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
   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 along
  17     with this program; if not, write to the Free Software Foundation, Inc.,
  18     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19 */
  20
  21 #include "system.h"
  22
  23 #include <openssl/pem.h>
  24 #include <openssl/rsa.h>
  25 #include <openssl/rand.h>
  26 #include <openssl/err.h>
  27 #include <openssl/evp.h>
  28
  29 #include "avl_tree.h"
  30 #include "conf.h"
  31 #include "connection.h"
  32 #include "device.h"
  33 #include "event.h"
  34 #include "graph.h"
  35 #include "logger.h"
  36 #include "net.h"
  37 #include "netutl.h"
  38 #include "process.h"
  39 #include "protocol.h"
  40 #include "route.h"
  41 #include "subnet.h"
  42 #include "utils.h"
  43 #include "xalloc.h"
  44
  45 char *myport;
  46
  47 bool read_rsa_public_key(connection_t *c) {
  48         FILE *fp;
  49         char *fname;
  50         char *key;
  51
  52         cp();
  53
  54         if(!c->rsa_key) {
  55                 c->rsa_key = RSA_new();
  56 //              RSA_blinding_on(c->rsa_key, NULL);
  57         }
  58
  59         /* First, check for simple PublicKey statement */
  60
  61         if(get_config_string(lookup_config(c->config_tree, "PublicKey"), &key)) {
  62                 BN_hex2bn(&c->rsa_key->n, key);
  63                 BN_hex2bn(&c->rsa_key->e, "FFFF");
  64                 free(key);
  65                 return true;
  66         }
  67
  68         /* Else, check for PublicKeyFile statement and read it */
  69
  70         if(get_config_string(lookup_config(c->config_tree, "PublicKeyFile"), &fname)) {
  71                 fp = fopen(fname, "r");
  72
  73                 if(!fp) {
  74                         logger(LOG_ERR, _("Error reading RSA public key file `%s': %s"),
  75                                    fname, strerror(errno));
  76                         free(fname);
  77                         return false;
  78                 }
  79
  80                 free(fname);
  81                 c->rsa_key = PEM_read_RSAPublicKey(fp, &c->rsa_key, NULL, NULL);
  82                 fclose(fp);
  83
  84                 if(c->rsa_key)
  85                         return true;            /* Woohoo. */
  86
  87                 /* If it fails, try PEM_read_RSA_PUBKEY. */
  88                 fp = fopen(fname, "r");
  89
  90                 if(!fp) {
  91                         logger(LOG_ERR, _("Error reading RSA public key file `%s': %s"),
  92                                    fname, strerror(errno));
  93                         free(fname);
  94                         return false;
  95                 }
  96
  97                 free(fname);
  98                 c->rsa_key = PEM_read_RSA_PUBKEY(fp, &c->rsa_key, NULL, NULL);
  99                 fclose(fp);
 100
 101                 if(c->rsa_key) {
 102 //                              RSA_blinding_on(c->rsa_key, NULL);
 103                         return true;
 104                 }
 105
 106                 logger(LOG_ERR, _("Reading RSA public key file `%s' failed: %s"),
 107                            fname, strerror(errno));
 108                 return false;
 109         }
 110
 111         /* Else, check if a harnessed public key is in the config file */
 112
 113         xasprintf(&fname, "%s/hosts/%s", confbase, c->name);
 114         fp = fopen(fname, "r");
 115
 116         if(fp) {
 117                 c->rsa_key = PEM_read_RSAPublicKey(fp, &c->rsa_key, NULL, NULL);
 118                 fclose(fp);
 119         }
 120
 121         free(fname);
 122
 123         if(c->rsa_key)
 124                 return true;
 125
 126         /* Try again with PEM_read_RSA_PUBKEY. */
 127
 128         xasprintf(&fname, "%s/hosts/%s", confbase, c->name);
 129         fp = fopen(fname, "r");
 130
 131         if(fp) {
 132                 c->rsa_key = PEM_read_RSA_PUBKEY(fp, &c->rsa_key, NULL, NULL);
 133 //              RSA_blinding_on(c->rsa_key, NULL);
 134                 fclose(fp);
 135         }
 136
 137         free(fname);
 138
 139         if(c->rsa_key)
 140                 return true;
 141
 142         logger(LOG_ERR, _("No public key for %s specified!"), c->name);
 143
 144         return false;
 145 }
 146
 147 bool read_rsa_private_key(void) {
 148         FILE *fp;
 149         char *fname, *key, *pubkey;
 150         struct stat s;
 151
 152         cp();
 153
 154         if(get_config_string(lookup_config(config_tree, "PrivateKey"), &key)) {
 155                 if(!get_config_string(lookup_config(myself->connection->config_tree, "PublicKey"), &pubkey)) {
 156                         logger(LOG_ERR, _("PrivateKey used but no PublicKey found!"));
 157                         return false;
 158                 }
 159                 myself->connection->rsa_key = RSA_new();
 160 //              RSA_blinding_on(myself->connection->rsa_key, NULL);
 161                 BN_hex2bn(&myself->connection->rsa_key->d, key);
 162                 BN_hex2bn(&myself->connection->rsa_key->n, pubkey);
 163                 BN_hex2bn(&myself->connection->rsa_key->e, "FFFF");
 164                 free(key);
 165                 free(pubkey);
 166                 return true;
 167         }
 168
 169         if(!get_config_string(lookup_config(config_tree, "PrivateKeyFile"), &fname))
 170                 xasprintf(&fname, "%s/rsa_key.priv", confbase);
 171
 172         fp = fopen(fname, "r");
 173
 174         if(!fp) {
 175                 logger(LOG_ERR, _("Error reading RSA private key file `%s': %s"),
 176                            fname, strerror(errno));
 177                 free(fname);
 178                 return false;
 179         }
 180
 181 #if !defined(HAVE_MINGW) && !defined(HAVE_CYGWIN)
 182         if(fstat(fileno(fp), &s)) {
 183                 logger(LOG_ERR, _("Could not stat RSA private key file `%s': %s'"),
 184                                 fname, strerror(errno));
 185                 free(fname);
 186                 return false;
 187         }
 188
 189         if(s.st_mode & ~0100700)
 190                 logger(LOG_WARNING, _("Warning: insecure file permissions for RSA private key file `%s'!"), fname);
 191 #endif
 192
 193         myself->connection->rsa_key = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
 194         fclose(fp);
 195
 196         if(!myself->connection->rsa_key) {
 197                 logger(LOG_ERR, _("Reading RSA private key file `%s' failed: %s"),
 198                            fname, strerror(errno));
 199                 free(fname);
 200                 return false;
 201         }
 202
 203         free(fname);
 204         return true;
 205 }
 206
 207 /*
 208   Configure node_t myself and set up the local sockets (listen only)
 209 */
 210 bool setup_myself(void) {
 211         config_t *cfg;
 212         subnet_t *subnet;
 213         char *name, *hostname, *mode, *afname, *cipher, *digest;
 214         char *address = NULL;
 215         char *envp[5];
 216         struct addrinfo *ai, *aip, hint = {0};
 217         bool choice;
 218         int i, err;
 219
 220         cp();
 221
 222         myself = new_node();
 223         myself->connection = new_connection();
 224         init_configuration(&myself->connection->config_tree);
 225
 226         xasprintf(&myself->hostname, _("MYSELF"));
 227         xasprintf(&myself->connection->hostname, _("MYSELF"));
 228
 229         myself->connection->options = 0;
 230         myself->connection->protocol_version = PROT_CURRENT;
 231
 232         if(!get_config_string(lookup_config(config_tree, "Name"), &name)) {     /* Not acceptable */
 233                 logger(LOG_ERR, _("Name for tinc daemon required!"));
 234                 return false;
 235         }
 236
 237         if(!check_id(name)) {
 238                 logger(LOG_ERR, _("Invalid name for myself!"));
 239                 free(name);
 240                 return false;
 241         }
 242
 243         myself->name = name;
 244         myself->connection->name = xstrdup(name);
 245
 246         if(!read_connection_config(myself->connection)) {
 247                 logger(LOG_ERR, _("Cannot open host configuration file for myself!"));
 248                 return false;
 249         }
 250
 251         if(!read_rsa_private_key())
 252                 return false;
 253
 254         if(!get_config_string(lookup_config(myself->connection->config_tree, "Port"), &myport))
 255                 xasprintf(&myport, "655");
 256
 257         /* Read in all the subnets specified in the host configuration file */
 258
 259         cfg = lookup_config(myself->connection->config_tree, "Subnet");
 260
 261         while(cfg) {
 262                 if(!get_config_subnet(cfg, &subnet))
 263                         return false;
 264
 265                 subnet_add(myself, subnet);
 266
 267                 cfg = lookup_config_next(myself->connection->config_tree, cfg);
 268         }
 269
 270         /* Check some options */
 271
 272         if(get_config_bool(lookup_config(config_tree, "IndirectData"), &choice) && choice)
 273                 myself->options |= OPTION_INDIRECT;
 274
 275         if(get_config_bool(lookup_config(config_tree, "TCPOnly"), &choice) && choice)
 276                 myself->options |= OPTION_TCPONLY;
 277
 278         if(get_config_bool(lookup_config(myself->connection->config_tree, "IndirectData"), &choice) && choice)
 279                 myself->options |= OPTION_INDIRECT;
 280
 281         if(get_config_bool(lookup_config(myself->connection->config_tree, "TCPOnly"), &choice) && choice)
 282                 myself->options |= OPTION_TCPONLY;
 283
 284         if(myself->options & OPTION_TCPONLY)
 285                 myself->options |= OPTION_INDIRECT;
 286
 287         get_config_bool(lookup_config(config_tree, "TunnelServer"), &tunnelserver);
 288
 289         if(get_config_string(lookup_config(config_tree, "Mode"), &mode)) {
 290                 if(!strcasecmp(mode, "router"))
 291                         routing_mode = RMODE_ROUTER;
 292                 else if(!strcasecmp(mode, "switch"))
 293                         routing_mode = RMODE_SWITCH;
 294                 else if(!strcasecmp(mode, "hub"))
 295                         routing_mode = RMODE_HUB;
 296                 else {
 297                         logger(LOG_ERR, _("Invalid routing mode!"));
 298                         return false;
 299                 }
 300                 free(mode);
 301         } else
 302                 routing_mode = RMODE_ROUTER;
 303
 304         // Enable PMTUDiscovery by default if we are in router mode.
 305
 306         choice = routing_mode == RMODE_ROUTER;
 307         get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice);
 308         if(choice)
 309                 myself->options |= OPTION_PMTU_DISCOVERY;
 310
 311         get_config_bool(lookup_config(config_tree, "PriorityInheritance"), &priorityinheritance);
 312
 313 #if !defined(SOL_IP) || !defined(IP_TOS)
 314         if(priorityinheritance)
 315                 logger(LOG_WARNING, _("%s not supported on this platform"), "PriorityInheritance");
 316 #endif
 317
 318         if(!get_config_int(lookup_config(config_tree, "MACExpire"), &macexpire))
 319                 macexpire = 600;
 320
 321         if(get_config_int(lookup_config(config_tree, "MaxTimeout"), &maxtimeout)) {
 322                 if(maxtimeout <= 0) {
 323                         logger(LOG_ERR, _("Bogus maximum timeout!"));
 324                         return false;
 325                 }
 326         } else
 327                 maxtimeout = 900;
 328
 329         if(get_config_string(lookup_config(config_tree, "AddressFamily"), &afname)) {
 330                 if(!strcasecmp(afname, "IPv4"))
 331                         addressfamily = AF_INET;
 332                 else if(!strcasecmp(afname, "IPv6"))
 333                         addressfamily = AF_INET6;
 334                 else if(!strcasecmp(afname, "any"))
 335                         addressfamily = AF_UNSPEC;
 336                 else {
 337                         logger(LOG_ERR, _("Invalid address family!"));
 338                         return false;
 339                 }
 340                 free(afname);
 341         }
 342
 343         get_config_bool(lookup_config(config_tree, "Hostnames"), &hostnames);
 344
 345         /* Generate packet encryption key */
 346
 347         if(get_config_string
 348            (lookup_config(myself->connection->config_tree, "Cipher"), &cipher)) {
 349                 if(!strcasecmp(cipher, "none")) {
 350                         myself->incipher = NULL;
 351                 } else {
 352                         myself->incipher = EVP_get_cipherbyname(cipher);
 353
 354                         if(!myself->incipher) {
 355                                 logger(LOG_ERR, _("Unrecognized cipher type!"));
 356                                 return false;
 357                         }
 358                 }
 359         } else
 360                 myself->incipher = EVP_aes_256_cbc();
 361
 362         if(myself->incipher)
 363                 myself->inkeylength = myself->incipher->key_len + myself->incipher->iv_len;
 364         else
 365                 myself->inkeylength = 1;
 366
 367         myself->connection->outcipher = EVP_aes_256_ofb();
 368
 369         if(!get_config_int(lookup_config(config_tree, "KeyExpire"), &keylifetime))
 370                 keylifetime = 3600;
 371
 372         keyexpires = now + keylifetime;
 373
 374         /* Check if we want to use message authentication codes... */
 375
 376         if(get_config_string(lookup_config(myself->connection->config_tree, "Digest"), &digest)) {
 377                 if(!strcasecmp(digest, "none")) {
 378                         myself->indigest = NULL;
 379                 } else {
 380                         myself->indigest = EVP_get_digestbyname(digest);
 381
 382                         if(!myself->indigest) {
 383                                 logger(LOG_ERR, _("Unrecognized digest type!"));
 384                                 return false;
 385                         }
 386                 }
 387         } else
 388                 myself->indigest = EVP_sha256();
 389
 390         myself->connection->outdigest = EVP_sha256();
 391
 392         if(get_config_int(lookup_config(myself->connection->config_tree, "MACLength"), &myself->inmaclength)) {
 393                 if(myself->indigest) {
 394                         if(myself->inmaclength > myself->indigest->md_size) {
 395                                 logger(LOG_ERR, _("MAC length exceeds size of digest!"));
 396                                 return false;
 397                         } else if(myself->inmaclength < 0) {
 398                                 logger(LOG_ERR, _("Bogus MAC length!"));
 399                                 return false;
 400                         }
 401                 }
 402         } else
 403                 myself->inmaclength = 4;
 404
 405         myself->connection->outmaclength = 0;
 406
 407         /* Compression */
 408
 409         if(get_config_int(lookup_config(myself->connection->config_tree, "Compression"), &myself->incompression)) {
 410                 if(myself->incompression < 0 || myself->incompression > 11) {
 411                         logger(LOG_ERR, _("Bogus compression level!"));
 412                         return false;
 413                 }
 414         } else
 415                 myself->incompression = 0;
 416
 417         myself->connection->outcompression = 0;
 418
 419         /* Done */
 420
 421         myself->nexthop = myself;
 422         myself->via = myself;
 423         myself->status.reachable = true;
 424         node_add(myself);
 425
 426         graph();
 427
 428         /* Open device */
 429
 430         if(!setup_device())
 431                 return false;
 432
 433         /* Run tinc-up script to further initialize the tap interface */
 434         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 435         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 436         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 437         xasprintf(&envp[3], "NAME=%s", myself->name);
 438         envp[4] = NULL;
 439
 440         execute_script("tinc-up", envp);
 441
 442         for(i = 0; i < 5; i++)
 443                 free(envp[i]);
 444
 445         /* Run subnet-up scripts for our own subnets */
 446
 447         subnet_update(myself, NULL, true);
 448
 449         /* Open sockets */
 450
 451         get_config_string(lookup_config(config_tree, "BindToAddress"), &address);
 452
 453         hint.ai_family = addressfamily;
 454         hint.ai_socktype = SOCK_STREAM;
 455         hint.ai_protocol = IPPROTO_TCP;
 456         hint.ai_flags = AI_PASSIVE;
 457
 458         err = getaddrinfo(address, myport, &hint, &ai);
 459
 460         if(err || !ai) {
 461                 logger(LOG_ERR, _("System call `%s' failed: %s"), "getaddrinfo",
 462                            gai_strerror(err));
 463                 return false;
 464         }
 465
 466         listen_sockets = 0;
 467
 468         for(aip = ai; aip; aip = aip->ai_next) {
 469                 listen_socket[listen_sockets].tcp =
 470                         setup_listen_socket((sockaddr_t *) aip->ai_addr);
 471
 472                 if(listen_socket[listen_sockets].tcp < 0)
 473                         continue;
 474
 475                 listen_socket[listen_sockets].udp =
 476                         setup_vpn_in_socket((sockaddr_t *) aip->ai_addr);
 477
 478                 if(listen_socket[listen_sockets].udp < 0)
 479                         continue;
 480
 481                 ifdebug(CONNECTIONS) {
 482                         hostname = sockaddr2hostname((sockaddr_t *) aip->ai_addr);
 483                         logger(LOG_NOTICE, _("Listening on %s"), hostname);
 484                         free(hostname);
 485                 }
 486
 487                 memcpy(&listen_socket[listen_sockets].sa, aip->ai_addr, aip->ai_addrlen);
 488                 listen_sockets++;
 489         }
 490
 491         freeaddrinfo(ai);
 492
 493         if(listen_sockets)
 494                 logger(LOG_NOTICE, _("Ready"));
 495         else {
 496                 logger(LOG_ERR, _("Unable to create any listening socket!"));
 497                 return false;
 498         }
 499
 500         return true;
 501 }
 502
 503 /*
 504   initialize network
 505 */
 506 bool setup_network(void) {
 507         cp();
 508
 509         now = time(NULL);
 510
 511         init_events();
 512         init_connections();
 513         init_subnets();
 514         init_nodes();
 515         init_edges();
 516         init_requests();
 517
 518         if(get_config_int(lookup_config(config_tree, "PingInterval"), &pinginterval)) {
 519                 if(pinginterval < 1) {
 520                         pinginterval = 86400;
 521                 }
 522         } else
 523                 pinginterval = 60;
 524
 525         if(!get_config_int(lookup_config(config_tree, "PingTimeout"), &pingtimeout))
 526                 pingtimeout = 5;
 527         if(pingtimeout < 1 || pingtimeout > pinginterval)
 528                 pingtimeout = pinginterval;
 529
 530         if(!get_config_int(lookup_config(config_tree, "MaxOutputBufferSize"), &maxoutbufsize))
 531                 maxoutbufsize = 10 * MTU;
 532
 533         if(!setup_myself())
 534                 return false;
 535
 536         return true;
 537 }
 538
 539 /*
 540   close all open network connections
 541 */
 542 void close_network_connections(void) {
 543         avl_node_t *node, *next;
 544         connection_t *c;
 545         char *envp[5];
 546         int i;
 547
 548         cp();
 549
 550         for(node = connection_tree->head; node; node = next) {
 551                 next = node->next;
 552                 c = node->data;
 553                 c->outgoing = false;
 554                 terminate_connection(c, false);
 555         }
 556
 557         list_delete_list(outgoing_list);
 558
 559         if(myself && myself->connection) {
 560                 subnet_update(myself, NULL, false);
 561                 terminate_connection(myself->connection, false);
 562                 free_connection(myself->connection);
 563         }
 564
 565         for(i = 0; i < listen_sockets; i++) {
 566                 close(listen_socket[i].tcp);
 567                 close(listen_socket[i].udp);
 568         }
 569
 570         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 571         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 572         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 573         xasprintf(&envp[3], "NAME=%s", myself->name);
 574         envp[4] = NULL;
 575
 576         exit_requests();
 577         exit_edges();
 578         exit_subnets();
 579         exit_nodes();
 580         exit_connections();
 581         exit_events();
 582
 583         execute_script("tinc-down", envp);
 584
 585         if(myport) free(myport);
 586
 587         for(i = 0; i < 4; i++)
 588                 free(envp[i]);
 589
 590         close_device();
 591
 592         return;
 593 }