sort target protocols as TCP or UDP, so only appropriate probes are called by the listeners

Makefile

@@ -32,7 +32,7 @@ CC ?= gcc
 CFLAGS ?=-Wall -DLIBPCRE -g $(CFLAGS_COV) $(CFLAGS_SAN)
 
 LIBS=-lm -lpcre2-8
-OBJS=sslh-conf.o common.o log.o sslh-main.o probe.o tls.o argtable3.o collection.o gap.o 
+OBJS=sslh-conf.o common.o log.o sslh-main.o probe.o tls.o argtable3.o collection.o gap.o tcp-probe.o
 FORK_OBJS=$(OBJS) sslh-fork.o
 SELECT_OBJS=$(OBJS) processes.o udp-listener.o sslh-select.o hash.o tcp-listener.o
 EV_OBJS=$(OBJS) processes.o udp-listener.o sslh-ev.o hash.o tcp-listener.o

probe.c

@@ -340,12 +340,20 @@ static int regex_probe(const char *p, ssize_t len, struct sslhcfg_protocols_item
 }
 
 /* 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;
@@ -353,17 +361,17 @@ int probe_buffer(char* buf, int len, struct sslhcfg_protocols_item** proto)
     print_message(msg_packets, "hexdump of incoming packet:\n");
     hexdump(msg_packets, buf, len);
 
-    *proto = NULL;
+    *proto_out = NULL;
-    for (i = 0; i < cfg.protocols_len; i++) {
+    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;
 
         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 )) {
@@ -377,7 +385,7 @@ int probe_buffer(char* buf, int len, struct sslhcfg_protocols_item** proto)
         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)
@@ -387,37 +395,7 @@ 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];
+    *proto_out = proto_in[proto_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);
-    }
-
-    /* read() returned an error, so just connect to the last protocol to die */
-    cnx->proto = &cfg.protocols[cfg.protocols_len-1];
     return PROBE_MATCH;
 }
 

probe.h

@@ -48,8 +48,12 @@ void set_protocol_list(struct sslhcfg_protocols_item*);
  */
 int probe_client_protocol(struct connection *cnx);
 
-/* Probe, but on a buffer */
+/* Probe on a buffer */
-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
+                 );
 
 /* set the protocol to connect to in case of timeout */
 void set_ontimeout(const char* name);

sslh-ev.c

@@ -143,6 +143,7 @@ void main_loop(struct listen_endpoint listen_sockets[], int num_addr_listen)
     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);

sslh-fork.c

@@ -23,7 +23,7 @@
 #include "common.h"
 #include "probe.h"
 #include "sslh-conf.h"
-#include "udp-listener.h"
+#include "tcp-probe.h"
 #include "log.h"
 
 #ifdef LIBBSD
@@ -207,6 +207,8 @@ 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();

sslh-select.c

@@ -131,6 +131,7 @@ void main_loop(struct listen_endpoint listen_sockets[], int num_addr_listen)
     fd_info.num_probing = 0; 
     fd_info.probing_list = gap_init(0);
     udp_init(&fd_info);
+    tcp_init();
 
     watchers_init(&fd_info.watchers, listen_sockets, num_addr_listen);
 

t_load

@@ -65,21 +65,21 @@ my %connect_params = (
         test_data => "foo bar",
         resp_len => 12,
     },
-    #        ssh => {
+    ssh => {
-    #        sleep => 20,  # So it times out 50% of connections
+        sleep => 20,  # So it times out 50% of connections
-    #        test_data => "SSH-2.0 hello",
+        test_data => "SSH-2.0 hello",
-    #        resp_len => 18,  # length "ssh: SSH-2.0 hello" => 18
+        resp_len => 18,  # length "ssh: SSH-2.0 hello" => 18
-    #    },
+    },
-    #    tinc => {
+    tinc => {
-    #        sleep => 0,
+        sleep => 0,
-    #        test_data => "0 ",
+        test_data => "0 ",
-    #        resp_len => 8, # length "tinc: 0 " => 10 
+        resp_len => 8, # length "tinc: 0 " => 10
-    #    },
+    },
-    #    openvpn => {
+    openvpn => {
-    #        sleep => 0,
+        sleep => 0,
-    #        test_data => "\x00\x00",
+        test_data => "\x00\x00",
-    #        resp_len => 11,  # length "openvpn: \x0\x0" => 11
+        resp_len => 11,  # length "openvpn: \x0\x0" => 11
-    #    },
+    },
 );
 
 sub connect_service {

tcp-listener.h

@@ -3,6 +3,7 @@
 
 #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);

tcp-probe.c

@@ -0,0 +1,76 @@
+/*
+# 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;
+        }
+    }
+}
+
+void tcp_init(void)
+{
+    tcp_protocol_list_init();
+}

tcp-probe.h

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

test.cfg

@@ -36,6 +36,10 @@ listen:
 );
 
 
+# Tester beware: when using fork, the forked process loses
+# track of buffers of other, concurrent connections. Memory
+# leak tools thus complain each time a forked process stops.
+ 
 protocols:
 (
      { name: "ssh";  host: "localhost"; port: "9000"; fork: true; transparent: true; },

udp-listener.c

@@ -76,6 +76,21 @@ static int hash_make_key(hash_item new)
     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;
+        }
+    }
+}
+
 /* Init the UDP subsystem.
  * - Initialise the hash
  * - that's all, folks
@@ -83,6 +98,8 @@ static int hash_make_key(hash_item new)
 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();
 }
 
 
@@ -215,7 +232,7 @@ int udp_c2s_forward(int sockfd, struct loop_info* fd_info)
                   len, target, sprintaddr(addr_str, sizeof(addr_str), &addrinfo));
 
     if (target == -1) {
-        res = probe_buffer(data, len, &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 */