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"
36 /* Needed on Mac OS/X */
38 #define SOL_TCP IPPROTO_TCP
41 int addressfamily = AF_UNSPEC;
43 int seconds_till_retry = 5;
47 listen_socket_t listen_socket[MAXSOCKETS];
49 list_t *outgoing_list = NULL;
53 static void configure_tcp(connection_t *c) {
57 int flags = fcntl(c->socket, F_GETFL);
59 if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
60 logger(DEBUG_ALWAYS, LOG_ERR, "fcntl for %s: %s", c->hostname, strerror(errno));
63 unsigned long arg = 1;
65 if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
66 logger(DEBUG_ALWAYS, LOG_ERR, "ioctlsocket for %s: %d", c->hostname, sockstrerror(sockerrno));
70 #if defined(SOL_TCP) && defined(TCP_NODELAY)
72 setsockopt(c->socket, SOL_TCP, TCP_NODELAY, (void *)&option, sizeof option);
75 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
76 option = IPTOS_LOWDELAY;
77 setsockopt(c->socket, SOL_IP, IP_TOS, (void *)&option, sizeof option);
81 static bool bind_to_interface(int sd) {
84 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
87 #endif /* defined(SOL_SOCKET) && defined(SO_BINDTODEVICE) */
89 if(!get_config_string (lookup_config (config_tree, "BindToInterface"), &iface))
92 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
93 memset(&ifr, 0, sizeof(ifr));
94 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
95 ifr.ifr_ifrn.ifrn_name[IFNAMSIZ - 1] = 0;
97 status = setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr));
99 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
103 #else /* if !defined(SOL_SOCKET) || !defined(SO_BINDTODEVICE) */
104 logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform", "BindToInterface");
110 int setup_listen_socket(const sockaddr_t *sa) {
116 nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
119 logger(DEBUG_STATUS, LOG_ERR, "Creating metasocket failed: %s", sockstrerror(sockerrno));
124 fcntl(nfd, F_SETFD, FD_CLOEXEC);
127 /* Optimize TCP settings */
130 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof option);
132 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
133 if(sa->sa.sa_family == AF_INET6)
134 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
138 (lookup_config(config_tree, "BindToInterface"), &iface)) {
139 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
142 memset(&ifr, 0, sizeof ifr);
143 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
145 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof ifr)) {
147 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
148 strerror(sockerrno));
152 logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform", "BindToInterface");
156 if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
158 addrstr = sockaddr2hostname(sa);
159 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/tcp: %s", addrstr, sockstrerror(sockerrno));
166 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "listen", sockstrerror(sockerrno));
173 int setup_vpn_in_socket(const sockaddr_t *sa) {
178 nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
181 logger(DEBUG_ALWAYS, LOG_ERR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
186 fcntl(nfd, F_SETFD, FD_CLOEXEC);
191 int flags = fcntl(nfd, F_GETFL);
193 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
195 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "fcntl",
202 unsigned long arg = 1;
203 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
205 logger(DEBUG_ALWAYS, LOG_ERR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
212 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof option);
213 setsockopt(nfd, SOL_SOCKET, SO_BROADCAST, (void *)&option, sizeof option);
215 if(udp_rcvbuf && setsockopt(nfd, SOL_SOCKET, SO_RCVBUF, (void *)&udp_rcvbuf, sizeof(udp_rcvbuf)))
216 logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP SO_RCVBUF to %i: %s", udp_rcvbuf, strerror(errno));
218 if(udp_sndbuf && setsockopt(nfd, SOL_SOCKET, SO_SNDBUF, (void *)&udp_sndbuf, sizeof(udp_sndbuf)))
219 logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP SO_SNDBUF to %i: %s", udp_sndbuf, strerror(errno));
221 #if defined(IPPROTO_IPV6) && defined(IPV6_V6ONLY)
222 if(sa->sa.sa_family == AF_INET6)
223 setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
226 #if defined(IP_DONTFRAG) && !defined(IP_DONTFRAGMENT)
227 #define IP_DONTFRAGMENT IP_DONTFRAG
230 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
231 if(myself->options & OPTION_PMTU_DISCOVERY) {
232 option = IP_PMTUDISC_DO;
233 setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
235 #elif defined(IPPROTO_IP) && defined(IP_DONTFRAGMENT)
236 if(myself->options & OPTION_PMTU_DISCOVERY) {
238 setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, (void *)&option, sizeof(option));
241 #warning No way to disable IPv4 fragmentation
244 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
245 if(myself->options & OPTION_PMTU_DISCOVERY) {
246 option = IPV6_PMTUDISC_DO;
247 setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
249 #elif defined(IPPROTO_IPV6) && defined(IPV6_DONTFRAG)
250 if(myself->options & OPTION_PMTU_DISCOVERY) {
252 setsockopt(nfd, IPPROTO_IPV6, IPV6_DONTFRAG, (void *)&option, sizeof(option));
255 #warning No way to disable IPv6 fragmentation
258 if (!bind_to_interface(nfd)) {
263 if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
265 addrstr = sockaddr2hostname(sa);
266 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/udp: %s", addrstr, sockstrerror(sockerrno));
272 } /* int setup_vpn_in_socket */
274 static void retry_outgoing_handler(int fd, short events, void *data) {
275 setup_outgoing_connection(data);
278 void retry_outgoing(outgoing_t *outgoing) {
279 outgoing->timeout += 5;
281 if(outgoing->timeout > maxtimeout)
282 outgoing->timeout = maxtimeout;
284 timeout_set(&outgoing->ev, retry_outgoing_handler, outgoing);
285 event_add(&outgoing->ev, &(struct timeval){outgoing->timeout, 0});
287 logger(DEBUG_CONNECTIONS, LOG_NOTICE,
288 "Trying to re-establish outgoing connection in %d seconds",
292 void finish_connecting(connection_t *c) {
293 logger(DEBUG_CONNECTIONS, LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
295 if(proxytype != PROXY_EXEC)
298 c->last_ping_time = time(NULL);
299 c->status.connecting = false;
304 static void do_outgoing_pipe(connection_t *c, char *command) {
308 if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
309 logger(DEBUG_ALWAYS, LOG_ERR, "Could not create socketpair: %s", strerror(errno));
316 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Using proxy %s", command);
327 // Other filedescriptors should be closed automatically by CLOEXEC
332 sockaddr2str(&c->address, &host, &port);
333 setenv("REMOTEADDRESS", host, true);
334 setenv("REMOTEPORT", port, true);
335 setenv("NODE", c->name, true);
336 setenv("NAME", myself->name, true);
338 setenv("NETNAME", netname, true);
340 int result = system(command);
342 logger(DEBUG_ALWAYS, LOG_ERR, "Could not execute %s: %s", command, strerror(errno));
344 logger(DEBUG_ALWAYS, LOG_ERR, "%s exited with non-zero status %d", command, result);
347 logger(DEBUG_ALWAYS, LOG_ERR, "Proxy type exec not supported on this platform!");
352 static void handle_meta_write(int sock, short events, void *data) {
353 connection_t *c = data;
355 ssize_t outlen = send(c->socket, c->outbuf.data + c->outbuf.offset, c->outbuf.len - c->outbuf.offset, 0);
357 if(!errno || errno == EPIPE) {
358 logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection closed by %s (%s)", c->name, c->hostname);
359 } else if(sockwouldblock(sockerrno)) {
360 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Sending %d bytes to %s (%s) would block", c->outbuf.len - c->outbuf.offset, c->name, c->hostname);
363 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));
366 terminate_connection(c, c->status.active);
370 buffer_read(&c->outbuf, outlen);
371 if(!c->outbuf.len && event_initialized(&c->outevent))
372 event_del(&c->outevent);
376 bool do_outgoing_connection(outgoing_t *outgoing) {
377 char *address, *port, *space;
378 struct addrinfo *proxyai = NULL;
384 logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not set up a meta connection to %s", outgoing->name);
385 retry_outgoing(outgoing);
389 get_config_string(outgoing->cfg, &address);
391 space = strchr(address, ' ');
393 port = xstrdup(space + 1);
396 if(!get_config_string(lookup_config(outgoing->config_tree, "Port"), &port))
397 port = xstrdup("655");
400 outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
404 outgoing->aip = outgoing->ai;
405 outgoing->cfg = lookup_config_next(outgoing->config_tree, outgoing->cfg);
410 freeaddrinfo(outgoing->ai);
415 connection_t *c = new_connection();
416 c->outgoing = outgoing;
418 memcpy(&c->address, outgoing->aip->ai_addr, outgoing->aip->ai_addrlen);
419 outgoing->aip = outgoing->aip->ai_next;
421 c->hostname = sockaddr2hostname(&c->address);
423 logger(DEBUG_CONNECTIONS, LOG_INFO, "Trying to connect to %s (%s)", outgoing->name, c->hostname);
426 c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
428 } else if(proxytype == PROXY_EXEC) {
429 do_outgoing_pipe(c, proxyhost);
431 proxyai = str2addrinfo(proxyhost, proxyport, SOCK_STREAM);
436 logger(DEBUG_CONNECTIONS, LOG_INFO, "Using proxy at %s port %s", proxyhost, proxyport);
437 c->socket = socket(proxyai->ai_family, SOCK_STREAM, IPPROTO_TCP);
440 if(c->socket == -1) {
441 logger(DEBUG_CONNECTIONS, LOG_ERR, "Creating socket for %s failed: %s", c->hostname, sockstrerror(sockerrno));
447 fcntl(c->socket, F_SETFD, FD_CLOEXEC);
450 if(proxytype != PROXY_EXEC) {
451 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
453 if(c->address.sa.sa_family == AF_INET6)
454 setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
457 bind_to_interface(c->socket);
463 result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
464 } else if(proxytype == PROXY_EXEC) {
467 result = connect(c->socket, proxyai->ai_addr, proxyai->ai_addrlen);
468 freeaddrinfo(proxyai);
471 if(result == -1 && !sockinprogress(sockerrno)) {
472 logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not connect to %s (%s): %s", outgoing->name, c->hostname, sockstrerror(sockerrno));
478 /* Now that there is a working socket, fill in the rest and register this connection. */
480 c->status.connecting = true;
481 c->name = xstrdup(outgoing->name);
482 c->outcipher = myself->connection->outcipher;
483 c->outdigest = myself->connection->outdigest;
484 c->outmaclength = myself->connection->outmaclength;
485 c->outcompression = myself->connection->outcompression;
486 c->last_ping_time = time(NULL);
490 event_set(&c->inevent, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c);
491 event_set(&c->outevent, c->socket, EV_WRITE | EV_PERSIST, handle_meta_write, c);
492 event_add(&c->inevent, NULL);
497 void setup_outgoing_connection(outgoing_t *outgoing) {
498 if(event_initialized(&outgoing->ev))
499 event_del(&outgoing->ev);
501 node_t *n = lookup_node(outgoing->name);
503 if(n && n->connection) {
504 logger(DEBUG_CONNECTIONS, LOG_INFO, "Already connected to %s", outgoing->name);
506 n->connection->outgoing = outgoing;
510 init_configuration(&outgoing->config_tree);
511 read_host_config(outgoing->config_tree, outgoing->name);
512 outgoing->cfg = lookup_config(outgoing->config_tree, "Address");
515 logger(DEBUG_ALWAYS, LOG_ERR, "No address specified for %s", outgoing->name);
519 do_outgoing_connection(outgoing);
523 accept a new tcp connect and create a
526 void handle_new_meta_connection(int sock, short events, void *data) {
530 socklen_t len = sizeof sa;
532 fd = accept(sock, &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 event_set(&c->inevent, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c);
556 event_set(&c->outevent, c->socket, EV_WRITE | EV_PERSIST, handle_meta_write, c);
557 event_add(&c->inevent, NULL);
563 c->allow_request = ID;
567 static void free_outgoing(outgoing_t *outgoing) {
568 if(event_initialized(&outgoing->ev))
569 event_del(&outgoing->ev);
572 freeaddrinfo(outgoing->ai);
574 if(outgoing->config_tree)
575 exit_configuration(&outgoing->config_tree);
578 free(outgoing->name);
583 void try_outgoing_connections(void) {
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_each(outgoing_t, outgoing, outgoing_list)
590 outgoing->timeout = -1;
593 /* Make sure there is one outgoing_t in the list for each ConnectTo. */
595 for(config_t *cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
597 get_config_string(cfg, &name);
599 if(!check_id(name)) {
600 logger(DEBUG_ALWAYS, LOG_ERR,
601 "Invalid name for outgoing connection in %s line %d",
602 cfg->file, cfg->line);
609 for list_each(outgoing_t, outgoing, outgoing_list) {
610 if(!strcmp(outgoing->name, name)) {
612 outgoing->timeout = 0;
618 outgoing_t *outgoing = xmalloc_and_zero(sizeof *outgoing);
619 outgoing->name = name;
620 list_insert_tail(outgoing_list, outgoing);
621 setup_outgoing_connection(outgoing);
625 /* Terminate any connections whose outgoing_t is to be deleted. */
627 for list_each(connection_t, c, connection_list) {
628 if(c->outgoing && c->outgoing->timeout == -1) {
630 logger(DEBUG_CONNECTIONS, LOG_INFO, "No more outgoing connection to %s", c->name);
631 terminate_connection(c, c->status.active);
635 /* Delete outgoing_ts for which there is no ConnectTo. */
637 for list_each(outgoing_t, outgoing, outgoing_list)
638 if(outgoing->timeout == -1)
639 list_delete_node(outgoing_list, node);