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 seconds_till_retry = 5;
  41 int max_connection_burst = 100;
  42
  43 /* Setup sockets */
  44
  45 static void configure_tcp(connection_t *c) {
  46 #ifdef O_NONBLOCK
  47         int flags = fcntl(c->socket, F_GETFL);
  48
  49         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
  50                 logger(DEBUG_ALWAYS, LOG_ERR, "fcntl for %s: %s", c->hostname, strerror(errno));
  51         }
  52 #elif defined(WIN32)
  53         unsigned long arg = 1;
  54
  55         if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
  56                 logger(DEBUG_ALWAYS, LOG_ERR, "ioctlsocket for %s: %s", c->hostname, sockstrerror(sockerrno));
  57         }
  58 #endif
  59
  60 #if defined(SOL_TCP) && defined(TCP_NODELAY)
  61         int nodelay = 1;
  62         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, (void *)&nodelay, sizeof nodelay);
  63 #endif
  64
  65 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
  66         int lowdelay = IPTOS_LOWDELAY;
  67         setsockopt(c->socket, SOL_IP, IP_TOS, (void *)&lowdelay, sizeof lowdelay);
  68 #endif
  69 }
  70
  71 static bool bind_to_address(meshlink_handle_t *mesh, connection_t *c) {
  72         int s = -1;
  73
  74         for(int i = 0; i < mesh->listen_sockets && mesh->listen_socket[i].bindto; i++) {
  75                 if(mesh->listen_socket[i].sa.sa.sa_family != c->address.sa.sa_family)
  76                         continue;
  77                 if(s >= 0)
  78                         return false;
  79                 s = i;
  80         }
  81
  82         if(s < 0)
  83                 return false;
  84
  85         sockaddr_t sa = mesh->listen_socket[s].sa;
  86         if(sa.sa.sa_family == AF_INET)
  87                 sa.in.sin_port = 0;
  88         else if(sa.sa.sa_family == AF_INET6)
  89                 sa.in6.sin6_port = 0;
  90
  91         if(bind(c->socket, &sa.sa, SALEN(sa.sa))) {
  92                 logger(DEBUG_CONNECTIONS, LOG_WARNING, "Can't bind outgoing socket: %s", strerror(errno));
  93                 return false;
  94         }
  95
  96         return true;
  97 }
  98
  99 int setup_listen_socket(const sockaddr_t *sa) {
 100         int nfd;
 101         char *addrstr;
 102         int option;
 103
 104         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 105
 106         if(nfd < 0) {
 107                 logger(DEBUG_STATUS, LOG_ERR, "Creating metasocket failed: %s", sockstrerror(sockerrno));
 108                 return -1;
 109         }
 110
 111 #ifdef FD_CLOEXEC
 112         fcntl(nfd, F_SETFD, FD_CLOEXEC);
 113 #endif
 114
 115         /* Optimize TCP settings */
 116
 117         option = 1;
 118         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof option);
 119
 120 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 121         if(sa->sa.sa_family == AF_INET6)
 122                 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
 123 #endif
 124
 125         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 126                 closesocket(nfd);
 127                 addrstr = sockaddr2hostname(sa);
 128                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/tcp: %s", addrstr, sockstrerror(sockerrno));
 129                 free(addrstr);
 130                 return -1;
 131         }
 132
 133         if(listen(nfd, 3)) {
 134                 closesocket(nfd);
 135                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "listen", sockstrerror(sockerrno));
 136                 return -1;
 137         }
 138
 139         return nfd;
 140 }
 141
 142 int setup_vpn_in_socket(meshlink_handle_t *mesh, const sockaddr_t *sa) {
 143         int nfd;
 144         char *addrstr;
 145         int option;
 146
 147         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 148
 149         if(nfd < 0) {
 150                 logger(DEBUG_ALWAYS, LOG_ERR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
 151                 return -1;
 152         }
 153
 154 #ifdef FD_CLOEXEC
 155         fcntl(nfd, F_SETFD, FD_CLOEXEC);
 156 #endif
 157
 158 #ifdef O_NONBLOCK
 159         {
 160                 int flags = fcntl(nfd, F_GETFL);
 161
 162                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 163                         closesocket(nfd);
 164                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "fcntl",
 165                                    strerror(errno));
 166                         return -1;
 167                 }
 168         }
 169 #elif defined(WIN32)
 170         {
 171                 unsigned long arg = 1;
 172                 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 173                         closesocket(nfd);
 174                         logger(DEBUG_ALWAYS, LOG_ERR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
 175                         return -1;
 176                 }
 177         }
 178 #endif
 179
 180         option = 1;
 181         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof option);
 182         setsockopt(nfd, SOL_SOCKET, SO_BROADCAST, (void *)&option, sizeof option);
 183
 184 #if defined(IPPROTO_IPV6) && defined(IPV6_V6ONLY)
 185         if(sa->sa.sa_family == AF_INET6)
 186                 setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
 187 #endif
 188
 189 #if defined(IP_DONTFRAG) && !defined(IP_DONTFRAGMENT)
 190 #define IP_DONTFRAGMENT IP_DONTFRAG
 191 #endif
 192
 193 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 194         if(mesh->self->options & OPTION_PMTU_DISCOVERY) {
 195                 option = IP_PMTUDISC_DO;
 196                 setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
 197         }
 198 #elif defined(IPPROTO_IP) && defined(IP_DONTFRAGMENT)
 199         if(mesh->self->options & OPTION_PMTU_DISCOVERY) {
 200                 option = 1;
 201                 setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, (void *)&option, sizeof(option));
 202         }
 203 #else
 204 #warning No way to disable IPv4 fragmentation
 205 #endif
 206
 207 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 208         if(mesh->self->options & OPTION_PMTU_DISCOVERY) {
 209                 option = IPV6_PMTUDISC_DO;
 210                 setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
 211         }
 212 #elif defined(IPPROTO_IPV6) && defined(IPV6_DONTFRAG)
 213         if(mesh->self->options & OPTION_PMTU_DISCOVERY) {
 214                 option = 1;
 215                 setsockopt(nfd, IPPROTO_IPV6, IPV6_DONTFRAG, (void *)&option, sizeof(option));
 216         }
 217 #else
 218 #warning No way to disable IPv6 fragmentation
 219 #endif
 220
 221         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 222                 closesocket(nfd);
 223                 addrstr = sockaddr2hostname(sa);
 224                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/udp: %s", addrstr, sockstrerror(sockerrno));
 225                 free(addrstr);
 226                 return -1;
 227         }
 228
 229         return nfd;
 230 } /* int setup_vpn_in_socket */
 231
 232 static void retry_outgoing_handler(event_loop_t *loop, void *data) {
 233         meshlink_handle_t *mesh = loop->data;
 234         outgoing_t *outgoing = data;
 235         setup_outgoing_connection(mesh, outgoing);
 236 }
 237
 238 void retry_outgoing(meshlink_handle_t *mesh, outgoing_t *outgoing) {
 239         outgoing->timeout += 5;
 240
 241         if(outgoing->timeout > mesh->maxtimeout)
 242                 outgoing->timeout = mesh->maxtimeout;
 243
 244         timeout_add(&mesh->loop, &outgoing->ev, retry_outgoing_handler, outgoing, &(struct timeval){outgoing->timeout, rand() % 100000});
 245
 246         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Trying to re-establish outgoing connection in %d seconds", outgoing->timeout);
 247 }
 248
 249 void finish_connecting(meshlink_handle_t *mesh, connection_t *c) {
 250         logger(DEBUG_CONNECTIONS, LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
 251
 252         c->last_ping_time = mesh->loop.now.tv_sec;
 253         c->status.connecting = false;
 254
 255         send_id(mesh, c);
 256 }
 257
 258 static void do_outgoing_pipe(meshlink_handle_t *mesh, connection_t *c, char *command) {
 259 #ifndef HAVE_MINGW
 260         int fd[2];
 261
 262         if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
 263                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not create socketpair: %s", strerror(errno));
 264                 return;
 265         }
 266
 267         if(fork()) {
 268                 c->socket = fd[0];
 269                 close(fd[1]);
 270                 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Using proxy %s", command);
 271                 return;
 272         }
 273
 274         close(0);
 275         close(1);
 276         close(fd[0]);
 277         dup2(fd[1], 0);
 278         dup2(fd[1], 1);
 279         close(fd[1]);
 280
 281         // Other filedescriptors should be closed automatically by CLOEXEC
 282
 283         char *host = NULL;
 284         char *port = NULL;
 285
 286         sockaddr2str(&c->address, &host, &port);
 287         setenv("REMOTEADDRESS", host, true);
 288         setenv("REMOTEPORT", port, true);
 289         setenv("NODE", c->name, true);
 290         setenv("NAME", mesh->self->name, true);
 291
 292         int result = system(command);
 293         if(result < 0)
 294                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not execute %s: %s", command, strerror(errno));
 295         else if(result)
 296                 logger(DEBUG_ALWAYS, LOG_ERR, "%s exited with non-zero status %d", command, result);
 297         exit(result);
 298 #else
 299         logger(DEBUG_ALWAYS, LOG_ERR, "Proxy type exec not supported on this platform!");
 300         return;
 301 #endif
 302 }
 303
 304 static void handle_meta_write(meshlink_handle_t *mesh, connection_t *c) {
 305         if(c->outbuf.len <= c->outbuf.offset)
 306                 return;
 307
 308         ssize_t outlen = send(c->socket, c->outbuf.data + c->outbuf.offset, c->outbuf.len - c->outbuf.offset, MSG_NOSIGNAL);
 309         if(outlen <= 0) {
 310                 if(!errno || errno == EPIPE) {
 311                         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection closed by %s (%s)", c->name, c->hostname);
 312                 } else if(sockwouldblock(sockerrno)) {
 313                         logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Sending %d bytes to %s (%s) would block", c->outbuf.len - c->outbuf.offset, c->name, c->hostname);
 314                         return;
 315                 } else {
 316                         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));
 317                 }
 318
 319                 terminate_connection(mesh, c, c->status.active);
 320                 return;
 321         }
 322
 323         buffer_read(&c->outbuf, outlen);
 324         if(!c->outbuf.len)
 325                 io_set(&mesh->loop, &c->io, IO_READ);
 326 }
 327
 328 static void handle_meta_io(event_loop_t *loop, void *data, int flags) {
 329         meshlink_handle_t *mesh = loop->data;
 330         connection_t *c = data;
 331
 332         if(c->status.connecting) {
 333                 c->status.connecting = false;
 334
 335                 int result;
 336                 socklen_t len = sizeof result;
 337                 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, (void *)&result, &len);
 338
 339                 if(!result)
 340                         finish_connecting(mesh, c);
 341                 else {
 342                         logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Error while connecting to %s (%s): %s", c->name, c->hostname, sockstrerror(result));
 343                         terminate_connection(mesh, c, false);
 344                         return;
 345                 }
 346         }
 347
 348         if(flags & IO_WRITE)
 349                 handle_meta_write(mesh, c);
 350         else
 351                 handle_meta_connection_data(mesh, c);
 352 }
 353
 354 bool do_outgoing_connection(meshlink_handle_t *mesh, outgoing_t *outgoing) {
 355         char *address, *port, *space;
 356         struct addrinfo *proxyai = NULL;
 357         int result;
 358
 359 begin:
 360         if(!outgoing->ai) {
 361                 if(!outgoing->cfg) {
 362                         logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not set up a meta connection to %s", outgoing->name);
 363                         retry_outgoing(mesh, outgoing);
 364                         return false;
 365                 }
 366
 367                 get_config_string(outgoing->cfg, &address);
 368
 369                 space = strchr(address, ' ');
 370                 if(space) {
 371                         port = xstrdup(space + 1);
 372                         *space = 0;
 373                 } else {
 374                         // TODO: Only allow Address statements?
 375                         if(!get_config_string(lookup_config(outgoing->config_tree, "Port"), &port)) {
 376                                 logger(DEBUG_CONNECTIONS, LOG_ERR, "No Port known for %s", outgoing->name);
 377                                 retry_outgoing(mesh, outgoing);
 378                                 return false;
 379                         }
 380                 }
 381
 382                 outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 383                 free(address);
 384                 free(port);
 385
 386                 outgoing->aip = outgoing->ai;
 387                 outgoing->cfg = lookup_config_next(outgoing->config_tree, outgoing->cfg);
 388         }
 389
 390         if(!outgoing->aip) {
 391                 if(outgoing->ai)
 392                         freeaddrinfo(outgoing->ai);
 393                 outgoing->ai = NULL;
 394                 goto begin;
 395         }
 396
 397         connection_t *c = new_connection();
 398         c->outgoing = outgoing;
 399
 400         memcpy(&c->address, outgoing->aip->ai_addr, outgoing->aip->ai_addrlen);
 401         outgoing->aip = outgoing->aip->ai_next;
 402
 403         c->hostname = sockaddr2hostname(&c->address);
 404
 405         logger(DEBUG_CONNECTIONS, LOG_INFO, "Trying to connect to %s (%s)", outgoing->name, c->hostname);
 406
 407         if(!mesh->proxytype) {
 408                 c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 409                 configure_tcp(c);
 410         } else if(mesh->proxytype == PROXY_EXEC) {
 411                 do_outgoing_pipe(mesh, c, mesh->proxyhost);
 412         } else {
 413                 proxyai = str2addrinfo(mesh->proxyhost, mesh->proxyport, SOCK_STREAM);
 414                 if(!proxyai) {
 415                         free_connection(c);
 416                         goto begin;
 417                 }
 418                 logger(DEBUG_CONNECTIONS, LOG_INFO, "Using proxy at %s port %s", mesh->proxyhost, mesh->proxyport);
 419                 c->socket = socket(proxyai->ai_family, SOCK_STREAM, IPPROTO_TCP);
 420                 configure_tcp(c);
 421         }
 422
 423         if(c->socket == -1) {
 424                 logger(DEBUG_CONNECTIONS, LOG_ERR, "Creating socket for %s failed: %s", c->hostname, sockstrerror(sockerrno));
 425                 free_connection(c);
 426                 goto begin;
 427         }
 428
 429 #ifdef FD_CLOEXEC
 430         fcntl(c->socket, F_SETFD, FD_CLOEXEC);
 431 #endif
 432
 433         if(mesh->proxytype != PROXY_EXEC) {
 434 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 435                 int option = 1;
 436                 if(c->address.sa.sa_family == AF_INET6)
 437                         setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
 438 #endif
 439
 440                 bind_to_address(mesh, c);
 441         }
 442
 443         /* Connect */
 444
 445         if(!mesh->proxytype) {
 446                 result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 447         } else if(mesh->proxytype == PROXY_EXEC) {
 448                 result = 0;
 449         } else {
 450                 result = connect(c->socket, proxyai->ai_addr, proxyai->ai_addrlen);
 451                 freeaddrinfo(proxyai);
 452         }
 453
 454         if(result == -1 && !sockinprogress(sockerrno)) {
 455                 logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not connect to %s (%s): %s", outgoing->name, c->hostname, sockstrerror(sockerrno));
 456                 free_connection(c);
 457
 458                 goto begin;
 459         }
 460
 461         /* Now that there is a working socket, fill in the rest and register this connection. */
 462
 463         c->status.connecting = true;
 464         c->name = xstrdup(outgoing->name);
 465         c->outcompression = mesh->self->connection->outcompression;
 466         c->last_ping_time = mesh->loop.now.tv_sec;
 467
 468         connection_add(mesh, c);
 469
 470         io_add(&mesh->loop, &c->io, handle_meta_io, c, c->socket, IO_READ|IO_WRITE);
 471
 472         return true;
 473 }
 474
 475 // Find edges pointing to this node, and use them to build a list of unique, known addresses.
 476 static struct addrinfo *get_known_addresses(node_t *n) {
 477         struct addrinfo *ai = NULL;
 478
 479         for splay_each(edge_t, e, n->edge_tree) {
 480                 if(!e->reverse)
 481                         continue;
 482
 483                 bool found = false;
 484                 for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
 485                         if(!sockaddrcmp(&e->reverse->address, (sockaddr_t *)aip->ai_addr)) {
 486                                 found = true;
 487                                 break;
 488                         }
 489                 }
 490                 if(found)
 491                         continue;
 492
 493                 struct addrinfo *nai = xzalloc(sizeof *nai);
 494                 if(ai)
 495                         ai->ai_next = nai;
 496                 ai = nai;
 497                 ai->ai_family = e->reverse->address.sa.sa_family;
 498                 ai->ai_socktype = SOCK_STREAM;
 499                 ai->ai_protocol = IPPROTO_TCP;
 500                 ai->ai_addrlen = SALEN(e->reverse->address.sa);
 501                 ai->ai_addr = xmalloc(ai->ai_addrlen);
 502                 memcpy(ai->ai_addr, &e->reverse->address, ai->ai_addrlen);
 503         }
 504
 505         return ai;
 506 }
 507
 508 void setup_outgoing_connection(meshlink_handle_t *mesh, outgoing_t *outgoing) {
 509         bool blacklisted = false;
 510         timeout_del(&mesh->loop, &outgoing->ev);
 511
 512         node_t *n = lookup_node(mesh, outgoing->name);
 513
 514         if(n && n->connection) {
 515                 logger(DEBUG_CONNECTIONS, LOG_INFO, "Already connected to %s", outgoing->name);
 516
 517                 n->connection->outgoing = outgoing;
 518                 return;
 519         }
 520
 521         init_configuration(&outgoing->config_tree);
 522         read_host_config(mesh, outgoing->config_tree, outgoing->name);
 523         outgoing->cfg = lookup_config(outgoing->config_tree, "Address");
 524
 525         get_config_bool(lookup_config(outgoing->config_tree, "blacklisted"), &blacklisted);
 526         if (blacklisted) return;
 527
 528         if(!outgoing->cfg) {
 529                 if(n)
 530                         outgoing->aip = outgoing->ai = get_known_addresses(n);
 531                 if(!outgoing->ai) {
 532                         logger(DEBUG_ALWAYS, LOG_ERR, "No address known for %s", outgoing->name);
 533                         return;
 534                 }
 535         }
 536
 537         do_outgoing_connection(mesh, outgoing);
 538 }
 539
 540 /*
 541   accept a new tcp connect and create a
 542   new connection
 543 */
 544 void handle_new_meta_connection(event_loop_t *loop, void *data, int flags) {
 545         meshlink_handle_t *mesh = loop->data;
 546         listen_socket_t *l = data;
 547         connection_t *c;
 548         sockaddr_t sa;
 549         int fd;
 550         socklen_t len = sizeof sa;
 551
 552         fd = accept(l->tcp.fd, &sa.sa, &len);
 553
 554         if(fd < 0) {
 555                 if(errno == EINVAL) { // TODO: check if Windows agrees
 556                         event_loop_stop(loop);
 557                         return;
 558                 }
 559
 560                 logger(DEBUG_ALWAYS, LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
 561                 return;
 562         }
 563
 564         sockaddrunmap(&sa);
 565
 566         // Check if we get many connections from the same host
 567
 568         static sockaddr_t prev_sa;
 569         static int tarpit = -1;
 570
 571         if(tarpit >= 0) {
 572                 closesocket(tarpit);
 573                 tarpit = -1;
 574         }
 575
 576         if(!sockaddrcmp_noport(&sa, &prev_sa)) {
 577                 static int samehost_burst;
 578                 static int samehost_burst_time;
 579
 580                 if(mesh->loop.now.tv_sec - samehost_burst_time > samehost_burst)
 581                         samehost_burst = 0;
 582                 else
 583                         samehost_burst -= mesh->loop.now.tv_sec - samehost_burst_time;
 584
 585                 samehost_burst_time = mesh->loop.now.tv_sec;
 586                 samehost_burst++;
 587
 588                 if(samehost_burst > max_connection_burst) {
 589                         tarpit = fd;
 590                         return;
 591                 }
 592         }
 593
 594         memcpy(&prev_sa, &sa, sizeof sa);
 595
 596         // Check if we get many connections from different hosts
 597
 598         static int connection_burst;
 599         static int connection_burst_time;
 600
 601         if(mesh->loop.now.tv_sec - connection_burst_time > connection_burst)
 602                 connection_burst = 0;
 603         else
 604                 connection_burst -= mesh->loop.now.tv_sec - connection_burst_time;
 605
 606         connection_burst_time = mesh->loop.now.tv_sec;
 607         connection_burst++;
 608
 609         if(connection_burst >= max_connection_burst) {
 610                 connection_burst = max_connection_burst;
 611                 tarpit = fd;
 612                 return;
 613         }
 614
 615         // Accept the new connection
 616
 617         c = new_connection();
 618         c->name = xstrdup("<unknown>");
 619         c->outcompression = mesh->self->connection->outcompression;
 620
 621         c->address = sa;
 622         c->hostname = sockaddr2hostname(&sa);
 623         c->socket = fd;
 624         c->last_ping_time = mesh->loop.now.tv_sec;
 625
 626         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection from %s", c->hostname);
 627
 628         io_add(&mesh->loop, &c->io, handle_meta_io, c, c->socket, IO_READ);
 629
 630         configure_tcp(c);
 631
 632         connection_add(mesh, c);
 633
 634         c->allow_request = ID;
 635         send_id(mesh, c);
 636 }
 637
 638 static void free_outgoing(outgoing_t *outgoing) {
 639         meshlink_handle_t *mesh = outgoing->mesh;
 640
 641         timeout_del(&mesh->loop, &outgoing->ev);
 642
 643         if(outgoing->ai)
 644                 freeaddrinfo(outgoing->ai);
 645
 646         if(outgoing->config_tree)
 647                 exit_configuration(&outgoing->config_tree);
 648
 649         if(outgoing->name)
 650                 free(outgoing->name);
 651
 652         free(outgoing);
 653 }
 654
 655 void try_outgoing_connections(meshlink_handle_t *mesh) {
 656         /* If there is no outgoing list yet, create one. Otherwise, mark all outgoings as deleted. */
 657
 658         if(!mesh->outgoings) {
 659                 mesh->outgoings = list_alloc((list_action_t)free_outgoing);
 660         } else {
 661                 for list_each(outgoing_t, outgoing, mesh->outgoings)
 662                         outgoing->timeout = -1;
 663         }
 664
 665         /* Make sure there is one outgoing_t in the list for each ConnectTo. */
 666
 667         // TODO: Drop support for ConnectTo since AutoConnect is now always on?
 668         for(config_t *cfg = lookup_config(mesh->config, "ConnectTo"); cfg; cfg = lookup_config_next(mesh->config, cfg)) {
 669                 char *name;
 670                 get_config_string(cfg, &name);
 671
 672                 if(!check_id(name)) {
 673                         logger(DEBUG_ALWAYS, LOG_ERR,
 674                                    "Invalid name for outgoing connection in %s line %d",
 675                                    cfg->file, cfg->line);
 676                         free(name);
 677                         continue;
 678                 }
 679
 680                 bool found = false;
 681
 682                 for list_each(outgoing_t, outgoing, mesh->outgoings) {
 683                         if(!strcmp(outgoing->name, name)) {
 684                                 found = true;
 685                                 outgoing->timeout = 0;
 686                                 break;
 687                         }
 688                 }
 689
 690                 if(!found) {
 691                         outgoing_t *outgoing = xzalloc(sizeof *outgoing);
 692                         outgoing->mesh = mesh;
 693                         outgoing->name = name;
 694                         list_insert_tail(mesh->outgoings, outgoing);
 695                         setup_outgoing_connection(mesh, outgoing);
 696                 }
 697         }
 698
 699         /* Terminate any connections whose outgoing_t is to be deleted. */
 700
 701         for list_each(connection_t, c, mesh->connections) {
 702                 if(c->outgoing && c->outgoing->timeout == -1) {
 703                         c->outgoing = NULL;
 704                         logger(DEBUG_CONNECTIONS, LOG_INFO, "No more outgoing connection to %s", c->name);
 705                         terminate_connection(mesh, c, c->status.active);
 706                 }
 707         }
 708
 709         /* Delete outgoing_ts for which there is no ConnectTo. */
 710
 711         for list_each(outgoing_t, outgoing, mesh->outgoings)
 712                 if(outgoing->timeout == -1)
 713                         list_delete_node(mesh->outgoings, node);
 714 }