www.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                   2000-2008 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
  53 /* Setup sockets */
  54
  55 static void configure_tcp(connection_t *c)
  56 {
  57         int option;
  58
  59 #ifdef O_NONBLOCK
  60         int flags = fcntl(c->socket, F_GETFL);
  61
  62         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
  63                 logger(LOG_ERR, _("fcntl for %s: %s"), c->hostname, strerror(errno));
  64         }
  65 #elif defined(WIN32)
  66         unsigned long arg = 1;
  67
  68         if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
  69                 logger(LOG_ERR, _("ioctlsocket for %s: WSA error %d"), c->hostname, WSAGetLastError());
  70         }
  71 #endif
  72
  73 #if defined(SOL_TCP) && defined(TCP_NODELAY)
  74         option = 1;
  75         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
  76 #endif
  77
  78 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
  79         option = IPTOS_LOWDELAY;
  80         setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof(option));
  81 #endif
  82 }
  83
  84 int setup_listen_socket(const sockaddr_t *sa)
  85 {
  86         int nfd;
  87         char *addrstr;
  88         int option;
  89         char *iface;
  90
  91         cp();
  92
  93         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
  94
  95         if(nfd < 0) {
  96                 ifdebug(STATUS) logger(LOG_ERR, _("Creating metasocket failed: %s"), strerror(errno));
  97                 return -1;
  98         }
  99
 100         /* Optimize TCP settings */
 101
 102         option = 1;
 103         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
 104
 105 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 106         if(sa->sa.sa_family == AF_INET6)
 107                 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
 108 #endif
 109
 110         if(get_config_string
 111            (lookup_config(config_tree, "BindToInterface"), &iface)) {
 112 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 113                 struct ifreq ifr;
 114
 115                 memset(&ifr, 0, sizeof(ifr));
 116                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 117
 118                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 119                         closesocket(nfd);
 120                         logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 121                                    strerror(errno));
 122                         return -1;
 123                 }
 124 #else
 125                 logger(LOG_WARNING, _("BindToInterface not supported on this platform"));
 126 #endif
 127         }
 128
 129         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 130                 closesocket(nfd);
 131                 addrstr = sockaddr2hostname(sa);
 132                 logger(LOG_ERR, _("Can't bind to %s/tcp: %s"), addrstr,
 133                            strerror(errno));
 134                 free(addrstr);
 135                 return -1;
 136         }
 137
 138         if(listen(nfd, 3)) {
 139                 closesocket(nfd);
 140                 logger(LOG_ERR, _("System call `%s' failed: %s"), "listen",
 141                            strerror(errno));
 142                 return -1;
 143         }
 144
 145         return nfd;
 146 }
 147
 148 int setup_vpn_in_socket(const sockaddr_t *sa)
 149 {
 150         int nfd;
 151         char *addrstr;
 152         int option;
 153
 154         cp();
 155
 156         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 157
 158         if(nfd < 0) {
 159                 logger(LOG_ERR, _("Creating UDP socket failed: %s"), strerror(errno));
 160                 return -1;
 161         }
 162
 163 #ifdef O_NONBLOCK
 164         {
 165                 int flags = fcntl(nfd, F_GETFL);
 166
 167                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 168                         closesocket(nfd);
 169                         logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
 170                                    strerror(errno));
 171                         return -1;
 172                 }
 173         }
 174 #elif defined(WIN32)
 175         {
 176                 unsigned long arg = 1;
 177                 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 178                         closesocket(nfd);
 179                         logger(LOG_ERR, _("Call to `%s' failed: WSA error %d"), "ioctlsocket",
 180                                 WSAGetLastError());
 181                         return -1;
 182                 }
 183         }
 184 #endif
 185
 186         option = 1;
 187         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
 188
 189 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 190         if(sa->sa.sa_family == AF_INET6)
 191                 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
 192 #endif
 193
 194 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 195         {
 196                 bool choice;
 197
 198                 if(!get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) || choice) {
 199                         option = IP_PMTUDISC_DO;
 200                         setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, &option, sizeof(option));
 201                 }
 202         }
 203 #endif
 204
 205 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 206         {
 207                 bool choice;
 208
 209                 if(!get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) || choice) {
 210                         option = IPV6_PMTUDISC_DO;
 211                         setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, &option, sizeof(option));
 212                 }
 213         }
 214 #endif
 215
 216 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 217         {
 218                 char *iface;
 219                 struct ifreq ifr;
 220
 221                 if(get_config_string(lookup_config(config_tree, "BindToInterface"), &iface)) {
 222                         memset(&ifr, 0, sizeof(ifr));
 223                         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 224
 225                         if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 226                                 closesocket(nfd);
 227                                 logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 228                                            strerror(errno));
 229                                 return -1;
 230                         }
 231                 }
 232         }
 233 #endif
 234
 235         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 236                 closesocket(nfd);
 237                 addrstr = sockaddr2hostname(sa);
 238                 logger(LOG_ERR, _("Can't bind to %s/udp: %s"), addrstr,
 239                            strerror(errno));
 240                 free(addrstr);
 241                 return -1;
 242         }
 243
 244         return nfd;
 245 }
 246
 247 void retry_outgoing(outgoing_t *outgoing)
 248 {
 249         event_t *event;
 250
 251         cp();
 252
 253         outgoing->timeout += 5;
 254
 255         if(outgoing->timeout > maxtimeout)
 256                 outgoing->timeout = maxtimeout;
 257
 258         event = new_event();
 259         event->handler = (event_handler_t) setup_outgoing_connection;
 260         event->time = now + outgoing->timeout;
 261         event->data = outgoing;
 262         event_add(event);
 263
 264         ifdebug(CONNECTIONS) logger(LOG_NOTICE,
 265                            _("Trying to re-establish outgoing connection in %d seconds"),
 266                            outgoing->timeout);
 267 }
 268
 269 void finish_connecting(connection_t *c)
 270 {
 271         cp();
 272
 273         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Connected to %s (%s)"), c->name, c->hostname);
 274
 275         configure_tcp(c);
 276
 277         c->last_ping_time = now;
 278
 279         send_id(c);
 280 }
 281
 282 void do_outgoing_connection(connection_t *c)
 283 {
 284         char *address, *port;
 285         int result;
 286
 287         cp();
 288
 289 begin:
 290         if(!c->outgoing->ai) {
 291                 if(!c->outgoing->cfg) {
 292                         ifdebug(CONNECTIONS) logger(LOG_ERR, _("Could not set up a meta connection to %s"),
 293                                            c->name);
 294                         c->status.remove = true;
 295                         retry_outgoing(c->outgoing);
 296                         return;
 297                 }
 298
 299                 get_config_string(c->outgoing->cfg, &address);
 300
 301                 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
 302                         asprintf(&port, "655");
 303
 304                 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 305                 free(address);
 306                 free(port);
 307
 308                 c->outgoing->aip = c->outgoing->ai;
 309                 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
 310         }
 311
 312         if(!c->outgoing->aip) {
 313                 if(c->outgoing->ai)
 314                         freeaddrinfo(c->outgoing->ai);
 315                 c->outgoing->ai = NULL;
 316                 goto begin;
 317         }
 318
 319         memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
 320         c->outgoing->aip = c->outgoing->aip->ai_next;
 321
 322         if(c->hostname)
 323                 free(c->hostname);
 324
 325         c->hostname = sockaddr2hostname(&c->address);
 326
 327         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Trying to connect to %s (%s)"), c->name,
 328                            c->hostname);
 329
 330         c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 331
 332         if(c->socket == -1) {
 333                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("Creating socket for %s failed: %s"), c->hostname,
 334                                    strerror(errno));
 335
 336                 goto begin;
 337         }
 338
 339 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 340         int option = 1;
 341         if(c->address.sa.sa_family == AF_INET6)
 342                 setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
 343 #endif
 344
 345         /* Optimize TCP settings */
 346
 347         configure_tcp(c);
 348
 349         /* Connect */
 350
 351         result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 352
 353         if(result == -1) {
 354                 if(errno == EINPROGRESS
 355 #if defined(WIN32) && !defined(O_NONBLOCK)
 356                    || WSAGetLastError() == WSAEWOULDBLOCK
 357 #endif
 358                 ) {
 359                         c->status.connecting = true;
 360                         return;
 361                 }
 362
 363                 closesocket(c->socket);
 364
 365                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("%s: %s"), c->hostname, strerror(errno));
 366
 367                 goto begin;
 368         }
 369
 370         finish_connecting(c);
 371
 372         return;
 373 }
 374
 375 void setup_outgoing_connection(outgoing_t *outgoing)
 376 {
 377         connection_t *c;
 378         node_t *n;
 379
 380         cp();
 381
 382         n = lookup_node(outgoing->name);
 383
 384         if(n)
 385                 if(n->connection) {
 386                         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Already connected to %s"), outgoing->name);
 387
 388                         n->connection->outgoing = outgoing;
 389                         return;
 390                 }
 391
 392         c = new_connection();
 393         c->name = xstrdup(outgoing->name);
 394         c->outcipher = myself->connection->outcipher;
 395         c->outdigest = myself->connection->outdigest;
 396         c->outmaclength = myself->connection->outmaclength;
 397         c->outcompression = myself->connection->outcompression;
 398
 399         init_configuration(&c->config_tree);
 400         read_connection_config(c);
 401
 402         outgoing->cfg = lookup_config(c->config_tree, "Address");
 403
 404         if(!outgoing->cfg) {
 405                 logger(LOG_ERR, _("No address specified for %s"), c->name);
 406                 free_connection(c);
 407                 free(outgoing->name);
 408                 free(outgoing);
 409                 return;
 410         }
 411
 412         c->outgoing = outgoing;
 413         c->last_ping_time = now;
 414
 415         connection_add(c);
 416
 417         do_outgoing_connection(c);
 418 }
 419
 420 /*
 421   accept a new tcp connect and create a
 422   new connection
 423 */
 424 bool handle_new_meta_connection(int sock)
 425 {
 426         connection_t *c;
 427         sockaddr_t sa;
 428         int fd;
 429         socklen_t len = sizeof(sa);
 430
 431         cp();
 432
 433         fd = accept(sock, &sa.sa, &len);
 434
 435         if(fd < 0) {
 436                 logger(LOG_ERR, _("Accepting a new connection failed: %s"),
 437                            strerror(errno));
 438                 return false;
 439         }
 440
 441         sockaddrunmap(&sa);
 442
 443         c = new_connection();
 444         c->name = xstrdup("<unknown>");
 445         c->outcipher = myself->connection->outcipher;
 446         c->outdigest = myself->connection->outdigest;
 447         c->outmaclength = myself->connection->outmaclength;
 448         c->outcompression = myself->connection->outcompression;
 449
 450         c->address = sa;
 451         c->hostname = sockaddr2hostname(&sa);
 452         c->socket = fd;
 453         c->last_ping_time = now;
 454
 455         ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection from %s"), c->hostname);
 456
 457         configure_tcp(c);
 458
 459         connection_add(c);
 460
 461         c->allow_request = ID;
 462         send_id(c);
 463
 464         return true;
 465 }
 466
 467 void try_outgoing_connections(void)
 468 {
 469         static config_t *cfg = NULL;
 470         char *name;
 471         outgoing_t *outgoing;
 472
 473         cp();
 474
 475         for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 476                 get_config_string(cfg, &name);
 477
 478                 if(!check_id(name)) {
 479                         logger(LOG_ERR,
 480                                    _("Invalid name for outgoing connection in %s line %d"),
 481                                    cfg->file, cfg->line);
 482                         free(name);
 483                         continue;
 484                 }
 485
 486                 outgoing = xmalloc_and_zero(sizeof(*outgoing));
 487                 outgoing->name = name;
 488                 setup_outgoing_connection(outgoing);
 489         }
 490 }