git.meshlink.io Git - meshlink/blob - src/net_socket.c

   1 /*
   2     net_socket.c -- Handle various kinds of sockets.
   3     Copyright (C) 1998-2005 Ivo Timmermans,
   4                   2000-2009 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 "splay_tree.h"
  26 #include "conf.h"
  27 #include "connection.h"
  28 #include "logger.h"
  29 #include "meta.h"
  30 #include "net.h"
  31 #include "netutl.h"
  32 #include "protocol.h"
  33 #include "utils.h"
  34 #include "xalloc.h"
  35
  36 #ifdef WSAEINPROGRESS
  37 #define EINPROGRESS WSAEINPROGRESS
  38 #endif
  39
  40 /* Needed on Mac OS/X */
  41 #ifndef SOL_TCP
  42 #define SOL_TCP IPPROTO_TCP
  43 #endif
  44
  45 int addressfamily = AF_UNSPEC;
  46 int maxtimeout = 900;
  47 int seconds_till_retry = 5;
  48
  49 listen_socket_t listen_socket[MAXSOCKETS];
  50 int listen_sockets;
  51 list_t *outgoing_list = NULL;
  52
  53 /* Setup sockets */
  54
  55 static void configure_tcp(connection_t *c) {
  56         int option;
  57
  58 #ifdef O_NONBLOCK
  59         int flags = fcntl(c->socket, F_GETFL);
  60
  61         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
  62                 logger(LOG_ERR, _("fcntl for %s: %s"), c->hostname, strerror(errno));
  63         }
  64 #elif defined(WIN32)
  65         unsigned long arg = 1;
  66
  67         if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
  68                 logger(LOG_ERR, _("ioctlsocket for %s: WSA error %d"), c->hostname, WSAGetLastError());
  69         }
  70 #endif
  71
  72 #if defined(SOL_TCP) && defined(TCP_NODELAY)
  73         option = 1;
  74         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, &option, sizeof option);
  75 #endif
  76
  77 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
  78         option = IPTOS_LOWDELAY;
  79         setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof option);
  80 #endif
  81 }
  82
  83 int setup_listen_socket(const sockaddr_t *sa) {
  84         int nfd;
  85         char *addrstr;
  86         int option;
  87         char *iface;
  88
  89         cp();
  90
  91         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
  92
  93         if(nfd < 0) {
  94                 ifdebug(STATUS) logger(LOG_ERR, _("Creating metasocket failed: %s"), strerror(errno));
  95                 return -1;
  96         }
  97
  98         /* Optimize TCP settings */
  99
 100         option = 1;
 101         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof option);
 102
 103 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 104         if(sa->sa.sa_family == AF_INET6)
 105                 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
 106 #endif
 107
 108         if(get_config_string
 109            (lookup_config(config_tree, "BindToInterface"), &iface)) {
 110 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 111                 struct ifreq ifr;
 112
 113                 memset(&ifr, 0, sizeof ifr);
 114                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 115
 116                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof ifr)) {
 117                         closesocket(nfd);
 118                         logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 119                                    strerror(errno));
 120                         return -1;
 121                 }
 122 #else
 123                 logger(LOG_WARNING, _("BindToInterface not supported on this platform"));
 124 #endif
 125         }
 126
 127         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 128                 closesocket(nfd);
 129                 addrstr = sockaddr2hostname(sa);
 130                 logger(LOG_ERR, _("Can't bind to %s/tcp: %s"), addrstr,
 131                            strerror(errno));
 132                 free(addrstr);
 133                 return -1;
 134         }
 135
 136         if(listen(nfd, 3)) {
 137                 closesocket(nfd);
 138                 logger(LOG_ERR, _("System call `%s' failed: %s"), "listen",
 139                            strerror(errno));
 140                 return -1;
 141         }
 142
 143         return nfd;
 144 }
 145
 146 int setup_vpn_in_socket(const sockaddr_t *sa) {
 147         int nfd;
 148         char *addrstr;
 149         int option;
 150
 151         cp();
 152
 153         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 154
 155         if(nfd < 0) {
 156                 logger(LOG_ERR, _("Creating UDP socket failed: %s"), strerror(errno));
 157                 return -1;
 158         }
 159
 160 #ifdef O_NONBLOCK
 161         {
 162                 int flags = fcntl(nfd, F_GETFL);
 163
 164                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 165                         closesocket(nfd);
 166                         logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
 167                                    strerror(errno));
 168                         return -1;
 169                 }
 170         }
 171 #elif defined(WIN32)
 172         {
 173                 unsigned long arg = 1;
 174                 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 175                         closesocket(nfd);
 176                         logger(LOG_ERR, _("Call to `%s' failed: WSA error %d"), "ioctlsocket",
 177                                 WSAGetLastError());
 178                         return -1;
 179                 }
 180         }
 181 #endif
 182
 183         option = 1;
 184         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof option);
 185
 186 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 187         if(sa->sa.sa_family == AF_INET6)
 188                 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
 189 #endif
 190
 191 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 192         if(myself->options & OPTION_PMTU_DISCOVERY) {
 193                 option = IP_PMTUDISC_DO;
 194                 setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, &option, sizeof(option));
 195         }
 196 #endif
 197
 198 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 199         if(myself->options & OPTION_PMTU_DISCOVERY) {
 200                 option = IPV6_PMTUDISC_DO;
 201                 setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, &option, sizeof(option));
 202         }
 203 #endif
 204
 205 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 206         {
 207                 char *iface;
 208                 struct ifreq ifr;
 209
 210                 if(get_config_string(lookup_config(config_tree, "BindToInterface"), &iface)) {
 211                         memset(&ifr, 0, sizeof ifr);
 212                         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 213
 214                         if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof ifr)) {
 215                                 closesocket(nfd);
 216                                 logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 217                                            strerror(errno));
 218                                 return -1;
 219                         }
 220                 }
 221         }
 222 #endif
 223
 224         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 225                 closesocket(nfd);
 226                 addrstr = sockaddr2hostname(sa);
 227                 logger(LOG_ERR, _("Can't bind to %s/udp: %s"), addrstr,
 228                            strerror(errno));
 229                 free(addrstr);
 230                 return -1;
 231         }
 232
 233         return nfd;
 234 }
 235
 236 static void retry_outgoing_handler(int fd, short events, void *data) {
 237         setup_outgoing_connection(data);
 238 }
 239
 240 void retry_outgoing(outgoing_t *outgoing) {
 241         cp();
 242
 243         outgoing->timeout += 5;
 244
 245         if(outgoing->timeout > maxtimeout)
 246                 outgoing->timeout = maxtimeout;
 247
 248         timeout_set(&outgoing->ev, retry_outgoing_handler, outgoing);
 249         event_add(&outgoing->ev, &(struct timeval){outgoing->timeout, 0});
 250
 251         ifdebug(CONNECTIONS) logger(LOG_NOTICE,
 252                            _("Trying to re-establish outgoing connection in %d seconds"),
 253                            outgoing->timeout);
 254 }
 255
 256 void finish_connecting(connection_t *c) {
 257         cp();
 258
 259         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Connected to %s (%s)"), c->name, c->hostname);
 260
 261         configure_tcp(c);
 262
 263         c->last_ping_time = time(NULL);
 264         c->status.connecting = false;
 265
 266         send_id(c);
 267 }
 268
 269 void do_outgoing_connection(connection_t *c) {
 270         char *address, *port;
 271         int result;
 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                         retry_outgoing(c->outgoing);
 281                         c->outgoing = NULL;
 282                         connection_del(c);
 283                         return;
 284                 }
 285
 286                 get_config_string(c->outgoing->cfg, &address);
 287
 288                 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
 289                         asprintf(&port, "655");
 290
 291                 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 292                 free(address);
 293                 free(port);
 294
 295                 c->outgoing->aip = c->outgoing->ai;
 296                 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
 297         }
 298
 299         if(!c->outgoing->aip) {
 300                 if(c->outgoing->ai)
 301                         freeaddrinfo(c->outgoing->ai);
 302                 c->outgoing->ai = NULL;
 303                 goto begin;
 304         }
 305
 306         memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
 307         c->outgoing->aip = c->outgoing->aip->ai_next;
 308
 309         if(c->hostname)
 310                 free(c->hostname);
 311
 312         c->hostname = sockaddr2hostname(&c->address);
 313
 314         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Trying to connect to %s (%s)"), c->name,
 315                            c->hostname);
 316
 317         c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 318
 319         if(c->socket == -1) {
 320                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("Creating socket for %s failed: %s"), c->hostname,
 321                                    strerror(errno));
 322
 323                 goto begin;
 324         }
 325
 326 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 327         int option = 1;
 328         if(c->address.sa.sa_family == AF_INET6)
 329                 setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
 330 #endif
 331
 332         /* Optimize TCP settings */
 333
 334         configure_tcp(c);
 335
 336         /* Connect */
 337
 338         result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 339
 340         if(result == -1) {
 341                 if(errno == EINPROGRESS
 342 #if defined(WIN32) && !defined(O_NONBLOCK)
 343                    || WSAGetLastError() == WSAEWOULDBLOCK
 344 #endif
 345                 ) {
 346                         c->status.connecting = true;
 347                         return;
 348                 }
 349
 350                 closesocket(c->socket);
 351
 352                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("%s: %s"), c->hostname, strerror(errno));
 353
 354                 goto begin;
 355         }
 356
 357         finish_connecting(c);
 358
 359         return;
 360 }
 361
 362 void handle_meta_read(struct bufferevent *event, void *data) {
 363         logger(LOG_EMERG, _("handle_meta_read() called"));
 364         abort();
 365 }
 366
 367 void handle_meta_write(struct bufferevent *event, void *data) {
 368         ifdebug(META) logger(LOG_DEBUG, _("handle_meta_write() called"));
 369 }
 370
 371 void handle_meta_connection_error(struct bufferevent *event, short what, void *data) {
 372         connection_t *c = data;
 373         logger(LOG_EMERG, _("handle_meta_connection_error() called: %d: %s"), what, strerror(errno));
 374         terminate_connection(c, c->status.active);
 375 }
 376
 377 void setup_outgoing_connection(outgoing_t *outgoing) {
 378         connection_t *c;
 379         node_t *n;
 380
 381         cp();
 382
 383         n = lookup_node(outgoing->name);
 384
 385         if(n)
 386                 if(n->connection) {
 387                         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Already connected to %s"), outgoing->name);
 388
 389                         n->connection->outgoing = outgoing;
 390                         return;
 391                 }
 392
 393         c = new_connection();
 394         c->name = xstrdup(outgoing->name);
 395         c->outcipher = myself->connection->outcipher;
 396         c->outdigest = myself->connection->outdigest;
 397         c->outmaclength = myself->connection->outmaclength;
 398         c->outcompression = myself->connection->outcompression;
 399
 400         init_configuration(&c->config_tree);
 401         read_connection_config(c);
 402
 403         outgoing->cfg = lookup_config(c->config_tree, "Address");
 404
 405         if(!outgoing->cfg) {
 406                 logger(LOG_ERR, _("No address specified for %s"), c->name);
 407                 free_connection(c);
 408                 return;
 409         }
 410
 411         c->outgoing = outgoing;
 412         c->last_ping_time = time(NULL);
 413
 414         connection_add(c);
 415
 416         do_outgoing_connection(c);
 417
 418         event_set(&c->inevent, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c);
 419         event_add(&c->inevent, NULL);
 420         c->buffer = bufferevent_new(c->socket, handle_meta_read, handle_meta_write, handle_meta_connection_error, c);
 421         if(!c->buffer) {
 422                 logger(LOG_EMERG, _("bufferevent_new() failed: %s"), strerror(errno));
 423                 abort();
 424         }
 425         bufferevent_disable(c->buffer, EV_READ);
 426 }
 427
 428 /*
 429   accept a new tcp connect and create a
 430   new connection
 431 */
 432 void handle_new_meta_connection(int sock, short events, void *data) {
 433         connection_t *c;
 434         sockaddr_t sa;
 435         int fd;
 436         socklen_t len = sizeof sa;
 437
 438         cp();
 439
 440         fd = accept(sock, &sa.sa, &len);
 441
 442         if(fd < 0) {
 443                 logger(LOG_ERR, _("Accepting a new connection failed: %s"), strerror(errno));
 444                 return;
 445         }
 446
 447         sockaddrunmap(&sa);
 448
 449         c = new_connection();
 450         c->name = xstrdup("<unknown>");
 451         c->outcipher = myself->connection->outcipher;
 452         c->outdigest = myself->connection->outdigest;
 453         c->outmaclength = myself->connection->outmaclength;
 454         c->outcompression = myself->connection->outcompression;
 455
 456         c->address = sa;
 457         c->hostname = sockaddr2hostname(&sa);
 458         c->socket = fd;
 459         c->last_ping_time = time(NULL);
 460
 461         ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection from %s"), c->hostname);
 462
 463         event_set(&c->inevent, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c);
 464         event_add(&c->inevent, NULL);
 465         c->buffer = bufferevent_new(c->socket, NULL, handle_meta_write, handle_meta_connection_error, c);
 466         if(!c->buffer) {
 467                 logger(LOG_EMERG, _("bufferevent_new() failed: %s"), strerror(errno));
 468                 abort();
 469         }
 470         bufferevent_disable(c->buffer, EV_READ);
 471
 472         configure_tcp(c);
 473
 474         connection_add(c);
 475
 476         c->allow_request = ID;
 477         send_id(c);
 478 }
 479
 480 void free_outgoing(outgoing_t *outgoing) {
 481         if(outgoing->ai)
 482                 freeaddrinfo(outgoing->ai);
 483
 484         if(outgoing->name)
 485                 free(outgoing->name);
 486
 487         free(outgoing);
 488 }
 489
 490 void try_outgoing_connections(void)
 491 {
 492         static config_t *cfg = NULL;
 493         char *name;
 494         outgoing_t *outgoing;
 495         connection_t *c;
 496         splay_node_t *node;
 497
 498         cp();
 499
 500         if(outgoing_list) {
 501                 for(node = connection_tree->head; node; node = node->next) {
 502                         c = node->data;
 503                         c->outgoing = NULL;
 504                 }
 505
 506                 list_delete_list(outgoing_list);
 507         }
 508
 509         outgoing_list = list_alloc((list_action_t)free_outgoing);
 510
 511         for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 512                 get_config_string(cfg, &name);
 513
 514                 if(!check_id(name)) {
 515                         logger(LOG_ERR,
 516                                    _("Invalid name for outgoing connection in %s line %d"),
 517                                    cfg->file, cfg->line);
 518                         free(name);
 519                         continue;
 520                 }
 521
 522                 outgoing = xmalloc_and_zero(sizeof *outgoing);
 523                 outgoing->name = name;
 524                 list_insert_tail(outgoing_list, outgoing);
 525                 setup_outgoing_connection(outgoing);
 526         }
 527 }