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

   1 /*
   2     net_socket.c -- Handle various kinds of sockets.
   3     Copyright (C) 1998-2003 Ivo Timmermans <ivo@o2w.nl>,
   4                   2000-2003 Guus Sliepen <guus@sliepen.eu.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: net_socket.c,v 1.1.2.26 2003/07/12 17:41:46 guus Exp $
  21 */
  22
  23 #include "config.h"
  24
  25 #include <errno.h>
  26 #include <fcntl.h>
  27 #include <netdb.h>
  28 #include <netinet/in.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <signal.h>
  33 #include <sys/time.h>
  34 #include <sys/types.h>
  35 #include <unistd.h>
  36 #include <sys/ioctl.h>
  37 /* SunOS really wants sys/socket.h BEFORE net/if.h,
  38    and FreeBSD wants these lines below the rest. */
  39 #include <arpa/inet.h>
  40 #include <sys/socket.h>
  41 #include <net/if.h>
  42 #ifdef HAVE_NETINET_IN_SYSTM_H
  43 #include <netinet/in_systm.h>
  44 #endif
  45 #ifdef HAVE_NETINET_IP_H
  46 #include <netinet/ip.h>
  47 #endif
  48 #ifdef HAVE_NETINET_TCP_H
  49 #include <netinet/tcp.h>
  50 #endif
  51
  52 #include <utils.h>
  53 #include <xalloc.h>
  54 #include <avl_tree.h>
  55 #include <list.h>
  56
  57 #include "conf.h"
  58 #include "connection.h"
  59 #include "meta.h"
  60 #include "net.h"
  61 #include "netutl.h"
  62 #include "process.h"
  63 #include "protocol.h"
  64 #include "subnet.h"
  65 #include "graph.h"
  66 #include "process.h"
  67 #include "route.h"
  68 #include "device.h"
  69 #include "event.h"
  70 #include "logger.h"
  71
  72 #include "system.h"
  73
  74 #ifndef HAVE_RAND_PSEUDO_BYTES
  75 #define RAND_pseudo_bytes RAND_bytes
  76 #endif
  77
  78 int addressfamily = AF_UNSPEC;
  79 int maxtimeout = 900;
  80 int seconds_till_retry = 5;
  81
  82 listen_socket_t listen_socket[MAXSOCKETS];
  83 int listen_sockets;
  84
  85 /* Setup sockets */
  86
  87 int setup_listen_socket(sockaddr_t *sa)
  88 {
  89         int nfd, flags;
  90         char *addrstr;
  91         int option;
  92 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
  93         char *interface;
  94         struct ifreq ifr;
  95 #endif
  96
  97         cp();
  98
  99         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 100
 101         if(nfd < 0) {
 102                 logger(LOG_ERR, _("Creating metasocket failed: %s"), strerror(errno));
 103                 return -1;
 104         }
 105
 106         flags = fcntl(nfd, F_GETFL);
 107
 108         if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 109                 close(nfd);
 110                 logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
 111                            strerror(errno));
 112                 return -1;
 113         }
 114
 115         /* Optimize TCP settings */
 116
 117         option = 1;
 118         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
 119
 120 #if defined(SOL_TCP) && defined(TCP_NODELAY)
 121         setsockopt(nfd, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
 122 #endif
 123
 124 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
 125         option = IPTOS_LOWDELAY;
 126         setsockopt(nfd, SOL_IP, IP_TOS, &option, sizeof(option));
 127 #endif
 128
 129         if(get_config_string
 130            (lookup_config(config_tree, "BindToInterface"), &interface)) {
 131 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 132                 memset(&ifr, 0, sizeof(ifr));
 133                 strncpy(ifr.ifr_ifrn.ifrn_name, interface, IFNAMSIZ);
 134
 135                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 136                         close(nfd);
 137                         logger(LOG_ERR, _("Can't bind to interface %s: %s"), interface,
 138                                    strerror(errno));
 139                         return -1;
 140                 }
 141 #else
 142                 logger(LOG_WARNING, _("BindToInterface not supported on this platform"));
 143 #endif
 144         }
 145
 146         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 147                 close(nfd);
 148                 addrstr = sockaddr2hostname(sa);
 149                 logger(LOG_ERR, _("Can't bind to %s/tcp: %s"), addrstr,
 150                            strerror(errno));
 151                 free(addrstr);
 152                 return -1;
 153         }
 154
 155         if(listen(nfd, 3)) {
 156                 close(nfd);
 157                 logger(LOG_ERR, _("System call `%s' failed: %s"), "listen",
 158                            strerror(errno));
 159                 return -1;
 160         }
 161
 162         return nfd;
 163 }
 164
 165 int setup_vpn_in_socket(sockaddr_t *sa)
 166 {
 167         int nfd, flags;
 168         char *addrstr;
 169         int option;
 170 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 171         char *interface;
 172         struct ifreq ifr;
 173 #endif
 174
 175         cp();
 176
 177         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 178
 179         if(nfd < 0) {
 180                 logger(LOG_ERR, _("Creating UDP socket failed: %s"), strerror(errno));
 181                 return -1;
 182         }
 183
 184         flags = fcntl(nfd, F_GETFL);
 185         if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 186                 close(nfd);
 187                 logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
 188                            strerror(errno));
 189                 return -1;
 190         }
 191
 192         option = 1;
 193         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
 194
 195 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 196         if(get_config_string
 197            (lookup_config(config_tree, "BindToInterface"), &interface)) {
 198                 memset(&ifr, 0, sizeof(ifr));
 199                 strncpy(ifr.ifr_ifrn.ifrn_name, interface, IFNAMSIZ);
 200
 201                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
 202                         close(nfd);
 203                         logger(LOG_ERR, _("Can't bind to interface %s: %s"), interface,
 204                                    strerror(errno));
 205                         return -1;
 206                 }
 207         }
 208 #endif
 209
 210         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 211                 close(nfd);
 212                 addrstr = sockaddr2hostname(sa);
 213                 logger(LOG_ERR, _("Can't bind to %s/udp: %s"), addrstr,
 214                            strerror(errno));
 215                 free(addrstr);
 216                 return -1;
 217         }
 218
 219         return nfd;
 220 }
 221
 222 void retry_outgoing(outgoing_t *outgoing)
 223 {
 224         event_t *event;
 225
 226         cp();
 227
 228         outgoing->timeout += 5;
 229
 230         if(outgoing->timeout > maxtimeout)
 231                 outgoing->timeout = maxtimeout;
 232
 233         event = new_event();
 234         event->handler = (event_handler_t) setup_outgoing_connection;
 235         event->time = now + outgoing->timeout;
 236         event->data = outgoing;
 237         event_add(event);
 238
 239         ifdebug(CONNECTIONS) logger(LOG_NOTICE,
 240                            _("Trying to re-establish outgoing connection in %d seconds"),
 241                            outgoing->timeout);
 242 }
 243
 244 void finish_connecting(connection_t *c)
 245 {
 246         cp();
 247
 248         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Connected to %s (%s)"), c->name, c->hostname);
 249
 250         c->last_ping_time = now;
 251
 252         send_id(c);
 253 }
 254
 255 void do_outgoing_connection(connection_t *c)
 256 {
 257         char *address, *port;
 258         int option, result, flags;
 259
 260         cp();
 261
 262 begin:
 263         if(!c->outgoing->ai) {
 264                 if(!c->outgoing->cfg) {
 265                         ifdebug(CONNECTIONS) logger(LOG_ERR, _("Could not set up a meta connection to %s"),
 266                                            c->name);
 267                         c->status.remove = 1;
 268                         retry_outgoing(c->outgoing);
 269                         return;
 270                 }
 271
 272                 get_config_string(c->outgoing->cfg, &address);
 273
 274                 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
 275                         asprintf(&port, "655");
 276
 277                 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 278                 free(address);
 279                 free(port);
 280
 281                 c->outgoing->aip = c->outgoing->ai;
 282                 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
 283         }
 284
 285         if(!c->outgoing->aip) {
 286                 freeaddrinfo(c->outgoing->ai);
 287                 c->outgoing->ai = NULL;
 288                 goto begin;
 289         }
 290
 291         memcpy(&c->address, c->outgoing->aip->ai_addr,
 292                    c->outgoing->aip->ai_addrlen);
 293         c->outgoing->aip = c->outgoing->aip->ai_next;
 294
 295         if(c->hostname)
 296                 free(c->hostname);
 297
 298         c->hostname = sockaddr2hostname(&c->address);
 299
 300         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Trying to connect to %s (%s)"), c->name,
 301                            c->hostname);
 302
 303         c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 304
 305         if(c->socket == -1) {
 306                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("Creating socket for %s failed: %s"), c->hostname,
 307                                    strerror(errno));
 308
 309                 goto begin;
 310         }
 311
 312         /* Optimize TCP settings */
 313
 314 #if defined(SOL_TCP) && defined(TCP_NODELAY)
 315         option = 1;
 316         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
 317 #endif
 318
 319 #if defined(SOL_IP) && defined(IP_TOS)
 320         option = IPTOS_LOWDELAY;
 321         setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof(option));
 322 #endif
 323
 324         /* Non-blocking */
 325
 326         flags = fcntl(c->socket, F_GETFL);
 327
 328         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
 329                 logger(LOG_ERR, _("fcntl for %s: %s"), c->hostname, strerror(errno));
 330         }
 331
 332         /* Connect */
 333
 334         result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 335
 336         if(result == -1) {
 337                 if(errno == EINPROGRESS) {
 338                         c->status.connecting = 1;
 339                         return;
 340                 }
 341
 342                 close(c->socket);
 343
 344                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("%s: %s"), c->hostname, strerror(errno));
 345
 346                 goto begin;
 347         }
 348
 349         finish_connecting(c);
 350
 351         return;
 352 }
 353
 354 void setup_outgoing_connection(outgoing_t *outgoing)
 355 {
 356         connection_t *c;
 357         node_t *n;
 358
 359         cp();
 360
 361         n = lookup_node(outgoing->name);
 362
 363         if(n)
 364                 if(n->connection) {
 365                         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Already connected to %s"), outgoing->name);
 366
 367                         n->connection->outgoing = outgoing;
 368                         return;
 369                 }
 370
 371         c = new_connection();
 372         c->name = xstrdup(outgoing->name);
 373         c->outcipher = myself->connection->outcipher;
 374         c->outdigest = myself->connection->outdigest;
 375         c->outmaclength = myself->connection->outmaclength;
 376         c->outcompression = myself->connection->outcompression;
 377
 378         init_configuration(&c->config_tree);
 379         read_connection_config(c);
 380
 381         outgoing->cfg = lookup_config(c->config_tree, "Address");
 382
 383         if(!outgoing->cfg) {
 384                 logger(LOG_ERR, _("No address specified for %s"), c->name);
 385                 free_connection(c);
 386                 free(outgoing->name);
 387                 free(outgoing);
 388                 return;
 389         }
 390
 391         c->outgoing = outgoing;
 392         c->last_ping_time = now;
 393
 394         connection_add(c);
 395
 396         do_outgoing_connection(c);
 397 }
 398
 399 /*
 400   accept a new tcp connect and create a
 401   new connection
 402 */
 403 int handle_new_meta_connection(int sock)
 404 {
 405         connection_t *c;
 406         sockaddr_t sa;
 407         int fd, len = sizeof(sa);
 408
 409         cp();
 410
 411         fd = accept(sock, &sa.sa, &len);
 412
 413         if(fd < 0) {
 414                 logger(LOG_ERR, _("Accepting a new connection failed: %s"),
 415                            strerror(errno));
 416                 return -1;
 417         }
 418
 419         sockaddrunmap(&sa);
 420
 421         c = new_connection();
 422         c->outcipher = myself->connection->outcipher;
 423         c->outdigest = myself->connection->outdigest;
 424         c->outmaclength = myself->connection->outmaclength;
 425         c->outcompression = myself->connection->outcompression;
 426
 427         c->address = sa;
 428         c->hostname = sockaddr2hostname(&sa);
 429         c->socket = fd;
 430         c->last_ping_time = now;
 431
 432         ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection from %s"), c->hostname);
 433
 434         connection_add(c);
 435
 436         c->allow_request = ID;
 437         send_id(c);
 438
 439         return 0;
 440 }
 441
 442 void try_outgoing_connections(void)
 443 {
 444         static config_t *cfg = NULL;
 445         char *name;
 446         outgoing_t *outgoing;
 447
 448         cp();
 449
 450         for(cfg = lookup_config(config_tree, "ConnectTo"); cfg;
 451                 cfg = lookup_config_next(config_tree, cfg)) {
 452                 get_config_string(cfg, &name);
 453
 454                 if(check_id(name)) {
 455                         logger(LOG_ERR,
 456                                    _("Invalid name for outgoing connection in %s line %d"),
 457                                    cfg->file, cfg->line);
 458                         free(name);
 459                         continue;
 460                 }
 461
 462                 outgoing = xmalloc_and_zero(sizeof(*outgoing));
 463                 outgoing->name = name;
 464                 setup_outgoing_connection(outgoing);
 465         }
 466 }