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 "splay_tree.h"
  25 #include "cipher.h"
  26 #include "conf.h"
  27 #include "connection.h"
  28 #include "control.h"
  29 #include "device.h"
  30 #include "digest.h"
  31 #include "graph.h"
  32 #include "logger.h"
  33 #include "net.h"
  34 #include "netutl.h"
  35 #include "process.h"
  36 #include "protocol.h"
  37 #include "route.h"
  38 #include "rsa.h"
  39 #include "subnet.h"
  40 #include "utils.h"
  41 #include "xalloc.h"
  42
  43 char *myport;
  44 static struct event device_ev;
  45
  46 bool read_rsa_public_key(connection_t *c) {
  47         FILE *fp;
  48         char *fname;
  49         char *n;
  50         bool result;
  51
  52         /* First, check for simple PublicKey statement */
  53
  54         if(get_config_string(lookup_config(c->config_tree, "PublicKey"), &n)) {
  55                 result = rsa_set_hex_public_key(&c->rsa, n, "FFFF");
  56                 free(n);
  57                 return result;
  58         }
  59
  60         /* Else, check for PublicKeyFile statement and read it */
  61
  62         if(!get_config_string(lookup_config(c->config_tree, "PublicKeyFile"), &fname))
  63                 xasprintf(&fname, "%s/hosts/%s", confbase, c->name);
  64
  65         fp = fopen(fname, "r");
  66
  67         if(!fp) {
  68                 logger(LOG_ERR, "Error reading RSA public key file `%s': %s",
  69                            fname, strerror(errno));
  70                 free(fname);
  71                 return false;
  72         }
  73
  74         result = rsa_read_pem_public_key(&c->rsa, fp);
  75         fclose(fp);
  76
  77         if(!result)
  78                 logger(LOG_ERR, "Reading RSA public key file `%s' failed: %s", fname, strerror(errno));
  79         free(fname);
  80         return result;
  81 }
  82
  83 bool read_rsa_private_key() {
  84         FILE *fp;
  85         char *fname;
  86         char *n, *d;
  87         bool result;
  88
  89         /* First, check for simple PrivateKey statement */
  90
  91         if(get_config_string(lookup_config(config_tree, "PrivateKey"), &d)) {
  92                 if(!get_config_string(lookup_config(myself->connection->config_tree, "PublicKey"), &n)) {
  93                         logger(LOG_ERR, "PrivateKey used but no PublicKey found!");
  94                         free(d);
  95                         return false;
  96                 }
  97                 result = rsa_set_hex_private_key(&myself->connection->rsa, n, "FFFF", d);
  98                 free(n);
  99                 free(d);
 100                 return true;
 101         }
 102
 103         /* Else, check for PrivateKeyFile statement and read it */
 104
 105         if(!get_config_string(lookup_config(config_tree, "PrivateKeyFile"), &fname))
 106                 xasprintf(&fname, "%s/rsa_key.priv", confbase);
 107
 108         fp = fopen(fname, "r");
 109
 110         if(!fp) {
 111                 logger(LOG_ERR, "Error reading RSA private key file `%s': %s",
 112                            fname, strerror(errno));
 113                 free(fname);
 114                 return false;
 115         }
 116
 117 #if !defined(HAVE_MINGW) && !defined(HAVE_CYGWIN)
 118         struct stat s;
 119
 120         if(fstat(fileno(fp), &s)) {
 121                 logger(LOG_ERR, "Could not stat RSA private key file `%s': %s'", fname, strerror(errno));
 122                 free(fname);
 123                 return false;
 124         }
 125
 126         if(s.st_mode & ~0100700)
 127                 logger(LOG_WARNING, "Warning: insecure file permissions for RSA private key file `%s'!", fname);
 128 #endif
 129
 130         result = rsa_read_pem_private_key(&myself->connection->rsa, fp);
 131         fclose(fp);
 132
 133         if(!result)
 134                 logger(LOG_ERR, "Reading RSA private key file `%s' failed: %s", fname, strerror(errno));
 135         free(fname);
 136         return result;
 137 }
 138
 139 static struct event keyexpire_event;
 140
 141 static void keyexpire_handler(int fd, short events, void *data) {
 142         regenerate_key();
 143 }
 144
 145 void regenerate_key() {
 146         if(timeout_initialized(&keyexpire_event)) {
 147                 ifdebug(STATUS) logger(LOG_INFO, "Expiring symmetric keys");
 148                 event_del(&keyexpire_event);
 149                 send_key_changed(broadcast, myself);
 150         } else {
 151                 timeout_set(&keyexpire_event, keyexpire_handler, NULL);
 152         }
 153
 154         event_add(&keyexpire_event, &(struct timeval){keylifetime, 0});
 155 }
 156
 157 /*
 158   Read Subnets from all host config files
 159 */
 160 static void load_all_subnets(void) {
 161         DIR *dir;
 162         struct dirent *ent;
 163         char *dname;
 164         char *fname;
 165         splay_tree_t *config_tree;
 166         config_t *cfg;
 167         subnet_t *s;
 168         node_t *n;
 169         bool result;
 170
 171         xasprintf(&dname, "%s/hosts", confbase);
 172         dir = opendir(dname);
 173         if(!dir) {
 174                 logger(LOG_ERR, "Could not open %s: %s", dname, strerror(errno));
 175                 free(dname);
 176                 return;
 177         }
 178
 179         while((ent = readdir(dir))) {
 180                 if(!check_id(ent->d_name))
 181                         continue;
 182
 183                 n = lookup_node(ent->d_name);
 184                 if(n)
 185                         continue;
 186
 187                 #ifdef _DIRENT_HAVE_D_TYPE
 188                 //if(ent->d_type != DT_REG)
 189                 //      continue;
 190                 #endif
 191
 192                 xasprintf(&fname, "%s/hosts/%s", confbase, ent->d_name);
 193                 init_configuration(&config_tree);
 194                 result = read_config_file(config_tree, fname);
 195                 free(fname);
 196                 if(!result)
 197                         continue;
 198
 199                 n = new_node();
 200                 n->name = xstrdup(ent->d_name);
 201                 node_add(n);
 202
 203                 for(cfg = lookup_config(config_tree, "Subnet"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 204                         if(!get_config_subnet(cfg, &s))
 205                                 continue;
 206
 207                         subnet_add(n, s);
 208                 }
 209
 210                 exit_configuration(&config_tree);
 211         }
 212
 213         closedir(dir);
 214 }
 215
 216 /*
 217   Configure node_t myself and set up the local sockets (listen only)
 218 */
 219 bool setup_myself(void) {
 220         config_t *cfg;
 221         subnet_t *subnet;
 222         char *name, *hostname, *mode, *afname, *cipher, *digest;
 223         char *address = NULL;
 224         char *envp[5];
 225         struct addrinfo *ai, *aip, hint = {0};
 226         bool choice;
 227         int i, err;
 228
 229         myself = new_node();
 230         myself->connection = new_connection();
 231         init_configuration(&myself->connection->config_tree);
 232
 233         myself->hostname = xstrdup("MYSELF");
 234         myself->connection->hostname = xstrdup("MYSELF");
 235
 236         myself->connection->options = 0;
 237         myself->connection->protocol_version = PROT_CURRENT;
 238
 239         if(!get_config_string(lookup_config(config_tree, "Name"), &name)) {     /* Not acceptable */
 240                 logger(LOG_ERR, "Name for tinc daemon required!");
 241                 return false;
 242         }
 243
 244         if(!check_id(name)) {
 245                 logger(LOG_ERR, "Invalid name for myself!");
 246                 free(name);
 247                 return false;
 248         }
 249
 250         myself->name = name;
 251         myself->connection->name = xstrdup(name);
 252
 253         if(!read_connection_config(myself->connection)) {
 254                 logger(LOG_ERR, "Cannot open host configuration file for myself!");
 255                 return false;
 256         }
 257
 258         if(!read_rsa_private_key())
 259                 return false;
 260
 261         if(!get_config_string(lookup_config(config_tree, "Port"), &myport)
 262                         && !get_config_string(lookup_config(myself->connection->config_tree, "Port"), &myport))
 263                 myport = xstrdup("655");
 264
 265         /* Read in all the subnets specified in the host configuration file */
 266
 267         cfg = lookup_config(myself->connection->config_tree, "Subnet");
 268
 269         while(cfg) {
 270                 if(!get_config_subnet(cfg, &subnet))
 271                         return false;
 272
 273                 subnet_add(myself, subnet);
 274
 275                 cfg = lookup_config_next(myself->connection->config_tree, cfg);
 276         }
 277
 278         /* Check some options */
 279
 280         if(get_config_bool(lookup_config(config_tree, "IndirectData"), &choice) && choice)
 281                 myself->options |= OPTION_INDIRECT;
 282
 283         if(get_config_bool(lookup_config(config_tree, "TCPOnly"), &choice) && choice)
 284                 myself->options |= OPTION_TCPONLY;
 285
 286         if(get_config_bool(lookup_config(myself->connection->config_tree, "IndirectData"), &choice) && choice)
 287                 myself->options |= OPTION_INDIRECT;
 288
 289         if(get_config_bool(lookup_config(myself->connection->config_tree, "TCPOnly"), &choice) && choice)
 290                 myself->options |= OPTION_TCPONLY;
 291
 292         if(myself->options & OPTION_TCPONLY)
 293                 myself->options |= OPTION_INDIRECT;
 294
 295         get_config_bool(lookup_config(config_tree, "DirectOnly"), &directonly);
 296         get_config_bool(lookup_config(config_tree, "StrictSubnets"), &strictsubnets);
 297         get_config_bool(lookup_config(config_tree, "TunnelServer"), &tunnelserver);
 298         strictsubnets |= tunnelserver;
 299
 300         if(get_config_string(lookup_config(config_tree, "Mode"), &mode)) {
 301                 if(!strcasecmp(mode, "router"))
 302                         routing_mode = RMODE_ROUTER;
 303                 else if(!strcasecmp(mode, "switch"))
 304                         routing_mode = RMODE_SWITCH;
 305                 else if(!strcasecmp(mode, "hub"))
 306                         routing_mode = RMODE_HUB;
 307                 else {
 308                         logger(LOG_ERR, "Invalid routing mode!");
 309                         return false;
 310                 }
 311                 free(mode);
 312         }
 313
 314         if(get_config_string(lookup_config(config_tree, "Forwarding"), &mode)) {
 315                 if(!strcasecmp(mode, "off"))
 316                         forwarding_mode = FMODE_OFF;
 317                 else if(!strcasecmp(mode, "internal"))
 318                         forwarding_mode = FMODE_INTERNAL;
 319                 else if(!strcasecmp(mode, "kernel"))
 320                         forwarding_mode = FMODE_KERNEL;
 321                 else {
 322                         logger(LOG_ERR, "Invalid forwarding mode!");
 323                         return false;
 324                 }
 325                 free(mode);
 326         }
 327
 328         choice = true;
 329         get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice);
 330         get_config_bool(lookup_config(config_tree, "PMTUDiscovery"), &choice);
 331         if(choice)
 332                 myself->options |= OPTION_PMTU_DISCOVERY;
 333
 334         choice = true;
 335         get_config_bool(lookup_config(config_tree, "ClampMSS"), &choice);
 336         get_config_bool(lookup_config(myself->connection->config_tree, "ClampMSS"), &choice);
 337         if(choice)
 338                 myself->options |= OPTION_CLAMP_MSS;
 339
 340         get_config_bool(lookup_config(config_tree, "PriorityInheritance"), &priorityinheritance);
 341
 342 #if !defined(SOL_IP) || !defined(IP_TOS)
 343         if(priorityinheritance)
 344                 logger(LOG_WARNING, "%s not supported on this platform", "PriorityInheritance");
 345 #endif
 346
 347         if(!get_config_int(lookup_config(config_tree, "MACExpire"), &macexpire))
 348                 macexpire = 600;
 349
 350         if(get_config_int(lookup_config(config_tree, "MaxTimeout"), &maxtimeout)) {
 351                 if(maxtimeout <= 0) {
 352                         logger(LOG_ERR, "Bogus maximum timeout!");
 353                         return false;
 354                 }
 355         } else
 356                 maxtimeout = 900;
 357
 358         if(get_config_string(lookup_config(config_tree, "AddressFamily"), &afname)) {
 359                 if(!strcasecmp(afname, "IPv4"))
 360                         addressfamily = AF_INET;
 361                 else if(!strcasecmp(afname, "IPv6"))
 362                         addressfamily = AF_INET6;
 363                 else if(!strcasecmp(afname, "any"))
 364                         addressfamily = AF_UNSPEC;
 365                 else {
 366                         logger(LOG_ERR, "Invalid address family!");
 367                         return false;
 368                 }
 369                 free(afname);
 370         }
 371
 372         get_config_bool(lookup_config(config_tree, "Hostnames"), &hostnames);
 373
 374         /* Generate packet encryption key */
 375
 376         if(!get_config_string(lookup_config(myself->connection->config_tree, "Cipher"), &cipher))
 377                 cipher = xstrdup("blowfish");
 378
 379         if(!cipher_open_by_name(&myself->incipher, cipher)) {
 380                 logger(LOG_ERR, "Unrecognized cipher type!");
 381                 return false;
 382         }
 383
 384         if(!get_config_int(lookup_config(config_tree, "KeyExpire"), &keylifetime))
 385                 keylifetime = 3600;
 386
 387         regenerate_key();
 388
 389         /* Check if we want to use message authentication codes... */
 390
 391         if(!get_config_string(lookup_config(myself->connection->config_tree, "Digest"), &digest))
 392                 digest = xstrdup("sha1");
 393
 394         int maclength = 4;
 395         get_config_int(lookup_config(myself->connection->config_tree, "MACLength"), &maclength);
 396
 397         if(maclength < 0) {
 398                 logger(LOG_ERR, "Bogus MAC length!");
 399                 return false;
 400         }
 401
 402         if(!digest_open_by_name(&myself->indigest, digest, maclength)) {
 403                 logger(LOG_ERR, "Unrecognized digest type!");
 404                 return false;
 405         }
 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         if(strictsubnets)
 429                 load_all_subnets();
 430
 431         /* Open device */
 432
 433         if(!setup_device())
 434                 return false;
 435
 436         if(device_fd >= 0) {
 437                 event_set(&device_ev, device_fd, EV_READ|EV_PERSIST, handle_device_data, NULL);
 438
 439                 if (event_add(&device_ev, NULL) < 0) {
 440                         logger(LOG_ERR, "event_add failed: %s", strerror(errno));
 441                         close_device();
 442                         return false;
 443                 }
 444         }
 445
 446         /* Run tinc-up script to further initialize the tap interface */
 447         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 448         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 449         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 450         xasprintf(&envp[3], "NAME=%s", myself->name);
 451         envp[4] = NULL;
 452
 453         execute_script("tinc-up", envp);
 454
 455         for(i = 0; i < 5; i++)
 456                 free(envp[i]);
 457
 458         /* Run subnet-up scripts for our own subnets */
 459
 460         subnet_update(myself, NULL, true);
 461
 462         /* Open sockets */
 463
 464         get_config_string(lookup_config(config_tree, "BindToAddress"), &address);
 465
 466         hint.ai_family = addressfamily;
 467         hint.ai_socktype = SOCK_STREAM;
 468         hint.ai_protocol = IPPROTO_TCP;
 469         hint.ai_flags = AI_PASSIVE;
 470
 471         err = getaddrinfo(address, myport, &hint, &ai);
 472
 473         if(err || !ai) {
 474                 logger(LOG_ERR, "System call `%s' failed: %s", "getaddrinfo",
 475                            gai_strerror(err));
 476                 return false;
 477         }
 478
 479         listen_sockets = 0;
 480
 481         for(aip = ai; aip; aip = aip->ai_next) {
 482                 listen_socket[listen_sockets].tcp =
 483                         setup_listen_socket((sockaddr_t *) aip->ai_addr);
 484
 485                 if(listen_socket[listen_sockets].tcp < 0)
 486                         continue;
 487
 488                 listen_socket[listen_sockets].udp =
 489                         setup_vpn_in_socket((sockaddr_t *) aip->ai_addr);
 490
 491                 if(listen_socket[listen_sockets].udp < 0) {
 492                         close(listen_socket[listen_sockets].tcp);
 493                         continue;
 494                 }
 495
 496                 event_set(&listen_socket[listen_sockets].ev_tcp,
 497                                   listen_socket[listen_sockets].tcp,
 498                                   EV_READ|EV_PERSIST,
 499                                   handle_new_meta_connection, NULL);
 500                 if(event_add(&listen_socket[listen_sockets].ev_tcp, NULL) < 0) {
 501                         logger(LOG_ERR, "event_add failed: %s", strerror(errno));
 502                         abort();
 503                 }
 504
 505                 event_set(&listen_socket[listen_sockets].ev_udp,
 506                                   listen_socket[listen_sockets].udp,
 507                                   EV_READ|EV_PERSIST,
 508                                   handle_incoming_vpn_data, NULL);
 509                 if(event_add(&listen_socket[listen_sockets].ev_udp, NULL) < 0) {
 510                         logger(LOG_ERR, "event_add failed: %s", strerror(errno));
 511                         abort();
 512                 }
 513
 514                 ifdebug(CONNECTIONS) {
 515                         hostname = sockaddr2hostname((sockaddr_t *) aip->ai_addr);
 516                         logger(LOG_NOTICE, "Listening on %s", hostname);
 517                         free(hostname);
 518                 }
 519
 520                 memcpy(&listen_socket[listen_sockets].sa, aip->ai_addr, aip->ai_addrlen);
 521                 listen_sockets++;
 522
 523                 if(listen_sockets >= MAXSOCKETS) {
 524                         logger(LOG_WARNING, "Maximum of %d listening sockets reached", MAXSOCKETS);
 525                         break;
 526                 }
 527         }
 528
 529         freeaddrinfo(ai);
 530
 531         if(listen_sockets)
 532                 logger(LOG_NOTICE, "Ready");
 533         else {
 534                 logger(LOG_ERR, "Unable to create any listening socket!");
 535                 return false;
 536         }
 537
 538         return true;
 539 }
 540
 541 /*
 542   initialize network
 543 */
 544 bool setup_network(void) {
 545         init_connections();
 546         init_subnets();
 547         init_nodes();
 548         init_edges();
 549         init_requests();
 550
 551         if(get_config_int(lookup_config(config_tree, "PingInterval"), &pinginterval)) {
 552                 if(pinginterval < 1) {
 553                         pinginterval = 86400;
 554                 }
 555         } else
 556                 pinginterval = 60;
 557
 558         if(!get_config_int(lookup_config(config_tree, "PingTimeout"), &pingtimeout))
 559                 pingtimeout = 5;
 560         if(pingtimeout < 1 || pingtimeout > pinginterval)
 561                 pingtimeout = pinginterval;
 562
 563         if(!get_config_int(lookup_config(config_tree, "MaxOutputBufferSize"), &maxoutbufsize))
 564                 maxoutbufsize = 10 * MTU;
 565
 566         if(!setup_myself())
 567                 return false;
 568
 569         return true;
 570 }
 571
 572 /*
 573   close all open network connections
 574 */
 575 void close_network_connections(void) {
 576         splay_node_t *node, *next;
 577         connection_t *c;
 578         char *envp[5];
 579         int i;
 580
 581         for(node = connection_tree->head; node; node = next) {
 582                 next = node->next;
 583                 c = node->data;
 584                 c->outgoing = false;
 585                 terminate_connection(c, false);
 586         }
 587
 588         list_delete_list(outgoing_list);
 589
 590         if(myself && myself->connection) {
 591                 subnet_update(myself, NULL, false);
 592                 terminate_connection(myself->connection, false);
 593                 free_connection(myself->connection);
 594         }
 595
 596         for(i = 0; i < listen_sockets; i++) {
 597                 event_del(&listen_socket[i].ev_tcp);
 598                 event_del(&listen_socket[i].ev_udp);
 599                 close(listen_socket[i].tcp);
 600                 close(listen_socket[i].udp);
 601         }
 602
 603         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 604         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 605         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 606         xasprintf(&envp[3], "NAME=%s", myself->name);
 607         envp[4] = NULL;
 608
 609         exit_requests();
 610         exit_edges();
 611         exit_subnets();
 612         exit_nodes();
 613         exit_connections();
 614
 615         execute_script("tinc-down", envp);
 616
 617         if(myport) free(myport);
 618
 619         for(i = 0; i < 4; i++)
 620                 free(envp[i]);
 621
 622         close_device();
 623
 624         return;
 625 }