www.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 <gnutls/gnutls.h>
  26
  27 #include "avl_tree.h"
  28 #include "conf.h"
  29 #include "connection.h"
  30 #include "event.h"
  31 #include "logger.h"
  32 #include "meta.h"
  33 #include "net.h"
  34 #include "netutl.h"
  35 #include "protocol.h"
  36 #include "utils.h"
  37 #include "xalloc.h"
  38
  39 #ifdef WSAEINPROGRESS
  40 #define EINPROGRESS WSAEINPROGRESS
  41 #endif
  42
  43 int addressfamily = AF_UNSPEC;
  44 int maxtimeout = 900;
  45 int seconds_till_retry = 5;
  46
  47 listen_socket_t listen_socket[MAXSOCKETS];
  48 int listen_sockets;
  49
  50 int certselfunc(gnutls_session session,  const gnutls_datum *client_cert, int ncerts, const gnutls_datum* req_ca_cert, int nreqs) {
  51         logger(LOG_DEBUG, "Client certificate select function called with %d certs, %d requests\n", ncerts, nreqs);
  52         return 0;
  53 }
  54
  55 int scertselfunc(gnutls_session session,  const gnutls_datum *server_cert, int ncerts) {
  56         logger(LOG_DEBUG, "Server certificate select function called with %d certs\n", ncerts);
  57         return 0;
  58 }
  59
  60 /* Setup sockets */
  61
  62 int setup_listen_socket(const sockaddr_t *sa)
  63 {
  64         int nfd;
  65         char *addrstr;
  66         int option;
  67         char *iface;
  68
  69         cp();
  70
  71         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
  72
  73         if(nfd < 0) {
  74                 ifdebug(STATUS) logger(LOG_ERR, _("Creating metasocket failed: %s"), strerror(errno));
  75                 return -1;
  76         }
  77
  78 #ifdef O_NONBLOCK
  79         {
  80                 int flags = fcntl(nfd, F_GETFL);
  81
  82                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
  83                         closesocket(nfd);
  84                         logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
  85                                    strerror(errno));
  86                         return -1;
  87                 }
  88         }
  89 #endif
  90
  91         /* Optimize TCP settings */
  92
  93         option = 1;
  94         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
  95
  96 #if defined(SOL_TCP) && defined(TCP_NODELAY)
  97         setsockopt(nfd, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
  98 #endif
  99
 100 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
 101         option = IPTOS_LOWDELAY;
 102         setsockopt(nfd, SOL_IP, IP_TOS, &option, sizeof(option));
 103 #endif
 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 #endif
 170
 171         option = 1;
 172         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
 173
 174 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 175         {
 176                 bool choice;
 177
 178                 if(get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) && choice) {
 179                         option = IP_PMTUDISC_DO;
 180                         setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, &option, sizeof(option));
 181                 }
 182         }
 183 #endif
 184
 185 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 186         {
 187                 bool choice;
 188
 189                 if(get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) && choice) {
 190                         option = IPV6_PMTUDISC_DO;
 191                         setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, &option, sizeof(option));
 192                 }
 193         }
 194 #endif
 195
 196 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 197         {
 198                 char *iface;
 199                 struct ifreq ifr;
 200
 201                 if(get_config_string(lookup_config(config_tree, "BindToInterface"), &iface)) {
 202                         memset(&ifr, 0, sizeof(ifr));
 203                         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 204
 205                         if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 206                                 closesocket(nfd);
 207                                 logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 208                                            strerror(errno));
 209                                 return -1;
 210                         }
 211                 }
 212         }
 213 #endif
 214
 215         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 216                 closesocket(nfd);
 217                 addrstr = sockaddr2hostname(sa);
 218                 logger(LOG_ERR, _("Can't bind to %s/udp: %s"), addrstr,
 219                            strerror(errno));
 220                 free(addrstr);
 221                 return -1;
 222         }
 223
 224         return nfd;
 225 }
 226
 227 void retry_outgoing(outgoing_t *outgoing)
 228 {
 229         event_t *event;
 230
 231         cp();
 232
 233         outgoing->timeout += 5;
 234
 235         if(outgoing->timeout > maxtimeout)
 236                 outgoing->timeout = maxtimeout;
 237
 238         event = new_event();
 239         event->handler = (event_handler_t) setup_outgoing_connection;
 240         event->time = now + outgoing->timeout;
 241         event->data = outgoing;
 242         event_add(event);
 243
 244         ifdebug(CONNECTIONS) logger(LOG_NOTICE,
 245                            _("Trying to re-establish outgoing connection in %d seconds"),
 246                            outgoing->timeout);
 247 }
 248
 249 void finish_connecting(connection_t *c)
 250 {
 251         int result;
 252
 253         cp();
 254
 255         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Connected to %s (%s)"), c->name, c->hostname);
 256
 257         c->last_ping_time = now;
 258
 259         gnutls_init(&c->session, GNUTLS_SERVER);
 260         gnutls_set_default_priority(c->session);
 261         gnutls_credentials_set(c->session, GNUTLS_CRD_CERTIFICATE, myself->connection->credentials);
 262         gnutls_certificate_server_set_request(c->session, GNUTLS_CERT_REQUEST);
 263 //      gnutls_certificate_client_set_select_function(c->session, certselfunc);
 264 //      gnutls_certificate_server_set_select_function(c->session, scertselfunc);
 265         gnutls_transport_set_ptr(c->session, c->socket);
 266 }
 267
 268 void do_outgoing_connection(connection_t *c)
 269 {
 270         char *address, *port;
 271         int option, result, flags;
 272
 273         cp();
 274
 275 begin:
 276         if(!c->outgoing->ai) {
 277                 if(!c->outgoing->cfg) {
 278                         ifdebug(CONNECTIONS) logger(LOG_ERR, _("Could not set up a meta connection to %s"),
 279                                            c->name);
 280                         c->status.remove = true;
 281                         retry_outgoing(c->outgoing);
 282                         return;
 283                 }
 284
 285                 get_config_string(c->outgoing->cfg, &address);
 286
 287                 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
 288                         asprintf(&port, "655");
 289
 290                 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 291                 free(address);
 292                 free(port);
 293
 294                 c->outgoing->aip = c->outgoing->ai;
 295                 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
 296         }
 297
 298         if(!c->outgoing->aip) {
 299                 freeaddrinfo(c->outgoing->ai);
 300                 c->outgoing->ai = NULL;
 301                 goto begin;
 302         }
 303
 304         memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
 305         c->outgoing->aip = c->outgoing->aip->ai_next;
 306
 307         if(c->hostname)
 308                 free(c->hostname);
 309
 310         c->hostname = sockaddr2hostname(&c->address);
 311
 312         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Trying to connect to %s (%s)"), c->name,
 313                            c->hostname);
 314
 315         c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 316
 317         if(c->socket == -1) {
 318                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("Creating socket for %s failed: %s"), c->hostname,
 319                                    strerror(errno));
 320
 321                 goto begin;
 322         }
 323
 324         /* Optimize TCP settings */
 325
 326 #if defined(SOL_TCP) && defined(TCP_NODELAY)
 327         option = 1;
 328         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
 329 #endif
 330
 331 #if defined(SOL_IP) && defined(IP_TOS)
 332         option = IPTOS_LOWDELAY;
 333         setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof(option));
 334 #endif
 335
 336         /* Non-blocking */
 337
 338 #ifdef O_NONBLOCK
 339         flags = fcntl(c->socket, F_GETFL);
 340
 341         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
 342                 logger(LOG_ERR, _("fcntl for %s: %s"), c->hostname, strerror(errno));
 343         }
 344 #endif
 345
 346         /* Connect */
 347
 348         result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 349
 350         if(result == -1) {
 351                 if(errno == EINPROGRESS) {
 352                         c->status.connecting = true;
 353                         return;
 354                 }
 355
 356                 closesocket(c->socket);
 357
 358                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("%s: %s"), c->hostname, strerror(errno));
 359
 360                 goto begin;
 361         }
 362
 363         logger(LOG_DEBUG, _("finishing connection"));
 364         finish_connecting(c);
 365
 366         return;
 367 }
 368
 369 void setup_outgoing_connection(outgoing_t *outgoing)
 370 {
 371         connection_t *c;
 372         node_t *n;
 373
 374         cp();
 375
 376         n = lookup_node(outgoing->name);
 377
 378         if(n)
 379                 if(n->connection) {
 380                         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Already connected to %s"), outgoing->name);
 381
 382                         n->connection->outgoing = outgoing;
 383                         return;
 384                 }
 385
 386         c = new_connection();
 387         c->name = xstrdup(outgoing->name);
 388
 389         init_configuration(&c->config_tree);
 390         read_connection_config(c);
 391
 392         outgoing->cfg = lookup_config(c->config_tree, "Address");
 393
 394         if(!outgoing->cfg) {
 395                 logger(LOG_ERR, _("No address specified for %s"), c->name);
 396                 free_connection(c);
 397                 free(outgoing->name);
 398                 free(outgoing);
 399                 return;
 400         }
 401
 402         c->outgoing = outgoing;
 403         c->last_ping_time = now;
 404
 405         connection_add(c);
 406
 407         do_outgoing_connection(c);
 408 }
 409
 410 /*
 411   accept a new tcp connect and create a
 412   new connection
 413 */
 414 bool handle_new_meta_connection(int sock)
 415 {
 416         connection_t *c;
 417         sockaddr_t sa;
 418         int fd, len = sizeof(sa);
 419         int result;
 420
 421         cp();
 422
 423         fd = accept(sock, &sa.sa, &len);
 424
 425         if(fd < 0) {
 426                 logger(LOG_ERR, _("Accepting a new connection failed: %s"),
 427                            strerror(errno));
 428                 return false;
 429         }
 430
 431 #ifdef O_NONBLOCK
 432         {
 433                 int flags = fcntl(fd, F_GETFL);
 434
 435                 if(fcntl(fd, F_SETFL, flags | O_NONBLOCK) < 0) {
 436                         closesocket(fd);
 437                         logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
 438                                    strerror(errno));
 439                         return -1;
 440                 }
 441         }
 442 #endif
 443
 444         sockaddrunmap(&sa);
 445
 446         c = new_connection();
 447
 448         c->address = sa;
 449         c->hostname = sockaddr2hostname(&sa);
 450         c->socket = fd;
 451         c->last_ping_time = now;
 452
 453         ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection from %s"), c->hostname);
 454
 455         connection_add(c);
 456
 457         c->allow_request = ID;
 458         gnutls_init(&c->session, GNUTLS_CLIENT);
 459         gnutls_set_default_priority(c->session);
 460         gnutls_credentials_set(c->session, GNUTLS_CRD_CERTIFICATE, myself->connection->credentials);
 461         gnutls_certificate_server_set_request(c->session, GNUTLS_CERT_REQUEST);
 462 //      gnutls_certificate_client_set_select_function(c->session, certselfunc);
 463 //      gnutls_certificate_server_set_select_function(c->session, scertselfunc);
 464         gnutls_transport_set_ptr(c->session, c->socket);
 465         gnutls_handshake(c->session);
 466
 467         return true;
 468 }
 469
 470 void try_outgoing_connections(void)
 471 {
 472         static config_t *cfg = NULL;
 473         char *name;
 474         outgoing_t *outgoing;
 475
 476         cp();
 477
 478         for(cfg = lookup_config(config_tree, "ConnectTo"); cfg;
 479                 cfg = lookup_config_next(config_tree, cfg)) {
 480                 get_config_string(cfg, &name);
 481
 482                 if(!check_id(name)) {
 483                         logger(LOG_ERR,
 484                                    _("Invalid name for outgoing connection in %s line %d"),
 485                                    cfg->file, cfg->line);
 486                         free(name);
 487                         continue;
 488                 }
 489
 490                 outgoing = xmalloc_and_zero(sizeof(*outgoing));
 491                 outgoing->name = name;
 492                 setup_outgoing_connection(outgoing);
 493         }
 494 }