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 <openssl/pem.h>
  25 #include <openssl/rsa.h>
  26 #include <openssl/rand.h>
  27 #include <openssl/err.h>
  28 #include <openssl/evp.h>
  29
  30 #include "avl_tree.h"
  31 #include "conf.h"
  32 #include "connection.h"
  33 #include "device.h"
  34 #include "event.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
  48 bool read_rsa_public_key(connection_t *c) {
  49         FILE *fp;
  50         char *fname;
  51         char *key;
  52
  53         if(!c->rsa_key) {
  54                 c->rsa_key = RSA_new();
  55 //              RSA_blinding_on(c->rsa_key, NULL);
  56         }
  57
  58         /* First, check for simple PublicKey statement */
  59
  60         if(get_config_string(lookup_config(c->config_tree, "PublicKey"), &key)) {
  61                 BN_hex2bn(&c->rsa_key->n, key);
  62                 BN_hex2bn(&c->rsa_key->e, "FFFF");
  63                 free(key);
  64                 return true;
  65         }
  66
  67         /* Else, check for PublicKeyFile statement and read it */
  68
  69         if(get_config_string(lookup_config(c->config_tree, "PublicKeyFile"), &fname)) {
  70                 fp = fopen(fname, "r");
  71
  72                 if(!fp) {
  73                         logger(LOG_ERR, "Error reading RSA public key file `%s': %s",
  74                                    fname, strerror(errno));
  75                         free(fname);
  76                         return false;
  77                 }
  78
  79                 free(fname);
  80                 c->rsa_key = PEM_read_RSAPublicKey(fp, &c->rsa_key, NULL, NULL);
  81                 fclose(fp);
  82
  83                 if(c->rsa_key)
  84                         return true;            /* Woohoo. */
  85
  86                 /* If it fails, try PEM_read_RSA_PUBKEY. */
  87                 fp = fopen(fname, "r");
  88
  89                 if(!fp) {
  90                         logger(LOG_ERR, "Error reading RSA public key file `%s': %s",
  91                                    fname, strerror(errno));
  92                         free(fname);
  93                         return false;
  94                 }
  95
  96                 free(fname);
  97                 c->rsa_key = PEM_read_RSA_PUBKEY(fp, &c->rsa_key, NULL, NULL);
  98                 fclose(fp);
  99
 100                 if(c->rsa_key) {
 101 //                              RSA_blinding_on(c->rsa_key, NULL);
 102                         return true;
 103                 }
 104
 105                 logger(LOG_ERR, "Reading RSA public key file `%s' failed: %s",
 106                            fname, strerror(errno));
 107                 return false;
 108         }
 109
 110         /* Else, check if a harnessed public key is in the config file */
 111
 112         xasprintf(&fname, "%s/hosts/%s", confbase, c->name);
 113         fp = fopen(fname, "r");
 114
 115         if(fp) {
 116                 c->rsa_key = PEM_read_RSAPublicKey(fp, &c->rsa_key, NULL, NULL);
 117                 fclose(fp);
 118         }
 119
 120         free(fname);
 121
 122         if(c->rsa_key)
 123                 return true;
 124
 125         /* Try again with PEM_read_RSA_PUBKEY. */
 126
 127         xasprintf(&fname, "%s/hosts/%s", confbase, c->name);
 128         fp = fopen(fname, "r");
 129
 130         if(fp) {
 131                 c->rsa_key = PEM_read_RSA_PUBKEY(fp, &c->rsa_key, NULL, NULL);
 132 //              RSA_blinding_on(c->rsa_key, NULL);
 133                 fclose(fp);
 134         }
 135
 136         free(fname);
 137
 138         if(c->rsa_key)
 139                 return true;
 140
 141         logger(LOG_ERR, "No public key for %s specified!", c->name);
 142
 143         return false;
 144 }
 145
 146 bool read_rsa_private_key(void) {
 147         FILE *fp;
 148         char *fname, *key, *pubkey;
 149         struct stat s;
 150
 151         if(get_config_string(lookup_config(config_tree, "PrivateKey"), &key)) {
 152                 if(!get_config_string(lookup_config(config_tree, "PublicKey"), &pubkey)) {
 153                         logger(LOG_ERR, "PrivateKey used but no PublicKey found!");
 154                         return false;
 155                 }
 156                 myself->connection->rsa_key = RSA_new();
 157 //              RSA_blinding_on(myself->connection->rsa_key, NULL);
 158                 BN_hex2bn(&myself->connection->rsa_key->d, key);
 159                 BN_hex2bn(&myself->connection->rsa_key->n, pubkey);
 160                 BN_hex2bn(&myself->connection->rsa_key->e, "FFFF");
 161                 free(key);
 162                 free(pubkey);
 163                 return true;
 164         }
 165
 166         if(!get_config_string(lookup_config(config_tree, "PrivateKeyFile"), &fname))
 167                 xasprintf(&fname, "%s/rsa_key.priv", confbase);
 168
 169         fp = fopen(fname, "r");
 170
 171         if(!fp) {
 172                 logger(LOG_ERR, "Error reading RSA private key file `%s': %s",
 173                            fname, strerror(errno));
 174                 free(fname);
 175                 return false;
 176         }
 177
 178 #if !defined(HAVE_MINGW) && !defined(HAVE_CYGWIN)
 179         if(fstat(fileno(fp), &s)) {
 180                 logger(LOG_ERR, "Could not stat RSA private key file `%s': %s'",
 181                                 fname, strerror(errno));
 182                 free(fname);
 183                 return false;
 184         }
 185
 186         if(s.st_mode & ~0100700)
 187                 logger(LOG_WARNING, "Warning: insecure file permissions for RSA private key file `%s'!", fname);
 188 #endif
 189
 190         myself->connection->rsa_key = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
 191         fclose(fp);
 192
 193         if(!myself->connection->rsa_key) {
 194                 logger(LOG_ERR, "Reading RSA private key file `%s' failed: %s",
 195                            fname, strerror(errno));
 196                 free(fname);
 197                 return false;
 198         }
 199
 200         free(fname);
 201         return true;
 202 }
 203
 204 /*
 205   Read Subnets from all host config files
 206 */
 207 void load_all_subnets(void) {
 208         DIR *dir;
 209         struct dirent *ent;
 210         char *dname;
 211         char *fname;
 212         avl_tree_t *config_tree;
 213         config_t *cfg;
 214         subnet_t *s, *s2;
 215         node_t *n;
 216         bool result;
 217
 218         xasprintf(&dname, "%s/hosts", confbase);
 219         dir = opendir(dname);
 220         if(!dir) {
 221                 logger(LOG_ERR, "Could not open %s: %s", dname, strerror(errno));
 222                 free(dname);
 223                 return;
 224         }
 225
 226         while((ent = readdir(dir))) {
 227                 if(!check_id(ent->d_name))
 228                         continue;
 229
 230                 n = lookup_node(ent->d_name);
 231                 #ifdef _DIRENT_HAVE_D_TYPE
 232                 //if(ent->d_type != DT_REG)
 233                 //      continue;
 234                 #endif
 235
 236                 xasprintf(&fname, "%s/hosts/%s", confbase, ent->d_name);
 237                 init_configuration(&config_tree);
 238                 result = read_config_file(config_tree, fname);
 239                 free(fname);
 240                 if(!result)
 241                         continue;
 242
 243                 if(!n) {
 244                         n = new_node();
 245                         n->name = xstrdup(ent->d_name);
 246                         node_add(n);
 247                 }
 248
 249                 for(cfg = lookup_config(config_tree, "Subnet"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 250                         if(!get_config_subnet(cfg, &s))
 251                                 continue;
 252
 253                         if((s2 = lookup_subnet(n, s))) {
 254                                 s2->expires = -1;
 255                         } else {
 256                                 subnet_add(n, s);
 257                         }
 258                 }
 259
 260                 exit_configuration(&config_tree);
 261         }
 262
 263         closedir(dir);
 264 }
 265
 266 /*
 267   Configure node_t myself and set up the local sockets (listen only)
 268 */
 269 bool setup_myself(void) {
 270         config_t *cfg;
 271         subnet_t *subnet;
 272         char *name, *hostname, *mode, *afname, *cipher, *digest;
 273         char *fname = NULL;
 274         char *address = NULL;
 275         char *envp[5];
 276         struct addrinfo *ai, *aip, hint = {0};
 277         bool choice;
 278         int i, err;
 279
 280         myself = new_node();
 281         myself->connection = new_connection();
 282
 283         myself->hostname = xstrdup("MYSELF");
 284         myself->connection->hostname = xstrdup("MYSELF");
 285
 286         myself->connection->options = 0;
 287         myself->connection->protocol_version = PROT_CURRENT;
 288
 289         if(!get_config_string(lookup_config(config_tree, "Name"), &name)) {     /* Not acceptable */
 290                 logger(LOG_ERR, "Name for tinc daemon required!");
 291                 return false;
 292         }
 293
 294         if(!check_id(name)) {
 295                 logger(LOG_ERR, "Invalid name for myself!");
 296                 free(name);
 297                 return false;
 298         }
 299
 300         myself->name = name;
 301         myself->connection->name = xstrdup(name);
 302         xasprintf(&fname, "%s/hosts/%s", confbase, name);
 303         read_config_options(config_tree, name);
 304         read_config_file(config_tree, fname);
 305         free(fname);
 306
 307         if(!read_rsa_private_key())
 308                 return false;
 309
 310         if(!get_config_string(lookup_config(config_tree, "Port"), &myport))
 311                 myport = xstrdup("655");
 312
 313         if(!atoi(myport)) {
 314                 struct addrinfo *ai = str2addrinfo("localhost", myport, SOCK_DGRAM);
 315                 sockaddr_t sa;
 316                 if(!ai || !ai->ai_addr)
 317                         return false;
 318                 free(myport);
 319                 memcpy(&sa, ai->ai_addr, ai->ai_addrlen);
 320                 sockaddr2str(&sa, NULL, &myport);
 321         }
 322
 323         /* Read in all the subnets specified in the host configuration file */
 324
 325         cfg = lookup_config(config_tree, "Subnet");
 326
 327         while(cfg) {
 328                 if(!get_config_subnet(cfg, &subnet))
 329                         return false;
 330
 331                 subnet_add(myself, subnet);
 332
 333                 cfg = lookup_config_next(config_tree, cfg);
 334         }
 335
 336         /* Check some options */
 337
 338         if(get_config_bool(lookup_config(config_tree, "IndirectData"), &choice) && choice)
 339                 myself->options |= OPTION_INDIRECT;
 340
 341         if(get_config_bool(lookup_config(config_tree, "TCPOnly"), &choice) && choice)
 342                 myself->options |= OPTION_TCPONLY;
 343
 344         if(myself->options & OPTION_TCPONLY)
 345                 myself->options |= OPTION_INDIRECT;
 346
 347         get_config_bool(lookup_config(config_tree, "DirectOnly"), &directonly);
 348         get_config_bool(lookup_config(config_tree, "StrictSubnets"), &strictsubnets);
 349         get_config_bool(lookup_config(config_tree, "TunnelServer"), &tunnelserver);
 350         strictsubnets |= tunnelserver;
 351
 352         if(get_config_string(lookup_config(config_tree, "Mode"), &mode)) {
 353                 if(!strcasecmp(mode, "router"))
 354                         routing_mode = RMODE_ROUTER;
 355                 else if(!strcasecmp(mode, "switch"))
 356                         routing_mode = RMODE_SWITCH;
 357                 else if(!strcasecmp(mode, "hub"))
 358                         routing_mode = RMODE_HUB;
 359                 else {
 360                         logger(LOG_ERR, "Invalid routing mode!");
 361                         return false;
 362                 }
 363                 free(mode);
 364         }
 365
 366         if(get_config_string(lookup_config(config_tree, "Forwarding"), &mode)) {
 367                 if(!strcasecmp(mode, "off"))
 368                         forwarding_mode = FMODE_OFF;
 369                 else if(!strcasecmp(mode, "internal"))
 370                         forwarding_mode = FMODE_INTERNAL;
 371                 else if(!strcasecmp(mode, "kernel"))
 372                         forwarding_mode = FMODE_KERNEL;
 373                 else {
 374                         logger(LOG_ERR, "Invalid forwarding mode!");
 375                         return false;
 376                 }
 377                 free(mode);
 378         }
 379
 380         choice = true;
 381         get_config_bool(lookup_config(config_tree, "PMTUDiscovery"), &choice);
 382         if(choice)
 383                 myself->options |= OPTION_PMTU_DISCOVERY;
 384
 385         choice = true;
 386         get_config_bool(lookup_config(config_tree, "ClampMSS"), &choice);
 387         if(choice)
 388                 myself->options |= OPTION_CLAMP_MSS;
 389
 390         get_config_bool(lookup_config(config_tree, "PriorityInheritance"), &priorityinheritance);
 391
 392 #if !defined(SOL_IP) || !defined(IP_TOS)
 393         if(priorityinheritance)
 394                 logger(LOG_WARNING, "%s not supported on this platform", "PriorityInheritance");
 395 #endif
 396
 397         if(!get_config_int(lookup_config(config_tree, "MACExpire"), &macexpire))
 398                 macexpire = 600;
 399
 400         if(get_config_int(lookup_config(config_tree, "MaxTimeout"), &maxtimeout)) {
 401                 if(maxtimeout <= 0) {
 402                         logger(LOG_ERR, "Bogus maximum timeout!");
 403                         return false;
 404                 }
 405         } else
 406                 maxtimeout = 900;
 407
 408         if(get_config_string(lookup_config(config_tree, "AddressFamily"), &afname)) {
 409                 if(!strcasecmp(afname, "IPv4"))
 410                         addressfamily = AF_INET;
 411                 else if(!strcasecmp(afname, "IPv6"))
 412                         addressfamily = AF_INET6;
 413                 else if(!strcasecmp(afname, "any"))
 414                         addressfamily = AF_UNSPEC;
 415                 else {
 416                         logger(LOG_ERR, "Invalid address family!");
 417                         return false;
 418                 }
 419                 free(afname);
 420         }
 421
 422         get_config_bool(lookup_config(config_tree, "Hostnames"), &hostnames);
 423
 424         /* Generate packet encryption key */
 425
 426         if(get_config_string
 427            (lookup_config(config_tree, "Cipher"), &cipher)) {
 428                 if(!strcasecmp(cipher, "none")) {
 429                         myself->incipher = NULL;
 430                 } else {
 431                         myself->incipher = EVP_get_cipherbyname(cipher);
 432
 433                         if(!myself->incipher) {
 434                                 logger(LOG_ERR, "Unrecognized cipher type!");
 435                                 return false;
 436                         }
 437                 }
 438         } else
 439                 myself->incipher = EVP_bf_cbc();
 440
 441         if(myself->incipher)
 442                 myself->inkeylength = myself->incipher->key_len + myself->incipher->iv_len;
 443         else
 444                 myself->inkeylength = 1;
 445
 446         myself->connection->outcipher = EVP_bf_ofb();
 447
 448         if(!get_config_int(lookup_config(config_tree, "KeyExpire"), &keylifetime))
 449                 keylifetime = 3600;
 450
 451         keyexpires = now + keylifetime;
 452
 453         /* Check if we want to use message authentication codes... */
 454
 455         if(get_config_string(lookup_config(config_tree, "Digest"), &digest)) {
 456                 if(!strcasecmp(digest, "none")) {
 457                         myself->indigest = NULL;
 458                 } else {
 459                         myself->indigest = EVP_get_digestbyname(digest);
 460
 461                         if(!myself->indigest) {
 462                                 logger(LOG_ERR, "Unrecognized digest type!");
 463                                 return false;
 464                         }
 465                 }
 466         } else
 467                 myself->indigest = EVP_sha1();
 468
 469         myself->connection->outdigest = EVP_sha1();
 470
 471         if(get_config_int(lookup_config(config_tree, "MACLength"), &myself->inmaclength)) {
 472                 if(myself->indigest) {
 473                         if(myself->inmaclength > myself->indigest->md_size) {
 474                                 logger(LOG_ERR, "MAC length exceeds size of digest!");
 475                                 return false;
 476                         } else if(myself->inmaclength < 0) {
 477                                 logger(LOG_ERR, "Bogus MAC length!");
 478                                 return false;
 479                         }
 480                 }
 481         } else
 482                 myself->inmaclength = 4;
 483
 484         myself->connection->outmaclength = 0;
 485
 486         /* Compression */
 487
 488         if(get_config_int(lookup_config(config_tree, "Compression"), &myself->incompression)) {
 489                 if(myself->incompression < 0 || myself->incompression > 11) {
 490                         logger(LOG_ERR, "Bogus compression level!");
 491                         return false;
 492                 }
 493         } else
 494                 myself->incompression = 0;
 495
 496         myself->connection->outcompression = 0;
 497
 498         /* Done */
 499
 500         myself->nexthop = myself;
 501         myself->via = myself;
 502         myself->status.reachable = true;
 503         node_add(myself);
 504
 505         graph();
 506
 507         if(strictsubnets)
 508                 load_all_subnets();
 509
 510         /* Open device */
 511
 512         if(!setup_device())
 513                 return false;
 514
 515         /* Run tinc-up script to further initialize the tap interface */
 516         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 517         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 518         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 519         xasprintf(&envp[3], "NAME=%s", myself->name);
 520         envp[4] = NULL;
 521
 522         execute_script("tinc-up", envp);
 523
 524         for(i = 0; i < 5; i++)
 525                 free(envp[i]);
 526
 527         /* Run subnet-up scripts for our own subnets */
 528
 529         subnet_update(myself, NULL, true);
 530
 531         /* Open sockets */
 532
 533         get_config_string(lookup_config(config_tree, "BindToAddress"), &address);
 534
 535         hint.ai_family = addressfamily;
 536         hint.ai_socktype = SOCK_STREAM;
 537         hint.ai_protocol = IPPROTO_TCP;
 538         hint.ai_flags = AI_PASSIVE;
 539
 540         err = getaddrinfo(address, myport, &hint, &ai);
 541
 542         if(err || !ai) {
 543                 logger(LOG_ERR, "System call `%s' failed: %s", "getaddrinfo",
 544                            gai_strerror(err));
 545                 return false;
 546         }
 547
 548         listen_sockets = 0;
 549
 550         for(aip = ai; aip; aip = aip->ai_next) {
 551                 listen_socket[listen_sockets].tcp =
 552                         setup_listen_socket((sockaddr_t *) aip->ai_addr);
 553
 554                 if(listen_socket[listen_sockets].tcp < 0)
 555                         continue;
 556
 557                 listen_socket[listen_sockets].udp =
 558                         setup_vpn_in_socket((sockaddr_t *) aip->ai_addr);
 559
 560                 if(listen_socket[listen_sockets].udp < 0)
 561                         continue;
 562
 563                 ifdebug(CONNECTIONS) {
 564                         hostname = sockaddr2hostname((sockaddr_t *) aip->ai_addr);
 565                         logger(LOG_NOTICE, "Listening on %s", hostname);
 566                         free(hostname);
 567                 }
 568
 569                 memcpy(&listen_socket[listen_sockets].sa, aip->ai_addr, aip->ai_addrlen);
 570                 listen_sockets++;
 571         }
 572
 573         freeaddrinfo(ai);
 574
 575         if(listen_sockets)
 576                 logger(LOG_NOTICE, "Ready");
 577         else {
 578                 logger(LOG_ERR, "Unable to create any listening socket!");
 579                 return false;
 580         }
 581
 582         return true;
 583 }
 584
 585 /*
 586   initialize network
 587 */
 588 bool setup_network(void) {
 589         now = time(NULL);
 590
 591         init_events();
 592         init_connections();
 593         init_subnets();
 594         init_nodes();
 595         init_edges();
 596         init_requests();
 597
 598         if(get_config_int(lookup_config(config_tree, "PingInterval"), &pinginterval)) {
 599                 if(pinginterval < 1) {
 600                         pinginterval = 86400;
 601                 }
 602         } else
 603                 pinginterval = 60;
 604
 605         if(!get_config_int(lookup_config(config_tree, "PingTimeout"), &pingtimeout))
 606                 pingtimeout = 5;
 607         if(pingtimeout < 1 || pingtimeout > pinginterval)
 608                 pingtimeout = pinginterval;
 609
 610         if(!get_config_int(lookup_config(config_tree, "MaxOutputBufferSize"), &maxoutbufsize))
 611                 maxoutbufsize = 10 * MTU;
 612
 613         if(!setup_myself())
 614                 return false;
 615
 616         return true;
 617 }
 618
 619 /*
 620   close all open network connections
 621 */
 622 void close_network_connections(void) {
 623         avl_node_t *node, *next;
 624         connection_t *c;
 625         char *envp[5];
 626         int i;
 627
 628         for(node = connection_tree->head; node; node = next) {
 629                 next = node->next;
 630                 c = node->data;
 631                 c->outgoing = NULL;
 632                 terminate_connection(c, false);
 633         }
 634
 635         for(list_node_t *node = outgoing_list->head; node; node = node->next) {
 636                 outgoing_t *outgoing = node->data;
 637
 638                 if(outgoing->event)
 639                         event_del(outgoing->event);
 640         }
 641
 642         list_delete_list(outgoing_list);
 643
 644         if(myself && myself->connection) {
 645                 subnet_update(myself, NULL, false);
 646                 terminate_connection(myself->connection, false);
 647                 free_connection(myself->connection);
 648         }
 649
 650         for(i = 0; i < listen_sockets; i++) {
 651                 close(listen_socket[i].tcp);
 652                 close(listen_socket[i].udp);
 653         }
 654
 655         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 656         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 657         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 658         xasprintf(&envp[3], "NAME=%s", myself->name);
 659         envp[4] = NULL;
 660
 661         exit_requests();
 662         exit_edges();
 663         exit_subnets();
 664         exit_nodes();
 665         exit_connections();
 666         exit_events();
 667
 668         execute_script("tinc-down", envp);
 669
 670         if(myport) free(myport);
 671
 672         for(i = 0; i < 4; i++)
 673                 free(envp[i]);
 674
 675         close_device();
 676
 677         return;
 678 }