Added support for logging to a file.

* Added ASAN/LSAN/UBSAN support via Makefile
 * Fixed a memory leak

Signed-off-by: lns <matzeton@googlemail.com>

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?
@@ -19,12 +20,16 @@ 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)
+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

example.cfg

@@ -13,7 +13,7 @@ pidfile: "/var/run/sslh.pid";
 chroot: "/var/empty";
 
 # Logging configuration
-# Value: 1: stdout; 2: syslog; 3: both
+# 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
@@ -29,6 +29,10 @@ 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 which syslog facility to use (names for your
 # system are usually defined in /usr/include/*/sys/syslog.h
 # or equivalent)

log.c

@@ -23,6 +23,7 @@
 
 #define SYSLOG_NAMES
 #define _GNU_SOURCE
+#include <errno.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include "sslh-conf.h"
@@ -97,6 +98,9 @@ msg_info msg_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, ...)
@@ -113,6 +117,13 @@ void print_message(msg_info info, const char* 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" */
@@ -145,6 +156,29 @@ void setup_syslog(const char* bin_name) {
     /* 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

log.h

@@ -5,6 +5,10 @@
 
 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{

sslh-conf.c

@@ -1,5 +1,5 @@
 /* Generated by conf2struct (https://www.rutschle.net/tech/conf2struct/README)
- * on Sun Apr 10 08:52:30 2022. 
+ * on Thu Apr 28 14:54:03 2022.
 
 # conf2struct: generate libconf parsers that read to structs
 # Copyright (C) 2018-2021  Yves Rutschle
@@ -465,6 +465,7 @@ struct arg_file* sslhcfg_conffile;
  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;
@@ -1166,6 +1167,22 @@ 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, 
@@ -1326,7 +1343,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: listen */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_listen,
-            .base_entry =      & table_sslhcfg [24],
+            .base_entry =      & table_sslhcfg [25],
             .targets =         sslhcfg_listen_targets,
 
 
@@ -1338,7 +1355,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: ssh */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_ssh,
-            .base_entry =      & table_sslhcfg [25],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_ssh_targets,
 
 
@@ -1350,7 +1367,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: tls */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_tls,
-            .base_entry =      & table_sslhcfg [25],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_tls_targets,
 
 
@@ -1362,7 +1379,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: openvpn */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_openvpn,
-            .base_entry =      & table_sslhcfg [25],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_openvpn_targets,
 
 
@@ -1374,7 +1391,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: tinc */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_tinc,
-            .base_entry =      & table_sslhcfg [25],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_tinc_targets,
 
 
@@ -1386,7 +1403,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: xmpp */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_xmpp,
-            .base_entry =      & table_sslhcfg [25],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_xmpp_targets,
 
 
@@ -1398,7 +1415,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: http */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_http,
-            .base_entry =      & table_sslhcfg [25],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_http_targets,
 
 
@@ -1410,7 +1427,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: adb */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_adb,
-            .base_entry =      & table_sslhcfg [25],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_adb_targets,
 
 
@@ -1422,7 +1439,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: socks5 */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_socks5,
-            .base_entry =      & table_sslhcfg [25],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_socks5_targets,
 
 
@@ -1434,7 +1451,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: syslog */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_syslog,
-            .base_entry =      & table_sslhcfg [25],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_syslog_targets,
 
 
@@ -1446,7 +1463,7 @@ static struct compound_cl_arg compound_cl_args[] = {
         {   /* arg: anyprot */
             .regex =           "(.+):(\\w+)",
             .arg_cl =          & sslhcfg_anyprot,
-            .base_entry =      & table_sslhcfg [25],
+            .base_entry =      & table_sslhcfg [26],
             .targets =         sslhcfg_anyprot_targets,
 
 
@@ -2133,6 +2150,7 @@ int sslhcfg_cl_parse(int argc, char* argv[], struct sslhcfg_item* cfg)
          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"),
@@ -2366,6 +2384,11 @@ 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 Sun Apr 10 08:52:30 2022. 
+ * on Thu Apr 28 14:54:03 2022.
 
 # conf2struct: generate libconf parsers that read to structs
 # Copyright (C) 2018-2021  Yves Rutschle
@@ -100,6 +100,8 @@ 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-main.c

@@ -240,6 +240,9 @@ 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);
 
@@ -249,5 +252,9 @@ int main(int argc, char *argv[], char* envp[])
 
    main_loop(listen_sockets, num_addr_listen);
 
+   close_logfile();
+
+   free(listen_sockets);
+
    return 0;
 }

sslhconf.cfg

@@ -80,6 +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"; },