tinc-vpn.org Git - tinc/blob - src/net_setup.c

   1 /*
   2     net_setup.c -- Setup.
   3     Copyright (C) 1998-2005 Ivo Timmermans,
   4                   2000-2006 Guus Sliepen <guus@tinc-vpn.org>
   5
   6     This program is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     This program is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with this program; if not, write to the Free Software
  18     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19
  20     $Id$
  21 */
  22
  23 #include "system.h"
  24
  25 #include <gcrypt.h>
  26
  27 #include <openssl/pem.h>
  28 #include <openssl/rsa.h>
  29 #include <openssl/rand.h>
  30 #include <openssl/err.h>
  31 #include <openssl/evp.h>
  32
  33 #include "splay_tree.h"
  34 #include "conf.h"
  35 #include "connection.h"
  36 #include "control.h"
  37 #include "device.h"
  38 #include "graph.h"
  39 #include "logger.h"
  40 #include "net.h"
  41 #include "netutl.h"
  42 #include "process.h"
  43 #include "protocol.h"
  44 #include "route.h"
  45 #include "rsa.h"
  46 #include "subnet.h"
  47 #include "utils.h"
  48 #include "xalloc.h"
  49
  50 char *myport;
  51 static struct event device_ev;
  52
  53 bool read_rsa_public_key(connection_t *c) {
  54         FILE *fp;
  55         char *fname;
  56         bool result;
  57
  58         cp();
  59
  60         if(!get_config_string(lookup_config(c->config_tree, "PublicKeyFile"), &fname))
  61                 asprintf(&fname, "%s/hosts/%s", confbase, c->name);
  62
  63         fp = fopen(fname, "r");
  64
  65         if(!fp) {
  66                 logger(LOG_ERR, _("Error reading RSA public key file `%s': %s"),
  67                            fname, strerror(errno));
  68                 free(fname);
  69                 return false;
  70         }
  71
  72         result = read_pem_rsa_public_key(fp, &c->rsa_key);
  73         fclose(fp);
  74
  75         if(!result)
  76                 logger(LOG_ERR, _("Reading RSA public key file `%s' failed: %s"), fname, strerror(errno));
  77         free(fname);
  78         return result;
  79 }
  80
  81 bool read_rsa_private_key() {
  82         FILE *fp;
  83         char *fname;
  84         bool result;
  85
  86         cp();
  87
  88         if(!get_config_string(lookup_config(config_tree, "PrivateKeyFile"), &fname))
  89                 asprintf(&fname, "%s/rsa_key.priv", confbase);
  90
  91         fp = fopen(fname, "r");
  92
  93         if(!fp) {
  94                 logger(LOG_ERR, _("Error reading RSA private key file `%s': %s"),
  95                            fname, strerror(errno));
  96                 free(fname);
  97                 return false;
  98         }
  99
 100 #if !defined(HAVE_MINGW) && !defined(HAVE_CYGWIN)
 101         struct stat s;
 102
 103         if(fstat(fileno(fp), &s)) {
 104                 logger(LOG_ERR, _("Could not stat RSA private key file `%s': %s'"), fname, strerror(errno));
 105                 free(fname);
 106                 return false;
 107         }
 108
 109         if(s.st_mode & ~0100700)
 110                 logger(LOG_WARNING, _("Warning: insecure file permissions for RSA private key file `%s'!"), fname);
 111 #endif
 112
 113         result = read_pem_rsa_private_key(fp, &myself->connection->rsa_key);
 114         fclose(fp);
 115
 116         if(!result)
 117                 logger(LOG_ERR, _("Reading RSA private key file `%s' failed: %s"), fname, strerror(errno));
 118         free(fname);
 119         return result;
 120 }
 121
 122 static struct event keyexpire_event;
 123
 124 static void keyexpire_handler(int fd, short events, void *data) {
 125         regenerate_key();
 126 }
 127
 128 void regenerate_key() {
 129         RAND_pseudo_bytes((unsigned char *)myself->key, myself->keylength);
 130
 131         if(timeout_initialized(&keyexpire_event)) {
 132                 ifdebug(STATUS) logger(LOG_INFO, _("Regenerating symmetric key"));
 133                 event_del(&keyexpire_event);
 134                 send_key_changed(broadcast, myself);
 135         } else {
 136                 timeout_set(&keyexpire_event, keyexpire_handler, NULL);
 137         }
 138
 139         event_add(&keyexpire_event, &(struct timeval){keylifetime, 0});
 140
 141         if(myself->cipher) {
 142                 EVP_CIPHER_CTX_init(&packet_ctx);
 143                 if(!EVP_DecryptInit_ex(&packet_ctx, myself->cipher, NULL, (unsigned char *)myself->key, (unsigned char *)myself->key + myself->cipher->key_len)) {
 144                         logger(LOG_ERR, _("Error during initialisation of cipher for %s (%s): %s"),
 145                                         myself->name, myself->hostname, ERR_error_string(ERR_get_error(), NULL));
 146                         abort();
 147                 }
 148
 149         }
 150 }
 151
 152 /*
 153   Configure node_t myself and set up the local sockets (listen only)
 154 */
 155 bool setup_myself(void) {
 156         config_t *cfg;
 157         subnet_t *subnet;
 158         char *name, *hostname, *mode, *afname, *cipher, *digest;
 159         char *address = NULL;
 160         char *envp[5];
 161         struct addrinfo *ai, *aip, hint = {0};
 162         bool choice;
 163         int i, err;
 164
 165         cp();
 166
 167         myself = new_node();
 168         myself->connection = new_connection();
 169         init_configuration(&myself->connection->config_tree);
 170
 171         asprintf(&myself->hostname, _("MYSELF"));
 172         asprintf(&myself->connection->hostname, _("MYSELF"));
 173
 174         myself->connection->options = 0;
 175         myself->connection->protocol_version = PROT_CURRENT;
 176
 177         if(!get_config_string(lookup_config(config_tree, "Name"), &name)) {     /* Not acceptable */
 178                 logger(LOG_ERR, _("Name for tinc daemon required!"));
 179                 return false;
 180         }
 181
 182         if(!check_id(name)) {
 183                 logger(LOG_ERR, _("Invalid name for myself!"));
 184                 free(name);
 185                 return false;
 186         }
 187
 188         myself->name = name;
 189         myself->connection->name = xstrdup(name);
 190
 191         if(!read_connection_config(myself->connection)) {
 192                 logger(LOG_ERR, _("Cannot open host configuration file for myself!"));
 193                 return false;
 194         }
 195
 196         if(!read_rsa_private_key())
 197                 return false;
 198
 199         if(!get_config_string(lookup_config(myself->connection->config_tree, "Port"), &myport))
 200                 asprintf(&myport, "655");
 201
 202         /* Read in all the subnets specified in the host configuration file */
 203
 204         cfg = lookup_config(myself->connection->config_tree, "Subnet");
 205
 206         while(cfg) {
 207                 if(!get_config_subnet(cfg, &subnet))
 208                         return false;
 209
 210                 subnet_add(myself, subnet);
 211
 212                 cfg = lookup_config_next(myself->connection->config_tree, cfg);
 213         }
 214
 215         /* Check some options */
 216
 217         if(get_config_bool(lookup_config(config_tree, "IndirectData"), &choice) && choice)
 218                 myself->options |= OPTION_INDIRECT;
 219
 220         if(get_config_bool(lookup_config(config_tree, "TCPOnly"), &choice) && choice)
 221                 myself->options |= OPTION_TCPONLY;
 222
 223         if(get_config_bool(lookup_config(myself->connection->config_tree, "IndirectData"), &choice) && choice)
 224                 myself->options |= OPTION_INDIRECT;
 225
 226         if(get_config_bool(lookup_config(myself->connection->config_tree, "TCPOnly"), &choice) && choice)
 227                 myself->options |= OPTION_TCPONLY;
 228
 229         if(get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice) && choice)
 230                 myself->options |= OPTION_PMTU_DISCOVERY;
 231
 232         if(myself->options & OPTION_TCPONLY)
 233                 myself->options |= OPTION_INDIRECT;
 234
 235         get_config_bool(lookup_config(config_tree, "TunnelServer"), &tunnelserver);
 236
 237         if(get_config_string(lookup_config(config_tree, "Mode"), &mode)) {
 238                 if(!strcasecmp(mode, "router"))
 239                         routing_mode = RMODE_ROUTER;
 240                 else if(!strcasecmp(mode, "switch"))
 241                         routing_mode = RMODE_SWITCH;
 242                 else if(!strcasecmp(mode, "hub"))
 243                         routing_mode = RMODE_HUB;
 244                 else {
 245                         logger(LOG_ERR, _("Invalid routing mode!"));
 246                         return false;
 247                 }
 248                 free(mode);
 249         } else
 250                 routing_mode = RMODE_ROUTER;
 251
 252         get_config_bool(lookup_config(config_tree, "PriorityInheritance"), &priorityinheritance);
 253
 254 #if !defined(SOL_IP) || !defined(IP_TOS)
 255         if(priorityinheritance)
 256                 logger(LOG_WARNING, _("PriorityInheritance not supported on this platform"));
 257 #endif
 258
 259         if(!get_config_int(lookup_config(config_tree, "MACExpire"), &macexpire))
 260                 macexpire = 600;
 261
 262         if(get_config_int(lookup_config(config_tree, "MaxTimeout"), &maxtimeout)) {
 263                 if(maxtimeout <= 0) {
 264                         logger(LOG_ERR, _("Bogus maximum timeout!"));
 265                         return false;
 266                 }
 267         } else
 268                 maxtimeout = 900;
 269
 270         if(get_config_string(lookup_config(config_tree, "AddressFamily"), &afname)) {
 271                 if(!strcasecmp(afname, "IPv4"))
 272                         addressfamily = AF_INET;
 273                 else if(!strcasecmp(afname, "IPv6"))
 274                         addressfamily = AF_INET6;
 275                 else if(!strcasecmp(afname, "any"))
 276                         addressfamily = AF_UNSPEC;
 277                 else {
 278                         logger(LOG_ERR, _("Invalid address family!"));
 279                         return false;
 280                 }
 281                 free(afname);
 282         }
 283
 284         get_config_bool(lookup_config(config_tree, "Hostnames"), &hostnames);
 285
 286         /* Generate packet encryption key */
 287
 288         if(get_config_string
 289            (lookup_config(myself->connection->config_tree, "Cipher"), &cipher)) {
 290                 if(!strcasecmp(cipher, "none")) {
 291                         myself->cipher = NULL;
 292                 } else {
 293                         myself->cipher = EVP_get_cipherbyname(cipher);
 294
 295                         if(!myself->cipher) {
 296                                 logger(LOG_ERR, _("Unrecognized cipher type!"));
 297                                 return false;
 298                         }
 299                 }
 300         } else
 301                 myself->cipher = EVP_bf_cbc();
 302
 303         if(myself->cipher)
 304                 myself->keylength = myself->cipher->key_len + myself->cipher->iv_len;
 305         else
 306                 myself->keylength = 1;
 307
 308         myself->connection->outcipher = EVP_bf_ofb();
 309
 310         myself->key = xmalloc(myself->keylength);
 311
 312         if(!get_config_int(lookup_config(config_tree, "KeyExpire"), &keylifetime))
 313                 keylifetime = 3600;
 314
 315         regenerate_key();
 316         /* Check if we want to use message authentication codes... */
 317
 318         if(get_config_string
 319            (lookup_config(myself->connection->config_tree, "Digest"), &digest)) {
 320                 if(!strcasecmp(digest, "none")) {
 321                         myself->digest = NULL;
 322                 } else {
 323                         myself->digest = EVP_get_digestbyname(digest);
 324
 325                         if(!myself->digest) {
 326                                 logger(LOG_ERR, _("Unrecognized digest type!"));
 327                                 return false;
 328                         }
 329                 }
 330         } else
 331                 myself->digest = EVP_sha1();
 332
 333         myself->connection->outdigest = EVP_sha1();
 334
 335         if(get_config_int(lookup_config(myself->connection->config_tree, "MACLength"),
 336                 &myself->maclength)) {
 337                 if(myself->digest) {
 338                         if(myself->maclength > myself->digest->md_size) {
 339                                 logger(LOG_ERR, _("MAC length exceeds size of digest!"));
 340                                 return false;
 341                         } else if(myself->maclength < 0) {
 342                                 logger(LOG_ERR, _("Bogus MAC length!"));
 343                                 return false;
 344                         }
 345                 }
 346         } else
 347                 myself->maclength = 4;
 348
 349         myself->connection->outmaclength = 0;
 350
 351         /* Compression */
 352
 353         if(get_config_int(lookup_config(myself->connection->config_tree, "Compression"),
 354                 &myself->compression)) {
 355                 if(myself->compression < 0 || myself->compression > 11) {
 356                         logger(LOG_ERR, _("Bogus compression level!"));
 357                         return false;
 358                 }
 359         } else
 360                 myself->compression = 0;
 361
 362         myself->connection->outcompression = 0;
 363
 364         /* Done */
 365
 366         myself->nexthop = myself;
 367         myself->via = myself;
 368         myself->status.reachable = true;
 369         node_add(myself);
 370
 371         graph();
 372
 373         /* Open device */
 374
 375         if(!setup_device())
 376                 return false;
 377
 378         event_set(&device_ev, device_fd, EV_READ|EV_PERSIST,
 379                           handle_device_data, NULL);
 380         if (event_add(&device_ev, NULL) < 0) {
 381                 logger(LOG_ERR, _("event_add failed: %s"), strerror(errno));
 382                 close_device();
 383                 return false;
 384         }
 385
 386         /* Run tinc-up script to further initialize the tap interface */
 387         asprintf(&envp[0], "NETNAME=%s", netname ? : "");
 388         asprintf(&envp[1], "DEVICE=%s", device ? : "");
 389         asprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 390         asprintf(&envp[3], "NAME=%s", myself->name);
 391         envp[4] = NULL;
 392
 393         execute_script("tinc-up", envp);
 394
 395         for(i = 0; i < 5; i++)
 396                 free(envp[i]);
 397
 398         /* Run subnet-up scripts for our own subnets */
 399
 400         subnet_update(myself, NULL, true);
 401
 402         /* Open sockets */
 403
 404         get_config_string(lookup_config(config_tree, "BindToAddress"), &address);
 405
 406         hint.ai_family = addressfamily;
 407         hint.ai_socktype = SOCK_STREAM;
 408         hint.ai_protocol = IPPROTO_TCP;
 409         hint.ai_flags = AI_PASSIVE;
 410
 411         err = getaddrinfo(address, myport, &hint, &ai);
 412
 413         if(err || !ai) {
 414                 logger(LOG_ERR, _("System call `%s' failed: %s"), "getaddrinfo",
 415                            gai_strerror(err));
 416                 return false;
 417         }
 418
 419         listen_sockets = 0;
 420
 421         for(aip = ai; aip; aip = aip->ai_next) {
 422                 listen_socket[listen_sockets].tcp =
 423                         setup_listen_socket((sockaddr_t *) aip->ai_addr);
 424
 425                 if(listen_socket[listen_sockets].tcp < 0)
 426                         continue;
 427
 428                 listen_socket[listen_sockets].udp =
 429                         setup_vpn_in_socket((sockaddr_t *) aip->ai_addr);
 430
 431                 if(listen_socket[listen_sockets].udp < 0) {
 432                         close(listen_socket[listen_sockets].tcp);
 433                         continue;
 434                 }
 435
 436                 event_set(&listen_socket[listen_sockets].ev_tcp,
 437                                   listen_socket[listen_sockets].tcp,
 438                                   EV_READ|EV_PERSIST,
 439                                   handle_new_meta_connection, NULL);
 440                 if(event_add(&listen_socket[listen_sockets].ev_tcp, NULL) < 0) {
 441                         logger(LOG_EMERG, _("event_add failed: %s"), strerror(errno));
 442                         abort();
 443                 }
 444
 445                 event_set(&listen_socket[listen_sockets].ev_udp,
 446                                   listen_socket[listen_sockets].udp,
 447                                   EV_READ|EV_PERSIST,
 448                                   handle_incoming_vpn_data, NULL);
 449                 if(event_add(&listen_socket[listen_sockets].ev_udp, NULL) < 0) {
 450                         logger(LOG_EMERG, _("event_add failed: %s"), strerror(errno));
 451                         abort();
 452                 }
 453
 454                 ifdebug(CONNECTIONS) {
 455                         hostname = sockaddr2hostname((sockaddr_t *) aip->ai_addr);
 456                         logger(LOG_NOTICE, _("Listening on %s"), hostname);
 457                         free(hostname);
 458                 }
 459
 460                 memcpy(&listen_socket[listen_sockets].sa, aip->ai_addr, aip->ai_addrlen);
 461                 listen_sockets++;
 462
 463                 if(listen_sockets >= MAXSOCKETS) {
 464                         logger(LOG_WARNING, _("Maximum of %d listening sockets reached"), MAXSOCKETS);
 465                         break;
 466                 }
 467         }
 468
 469         freeaddrinfo(ai);
 470
 471         if(listen_sockets)
 472                 logger(LOG_NOTICE, _("Ready"));
 473         else {
 474                 logger(LOG_ERR, _("Unable to create any listening socket!"));
 475                 return false;
 476         }
 477
 478         return true;
 479 }
 480
 481 /*
 482   setup all initial network connections
 483 */
 484 bool setup_network_connections(void) {
 485         cp();
 486
 487         init_connections();
 488         init_subnets();
 489         init_nodes();
 490         init_edges();
 491         init_requests();
 492
 493         if(get_config_int(lookup_config(config_tree, "PingInterval"), &pinginterval)) {
 494                 if(pinginterval < 1) {
 495                         pinginterval = 86400;
 496                 }
 497         } else
 498                 pinginterval = 60;
 499
 500         if(!get_config_int(lookup_config(config_tree, "PingTimeout"), &pingtimeout))
 501                 pingtimeout = 5;
 502         if(pingtimeout < 1 || pingtimeout > pinginterval)
 503                 pingtimeout = pinginterval;
 504
 505         if(!get_config_int(lookup_config(config_tree, "MaxOutputBufferSize"), &maxoutbufsize))
 506                 maxoutbufsize = 4 * MTU;
 507
 508         if(!setup_myself())
 509                 return false;
 510
 511         try_outgoing_connections();
 512
 513         return true;
 514 }
 515
 516 /*
 517   close all open network connections
 518 */
 519 void close_network_connections(void) {
 520         splay_node_t *node, *next;
 521         connection_t *c;
 522         char *envp[5];
 523         int i;
 524
 525         cp();
 526
 527         for(node = connection_tree->head; node; node = next) {
 528                 next = node->next;
 529                 c = node->data;
 530
 531                 if(c->outgoing) {
 532                         if(c->outgoing->ai)
 533                                 freeaddrinfo(c->outgoing->ai);
 534                         free(c->outgoing->name);
 535                         free(c->outgoing);
 536                         c->outgoing = NULL;
 537                 }
 538
 539                 terminate_connection(c, false);
 540         }
 541
 542         if(myself && myself->connection) {
 543                 subnet_update(myself, NULL, false);
 544                 terminate_connection(myself->connection, false);
 545         }
 546
 547         for(i = 0; i < listen_sockets; i++) {
 548                 event_del(&listen_socket[i].ev_tcp);
 549                 event_del(&listen_socket[i].ev_udp);
 550                 close(listen_socket[i].tcp);
 551                 close(listen_socket[i].udp);
 552         }
 553
 554         asprintf(&envp[0], "NETNAME=%s", netname ? : "");
 555         asprintf(&envp[1], "DEVICE=%s", device ? : "");
 556         asprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 557         asprintf(&envp[3], "NAME=%s", myself->name);
 558         envp[4] = NULL;
 559
 560         exit_requests();
 561         exit_edges();
 562         exit_subnets();
 563         exit_nodes();
 564         exit_connections();
 565
 566         execute_script("tinc-down", envp);
 567
 568         for(i = 0; i < 4; i++)
 569                 free(envp[i]);
 570
 571         close_device();
 572
 573         return;
 574 }