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                   2000-2017 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 "address_cache.h"
  26 #include "conf.h"
  27 #include "connection.h"
  28 #include "control_common.h"
  29 #include "list.h"
  30 #include "logger.h"
  31 #include "meta.h"
  32 #include "names.h"
  33 #include "net.h"
  34 #include "netutl.h"
  35 #include "protocol.h"
  36 #include "utils.h"
  37 #include "xalloc.h"
  38
  39 int addressfamily = AF_UNSPEC;
  40 int maxtimeout = 900;
  41 int seconds_till_retry = 5;
  42 int udp_rcvbuf = 1024 * 1024;
  43 int udp_sndbuf = 1024 * 1024;
  44 int max_connection_burst = 10;
  45 int fwmark;
  46
  47 listen_socket_t listen_socket[MAXSOCKETS];
  48 int listen_sockets;
  49 #ifndef HAVE_MINGW
  50 io_t unix_socket;
  51 #endif
  52 list_t *outgoing_list = NULL;
  53
  54 /* Setup sockets */
  55
  56 static void configure_tcp(connection_t *c) {
  57         int option;
  58
  59 #ifdef O_NONBLOCK
  60         int flags = fcntl(c->socket, F_GETFL);
  61
  62         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
  63                 logger(DEBUG_ALWAYS, LOG_ERR, "fcntl for %s fd %d: %s", c->hostname, c->socket, strerror(errno));
  64         }
  65
  66 #elif defined(WIN32)
  67         unsigned long arg = 1;
  68
  69         if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
  70                 logger(DEBUG_ALWAYS, LOG_ERR, "ioctlsocket for %s fd %d: %s", c->hostname, c->socket, sockstrerror(sockerrno));
  71         }
  72
  73 #endif
  74
  75 #if defined(TCP_NODELAY)
  76         option = 1;
  77         setsockopt(c->socket, IPPROTO_TCP, TCP_NODELAY, (void *)&option, sizeof(option));
  78 #endif
  79
  80 #if defined(IP_TOS) && defined(IPTOS_LOWDELAY)
  81         option = IPTOS_LOWDELAY;
  82         setsockopt(c->socket, IPPROTO_IP, IP_TOS, (void *)&option, sizeof(option));
  83 #endif
  84
  85 #if defined(IPV6_TCLASS) && defined(IPTOS_LOWDELAY)
  86         option = IPTOS_LOWDELAY;
  87         setsockopt(c->socket, IPPROTO_IPV6, IPV6_TCLASS, (void *)&option, sizeof(option));
  88 #endif
  89
  90 #if defined(SO_MARK)
  91
  92         if(fwmark) {
  93                 setsockopt(c->socket, SOL_SOCKET, SO_MARK, (void *)&fwmark, sizeof(fwmark));
  94         }
  95
  96 #endif
  97 }
  98
  99 static bool bind_to_interface(int sd) {
 100         char *iface;
 101
 102 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 103         struct ifreq ifr;
 104         int status;
 105 #endif /* defined(SOL_SOCKET) && defined(SO_BINDTODEVICE) */
 106
 107         if(!get_config_string(lookup_config(config_tree, "BindToInterface"), &iface)) {
 108                 return true;
 109         }
 110
 111 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 112         memset(&ifr, 0, sizeof(ifr));
 113         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 114         ifr.ifr_ifrn.ifrn_name[IFNAMSIZ - 1] = 0;
 115
 116         status = setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr));
 117
 118         if(status) {
 119                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
 120                        sockstrerror(sockerrno));
 121                 return false;
 122         }
 123
 124 #else /* if !defined(SOL_SOCKET) || !defined(SO_BINDTODEVICE) */
 125         logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform", "BindToInterface");
 126 #endif
 127
 128         return true;
 129 }
 130
 131 static bool bind_to_address(connection_t *c) {
 132         int s = -1;
 133
 134         for(int i = 0; i < listen_sockets && listen_socket[i].bindto; i++) {
 135                 if(listen_socket[i].sa.sa.sa_family != c->address.sa.sa_family) {
 136                         continue;
 137                 }
 138
 139                 if(s >= 0) {
 140                         return false;
 141                 }
 142
 143                 s = i;
 144         }
 145
 146         if(s < 0) {
 147                 return false;
 148         }
 149
 150         sockaddr_t sa = listen_socket[s].sa;
 151
 152         if(sa.sa.sa_family == AF_INET) {
 153                 sa.in.sin_port = 0;
 154         } else if(sa.sa.sa_family == AF_INET6) {
 155                 sa.in6.sin6_port = 0;
 156         }
 157
 158         if(bind(c->socket, &sa.sa, SALEN(sa.sa))) {
 159                 logger(DEBUG_CONNECTIONS, LOG_WARNING, "Can't bind outgoing socket: %s", sockstrerror(sockerrno));
 160                 return false;
 161         }
 162
 163         return true;
 164 }
 165
 166 int setup_listen_socket(const sockaddr_t *sa) {
 167         int nfd;
 168         char *addrstr;
 169         int option;
 170         char *iface;
 171
 172         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 173
 174         if(nfd < 0) {
 175                 logger(DEBUG_STATUS, LOG_ERR, "Creating metasocket failed: %s", sockstrerror(sockerrno));
 176                 return -1;
 177         }
 178
 179 #ifdef FD_CLOEXEC
 180         fcntl(nfd, F_SETFD, FD_CLOEXEC);
 181 #endif
 182
 183         /* Optimize TCP settings */
 184
 185         option = 1;
 186         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
 187
 188 #if defined(IPV6_V6ONLY)
 189
 190         if(sa->sa.sa_family == AF_INET6) {
 191                 setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
 192         }
 193
 194 #else
 195 #warning IPV6_V6ONLY not defined
 196 #endif
 197
 198 #if defined(SO_MARK)
 199
 200         if(fwmark) {
 201                 setsockopt(nfd, SOL_SOCKET, SO_MARK, (void *)&fwmark, sizeof(fwmark));
 202         }
 203
 204 #endif
 205
 206         if(get_config_string
 207                         (lookup_config(config_tree, "BindToInterface"), &iface)) {
 208 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 209                 struct ifreq ifr;
 210
 211                 memset(&ifr, 0, sizeof(ifr));
 212                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 213                 ifr.ifr_ifrn.ifrn_name[IFNAMSIZ - 1] = 0;
 214
 215                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr))) {
 216                         closesocket(nfd);
 217                         logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
 218                                sockstrerror(sockerrno));
 219                         return -1;
 220                 }
 221
 222 #else
 223                 logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform", "BindToInterface");
 224 #endif
 225         }
 226
 227         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 228                 closesocket(nfd);
 229                 addrstr = sockaddr2hostname(sa);
 230                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/tcp: %s", addrstr, sockstrerror(sockerrno));
 231                 free(addrstr);
 232                 return -1;
 233         }
 234
 235         if(listen(nfd, 3)) {
 236                 closesocket(nfd);
 237                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "listen", sockstrerror(sockerrno));
 238                 return -1;
 239         }
 240
 241         return nfd;
 242 }
 243
 244 int setup_vpn_in_socket(const sockaddr_t *sa) {
 245         int nfd;
 246         char *addrstr;
 247         int option;
 248
 249         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 250
 251         if(nfd < 0) {
 252                 logger(DEBUG_ALWAYS, LOG_ERR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
 253                 return -1;
 254         }
 255
 256 #ifdef FD_CLOEXEC
 257         fcntl(nfd, F_SETFD, FD_CLOEXEC);
 258 #endif
 259
 260 #ifdef O_NONBLOCK
 261         {
 262                 int flags = fcntl(nfd, F_GETFL);
 263
 264                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 265                         closesocket(nfd);
 266                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "fcntl",
 267                                strerror(errno));
 268                         return -1;
 269                 }
 270         }
 271 #elif defined(WIN32)
 272         {
 273                 unsigned long arg = 1;
 274
 275                 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 276                         closesocket(nfd);
 277                         logger(DEBUG_ALWAYS, LOG_ERR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
 278                         return -1;
 279                 }
 280         }
 281 #endif
 282
 283         option = 1;
 284         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
 285         setsockopt(nfd, SOL_SOCKET, SO_BROADCAST, (void *)&option, sizeof(option));
 286
 287         if(udp_rcvbuf && setsockopt(nfd, SOL_SOCKET, SO_RCVBUF, (void *)&udp_rcvbuf, sizeof(udp_rcvbuf))) {
 288                 logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP SO_RCVBUF to %i: %s", udp_rcvbuf, sockstrerror(sockerrno));
 289         }
 290
 291         if(udp_sndbuf && setsockopt(nfd, SOL_SOCKET, SO_SNDBUF, (void *)&udp_sndbuf, sizeof(udp_sndbuf))) {
 292                 logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP SO_SNDBUF to %i: %s", udp_sndbuf, sockstrerror(sockerrno));
 293         }
 294
 295 #if defined(IPV6_V6ONLY)
 296
 297         if(sa->sa.sa_family == AF_INET6) {
 298                 setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
 299         }
 300
 301 #endif
 302
 303 #if defined(IP_DONTFRAG) && !defined(IP_DONTFRAGMENT)
 304 #define IP_DONTFRAGMENT IP_DONTFRAG
 305 #endif
 306
 307 #if defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 308
 309         if(myself->options & OPTION_PMTU_DISCOVERY) {
 310                 option = IP_PMTUDISC_DO;
 311                 setsockopt(nfd, IPPROTO_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
 312         }
 313
 314 #elif defined(IP_DONTFRAGMENT)
 315
 316         if(myself->options & OPTION_PMTU_DISCOVERY) {
 317                 option = 1;
 318                 setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, (void *)&option, sizeof(option));
 319         }
 320
 321 #endif
 322
 323 #if defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 324
 325         if(myself->options & OPTION_PMTU_DISCOVERY) {
 326                 option = IPV6_PMTUDISC_DO;
 327                 setsockopt(nfd, IPPROTO_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
 328         }
 329
 330 #elif defined(IPV6_DONTFRAG)
 331
 332         if(myself->options & OPTION_PMTU_DISCOVERY) {
 333                 option = 1;
 334                 setsockopt(nfd, IPPROTO_IPV6, IPV6_DONTFRAG, (void *)&option, sizeof(option));
 335         }
 336
 337 #endif
 338
 339 #if defined(SO_MARK)
 340
 341         if(fwmark) {
 342                 setsockopt(nfd, SOL_SOCKET, SO_MARK, (void *)&fwmark, sizeof(fwmark));
 343         }
 344
 345 #endif
 346
 347         if(!bind_to_interface(nfd)) {
 348                 closesocket(nfd);
 349                 return -1;
 350         }
 351
 352         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
 353                 closesocket(nfd);
 354                 addrstr = sockaddr2hostname(sa);
 355                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/udp: %s", addrstr, sockstrerror(sockerrno));
 356                 free(addrstr);
 357                 return -1;
 358         }
 359
 360         return nfd;
 361 } /* int setup_vpn_in_socket */
 362
 363 static void retry_outgoing_handler(void *data) {
 364         setup_outgoing_connection(data, true);
 365 }
 366
 367 void retry_outgoing(outgoing_t *outgoing) {
 368         outgoing->timeout += 5;
 369
 370         if(outgoing->timeout > maxtimeout) {
 371                 outgoing->timeout = maxtimeout;
 372         }
 373
 374         timeout_add(&outgoing->ev, retry_outgoing_handler, outgoing, &(struct timeval) {
 375                 outgoing->timeout, rand() % 100000
 376         });
 377
 378         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Trying to re-establish outgoing connection in %d seconds", outgoing->timeout);
 379 }
 380
 381 void finish_connecting(connection_t *c) {
 382         logger(DEBUG_CONNECTIONS, LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
 383
 384         c->last_ping_time = now.tv_sec;
 385         c->status.connecting = false;
 386
 387         send_id(c);
 388 }
 389
 390 static void do_outgoing_pipe(connection_t *c, char *command) {
 391 #ifndef HAVE_MINGW
 392         int fd[2];
 393
 394         if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
 395                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not create socketpair: %s", sockstrerror(sockerrno));
 396                 return;
 397         }
 398
 399         if(fork()) {
 400                 c->socket = fd[0];
 401                 close(fd[1]);
 402                 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Using proxy %s", command);
 403                 return;
 404         }
 405
 406         close(0);
 407         close(1);
 408         close(fd[0]);
 409         dup2(fd[1], 0);
 410         dup2(fd[1], 1);
 411         close(fd[1]);
 412
 413         // Other filedescriptors should be closed automatically by CLOEXEC
 414
 415         char *host = NULL;
 416         char *port = NULL;
 417
 418         sockaddr2str(&c->address, &host, &port);
 419         setenv("REMOTEADDRESS", host, true);
 420         setenv("REMOTEPORT", port, true);
 421         setenv("NODE", c->name, true);
 422         setenv("NAME", myself->name, true);
 423
 424         if(netname) {
 425                 setenv("NETNAME", netname, true);
 426         }
 427
 428         int result = system(command);
 429
 430         if(result < 0) {
 431                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not execute %s: %s", command, strerror(errno));
 432         } else if(result) {
 433                 logger(DEBUG_ALWAYS, LOG_ERR, "%s exited with non-zero status %d", command, result);
 434         }
 435
 436         exit(result);
 437 #else
 438         logger(DEBUG_ALWAYS, LOG_ERR, "Proxy type exec not supported on this platform!");
 439         return;
 440 #endif
 441 }
 442
 443 static void handle_meta_write(connection_t *c) {
 444         if(c->outbuf.len <= c->outbuf.offset) {
 445                 return;
 446         }
 447
 448         ssize_t outlen = send(c->socket, c->outbuf.data + c->outbuf.offset, c->outbuf.len - c->outbuf.offset, 0);
 449
 450         if(outlen <= 0) {
 451                 if(!sockerrno || sockerrno == EPIPE) {
 452                         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection closed by %s (%s)", c->name, c->hostname);
 453                 } else if(sockwouldblock(sockerrno)) {
 454                         logger(DEBUG_META, LOG_DEBUG, "Sending %d bytes to %s (%s) would block", c->outbuf.len - c->outbuf.offset, c->name, c->hostname);
 455                         return;
 456                 } else {
 457                         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));
 458                 }
 459
 460                 terminate_connection(c, c->edge);
 461                 return;
 462         }
 463
 464         buffer_read(&c->outbuf, outlen);
 465
 466         if(!c->outbuf.len) {
 467                 io_set(&c->io, IO_READ);
 468         }
 469 }
 470
 471 static void handle_meta_io(void *data, int flags) {
 472         connection_t *c = data;
 473
 474         if(c->status.connecting) {
 475                 /*
 476                    The event loop does not protect against spurious events. Verify that we are actually connected
 477                    by issuing an empty send() call.
 478
 479                    Note that the behavior of send() on potentially unconnected sockets differ between platforms:
 480                    +------------+-----------+-------------+-----------+
 481                    |   Event    |   POSIX   |    Linux    |  Windows  |
 482                    +------------+-----------+-------------+-----------+
 483                    | Spurious   | ENOTCONN  | EWOULDBLOCK | ENOTCONN  |
 484                    | Failed     | ENOTCONN  | (cause)     | ENOTCONN  |
 485                    | Successful | (success) | (success)   | (success) |
 486                    +------------+-----------+-------------+-----------+
 487                 */
 488                 if(send(c->socket, NULL, 0, 0) != 0) {
 489                         if(sockwouldblock(sockerrno)) {
 490                                 return;
 491                         }
 492
 493                         int socket_error;
 494
 495                         if(!socknotconn(sockerrno)) {
 496                                 socket_error = sockerrno;
 497                         } else {
 498                                 socklen_t len = sizeof(socket_error);
 499                                 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, (void *)&socket_error, &len);
 500                         }
 501
 502                         if(socket_error) {
 503                                 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Error while connecting to %s (%s): %s", c->name, c->hostname, sockstrerror(socket_error));
 504                                 terminate_connection(c, false);
 505                         }
 506
 507                         return;
 508                 }
 509
 510                 c->status.connecting = false;
 511                 finish_connecting(c);
 512         }
 513
 514         if(flags & IO_WRITE) {
 515                 handle_meta_write(c);
 516         } else {
 517                 handle_meta_connection_data(c);
 518         }
 519 }
 520
 521 bool do_outgoing_connection(outgoing_t *outgoing) {
 522         const sockaddr_t *sa;
 523         struct addrinfo *proxyai = NULL;
 524         int result;
 525
 526 begin:
 527         sa = get_recent_address(outgoing->address_cache);
 528
 529         if(!sa) {
 530                 logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not set up a meta connection to %s", outgoing->node->name);
 531                 retry_outgoing(outgoing);
 532                 return false;
 533         }
 534
 535         connection_t *c = new_connection();
 536         c->outgoing = outgoing;
 537         memcpy(&c->address, sa, SALEN(sa->sa));
 538         c->hostname = sockaddr2hostname(&c->address);
 539
 540         logger(DEBUG_CONNECTIONS, LOG_INFO, "Trying to connect to %s (%s)", outgoing->node->name, c->hostname);
 541
 542         if(!proxytype) {
 543                 c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 544                 configure_tcp(c);
 545         } else if(proxytype == PROXY_EXEC) {
 546                 do_outgoing_pipe(c, proxyhost);
 547         } else {
 548                 proxyai = str2addrinfo(proxyhost, proxyport, SOCK_STREAM);
 549
 550                 if(!proxyai) {
 551                         free_connection(c);
 552                         goto begin;
 553                 }
 554
 555                 logger(DEBUG_CONNECTIONS, LOG_INFO, "Using proxy at %s port %s", proxyhost, proxyport);
 556                 c->socket = socket(proxyai->ai_family, SOCK_STREAM, IPPROTO_TCP);
 557                 configure_tcp(c);
 558         }
 559
 560         if(c->socket == -1) {
 561                 logger(DEBUG_CONNECTIONS, LOG_ERR, "Creating socket for %s failed: %s", c->hostname, sockstrerror(sockerrno));
 562                 free_connection(c);
 563                 goto begin;
 564         }
 565
 566 #ifdef FD_CLOEXEC
 567         fcntl(c->socket, F_SETFD, FD_CLOEXEC);
 568 #endif
 569
 570         if(proxytype != PROXY_EXEC) {
 571 #if defined(IPV6_V6ONLY)
 572                 int option = 1;
 573
 574                 if(c->address.sa.sa_family == AF_INET6) {
 575                         setsockopt(c->socket, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
 576                 }
 577
 578 #endif
 579
 580                 bind_to_interface(c->socket);
 581                 bind_to_address(c);
 582         }
 583
 584         /* Connect */
 585
 586         if(!proxytype) {
 587                 result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 588         } else if(proxytype == PROXY_EXEC) {
 589                 result = 0;
 590         } else {
 591                 if(!proxyai) {
 592                         abort();
 593                 }
 594
 595                 result = connect(c->socket, proxyai->ai_addr, proxyai->ai_addrlen);
 596                 freeaddrinfo(proxyai);
 597         }
 598
 599         if(result == -1 && !sockinprogress(sockerrno)) {
 600                 logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not connect to %s (%s): %s", outgoing->node->name, c->hostname, sockstrerror(sockerrno));
 601                 free_connection(c);
 602
 603                 goto begin;
 604         }
 605
 606         /* Now that there is a working socket, fill in the rest and register this connection. */
 607
 608         c->last_ping_time = time(NULL);
 609         c->status.connecting = true;
 610         c->name = xstrdup(outgoing->node->name);
 611 #ifndef DISABLE_LEGACY
 612         c->outcipher = myself->connection->outcipher;
 613         c->outdigest = myself->connection->outdigest;
 614 #endif
 615         c->outmaclength = myself->connection->outmaclength;
 616         c->outcompression = myself->connection->outcompression;
 617         c->last_ping_time = now.tv_sec;
 618
 619         connection_add(c);
 620
 621         io_add(&c->io, handle_meta_io, c, c->socket, IO_READ | IO_WRITE);
 622
 623         return true;
 624 }
 625
 626 void setup_outgoing_connection(outgoing_t *outgoing, bool verbose) {
 627         (void)verbose;
 628         timeout_del(&outgoing->ev);
 629
 630         node_t *n = outgoing->node;
 631
 632         if(n->connection) {
 633                 logger(DEBUG_CONNECTIONS, LOG_INFO, "Already connected to %s", n->name);
 634
 635                 if(!n->connection->outgoing) {
 636                         n->connection->outgoing = outgoing;
 637                         return;
 638                 } else {
 639                         goto remove;
 640                 }
 641         }
 642
 643         if(!outgoing->address_cache) {
 644                 outgoing->address_cache = open_address_cache(n);
 645         }
 646
 647         do_outgoing_connection(outgoing);
 648         return;
 649
 650 remove:
 651         list_delete(outgoing_list, outgoing);
 652 }
 653
 654 /*
 655   accept a new tcp connect and create a
 656   new connection
 657 */
 658 void handle_new_meta_connection(void *data, int flags) {
 659         (void)flags;
 660         listen_socket_t *l = data;
 661         connection_t *c;
 662         sockaddr_t sa;
 663         int fd;
 664         socklen_t len = sizeof(sa);
 665
 666         fd = accept(l->tcp.fd, &sa.sa, &len);
 667
 668         if(fd < 0) {
 669                 logger(DEBUG_ALWAYS, LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
 670                 return;
 671         }
 672
 673         sockaddrunmap(&sa);
 674
 675         // Check if we get many connections from the same host
 676
 677         static sockaddr_t prev_sa;
 678
 679         if(!sockaddrcmp_noport(&sa, &prev_sa)) {
 680                 static int samehost_burst;
 681                 static int samehost_burst_time;
 682
 683                 if(now.tv_sec - samehost_burst_time > samehost_burst) {
 684                         samehost_burst = 0;
 685                 } else {
 686                         samehost_burst -= now.tv_sec - samehost_burst_time;
 687                 }
 688
 689                 samehost_burst_time = now.tv_sec;
 690                 samehost_burst++;
 691
 692                 if(samehost_burst > max_connection_burst) {
 693                         tarpit(fd);
 694                         return;
 695                 }
 696         }
 697
 698         memcpy(&prev_sa, &sa, sizeof(sa));
 699
 700         // Check if we get many connections from different hosts
 701
 702         static int connection_burst;
 703         static int connection_burst_time;
 704
 705         if(now.tv_sec - connection_burst_time > connection_burst) {
 706                 connection_burst = 0;
 707         } else {
 708                 connection_burst -= now.tv_sec - connection_burst_time;
 709         }
 710
 711         connection_burst_time = now.tv_sec;
 712         connection_burst++;
 713
 714         if(connection_burst >= max_connection_burst) {
 715                 connection_burst = max_connection_burst;
 716                 tarpit(fd);
 717                 return;
 718         }
 719
 720         // Accept the new connection
 721
 722         c = new_connection();
 723         c->name = xstrdup("<unknown>");
 724 #ifndef DISABLE_LEGACY
 725         c->outcipher = myself->connection->outcipher;
 726         c->outdigest = myself->connection->outdigest;
 727 #endif
 728         c->outmaclength = myself->connection->outmaclength;
 729         c->outcompression = myself->connection->outcompression;
 730
 731         c->address = sa;
 732         c->hostname = sockaddr2hostname(&sa);
 733         c->socket = fd;
 734         c->last_ping_time = now.tv_sec;
 735
 736         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection from %s", c->hostname);
 737
 738         io_add(&c->io, handle_meta_io, c, c->socket, IO_READ);
 739
 740         configure_tcp(c);
 741
 742         connection_add(c);
 743
 744         c->allow_request = ID;
 745 }
 746
 747 #ifndef HAVE_MINGW
 748 /*
 749   accept a new UNIX socket connection
 750 */
 751 void handle_new_unix_connection(void *data, int flags) {
 752         (void)flags;
 753         io_t *io = data;
 754         connection_t *c;
 755         sockaddr_t sa;
 756         int fd;
 757         socklen_t len = sizeof(sa);
 758
 759         fd = accept(io->fd, &sa.sa, &len);
 760
 761         if(fd < 0) {
 762                 logger(DEBUG_ALWAYS, LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
 763                 return;
 764         }
 765
 766         sockaddrunmap(&sa);
 767
 768         c = new_connection();
 769         c->name = xstrdup("<control>");
 770         c->address = sa;
 771         c->hostname = xstrdup("localhost port unix");
 772         c->socket = fd;
 773         c->last_ping_time = now.tv_sec;
 774
 775         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection from %s", c->hostname);
 776
 777         io_add(&c->io, handle_meta_io, c, c->socket, IO_READ);
 778
 779         connection_add(c);
 780
 781         c->allow_request = ID;
 782 }
 783 #endif
 784
 785 static void free_outgoing(outgoing_t *outgoing) {
 786         timeout_del(&outgoing->ev);
 787
 788         if(outgoing->address_cache) {
 789                 close_address_cache(outgoing->address_cache);
 790         }
 791
 792         free(outgoing);
 793 }
 794
 795 void try_outgoing_connections(void) {
 796         /* If there is no outgoing list yet, create one. Otherwise, mark all outgoings as deleted. */
 797
 798         if(!outgoing_list) {
 799                 outgoing_list = list_alloc((list_action_t)free_outgoing);
 800         } else {
 801                 for list_each(outgoing_t, outgoing, outgoing_list) {
 802                         outgoing->timeout = -1;
 803                 }
 804         }
 805
 806         /* Make sure there is one outgoing_t in the list for each ConnectTo. */
 807
 808         for(config_t *cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
 809                 char *name;
 810                 get_config_string(cfg, &name);
 811
 812                 if(!check_id(name)) {
 813                         logger(DEBUG_ALWAYS, LOG_ERR,
 814                                "Invalid name for outgoing connection in %s line %d",
 815                                cfg->file, cfg->line);
 816                         free(name);
 817                         continue;
 818                 }
 819
 820                 if(!strcmp(name, myself->name)) {
 821                         free(name);
 822                         continue;
 823                 }
 824
 825                 bool found = false;
 826
 827                 for list_each(outgoing_t, outgoing, outgoing_list) {
 828                         if(!strcmp(outgoing->node->name, name)) {
 829                                 found = true;
 830                                 outgoing->timeout = 0;
 831                                 break;
 832                         }
 833                 }
 834
 835                 if(!found) {
 836                         outgoing_t *outgoing = xzalloc(sizeof(*outgoing));
 837                         node_t *n = lookup_node(name);
 838
 839                         if(!n) {
 840                                 n = new_node();
 841                                 n->name = xstrdup(name);
 842                                 node_add(n);
 843                         }
 844
 845                         outgoing->node = n;
 846                         list_insert_tail(outgoing_list, outgoing);
 847                         setup_outgoing_connection(outgoing, true);
 848                 }
 849         }
 850
 851         /* Terminate any connections whose outgoing_t is to be deleted. */
 852
 853         for list_each(connection_t, c, connection_list) {
 854                 if(c->outgoing && c->outgoing->timeout == -1) {
 855                         c->outgoing = NULL;
 856                         logger(DEBUG_CONNECTIONS, LOG_INFO, "No more outgoing connection to %s", c->name);
 857                         terminate_connection(c, c->edge);
 858                 }
 859         }
 860
 861         /* Delete outgoing_ts for which there is no ConnectTo. */
 862
 863         for list_each(outgoing_t, outgoing, outgoing_list)
 864                 if(outgoing->timeout == -1) {
 865                         list_delete_node(outgoing_list, node);
 866                 }
 867 }