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