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 {
  51         FILE *fp;
  52         char *fname;
  53         char *key;
  54
  55         cp();
  56
  57         if(!c->rsa_key) {
  58                 c->rsa_key = RSA_new();
  59 //              RSA_blinding_on(c->rsa_key, NULL);
  60         }
  61
  62         /* First, check for simple PublicKey statement */
  63
  64         if(get_config_string(lookup_config(c->config_tree, "PublicKey"), &key)) {
  65                 BN_hex2bn(&c->rsa_key->n, key);
  66                 BN_hex2bn(&c->rsa_key->e, "FFFF");
  67                 free(key);
  68                 return true;
  69         }
  70
  71         /* Else, check for PublicKeyFile statement and read it */
  72
  73         if(get_config_string(lookup_config(c->config_tree, "PublicKeyFile"), &fname)) {
  74                 fp = fopen(fname, "r");
  75
  76                 if(!fp) {
  77                         logger(LOG_ERR, _("Error reading RSA public key file `%s': %s"),
  78                                    fname, strerror(errno));
  79                         free(fname);
  80                         return false;
  81                 }
  82
  83                 free(fname);
  84                 c->rsa_key = PEM_read_RSAPublicKey(fp, &c->rsa_key, NULL, NULL);
  85                 fclose(fp);
  86
  87                 if(c->rsa_key)
  88                         return true;            /* Woohoo. */
  89
  90                 /* If it fails, try PEM_read_RSA_PUBKEY. */
  91                 fp = fopen(fname, "r");
  92
  93                 if(!fp) {
  94                         logger(LOG_ERR, _("Error reading RSA public key file `%s': %s"),
  95                                    fname, strerror(errno));
  96                         free(fname);
  97                         return false;
  98                 }
  99
 100                 free(fname);
 101                 c->rsa_key = PEM_read_RSA_PUBKEY(fp, &c->rsa_key, NULL, NULL);
 102                 fclose(fp);
 103
 104                 if(c->rsa_key) {
 105 //                              RSA_blinding_on(c->rsa_key, NULL);
 106                         return true;
 107                 }
 108
 109                 logger(LOG_ERR, _("Reading RSA public key file `%s' failed: %s"),
 110                            fname, strerror(errno));
 111                 return false;
 112         }
 113
 114         /* Else, check if a harnessed public key is in the config file */
 115
 116         asprintf(&fname, "%s/hosts/%s", confbase, c->name);
 117         fp = fopen(fname, "r");
 118
 119         if(fp) {
 120                 c->rsa_key = PEM_read_RSAPublicKey(fp, &c->rsa_key, NULL, NULL);
 121                 fclose(fp);
 122         }
 123
 124         free(fname);
 125
 126         if(c->rsa_key)
 127                 return true;
 128
 129         /* Try again with PEM_read_RSA_PUBKEY. */
 130
 131         asprintf(&fname, "%s/hosts/%s", confbase, c->name);
 132         fp = fopen(fname, "r");
 133
 134         if(fp) {
 135                 c->rsa_key = PEM_read_RSA_PUBKEY(fp, &c->rsa_key, NULL, NULL);
 136 //              RSA_blinding_on(c->rsa_key, NULL);
 137                 fclose(fp);
 138         }
 139
 140         free(fname);
 141
 142         if(c->rsa_key)
 143                 return true;
 144
 145         logger(LOG_ERR, _("No public key for %s specified!"), c->name);
 146
 147         return false;
 148 }
 149
 150 bool read_rsa_private_key(void)
 151 {
 152         FILE *fp;
 153         char *fname, *key, *pubkey;
 154         struct stat s;
 155
 156         cp();
 157
 158         if(get_config_string(lookup_config(config_tree, "PrivateKey"), &key)) {
 159                 if(!get_config_string(lookup_config(myself->connection->config_tree, "PublicKey"), &pubkey)) {
 160                         logger(LOG_ERR, _("PrivateKey used but no PublicKey found!"));
 161                         return false;
 162                 }
 163                 myself->connection->rsa_key = RSA_new();
 164 //              RSA_blinding_on(myself->connection->rsa_key, NULL);
 165                 BN_hex2bn(&myself->connection->rsa_key->d, key);
 166                 BN_hex2bn(&myself->connection->rsa_key->n, pubkey);
 167                 BN_hex2bn(&myself->connection->rsa_key->e, "FFFF");
 168                 free(key);
 169                 free(pubkey);
 170                 return true;
 171         }
 172
 173         if(!get_config_string(lookup_config(config_tree, "PrivateKeyFile"), &fname))
 174                 asprintf(&fname, "%s/rsa_key.priv", confbase);
 175
 176         fp = fopen(fname, "r");
 177
 178         if(!fp) {
 179                 logger(LOG_ERR, _("Error reading RSA private key file `%s': %s"),
 180                            fname, strerror(errno));
 181                 free(fname);
 182                 return false;
 183         }
 184
 185 #if !defined(HAVE_MINGW) && !defined(HAVE_CYGWIN)
 186         if(fstat(fileno(fp), &s)) {
 187                 logger(LOG_ERR, _("Could not stat RSA private key file `%s': %s'"),
 188                                 fname, strerror(errno));
 189                 free(fname);
 190                 return false;
 191         }
 192
 193         if(s.st_mode & ~0100700)
 194                 logger(LOG_WARNING, _("Warning: insecure file permissions for RSA private key file `%s'!"), fname);
 195 #endif
 196
 197         myself->connection->rsa_key = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
 198         fclose(fp);
 199
 200         if(!myself->connection->rsa_key) {
 201                 logger(LOG_ERR, _("Reading RSA private key file `%s' failed: %s"),
 202                            fname, strerror(errno));
 203                 free(fname);
 204                 return false;
 205         }
 206
 207         free(fname);
 208         return true;
 209 }
 210
 211 static struct event keyexpire_event;
 212
 213 static void keyexpire_handler(int fd, short events, void *data) {
 214         regenerate_key();
 215 }
 216
 217 void regenerate_key() {
 218         RAND_pseudo_bytes((unsigned char *)myself->key, myself->keylength);
 219
 220         if(timeout_initialized(&keyexpire_event)) {
 221                 ifdebug(STATUS) logger(LOG_INFO, _("Regenerating symmetric key"));
 222                 event_del(&keyexpire_event);
 223                 send_key_changed(broadcast, myself);
 224         } else {
 225                 timeout_set(&keyexpire_event, keyexpire_handler, NULL);
 226         }
 227
 228         event_add(&keyexpire_event, &(struct timeval){keylifetime, 0});
 229
 230         if(myself->cipher) {
 231                 EVP_CIPHER_CTX_init(&packet_ctx);
 232                 if(!EVP_DecryptInit_ex(&packet_ctx, myself->cipher, NULL, (unsigned char *)myself->key, (unsigned char *)myself->key + myself->cipher->key_len)) {
 233                         logger(LOG_ERR, _("Error during initialisation of cipher for %s (%s): %s"),
 234                                         myself->name, myself->hostname, ERR_error_string(ERR_get_error(), NULL));
 235                         abort();
 236                 }
 237
 238         }
 239 }
 240
 241 /*
 242   Configure node_t myself and set up the local sockets (listen only)
 243 */
 244 bool setup_myself(void)
 245 {
 246         config_t *cfg;
 247         subnet_t *subnet;
 248         char *name, *hostname, *mode, *afname, *cipher, *digest;
 249         char *address = NULL;
 250         char *envp[5];
 251         struct addrinfo *ai, *aip, hint = {0};
 252         bool choice;
 253         int i, err;
 254
 255         cp();
 256
 257         myself = new_node();
 258         myself->connection = new_connection();
 259         init_configuration(&myself->connection->config_tree);
 260
 261         asprintf(&myself->hostname, _("MYSELF"));
 262         asprintf(&myself->connection->hostname, _("MYSELF"));
 263
 264         myself->connection->options = 0;
 265         myself->connection->protocol_version = PROT_CURRENT;
 266
 267         if(!get_config_string(lookup_config(config_tree, "Name"), &name)) {     /* Not acceptable */
 268                 logger(LOG_ERR, _("Name for tinc daemon required!"));
 269                 return false;
 270         }
 271
 272         if(!check_id(name)) {
 273                 logger(LOG_ERR, _("Invalid name for myself!"));
 274                 free(name);
 275                 return false;
 276         }
 277
 278         myself->name = name;
 279         myself->connection->name = xstrdup(name);
 280
 281         if(!read_connection_config(myself->connection)) {
 282                 logger(LOG_ERR, _("Cannot open host configuration file for myself!"));
 283                 return false;
 284         }
 285
 286         if(!read_rsa_private_key())
 287                 return false;
 288
 289         if(!get_config_string(lookup_config(myself->connection->config_tree, "Port"), &myport))
 290                 asprintf(&myport, "655");
 291
 292         /* Read in all the subnets specified in the host configuration file */
 293
 294         cfg = lookup_config(myself->connection->config_tree, "Subnet");
 295
 296         while(cfg) {
 297                 if(!get_config_subnet(cfg, &subnet))
 298                         return false;
 299
 300                 subnet_add(myself, subnet);
 301
 302                 cfg = lookup_config_next(myself->connection->config_tree, cfg);
 303         }
 304
 305         /* Check some options */
 306
 307         if(get_config_bool(lookup_config(config_tree, "IndirectData"), &choice) && choice)
 308                 myself->options |= OPTION_INDIRECT;
 309
 310         if(get_config_bool(lookup_config(config_tree, "TCPOnly"), &choice) && choice)
 311                 myself->options |= OPTION_TCPONLY;
 312
 313         if(get_config_bool(lookup_config(myself->connection->config_tree, "IndirectData"), &choice) && choice)
 314                 myself->options |= OPTION_INDIRECT;
 315
 316         if(get_config_bool(lookup_config(myself->connection->config_tree, "TCPOnly"), &choice) && choice)
 317                 myself->options |= OPTION_TCPONLY;
 318
 319         if(get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) && choice)
 320                 myself->options |= OPTION_PMTU_DISCOVERY;
 321
 322         if(myself->options & OPTION_TCPONLY)
 323                 myself->options |= OPTION_INDIRECT;
 324
 325         get_config_bool(lookup_config(config_tree, "TunnelServer"), &tunnelserver);
 326
 327         if(get_config_string(lookup_config(config_tree, "Mode"), &mode)) {
 328                 if(!strcasecmp(mode, "router"))
 329                         routing_mode = RMODE_ROUTER;
 330                 else if(!strcasecmp(mode, "switch"))
 331                         routing_mode = RMODE_SWITCH;
 332                 else if(!strcasecmp(mode, "hub"))
 333                         routing_mode = RMODE_HUB;
 334                 else {
 335                         logger(LOG_ERR, _("Invalid routing mode!"));
 336                         return false;
 337                 }
 338                 free(mode);
 339         } else
 340                 routing_mode = RMODE_ROUTER;
 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, _("PriorityInheritance not supported on this platform"));
 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_string(lookup_config(config_tree, "AddressFamily"), &afname)) {
 361                 if(!strcasecmp(afname, "IPv4"))
 362                         addressfamily = AF_INET;
 363                 else if(!strcasecmp(afname, "IPv6"))
 364                         addressfamily = AF_INET6;
 365                 else if(!strcasecmp(afname, "any"))
 366                         addressfamily = AF_UNSPEC;
 367                 else {
 368                         logger(LOG_ERR, _("Invalid address family!"));
 369                         return false;
 370                 }
 371                 free(afname);
 372         }
 373
 374         get_config_bool(lookup_config(config_tree, "Hostnames"), &hostnames);
 375
 376         /* Generate packet encryption key */
 377
 378         if(get_config_string
 379            (lookup_config(myself->connection->config_tree, "Cipher"), &cipher)) {
 380                 if(!strcasecmp(cipher, "none")) {
 381                         myself->cipher = NULL;
 382                 } else {
 383                         myself->cipher = EVP_get_cipherbyname(cipher);
 384
 385                         if(!myself->cipher) {
 386                                 logger(LOG_ERR, _("Unrecognized cipher type!"));
 387                                 return false;
 388                         }
 389                 }
 390         } else
 391                 myself->cipher = EVP_bf_cbc();
 392
 393         if(myself->cipher)
 394                 myself->keylength = myself->cipher->key_len + myself->cipher->iv_len;
 395         else
 396                 myself->keylength = 1;
 397
 398         myself->connection->outcipher = EVP_bf_ofb();
 399
 400         myself->key = xmalloc(myself->keylength);
 401
 402         if(!get_config_int(lookup_config(config_tree, "KeyExpire"), &keylifetime))
 403                 keylifetime = 3600;
 404
 405         regenerate_key();
 406         /* Check if we want to use message authentication codes... */
 407
 408         if(get_config_string
 409            (lookup_config(myself->connection->config_tree, "Digest"), &digest)) {
 410                 if(!strcasecmp(digest, "none")) {
 411                         myself->digest = NULL;
 412                 } else {
 413                         myself->digest = EVP_get_digestbyname(digest);
 414
 415                         if(!myself->digest) {
 416                                 logger(LOG_ERR, _("Unrecognized digest type!"));
 417                                 return false;
 418                         }
 419                 }
 420         } else
 421                 myself->digest = EVP_sha1();
 422
 423         myself->connection->outdigest = EVP_sha1();
 424
 425         if(get_config_int(lookup_config(myself->connection->config_tree, "MACLength"),
 426                 &myself->maclength)) {
 427                 if(myself->digest) {
 428                         if(myself->maclength > myself->digest->md_size) {
 429                                 logger(LOG_ERR, _("MAC length exceeds size of digest!"));
 430                                 return false;
 431                         } else if(myself->maclength < 0) {
 432                                 logger(LOG_ERR, _("Bogus MAC length!"));
 433                                 return false;
 434                         }
 435                 }
 436         } else
 437                 myself->maclength = 4;
 438
 439         myself->connection->outmaclength = 0;
 440
 441         /* Compression */
 442
 443         if(get_config_int(lookup_config(myself->connection->config_tree, "Compression"),
 444                 &myself->compression)) {
 445                 if(myself->compression < 0 || myself->compression > 11) {
 446                         logger(LOG_ERR, _("Bogus compression level!"));
 447                         return false;
 448                 }
 449         } else
 450                 myself->compression = 0;
 451
 452         myself->connection->outcompression = 0;
 453
 454         /* Done */
 455
 456         myself->nexthop = myself;
 457         myself->via = myself;
 458         myself->status.reachable = true;
 459         node_add(myself);
 460
 461         graph();
 462
 463         /* Open device */
 464
 465         if(!setup_device())
 466                 return false;
 467
 468         event_set(&device_ev, device_fd, EV_READ|EV_PERSIST,
 469                           handle_device_data, NULL);
 470         if (event_add(&device_ev, NULL) < 0) {
 471                 logger(LOG_ERR, _("event_add failed: %s"), strerror(errno));
 472                 close_device();
 473                 return false;
 474         }
 475
 476         /* Run tinc-up script to further initialize the tap interface */
 477         asprintf(&envp[0], "NETNAME=%s", netname ? : "");
 478         asprintf(&envp[1], "DEVICE=%s", device ? : "");
 479         asprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 480         asprintf(&envp[3], "NAME=%s", myself->name);
 481         envp[4] = NULL;
 482
 483         execute_script("tinc-up", envp);
 484
 485         for(i = 0; i < 5; i++)
 486                 free(envp[i]);
 487
 488         /* Run subnet-up scripts for our own subnets */
 489
 490         subnet_update(myself, NULL, true);
 491
 492         /* Open sockets */
 493
 494         get_config_string(lookup_config(config_tree, "BindToAddress"), &address);
 495
 496         hint.ai_family = addressfamily;
 497         hint.ai_socktype = SOCK_STREAM;
 498         hint.ai_protocol = IPPROTO_TCP;
 499         hint.ai_flags = AI_PASSIVE;
 500
 501         err = getaddrinfo(address, myport, &hint, &ai);
 502
 503         if(err || !ai) {
 504                 logger(LOG_ERR, _("System call `%s' failed: %s"), "getaddrinfo",
 505                            gai_strerror(err));
 506                 return false;
 507         }
 508
 509         listen_sockets = 0;
 510
 511         for(aip = ai; aip; aip = aip->ai_next) {
 512                 listen_socket[listen_sockets].tcp =
 513                         setup_listen_socket((sockaddr_t *) aip->ai_addr);
 514
 515                 if(listen_socket[listen_sockets].tcp < 0)
 516                         continue;
 517
 518                 listen_socket[listen_sockets].udp =
 519                         setup_vpn_in_socket((sockaddr_t *) aip->ai_addr);
 520
 521                 if(listen_socket[listen_sockets].udp < 0) {
 522                         close(listen_socket[listen_sockets].tcp);
 523                         continue;
 524                 }
 525
 526                 event_set(&listen_socket[listen_sockets].ev_tcp,
 527                                   listen_socket[listen_sockets].tcp,
 528                                   EV_READ|EV_PERSIST,
 529                                   handle_new_meta_connection, NULL);
 530                 if(event_add(&listen_socket[listen_sockets].ev_tcp, NULL) < 0) {
 531                         logger(LOG_WARNING, _("event_add failed: %s"), strerror(errno));
 532                         close(listen_socket[listen_sockets].tcp);
 533                         close(listen_socket[listen_sockets].udp);
 534                         continue;
 535                 }
 536
 537                 event_set(&listen_socket[listen_sockets].ev_udp,
 538                                   listen_socket[listen_sockets].udp,
 539                                   EV_READ|EV_PERSIST,
 540                                   handle_incoming_vpn_data, NULL);
 541                 if(event_add(&listen_socket[listen_sockets].ev_udp, NULL) < 0) {
 542                         logger(LOG_WARNING, _("event_add failed: %s"), strerror(errno));
 543                         close(listen_socket[listen_sockets].tcp);
 544                         close(listen_socket[listen_sockets].udp);
 545                         event_del(&listen_socket[listen_sockets].ev_tcp);
 546                         continue;
 547                 }
 548
 549                 ifdebug(CONNECTIONS) {
 550                         hostname = sockaddr2hostname((sockaddr_t *) aip->ai_addr);
 551                         logger(LOG_NOTICE, _("Listening on %s"), hostname);
 552                         free(hostname);
 553                 }
 554
 555                 memcpy(&listen_socket[listen_sockets].sa, aip->ai_addr, aip->ai_addrlen);
 556                 listen_sockets++;
 557
 558                 if(listen_sockets >= MAXSOCKETS) {
 559                         logger(LOG_WARNING, _("Maximum of %d listening sockets reached"), MAXSOCKETS);
 560                         break;
 561                 }
 562         }
 563
 564         freeaddrinfo(ai);
 565
 566         if(listen_sockets)
 567                 logger(LOG_NOTICE, _("Ready"));
 568         else {
 569                 logger(LOG_ERR, _("Unable to create any listening socket!"));
 570                 return false;
 571         }
 572
 573         return true;
 574 }
 575
 576 /*
 577   setup all initial network connections
 578 */
 579 bool setup_network_connections(void)
 580 {
 581         cp();
 582
 583         init_connections();
 584         init_subnets();
 585         init_nodes();
 586         init_edges();
 587         init_requests();
 588
 589         if(get_config_int(lookup_config(config_tree, "PingInterval"), &pinginterval)) {
 590                 if(pinginterval < 1) {
 591                         pinginterval = 86400;
 592                 }
 593         } else
 594                 pinginterval = 60;
 595
 596         if(!get_config_int(lookup_config(config_tree, "PingTimeout"), &pingtimeout))
 597                 pingtimeout = 5;
 598         if(pingtimeout < 1 || pingtimeout > pinginterval)
 599                 pingtimeout = pinginterval;
 600
 601         if(!get_config_int(lookup_config(config_tree, "MaxOutputBufferSize"), &maxoutbufsize))
 602                 maxoutbufsize = 4 * MTU;
 603
 604         if(!setup_myself())
 605                 return false;
 606
 607         try_outgoing_connections();
 608
 609         return true;
 610 }
 611
 612 /*
 613   close all open network connections
 614 */
 615 void close_network_connections(void)
 616 {
 617         avl_node_t *node, *next;
 618         connection_t *c;
 619         char *envp[5];
 620         int i;
 621
 622         cp();
 623
 624         for(node = connection_tree->head; node; node = next) {
 625                 next = node->next;
 626                 c = node->data;
 627
 628                 if(c->outgoing) {
 629                         if(c->outgoing->ai)
 630                                 freeaddrinfo(c->outgoing->ai);
 631                         free(c->outgoing->name);
 632                         free(c->outgoing);
 633                         c->outgoing = NULL;
 634                 }
 635
 636                 terminate_connection(c, false);
 637         }
 638
 639         if(myself && myself->connection) {
 640                 subnet_update(myself, NULL, false);
 641                 terminate_connection(myself->connection, false);
 642         }
 643
 644         for(i = 0; i < listen_sockets; i++) {
 645                 event_del(&listen_socket[i].ev_tcp);
 646                 event_del(&listen_socket[i].ev_udp);
 647                 close(listen_socket[i].tcp);
 648                 close(listen_socket[i].udp);
 649         }
 650
 651         asprintf(&envp[0], "NETNAME=%s", netname ? : "");
 652         asprintf(&envp[1], "DEVICE=%s", device ? : "");
 653         asprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 654         asprintf(&envp[3], "NAME=%s", myself->name);
 655         envp[4] = NULL;
 656
 657         exit_requests();
 658         exit_edges();
 659         exit_subnets();
 660         exit_nodes();
 661         exit_connections();
 662
 663         execute_script("tinc-down", envp);
 664
 665         for(i = 0; i < 4; i++)
 666                 free(envp[i]);
 667
 668         close_device();
 669
 670         return;
 671 }