git.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                   2000-2006 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(get_config_string
 106            (lookup_config(config_tree, "BindToInterface"), &iface)) {
 107 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 108                 struct ifreq ifr;
 109
 110                 memset(&ifr, 0, sizeof(ifr));
 111                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 112
 113                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 114                         closesocket(nfd);
 115                         logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 116                                    strerror(errno));
 117                         return -1;
 118                 }
 119 #else
 120                 logger(LOG_WARNING, _("BindToInterface not supported on this platform"));
 121 #endif
 122         }
 123
 124         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 125                 closesocket(nfd);
 126                 addrstr = sockaddr2hostname(sa);
 127                 logger(LOG_ERR, _("Can't bind to %s/tcp: %s"), addrstr,
 128                            strerror(errno));
 129                 free(addrstr);
 130                 return -1;
 131         }
 132
 133         if(listen(nfd, 3)) {
 134                 closesocket(nfd);
 135                 logger(LOG_ERR, _("System call `%s' failed: %s"), "listen",
 136                            strerror(errno));
 137                 return -1;
 138         }
 139
 140         return nfd;
 141 }
 142
 143 int setup_vpn_in_socket(const sockaddr_t *sa)
 144 {
 145         int nfd;
 146         char *addrstr;
 147         int option;
 148
 149         cp();
 150
 151         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 152
 153         if(nfd < 0) {
 154                 logger(LOG_ERR, _("Creating UDP socket failed: %s"), strerror(errno));
 155                 return -1;
 156         }
 157
 158 #ifdef O_NONBLOCK
 159         {
 160                 int flags = fcntl(nfd, F_GETFL);
 161
 162                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 163                         closesocket(nfd);
 164                         logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
 165                                    strerror(errno));
 166                         return -1;
 167                 }
 168         }
 169 #elif defined(WIN32)
 170         {
 171                 unsigned long arg = 1;
 172                 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 173                         closesocket(nfd);
 174                         logger(LOG_ERR, _("Call to `%s' failed: WSA error %d"), "ioctlsocket",
 175                                 WSAGetLastError());
 176                         return -1;
 177                 }
 178         }
 179 #endif
 180
 181         option = 1;
 182         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
 183
 184 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 185         {
 186                 bool choice;
 187
 188                 if(get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) && choice) {
 189                         option = IP_PMTUDISC_DO;
 190                         setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, &option, sizeof(option));
 191                 }
 192         }
 193 #endif
 194
 195 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 196         {
 197                 bool choice;
 198
 199                 if(get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) && choice) {
 200                         option = IPV6_PMTUDISC_DO;
 201                         setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, &option, sizeof(option));
 202                 }
 203         }
 204 #endif
 205
 206 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 207         {
 208                 char *iface;
 209                 struct ifreq ifr;
 210
 211                 if(get_config_string(lookup_config(config_tree, "BindToInterface"), &iface)) {
 212                         memset(&ifr, 0, sizeof(ifr));
 213                         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 214
 215                         if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 216                                 closesocket(nfd);
 217                                 logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 218                                            strerror(errno));
 219                                 return -1;
 220                         }
 221                 }
 222         }
 223 #endif
 224
 225         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 226                 closesocket(nfd);
 227                 addrstr = sockaddr2hostname(sa);
 228                 logger(LOG_ERR, _("Can't bind to %s/udp: %s"), addrstr,
 229                            strerror(errno));
 230                 free(addrstr);
 231                 return -1;
 232         }
 233
 234         return nfd;
 235 }
 236
 237 void retry_outgoing(outgoing_t *outgoing)
 238 {
 239         event_t *event;
 240
 241         cp();
 242
 243         outgoing->timeout += 5;
 244
 245         if(outgoing->timeout > maxtimeout)
 246                 outgoing->timeout = maxtimeout;
 247
 248         event = new_event();
 249         event->handler = (event_handler_t) setup_outgoing_connection;
 250         event->time = now + outgoing->timeout;
 251         event->data = outgoing;
 252         event_add(event);
 253
 254         ifdebug(CONNECTIONS) logger(LOG_NOTICE,
 255                            _("Trying to re-establish outgoing connection in %d seconds"),
 256                            outgoing->timeout);
 257 }
 258
 259 void finish_connecting(connection_t *c)
 260 {
 261         cp();
 262
 263         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Connected to %s (%s)"), c->name, c->hostname);
 264
 265         configure_tcp(c);
 266
 267         c->last_ping_time = now;
 268
 269         send_id(c);
 270 }
 271
 272 void do_outgoing_connection(connection_t *c)
 273 {
 274         char *address, *port;
 275         int result;
 276
 277         cp();
 278
 279 begin:
 280         if(!c->outgoing->ai) {
 281                 if(!c->outgoing->cfg) {
 282                         ifdebug(CONNECTIONS) logger(LOG_ERR, _("Could not set up a meta connection to %s"),
 283                                            c->name);
 284                         c->status.remove = true;
 285                         retry_outgoing(c->outgoing);
 286                         return;
 287                 }
 288
 289                 get_config_string(c->outgoing->cfg, &address);
 290
 291                 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
 292                         asprintf(&port, "655");
 293
 294                 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 295                 free(address);
 296                 free(port);
 297
 298                 c->outgoing->aip = c->outgoing->ai;
 299                 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
 300         }
 301
 302         if(!c->outgoing->aip) {
 303                 freeaddrinfo(c->outgoing->ai);
 304                 c->outgoing->ai = NULL;
 305                 goto begin;
 306         }
 307
 308         memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
 309         c->outgoing->aip = c->outgoing->aip->ai_next;
 310
 311         if(c->hostname)
 312                 free(c->hostname);
 313
 314         c->hostname = sockaddr2hostname(&c->address);
 315
 316         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Trying to connect to %s (%s)"), c->name,
 317                            c->hostname);
 318
 319         c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 320
 321         if(c->socket == -1) {
 322                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("Creating socket for %s failed: %s"), c->hostname,
 323                                    strerror(errno));
 324
 325                 goto begin;
 326         }
 327
 328         /* Optimize TCP settings */
 329
 330         configure_tcp(c);
 331
 332         /* Connect */
 333
 334         result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 335
 336         if(result == -1) {
 337                 if(errno == EINPROGRESS
 338 #if defined(WIN32) && !defined(O_NONBLOCK)
 339                    || WSAGetLastError() == WSAEWOULDBLOCK
 340 #endif
 341                 ) {
 342                         c->status.connecting = true;
 343                         return;
 344                 }
 345
 346                 closesocket(c->socket);
 347
 348                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("%s: %s"), c->hostname, strerror(errno));
 349
 350                 goto begin;
 351         }
 352
 353         finish_connecting(c);
 354
 355         return;
 356 }
 357
 358 void setup_outgoing_connection(outgoing_t *outgoing)
 359 {
 360         connection_t *c;
 361         node_t *n;
 362
 363         cp();
 364
 365         n = lookup_node(outgoing->name);
 366
 367         if(n)
 368                 if(n->connection) {
 369                         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Already connected to %s"), outgoing->name);
 370
 371                         n->connection->outgoing = outgoing;
 372                         return;
 373                 }
 374
 375         c = new_connection();
 376         c->name = xstrdup(outgoing->name);
 377         c->outcipher = myself->connection->outcipher;
 378         c->outdigest = myself->connection->outdigest;
 379         c->outmaclength = myself->connection->outmaclength;
 380         c->outcompression = myself->connection->outcompression;
 381
 382         init_configuration(&c->config_tree);
 383         read_connection_config(c);
 384
 385         outgoing->cfg = lookup_config(c->config_tree, "Address");
 386
 387         if(!outgoing->cfg) {
 388                 logger(LOG_ERR, _("No address specified for %s"), c->name);
 389                 free_connection(c);
 390                 free(outgoing->name);
 391                 free(outgoing);
 392                 return;
 393         }
 394
 395         c->outgoing = outgoing;
 396         c->last_ping_time = now;
 397
 398         connection_add(c);
 399
 400         do_outgoing_connection(c);
 401 }
 402
 403 /*
 404   accept a new tcp connect and create a
 405   new connection
 406 */
 407 bool handle_new_meta_connection(int sock)
 408 {
 409         connection_t *c;
 410         sockaddr_t sa;
 411         int fd;
 412         socklen_t len = sizeof(sa);
 413
 414         cp();
 415
 416         fd = accept(sock, &sa.sa, &len);
 417
 418         if(fd < 0) {
 419                 logger(LOG_ERR, _("Accepting a new connection failed: %s"),
 420                            strerror(errno));
 421                 return false;
 422         }
 423
 424         sockaddrunmap(&sa);
 425
 426         c = new_connection();
 427         c->name = NULL;
 428         c->outcipher = myself->connection->outcipher;
 429         c->outdigest = myself->connection->outdigest;
 430         c->outmaclength = myself->connection->outmaclength;
 431         c->outcompression = myself->connection->outcompression;
 432
 433         c->address = sa;
 434         c->hostname = sockaddr2hostname(&sa);
 435         c->socket = fd;
 436         c->last_ping_time = now;
 437
 438         ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection from %s"), c->hostname);
 439
 440         configure_tcp(c);
 441
 442         connection_add(c);
 443
 444         c->allow_request = ID;
 445         send_id(c);
 446
 447         return true;
 448 }
 449
 450 void try_outgoing_connections(void)
 451 {
 452         static config_t *cfg = NULL;
 453         char *name;
 454         outgoing_t *outgoing;
 455
 456         cp();
 457
 458         for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 459                 get_config_string(cfg, &name);
 460
 461                 if(!check_id(name)) {
 462                         logger(LOG_ERR,
 463                                    _("Invalid name for outgoing connection in %s line %d"),
 464                                    cfg->file, cfg->line);
 465                         free(name);
 466                         continue;
 467                 }
 468
 469                 outgoing = xmalloc_and_zero(sizeof(*outgoing));
 470                 outgoing->name = name;
 471                 setup_outgoing_connection(outgoing);
 472         }
 473 }