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

   1 /*
   2     net_socket.c -- Handle various kinds of sockets.
   3     Copyright (C) 2014-2017 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 static const int max_connection_burst = 100;
  44
  45 /* Setup sockets */
  46
  47 static void configure_tcp(connection_t *c) {
  48 #ifdef O_NONBLOCK
  49         int flags = fcntl(c->socket, F_GETFL);
  50
  51         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
  52                 logger(c->mesh, MESHLINK_ERROR, "System call `%s' failed: %s", "fcntl", strerror(errno));
  53         }
  54
  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         }
  61
  62 #endif
  63
  64 #if defined(SOL_TCP) && defined(TCP_NODELAY)
  65         int nodelay = 1;
  66         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, (void *)&nodelay, sizeof(nodelay));
  67 #endif
  68
  69 #if defined(IP_TOS) && defined(IPTOS_LOWDELAY)
  70         int lowdelay = IPTOS_LOWDELAY;
  71         setsockopt(c->socket, IPPROTO_IP, IP_TOS, (void *)&lowdelay, sizeof(lowdelay));
  72 #endif
  73 }
  74
  75 static bool bind_to_address(meshlink_handle_t *mesh, connection_t *c) {
  76         int s = -1;
  77
  78         for(int i = 0; i < mesh->listen_sockets && mesh->listen_socket[i].bindto; i++) {
  79                 if(mesh->listen_socket[i].sa.sa.sa_family != c->address.sa.sa_family) {
  80                         continue;
  81                 }
  82
  83                 if(s >= 0) {
  84                         return false;
  85                 }
  86
  87                 s = i;
  88         }
  89
  90         if(s < 0) {
  91                 return false;
  92         }
  93
  94         sockaddr_t sa = mesh->listen_socket[s].sa;
  95
  96         if(sa.sa.sa_family == AF_INET) {
  97                 sa.in.sin_port = 0;
  98         } else if(sa.sa.sa_family == AF_INET6) {
  99                 sa.in6.sin6_port = 0;
 100         }
 101
 102         if(bind(c->socket, &sa.sa, SALEN(sa.sa))) {
 103                 logger(mesh, MESHLINK_WARNING, "Can't bind outgoing socket: %s", strerror(errno));
 104                 return false;
 105         }
 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
 115         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 116
 117         if(nfd < 0) {
 118                 logger(NULL, MESHLINK_ERROR, "Creating metasocket failed: %s", sockstrerror(sockerrno));
 119                 return -1;
 120         }
 121
 122 #ifdef FD_CLOEXEC
 123         fcntl(nfd, F_SETFD, FD_CLOEXEC);
 124 #endif
 125
 126         /* Optimize TCP settings */
 127
 128         option = 1;
 129         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
 130
 131 #if defined(IPV6_V6ONLY)
 132
 133         if(sa->sa.sa_family == AF_INET6) {
 134                 setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
 135         }
 136
 137 #else
 138 #warning IPV6_V6ONLY not defined
 139 #endif
 140
 141         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 142                 closesocket(nfd);
 143                 addrstr = sockaddr2hostname(sa);
 144                 logger(NULL, MESHLINK_ERROR, "Can't bind to %s/tcp: %s", addrstr, sockstrerror(sockerrno));
 145                 free(addrstr);
 146                 return -1;
 147         }
 148
 149         if(listen(nfd, 3)) {
 150                 closesocket(nfd);
 151                 logger(NULL, MESHLINK_ERROR, "System call `%s' failed: %s", "listen", sockstrerror(sockerrno));
 152                 return -1;
 153         }
 154
 155         return nfd;
 156 }
 157
 158 int setup_vpn_in_socket(meshlink_handle_t *mesh, const sockaddr_t *sa) {
 159         int nfd;
 160         char *addrstr;
 161         int option;
 162
 163         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 164
 165         if(nfd < 0) {
 166                 logger(mesh, MESHLINK_ERROR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
 167                 return -1;
 168         }
 169
 170 #ifdef FD_CLOEXEC
 171         fcntl(nfd, F_SETFD, FD_CLOEXEC);
 172 #endif
 173
 174 #ifdef O_NONBLOCK
 175         {
 176                 int flags = fcntl(nfd, F_GETFL);
 177
 178                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 179                         closesocket(nfd);
 180                         logger(mesh, MESHLINK_ERROR, "System call `%s' failed: %s", "fcntl",
 181                                strerror(errno));
 182                         return -1;
 183                 }
 184         }
 185 #elif defined(WIN32)
 186         {
 187                 unsigned long arg = 1;
 188
 189                 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 190                         closesocket(nfd);
 191                         logger(mesh, MESHLINK_ERROR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
 192                         return -1;
 193                 }
 194         }
 195 #endif
 196
 197         option = 1;
 198         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
 199         setsockopt(nfd, SOL_SOCKET, SO_BROADCAST, (void *)&option, sizeof(option));
 200
 201 #if defined(IPV6_V6ONLY)
 202
 203         if(sa->sa.sa_family == AF_INET6) {
 204                 setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
 205         }
 206
 207 #endif
 208
 209 #if defined(IP_DONTFRAG) && !defined(IP_DONTFRAGMENT)
 210 #define IP_DONTFRAGMENT IP_DONTFRAG
 211 #endif
 212
 213 #if defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 214         option = IP_PMTUDISC_DO;
 215         setsockopt(nfd, IPPROTO_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
 216 #elif defined(IP_DONTFRAGMENT)
 217         option = 1;
 218         setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, (void *)&option, sizeof(option));
 219 #endif
 220
 221 #if defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 222         option = IPV6_PMTUDISC_DO;
 223         setsockopt(nfd, IPPROTO_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
 224 #elif defined(IPV6_DONTFRAG)
 225         option = 1;
 226         setsockopt(nfd, IPPROTO_IPV6, IPV6_DONTFRAG, (void *)&option, sizeof(option));
 227 #endif
 228
 229         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 230                 closesocket(nfd);
 231                 addrstr = sockaddr2hostname(sa);
 232                 logger(mesh, MESHLINK_ERROR, "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(event_loop_t *loop, void *data) {
 241         meshlink_handle_t *mesh = loop->data;
 242         outgoing_t *outgoing = data;
 243         setup_outgoing_connection(mesh, outgoing);
 244 }
 245
 246 void retry_outgoing(meshlink_handle_t *mesh, outgoing_t *outgoing) {
 247         outgoing->timeout += 5;
 248
 249         if(outgoing->timeout > mesh->maxtimeout) {
 250                 outgoing->timeout = mesh->maxtimeout;
 251         }
 252
 253         timeout_add(&mesh->loop, &outgoing->ev, retry_outgoing_handler, outgoing, &(struct timeval) {
 254                 outgoing->timeout, rand() % 100000
 255         });
 256
 257         logger(mesh, MESHLINK_INFO, "Trying to re-establish outgoing connection in %d seconds", outgoing->timeout);
 258 }
 259
 260 void finish_connecting(meshlink_handle_t *mesh, connection_t *c) {
 261         logger(mesh, MESHLINK_INFO, "Connected to %s", c->name);
 262
 263         c->last_ping_time = mesh->loop.now.tv_sec;
 264         c->status.connecting = false;
 265
 266         send_id(mesh, c);
 267 }
 268
 269 static void handle_meta_write(meshlink_handle_t *mesh, connection_t *c) {
 270         if(c->outbuf.len <= c->outbuf.offset) {
 271                 return;
 272         }
 273
 274         ssize_t outlen = send(c->socket, c->outbuf.data + c->outbuf.offset, c->outbuf.len - c->outbuf.offset, MSG_NOSIGNAL);
 275
 276         if(outlen <= 0) {
 277                 if(!errno || errno == EPIPE) {
 278                         logger(mesh, MESHLINK_INFO, "Connection closed by %s", c->name);
 279                 } else if(sockwouldblock(sockerrno)) {
 280                         logger(mesh, MESHLINK_DEBUG, "Sending %lu bytes to %s would block", (unsigned long)(c->outbuf.len - c->outbuf.offset), c->name);
 281                         return;
 282                 } else {
 283                         logger(mesh, MESHLINK_ERROR, "Could not send %lu bytes of data to %s: %s", (unsigned long)(c->outbuf.len - c->outbuf.offset), c->name, strerror(errno));
 284                 }
 285
 286                 terminate_connection(mesh, c, c->status.active);
 287                 return;
 288         }
 289
 290         buffer_read(&c->outbuf, outlen);
 291
 292         if(!c->outbuf.len) {
 293                 io_set(&mesh->loop, &c->io, IO_READ);
 294         }
 295 }
 296
 297 static void handle_meta_io(event_loop_t *loop, void *data, int flags) {
 298         meshlink_handle_t *mesh = loop->data;
 299         connection_t *c = data;
 300
 301         if(c->status.connecting) {
 302                 c->status.connecting = false;
 303
 304                 int result;
 305                 socklen_t len = sizeof(result);
 306                 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, (void *)&result, &len);
 307
 308                 if(!result) {
 309                         finish_connecting(mesh, c);
 310                 } else {
 311                         logger(mesh, MESHLINK_DEBUG, "Error while connecting to %s: %s", c->name, sockstrerror(result));
 312                         terminate_connection(mesh, c, false);
 313                         return;
 314                 }
 315         }
 316
 317         if(flags & IO_WRITE) {
 318                 handle_meta_write(mesh, c);
 319         } else {
 320                 handle_meta_connection_data(mesh, c);
 321         }
 322 }
 323
 324 // Find edges pointing to this node, and use them to build a list of unique, known addresses.
 325 static struct addrinfo *get_known_addresses(node_t *n) {
 326         struct addrinfo *ai = NULL;
 327
 328         for splay_each(edge_t, e, n->edge_tree) {
 329                 if(!e->reverse) {
 330                         continue;
 331                 }
 332
 333                 bool found = false;
 334
 335                 for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
 336                         if(!sockaddrcmp(&e->reverse->address, (sockaddr_t *)aip->ai_addr)) {
 337                                 found = true;
 338                                 break;
 339                         }
 340                 }
 341
 342                 if(found) {
 343                         continue;
 344                 }
 345
 346                 // Create a new struct addrinfo, and put it at the head of the list.
 347                 struct addrinfo *nai = xzalloc(sizeof(*nai) + SALEN(e->reverse->address.sa));
 348                 nai->ai_next = ai;
 349                 ai = nai;
 350
 351                 ai->ai_family = e->reverse->address.sa.sa_family;
 352                 ai->ai_socktype = SOCK_STREAM;
 353                 ai->ai_protocol = IPPROTO_TCP;
 354                 ai->ai_addrlen = SALEN(e->reverse->address.sa);
 355                 ai->ai_addr = (struct sockaddr *)(nai + 1);
 356                 memcpy(ai->ai_addr, &e->reverse->address, ai->ai_addrlen);
 357         }
 358
 359         return ai;
 360 }
 361
 362 // Build a list of recently seen addresses.
 363 static struct addrinfo *get_recent_addresses(node_t *n) {
 364         struct addrinfo *ai = NULL;
 365         struct addrinfo *aip;
 366
 367         for(int i = 0; i < 5; i++) {
 368                 if(!n->recent[i].sa.sa_family) {
 369                         break;
 370                 }
 371
 372                 // Create a new struct addrinfo, and put it at the end of the list.
 373                 struct addrinfo *nai = xzalloc(sizeof(*nai) + SALEN(n->recent[i].sa));
 374
 375                 if(!ai) {
 376                         ai = nai;
 377                 } else {
 378                         aip->ai_next = nai;
 379                 }
 380
 381                 aip = nai;
 382
 383                 nai->ai_family = n->recent[i].sa.sa_family;
 384                 nai->ai_socktype = SOCK_STREAM;
 385                 nai->ai_protocol = IPPROTO_TCP;
 386                 nai->ai_addrlen = SALEN(n->recent[i].sa);
 387                 nai->ai_addr = (struct sockaddr *)(nai + 1);
 388                 memcpy(nai->ai_addr, &n->recent[i], nai->ai_addrlen);
 389         }
 390
 391         return ai;
 392 }
 393
 394 // Free struct addrinfo list from get_known_addresses().
 395 static void free_known_addresses(struct addrinfo *ai) {
 396         for(struct addrinfo *aip = ai, *next; aip; aip = next) {
 397                 next = aip->ai_next;
 398                 free(aip);
 399         }
 400 }
 401
 402 static struct addrinfo *get_canonical_address(node_t *n) {
 403         if(!n->canonical_address) {
 404                 return false;
 405         }
 406
 407         char *address = xstrdup(n->canonical_address);
 408         char *port = strchr(address, ' ');
 409
 410         if(!port) {
 411                 free(address);
 412                 return false;
 413         }
 414
 415         *port++ = 0;
 416
 417         struct addrinfo *ai = str2addrinfo(address, port, SOCK_STREAM);
 418         free(address);
 419
 420         return ai;
 421 }
 422
 423 static bool get_next_outgoing_address(meshlink_handle_t *mesh, outgoing_t *outgoing) {
 424         (void)mesh;
 425
 426         bool start = false;
 427
 428         if(outgoing->state == OUTGOING_START) {
 429                 start = true;
 430                 outgoing->state = OUTGOING_CANONICAL;
 431         }
 432
 433         if(outgoing->state == OUTGOING_CANONICAL) {
 434                 if(!outgoing->aip) {
 435                         outgoing->ai = get_canonical_address(outgoing->node);
 436                         outgoing->aip = outgoing->ai;
 437                 } else {
 438                         outgoing->aip = outgoing->aip->ai_next;
 439                 }
 440
 441                 if(outgoing->aip) {
 442                         return true;
 443                 }
 444
 445                 freeaddrinfo(outgoing->ai);
 446                 outgoing->ai = NULL;
 447                 outgoing->aip = NULL;
 448                 outgoing->state = OUTGOING_RECENT;
 449         }
 450
 451         if(outgoing->state == OUTGOING_RECENT) {
 452                 if(!outgoing->aip) {
 453                         outgoing->ai = get_recent_addresses(outgoing->node);
 454                         outgoing->aip = outgoing->ai;
 455                 } else {
 456                         outgoing->aip = outgoing->aip->ai_next;
 457                 }
 458
 459                 if(outgoing->aip) {
 460                         return true;
 461                 }
 462
 463                 free_known_addresses(outgoing->ai);
 464                 outgoing->ai = NULL;
 465                 outgoing->aip = NULL;
 466                 outgoing->state = OUTGOING_KNOWN;
 467         }
 468
 469         if(outgoing->state == OUTGOING_KNOWN) {
 470                 if(!outgoing->aip) {
 471                         outgoing->ai = get_known_addresses(outgoing->node);
 472                         outgoing->aip = outgoing->ai;
 473                 } else {
 474                         outgoing->aip = outgoing->aip->ai_next;
 475                 }
 476
 477                 if(outgoing->aip) {
 478                         return true;
 479                 }
 480
 481                 free_known_addresses(outgoing->ai);
 482                 outgoing->ai = NULL;
 483                 outgoing->aip = NULL;
 484                 outgoing->state = OUTGOING_END;
 485         }
 486
 487         if(start) {
 488                 outgoing->state = OUTGOING_NO_KNOWN_ADDRESSES;
 489         }
 490
 491         return false;
 492 }
 493
 494 bool do_outgoing_connection(meshlink_handle_t *mesh, outgoing_t *outgoing) {
 495         struct addrinfo *proxyai = NULL;
 496         int result;
 497
 498 begin:
 499
 500         if(!get_next_outgoing_address(mesh, outgoing)) {
 501                 if(outgoing->state == OUTGOING_NO_KNOWN_ADDRESSES) {
 502                         logger(mesh, MESHLINK_ERROR, "No known addresses for %s", outgoing->node->name);
 503                 } else {
 504                         logger(mesh, MESHLINK_ERROR, "Could not set up a meta connection to %s", outgoing->node->name);
 505                         retry_outgoing(mesh, outgoing);
 506                 }
 507
 508                 return false;
 509         }
 510
 511         connection_t *c = new_connection();
 512         c->outgoing = outgoing;
 513
 514         memcpy(&c->address, outgoing->aip->ai_addr, outgoing->aip->ai_addrlen);
 515
 516         char *hostname = sockaddr2hostname(&c->address);
 517
 518         logger(mesh, MESHLINK_INFO, "Trying to connect to %s at %s", outgoing->node->name, hostname);
 519
 520         if(!mesh->proxytype) {
 521                 c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 522                 configure_tcp(c);
 523         } else {
 524                 proxyai = str2addrinfo(mesh->proxyhost, mesh->proxyport, SOCK_STREAM);
 525
 526                 if(!proxyai) {
 527                         free_connection(c);
 528                         free(hostname);
 529                         goto begin;
 530                 }
 531
 532                 logger(mesh, MESHLINK_INFO, "Using proxy at %s port %s", mesh->proxyhost, mesh->proxyport);
 533                 c->socket = socket(proxyai->ai_family, SOCK_STREAM, IPPROTO_TCP);
 534                 configure_tcp(c);
 535         }
 536
 537         if(c->socket == -1) {
 538                 logger(mesh, MESHLINK_ERROR, "Creating socket for %s at %s failed: %s", c->name, hostname, sockstrerror(sockerrno));
 539                 free_connection(c);
 540                 free(hostname);
 541                 goto begin;
 542         }
 543
 544         free(hostname);
 545
 546 #ifdef FD_CLOEXEC
 547         fcntl(c->socket, F_SETFD, FD_CLOEXEC);
 548 #endif
 549
 550 #if defined(IPV6_V6ONLY)
 551
 552         if(c->address.sa.sa_family == AF_INET6) {
 553                 static const int option = 1;
 554                 setsockopt(c->socket, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
 555         }
 556
 557 #endif
 558
 559         bind_to_address(mesh, c);
 560
 561         /* Connect */
 562
 563         if(!mesh->proxytype) {
 564                 result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 565         } else {
 566                 result = connect(c->socket, proxyai->ai_addr, proxyai->ai_addrlen);
 567                 freeaddrinfo(proxyai);
 568         }
 569
 570         if(result == -1 && !sockinprogress(sockerrno)) {
 571                 logger(mesh, MESHLINK_ERROR, "Could not connect to %s: %s", outgoing->node->name, sockstrerror(sockerrno));
 572                 free_connection(c);
 573
 574                 goto begin;
 575         }
 576
 577         /* Now that there is a working socket, fill in the rest and register this connection. */
 578
 579         c->status.connecting = true;
 580         c->status.initiator = true;
 581         c->name = xstrdup(outgoing->node->name);
 582         c->last_ping_time = mesh->loop.now.tv_sec;
 583
 584         connection_add(mesh, c);
 585
 586         io_add(&mesh->loop, &c->io, handle_meta_io, c, c->socket, IO_READ | IO_WRITE);
 587
 588         return true;
 589 }
 590
 591 void setup_outgoing_connection(meshlink_handle_t *mesh, outgoing_t *outgoing) {
 592         timeout_del(&mesh->loop, &outgoing->ev);
 593
 594         if(outgoing->node->connection) {
 595                 logger(mesh, MESHLINK_INFO, "Already connected to %s", outgoing->node->name);
 596
 597                 outgoing->node->connection->outgoing = outgoing;
 598                 return;
 599         }
 600
 601
 602         if(outgoing->ai) {
 603                 if(outgoing->state == OUTGOING_RECENT || outgoing->state == OUTGOING_KNOWN) {
 604                         free_known_addresses(outgoing->ai);
 605                 } else {
 606                         freeaddrinfo(outgoing->ai);
 607                 }
 608         }
 609
 610         outgoing->state = OUTGOING_START;
 611
 612         if(outgoing->node->status.blacklisted) {
 613                 return;
 614         }
 615
 616         if(mesh->connection_try_cb) {
 617                 mesh->connection_try_cb(mesh, (meshlink_node_t *)outgoing->node);
 618         }
 619
 620         do_outgoing_connection(mesh, outgoing);
 621 }
 622
 623 /// Delayed close of a filedescriptor.
 624 static void tarpit(meshlink_handle_t *mesh, int fd) {
 625         if(!fd) {
 626                 return;
 627         }
 628
 629         if(mesh->pits[mesh->next_pit]) {
 630                 closesocket(mesh->pits[mesh->next_pit]);
 631         }
 632
 633         mesh->pits[mesh->next_pit++] = fd;
 634
 635         if(mesh->next_pit >= (int)(sizeof mesh->pits / sizeof mesh->pits[0])) {
 636                 mesh->next_pit = 0;
 637         }
 638 }
 639
 640 /*
 641   accept a new tcp connect and create a
 642   new connection
 643 */
 644 void handle_new_meta_connection(event_loop_t *loop, void *data, int flags) {
 645         (void)flags;
 646         meshlink_handle_t *mesh = loop->data;
 647         listen_socket_t *l = data;
 648         connection_t *c;
 649         sockaddr_t sa;
 650         int fd;
 651         socklen_t len = sizeof(sa);
 652
 653         memset(&sa, 0, sizeof(sa));
 654
 655         fd = accept(l->tcp.fd, &sa.sa, &len);
 656
 657         if(fd < 0) {
 658                 if(errno == EINVAL) { // TODO: check if Windows agrees
 659                         event_loop_stop(loop);
 660                         return;
 661                 }
 662
 663                 logger(mesh, MESHLINK_ERROR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
 664                 return;
 665         }
 666
 667         sockaddrunmap(&sa);
 668
 669         /* Rate limit incoming connections to max_connection_burst/second. */
 670
 671         if(mesh->loop.now.tv_sec != mesh->connection_burst_time) {
 672                 mesh->connection_burst_time = mesh->loop.now.tv_sec;
 673                 mesh->connection_burst = 0;
 674         }
 675
 676         if(mesh->connection_burst >= max_connection_burst) {
 677                 tarpit(mesh, fd);
 678                 return;
 679         }
 680
 681         mesh->connection_burst++;
 682
 683         // Accept the new connection
 684
 685         c = new_connection();
 686         c->name = xstrdup("<unknown>");
 687
 688         c->address = sa;
 689         c->socket = fd;
 690         c->last_ping_time = mesh->loop.now.tv_sec;
 691
 692         char *hostname = sockaddr2hostname(&sa);
 693         logger(mesh, MESHLINK_INFO, "Connection from %s", hostname);
 694         free(hostname);
 695
 696         io_add(&mesh->loop, &c->io, handle_meta_io, c, c->socket, IO_READ);
 697
 698         configure_tcp(c);
 699
 700         connection_add(mesh, c);
 701
 702         c->allow_request = ID;
 703         send_id(mesh, c);
 704 }
 705
 706 static void free_outgoing(outgoing_t *outgoing) {
 707         meshlink_handle_t *mesh = outgoing->node->mesh;
 708
 709         timeout_del(&mesh->loop, &outgoing->ev);
 710
 711         if(outgoing->ai) {
 712                 if(outgoing->state == OUTGOING_RECENT || outgoing->state == OUTGOING_KNOWN) {
 713                         free_known_addresses(outgoing->ai);
 714                 } else {
 715                         freeaddrinfo(outgoing->ai);
 716                 }
 717         }
 718
 719         free(outgoing);
 720 }
 721
 722 void init_outgoings(meshlink_handle_t *mesh) {
 723         mesh->outgoings = list_alloc((list_action_t)free_outgoing);
 724 }
 725
 726 void exit_outgoings(meshlink_handle_t *mesh) {
 727         if(mesh->outgoings) {
 728                 list_delete_list(mesh->outgoings);
 729                 mesh->outgoings = NULL;
 730         }
 731 }