downgrade TLS error to info (fix #367)

Fix typo

ChangeLog

@@ -1,3 +1,32 @@
+v2.0:
+	New sslh-ev: this is functionaly 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`

Dockerfile

@@ -8,7 +8,7 @@ RUN \
     libconfig-dev \
     make \
     musl-dev \
-    pcre-dev \
+    pcre2-dev \
     perl && \
   cd /sslh && \
   make sslh-select && \
@@ -18,6 +18,6 @@ FROM alpine:latest
 
 COPY --from=build /sslh/sslh-select /sslh
 
-RUN apk --no-cache add libconfig pcre
+RUN apk --no-cache add libconfig pcre2
 
 ENTRYPOINT [ "/sslh", "--foreground"]

Makefile

@@ -3,6 +3,7 @@ VERSION=$(shell ./genver.sh -r)
 
 # Configuration -- you probably need to `make clean` if you
 # change any of these
+ENABLE_SANITIZER= # Enable ASAN/LSAN/UBSAN
 ENABLE_REGEX=1  # Enable regex probes
 USELIBCONFIG=1	# Use libconfig? (necessary to use configuration files)
 USELIBWRAP?=	# Use libwrap?
@@ -19,15 +20,24 @@ 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
+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=
 
@@ -64,26 +74,31 @@ endif
 
 all: sslh $(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
+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
 
-$(OBJS): version.h common.h collection.h sslh-conf.h gap.h
 
 sslh-conf.c sslh-conf.h: sslhconf.cfg
 	conf2struct sslhconf.cfg
 
-sslh-fork: version.h $(OBJS) sslh-fork.o Makefile
-	$(CC) $(CFLAGS) $(LDFLAGS) -o sslh-fork sslh-fork.o $(OBJS) $(LIBS)
-	#strip sslh-fork
+sslh-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
@@ -133,7 +148,7 @@ 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 sslh-ev echosrv version.h $(MAN) systemd-sslh-generator *.o *.gcov *.gcno *.gcda *.png *.html *.css *.info
 
 tags:
 	ctags --globals -T *.[ch]

README.md

@@ -50,19 +50,18 @@ Build docker image
 
 
 ```bash
-docker container run \
+docker run \
   --rm \
   -it \
+  sslh:latest \
   --listen=0.0.0.0:443 \
   --ssh=hostname:22 \
-  --tlshostname:443 \
-  sslh:latest
+  --tls=hostname:443
 ```
 
 docker-compose example
 
 ```
----
 version: "3"
 
 services:
@@ -70,19 +69,17 @@ services:
     image: sslh:latest
     hostname: sslh
     ports:
-      - 443:443/tcp
-    command: --listen=0.0.0.0:443 --tlshostname:443 --openvpn=openvpn:1194
+      - 443:443
+    command: --listen=0.0.0.0:443 --tls=nginx:443 --openvpn=openvpn:1194
     depends_on:
       - nginx
       - openvpn
 
   nginx:
     image: nginx
-    hostname: nginx
 
   openvpn:
-    image: openvpn:latest
-    hostname: openvpn
+    image: openvpn
 ```
 
 Comments? Questions?

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; },

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) {
@@ -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;
@@ -191,10 +189,9 @@ int start_listen_sockets(struct listen_endpoint *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);
     }
@@ -322,19 +319,23 @@ 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;
@@ -354,7 +355,7 @@ 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 +375,8 @@ 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 +397,7 @@ 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 +429,12 @@ 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);
 }
 
 
@@ -459,8 +459,6 @@ 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:
@@ -511,7 +509,7 @@ 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 +517,7 @@ 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, "?");
        }
@@ -548,7 +546,7 @@ 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 +555,7 @@ 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, "%s `%s:%s'\n", gai_strerror(res), host, serv);
    return res;
 }
 
@@ -573,7 +571,7 @@ 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 +581,13 @@ 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 +622,6 @@ 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 +665,7 @@ 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 +673,12 @@ 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 +713,6 @@ 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 +790,14 @@ 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 +827,24 @@ 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

@@ -40,20 +40,20 @@
 
 #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 +83,6 @@ 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 +92,12 @@ 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 */
@@ -116,6 +119,9 @@ struct connection {
 
     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 +166,6 @@ 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);
 

doc/INSTALL.md

@@ -7,7 +7,7 @@ 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 +29,13 @@ 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 +51,10 @@ 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
 -----------
 
@@ -71,8 +82,8 @@ of the Makefile:
 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 +92,17 @@ 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/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
 --------------------
@@ -99,158 +99,12 @@ Then you can run sslh-select as an unpriviledged user, e.g.:
 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).
+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.
 
-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.
+Set up can get complicated, so it has its own [document](tproxy.md).
 
 Systemd Socket Activation
 -------------------------
@@ -335,7 +189,7 @@ 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

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
+
+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 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

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

@@ -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

@@ -31,11 +31,6 @@
 #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)
 {
@@ -61,12 +56,7 @@ gap_array* gap_init(int len)
     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);
@@ -84,17 +74,6 @@ static int gap_extend(gap_array* gap)
     return 0;
 }
 
-int 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;
-}
-
 void gap_destroy(gap_array* gap) 
 {
     free(gap->array);

gap.h

@@ -4,10 +4,35 @@
 typedef struct gap_array gap_array;
 
 gap_array* gap_init(int len);
-void* gap_get(gap_array* gap, int index);
-int gap_set(gap_array* gap, int index, void* ptr);
+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)
+{
+    return gap->array[index];
+}
+
 #endif

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 discrepency 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;
+

log.c

@@ -0,0 +1,206 @@
+/*
+# 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;
+
+    va_start(ap, str);
+
+    if ((*info.verbose & MSG_STDOUT) && ! cfg.inetd)
+        vfprintf(stderr, str, 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;
+        get_connection_desc(desc, cnx);
+    }
+
+    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))
+            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))
+            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/fail2ban/sslh-ssh.conf

@@ -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 Tue Aug 24 13:53:04 2021. 
+ * on Sun Sep 11 21:43:25 2022. 
 
 # conf2struct: generate libconf parsers that read to structs
 # Copyright (C) 2018-2021  Yves Rutschle
@@ -443,17 +443,29 @@ 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;
@@ -461,15 +473,17 @@ struct arg_file* sslhcfg_conffile;
  	struct arg_str* sslhcfg_tls;
  	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[] = {
 
 
@@ -617,6 +631,22 @@ 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, 
@@ -783,17 +813,17 @@ 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), 
@@ -803,6 +833,166 @@ 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, 
@@ -899,6 +1089,22 @@ 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, 
@@ -963,6 +1169,22 @@ 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, 
@@ -1032,7 +1254,15 @@ 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 }
 };
 
@@ -1040,7 +1270,7 @@ 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 }
 };
 
@@ -1048,7 +1278,7 @@ 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 }
 };
 
@@ -1056,7 +1286,7 @@ 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 }
 };
 
@@ -1064,7 +1294,7 @@ 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 }
 };
 
@@ -1072,7 +1302,16 @@ 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 }
 };
 
@@ -1080,7 +1319,7 @@ 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 }
 };
@@ -1089,7 +1328,7 @@ 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 }
 };
@@ -1098,7 +1337,7 @@ 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 }
 };
@@ -1108,7 +1347,7 @@ 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 }
 };
@@ -1123,7 +1362,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: listen */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_listen,
-            .base_entry =      & table_sslhcfg [13],
+            .base_entry =      & table_sslhcfg [25],
             .targets =         sslhcfg_listen_targets,
 
 
@@ -1135,7 +1374,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: ssh */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_ssh,
-            .base_entry =      & table_sslhcfg [14],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_ssh_targets,
 
 
@@ -1147,7 +1386,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: tls */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_tls,
-            .base_entry =      & table_sslhcfg [14],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_tls_targets,
 
 
@@ -1159,7 +1398,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: openvpn */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_openvpn,
-            .base_entry =      & table_sslhcfg [14],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_openvpn_targets,
 
 
@@ -1171,7 +1410,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: tinc */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_tinc,
-            .base_entry =      & table_sslhcfg [14],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_tinc_targets,
 
 
@@ -1180,10 +1419,22 @@ 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 [14],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_xmpp_targets,
 
 
@@ -1195,7 +1446,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: http */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_http,
-            .base_entry =      & table_sslhcfg [14],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_http_targets,
 
 
@@ -1207,7 +1458,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: adb */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_adb,
-            .base_entry =      & table_sslhcfg [14],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_adb_targets,
 
 
@@ -1219,7 +1470,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: socks5 */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_socks5,
-            .base_entry =      & table_sslhcfg [14],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_socks5_targets,
 
 
@@ -1231,7 +1482,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: syslog */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_syslog,
-            .base_entry =      & table_sslhcfg [14],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_syslog_targets,
 
 
@@ -1240,10 +1491,22 @@ 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 [14],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_anyprot_targets,
 
 
@@ -1908,17 +2171,29 @@ 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"),
@@ -1926,11 +2201,13 @@ int sslhcfg_cl_parse(int argc, char* argv[], struct sslhcfg_item* cfg)
  	sslhcfg_tls = arg_strn(NULL, "tls", "<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)
 
@@ -2020,6 +2297,9 @@ 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);
@@ -2077,7 +2357,37 @@ 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);
@@ -2098,6 +2408,9 @@ 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>");
@@ -2116,6 +2429,11 @@ 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 Tue Aug 24 13:53:04 2021. 
+ * on Sun Sep 11 21:43:25 2022. 
 
 # 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;
@@ -71,16 +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;
@@ -88,6 +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 +1,159 @@
+/*
+   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 */
+
+    int max_fd; /* legacy to be removed, still required for UDP */
+};
+
+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);
+
+    if (fd > w->max_fd) w->max_fd = fd + 1;
+}
+
+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);
+
+    if (fd > w->max_fd) w->max_fd = fd + 1;
+}
+
+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);
 }
@@ -179,10 +177,10 @@ 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);
+        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 */
@@ -209,18 +207,20 @@ 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);
 	    break;

sslh-main.c

@@ -36,6 +36,7 @@
 
 #include "common.h"
 #include "probe.h"
+#include "log.h"
 
 /* Constants for options that have no one-character shorthand */
 #define OPT_ONTIMEOUT   257
@@ -50,7 +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);
@@ -65,21 +66,26 @@ static void printsettings(void)
     
     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" : ""
-                );
+        print_message(msg_config, 
+                      "%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" : ""
+                     );
     }
-    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);
 }
 
 
@@ -103,7 +109,7 @@ 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);
         }
@@ -123,14 +129,19 @@ 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);
         }
 
@@ -149,23 +160,55 @@ 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);
+            }
+        }
+    }
 }
 
 
@@ -184,8 +227,6 @@ 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);
@@ -197,19 +238,18 @@ int main(int argc, char *argv[], char* envp[])
 
    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
@@ -232,13 +272,21 @@ 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);
 
-   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

@@ -25,483 +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;
-
-    time_t next_timeout = INT_MAX;
-
-    for (int i = 0; i < fd_info->max_fd; i++) {
-        /* 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 (!timeout) continue; /* Not a UDP connection */
-                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
@@ -519,48 +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(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.max_fd);
+    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);
@@ -568,8 +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);
             }
         }
@@ -578,24 +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=%0xp\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);
                 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);
             }
         }
@@ -604,7 +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 +25,31 @@ 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"; },
@@ -43,6 +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"; },
@@ -54,6 +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"; },
@@ -84,8 +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",
@@ -105,7 +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" }
                 )
             }
         )
@@ -179,6 +210,18 @@ 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";
@@ -234,6 +277,17 @@ 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 */

t_load

@@ -20,7 +20,7 @@ use Conf::Libconfig;
 
 # 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
 
@@ -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,

tcp-listener.c

@@ -0,0 +1,335 @@
+/*
+   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 */
+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);
+    return -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) {
+            /*
+            FD_SET(q->fd, &fd_info->watchers->fds_w);
+            FD_CLR(cnx->q[0].fd, &fd_info->watchers->fds_r); */
+            watchers_add_write(fd_info->watchers, q->fd);
+            watchers_del_read(fd_info->watchers, cnx->q[0].fd);
+        }
+        /* FD_SET(q->fd, &fd_info->watchers->fds_r); */
+        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 +1,98 @@
+/*
+# 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));
+            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:
@@ -21,6 +35,10 @@ 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:
 (

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
@@ -20,45 +20,219 @@
 
 */
 
+#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* 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* 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* addr = &new->client_addr;
+    //socklen_t addrlen = new->addrlen;
+    struct sockaddr_in* addr4;
+    struct sockaddr_in6* addr6;
+    int out;
+
+    switch (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));
+            udp_protocols[udp_protocols_len-1] = p;
         }
     }
-    return -1;
 }
 
+/* Configuration sanity check for UDP:
+ * - If there is a listening addres, 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* 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);
+}
+
+
 /* 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 addrinfo addrinfo;
     struct sslhcfg_protocols_item* proto;
+    cnx_collection* collection = fd_info->collection;
     struct connection* cnx;
     ssize_t len;
     socklen_t addrlen;
@@ -67,31 +241,36 @@ int udp_c2s_forward(int sockfd, cnx_collection* collection, int max_fd)
                          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);
     if (len < 0) {
         perror("recvfrom");
-        return -1;
+        return NULL;
     }
-    target = known_source(collection, max_fd, &src_addr, addrlen);
+    target = known_source(fd_info->hash_sources, &src_addr, addrlen);
     addrinfo.ai_addr = &src_addr;
     addrinfo.ai_addrlen = addrlen;
-    if (cfg.verbose) 
-        fprintf(stderr, "received %ld UDP from %d:%s\n", len, target, sprintaddr(addr_str, sizeof(addr_str), &addrinfo));
+    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);
+        res = set_nonblock(out);
+        CHECK_RES_RETURN(res, "udp:socket:nonblock", 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 +278,25 @@ 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 -- increaѕe 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 +305,10 @@ 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;
+    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 */