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: %s", 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(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_add(&outgoing->ev, retry_outgoing_handler, outgoing, &(struct timeval){outgoing->timeout, rand() % 100000});
286 logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Trying to re-establish outgoing connection in %d seconds", outgoing->timeout);
289 void finish_connecting(connection_t *c) {
290 logger(DEBUG_CONNECTIONS, LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
292 if(proxytype != PROXY_EXEC)
295 c->last_ping_time = time(NULL);
296 c->status.connecting = false;
301 static void do_outgoing_pipe(connection_t *c, char *command) {
305 if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
306 logger(DEBUG_ALWAYS, LOG_ERR, "Could not create socketpair: %s", strerror(errno));
313 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Using proxy %s", command);
324 // Other filedescriptors should be closed automatically by CLOEXEC
329 sockaddr2str(&c->address, &host, &port);
330 setenv("REMOTEADDRESS", host, true);
331 setenv("REMOTEPORT", port, true);
332 setenv("NODE", c->name, true);
333 setenv("NAME", myself->name, true);
335 setenv("NETNAME", netname, true);
337 int result = system(command);
339 logger(DEBUG_ALWAYS, LOG_ERR, "Could not execute %s: %s", command, strerror(errno));
341 logger(DEBUG_ALWAYS, LOG_ERR, "%s exited with non-zero status %d", command, result);
344 logger(DEBUG_ALWAYS, LOG_ERR, "Proxy type exec not supported on this platform!");
349 static void handle_meta_write(connection_t *c) {
350 ssize_t outlen = send(c->socket, c->outbuf.data + c->outbuf.offset, c->outbuf.len - c->outbuf.offset, 0);
352 if(!errno || errno == EPIPE) {
353 logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection closed by %s (%s)", c->name, c->hostname);
354 } else if(sockwouldblock(sockerrno)) {
355 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Sending %d bytes to %s (%s) would block", c->outbuf.len - c->outbuf.offset, c->name, c->hostname);
358 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));
361 terminate_connection(c, c->status.active);
365 buffer_read(&c->outbuf, outlen);
367 io_set(&c->io, IO_READ);
370 static void handle_meta_io(void *data, int flags) {
372 handle_meta_write(data);
374 handle_meta_connection_data(data);
377 bool do_outgoing_connection(outgoing_t *outgoing) {
378 char *address, *port, *space;
379 struct addrinfo *proxyai = NULL;
385 logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not set up a meta connection to %s", outgoing->name);
386 retry_outgoing(outgoing);
390 get_config_string(outgoing->cfg, &address);
392 space = strchr(address, ' ');
394 port = xstrdup(space + 1);
397 if(!get_config_string(lookup_config(outgoing->config_tree, "Port"), &port))
398 port = xstrdup("655");
401 outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
405 outgoing->aip = outgoing->ai;
406 outgoing->cfg = lookup_config_next(outgoing->config_tree, outgoing->cfg);
411 freeaddrinfo(outgoing->ai);
416 connection_t *c = new_connection();
417 c->outgoing = outgoing;
419 memcpy(&c->address, outgoing->aip->ai_addr, outgoing->aip->ai_addrlen);
420 outgoing->aip = outgoing->aip->ai_next;
422 c->hostname = sockaddr2hostname(&c->address);
424 logger(DEBUG_CONNECTIONS, LOG_INFO, "Trying to connect to %s (%s)", outgoing->name, c->hostname);
427 c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
429 } else if(proxytype == PROXY_EXEC) {
430 do_outgoing_pipe(c, proxyhost);
432 proxyai = str2addrinfo(proxyhost, proxyport, SOCK_STREAM);
437 logger(DEBUG_CONNECTIONS, LOG_INFO, "Using proxy at %s port %s", proxyhost, proxyport);
438 c->socket = socket(proxyai->ai_family, SOCK_STREAM, IPPROTO_TCP);
441 if(c->socket == -1) {
442 logger(DEBUG_CONNECTIONS, LOG_ERR, "Creating socket for %s failed: %s", c->hostname, sockstrerror(sockerrno));
448 fcntl(c->socket, F_SETFD, FD_CLOEXEC);
451 if(proxytype != PROXY_EXEC) {
452 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
454 if(c->address.sa.sa_family == AF_INET6)
455 setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
458 bind_to_interface(c->socket);
464 result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
465 } else if(proxytype == PROXY_EXEC) {
468 result = connect(c->socket, proxyai->ai_addr, proxyai->ai_addrlen);
469 freeaddrinfo(proxyai);
472 if(result == -1 && !sockinprogress(sockerrno)) {
473 logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not connect to %s (%s): %s", outgoing->name, c->hostname, sockstrerror(sockerrno));
479 /* Now that there is a working socket, fill in the rest and register this connection. */
481 c->status.connecting = true;
482 c->name = xstrdup(outgoing->name);
483 c->outcipher = myself->connection->outcipher;
484 c->outdigest = myself->connection->outdigest;
485 c->outmaclength = myself->connection->outmaclength;
486 c->outcompression = myself->connection->outcompression;
487 c->last_ping_time = time(NULL);
491 io_add(&c->io, handle_meta_io, c, c->socket, IO_READ);
496 void setup_outgoing_connection(outgoing_t *outgoing) {
497 timeout_del(&outgoing->ev);
499 node_t *n = lookup_node(outgoing->name);
501 if(n && n->connection) {
502 logger(DEBUG_CONNECTIONS, LOG_INFO, "Already connected to %s", outgoing->name);
504 n->connection->outgoing = outgoing;
508 init_configuration(&outgoing->config_tree);
509 read_host_config(outgoing->config_tree, outgoing->name);
510 outgoing->cfg = lookup_config(outgoing->config_tree, "Address");
513 logger(DEBUG_ALWAYS, LOG_ERR, "No address specified for %s", outgoing->name);
517 do_outgoing_connection(outgoing);
521 accept a new tcp connect and create a
524 void handle_new_meta_connection(void *data, int flags) {
525 listen_socket_t *l = data;
529 socklen_t len = sizeof sa;
531 fd = accept(l->tcp.fd, &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 io_add(&c->io, handle_meta_io, c, c->socket, IO_READ);
560 c->allow_request = ID;
564 static void free_outgoing(outgoing_t *outgoing) {
565 timeout_del(&outgoing->ev);
568 freeaddrinfo(outgoing->ai);
570 if(outgoing->config_tree)
571 exit_configuration(&outgoing->config_tree);
574 free(outgoing->name);
579 void try_outgoing_connections(void) {
580 /* If there is no outgoing list yet, create one. Otherwise, mark all outgoings as deleted. */
583 outgoing_list = list_alloc((list_action_t)free_outgoing);
585 for list_each(outgoing_t, outgoing, outgoing_list)
586 outgoing->timeout = -1;
589 /* Make sure there is one outgoing_t in the list for each ConnectTo. */
591 for(config_t *cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
593 get_config_string(cfg, &name);
595 if(!check_id(name)) {
596 logger(DEBUG_ALWAYS, LOG_ERR,
597 "Invalid name for outgoing connection in %s line %d",
598 cfg->file, cfg->line);
605 for list_each(outgoing_t, outgoing, outgoing_list) {
606 if(!strcmp(outgoing->name, name)) {
608 outgoing->timeout = 0;
614 outgoing_t *outgoing = xmalloc_and_zero(sizeof *outgoing);
615 outgoing->name = name;
616 list_insert_tail(outgoing_list, outgoing);
617 setup_outgoing_connection(outgoing);
621 /* Terminate any connections whose outgoing_t is to be deleted. */
623 for list_each(connection_t, c, connection_list) {
624 if(c->outgoing && c->outgoing->timeout == -1) {
626 logger(DEBUG_CONNECTIONS, LOG_INFO, "No more outgoing connection to %s", c->name);
627 terminate_connection(c, c->status.active);
631 /* Delete outgoing_ts for which there is no ConnectTo. */
633 for list_each(outgoing_t, outgoing, outgoing_list)
634 if(outgoing->timeout == -1)
635 list_delete_node(outgoing_list, node);