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

   1 /*
   2     net_setup.c -- Setup.
   3     Copyright (C) 1998-2005 Ivo Timmermans,
   4                   2000-2021 Guus Sliepen <guus@tinc-vpn.org>
   5                   2006      Scott Lamb <slamb@slamb.org>
   6                   2010      Brandon Black <blblack@gmail.com>
   7
   8     This program is free software; you can redistribute it and/or modify
   9     it under the terms of the GNU General Public License as published by
  10     the Free Software Foundation; either version 2 of the License, or
  11     (at your option) any later version.
  12
  13     This program is distributed in the hope that it will be useful,
  14     but WITHOUT ANY WARRANTY; without even the implied warranty of
  15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16     GNU General Public License for more details.
  17
  18     You should have received a copy of the GNU General Public License along
  19     with this program; if not, write to the Free Software Foundation, Inc.,
  20     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21 */
  22
  23 #include "system.h"
  24
  25 #include "cipher.h"
  26 #include "conf_net.h"
  27 #include "conf.h"
  28 #include "connection.h"
  29 #include "compression.h"
  30 #include "control.h"
  31 #include "crypto.h"
  32 #include "device.h"
  33 #include "digest.h"
  34 #include "ecdsa.h"
  35 #include "graph.h"
  36 #include "logger.h"
  37 #include "names.h"
  38 #include "net.h"
  39 #include "netutl.h"
  40 #include "process.h"
  41 #include "protocol.h"
  42 #include "route.h"
  43 #include "script.h"
  44 #include "subnet.h"
  45 #include "utils.h"
  46 #include "xalloc.h"
  47 #include "keys.h"
  48 #include "sandbox.h"
  49
  50 #ifdef HAVE_MINIUPNPC
  51 #include "upnp.h"
  52 #endif
  53
  54 ports_t myport;
  55 static io_t device_io;
  56 devops_t devops;
  57 bool device_standby = false;
  58
  59 char *proxyhost = NULL;
  60 char *proxyport = NULL;
  61 char *proxyuser = NULL;
  62 char *proxypass = NULL;
  63
  64 proxytype_t proxytype;
  65 bool autoconnect;
  66 bool disablebuggypeers;
  67
  68 char *scriptinterpreter;
  69 char *scriptextension;
  70
  71 bool node_read_ecdsa_public_key(node_t *n) {
  72         if(ecdsa_active(n->ecdsa)) {
  73                 return true;
  74         }
  75
  76         FILE *fp;
  77         char *pubname = NULL;
  78         char *p;
  79
  80         splay_tree_t config;
  81         init_configuration(&config);
  82
  83         if(!read_host_config(&config, n->name, true)) {
  84                 goto exit;
  85         }
  86
  87         /* First, check for simple Ed25519PublicKey statement */
  88
  89         if(get_config_string(lookup_config(&config, "Ed25519PublicKey"), &p)) {
  90                 n->ecdsa = ecdsa_set_base64_public_key(p);
  91                 free(p);
  92                 goto exit;
  93         }
  94
  95         /* Else, check for Ed25519PublicKeyFile statement and read it */
  96
  97         if(!get_config_string(lookup_config(&config, "Ed25519PublicKeyFile"), &pubname)) {
  98                 xasprintf(&pubname, "%s" SLASH "hosts" SLASH "%s", confbase, n->name);
  99         }
 100
 101         fp = fopen(pubname, "r");
 102
 103         if(!fp) {
 104                 goto exit;
 105         }
 106
 107         n->ecdsa = ecdsa_read_pem_public_key(fp);
 108         fclose(fp);
 109
 110 exit:
 111         splay_empty_tree(&config);
 112         free(pubname);
 113         return n->ecdsa;
 114 }
 115
 116 static bool read_invitation_key(void) {
 117         FILE *fp;
 118         char fname[PATH_MAX];
 119
 120         if(invitation_key) {
 121                 ecdsa_free(invitation_key);
 122                 invitation_key = NULL;
 123         }
 124
 125         snprintf(fname, sizeof(fname), "%s" SLASH "invitations" SLASH "ed25519_key.priv", confbase);
 126
 127         fp = fopen(fname, "r");
 128
 129         if(fp) {
 130                 invitation_key = ecdsa_read_pem_private_key(fp);
 131                 fclose(fp);
 132
 133                 if(!invitation_key) {
 134                         logger(DEBUG_ALWAYS, LOG_ERR, "Reading Ed25519 private key file `%s' failed", fname);
 135                 }
 136         }
 137
 138         return invitation_key;
 139 }
 140
 141 #ifndef DISABLE_LEGACY
 142 static timeout_t keyexpire_timeout;
 143
 144 static void keyexpire_handler(void *data) {
 145         regenerate_key();
 146         timeout_set(data, &(struct timeval) {
 147                 keylifetime, jitter()
 148         });
 149 }
 150 #endif
 151
 152 void regenerate_key(void) {
 153         logger(DEBUG_STATUS, LOG_INFO, "Expiring symmetric keys");
 154         send_key_changed();
 155
 156         for splay_each(node_t, n, &node_tree) {
 157                 n->status.validkey_in = false;
 158         }
 159 }
 160
 161 void load_all_nodes(void) {
 162         DIR *dir;
 163         struct dirent *ent;
 164         char dname[PATH_MAX];
 165
 166         snprintf(dname, sizeof(dname), "%s" SLASH "hosts", confbase);
 167         dir = opendir(dname);
 168
 169         if(!dir) {
 170                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not open %s: %s", dname, strerror(errno));
 171                 return;
 172         }
 173
 174         while((ent = readdir(dir))) {
 175                 if(!check_id(ent->d_name)) {
 176                         continue;
 177                 }
 178
 179                 node_t *n = lookup_node(ent->d_name);
 180
 181                 splay_tree_t config;
 182                 init_configuration(&config);
 183                 read_config_options(&config, ent->d_name);
 184                 read_host_config(&config, ent->d_name, true);
 185
 186                 if(!n) {
 187                         n = new_node(ent->d_name);
 188                         node_add(n);
 189                 }
 190
 191                 if(strictsubnets) {
 192                         for(config_t *cfg = lookup_config(&config, "Subnet"); cfg; cfg = lookup_config_next(&config, cfg)) {
 193                                 subnet_t *s, *s2;
 194
 195                                 if(!get_config_subnet(cfg, &s)) {
 196                                         continue;
 197                                 }
 198
 199                                 if((s2 = lookup_subnet(n, s))) {
 200                                         s2->expires = -1;
 201                                         free(s);
 202                                 } else {
 203                                         subnet_add(n, s);
 204                                 }
 205                         }
 206                 }
 207
 208                 if(lookup_config(&config, "Address")) {
 209                         n->status.has_address = true;
 210                 }
 211
 212                 splay_empty_tree(&config);
 213         }
 214
 215         closedir(dir);
 216 }
 217
 218 char *get_name(void) {
 219         char *name = NULL;
 220         char *returned_name;
 221
 222         get_config_string(lookup_config(&config_tree, "Name"), &name);
 223
 224         if(!name) {
 225                 return NULL;
 226         }
 227
 228         returned_name = replace_name(name);
 229         free(name);
 230         return returned_name;
 231 }
 232
 233 static void read_interpreter(void) {
 234         char *interpreter = NULL;
 235         get_config_string(lookup_config(&config_tree, "ScriptsInterpreter"), &interpreter);
 236
 237         if(!interpreter || (sandbox_can(START_PROCESSES, AFTER_SANDBOX) && sandbox_can(USE_NEW_PATHS, AFTER_SANDBOX))) {
 238                 free(scriptinterpreter);
 239                 scriptinterpreter = interpreter;
 240                 return;
 241         }
 242
 243         if(!string_eq(interpreter, scriptinterpreter)) {
 244                 logger(DEBUG_ALWAYS, LOG_NOTICE, "Not changing ScriptsInterpreter because of sandbox.");
 245         }
 246
 247         free(interpreter);
 248 }
 249
 250 bool setup_myself_reloadable(void) {
 251         read_interpreter();
 252
 253         free(scriptextension);
 254
 255         if(!get_config_string(lookup_config(&config_tree, "ScriptsExtension"), &scriptextension)) {
 256                 scriptextension = xstrdup("");
 257         }
 258
 259         char *proxy = NULL;
 260
 261         get_config_string(lookup_config(&config_tree, "Proxy"), &proxy);
 262
 263         if(proxy) {
 264                 char *space;
 265
 266                 if((space = strchr(proxy, ' '))) {
 267                         *space++ = 0;
 268                 }
 269
 270                 if(!strcasecmp(proxy, "none")) {
 271                         proxytype = PROXY_NONE;
 272                 } else if(!strcasecmp(proxy, "socks4")) {
 273                         proxytype = PROXY_SOCKS4;
 274                 } else if(!strcasecmp(proxy, "socks4a")) {
 275                         proxytype = PROXY_SOCKS4A;
 276                 } else if(!strcasecmp(proxy, "socks5")) {
 277                         proxytype = PROXY_SOCKS5;
 278                 } else if(!strcasecmp(proxy, "http")) {
 279                         proxytype = PROXY_HTTP;
 280                 } else if(!strcasecmp(proxy, "exec")) {
 281                         if(sandbox_can(START_PROCESSES, AFTER_SANDBOX)) {
 282                                 proxytype = PROXY_EXEC;
 283                         } else {
 284                                 logger(DEBUG_ALWAYS, LOG_ERR, "Cannot use exec proxies with current sandbox level.");
 285                                 return false;
 286                         }
 287                 } else {
 288                         logger(DEBUG_ALWAYS, LOG_ERR, "Unknown proxy type %s!", proxy);
 289                         free_string(proxy);
 290                         return false;
 291                 }
 292
 293                 free(proxyhost);
 294                 proxyhost = NULL;
 295
 296                 free(proxyport);
 297                 proxyport = NULL;
 298
 299                 free_string(proxyuser);
 300                 proxyuser = NULL;
 301
 302                 free_string(proxypass);
 303                 proxypass = NULL;
 304
 305                 switch(proxytype) {
 306                 case PROXY_NONE:
 307                 default:
 308                         break;
 309
 310                 case PROXY_EXEC:
 311                         if(!space || !*space) {
 312                                 logger(DEBUG_ALWAYS, LOG_ERR, "Argument expected for proxy type exec!");
 313                                 free_string(proxy);
 314                                 return false;
 315                         }
 316
 317                         if(!sandbox_can(USE_NEW_PATHS, AFTER_SANDBOX)) {
 318                                 logger(DEBUG_ALWAYS, LOG_NOTICE, "Changed exec proxy may fail to work because of sandbox.");
 319                         }
 320
 321                         proxyhost = xstrdup(space);
 322                         break;
 323
 324                 case PROXY_SOCKS4:
 325                 case PROXY_SOCKS4A:
 326                 case PROXY_SOCKS5:
 327                 case PROXY_HTTP:
 328                         proxyhost = space;
 329
 330                         if(space && (space = strchr(space, ' '))) {
 331                                 *space++ = 0, proxyport = space;
 332                         }
 333
 334                         if(!proxyhost || !*proxyhost || !proxyport || !*proxyport) {
 335                                 logger(DEBUG_ALWAYS, LOG_ERR, "Host and port argument expected for proxy!");
 336                                 proxyport = NULL;
 337                                 proxyhost = NULL;
 338                                 free_string(proxy);
 339                                 return false;
 340                         }
 341
 342                         if(space && (space = strchr(space, ' '))) {
 343                                 *space++ = 0, proxyuser = space;
 344                         }
 345
 346                         if(space && (space = strchr(space, ' '))) {
 347                                 *space++ = 0, proxypass = space;
 348                         }
 349
 350                         proxyhost = xstrdup(proxyhost);
 351                         proxyport = xstrdup(proxyport);
 352
 353                         if(proxyuser && *proxyuser) {
 354                                 proxyuser = xstrdup(proxyuser);
 355                         }
 356
 357                         if(proxypass && *proxypass) {
 358                                 proxypass = xstrdup(proxypass);
 359                         }
 360
 361                         break;
 362                 }
 363
 364                 free_string(proxy);
 365         }
 366
 367         bool choice;
 368
 369         if(get_config_bool(lookup_config(&config_tree, "IndirectData"), &choice) && choice) {
 370                 myself->options |= OPTION_INDIRECT;
 371         }
 372
 373         if(get_config_bool(lookup_config(&config_tree, "TCPOnly"), &choice) && choice) {
 374                 myself->options |= OPTION_TCPONLY;
 375         }
 376
 377         if(myself->options & OPTION_TCPONLY) {
 378                 myself->options |= OPTION_INDIRECT;
 379         }
 380
 381         get_config_bool(lookup_config(&config_tree, "UDPDiscovery"), &udp_discovery);
 382         get_config_int(lookup_config(&config_tree, "UDPDiscoveryKeepaliveInterval"), &udp_discovery_keepalive_interval);
 383         get_config_int(lookup_config(&config_tree, "UDPDiscoveryInterval"), &udp_discovery_interval);
 384         get_config_int(lookup_config(&config_tree, "UDPDiscoveryTimeout"), &udp_discovery_timeout);
 385
 386         get_config_int(lookup_config(&config_tree, "MTUInfoInterval"), &mtu_info_interval);
 387         get_config_int(lookup_config(&config_tree, "UDPInfoInterval"), &udp_info_interval);
 388
 389         get_config_bool(lookup_config(&config_tree, "DirectOnly"), &directonly);
 390         get_config_bool(lookup_config(&config_tree, "LocalDiscovery"), &localdiscovery);
 391
 392         char *rmode = NULL;
 393
 394         if(get_config_string(lookup_config(&config_tree, "Mode"), &rmode)) {
 395                 if(!strcasecmp(rmode, "router")) {
 396                         routing_mode = RMODE_ROUTER;
 397                 } else if(!strcasecmp(rmode, "switch")) {
 398                         routing_mode = RMODE_SWITCH;
 399                 } else if(!strcasecmp(rmode, "hub")) {
 400                         routing_mode = RMODE_HUB;
 401                 } else {
 402                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid routing mode!");
 403                         free(rmode);
 404                         return false;
 405                 }
 406
 407                 free(rmode);
 408         }
 409
 410         char *fmode = NULL;
 411
 412         if(get_config_string(lookup_config(&config_tree, "Forwarding"), &fmode)) {
 413                 if(!strcasecmp(fmode, "off")) {
 414                         forwarding_mode = FMODE_OFF;
 415                 } else if(!strcasecmp(fmode, "internal")) {
 416                         forwarding_mode = FMODE_INTERNAL;
 417                 } else if(!strcasecmp(fmode, "kernel")) {
 418                         forwarding_mode = FMODE_KERNEL;
 419                 } else {
 420                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid forwarding mode!");
 421                         free(fmode);
 422                         return false;
 423                 }
 424
 425                 free(fmode);
 426         }
 427
 428         choice = !(myself->options & OPTION_TCPONLY);
 429         get_config_bool(lookup_config(&config_tree, "PMTUDiscovery"), &choice);
 430
 431         if(choice) {
 432                 myself->options |= OPTION_PMTU_DISCOVERY;
 433         }
 434
 435         choice = true;
 436         get_config_bool(lookup_config(&config_tree, "ClampMSS"), &choice);
 437
 438         if(choice) {
 439                 myself->options |= OPTION_CLAMP_MSS;
 440         }
 441
 442         get_config_bool(lookup_config(&config_tree, "PriorityInheritance"), &priorityinheritance);
 443         get_config_bool(lookup_config(&config_tree, "DecrementTTL"), &decrement_ttl);
 444
 445         char *bmode = NULL;
 446
 447         if(get_config_string(lookup_config(&config_tree, "Broadcast"), &bmode)) {
 448                 if(!strcasecmp(bmode, "no")) {
 449                         broadcast_mode = BMODE_NONE;
 450                 } else if(!strcasecmp(bmode, "yes") || !strcasecmp(bmode, "mst")) {
 451                         broadcast_mode = BMODE_MST;
 452                 } else if(!strcasecmp(bmode, "direct")) {
 453                         broadcast_mode = BMODE_DIRECT;
 454                 } else {
 455                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid broadcast mode!");
 456                         free(bmode);
 457                         return false;
 458                 }
 459
 460                 free(bmode);
 461         }
 462
 463         /* Delete all broadcast subnets before re-adding them */
 464
 465         for splay_each(subnet_t, s, &subnet_tree) {
 466                 if(!s->owner) {
 467                         splay_delete_node(&subnet_tree, node);
 468                 }
 469         }
 470
 471         const char *const DEFAULT_BROADCAST_SUBNETS[] = { "ff:ff:ff:ff:ff:ff", "255.255.255.255", "224.0.0.0/4", "ff00::/8" };
 472
 473         for(size_t i = 0; i < sizeof(DEFAULT_BROADCAST_SUBNETS) / sizeof(*DEFAULT_BROADCAST_SUBNETS); i++) {
 474                 subnet_t *s = new_subnet();
 475
 476                 if(!str2net(s, DEFAULT_BROADCAST_SUBNETS[i])) {
 477                         abort();
 478                 }
 479
 480                 subnet_add(NULL, s);
 481         }
 482
 483         for(config_t *cfg = lookup_config(&config_tree, "BroadcastSubnet"); cfg; cfg = lookup_config_next(&config_tree, cfg)) {
 484                 subnet_t *s;
 485
 486                 if(!get_config_subnet(cfg, &s)) {
 487                         continue;
 488                 }
 489
 490                 subnet_add(NULL, s);
 491         }
 492
 493 #if !defined(IP_TOS)
 494
 495         if(priorityinheritance) {
 496                 logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform for IPv4 connections", "PriorityInheritance");
 497         }
 498
 499 #endif
 500
 501 #if !defined(IPV6_TCLASS)
 502
 503         if(priorityinheritance) {
 504                 logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform for IPv6 connections", "PriorityInheritance");
 505         }
 506
 507 #endif
 508
 509         if(!get_config_int(lookup_config(&config_tree, "MACExpire"), &macexpire)) {
 510                 macexpire = 600;
 511         }
 512
 513         if(get_config_int(lookup_config(&config_tree, "MaxTimeout"), &maxtimeout)) {
 514                 if(maxtimeout <= 0) {
 515                         logger(DEBUG_ALWAYS, LOG_ERR, "Bogus maximum timeout!");
 516                         return false;
 517                 }
 518         } else {
 519                 maxtimeout = 900;
 520         }
 521
 522         char *afname = NULL;
 523
 524         if(get_config_string(lookup_config(&config_tree, "AddressFamily"), &afname)) {
 525                 if(!strcasecmp(afname, "IPv4")) {
 526                         addressfamily = AF_INET;
 527                 } else if(!strcasecmp(afname, "IPv6")) {
 528                         addressfamily = AF_INET6;
 529                 } else if(!strcasecmp(afname, "any")) {
 530                         addressfamily = AF_UNSPEC;
 531                 } else {
 532                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid address family!");
 533                         free(afname);
 534                         return false;
 535                 }
 536
 537                 free(afname);
 538         }
 539
 540         get_config_bool(lookup_config(&config_tree, "Hostnames"), &hostnames);
 541
 542         if(!get_config_int(lookup_config(&config_tree, "KeyExpire"), &keylifetime)) {
 543                 keylifetime = 3600;
 544         }
 545
 546         if(!get_config_bool(lookup_config(&config_tree, "AutoConnect"), &autoconnect)) {
 547                 autoconnect = true;
 548         }
 549
 550         get_config_bool(lookup_config(&config_tree, "DisableBuggyPeers"), &disablebuggypeers);
 551
 552         if(!get_config_int(lookup_config(&config_tree, "InvitationExpire"), &invitation_lifetime)) {
 553                 invitation_lifetime = 604800;        // 1 week
 554         }
 555
 556         read_invitation_key();
 557
 558         return true;
 559 }
 560
 561 // Get the port that `from_fd` is listening on, and assign it to
 562 // `sa` if `sa` has a dynamically allocated (zero) port.
 563 static bool assign_static_port(sockaddr_t *sa, int from_fd) {
 564         // We cannot get a port from a bad FD. Bail out.
 565         if(from_fd <= 0) {
 566                 return false;
 567         }
 568
 569         int port = get_bound_port(from_fd);
 570
 571         if(!port) {
 572                 return false;
 573         }
 574
 575         // If the port is non-zero, don't reassign it as it's already static.
 576         switch(sa->sa.sa_family) {
 577         case AF_INET:
 578                 if(!sa->in.sin_port) {
 579                         sa->in.sin_port = htons(port);
 580                 }
 581
 582                 return true;
 583
 584         case AF_INET6:
 585                 if(!sa->in6.sin6_port) {
 586                         sa->in6.sin6_port = htons(port);
 587                 }
 588
 589                 return true;
 590
 591         default:
 592                 logger(DEBUG_ALWAYS, LOG_ERR, "Unknown address family 0x%x", sa->sa.sa_family);
 593                 return false;
 594         }
 595 }
 596
 597 typedef int (*bind_fn_t)(const sockaddr_t *);
 598
 599 static int bind_reusing_port(const sockaddr_t *sa, int from_fd, bind_fn_t setup) {
 600         sockaddr_t reuse_sa;
 601         memcpy(&reuse_sa, sa, SALEN(sa->sa));
 602
 603         int fd = -1;
 604
 605         // Check if the address we've been passed here is using port 0.
 606         // If it is, try to get an actual port from an already bound socket, and reuse it here.
 607         if(assign_static_port(&reuse_sa, from_fd)) {
 608                 fd = setup(&reuse_sa);
 609         }
 610
 611         // If we're binding to a hardcoded non-zero port, or no socket is listening yet,
 612         // or binding failed, try the original address.
 613         if(fd < 0) {
 614                 fd = setup(sa);
 615         }
 616
 617         return fd;
 618 }
 619
 620 /*
 621   Add listening sockets.
 622 */
 623 static bool add_listen_address(char *address, bool bindto) {
 624         char *port = myport.tcp;
 625
 626         if(address) {
 627                 char *space = strchr(address, ' ');
 628
 629                 if(space) {
 630                         *space++ = 0;
 631                         port = space;
 632                 }
 633
 634                 if(!strcmp(address, "*")) {
 635                         *address = 0;
 636                 }
 637         }
 638
 639         struct addrinfo *ai, hint = {0};
 640
 641         hint.ai_family = addressfamily;
 642
 643         hint.ai_socktype = SOCK_STREAM;
 644
 645         hint.ai_protocol = IPPROTO_TCP;
 646
 647         hint.ai_flags = AI_PASSIVE;
 648
 649 #if HAVE_DECL_RES_INIT
 650         res_init();
 651
 652 #endif
 653         int err = getaddrinfo(address && *address ? address : NULL, port, &hint, &ai);
 654
 655         free(address);
 656
 657         if(err || !ai) {
 658                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "getaddrinfo", err == EAI_SYSTEM ? strerror(err) : gai_strerror(err));
 659                 return false;
 660         }
 661
 662         for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
 663                 // Ignore duplicate addresses
 664                 bool found = false;
 665
 666                 for(int i = 0; i < listen_sockets; i++)
 667                         if(!memcmp(&listen_socket[i].sa, aip->ai_addr, aip->ai_addrlen)) {
 668                                 found = true;
 669                                 break;
 670                         }
 671
 672                 if(found) {
 673                         continue;
 674                 }
 675
 676                 if(listen_sockets >= MAXSOCKETS) {
 677                         listen_sockets = MAXSOCKETS;
 678                         logger(DEBUG_ALWAYS, LOG_ERR, "Too many listening sockets");
 679                         freeaddrinfo(ai);
 680                         return false;
 681                 }
 682
 683                 const sockaddr_t *sa = (sockaddr_t *) aip->ai_addr;
 684                 int from_fd = listen_socket[0].tcp.fd;
 685
 686                 // If we're binding to a dynamically allocated (zero) port, try to get the actual
 687                 // port of the first TCP socket, and use it for this one. If that succeeds, our
 688                 // tincd instance will use the same port for all addresses it listens on.
 689                 int tcp_fd = bind_reusing_port(sa, from_fd, setup_listen_socket);
 690
 691                 if(tcp_fd < 0) {
 692                         continue;
 693                 }
 694
 695                 // If we just successfully bound the first socket, use it for the UDP procedure below.
 696                 // Otherwise, keep using the socket we've obtained from listen_socket[0].
 697                 if(!from_fd) {
 698                         from_fd = tcp_fd;
 699                 }
 700
 701                 int udp_fd = bind_reusing_port(sa, from_fd, setup_vpn_in_socket);
 702
 703                 if(udp_fd < 0) {
 704                         closesocket(tcp_fd);
 705                         continue;
 706                 }
 707
 708                 listen_socket_t *sock = &listen_socket[listen_sockets];
 709                 io_add(&sock->tcp, handle_new_meta_connection, sock, tcp_fd, IO_READ);
 710                 io_add(&sock->udp, handle_incoming_vpn_data, sock, udp_fd, IO_READ);
 711
 712                 if(debug_level >= DEBUG_CONNECTIONS) {
 713                         int tcp_port = get_bound_port(tcp_fd);
 714                         char *hostname = NULL;
 715                         sockaddr2str(sa, &hostname, NULL);
 716                         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Listening on %s port %d", hostname, tcp_port);
 717                         free(hostname);
 718                 }
 719
 720                 sock->bindto = bindto;
 721                 memcpy(&sock->sa, aip->ai_addr, aip->ai_addrlen);
 722                 listen_sockets++;
 723         }
 724
 725         freeaddrinfo(ai);
 726         return true;
 727 }
 728
 729 void device_enable(void) {
 730         if(devops.enable) {
 731                 devops.enable();
 732         }
 733
 734         /* Run tinc-up script to further initialize the tap interface */
 735
 736         environment_t env;
 737         environment_init(&env);
 738         execute_script("tinc-up", &env);
 739         environment_exit(&env);
 740 }
 741
 742 void device_disable(void) {
 743         environment_t env;
 744         environment_init(&env);
 745         execute_script("tinc-down", &env);
 746         environment_exit(&env);
 747
 748         if(devops.disable) {
 749                 devops.disable();
 750         }
 751 }
 752
 753 /*
 754   Configure node_t myself and set up the local sockets (listen only)
 755 */
 756 static bool setup_myself(void) {
 757         char *name, *type;
 758         char *address = NULL;
 759         bool port_specified = false;
 760
 761         if(!(name = get_name())) {
 762                 logger(DEBUG_ALWAYS, LOG_ERR, "Name for tinc daemon required!");
 763                 return false;
 764         }
 765
 766         myname = xstrdup(name);
 767         myself = new_node(name);
 768         myself->connection = new_connection();
 769         myself->connection->name = name;
 770         read_host_config(&config_tree, name, true);
 771
 772         if(!get_config_string(lookup_config(&config_tree, "Port"), &myport.tcp)) {
 773                 myport.tcp = xstrdup("655");
 774         } else {
 775                 port_specified = true;
 776         }
 777
 778         myport.udp = xstrdup(myport.tcp);
 779
 780         myself->connection->options = 0;
 781         myself->connection->protocol_major = PROT_MAJOR;
 782         myself->connection->protocol_minor = PROT_MINOR;
 783
 784         myself->options |= PROT_MINOR << 24;
 785
 786 #ifdef DISABLE_LEGACY
 787         myself->connection->ecdsa = read_ecdsa_private_key(&config_tree, NULL);
 788         experimental = myself->connection->ecdsa != NULL;
 789
 790         if(!experimental) {
 791                 logger(DEBUG_ALWAYS, LOG_ERR, "No private key available, cannot start tinc!");
 792                 return false;
 793         }
 794
 795 #else
 796
 797         if(!get_config_bool(lookup_config(&config_tree, "ExperimentalProtocol"), &experimental)) {
 798                 myself->connection->ecdsa = read_ecdsa_private_key(&config_tree, NULL);
 799                 experimental = myself->connection->ecdsa != NULL;
 800
 801                 if(!experimental) {
 802                         logger(DEBUG_ALWAYS, LOG_WARNING, "Support for SPTPS disabled.");
 803                 }
 804         } else {
 805                 if(experimental) {
 806                         myself->connection->ecdsa = read_ecdsa_private_key(&config_tree, NULL);
 807
 808                         if(!myself->connection->ecdsa) {
 809                                 return false;
 810                         }
 811                 }
 812         }
 813
 814         rsa_t *rsa = read_rsa_private_key(&config_tree, NULL);
 815
 816         if(rsa) {
 817                 myself->connection->legacy = new_legacy_ctx(rsa);
 818         } else {
 819                 if(experimental) {
 820                         logger(DEBUG_ALWAYS, LOG_WARNING, "Support for legacy protocol disabled.");
 821                 } else {
 822                         logger(DEBUG_ALWAYS, LOG_ERR, "No private keys available, cannot start tinc!");
 823                         return false;
 824                 }
 825         }
 826
 827 #endif
 828
 829         /* Ensure myport is numeric */
 830         if(!is_decimal(myport.tcp)) {
 831                 uint16_t port = service_to_port(myport.tcp);
 832
 833                 if(!port) {
 834                         return false;
 835                 }
 836
 837                 free(myport.tcp);
 838                 myport.tcp = int_to_str(port);
 839
 840                 free(myport.udp);
 841                 myport.udp = xstrdup(myport.tcp);
 842         }
 843
 844         /* Read in all the subnets specified in the host configuration file */
 845
 846         for(config_t *cfg = lookup_config(&config_tree, "Subnet"); cfg; cfg = lookup_config_next(&config_tree, cfg)) {
 847                 subnet_t *subnet;
 848
 849                 if(!get_config_subnet(cfg, &subnet)) {
 850                         return false;
 851                 }
 852
 853                 subnet_add(myself, subnet);
 854         }
 855
 856         /* Check some options */
 857
 858         if(!setup_myself_reloadable()) {
 859                 return false;
 860         }
 861
 862         get_config_bool(lookup_config(&config_tree, "StrictSubnets"), &strictsubnets);
 863         get_config_bool(lookup_config(&config_tree, "TunnelServer"), &tunnelserver);
 864         strictsubnets |= tunnelserver;
 865
 866         if(get_config_int(lookup_config(&config_tree, "MaxConnectionBurst"), &max_connection_burst)) {
 867                 if(max_connection_burst <= 0) {
 868                         logger(DEBUG_ALWAYS, LOG_ERR, "MaxConnectionBurst cannot be negative!");
 869                         return false;
 870                 }
 871         }
 872
 873         if(get_config_int(lookup_config(&config_tree, "UDPRcvBuf"), &udp_rcvbuf)) {
 874                 if(udp_rcvbuf < 0) {
 875                         logger(DEBUG_ALWAYS, LOG_ERR, "UDPRcvBuf cannot be negative!");
 876                         return false;
 877                 }
 878
 879                 udp_rcvbuf_warnings = true;
 880         }
 881
 882         if(get_config_int(lookup_config(&config_tree, "UDPSndBuf"), &udp_sndbuf)) {
 883                 if(udp_sndbuf < 0) {
 884                         logger(DEBUG_ALWAYS, LOG_ERR, "UDPSndBuf cannot be negative!");
 885                         return false;
 886                 }
 887
 888                 udp_sndbuf_warnings = true;
 889         }
 890
 891         get_config_int(lookup_config(&config_tree, "FWMark"), &fwmark);
 892 #ifndef SO_MARK
 893
 894         if(fwmark) {
 895                 logger(DEBUG_ALWAYS, LOG_ERR, "FWMark not supported on this platform!");
 896                 return false;
 897         }
 898
 899 #endif
 900
 901         int replaywin_int;
 902
 903         if(get_config_int(lookup_config(&config_tree, "ReplayWindow"), &replaywin_int)) {
 904                 if(replaywin_int < 0) {
 905                         logger(DEBUG_ALWAYS, LOG_ERR, "ReplayWindow cannot be negative!");
 906                         return false;
 907                 }
 908
 909                 replaywin = (unsigned)replaywin_int;
 910                 sptps_replaywin = replaywin;
 911         }
 912
 913 #ifndef DISABLE_LEGACY
 914         /* Generate packet encryption key */
 915
 916         char *cipher;
 917
 918         if(!get_config_string(lookup_config(&config_tree, "Cipher"), &cipher)) {
 919                 cipher = xstrdup("aes-256-cbc");
 920         }
 921
 922         if(!strcasecmp(cipher, "none")) {
 923                 myself->incipher = NULL;
 924         } else {
 925                 myself->incipher = cipher_alloc();
 926
 927                 if(!cipher_open_by_name(myself->incipher, cipher)) {
 928                         logger(DEBUG_ALWAYS, LOG_ERR, "Unrecognized cipher type!");
 929                         cipher_free(myself->incipher);
 930                         myself->incipher = NULL;
 931                         free(cipher);
 932                         return false;
 933                 }
 934         }
 935
 936         free(cipher);
 937
 938         timeout_add(&keyexpire_timeout, keyexpire_handler, &keyexpire_timeout, &(struct timeval) {
 939                 keylifetime, jitter()
 940         });
 941
 942         /* Check if we want to use message authentication codes... */
 943
 944         int maclength = 4;
 945         get_config_int(lookup_config(&config_tree, "MACLength"), &maclength);
 946
 947         if(maclength < 0) {
 948                 logger(DEBUG_ALWAYS, LOG_ERR, "Bogus MAC length!");
 949                 return false;
 950         }
 951
 952         char *digest;
 953
 954         if(!get_config_string(lookup_config(&config_tree, "Digest"), &digest)) {
 955                 digest = xstrdup("sha256");
 956         }
 957
 958         if(!strcasecmp(digest, "none")) {
 959                 myself->indigest = NULL;
 960         } else {
 961                 myself->indigest = digest_alloc();
 962
 963                 if(!digest_open_by_name(myself->indigest, digest, maclength)) {
 964                         logger(DEBUG_ALWAYS, LOG_ERR, "Unrecognized digest type!");
 965                         digest_free(myself->indigest);
 966                         myself->indigest = NULL;
 967                         free(digest);
 968                         return false;
 969                 }
 970         }
 971
 972         free(digest);
 973 #endif
 974
 975         /* Compression */
 976         int incompression = 0;
 977
 978         if(get_config_int(lookup_config(&config_tree, "Compression"), &incompression)) {
 979                 myself->incompression = incompression;
 980
 981                 switch(myself->incompression) {
 982                 case COMPRESS_LZ4:
 983 #ifdef HAVE_LZ4
 984                         break;
 985 #else
 986                         logger(DEBUG_ALWAYS, LOG_ERR, "Bogus compression level!");
 987                         logger(DEBUG_ALWAYS, LOG_ERR, "LZ4 compression is unavailable on this node.");
 988                         return false;
 989 #endif
 990
 991                 case COMPRESS_LZO_HI:
 992                 case COMPRESS_LZO_LO:
 993 #ifdef HAVE_LZO
 994                         break;
 995 #else
 996                         logger(DEBUG_ALWAYS, LOG_ERR, "Bogus compression level!");
 997                         logger(DEBUG_ALWAYS, LOG_ERR, "LZO compression is unavailable on this node.");
 998                         return false;
 999 #endif
1000
1001                 case COMPRESS_ZLIB_9:
1002                 case COMPRESS_ZLIB_8:
1003                 case COMPRESS_ZLIB_7:
1004                 case COMPRESS_ZLIB_6:
1005                 case COMPRESS_ZLIB_5:
1006                 case COMPRESS_ZLIB_4:
1007                 case COMPRESS_ZLIB_3:
1008                 case COMPRESS_ZLIB_2:
1009                 case COMPRESS_ZLIB_1:
1010 #ifdef HAVE_ZLIB
1011                         break;
1012 #else
1013                         logger(DEBUG_ALWAYS, LOG_ERR, "Bogus compression level!");
1014                         logger(DEBUG_ALWAYS, LOG_ERR, "ZLIB compression is unavailable on this node.");
1015                         return false;
1016 #endif
1017
1018                 case COMPRESS_NONE:
1019                         break;
1020
1021                 default:
1022                         logger(DEBUG_ALWAYS, LOG_ERR, "Bogus compression level!");
1023                         logger(DEBUG_ALWAYS, LOG_ERR, "Compression level %i is unrecognized by this node.", myself->incompression);
1024                         return false;
1025                 }
1026         } else {
1027                 myself->incompression = COMPRESS_NONE;
1028         }
1029
1030         /* Done */
1031
1032         myself->nexthop = myself;
1033         myself->via = myself;
1034         myself->status.reachable = true;
1035         myself->last_state_change = now.tv_sec;
1036         myself->status.sptps = experimental;
1037         node_add(myself);
1038
1039         graph();
1040
1041         load_all_nodes();
1042
1043         /* Open device */
1044
1045         devops = os_devops;
1046
1047         if(get_config_string(lookup_config(&config_tree, "DeviceType"), &type)) {
1048                 if(!strcasecmp(type, DEVICE_DUMMY)) {
1049                         devops = dummy_devops;
1050                 } else if(!strcasecmp(type, "raw_socket")) {
1051                         devops = raw_socket_devops;
1052                 } else if(!strcasecmp(type, "multicast")) {
1053                         devops = multicast_devops;
1054                 }
1055
1056 #ifdef HAVE_SYS_UN_H
1057                 else if(!strcasecmp(type, "fd")) {
1058                         devops = fd_devops;
1059                 }
1060
1061 #endif
1062 #ifdef ENABLE_UML
1063                 else if(!strcasecmp(type, "uml")) {
1064                         devops = uml_devops;
1065                 }
1066
1067 #endif
1068 #ifdef ENABLE_VDE
1069                 else if(!strcasecmp(type, "vde")) {
1070                         devops = vde_devops;
1071                 }
1072
1073 #endif
1074                 free(type);
1075         }
1076
1077         get_config_bool(lookup_config(&config_tree, "DeviceStandby"), &device_standby);
1078
1079         if(!devops.setup()) {
1080                 return false;
1081         }
1082
1083         if(device_fd >= 0) {
1084                 io_add(&device_io, handle_device_data, NULL, device_fd, IO_READ);
1085         }
1086
1087         /* Open sockets */
1088
1089         if(!do_detach && getenv("LISTEN_FDS")) {
1090                 sockaddr_t sa;
1091                 socklen_t salen;
1092
1093                 listen_sockets = atoi(getenv("LISTEN_FDS"));
1094 #ifdef HAVE_UNSETENV
1095                 unsetenv("LISTEN_FDS");
1096 #endif
1097
1098                 if(listen_sockets > MAXSOCKETS) {
1099                         listen_sockets = MAXSOCKETS;
1100                         logger(DEBUG_ALWAYS, LOG_ERR, "Too many listening sockets");
1101                         return false;
1102                 }
1103
1104                 for(int i = 0; i < listen_sockets; i++) {
1105                         const int tcp_fd = i + 3;
1106                         salen = sizeof(sa);
1107
1108                         if(getsockname(tcp_fd, &sa.sa, &salen) < 0) {
1109                                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not get address of listen fd %d: %s", tcp_fd, sockstrerror(sockerrno));
1110                                 return false;
1111                         }
1112
1113 #ifdef FD_CLOEXEC
1114                         fcntl(tcp_fd, F_SETFD, FD_CLOEXEC);
1115 #endif
1116
1117                         int udp_fd = setup_vpn_in_socket(&sa);
1118
1119                         if(udp_fd < 0) {
1120                                 return false;
1121                         }
1122
1123                         io_add(&listen_socket[i].tcp, (io_cb_t)handle_new_meta_connection, &listen_socket[i], tcp_fd, IO_READ);
1124                         io_add(&listen_socket[i].udp, (io_cb_t)handle_incoming_vpn_data, &listen_socket[i], udp_fd, IO_READ);
1125
1126                         if(debug_level >= DEBUG_CONNECTIONS) {
1127                                 char *hostname = sockaddr2hostname(&sa);
1128                                 logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Listening on %s", hostname);
1129                                 free(hostname);
1130                         }
1131
1132                         memcpy(&listen_socket[i].sa, &sa, salen);
1133                 }
1134         } else {
1135                 listen_sockets = 0;
1136                 int cfgs = 0;
1137
1138                 for(config_t *cfg = lookup_config(&config_tree, "BindToAddress"); cfg; cfg = lookup_config_next(&config_tree, cfg)) {
1139                         cfgs++;
1140                         get_config_string(cfg, &address);
1141
1142                         if(!add_listen_address(address, true)) {
1143                                 return false;
1144                         }
1145                 }
1146
1147                 for(config_t *cfg = lookup_config(&config_tree, "ListenAddress"); cfg; cfg = lookup_config_next(&config_tree, cfg)) {
1148                         cfgs++;
1149                         get_config_string(cfg, &address);
1150
1151                         if(!add_listen_address(address, false)) {
1152                                 return false;
1153                         }
1154                 }
1155
1156                 if(!cfgs)
1157                         if(!add_listen_address(address, NULL)) {
1158                                 return false;
1159                         }
1160         }
1161
1162         if(!listen_sockets) {
1163                 logger(DEBUG_ALWAYS, LOG_ERR, "Unable to create any listening socket!");
1164                 return false;
1165         }
1166
1167         /* If no Port option was specified, set myport to the port used by the first listening socket. */
1168
1169         if(!port_specified || atoi(myport.tcp) == 0) {
1170                 listen_socket_t *sock = &listen_socket[0];
1171
1172                 uint16_t tcp = get_bound_port(sock->tcp.fd);
1173                 free(myport.tcp);
1174                 myport.tcp = int_to_str(tcp);
1175
1176                 uint16_t udp = get_bound_port(sock->udp.fd);
1177                 free(myport.udp);
1178                 myport.udp = int_to_str(udp);
1179         }
1180
1181         xasprintf(&myself->hostname, "MYSELF port %s", myport.tcp);
1182         myself->connection->hostname = xstrdup(myself->hostname);
1183
1184         char *upnp = NULL;
1185         get_config_string(lookup_config(&config_tree, "UPnP"), &upnp);
1186         bool upnp_tcp = false;
1187         bool upnp_udp = false;
1188
1189         if(upnp) {
1190                 if(!strcasecmp(upnp, "yes")) {
1191                         upnp_tcp = upnp_udp = true;
1192                 } else if(!strcasecmp(upnp, "udponly")) {
1193                         upnp_udp = true;
1194                 }
1195
1196                 free(upnp);
1197         }
1198
1199         if(upnp_tcp || upnp_udp) {
1200 #ifdef HAVE_MINIUPNPC
1201                 upnp_init(upnp_tcp, upnp_udp);
1202 #else
1203                 logger(DEBUG_ALWAYS, LOG_WARNING, "UPnP was requested, but tinc isn't built with miniupnpc support!");
1204 #endif
1205         }
1206
1207         /* Done. */
1208
1209         last_config_check = now.tv_sec;
1210
1211         return true;
1212 }
1213
1214 /*
1215   initialize network
1216 */
1217 bool setup_network(void) {
1218         init_connections();
1219         init_subnets();
1220
1221         if(get_config_int(lookup_config(&config_tree, "PingInterval"), &pinginterval)) {
1222                 if(pinginterval < 1) {
1223                         pinginterval = 86400;
1224                 }
1225         } else {
1226                 pinginterval = 60;
1227         }
1228
1229         if(!get_config_int(lookup_config(&config_tree, "PingTimeout"), &pingtimeout)) {
1230                 pingtimeout = 5;
1231         }
1232
1233         if(pingtimeout < 1 || pingtimeout > pinginterval) {
1234                 pingtimeout = pinginterval;
1235         }
1236
1237         if(!get_config_int(lookup_config(&config_tree, "MaxOutputBufferSize"), &maxoutbufsize)) {
1238                 maxoutbufsize = 10 * MTU;
1239         }
1240
1241         if(!setup_myself()) {
1242                 return false;
1243         }
1244
1245         if(!init_control()) {
1246                 return false;
1247         }
1248
1249         if(!device_standby) {
1250                 device_enable();
1251         }
1252
1253         /* Run subnet-up scripts for our own subnets */
1254
1255         subnet_update(myself, NULL, true);
1256
1257         return true;
1258 }
1259
1260 /*
1261   close all open network connections
1262 */
1263 void close_network_connections(void) {
1264         for(list_node_t *node = connection_list.head, *next; node; node = next) {
1265                 next = node->next;
1266                 connection_t *c = node->data;
1267
1268                 /* Keep control connections open until the end, so they know when we really terminated */
1269                 if(c->status.control) {
1270                         c->socket = -1;
1271                 }
1272
1273                 c->outgoing = NULL;
1274                 terminate_connection(c, false);
1275         }
1276
1277         list_empty_list(&outgoing_list);
1278
1279         if(myself && myself->connection) {
1280                 subnet_update(myself, NULL, false);
1281                 free_connection(myself->connection);
1282         }
1283
1284         for(int i = 0; i < listen_sockets; i++) {
1285                 io_del(&listen_socket[i].tcp);
1286                 io_del(&listen_socket[i].udp);
1287                 closesocket(listen_socket[i].tcp.fd);
1288                 closesocket(listen_socket[i].udp.fd);
1289         }
1290
1291         exit_requests();
1292         exit_edges();
1293         exit_subnets();
1294         exit_nodes();
1295         exit_connections();
1296
1297         if(!device_standby) {
1298                 device_disable();
1299         }
1300
1301         free(myport.tcp);
1302         free(myport.udp);
1303
1304         if(device_fd >= 0) {
1305                 io_del(&device_io);
1306         }
1307
1308         if(devops.close) {
1309                 devops.close();
1310         }
1311
1312         exit_control();
1313
1314         free(scriptextension);
1315         free(scriptinterpreter);
1316
1317         return;
1318 }