git.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                   2000-2013 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                                 strerror(errno));
 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 int setup_listen_socket(const sockaddr_t *sa) {
 117         int nfd;
 118         char *addrstr;
 119         int option;
 120         char *iface;
 121
 122         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 123
 124         if(nfd < 0) {
 125                 logger(DEBUG_STATUS, LOG_ERR, "Creating metasocket failed: %s", sockstrerror(sockerrno));
 126                 return -1;
 127         }
 128
 129 #ifdef FD_CLOEXEC
 130         fcntl(nfd, F_SETFD, FD_CLOEXEC);
 131 #endif
 132
 133         /* Optimize TCP settings */
 134
 135         option = 1;
 136         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof option);
 137
 138 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 139         if(sa->sa.sa_family == AF_INET6)
 140                 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
 141 #endif
 142
 143         if(get_config_string
 144            (lookup_config(config_tree, "BindToInterface"), &iface)) {
 145 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 146                 struct ifreq ifr;
 147
 148                 memset(&ifr, 0, sizeof ifr);
 149                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 150
 151                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof ifr)) {
 152                         closesocket(nfd);
 153                         logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
 154                                    strerror(sockerrno));
 155                         return -1;
 156                 }
 157 #else
 158                 logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform", "BindToInterface");
 159 #endif
 160         }
 161
 162         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 163                 closesocket(nfd);
 164                 addrstr = sockaddr2hostname(sa);
 165                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/tcp: %s", addrstr, sockstrerror(sockerrno));
 166                 free(addrstr);
 167                 return -1;
 168         }
 169
 170         if(listen(nfd, 3)) {
 171                 closesocket(nfd);
 172                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "listen", sockstrerror(sockerrno));
 173                 return -1;
 174         }
 175
 176         return nfd;
 177 }
 178
 179 int setup_vpn_in_socket(const sockaddr_t *sa) {
 180         int nfd;
 181         char *addrstr;
 182         int option;
 183
 184         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 185
 186         if(nfd < 0) {
 187                 logger(DEBUG_ALWAYS, LOG_ERR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
 188                 return -1;
 189         }
 190
 191 #ifdef FD_CLOEXEC
 192         fcntl(nfd, F_SETFD, FD_CLOEXEC);
 193 #endif
 194
 195 #ifdef O_NONBLOCK
 196         {
 197                 int flags = fcntl(nfd, F_GETFL);
 198
 199                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 200                         closesocket(nfd);
 201                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "fcntl",
 202                                    strerror(errno));
 203                         return -1;
 204                 }
 205         }
 206 #elif defined(WIN32)
 207         {
 208                 unsigned long arg = 1;
 209                 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 210                         closesocket(nfd);
 211                         logger(DEBUG_ALWAYS, LOG_ERR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
 212                         return -1;
 213                 }
 214         }
 215 #endif
 216
 217         option = 1;
 218         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof option);
 219         setsockopt(nfd, SOL_SOCKET, SO_BROADCAST, (void *)&option, sizeof option);
 220
 221         if(udp_rcvbuf && setsockopt(nfd, SOL_SOCKET, SO_RCVBUF, (void *)&udp_rcvbuf, sizeof(udp_rcvbuf)))
 222                 logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP SO_RCVBUF to %i: %s", udp_rcvbuf, strerror(errno));
 223
 224         if(udp_sndbuf && setsockopt(nfd, SOL_SOCKET, SO_SNDBUF, (void *)&udp_sndbuf, sizeof(udp_sndbuf)))
 225                 logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP SO_SNDBUF to %i: %s", udp_sndbuf, strerror(errno));
 226
 227 #if defined(IPPROTO_IPV6) && defined(IPV6_V6ONLY)
 228         if(sa->sa.sa_family == AF_INET6)
 229                 setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
 230 #endif
 231
 232 #if defined(IP_DONTFRAG) && !defined(IP_DONTFRAGMENT)
 233 #define IP_DONTFRAGMENT IP_DONTFRAG
 234 #endif
 235
 236 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 237         if(myself->options & OPTION_PMTU_DISCOVERY) {
 238                 option = IP_PMTUDISC_DO;
 239                 setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
 240         }
 241 #elif defined(IPPROTO_IP) && defined(IP_DONTFRAGMENT)
 242         if(myself->options & OPTION_PMTU_DISCOVERY) {
 243                 option = 1;
 244                 setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, (void *)&option, sizeof(option));
 245         }
 246 #else
 247 #warning No way to disable IPv4 fragmentation
 248 #endif
 249
 250 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 251         if(myself->options & OPTION_PMTU_DISCOVERY) {
 252                 option = IPV6_PMTUDISC_DO;
 253                 setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
 254         }
 255 #elif defined(IPPROTO_IPV6) && defined(IPV6_DONTFRAG)
 256         if(myself->options & OPTION_PMTU_DISCOVERY) {
 257                 option = 1;
 258                 setsockopt(nfd, IPPROTO_IPV6, IPV6_DONTFRAG, (void *)&option, sizeof(option));
 259         }
 260 #else
 261 #warning No way to disable IPv6 fragmentation
 262 #endif
 263
 264         if (!bind_to_interface(nfd)) {
 265                 closesocket(nfd);
 266                 return -1;
 267         }
 268
 269         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 270                 closesocket(nfd);
 271                 addrstr = sockaddr2hostname(sa);
 272                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/udp: %s", addrstr, sockstrerror(sockerrno));
 273                 free(addrstr);
 274                 return -1;
 275         }
 276
 277         return nfd;
 278 } /* int setup_vpn_in_socket */
 279
 280 static void retry_outgoing_handler(void *data) {
 281         setup_outgoing_connection(data);
 282 }
 283
 284 void retry_outgoing(outgoing_t *outgoing) {
 285         outgoing->timeout += 5;
 286
 287         if(outgoing->timeout > maxtimeout)
 288                 outgoing->timeout = maxtimeout;
 289
 290         timeout_add(&outgoing->ev, retry_outgoing_handler, outgoing, &(struct timeval){outgoing->timeout, rand() % 100000});
 291
 292         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Trying to re-establish outgoing connection in %d seconds", outgoing->timeout);
 293 }
 294
 295 void finish_connecting(connection_t *c) {
 296         logger(DEBUG_CONNECTIONS, LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
 297
 298         c->last_ping_time = now.tv_sec;
 299         c->status.connecting = false;
 300
 301         send_id(c);
 302 }
 303
 304 static void do_outgoing_pipe(connection_t *c, char *command) {
 305 #ifndef HAVE_MINGW
 306         int fd[2];
 307
 308         if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
 309                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not create socketpair: %s", strerror(errno));
 310                 return;
 311         }
 312
 313         if(fork()) {
 314                 c->socket = fd[0];
 315                 close(fd[1]);
 316                 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Using proxy %s", command);
 317                 return;
 318         }
 319
 320         close(0);
 321         close(1);
 322         close(fd[0]);
 323         dup2(fd[1], 0);
 324         dup2(fd[1], 1);
 325         close(fd[1]);
 326
 327         // Other filedescriptors should be closed automatically by CLOEXEC
 328
 329         char *host = NULL;
 330         char *port = NULL;
 331
 332         sockaddr2str(&c->address, &host, &port);
 333         setenv("REMOTEADDRESS", host, true);
 334         setenv("REMOTEPORT", port, true);
 335         setenv("NODE", c->name, true);
 336         setenv("NAME", myself->name, true);
 337         if(netname)
 338                 setenv("NETNAME", netname, true);
 339
 340         int result = system(command);
 341         if(result < 0)
 342                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not execute %s: %s", command, strerror(errno));
 343         else if(result)
 344                 logger(DEBUG_ALWAYS, LOG_ERR, "%s exited with non-zero status %d", command, result);
 345         exit(result);
 346 #else
 347         logger(DEBUG_ALWAYS, LOG_ERR, "Proxy type exec not supported on this platform!");
 348         return;
 349 #endif
 350 }
 351
 352 static void handle_meta_write(connection_t *c) {
 353         if(c->outbuf.len <= c->outbuf.offset)
 354                 return;
 355
 356         ssize_t outlen = send(c->socket, c->outbuf.data + c->outbuf.offset, c->outbuf.len - c->outbuf.offset, 0);
 357         if(outlen <= 0) {
 358                 if(!errno || errno == EPIPE) {
 359                         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection closed by %s (%s)", c->name, c->hostname);
 360                 } else if(sockwouldblock(sockerrno)) {
 361                         logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Sending %d bytes to %s (%s) would block", c->outbuf.len - c->outbuf.offset, c->name, c->hostname);
 362                         return;
 363                 } else {
 364                         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));
 365                 }
 366
 367                 terminate_connection(c, c->status.active);
 368                 return;
 369         }
 370
 371         buffer_read(&c->outbuf, outlen);
 372         if(!c->outbuf.len)
 373                 io_set(&c->io, IO_READ);
 374 }
 375
 376 static void handle_meta_io(void *data, int flags) {
 377         connection_t *c = data;
 378
 379         if(c->status.connecting) {
 380                 c->status.connecting = false;
 381
 382                 int result;
 383                 socklen_t len = sizeof result;
 384                 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, (void *)&result, &len);
 385
 386                 if(!result)
 387                         finish_connecting(c);
 388                 else {
 389                         logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Error while connecting to %s (%s): %s", c->name, c->hostname, sockstrerror(result));
 390                         terminate_connection(c, false);
 391                         return;
 392                 }
 393         }
 394
 395         if(flags & IO_WRITE)
 396                 handle_meta_write(c);
 397         else
 398                 handle_meta_connection_data(c);
 399 }
 400
 401 bool do_outgoing_connection(outgoing_t *outgoing) {
 402         char *address, *port, *space;
 403         struct addrinfo *proxyai = NULL;
 404         int result;
 405
 406 begin:
 407         if(!outgoing->ai) {
 408                 if(!outgoing->cfg) {
 409                         logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not set up a meta connection to %s", outgoing->name);
 410                         retry_outgoing(outgoing);
 411                         return false;
 412                 }
 413
 414                 get_config_string(outgoing->cfg, &address);
 415
 416                 space = strchr(address, ' ');
 417                 if(space) {
 418                         port = xstrdup(space + 1);
 419                         *space = 0;
 420                 } else {
 421                         if(!get_config_string(lookup_config(outgoing->config_tree, "Port"), &port))
 422                                 port = xstrdup("655");
 423                 }
 424
 425                 outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
 426                 free(address);
 427                 free(port);
 428
 429                 outgoing->aip = outgoing->ai;
 430                 outgoing->cfg = lookup_config_next(outgoing->config_tree, outgoing->cfg);
 431         }
 432
 433         if(!outgoing->aip) {
 434                 if(outgoing->ai)
 435                         freeaddrinfo(outgoing->ai);
 436                 outgoing->ai = NULL;
 437                 goto begin;
 438         }
 439
 440         connection_t *c = new_connection();
 441         c->outgoing = outgoing;
 442
 443         memcpy(&c->address, outgoing->aip->ai_addr, outgoing->aip->ai_addrlen);
 444         outgoing->aip = outgoing->aip->ai_next;
 445
 446         c->hostname = sockaddr2hostname(&c->address);
 447
 448         logger(DEBUG_CONNECTIONS, LOG_INFO, "Trying to connect to %s (%s)", outgoing->name, c->hostname);
 449
 450         if(!proxytype) {
 451                 c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 452                 configure_tcp(c);
 453         } else if(proxytype == PROXY_EXEC) {
 454                 do_outgoing_pipe(c, proxyhost);
 455         } else {
 456                 proxyai = str2addrinfo(proxyhost, proxyport, SOCK_STREAM);
 457                 if(!proxyai) {
 458                         free_connection(c);
 459                         goto begin;
 460                 }
 461                 logger(DEBUG_CONNECTIONS, LOG_INFO, "Using proxy at %s port %s", proxyhost, proxyport);
 462                 c->socket = socket(proxyai->ai_family, SOCK_STREAM, IPPROTO_TCP);
 463                 configure_tcp(c);
 464         }
 465
 466         if(c->socket == -1) {
 467                 logger(DEBUG_CONNECTIONS, LOG_ERR, "Creating socket for %s failed: %s", c->hostname, sockstrerror(sockerrno));
 468                 free_connection(c);
 469                 goto begin;
 470         }
 471
 472 #ifdef FD_CLOEXEC
 473         fcntl(c->socket, F_SETFD, FD_CLOEXEC);
 474 #endif
 475
 476         if(proxytype != PROXY_EXEC) {
 477 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
 478                 int option = 1;
 479                 if(c->address.sa.sa_family == AF_INET6)
 480                         setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
 481 #endif
 482
 483                 bind_to_interface(c->socket);
 484         }
 485
 486         /* Connect */
 487
 488         if(!proxytype) {
 489                 result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 490         } else if(proxytype == PROXY_EXEC) {
 491                 result = 0;
 492         } else {
 493                 result = connect(c->socket, proxyai->ai_addr, proxyai->ai_addrlen);
 494                 freeaddrinfo(proxyai);
 495         }
 496
 497         if(result == -1 && !sockinprogress(sockerrno)) {
 498                 logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not connect to %s (%s): %s", outgoing->name, c->hostname, sockstrerror(sockerrno));
 499                 free_connection(c);
 500
 501                 goto begin;
 502         }
 503
 504         /* Now that there is a working socket, fill in the rest and register this connection. */
 505
 506         c->status.connecting = true;
 507         c->name = xstrdup(outgoing->name);
 508         c->outcipher = myself->connection->outcipher;
 509         c->outdigest = myself->connection->outdigest;
 510         c->outmaclength = myself->connection->outmaclength;
 511         c->outcompression = myself->connection->outcompression;
 512         c->last_ping_time = now.tv_sec;
 513
 514         connection_add(c);
 515
 516         io_add(&c->io, handle_meta_io, c, c->socket, IO_READ|IO_WRITE);
 517
 518         return true;
 519 }
 520
 521 void setup_outgoing_connection(outgoing_t *outgoing) {
 522         timeout_del(&outgoing->ev);
 523
 524         node_t *n = lookup_node(outgoing->name);
 525
 526         if(n && n->connection) {
 527                 logger(DEBUG_CONNECTIONS, LOG_INFO, "Already connected to %s", outgoing->name);
 528
 529                 n->connection->outgoing = outgoing;
 530                 return;
 531         }
 532
 533         init_configuration(&outgoing->config_tree);
 534         read_host_config(outgoing->config_tree, outgoing->name);
 535         outgoing->cfg = lookup_config(outgoing->config_tree, "Address");
 536
 537         if(!outgoing->cfg) {
 538                 logger(DEBUG_ALWAYS, LOG_ERR, "No address specified for %s", outgoing->name);
 539                 return;
 540         }
 541
 542         do_outgoing_connection(outgoing);
 543 }
 544
 545 /*
 546   accept a new tcp connect and create a
 547   new connection
 548 */
 549 void handle_new_meta_connection(void *data, int flags) {
 550         listen_socket_t *l = data;
 551         connection_t *c;
 552         sockaddr_t sa;
 553         int fd;
 554         socklen_t len = sizeof sa;
 555
 556         fd = accept(l->tcp.fd, &sa.sa, &len);
 557
 558         if(fd < 0) {
 559                 logger(DEBUG_ALWAYS, LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
 560                 return;
 561         }
 562
 563         sockaddrunmap(&sa);
 564
 565         // Check if we get many connections from the same host
 566
 567         static sockaddr_t prev_sa;
 568         static time_t prev_time;
 569         static int tarpit = -1;
 570
 571         if(tarpit >= 0) {
 572                 closesocket(tarpit);
 573                 tarpit = -1;
 574         }
 575
 576         if(prev_time == now.tv_sec && !sockaddrcmp_noport(&sa, &prev_sa)) {
 577                 // if so, keep the connection open but ignore it completely.
 578                 tarpit = fd;
 579                 return;
 580         }
 581
 582         memcpy(&prev_sa, &sa, sizeof sa);
 583         prev_time = now.tv_sec;
 584
 585         // Check if we get many connections from different hosts
 586
 587         static int connection_burst;
 588         static int connection_burst_time;
 589
 590         if(now.tv_sec - connection_burst_time > connection_burst)
 591                 connection_burst = 0;
 592         else
 593                 connection_burst -= now.tv_sec - connection_burst_time;
 594
 595         connection_burst_time = now.tv_sec;
 596         connection_burst++;
 597
 598         if(connection_burst >= max_connection_burst) {
 599                 connection_burst = max_connection_burst;
 600                 tarpit = fd;
 601                 return;
 602         }
 603
 604         // Accept the new connection
 605
 606         c = new_connection();
 607         c->name = xstrdup("<unknown>");
 608         c->outcipher = myself->connection->outcipher;
 609         c->outdigest = myself->connection->outdigest;
 610         c->outmaclength = myself->connection->outmaclength;
 611         c->outcompression = myself->connection->outcompression;
 612
 613         c->address = sa;
 614         c->hostname = sockaddr2hostname(&sa);
 615         c->socket = fd;
 616         c->last_ping_time = now.tv_sec;
 617
 618         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection from %s", c->hostname);
 619
 620         io_add(&c->io, handle_meta_io, c, c->socket, IO_READ);
 621
 622         configure_tcp(c);
 623
 624         connection_add(c);
 625
 626         c->allow_request = ID;
 627         send_id(c);
 628 }
 629
 630 #ifndef HAVE_MINGW
 631 /*
 632   accept a new UNIX socket connection
 633 */
 634 void handle_new_unix_connection(void *data, int flags) {
 635         io_t *io = data;
 636         connection_t *c;
 637         sockaddr_t sa;
 638         int fd;
 639         socklen_t len = sizeof sa;
 640
 641         fd = accept(io->fd, &sa.sa, &len);
 642
 643         if(fd < 0) {
 644                 logger(DEBUG_ALWAYS, LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
 645                 return;
 646         }
 647
 648         sockaddrunmap(&sa);
 649
 650         c = new_connection();
 651         c->name = xstrdup("<control>");
 652         c->address = sa;
 653         c->hostname = xstrdup("localhost port unix");
 654         c->socket = fd;
 655         c->last_ping_time = now.tv_sec;
 656
 657         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection from %s", c->hostname);
 658
 659         io_add(&c->io, handle_meta_io, c, c->socket, IO_READ);
 660
 661         connection_add(c);
 662
 663         c->allow_request = ID;
 664
 665         send_id(c);
 666 }
 667 #endif
 668
 669 static void free_outgoing(outgoing_t *outgoing) {
 670         timeout_del(&outgoing->ev);
 671
 672         if(outgoing->ai)
 673                 freeaddrinfo(outgoing->ai);
 674
 675         if(outgoing->config_tree)
 676                 exit_configuration(&outgoing->config_tree);
 677
 678         if(outgoing->name)
 679                 free(outgoing->name);
 680
 681         free(outgoing);
 682 }
 683
 684 void try_outgoing_connections(void) {
 685         /* If there is no outgoing list yet, create one. Otherwise, mark all outgoings as deleted. */
 686
 687         if(!outgoing_list) {
 688                 outgoing_list = list_alloc((list_action_t)free_outgoing);
 689         } else {
 690                 for list_each(outgoing_t, outgoing, outgoing_list)
 691                         outgoing->timeout = -1;
 692         }
 693
 694         /* Make sure there is one outgoing_t in the list for each ConnectTo. */
 695
 696         for(config_t *cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 697                 char *name;
 698                 get_config_string(cfg, &name);
 699
 700                 if(!check_id(name)) {
 701                         logger(DEBUG_ALWAYS, LOG_ERR,
 702                                    "Invalid name for outgoing connection in %s line %d",
 703                                    cfg->file, cfg->line);
 704                         free(name);
 705                         continue;
 706                 }
 707
 708                 bool found = false;
 709
 710                 for list_each(outgoing_t, outgoing, outgoing_list) {
 711                         if(!strcmp(outgoing->name, name)) {
 712                                 found = true;
 713                                 outgoing->timeout = 0;
 714                                 break;
 715                         }
 716                 }
 717
 718                 if(!found) {
 719                         outgoing_t *outgoing = xzalloc(sizeof *outgoing);
 720                         outgoing->name = name;
 721                         list_insert_tail(outgoing_list, outgoing);
 722                         setup_outgoing_connection(outgoing);
 723                 }
 724         }
 725
 726         /* Terminate any connections whose outgoing_t is to be deleted. */
 727
 728         for list_each(connection_t, c, connection_list) {
 729                 if(c->outgoing && c->outgoing->timeout == -1) {
 730                         c->outgoing = NULL;
 731                         logger(DEBUG_CONNECTIONS, LOG_INFO, "No more outgoing connection to %s", c->name);
 732                         terminate_connection(c, c->status.active);
 733                 }
 734         }
 735
 736         /* Delete outgoing_ts for which there is no ConnectTo. */
 737
 738         for list_each(outgoing_t, outgoing, outgoing_list)
 739                 if(outgoing->timeout == -1)
 740                         list_delete_node(outgoing_list, node);
 741 }