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                   2000-2007 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
  52 /* Setup sockets */
  53
  54 static void configure_tcp(connection_t *c) {
  55         int option;
  56
  57 #ifdef O_NONBLOCK
  58         int flags = fcntl(c->socket, F_GETFL);
  59
  60         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
  61                 logger(LOG_ERR, _("fcntl for %s: %s"), c->hostname, strerror(errno));
  62         }
  63 #elif defined(WIN32)
  64         unsigned long arg = 1;
  65
  66         if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
  67                 logger(LOG_ERR, _("ioctlsocket for %s: WSA error %d"), c->hostname, WSAGetLastError());
  68         }
  69 #endif
  70
  71 #if defined(SOL_TCP) && defined(TCP_NODELAY)
  72         option = 1;
  73         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, &option, sizeof option);
  74 #endif
  75
  76 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
  77         option = IPTOS_LOWDELAY;
  78         setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof option);
  79 #endif
  80 }
  81
  82 int setup_listen_socket(const sockaddr_t *sa) {
  83         int nfd;
  84         char *addrstr;
  85         int option;
  86         char *iface;
  87
  88         cp();
  89
  90         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
  91
  92         if(nfd < 0) {
  93                 ifdebug(STATUS) logger(LOG_ERR, _("Creating metasocket failed: %s"), strerror(errno));
  94                 return -1;
  95         }
  96
  97         /* Optimize TCP settings */
  98
  99         option = 1;
 100         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof option);
 101
 102 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 103         if(sa->sa.sa_family == AF_INET6)
 104                 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
 105 #endif
 106
 107         if(get_config_string
 108            (lookup_config(config_tree, "BindToInterface"), &iface)) {
 109 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 110                 struct ifreq ifr;
 111
 112                 memset(&ifr, 0, sizeof ifr);
 113                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 114
 115                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof ifr)) {
 116                         closesocket(nfd);
 117                         logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 118                                    strerror(errno));
 119                         return -1;
 120                 }
 121 #else
 122                 logger(LOG_WARNING, _("BindToInterface not supported on this platform"));
 123 #endif
 124         }
 125
 126         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 127                 closesocket(nfd);
 128                 addrstr = sockaddr2hostname(sa);
 129                 logger(LOG_ERR, _("Can't bind to %s/tcp: %s"), addrstr,
 130                            strerror(errno));
 131                 free(addrstr);
 132                 return -1;
 133         }
 134
 135         if(listen(nfd, 3)) {
 136                 closesocket(nfd);
 137                 logger(LOG_ERR, _("System call `%s' failed: %s"), "listen",
 138                            strerror(errno));
 139                 return -1;
 140         }
 141
 142         return nfd;
 143 }
 144
 145 int setup_vpn_in_socket(const sockaddr_t *sa) {
 146         int nfd;
 147         char *addrstr;
 148         int option;
 149
 150         cp();
 151
 152         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 153
 154         if(nfd < 0) {
 155                 logger(LOG_ERR, _("Creating UDP socket failed: %s"), strerror(errno));
 156                 return -1;
 157         }
 158
 159 #ifdef O_NONBLOCK
 160         {
 161                 int flags = fcntl(nfd, F_GETFL);
 162
 163                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 164                         closesocket(nfd);
 165                         logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
 166                                    strerror(errno));
 167                         return -1;
 168                 }
 169         }
 170 #elif defined(WIN32)
 171         {
 172                 unsigned long arg = 1;
 173                 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 174                         closesocket(nfd);
 175                         logger(LOG_ERR, _("Call to `%s' failed: WSA error %d"), "ioctlsocket",
 176                                 WSAGetLastError());
 177                         return -1;
 178                 }
 179         }
 180 #endif
 181
 182         option = 1;
 183         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof option);
 184
 185 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 186         if(sa->sa.sa_family == AF_INET6)
 187                 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
 188 #endif
 189
 190 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 191         {
 192                 bool choice;
 193
 194                 if(get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) && choice) {
 195                         option = IP_PMTUDISC_DO;
 196                         setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, &option, sizeof option);
 197                 }
 198         }
 199 #endif
 200
 201 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 202         {
 203                 bool choice;
 204
 205                 if(get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) && choice) {
 206                         option = IPV6_PMTUDISC_DO;
 207                         setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, &option, sizeof option);
 208                 }
 209         }
 210 #endif
 211
 212 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 213         {
 214                 char *iface;
 215                 struct ifreq ifr;
 216
 217                 if(get_config_string(lookup_config(config_tree, "BindToInterface"), &iface)) {
 218                         memset(&ifr, 0, sizeof ifr);
 219                         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 220
 221                         if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof ifr)) {
 222                                 closesocket(nfd);
 223                                 logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 224                                            strerror(errno));
 225                                 return -1;
 226                         }
 227                 }
 228         }
 229 #endif
 230
 231         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 232                 closesocket(nfd);
 233                 addrstr = sockaddr2hostname(sa);
 234                 logger(LOG_ERR, _("Can't bind to %s/udp: %s"), addrstr,
 235                            strerror(errno));
 236                 free(addrstr);
 237                 return -1;
 238         }
 239
 240         return nfd;
 241 }
 242
 243 static void retry_outgoing_handler(int fd, short events, void *data) {
 244         setup_outgoing_connection(data);
 245 }
 246
 247 void retry_outgoing(outgoing_t *outgoing) {
 248         cp();
 249
 250         outgoing->timeout += 5;
 251
 252         if(outgoing->timeout > maxtimeout)
 253                 outgoing->timeout = maxtimeout;
 254
 255         timeout_set(&outgoing->ev, retry_outgoing_handler, outgoing);
 256         event_add(&outgoing->ev, &(struct timeval){outgoing->timeout, 0});
 257
 258         ifdebug(CONNECTIONS) logger(LOG_NOTICE,
 259                            _("Trying to re-establish outgoing connection in %d seconds"),
 260                            outgoing->timeout);
 261 }
 262
 263 void finish_connecting(connection_t *c) {
 264         cp();
 265
 266         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Connected to %s (%s)"), c->name, c->hostname);
 267
 268         configure_tcp(c);
 269
 270         c->last_ping_time = time(NULL);
 271         c->status.connecting = false;
 272
 273         send_id(c);
 274 }
 275
 276 void do_outgoing_connection(connection_t *c) {
 277         char *address, *port;
 278         int result;
 279
 280         cp();
 281
 282 begin:
 283         if(!c->outgoing->ai) {
 284                 if(!c->outgoing->cfg) {
 285                         ifdebug(CONNECTIONS) logger(LOG_ERR, _("Could not set up a meta connection to %s"),
 286                                            c->name);
 287                         retry_outgoing(c->outgoing);
 288                         c->outgoing = NULL;
 289                         connection_del(c);
 290                         return;
 291                 }
 292
 293                 get_config_string(c->outgoing->cfg, &address);
 294
 295                 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
 296                         asprintf(&port, "655");
 297
 298                 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 299                 free(address);
 300                 free(port);
 301
 302                 c->outgoing->aip = c->outgoing->ai;
 303                 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
 304         }
 305
 306         if(!c->outgoing->aip) {
 307                 if(c->outgoing->ai)
 308                         freeaddrinfo(c->outgoing->ai);
 309                 c->outgoing->ai = NULL;
 310                 goto begin;
 311         }
 312
 313         memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
 314         c->outgoing->aip = c->outgoing->aip->ai_next;
 315
 316         if(c->hostname)
 317                 free(c->hostname);
 318
 319         c->hostname = sockaddr2hostname(&c->address);
 320
 321         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Trying to connect to %s (%s)"), c->name,
 322                            c->hostname);
 323
 324         c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 325
 326         if(c->socket == -1) {
 327                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("Creating socket for %s failed: %s"), c->hostname,
 328                                    strerror(errno));
 329
 330                 goto begin;
 331         }
 332
 333 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 334         int option = 1;
 335         if(c->address.sa.sa_family == AF_INET6)
 336                 setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
 337 #endif
 338
 339         /* Optimize TCP settings */
 340
 341         configure_tcp(c);
 342
 343         /* Connect */
 344
 345         result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 346
 347         if(result == -1) {
 348                 if(errno == EINPROGRESS
 349 #if defined(WIN32) && !defined(O_NONBLOCK)
 350                    || WSAGetLastError() == WSAEWOULDBLOCK
 351 #endif
 352                 ) {
 353                         c->status.connecting = true;
 354                         return;
 355                 }
 356
 357                 closesocket(c->socket);
 358
 359                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("%s: %s"), c->hostname, strerror(errno));
 360
 361                 goto begin;
 362         }
 363
 364         finish_connecting(c);
 365
 366         return;
 367 }
 368
 369 void handle_meta_read(struct bufferevent *event, void *data) {
 370         logger(LOG_EMERG, _("handle_meta_read() called"));
 371         abort();
 372 }
 373
 374 void handle_meta_write(struct bufferevent *event, void *data) {
 375         ifdebug(META) logger(LOG_DEBUG, _("handle_meta_write() called"));
 376 }
 377
 378 void handle_meta_connection_error(struct bufferevent *event, short what, void *data) {
 379         connection_t *c = data;
 380         logger(LOG_EMERG, _("handle_meta_connection_error() called: %d: %s"), what, strerror(errno));
 381         terminate_connection(c, c->status.active);
 382 }
 383
 384 void setup_outgoing_connection(outgoing_t *outgoing) {
 385         connection_t *c;
 386         node_t *n;
 387
 388         cp();
 389
 390         n = lookup_node(outgoing->name);
 391
 392         if(n)
 393                 if(n->connection) {
 394                         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Already connected to %s"), outgoing->name);
 395
 396                         n->connection->outgoing = outgoing;
 397                         return;
 398                 }
 399
 400         c = new_connection();
 401         c->name = xstrdup(outgoing->name);
 402         c->outcipher = myself->connection->outcipher;
 403         c->outdigest = myself->connection->outdigest;
 404         c->outmaclength = myself->connection->outmaclength;
 405         c->outcompression = myself->connection->outcompression;
 406
 407         init_configuration(&c->config_tree);
 408         read_connection_config(c);
 409
 410         outgoing->cfg = lookup_config(c->config_tree, "Address");
 411
 412         if(!outgoing->cfg) {
 413                 logger(LOG_ERR, _("No address specified for %s"), c->name);
 414                 free_connection(c);
 415                 free(outgoing->name);
 416                 free(outgoing);
 417                 return;
 418         }
 419
 420         c->outgoing = outgoing;
 421         c->last_ping_time = time(NULL);
 422
 423         connection_add(c);
 424
 425         do_outgoing_connection(c);
 426
 427         event_set(&c->inevent, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c);
 428         event_add(&c->inevent, NULL);
 429         c->buffer = bufferevent_new(c->socket, handle_meta_read, handle_meta_write, handle_meta_connection_error, c);
 430         if(!c->buffer) {
 431                 logger(LOG_EMERG, _("bufferevent_new() failed: %s"), strerror(errno));
 432                 abort();
 433         }
 434         bufferevent_disable(c->buffer, EV_READ);
 435 }
 436
 437 /*
 438   accept a new tcp connect and create a
 439   new connection
 440 */
 441 void handle_new_meta_connection(int sock, short events, void *data) {
 442         connection_t *c;
 443         sockaddr_t sa;
 444         int fd;
 445         socklen_t len = sizeof sa;
 446
 447         cp();
 448
 449         fd = accept(sock, &sa.sa, &len);
 450
 451         if(fd < 0) {
 452                 logger(LOG_ERR, _("Accepting a new connection failed: %s"), strerror(errno));
 453                 return;
 454         }
 455
 456         sockaddrunmap(&sa);
 457
 458         c = new_connection();
 459         c->name = xstrdup("<unknown>");
 460         c->outcipher = myself->connection->outcipher;
 461         c->outdigest = myself->connection->outdigest;
 462         c->outmaclength = myself->connection->outmaclength;
 463         c->outcompression = myself->connection->outcompression;
 464
 465         c->address = sa;
 466         c->hostname = sockaddr2hostname(&sa);
 467         c->socket = fd;
 468         c->last_ping_time = time(NULL);
 469
 470         ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection from %s"), c->hostname);
 471
 472         event_set(&c->inevent, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c);
 473         event_add(&c->inevent, NULL);
 474         c->buffer = bufferevent_new(c->socket, NULL, handle_meta_write, handle_meta_connection_error, c);
 475         if(!c->buffer) {
 476                 logger(LOG_EMERG, _("bufferevent_new() failed: %s"), strerror(errno));
 477                 abort();
 478         }
 479         bufferevent_disable(c->buffer, EV_READ);
 480
 481         configure_tcp(c);
 482
 483         connection_add(c);
 484
 485         c->allow_request = ID;
 486         send_id(c);
 487 }
 488
 489 void try_outgoing_connections(void) {
 490         static config_t *cfg = NULL;
 491         char *name;
 492         outgoing_t *outgoing;
 493
 494         cp();
 495
 496         for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 497                 get_config_string(cfg, &name);
 498
 499                 if(!check_id(name)) {
 500                         logger(LOG_ERR,
 501                                    _("Invalid name for outgoing connection in %s line %d"),
 502                                    cfg->file, cfg->line);
 503                         free(name);
 504                         continue;
 505                 }
 506
 507                 outgoing = xmalloc_and_zero(sizeof *outgoing);
 508                 outgoing->name = name;
 509                 setup_outgoing_connection(outgoing);
 510         }
 511 }