Add experimental option --tun

Switch from pppd/ppp to a tun device and internal PPP code.

src/config.c

@@ -51,6 +51,7 @@ const struct vpn_config invalid_cfg = {
 	.no_ftm_push = -1,
 	.pinentry = NULL,
 	.realm = {'\0'},
+	.tun = -1,
 	.iface_name = {'\0'},
 	.sni = {'\0'},
 	.set_routes = -1,

src/config.h

@@ -95,6 +95,7 @@ struct vpn_config {
 	unsigned int		otp_delay;
 	int			no_ftm_push;
 	char			*pinentry;
+	int			tun;
 	char			iface_name[IF_NAMESIZE];
 	char			realm[REALM_SIZE + 1];
 

src/http.c

@@ -832,7 +832,7 @@ static int parse_xml_config(struct tunnel *tunnel, const char *buffer)
 	if (!gateway)
 		log_warn("No gateway address, using interface for routing\n");
 
-	if (tunnel->use_tun) {
+	if (tunnel->config->tun) {
 		tunnel->ipv4.ip_addr.s_addr = inet_addr(gateway);
 		tunnel->ipv4.peer_addr.s_addr = inet_addr("192.0.2.1");
 	}

src/io.c

@@ -1083,7 +1083,7 @@ static void *pppd_read(void *arg)
 
 	log_debug("%s thread\n", __func__);
 
-	if (tunnel->use_tun) {
+	if (tunnel->config->tun) {
 		switch (tunnel->tun_state) {
 		case TUN_PPP_LCP:
 			conf_request(tunnel);
@@ -1120,7 +1120,7 @@ static void *pppd_read(void *arg)
 			SEM_POST(&sem_pppd_ready);
 			first_time = 0;
 		}
-		if (tunnel->use_tun) {
+		if (tunnel->config->tun) {
 			ssize_t pktsize = n + 2;
 			struct ppp_packet *packet = NULL;
 
@@ -1233,7 +1233,7 @@ static void *pppd_write(void *arg)
 		// This waits until a packet has arrived from the gateway
 		packet = pool_pop(&tunnel->ssl_to_pty_pool);
 
-		if (tunnel->use_tun) {
+		if (tunnel->config->tun) {
 			void *pkt_type = pkt_data(packet);
 
 			hdlc_bufsize = len = packet->len;
@@ -1451,7 +1451,7 @@ static void *ssl_read(void *arg)
 
 				set_tunnel_ips(tunnel, packet);
 
-				if (tunnel->use_tun)
+				if (tunnel->config->tun)
 					tun_ifup(tunnel->tun_iface,
 					         tunnel->ipv4.ip_addr.s_addr, 0);
 				strcpy(line, "[");

src/main.c

@@ -80,7 +80,7 @@
 "                    [--cookie=<cookie>] [--cookie-on-stdin]\n" \
 "                    [--otp=<otp>] [--otp-delay=<delay>] [--otp-prompt=<prompt>]\n" \
 "                    [--pinentry=<program>] [--realm=<realm>]\n" \
-"                    [--ifname=<ifname>] [--set-routes=<0|1>]\n" \
+"                    [--tun=<0|1>] [--ifname=<ifname>] [--set-routes=<0|1>]\n" \
 "                    [--half-internet-routes=<0|1>] [--set-dns=<0|1>]\n" \
 PPPD_USAGE \
 "                    " RESOLVCONF_USAGE "[--ca-file=<file>]\n" \
@@ -123,6 +123,7 @@ PPPD_USAGE \
 "  --no-ftm-push                 Do not use FTM push if the server provides the option.\n" \
 "  --pinentry=<program>          Use the program to supply a secret instead of asking for it.\n" \
 "  --realm=<realm>               Use specified authentication realm.\n" \
+"  --tun=[01]                    Create a TUN device and use internal PPP code (experimental).\n" \
 "  --ifname=<interface>          Bind to interface.\n" \
 "  --set-routes=[01]             Set if openfortivpn should configure routes\n" \
 "                                when tunnel is up.\n"               \
@@ -290,6 +291,7 @@ int main(int argc, char *argv[])
 		{"otp-prompt",           required_argument, NULL, 0},
 		{"otp-delay",            required_argument, NULL, 0},
 		{"no-ftm-push",          no_argument, &cli_cfg.no_ftm_push, 1},
+		{"tun",                  required_argument, NULL, 0},
 		{"ifname",               required_argument, NULL, 0},
 		{"set-routes",	         required_argument, NULL, 0},
 		{"sni",                  required_argument, NULL, 0},
@@ -514,6 +516,18 @@ int main(int argc, char *argv[])
 				cli_cfg.otp_prompt = strdup(optarg);
 				break;
 			}
+			if (strcmp(long_options[option_index].name,
+			           "tun") == 0) {
+				int tun = strtob(optarg);
+
+				if (tun < 0) {
+					log_warn("Bad tun option: \"%s\"\n",
+					         optarg);
+					break;
+				}
+				cli_cfg.tun = tun;
+				break;
+			}
 			if (strcmp(long_options[option_index].name,
 			           "ifname") == 0) {
 				strncpy(cli_cfg.iface_name, optarg, IF_NAMESIZE - 1);
@@ -677,6 +691,41 @@ int main(int argc, char *argv[])
 	merge_config(&cfg, &cli_cfg);
 	set_syslog(cfg.use_syslog);
 
+	if (cfg.tun) {
+#if HAVE_USR_SBIN_PPPD
+		if (cfg.pppd_use_peerdns) {
+			log_error("Option pppd_use_peerdns is not compatible with option tun\n");
+			exit(EXIT_FAILURE);
+		}
+		if (cfg.pppd_plugin) {
+			log_error("Option pppd_plugin is not compatible with option tun\n");
+			exit(EXIT_FAILURE);
+		}
+		if (cfg.pppd_ifname) {
+			log_error("Option pppd_ifname is not compatible with option tun\n");
+			exit(EXIT_FAILURE);
+		}
+		if (cfg.pppd_ipparam) {
+			log_error("Option pppd_ipparam is not compatible with option tun\n");
+			exit(EXIT_FAILURE);
+		}
+		if (cfg.pppd_call) {
+			log_error("Option pppd_call is not compatible with option tun\n");
+			exit(EXIT_FAILURE);
+		}
+		if (cfg.pppd_plugin) {
+			log_error("Option pppd_plugin is not compatible with option tun\n");
+			exit(EXIT_FAILURE);
+		}
+#endif
+#if HAVE_USR_SBIN_PPP
+		if (cfg.ppp_system) {
+			log_error("Option ppp_system is not compatible with option tun\n");
+			exit(EXIT_FAILURE);
+		}
+#endif
+	}
+
 	// Set default UA
 	if (cfg.user_agent == NULL)
 		cfg.user_agent = strdup("Mozilla/5.0 SV1");

src/tunnel.c

@@ -1422,7 +1422,6 @@ int run_tunnel(struct vpn_config *config)
 		goto err_tunnel;
 
 	// Step 3: get configuration
-	tunnel.use_tun = 1;
 	log_info("Retrieving configuration\n");
 	ret = auth_get_config(&tunnel);
 	if (ret != 1) {
@@ -1434,7 +1433,7 @@ int run_tunnel(struct vpn_config *config)
 
 	// Step 4: run a pppd process
 	log_info("Establishing the tunnel\n");
-	if (tunnel.use_tun)
+	if (config->tun)
 		ret = tun_setup(&tunnel);
 	else
 		ret = pppd_run(&tunnel);
@@ -1467,7 +1466,7 @@ int run_tunnel(struct vpn_config *config)
 	tunnel.state = STATE_DISCONNECTING;
 
 err_start_tunnel:
-	if (!tunnel.use_tun) {
+	if (!config->tun) {
 		ret = pppd_terminate(&tunnel);
 		log_info("Terminated %s.\n", PPP_DAEMON);
 	}

src/tunnel.h

@@ -72,7 +72,6 @@ struct tunnel {
 
 	pid_t	pppd_pid;
 	pid_t	pppd_pty;
-	int	use_tun;
 	char	tun_iface[ROUTE_IFACE_LEN];
 	char	ppp_iface[ROUTE_IFACE_LEN];