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, _("BindToInterface not supported on this platform"));
 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         {
 197                 bool choice;
 198
 199                 if(!get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) || choice) {
 200                         option = IP_PMTUDISC_DO;
 201                         setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, &option, sizeof(option));
 202                 }
 203         }
 204 #endif
 205
 206 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 207         {
 208                 bool choice;
 209
 210                 if(!get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) || choice) {
 211                         option = IPV6_PMTUDISC_DO;
 212                         setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, &option, sizeof(option));
 213                 }
 214         }
 215 #endif
 216
 217 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 218         {
 219                 char *iface;
 220                 struct ifreq ifr;
 221
 222                 if(get_config_string(lookup_config(config_tree, "BindToInterface"), &iface)) {
 223                         memset(&ifr, 0, sizeof(ifr));
 224                         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 225
 226                         if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 227                                 closesocket(nfd);
 228                                 logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 229                                            strerror(errno));
 230                                 return -1;
 231                         }
 232                 }
 233         }
 234 #endif
 235
 236         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 237                 closesocket(nfd);
 238                 addrstr = sockaddr2hostname(sa);
 239                 logger(LOG_ERR, _("Can't bind to %s/udp: %s"), addrstr,
 240                            strerror(errno));
 241                 free(addrstr);
 242                 return -1;
 243         }
 244
 245         return nfd;
 246 }
 247
 248 void retry_outgoing(outgoing_t *outgoing)
 249 {
 250         event_t *event;
 251
 252         cp();
 253
 254         outgoing->timeout += 5;
 255
 256         if(outgoing->timeout > maxtimeout)
 257                 outgoing->timeout = maxtimeout;
 258
 259         event = new_event();
 260         event->handler = (event_handler_t) setup_outgoing_connection;
 261         event->time = now + outgoing->timeout;
 262         event->data = outgoing;
 263         event_add(event);
 264
 265         ifdebug(CONNECTIONS) logger(LOG_NOTICE,
 266                            _("Trying to re-establish outgoing connection in %d seconds"),
 267                            outgoing->timeout);
 268 }
 269
 270 void finish_connecting(connection_t *c)
 271 {
 272         cp();
 273
 274         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Connected to %s (%s)"), c->name, c->hostname);
 275
 276         configure_tcp(c);
 277
 278         c->last_ping_time = now;
 279
 280         send_id(c);
 281 }
 282
 283 void do_outgoing_connection(connection_t *c)
 284 {
 285         char *address, *port;
 286         int result;
 287
 288         cp();
 289
 290 begin:
 291         if(!c->outgoing->ai) {
 292                 if(!c->outgoing->cfg) {
 293                         ifdebug(CONNECTIONS) logger(LOG_ERR, _("Could not set up a meta connection to %s"),
 294                                            c->name);
 295                         c->status.remove = true;
 296                         retry_outgoing(c->outgoing);
 297                         return;
 298                 }
 299
 300                 get_config_string(c->outgoing->cfg, &address);
 301
 302                 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
 303                         asprintf(&port, "655");
 304
 305                 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 306                 free(address);
 307                 free(port);
 308
 309                 c->outgoing->aip = c->outgoing->ai;
 310                 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
 311         }
 312
 313         if(!c->outgoing->aip) {
 314                 if(c->outgoing->ai)
 315                         freeaddrinfo(c->outgoing->ai);
 316                 c->outgoing->ai = NULL;
 317                 goto begin;
 318         }
 319
 320         memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
 321         c->outgoing->aip = c->outgoing->aip->ai_next;
 322
 323         if(c->hostname)
 324                 free(c->hostname);
 325
 326         c->hostname = sockaddr2hostname(&c->address);
 327
 328         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Trying to connect to %s (%s)"), c->name,
 329                            c->hostname);
 330
 331         c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 332
 333         if(c->socket == -1) {
 334                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("Creating socket for %s failed: %s"), c->hostname,
 335                                    strerror(errno));
 336
 337                 goto begin;
 338         }
 339
 340 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 341         int option = 1;
 342         if(c->address.sa.sa_family == AF_INET6)
 343                 setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
 344 #endif
 345
 346         /* Optimize TCP settings */
 347
 348         configure_tcp(c);
 349
 350         /* Connect */
 351
 352         result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 353
 354         if(result == -1) {
 355                 if(errno == EINPROGRESS
 356 #if defined(WIN32) && !defined(O_NONBLOCK)
 357                    || WSAGetLastError() == WSAEWOULDBLOCK
 358 #endif
 359                 ) {
 360                         c->status.connecting = true;
 361                         return;
 362                 }
 363
 364                 closesocket(c->socket);
 365
 366                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("%s: %s"), c->hostname, strerror(errno));
 367
 368                 goto begin;
 369         }
 370
 371         finish_connecting(c);
 372
 373         return;
 374 }
 375
 376 void setup_outgoing_connection(outgoing_t *outgoing)
 377 {
 378         connection_t *c;
 379         node_t *n;
 380
 381         cp();
 382
 383         n = lookup_node(outgoing->name);
 384
 385         if(n)
 386                 if(n->connection) {
 387                         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Already connected to %s"), outgoing->name);
 388
 389                         n->connection->outgoing = outgoing;
 390                         return;
 391                 }
 392
 393         c = new_connection();
 394         c->name = xstrdup(outgoing->name);
 395         c->outcipher = myself->connection->outcipher;
 396         c->outdigest = myself->connection->outdigest;
 397         c->outmaclength = myself->connection->outmaclength;
 398         c->outcompression = myself->connection->outcompression;
 399
 400         init_configuration(&c->config_tree);
 401         read_connection_config(c);
 402
 403         outgoing->cfg = lookup_config(c->config_tree, "Address");
 404
 405         if(!outgoing->cfg) {
 406                 logger(LOG_ERR, _("No address specified for %s"), c->name);
 407                 free_connection(c);
 408                 return;
 409         }
 410
 411         c->outgoing = outgoing;
 412         c->last_ping_time = now;
 413
 414         connection_add(c);
 415
 416         do_outgoing_connection(c);
 417 }
 418
 419 /*
 420   accept a new tcp connect and create a
 421   new connection
 422 */
 423 bool handle_new_meta_connection(int sock)
 424 {
 425         connection_t *c;
 426         sockaddr_t sa;
 427         int fd;
 428         socklen_t len = sizeof(sa);
 429
 430         cp();
 431
 432         fd = accept(sock, &sa.sa, &len);
 433
 434         if(fd < 0) {
 435                 logger(LOG_ERR, _("Accepting a new connection failed: %s"),
 436                            strerror(errno));
 437                 return false;
 438         }
 439
 440         sockaddrunmap(&sa);
 441
 442         c = new_connection();
 443         c->name = xstrdup("<unknown>");
 444         c->outcipher = myself->connection->outcipher;
 445         c->outdigest = myself->connection->outdigest;
 446         c->outmaclength = myself->connection->outmaclength;
 447         c->outcompression = myself->connection->outcompression;
 448
 449         c->address = sa;
 450         c->hostname = sockaddr2hostname(&sa);
 451         c->socket = fd;
 452         c->last_ping_time = now;
 453
 454         ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection from %s"), c->hostname);
 455
 456         configure_tcp(c);
 457
 458         connection_add(c);
 459
 460         c->allow_request = ID;
 461         send_id(c);
 462
 463         return true;
 464 }
 465
 466 void free_outgoing(outgoing_t *outgoing) {
 467         if(outgoing->ai)
 468                 freeaddrinfo(outgoing->ai);
 469
 470         if(outgoing->name)
 471                 free(outgoing->name);
 472
 473         free(outgoing);
 474 }
 475
 476 void try_outgoing_connections(void)
 477 {
 478         static config_t *cfg = NULL;
 479         char *name;
 480         outgoing_t *outgoing;
 481         connection_t *c;
 482         avl_node_t *node;
 483
 484         cp();
 485
 486         if(outgoing_list) {
 487                 for(node = connection_tree->head; node; node = node->next) {
 488                         c = node->data;
 489                         c->outgoing = NULL;
 490                 }
 491
 492                 list_delete_list(outgoing_list);
 493         }
 494
 495         outgoing_list = list_alloc((list_action_t)free_outgoing);
 496
 497         for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 498                 get_config_string(cfg, &name);
 499
 500                 if(!check_id(name)) {
 501                         logger(LOG_ERR,
 502                                    _("Invalid name for outgoing connection in %s line %d"),
 503                                    cfg->file, cfg->line);
 504                         free(name);
 505                         continue;
 506                 }
 507
 508                 outgoing = xmalloc_and_zero(sizeof(*outgoing));
 509                 outgoing->name = name;
 510                 list_insert_tail(outgoing_list, outgoing);
 511                 setup_outgoing_connection(outgoing);
 512         }
 513 }