git.meshlink.io Git - meshlink/blob - src/net_socket.c

   1 /*
   2     net_socket.c -- Handle various kinds of sockets.
   3     Copyright (C) 1998-2005 Ivo Timmermans,
   4                   2000-2012 Guus Sliepen <guus@tinc-vpn.org>
   5                   2006      Scott Lamb <slamb@slamb.org>
   6                   2009      Florian Forster <octo@verplant.org>
   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 "splay_tree.h"
  26 #include "conf.h"
  27 #include "connection.h"
  28 #include "logger.h"
  29 #include "meta.h"
  30 #include "net.h"
  31 #include "netutl.h"
  32 #include "protocol.h"
  33 #include "utils.h"
  34 #include "xalloc.h"
  35
  36 /* Needed on Mac OS/X */
  37 #ifndef SOL_TCP
  38 #define SOL_TCP IPPROTO_TCP
  39 #endif
  40
  41 int addressfamily = AF_UNSPEC;
  42 int maxtimeout = 900;
  43 int seconds_till_retry = 5;
  44 int udp_rcvbuf = 0;
  45 int udp_sndbuf = 0;
  46
  47 listen_socket_t listen_socket[MAXSOCKETS];
  48 int listen_sockets;
  49 list_t *outgoing_list = NULL;
  50
  51 /* Setup sockets */
  52
  53 static void configure_tcp(connection_t *c) {
  54         int option;
  55
  56 #ifdef O_NONBLOCK
  57         int flags = fcntl(c->socket, F_GETFL);
  58
  59         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
  60                 logger(DEBUG_ALWAYS, LOG_ERR, "fcntl for %s: %s", c->hostname, strerror(errno));
  61         }
  62 #elif defined(WIN32)
  63         unsigned long arg = 1;
  64
  65         if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
  66                 logger(DEBUG_ALWAYS, LOG_ERR, "ioctlsocket for %s: %d", c->hostname, sockstrerror(sockerrno));
  67         }
  68 #endif
  69
  70 #if defined(SOL_TCP) && defined(TCP_NODELAY)
  71         option = 1;
  72         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, (void *)&option, sizeof option);
  73 #endif
  74
  75 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
  76         option = IPTOS_LOWDELAY;
  77         setsockopt(c->socket, SOL_IP, IP_TOS, (void *)&option, sizeof option);
  78 #endif
  79 }
  80
  81 static bool bind_to_interface(int sd) {
  82         char *iface;
  83
  84 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
  85         struct ifreq ifr;
  86         int status;
  87 #endif /* defined(SOL_SOCKET) && defined(SO_BINDTODEVICE) */
  88
  89         if(!get_config_string (lookup_config (config_tree, "BindToInterface"), &iface))
  90                 return true;
  91
  92 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
  93         memset(&ifr, 0, sizeof(ifr));
  94         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
  95         ifr.ifr_ifrn.ifrn_name[IFNAMSIZ - 1] = 0;
  96
  97         status = setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr));
  98         if(status) {
  99                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
 100                                 strerror(errno));
 101                 return false;
 102         }
 103 #else /* if !defined(SOL_SOCKET) || !defined(SO_BINDTODEVICE) */
 104         logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform", "BindToInterface");
 105 #endif
 106
 107         return true;
 108 }
 109
 110 int setup_listen_socket(const sockaddr_t *sa) {
 111         int nfd;
 112         char *addrstr;
 113         int option;
 114         char *iface;
 115
 116         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 117
 118         if(nfd < 0) {
 119                 logger(DEBUG_STATUS, LOG_ERR, "Creating metasocket failed: %s", sockstrerror(sockerrno));
 120                 return -1;
 121         }
 122
 123 #ifdef FD_CLOEXEC
 124         fcntl(nfd, F_SETFD, FD_CLOEXEC);
 125 #endif
 126
 127         /* Optimize TCP settings */
 128
 129         option = 1;
 130         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof option);
 131
 132 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 133         if(sa->sa.sa_family == AF_INET6)
 134                 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
 135 #endif
 136
 137         if(get_config_string
 138            (lookup_config(config_tree, "BindToInterface"), &iface)) {
 139 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 140                 struct ifreq ifr;
 141
 142                 memset(&ifr, 0, sizeof ifr);
 143                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 144
 145                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof ifr)) {
 146                         closesocket(nfd);
 147                         logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
 148                                    strerror(sockerrno));
 149                         return -1;
 150                 }
 151 #else
 152                 logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform", "BindToInterface");
 153 #endif
 154         }
 155
 156         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 157                 closesocket(nfd);
 158                 addrstr = sockaddr2hostname(sa);
 159                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/tcp: %s", addrstr, sockstrerror(sockerrno));
 160                 free(addrstr);
 161                 return -1;
 162         }
 163
 164         if(listen(nfd, 3)) {
 165                 closesocket(nfd);
 166                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "listen", sockstrerror(sockerrno));
 167                 return -1;
 168         }
 169
 170         return nfd;
 171 }
 172
 173 int setup_vpn_in_socket(const sockaddr_t *sa) {
 174         int nfd;
 175         char *addrstr;
 176         int option;
 177
 178         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 179
 180         if(nfd < 0) {
 181                 logger(DEBUG_ALWAYS, LOG_ERR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
 182                 return -1;
 183         }
 184
 185 #ifdef FD_CLOEXEC
 186         fcntl(nfd, F_SETFD, FD_CLOEXEC);
 187 #endif
 188
 189 #ifdef O_NONBLOCK
 190         {
 191                 int flags = fcntl(nfd, F_GETFL);
 192
 193                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 194                         closesocket(nfd);
 195                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "fcntl",
 196                                    strerror(errno));
 197                         return -1;
 198                 }
 199         }
 200 #elif defined(WIN32)
 201         {
 202                 unsigned long arg = 1;
 203                 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 204                         closesocket(nfd);
 205                         logger(DEBUG_ALWAYS, LOG_ERR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
 206                         return -1;
 207                 }
 208         }
 209 #endif
 210
 211         option = 1;
 212         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof option);
 213         setsockopt(nfd, SOL_SOCKET, SO_BROADCAST, (void *)&option, sizeof option);
 214
 215         if(udp_rcvbuf && setsockopt(nfd, SOL_SOCKET, SO_RCVBUF, (void *)&udp_rcvbuf, sizeof(udp_rcvbuf)))
 216                 logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP SO_RCVBUF to %i: %s", udp_rcvbuf, strerror(errno));
 217
 218         if(udp_sndbuf && setsockopt(nfd, SOL_SOCKET, SO_SNDBUF, (void *)&udp_sndbuf, sizeof(udp_sndbuf)))
 219                 logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP SO_SNDBUF to %i: %s", udp_sndbuf, strerror(errno));
 220
 221 #if defined(IPPROTO_IPV6) && defined(IPV6_V6ONLY)
 222         if(sa->sa.sa_family == AF_INET6)
 223                 setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
 224 #endif
 225
 226 #if defined(IP_DONTFRAG) && !defined(IP_DONTFRAGMENT)
 227 #define IP_DONTFRAGMENT IP_DONTFRAG
 228 #endif
 229
 230 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 231         if(myself->options & OPTION_PMTU_DISCOVERY) {
 232                 option = IP_PMTUDISC_DO;
 233                 setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
 234         }
 235 #elif defined(IPPROTO_IP) && defined(IP_DONTFRAGMENT)
 236         if(myself->options & OPTION_PMTU_DISCOVERY) {
 237                 option = 1;
 238                 setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, (void *)&option, sizeof(option));
 239         }
 240 #else
 241 #warning No way to disable IPv4 fragmentation
 242 #endif
 243
 244 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 245         if(myself->options & OPTION_PMTU_DISCOVERY) {
 246                 option = IPV6_PMTUDISC_DO;
 247                 setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
 248         }
 249 #elif defined(IPPROTO_IPV6) && defined(IPV6_DONTFRAG)
 250         if(myself->options & OPTION_PMTU_DISCOVERY) {
 251                 option = 1;
 252                 setsockopt(nfd, IPPROTO_IPV6, IPV6_DONTFRAG, (void *)&option, sizeof(option));
 253         }
 254 #else
 255 #warning No way to disable IPv6 fragmentation
 256 #endif
 257
 258         if (!bind_to_interface(nfd)) {
 259                 closesocket(nfd);
 260                 return -1;
 261         }
 262
 263         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 264                 closesocket(nfd);
 265                 addrstr = sockaddr2hostname(sa);
 266                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/udp: %s", addrstr, sockstrerror(sockerrno));
 267                 free(addrstr);
 268                 return -1;
 269         }
 270
 271         return nfd;
 272 } /* int setup_vpn_in_socket */
 273
 274 static void retry_outgoing_handler(int fd, short events, void *data) {
 275         setup_outgoing_connection(data);
 276 }
 277
 278 void retry_outgoing(outgoing_t *outgoing) {
 279         outgoing->timeout += 5;
 280
 281         if(outgoing->timeout > maxtimeout)
 282                 outgoing->timeout = maxtimeout;
 283
 284         timeout_set(&outgoing->ev, retry_outgoing_handler, outgoing);
 285         event_add(&outgoing->ev, &(struct timeval){outgoing->timeout, 0});
 286
 287         logger(DEBUG_CONNECTIONS, LOG_NOTICE,
 288                            "Trying to re-establish outgoing connection in %d seconds",
 289                            outgoing->timeout);
 290 }
 291
 292 void finish_connecting(connection_t *c) {
 293         logger(DEBUG_CONNECTIONS, LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
 294
 295         if(proxytype != PROXY_EXEC)
 296                 configure_tcp(c);
 297
 298         c->last_ping_time = time(NULL);
 299         c->status.connecting = false;
 300
 301         send_id(c);
 302 }
 303
 304 static void do_outgoing_pipe(connection_t *c, char *command) {
 305 #ifndef HAVE_MINGW
 306         int fd[2];
 307
 308         if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
 309                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not create socketpair: %s", strerror(errno));
 310                 return;
 311         }
 312
 313         if(fork()) {
 314                 c->socket = fd[0];
 315                 close(fd[1]);
 316                 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Using proxy %s", command);
 317                 return;
 318         }
 319
 320         close(0);
 321         close(1);
 322         close(fd[0]);
 323         dup2(fd[1], 0);
 324         dup2(fd[1], 1);
 325         close(fd[1]);
 326
 327         // Other filedescriptors should be closed automatically by CLOEXEC
 328
 329         char *host = NULL;
 330         char *port = NULL;
 331
 332         sockaddr2str(&c->address, &host, &port);
 333         setenv("REMOTEADDRESS", host, true);
 334         setenv("REMOTEPORT", port, true);
 335         setenv("NODE", c->name, true);
 336         setenv("NAME", myself->name, true);
 337         if(netname)
 338                 setenv("NETNAME", netname, true);
 339
 340         int result = system(command);
 341         if(result < 0)
 342                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not execute %s: %s", command, strerror(errno));
 343         else if(result)
 344                 logger(DEBUG_ALWAYS, LOG_ERR, "%s exited with non-zero status %d", command, result);
 345         exit(result);
 346 #else
 347         logger(DEBUG_ALWAYS, LOG_ERR, "Proxy type exec not supported on this platform!");
 348         return;
 349 #endif
 350 }
 351
 352 bool do_outgoing_connection(connection_t *c) {
 353         char *address, *port, *space;
 354         struct addrinfo *proxyai = NULL;
 355         int result;
 356
 357         if(!c->outgoing) {
 358                 logger(DEBUG_ALWAYS, LOG_ERR, "do_outgoing_connection() for %s called without c->outgoing", c->name);
 359                 abort();
 360         }
 361
 362 begin:
 363         if(!c->outgoing->ai) {
 364                 if(!c->outgoing->cfg) {
 365                         logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not set up a meta connection to %s",
 366                                            c->name);
 367                         retry_outgoing(c->outgoing);
 368                         c->outgoing = NULL;
 369                         connection_del(c);
 370                         return false;
 371                 }
 372
 373                 get_config_string(c->outgoing->cfg, &address);
 374
 375                 space = strchr(address, ' ');
 376                 if(space) {
 377                         port = xstrdup(space + 1);
 378                         *space = 0;
 379                 } else {
 380                         if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
 381                                 port = xstrdup("655");
 382                 }
 383
 384                 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 385                 free(address);
 386                 free(port);
 387
 388                 c->outgoing->aip = c->outgoing->ai;
 389                 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
 390         }
 391
 392         if(!c->outgoing->aip) {
 393                 if(c->outgoing->ai)
 394                         freeaddrinfo(c->outgoing->ai);
 395                 c->outgoing->ai = NULL;
 396                 goto begin;
 397         }
 398
 399         memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
 400         c->outgoing->aip = c->outgoing->aip->ai_next;
 401
 402         if(c->hostname)
 403                 free(c->hostname);
 404
 405         c->hostname = sockaddr2hostname(&c->address);
 406
 407         logger(DEBUG_CONNECTIONS, LOG_INFO, "Trying to connect to %s (%s)", c->name,
 408                            c->hostname);
 409
 410         if(!proxytype) {
 411                 c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 412                 configure_tcp(c);
 413         } else if(proxytype == PROXY_EXEC) {
 414                 do_outgoing_pipe(c, proxyhost);
 415         } else {
 416                 proxyai = str2addrinfo(proxyhost, proxyport, SOCK_STREAM);
 417                 if(!proxyai)
 418                         goto begin;
 419                 logger(DEBUG_CONNECTIONS, LOG_INFO, "Using proxy at %s port %s", proxyhost, proxyport);
 420                 c->socket = socket(proxyai->ai_family, SOCK_STREAM, IPPROTO_TCP);
 421         }
 422
 423         if(c->socket == -1) {
 424                 logger(DEBUG_CONNECTIONS, LOG_ERR, "Creating socket for %s failed: %s", c->hostname, sockstrerror(sockerrno));
 425                 goto begin;
 426         }
 427
 428 #ifdef FD_CLOEXEC
 429         fcntl(c->socket, F_SETFD, FD_CLOEXEC);
 430 #endif
 431
 432         if(proxytype != PROXY_EXEC) {
 433 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 434                 int option = 1;
 435                 if(c->address.sa.sa_family == AF_INET6)
 436                         setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
 437 #endif
 438
 439                 bind_to_interface(c->socket);
 440         }
 441
 442         /* Connect */
 443
 444         if(!proxytype) {
 445                 result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 446         } else if(proxytype == PROXY_EXEC) {
 447                 result = 0;
 448         } else {
 449                 result = connect(c->socket, proxyai->ai_addr, proxyai->ai_addrlen);
 450                 freeaddrinfo(proxyai);
 451         }
 452
 453         if(result == -1) {
 454                 if(sockinprogress(sockerrno)) {
 455                         c->status.connecting = true;
 456                         return true;
 457                 }
 458
 459                 closesocket(c->socket);
 460
 461                 logger(DEBUG_CONNECTIONS, LOG_ERR, "%s: %s", c->hostname, sockstrerror(sockerrno));
 462
 463                 goto begin;
 464         }
 465
 466         finish_connecting(c);
 467
 468         return true;
 469 }
 470
 471 static void handle_meta_write(int sock, short events, void *data) {
 472         connection_t *c = data;
 473
 474         ssize_t outlen = send(c->socket, c->outbuf.data + c->outbuf.offset, c->outbuf.len - c->outbuf.offset, 0);
 475         if(outlen <= 0) {
 476                 if(!errno || errno == EPIPE) {
 477                         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection closed by %s (%s)", c->name, c->hostname);
 478                 } else if(sockwouldblock(sockerrno)) {
 479                         logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Sending %d bytes to %s (%s) would block", c->outbuf.len - c->outbuf.offset, c->name, c->hostname);
 480                         return;
 481                 } else {
 482                         logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not send %d bytes of data to %s (%s): %s", c->outbuf.len - c->outbuf.offset, c->name, c->hostname, strerror(errno));
 483                 }
 484
 485                 terminate_connection(c, c->status.active);
 486                 return;
 487         }
 488
 489         buffer_read(&c->outbuf, outlen);
 490         if(!c->outbuf.len && event_initialized(&c->outevent))
 491                 event_del(&c->outevent);
 492 }
 493
 494 void setup_outgoing_connection(outgoing_t *outgoing) {
 495         connection_t *c;
 496         node_t *n;
 497
 498         if(event_initialized(&outgoing->ev))
 499                 event_del(&outgoing->ev);
 500
 501         n = lookup_node(outgoing->name);
 502
 503         if(n)
 504                 if(n->connection) {
 505                         logger(DEBUG_CONNECTIONS, LOG_INFO, "Already connected to %s", outgoing->name);
 506
 507                         n->connection->outgoing = outgoing;
 508                         return;
 509                 }
 510
 511         c = new_connection();
 512         c->name = xstrdup(outgoing->name);
 513         c->outcipher = myself->connection->outcipher;
 514         c->outdigest = myself->connection->outdigest;
 515         c->outmaclength = myself->connection->outmaclength;
 516         c->outcompression = myself->connection->outcompression;
 517
 518         init_configuration(&c->config_tree);
 519         read_connection_config(c);
 520
 521         outgoing->cfg = lookup_config(c->config_tree, "Address");
 522
 523         if(!outgoing->cfg) {
 524                 logger(DEBUG_ALWAYS, LOG_ERR, "No address specified for %s", c->name);
 525                 free_connection(c);
 526                 return;
 527         }
 528
 529         c->outgoing = outgoing;
 530         c->last_ping_time = time(NULL);
 531
 532         connection_add(c);
 533
 534         if (do_outgoing_connection(c)) {
 535                 event_set(&c->inevent, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c);
 536                 event_set(&c->outevent, c->socket, EV_WRITE | EV_PERSIST, handle_meta_write, c);
 537                 event_add(&c->inevent, NULL);
 538         }
 539 }
 540
 541 /*
 542   accept a new tcp connect and create a
 543   new connection
 544 */
 545 void handle_new_meta_connection(int sock, short events, void *data) {
 546         connection_t *c;
 547         sockaddr_t sa;
 548         int fd;
 549         socklen_t len = sizeof sa;
 550
 551         fd = accept(sock, &sa.sa, &len);
 552
 553         if(fd < 0) {
 554                 logger(DEBUG_ALWAYS, LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
 555                 return;
 556         }
 557
 558         sockaddrunmap(&sa);
 559
 560         c = new_connection();
 561         c->name = xstrdup("<unknown>");
 562         c->outcipher = myself->connection->outcipher;
 563         c->outdigest = myself->connection->outdigest;
 564         c->outmaclength = myself->connection->outmaclength;
 565         c->outcompression = myself->connection->outcompression;
 566
 567         c->address = sa;
 568         c->hostname = sockaddr2hostname(&sa);
 569         c->socket = fd;
 570         c->last_ping_time = time(NULL);
 571
 572         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection from %s", c->hostname);
 573
 574         event_set(&c->inevent, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c);
 575         event_set(&c->outevent, c->socket, EV_WRITE | EV_PERSIST, handle_meta_write, c);
 576         event_add(&c->inevent, NULL);
 577
 578         configure_tcp(c);
 579
 580         connection_add(c);
 581
 582         c->allow_request = ID;
 583         send_id(c);
 584 }
 585
 586 static void free_outgoing(outgoing_t *outgoing) {
 587         if(event_initialized(&outgoing->ev))
 588                 event_del(&outgoing->ev);
 589
 590         if(outgoing->ai)
 591                 freeaddrinfo(outgoing->ai);
 592
 593         if(outgoing->name)
 594                 free(outgoing->name);
 595
 596         free(outgoing);
 597 }
 598
 599 void try_outgoing_connections(void) {
 600         static config_t *cfg = NULL;
 601         char *name;
 602         outgoing_t *outgoing;
 603
 604         /* If there is no outgoing list yet, create one. Otherwise, mark all outgoings as deleted. */
 605
 606         if(!outgoing_list) {
 607                 outgoing_list = list_alloc((list_action_t)free_outgoing);
 608         } else {
 609                 for(list_node_t *i = outgoing_list->head; i; i = i->next) {
 610                         outgoing = i->data;
 611                         outgoing->timeout = -1;
 612                 }
 613         }
 614
 615         /* Make sure there is one outgoing_t in the list for each ConnectTo. */
 616
 617         for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 618                 get_config_string(cfg, &name);
 619
 620                 if(!check_id(name)) {
 621                         logger(DEBUG_ALWAYS, LOG_ERR,
 622                                    "Invalid name for outgoing connection in %s line %d",
 623                                    cfg->file, cfg->line);
 624                         free(name);
 625                         continue;
 626                 }
 627
 628                 bool found = false;
 629
 630                 for(list_node_t *i = outgoing_list->head; i; i = i->next) {
 631                         outgoing = i->data;
 632                         if(!strcmp(outgoing->name, name)) {
 633                                 found = true;
 634                                 outgoing->timeout = 0;
 635                                 break;
 636                         }
 637                 }
 638
 639                 if(!found) {
 640                         outgoing = xmalloc_and_zero(sizeof *outgoing);
 641                         outgoing->name = name;
 642                         list_insert_tail(outgoing_list, outgoing);
 643                         setup_outgoing_connection(outgoing);
 644                 }
 645         }
 646
 647         /* Terminate any connections whose outgoing_t is to be deleted. */
 648
 649         for(splay_node_t *n = connection_tree->head, *next; n; n = next) {
 650                 next = n->next;
 651                 connection_t *c = n->data;
 652                 if(c->outgoing && c->outgoing->timeout == -1) {
 653                         c->outgoing = NULL;
 654                         terminate_connection(c, c->status.active);
 655                 }
 656         }
 657
 658         /* Delete outgoing_ts for which there is no ConnectTo. */
 659
 660         for(list_node_t *i = outgoing_list->head, *next; i; i = next) {
 661                 next = i->next;
 662                 outgoing = i->data;
 663                 if(outgoing->timeout == -1)
 664                         list_delete_node(outgoing_list, i);
 665         }
 666 }