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

   1 /*
   2     net_setup.c -- Setup.
   3     Copyright (C) 1998-2005 Ivo Timmermans,
   4                   2000-2006 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 <openssl/pem.h>
  26 #include <openssl/rsa.h>
  27 #include <openssl/rand.h>
  28 #include <openssl/err.h>
  29 #include <openssl/evp.h>
  30
  31 #include "avl_tree.h"
  32 #include "conf.h"
  33 #include "connection.h"
  34 #include "device.h"
  35 #include "graph.h"
  36 #include "logger.h"
  37 #include "net.h"
  38 #include "netutl.h"
  39 #include "process.h"
  40 #include "protocol.h"
  41 #include "route.h"
  42 #include "subnet.h"
  43 #include "utils.h"
  44 #include "xalloc.h"
  45
  46 char *myport;
  47 static struct event device_ev;
  48
  49 bool read_rsa_public_key(connection_t *c) {
  50         FILE *fp;
  51         char *fname;
  52         char *key;
  53
  54         cp();
  55
  56         if(!c->rsa_key) {
  57                 c->rsa_key = RSA_new();
  58 //              RSA_blinding_on(c->rsa_key, NULL);
  59         }
  60
  61         /* First, check for simple PublicKey statement */
  62
  63         if(get_config_string(lookup_config(c->config_tree, "PublicKey"), &key)) {
  64                 BN_hex2bn(&c->rsa_key->n, key);
  65                 BN_hex2bn(&c->rsa_key->e, "FFFF");
  66                 free(key);
  67                 return true;
  68         }
  69
  70         /* Else, check for PublicKeyFile statement and read it */
  71
  72         if(get_config_string(lookup_config(c->config_tree, "PublicKeyFile"), &fname)) {
  73                 fp = fopen(fname, "r");
  74
  75                 if(!fp) {
  76                         logger(LOG_ERR, _("Error reading RSA public key file `%s': %s"),
  77                                    fname, strerror(errno));
  78                         free(fname);
  79                         return false;
  80                 }
  81
  82                 free(fname);
  83                 c->rsa_key = PEM_read_RSAPublicKey(fp, &c->rsa_key, NULL, NULL);
  84                 fclose(fp);
  85
  86                 if(c->rsa_key)
  87                         return true;            /* Woohoo. */
  88
  89                 /* If it fails, try PEM_read_RSA_PUBKEY. */
  90                 fp = fopen(fname, "r");
  91
  92                 if(!fp) {
  93                         logger(LOG_ERR, _("Error reading RSA public key file `%s': %s"),
  94                                    fname, strerror(errno));
  95                         free(fname);
  96                         return false;
  97                 }
  98
  99                 free(fname);
 100                 c->rsa_key = PEM_read_RSA_PUBKEY(fp, &c->rsa_key, NULL, NULL);
 101                 fclose(fp);
 102
 103                 if(c->rsa_key) {
 104 //                              RSA_blinding_on(c->rsa_key, NULL);
 105                         return true;
 106                 }
 107
 108                 logger(LOG_ERR, _("Reading RSA public key file `%s' failed: %s"),
 109                            fname, strerror(errno));
 110                 return false;
 111         }
 112
 113         /* Else, check if a harnessed public key is in the config file */
 114
 115         asprintf(&fname, "%s/hosts/%s", confbase, c->name);
 116         fp = fopen(fname, "r");
 117
 118         if(fp) {
 119                 c->rsa_key = PEM_read_RSAPublicKey(fp, &c->rsa_key, NULL, NULL);
 120                 fclose(fp);
 121         }
 122
 123         free(fname);
 124
 125         if(c->rsa_key)
 126                 return true;
 127
 128         /* Try again with PEM_read_RSA_PUBKEY. */
 129
 130         asprintf(&fname, "%s/hosts/%s", confbase, c->name);
 131         fp = fopen(fname, "r");
 132
 133         if(fp) {
 134                 c->rsa_key = PEM_read_RSA_PUBKEY(fp, &c->rsa_key, NULL, NULL);
 135 //              RSA_blinding_on(c->rsa_key, NULL);
 136                 fclose(fp);
 137         }
 138
 139         free(fname);
 140
 141         if(c->rsa_key)
 142                 return true;
 143
 144         logger(LOG_ERR, _("No public key for %s specified!"), c->name);
 145
 146         return false;
 147 }
 148
 149 bool read_rsa_private_key(void) {
 150         FILE *fp;
 151         char *fname, *key, *pubkey;
 152         struct stat s;
 153
 154         cp();
 155
 156         if(get_config_string(lookup_config(config_tree, "PrivateKey"), &key)) {
 157                 if(!get_config_string(lookup_config(myself->connection->config_tree, "PublicKey"), &pubkey)) {
 158                         logger(LOG_ERR, _("PrivateKey used but no PublicKey found!"));
 159                         return false;
 160                 }
 161                 myself->connection->rsa_key = RSA_new();
 162 //              RSA_blinding_on(myself->connection->rsa_key, NULL);
 163                 BN_hex2bn(&myself->connection->rsa_key->d, key);
 164                 BN_hex2bn(&myself->connection->rsa_key->n, pubkey);
 165                 BN_hex2bn(&myself->connection->rsa_key->e, "FFFF");
 166                 free(key);
 167                 free(pubkey);
 168                 return true;
 169         }
 170
 171         if(!get_config_string(lookup_config(config_tree, "PrivateKeyFile"), &fname))
 172                 asprintf(&fname, "%s/rsa_key.priv", confbase);
 173
 174         fp = fopen(fname, "r");
 175
 176         if(!fp) {
 177                 logger(LOG_ERR, _("Error reading RSA private key file `%s': %s"),
 178                            fname, strerror(errno));
 179                 free(fname);
 180                 return false;
 181         }
 182
 183 #if !defined(HAVE_MINGW) && !defined(HAVE_CYGWIN)
 184         if(fstat(fileno(fp), &s)) {
 185                 logger(LOG_ERR, _("Could not stat RSA private key file `%s': %s'"),
 186                                 fname, strerror(errno));
 187                 free(fname);
 188                 return false;
 189         }
 190
 191         if(s.st_mode & ~0100700)
 192                 logger(LOG_WARNING, _("Warning: insecure file permissions for RSA private key file `%s'!"), fname);
 193 #endif
 194
 195         myself->connection->rsa_key = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
 196         fclose(fp);
 197
 198         if(!myself->connection->rsa_key) {
 199                 logger(LOG_ERR, _("Reading RSA private key file `%s' failed: %s"),
 200                            fname, strerror(errno));
 201                 free(fname);
 202                 return false;
 203         }
 204
 205         free(fname);
 206         return true;
 207 }
 208
 209 static struct event keyexpire_event;
 210
 211 static void keyexpire_handler(int fd, short events, void *data) {
 212         regenerate_key();
 213 }
 214
 215 void regenerate_key() {
 216         RAND_pseudo_bytes((unsigned char *)myself->key, myself->keylength);
 217
 218         if(timeout_initialized(&keyexpire_event)) {
 219                 ifdebug(STATUS) logger(LOG_INFO, _("Regenerating symmetric key"));
 220                 event_del(&keyexpire_event);
 221                 send_key_changed(broadcast, myself);
 222         } else {
 223                 timeout_set(&keyexpire_event, keyexpire_handler, NULL);
 224         }
 225
 226         event_add(&keyexpire_event, &(struct timeval){keylifetime, 0});
 227
 228         if(myself->cipher) {
 229                 EVP_CIPHER_CTX_init(&packet_ctx);
 230                 if(!EVP_DecryptInit_ex(&packet_ctx, myself->cipher, NULL, (unsigned char *)myself->key, (unsigned char *)myself->key + myself->cipher->key_len)) {
 231                         logger(LOG_ERR, _("Error during initialisation of cipher for %s (%s): %s"),
 232                                         myself->name, myself->hostname, ERR_error_string(ERR_get_error(), NULL));
 233                         abort();
 234                 }
 235
 236         }
 237 }
 238
 239 /*
 240   Configure node_t myself and set up the local sockets (listen only)
 241 */
 242 bool setup_myself(void) {
 243         config_t *cfg;
 244         subnet_t *subnet;
 245         char *name, *hostname, *mode, *afname, *cipher, *digest;
 246         char *address = NULL;
 247         char *envp[5];
 248         struct addrinfo *ai, *aip, hint = {0};
 249         bool choice;
 250         int i, err;
 251
 252         cp();
 253
 254         myself = new_node();
 255         myself->connection = new_connection();
 256         init_configuration(&myself->connection->config_tree);
 257
 258         asprintf(&myself->hostname, _("MYSELF"));
 259         asprintf(&myself->connection->hostname, _("MYSELF"));
 260
 261         myself->connection->options = 0;
 262         myself->connection->protocol_version = PROT_CURRENT;
 263
 264         if(!get_config_string(lookup_config(config_tree, "Name"), &name)) {     /* Not acceptable */
 265                 logger(LOG_ERR, _("Name for tinc daemon required!"));
 266                 return false;
 267         }
 268
 269         if(!check_id(name)) {
 270                 logger(LOG_ERR, _("Invalid name for myself!"));
 271                 free(name);
 272                 return false;
 273         }
 274
 275         myself->name = name;
 276         myself->connection->name = xstrdup(name);
 277
 278         if(!read_connection_config(myself->connection)) {
 279                 logger(LOG_ERR, _("Cannot open host configuration file for myself!"));
 280                 return false;
 281         }
 282
 283         if(!read_rsa_private_key())
 284                 return false;
 285
 286         if(!get_config_string(lookup_config(myself->connection->config_tree, "Port"), &myport))
 287                 asprintf(&myport, "655");
 288
 289         /* Read in all the subnets specified in the host configuration file */
 290
 291         cfg = lookup_config(myself->connection->config_tree, "Subnet");
 292
 293         while(cfg) {
 294                 if(!get_config_subnet(cfg, &subnet))
 295                         return false;
 296
 297                 subnet_add(myself, subnet);
 298
 299                 cfg = lookup_config_next(myself->connection->config_tree, cfg);
 300         }
 301
 302         /* Check some options */
 303
 304         if(get_config_bool(lookup_config(config_tree, "IndirectData"), &choice) && choice)
 305                 myself->options |= OPTION_INDIRECT;
 306
 307         if(get_config_bool(lookup_config(config_tree, "TCPOnly"), &choice) && choice)
 308                 myself->options |= OPTION_TCPONLY;
 309
 310         if(get_config_bool(lookup_config(myself->connection->config_tree, "IndirectData"), &choice) && choice)
 311                 myself->options |= OPTION_INDIRECT;
 312
 313         if(get_config_bool(lookup_config(myself->connection->config_tree, "TCPOnly"), &choice) && choice)
 314                 myself->options |= OPTION_TCPONLY;
 315
 316         if(get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) && choice)
 317                 myself->options |= OPTION_PMTU_DISCOVERY;
 318
 319         if(myself->options & OPTION_TCPONLY)
 320                 myself->options |= OPTION_INDIRECT;
 321
 322         get_config_bool(lookup_config(config_tree, "TunnelServer"), &tunnelserver);
 323
 324         if(get_config_string(lookup_config(config_tree, "Mode"), &mode)) {
 325                 if(!strcasecmp(mode, "router"))
 326                         routing_mode = RMODE_ROUTER;
 327                 else if(!strcasecmp(mode, "switch"))
 328                         routing_mode = RMODE_SWITCH;
 329                 else if(!strcasecmp(mode, "hub"))
 330                         routing_mode = RMODE_HUB;
 331                 else {
 332                         logger(LOG_ERR, _("Invalid routing mode!"));
 333                         return false;
 334                 }
 335                 free(mode);
 336         } else
 337                 routing_mode = RMODE_ROUTER;
 338
 339         get_config_bool(lookup_config(config_tree, "PriorityInheritance"), &priorityinheritance);
 340
 341 #if !defined(SOL_IP) || !defined(IP_TOS)
 342         if(priorityinheritance)
 343                 logger(LOG_WARNING, _("PriorityInheritance not supported on this platform"));
 344 #endif
 345
 346         if(!get_config_int(lookup_config(config_tree, "MACExpire"), &macexpire))
 347                 macexpire = 600;
 348
 349         if(get_config_int(lookup_config(config_tree, "MaxTimeout"), &maxtimeout)) {
 350                 if(maxtimeout <= 0) {
 351                         logger(LOG_ERR, _("Bogus maximum timeout!"));
 352                         return false;
 353                 }
 354         } else
 355                 maxtimeout = 900;
 356
 357         if(get_config_string(lookup_config(config_tree, "AddressFamily"), &afname)) {
 358                 if(!strcasecmp(afname, "IPv4"))
 359                         addressfamily = AF_INET;
 360                 else if(!strcasecmp(afname, "IPv6"))
 361                         addressfamily = AF_INET6;
 362                 else if(!strcasecmp(afname, "any"))
 363                         addressfamily = AF_UNSPEC;
 364                 else {
 365                         logger(LOG_ERR, _("Invalid address family!"));
 366                         return false;
 367                 }
 368                 free(afname);
 369         }
 370
 371         get_config_bool(lookup_config(config_tree, "Hostnames"), &hostnames);
 372
 373         /* Generate packet encryption key */
 374
 375         if(get_config_string
 376            (lookup_config(myself->connection->config_tree, "Cipher"), &cipher)) {
 377                 if(!strcasecmp(cipher, "none")) {
 378                         myself->cipher = NULL;
 379                 } else {
 380                         myself->cipher = EVP_get_cipherbyname(cipher);
 381
 382                         if(!myself->cipher) {
 383                                 logger(LOG_ERR, _("Unrecognized cipher type!"));
 384                                 return false;
 385                         }
 386                 }
 387         } else
 388                 myself->cipher = EVP_bf_cbc();
 389
 390         if(myself->cipher)
 391                 myself->keylength = myself->cipher->key_len + myself->cipher->iv_len;
 392         else
 393                 myself->keylength = 1;
 394
 395         myself->connection->outcipher = EVP_bf_ofb();
 396
 397         myself->key = xmalloc(myself->keylength);
 398
 399         if(!get_config_int(lookup_config(config_tree, "KeyExpire"), &keylifetime))
 400                 keylifetime = 3600;
 401
 402         regenerate_key();
 403         /* Check if we want to use message authentication codes... */
 404
 405         if(get_config_string
 406            (lookup_config(myself->connection->config_tree, "Digest"), &digest)) {
 407                 if(!strcasecmp(digest, "none")) {
 408                         myself->digest = NULL;
 409                 } else {
 410                         myself->digest = EVP_get_digestbyname(digest);
 411
 412                         if(!myself->digest) {
 413                                 logger(LOG_ERR, _("Unrecognized digest type!"));
 414                                 return false;
 415                         }
 416                 }
 417         } else
 418                 myself->digest = EVP_sha1();
 419
 420         myself->connection->outdigest = EVP_sha1();
 421
 422         if(get_config_int(lookup_config(myself->connection->config_tree, "MACLength"),
 423                 &myself->maclength)) {
 424                 if(myself->digest) {
 425                         if(myself->maclength > myself->digest->md_size) {
 426                                 logger(LOG_ERR, _("MAC length exceeds size of digest!"));
 427                                 return false;
 428                         } else if(myself->maclength < 0) {
 429                                 logger(LOG_ERR, _("Bogus MAC length!"));
 430                                 return false;
 431                         }
 432                 }
 433         } else
 434                 myself->maclength = 4;
 435
 436         myself->connection->outmaclength = 0;
 437
 438         /* Compression */
 439
 440         if(get_config_int(lookup_config(myself->connection->config_tree, "Compression"),
 441                 &myself->compression)) {
 442                 if(myself->compression < 0 || myself->compression > 11) {
 443                         logger(LOG_ERR, _("Bogus compression level!"));
 444                         return false;
 445                 }
 446         } else
 447                 myself->compression = 0;
 448
 449         myself->connection->outcompression = 0;
 450
 451         /* Done */
 452
 453         myself->nexthop = myself;
 454         myself->via = myself;
 455         myself->status.reachable = true;
 456         node_add(myself);
 457
 458         graph();
 459
 460         /* Open device */
 461
 462         if(!setup_device())
 463                 return false;
 464
 465         event_set(&device_ev, device_fd, EV_READ|EV_PERSIST,
 466                           handle_device_data, NULL);
 467         if (event_add(&device_ev, NULL) < 0) {
 468                 logger(LOG_ERR, _("event_add failed: %s"), strerror(errno));
 469                 close_device();
 470                 return false;
 471         }
 472
 473         /* Run tinc-up script to further initialize the tap interface */
 474         asprintf(&envp[0], "NETNAME=%s", netname ? : "");
 475         asprintf(&envp[1], "DEVICE=%s", device ? : "");
 476         asprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 477         asprintf(&envp[3], "NAME=%s", myself->name);
 478         envp[4] = NULL;
 479
 480         execute_script("tinc-up", envp);
 481
 482         for(i = 0; i < 5; i++)
 483                 free(envp[i]);
 484
 485         /* Run subnet-up scripts for our own subnets */
 486
 487         subnet_update(myself, NULL, true);
 488
 489         /* Open sockets */
 490
 491         get_config_string(lookup_config(config_tree, "BindToAddress"), &address);
 492
 493         hint.ai_family = addressfamily;
 494         hint.ai_socktype = SOCK_STREAM;
 495         hint.ai_protocol = IPPROTO_TCP;
 496         hint.ai_flags = AI_PASSIVE;
 497
 498         err = getaddrinfo(address, myport, &hint, &ai);
 499
 500         if(err || !ai) {
 501                 logger(LOG_ERR, _("System call `%s' failed: %s"), "getaddrinfo",
 502                            gai_strerror(err));
 503                 return false;
 504         }
 505
 506         listen_sockets = 0;
 507
 508         for(aip = ai; aip; aip = aip->ai_next) {
 509                 listen_socket[listen_sockets].tcp =
 510                         setup_listen_socket((sockaddr_t *) aip->ai_addr);
 511
 512                 if(listen_socket[listen_sockets].tcp < 0)
 513                         continue;
 514
 515                 listen_socket[listen_sockets].udp =
 516                         setup_vpn_in_socket((sockaddr_t *) aip->ai_addr);
 517
 518                 if(listen_socket[listen_sockets].udp < 0) {
 519                         close(listen_socket[listen_sockets].tcp);
 520                         continue;
 521                 }
 522
 523                 event_set(&listen_socket[listen_sockets].ev_tcp,
 524                                   listen_socket[listen_sockets].tcp,
 525                                   EV_READ|EV_PERSIST,
 526                                   handle_new_meta_connection, NULL);
 527                 if(event_add(&listen_socket[listen_sockets].ev_tcp, NULL) < 0) {
 528                         logger(LOG_WARNING, _("event_add failed: %s"), strerror(errno));
 529                         close(listen_socket[listen_sockets].tcp);
 530                         close(listen_socket[listen_sockets].udp);
 531                         continue;
 532                 }
 533
 534                 event_set(&listen_socket[listen_sockets].ev_udp,
 535                                   listen_socket[listen_sockets].udp,
 536                                   EV_READ|EV_PERSIST,
 537                                   handle_incoming_vpn_data, NULL);
 538                 if(event_add(&listen_socket[listen_sockets].ev_udp, NULL) < 0) {
 539                         logger(LOG_WARNING, _("event_add failed: %s"), strerror(errno));
 540                         close(listen_socket[listen_sockets].tcp);
 541                         close(listen_socket[listen_sockets].udp);
 542                         event_del(&listen_socket[listen_sockets].ev_tcp);
 543                         continue;
 544                 }
 545
 546                 ifdebug(CONNECTIONS) {
 547                         hostname = sockaddr2hostname((sockaddr_t *) aip->ai_addr);
 548                         logger(LOG_NOTICE, _("Listening on %s"), hostname);
 549                         free(hostname);
 550                 }
 551
 552                 memcpy(&listen_socket[listen_sockets].sa, aip->ai_addr, aip->ai_addrlen);
 553                 listen_sockets++;
 554
 555                 if(listen_sockets >= MAXSOCKETS) {
 556                         logger(LOG_WARNING, _("Maximum of %d listening sockets reached"), MAXSOCKETS);
 557                         break;
 558                 }
 559         }
 560
 561         freeaddrinfo(ai);
 562
 563         if(listen_sockets)
 564                 logger(LOG_NOTICE, _("Ready"));
 565         else {
 566                 logger(LOG_ERR, _("Unable to create any listening socket!"));
 567                 return false;
 568         }
 569
 570         return true;
 571 }
 572
 573 /*
 574   setup all initial network connections
 575 */
 576 bool setup_network_connections(void) {
 577         cp();
 578
 579         init_connections();
 580         init_subnets();
 581         init_nodes();
 582         init_edges();
 583         init_requests();
 584
 585         if(get_config_int(lookup_config(config_tree, "PingInterval"), &pinginterval)) {
 586                 if(pinginterval < 1) {
 587                         pinginterval = 86400;
 588                 }
 589         } else
 590                 pinginterval = 60;
 591
 592         if(!get_config_int(lookup_config(config_tree, "PingTimeout"), &pingtimeout))
 593                 pingtimeout = 5;
 594         if(pingtimeout < 1 || pingtimeout > pinginterval)
 595                 pingtimeout = pinginterval;
 596
 597         if(!get_config_int(lookup_config(config_tree, "MaxOutputBufferSize"), &maxoutbufsize))
 598                 maxoutbufsize = 4 * MTU;
 599
 600         if(!setup_myself())
 601                 return false;
 602
 603         try_outgoing_connections();
 604
 605         return true;
 606 }
 607
 608 /*
 609   close all open network connections
 610 */
 611 void close_network_connections(void) {
 612         avl_node_t *node, *next;
 613         connection_t *c;
 614         char *envp[5];
 615         int i;
 616
 617         cp();
 618
 619         for(node = connection_tree->head; node; node = next) {
 620                 next = node->next;
 621                 c = node->data;
 622
 623                 if(c->outgoing) {
 624                         if(c->outgoing->ai)
 625                                 freeaddrinfo(c->outgoing->ai);
 626                         free(c->outgoing->name);
 627                         free(c->outgoing);
 628                         c->outgoing = NULL;
 629                 }
 630
 631                 terminate_connection(c, false);
 632         }
 633
 634         if(myself && myself->connection) {
 635                 subnet_update(myself, NULL, false);
 636                 terminate_connection(myself->connection, false);
 637         }
 638
 639         for(i = 0; i < listen_sockets; i++) {
 640                 event_del(&listen_socket[i].ev_tcp);
 641                 event_del(&listen_socket[i].ev_udp);
 642                 close(listen_socket[i].tcp);
 643                 close(listen_socket[i].udp);
 644         }
 645
 646         asprintf(&envp[0], "NETNAME=%s", netname ? : "");
 647         asprintf(&envp[1], "DEVICE=%s", device ? : "");
 648         asprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 649         asprintf(&envp[3], "NAME=%s", myself->name);
 650         envp[4] = NULL;
 651
 652         exit_requests();
 653         exit_edges();
 654         exit_subnets();
 655         exit_nodes();
 656         exit_connections();
 657
 658         execute_script("tinc-down", envp);
 659
 660         for(i = 0; i < 4; i++)
 661                 free(envp[i]);
 662
 663         close_device();
 664
 665         return;
 666 }