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

   1 /*
   2     net_socket.c -- Handle various kinds of sockets.
   3     Copyright (C) 1998-2003 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 1.1.2.34 2003/10/06 14:41:45 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, flags;
  53         char *addrstr;
  54         int option;
  55         char *iface;
  56 #ifdef SO_BINDTODEVICE
  57         struct ifreq ifr;
  58 #endif
  59
  60         cp();
  61
  62         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
  63
  64         if(nfd < 0) {
  65                 ifdebug(STATUS) logger(LOG_ERR, _("Creating metasocket failed: %s"), strerror(errno));
  66                 return -1;
  67         }
  68
  69 #ifdef O_NONBLOCK
  70         flags = fcntl(nfd, F_GETFL);
  71
  72         if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
  73                 closesocket(nfd);
  74                 logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
  75                            strerror(errno));
  76                 return -1;
  77         }
  78 #endif
  79
  80         /* Optimize TCP settings */
  81
  82         option = 1;
  83         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
  84
  85 #if defined(SOL_TCP) && defined(TCP_NODELAY)
  86         setsockopt(nfd, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
  87 #endif
  88
  89 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
  90         option = IPTOS_LOWDELAY;
  91         setsockopt(nfd, SOL_IP, IP_TOS, &option, sizeof(option));
  92 #endif
  93
  94         if(get_config_string
  95            (lookup_config(config_tree, "BindToInterface"), &iface)) {
  96 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
  97                 memset(&ifr, 0, sizeof(ifr));
  98                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
  99
 100                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 101                         closesocket(nfd);
 102                         logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 103                                    strerror(errno));
 104                         return -1;
 105                 }
 106 #else
 107                 logger(LOG_WARNING, _("BindToInterface not supported on this platform"));
 108 #endif
 109         }
 110
 111         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 112                 closesocket(nfd);
 113                 addrstr = sockaddr2hostname(sa);
 114                 logger(LOG_ERR, _("Can't bind to %s/tcp: %s"), addrstr,
 115                            strerror(errno));
 116                 free(addrstr);
 117                 return -1;
 118         }
 119
 120         if(listen(nfd, 3)) {
 121                 closesocket(nfd);
 122                 logger(LOG_ERR, _("System call `%s' failed: %s"), "listen",
 123                            strerror(errno));
 124                 return -1;
 125         }
 126
 127         return nfd;
 128 }
 129
 130 int setup_vpn_in_socket(const sockaddr_t *sa)
 131 {
 132         int nfd, flags;
 133         char *addrstr;
 134         int option;
 135 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 136         char *iface;
 137         struct ifreq ifr;
 138 #endif
 139
 140         cp();
 141
 142         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 143
 144         if(nfd < 0) {
 145                 logger(LOG_ERR, _("Creating UDP socket failed: %s"), strerror(errno));
 146                 return -1;
 147         }
 148
 149 #ifdef O_NONBLOCK
 150         flags = fcntl(nfd, F_GETFL);
 151         if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 152                 closesocket(nfd);
 153                 logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
 154                            strerror(errno));
 155                 return -1;
 156         }
 157 #endif
 158
 159         option = 1;
 160         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
 161
 162 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 163         if(get_config_string
 164            (lookup_config(config_tree, "BindToInterface"), &iface)) {
 165                 memset(&ifr, 0, sizeof(ifr));
 166                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 167
 168                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 169                         closesocket(nfd);
 170                         logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 171                                    strerror(errno));
 172                         return -1;
 173                 }
 174         }
 175 #endif
 176
 177         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 178                 closesocket(nfd);
 179                 addrstr = sockaddr2hostname(sa);
 180                 logger(LOG_ERR, _("Can't bind to %s/udp: %s"), addrstr,
 181                            strerror(errno));
 182                 free(addrstr);
 183                 return -1;
 184         }
 185
 186         return nfd;
 187 }
 188
 189 void retry_outgoing(outgoing_t *outgoing)
 190 {
 191         event_t *event;
 192
 193         cp();
 194
 195         outgoing->timeout += 5;
 196
 197         if(outgoing->timeout > maxtimeout)
 198                 outgoing->timeout = maxtimeout;
 199
 200         event = new_event();
 201         event->handler = (event_handler_t) setup_outgoing_connection;
 202         event->time = now + outgoing->timeout;
 203         event->data = outgoing;
 204         event_add(event);
 205
 206         ifdebug(CONNECTIONS) logger(LOG_NOTICE,
 207                            _("Trying to re-establish outgoing connection in %d seconds"),
 208                            outgoing->timeout);
 209 }
 210
 211 void finish_connecting(connection_t *c)
 212 {
 213         cp();
 214
 215         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Connected to %s (%s)"), c->name, c->hostname);
 216
 217         c->last_ping_time = now;
 218
 219         send_id(c);
 220 }
 221
 222 void do_outgoing_connection(connection_t *c)
 223 {
 224         char *address, *port;
 225         int option, result, flags;
 226
 227         cp();
 228
 229 begin:
 230         if(!c->outgoing->ai) {
 231                 if(!c->outgoing->cfg) {
 232                         ifdebug(CONNECTIONS) logger(LOG_ERR, _("Could not set up a meta connection to %s"),
 233                                            c->name);
 234                         c->status.remove = true;
 235                         retry_outgoing(c->outgoing);
 236                         return;
 237                 }
 238
 239                 get_config_string(c->outgoing->cfg, &address);
 240
 241                 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
 242                         asprintf(&port, "655");
 243
 244                 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 245                 free(address);
 246                 free(port);
 247
 248                 c->outgoing->aip = c->outgoing->ai;
 249                 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
 250         }
 251
 252         if(!c->outgoing->aip) {
 253                 freeaddrinfo(c->outgoing->ai);
 254                 c->outgoing->ai = NULL;
 255                 goto begin;
 256         }
 257
 258         memcpy(&c->address, c->outgoing->aip->ai_addr,
 259                    c->outgoing->aip->ai_addrlen);
 260         c->outgoing->aip = c->outgoing->aip->ai_next;
 261
 262         if(c->hostname)
 263                 free(c->hostname);
 264
 265         c->hostname = sockaddr2hostname(&c->address);
 266
 267         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Trying to connect to %s (%s)"), c->name,
 268                            c->hostname);
 269
 270         c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 271
 272         if(c->socket == -1) {
 273                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("Creating socket for %s failed: %s"), c->hostname,
 274                                    strerror(errno));
 275
 276                 goto begin;
 277         }
 278
 279         /* Optimize TCP settings */
 280
 281 #if defined(SOL_TCP) && defined(TCP_NODELAY)
 282         option = 1;
 283         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
 284 #endif
 285
 286 #if defined(SOL_IP) && defined(IP_TOS)
 287         option = IPTOS_LOWDELAY;
 288         setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof(option));
 289 #endif
 290
 291         /* Non-blocking */
 292
 293 #ifdef O_NONBLOCK
 294         flags = fcntl(c->socket, F_GETFL);
 295
 296         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
 297                 logger(LOG_ERR, _("fcntl for %s: %s"), c->hostname, strerror(errno));
 298         }
 299 #endif
 300
 301         /* Connect */
 302
 303         result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 304
 305         if(result == -1) {
 306                 if(errno == EINPROGRESS) {
 307                         c->status.connecting = true;
 308                         return;
 309                 }
 310
 311                 closesocket(c->socket);
 312
 313                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("%s: %s"), c->hostname, strerror(errno));
 314
 315                 goto begin;
 316         }
 317
 318         finish_connecting(c);
 319
 320         return;
 321 }
 322
 323 void setup_outgoing_connection(outgoing_t *outgoing)
 324 {
 325         connection_t *c;
 326         node_t *n;
 327
 328         cp();
 329
 330         n = lookup_node(outgoing->name);
 331
 332         if(n)
 333                 if(n->connection) {
 334                         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Already connected to %s"), outgoing->name);
 335
 336                         n->connection->outgoing = outgoing;
 337                         return;
 338                 }
 339
 340         c = new_connection();
 341         c->name = xstrdup(outgoing->name);
 342         c->outcipher = myself->connection->outcipher;
 343         c->outdigest = myself->connection->outdigest;
 344         c->outmaclength = myself->connection->outmaclength;
 345         c->outcompression = myself->connection->outcompression;
 346
 347         init_configuration(&c->config_tree);
 348         read_connection_config(c);
 349
 350         outgoing->cfg = lookup_config(c->config_tree, "Address");
 351
 352         if(!outgoing->cfg) {
 353                 logger(LOG_ERR, _("No address specified for %s"), c->name);
 354                 free_connection(c);
 355                 free(outgoing->name);
 356                 free(outgoing);
 357                 return;
 358         }
 359
 360         c->outgoing = outgoing;
 361         c->last_ping_time = now;
 362
 363         connection_add(c);
 364
 365         do_outgoing_connection(c);
 366 }
 367
 368 /*
 369   accept a new tcp connect and create a
 370   new connection
 371 */
 372 bool handle_new_meta_connection(int sock)
 373 {
 374         connection_t *c;
 375         sockaddr_t sa;
 376         int fd, len = sizeof(sa);
 377
 378         cp();
 379
 380         fd = accept(sock, &sa.sa, &len);
 381
 382         if(fd < 0) {
 383                 logger(LOG_ERR, _("Accepting a new connection failed: %s"),
 384                            strerror(errno));
 385                 return false;
 386         }
 387
 388         sockaddrunmap(&sa);
 389
 390         c = new_connection();
 391         c->outcipher = myself->connection->outcipher;
 392         c->outdigest = myself->connection->outdigest;
 393         c->outmaclength = myself->connection->outmaclength;
 394         c->outcompression = myself->connection->outcompression;
 395
 396         c->address = sa;
 397         c->hostname = sockaddr2hostname(&sa);
 398         c->socket = fd;
 399         c->last_ping_time = now;
 400
 401         ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection from %s"), c->hostname);
 402
 403         connection_add(c);
 404
 405         c->allow_request = ID;
 406         send_id(c);
 407
 408         return true;
 409 }
 410
 411 void try_outgoing_connections(void)
 412 {
 413         static config_t *cfg = NULL;
 414         char *name;
 415         outgoing_t *outgoing;
 416
 417         cp();
 418
 419         for(cfg = lookup_config(config_tree, "ConnectTo"); cfg;
 420                 cfg = lookup_config_next(config_tree, cfg)) {
 421                 get_config_string(cfg, &name);
 422
 423                 if(!check_id(name)) {
 424                         logger(LOG_ERR,
 425                                    _("Invalid name for outgoing connection in %s line %d"),
 426                                    cfg->file, cfg->line);
 427                         free(name);
 428                         continue;
 429                 }
 430
 431                 outgoing = xmalloc_and_zero(sizeof(*outgoing));
 432                 outgoing->name = name;
 433                 setup_outgoing_connection(outgoing);
 434         }
 435 }