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 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, *s2;
 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                 #ifdef _DIRENT_HAVE_D_TYPE
 185                 //if(ent->d_type != DT_REG)
 186                 //      continue;
 187                 #endif
 188
 189                 xasprintf(&fname, "%s/hosts/%s", confbase, ent->d_name);
 190                 init_configuration(&config_tree);
 191                 result = read_config_file(config_tree, fname);
 192                 free(fname);
 193                 if(!result)
 194                         continue;
 195
 196                 if(!n) {
 197                         n = new_node();
 198                         n->name = xstrdup(ent->d_name);
 199                         node_add(n);
 200                 }
 201
 202                 for(cfg = lookup_config(config_tree, "Subnet"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 203                         if(!get_config_subnet(cfg, &s))
 204                                 continue;
 205
 206                         if((s2 = lookup_subnet(n, s))) {
 207                                 s2->expires = -1;
 208                         } else {
 209                                 subnet_add(n, s);
 210                         }
 211                 }
 212
 213                 exit_configuration(&config_tree);
 214         }
 215
 216         closedir(dir);
 217 }
 218
 219 /*
 220   Configure node_t myself and set up the local sockets (listen only)
 221 */
 222 bool setup_myself(void) {
 223         config_t *cfg;
 224         subnet_t *subnet;
 225         char *name, *hostname, *mode, *afname, *cipher, *digest;
 226         char *address = NULL;
 227         char *envp[5];
 228         struct addrinfo *ai, *aip, hint = {0};
 229         bool choice;
 230         int i, err;
 231
 232         myself = new_node();
 233         myself->connection = new_connection();
 234         init_configuration(&myself->connection->config_tree);
 235
 236         myself->hostname = xstrdup("MYSELF");
 237         myself->connection->hostname = xstrdup("MYSELF");
 238
 239         myself->connection->options = 0;
 240         myself->connection->protocol_version = PROT_CURRENT;
 241
 242         if(!get_config_string(lookup_config(config_tree, "Name"), &name)) {     /* Not acceptable */
 243                 logger(LOG_ERR, "Name for tinc daemon required!");
 244                 return false;
 245         }
 246
 247         if(!check_id(name)) {
 248                 logger(LOG_ERR, "Invalid name for myself!");
 249                 free(name);
 250                 return false;
 251         }
 252
 253         myself->name = name;
 254         myself->connection->name = xstrdup(name);
 255
 256         if(!read_connection_config(myself->connection)) {
 257                 logger(LOG_ERR, "Cannot open host configuration file for myself!");
 258                 return false;
 259         }
 260
 261         if(!read_rsa_private_key())
 262                 return false;
 263
 264         if(!get_config_string(lookup_config(config_tree, "Port"), &myport)
 265                         && !get_config_string(lookup_config(myself->connection->config_tree, "Port"), &myport))
 266                 myport = xstrdup("655");
 267
 268         if(!atoi(myport)) {
 269                 struct addrinfo *ai = str2addrinfo("localhost", myport, SOCK_DGRAM);
 270                 sockaddr_t sa;
 271                 if(!ai || !ai->ai_addr)
 272                         return false;
 273                 free(myport);
 274                 memcpy(&sa, ai->ai_addr, ai->ai_addrlen);
 275                 sockaddr2str(&sa, NULL, &myport);
 276         }
 277
 278         /* Read in all the subnets specified in the host configuration file */
 279
 280         cfg = lookup_config(myself->connection->config_tree, "Subnet");
 281
 282         while(cfg) {
 283                 if(!get_config_subnet(cfg, &subnet))
 284                         return false;
 285
 286                 subnet_add(myself, subnet);
 287
 288                 cfg = lookup_config_next(myself->connection->config_tree, cfg);
 289         }
 290
 291         /* Check some options */
 292
 293         if(get_config_bool(lookup_config(config_tree, "IndirectData"), &choice) && choice)
 294                 myself->options |= OPTION_INDIRECT;
 295
 296         if(get_config_bool(lookup_config(config_tree, "TCPOnly"), &choice) && choice)
 297                 myself->options |= OPTION_TCPONLY;
 298
 299         if(get_config_bool(lookup_config(myself->connection->config_tree, "IndirectData"), &choice) && choice)
 300                 myself->options |= OPTION_INDIRECT;
 301
 302         if(get_config_bool(lookup_config(myself->connection->config_tree, "TCPOnly"), &choice) && choice)
 303                 myself->options |= OPTION_TCPONLY;
 304
 305         if(myself->options & OPTION_TCPONLY)
 306                 myself->options |= OPTION_INDIRECT;
 307
 308         get_config_bool(lookup_config(config_tree, "DirectOnly"), &directonly);
 309         get_config_bool(lookup_config(config_tree, "StrictSubnets"), &strictsubnets);
 310         get_config_bool(lookup_config(config_tree, "TunnelServer"), &tunnelserver);
 311         strictsubnets |= tunnelserver;
 312
 313         if(get_config_string(lookup_config(config_tree, "Mode"), &mode)) {
 314                 if(!strcasecmp(mode, "router"))
 315                         routing_mode = RMODE_ROUTER;
 316                 else if(!strcasecmp(mode, "switch"))
 317                         routing_mode = RMODE_SWITCH;
 318                 else if(!strcasecmp(mode, "hub"))
 319                         routing_mode = RMODE_HUB;
 320                 else {
 321                         logger(LOG_ERR, "Invalid routing mode!");
 322                         return false;
 323                 }
 324                 free(mode);
 325         }
 326
 327         if(get_config_string(lookup_config(config_tree, "Forwarding"), &mode)) {
 328                 if(!strcasecmp(mode, "off"))
 329                         forwarding_mode = FMODE_OFF;
 330                 else if(!strcasecmp(mode, "internal"))
 331                         forwarding_mode = FMODE_INTERNAL;
 332                 else if(!strcasecmp(mode, "kernel"))
 333                         forwarding_mode = FMODE_KERNEL;
 334                 else {
 335                         logger(LOG_ERR, "Invalid forwarding mode!");
 336                         return false;
 337                 }
 338                 free(mode);
 339         }
 340
 341         choice = true;
 342         get_config_bool(lookup_config(myself->connection->config_tree, "PMTUDiscovery"), &choice);
 343         get_config_bool(lookup_config(config_tree, "PMTUDiscovery"), &choice);
 344         if(choice)
 345                 myself->options |= OPTION_PMTU_DISCOVERY;
 346
 347         choice = true;
 348         get_config_bool(lookup_config(config_tree, "ClampMSS"), &choice);
 349         get_config_bool(lookup_config(myself->connection->config_tree, "ClampMSS"), &choice);
 350         if(choice)
 351                 myself->options |= OPTION_CLAMP_MSS;
 352
 353         get_config_bool(lookup_config(config_tree, "PriorityInheritance"), &priorityinheritance);
 354
 355 #if !defined(SOL_IP) || !defined(IP_TOS)
 356         if(priorityinheritance)
 357                 logger(LOG_WARNING, "%s not supported on this platform", "PriorityInheritance");
 358 #endif
 359
 360         if(!get_config_int(lookup_config(config_tree, "MACExpire"), &macexpire))
 361                 macexpire = 600;
 362
 363         if(get_config_int(lookup_config(config_tree, "MaxTimeout"), &maxtimeout)) {
 364                 if(maxtimeout <= 0) {
 365                         logger(LOG_ERR, "Bogus maximum timeout!");
 366                         return false;
 367                 }
 368         } else
 369                 maxtimeout = 900;
 370
 371         if(get_config_string(lookup_config(config_tree, "AddressFamily"), &afname)) {
 372                 if(!strcasecmp(afname, "IPv4"))
 373                         addressfamily = AF_INET;
 374                 else if(!strcasecmp(afname, "IPv6"))
 375                         addressfamily = AF_INET6;
 376                 else if(!strcasecmp(afname, "any"))
 377                         addressfamily = AF_UNSPEC;
 378                 else {
 379                         logger(LOG_ERR, "Invalid address family!");
 380                         return false;
 381                 }
 382                 free(afname);
 383         }
 384
 385         get_config_bool(lookup_config(config_tree, "Hostnames"), &hostnames);
 386
 387         /* Generate packet encryption key */
 388
 389         if(!get_config_string(lookup_config(myself->connection->config_tree, "Cipher"), &cipher))
 390                 cipher = xstrdup("blowfish");
 391
 392         if(!cipher_open_by_name(&myself->incipher, cipher)) {
 393                 logger(LOG_ERR, "Unrecognized cipher type!");
 394                 return false;
 395         }
 396
 397         if(!get_config_int(lookup_config(config_tree, "KeyExpire"), &keylifetime))
 398                 keylifetime = 3600;
 399
 400         regenerate_key();
 401
 402         /* Check if we want to use message authentication codes... */
 403
 404         if(!get_config_string(lookup_config(myself->connection->config_tree, "Digest"), &digest))
 405                 digest = xstrdup("sha1");
 406
 407         int maclength = 4;
 408         get_config_int(lookup_config(myself->connection->config_tree, "MACLength"), &maclength);
 409
 410         if(maclength < 0) {
 411                 logger(LOG_ERR, "Bogus MAC length!");
 412                 return false;
 413         }
 414
 415         if(!digest_open_by_name(&myself->indigest, digest, maclength)) {
 416                 logger(LOG_ERR, "Unrecognized digest type!");
 417                 return false;
 418         }
 419
 420         /* Compression */
 421
 422         if(get_config_int(lookup_config(myself->connection->config_tree, "Compression"), &myself->incompression)) {
 423                 if(myself->incompression < 0 || myself->incompression > 11) {
 424                         logger(LOG_ERR, "Bogus compression level!");
 425                         return false;
 426                 }
 427         } else
 428                 myself->incompression = 0;
 429
 430         myself->connection->outcompression = 0;
 431
 432         /* Done */
 433
 434         myself->nexthop = myself;
 435         myself->via = myself;
 436         myself->status.reachable = true;
 437         node_add(myself);
 438
 439         graph();
 440
 441         if(strictsubnets)
 442                 load_all_subnets();
 443
 444         /* Open device */
 445
 446         if(!setup_device())
 447                 return false;
 448
 449         if(device_fd >= 0) {
 450                 event_set(&device_ev, device_fd, EV_READ|EV_PERSIST, handle_device_data, NULL);
 451
 452                 if (event_add(&device_ev, NULL) < 0) {
 453                         logger(LOG_ERR, "event_add failed: %s", strerror(errno));
 454                         close_device();
 455                         return false;
 456                 }
 457         }
 458
 459         /* Run tinc-up script to further initialize the tap interface */
 460         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 461         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 462         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 463         xasprintf(&envp[3], "NAME=%s", myself->name);
 464         envp[4] = NULL;
 465
 466         execute_script("tinc-up", envp);
 467
 468         for(i = 0; i < 4; i++)
 469                 free(envp[i]);
 470
 471         /* Run subnet-up scripts for our own subnets */
 472
 473         subnet_update(myself, NULL, true);
 474
 475         /* Open sockets */
 476
 477         get_config_string(lookup_config(config_tree, "BindToAddress"), &address);
 478
 479         hint.ai_family = addressfamily;
 480         hint.ai_socktype = SOCK_STREAM;
 481         hint.ai_protocol = IPPROTO_TCP;
 482         hint.ai_flags = AI_PASSIVE;
 483
 484         err = getaddrinfo(address, myport, &hint, &ai);
 485
 486         if(err || !ai) {
 487                 logger(LOG_ERR, "System call `%s' failed: %s", "getaddrinfo",
 488                            gai_strerror(err));
 489                 return false;
 490         }
 491
 492         listen_sockets = 0;
 493
 494         for(aip = ai; aip; aip = aip->ai_next) {
 495                 listen_socket[listen_sockets].tcp =
 496                         setup_listen_socket((sockaddr_t *) aip->ai_addr);
 497
 498                 if(listen_socket[listen_sockets].tcp < 0)
 499                         continue;
 500
 501                 listen_socket[listen_sockets].udp =
 502                         setup_vpn_in_socket((sockaddr_t *) aip->ai_addr);
 503
 504                 if(listen_socket[listen_sockets].udp < 0) {
 505                         close(listen_socket[listen_sockets].tcp);
 506                         continue;
 507                 }
 508
 509                 event_set(&listen_socket[listen_sockets].ev_tcp,
 510                                   listen_socket[listen_sockets].tcp,
 511                                   EV_READ|EV_PERSIST,
 512                                   handle_new_meta_connection, NULL);
 513                 if(event_add(&listen_socket[listen_sockets].ev_tcp, NULL) < 0) {
 514                         logger(LOG_ERR, "event_add failed: %s", strerror(errno));
 515                         abort();
 516                 }
 517
 518                 event_set(&listen_socket[listen_sockets].ev_udp,
 519                                   listen_socket[listen_sockets].udp,
 520                                   EV_READ|EV_PERSIST,
 521                                   handle_incoming_vpn_data, NULL);
 522                 if(event_add(&listen_socket[listen_sockets].ev_udp, NULL) < 0) {
 523                         logger(LOG_ERR, "event_add failed: %s", strerror(errno));
 524                         abort();
 525                 }
 526
 527                 ifdebug(CONNECTIONS) {
 528                         hostname = sockaddr2hostname((sockaddr_t *) aip->ai_addr);
 529                         logger(LOG_NOTICE, "Listening on %s", hostname);
 530                         free(hostname);
 531                 }
 532
 533                 memcpy(&listen_socket[listen_sockets].sa, aip->ai_addr, aip->ai_addrlen);
 534                 listen_sockets++;
 535
 536                 if(listen_sockets >= MAXSOCKETS) {
 537                         logger(LOG_WARNING, "Maximum of %d listening sockets reached", MAXSOCKETS);
 538                         break;
 539                 }
 540         }
 541
 542         freeaddrinfo(ai);
 543
 544         if(listen_sockets)
 545                 logger(LOG_NOTICE, "Ready");
 546         else {
 547                 logger(LOG_ERR, "Unable to create any listening socket!");
 548                 return false;
 549         }
 550
 551         return true;
 552 }
 553
 554 /*
 555   initialize network
 556 */
 557 bool setup_network(void) {
 558         init_connections();
 559         init_subnets();
 560         init_nodes();
 561         init_edges();
 562         init_requests();
 563
 564         if(get_config_int(lookup_config(config_tree, "PingInterval"), &pinginterval)) {
 565                 if(pinginterval < 1) {
 566                         pinginterval = 86400;
 567                 }
 568         } else
 569                 pinginterval = 60;
 570
 571         if(!get_config_int(lookup_config(config_tree, "PingTimeout"), &pingtimeout))
 572                 pingtimeout = 5;
 573         if(pingtimeout < 1 || pingtimeout > pinginterval)
 574                 pingtimeout = pinginterval;
 575
 576         if(!get_config_int(lookup_config(config_tree, "MaxOutputBufferSize"), &maxoutbufsize))
 577                 maxoutbufsize = 10 * MTU;
 578
 579         if(!setup_myself())
 580                 return false;
 581
 582         return true;
 583 }
 584
 585 /*
 586   close all open network connections
 587 */
 588 void close_network_connections(void) {
 589         splay_node_t *node, *next;
 590         connection_t *c;
 591         char *envp[5];
 592         int i;
 593
 594         for(node = connection_tree->head; node; node = next) {
 595                 next = node->next;
 596                 c = node->data;
 597                 c->outgoing = false;
 598                 terminate_connection(c, false);
 599         }
 600
 601         list_delete_list(outgoing_list);
 602
 603         if(myself && myself->connection) {
 604                 subnet_update(myself, NULL, false);
 605                 terminate_connection(myself->connection, false);
 606                 free_connection(myself->connection);
 607         }
 608
 609         for(i = 0; i < listen_sockets; i++) {
 610                 event_del(&listen_socket[i].ev_tcp);
 611                 event_del(&listen_socket[i].ev_udp);
 612                 close(listen_socket[i].tcp);
 613                 close(listen_socket[i].udp);
 614         }
 615
 616         xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
 617         xasprintf(&envp[1], "DEVICE=%s", device ? : "");
 618         xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
 619         xasprintf(&envp[3], "NAME=%s", myself->name);
 620         envp[4] = NULL;
 621
 622         exit_requests();
 623         exit_edges();
 624         exit_subnets();
 625         exit_nodes();
 626         exit_connections();
 627
 628         execute_script("tinc-down", envp);
 629
 630         if(myport) free(myport);
 631
 632         for(i = 0; i < 4; i++)
 633                 free(envp[i]);
 634
 635         close_device();
 636
 637         return;
 638 }