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