X-Git-Url: https://www.tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fnet_setup.c;h=3ac5a6796fd5c453f2527078395fee0db9fa3160;hb=4436af55e55e79b496264fe114039fbc1198d71f;hp=d2adc13f32a1b220527bdce4a1a4c495c848d2c3;hpb=bcac314fe2d758e85335d499dbb4300bfa8a599e;p=tinc

diff --git a/src/net_setup.c b/src/net_setup.c
index d2adc13f..3ac5a679 100644
--- a/src/net_setup.c
+++ b/src/net_setup.c
@@ -28,6 +28,7 @@
 #include "connection.h"
 #include "compression.h"
 #include "control.h"
+#include "crypto.h"
 #include "device.h"
 #include "digest.h"
 #include "ecdsa.h"
@@ -44,12 +45,13 @@
 #include "utils.h"
 #include "xalloc.h"
 #include "keys.h"
+#include "sandbox.h"
 
 #ifdef HAVE_MINIUPNPC
 #include "upnp.h"
 #endif
 
-char *myport;
+ports_t myport;
 static io_t device_io;
 devops_t devops;
 bool device_standby = false;
@@ -142,7 +144,7 @@ static timeout_t keyexpire_timeout;
 static void keyexpire_handler(void *data) {
 	regenerate_key();
 	timeout_set(data, &(struct timeval) {
-		keylifetime, rand() % 100000
+		keylifetime, jitter()
 	});
 }
 #endif
@@ -229,11 +231,25 @@ char *get_name(void) {
 	return returned_name;
 }
 
-bool setup_myself_reloadable(void) {
-	free(scriptinterpreter);
-	scriptinterpreter = NULL;
+static void read_interpreter(void) {
+	char *interpreter = NULL;
+	get_config_string(lookup_config(&config_tree, "ScriptsInterpreter"), &interpreter);
+
+	if(!interpreter || (sandbox_can(START_PROCESSES, AFTER_SANDBOX) && sandbox_can(USE_NEW_PATHS, AFTER_SANDBOX))) {
+		free(scriptinterpreter);
+		scriptinterpreter = interpreter;
+		return;
+	}
+
+	if(!string_eq(interpreter, scriptinterpreter)) {
+		logger(DEBUG_ALWAYS, LOG_NOTICE, "Not changing ScriptsInterpreter because of sandbox.");
+	}
 
-	get_config_string(lookup_config(&config_tree, "ScriptsInterpreter"), &scriptinterpreter);
+	free(interpreter);
+}
+
+bool setup_myself_reloadable(void) {
+	read_interpreter();
 
 	free(scriptextension);
 
@@ -263,10 +279,15 @@ bool setup_myself_reloadable(void) {
 		} else if(!strcasecmp(proxy, "http")) {
 			proxytype = PROXY_HTTP;
 		} else if(!strcasecmp(proxy, "exec")) {
-			proxytype = PROXY_EXEC;
+			if(sandbox_can(START_PROCESSES, AFTER_SANDBOX)) {
+				proxytype = PROXY_EXEC;
+			} else {
+				logger(DEBUG_ALWAYS, LOG_ERR, "Cannot use exec proxies with current sandbox level.");
+				return false;
+			}
 		} else {
 			logger(DEBUG_ALWAYS, LOG_ERR, "Unknown proxy type %s!", proxy);
-			free(proxy);
+			free_string(proxy);
 			return false;
 		}
 
@@ -276,10 +297,10 @@ bool setup_myself_reloadable(void) {
 		free(proxyport);
 		proxyport = NULL;
 
-		free(proxyuser);
+		free_string(proxyuser);
 		proxyuser = NULL;
 
-		free(proxypass);
+		free_string(proxypass);
 		proxypass = NULL;
 
 		switch(proxytype) {
@@ -290,10 +311,14 @@ bool setup_myself_reloadable(void) {
 		case PROXY_EXEC:
 			if(!space || !*space) {
 				logger(DEBUG_ALWAYS, LOG_ERR, "Argument expected for proxy type exec!");
-				free(proxy);
+				free_string(proxy);
 				return false;
 			}
 
+			if(!sandbox_can(USE_NEW_PATHS, AFTER_SANDBOX)) {
+				logger(DEBUG_ALWAYS, LOG_NOTICE, "Changed exec proxy may fail to work because of sandbox.");
+			}
+
 			proxyhost = xstrdup(space);
 			break;
 
@@ -311,7 +336,7 @@ bool setup_myself_reloadable(void) {
 				logger(DEBUG_ALWAYS, LOG_ERR, "Host and port argument expected for proxy!");
 				proxyport = NULL;
 				proxyhost = NULL;
-				free(proxy);
+				free_string(proxy);
 				return false;
 			}
 
@@ -337,7 +362,7 @@ bool setup_myself_reloadable(void) {
 			break;
 		}
 
-		free(proxy);
+		free_string(proxy);
 	}
 
 	bool choice;
@@ -534,11 +559,70 @@ bool setup_myself_reloadable(void) {
 	return true;
 }
 
+// Get the port that `from_fd` is listening on, and assign it to
+// `sa` if `sa` has a dynamically allocated (zero) port.
+static bool assign_static_port(sockaddr_t *sa, int from_fd) {
+	// We cannot get a port from a bad FD. Bail out.
+	if(from_fd <= 0) {
+		return false;
+	}
+
+	int port = get_bound_port(from_fd);
+
+	if(!port) {
+		return false;
+	}
+
+	// If the port is non-zero, don't reassign it as it's already static.
+	switch(sa->sa.sa_family) {
+	case AF_INET:
+		if(!sa->in.sin_port) {
+			sa->in.sin_port = htons(port);
+		}
+
+		return true;
+
+	case AF_INET6:
+		if(!sa->in6.sin6_port) {
+			sa->in6.sin6_port = htons(port);
+		}
+
+		return true;
+
+	default:
+		logger(DEBUG_ALWAYS, LOG_ERR, "Unknown address family 0x%x", sa->sa.sa_family);
+		return false;
+	}
+}
+
+typedef int (*bind_fn_t)(const sockaddr_t *);
+
+static int bind_reusing_port(const sockaddr_t *sa, int from_fd, bind_fn_t setup) {
+	sockaddr_t reuse_sa;
+	memcpy(&reuse_sa, sa, SALEN(sa->sa));
+
+	int fd = -1;
+
+	// Check if the address we've been passed here is using port 0.
+	// If it is, try to get an actual port from an already bound socket, and reuse it here.
+	if(assign_static_port(&reuse_sa, from_fd)) {
+		fd = setup(&reuse_sa);
+	}
+
+	// If we're binding to a hardcoded non-zero port, or no socket is listening yet,
+	// or binding failed, try the original address.
+	if(fd < 0) {
+		fd = setup(sa);
+	}
+
+	return fd;
+}
+
 /*
   Add listening sockets.
 */
 static bool add_listen_address(char *address, bool bindto) {
-	char *port = myport;
+	char *port = myport.tcp;
 
 	if(address) {
 		char *space = strchr(address, ' ');
@@ -596,30 +680,45 @@ static bool add_listen_address(char *address, bool bindto) {
 			return false;
 		}
 
-		int tcp_fd = setup_listen_socket((sockaddr_t *) aip->ai_addr);
+		const sockaddr_t *sa = (sockaddr_t *) aip->ai_addr;
+		int from_fd = listen_socket[0].tcp.fd;
+
+		// If we're binding to a dynamically allocated (zero) port, try to get the actual
+		// port of the first TCP socket, and use it for this one. If that succeeds, our
+		// tincd instance will use the same port for all addresses it listens on.
+		int tcp_fd = bind_reusing_port(sa, from_fd, setup_listen_socket);
 
 		if(tcp_fd < 0) {
 			continue;
 		}
 
-		int udp_fd = setup_vpn_in_socket((sockaddr_t *) aip->ai_addr);
+		// If we just successfully bound the first socket, use it for the UDP procedure below.
+		// Otherwise, keep using the socket we've obtained from listen_socket[0].
+		if(!from_fd) {
+			from_fd = tcp_fd;
+		}
+
+		int udp_fd = bind_reusing_port(sa, from_fd, setup_vpn_in_socket);
 
 		if(udp_fd < 0) {
-			close(tcp_fd);
+			closesocket(tcp_fd);
 			continue;
 		}
 
-		io_add(&listen_socket[listen_sockets].tcp, handle_new_meta_connection, &listen_socket[listen_sockets], tcp_fd, IO_READ);
-		io_add(&listen_socket[listen_sockets].udp, handle_incoming_vpn_data, &listen_socket[listen_sockets], udp_fd, IO_READ);
+		listen_socket_t *sock = &listen_socket[listen_sockets];
+		io_add(&sock->tcp, handle_new_meta_connection, sock, tcp_fd, IO_READ);
+		io_add(&sock->udp, handle_incoming_vpn_data, sock, udp_fd, IO_READ);
 
 		if(debug_level >= DEBUG_CONNECTIONS) {
-			char *hostname = sockaddr2hostname((sockaddr_t *) aip->ai_addr);
-			logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Listening on %s", hostname);
+			int tcp_port = get_bound_port(tcp_fd);
+			char *hostname = NULL;
+			sockaddr2str(sa, &hostname, NULL);
+			logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Listening on %s port %d", hostname, tcp_port);
 			free(hostname);
 		}
 
-		listen_socket[listen_sockets].bindto = bindto;
-		memcpy(&listen_socket[listen_sockets].sa, aip->ai_addr, aip->ai_addrlen);
+		sock->bindto = bindto;
+		memcpy(&sock->sa, aip->ai_addr, aip->ai_addrlen);
 		listen_sockets++;
 	}
 
@@ -655,7 +754,7 @@ void device_disable(void) {
   Configure node_t myself and set up the local sockets (listen only)
 */
 static bool setup_myself(void) {
-	char *name, *hostname, *type;
+	char *name, *type;
 	char *address = NULL;
 	bool port_specified = false;
 
@@ -671,12 +770,14 @@ static bool setup_myself(void) {
 	myself->connection->name = xstrdup(name);
 	read_host_config(&config_tree, name, true);
 
-	if(!get_config_string(lookup_config(&config_tree, "Port"), &myport)) {
-		myport = xstrdup("655");
+	if(!get_config_string(lookup_config(&config_tree, "Port"), &myport.tcp)) {
+		myport.tcp = xstrdup("655");
 	} else {
 		port_specified = true;
 	}
 
+	myport.udp = xstrdup(myport.tcp);
+
 	myself->connection->options = 0;
 	myself->connection->protocol_major = PROT_MAJOR;
 	myself->connection->protocol_minor = PROT_MINOR;
@@ -711,9 +812,11 @@ static bool setup_myself(void) {
 		}
 	}
 
-	myself->connection->rsa = read_rsa_private_key(&config_tree, NULL);
+	rsa_t *rsa = read_rsa_private_key(&config_tree, NULL);
 
-	if(!myself->connection->rsa) {
+	if(rsa) {
+		myself->connection->legacy = new_legacy_ctx(rsa);
+	} else {
 		if(experimental) {
 			logger(DEBUG_ALWAYS, LOG_WARNING, "Support for legacy protocol disabled.");
 		} else {
@@ -725,19 +828,18 @@ static bool setup_myself(void) {
 #endif
 
 	/* Ensure myport is numeric */
+	if(!is_decimal(myport.tcp)) {
+		uint16_t port = service_to_port(myport.tcp);
 
-	if(!atoi(myport)) {
-		struct addrinfo *ai = str2addrinfo("localhost", myport, SOCK_DGRAM);
-		sockaddr_t sa;
-
-		if(!ai || !ai->ai_addr) {
+		if(!port) {
 			return false;
 		}
 
-		free(myport);
-		memcpy(&sa, ai->ai_addr, ai->ai_addrlen);
-		freeaddrinfo(ai);
-		sockaddr2str(&sa, NULL, &myport);
+		free(myport.tcp);
+		myport.tcp = int_to_str(port);
+
+		free(myport.udp);
+		myport.udp = xstrdup(myport.tcp);
 	}
 
 	/* Read in all the subnets specified in the host configuration file */
@@ -825,7 +927,8 @@ static bool setup_myself(void) {
 
 		if(!cipher_open_by_name(myself->incipher, cipher)) {
 			logger(DEBUG_ALWAYS, LOG_ERR, "Unrecognized cipher type!");
-			cipher_free(&myself->incipher);
+			cipher_free(myself->incipher);
+			myself->incipher = NULL;
 			free(cipher);
 			return false;
 		}
@@ -834,7 +937,7 @@ static bool setup_myself(void) {
 	free(cipher);
 
 	timeout_add(&keyexpire_timeout, keyexpire_handler, &keyexpire_timeout, &(struct timeval) {
-		keylifetime, rand() % 100000
+		keylifetime, jitter()
 	});
 
 	/* Check if we want to use message authentication codes... */
@@ -860,7 +963,8 @@ static bool setup_myself(void) {
 
 		if(!digest_open_by_name(myself->indigest, digest, maclength)) {
 			logger(DEBUG_ALWAYS, LOG_ERR, "Unrecognized digest type!");
-			digest_free(&myself->indigest);
+			digest_free(myself->indigest);
+			myself->indigest = NULL;
 			free(digest);
 			return false;
 		}
@@ -870,7 +974,11 @@ static bool setup_myself(void) {
 #endif
 
 	/* Compression */
-	if(get_config_int(lookup_config(&config_tree, "Compression"), &myself->incompression)) {
+	int incompression = 0;
+
+	if(get_config_int(lookup_config(&config_tree, "Compression"), &incompression)) {
+		myself->incompression = incompression;
+
 		switch(myself->incompression) {
 		case COMPRESS_LZ4:
 #ifdef HAVE_LZ4
@@ -920,8 +1028,6 @@ static bool setup_myself(void) {
 		myself->incompression = COMPRESS_NONE;
 	}
 
-	myself->connection->outcompression = COMPRESS_NONE;
-
 	/* Done */
 
 	myself->nexthop = myself;
@@ -940,7 +1046,7 @@ static bool setup_myself(void) {
 	devops = os_devops;
 
 	if(get_config_string(lookup_config(&config_tree, "DeviceType"), &type)) {
-		if(!strcasecmp(type, "dummy")) {
+		if(!strcasecmp(type, DEVICE_DUMMY)) {
 			devops = dummy_devops;
 		} else if(!strcasecmp(type, "raw_socket")) {
 			devops = raw_socket_devops;
@@ -996,15 +1102,16 @@ static bool setup_myself(void) {
 		}
 
 		for(int i = 0; i < listen_sockets; i++) {
+			const int tcp_fd = i + 3;
 			salen = sizeof(sa);
 
-			if(getsockname(i + 3, &sa.sa, &salen) < 0) {
-				logger(DEBUG_ALWAYS, LOG_ERR, "Could not get address of listen fd %d: %s", i + 3, sockstrerror(sockerrno));
+			if(getsockname(tcp_fd, &sa.sa, &salen) < 0) {
+				logger(DEBUG_ALWAYS, LOG_ERR, "Could not get address of listen fd %d: %s", tcp_fd, sockstrerror(sockerrno));
 				return false;
 			}
 
 #ifdef FD_CLOEXEC
-			fcntl(i + 3, F_SETFD, FD_CLOEXEC);
+			fcntl(tcp_fd, F_SETFD, FD_CLOEXEC);
 #endif
 
 			int udp_fd = setup_vpn_in_socket(&sa);
@@ -1013,11 +1120,11 @@ static bool setup_myself(void) {
 				return false;
 			}
 
-			io_add(&listen_socket[i].tcp, (io_cb_t)handle_new_meta_connection, &listen_socket[i], i + 3, IO_READ);
+			io_add(&listen_socket[i].tcp, (io_cb_t)handle_new_meta_connection, &listen_socket[i], tcp_fd, IO_READ);
 			io_add(&listen_socket[i].udp, (io_cb_t)handle_incoming_vpn_data, &listen_socket[i], udp_fd, IO_READ);
 
 			if(debug_level >= DEBUG_CONNECTIONS) {
-				hostname = sockaddr2hostname(&sa);
+				char *hostname = sockaddr2hostname(&sa);
 				logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Listening on %s", hostname);
 				free(hostname);
 			}
@@ -1059,21 +1166,19 @@ static bool setup_myself(void) {
 
 	/* If no Port option was specified, set myport to the port used by the first listening socket. */
 
-	if(!port_specified || atoi(myport) == 0) {
-		sockaddr_t sa;
-		socklen_t salen = sizeof(sa);
+	if(!port_specified || atoi(myport.tcp) == 0) {
+		listen_socket_t *sock = &listen_socket[0];
 
-		if(!getsockname(listen_socket[0].udp.fd, &sa.sa, &salen)) {
-			free(myport);
-			sockaddr2str(&sa, NULL, &myport);
+		uint16_t tcp = get_bound_port(sock->tcp.fd);
+		free(myport.tcp);
+		myport.tcp = int_to_str(tcp);
 
-			if(!myport) {
-				myport = xstrdup("655");
-			}
-		}
+		uint16_t udp = get_bound_port(sock->udp.fd);
+		free(myport.udp);
+		myport.udp = int_to_str(udp);
 	}
 
-	xasprintf(&myself->hostname, "MYSELF port %s", myport);
+	xasprintf(&myself->hostname, "MYSELF port %s", myport.tcp);
 	myself->connection->hostname = xstrdup(myself->hostname);
 
 	char *upnp = NULL;
@@ -1179,8 +1284,8 @@ void close_network_connections(void) {
 	for(int i = 0; i < listen_sockets; i++) {
 		io_del(&listen_socket[i].tcp);
 		io_del(&listen_socket[i].udp);
-		close(listen_socket[i].tcp.fd);
-		close(listen_socket[i].udp.fd);
+		closesocket(listen_socket[i].tcp.fd);
+		closesocket(listen_socket[i].udp.fd);
 	}
 
 	exit_requests();
@@ -1193,7 +1298,8 @@ void close_network_connections(void) {
 		device_disable();
 	}
 
-	free(myport);
+	free(myport.tcp);
+	free(myport.udp);
 
 	if(device_fd >= 0) {
 		io_del(&device_io);