src/net_setup.c

   1 /*
   2     net_setup.c -- Setup.
   3     Copyright (C) 1998-2005 Ivo Timmermans,
   4                   2000-2009 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   Configure node_t myself and set up the local sockets (listen only)
 206 */
 207 bool setup_myself(void) {
 208         config_t *cfg;
 209         subnet_t *subnet;
 210         char *name, *hostname, *mode, *afname, *cipher, *digest;
 211         char *address = NULL;
 212         char *envp[5];
 213         struct addrinfo *ai, *aip, hint = {0};
 214         bool choice;
 215         int i, err;
 216
 217         myself = new_node();
 218         myself->connection = new_connection();
 219         init_configuration(&myself->connection->config_tree);
 220
 221         xasprintf(&myself->hostname, "MYSELF");
 222         xasprintf(&myself->connection->hostname, "MYSELF");
 223
 224         myself->connection->options = 0;
 225         myself->connection->protocol_version = PROT_CURRENT;
 226
 227         if(!get_config_string(lookup_config(config_tree, "Name"), &name)) {     /* Not acceptable */
 228                 logger(LOG_ERR, "Name for tinc daemon required!");
 229                 return false;
 230         }
 231
 232         if(!check_id(name)) {
 233                 logger(LOG_ERR, "Invalid name for myself!");
 234                 free(name);
 235                 return false;
 236         }
 237
 238         myself->name = name;
 239         myself->connection->name = xstrdup(name);
 240
 241         if(!read_connection_config(myself->connection)) {
 242                 logger(LOG_ERR, "Cannot open host configuration file for myself!");
 243                 return false;
 244         }
 245
 246         if(!read_rsa_private_key())
 247                 return false;
 248
 249         if(!get_config_string(lookup_config(myself->connection->config_tree, "Port"), &myport))
 250                 xasprintf(&myport, "655");
 251
 252         /* Read in all the subnets specified in the host configuration file */
 253
 254         cfg = lookup_config(myself->connection->config_tree, "Subnet");
 255
 256         while(cfg) {
 257                 if(!get_config_subnet(cfg, &subnet))
 258                         return false;
 259
 260                 subnet_add(myself, subnet);
 261
 262                 cfg = lookup_config_next(myself->connection->config_tree, cfg);
 263         }
 264
 265         /* Check some options */
 266
 267         if(get_config_bool(lookup_config(config_tree, "IndirectData"), &choice) && choice)
 268                 myself->options |= OPTION_INDIRECT;
 269
 270         if(get_config_bool(lookup_config(config_tree, "TCPOnly"), &choice) && choice)
 271                 myself->options |= OPTION_TCPONLY;
 272
 273         if(get_config_bool(lookup_config(myself->connection->config_tree, "IndirectData"), &choice) && choice)
 274                 myself->options |= OPTION_INDIRECT;
 275
 276         if(get_config_bool(lookup_config(myself->connection->config_tree, "TCPOnly"), &choice) && choice)
 277                 myself->options |= OPTION_TCPONLY;
 278
 279         if(myself->options & OPTION_TCPONLY)
 280                 myself->options |= OPTION_INDIRECT;
 281
 282         get_config_bool(lookup_config(config_tree, "TunnelServer"), &tunnelserver);
 283
 284         if(get_config_string(lookup_config(config_tree, "Mode"), &mode)) {
 285                 if(!strcasecmp(mode, "router"))
 286                         routing_mode = RMODE_ROUTER;
 287                 else if(!strcasecmp(mode, "switch"))
 288                         routing_mode = RMODE_SWITCH;
 289                 else if(!strcasecmp(mode, "hub"))
 290                         routing_mode = RMODE_HUB;
 291                 else {
 292                         logger(LOG_ERR, "Invalid routing mode!");
 293                         return false;
 294                 }
 295                 free(mode);
 296         } else
 297                 routing_mode = RMODE_ROUTER;
 298
 299         // Enable PMTUDiscovery by default if we are in router mode.
 300
 301         choice = routing_mode == RMODE_ROUTER;
 302         get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice);
 303         if(choice)
 304                 myself->options |= OPTION_PMTU_DISCOVERY;
 305
 306         get_config_bool(lookup_config(config_tree, "PriorityInheritance"), &priorityinheritance);
 307
 308 #if !defined(SOL_IP) || !defined(IP_TOS)
 309         if(priorityinheritance)
 310                 logger(LOG_WARNING, "%s not supported on this platform", "PriorityInheritance");
 311 #endif
 312
 313         if(!get_config_int(lookup_config(config_tree, "MACExpire"), &macexpire))
 314                 macexpire = 600;
 315
 316         if(get_config_int(lookup_config(config_tree, "MaxTimeout"), &maxtimeout)) {
 317                 if(maxtimeout <= 0) {
 318                         logger(LOG_ERR, "Bogus maximum timeout!");
 319                         return false;
 320                 }
 321         } else
 322                 maxtimeout = 900;
 323
 324         if(get_config_string(lookup_config(config_tree, "AddressFamily"), &afname)) {
 325                 if(!strcasecmp(afname, "IPv4"))
 326                         addressfamily = AF_INET;
 327                 else if(!strcasecmp(afname, "IPv6"))
 328                         addressfamily = AF_INET6;
 329                 else if(!strcasecmp(afname, "any"))
 330                         addressfamily = AF_UNSPEC;
 331                 else {
 332                         logger(LOG_ERR, "Invalid address family!");
 333                         return false;
 334                 }
 335                 free(afname);
 336         }
 337
 338         get_config_bool(lookup_config(config_tree, "Hostnames"), &hostnames);
 339
 340         /* Generate packet encryption key */
 341
 342         if(get_config_string
 343            (lookup_config(myself->connection->config_tree, "Cipher"), &cipher)) {
 344                 if(!strcasecmp(cipher, "none")) {
 345                         myself->incipher = NULL;
 346                 } else {
 347                         myself->incipher = EVP_get_cipherbyname(cipher);
 348
 349                         if(!myself->incipher) {
 350                                 logger(LOG_ERR, "Unrecognized cipher type!");
 351                                 return false;
 352                         }
 353                 }
 354         } else
 355                 myself->incipher = EVP_aes_256_cbc();
 356
 357         if(myself->incipher)
 358                 myself->inkeylength = myself->incipher->key_len + myself->incipher->iv_len;
 359         else
 360                 myself->inkeylength = 1;
 361
 362         myself->connection->outcipher = EVP_aes_256_ofb();
 363
 364         if(!get_config_int(lookup_config(config_tree, "KeyExpire"), &keylifetime))
 365                 keylifetime = 3600;
 366
 367         keyexpires = now + keylifetime;
 368
 369         /* Check if we want to use message authentication codes... */
 370
 371         if(get_config_string(lookup_config(myself->connection->config_tree, "Digest"), &digest)) {
 372                 if(!strcasecmp(digest, "none")) {
 373                         myself->indigest = NULL;
 374                 } else {
 375                         myself->indigest = EVP_get_digestbyname(digest);
 376
 377                         if(!myself->indigest) {
 378                                 logger(LOG_ERR, "Unrecognized digest type!");
 379                                 return false;
 380                         }
 381                 }
 382         } else
 383                 myself->indigest = EVP_sha256();
 384
 385         myself->connection->outdigest = EVP_sha256();
 386
 387         if(get_config_int(lookup_config(myself->connection->config_tree, "MACLength"), &myself->inmaclength)) {
 388                 if(myself->indigest) {
 389                         if(myself->inmaclength > myself->indigest->md_size) {
 390                                 logger(LOG_ERR, "MAC length exceeds size of digest!");
 391                                 return false;
 392                         } else if(myself->inmaclength < 0) {
 393                                 logger(LOG_ERR, "Bogus MAC length!");
 394                                 return false;
 395                         }
 396                 }
 397         } else
 398                 myself->inmaclength = 4;
 399
 400         myself->connection->outmaclength = 0;
 401
 402         /* Compression */
 403
 404         if(get_config_int(lookup_config(myself->connection->config_tree, "Compression"), &myself->incompression)) {
 405                 if(myself->incompression < 0 || myself->incompression > 11) {
 406                         logger(LOG_ERR, "Bogus compression level!");
 407                         return false;
 408                 }
 409         } else
 410                 myself->incompression = 0;
 411
 412         myself->connection->outcompression = 0;
 413
 414         /* Done */
 415
 416         myself->nexthop = myself;
 417         myself->via = myself;
 418         myself->status.reachable = true;
 419         node_add(myself);
 420
 421         graph();
 422
 423         /* Open device */
 424
 425         if(!setup_device())
 426                 return false;
 427
 428         /* Run tinc-up script to further initialize the tap interface */
 429         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 430         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 431         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 432         xasprintf(&envp[3], "NAME=%s", myself->name);
 433         envp[4] = NULL;
 434
 435         execute_script("tinc-up", envp);
 436
 437         for(i = 0; i < 5; i++)
 438                 free(envp[i]);
 439
 440         /* Run subnet-up scripts for our own subnets */
 441
 442         subnet_update(myself, NULL, true);
 443
 444         /* Open sockets */
 445
 446         get_config_string(lookup_config(config_tree, "BindToAddress"), &address);
 447
 448         hint.ai_family = addressfamily;
 449         hint.ai_socktype = SOCK_STREAM;
 450         hint.ai_protocol = IPPROTO_TCP;
 451         hint.ai_flags = AI_PASSIVE;
 452
 453         err = getaddrinfo(address, myport, &hint, &ai);
 454
 455         if(err || !ai) {
 456                 logger(LOG_ERR, "System call `%s' failed: %s", "getaddrinfo",
 457                            gai_strerror(err));
 458                 return false;
 459         }
 460
 461         listen_sockets = 0;
 462
 463         for(aip = ai; aip; aip = aip->ai_next) {
 464                 listen_socket[listen_sockets].tcp =
 465                         setup_listen_socket((sockaddr_t *) aip->ai_addr);
 466
 467                 if(listen_socket[listen_sockets].tcp < 0)
 468                         continue;
 469
 470                 listen_socket[listen_sockets].udp =
 471                         setup_vpn_in_socket((sockaddr_t *) aip->ai_addr);
 472
 473                 if(listen_socket[listen_sockets].udp < 0)
 474                         continue;
 475
 476                 ifdebug(CONNECTIONS) {
 477                         hostname = sockaddr2hostname((sockaddr_t *) aip->ai_addr);
 478                         logger(LOG_NOTICE, "Listening on %s", hostname);
 479                         free(hostname);
 480                 }
 481
 482                 memcpy(&listen_socket[listen_sockets].sa, aip->ai_addr, aip->ai_addrlen);
 483                 listen_sockets++;
 484         }
 485
 486         freeaddrinfo(ai);
 487
 488         if(listen_sockets)
 489                 logger(LOG_NOTICE, "Ready");
 490         else {
 491                 logger(LOG_ERR, "Unable to create any listening socket!");
 492                 return false;
 493         }
 494
 495         return true;
 496 }
 497
 498 /*
 499   initialize network
 500 */
 501 bool setup_network(void) {
 502         now = time(NULL);
 503
 504         init_events();
 505         init_connections();
 506         init_subnets();
 507         init_nodes();
 508         init_edges();
 509         init_requests();
 510
 511         if(get_config_int(lookup_config(config_tree, "PingInterval"), &pinginterval)) {
 512                 if(pinginterval < 1) {
 513                         pinginterval = 86400;
 514                 }
 515         } else
 516                 pinginterval = 60;
 517
 518         if(!get_config_int(lookup_config(config_tree, "PingTimeout"), &pingtimeout))
 519                 pingtimeout = 5;
 520         if(pingtimeout < 1 || pingtimeout > pinginterval)
 521                 pingtimeout = pinginterval;
 522
 523         if(!get_config_int(lookup_config(config_tree, "MaxOutputBufferSize"), &maxoutbufsize))
 524                 maxoutbufsize = 10 * MTU;
 525
 526         if(!setup_myself())
 527                 return false;
 528
 529         return true;
 530 }
 531
 532 /*
 533   close all open network connections
 534 */
 535 void close_network_connections(void) {
 536         avl_node_t *node, *next;
 537         connection_t *c;
 538         char *envp[5];
 539         int i;
 540
 541         for(node = connection_tree->head; node; node = next) {
 542                 next = node->next;
 543                 c = node->data;
 544                 c->outgoing = false;
 545                 terminate_connection(c, false);
 546         }
 547
 548         list_delete_list(outgoing_list);
 549
 550         if(myself && myself->connection) {
 551                 subnet_update(myself, NULL, false);
 552                 terminate_connection(myself->connection, false);
 553                 free_connection(myself->connection);
 554         }
 555
 556         for(i = 0; i < listen_sockets; i++) {
 557                 close(listen_socket[i].tcp);
 558                 close(listen_socket[i].udp);
 559         }
 560
 561         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 562         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 563         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 564         xasprintf(&envp[3], "NAME=%s", myself->name);
 565         envp[4] = NULL;
 566
 567         exit_requests();
 568         exit_edges();
 569         exit_subnets();
 570         exit_nodes();
 571         exit_connections();
 572         exit_events();
 573
 574         execute_script("tinc-down", envp);
 575
 576         if(myport) free(myport);
 577
 578         for(i = 0; i < 4; i++)
 579                 free(envp[i]);
 580
 581         close_device();
 582
 583         return;
 584 }