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