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