src/net_setup.c

   1 /*
   2     net_setup.c -- Setup.
   3     Copyright (C) 1998-2005 Ivo Timmermans,
   4                   2000-2010 Guus Sliepen <guus@tinc-vpn.org>
   5                   2006      Scott Lamb <slamb@slamb.org>
   6                   2010      Brandon Black <blblack@gmail.com>
   7
   8     This program is free software; you can redistribute it and/or modify
   9     it under the terms of the GNU General Public License as published by
  10     the Free Software Foundation; either version 2 of the License, or
  11     (at your option) any later version.
  12
  13     This program is distributed in the hope that it will be useful,
  14     but WITHOUT ANY WARRANTY; without even the implied warranty of
  15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16     GNU General Public License for more details.
  17
  18     You should have received a copy of the GNU General Public License along
  19     with this program; if not, write to the Free Software Foundation, Inc.,
  20     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21 */
  22
  23 #include "system.h"
  24
  25 #include "splay_tree.h"
  26 #include "cipher.h"
  27 #include "conf.h"
  28 #include "connection.h"
  29 #include "control.h"
  30 #include "device.h"
  31 #include "digest.h"
  32 #include "graph.h"
  33 #include "logger.h"
  34 #include "net.h"
  35 #include "netutl.h"
  36 #include "process.h"
  37 #include "protocol.h"
  38 #include "route.h"
  39 #include "rsa.h"
  40 #include "subnet.h"
  41 #include "utils.h"
  42 #include "xalloc.h"
  43
  44 char *myport;
  45 static struct event device_ev;
  46
  47 bool read_rsa_public_key(connection_t *c) {
  48         FILE *fp;
  49         char *fname;
  50         char *n;
  51         bool result;
  52
  53         /* First, check for simple PublicKey statement */
  54
  55         if(get_config_string(lookup_config(c->config_tree, "PublicKey"), &n)) {
  56                 result = rsa_set_hex_public_key(&c->rsa, n, "FFFF");
  57                 free(n);
  58                 return result;
  59         }
  60
  61         /* Else, check for PublicKeyFile statement and read it */
  62
  63         if(!get_config_string(lookup_config(c->config_tree, "PublicKeyFile"), &fname))
  64                 xasprintf(&fname, "%s/hosts/%s", confbase, c->name);
  65
  66         fp = fopen(fname, "r");
  67
  68         if(!fp) {
  69                 logger(LOG_ERR, "Error reading RSA public key file `%s': %s",
  70                            fname, strerror(errno));
  71                 free(fname);
  72                 return false;
  73         }
  74
  75         result = rsa_read_pem_public_key(&c->rsa, fp);
  76         fclose(fp);
  77
  78         if(!result)
  79                 logger(LOG_ERR, "Reading RSA public key file `%s' failed: %s", fname, strerror(errno));
  80         free(fname);
  81         return result;
  82 }
  83
  84 bool read_rsa_private_key() {
  85         FILE *fp;
  86         char *fname;
  87         char *n, *d;
  88         bool result;
  89
  90         /* First, check for simple PrivateKey statement */
  91
  92         if(get_config_string(lookup_config(config_tree, "PrivateKey"), &d)) {
  93                 if(!get_config_string(lookup_config(config_tree, "PublicKey"), &n)) {
  94                         logger(LOG_ERR, "PrivateKey used but no PublicKey found!");
  95                         free(d);
  96                         return false;
  97                 }
  98                 result = rsa_set_hex_private_key(&myself->connection->rsa, n, "FFFF", d);
  99                 free(n);
 100                 free(d);
 101                 return true;
 102         }
 103
 104         /* Else, check for PrivateKeyFile statement and read it */
 105
 106         if(!get_config_string(lookup_config(config_tree, "PrivateKeyFile"), &fname))
 107                 xasprintf(&fname, "%s/rsa_key.priv", confbase);
 108
 109         fp = fopen(fname, "r");
 110
 111         if(!fp) {
 112                 logger(LOG_ERR, "Error reading RSA private key file `%s': %s",
 113                            fname, strerror(errno));
 114                 free(fname);
 115                 return false;
 116         }
 117
 118 #if !defined(HAVE_MINGW) && !defined(HAVE_CYGWIN)
 119         struct stat s;
 120
 121         if(fstat(fileno(fp), &s)) {
 122                 logger(LOG_ERR, "Could not stat RSA private key file `%s': %s'", fname, strerror(errno));
 123                 free(fname);
 124                 return false;
 125         }
 126
 127         if(s.st_mode & ~0100700)
 128                 logger(LOG_WARNING, "Warning: insecure file permissions for RSA private key file `%s'!", fname);
 129 #endif
 130
 131         result = rsa_read_pem_private_key(&myself->connection->rsa, fp);
 132         fclose(fp);
 133
 134         if(!result)
 135                 logger(LOG_ERR, "Reading RSA private key file `%s' failed: %s", fname, strerror(errno));
 136         free(fname);
 137         return result;
 138 }
 139
 140 static struct event keyexpire_event;
 141
 142 static void keyexpire_handler(void *data) {
 143         regenerate_key();
 144 }
 145
 146 void regenerate_key() {
 147         ifdebug(STATUS) logger(LOG_INFO, "Expiring symmetric keys");
 148         event_del(&keyexpire_event);
 149         send_key_changed(broadcast, myself);
 150         keyexpire_event.time = time(NULL) + keylifetime;
 151         keyexpire_event.handler = keyexpire_handler;
 152         event_add(&keyexpire_event);
 153 }
 154
 155 /*
 156   Read Subnets from all host config files
 157 */
 158 void load_all_subnets(void) {
 159         DIR *dir;
 160         struct dirent *ent;
 161         char *dname;
 162         char *fname;
 163         splay_tree_t *config_tree;
 164         config_t *cfg;
 165         subnet_t *s, *s2;
 166         node_t *n;
 167         bool result;
 168
 169         xasprintf(&dname, "%s/hosts", confbase);
 170         dir = opendir(dname);
 171         if(!dir) {
 172                 logger(LOG_ERR, "Could not open %s: %s", dname, strerror(errno));
 173                 free(dname);
 174                 return;
 175         }
 176
 177         while((ent = readdir(dir))) {
 178                 if(!check_id(ent->d_name))
 179                         continue;
 180
 181                 n = lookup_node(ent->d_name);
 182                 #ifdef _DIRENT_HAVE_D_TYPE
 183                 //if(ent->d_type != DT_REG)
 184                 //      continue;
 185                 #endif
 186
 187                 xasprintf(&fname, "%s/hosts/%s", confbase, ent->d_name);
 188                 init_configuration(&config_tree);
 189                 result = read_config_file(config_tree, fname);
 190                 free(fname);
 191                 if(!result)
 192                         continue;
 193
 194                 if(!n) {
 195                         n = new_node();
 196                         n->name = xstrdup(ent->d_name);
 197                         node_add(n);
 198                 }
 199
 200                 for(cfg = lookup_config(config_tree, "Subnet"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 201                         if(!get_config_subnet(cfg, &s))
 202                                 continue;
 203
 204                         if((s2 = lookup_subnet(n, s))) {
 205                                 s2->expires = -1;
 206                         } else {
 207                                 subnet_add(n, s);
 208                         }
 209                 }
 210
 211                 exit_configuration(&config_tree);
 212         }
 213
 214         closedir(dir);
 215 }
 216
 217 /*
 218   Configure node_t myself and set up the local sockets (listen only)
 219 */
 220 bool setup_myself(void) {
 221         config_t *cfg;
 222         subnet_t *subnet;
 223         char *name, *hostname, *mode, *afname, *cipher, *digest;
 224         char *fname = NULL;
 225         char *address = NULL;
 226         char *envp[5];
 227         struct addrinfo *ai, *aip, hint = {0};
 228         bool choice;
 229         int i, err;
 230         int replaywin_int;
 231
 232         myself = new_node();
 233         myself->connection = new_connection();
 234
 235         myself->hostname = xstrdup("MYSELF");
 236         myself->connection->hostname = xstrdup("MYSELF");
 237
 238         myself->connection->options = 0;
 239         myself->connection->protocol_version = PROT_CURRENT;
 240
 241         if(!get_config_string(lookup_config(config_tree, "Name"), &name)) {     /* Not acceptable */
 242                 logger(LOG_ERR, "Name for tinc daemon required!");
 243                 return false;
 244         }
 245
 246         if(!check_id(name)) {
 247                 logger(LOG_ERR, "Invalid name for myself!");
 248                 free(name);
 249                 return false;
 250         }
 251
 252         myself->name = name;
 253         myself->connection->name = xstrdup(name);
 254         xasprintf(&fname, "%s/hosts/%s", confbase, name);
 255         read_config_options(config_tree, name);
 256         read_config_file(config_tree, fname);
 257         free(fname);
 258
 259         if(!read_rsa_private_key())
 260                 return false;
 261
 262         if(!get_config_string(lookup_config(config_tree, "Port"), &myport))
 263                 myport = xstrdup("655");
 264
 265         if(!atoi(myport)) {
 266                 struct addrinfo *ai = str2addrinfo("localhost", myport, SOCK_DGRAM);
 267                 sockaddr_t sa;
 268                 if(!ai || !ai->ai_addr)
 269                         return false;
 270                 free(myport);
 271                 memcpy(&sa, ai->ai_addr, ai->ai_addrlen);
 272                 sockaddr2str(&sa, NULL, &myport);
 273         }
 274
 275         /* Read in all the subnets specified in the host configuration file */
 276
 277         cfg = lookup_config(config_tree, "Subnet");
 278
 279         while(cfg) {
 280                 if(!get_config_subnet(cfg, &subnet))
 281                         return false;
 282
 283                 subnet_add(myself, subnet);
 284
 285                 cfg = lookup_config_next(config_tree, cfg);
 286         }
 287
 288         /* Check some options */
 289
 290         if(get_config_bool(lookup_config(config_tree, "IndirectData"), &choice) && choice)
 291                 myself->options |= OPTION_INDIRECT;
 292
 293         if(get_config_bool(lookup_config(config_tree, "TCPOnly"), &choice) && choice)
 294                 myself->options |= OPTION_TCPONLY;
 295
 296         if(myself->options & OPTION_TCPONLY)
 297                 myself->options |= OPTION_INDIRECT;
 298
 299         get_config_bool(lookup_config(config_tree, "DirectOnly"), &directonly);
 300         get_config_bool(lookup_config(config_tree, "StrictSubnets"), &strictsubnets);
 301         get_config_bool(lookup_config(config_tree, "TunnelServer"), &tunnelserver);
 302         strictsubnets |= tunnelserver;
 303
 304         if(get_config_string(lookup_config(config_tree, "Mode"), &mode)) {
 305                 if(!strcasecmp(mode, "router"))
 306                         routing_mode = RMODE_ROUTER;
 307                 else if(!strcasecmp(mode, "switch"))
 308                         routing_mode = RMODE_SWITCH;
 309                 else if(!strcasecmp(mode, "hub"))
 310                         routing_mode = RMODE_HUB;
 311                 else {
 312                         logger(LOG_ERR, "Invalid routing mode!");
 313                         return false;
 314                 }
 315                 free(mode);
 316         }
 317
 318         if(get_config_string(lookup_config(config_tree, "Forwarding"), &mode)) {
 319                 if(!strcasecmp(mode, "off"))
 320                         forwarding_mode = FMODE_OFF;
 321                 else if(!strcasecmp(mode, "internal"))
 322                         forwarding_mode = FMODE_INTERNAL;
 323                 else if(!strcasecmp(mode, "kernel"))
 324                         forwarding_mode = FMODE_KERNEL;
 325                 else {
 326                         logger(LOG_ERR, "Invalid forwarding mode!");
 327                         return false;
 328                 }
 329                 free(mode);
 330         }
 331
 332         choice = true;
 333         get_config_bool(lookup_config(config_tree, "PMTUDiscovery"), &choice);
 334         if(choice)
 335                 myself->options |= OPTION_PMTU_DISCOVERY;
 336
 337         choice = true;
 338         get_config_bool(lookup_config(config_tree, "ClampMSS"), &choice);
 339         if(choice)
 340                 myself->options |= OPTION_CLAMP_MSS;
 341
 342         get_config_bool(lookup_config(config_tree, "PriorityInheritance"), &priorityinheritance);
 343
 344 #if !defined(SOL_IP) || !defined(IP_TOS)
 345         if(priorityinheritance)
 346                 logger(LOG_WARNING, "%s not supported on this platform", "PriorityInheritance");
 347 #endif
 348
 349         if(!get_config_int(lookup_config(config_tree, "MACExpire"), &macexpire))
 350                 macexpire = 600;
 351
 352         if(get_config_int(lookup_config(config_tree, "MaxTimeout"), &maxtimeout)) {
 353                 if(maxtimeout <= 0) {
 354                         logger(LOG_ERR, "Bogus maximum timeout!");
 355                         return false;
 356                 }
 357         } else
 358                 maxtimeout = 900;
 359
 360         if(get_config_int(lookup_config(config_tree, "UDPRcvBuf"), &udp_rcvbuf)) {
 361                 if(udp_rcvbuf <= 0) {
 362                         logger(LOG_ERR, "UDPRcvBuf cannot be negative!");
 363                         return false;
 364                 }
 365         }
 366
 367         if(get_config_int(lookup_config(config_tree, "UDPSndBuf"), &udp_sndbuf)) {
 368                 if(udp_sndbuf <= 0) {
 369                         logger(LOG_ERR, "UDPSndBuf cannot be negative!");
 370                         return false;
 371                 }
 372         }
 373
 374         if(get_config_int(lookup_config(config_tree, "ReplayWindow"), &replaywin_int)) {
 375                 if(replaywin_int < 0) {
 376                         logger(LOG_ERR, "ReplayWindow cannot be negative!");
 377                         return false;
 378                 }
 379                 replaywin = (unsigned)replaywin_int;
 380         }
 381
 382         if(get_config_string(lookup_config(config_tree, "AddressFamily"), &afname)) {
 383                 if(!strcasecmp(afname, "IPv4"))
 384                         addressfamily = AF_INET;
 385                 else if(!strcasecmp(afname, "IPv6"))
 386                         addressfamily = AF_INET6;
 387                 else if(!strcasecmp(afname, "any"))
 388                         addressfamily = AF_UNSPEC;
 389                 else {
 390                         logger(LOG_ERR, "Invalid address family!");
 391                         return false;
 392                 }
 393                 free(afname);
 394         }
 395
 396         get_config_bool(lookup_config(config_tree, "Hostnames"), &hostnames);
 397
 398         /* Generate packet encryption key */
 399
 400         if(!get_config_string(lookup_config(config_tree, "Cipher"), &cipher))
 401                 cipher = xstrdup("blowfish");
 402
 403         if(!cipher_open_by_name(&myself->incipher, cipher)) {
 404                 logger(LOG_ERR, "Unrecognized cipher type!");
 405                 return false;
 406         }
 407
 408         if(!get_config_int(lookup_config(config_tree, "KeyExpire"), &keylifetime))
 409                 keylifetime = 3600;
 410
 411         regenerate_key();
 412
 413         /* Check if we want to use message authentication codes... */
 414
 415         if(!get_config_string(lookup_config(config_tree, "Digest"), &digest))
 416                 digest = xstrdup("sha1");
 417
 418         int maclength = 4;
 419         get_config_int(lookup_config(config_tree, "MACLength"), &maclength);
 420
 421         if(maclength < 0) {
 422                 logger(LOG_ERR, "Bogus MAC length!");
 423                 return false;
 424         }
 425
 426         if(!digest_open_by_name(&myself->indigest, digest, maclength)) {
 427                 logger(LOG_ERR, "Unrecognized digest type!");
 428                 return false;
 429         }
 430
 431         /* Compression */
 432
 433         if(get_config_int(lookup_config(config_tree, "Compression"), &myself->incompression)) {
 434                 if(myself->incompression < 0 || myself->incompression > 11) {
 435                         logger(LOG_ERR, "Bogus compression level!");
 436                         return false;
 437                 }
 438         } else
 439                 myself->incompression = 0;
 440
 441         myself->connection->outcompression = 0;
 442
 443         /* Done */
 444
 445         myself->nexthop = myself;
 446         myself->via = myself;
 447         myself->status.reachable = true;
 448         node_add(myself);
 449
 450         graph();
 451
 452         if(strictsubnets)
 453                 load_all_subnets();
 454
 455         /* Open device */
 456
 457         if(!setup_device())
 458                 return false;
 459
 460         /* Run tinc-up script to further initialize the tap interface */
 461         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 462         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 463         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 464         xasprintf(&envp[3], "NAME=%s", myself->name);
 465         envp[4] = NULL;
 466
 467         execute_script("tinc-up", envp);
 468
 469         for(i = 0; i < 4; i++)
 470                 free(envp[i]);
 471
 472         /* Run subnet-up scripts for our own subnets */
 473
 474         subnet_update(myself, NULL, true);
 475
 476         /* Open sockets */
 477
 478         get_config_string(lookup_config(config_tree, "BindToAddress"), &address);
 479
 480         hint.ai_family = addressfamily;
 481         hint.ai_socktype = SOCK_STREAM;
 482         hint.ai_protocol = IPPROTO_TCP;
 483         hint.ai_flags = AI_PASSIVE;
 484
 485         err = getaddrinfo(address, myport, &hint, &ai);
 486
 487         if(err || !ai) {
 488                 logger(LOG_ERR, "System call `%s' failed: %s", "getaddrinfo",
 489                            gai_strerror(err));
 490                 return false;
 491         }
 492
 493         listen_sockets = 0;
 494
 495         for(aip = ai; aip; aip = aip->ai_next) {
 496                 listen_socket[listen_sockets].tcp =
 497                         setup_listen_socket((sockaddr_t *) aip->ai_addr);
 498
 499                 if(listen_socket[listen_sockets].tcp < 0)
 500                         continue;
 501
 502                 listen_socket[listen_sockets].udp =
 503                         setup_vpn_in_socket((sockaddr_t *) aip->ai_addr);
 504
 505                 if(listen_socket[listen_sockets].udp < 0) {
 506                         close(listen_socket[listen_sockets].tcp);
 507                         continue;
 508                 }
 509
 510                 memcpy(&listen_socket[listen_sockets].sa, aip->ai_addr, aip->ai_addrlen);
 511
 512                 if(!thread_create(&listen_socket[listen_sockets].tcp_thread, handle_new_meta_connection, &listen_socket[listen_sockets])) {
 513                         logger(LOG_ERR, "thread_create failed: %s", strerror(errno));
 514                         abort();
 515                 }
 516
 517                 if(!thread_create(&listen_socket[listen_sockets].udp_thread, handle_incoming_vpn_data, &listen_socket[listen_sockets])) {
 518                         logger(LOG_ERR, "thread_create failed: %s", strerror(errno));
 519                         abort();
 520                 }
 521
 522                 ifdebug(CONNECTIONS) {
 523                         hostname = sockaddr2hostname((sockaddr_t *) aip->ai_addr);
 524                         logger(LOG_NOTICE, "Listening on %s", hostname);
 525                         free(hostname);
 526                 }
 527
 528                 listen_sockets++;
 529
 530                 if(listen_sockets >= MAXSOCKETS) {
 531                         logger(LOG_WARNING, "Maximum of %d listening sockets reached", MAXSOCKETS);
 532                         break;
 533                 }
 534         }
 535
 536         freeaddrinfo(ai);
 537
 538         if(listen_sockets)
 539                 logger(LOG_NOTICE, "Ready");
 540         else {
 541                 logger(LOG_ERR, "Unable to create any listening socket!");
 542                 return false;
 543         }
 544
 545         return true;
 546 }
 547
 548 /*
 549   initialize network
 550 */
 551 bool setup_network(void) {
 552         init_connections();
 553         init_subnets();
 554         init_nodes();
 555         init_edges();
 556         init_requests();
 557
 558         if(get_config_int(lookup_config(config_tree, "PingInterval"), &pinginterval)) {
 559                 if(pinginterval < 1) {
 560                         pinginterval = 86400;
 561                 }
 562         } else
 563                 pinginterval = 60;
 564
 565         if(!get_config_int(lookup_config(config_tree, "PingTimeout"), &pingtimeout))
 566                 pingtimeout = 5;
 567         if(pingtimeout < 1 || pingtimeout > pinginterval)
 568                 pingtimeout = pinginterval;
 569
 570         if(!get_config_int(lookup_config(config_tree, "MaxOutputBufferSize"), &maxoutbufsize))
 571                 maxoutbufsize = 10 * MTU;
 572
 573         if(!setup_myself())
 574                 return false;
 575
 576         return true;
 577 }
 578
 579 /*
 580   close all open network connections
 581 */
 582 void close_network_connections(void) {
 583         splay_node_t *node, *next;
 584         connection_t *c;
 585         char *envp[5];
 586         int i;
 587
 588         for(node = connection_tree->head; node; node = next) {
 589                 next = node->next;
 590                 c = node->data;
 591                 c->outgoing = false;
 592                 terminate_connection(c, false);
 593         }
 594
 595         list_delete_list(outgoing_list);
 596
 597         if(myself && myself->connection) {
 598                 subnet_update(myself, NULL, false);
 599                 terminate_connection(myself->connection, false);
 600                 free_connection(myself->connection);
 601         }
 602
 603         for(i = 0; i < listen_sockets; i++) {
 604                 close(listen_socket[i].tcp);
 605                 close(listen_socket[i].udp);
 606                 thread_destroy(&listen_socket[i].tcp_thread);
 607                 thread_destroy(&listen_socket[i].udp_thread);
 608         }
 609
 610         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 611         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 612         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 613         xasprintf(&envp[3], "NAME=%s", myself->name);
 614         envp[4] = NULL;
 615
 616         exit_requests();
 617         exit_edges();
 618         exit_subnets();
 619         exit_nodes();
 620         exit_connections();
 621
 622         execute_script("tinc-down", envp);
 623
 624         if(myport) free(myport);
 625
 626         for(i = 0; i < 4; i++)
 627                 free(envp[i]);
 628
 629         close_device();
 630
 631         return;
 632 }