%I.cfg -f $DAEMON_OPTS
 KillMode=process
 #Hardening
 PrivateTmp=true

sslh-conf.c

@@ -1,5 +1,5 @@
 /* Generated by conf2struct (https://www.rutschle.net/tech/conf2struct/README)
- * on Sun Sep 11 21:43:25 2022. 
+ * on Tue Jan  2 21:25:47 2024. 
 
 # 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 arbitrary memory
+/* Copy the value of a string argument to arbitary memory
 * location that must be large enough, converting on the way
 * (i.e. CFG_INT gets atoi() and so on) */
 /* 0: success
@@ -471,6 +471,7 @@ struct arg_file* sslhcfg_conffile;
  	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;
@@ -1333,6 +1334,15 @@ static struct compound_cl_target sslhcfg_openvpn_targets [] = {
 	{ 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 }
+};
+
 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" },
@@ -1395,6 +1405,18 @@ 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,
@@ -1818,7 +1840,7 @@ 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
-                * discrepancy between the regex and the
+                * discrepency between the regex and the
                 * number of backreferences */
                 return 0;
             }
@@ -2111,7 +2133,7 @@ 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
-* responsibility. 
+* responsability. 
 * Returns the number of scalars in the configuration */
 static int cfg_as_string(config_setting_t* parent, const char* path, char** strp)
 {
@@ -2199,6 +2221,7 @@ int sslhcfg_cl_parse(int argc, char* argv[], struct sslhcfg_item* cfg)
  	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"),
@@ -2216,10 +2239,13 @@ int sslhcfg_cl_parse(int argc, char* argv[], struct sslhcfg_item* cfg)
     /* Parse command line */
     nerrors = arg_parse(argc, argv, argtable);
     if (nerrors) {
-        arg_print_errors(stdout, sslhcfg_end, "sslhcfg"); 
+        // print bad args
+        arg_print_errors(stdout, sslhcfg_end, "sslhcfg");
+        // print usage
         arg_print_syntax(stdout, argtable, "\n");
+        // print options
         arg_print_glossary(stdout, argtable, "  %-25s\t%s\n");
-        return -1;
+        fprintf(stderr, "Invalid args are ignored, please fix them\n");
     }
 
 

sslh-conf.h

@@ -1,5 +1,5 @@
 /* Generated by conf2struct (https://www.rutschle.net/tech/conf2struct/README)
- * on Sun Sep 11 21:43:25 2022. 
+ * on Tue Jan  2 21:25:47 2024. 
 
 # conf2struct: generate libconf parsers that read to structs
 # Copyright (C) 2018-2021  Yves Rutschle

sslh-fork.c

@@ -164,6 +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
@@ -178,6 +185,25 @@ void tcp_listener(struct listen_endpoint* endpoint, int num_endpoints, int activ
     while (1) {
         in_socket = accept(endpoint[active_endpoint].socketfd, 0, 0);
         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()) {
@@ -224,6 +250,8 @@ void main_loop(struct listen_endpoint listen_sockets[], int num_addr_listen)
                 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

@@ -37,6 +37,7 @@
 #include "common.h"
 #include "probe.h"
 #include "log.h"
+#include "tcp-probe.h"
 
 /* Constants for options that have no one-character shorthand */
 #define OPT_ONTIMEOUT   257
@@ -69,7 +70,7 @@ static void printsettings(void)
         strcpy(buf, "resolve on forward");
         if (!p->resolve_on_forward) {
             sprintaddr(buf, sizeof(buf), p->saddr);
-            int len = strlen(buf);
+            size_t len = strlen(buf);
             sprintf(buf+len, " family %d %d", 
                     p->saddr->ai_family,
                     p->saddr->ai_addr->sa_family);
@@ -98,7 +99,8 @@ static void printsettings(void)
 static void setup_regex_probe(struct sslhcfg_protocols_item *p)
 #ifdef ENABLE_REGEX
 {
-    int num_patterns, i, error;
+    size_t num_patterns, i;
+    int error;
     pcre2_code** pattern_list;
     PCRE2_SIZE error_offset;
     PCRE2_UCHAR8 err_str[120];
@@ -186,7 +188,7 @@ void config_sanity_check(struct sslhcfg_item* cfg)
 #endif
 
     for (i = 0; i < cfg->protocols_len; ++i) {
-        if (strcmp(cfg->protocols[i].name, "tls")) {
+        if (strcmp(cfg->protocols[i].name, "tls") != 0) {
             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",
@@ -245,6 +247,7 @@ int main(int argc, char *argv[], char* envp[])
    if (cfg.inetd)
    {
        close(fileno(stderr)); /* Make sure no error will go to client */
+       tcp_init();
        start_shoveler(0);
        exit(0);
    }
@@ -283,6 +286,7 @@ int main(int argc, char *argv[], char* envp[])
 
    if (cfg.user || cfg.chroot)
        drop_privileges(cfg.user, cfg.chroot);
+   setup_landlock();
 
    printcaps();
 

sslh-select.c

@@ -67,7 +67,7 @@ static void watchers_init(watchers** w, struct listen_endpoint* listen_sockets,
 void watchers_add_read(watchers* w, int fd)
 {
     FD_SET(fd, &w->fds_r); 
-    if (fd > w->max_fd)
+    if (fd + 1 > w->max_fd)
         w->max_fd = fd + 1;
 }
 
@@ -148,7 +148,7 @@ void main_loop(struct listen_endpoint listen_sockets[], int num_addr_listen)
 
         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,
+        res = select(fd_info.watchers->max_fd, &readfds, &writefds,
                      NULL, fd_info.num_probing ? &tv : NULL);
         if (res < 0)
             perror("select");

sslhconf.cfg

@@ -186,6 +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";

systemd-sslh-generator.c

@@ -1,39 +1,72 @@
 #include <libconfig.h>
+#include <dirent.h>
 #include <stdio.h>
+#include <errno.h>
 #include <string.h>
 #include <stdlib.h>
+#include <stdbool.h>
+#include <stdarg.h>
+#include <sys/stat.h>
 #include "common.h"
 
 
-#define print_message(sink, format, file, line) fprintf(stderr, format, file, line)
+#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 */
-    char *conn = malloc(strlen(hostname)+strlen(port)+2);
-    CHECK_ALLOC(conn, "malloc");
+typedef struct FileList FileList;
+
+struct FileList {
+    char *name;
+    struct FileList *prev;
+};
+
+static void free_file_list(FileList *fl) {
+    while (fl != NULL) {
+        FileList *prev = fl->prev;
+        free(fl->name);
+        free(fl);
+        fl = prev;
+    }
+}
+
+static FILE *err_log;
+static bool systemd_invoked = false;
+static const char
+        *socket_ext = ".socket",
+        *dropin_ext = ".conf",
+        *service_ext = ".service.d/",
+        *fork_unit_file = "/sslh@",
+        *select_unit_file = "/sslh-select@",
+        *fork_unit = "# Automatically generated by systemd-sslh-generator\n\n"
+                     "[Unit]\n"
+                     "Requires=sslh@%s.socket\n"
+                     "Conflicts=sslh-select@%s.service\n"
+                     "PartOf=sslh@%s.socket\n",
+        *select_unit = "# Automatically generated by systemd-sslh-generator\n\n"
+                       "[Unit]\n"
+                       "Requires=sslh@%s.socket\n"
+                       "Conflicts=sslh@%s.service\n"
+                       "PartOf=sslh@%s.socket\n";
+
+static char *resolve_listen(const char *hostname, const char *port) {
+    char *conn = calloc(1, strlen(hostname) + strlen(port) + 2);
+    CHECK_ALLOC(conn, "malloc")
     strcpy(conn, hostname);
     strcat(conn, ":");
     strcat(conn, port);
-
     return conn;
-
 }
 
-
 static int get_listen_from_conf(const char *filename, char **listen[]) {
     config_t config;
     config_setting_t *setting, *addr;
     const char *hostname, *port;
     int len = 0;
 
-    /* look up the listen stanzas in the config file so these
-     * can be used in the socket file generated */
     config_init(&config);
     if (config_read_file(&config, filename) == CONFIG_FALSE) {
-        /* we don't care if file is missing, skip it */
         if (config_error_line(&config) != 0) {
-            fprintf(stderr, "%s:%d:%s\n",
+            fprintf(err_log,
+                    "systemd-sslh-generator: %s%d%s\n",
                     filename,
                     config_error_line(&config),
                     config_error_text(&config));
@@ -42,118 +75,247 @@ static int get_listen_from_conf(const char *filename, char **listen[]) {
     } else {
         setting = config_lookup(&config, "listen");
         if (setting) {
-	    int i;
             len = config_setting_length(setting);
             *listen = malloc(len * sizeof(**listen));
-            CHECK_ALLOC(*listen, "malloc");
-            for (i = 0; i < len; i++) {
+            CHECK_ALLOC(*listen, "malloc")
+            for (int i = 0; i < len; i++) {
                 addr = config_setting_get_elem(setting, i);
-                if (! (config_setting_lookup_string(addr, "host", &hostname) &&
-                       config_setting_lookup_string(addr, "port", &port))) {
-                    fprintf(stderr,
-                            "line %d:Incomplete specification (hostname and port required)\n",
+                if (!(config_setting_lookup_string(addr, "host", &hostname) && config_setting_lookup_string(addr, "port", &port))) {
+                    fprintf(err_log,
+                            "systemd-sslh-generator: line %d:Incomplete specification (hostname and port required)\n",
                             config_setting_source_line(addr));
                     return -1;
                 } else {
-                    char *resolved_listen = resolve_listen(hostname, port);
-
-                    (*listen)[i] = malloc(strlen(resolved_listen));
-                    CHECK_ALLOC((*listen)[i], "malloc");
-                    strcpy((*listen)[i], resolved_listen);
-                    free(resolved_listen);
+                    (*listen)[i] = resolve_listen(hostname, port);
                 }
             }
         }
     }
-
     return len;
-
 }
 
-static int write_socket_unit(FILE *socket, char *listen[], int num_addr, const char *source) {
-    int i;
-
+static void write_socket_unit(FILE *socket, char *listen[], int num_addr, const char *cfg, const char *source) {
     fprintf(socket,
             "# Automatically generated by systemd-sslh-generator\n\n"
             "[Unit]\n"
-            "Before=sslh.service\n"
+            "Before=sslh@%s.service\n"
             "SourcePath=%s\n"
+            "PartOf=sslh@%s.service\n"
             "Documentation=man:sslh(8) man:systemd-sslh-generator(8)\n\n"
             "[Socket]\n"
             "FreeBind=true\n",
-            source);
-
-    for (i = 0; i < num_addr; i++) {
+            cfg,
+            source,
+            cfg);
+    for (int i = 0; i < num_addr; i++) {
         fprintf(socket, "ListenStream=%s\n", listen[i]);
     }
+    fprintf(socket,
+           "\n[Install]\n"
+           "WantedBy=sockets.target\n");
+}
 
+static int write_unit_dropin(const char *runtime_unit_dir, const bool is_fork, const char *cfg) {
+    const char
+        *unit_file = is_fork ? fork_unit_file : select_unit_file,
+        *unit_string = is_fork ? fork_unit : select_unit;
+    FILE *dropin_fd = stdout;
+    if (systemd_invoked) {
+        //Systemd drop-in configuration for the base select service sslh@%I.service
+        const size_t runtime_len = strlen(runtime_unit_dir);
+        size_t len = strlen(unit_file) + strlen(cfg) + strlen(service_ext) + strlen(dropin_ext);
+        char dropin_dir[runtime_len + len + 1];
+        strcpy(dropin_dir, runtime_unit_dir);
+        strcat(dropin_dir, unit_file);
+        strcat(dropin_dir, cfg);
+        strcat(dropin_dir, service_ext);
+
+        if (mkdir(dropin_dir, S_IRWXU | S_IRWXG | S_IROTH)) {
+            fprintf(err_log,
+                    "systemd-sslh-generator: Could not create directory '%s' to generate drop-in configuration: %s\n",
+                    dropin_dir,
+                    strerror(errno));
+            return errno;
+        }
+
+        len = len + strlen(cfg) + strlen(dropin_ext);
+        char dropin_path[len + 1];
+        strcpy(dropin_path, dropin_dir);
+        strcat(dropin_path, cfg);
+        strcat(dropin_path, dropin_ext);
+        dropin_fd = fopen(dropin_path, "w");
+        if (!dropin_fd) {
+            fprintf(err_log,
+                    "systemd-sslh-generator: Could not open '%s' to generate drop-in configuration: %s\n",
+                    dropin_path,
+                    strerror(errno));
+            return errno;
+        }
+    }
+    fprintf(dropin_fd, unit_string, cfg, cfg, cfg);
+    if (systemd_invoked) {
+        fclose(dropin_fd);
+    }
     return 0;
 }
 
 static int gen_sslh_config(char *runtime_unit_dir) {
-    char *sslh_conf;
-    int num_addr;
-    FILE *config;
+    int status = 0;
+    const char *config_dir = "/etc/sslh/";
     char **listen;
-    FILE *runtime_conf_fd = stdout;
-    const char *unit_file;
+    DIR *d = opendir(config_dir);
+    FileList *fa = NULL;
 
-    /* There are two default locations so check both with first given preference */
-    sslh_conf = "/etc/sslh.cfg";
-
-    config = fopen(sslh_conf, "r");
-    if (config  == NULL) {
-        sslh_conf="/etc/sslh/sslh.cfg";
-        config = fopen(sslh_conf, "r");
-        if (config == NULL) {
-            return -1;
+    if (d) {
+        struct dirent *dir;
+        while ((dir = readdir(d)) != NULL) {
+            if ((strcmp(dir->d_name, ".") == 0) || (strcmp(dir->d_name, "..") == 0)) {
+                continue;
+            }
+            FileList *lfa = malloc(sizeof(FileList));
+            CHECK_ALLOC(lfa, "malloc")
+            lfa->name = malloc(strlen(dir->d_name) + 1);
+            CHECK_ALLOC(lfa->name, "malloc")
+            strcpy(lfa->name, dir->d_name);
+            lfa->prev = NULL;
+            if (fa) {
+                lfa->prev = fa;
+            }
+            fa = lfa;
         }
+        closedir(d);
+    } else {
+        fprintf(err_log,
+                "systemd-sslh-generator: Configuration directory '/etc/sslh/' does not exist! No units generated.\n");
+        //Config directory /etc/sslh/ does not exist
+        return 0;
     }
-
-    fclose(config);
-
-    num_addr = get_listen_from_conf(sslh_conf, &listen);
-    if (num_addr < 0)
-        return -1;
-
-    /* If this is run by systemd directly write to the location told to
-     * otherwise write to standard out so that it's trivial to check what
-     * will be written */
-    if (runtime_unit_dir && *runtime_unit_dir) {
-        unit_file = "/sslh.socket";
-        size_t uf_len = strlen(unit_file);
-        size_t runtime_len = strlen(runtime_unit_dir) + uf_len + 1;
-        char *runtime_conf = malloc(runtime_len);
-        CHECK_ALLOC(runtime_conf, "malloc");
-        strcpy(runtime_conf, runtime_unit_dir);
-        strcat(runtime_conf, unit_file);
-        runtime_conf_fd = fopen(runtime_conf, "w");
-        free(runtime_conf);
+    if (!fa) {
+        fprintf(err_log,
+                "systemd-sslh-generator: Configuration directory '/etc/sslh/' is empty! No units generated.\n");
+        //No configuration files in /etc/sslh/
+        return 0;
     }
+    FileList *fa_ref = fa;
+//    size_t num_listen_addresses = 0;
+//    char **listen_addresses = NULL;
+    //Process all config files
+    do {
+        char *end = strstr(fa->name, ".cfg");
+        if (!end) {
+            continue;
+        }
+        //Current sslh config name
+        const size_t end_count = end - fa->name;
+        char config_name[end_count + 1];
+        memcpy(config_name, fa->name, end_count);
+        config_name[end_count] = '\0';
 
-
-    return write_socket_unit(runtime_conf_fd, listen, num_addr, sslh_conf);
+        //Full path to current sslh config
+        char full_path[strlen(config_dir) + strlen(fa->name) + 1];
+        strcpy(full_path, config_dir);
+        strcat(full_path, fa->name);
+        FILE *config = fopen(full_path, "r");
+        if (!config) {
+            fprintf(err_log,
+                    "systemd-sslh-generator: Could not open config file '%s': %s\n",
+                    full_path,
+                    strerror(errno));
+            return errno;
+        } else {
+            fclose(config);
+            int num_addr = get_listen_from_conf(full_path, &listen);
+            if (num_addr <= 0) {
+                fprintf(err_log,
+                        "systemd-sslh-generator: sslh config '%s' contains no valid listen configurations!\n",
+                        fa->name);
+                status |= -1;
+                continue;
+            }
+            FILE *socket_fd = stdout;
+            if (systemd_invoked) {
+                //Systemd socket for the current sslh config
+                const size_t len = strlen(runtime_unit_dir) + strlen(fork_unit_file) + strlen(config_name) + strlen(socket_ext);
+                char socket_path[len + 1];
+                strcpy(socket_path, runtime_unit_dir);
+                strcat(socket_path, fork_unit_file);
+                strcat(socket_path, config_name);
+                strcat(socket_path, socket_ext);
+                socket_fd = fopen(socket_path, "w");
+                if (!socket_fd) {
+                    fprintf(err_log,
+                            "systemd-sslh-generator: Could not open '%s' to generate socket configuration: %s\n",
+                            socket_path,
+                            strerror(errno));
+                    status |= errno;
+                    continue;
+                }
+            }
+            //Write socket unit
+            write_socket_unit(socket_fd, listen, num_addr, config_name, full_path);
+            //Write forking drop-in config
+            status |= write_unit_dropin(runtime_unit_dir, false, config_name);
+            //Write select drop-in config
+            status |= write_unit_dropin(runtime_unit_dir, true, config_name);
+            if (systemd_invoked) {
+                fclose(socket_fd);
+            }
+//            if (listen_addresses) {
+//                //Check for overlapping addresses
+//                for (size_t i = 0; i < num_listen_addresses; i++) {
+//                    for (size_t j = 0; j < num_addr; j++) {
+//                        if (strcmp(*(listen_addresses + i), *(listen + j)) == 0) {
+//                            fprintf(err_log, "systemd-sslh-generator: Overlapping listen addresses across sslh configurations!");
+//                            return -1;
+//                        }
+//                    }
+//                }
+//            }
+//            char *listen_addresses_copy[num_listen_addresses + num_addr];
+//            if (listen_addresses) {
+//                //Copy previous configurations' listen addresses into temp
+//                memcpy(listen_addresses_copy, listen_addresses, num_listen_addresses);
+//                //Free global list of listen addresses
+//                free(listen_addresses);
+//            }
+//            //Copy listen addresses from current configuration into temp
+//            memcpy(listen_addresses_copy + num_listen_addresses, listen, num_addr);
+//            num_listen_addresses += num_addr;
+//            listen_addresses = malloc(num_listen_addresses * sizeof(char *));
+//            CHECK_ALLOC(listen_addresses, "malloc")
+//            //Append all addresses to global list
+//            memcpy(listen_addresses, listen_addresses_copy, num_listen_addresses);
+            //Free all allocated listen strings
+            for (size_t i = 0; i < num_addr; i++) {
+                free(*(listen + i));
+            }
+        }
+    } while((fa = fa->prev));
+    free_file_list(fa_ref);
+    return status;
 }
 
-
-int main(int argc, char *argv[]){
-    int r = 0;
-    int k;
-    char *runtime_unit_dest = "";
-
-    if (argc > 1 && (argc != 4) ) {
+int main(int argc, char *argv[]) {
+    if (argc == 1 || argc == 4) {
+        systemd_invoked = argc == 4;
+        if (systemd_invoked) {
+            err_log = fopen("/dev/kmsg", "w");
+            if (!err_log) {
+                return -1;
+            }
+        } else {
+            err_log = stderr;
+        }
+        const int r = gen_sslh_config(systemd_invoked ? argv[1] : "");
+        if (systemd_invoked) {
+            fclose(err_log);
+        }
+        if (!r) {
+            fprintf(err_log, "systemd-sslh-generator: Successfully generated all targets.\n");
+        }
+        return r < 0 ? -1 : 0;
+    } else {
         printf("This program takes three or no arguments.\n");
         return -1;
     }
-
-    if (argc  > 1)
-        runtime_unit_dest = argv[1];
-
-    k = gen_sslh_config(runtime_unit_dest);
-    if (k < 0)
-        r = k;
-
-    return r < 0 ? -1 : 0;
 }
-
-

tcp-probe.c

@@ -60,13 +60,13 @@ int probe_client_protocol(struct connection *cnx)
 
 static void tcp_protocol_list_init(void)
 {
+    tcp_protocols = calloc(cfg.protocols_len, sizeof(tcp_protocols));
+    CHECK_ALLOC(tcp_protocols, "tcp_protocols");
     for (int i = 0; i < cfg.protocols_len; i++) {
         struct sslhcfg_protocols_item* p = &cfg.protocols[i];
         if (!p->is_udp) {
+            tcp_protocols[tcp_protocols_len] = p;
             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;
         }
     }
 }

tls.c

@@ -224,7 +224,7 @@ parse_server_name_extension(const struct TLSProtocol *tls_data, const char *data
         switch (data[pos]) { /* name type */
             case 0x00: /* host_name */
                 if(has_match(tls_data->sni_hostname_list, tls_data->sni_list_len, data + pos + 3, len)) {
-                    return len;
+                    return (int)len;
                 } else {
                     return TLS_ENOEXT;
                 }
@@ -253,7 +253,7 @@ parse_alpn_extension(const struct TLSProtocol *tls_data, const char *data, size_
             return TLS_EPROTOCOL;
 
         if (len > 0 && has_match(tls_data->alpn_protocol_list, tls_data->alpn_list_len, data + pos + 1, len)) {
-            return len;
+            return (int)len;
         } else if (len > 0) {
             print_message(msg_probe_error, "Unknown ALPN name: %.*s\n", (int)len, data + pos + 1);
         }
@@ -301,11 +301,11 @@ struct TLSProtocol *
 tls_data_set_list(struct TLSProtocol *tls_data, int alpn, const char** list, size_t list_len) {
     if (alpn) {
         tls_data->alpn_protocol_list = list;
-        tls_data->alpn_list_len = list_len;
+        tls_data->alpn_list_len = (int)list_len;
         tls_data->match_mode.tls_match_alpn = 1;
     } else {
         tls_data->sni_hostname_list = list;
-        tls_data->sni_list_len = list_len;
+        tls_data->sni_list_len = (int)list_len;
         tls_data->match_mode.tls_match_sni = 1;
     }
 

udp-listener.c

@@ -36,10 +36,10 @@
 
 static int cnx_cmp(struct connection* cnx1, struct connection* cnx2)
 {
-    struct sockaddr* addr1 = &cnx1->client_addr;
+    struct sockaddr_storage* addr1 = &cnx1->client_addr;
     socklen_t addrlen1 = cnx1->addrlen;
 
-    struct sockaddr* addr2 = &cnx2->client_addr;
+    struct sockaddr_storage* addr2 = &cnx2->client_addr;
     socklen_t addrlen2 = cnx2->addrlen;
 
     if (addrlen1 != addrlen2) return -1;
@@ -52,13 +52,13 @@ static int cnx_cmp(struct connection* cnx1, struct connection* cnx2)
  * lowest bytes of remote port */
 static int hash_make_key(hash_item new)
 {
-    struct sockaddr* addr = &new->client_addr;
+    struct sockaddr_storage* addr = &new->client_addr;
     //socklen_t addrlen = new->addrlen;
     struct sockaddr_in* addr4;
     struct sockaddr_in6* addr6;
     int out;
 
-    switch (addr->sa_family) {
+    switch (((struct sockaddr*)addr)->sa_family) {
     case AF_INET:
         addr4 = (struct sockaddr_in*)addr;
         out = addr4->sin_port;
@@ -225,13 +225,16 @@ static void mark_active(struct connection* cnx)
 /* Creates a new non-blocking socket */
 static int nonblocking_socket(struct sslhcfg_protocols_item* proto)
 {
+    int res;
+
     if (proto->resolve_on_forward) {
-        resolve_split_name(&(proto->saddr), proto->host,
-                           proto->port);
+        res = resolve_split_name(&(proto->saddr), proto->host,
+                                 proto->port);
+        if (res) return -1;
     }
 
     int out = socket(proto->saddr->ai_family, SOCK_DGRAM, 0);
-    int res = set_nonblock(out);
+    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);
@@ -256,7 +259,8 @@ struct connection* udp_c2s_forward(int sockfd, struct loop_info* fd_info)
     struct connection* cnx;
     ssize_t len;
     socklen_t addrlen;
-    int res, target, out = -1;
+    ssize_t res;
+    int target, out = -1;
     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 */
@@ -277,7 +281,7 @@ struct connection* udp_c2s_forward(int sockfd, struct loop_info* fd_info)
                   len, target, sprintaddr(addr_str, sizeof(addr_str), &addrinfo));
 
     if (target == -1) {
-        res = probe_buffer(data, len, udp_protocols, udp_protocols_len, &proto);
+        res = probe_buffer(data, (int)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 */
@@ -321,13 +325,13 @@ void udp_s2c_forward(struct connection* cnx)
 {
     int sockfd = cnx->target_sock;
     char data[65536];
-    int res;
+    ssize_t res;
 
     res = recvfrom(sockfd, data, sizeof(data), 0, NULL, NULL);
     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);
+                 (struct sockaddr*)&cnx->client_addr, cnx->addrlen);
     mark_active(cnx);
 }