2 net_socket.c -- Handle various kinds of sockets.
3 Copyright (C) 1998-2005 Ivo Timmermans,
4 2000-2012 Guus Sliepen <guus@tinc-vpn.org>
5 2006 Scott Lamb <slamb@slamb.org>
6 2009 Florian Forster <octo@verplant.org>
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License along
19 with this program; if not, write to the Free Software Foundation, Inc.,
20 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
27 #include "connection.h"
37 /* Needed on Mac OS/X */
39 #define SOL_TCP IPPROTO_TCP
42 int addressfamily = AF_UNSPEC;
44 int seconds_till_retry = 5;
48 listen_socket_t listen_socket[MAXSOCKETS];
50 list_t *outgoing_list = NULL;
54 static void configure_tcp(connection_t *c) {
58 int flags = fcntl(c->socket, F_GETFL);
60 if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
61 logger(LOG_ERR, "fcntl for %s: %s", c->hostname, strerror(errno));
64 unsigned long arg = 1;
66 if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
67 logger(LOG_ERR, "ioctlsocket for %s: %d", c->hostname, sockstrerror(sockerrno));
71 #if defined(SOL_TCP) && defined(TCP_NODELAY)
73 setsockopt(c->socket, SOL_TCP, TCP_NODELAY, (void *)&option, sizeof(option));
76 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
77 option = IPTOS_LOWDELAY;
78 setsockopt(c->socket, SOL_IP, IP_TOS, (void *)&option, sizeof(option));
82 static bool bind_to_interface(int sd) {
85 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
88 #endif /* defined(SOL_SOCKET) && defined(SO_BINDTODEVICE) */
90 if(!get_config_string (lookup_config (config_tree, "BindToInterface"), &iface))
93 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
94 memset(&ifr, 0, sizeof(ifr));
95 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
96 ifr.ifr_ifrn.ifrn_name[IFNAMSIZ - 1] = 0;
98 status = setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr));
100 logger(LOG_ERR, "Can't bind to interface %s: %s", iface,
104 #else /* if !defined(SOL_SOCKET) || !defined(SO_BINDTODEVICE) */
105 logger(LOG_WARNING, "%s not supported on this platform", "BindToInterface");
111 int setup_listen_socket(const sockaddr_t *sa) {
117 nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
120 ifdebug(STATUS) logger(LOG_ERR, "Creating metasocket failed: %s", sockstrerror(sockerrno));
125 fcntl(nfd, F_SETFD, FD_CLOEXEC);
128 /* Optimize TCP settings */
131 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
133 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
134 if(sa->sa.sa_family == AF_INET6)
135 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
139 (lookup_config(config_tree, "BindToInterface"), &iface)) {
140 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
143 memset(&ifr, 0, sizeof(ifr));
144 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
146 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr))) {
148 logger(LOG_ERR, "Can't bind to interface %s: %s", iface,
149 strerror(sockerrno));
153 logger(LOG_WARNING, "%s not supported on this platform", "BindToInterface");
157 if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
159 addrstr = sockaddr2hostname(sa);
160 logger(LOG_ERR, "Can't bind to %s/tcp: %s", addrstr, sockstrerror(sockerrno));
167 logger(LOG_ERR, "System call `%s' failed: %s", "listen", sockstrerror(sockerrno));
174 int setup_vpn_in_socket(const sockaddr_t *sa) {
179 nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
182 logger(LOG_ERR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
187 fcntl(nfd, F_SETFD, FD_CLOEXEC);
192 int flags = fcntl(nfd, F_GETFL);
194 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
196 logger(LOG_ERR, "System call `%s' failed: %s", "fcntl",
203 unsigned long arg = 1;
204 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
206 logger(LOG_ERR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
213 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
214 setsockopt(nfd, SOL_SOCKET, SO_BROADCAST, (void *)&option, sizeof(option));
216 if(udp_rcvbuf && setsockopt(nfd, SOL_SOCKET, SO_RCVBUF, (void *)&udp_rcvbuf, sizeof(udp_rcvbuf)))
217 logger(LOG_WARNING, "Can't set UDP SO_RCVBUF to %i: %s", udp_rcvbuf, strerror(errno));
219 if(udp_sndbuf && setsockopt(nfd, SOL_SOCKET, SO_SNDBUF, (void *)&udp_sndbuf, sizeof(udp_sndbuf)))
220 logger(LOG_WARNING, "Can't set UDP SO_SNDBUF to %i: %s", udp_sndbuf, strerror(errno));
222 #if defined(IPPROTO_IPV6) && defined(IPV6_V6ONLY)
223 if(sa->sa.sa_family == AF_INET6)
224 setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
227 #if defined(IP_DONTFRAG) && !defined(IP_DONTFRAGMENT)
228 #define IP_DONTFRAGMENT IP_DONTFRAG
231 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
232 if(myself->options & OPTION_PMTU_DISCOVERY) {
233 option = IP_PMTUDISC_DO;
234 setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
236 #elif defined(IPPROTO_IP) && defined(IP_DONTFRAGMENT)
237 if(myself->options & OPTION_PMTU_DISCOVERY) {
239 setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, (void *)&option, sizeof(option));
242 #warning No way to disable IPv4 fragmentation
245 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
246 if(myself->options & OPTION_PMTU_DISCOVERY) {
247 option = IPV6_PMTUDISC_DO;
248 setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
250 #elif defined(IPPROTO_IPV6) && defined(IPV6_DONTFRAG)
251 if(myself->options & OPTION_PMTU_DISCOVERY) {
253 setsockopt(nfd, IPPROTO_IPV6, IPV6_DONTFRAG, (void *)&option, sizeof(option));
256 #warning No way to disable IPv6 fragmentation
259 if (!bind_to_interface(nfd)) {
264 if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
266 addrstr = sockaddr2hostname(sa);
267 logger(LOG_ERR, "Can't bind to %s/udp: %s", addrstr, sockstrerror(sockerrno));
273 } /* int setup_vpn_in_socket */
275 void retry_outgoing(outgoing_t *outgoing) {
276 outgoing->timeout += 5;
278 if(outgoing->timeout > maxtimeout)
279 outgoing->timeout = maxtimeout;
282 event_del(outgoing->event);
283 outgoing->event = new_event();
284 outgoing->event->handler = (event_handler_t) setup_outgoing_connection;
285 outgoing->event->time = now + outgoing->timeout;
286 outgoing->event->data = outgoing;
287 event_add(outgoing->event);
289 ifdebug(CONNECTIONS) logger(LOG_NOTICE,
290 "Trying to re-establish outgoing connection in %d seconds",
294 void finish_connecting(connection_t *c) {
295 ifdebug(CONNECTIONS) logger(LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
297 if(proxytype != PROXY_EXEC)
300 c->last_ping_time = now;
305 static void do_outgoing_pipe(connection_t *c, char *command) {
309 if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
310 logger(LOG_ERR, "Could not create socketpair: %s\n", strerror(errno));
317 logger(LOG_DEBUG, "Using proxy %s", command);
328 // Other filedescriptors should be closed automatically by CLOEXEC
333 sockaddr2str(&c->address, &host, &port);
334 setenv("REMOTEADDRESS", host, true);
335 setenv("REMOTEPORT", port, true);
336 setenv("NODE", c->name, true);
337 setenv("NAME", myself->name, true);
339 setenv("NETNAME", netname, true);
341 int result = system(command);
343 logger(LOG_ERR, "Could not execute %s: %s\n", command, strerror(errno));
345 logger(LOG_ERR, "%s exited with non-zero status %d", command, result);
348 logger(LOG_ERR, "Proxy type exec not supported on this platform!");
353 void do_outgoing_connection(connection_t *c) {
354 char *address, *port, *space;
355 struct addrinfo *proxyai = NULL;
359 logger(LOG_ERR, "do_outgoing_connection() for %s called without c->outgoing", c->name);
364 if(!c->outgoing->ai) {
365 if(!c->outgoing->cfg) {
366 ifdebug(CONNECTIONS) logger(LOG_ERR, "Could not set up a meta connection to %s",
368 c->status.remove = true;
369 retry_outgoing(c->outgoing);
374 get_config_string(c->outgoing->cfg, &address);
376 space = strchr(address, ' ');
378 port = xstrdup(space + 1);
381 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
382 port = xstrdup("655");
385 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
389 c->outgoing->aip = c->outgoing->ai;
390 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
393 if(!c->outgoing->aip) {
395 freeaddrinfo(c->outgoing->ai);
396 c->outgoing->ai = NULL;
400 memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
401 c->outgoing->aip = c->outgoing->aip->ai_next;
406 c->hostname = sockaddr2hostname(&c->address);
408 ifdebug(CONNECTIONS) logger(LOG_INFO, "Trying to connect to %s (%s)", c->name,
412 c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
414 } else if(proxytype == PROXY_EXEC) {
415 do_outgoing_pipe(c, proxyhost);
417 proxyai = str2addrinfo(proxyhost, proxyport, SOCK_STREAM);
420 ifdebug(CONNECTIONS) logger(LOG_INFO, "Using proxy at %s port %s", proxyhost, proxyport);
421 c->socket = socket(proxyai->ai_family, SOCK_STREAM, IPPROTO_TCP);
424 if(c->socket == -1) {
425 ifdebug(CONNECTIONS) logger(LOG_ERR, "Creating socket for %s failed: %s", c->hostname, sockstrerror(sockerrno));
430 fcntl(c->socket, F_SETFD, FD_CLOEXEC);
433 if(proxytype != PROXY_EXEC) {
434 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
436 if(c->address.sa.sa_family == AF_INET6)
437 setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
440 bind_to_interface(c->socket);
446 result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
447 } else if(proxytype == PROXY_EXEC) {
450 result = connect(c->socket, proxyai->ai_addr, proxyai->ai_addrlen);
451 freeaddrinfo(proxyai);
455 if(sockinprogress(sockerrno)) {
456 c->status.connecting = true;
460 closesocket(c->socket);
462 ifdebug(CONNECTIONS) logger(LOG_ERR, "%s: %s", c->hostname, sockstrerror(sockerrno));
467 finish_connecting(c);
472 void setup_outgoing_connection(outgoing_t *outgoing) {
476 outgoing->event = NULL;
478 n = lookup_node(outgoing->name);
482 ifdebug(CONNECTIONS) logger(LOG_INFO, "Already connected to %s", outgoing->name);
484 n->connection->outgoing = outgoing;
488 c = new_connection();
489 c->name = xstrdup(outgoing->name);
490 c->outcipher = myself->connection->outcipher;
491 c->outdigest = myself->connection->outdigest;
492 c->outmaclength = myself->connection->outmaclength;
493 c->outcompression = myself->connection->outcompression;
495 init_configuration(&c->config_tree);
496 read_connection_config(c);
498 outgoing->cfg = lookup_config(c->config_tree, "Address");
501 logger(LOG_ERR, "No address specified for %s", c->name);
506 c->outgoing = outgoing;
507 c->last_ping_time = now;
511 do_outgoing_connection(c);
515 accept a new tcp connect and create a
518 bool handle_new_meta_connection(int sock) {
522 socklen_t len = sizeof(sa);
524 fd = accept(sock, &sa.sa, &len);
527 logger(LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
533 c = new_connection();
534 c->name = xstrdup("<unknown>");
535 c->outcipher = myself->connection->outcipher;
536 c->outdigest = myself->connection->outdigest;
537 c->outmaclength = myself->connection->outmaclength;
538 c->outcompression = myself->connection->outcompression;
541 c->hostname = sockaddr2hostname(&sa);
543 c->last_ping_time = now;
545 ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Connection from %s", c->hostname);
551 c->allow_request = ID;
557 static void free_outgoing(outgoing_t *outgoing) {
559 freeaddrinfo(outgoing->ai);
562 free(outgoing->name);
567 void try_outgoing_connections(void) {
568 static config_t *cfg = NULL;
570 outgoing_t *outgoing;
572 outgoing_list = list_alloc((list_action_t)free_outgoing);
574 for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
575 get_config_string(cfg, &name);
577 if(!check_id(name)) {
579 "Invalid name for outgoing connection in %s line %d",
580 cfg->file, cfg->line);
585 outgoing = xmalloc_and_zero(sizeof(*outgoing));
586 outgoing->name = name;
587 list_insert_tail(outgoing_list, outgoing);
588 setup_outgoing_connection(outgoing);