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 "splay_tree.h"
  26 #include "conf.h"
  27 #include "connection.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         int option;
  59
  60 #ifdef O_NONBLOCK
  61         int flags = fcntl(c->socket, F_GETFL);
  62
  63         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
  64                 logger(LOG_ERR, _("fcntl for %s: %s"), c->hostname, strerror(errno));
  65         }
  66 #elif defined(WIN32)
  67         unsigned long arg = 1;
  68
  69         if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
  70                 logger(LOG_ERR, _("ioctlsocket for %s: WSA error %d"), c->hostname, WSAGetLastError());
  71         }
  72 #endif
  73
  74 #if defined(SOL_TCP) && defined(TCP_NODELAY)
  75         option = 1;
  76         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, &option, sizeof option);
  77 #endif
  78
  79 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
  80         option = IPTOS_LOWDELAY;
  81         setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof option);
  82 #endif
  83 }
  84
  85 static bool bind_to_interface(int sd) { /* {{{ */
  86         char *iface;
  87
  88 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
  89         struct ifreq ifr;
  90         int status;
  91 #endif /* defined(SOL_SOCKET) && defined(SO_BINDTODEVICE) */
  92
  93         if(!get_config_string (lookup_config (config_tree, "BindToInterface"), &iface))
  94                 return true;
  95
  96 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
  97         memset(&ifr, 0, sizeof(ifr));
  98         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
  99         ifr.ifr_ifrn.ifrn_name[IFNAMSIZ - 1] = 0;
 100
 101         status = setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr));
 102         if(status) {
 103                 logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 104                                 strerror(errno));
 105                 return false;
 106         }
 107 #else /* if !defined(SOL_SOCKET) || !defined(SO_BINDTODEVICE) */
 108         logger(LOG_WARNING, _("%s not supported on this platform"), "BindToInterface");
 109 #endif
 110
 111         return true;
 112 } /* }}} bool bind_to_interface */
 113
 114 static bool bind_to_address(connection_t *c) { /* {{{ */
 115         char *node;
 116         struct addrinfo *ai_list;
 117         struct addrinfo *ai_ptr;
 118         struct addrinfo ai_hints;
 119         int status;
 120
 121         assert(c != NULL);
 122         assert(c->socket >= 0);
 123
 124         node = NULL;
 125         if(!get_config_string(lookup_config(config_tree, "BindToAddress"),
 126                                 &node))
 127                 return true;
 128
 129         assert(node != NULL);
 130
 131         memset(&ai_hints, 0, sizeof(ai_hints));
 132         ai_hints.ai_family = c->address.sa.sa_family;
 133         /* We're called from `do_outgoing_connection' only. */
 134         ai_hints.ai_socktype = SOCK_STREAM;
 135         ai_hints.ai_protocol = IPPROTO_TCP;
 136
 137         ai_list = NULL;
 138
 139         status = getaddrinfo(node, /* service = */ NULL,
 140                         &ai_hints, &ai_list);
 141         if(status) {
 142                 free(node);
 143                 logger(LOG_WARNING, _("Error looking up %s port %s: %s"),
 144                                 node, _("any"), gai_strerror(status));
 145                 return false;
 146         }
 147         assert(ai_list != NULL);
 148
 149         status = -1;
 150         for(ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next) {
 151                 status = bind(c->socket,
 152                                 ai_list->ai_addr, ai_list->ai_addrlen);
 153                 if(!status)
 154                         break;
 155         }
 156
 157
 158         if(status) {
 159                 logger(LOG_ERR, _("Can't bind to %s/tcp: %s"), node,
 160                                 strerror(errno));
 161         } else ifdebug(CONNECTIONS) {
 162                 logger(LOG_DEBUG, "Successfully bound outgoing "
 163                                 "TCP socket to %s", node);
 164         }
 165
 166         free(node);
 167         freeaddrinfo(ai_list);
 168
 169         return status ? false : true;
 170 } /* }}} bool bind_to_address */
 171
 172 int setup_listen_socket(const sockaddr_t *sa)
 173 {
 174         int nfd;
 175         char *addrstr;
 176         int option;
 177         char *iface;
 178
 179         cp();
 180
 181         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 182
 183         if(nfd < 0) {
 184                 ifdebug(STATUS) logger(LOG_ERR, _("Creating metasocket failed: %s"), strerror(errno));
 185                 return -1;
 186         }
 187
 188         /* Optimize TCP settings */
 189
 190         option = 1;
 191         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof option);
 192
 193 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 194         if(sa->sa.sa_family == AF_INET6)
 195                 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
 196 #endif
 197
 198         if(get_config_string
 199            (lookup_config(config_tree, "BindToInterface"), &iface)) {
 200 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 201                 struct ifreq ifr;
 202
 203                 memset(&ifr, 0, sizeof ifr);
 204                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 205
 206                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof ifr)) {
 207                         closesocket(nfd);
 208                         logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 209                                    strerror(errno));
 210                         return -1;
 211                 }
 212 #else
 213                 logger(LOG_WARNING, _("%s not supported on this platform"), "BindToInterface");
 214 #endif
 215         }
 216
 217         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 218                 closesocket(nfd);
 219                 addrstr = sockaddr2hostname(sa);
 220                 logger(LOG_ERR, _("Can't bind to %s/tcp: %s"), addrstr,
 221                            strerror(errno));
 222                 free(addrstr);
 223                 return -1;
 224         }
 225
 226         if(listen(nfd, 3)) {
 227                 closesocket(nfd);
 228                 logger(LOG_ERR, _("System call `%s' failed: %s"), "listen",
 229                            strerror(errno));
 230                 return -1;
 231         }
 232
 233         return nfd;
 234 }
 235
 236 int setup_vpn_in_socket(const sockaddr_t *sa) {
 237         int nfd;
 238         char *addrstr;
 239         int option;
 240
 241         cp();
 242
 243         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 244
 245         if(nfd < 0) {
 246                 logger(LOG_ERR, _("Creating UDP socket failed: %s"), strerror(errno));
 247                 return -1;
 248         }
 249
 250 #ifdef O_NONBLOCK
 251         {
 252                 int flags = fcntl(nfd, F_GETFL);
 253
 254                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 255                         closesocket(nfd);
 256                         logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
 257                                    strerror(errno));
 258                         return -1;
 259                 }
 260         }
 261 #elif defined(WIN32)
 262         {
 263                 unsigned long arg = 1;
 264                 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 265                         closesocket(nfd);
 266                         logger(LOG_ERR, _("Call to `%s' failed: WSA error %d"), "ioctlsocket",
 267                                 WSAGetLastError());
 268                         return -1;
 269                 }
 270         }
 271 #endif
 272
 273         option = 1;
 274         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof option);
 275
 276 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 277         if(sa->sa.sa_family == AF_INET6)
 278                 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
 279 #endif
 280
 281 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 282         if(myself->options & OPTION_PMTU_DISCOVERY) {
 283                 option = IP_PMTUDISC_DO;
 284                 setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, &option, sizeof(option));
 285         }
 286 #endif
 287
 288 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 289         if(myself->options & OPTION_PMTU_DISCOVERY) {
 290                 option = IPV6_PMTUDISC_DO;
 291                 setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, &option, sizeof(option));
 292         }
 293 #endif
 294
 295         if (!bind_to_interface(nfd)) {
 296                 closesocket(nfd);
 297                 return -1;
 298         }
 299
 300         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 301                 closesocket(nfd);
 302                 addrstr = sockaddr2hostname(sa);
 303                 logger(LOG_ERR, _("Can't bind to %s/udp: %s"), addrstr,
 304                            strerror(errno));
 305                 free(addrstr);
 306                 return -1;
 307         }
 308
 309         return nfd;
 310 } /* int setup_vpn_in_socket */
 311
 312 static void retry_outgoing_handler(int fd, short events, void *data) {
 313         setup_outgoing_connection(data);
 314 }
 315
 316 void retry_outgoing(outgoing_t *outgoing) {
 317         cp();
 318
 319         outgoing->timeout += 5;
 320
 321         if(outgoing->timeout > maxtimeout)
 322                 outgoing->timeout = maxtimeout;
 323
 324         timeout_set(&outgoing->ev, retry_outgoing_handler, outgoing);
 325         event_add(&outgoing->ev, &(struct timeval){outgoing->timeout, 0});
 326
 327         ifdebug(CONNECTIONS) logger(LOG_NOTICE,
 328                            _("Trying to re-establish outgoing connection in %d seconds"),
 329                            outgoing->timeout);
 330 }
 331
 332 void finish_connecting(connection_t *c) {
 333         cp();
 334
 335         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Connected to %s (%s)"), c->name, c->hostname);
 336
 337         configure_tcp(c);
 338
 339         c->last_ping_time = time(NULL);
 340         c->status.connecting = false;
 341
 342         send_id(c);
 343 }
 344
 345 void do_outgoing_connection(connection_t *c) {
 346         char *address, *port;
 347         int result;
 348
 349         cp();
 350
 351 begin:
 352         if(!c->outgoing->ai) {
 353                 if(!c->outgoing->cfg) {
 354                         ifdebug(CONNECTIONS) logger(LOG_ERR, _("Could not set up a meta connection to %s"),
 355                                            c->name);
 356                         retry_outgoing(c->outgoing);
 357                         c->outgoing = NULL;
 358                         connection_del(c);
 359                         return;
 360                 }
 361
 362                 get_config_string(c->outgoing->cfg, &address);
 363
 364                 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
 365                         asprintf(&port, "655");
 366
 367                 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 368                 free(address);
 369                 free(port);
 370
 371                 c->outgoing->aip = c->outgoing->ai;
 372                 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
 373         }
 374
 375         if(!c->outgoing->aip) {
 376                 if(c->outgoing->ai)
 377                         freeaddrinfo(c->outgoing->ai);
 378                 c->outgoing->ai = NULL;
 379                 goto begin;
 380         }
 381
 382         memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
 383         c->outgoing->aip = c->outgoing->aip->ai_next;
 384
 385         if(c->hostname)
 386                 free(c->hostname);
 387
 388         c->hostname = sockaddr2hostname(&c->address);
 389
 390         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Trying to connect to %s (%s)"), c->name,
 391                            c->hostname);
 392
 393         c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 394
 395         if(c->socket == -1) {
 396                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("Creating socket for %s failed: %s"), c->hostname,
 397                                    strerror(errno));
 398
 399                 goto begin;
 400         }
 401
 402 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 403         int option = 1;
 404         if(c->address.sa.sa_family == AF_INET6)
 405                 setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
 406 #endif
 407
 408         bind_to_interface(c->socket);
 409         bind_to_address(c);
 410
 411         /* Optimize TCP settings */
 412
 413         configure_tcp(c);
 414
 415         /* Connect */
 416
 417         result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 418
 419         if(result == -1) {
 420                 if(errno == EINPROGRESS
 421 #if defined(WIN32) && !defined(O_NONBLOCK)
 422                    || WSAGetLastError() == WSAEWOULDBLOCK
 423 #endif
 424                 ) {
 425                         c->status.connecting = true;
 426                         return;
 427                 }
 428
 429                 closesocket(c->socket);
 430
 431                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("%s: %s"), c->hostname, strerror(errno));
 432
 433                 goto begin;
 434         }
 435
 436         finish_connecting(c);
 437
 438         return;
 439 }
 440
 441 void handle_meta_read(struct bufferevent *event, void *data) {
 442         logger(LOG_EMERG, _("handle_meta_read() called"));
 443         abort();
 444 }
 445
 446 void handle_meta_write(struct bufferevent *event, void *data) {
 447         ifdebug(META) logger(LOG_DEBUG, _("handle_meta_write() called"));
 448 }
 449
 450 void handle_meta_connection_error(struct bufferevent *event, short what, void *data) {
 451         connection_t *c = data;
 452         logger(LOG_EMERG, _("handle_meta_connection_error() called: %d: %s"), what, strerror(errno));
 453         terminate_connection(c, c->status.active);
 454 }
 455
 456 void setup_outgoing_connection(outgoing_t *outgoing) {
 457         connection_t *c;
 458         node_t *n;
 459
 460         cp();
 461
 462         n = lookup_node(outgoing->name);
 463
 464         if(n)
 465                 if(n->connection) {
 466                         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Already connected to %s"), outgoing->name);
 467
 468                         n->connection->outgoing = outgoing;
 469                         return;
 470                 }
 471
 472         c = new_connection();
 473         c->name = xstrdup(outgoing->name);
 474         c->outcipher = myself->connection->outcipher;
 475         c->outdigest = myself->connection->outdigest;
 476         c->outmaclength = myself->connection->outmaclength;
 477         c->outcompression = myself->connection->outcompression;
 478
 479         init_configuration(&c->config_tree);
 480         read_connection_config(c);
 481
 482         outgoing->cfg = lookup_config(c->config_tree, "Address");
 483
 484         if(!outgoing->cfg) {
 485                 logger(LOG_ERR, _("No address specified for %s"), c->name);
 486                 free_connection(c);
 487                 return;
 488         }
 489
 490         c->outgoing = outgoing;
 491         c->last_ping_time = time(NULL);
 492
 493         connection_add(c);
 494
 495         do_outgoing_connection(c);
 496
 497         event_set(&c->inevent, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c);
 498         event_add(&c->inevent, NULL);
 499         c->buffer = bufferevent_new(c->socket, handle_meta_read, handle_meta_write, handle_meta_connection_error, c);
 500         if(!c->buffer) {
 501                 logger(LOG_EMERG, _("bufferevent_new() failed: %s"), strerror(errno));
 502                 abort();
 503         }
 504         bufferevent_disable(c->buffer, EV_READ);
 505 }
 506
 507 /*
 508   accept a new tcp connect and create a
 509   new connection
 510 */
 511 void handle_new_meta_connection(int sock, short events, void *data) {
 512         connection_t *c;
 513         sockaddr_t sa;
 514         int fd;
 515         socklen_t len = sizeof sa;
 516
 517         cp();
 518
 519         fd = accept(sock, &sa.sa, &len);
 520
 521         if(fd < 0) {
 522                 logger(LOG_ERR, _("Accepting a new connection failed: %s"), strerror(errno));
 523                 return;
 524         }
 525
 526         sockaddrunmap(&sa);
 527
 528         c = new_connection();
 529         c->name = xstrdup("<unknown>");
 530         c->outcipher = myself->connection->outcipher;
 531         c->outdigest = myself->connection->outdigest;
 532         c->outmaclength = myself->connection->outmaclength;
 533         c->outcompression = myself->connection->outcompression;
 534
 535         c->address = sa;
 536         c->hostname = sockaddr2hostname(&sa);
 537         c->socket = fd;
 538         c->last_ping_time = time(NULL);
 539
 540         ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection from %s"), c->hostname);
 541
 542         event_set(&c->inevent, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c);
 543         event_add(&c->inevent, NULL);
 544         c->buffer = bufferevent_new(c->socket, NULL, handle_meta_write, handle_meta_connection_error, c);
 545         if(!c->buffer) {
 546                 logger(LOG_EMERG, _("bufferevent_new() failed: %s"), strerror(errno));
 547                 abort();
 548         }
 549         bufferevent_disable(c->buffer, EV_READ);
 550
 551         configure_tcp(c);
 552
 553         connection_add(c);
 554
 555         c->allow_request = ID;
 556         send_id(c);
 557 }
 558
 559 void free_outgoing(outgoing_t *outgoing) {
 560         if(outgoing->ai)
 561                 freeaddrinfo(outgoing->ai);
 562
 563         if(outgoing->name)
 564                 free(outgoing->name);
 565
 566         free(outgoing);
 567 }
 568
 569 void try_outgoing_connections(void)
 570 {
 571         static config_t *cfg = NULL;
 572         char *name;
 573         outgoing_t *outgoing;
 574         connection_t *c;
 575         splay_node_t *node;
 576
 577         cp();
 578
 579         if(outgoing_list) {
 580                 for(node = connection_tree->head; node; node = node->next) {
 581                         c = node->data;
 582                         c->outgoing = NULL;
 583                 }
 584
 585                 list_delete_list(outgoing_list);
 586         }
 587
 588         outgoing_list = list_alloc((list_action_t)free_outgoing);
 589
 590         for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 591                 get_config_string(cfg, &name);
 592
 593                 if(!check_id(name)) {
 594                         logger(LOG_ERR,
 595                                    _("Invalid name for outgoing connection in %s line %d"),
 596                                    cfg->file, cfg->line);
 597                         free(name);
 598                         continue;
 599                 }
 600
 601                 outgoing = xmalloc_and_zero(sizeof *outgoing);
 602                 outgoing->name = name;
 603                 list_insert_tail(outgoing_list, outgoing);
 604                 setup_outgoing_connection(outgoing);
 605         }
 606 }