src/net_socket.c

   1 /*
   2     net_socket.c -- Handle various kinds of sockets.
   3     Copyright (C) 1998-2005 Ivo Timmermans <ivo@tinc-vpn.org>,
   4                   2000-2005 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 /* Needed on Mac OS/X */
  42 #ifndef SOL_TCP
  43 #define SOL_TCP IPPROTO_TCP
  44 #endif
  45
  46 int addressfamily = AF_UNSPEC;
  47 int maxtimeout = 900;
  48 int seconds_till_retry = 5;
  49 bool blockingtcp = false;
  50
  51 listen_socket_t listen_socket[MAXSOCKETS];
  52 int listen_sockets;
  53
  54 /* Setup sockets */
  55
  56 static void configure_tcp(connection_t *c)
  57 {
  58         int option;
  59
  60 #ifdef O_NONBLOCK
  61         if(!blockingtcp) {
  62                 int flags = fcntl(c->socket, F_GETFL);
  63
  64                 if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
  65                         logger(LOG_ERR, _("fcntl for %s: %s"), c->hostname, strerror(errno));
  66                 }
  67         }
  68 #endif
  69
  70 #if defined(SOL_TCP) && defined(TCP_NODELAY)
  71         option = 1;
  72         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
  73 #endif
  74
  75 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
  76         option = IPTOS_LOWDELAY;
  77         setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof(option));
  78 #endif
  79 }
  80
  81 int setup_listen_socket(const sockaddr_t *sa)
  82 {
  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 {
 142         int nfd;
 143         char *addrstr;
 144         int option;
 145
 146         cp();
 147
 148         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 149
 150         if(nfd < 0) {
 151                 logger(LOG_ERR, _("Creating UDP socket failed: %s"), strerror(errno));
 152                 return -1;
 153         }
 154
 155 #ifdef O_NONBLOCK
 156         {
 157                 int flags = fcntl(nfd, F_GETFL);
 158
 159                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 160                         closesocket(nfd);
 161                         logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
 162                                    strerror(errno));
 163                         return -1;
 164                 }
 165         }
 166 #endif
 167
 168         option = 1;
 169         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
 170
 171 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 172         {
 173                 bool choice;
 174
 175                 if(get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) && choice) {
 176                         option = IP_PMTUDISC_DO;
 177                         setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, &option, sizeof(option));
 178                 }
 179         }
 180 #endif
 181
 182 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 183         {
 184                 bool choice;
 185
 186                 if(get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) && choice) {
 187                         option = IPV6_PMTUDISC_DO;
 188                         setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, &option, sizeof(option));
 189                 }
 190         }
 191 #endif
 192
 193 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 194         {
 195                 char *iface;
 196                 struct ifreq ifr;
 197
 198                 if(get_config_string(lookup_config(config_tree, "BindToInterface"), &iface)) {
 199                         memset(&ifr, 0, sizeof(ifr));
 200                         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 201
 202                         if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 203                                 closesocket(nfd);
 204                                 logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
 205                                            strerror(errno));
 206                                 return -1;
 207                         }
 208                 }
 209         }
 210 #endif
 211
 212         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 213                 closesocket(nfd);
 214                 addrstr = sockaddr2hostname(sa);
 215                 logger(LOG_ERR, _("Can't bind to %s/udp: %s"), addrstr,
 216                            strerror(errno));
 217                 free(addrstr);
 218                 return -1;
 219         }
 220
 221         return nfd;
 222 }
 223
 224 void retry_outgoing(outgoing_t *outgoing)
 225 {
 226         event_t *event;
 227
 228         cp();
 229
 230         outgoing->timeout += 5;
 231
 232         if(outgoing->timeout > maxtimeout)
 233                 outgoing->timeout = maxtimeout;
 234
 235         event = new_event();
 236         event->handler = (event_handler_t) setup_outgoing_connection;
 237         event->time = now + outgoing->timeout;
 238         event->data = outgoing;
 239         event_add(event);
 240
 241         ifdebug(CONNECTIONS) logger(LOG_NOTICE,
 242                            _("Trying to re-establish outgoing connection in %d seconds"),
 243                            outgoing->timeout);
 244 }
 245
 246 void finish_connecting(connection_t *c)
 247 {
 248         int option;
 249
 250         cp();
 251
 252         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Connected to %s (%s)"), c->name, c->hostname);
 253
 254         configure_tcp(c);
 255
 256         c->last_ping_time = now;
 257
 258         send_id(c);
 259 }
 260
 261 void do_outgoing_connection(connection_t *c)
 262 {
 263         char *address, *port;
 264         int option, result, flags;
 265
 266         cp();
 267
 268 begin:
 269         if(!c->outgoing->ai) {
 270                 if(!c->outgoing->cfg) {
 271                         ifdebug(CONNECTIONS) logger(LOG_ERR, _("Could not set up a meta connection to %s"),
 272                                            c->name);
 273                         c->status.remove = true;
 274                         retry_outgoing(c->outgoing);
 275                         return;
 276                 }
 277
 278                 get_config_string(c->outgoing->cfg, &address);
 279
 280                 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
 281                         asprintf(&port, "655");
 282
 283                 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 284                 free(address);
 285                 free(port);
 286
 287                 c->outgoing->aip = c->outgoing->ai;
 288                 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
 289         }
 290
 291         if(!c->outgoing->aip) {
 292                 freeaddrinfo(c->outgoing->ai);
 293                 c->outgoing->ai = NULL;
 294                 goto begin;
 295         }
 296
 297         memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
 298         c->outgoing->aip = c->outgoing->aip->ai_next;
 299
 300         if(c->hostname)
 301                 free(c->hostname);
 302
 303         c->hostname = sockaddr2hostname(&c->address);
 304
 305         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Trying to connect to %s (%s)"), c->name,
 306                            c->hostname);
 307
 308         c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 309
 310         if(c->socket == -1) {
 311                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("Creating socket for %s failed: %s"), c->hostname,
 312                                    strerror(errno));
 313
 314                 goto begin;
 315         }
 316
 317         /* Optimize TCP settings */
 318
 319         configure_tcp(c);
 320
 321         /* Connect */
 322
 323         result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 324
 325         if(result == -1) {
 326                 if(errno == EINPROGRESS) {
 327                         c->status.connecting = true;
 328                         return;
 329                 }
 330
 331                 closesocket(c->socket);
 332
 333                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("%s: %s"), c->hostname, strerror(errno));
 334
 335                 goto begin;
 336         }
 337
 338         finish_connecting(c);
 339
 340         return;
 341 }
 342
 343 void setup_outgoing_connection(outgoing_t *outgoing)
 344 {
 345         connection_t *c;
 346         node_t *n;
 347
 348         cp();
 349
 350         n = lookup_node(outgoing->name);
 351
 352         if(n)
 353                 if(n->connection) {
 354                         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Already connected to %s"), outgoing->name);
 355
 356                         n->connection->outgoing = outgoing;
 357                         return;
 358                 }
 359
 360         c = new_connection();
 361         c->name = xstrdup(outgoing->name);
 362         c->outcipher = myself->connection->outcipher;
 363         c->outdigest = myself->connection->outdigest;
 364         c->outmaclength = myself->connection->outmaclength;
 365         c->outcompression = myself->connection->outcompression;
 366
 367         init_configuration(&c->config_tree);
 368         read_connection_config(c);
 369
 370         outgoing->cfg = lookup_config(c->config_tree, "Address");
 371
 372         if(!outgoing->cfg) {
 373                 logger(LOG_ERR, _("No address specified for %s"), c->name);
 374                 free_connection(c);
 375                 free(outgoing->name);
 376                 free(outgoing);
 377                 return;
 378         }
 379
 380         c->outgoing = outgoing;
 381         c->last_ping_time = now;
 382
 383         connection_add(c);
 384
 385         do_outgoing_connection(c);
 386 }
 387
 388 /*
 389   accept a new tcp connect and create a
 390   new connection
 391 */
 392 bool handle_new_meta_connection(int sock)
 393 {
 394         int option;
 395         connection_t *c;
 396         sockaddr_t sa;
 397         int fd, len = sizeof(sa);
 398
 399         cp();
 400
 401         fd = accept(sock, &sa.sa, &len);
 402
 403         if(fd < 0) {
 404                 logger(LOG_ERR, _("Accepting a new connection failed: %s"),
 405                            strerror(errno));
 406                 return false;
 407         }
 408
 409         sockaddrunmap(&sa);
 410
 411         c = new_connection();
 412         c->name = NULL;
 413         c->outcipher = myself->connection->outcipher;
 414         c->outdigest = myself->connection->outdigest;
 415         c->outmaclength = myself->connection->outmaclength;
 416         c->outcompression = myself->connection->outcompression;
 417
 418         c->address = sa;
 419         c->hostname = sockaddr2hostname(&sa);
 420         c->socket = fd;
 421         c->last_ping_time = now;
 422
 423         ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection from %s"), c->hostname);
 424
 425         configure_tcp(c);
 426
 427         connection_add(c);
 428
 429         c->allow_request = ID;
 430         send_id(c);
 431
 432         return true;
 433 }
 434
 435 void try_outgoing_connections(void)
 436 {
 437         static config_t *cfg = NULL;
 438         char *name;
 439         outgoing_t *outgoing;
 440
 441         cp();
 442
 443         for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 444                 get_config_string(cfg, &name);
 445
 446                 if(!check_id(name)) {
 447                         logger(LOG_ERR,
 448                                    _("Invalid name for outgoing connection in %s line %d"),
 449                                    cfg->file, cfg->line);
 450                         free(name);
 451                         continue;
 452                 }
 453
 454                 outgoing = xmalloc_and_zero(sizeof(*outgoing));
 455                 outgoing->name = name;
 456                 setup_outgoing_connection(outgoing);
 457         }
 458 }