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(myself->connection->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 static 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;
 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                 if(n)
 232                         continue;
 233
 234                 #ifdef _DIRENT_HAVE_D_TYPE
 235                 //if(ent->d_type != DT_REG)
 236                 //      continue;
 237                 #endif
 238
 239                 xasprintf(&fname, "%s/hosts/%s", confbase, ent->d_name);
 240                 init_configuration(&config_tree);
 241                 result = read_config_file(config_tree, fname);
 242                 free(fname);
 243                 if(!result)
 244                         continue;
 245
 246                 n = new_node();
 247                 n->name = xstrdup(ent->d_name);
 248                 node_add(n);
 249
 250                 for(cfg = lookup_config(config_tree, "Subnet"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 251                         if(!get_config_subnet(cfg, &s))
 252                                 continue;
 253
 254                         subnet_add(n, s);
 255                 }
 256
 257                 exit_configuration(&config_tree);
 258         }
 259
 260         closedir(dir);
 261 }
 262
 263 /*
 264   Configure node_t myself and set up the local sockets (listen only)
 265 */
 266 bool setup_myself(void) {
 267         config_t *cfg;
 268         subnet_t *subnet;
 269         char *name, *hostname, *mode, *afname, *cipher, *digest;
 270         char *address = NULL;
 271         char *envp[5];
 272         struct addrinfo *ai, *aip, hint = {0};
 273         bool choice;
 274         int i, err;
 275
 276         myself = new_node();
 277         myself->connection = new_connection();
 278         init_configuration(&myself->connection->config_tree);
 279
 280         myself->hostname = xstrdup("MYSELF");
 281         myself->connection->hostname = xstrdup("MYSELF");
 282
 283         myself->connection->options = 0;
 284         myself->connection->protocol_version = PROT_CURRENT;
 285
 286         if(!get_config_string(lookup_config(config_tree, "Name"), &name)) {     /* Not acceptable */
 287                 logger(LOG_ERR, "Name for tinc daemon required!");
 288                 return false;
 289         }
 290
 291         if(!check_id(name)) {
 292                 logger(LOG_ERR, "Invalid name for myself!");
 293                 free(name);
 294                 return false;
 295         }
 296
 297         myself->name = name;
 298         myself->connection->name = xstrdup(name);
 299
 300         if(!read_connection_config(myself->connection)) {
 301                 logger(LOG_ERR, "Cannot open host configuration file for myself!");
 302                 return false;
 303         }
 304
 305         if(!read_rsa_private_key())
 306                 return false;
 307
 308         if(!get_config_string(lookup_config(config_tree, "Port"), &myport)
 309                         && !get_config_string(lookup_config(myself->connection->config_tree, "Port"), &myport))
 310                 myport = xstrdup("655");
 311
 312         /* Read in all the subnets specified in the host configuration file */
 313
 314         cfg = lookup_config(myself->connection->config_tree, "Subnet");
 315
 316         while(cfg) {
 317                 if(!get_config_subnet(cfg, &subnet))
 318                         return false;
 319
 320                 subnet_add(myself, subnet);
 321
 322                 cfg = lookup_config_next(myself->connection->config_tree, cfg);
 323         }
 324
 325         /* Check some options */
 326
 327         if(get_config_bool(lookup_config(config_tree, "IndirectData"), &choice) && choice)
 328                 myself->options |= OPTION_INDIRECT;
 329
 330         if(get_config_bool(lookup_config(config_tree, "TCPOnly"), &choice) && choice)
 331                 myself->options |= OPTION_TCPONLY;
 332
 333         if(get_config_bool(lookup_config(myself->connection->config_tree, "IndirectData"), &choice) && choice)
 334                 myself->options |= OPTION_INDIRECT;
 335
 336         if(get_config_bool(lookup_config(myself->connection->config_tree, "TCPOnly"), &choice) && choice)
 337                 myself->options |= OPTION_TCPONLY;
 338
 339         if(myself->options & OPTION_TCPONLY)
 340                 myself->options |= OPTION_INDIRECT;
 341
 342         get_config_bool(lookup_config(config_tree, "StrictSubnets"), &strictsubnets);
 343         get_config_bool(lookup_config(config_tree, "TunnelServer"), &tunnelserver);
 344         strictsubnets |= tunnelserver;
 345
 346         if(get_config_string(lookup_config(config_tree, "Mode"), &mode)) {
 347                 if(!strcasecmp(mode, "router"))
 348                         routing_mode = RMODE_ROUTER;
 349                 else if(!strcasecmp(mode, "switch"))
 350                         routing_mode = RMODE_SWITCH;
 351                 else if(!strcasecmp(mode, "hub"))
 352                         routing_mode = RMODE_HUB;
 353                 else {
 354                         logger(LOG_ERR, "Invalid routing mode!");
 355                         return false;
 356                 }
 357                 free(mode);
 358         } else
 359                 routing_mode = RMODE_ROUTER;
 360
 361         choice = true;
 362         get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice);
 363         get_config_bool(lookup_config(config_tree, "PMTUDiscovery"), &choice);
 364         if(choice)
 365                 myself->options |= OPTION_PMTU_DISCOVERY;
 366
 367         choice = true;
 368         get_config_bool(lookup_config(config_tree, "ClampMSS"), &choice);
 369         get_config_bool(lookup_config(myself->connection->config_tree, "ClampMSS"), &choice);
 370         if(choice)
 371                 myself->options |= OPTION_CLAMP_MSS;
 372
 373         get_config_bool(lookup_config(config_tree, "PriorityInheritance"), &priorityinheritance);
 374
 375 #if !defined(SOL_IP) || !defined(IP_TOS)
 376         if(priorityinheritance)
 377                 logger(LOG_WARNING, "%s not supported on this platform", "PriorityInheritance");
 378 #endif
 379
 380         if(!get_config_int(lookup_config(config_tree, "MACExpire"), &macexpire))
 381                 macexpire = 600;
 382
 383         if(get_config_int(lookup_config(config_tree, "MaxTimeout"), &maxtimeout)) {
 384                 if(maxtimeout <= 0) {
 385                         logger(LOG_ERR, "Bogus maximum timeout!");
 386                         return false;
 387                 }
 388         } else
 389                 maxtimeout = 900;
 390
 391         if(get_config_string(lookup_config(config_tree, "AddressFamily"), &afname)) {
 392                 if(!strcasecmp(afname, "IPv4"))
 393                         addressfamily = AF_INET;
 394                 else if(!strcasecmp(afname, "IPv6"))
 395                         addressfamily = AF_INET6;
 396                 else if(!strcasecmp(afname, "any"))
 397                         addressfamily = AF_UNSPEC;
 398                 else {
 399                         logger(LOG_ERR, "Invalid address family!");
 400                         return false;
 401                 }
 402                 free(afname);
 403         }
 404
 405         get_config_bool(lookup_config(config_tree, "Hostnames"), &hostnames);
 406
 407         /* Generate packet encryption key */
 408
 409         if(get_config_string
 410            (lookup_config(myself->connection->config_tree, "Cipher"), &cipher)) {
 411                 if(!strcasecmp(cipher, "none")) {
 412                         myself->incipher = NULL;
 413                 } else {
 414                         myself->incipher = EVP_get_cipherbyname(cipher);
 415
 416                         if(!myself->incipher) {
 417                                 logger(LOG_ERR, "Unrecognized cipher type!");
 418                                 return false;
 419                         }
 420                 }
 421         } else
 422                 myself->incipher = EVP_bf_cbc();
 423
 424         if(myself->incipher)
 425                 myself->inkeylength = myself->incipher->key_len + myself->incipher->iv_len;
 426         else
 427                 myself->inkeylength = 1;
 428
 429         myself->connection->outcipher = EVP_bf_ofb();
 430
 431         if(!get_config_int(lookup_config(config_tree, "KeyExpire"), &keylifetime))
 432                 keylifetime = 3600;
 433
 434         keyexpires = now + keylifetime;
 435
 436         /* Check if we want to use message authentication codes... */
 437
 438         if(get_config_string(lookup_config(myself->connection->config_tree, "Digest"), &digest)) {
 439                 if(!strcasecmp(digest, "none")) {
 440                         myself->indigest = NULL;
 441                 } else {
 442                         myself->indigest = EVP_get_digestbyname(digest);
 443
 444                         if(!myself->indigest) {
 445                                 logger(LOG_ERR, "Unrecognized digest type!");
 446                                 return false;
 447                         }
 448                 }
 449         } else
 450                 myself->indigest = EVP_sha1();
 451
 452         myself->connection->outdigest = EVP_sha1();
 453
 454         if(get_config_int(lookup_config(myself->connection->config_tree, "MACLength"), &myself->inmaclength)) {
 455                 if(myself->indigest) {
 456                         if(myself->inmaclength > myself->indigest->md_size) {
 457                                 logger(LOG_ERR, "MAC length exceeds size of digest!");
 458                                 return false;
 459                         } else if(myself->inmaclength < 0) {
 460                                 logger(LOG_ERR, "Bogus MAC length!");
 461                                 return false;
 462                         }
 463                 }
 464         } else
 465                 myself->inmaclength = 4;
 466
 467         myself->connection->outmaclength = 0;
 468
 469         /* Compression */
 470
 471         if(get_config_int(lookup_config(myself->connection->config_tree, "Compression"), &myself->incompression)) {
 472                 if(myself->incompression < 0 || myself->incompression > 11) {
 473                         logger(LOG_ERR, "Bogus compression level!");
 474                         return false;
 475                 }
 476         } else
 477                 myself->incompression = 0;
 478
 479         myself->connection->outcompression = 0;
 480
 481         /* Done */
 482
 483         myself->nexthop = myself;
 484         myself->via = myself;
 485         myself->status.reachable = true;
 486         node_add(myself);
 487
 488         graph();
 489
 490         if(strictsubnets)
 491                 load_all_subnets();
 492
 493         /* Open device */
 494
 495         if(!setup_device())
 496                 return false;
 497
 498         /* Run tinc-up script to further initialize the tap interface */
 499         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 500         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 501         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 502         xasprintf(&envp[3], "NAME=%s", myself->name);
 503         envp[4] = NULL;
 504
 505         execute_script("tinc-up", envp);
 506
 507         for(i = 0; i < 5; i++)
 508                 free(envp[i]);
 509
 510         /* Run subnet-up scripts for our own subnets */
 511
 512         subnet_update(myself, NULL, true);
 513
 514         /* Open sockets */
 515
 516         get_config_string(lookup_config(config_tree, "BindToAddress"), &address);
 517
 518         hint.ai_family = addressfamily;
 519         hint.ai_socktype = SOCK_STREAM;
 520         hint.ai_protocol = IPPROTO_TCP;
 521         hint.ai_flags = AI_PASSIVE;
 522
 523         err = getaddrinfo(address, myport, &hint, &ai);
 524
 525         if(err || !ai) {
 526                 logger(LOG_ERR, "System call `%s' failed: %s", "getaddrinfo",
 527                            gai_strerror(err));
 528                 return false;
 529         }
 530
 531         listen_sockets = 0;
 532
 533         for(aip = ai; aip; aip = aip->ai_next) {
 534                 listen_socket[listen_sockets].tcp =
 535                         setup_listen_socket((sockaddr_t *) aip->ai_addr);
 536
 537                 if(listen_socket[listen_sockets].tcp < 0)
 538                         continue;
 539
 540                 listen_socket[listen_sockets].udp =
 541                         setup_vpn_in_socket((sockaddr_t *) aip->ai_addr);
 542
 543                 if(listen_socket[listen_sockets].udp < 0)
 544                         continue;
 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
 556         freeaddrinfo(ai);
 557
 558         if(listen_sockets)
 559                 logger(LOG_NOTICE, "Ready");
 560         else {
 561                 logger(LOG_ERR, "Unable to create any listening socket!");
 562                 return false;
 563         }
 564
 565         return true;
 566 }
 567
 568 /*
 569   initialize network
 570 */
 571 bool setup_network(void) {
 572         now = time(NULL);
 573
 574         init_events();
 575         init_connections();
 576         init_subnets();
 577         init_nodes();
 578         init_edges();
 579         init_requests();
 580
 581         if(get_config_int(lookup_config(config_tree, "PingInterval"), &pinginterval)) {
 582                 if(pinginterval < 1) {
 583                         pinginterval = 86400;
 584                 }
 585         } else
 586                 pinginterval = 60;
 587
 588         if(!get_config_int(lookup_config(config_tree, "PingTimeout"), &pingtimeout))
 589                 pingtimeout = 5;
 590         if(pingtimeout < 1 || pingtimeout > pinginterval)
 591                 pingtimeout = pinginterval;
 592
 593         if(!get_config_int(lookup_config(config_tree, "MaxOutputBufferSize"), &maxoutbufsize))
 594                 maxoutbufsize = 10 * MTU;
 595
 596         if(!setup_myself())
 597                 return false;
 598
 599         return true;
 600 }
 601
 602 /*
 603   close all open network connections
 604 */
 605 void close_network_connections(void) {
 606         avl_node_t *node, *next;
 607         connection_t *c;
 608         char *envp[5];
 609         int i;
 610
 611         for(node = connection_tree->head; node; node = next) {
 612                 next = node->next;
 613                 c = node->data;
 614                 c->outgoing = NULL;
 615                 terminate_connection(c, false);
 616         }
 617
 618         for(list_node_t *node = outgoing_list->head; node; node = node->next) {
 619                 outgoing_t *outgoing = node->data;
 620
 621                 if(outgoing->event)
 622                         event_del(outgoing->event);
 623         }
 624
 625         list_delete_list(outgoing_list);
 626
 627         if(myself && myself->connection) {
 628                 subnet_update(myself, NULL, false);
 629                 terminate_connection(myself->connection, false);
 630                 free_connection(myself->connection);
 631         }
 632
 633         for(i = 0; i < listen_sockets; i++) {
 634                 close(listen_socket[i].tcp);
 635                 close(listen_socket[i].udp);
 636         }
 637
 638         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 639         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 640         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 641         xasprintf(&envp[3], "NAME=%s", myself->name);
 642         envp[4] = NULL;
 643
 644         exit_requests();
 645         exit_edges();
 646         exit_subnets();
 647         exit_nodes();
 648         exit_connections();
 649         exit_events();
 650
 651         execute_script("tinc-down", envp);
 652
 653         if(myport) free(myport);
 654
 655         for(i = 0; i < 4; i++)
 656                 free(envp[i]);
 657
 658         close_device();
 659
 660         return;
 661 }