2 net_socket.c -- Handle various kinds of sockets.
3 Copyright (C) 1998-2005 Ivo Timmermans,
4 2000-2014 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: %s", 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;
99 status = setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr));
101 logger(LOG_ERR, "Can't bind to interface %s: %s", ifr.ifr_ifrn.ifrn_name, strerror(errno));
105 #else /* if !defined(SOL_SOCKET) || !defined(SO_BINDTODEVICE) */
106 logger(LOG_WARNING, "%s not supported on this platform", "BindToInterface");
112 int setup_listen_socket(const sockaddr_t *sa) {
118 nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
121 ifdebug(STATUS) logger(LOG_ERR, "Creating metasocket failed: %s", sockstrerror(sockerrno));
126 fcntl(nfd, F_SETFD, FD_CLOEXEC);
129 /* Optimize TCP settings */
132 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
134 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
135 if(sa->sa.sa_family == AF_INET6)
136 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
139 if(get_config_string(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);
145 ifr.ifr_ifrn.ifrn_name[IFNAMSIZ - 1] = 0;
148 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr))) {
150 logger(LOG_ERR, "Can't bind to interface %s: %s", ifr.ifr_ifrn.ifrn_name, strerror(sockerrno));
155 logger(LOG_WARNING, "%s not supported on this platform", "BindToInterface");
159 if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
161 addrstr = sockaddr2hostname(sa);
162 logger(LOG_ERR, "Can't bind to %s/tcp: %s", addrstr, sockstrerror(sockerrno));
169 logger(LOG_ERR, "System call `%s' failed: %s", "listen", sockstrerror(sockerrno));
176 int setup_vpn_in_socket(const sockaddr_t *sa) {
181 nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
184 logger(LOG_ERR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
189 fcntl(nfd, F_SETFD, FD_CLOEXEC);
194 int flags = fcntl(nfd, F_GETFL);
196 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
198 logger(LOG_ERR, "System call `%s' failed: %s", "fcntl",
205 unsigned long arg = 1;
206 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
208 logger(LOG_ERR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
215 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
216 setsockopt(nfd, SOL_SOCKET, SO_BROADCAST, (void *)&option, sizeof(option));
218 if(udp_rcvbuf && setsockopt(nfd, SOL_SOCKET, SO_RCVBUF, (void *)&udp_rcvbuf, sizeof(udp_rcvbuf)))
219 logger(LOG_WARNING, "Can't set UDP SO_RCVBUF to %i: %s", udp_rcvbuf, strerror(errno));
221 if(udp_sndbuf && setsockopt(nfd, SOL_SOCKET, SO_SNDBUF, (void *)&udp_sndbuf, sizeof(udp_sndbuf)))
222 logger(LOG_WARNING, "Can't set UDP SO_SNDBUF to %i: %s", udp_sndbuf, strerror(errno));
224 #if defined(IPPROTO_IPV6) && defined(IPV6_V6ONLY)
225 if(sa->sa.sa_family == AF_INET6)
226 setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
229 #if defined(IP_DONTFRAG) && !defined(IP_DONTFRAGMENT)
230 #define IP_DONTFRAGMENT IP_DONTFRAG
233 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
234 if(myself->options & OPTION_PMTU_DISCOVERY) {
235 option = IP_PMTUDISC_DO;
236 setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
238 #elif defined(IPPROTO_IP) && defined(IP_DONTFRAGMENT)
239 if(myself->options & OPTION_PMTU_DISCOVERY) {
241 setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, (void *)&option, sizeof(option));
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));
257 if (!bind_to_interface(nfd)) {
262 if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
264 addrstr = sockaddr2hostname(sa);
265 logger(LOG_ERR, "Can't bind to %s/udp: %s", addrstr, sockstrerror(sockerrno));
271 } /* int setup_vpn_in_socket */
273 void retry_outgoing(outgoing_t *outgoing) {
274 outgoing->timeout += 5;
276 if(outgoing->timeout > maxtimeout)
277 outgoing->timeout = maxtimeout;
280 event_del(outgoing->event);
281 outgoing->event = new_event();
282 outgoing->event->handler = (event_handler_t) setup_outgoing_connection;
283 outgoing->event->time = now + outgoing->timeout;
284 outgoing->event->data = outgoing;
285 event_add(outgoing->event);
287 ifdebug(CONNECTIONS) logger(LOG_NOTICE,
288 "Trying to re-establish outgoing connection in %d seconds",
292 void finish_connecting(connection_t *c) {
293 ifdebug(CONNECTIONS) logger(LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
295 c->last_ping_time = now;
300 static void do_outgoing_pipe(connection_t *c, char *command) {
304 if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
305 logger(LOG_ERR, "Could not create socketpair: %s\n", strerror(errno));
312 ifdebug(CONNECTIONS) logger(LOG_DEBUG, "Using proxy %s", command);
323 // Other filedescriptors should be closed automatically by CLOEXEC
328 sockaddr2str(&c->address, &host, &port);
329 setenv("REMOTEADDRESS", host, true);
330 setenv("REMOTEPORT", port, true);
331 setenv("NODE", c->name, true);
332 setenv("NAME", myself->name, true);
334 setenv("NETNAME", netname, true);
336 int result = system(command);
338 logger(LOG_ERR, "Could not execute %s: %s\n", command, strerror(errno));
340 logger(LOG_ERR, "%s exited with non-zero status %d", command, result);
343 logger(LOG_ERR, "Proxy type exec not supported on this platform!");
348 void do_outgoing_connection(connection_t *c) {
349 char *address, *port, *space;
350 struct addrinfo *proxyai = NULL;
354 logger(LOG_ERR, "do_outgoing_connection() for %s called without c->outgoing", c->name);
359 if(!c->outgoing->ai) {
360 if(!c->outgoing->cfg) {
361 ifdebug(CONNECTIONS) logger(LOG_ERR, "Could not set up a meta connection to %s",
363 c->status.remove = true;
364 retry_outgoing(c->outgoing);
369 get_config_string(c->outgoing->cfg, &address);
371 space = strchr(address, ' ');
373 port = xstrdup(space + 1);
376 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
377 port = xstrdup("655");
380 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
384 c->outgoing->aip = c->outgoing->ai;
385 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
388 if(!c->outgoing->aip) {
390 freeaddrinfo(c->outgoing->ai);
391 c->outgoing->ai = NULL;
395 memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
396 c->outgoing->aip = c->outgoing->aip->ai_next;
401 c->hostname = sockaddr2hostname(&c->address);
403 ifdebug(CONNECTIONS) logger(LOG_INFO, "Trying to connect to %s (%s)", c->name,
407 c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
408 } else if(proxytype == PROXY_EXEC) {
409 do_outgoing_pipe(c, proxyhost);
411 proxyai = str2addrinfo(proxyhost, proxyport, SOCK_STREAM);
414 ifdebug(CONNECTIONS) logger(LOG_INFO, "Using proxy at %s port %s", proxyhost, proxyport);
415 c->socket = socket(proxyai->ai_family, SOCK_STREAM, IPPROTO_TCP);
418 if(c->socket == -1) {
419 ifdebug(CONNECTIONS) logger(LOG_ERR, "Creating socket for %s failed: %s", c->hostname, sockstrerror(sockerrno));
423 if(proxytype != PROXY_EXEC)
427 fcntl(c->socket, F_SETFD, FD_CLOEXEC);
430 if(proxytype != PROXY_EXEC) {
431 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
433 if(c->address.sa.sa_family == AF_INET6)
434 setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
437 bind_to_interface(c->socket);
443 result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
444 } else if(proxytype == PROXY_EXEC) {
447 result = connect(c->socket, proxyai->ai_addr, proxyai->ai_addrlen);
448 freeaddrinfo(proxyai);
452 if(sockinprogress(sockerrno)) {
453 c->status.connecting = true;
457 closesocket(c->socket);
459 ifdebug(CONNECTIONS) logger(LOG_ERR, "%s: %s", c->hostname, sockstrerror(sockerrno));
464 finish_connecting(c);
469 void setup_outgoing_connection(outgoing_t *outgoing) {
473 outgoing->event = NULL;
475 n = lookup_node(outgoing->name);
479 ifdebug(CONNECTIONS) logger(LOG_INFO, "Already connected to %s", outgoing->name);
481 n->connection->outgoing = outgoing;
485 c = new_connection();
486 c->name = xstrdup(outgoing->name);
487 c->outcipher = myself->connection->outcipher;
488 c->outdigest = myself->connection->outdigest;
489 c->outmaclength = myself->connection->outmaclength;
490 c->outcompression = myself->connection->outcompression;
492 init_configuration(&c->config_tree);
493 read_connection_config(c);
495 outgoing->cfg = lookup_config(c->config_tree, "Address");
498 logger(LOG_ERR, "No address specified for %s", c->name);
503 c->outgoing = outgoing;
504 c->last_ping_time = now;
508 do_outgoing_connection(c);
512 accept a new tcp connect and create a
515 bool handle_new_meta_connection(int sock) {
519 socklen_t len = sizeof(sa);
521 fd = accept(sock, &sa.sa, &len);
524 logger(LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
530 c = new_connection();
531 c->name = xstrdup("<unknown>");
532 c->outcipher = myself->connection->outcipher;
533 c->outdigest = myself->connection->outdigest;
534 c->outmaclength = myself->connection->outmaclength;
535 c->outcompression = myself->connection->outcompression;
538 c->hostname = sockaddr2hostname(&sa);
540 c->last_ping_time = now;
542 ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Connection from %s", c->hostname);
548 c->allow_request = ID;
554 static void free_outgoing(outgoing_t *outgoing) {
556 freeaddrinfo(outgoing->ai);
559 free(outgoing->name);
564 void try_outgoing_connections(void) {
565 static config_t *cfg = NULL;
567 outgoing_t *outgoing;
569 outgoing_list = list_alloc((list_action_t)free_outgoing);
571 for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
572 get_config_string(cfg, &name);
574 if(!check_id(name)) {
576 "Invalid name for outgoing connection in %s line %d",
577 cfg->file, cfg->line);
582 outgoing = xmalloc_and_zero(sizeof(*outgoing));
583 outgoing->name = name;
584 list_insert_tail(outgoing_list, outgoing);
585 setup_outgoing_connection(outgoing);