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                   2000-2007 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 "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 #ifdef WSAEINPROGRESS
  37 #define EINPROGRESS WSAEINPROGRESS
  38 #endif
  39
  40 /* Needed on Mac OS/X */
  41 #ifndef SOL_TCP
  42 #define SOL_TCP IPPROTO_TCP
  43 #endif
  44
  45 int addressfamily = AF_UNSPEC;
  46 int maxtimeout = 900;
  47 int seconds_till_retry = 5;
  48
  49 listen_socket_t listen_socket[MAXSOCKETS];
  50 int listen_sockets;
  51
  52 /* Setup sockets */
  53
  54 static void configure_tcp(connection_t *c)
  55 {
  56         int option;
  57
  58 #ifdef O_NONBLOCK
  59         int flags = fcntl(c->socket, F_GETFL);
  60
  61         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
  62                 logger(LOG_ERR, _("fcntl for %s: %s"), c->hostname, strerror(errno));
  63         }
  64 #elif defined(WIN32)
  65         unsigned long arg = 1;
  66
  67         if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
  68                 logger(LOG_ERR, _("ioctlsocket for %s: WSA error %d"), c->hostname, WSAGetLastError());
  69         }
  70 #endif
  71
  72 #if defined(SOL_TCP) && defined(TCP_NODELAY)
  73         option = 1;
  74         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
  75 #endif
  76
  77 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
  78         option = IPTOS_LOWDELAY;
  79         setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof(option));
  80 #endif
  81 }
  82
  83 int setup_listen_socket(const sockaddr_t *sa)
  84 {
  85         int nfd;
  86         char *addrstr;
  87         int option;
  88         char *iface;
  89
  90         cp();
  91
  92         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
  93
  94         if(nfd < 0) {
  95                 ifdebug(STATUS) logger(LOG_ERR, _("Creating metasocket failed: %s"), strerror(errno));
  96                 return -1;
  97         }
  98
  99         /* Optimize TCP settings */
 100
 101         option = 1;
 102         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
 103
 104         if(get_config_string
 105            (lookup_config(config_tree, "BindToInterface"), &iface)) {
 106 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 107                 struct ifreq ifr;
 108
 109                 memset(&ifr, 0, sizeof(ifr));
 110                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 111
 112                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 113                         closesocket(nfd);
 114                         logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 115                                    strerror(errno));
 116                         return -1;
 117                 }
 118 #else
 119                 logger(LOG_WARNING, _("BindToInterface not supported on this platform"));
 120 #endif
 121         }
 122
 123         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 124                 closesocket(nfd);
 125                 addrstr = sockaddr2hostname(sa);
 126                 logger(LOG_ERR, _("Can't bind to %s/tcp: %s"), addrstr,
 127                            strerror(errno));
 128                 free(addrstr);
 129                 return -1;
 130         }
 131
 132         if(listen(nfd, 3)) {
 133                 closesocket(nfd);
 134                 logger(LOG_ERR, _("System call `%s' failed: %s"), "listen",
 135                            strerror(errno));
 136                 return -1;
 137         }
 138
 139         return nfd;
 140 }
 141
 142 int setup_vpn_in_socket(const sockaddr_t *sa)
 143 {
 144         int nfd;
 145         char *addrstr;
 146         int option;
 147
 148         cp();
 149
 150         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 151
 152         if(nfd < 0) {
 153                 logger(LOG_ERR, _("Creating UDP socket failed: %s"), strerror(errno));
 154                 return -1;
 155         }
 156
 157 #ifdef O_NONBLOCK
 158         {
 159                 int flags = fcntl(nfd, F_GETFL);
 160
 161                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 162                         closesocket(nfd);
 163                         logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
 164                                    strerror(errno));
 165                         return -1;
 166                 }
 167         }
 168 #elif defined(WIN32)
 169         {
 170                 unsigned long arg = 1;
 171                 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 172                         closesocket(nfd);
 173                         logger(LOG_ERR, _("Call to `%s' failed: WSA error %d"), "ioctlsocket",
 174                                 WSAGetLastError());
 175                         return -1;
 176                 }
 177         }
 178 #endif
 179
 180         option = 1;
 181         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
 182
 183 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 184         {
 185                 bool choice;
 186
 187                 if(get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) && choice) {
 188                         option = IP_PMTUDISC_DO;
 189                         setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, &option, sizeof(option));
 190                 }
 191         }
 192 #endif
 193
 194 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 195         {
 196                 bool choice;
 197
 198                 if(get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) && choice) {
 199                         option = IPV6_PMTUDISC_DO;
 200                         setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, &option, sizeof(option));
 201                 }
 202         }
 203 #endif
 204
 205 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 206         {
 207                 char *iface;
 208                 struct ifreq ifr;
 209
 210                 if(get_config_string(lookup_config(config_tree, "BindToInterface"), &iface)) {
 211                         memset(&ifr, 0, sizeof(ifr));
 212                         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 213
 214                         if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 215                                 closesocket(nfd);
 216                                 logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 217                                            strerror(errno));
 218                                 return -1;
 219                         }
 220                 }
 221         }
 222 #endif
 223
 224         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 225                 closesocket(nfd);
 226                 addrstr = sockaddr2hostname(sa);
 227                 logger(LOG_ERR, _("Can't bind to %s/udp: %s"), addrstr,
 228                            strerror(errno));
 229                 free(addrstr);
 230                 return -1;
 231         }
 232
 233         return nfd;
 234 }
 235
 236 static void retry_outgoing_handler(int fd, short events, void *data) {
 237         do_outgoing_connection(data);
 238 }
 239
 240 void retry_outgoing(outgoing_t *outgoing) {
 241         cp();
 242
 243         outgoing->timeout += 5;
 244
 245         if(outgoing->timeout > maxtimeout)
 246                 outgoing->timeout = maxtimeout;
 247
 248         timeout_set(&outgoing->ev, retry_outgoing_handler, outgoing);
 249         event_add(&outgoing->ev, &(struct timeval){outgoing->timeout, 0});
 250
 251         ifdebug(CONNECTIONS) logger(LOG_NOTICE,
 252                            _("Trying to re-establish outgoing connection in %d seconds"),
 253                            outgoing->timeout);
 254 }
 255
 256 void finish_connecting(connection_t *c)
 257 {
 258         cp();
 259
 260         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Connected to %s (%s)"), c->name, c->hostname);
 261
 262         configure_tcp(c);
 263
 264         c->last_ping_time = time(NULL);
 265         c->status.connecting = false;
 266
 267         send_id(c);
 268 }
 269
 270 void do_outgoing_connection(connection_t *c)
 271 {
 272         char *address, *port;
 273         int result;
 274
 275         cp();
 276
 277 begin:
 278         if(!c->outgoing->ai) {
 279                 if(!c->outgoing->cfg) {
 280                         ifdebug(CONNECTIONS) logger(LOG_ERR, _("Could not set up a meta connection to %s"),
 281                                            c->name);
 282                         c->status.remove = true;
 283                         retry_outgoing(c->outgoing);
 284                         return;
 285                 }
 286
 287                 get_config_string(c->outgoing->cfg, &address);
 288
 289                 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
 290                         asprintf(&port, "655");
 291
 292                 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 293                 free(address);
 294                 free(port);
 295
 296                 c->outgoing->aip = c->outgoing->ai;
 297                 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
 298         }
 299
 300         if(!c->outgoing->aip) {
 301                 freeaddrinfo(c->outgoing->ai);
 302                 c->outgoing->ai = NULL;
 303                 goto begin;
 304         }
 305
 306         memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
 307         c->outgoing->aip = c->outgoing->aip->ai_next;
 308
 309         if(c->hostname)
 310                 free(c->hostname);
 311
 312         c->hostname = sockaddr2hostname(&c->address);
 313
 314         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Trying to connect to %s (%s)"), c->name,
 315                            c->hostname);
 316
 317         c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 318
 319         if(c->socket == -1) {
 320                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("Creating socket for %s failed: %s"), c->hostname,
 321                                    strerror(errno));
 322
 323                 goto begin;
 324         }
 325
 326         /* Optimize TCP settings */
 327
 328         configure_tcp(c);
 329
 330         /* Connect */
 331
 332         result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 333
 334         if(result == -1) {
 335                 if(errno == EINPROGRESS
 336 #if defined(WIN32) && !defined(O_NONBLOCK)
 337                    || WSAGetLastError() == WSAEWOULDBLOCK
 338 #endif
 339                 ) {
 340                         c->status.connecting = true;
 341                         return;
 342                 }
 343
 344                 closesocket(c->socket);
 345
 346                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("%s: %s"), c->hostname, strerror(errno));
 347
 348                 goto begin;
 349         }
 350
 351         finish_connecting(c);
 352
 353         return;
 354 }
 355
 356 void setup_outgoing_connection(outgoing_t *outgoing)
 357 {
 358         connection_t *c;
 359         node_t *n;
 360
 361         cp();
 362
 363         n = lookup_node(outgoing->name);
 364
 365         if(n)
 366                 if(n->connection) {
 367                         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Already connected to %s"), outgoing->name);
 368
 369                         n->connection->outgoing = outgoing;
 370                         return;
 371                 }
 372
 373         c = new_connection();
 374         c->name = xstrdup(outgoing->name);
 375         c->outcipher = myself->connection->outcipher;
 376         c->outdigest = myself->connection->outdigest;
 377         c->outmaclength = myself->connection->outmaclength;
 378         c->outcompression = myself->connection->outcompression;
 379
 380         init_configuration(&c->config_tree);
 381         read_connection_config(c);
 382
 383         outgoing->cfg = lookup_config(c->config_tree, "Address");
 384
 385         if(!outgoing->cfg) {
 386                 logger(LOG_ERR, _("No address specified for %s"), c->name);
 387                 free_connection(c);
 388                 free(outgoing->name);
 389                 free(outgoing);
 390                 return;
 391         }
 392
 393         c->outgoing = outgoing;
 394         c->last_ping_time = time(NULL);
 395
 396         connection_add(c);
 397
 398         do_outgoing_connection(c);
 399
 400         event_set(&c->ev, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c);
 401         event_set(&c->outev, c->socket, EV_WRITE | EV_PERSIST, flush_meta, c);
 402         if(event_add(&c->ev, NULL) < 0) {
 403                 logger(LOG_EMERG, _("event_add failed: %s"), strerror(errno));
 404                 abort();
 405         }
 406 }
 407
 408 /*
 409   accept a new tcp connect and create a
 410   new connection
 411 */
 412 void handle_new_meta_connection(int sock, short events, void *data)
 413 {
 414         connection_t *c;
 415         sockaddr_t sa;
 416         int fd;
 417         socklen_t len = sizeof(sa);
 418
 419         cp();
 420
 421         fd = accept(sock, &sa.sa, &len);
 422
 423         if(fd < 0) {
 424                 logger(LOG_ERR, _("Accepting a new connection failed: %s"), strerror(errno));
 425                 return;
 426         }
 427
 428         sockaddrunmap(&sa);
 429
 430         c = new_connection();
 431         c->name = xstrdup("<unknown>");
 432         c->outcipher = myself->connection->outcipher;
 433         c->outdigest = myself->connection->outdigest;
 434         c->outmaclength = myself->connection->outmaclength;
 435         c->outcompression = myself->connection->outcompression;
 436
 437         c->address = sa;
 438         c->hostname = sockaddr2hostname(&sa);
 439         c->socket = fd;
 440         c->last_ping_time = time(NULL);
 441
 442         ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection from %s"), c->hostname);
 443
 444         event_set(&c->ev, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c);
 445         event_set(&c->outev, c->socket, EV_WRITE | EV_PERSIST, flush_meta, c);
 446         if(event_add(&c->ev, NULL) < 0) {
 447                 logger(LOG_ERR, _("event_add failed: %s"), strerror(errno));
 448                 connection_del(c);
 449                 return;
 450         }
 451
 452         configure_tcp(c);
 453
 454         connection_add(c);
 455
 456         c->allow_request = ID;
 457         send_id(c);
 458 }
 459
 460 void try_outgoing_connections(void)
 461 {
 462         static config_t *cfg = NULL;
 463         char *name;
 464         outgoing_t *outgoing;
 465
 466         cp();
 467
 468         for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 469                 get_config_string(cfg, &name);
 470
 471                 if(!check_id(name)) {
 472                         logger(LOG_ERR,
 473                                    _("Invalid name for outgoing connection in %s line %d"),
 474                                    cfg->file, cfg->line);
 475                         free(name);
 476                         continue;
 477                 }
 478
 479                 outgoing = xmalloc_and_zero(sizeof(*outgoing));
 480                 outgoing->name = name;
 481                 setup_outgoing_connection(outgoing);
 482         }
 483 }