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"
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(DEBUG_ALWAYS, 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(DEBUG_ALWAYS, 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;
98 status = setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr));
100 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
104 #else /* if !defined(SOL_SOCKET) || !defined(SO_BINDTODEVICE) */
105 logger(DEBUG_ALWAYS, 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 logger(DEBUG_STATUS, 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(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
149 strerror(sockerrno));
153 logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform", "BindToInterface");
157 if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
159 addrstr = sockaddr2hostname(sa);
160 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/tcp: %s", addrstr, sockstrerror(sockerrno));
167 logger(DEBUG_ALWAYS, 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(DEBUG_ALWAYS, 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(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "fcntl",
203 unsigned long arg = 1;
204 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
206 logger(DEBUG_ALWAYS, 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(DEBUG_ALWAYS, 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(DEBUG_ALWAYS, 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(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/udp: %s", addrstr, sockstrerror(sockerrno));
273 } /* int setup_vpn_in_socket */
275 static void retry_outgoing_handler(void *data) {
276 setup_outgoing_connection(data);
279 void retry_outgoing(outgoing_t *outgoing) {
280 outgoing->timeout += 5;
282 if(outgoing->timeout > maxtimeout)
283 outgoing->timeout = maxtimeout;
285 timeout_add(&outgoing->ev, retry_outgoing_handler, outgoing, &(struct timeval){outgoing->timeout, rand() % 100000});
287 logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Trying to re-establish outgoing connection in %d seconds", outgoing->timeout);
290 void finish_connecting(connection_t *c) {
291 logger(DEBUG_CONNECTIONS, LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
293 if(proxytype != PROXY_EXEC)
296 c->last_ping_time = time(NULL);
297 c->status.connecting = false;
302 static void do_outgoing_pipe(connection_t *c, char *command) {
306 if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
307 logger(DEBUG_ALWAYS, LOG_ERR, "Could not create socketpair: %s", strerror(errno));
314 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Using proxy %s", command);
325 // Other filedescriptors should be closed automatically by CLOEXEC
330 sockaddr2str(&c->address, &host, &port);
331 setenv("REMOTEADDRESS", host, true);
332 setenv("REMOTEPORT", port, true);
333 setenv("NODE", c->name, true);
334 setenv("NAME", myself->name, true);
336 setenv("NETNAME", netname, true);
338 int result = system(command);
340 logger(DEBUG_ALWAYS, LOG_ERR, "Could not execute %s: %s", command, strerror(errno));
342 logger(DEBUG_ALWAYS, LOG_ERR, "%s exited with non-zero status %d", command, result);
345 logger(DEBUG_ALWAYS, LOG_ERR, "Proxy type exec not supported on this platform!");
350 static void handle_meta_write(connection_t *c) {
351 ssize_t outlen = send(c->socket, c->outbuf.data + c->outbuf.offset, c->outbuf.len - c->outbuf.offset, 0);
353 if(!errno || errno == EPIPE) {
354 logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection closed by %s (%s)", c->name, c->hostname);
355 } else if(sockwouldblock(sockerrno)) {
356 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Sending %d bytes to %s (%s) would block", c->outbuf.len - c->outbuf.offset, c->name, c->hostname);
359 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));
362 terminate_connection(c, c->status.active);
366 buffer_read(&c->outbuf, outlen);
368 io_set(&c->io, IO_READ);
371 static void handle_meta_io(void *data, int flags) {
373 handle_meta_write(data);
375 handle_meta_connection_data(data);
378 bool do_outgoing_connection(outgoing_t *outgoing) {
379 char *address, *port, *space;
380 struct addrinfo *proxyai = NULL;
386 logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not set up a meta connection to %s", outgoing->name);
387 retry_outgoing(outgoing);
391 get_config_string(outgoing->cfg, &address);
393 space = strchr(address, ' ');
395 port = xstrdup(space + 1);
398 if(!get_config_string(lookup_config(outgoing->config_tree, "Port"), &port))
399 port = xstrdup("655");
402 outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
406 outgoing->aip = outgoing->ai;
407 outgoing->cfg = lookup_config_next(outgoing->config_tree, outgoing->cfg);
412 freeaddrinfo(outgoing->ai);
417 connection_t *c = new_connection();
418 c->outgoing = outgoing;
420 memcpy(&c->address, outgoing->aip->ai_addr, outgoing->aip->ai_addrlen);
421 outgoing->aip = outgoing->aip->ai_next;
423 c->hostname = sockaddr2hostname(&c->address);
425 logger(DEBUG_CONNECTIONS, LOG_INFO, "Trying to connect to %s (%s)", outgoing->name, c->hostname);
428 c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
430 } else if(proxytype == PROXY_EXEC) {
431 do_outgoing_pipe(c, proxyhost);
433 proxyai = str2addrinfo(proxyhost, proxyport, SOCK_STREAM);
438 logger(DEBUG_CONNECTIONS, LOG_INFO, "Using proxy at %s port %s", proxyhost, proxyport);
439 c->socket = socket(proxyai->ai_family, SOCK_STREAM, IPPROTO_TCP);
442 if(c->socket == -1) {
443 logger(DEBUG_CONNECTIONS, LOG_ERR, "Creating socket for %s failed: %s", c->hostname, sockstrerror(sockerrno));
449 fcntl(c->socket, F_SETFD, FD_CLOEXEC);
452 if(proxytype != PROXY_EXEC) {
453 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
455 if(c->address.sa.sa_family == AF_INET6)
456 setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
459 bind_to_interface(c->socket);
465 result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
466 } else if(proxytype == PROXY_EXEC) {
469 result = connect(c->socket, proxyai->ai_addr, proxyai->ai_addrlen);
470 freeaddrinfo(proxyai);
473 if(result == -1 && !sockinprogress(sockerrno)) {
474 logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not connect to %s (%s): %s", outgoing->name, c->hostname, sockstrerror(sockerrno));
480 /* Now that there is a working socket, fill in the rest and register this connection. */
482 c->status.connecting = true;
483 c->name = xstrdup(outgoing->name);
484 c->outcipher = myself->connection->outcipher;
485 c->outdigest = myself->connection->outdigest;
486 c->outmaclength = myself->connection->outmaclength;
487 c->outcompression = myself->connection->outcompression;
488 c->last_ping_time = time(NULL);
492 io_add(&c->io, handle_meta_io, c, c->socket, IO_READ);
497 void setup_outgoing_connection(outgoing_t *outgoing) {
498 timeout_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(void *data, int flags) {
526 listen_socket_t *l = data;
530 socklen_t len = sizeof sa;
532 fd = accept(l->tcp.fd, &sa.sa, &len);
535 logger(DEBUG_ALWAYS, LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
541 c = new_connection();
542 c->name = xstrdup("<unknown>");
543 c->outcipher = myself->connection->outcipher;
544 c->outdigest = myself->connection->outdigest;
545 c->outmaclength = myself->connection->outmaclength;
546 c->outcompression = myself->connection->outcompression;
549 c->hostname = sockaddr2hostname(&sa);
551 c->last_ping_time = time(NULL);
553 logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection from %s", c->hostname);
555 io_add(&c->io, handle_meta_io, c, c->socket, IO_READ);
561 c->allow_request = ID;
565 static void free_outgoing(outgoing_t *outgoing) {
566 timeout_del(&outgoing->ev);
569 freeaddrinfo(outgoing->ai);
571 if(outgoing->config_tree)
572 exit_configuration(&outgoing->config_tree);
575 free(outgoing->name);
580 void try_outgoing_connections(void) {
581 /* If there is no outgoing list yet, create one. Otherwise, mark all outgoings as deleted. */
584 outgoing_list = list_alloc((list_action_t)free_outgoing);
586 for list_each(outgoing_t, outgoing, outgoing_list)
587 outgoing->timeout = -1;
590 /* Make sure there is one outgoing_t in the list for each ConnectTo. */
592 for(config_t *cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
594 get_config_string(cfg, &name);
596 if(!check_id(name)) {
597 logger(DEBUG_ALWAYS, LOG_ERR,
598 "Invalid name for outgoing connection in %s line %d",
599 cfg->file, cfg->line);
606 for list_each(outgoing_t, outgoing, outgoing_list) {
607 if(!strcmp(outgoing->name, name)) {
609 outgoing->timeout = 0;
615 outgoing_t *outgoing = xmalloc_and_zero(sizeof *outgoing);
616 outgoing->name = name;
617 list_insert_tail(outgoing_list, outgoing);
618 setup_outgoing_connection(outgoing);
622 /* Terminate any connections whose outgoing_t is to be deleted. */
624 for list_each(connection_t, c, connection_list) {
625 if(c->outgoing && c->outgoing->timeout == -1) {
627 logger(DEBUG_CONNECTIONS, LOG_INFO, "No more outgoing connection to %s", c->name);
628 terminate_connection(c, c->status.active);
632 /* Delete outgoing_ts for which there is no ConnectTo. */
634 for list_each(outgoing_t, outgoing, outgoing_list)
635 if(outgoing->timeout == -1)
636 list_delete_node(outgoing_list, node);