www.tinc-vpn.org Git - tinc/blob - src/net_socket.c

   1 /*
   2     net_socket.c -- Handle various kinds of sockets.
   3     Copyright (C) 1998-2005 Ivo Timmermans,
   4                   2000-2009 Guus Sliepen <guus@tinc-vpn.org>
   5
   6     This program is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     This program is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with this program; if not, write to the Free Software
  18     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19
  20     $Id$
  21 */
  22
  23 #include "system.h"
  24
  25 #include "avl_tree.h"
  26 #include "conf.h"
  27 #include "connection.h"
  28 #include "event.h"
  29 #include "logger.h"
  30 #include "meta.h"
  31 #include "net.h"
  32 #include "netutl.h"
  33 #include "protocol.h"
  34 #include "utils.h"
  35 #include "xalloc.h"
  36
  37 #include <assert.h>
  38
  39 #ifdef WSAEINPROGRESS
  40 #define EINPROGRESS WSAEINPROGRESS
  41 #endif
  42
  43 /* Needed on Mac OS/X */
  44 #ifndef SOL_TCP
  45 #define SOL_TCP IPPROTO_TCP
  46 #endif
  47
  48 int addressfamily = AF_UNSPEC;
  49 int maxtimeout = 900;
  50 int seconds_till_retry = 5;
  51
  52 listen_socket_t listen_socket[MAXSOCKETS];
  53 int listen_sockets;
  54 list_t *outgoing_list = NULL;
  55
  56 /* Setup sockets */
  57
  58 static void configure_tcp(connection_t *c)
  59 {
  60         int option;
  61
  62 #ifdef O_NONBLOCK
  63         int flags = fcntl(c->socket, F_GETFL);
  64
  65         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
  66                 logger(LOG_ERR, _("fcntl for %s: %s"), c->hostname, strerror(errno));
  67         }
  68 #elif defined(WIN32)
  69         unsigned long arg = 1;
  70
  71         if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
  72                 logger(LOG_ERR, _("ioctlsocket for %s: WSA error %d"), c->hostname, WSAGetLastError());
  73         }
  74 #endif
  75
  76 #if defined(SOL_TCP) && defined(TCP_NODELAY)
  77         option = 1;
  78         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
  79 #endif
  80
  81 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
  82         option = IPTOS_LOWDELAY;
  83         setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof(option));
  84 #endif
  85 }
  86
  87 static bool bind_to_interface(int sd) { /* {{{ */
  88         char *iface;
  89
  90 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
  91         struct ifreq ifr;
  92         int status;
  93 #endif /* defined(SOL_SOCKET) && defined(SO_BINDTODEVICE) */
  94
  95         if(!get_config_string (lookup_config (config_tree, "BindToInterface"), &iface))
  96                 return true;
  97
  98 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
  99         memset(&ifr, 0, sizeof(ifr));
 100         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 101         ifr.ifr_ifrn.ifrn_name[IFNAMSIZ - 1] = 0;
 102
 103         status = setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr));
 104         if(status) {
 105                 logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 106                                 strerror(errno));
 107                 return false;
 108         }
 109 #else /* if !defined(SOL_SOCKET) || !defined(SO_BINDTODEVICE) */
 110         logger(LOG_WARNING, _("%s not supported on this platform"), "BindToInterface");
 111 #endif
 112
 113         return true;
 114 } /* }}} bool bind_to_interface */
 115
 116 static bool bind_to_address(connection_t *c) { /* {{{ */
 117         char *node;
 118         struct addrinfo *ai_list;
 119         struct addrinfo *ai_ptr;
 120         struct addrinfo ai_hints;
 121         int status;
 122
 123         assert(c != NULL);
 124         assert(c->socket >= 0);
 125
 126         node = NULL;
 127         if(!get_config_string(lookup_config(config_tree, "BindToAddress"),
 128                                 &node))
 129                 return true;
 130
 131         assert(node != NULL);
 132
 133         memset(&ai_hints, 0, sizeof(ai_hints));
 134         ai_hints.ai_family = c->address.sa.sa_family;
 135         /* We're called from `do_outgoing_connection' only. */
 136         ai_hints.ai_socktype = SOCK_STREAM;
 137         ai_hints.ai_protocol = IPPROTO_TCP;
 138
 139         ai_list = NULL;
 140
 141         status = getaddrinfo(node, /* service = */ NULL,
 142                         &ai_hints, &ai_list);
 143         if(status) {
 144                 free(node);
 145                 logger(LOG_WARNING, _("Error looking up %s port %s: %s"),
 146                                 node, _("any"), gai_strerror(status));
 147                 return false;
 148         }
 149         assert(ai_list != NULL);
 150
 151         status = -1;
 152         for(ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next) {
 153                 status = bind(c->socket,
 154                                 ai_list->ai_addr, ai_list->ai_addrlen);
 155                 if(!status)
 156                         break;
 157         }
 158
 159
 160         if(status) {
 161                 logger(LOG_ERR, _("Can't bind to %s/tcp: %s"), node,
 162                                 strerror(errno));
 163         } else ifdebug(CONNECTIONS) {
 164                 logger(LOG_DEBUG, "Successfully bound outgoing "
 165                                 "TCP socket to %s", node);
 166         }
 167
 168         free(node);
 169         freeaddrinfo(ai_list);
 170
 171         return status ? false : true;
 172 } /* }}} bool bind_to_address */
 173
 174 int setup_listen_socket(const sockaddr_t *sa)
 175 {
 176         int nfd;
 177         char *addrstr;
 178         int option;
 179         char *iface;
 180
 181         cp();
 182
 183         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 184
 185         if(nfd < 0) {
 186                 ifdebug(STATUS) logger(LOG_ERR, _("Creating metasocket failed: %s"), strerror(errno));
 187                 return -1;
 188         }
 189
 190         /* Optimize TCP settings */
 191
 192         option = 1;
 193         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
 194
 195 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 196         if(sa->sa.sa_family == AF_INET6)
 197                 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
 198 #endif
 199
 200         if(get_config_string
 201            (lookup_config(config_tree, "BindToInterface"), &iface)) {
 202 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 203                 struct ifreq ifr;
 204
 205                 memset(&ifr, 0, sizeof(ifr));
 206                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 207
 208                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 209                         closesocket(nfd);
 210                         logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 211                                    strerror(errno));
 212                         return -1;
 213                 }
 214 #else
 215                 logger(LOG_WARNING, _("%s not supported on this platform"), "BindToInterface");
 216 #endif
 217         }
 218
 219         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 220                 closesocket(nfd);
 221                 addrstr = sockaddr2hostname(sa);
 222                 logger(LOG_ERR, _("Can't bind to %s/tcp: %s"), addrstr,
 223                            strerror(errno));
 224                 free(addrstr);
 225                 return -1;
 226         }
 227
 228         if(listen(nfd, 3)) {
 229                 closesocket(nfd);
 230                 logger(LOG_ERR, _("System call `%s' failed: %s"), "listen",
 231                            strerror(errno));
 232                 return -1;
 233         }
 234
 235         return nfd;
 236 }
 237
 238 int setup_vpn_in_socket(const sockaddr_t *sa)
 239 {
 240         int nfd;
 241         char *addrstr;
 242         int option;
 243
 244         cp();
 245
 246         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 247
 248         if(nfd < 0) {
 249                 logger(LOG_ERR, _("Creating UDP socket failed: %s"), strerror(errno));
 250                 return -1;
 251         }
 252
 253 #ifdef O_NONBLOCK
 254         {
 255                 int flags = fcntl(nfd, F_GETFL);
 256
 257                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 258                         closesocket(nfd);
 259                         logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
 260                                    strerror(errno));
 261                         return -1;
 262                 }
 263         }
 264 #elif defined(WIN32)
 265         {
 266                 unsigned long arg = 1;
 267                 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 268                         closesocket(nfd);
 269                         logger(LOG_ERR, _("Call to `%s' failed: WSA error %d"), "ioctlsocket",
 270                                 WSAGetLastError());
 271                         return -1;
 272                 }
 273         }
 274 #endif
 275
 276         option = 1;
 277         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
 278
 279 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 280         if(sa->sa.sa_family == AF_INET6)
 281                 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
 282 #endif
 283
 284 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 285         if(myself->options & OPTION_PMTU_DISCOVERY) {
 286                 option = IP_PMTUDISC_DO;
 287                 setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, &option, sizeof(option));
 288         }
 289 #endif
 290
 291 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 292         if(myself->options & OPTION_PMTU_DISCOVERY) {
 293                 option = IPV6_PMTUDISC_DO;
 294                 setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, &option, sizeof(option));
 295         }
 296 #endif
 297
 298         if (!bind_to_interface(nfd)) {
 299                 closesocket(nfd);
 300                 return -1;
 301         }
 302
 303         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 304                 closesocket(nfd);
 305                 addrstr = sockaddr2hostname(sa);
 306                 logger(LOG_ERR, _("Can't bind to %s/udp: %s"), addrstr,
 307                            strerror(errno));
 308                 free(addrstr);
 309                 return -1;
 310         }
 311
 312         return nfd;
 313 } /* int setup_vpn_in_socket */
 314
 315 void retry_outgoing(outgoing_t *outgoing)
 316 {
 317         event_t *event;
 318
 319         cp();
 320
 321         outgoing->timeout += 5;
 322
 323         if(outgoing->timeout > maxtimeout)
 324                 outgoing->timeout = maxtimeout;
 325
 326         event = new_event();
 327         event->handler = (event_handler_t) setup_outgoing_connection;
 328         event->time = now + outgoing->timeout;
 329         event->data = outgoing;
 330         event_add(event);
 331
 332         ifdebug(CONNECTIONS) logger(LOG_NOTICE,
 333                            _("Trying to re-establish outgoing connection in %d seconds"),
 334                            outgoing->timeout);
 335 }
 336
 337 void finish_connecting(connection_t *c)
 338 {
 339         cp();
 340
 341         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Connected to %s (%s)"), c->name, c->hostname);
 342
 343         configure_tcp(c);
 344
 345         c->last_ping_time = now;
 346
 347         send_id(c);
 348 }
 349
 350 void do_outgoing_connection(connection_t *c)
 351 {
 352         char *address, *port;
 353         int result;
 354
 355         cp();
 356
 357 begin:
 358         if(!c->outgoing->ai) {
 359                 if(!c->outgoing->cfg) {
 360                         ifdebug(CONNECTIONS) logger(LOG_ERR, _("Could not set up a meta connection to %s"),
 361                                            c->name);
 362                         c->status.remove = true;
 363                         retry_outgoing(c->outgoing);
 364                         return;
 365                 }
 366
 367                 get_config_string(c->outgoing->cfg, &address);
 368
 369                 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
 370                         asprintf(&port, "655");
 371
 372                 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 373                 free(address);
 374                 free(port);
 375
 376                 c->outgoing->aip = c->outgoing->ai;
 377                 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
 378         }
 379
 380         if(!c->outgoing->aip) {
 381                 if(c->outgoing->ai)
 382                         freeaddrinfo(c->outgoing->ai);
 383                 c->outgoing->ai = NULL;
 384                 goto begin;
 385         }
 386
 387         memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
 388         c->outgoing->aip = c->outgoing->aip->ai_next;
 389
 390         if(c->hostname)
 391                 free(c->hostname);
 392
 393         c->hostname = sockaddr2hostname(&c->address);
 394
 395         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Trying to connect to %s (%s)"), c->name,
 396                            c->hostname);
 397
 398         c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 399
 400         if(c->socket == -1) {
 401                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("Creating socket for %s failed: %s"), c->hostname,
 402                                    strerror(errno));
 403
 404                 goto begin;
 405         }
 406
 407 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 408         int option = 1;
 409         if(c->address.sa.sa_family == AF_INET6)
 410                 setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
 411 #endif
 412
 413         bind_to_interface(c->socket);
 414         bind_to_address(c);
 415
 416         /* Optimize TCP settings */
 417
 418         configure_tcp(c);
 419
 420         /* Connect */
 421
 422         result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 423
 424         if(result == -1) {
 425                 if(errno == EINPROGRESS
 426 #if defined(WIN32) && !defined(O_NONBLOCK)
 427                    || WSAGetLastError() == WSAEWOULDBLOCK
 428 #endif
 429                 ) {
 430                         c->status.connecting = true;
 431                         return;
 432                 }
 433
 434                 closesocket(c->socket);
 435
 436                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("%s: %s"), c->hostname, strerror(errno));
 437
 438                 goto begin;
 439         }
 440
 441         finish_connecting(c);
 442
 443         return;
 444 }
 445
 446 void setup_outgoing_connection(outgoing_t *outgoing)
 447 {
 448         connection_t *c;
 449         node_t *n;
 450
 451         cp();
 452
 453         n = lookup_node(outgoing->name);
 454
 455         if(n)
 456                 if(n->connection) {
 457                         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Already connected to %s"), outgoing->name);
 458
 459                         n->connection->outgoing = outgoing;
 460                         return;
 461                 }
 462
 463         c = new_connection();
 464         c->name = xstrdup(outgoing->name);
 465         c->outcipher = myself->connection->outcipher;
 466         c->outdigest = myself->connection->outdigest;
 467         c->outmaclength = myself->connection->outmaclength;
 468         c->outcompression = myself->connection->outcompression;
 469
 470         init_configuration(&c->config_tree);
 471         read_connection_config(c);
 472
 473         outgoing->cfg = lookup_config(c->config_tree, "Address");
 474
 475         if(!outgoing->cfg) {
 476                 logger(LOG_ERR, _("No address specified for %s"), c->name);
 477                 free_connection(c);
 478                 return;
 479         }
 480
 481         c->outgoing = outgoing;
 482         c->last_ping_time = now;
 483
 484         connection_add(c);
 485
 486         do_outgoing_connection(c);
 487 }
 488
 489 /*
 490   accept a new tcp connect and create a
 491   new connection
 492 */
 493 bool handle_new_meta_connection(int sock)
 494 {
 495         connection_t *c;
 496         sockaddr_t sa;
 497         int fd;
 498         socklen_t len = sizeof(sa);
 499
 500         cp();
 501
 502         fd = accept(sock, &sa.sa, &len);
 503
 504         if(fd < 0) {
 505                 logger(LOG_ERR, _("Accepting a new connection failed: %s"),
 506                            strerror(errno));
 507                 return false;
 508         }
 509
 510         sockaddrunmap(&sa);
 511
 512         c = new_connection();
 513         c->name = xstrdup("<unknown>");
 514         c->outcipher = myself->connection->outcipher;
 515         c->outdigest = myself->connection->outdigest;
 516         c->outmaclength = myself->connection->outmaclength;
 517         c->outcompression = myself->connection->outcompression;
 518
 519         c->address = sa;
 520         c->hostname = sockaddr2hostname(&sa);
 521         c->socket = fd;
 522         c->last_ping_time = now;
 523
 524         ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection from %s"), c->hostname);
 525
 526         configure_tcp(c);
 527
 528         connection_add(c);
 529
 530         c->allow_request = ID;
 531         send_id(c);
 532
 533         return true;
 534 }
 535
 536 void free_outgoing(outgoing_t *outgoing) {
 537         if(outgoing->ai)
 538                 freeaddrinfo(outgoing->ai);
 539
 540         if(outgoing->name)
 541                 free(outgoing->name);
 542
 543         free(outgoing);
 544 }
 545
 546 void try_outgoing_connections(void)
 547 {
 548         static config_t *cfg = NULL;
 549         char *name;
 550         outgoing_t *outgoing;
 551         connection_t *c;
 552         avl_node_t *node;
 553
 554         cp();
 555
 556         if(outgoing_list) {
 557                 for(node = connection_tree->head; node; node = node->next) {
 558                         c = node->data;
 559                         c->outgoing = NULL;
 560                 }
 561
 562                 list_delete_list(outgoing_list);
 563         }
 564
 565         outgoing_list = list_alloc((list_action_t)free_outgoing);
 566
 567         for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 568                 get_config_string(cfg, &name);
 569
 570                 if(!check_id(name)) {
 571                         logger(LOG_ERR,
 572                                    _("Invalid name for outgoing connection in %s line %d"),
 573                                    cfg->file, cfg->line);
 574                         free(name);
 575                         continue;
 576                 }
 577
 578                 outgoing = xmalloc_and_zero(sizeof(*outgoing));
 579                 outgoing->name = name;
 580                 list_insert_tail(outgoing_list, outgoing);
 581                 setup_outgoing_connection(outgoing);
 582         }
 583 }