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.
26 #include "connection.h"
35 /* Needed on Mac OS/X */
37 #define SOL_TCP IPPROTO_TCP
40 int addressfamily = AF_UNSPEC;
42 int seconds_till_retry = 5;
46 listen_socket_t listen_socket[MAXSOCKETS];
48 list_t *outgoing_list = NULL;
52 static void configure_tcp(connection_t *c) {
56 int flags = fcntl(c->socket, F_GETFL);
58 if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
59 logger(DEBUG_ALWAYS, LOG_ERR, "fcntl for %s: %s", c->hostname, strerror(errno));
62 unsigned long arg = 1;
64 if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
65 logger(DEBUG_ALWAYS, LOG_ERR, "ioctlsocket for %s: %d", c->hostname, sockstrerror(sockerrno));
69 #if defined(SOL_TCP) && defined(TCP_NODELAY)
71 setsockopt(c->socket, SOL_TCP, TCP_NODELAY, (void *)&option, sizeof option);
74 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
75 option = IPTOS_LOWDELAY;
76 setsockopt(c->socket, SOL_IP, IP_TOS, (void *)&option, sizeof option);
80 static bool bind_to_interface(int sd) {
83 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
86 #endif /* defined(SOL_SOCKET) && defined(SO_BINDTODEVICE) */
88 if(!get_config_string (lookup_config (config_tree, "BindToInterface"), &iface))
91 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
92 memset(&ifr, 0, sizeof(ifr));
93 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
94 ifr.ifr_ifrn.ifrn_name[IFNAMSIZ - 1] = 0;
96 status = setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr));
98 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
102 #else /* if !defined(SOL_SOCKET) || !defined(SO_BINDTODEVICE) */
103 logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform", "BindToInterface");
109 int setup_listen_socket(const sockaddr_t *sa) {
115 nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
118 logger(DEBUG_STATUS, LOG_ERR, "Creating metasocket failed: %s", sockstrerror(sockerrno));
123 fcntl(nfd, F_SETFD, FD_CLOEXEC);
126 /* Optimize TCP settings */
129 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof option);
131 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
132 if(sa->sa.sa_family == AF_INET6)
133 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
137 (lookup_config(config_tree, "BindToInterface"), &iface)) {
138 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
141 memset(&ifr, 0, sizeof ifr);
142 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
144 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof ifr)) {
146 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
147 strerror(sockerrno));
151 logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform", "BindToInterface");
155 if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
157 addrstr = sockaddr2hostname(sa);
158 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/tcp: %s", addrstr, sockstrerror(sockerrno));
165 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "listen", sockstrerror(sockerrno));
172 int setup_vpn_in_socket(const sockaddr_t *sa) {
177 nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
180 logger(DEBUG_ALWAYS, LOG_ERR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
185 fcntl(nfd, F_SETFD, FD_CLOEXEC);
190 int flags = fcntl(nfd, F_GETFL);
192 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
194 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "fcntl",
201 unsigned long arg = 1;
202 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
204 logger(DEBUG_ALWAYS, LOG_ERR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
211 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof option);
212 setsockopt(nfd, SOL_SOCKET, SO_BROADCAST, (void *)&option, sizeof option);
214 if(udp_rcvbuf && setsockopt(nfd, SOL_SOCKET, SO_RCVBUF, (void *)&udp_rcvbuf, sizeof(udp_rcvbuf)))
215 logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP SO_RCVBUF to %i: %s", udp_rcvbuf, strerror(errno));
217 if(udp_sndbuf && setsockopt(nfd, SOL_SOCKET, SO_SNDBUF, (void *)&udp_sndbuf, sizeof(udp_sndbuf)))
218 logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP SO_SNDBUF to %i: %s", udp_sndbuf, strerror(errno));
220 #if defined(IPPROTO_IPV6) && defined(IPV6_V6ONLY)
221 if(sa->sa.sa_family == AF_INET6)
222 setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
225 #if defined(IP_DONTFRAG) && !defined(IP_DONTFRAGMENT)
226 #define IP_DONTFRAGMENT IP_DONTFRAG
229 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
230 if(myself->options & OPTION_PMTU_DISCOVERY) {
231 option = IP_PMTUDISC_DO;
232 setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
234 #elif defined(IPPROTO_IP) && defined(IP_DONTFRAGMENT)
235 if(myself->options & OPTION_PMTU_DISCOVERY) {
237 setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, (void *)&option, sizeof(option));
240 #warning No way to disable IPv4 fragmentation
243 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
244 if(myself->options & OPTION_PMTU_DISCOVERY) {
245 option = IPV6_PMTUDISC_DO;
246 setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
248 #elif defined(IPPROTO_IPV6) && defined(IPV6_DONTFRAG)
249 if(myself->options & OPTION_PMTU_DISCOVERY) {
251 setsockopt(nfd, IPPROTO_IPV6, IPV6_DONTFRAG, (void *)&option, sizeof(option));
254 #warning No way to disable IPv6 fragmentation
257 if (!bind_to_interface(nfd)) {
262 if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
264 addrstr = sockaddr2hostname(sa);
265 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/udp: %s", addrstr, sockstrerror(sockerrno));
271 } /* int setup_vpn_in_socket */
273 static void retry_outgoing_handler(int fd, short events, void *data) {
274 setup_outgoing_connection(data);
277 void retry_outgoing(outgoing_t *outgoing) {
278 outgoing->timeout += 5;
280 if(outgoing->timeout > maxtimeout)
281 outgoing->timeout = maxtimeout;
283 timeout_set(&outgoing->ev, retry_outgoing_handler, outgoing);
284 event_add(&outgoing->ev, &(struct timeval){outgoing->timeout, 0});
286 logger(DEBUG_CONNECTIONS, LOG_NOTICE,
287 "Trying to re-establish outgoing connection in %d seconds",
291 void finish_connecting(connection_t *c) {
292 logger(DEBUG_CONNECTIONS, LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
294 if(proxytype != PROXY_EXEC)
297 c->last_ping_time = time(NULL);
298 c->status.connecting = false;
303 static void do_outgoing_pipe(connection_t *c, char *command) {
307 if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
308 logger(DEBUG_ALWAYS, LOG_ERR, "Could not create socketpair: %s", strerror(errno));
315 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Using proxy %s", command);
326 // Other filedescriptors should be closed automatically by CLOEXEC
331 sockaddr2str(&c->address, &host, &port);
332 setenv("REMOTEADDRESS", host, true);
333 setenv("REMOTEPORT", port, true);
334 setenv("NODE", c->name, true);
335 setenv("NAME", myself->name, true);
337 setenv("NETNAME", netname, true);
339 int result = system(command);
341 logger(DEBUG_ALWAYS, LOG_ERR, "Could not execute %s: %s", command, strerror(errno));
343 logger(DEBUG_ALWAYS, LOG_ERR, "%s exited with non-zero status %d", command, result);
346 logger(DEBUG_ALWAYS, LOG_ERR, "Proxy type exec not supported on this platform!");
351 static void handle_meta_write(int sock, short events, void *data) {
352 connection_t *c = data;
354 ssize_t outlen = send(c->socket, c->outbuf.data + c->outbuf.offset, c->outbuf.len - c->outbuf.offset, 0);
356 if(!errno || errno == EPIPE) {
357 logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection closed by %s (%s)", c->name, c->hostname);
358 } else if(sockwouldblock(sockerrno)) {
359 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Sending %d bytes to %s (%s) would block", c->outbuf.len - c->outbuf.offset, c->name, c->hostname);
362 logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not send %d bytes of data to %s (%s): %s", c->outbuf.len - c->outbuf.offset, c->name, c->hostname, strerror(errno));
365 terminate_connection(c, c->status.active);
369 buffer_read(&c->outbuf, outlen);
370 if(!c->outbuf.len && event_initialized(&c->outevent))
371 event_del(&c->outevent);
375 bool do_outgoing_connection(outgoing_t *outgoing) {
376 char *address, *port, *space;
377 struct addrinfo *proxyai = NULL;
383 logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not set up a meta connection to %s", outgoing->name);
384 retry_outgoing(outgoing);
388 get_config_string(outgoing->cfg, &address);
390 space = strchr(address, ' ');
392 port = xstrdup(space + 1);
395 if(!get_config_string(lookup_config(outgoing->config_tree, "Port"), &port))
396 port = xstrdup("655");
399 outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
403 outgoing->aip = outgoing->ai;
404 outgoing->cfg = lookup_config_next(outgoing->config_tree, outgoing->cfg);
409 freeaddrinfo(outgoing->ai);
414 connection_t *c = new_connection();
415 c->outgoing = outgoing;
417 memcpy(&c->address, outgoing->aip->ai_addr, outgoing->aip->ai_addrlen);
418 outgoing->aip = outgoing->aip->ai_next;
420 c->hostname = sockaddr2hostname(&c->address);
422 logger(DEBUG_CONNECTIONS, LOG_INFO, "Trying to connect to %s (%s)", outgoing->name, c->hostname);
425 c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
427 } else if(proxytype == PROXY_EXEC) {
428 do_outgoing_pipe(c, proxyhost);
430 proxyai = str2addrinfo(proxyhost, proxyport, SOCK_STREAM);
435 logger(DEBUG_CONNECTIONS, LOG_INFO, "Using proxy at %s port %s", proxyhost, proxyport);
436 c->socket = socket(proxyai->ai_family, SOCK_STREAM, IPPROTO_TCP);
439 if(c->socket == -1) {
440 logger(DEBUG_CONNECTIONS, LOG_ERR, "Creating socket for %s failed: %s", c->hostname, sockstrerror(sockerrno));
446 fcntl(c->socket, F_SETFD, FD_CLOEXEC);
449 if(proxytype != PROXY_EXEC) {
450 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
452 if(c->address.sa.sa_family == AF_INET6)
453 setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
456 bind_to_interface(c->socket);
462 result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
463 } else if(proxytype == PROXY_EXEC) {
466 result = connect(c->socket, proxyai->ai_addr, proxyai->ai_addrlen);
467 freeaddrinfo(proxyai);
470 if(result == -1 && !sockinprogress(sockerrno)) {
471 logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not connect to %s (%s): %s", outgoing->name, c->hostname, sockstrerror(sockerrno));
477 /* Now that there is a working socket, fill in the rest and register this connection. */
479 c->status.connecting = true;
480 c->name = xstrdup(outgoing->name);
481 c->outcipher = myself->connection->outcipher;
482 c->outdigest = myself->connection->outdigest;
483 c->outmaclength = myself->connection->outmaclength;
484 c->outcompression = myself->connection->outcompression;
485 c->last_ping_time = time(NULL);
489 event_set(&c->inevent, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c);
490 event_set(&c->outevent, c->socket, EV_WRITE | EV_PERSIST, handle_meta_write, c);
491 event_add(&c->inevent, NULL);
496 void setup_outgoing_connection(outgoing_t *outgoing) {
497 if(event_initialized(&outgoing->ev))
498 event_del(&outgoing->ev);
500 node_t *n = lookup_node(outgoing->name);
502 if(n && n->connection) {
503 logger(DEBUG_CONNECTIONS, LOG_INFO, "Already connected to %s", outgoing->name);
505 n->connection->outgoing = outgoing;
509 init_configuration(&outgoing->config_tree);
510 read_host_config(outgoing->config_tree, outgoing->name);
511 outgoing->cfg = lookup_config(outgoing->config_tree, "Address");
514 logger(DEBUG_ALWAYS, LOG_ERR, "No address specified for %s", outgoing->name);
518 do_outgoing_connection(outgoing);
522 accept a new tcp connect and create a
525 void handle_new_meta_connection(int sock, short events, void *data) {
529 socklen_t len = sizeof sa;
531 fd = accept(sock, &sa.sa, &len);
534 logger(DEBUG_ALWAYS, LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
540 c = new_connection();
541 c->name = xstrdup("<unknown>");
542 c->outcipher = myself->connection->outcipher;
543 c->outdigest = myself->connection->outdigest;
544 c->outmaclength = myself->connection->outmaclength;
545 c->outcompression = myself->connection->outcompression;
548 c->hostname = sockaddr2hostname(&sa);
550 c->last_ping_time = time(NULL);
552 logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection from %s", c->hostname);
554 event_set(&c->inevent, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c);
555 event_set(&c->outevent, c->socket, EV_WRITE | EV_PERSIST, handle_meta_write, c);
556 event_add(&c->inevent, NULL);
562 c->allow_request = ID;
566 static void free_outgoing(outgoing_t *outgoing) {
567 if(event_initialized(&outgoing->ev))
568 event_del(&outgoing->ev);
571 freeaddrinfo(outgoing->ai);
574 free(outgoing->name);
579 void try_outgoing_connections(void) {
580 static config_t *cfg = NULL;
582 outgoing_t *outgoing;
584 /* If there is no outgoing list yet, create one. Otherwise, mark all outgoings as deleted. */
587 outgoing_list = list_alloc((list_action_t)free_outgoing);
589 for(list_node_t *i = outgoing_list->head; i; i = i->next) {
591 outgoing->timeout = -1;
595 /* Make sure there is one outgoing_t in the list for each ConnectTo. */
597 for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
598 get_config_string(cfg, &name);
600 if(!check_id(name)) {
601 logger(DEBUG_ALWAYS, LOG_ERR,
602 "Invalid name for outgoing connection in %s line %d",
603 cfg->file, cfg->line);
610 for(list_node_t *i = outgoing_list->head; i; i = i->next) {
612 if(!strcmp(outgoing->name, name)) {
614 outgoing->timeout = 0;
620 outgoing = xmalloc_and_zero(sizeof *outgoing);
621 outgoing->name = name;
622 list_insert_tail(outgoing_list, outgoing);
623 setup_outgoing_connection(outgoing);
627 /* Terminate any connections whose outgoing_t is to be deleted. */
629 for(list_node_t *node = connection_list->head, *next; node; node = next) {
631 connection_t *c = node->data;
632 if(c->outgoing && c->outgoing->timeout == -1) {
634 logger(DEBUG_CONNECTIONS, LOG_INFO, "No more outgoing connection to %s", c->name);
635 terminate_connection(c, c->status.active);
639 /* Delete outgoing_ts for which there is no ConnectTo. */
641 for(list_node_t *node = outgoing_list->head, *next; node; node = next) {
643 outgoing = node->data;
644 if(outgoing->timeout == -1)
645 list_delete_node(outgoing_list, node);