www.tinc-vpn.org Git - tinc/blob - src/net_socket.c

   1 /*
   2     net_socket.c -- Handle various kinds of sockets.
   3     Copyright (C) 1998-2005 Ivo Timmermans,
   4                   2000-2014 Guus Sliepen <guus@tinc-vpn.org>
   5                   2006      Scott Lamb <slamb@slamb.org>
   6                   2009      Florian Forster <octo@verplant.org>
   7
   8     This program is free software; you can redistribute it and/or modify
   9     it under the terms of the GNU General Public License as published by
  10     the Free Software Foundation; either version 2 of the License, or
  11     (at your option) any later version.
  12
  13     This program is distributed in the hope that it will be useful,
  14     but WITHOUT ANY WARRANTY; without even the implied warranty of
  15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16     GNU General Public License for more details.
  17
  18     You should have received a copy of the GNU General Public License along
  19     with this program; if not, write to the Free Software Foundation, Inc.,
  20     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21 */
  22
  23 #include "system.h"
  24
  25 #include "conf.h"
  26 #include "connection.h"
  27 #include "control_common.h"
  28 #include "list.h"
  29 #include "logger.h"
  30 #include "meta.h"
  31 #include "names.h"
  32 #include "net.h"
  33 #include "netutl.h"
  34 #include "protocol.h"
  35 #include "utils.h"
  36 #include "xalloc.h"
  37
  38 /* Needed on Mac OS/X */
  39 #ifndef SOL_TCP
  40 #define SOL_TCP IPPROTO_TCP
  41 #endif
  42
  43 int addressfamily = AF_UNSPEC;
  44 int maxtimeout = 900;
  45 int seconds_till_retry = 5;
  46 int udp_rcvbuf = 0;
  47 int udp_sndbuf = 0;
  48 int max_connection_burst = 100;
  49
  50 listen_socket_t listen_socket[MAXSOCKETS];
  51 int listen_sockets;
  52 #ifndef HAVE_MINGW
  53 io_t unix_socket;
  54 #endif
  55 list_t *outgoing_list = NULL;
  56
  57 /* Setup sockets */
  58
  59 static void configure_tcp(connection_t *c) {
  60         int option;
  61
  62 #ifdef O_NONBLOCK
  63         int flags = fcntl(c->socket, F_GETFL);
  64
  65         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
  66                 logger(DEBUG_ALWAYS, LOG_ERR, "fcntl for %s: %s", c->hostname, strerror(errno));
  67         }
  68 #elif defined(WIN32)
  69         unsigned long arg = 1;
  70
  71         if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
  72                 logger(DEBUG_ALWAYS, LOG_ERR, "ioctlsocket for %s: %s", c->hostname, sockstrerror(sockerrno));
  73         }
  74 #endif
  75
  76 #if defined(SOL_TCP) && defined(TCP_NODELAY)
  77         option = 1;
  78         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, (void *)&option, sizeof option);
  79 #endif
  80
  81 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
  82         option = IPTOS_LOWDELAY;
  83         setsockopt(c->socket, SOL_IP, IP_TOS, (void *)&option, sizeof option);
  84 #endif
  85 }
  86
  87 static bool bind_to_interface(int sd) {
  88         char *iface;
  89
  90 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
  91         struct ifreq ifr;
  92         int status;
  93 #endif /* defined(SOL_SOCKET) && defined(SO_BINDTODEVICE) */
  94
  95         if(!get_config_string (lookup_config (config_tree, "BindToInterface"), &iface))
  96                 return true;
  97
  98 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
  99         memset(&ifr, 0, sizeof(ifr));
 100         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 101         ifr.ifr_ifrn.ifrn_name[IFNAMSIZ - 1] = 0;
 102
 103         status = setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr));
 104         if(status) {
 105                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
 106                                 sockstrerror(sockerrno));
 107                 return false;
 108         }
 109 #else /* if !defined(SOL_SOCKET) || !defined(SO_BINDTODEVICE) */
 110         logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform", "BindToInterface");
 111 #endif
 112
 113         return true;
 114 }
 115
 116 static bool bind_to_address(connection_t *c) {
 117         int s = -1;
 118
 119         for(int i = 0; i < listen_sockets && listen_socket[i].bindto; i++) {
 120                 if(listen_socket[i].sa.sa.sa_family != c->address.sa.sa_family)
 121                         continue;
 122                 if(s >= 0)
 123                         return false;
 124                 s = i;
 125         }
 126
 127         if(s < 0)
 128                 return false;
 129
 130         sockaddr_t sa = listen_socket[s].sa;
 131         if(sa.sa.sa_family == AF_INET)
 132                 sa.in.sin_port = 0;
 133         else if(sa.sa.sa_family == AF_INET6)
 134                 sa.in6.sin6_port = 0;
 135
 136         if(bind(c->socket, &sa.sa, SALEN(sa.sa))) {
 137                 logger(DEBUG_CONNECTIONS, LOG_WARNING, "Can't bind outgoing socket: %s", sockstrerror(sockerrno));
 138                 return false;
 139         }
 140
 141         return true;
 142 }
 143
 144 int setup_listen_socket(const sockaddr_t *sa) {
 145         int nfd;
 146         char *addrstr;
 147         int option;
 148         char *iface;
 149
 150         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 151
 152         if(nfd < 0) {
 153                 logger(DEBUG_STATUS, LOG_ERR, "Creating metasocket failed: %s", sockstrerror(sockerrno));
 154                 return -1;
 155         }
 156
 157 #ifdef FD_CLOEXEC
 158         fcntl(nfd, F_SETFD, FD_CLOEXEC);
 159 #endif
 160
 161         /* Optimize TCP settings */
 162
 163         option = 1;
 164         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof option);
 165
 166 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 167         if(sa->sa.sa_family == AF_INET6)
 168                 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
 169 #endif
 170
 171         if(get_config_string
 172            (lookup_config(config_tree, "BindToInterface"), &iface)) {
 173 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 174                 struct ifreq ifr;
 175
 176                 memset(&ifr, 0, sizeof ifr);
 177                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 178
 179                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof ifr)) {
 180                         closesocket(nfd);
 181                         logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
 182                                    sockstrerror(sockerrno));
 183                         return -1;
 184                 }
 185 #else
 186                 logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform", "BindToInterface");
 187 #endif
 188         }
 189
 190         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 191                 closesocket(nfd);
 192                 addrstr = sockaddr2hostname(sa);
 193                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/tcp: %s", addrstr, sockstrerror(sockerrno));
 194                 free(addrstr);
 195                 return -1;
 196         }
 197
 198         if(listen(nfd, 3)) {
 199                 closesocket(nfd);
 200                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "listen", sockstrerror(sockerrno));
 201                 return -1;
 202         }
 203
 204         return nfd;
 205 }
 206
 207 int setup_vpn_in_socket(const sockaddr_t *sa) {
 208         int nfd;
 209         char *addrstr;
 210         int option;
 211
 212         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 213
 214         if(nfd < 0) {
 215                 logger(DEBUG_ALWAYS, LOG_ERR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
 216                 return -1;
 217         }
 218
 219 #ifdef FD_CLOEXEC
 220         fcntl(nfd, F_SETFD, FD_CLOEXEC);
 221 #endif
 222
 223 #ifdef O_NONBLOCK
 224         {
 225                 int flags = fcntl(nfd, F_GETFL);
 226
 227                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 228                         closesocket(nfd);
 229                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "fcntl",
 230                                    strerror(errno));
 231                         return -1;
 232                 }
 233         }
 234 #elif defined(WIN32)
 235         {
 236                 unsigned long arg = 1;
 237                 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 238                         closesocket(nfd);
 239                         logger(DEBUG_ALWAYS, LOG_ERR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
 240                         return -1;
 241                 }
 242         }
 243 #endif
 244
 245         option = 1;
 246         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof option);
 247         setsockopt(nfd, SOL_SOCKET, SO_BROADCAST, (void *)&option, sizeof option);
 248
 249         if(udp_rcvbuf && setsockopt(nfd, SOL_SOCKET, SO_RCVBUF, (void *)&udp_rcvbuf, sizeof(udp_rcvbuf)))
 250                 logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP SO_RCVBUF to %i: %s", udp_rcvbuf, sockstrerror(sockerrno));
 251
 252         if(udp_sndbuf && setsockopt(nfd, SOL_SOCKET, SO_SNDBUF, (void *)&udp_sndbuf, sizeof(udp_sndbuf)))
 253                 logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP SO_SNDBUF to %i: %s", udp_sndbuf, sockstrerror(sockerrno));
 254
 255 #if defined(IPPROTO_IPV6) && defined(IPV6_V6ONLY)
 256         if(sa->sa.sa_family == AF_INET6)
 257                 setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
 258 #endif
 259
 260 #if defined(IP_DONTFRAG) && !defined(IP_DONTFRAGMENT)
 261 #define IP_DONTFRAGMENT IP_DONTFRAG
 262 #endif
 263
 264 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 265         if(myself->options & OPTION_PMTU_DISCOVERY) {
 266                 option = IP_PMTUDISC_DO;
 267                 setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
 268         }
 269 #elif defined(IPPROTO_IP) && defined(IP_DONTFRAGMENT)
 270         if(myself->options & OPTION_PMTU_DISCOVERY) {
 271                 option = 1;
 272                 setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, (void *)&option, sizeof(option));
 273         }
 274 #endif
 275
 276 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 277         if(myself->options & OPTION_PMTU_DISCOVERY) {
 278                 option = IPV6_PMTUDISC_DO;
 279                 setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
 280         }
 281 #elif defined(IPPROTO_IPV6) && defined(IPV6_DONTFRAG)
 282         if(myself->options & OPTION_PMTU_DISCOVERY) {
 283                 option = 1;
 284                 setsockopt(nfd, IPPROTO_IPV6, IPV6_DONTFRAG, (void *)&option, sizeof(option));
 285         }
 286 #endif
 287
 288         if (!bind_to_interface(nfd)) {
 289                 closesocket(nfd);
 290                 return -1;
 291         }
 292
 293         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 294                 closesocket(nfd);
 295                 addrstr = sockaddr2hostname(sa);
 296                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/udp: %s", addrstr, sockstrerror(sockerrno));
 297                 free(addrstr);
 298                 return -1;
 299         }
 300
 301         return nfd;
 302 } /* int setup_vpn_in_socket */
 303
 304 static void retry_outgoing_handler(void *data) {
 305         setup_outgoing_connection(data);
 306 }
 307
 308 void retry_outgoing(outgoing_t *outgoing) {
 309         outgoing->timeout += 5;
 310
 311         if(outgoing->timeout > maxtimeout)
 312                 outgoing->timeout = maxtimeout;
 313
 314         timeout_add(&outgoing->ev, retry_outgoing_handler, outgoing, &(struct timeval){outgoing->timeout, rand() % 100000});
 315
 316         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Trying to re-establish outgoing connection in %d seconds", outgoing->timeout);
 317 }
 318
 319 void finish_connecting(connection_t *c) {
 320         logger(DEBUG_CONNECTIONS, LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
 321
 322         c->last_ping_time = now.tv_sec;
 323         c->status.connecting = false;
 324
 325         send_id(c);
 326 }
 327
 328 static void do_outgoing_pipe(connection_t *c, char *command) {
 329 #ifndef HAVE_MINGW
 330         int fd[2];
 331
 332         if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
 333                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not create socketpair: %s", sockstrerror(sockerrno));
 334                 return;
 335         }
 336
 337         if(fork()) {
 338                 c->socket = fd[0];
 339                 close(fd[1]);
 340                 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Using proxy %s", command);
 341                 return;
 342         }
 343
 344         close(0);
 345         close(1);
 346         close(fd[0]);
 347         dup2(fd[1], 0);
 348         dup2(fd[1], 1);
 349         close(fd[1]);
 350
 351         // Other filedescriptors should be closed automatically by CLOEXEC
 352
 353         char *host = NULL;
 354         char *port = NULL;
 355
 356         sockaddr2str(&c->address, &host, &port);
 357         setenv("REMOTEADDRESS", host, true);
 358         setenv("REMOTEPORT", port, true);
 359         setenv("NODE", c->name, true);
 360         setenv("NAME", myself->name, true);
 361         if(netname)
 362                 setenv("NETNAME", netname, true);
 363
 364         int result = system(command);
 365         if(result < 0)
 366                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not execute %s: %s", command, strerror(errno));
 367         else if(result)
 368                 logger(DEBUG_ALWAYS, LOG_ERR, "%s exited with non-zero status %d", command, result);
 369         exit(result);
 370 #else
 371         logger(DEBUG_ALWAYS, LOG_ERR, "Proxy type exec not supported on this platform!");
 372         return;
 373 #endif
 374 }
 375
 376 static void handle_meta_write(connection_t *c) {
 377         if(c->outbuf.len <= c->outbuf.offset)
 378                 return;
 379
 380         ssize_t outlen = send(c->socket, c->outbuf.data + c->outbuf.offset, c->outbuf.len - c->outbuf.offset, 0);
 381         if(outlen <= 0) {
 382                 if(!sockerrno || sockerrno == EPIPE) {
 383                         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection closed by %s (%s)", c->name, c->hostname);
 384                 } else if(sockwouldblock(sockerrno)) {
 385                         logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Sending %d bytes to %s (%s) would block", c->outbuf.len - c->outbuf.offset, c->name, c->hostname);
 386                         return;
 387                 } else {
 388                         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, sockstrerror(sockerrno));
 389                 }
 390
 391                 terminate_connection(c, c->status.active);
 392                 return;
 393         }
 394
 395         buffer_read(&c->outbuf, outlen);
 396         if(!c->outbuf.len)
 397                 io_set(&c->io, IO_READ);
 398 }
 399
 400 static void handle_meta_io(void *data, int flags) {
 401         connection_t *c = data;
 402
 403         if(c->status.connecting) {
 404                 c->status.connecting = false;
 405
 406                 int result;
 407                 socklen_t len = sizeof result;
 408                 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, (void *)&result, &len);
 409
 410                 if(!result)
 411                         finish_connecting(c);
 412                 else {
 413                         logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Error while connecting to %s (%s): %s", c->name, c->hostname, sockstrerror(result));
 414                         terminate_connection(c, false);
 415                         return;
 416                 }
 417         }
 418
 419         if(flags & IO_WRITE)
 420                 handle_meta_write(c);
 421         else
 422                 handle_meta_connection_data(c);
 423 }
 424
 425 bool do_outgoing_connection(outgoing_t *outgoing) {
 426         char *address, *port, *space;
 427         struct addrinfo *proxyai = NULL;
 428         int result;
 429
 430 begin:
 431         if(!outgoing->ai) {
 432                 if(!outgoing->cfg) {
 433                         logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not set up a meta connection to %s", outgoing->name);
 434                         retry_outgoing(outgoing);
 435                         return false;
 436                 }
 437
 438                 get_config_string(outgoing->cfg, &address);
 439
 440                 space = strchr(address, ' ');
 441                 if(space) {
 442                         port = xstrdup(space + 1);
 443                         *space = 0;
 444                 } else {
 445                         if(!get_config_string(lookup_config(outgoing->config_tree, "Port"), &port))
 446                                 port = xstrdup("655");
 447                 }
 448
 449                 outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 450                 free(address);
 451                 free(port);
 452
 453                 outgoing->aip = outgoing->ai;
 454                 outgoing->cfg = lookup_config_next(outgoing->config_tree, outgoing->cfg);
 455         }
 456
 457         if(!outgoing->aip) {
 458                 if(outgoing->ai)
 459                         freeaddrinfo(outgoing->ai);
 460                 outgoing->ai = NULL;
 461                 goto begin;
 462         }
 463
 464         connection_t *c = new_connection();
 465         c->outgoing = outgoing;
 466
 467         memcpy(&c->address, outgoing->aip->ai_addr, outgoing->aip->ai_addrlen);
 468         outgoing->aip = outgoing->aip->ai_next;
 469
 470         c->hostname = sockaddr2hostname(&c->address);
 471
 472         logger(DEBUG_CONNECTIONS, LOG_INFO, "Trying to connect to %s (%s)", outgoing->name, c->hostname);
 473
 474         if(!proxytype) {
 475                 c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 476                 configure_tcp(c);
 477         } else if(proxytype == PROXY_EXEC) {
 478                 do_outgoing_pipe(c, proxyhost);
 479         } else {
 480                 proxyai = str2addrinfo(proxyhost, proxyport, SOCK_STREAM);
 481                 if(!proxyai) {
 482                         free_connection(c);
 483                         goto begin;
 484                 }
 485                 logger(DEBUG_CONNECTIONS, LOG_INFO, "Using proxy at %s port %s", proxyhost, proxyport);
 486                 c->socket = socket(proxyai->ai_family, SOCK_STREAM, IPPROTO_TCP);
 487                 configure_tcp(c);
 488         }
 489
 490         if(c->socket == -1) {
 491                 logger(DEBUG_CONNECTIONS, LOG_ERR, "Creating socket for %s failed: %s", c->hostname, sockstrerror(sockerrno));
 492                 free_connection(c);
 493                 goto begin;
 494         }
 495
 496 #ifdef FD_CLOEXEC
 497         fcntl(c->socket, F_SETFD, FD_CLOEXEC);
 498 #endif
 499
 500         if(proxytype != PROXY_EXEC) {
 501 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 502                 int option = 1;
 503                 if(c->address.sa.sa_family == AF_INET6)
 504                         setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
 505 #endif
 506
 507                 bind_to_interface(c->socket);
 508                 bind_to_address(c);
 509         }
 510
 511         /* Connect */
 512
 513         if(!proxytype) {
 514                 result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 515         } else if(proxytype == PROXY_EXEC) {
 516                 result = 0;
 517         } else {
 518                 result = connect(c->socket, proxyai->ai_addr, proxyai->ai_addrlen);
 519                 freeaddrinfo(proxyai);
 520         }
 521
 522         if(result == -1 && !sockinprogress(sockerrno)) {
 523                 logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not connect to %s (%s): %s", outgoing->name, c->hostname, sockstrerror(sockerrno));
 524                 free_connection(c);
 525
 526                 goto begin;
 527         }
 528
 529         /* Now that there is a working socket, fill in the rest and register this connection. */
 530
 531         c->status.connecting = true;
 532         c->name = xstrdup(outgoing->name);
 533         c->outcipher = myself->connection->outcipher;
 534         c->outdigest = myself->connection->outdigest;
 535         c->outmaclength = myself->connection->outmaclength;
 536         c->outcompression = myself->connection->outcompression;
 537         c->last_ping_time = now.tv_sec;
 538
 539         connection_add(c);
 540
 541         io_add(&c->io, handle_meta_io, c, c->socket, IO_READ|IO_WRITE);
 542
 543         return true;
 544 }
 545
 546 // Find edges pointing to this node, and use them to build a list of unique, known addresses.
 547 static struct addrinfo *get_known_addresses(node_t *n) {
 548         struct addrinfo *ai = NULL;
 549
 550         for splay_each(edge_t, e, n->edge_tree) {
 551                 if(!e->reverse)
 552                         continue;
 553
 554                 bool found = false;
 555                 for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
 556                         if(!sockaddrcmp(&e->reverse->address, (sockaddr_t *)aip->ai_addr)) {
 557                                 found = true;
 558                                 break;
 559                         }
 560                 }
 561                 if(found)
 562                         continue;
 563
 564                 struct addrinfo *nai = xzalloc(sizeof *nai);
 565                 if(ai)
 566                         ai->ai_next = nai;
 567                 ai = nai;
 568                 ai->ai_family = e->reverse->address.sa.sa_family;
 569                 ai->ai_socktype = SOCK_STREAM;
 570                 ai->ai_protocol = IPPROTO_TCP;
 571                 ai->ai_addrlen = SALEN(e->reverse->address.sa);
 572                 ai->ai_addr = xmalloc(ai->ai_addrlen);
 573                 memcpy(ai->ai_addr, &e->reverse->address, ai->ai_addrlen);
 574         }
 575
 576         return ai;
 577 }
 578
 579 void setup_outgoing_connection(outgoing_t *outgoing) {
 580         timeout_del(&outgoing->ev);
 581
 582         node_t *n = lookup_node(outgoing->name);
 583
 584         if(n && n->connection) {
 585                 logger(DEBUG_CONNECTIONS, LOG_INFO, "Already connected to %s", outgoing->name);
 586
 587                 n->connection->outgoing = outgoing;
 588                 return;
 589         }
 590
 591         init_configuration(&outgoing->config_tree);
 592         read_host_config(outgoing->config_tree, outgoing->name);
 593         outgoing->cfg = lookup_config(outgoing->config_tree, "Address");
 594
 595         if(!outgoing->cfg) {
 596                 if(n)
 597                         outgoing->aip = outgoing->ai = get_known_addresses(n);
 598                 if(!outgoing->ai) {
 599                         logger(DEBUG_ALWAYS, LOG_ERR, "No address known for %s", outgoing->name);
 600                         return;
 601                 }
 602         }
 603
 604         do_outgoing_connection(outgoing);
 605 }
 606
 607 /*
 608   accept a new tcp connect and create a
 609   new connection
 610 */
 611 void handle_new_meta_connection(void *data, int flags) {
 612         listen_socket_t *l = data;
 613         connection_t *c;
 614         sockaddr_t sa;
 615         int fd;
 616         socklen_t len = sizeof sa;
 617
 618         fd = accept(l->tcp.fd, &sa.sa, &len);
 619
 620         if(fd < 0) {
 621                 logger(DEBUG_ALWAYS, LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
 622                 return;
 623         }
 624
 625         sockaddrunmap(&sa);
 626
 627         // Check if we get many connections from the same host
 628
 629         static sockaddr_t prev_sa;
 630         static int tarpit = -1;
 631
 632         if(tarpit >= 0) {
 633                 closesocket(tarpit);
 634                 tarpit = -1;
 635         }
 636
 637         if(!sockaddrcmp_noport(&sa, &prev_sa)) {
 638                 static int samehost_burst;
 639                 static int samehost_burst_time;
 640
 641                 if(now.tv_sec - samehost_burst_time > samehost_burst)
 642                         samehost_burst = 0;
 643                 else
 644                         samehost_burst -= now.tv_sec - samehost_burst_time;
 645
 646                 samehost_burst_time = now.tv_sec;
 647                 samehost_burst++;
 648
 649                 if(samehost_burst > max_connection_burst) {
 650                         tarpit = fd;
 651                         return;
 652                 }
 653         }
 654
 655         memcpy(&prev_sa, &sa, sizeof sa);
 656
 657         // Check if we get many connections from different hosts
 658
 659         static int connection_burst;
 660         static int connection_burst_time;
 661
 662         if(now.tv_sec - connection_burst_time > connection_burst)
 663                 connection_burst = 0;
 664         else
 665                 connection_burst -= now.tv_sec - connection_burst_time;
 666
 667         connection_burst_time = now.tv_sec;
 668         connection_burst++;
 669
 670         if(connection_burst >= max_connection_burst) {
 671                 connection_burst = max_connection_burst;
 672                 tarpit = fd;
 673                 return;
 674         }
 675
 676         // Accept the new connection
 677
 678         c = new_connection();
 679         c->name = xstrdup("<unknown>");
 680         c->outcipher = myself->connection->outcipher;
 681         c->outdigest = myself->connection->outdigest;
 682         c->outmaclength = myself->connection->outmaclength;
 683         c->outcompression = myself->connection->outcompression;
 684
 685         c->address = sa;
 686         c->hostname = sockaddr2hostname(&sa);
 687         c->socket = fd;
 688         c->last_ping_time = now.tv_sec;
 689
 690         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection from %s", c->hostname);
 691
 692         io_add(&c->io, handle_meta_io, c, c->socket, IO_READ);
 693
 694         configure_tcp(c);
 695
 696         connection_add(c);
 697
 698         c->allow_request = ID;
 699         send_id(c);
 700 }
 701
 702 #ifndef HAVE_MINGW
 703 /*
 704   accept a new UNIX socket connection
 705 */
 706 void handle_new_unix_connection(void *data, int flags) {
 707         io_t *io = data;
 708         connection_t *c;
 709         sockaddr_t sa;
 710         int fd;
 711         socklen_t len = sizeof sa;
 712
 713         fd = accept(io->fd, &sa.sa, &len);
 714
 715         if(fd < 0) {
 716                 logger(DEBUG_ALWAYS, LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
 717                 return;
 718         }
 719
 720         sockaddrunmap(&sa);
 721
 722         c = new_connection();
 723         c->name = xstrdup("<control>");
 724         c->address = sa;
 725         c->hostname = xstrdup("localhost port unix");
 726         c->socket = fd;
 727         c->last_ping_time = now.tv_sec;
 728
 729         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection from %s", c->hostname);
 730
 731         io_add(&c->io, handle_meta_io, c, c->socket, IO_READ);
 732
 733         connection_add(c);
 734
 735         c->allow_request = ID;
 736
 737         send_id(c);
 738 }
 739 #endif
 740
 741 static void free_outgoing(outgoing_t *outgoing) {
 742         timeout_del(&outgoing->ev);
 743
 744         if(outgoing->ai)
 745                 freeaddrinfo(outgoing->ai);
 746
 747         if(outgoing->config_tree)
 748                 exit_configuration(&outgoing->config_tree);
 749
 750         if(outgoing->name)
 751                 free(outgoing->name);
 752
 753         free(outgoing);
 754 }
 755
 756 void try_outgoing_connections(void) {
 757         /* If there is no outgoing list yet, create one. Otherwise, mark all outgoings as deleted. */
 758
 759         if(!outgoing_list) {
 760                 outgoing_list = list_alloc((list_action_t)free_outgoing);
 761         } else {
 762                 for list_each(outgoing_t, outgoing, outgoing_list)
 763                         outgoing->timeout = -1;
 764         }
 765
 766         /* Make sure there is one outgoing_t in the list for each ConnectTo. */
 767
 768         for(config_t *cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 769                 char *name;
 770                 get_config_string(cfg, &name);
 771
 772                 if(!check_id(name)) {
 773                         logger(DEBUG_ALWAYS, LOG_ERR,
 774                                    "Invalid name for outgoing connection in %s line %d",
 775                                    cfg->file, cfg->line);
 776                         free(name);
 777                         continue;
 778                 }
 779
 780                 bool found = false;
 781
 782                 for list_each(outgoing_t, outgoing, outgoing_list) {
 783                         if(!strcmp(outgoing->name, name)) {
 784                                 found = true;
 785                                 outgoing->timeout = 0;
 786                                 break;
 787                         }
 788                 }
 789
 790                 if(!found) {
 791                         outgoing_t *outgoing = xzalloc(sizeof *outgoing);
 792                         outgoing->name = name;
 793                         list_insert_tail(outgoing_list, outgoing);
 794                         setup_outgoing_connection(outgoing);
 795                 }
 796         }
 797
 798         /* Terminate any connections whose outgoing_t is to be deleted. */
 799
 800         for list_each(connection_t, c, connection_list) {
 801                 if(c->outgoing && c->outgoing->timeout == -1) {
 802                         c->outgoing = NULL;
 803                         logger(DEBUG_CONNECTIONS, LOG_INFO, "No more outgoing connection to %s", c->name);
 804                         terminate_connection(c, c->status.active);
 805                 }
 806         }
 807
 808         /* Delete outgoing_ts for which there is no ConnectTo. */
 809
 810         for list_each(outgoing_t, outgoing, outgoing_list)
 811                 if(outgoing->timeout == -1)
 812                         list_delete_node(outgoing_list, node);
 813 }