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     $Id$
  22 */
  23
  24 #include "system.h"
  25
  26 #include "avl_tree.h"
  27 #include "conf.h"
  28 #include "connection.h"
  29 #include "event.h"
  30 #include "logger.h"
  31 #include "meta.h"
  32 #include "net.h"
  33 #include "netutl.h"
  34 #include "protocol.h"
  35 #include "utils.h"
  36 #include "xalloc.h"
  37
  38 #include <assert.h>
  39
  40 #ifdef WSAEINPROGRESS
  41 #define EINPROGRESS WSAEINPROGRESS
  42 #endif
  43
  44 /* Needed on Mac OS/X */
  45 #ifndef SOL_TCP
  46 #define SOL_TCP IPPROTO_TCP
  47 #endif
  48
  49 int addressfamily = AF_UNSPEC;
  50 int maxtimeout = 900;
  51 int seconds_till_retry = 5;
  52
  53 listen_socket_t listen_socket[MAXSOCKETS];
  54 int listen_sockets;
  55 list_t *outgoing_list = NULL;
  56
  57 /* Setup sockets */
  58
  59 static void configure_tcp(connection_t *c)
  60 {
  61         int option;
  62
  63 #ifdef O_NONBLOCK
  64         int flags = fcntl(c->socket, F_GETFL);
  65
  66         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
  67                 logger(LOG_ERR, _("fcntl for %s: %s"), c->hostname, strerror(errno));
  68         }
  69 #elif defined(WIN32)
  70         unsigned long arg = 1;
  71
  72         if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
  73                 logger(LOG_ERR, _("ioctlsocket for %s: WSA error %d"), c->hostname, WSAGetLastError());
  74         }
  75 #endif
  76
  77 #if defined(SOL_TCP) && defined(TCP_NODELAY)
  78         option = 1;
  79         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
  80 #endif
  81
  82 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
  83         option = IPTOS_LOWDELAY;
  84         setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof(option));
  85 #endif
  86 }
  87
  88 static bool bind_to_interface(int sd) { /* {{{ */
  89         char *iface;
  90
  91 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
  92         struct ifreq ifr;
  93         int status;
  94 #endif /* defined(SOL_SOCKET) && defined(SO_BINDTODEVICE) */
  95
  96         if(!get_config_string (lookup_config (config_tree, "BindToInterface"), &iface))
  97                 return true;
  98
  99 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 100         memset(&ifr, 0, sizeof(ifr));
 101         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 102         ifr.ifr_ifrn.ifrn_name[IFNAMSIZ - 1] = 0;
 103
 104         status = setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr));
 105         if(status) {
 106                 logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 107                                 strerror(errno));
 108                 return false;
 109         }
 110 #else /* if !defined(SOL_SOCKET) || !defined(SO_BINDTODEVICE) */
 111         logger(LOG_WARNING, _("%s not supported on this platform"), "BindToInterface");
 112 #endif
 113
 114         return true;
 115 } /* }}} bool bind_to_interface */
 116
 117 static bool bind_to_address(connection_t *c) { /* {{{ */
 118         char *node;
 119         struct addrinfo *ai_list;
 120         struct addrinfo *ai_ptr;
 121         struct addrinfo ai_hints;
 122         int status;
 123
 124         assert(c != NULL);
 125         assert(c->socket >= 0);
 126
 127         node = NULL;
 128         if(!get_config_string(lookup_config(config_tree, "BindToAddress"),
 129                                 &node))
 130                 return true;
 131
 132         assert(node != NULL);
 133
 134         memset(&ai_hints, 0, sizeof(ai_hints));
 135         ai_hints.ai_family = c->address.sa.sa_family;
 136         /* We're called from `do_outgoing_connection' only. */
 137         ai_hints.ai_socktype = SOCK_STREAM;
 138         ai_hints.ai_protocol = IPPROTO_TCP;
 139
 140         ai_list = NULL;
 141
 142         status = getaddrinfo(node, /* service = */ NULL,
 143                         &ai_hints, &ai_list);
 144         if(status) {
 145                 free(node);
 146                 logger(LOG_WARNING, _("Error looking up %s port %s: %s"),
 147                                 node, _("any"), gai_strerror(status));
 148                 return false;
 149         }
 150         assert(ai_list != NULL);
 151
 152         status = -1;
 153         for(ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next) {
 154                 status = bind(c->socket,
 155                                 ai_list->ai_addr, ai_list->ai_addrlen);
 156                 if(!status)
 157                         break;
 158         }
 159
 160
 161         if(status) {
 162                 logger(LOG_ERR, _("Can't bind to %s/tcp: %s"), node,
 163                                 strerror(errno));
 164         } else ifdebug(CONNECTIONS) {
 165                 logger(LOG_DEBUG, "Successfully bound outgoing "
 166                                 "TCP socket to %s", node);
 167         }
 168
 169         free(node);
 170         freeaddrinfo(ai_list);
 171
 172         return status ? false : true;
 173 } /* }}} bool bind_to_address */
 174
 175 int setup_listen_socket(const sockaddr_t *sa)
 176 {
 177         int nfd;
 178         char *addrstr;
 179         int option;
 180         char *iface;
 181
 182         cp();
 183
 184         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 185
 186         if(nfd < 0) {
 187                 ifdebug(STATUS) logger(LOG_ERR, _("Creating metasocket failed: %s"), strerror(errno));
 188                 return -1;
 189         }
 190
 191         /* Optimize TCP settings */
 192
 193         option = 1;
 194         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
 195
 196 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 197         if(sa->sa.sa_family == AF_INET6)
 198                 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
 199 #endif
 200
 201         if(get_config_string
 202            (lookup_config(config_tree, "BindToInterface"), &iface)) {
 203 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 204                 struct ifreq ifr;
 205
 206                 memset(&ifr, 0, sizeof(ifr));
 207                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 208
 209                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 210                         closesocket(nfd);
 211                         logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 212                                    strerror(errno));
 213                         return -1;
 214                 }
 215 #else
 216                 logger(LOG_WARNING, _("%s not supported on this platform"), "BindToInterface");
 217 #endif
 218         }
 219
 220         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 221                 closesocket(nfd);
 222                 addrstr = sockaddr2hostname(sa);
 223                 logger(LOG_ERR, _("Can't bind to %s/tcp: %s"), addrstr,
 224                            strerror(errno));
 225                 free(addrstr);
 226                 return -1;
 227         }
 228
 229         if(listen(nfd, 3)) {
 230                 closesocket(nfd);
 231                 logger(LOG_ERR, _("System call `%s' failed: %s"), "listen",
 232                            strerror(errno));
 233                 return -1;
 234         }
 235
 236         return nfd;
 237 }
 238
 239 int setup_vpn_in_socket(const sockaddr_t *sa)
 240 {
 241         int nfd;
 242         char *addrstr;
 243         int option;
 244
 245         cp();
 246
 247         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 248
 249         if(nfd < 0) {
 250                 logger(LOG_ERR, _("Creating UDP socket failed: %s"), strerror(errno));
 251                 return -1;
 252         }
 253
 254 #ifdef O_NONBLOCK
 255         {
 256                 int flags = fcntl(nfd, F_GETFL);
 257
 258                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 259                         closesocket(nfd);
 260                         logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
 261                                    strerror(errno));
 262                         return -1;
 263                 }
 264         }
 265 #elif defined(WIN32)
 266         {
 267                 unsigned long arg = 1;
 268                 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 269                         closesocket(nfd);
 270                         logger(LOG_ERR, _("Call to `%s' failed: WSA error %d"), "ioctlsocket",
 271                                 WSAGetLastError());
 272                         return -1;
 273                 }
 274         }
 275 #endif
 276
 277         option = 1;
 278         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
 279
 280 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 281         if(sa->sa.sa_family == AF_INET6)
 282                 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
 283 #endif
 284
 285 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 286         if(myself->options & OPTION_PMTU_DISCOVERY) {
 287                 option = IP_PMTUDISC_DO;
 288                 setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, &option, sizeof(option));
 289         }
 290 #endif
 291
 292 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 293         if(myself->options & OPTION_PMTU_DISCOVERY) {
 294                 option = IPV6_PMTUDISC_DO;
 295                 setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, &option, sizeof(option));
 296         }
 297 #endif
 298
 299         if (!bind_to_interface(nfd)) {
 300                 closesocket(nfd);
 301                 return -1;
 302         }
 303
 304         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 305                 closesocket(nfd);
 306                 addrstr = sockaddr2hostname(sa);
 307                 logger(LOG_ERR, _("Can't bind to %s/udp: %s"), addrstr,
 308                            strerror(errno));
 309                 free(addrstr);
 310                 return -1;
 311         }
 312
 313         return nfd;
 314 } /* int setup_vpn_in_socket */
 315
 316 void retry_outgoing(outgoing_t *outgoing)
 317 {
 318         event_t *event;
 319
 320         cp();
 321
 322         outgoing->timeout += 5;
 323
 324         if(outgoing->timeout > maxtimeout)
 325                 outgoing->timeout = maxtimeout;
 326
 327         event = new_event();
 328         event->handler = (event_handler_t) setup_outgoing_connection;
 329         event->time = now + outgoing->timeout;
 330         event->data = outgoing;
 331         event_add(event);
 332
 333         ifdebug(CONNECTIONS) logger(LOG_NOTICE,
 334                            _("Trying to re-establish outgoing connection in %d seconds"),
 335                            outgoing->timeout);
 336 }
 337
 338 void finish_connecting(connection_t *c)
 339 {
 340         cp();
 341
 342         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Connected to %s (%s)"), c->name, c->hostname);
 343
 344         configure_tcp(c);
 345
 346         c->last_ping_time = now;
 347
 348         send_id(c);
 349 }
 350
 351 void do_outgoing_connection(connection_t *c)
 352 {
 353         char *address, *port;
 354         int result;
 355
 356         cp();
 357
 358 begin:
 359         if(!c->outgoing->ai) {
 360                 if(!c->outgoing->cfg) {
 361                         ifdebug(CONNECTIONS) logger(LOG_ERR, _("Could not set up a meta connection to %s"),
 362                                            c->name);
 363                         c->status.remove = true;
 364                         retry_outgoing(c->outgoing);
 365                         return;
 366                 }
 367
 368                 get_config_string(c->outgoing->cfg, &address);
 369
 370                 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
 371                         xasprintf(&port, "655");
 372
 373                 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 374                 free(address);
 375                 free(port);
 376
 377                 c->outgoing->aip = c->outgoing->ai;
 378                 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
 379         }
 380
 381         if(!c->outgoing->aip) {
 382                 if(c->outgoing->ai)
 383                         freeaddrinfo(c->outgoing->ai);
 384                 c->outgoing->ai = NULL;
 385                 goto begin;
 386         }
 387
 388         memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
 389         c->outgoing->aip = c->outgoing->aip->ai_next;
 390
 391         if(c->hostname)
 392                 free(c->hostname);
 393
 394         c->hostname = sockaddr2hostname(&c->address);
 395
 396         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Trying to connect to %s (%s)"), c->name,
 397                            c->hostname);
 398
 399         c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 400
 401         if(c->socket == -1) {
 402                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("Creating socket for %s failed: %s"), c->hostname,
 403                                    strerror(errno));
 404
 405                 goto begin;
 406         }
 407
 408 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 409         int option = 1;
 410         if(c->address.sa.sa_family == AF_INET6)
 411                 setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
 412 #endif
 413
 414         bind_to_interface(c->socket);
 415         bind_to_address(c);
 416
 417         /* Optimize TCP settings */
 418
 419         configure_tcp(c);
 420
 421         /* Connect */
 422
 423         result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 424
 425         if(result == -1) {
 426                 if(errno == EINPROGRESS
 427 #if defined(WIN32) && !defined(O_NONBLOCK)
 428                    || WSAGetLastError() == WSAEWOULDBLOCK
 429 #endif
 430                 ) {
 431                         c->status.connecting = true;
 432                         return;
 433                 }
 434
 435                 closesocket(c->socket);
 436
 437                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("%s: %s"), c->hostname, strerror(errno));
 438
 439                 goto begin;
 440         }
 441
 442         finish_connecting(c);
 443
 444         return;
 445 }
 446
 447 void setup_outgoing_connection(outgoing_t *outgoing)
 448 {
 449         connection_t *c;
 450         node_t *n;
 451
 452         cp();
 453
 454         n = lookup_node(outgoing->name);
 455
 456         if(n)
 457                 if(n->connection) {
 458                         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Already connected to %s"), outgoing->name);
 459
 460                         n->connection->outgoing = outgoing;
 461                         return;
 462                 }
 463
 464         c = new_connection();
 465         c->name = xstrdup(outgoing->name);
 466         c->outcipher = myself->connection->outcipher;
 467         c->outdigest = myself->connection->outdigest;
 468         c->outmaclength = myself->connection->outmaclength;
 469         c->outcompression = myself->connection->outcompression;
 470
 471         init_configuration(&c->config_tree);
 472         read_connection_config(c);
 473
 474         outgoing->cfg = lookup_config(c->config_tree, "Address");
 475
 476         if(!outgoing->cfg) {
 477                 logger(LOG_ERR, _("No address specified for %s"), c->name);
 478                 free_connection(c);
 479                 return;
 480         }
 481
 482         c->outgoing = outgoing;
 483         c->last_ping_time = now;
 484
 485         connection_add(c);
 486
 487         do_outgoing_connection(c);
 488 }
 489
 490 /*
 491   accept a new tcp connect and create a
 492   new connection
 493 */
 494 bool handle_new_meta_connection(int sock)
 495 {
 496         connection_t *c;
 497         sockaddr_t sa;
 498         int fd;
 499         socklen_t len = sizeof(sa);
 500
 501         cp();
 502
 503         fd = accept(sock, &sa.sa, &len);
 504
 505         if(fd < 0) {
 506                 logger(LOG_ERR, _("Accepting a new connection failed: %s"),
 507                            strerror(errno));
 508                 return false;
 509         }
 510
 511         sockaddrunmap(&sa);
 512
 513         c = new_connection();
 514         c->name = xstrdup("<unknown>");
 515         c->outcipher = myself->connection->outcipher;
 516         c->outdigest = myself->connection->outdigest;
 517         c->outmaclength = myself->connection->outmaclength;
 518         c->outcompression = myself->connection->outcompression;
 519
 520         c->address = sa;
 521         c->hostname = sockaddr2hostname(&sa);
 522         c->socket = fd;
 523         c->last_ping_time = now;
 524
 525         ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection from %s"), c->hostname);
 526
 527         configure_tcp(c);
 528
 529         connection_add(c);
 530
 531         c->allow_request = ID;
 532         send_id(c);
 533
 534         return true;
 535 }
 536
 537 void free_outgoing(outgoing_t *outgoing) {
 538         if(outgoing->ai)
 539                 freeaddrinfo(outgoing->ai);
 540
 541         if(outgoing->name)
 542                 free(outgoing->name);
 543
 544         free(outgoing);
 545 }
 546
 547 void try_outgoing_connections(void)
 548 {
 549         static config_t *cfg = NULL;
 550         char *name;
 551         outgoing_t *outgoing;
 552         connection_t *c;
 553         avl_node_t *node;
 554
 555         cp();
 556
 557         if(outgoing_list) {
 558                 for(node = connection_tree->head; node; node = node->next) {
 559                         c = node->data;
 560                         c->outgoing = NULL;
 561                 }
 562
 563                 list_delete_list(outgoing_list);
 564         }
 565
 566         outgoing_list = list_alloc((list_action_t)free_outgoing);
 567
 568         for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 569                 get_config_string(cfg, &name);
 570
 571                 if(!check_id(name)) {
 572                         logger(LOG_ERR,
 573                                    _("Invalid name for outgoing connection in %s line %d"),
 574                                    cfg->file, cfg->line);
 575                         free(name);
 576                         continue;
 577                 }
 578
 579                 outgoing = xmalloc_and_zero(sizeof(*outgoing));
 580                 outgoing->name = name;
 581                 list_insert_tail(outgoing_list, outgoing);
 582                 setup_outgoing_connection(outgoing);
 583         }
 584 }