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

   1 /*
   2     net_socket.c -- Handle various kinds of sockets.
   3     Copyright (C) 2014 Guus Sliepen <guus@meshlink.io>
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License along
  16     with this program; if not, write to the Free Software Foundation, Inc.,
  17     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #include "system.h"
  21
  22 #include "conf.h"
  23 #include "connection.h"
  24 #include "list.h"
  25 #include "logger.h"
  26 #include "meshlink_internal.h"
  27 #include "meta.h"
  28 #include "net.h"
  29 #include "netutl.h"
  30 #include "protocol.h"
  31 #include "utils.h"
  32 #include "xalloc.h"
  33
  34 /* Needed on Mac OS/X */
  35 #ifndef SOL_TCP
  36 #define SOL_TCP IPPROTO_TCP
  37 #endif
  38
  39 int addressfamily = AF_UNSPEC;
  40 int maxtimeout = 900;
  41 int seconds_till_retry = 5;
  42 int max_connection_burst = 100;
  43
  44 listen_socket_t listen_socket[MAXSOCKETS];
  45 int listen_sockets;
  46 list_t *outgoing_list = NULL;
  47
  48 /* Setup sockets */
  49
  50 static void configure_tcp(connection_t *c) {
  51         int option;
  52
  53 #ifdef O_NONBLOCK
  54         int flags = fcntl(c->socket, F_GETFL);
  55
  56         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
  57                 logger(DEBUG_ALWAYS, LOG_ERR, "fcntl for %s: %s", c->hostname, strerror(errno));
  58         }
  59 #elif defined(WIN32)
  60         unsigned long arg = 1;
  61
  62         if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
  63                 logger(DEBUG_ALWAYS, LOG_ERR, "ioctlsocket for %s: %s", c->hostname, sockstrerror(sockerrno));
  64         }
  65 #endif
  66
  67 #if defined(SOL_TCP) && defined(TCP_NODELAY)
  68         option = 1;
  69         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, (void *)&option, sizeof option);
  70 #endif
  71
  72 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
  73         option = IPTOS_LOWDELAY;
  74         setsockopt(c->socket, SOL_IP, IP_TOS, (void *)&option, sizeof option);
  75 #endif
  76 }
  77
  78 static bool bind_to_address(connection_t *c) {
  79         int s = -1;
  80
  81         for(int i = 0; i < listen_sockets && listen_socket[i].bindto; i++) {
  82                 if(listen_socket[i].sa.sa.sa_family != c->address.sa.sa_family)
  83                         continue;
  84                 if(s >= 0)
  85                         return false;
  86                 s = i;
  87         }
  88
  89         if(s < 0)
  90                 return false;
  91
  92         sockaddr_t sa = listen_socket[s].sa;
  93         if(sa.sa.sa_family == AF_INET)
  94                 sa.in.sin_port = 0;
  95         else if(sa.sa.sa_family == AF_INET6)
  96                 sa.in6.sin6_port = 0;
  97
  98         if(bind(c->socket, &sa.sa, SALEN(sa.sa))) {
  99                 logger(DEBUG_CONNECTIONS, LOG_WARNING, "Can't bind outgoing socket: %s", strerror(errno));
 100                 return false;
 101         }
 102
 103         return true;
 104 }
 105
 106 int setup_listen_socket(const sockaddr_t *sa) {
 107         int nfd;
 108         char *addrstr;
 109         int option;
 110         char *iface;
 111
 112         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 113
 114         if(nfd < 0) {
 115                 logger(DEBUG_STATUS, LOG_ERR, "Creating metasocket failed: %s", sockstrerror(sockerrno));
 116                 return -1;
 117         }
 118
 119 #ifdef FD_CLOEXEC
 120         fcntl(nfd, F_SETFD, FD_CLOEXEC);
 121 #endif
 122
 123         /* Optimize TCP settings */
 124
 125         option = 1;
 126         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof option);
 127
 128 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 129         if(sa->sa.sa_family == AF_INET6)
 130                 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
 131 #endif
 132
 133         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 134                 closesocket(nfd);
 135                 addrstr = sockaddr2hostname(sa);
 136                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/tcp: %s", addrstr, sockstrerror(sockerrno));
 137                 free(addrstr);
 138                 return -1;
 139         }
 140
 141         if(listen(nfd, 3)) {
 142                 closesocket(nfd);
 143                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "listen", sockstrerror(sockerrno));
 144                 return -1;
 145         }
 146
 147         return nfd;
 148 }
 149
 150 int setup_vpn_in_socket(const sockaddr_t *sa) {
 151         int nfd;
 152         char *addrstr;
 153         int option;
 154
 155         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 156
 157         if(nfd < 0) {
 158                 logger(DEBUG_ALWAYS, LOG_ERR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
 159                 return -1;
 160         }
 161
 162 #ifdef FD_CLOEXEC
 163         fcntl(nfd, F_SETFD, FD_CLOEXEC);
 164 #endif
 165
 166 #ifdef O_NONBLOCK
 167         {
 168                 int flags = fcntl(nfd, F_GETFL);
 169
 170                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 171                         closesocket(nfd);
 172                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "fcntl",
 173                                    strerror(errno));
 174                         return -1;
 175                 }
 176         }
 177 #elif defined(WIN32)
 178         {
 179                 unsigned long arg = 1;
 180                 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 181                         closesocket(nfd);
 182                         logger(DEBUG_ALWAYS, LOG_ERR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
 183                         return -1;
 184                 }
 185         }
 186 #endif
 187
 188         option = 1;
 189         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof option);
 190         setsockopt(nfd, SOL_SOCKET, SO_BROADCAST, (void *)&option, sizeof option);
 191
 192 #if defined(IPPROTO_IPV6) && defined(IPV6_V6ONLY)
 193         if(sa->sa.sa_family == AF_INET6)
 194                 setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
 195 #endif
 196
 197 #if defined(IP_DONTFRAG) && !defined(IP_DONTFRAGMENT)
 198 #define IP_DONTFRAGMENT IP_DONTFRAG
 199 #endif
 200
 201 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 202         if(mesh->self->options & OPTION_PMTU_DISCOVERY) {
 203                 option = IP_PMTUDISC_DO;
 204                 setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
 205         }
 206 #elif defined(IPPROTO_IP) && defined(IP_DONTFRAGMENT)
 207         if(mesh->self->options & OPTION_PMTU_DISCOVERY) {
 208                 option = 1;
 209                 setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, (void *)&option, sizeof(option));
 210         }
 211 #else
 212 #warning No way to disable IPv4 fragmentation
 213 #endif
 214
 215 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 216         if(mesh->self->options & OPTION_PMTU_DISCOVERY) {
 217                 option = IPV6_PMTUDISC_DO;
 218                 setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
 219         }
 220 #elif defined(IPPROTO_IPV6) && defined(IPV6_DONTFRAG)
 221         if(mesh->self->options & OPTION_PMTU_DISCOVERY) {
 222                 option = 1;
 223                 setsockopt(nfd, IPPROTO_IPV6, IPV6_DONTFRAG, (void *)&option, sizeof(option));
 224         }
 225 #else
 226 #warning No way to disable IPv6 fragmentation
 227 #endif
 228
 229         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 230                 closesocket(nfd);
 231                 addrstr = sockaddr2hostname(sa);
 232                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/udp: %s", addrstr, sockstrerror(sockerrno));
 233                 free(addrstr);
 234                 return -1;
 235         }
 236
 237         return nfd;
 238 } /* int setup_vpn_in_socket */
 239
 240 static void retry_outgoing_handler(void *data) {
 241         setup_outgoing_connection(data);
 242 }
 243
 244 void retry_outgoing(outgoing_t *outgoing) {
 245         outgoing->timeout += 5;
 246
 247         if(outgoing->timeout > maxtimeout)
 248                 outgoing->timeout = maxtimeout;
 249
 250         timeout_add(&outgoing->ev, retry_outgoing_handler, outgoing, &(struct timeval){outgoing->timeout, rand() % 100000});
 251
 252         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Trying to re-establish outgoing connection in %d seconds", outgoing->timeout);
 253 }
 254
 255 void finish_connecting(connection_t *c) {
 256         logger(DEBUG_CONNECTIONS, LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
 257
 258         c->last_ping_time = now.tv_sec;
 259         c->status.connecting = false;
 260
 261         send_id(c);
 262 }
 263
 264 static void do_outgoing_pipe(connection_t *c, char *command) {
 265 #ifndef HAVE_MINGW
 266         int fd[2];
 267
 268         if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
 269                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not create socketpair: %s", strerror(errno));
 270                 return;
 271         }
 272
 273         if(fork()) {
 274                 c->socket = fd[0];
 275                 close(fd[1]);
 276                 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Using proxy %s", command);
 277                 return;
 278         }
 279
 280         close(0);
 281         close(1);
 282         close(fd[0]);
 283         dup2(fd[1], 0);
 284         dup2(fd[1], 1);
 285         close(fd[1]);
 286
 287         // Other filedescriptors should be closed automatically by CLOEXEC
 288
 289         char *host = NULL;
 290         char *port = NULL;
 291
 292         sockaddr2str(&c->address, &host, &port);
 293         setenv("REMOTEADDRESS", host, true);
 294         setenv("REMOTEPORT", port, true);
 295         setenv("NODE", c->name, true);
 296         setenv("NAME", mesh->self->name, true);
 297
 298         int result = system(command);
 299         if(result < 0)
 300                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not execute %s: %s", command, strerror(errno));
 301         else if(result)
 302                 logger(DEBUG_ALWAYS, LOG_ERR, "%s exited with non-zero status %d", command, result);
 303         exit(result);
 304 #else
 305         logger(DEBUG_ALWAYS, LOG_ERR, "Proxy type exec not supported on this platform!");
 306         return;
 307 #endif
 308 }
 309
 310 static void handle_meta_write(connection_t *c) {
 311         if(c->outbuf.len <= c->outbuf.offset)
 312                 return;
 313
 314         ssize_t outlen = send(c->socket, c->outbuf.data + c->outbuf.offset, c->outbuf.len - c->outbuf.offset, 0);
 315         if(outlen <= 0) {
 316                 if(!errno || errno == EPIPE) {
 317                         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection closed by %s (%s)", c->name, c->hostname);
 318                 } else if(sockwouldblock(sockerrno)) {
 319                         logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Sending %d bytes to %s (%s) would block", c->outbuf.len - c->outbuf.offset, c->name, c->hostname);
 320                         return;
 321                 } else {
 322                         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));
 323                 }
 324
 325                 terminate_connection(c, c->status.active);
 326                 return;
 327         }
 328
 329         buffer_read(&c->outbuf, outlen);
 330         if(!c->outbuf.len)
 331                 io_set(&c->io, IO_READ);
 332 }
 333
 334 static void handle_meta_io(void *data, int flags) {
 335         connection_t *c = data;
 336
 337         if(c->status.connecting) {
 338                 c->status.connecting = false;
 339
 340                 int result;
 341                 socklen_t len = sizeof result;
 342                 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, (void *)&result, &len);
 343
 344                 if(!result)
 345                         finish_connecting(c);
 346                 else {
 347                         logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Error while connecting to %s (%s): %s", c->name, c->hostname, sockstrerror(result));
 348                         terminate_connection(c, false);
 349                         return;
 350                 }
 351         }
 352
 353         if(flags & IO_WRITE)
 354                 handle_meta_write(c);
 355         else
 356                 handle_meta_connection_data(c);
 357 }
 358
 359 bool do_outgoing_connection(outgoing_t *outgoing) {
 360         char *address, *port, *space;
 361         struct addrinfo *proxyai = NULL;
 362         int result;
 363
 364 begin:
 365         if(!outgoing->ai) {
 366                 if(!outgoing->cfg) {
 367                         logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not set up a meta connection to %s", outgoing->name);
 368                         retry_outgoing(outgoing);
 369                         return false;
 370                 }
 371
 372                 get_config_string(outgoing->cfg, &address);
 373
 374                 space = strchr(address, ' ');
 375                 if(space) {
 376                         port = xstrdup(space + 1);
 377                         *space = 0;
 378                 } else {
 379                         // TODO: Only allow Address statements?
 380                         if(!get_config_string(lookup_config(outgoing->config_tree, "Port"), &port))
 381                                 port = xstrdup("655");
 382                 }
 383
 384                 outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 385                 free(address);
 386                 free(port);
 387
 388                 outgoing->aip = outgoing->ai;
 389                 outgoing->cfg = lookup_config_next(outgoing->config_tree, outgoing->cfg);
 390         }
 391
 392         if(!outgoing->aip) {
 393                 if(outgoing->ai)
 394                         freeaddrinfo(outgoing->ai);
 395                 outgoing->ai = NULL;
 396                 goto begin;
 397         }
 398
 399         connection_t *c = new_connection();
 400         c->outgoing = outgoing;
 401
 402         memcpy(&c->address, outgoing->aip->ai_addr, outgoing->aip->ai_addrlen);
 403         outgoing->aip = outgoing->aip->ai_next;
 404
 405         c->hostname = sockaddr2hostname(&c->address);
 406
 407         logger(DEBUG_CONNECTIONS, LOG_INFO, "Trying to connect to %s (%s)", outgoing->name, c->hostname);
 408
 409         if(!proxytype) {
 410                 c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 411                 configure_tcp(c);
 412         } else if(proxytype == PROXY_EXEC) {
 413                 do_outgoing_pipe(c, proxyhost);
 414         } else {
 415                 proxyai = str2addrinfo(proxyhost, proxyport, SOCK_STREAM);
 416                 if(!proxyai) {
 417                         free_connection(c);
 418                         goto begin;
 419                 }
 420                 logger(DEBUG_CONNECTIONS, LOG_INFO, "Using proxy at %s port %s", proxyhost, proxyport);
 421                 c->socket = socket(proxyai->ai_family, SOCK_STREAM, IPPROTO_TCP);
 422                 configure_tcp(c);
 423         }
 424
 425         if(c->socket == -1) {
 426                 logger(DEBUG_CONNECTIONS, LOG_ERR, "Creating socket for %s failed: %s", c->hostname, sockstrerror(sockerrno));
 427                 free_connection(c);
 428                 goto begin;
 429         }
 430
 431 #ifdef FD_CLOEXEC
 432         fcntl(c->socket, F_SETFD, FD_CLOEXEC);
 433 #endif
 434
 435         if(proxytype != PROXY_EXEC) {
 436 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 437                 int option = 1;
 438                 if(c->address.sa.sa_family == AF_INET6)
 439                         setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
 440 #endif
 441
 442                 bind_to_address(c);
 443         }
 444
 445         /* Connect */
 446
 447         if(!proxytype) {
 448                 result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 449         } else if(proxytype == PROXY_EXEC) {
 450                 result = 0;
 451         } else {
 452                 result = connect(c->socket, proxyai->ai_addr, proxyai->ai_addrlen);
 453                 freeaddrinfo(proxyai);
 454         }
 455
 456         if(result == -1 && !sockinprogress(sockerrno)) {
 457                 logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not connect to %s (%s): %s", outgoing->name, c->hostname, sockstrerror(sockerrno));
 458                 free_connection(c);
 459
 460                 goto begin;
 461         }
 462
 463         /* Now that there is a working socket, fill in the rest and register this connection. */
 464
 465         c->status.connecting = true;
 466         c->name = xstrdup(outgoing->name);
 467         c->outcompression = mesh->self->connection->outcompression;
 468         c->last_ping_time = now.tv_sec;
 469
 470         connection_add(c);
 471
 472         io_add(&c->io, handle_meta_io, c, c->socket, IO_READ|IO_WRITE);
 473
 474         return true;
 475 }
 476
 477 // Find edges pointing to this node, and use them to build a list of unique, known addresses.
 478 static struct addrinfo *get_known_addresses(node_t *n) {
 479         struct addrinfo *ai = NULL;
 480
 481         for splay_each(edge_t, e, n->edge_tree) {
 482                 if(!e->reverse)
 483                         continue;
 484
 485                 bool found = false;
 486                 for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
 487                         if(!sockaddrcmp(&e->reverse->address, (sockaddr_t *)aip->ai_addr)) {
 488                                 found = true;
 489                                 break;
 490                         }
 491                 }
 492                 if(found)
 493                         continue;
 494
 495                 struct addrinfo *nai = xzalloc(sizeof *nai);
 496                 if(ai)
 497                         ai->ai_next = nai;
 498                 ai = nai;
 499                 ai->ai_family = e->reverse->address.sa.sa_family;
 500                 ai->ai_socktype = SOCK_STREAM;
 501                 ai->ai_protocol = IPPROTO_TCP;
 502                 ai->ai_addrlen = SALEN(e->reverse->address.sa);
 503                 ai->ai_addr = xmalloc(ai->ai_addrlen);
 504                 memcpy(ai->ai_addr, &e->reverse->address, ai->ai_addrlen);
 505         }
 506
 507         return ai;
 508 }
 509
 510 void setup_outgoing_connection(outgoing_t *outgoing) {
 511         timeout_del(&outgoing->ev);
 512
 513         node_t *n = lookup_node(outgoing->name);
 514
 515         if(n && n->connection) {
 516                 logger(DEBUG_CONNECTIONS, LOG_INFO, "Already connected to %s", outgoing->name);
 517
 518                 n->connection->outgoing = outgoing;
 519                 return;
 520         }
 521
 522         init_configuration(&outgoing->config_tree);
 523         read_host_config(outgoing->config_tree, outgoing->name);
 524         outgoing->cfg = lookup_config(outgoing->config_tree, "Address");
 525
 526         if(!outgoing->cfg) {
 527                 if(n)
 528                         outgoing->aip = outgoing->ai = get_known_addresses(n);
 529                 if(!outgoing->ai) {
 530                         logger(DEBUG_ALWAYS, LOG_ERR, "No address known for %s", outgoing->name);
 531                         return;
 532                 }
 533         }
 534
 535         do_outgoing_connection(outgoing);
 536 }
 537
 538 /*
 539   accept a new tcp connect and create a
 540   new connection
 541 */
 542 void handle_new_meta_connection(void *data, int flags) {
 543         listen_socket_t *l = data;
 544         connection_t *c;
 545         sockaddr_t sa;
 546         int fd;
 547         socklen_t len = sizeof sa;
 548
 549         fd = accept(l->tcp.fd, &sa.sa, &len);
 550
 551         if(fd < 0) {
 552                 logger(DEBUG_ALWAYS, LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
 553                 return;
 554         }
 555
 556         sockaddrunmap(&sa);
 557
 558         // Check if we get many connections from the same host
 559
 560         static sockaddr_t prev_sa;
 561         static int tarpit = -1;
 562
 563         if(tarpit >= 0) {
 564                 closesocket(tarpit);
 565                 tarpit = -1;
 566         }
 567
 568         if(!sockaddrcmp_noport(&sa, &prev_sa)) {
 569                 static int samehost_burst;
 570                 static int samehost_burst_time;
 571
 572                 if(now.tv_sec - samehost_burst_time > samehost_burst)
 573                         samehost_burst = 0;
 574                 else
 575                         samehost_burst -= now.tv_sec - samehost_burst_time;
 576
 577                 samehost_burst_time = now.tv_sec;
 578                 samehost_burst++;
 579
 580                 if(samehost_burst > max_connection_burst) {
 581                         tarpit = fd;
 582                         return;
 583                 }
 584         }
 585
 586         memcpy(&prev_sa, &sa, sizeof sa);
 587
 588         // Check if we get many connections from different hosts
 589
 590         static int connection_burst;
 591         static int connection_burst_time;
 592
 593         if(now.tv_sec - connection_burst_time > connection_burst)
 594                 connection_burst = 0;
 595         else
 596                 connection_burst -= now.tv_sec - connection_burst_time;
 597
 598         connection_burst_time = now.tv_sec;
 599         connection_burst++;
 600
 601         if(connection_burst >= max_connection_burst) {
 602                 connection_burst = max_connection_burst;
 603                 tarpit = fd;
 604                 return;
 605         }
 606
 607         // Accept the new connection
 608
 609         c = new_connection();
 610         c->name = xstrdup("<unknown>");
 611         c->outcompression = mesh->self->connection->outcompression;
 612
 613         c->address = sa;
 614         c->hostname = sockaddr2hostname(&sa);
 615         c->socket = fd;
 616         c->last_ping_time = now.tv_sec;
 617
 618         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection from %s", c->hostname);
 619
 620         io_add(&c->io, handle_meta_io, c, c->socket, IO_READ);
 621
 622         configure_tcp(c);
 623
 624         connection_add(c);
 625
 626         c->allow_request = ID;
 627         send_id(c);
 628 }
 629
 630 static void free_outgoing(outgoing_t *outgoing) {
 631         timeout_del(&outgoing->ev);
 632
 633         if(outgoing->ai)
 634                 freeaddrinfo(outgoing->ai);
 635
 636         if(outgoing->config_tree)
 637                 exit_configuration(&outgoing->config_tree);
 638
 639         if(outgoing->name)
 640                 free(outgoing->name);
 641
 642         free(outgoing);
 643 }
 644
 645 void try_outgoing_connections(void) {
 646         /* If there is no outgoing list yet, create one. Otherwise, mark all outgoings as deleted. */
 647
 648         if(!outgoing_list) {
 649                 outgoing_list = list_alloc((list_action_t)free_outgoing);
 650         } else {
 651                 for list_each(outgoing_t, outgoing, outgoing_list)
 652                         outgoing->timeout = -1;
 653         }
 654
 655         /* Make sure there is one outgoing_t in the list for each ConnectTo. */
 656
 657         // TODO: Drop support for ConnectTo since AutoConnect is now always on?
 658         for(config_t *cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 659                 char *name;
 660                 get_config_string(cfg, &name);
 661
 662                 if(!check_id(name)) {
 663                         logger(DEBUG_ALWAYS, LOG_ERR,
 664                                    "Invalid name for outgoing connection in %s line %d",
 665                                    cfg->file, cfg->line);
 666                         free(name);
 667                         continue;
 668                 }
 669
 670                 bool found = false;
 671
 672                 for list_each(outgoing_t, outgoing, outgoing_list) {
 673                         if(!strcmp(outgoing->name, name)) {
 674                                 found = true;
 675                                 outgoing->timeout = 0;
 676                                 break;
 677                         }
 678                 }
 679
 680                 if(!found) {
 681                         outgoing_t *outgoing = xzalloc(sizeof *outgoing);
 682                         outgoing->name = name;
 683                         list_insert_tail(outgoing_list, outgoing);
 684                         setup_outgoing_connection(outgoing);
 685                 }
 686         }
 687
 688         /* Terminate any connections whose outgoing_t is to be deleted. */
 689
 690         for list_each(connection_t, c, mesh->connections) {
 691                 if(c->outgoing && c->outgoing->timeout == -1) {
 692                         c->outgoing = NULL;
 693                         logger(DEBUG_CONNECTIONS, LOG_INFO, "No more outgoing connection to %s", c->name);
 694                         terminate_connection(c, c->status.active);
 695                 }
 696         }
 697
 698         /* Delete outgoing_ts for which there is no ConnectTo. */
 699
 700         for list_each(outgoing_t, outgoing, outgoing_list)
 701                 if(outgoing->timeout == -1)
 702                         list_delete_node(outgoing_list, node);
 703 }