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 1.1.2.36 2003/12/20 19:47:52 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, "DontFragment"), &choice) && choice) {
 167                         option = IP_PMTUDISC_DO;
 168                         if(setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, &option, sizeof(option))) {
 169                                 closesocket(nfd);
 170                                 logger(LOG_ERR, _("Can't set MTU discovery mode: %s"), strerror(errno));
 171                                 return -1;
 172                         }
 173                 }
 174         }
 175 #endif
 176
 177 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 178         {
 179                 char *iface;
 180                 struct ifreq ifr;
 181
 182                 if(get_config_string(lookup_config(config_tree, "BindToInterface"), &iface)) {
 183                         memset(&ifr, 0, sizeof(ifr));
 184                         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 185
 186                         if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 187                                 closesocket(nfd);
 188                                 logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 189                                            strerror(errno));
 190                                 return -1;
 191                         }
 192                 }
 193         }
 194 #endif
 195
 196         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 197                 closesocket(nfd);
 198                 addrstr = sockaddr2hostname(sa);
 199                 logger(LOG_ERR, _("Can't bind to %s/udp: %s"), addrstr,
 200                            strerror(errno));
 201                 free(addrstr);
 202                 return -1;
 203         }
 204
 205         return nfd;
 206 }
 207
 208 void retry_outgoing(outgoing_t *outgoing)
 209 {
 210         event_t *event;
 211
 212         cp();
 213
 214         outgoing->timeout += 5;
 215
 216         if(outgoing->timeout > maxtimeout)
 217                 outgoing->timeout = maxtimeout;
 218
 219         event = new_event();
 220         event->handler = (event_handler_t) setup_outgoing_connection;
 221         event->time = now + outgoing->timeout;
 222         event->data = outgoing;
 223         event_add(event);
 224
 225         ifdebug(CONNECTIONS) logger(LOG_NOTICE,
 226                            _("Trying to re-establish outgoing connection in %d seconds"),
 227                            outgoing->timeout);
 228 }
 229
 230 void finish_connecting(connection_t *c)
 231 {
 232         cp();
 233
 234         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Connected to %s (%s)"), c->name, c->hostname);
 235
 236         c->last_ping_time = now;
 237
 238         send_id(c);
 239 }
 240
 241 void do_outgoing_connection(connection_t *c)
 242 {
 243         char *address, *port;
 244         int option, result, flags;
 245
 246         cp();
 247
 248 begin:
 249         if(!c->outgoing->ai) {
 250                 if(!c->outgoing->cfg) {
 251                         ifdebug(CONNECTIONS) logger(LOG_ERR, _("Could not set up a meta connection to %s"),
 252                                            c->name);
 253                         c->status.remove = true;
 254                         retry_outgoing(c->outgoing);
 255                         return;
 256                 }
 257
 258                 get_config_string(c->outgoing->cfg, &address);
 259
 260                 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
 261                         asprintf(&port, "655");
 262
 263                 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 264                 free(address);
 265                 free(port);
 266
 267                 c->outgoing->aip = c->outgoing->ai;
 268                 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
 269         }
 270
 271         if(!c->outgoing->aip) {
 272                 freeaddrinfo(c->outgoing->ai);
 273                 c->outgoing->ai = NULL;
 274                 goto begin;
 275         }
 276
 277         memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
 278         c->outgoing->aip = c->outgoing->aip->ai_next;
 279
 280         if(c->hostname)
 281                 free(c->hostname);
 282
 283         c->hostname = sockaddr2hostname(&c->address);
 284
 285         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Trying to connect to %s (%s)"), c->name,
 286                            c->hostname);
 287
 288         c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 289
 290         if(c->socket == -1) {
 291                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("Creating socket for %s failed: %s"), c->hostname,
 292                                    strerror(errno));
 293
 294                 goto begin;
 295         }
 296
 297         /* Optimize TCP settings */
 298
 299 #if defined(SOL_TCP) && defined(TCP_NODELAY)
 300         option = 1;
 301         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
 302 #endif
 303
 304 #if defined(SOL_IP) && defined(IP_TOS)
 305         option = IPTOS_LOWDELAY;
 306         setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof(option));
 307 #endif
 308
 309         /* Non-blocking */
 310
 311 #ifdef O_NONBLOCK
 312         flags = fcntl(c->socket, F_GETFL);
 313
 314         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
 315                 logger(LOG_ERR, _("fcntl for %s: %s"), c->hostname, strerror(errno));
 316         }
 317 #endif
 318
 319         /* Connect */
 320
 321         result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 322
 323         if(result == -1) {
 324                 if(errno == EINPROGRESS) {
 325                         c->status.connecting = true;
 326                         return;
 327                 }
 328
 329                 closesocket(c->socket);
 330
 331                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("%s: %s"), c->hostname, strerror(errno));
 332
 333                 goto begin;
 334         }
 335
 336         finish_connecting(c);
 337
 338         return;
 339 }
 340
 341 void setup_outgoing_connection(outgoing_t *outgoing)
 342 {
 343         connection_t *c;
 344         node_t *n;
 345
 346         cp();
 347
 348         n = lookup_node(outgoing->name);
 349
 350         if(n)
 351                 if(n->connection) {
 352                         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Already connected to %s"), outgoing->name);
 353
 354                         n->connection->outgoing = outgoing;
 355                         return;
 356                 }
 357
 358         c = new_connection();
 359         c->name = xstrdup(outgoing->name);
 360         c->outcipher = myself->connection->outcipher;
 361         c->outdigest = myself->connection->outdigest;
 362         c->outmaclength = myself->connection->outmaclength;
 363         c->outcompression = myself->connection->outcompression;
 364
 365         init_configuration(&c->config_tree);
 366         read_connection_config(c);
 367
 368         outgoing->cfg = lookup_config(c->config_tree, "Address");
 369
 370         if(!outgoing->cfg) {
 371                 logger(LOG_ERR, _("No address specified for %s"), c->name);
 372                 free_connection(c);
 373                 free(outgoing->name);
 374                 free(outgoing);
 375                 return;
 376         }
 377
 378         c->outgoing = outgoing;
 379         c->last_ping_time = now;
 380
 381         connection_add(c);
 382
 383         do_outgoing_connection(c);
 384 }
 385
 386 /*
 387   accept a new tcp connect and create a
 388   new connection
 389 */
 390 bool handle_new_meta_connection(int sock)
 391 {
 392         connection_t *c;
 393         sockaddr_t sa;
 394         int fd, len = sizeof(sa);
 395
 396         cp();
 397
 398         fd = accept(sock, &sa.sa, &len);
 399
 400         if(fd < 0) {
 401                 logger(LOG_ERR, _("Accepting a new connection failed: %s"),
 402                            strerror(errno));
 403                 return false;
 404         }
 405
 406         sockaddrunmap(&sa);
 407
 408         c = new_connection();
 409         c->outcipher = myself->connection->outcipher;
 410         c->outdigest = myself->connection->outdigest;
 411         c->outmaclength = myself->connection->outmaclength;
 412         c->outcompression = myself->connection->outcompression;
 413
 414         c->address = sa;
 415         c->hostname = sockaddr2hostname(&sa);
 416         c->socket = fd;
 417         c->last_ping_time = now;
 418
 419         ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection from %s"), c->hostname);
 420
 421         connection_add(c);
 422
 423         c->allow_request = ID;
 424         send_id(c);
 425
 426         return true;
 427 }
 428
 429 void try_outgoing_connections(void)
 430 {
 431         static config_t *cfg = NULL;
 432         char *name;
 433         outgoing_t *outgoing;
 434
 435         cp();
 436
 437         for(cfg = lookup_config(config_tree, "ConnectTo"); cfg;
 438                 cfg = lookup_config_next(config_tree, cfg)) {
 439                 get_config_string(cfg, &name);
 440
 441                 if(!check_id(name)) {
 442                         logger(LOG_ERR,
 443                                    _("Invalid name for outgoing connection in %s line %d"),
 444                                    cfg->file, cfg->line);
 445                         free(name);
 446                         continue;
 447                 }
 448
 449                 outgoing = xmalloc_and_zero(sizeof(*outgoing));
 450                 outgoing->name = name;
 451                 setup_outgoing_connection(outgoing);
 452         }
 453 }