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

   1 /*
   2     net_socket.c -- Handle various kinds of sockets.
   3     Copyright (C) 1998-2004 Ivo Timmermans <ivo@tinc-vpn.org>,
   4                   2000-2004 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 "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 bool blockingtcp = false;
  45
  46 listen_socket_t listen_socket[MAXSOCKETS];
  47 int listen_sockets;
  48
  49 /* Setup sockets */
  50
  51 int setup_listen_socket(const sockaddr_t *sa)
  52 {
  53         int nfd;
  54         char *addrstr;
  55         int option;
  56         char *iface;
  57
  58         cp();
  59
  60         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
  61
  62         if(nfd < 0) {
  63                 ifdebug(STATUS) logger(LOG_ERR, _("Creating metasocket failed: %s"), strerror(errno));
  64                 return -1;
  65         }
  66
  67 #ifdef O_NONBLOCK
  68         {
  69                 int flags = fcntl(nfd, F_GETFL);
  70
  71                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
  72                         closesocket(nfd);
  73                         logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
  74                                    strerror(errno));
  75                         return -1;
  76                 }
  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                 struct ifreq ifr;
  98
  99                 memset(&ifr, 0, sizeof(ifr));
 100                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 101
 102                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 103                         closesocket(nfd);
 104                         logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 105                                    strerror(errno));
 106                         return -1;
 107                 }
 108 #else
 109                 logger(LOG_WARNING, _("BindToInterface not supported on this platform"));
 110 #endif
 111         }
 112
 113         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 114                 closesocket(nfd);
 115                 addrstr = sockaddr2hostname(sa);
 116                 logger(LOG_ERR, _("Can't bind to %s/tcp: %s"), addrstr,
 117                            strerror(errno));
 118                 free(addrstr);
 119                 return -1;
 120         }
 121
 122         if(listen(nfd, 3)) {
 123                 closesocket(nfd);
 124                 logger(LOG_ERR, _("System call `%s' failed: %s"), "listen",
 125                            strerror(errno));
 126                 return -1;
 127         }
 128
 129         return nfd;
 130 }
 131
 132 int setup_vpn_in_socket(const sockaddr_t *sa)
 133 {
 134         int nfd;
 135         char *addrstr;
 136         int option;
 137
 138         cp();
 139
 140         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 141
 142         if(nfd < 0) {
 143                 logger(LOG_ERR, _("Creating UDP socket failed: %s"), strerror(errno));
 144                 return -1;
 145         }
 146
 147 #ifdef O_NONBLOCK
 148         {
 149                 int flags = fcntl(nfd, F_GETFL);
 150
 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         }
 158 #endif
 159
 160         option = 1;
 161         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
 162
 163 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 164         {
 165                 bool choice;
 166
 167                 if(get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) && choice) {
 168                         option = IP_PMTUDISC_DO;
 169                         setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, &option, sizeof(option));
 170                 }
 171         }
 172 #endif
 173
 174 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 175         {
 176                 bool choice;
 177
 178                 if(get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) && choice) {
 179                         option = IPV6_PMTUDISC_DO;
 180                         setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, &option, sizeof(option));
 181                 }
 182         }
 183 #endif
 184
 185 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 186         {
 187                 char *iface;
 188                 struct ifreq ifr;
 189
 190                 if(get_config_string(lookup_config(config_tree, "BindToInterface"), &iface)) {
 191                         memset(&ifr, 0, sizeof(ifr));
 192                         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 193
 194                         if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 195                                 closesocket(nfd);
 196                                 logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 197                                            strerror(errno));
 198                                 return -1;
 199                         }
 200                 }
 201         }
 202 #endif
 203
 204         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 205                 closesocket(nfd);
 206                 addrstr = sockaddr2hostname(sa);
 207                 logger(LOG_ERR, _("Can't bind to %s/udp: %s"), addrstr,
 208                            strerror(errno));
 209                 free(addrstr);
 210                 return -1;
 211         }
 212
 213         return nfd;
 214 }
 215
 216 void retry_outgoing(outgoing_t *outgoing)
 217 {
 218         event_t *event;
 219
 220         cp();
 221
 222         outgoing->timeout += 5;
 223
 224         if(outgoing->timeout > maxtimeout)
 225                 outgoing->timeout = maxtimeout;
 226
 227         event = new_event();
 228         event->handler = (event_handler_t) setup_outgoing_connection;
 229         event->time = now + outgoing->timeout;
 230         event->data = outgoing;
 231         event_add(event);
 232
 233         ifdebug(CONNECTIONS) logger(LOG_NOTICE,
 234                            _("Trying to re-establish outgoing connection in %d seconds"),
 235                            outgoing->timeout);
 236 }
 237
 238 void finish_connecting(connection_t *c)
 239 {
 240         cp();
 241
 242         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Connected to %s (%s)"), c->name, c->hostname);
 243
 244 #ifdef O_NONBLOCK
 245         if(blockingtcp) {
 246                 int flags = fcntl(c->socket, F_GETFL);
 247
 248                 if(fcntl(c->socket, F_SETFL, flags & ~O_NONBLOCK) < 0) {
 249                         logger(LOG_ERR, _("fcntl for %s: %s"), c->hostname, strerror(errno));
 250                 }
 251         }
 252 #endif
 253
 254         c->last_ping_time = now;
 255
 256         send_id(c);
 257 }
 258
 259 void do_outgoing_connection(connection_t *c)
 260 {
 261         char *address, *port;
 262         int option, result, flags;
 263
 264         cp();
 265
 266 begin:
 267         if(!c->outgoing->ai) {
 268                 if(!c->outgoing->cfg) {
 269                         ifdebug(CONNECTIONS) logger(LOG_ERR, _("Could not set up a meta connection to %s"),
 270                                            c->name);
 271                         c->status.remove = true;
 272                         retry_outgoing(c->outgoing);
 273                         return;
 274                 }
 275
 276                 get_config_string(c->outgoing->cfg, &address);
 277
 278                 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
 279                         asprintf(&port, "655");
 280
 281                 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 282                 free(address);
 283                 free(port);
 284
 285                 c->outgoing->aip = c->outgoing->ai;
 286                 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
 287         }
 288
 289         if(!c->outgoing->aip) {
 290                 freeaddrinfo(c->outgoing->ai);
 291                 c->outgoing->ai = NULL;
 292                 goto begin;
 293         }
 294
 295         memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
 296         c->outgoing->aip = c->outgoing->aip->ai_next;
 297
 298         if(c->hostname)
 299                 free(c->hostname);
 300
 301         c->hostname = sockaddr2hostname(&c->address);
 302
 303         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Trying to connect to %s (%s)"), c->name,
 304                            c->hostname);
 305
 306         c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 307
 308         if(c->socket == -1) {
 309                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("Creating socket for %s failed: %s"), c->hostname,
 310                                    strerror(errno));
 311
 312                 goto begin;
 313         }
 314
 315         /* Optimize TCP settings */
 316
 317 #if defined(SOL_TCP) && defined(TCP_NODELAY)
 318         option = 1;
 319         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
 320 #endif
 321
 322 #if defined(SOL_IP) && defined(IP_TOS)
 323         option = IPTOS_LOWDELAY;
 324         setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof(option));
 325 #endif
 326
 327         /* Non-blocking */
 328
 329 #ifdef O_NONBLOCK
 330         flags = fcntl(c->socket, F_GETFL);
 331
 332         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
 333                 logger(LOG_ERR, _("fcntl for %s: %s"), c->hostname, strerror(errno));
 334         }
 335 #endif
 336
 337         /* Connect */
 338
 339         result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 340
 341         if(result == -1) {
 342                 if(errno == EINPROGRESS) {
 343                         c->status.connecting = true;
 344                         return;
 345                 }
 346
 347                 closesocket(c->socket);
 348
 349                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("%s: %s"), c->hostname, strerror(errno));
 350
 351                 goto begin;
 352         }
 353
 354         finish_connecting(c);
 355
 356         return;
 357 }
 358
 359 void setup_outgoing_connection(outgoing_t *outgoing)
 360 {
 361         connection_t *c;
 362         node_t *n;
 363
 364         cp();
 365
 366         n = lookup_node(outgoing->name);
 367
 368         if(n)
 369                 if(n->connection) {
 370                         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Already connected to %s"), outgoing->name);
 371
 372                         n->connection->outgoing = outgoing;
 373                         return;
 374                 }
 375
 376         c = new_connection();
 377         c->name = xstrdup(outgoing->name);
 378         c->outcipher = myself->connection->outcipher;
 379         c->outdigest = myself->connection->outdigest;
 380         c->outmaclength = myself->connection->outmaclength;
 381         c->outcompression = myself->connection->outcompression;
 382
 383         init_configuration(&c->config_tree);
 384         read_connection_config(c);
 385
 386         outgoing->cfg = lookup_config(c->config_tree, "Address");
 387
 388         if(!outgoing->cfg) {
 389                 logger(LOG_ERR, _("No address specified for %s"), c->name);
 390                 free_connection(c);
 391                 free(outgoing->name);
 392                 free(outgoing);
 393                 return;
 394         }
 395
 396         c->outgoing = outgoing;
 397         c->last_ping_time = now;
 398
 399         connection_add(c);
 400
 401         do_outgoing_connection(c);
 402 }
 403
 404 /*
 405   accept a new tcp connect and create a
 406   new connection
 407 */
 408 bool handle_new_meta_connection(int sock)
 409 {
 410         connection_t *c;
 411         sockaddr_t sa;
 412         int fd, len = sizeof(sa);
 413
 414         cp();
 415
 416         fd = accept(sock, &sa.sa, &len);
 417
 418         if(fd < 0) {
 419                 logger(LOG_ERR, _("Accepting a new connection failed: %s"),
 420                            strerror(errno));
 421                 return false;
 422         }
 423
 424         sockaddrunmap(&sa);
 425
 426         c = new_connection();
 427         c->outcipher = myself->connection->outcipher;
 428         c->outdigest = myself->connection->outdigest;
 429         c->outmaclength = myself->connection->outmaclength;
 430         c->outcompression = myself->connection->outcompression;
 431
 432         c->address = sa;
 433         c->hostname = sockaddr2hostname(&sa);
 434         c->socket = fd;
 435         c->last_ping_time = now;
 436
 437         ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection from %s"), c->hostname);
 438
 439 #ifdef O_NONBLOCK
 440         if(blockingtcp) {
 441                 int flags = fcntl(c->socket, F_GETFL);
 442
 443                 if(fcntl(c->socket, F_SETFL, flags & ~O_NONBLOCK) < 0) {
 444                         logger(LOG_ERR, _("fcntl for %s: %s"), c->hostname, strerror(errno));
 445                 }
 446         }
 447 #endif
 448
 449         connection_add(c);
 450
 451         c->allow_request = ID;
 452         send_id(c);
 453
 454         return true;
 455 }
 456
 457 void try_outgoing_connections(void)
 458 {
 459         static config_t *cfg = NULL;
 460         char *name;
 461         outgoing_t *outgoing;
 462
 463         cp();
 464
 465         for(cfg = lookup_config(config_tree, "ConnectTo"); cfg;
 466                 cfg = lookup_config_next(config_tree, cfg)) {
 467                 get_config_string(cfg, &name);
 468
 469                 if(!check_id(name)) {
 470                         logger(LOG_ERR,
 471                                    _("Invalid name for outgoing connection in %s line %d"),
 472                                    cfg->file, cfg->line);
 473                         free(name);
 474                         continue;
 475                 }
 476
 477                 outgoing = xmalloc_and_zero(sizeof(*outgoing));
 478                 outgoing->name = name;
 479                 setup_outgoing_connection(outgoing);
 480         }
 481 }