tinc-vpn.org Git - tinc/blob - src/net_socket.c

   1 /*
   2     net_socket.c -- Handle various kinds of sockets.
   3     Copyright (C) 1998-2003 Ivo Timmermans <ivo@o2w.nl>,
   4                   2000-2003 Guus Sliepen <guus@sliepen.eu.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: net_socket.c,v 1.1.2.38 2003/12/22 11:04:16 guus Exp $
  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 int addressfamily = AF_UNSPEC;
  42 int maxtimeout = 900;
  43 int seconds_till_retry = 5;
  44
  45 listen_socket_t listen_socket[MAXSOCKETS];
  46 int listen_sockets;
  47
  48 /* Setup sockets */
  49
  50 int setup_listen_socket(const sockaddr_t *sa)
  51 {
  52         int nfd;
  53         char *addrstr;
  54         int option;
  55         char *iface;
  56
  57         cp();
  58
  59         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
  60
  61         if(nfd < 0) {
  62                 ifdebug(STATUS) logger(LOG_ERR, _("Creating metasocket failed: %s"), strerror(errno));
  63                 return -1;
  64         }
  65
  66 #ifdef O_NONBLOCK
  67         {
  68                 int flags = fcntl(nfd, F_GETFL);
  69
  70                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
  71                         closesocket(nfd);
  72                         logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
  73                                    strerror(errno));
  74                         return -1;
  75                 }
  76         }
  77 #endif
  78
  79         /* Optimize TCP settings */
  80
  81         option = 1;
  82         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
  83
  84 #if defined(SOL_TCP) && defined(TCP_NODELAY)
  85         setsockopt(nfd, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
  86 #endif
  87
  88 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
  89         option = IPTOS_LOWDELAY;
  90         setsockopt(nfd, SOL_IP, IP_TOS, &option, sizeof(option));
  91 #endif
  92
  93         if(get_config_string
  94            (lookup_config(config_tree, "BindToInterface"), &iface)) {
  95 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
  96                 struct ifreq ifr;
  97
  98                 memset(&ifr, 0, sizeof(ifr));
  99                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 100
 101                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 102                         closesocket(nfd);
 103                         logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 104                                    strerror(errno));
 105                         return -1;
 106                 }
 107 #else
 108                 logger(LOG_WARNING, _("BindToInterface not supported on this platform"));
 109 #endif
 110         }
 111
 112         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 113                 closesocket(nfd);
 114                 addrstr = sockaddr2hostname(sa);
 115                 logger(LOG_ERR, _("Can't bind to %s/tcp: %s"), addrstr,
 116                            strerror(errno));
 117                 free(addrstr);
 118                 return -1;
 119         }
 120
 121         if(listen(nfd, 3)) {
 122                 closesocket(nfd);
 123                 logger(LOG_ERR, _("System call `%s' failed: %s"), "listen",
 124                            strerror(errno));
 125                 return -1;
 126         }
 127
 128         return nfd;
 129 }
 130
 131 int setup_vpn_in_socket(const sockaddr_t *sa)
 132 {
 133         int nfd;
 134         char *addrstr;
 135         int option;
 136
 137         cp();
 138
 139         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 140
 141         if(nfd < 0) {
 142                 logger(LOG_ERR, _("Creating UDP socket failed: %s"), strerror(errno));
 143                 return -1;
 144         }
 145
 146 #ifdef O_NONBLOCK
 147         {
 148                 int flags = fcntl(nfd, F_GETFL);
 149
 150                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 151                         closesocket(nfd);
 152                         logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
 153                                    strerror(errno));
 154                         return -1;
 155                 }
 156         }
 157 #endif
 158
 159         option = 1;
 160         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
 161
 162 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 163         {
 164                 bool choice;
 165
 166                 if(get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) && choice) {
 167                         option = IP_PMTUDISC_DO;
 168                         setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, &option, sizeof(option));
 169                 }
 170         }
 171 #endif
 172
 173 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 174         {
 175                 bool choice;
 176
 177                 if(get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) && choice) {
 178                         option = IPV6_PMTUDISC_DO;
 179                         setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, &option, sizeof(option));
 180                 }
 181         }
 182 #endif
 183
 184 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 185         {
 186                 char *iface;
 187                 struct ifreq ifr;
 188
 189                 if(get_config_string(lookup_config(config_tree, "BindToInterface"), &iface)) {
 190                         memset(&ifr, 0, sizeof(ifr));
 191                         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 192
 193                         if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 194                                 closesocket(nfd);
 195                                 logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 196                                            strerror(errno));
 197                                 return -1;
 198                         }
 199                 }
 200         }
 201 #endif
 202
 203         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 204                 closesocket(nfd);
 205                 addrstr = sockaddr2hostname(sa);
 206                 logger(LOG_ERR, _("Can't bind to %s/udp: %s"), addrstr,
 207                            strerror(errno));
 208                 free(addrstr);
 209                 return -1;
 210         }
 211
 212         return nfd;
 213 }
 214
 215 void retry_outgoing(outgoing_t *outgoing)
 216 {
 217         event_t *event;
 218
 219         cp();
 220
 221         outgoing->timeout += 5;
 222
 223         if(outgoing->timeout > maxtimeout)
 224                 outgoing->timeout = maxtimeout;
 225
 226         event = new_event();
 227         event->handler = (event_handler_t) setup_outgoing_connection;
 228         event->time = now + outgoing->timeout;
 229         event->data = outgoing;
 230         event_add(event);
 231
 232         ifdebug(CONNECTIONS) logger(LOG_NOTICE,
 233                            _("Trying to re-establish outgoing connection in %d seconds"),
 234                            outgoing->timeout);
 235 }
 236
 237 void finish_connecting(connection_t *c)
 238 {
 239         cp();
 240
 241         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Connected to %s (%s)"), c->name, c->hostname);
 242
 243         c->last_ping_time = now;
 244
 245         send_id(c);
 246 }
 247
 248 void do_outgoing_connection(connection_t *c)
 249 {
 250         char *address, *port;
 251         int option, result, flags;
 252
 253         cp();
 254
 255 begin:
 256         if(!c->outgoing->ai) {
 257                 if(!c->outgoing->cfg) {
 258                         ifdebug(CONNECTIONS) logger(LOG_ERR, _("Could not set up a meta connection to %s"),
 259                                            c->name);
 260                         c->status.remove = true;
 261                         retry_outgoing(c->outgoing);
 262                         return;
 263                 }
 264
 265                 get_config_string(c->outgoing->cfg, &address);
 266
 267                 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
 268                         asprintf(&port, "655");
 269
 270                 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 271                 free(address);
 272                 free(port);
 273
 274                 c->outgoing->aip = c->outgoing->ai;
 275                 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
 276         }
 277
 278         if(!c->outgoing->aip) {
 279                 freeaddrinfo(c->outgoing->ai);
 280                 c->outgoing->ai = NULL;
 281                 goto begin;
 282         }
 283
 284         memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
 285         c->outgoing->aip = c->outgoing->aip->ai_next;
 286
 287         if(c->hostname)
 288                 free(c->hostname);
 289
 290         c->hostname = sockaddr2hostname(&c->address);
 291
 292         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Trying to connect to %s (%s)"), c->name,
 293                            c->hostname);
 294
 295         c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 296
 297         if(c->socket == -1) {
 298                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("Creating socket for %s failed: %s"), c->hostname,
 299                                    strerror(errno));
 300
 301                 goto begin;
 302         }
 303
 304         /* Optimize TCP settings */
 305
 306 #if defined(SOL_TCP) && defined(TCP_NODELAY)
 307         option = 1;
 308         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
 309 #endif
 310
 311 #if defined(SOL_IP) && defined(IP_TOS)
 312         option = IPTOS_LOWDELAY;
 313         setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof(option));
 314 #endif
 315
 316         /* Non-blocking */
 317
 318 #ifdef O_NONBLOCK
 319         flags = fcntl(c->socket, F_GETFL);
 320
 321         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
 322                 logger(LOG_ERR, _("fcntl for %s: %s"), c->hostname, strerror(errno));
 323         }
 324 #endif
 325
 326         /* Connect */
 327
 328         result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 329
 330         if(result == -1) {
 331                 if(errno == EINPROGRESS) {
 332                         c->status.connecting = true;
 333                         return;
 334                 }
 335
 336                 closesocket(c->socket);
 337
 338                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("%s: %s"), c->hostname, strerror(errno));
 339
 340                 goto begin;
 341         }
 342
 343         finish_connecting(c);
 344
 345         return;
 346 }
 347
 348 void setup_outgoing_connection(outgoing_t *outgoing)
 349 {
 350         connection_t *c;
 351         node_t *n;
 352
 353         cp();
 354
 355         n = lookup_node(outgoing->name);
 356
 357         if(n)
 358                 if(n->connection) {
 359                         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Already connected to %s"), outgoing->name);
 360
 361                         n->connection->outgoing = outgoing;
 362                         return;
 363                 }
 364
 365         c = new_connection();
 366         c->name = xstrdup(outgoing->name);
 367         c->outcipher = myself->connection->outcipher;
 368         c->outdigest = myself->connection->outdigest;
 369         c->outmaclength = myself->connection->outmaclength;
 370         c->outcompression = myself->connection->outcompression;
 371
 372         init_configuration(&c->config_tree);
 373         read_connection_config(c);
 374
 375         outgoing->cfg = lookup_config(c->config_tree, "Address");
 376
 377         if(!outgoing->cfg) {
 378                 logger(LOG_ERR, _("No address specified for %s"), c->name);
 379                 free_connection(c);
 380                 free(outgoing->name);
 381                 free(outgoing);
 382                 return;
 383         }
 384
 385         c->outgoing = outgoing;
 386         c->last_ping_time = now;
 387
 388         connection_add(c);
 389
 390         do_outgoing_connection(c);
 391 }
 392
 393 /*
 394   accept a new tcp connect and create a
 395   new connection
 396 */
 397 bool handle_new_meta_connection(int sock)
 398 {
 399         connection_t *c;
 400         sockaddr_t sa;
 401         int fd, len = sizeof(sa);
 402
 403         cp();
 404
 405         fd = accept(sock, &sa.sa, &len);
 406
 407         if(fd < 0) {
 408                 logger(LOG_ERR, _("Accepting a new connection failed: %s"),
 409                            strerror(errno));
 410                 return false;
 411         }
 412
 413         sockaddrunmap(&sa);
 414
 415         c = new_connection();
 416         c->outcipher = myself->connection->outcipher;
 417         c->outdigest = myself->connection->outdigest;
 418         c->outmaclength = myself->connection->outmaclength;
 419         c->outcompression = myself->connection->outcompression;
 420
 421         c->address = sa;
 422         c->hostname = sockaddr2hostname(&sa);
 423         c->socket = fd;
 424         c->last_ping_time = now;
 425
 426         ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection from %s"), c->hostname);
 427
 428         connection_add(c);
 429
 430         c->allow_request = ID;
 431         send_id(c);
 432
 433         return true;
 434 }
 435
 436 void try_outgoing_connections(void)
 437 {
 438         static config_t *cfg = NULL;
 439         char *name;
 440         outgoing_t *outgoing;
 441
 442         cp();
 443
 444         for(cfg = lookup_config(config_tree, "ConnectTo"); cfg;
 445                 cfg = lookup_config_next(config_tree, cfg)) {
 446                 get_config_string(cfg, &name);
 447
 448                 if(!check_id(name)) {
 449                         logger(LOG_ERR,
 450                                    _("Invalid name for outgoing connection in %s line %d"),
 451                                    cfg->file, cfg->line);
 452                         free(name);
 453                         continue;
 454                 }
 455
 456                 outgoing = xmalloc_and_zero(sizeof(*outgoing));
 457                 outgoing->name = name;
 458                 setup_outgoing_connection(outgoing);
 459         }
 460 }