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 #ifndef MSG_NOSIGNAL
  40 #define MSG_NOSIGNAL 0
  41 #endif
  42
  43 int addressfamily = AF_UNSPEC;
  44 int seconds_till_retry = 5;
  45 int max_connection_burst = 100;
  46
  47 /* Setup sockets */
  48
  49 static void configure_tcp(connection_t *c) {
  50 #ifdef O_NONBLOCK
  51         int flags = fcntl(c->socket, F_GETFL);
  52
  53         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0)
  54                 logger(c->mesh, MESHLINK_ERROR, "System call `%s' failed: %s", "fcntl", strerror(errno));
  55 #elif defined(WIN32)
  56         unsigned long arg = 1;
  57
  58         if(ioctlsocket(c->socket, FIONBIO, &arg) != 0)
  59                 logger(c->mesh, MESHLINK_ERROR, "System call `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
  60 #endif
  61
  62 #if defined(SOL_TCP) && defined(TCP_NODELAY)
  63         int nodelay = 1;
  64         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, (void *)&nodelay, sizeof(nodelay));
  65 #endif
  66
  67 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
  68         int lowdelay = IPTOS_LOWDELAY;
  69         setsockopt(c->socket, SOL_IP, IP_TOS, (void *)&lowdelay, sizeof(lowdelay));
  70 #endif
  71 }
  72
  73 static bool bind_to_address(meshlink_handle_t *mesh, connection_t *c) {
  74         int s = -1;
  75
  76         for(int i = 0; i < mesh->listen_sockets && mesh->listen_socket[i].bindto; i++) {
  77                 if(mesh->listen_socket[i].sa.sa.sa_family != c->address.sa.sa_family)
  78                         continue;
  79                 if(s >= 0)
  80                         return false;
  81                 s = i;
  82         }
  83
  84         if(s < 0)
  85                 return false;
  86
  87         sockaddr_t sa = mesh->listen_socket[s].sa;
  88         if(sa.sa.sa_family == AF_INET)
  89                 sa.in.sin_port = 0;
  90         else if(sa.sa.sa_family == AF_INET6)
  91                 sa.in6.sin6_port = 0;
  92
  93         if(bind(c->socket, &sa.sa, SALEN(sa.sa))) {
  94                 logger(mesh, MESHLINK_WARNING, "Can't bind outgoing socket: %s", strerror(errno));
  95                 return false;
  96         }
  97
  98         return true;
  99 }
 100
 101 int setup_listen_socket(const sockaddr_t *sa) {
 102         int nfd;
 103         char *addrstr;
 104         int option;
 105
 106         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 107
 108         if(nfd < 0) {
 109                 logger(NULL, MESHLINK_ERROR, "Creating metasocket failed: %s", sockstrerror(sockerrno));
 110                 return -1;
 111         }
 112
 113 #ifdef FD_CLOEXEC
 114         fcntl(nfd, F_SETFD, FD_CLOEXEC);
 115 #endif
 116
 117         /* Optimize TCP settings */
 118
 119         option = 1;
 120         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
 121
 122 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 123         if(sa->sa.sa_family == AF_INET6)
 124                 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
 125 #endif
 126
 127         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 128                 closesocket(nfd);
 129                 addrstr = sockaddr2hostname(sa);
 130                 logger(NULL, MESHLINK_ERROR, "Can't bind to %s/tcp: %s", addrstr, sockstrerror(sockerrno));
 131                 free(addrstr);
 132                 return -1;
 133         }
 134
 135         if(listen(nfd, 3)) {
 136                 closesocket(nfd);
 137                 logger(NULL, MESHLINK_ERROR, "System call `%s' failed: %s", "listen", sockstrerror(sockerrno));
 138                 return -1;
 139         }
 140
 141         return nfd;
 142 }
 143
 144 int setup_vpn_in_socket(meshlink_handle_t *mesh, const sockaddr_t *sa) {
 145         int nfd;
 146         char *addrstr;
 147         int option;
 148
 149         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 150
 151         if(nfd < 0) {
 152                 logger(mesh, MESHLINK_ERROR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
 153                 return -1;
 154         }
 155
 156 #ifdef FD_CLOEXEC
 157         fcntl(nfd, F_SETFD, FD_CLOEXEC);
 158 #endif
 159
 160 #ifdef O_NONBLOCK
 161         {
 162                 int flags = fcntl(nfd, F_GETFL);
 163
 164                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 165                         closesocket(nfd);
 166                         logger(mesh, MESHLINK_ERROR, "System call `%s' failed: %s", "fcntl",
 167                                strerror(errno));
 168                         return -1;
 169                 }
 170         }
 171 #elif defined(WIN32)
 172         {
 173                 unsigned long arg = 1;
 174                 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 175                         closesocket(nfd);
 176                         logger(mesh, MESHLINK_ERROR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
 177                         return -1;
 178                 }
 179         }
 180 #endif
 181
 182         option = 1;
 183         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
 184         setsockopt(nfd, SOL_SOCKET, SO_BROADCAST, (void *)&option, sizeof(option));
 185
 186 #if defined(IPPROTO_IPV6) && defined(IPV6_V6ONLY)
 187         if(sa->sa.sa_family == AF_INET6)
 188                 setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
 189 #endif
 190
 191 #if defined(IP_DONTFRAG) && !defined(IP_DONTFRAGMENT)
 192 #define IP_DONTFRAGMENT IP_DONTFRAG
 193 #endif
 194
 195 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 196         if(mesh->self->options & OPTION_PMTU_DISCOVERY) {
 197                 option = IP_PMTUDISC_DO;
 198                 setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
 199         }
 200 #elif defined(IPPROTO_IP) && defined(IP_DONTFRAGMENT)
 201         if(mesh->self->options & OPTION_PMTU_DISCOVERY) {
 202                 option = 1;
 203                 setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, (void *)&option, sizeof(option));
 204         }
 205 #else
 206 #warning No way to disable IPv4 fragmentation
 207 #endif
 208
 209 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 210         if(mesh->self->options & OPTION_PMTU_DISCOVERY) {
 211                 option = IPV6_PMTUDISC_DO;
 212                 setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
 213         }
 214 #elif defined(IPPROTO_IPV6) && defined(IPV6_DONTFRAG)
 215         if(mesh->self->options & OPTION_PMTU_DISCOVERY) {
 216                 option = 1;
 217                 setsockopt(nfd, IPPROTO_IPV6, IPV6_DONTFRAG, (void *)&option, sizeof(option));
 218         }
 219 #else
 220 #warning No way to disable IPv6 fragmentation
 221 #endif
 222
 223         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 224                 closesocket(nfd);
 225                 addrstr = sockaddr2hostname(sa);
 226                 logger(mesh, MESHLINK_ERROR, "Can't bind to %s/udp: %s", addrstr, sockstrerror(sockerrno));
 227                 free(addrstr);
 228                 return -1;
 229         }
 230
 231         return nfd;
 232 } /* int setup_vpn_in_socket */
 233
 234 static void retry_outgoing_handler(event_loop_t *loop, void *data) {
 235         meshlink_handle_t *mesh = loop->data;
 236         outgoing_t *outgoing = data;
 237         setup_outgoing_connection(mesh, outgoing);
 238 }
 239
 240 void retry_outgoing(meshlink_handle_t *mesh, outgoing_t *outgoing) {
 241         outgoing->timeout += 5;
 242
 243         if(outgoing->timeout > mesh->maxtimeout)
 244                 outgoing->timeout = mesh->maxtimeout;
 245
 246         timeout_add(&mesh->loop, &outgoing->ev, retry_outgoing_handler, outgoing, &(struct timeval) {
 247                 outgoing->timeout, rand() % 100000
 248         });
 249
 250         logger(mesh, MESHLINK_INFO, "Trying to re-establish outgoing connection in %d seconds", outgoing->timeout);
 251 }
 252
 253 void finish_connecting(meshlink_handle_t *mesh, connection_t *c) {
 254         logger(mesh, MESHLINK_INFO, "Connected to %s", c->name);
 255
 256         c->last_ping_time = mesh->loop.now.tv_sec;
 257         c->status.connecting = false;
 258
 259         send_id(mesh, c);
 260 }
 261
 262 static void do_outgoing_pipe(meshlink_handle_t *mesh, connection_t *c, char *command) {
 263 #ifndef HAVE_MINGW
 264         int fd[2];
 265
 266         if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
 267                 logger(mesh, MESHLINK_ERROR, "Could not create socketpair: %s", strerror(errno));
 268                 return;
 269         }
 270
 271         if(fork()) {
 272                 c->socket = fd[0];
 273                 close(fd[1]);
 274                 logger(mesh, MESHLINK_DEBUG, "Using proxy %s", command);
 275                 return;
 276         }
 277
 278         close(0);
 279         close(1);
 280         close(fd[0]);
 281         dup2(fd[1], 0);
 282         dup2(fd[1], 1);
 283         close(fd[1]);
 284
 285         // Other filedescriptors should be closed automatically by CLOEXEC
 286
 287         char *host = NULL;
 288         char *port = NULL;
 289
 290         sockaddr2str(&c->address, &host, &port);
 291         setenv("REMOTEADDRESS", host, true);
 292         setenv("REMOTEPORT", port, true);
 293         setenv("NODE", c->name, true);
 294         setenv("NAME", mesh->self->name, true);
 295
 296         int result = system(command);
 297         if(result < 0)
 298                 logger(mesh, MESHLINK_ERROR, "Could not execute %s: %s", command, strerror(errno));
 299         else if(result)
 300                 logger(mesh, MESHLINK_ERROR, "%s exited with non-zero status %d", command, result);
 301         exit(result);
 302 #else
 303         logger(mesh, MESHLINK_ERROR, "Proxy type exec not supported on this platform!");
 304         return;
 305 #endif
 306 }
 307
 308 static void handle_meta_write(meshlink_handle_t *mesh, connection_t *c) {
 309         if(c->outbuf.len <= c->outbuf.offset)
 310                 return;
 311
 312         ssize_t outlen = send(c->socket, c->outbuf.data + c->outbuf.offset, c->outbuf.len - c->outbuf.offset, MSG_NOSIGNAL);
 313         if(outlen <= 0) {
 314                 if(!errno || errno == EPIPE)
 315                         logger(mesh, MESHLINK_INFO, "Connection closed by %s", c->name);
 316                 else if(sockwouldblock(sockerrno)) {
 317                         logger(mesh, MESHLINK_DEBUG, "Sending %d bytes to %s would block", c->outbuf.len - c->outbuf.offset, c->name);
 318                         return;
 319                 } else
 320                         logger(mesh, MESHLINK_ERROR, "Could not send %d bytes of data to %s: %s", c->outbuf.len - c->outbuf.offset, c->name, strerror(errno));
 321
 322                 terminate_connection(mesh, c, c->status.active);
 323                 return;
 324         }
 325
 326         buffer_read(&c->outbuf, outlen);
 327         if(!c->outbuf.len)
 328                 io_set(&mesh->loop, &c->io, IO_READ);
 329 }
 330
 331 static void handle_meta_io(event_loop_t *loop, void *data, int flags) {
 332         meshlink_handle_t *mesh = loop->data;
 333         connection_t *c = data;
 334
 335         if(c->status.connecting) {
 336                 c->status.connecting = false;
 337
 338                 int result;
 339                 socklen_t len = sizeof(result);
 340                 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, (void *)&result, &len);
 341
 342                 if(!result)
 343                         finish_connecting(mesh, c);
 344                 else {
 345                         logger(mesh, MESHLINK_DEBUG, "Error while connecting to %s: %s", c->name, sockstrerror(result));
 346                         terminate_connection(mesh, c, false);
 347                         return;
 348                 }
 349         }
 350
 351         if(flags & IO_WRITE)
 352                 handle_meta_write(mesh, c);
 353         else
 354                 handle_meta_connection_data(mesh, c);
 355 }
 356
 357 // Find edges pointing to this node, and use them to build a list of unique, known addresses.
 358 static struct addrinfo *get_known_addresses(node_t *n) {
 359         struct addrinfo *ai = NULL;
 360
 361         for splay_each(edge_t, e, n->edge_tree) {
 362                 if(!e->reverse)
 363                         continue;
 364
 365                 bool found = false;
 366                 for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
 367                         if(!sockaddrcmp(&e->reverse->address, (sockaddr_t *)aip->ai_addr)) {
 368                                 found = true;
 369                                 break;
 370                         }
 371                 }
 372                 if(found)
 373                         continue;
 374
 375                 // Create a new struct addrinfo, and put it at the head of the list.
 376                 struct addrinfo *nai = xzalloc(sizeof(*nai) + SALEN(e->reverse->address.sa));
 377                 nai->ai_next = ai;
 378                 ai = nai;
 379
 380                 ai->ai_family = e->reverse->address.sa.sa_family;
 381                 ai->ai_socktype = SOCK_STREAM;
 382                 ai->ai_protocol = IPPROTO_TCP;
 383                 ai->ai_addrlen = SALEN(e->reverse->address.sa);
 384                 ai->ai_addr = (struct sockaddr *)(nai + 1);
 385                 memcpy(ai->ai_addr, &e->reverse->address, ai->ai_addrlen);
 386         }
 387
 388         return ai;
 389 }
 390
 391 // Free struct addrinfo list from get_known_addresses().
 392 static void free_known_addresses(struct addrinfo *ai) {
 393         for(struct addrinfo *aip = ai, *next; aip; aip = next) {
 394                 next = aip->ai_next;
 395                 free(aip);
 396         }
 397 }
 398
 399 bool do_outgoing_connection(meshlink_handle_t *mesh, outgoing_t *outgoing) {
 400         char *address, *port, *space;
 401         struct addrinfo *proxyai = NULL;
 402         int result;
 403
 404 begin:
 405         if(!outgoing->ai && !outgoing->nai) {
 406                 if(!outgoing->cfg) {
 407                         logger(mesh, MESHLINK_ERROR, "Could not set up a meta connection to %s", outgoing->name);
 408                         retry_outgoing(mesh, outgoing);
 409                         return false;
 410                 }
 411
 412                 get_config_string(outgoing->cfg, &address);
 413
 414                 space = strchr(address, ' ');
 415                 if(space) {
 416                         port = xstrdup(space + 1);
 417                         *space = 0;
 418                 } else {
 419                         // TODO: Only allow Address statements?
 420                         if(!get_config_string(lookup_config(outgoing->config_tree, "Port"), &port)) {
 421                                 logger(mesh, MESHLINK_ERROR, "No Port known for %s", outgoing->name);
 422                                 retry_outgoing(mesh, outgoing);
 423                                 return false;
 424                         }
 425                 }
 426
 427                 outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 428                 free(address);
 429                 free(port);
 430
 431                 outgoing->aip = outgoing->ai;
 432                 outgoing->cfg = lookup_config_next(outgoing->config_tree, outgoing->cfg);
 433         }
 434
 435         if(!outgoing->aip) {
 436                 if(outgoing->ai)
 437                         freeaddrinfo(outgoing->ai);
 438                 outgoing->ai = NULL;
 439
 440                 if(outgoing->nai)
 441                         free_known_addresses(outgoing->nai);
 442                 outgoing->nai = NULL;
 443
 444                 goto begin;
 445         }
 446
 447         connection_t *c = new_connection();
 448         c->outgoing = outgoing;
 449
 450         memcpy(&c->address, outgoing->aip->ai_addr, outgoing->aip->ai_addrlen);
 451         outgoing->aip = outgoing->aip->ai_next;
 452
 453         char *hostname = sockaddr2hostname(&c->address);
 454
 455         logger(mesh, MESHLINK_INFO, "Trying to connect to %s at %s", outgoing->name, hostname);
 456
 457         if(!mesh->proxytype) {
 458                 c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 459                 configure_tcp(c);
 460         } else if(mesh->proxytype == PROXY_EXEC)
 461                 do_outgoing_pipe(mesh, c, mesh->proxyhost);
 462         else {
 463                 proxyai = str2addrinfo(mesh->proxyhost, mesh->proxyport, SOCK_STREAM);
 464                 if(!proxyai) {
 465                         free_connection(c);
 466                         free(hostname);
 467                         goto begin;
 468                 }
 469                 logger(mesh, MESHLINK_INFO, "Using proxy at %s port %s", mesh->proxyhost, mesh->proxyport);
 470                 c->socket = socket(proxyai->ai_family, SOCK_STREAM, IPPROTO_TCP);
 471                 configure_tcp(c);
 472         }
 473
 474         if(c->socket == -1) {
 475                 logger(mesh, MESHLINK_ERROR, "Creating socket for %s at %s failed: %s", c->name, c->hostname, sockstrerror(sockerrno));
 476                 free_connection(c);
 477                 free(hostname);
 478                 goto begin;
 479         }
 480
 481         free(hostname);
 482
 483 #ifdef FD_CLOEXEC
 484         fcntl(c->socket, F_SETFD, FD_CLOEXEC);
 485 #endif
 486
 487         if(mesh->proxytype != PROXY_EXEC) {
 488 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 489                 int option = 1;
 490                 if(c->address.sa.sa_family == AF_INET6)
 491                         setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
 492 #endif
 493
 494                 bind_to_address(mesh, c);
 495         }
 496
 497         /* Connect */
 498
 499         if(!mesh->proxytype)
 500                 result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 501         else if(mesh->proxytype == PROXY_EXEC)
 502                 result = 0;
 503         else {
 504                 result = connect(c->socket, proxyai->ai_addr, proxyai->ai_addrlen);
 505                 freeaddrinfo(proxyai);
 506         }
 507
 508         if(result == -1 && !sockinprogress(sockerrno)) {
 509                 logger(mesh, MESHLINK_ERROR, "Could not connect to %s: %s", outgoing->name, sockstrerror(sockerrno));
 510                 free_connection(c);
 511
 512                 goto begin;
 513         }
 514
 515         /* Now that there is a working socket, fill in the rest and register this connection. */
 516
 517         c->status.connecting = true;
 518         c->name = xstrdup(outgoing->name);
 519         c->outcompression = mesh->self->connection->outcompression;
 520         c->last_ping_time = mesh->loop.now.tv_sec;
 521
 522         connection_add(mesh, c);
 523
 524         io_add(&mesh->loop, &c->io, handle_meta_io, c, c->socket, IO_READ | IO_WRITE);
 525
 526         return true;
 527 }
 528
 529 void setup_outgoing_connection(meshlink_handle_t *mesh, outgoing_t *outgoing) {
 530         bool blacklisted = false;
 531         timeout_del(&mesh->loop, &outgoing->ev);
 532
 533         node_t *n = lookup_node(mesh, outgoing->name);
 534
 535         if(n && n->connection) {
 536                 logger(mesh, MESHLINK_INFO, "Already connected to %s", outgoing->name);
 537
 538                 n->connection->outgoing = outgoing;
 539                 return;
 540         }
 541
 542         exit_configuration(&outgoing->config_tree); // discard old configuration if present
 543         init_configuration(&outgoing->config_tree);
 544         read_host_config(mesh, outgoing->config_tree, outgoing->name);
 545         outgoing->cfg = lookup_config(outgoing->config_tree, "Address");
 546
 547         get_config_bool(lookup_config(outgoing->config_tree, "blacklisted"), &blacklisted);
 548         if(blacklisted) return;
 549
 550         if(!outgoing->cfg) {
 551                 if(n)
 552                         outgoing->aip = outgoing->nai = get_known_addresses(n);
 553                 if(!outgoing->nai) {
 554                         logger(mesh, MESHLINK_ERROR, "No address known for %s", outgoing->name);
 555                         return;
 556                 }
 557         }
 558
 559         do_outgoing_connection(mesh, outgoing);
 560 }
 561
 562 /*
 563   accept a new tcp connect and create a
 564   new connection
 565 */
 566 void handle_new_meta_connection(event_loop_t *loop, void *data, int flags) {
 567         meshlink_handle_t *mesh = loop->data;
 568         listen_socket_t *l = data;
 569         connection_t *c;
 570         sockaddr_t sa;
 571         int fd;
 572         socklen_t len = sizeof(sa);
 573
 574         fd = accept(l->tcp.fd, &sa.sa, &len);
 575
 576         if(fd < 0) {
 577                 if(errno == EINVAL) { // TODO: check if Windows agrees
 578                         event_loop_stop(loop);
 579                         return;
 580                 }
 581
 582                 logger(mesh, MESHLINK_ERROR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
 583                 return;
 584         }
 585
 586         sockaddrunmap(&sa);
 587
 588         // Check if we get many connections from the same host
 589
 590         static sockaddr_t prev_sa;
 591         static int tarpit = -1;
 592
 593         if(tarpit >= 0) {
 594                 closesocket(tarpit);
 595                 tarpit = -1;
 596         }
 597
 598         if(!sockaddrcmp_noport(&sa, &prev_sa)) {
 599                 static int samehost_burst;
 600                 static int samehost_burst_time;
 601
 602                 if(mesh->loop.now.tv_sec - samehost_burst_time > samehost_burst)
 603                         samehost_burst = 0;
 604                 else
 605                         samehost_burst -= mesh->loop.now.tv_sec - samehost_burst_time;
 606
 607                 samehost_burst_time = mesh->loop.now.tv_sec;
 608                 samehost_burst++;
 609
 610                 if(samehost_burst > max_connection_burst) {
 611                         tarpit = fd;
 612                         return;
 613                 }
 614         }
 615
 616         memcpy(&prev_sa, &sa, sizeof(sa));
 617
 618         // Check if we get many connections from different hosts
 619
 620         static int connection_burst;
 621         static int connection_burst_time;
 622
 623         if(mesh->loop.now.tv_sec - connection_burst_time > connection_burst)
 624                 connection_burst = 0;
 625         else
 626                 connection_burst -= mesh->loop.now.tv_sec - connection_burst_time;
 627
 628         connection_burst_time = mesh->loop.now.tv_sec;
 629         connection_burst++;
 630
 631         if(connection_burst >= max_connection_burst) {
 632                 connection_burst = max_connection_burst;
 633                 tarpit = fd;
 634                 return;
 635         }
 636
 637         // Accept the new connection
 638
 639         c = new_connection();
 640         c->name = xstrdup("<unknown>");
 641         c->outcompression = mesh->self->connection->outcompression;
 642
 643         c->address = sa;
 644         c->socket = fd;
 645         c->last_ping_time = mesh->loop.now.tv_sec;
 646
 647         char *hostname = sockaddr2hostname(&sa);
 648         logger(mesh, MESHLINK_INFO, "Connection from %s", c->hostname);
 649         free(hostname);
 650
 651         io_add(&mesh->loop, &c->io, handle_meta_io, c, c->socket, IO_READ);
 652
 653         configure_tcp(c);
 654
 655         connection_add(mesh, c);
 656
 657         c->allow_request = ID;
 658         send_id(mesh, c);
 659 }
 660
 661 static void free_outgoing(outgoing_t *outgoing) {
 662         meshlink_handle_t *mesh = outgoing->mesh;
 663
 664         timeout_del(&mesh->loop, &outgoing->ev);
 665
 666         if(outgoing->ai)
 667                 freeaddrinfo(outgoing->ai);
 668
 669         if(outgoing->nai)
 670                 free_known_addresses(outgoing->nai);
 671
 672         if(outgoing->config_tree)
 673                 exit_configuration(&outgoing->config_tree);
 674
 675         if(outgoing->name)
 676                 free(outgoing->name);
 677
 678         free(outgoing);
 679 }
 680
 681 void try_outgoing_connections(meshlink_handle_t *mesh) {
 682         /* If there is no outgoing list yet, create one. Otherwise, mark all outgoings as deleted. */
 683
 684         if(!mesh->outgoings)
 685                 mesh->outgoings = list_alloc((list_action_t)free_outgoing);
 686         else {
 687                 for list_each(outgoing_t, outgoing, mesh->outgoings)
 688                         outgoing->timeout = -1;
 689         }
 690
 691         /* Make sure there is one outgoing_t in the list for each ConnectTo. */
 692
 693         // TODO: Drop support for ConnectTo since AutoConnect is now always on?
 694         for(config_t *cfg = lookup_config(mesh->config, "ConnectTo"); cfg; cfg = lookup_config_next(mesh->config, cfg)) {
 695                 char *name;
 696                 get_config_string(cfg, &name);
 697
 698                 if(!check_id(name)) {
 699                         logger(mesh, MESHLINK_ERROR,
 700                                "Invalid name for outgoing connection in %s line %d",
 701                                cfg->file, cfg->line);
 702                         free(name);
 703                         continue;
 704                 }
 705
 706                 bool found = false;
 707
 708                 for list_each(outgoing_t, outgoing, mesh->outgoings) {
 709                         if(!strcmp(outgoing->name, name)) {
 710                                 found = true;
 711                                 outgoing->timeout = 0;
 712                                 break;
 713                         }
 714                 }
 715
 716                 if(!found) {
 717                         outgoing_t *outgoing = xzalloc(sizeof(*outgoing));
 718                         outgoing->mesh = mesh;
 719                         outgoing->name = name;
 720                         list_insert_tail(mesh->outgoings, outgoing);
 721                         setup_outgoing_connection(mesh, outgoing);
 722                 }
 723         }
 724
 725         /* Terminate any connections whose outgoing_t is to be deleted. */
 726
 727         for list_each(connection_t, c, mesh->connections) {
 728                 if(c->outgoing && c->outgoing->timeout == -1) {
 729                         c->outgoing = NULL;
 730                         logger(mesh, MESHLINK_INFO, "No more outgoing connection to %s", c->name);
 731                         terminate_connection(mesh, c, c->status.active);
 732                 }
 733         }
 734
 735         /* Delete outgoing_ts for which there is no ConnectTo. */
 736
 737         for list_each(outgoing_t, outgoing, mesh->outgoings)
 738                 if(outgoing->timeout == -1)
 739                         list_delete_node(mesh->outgoings, node);
 740 }