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                   2000-2018 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 "crypto.h"
  29 #include "list.h"
  30 #include "logger.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 int addressfamily = AF_UNSPEC;
  39 int maxtimeout = 900;
  40 int seconds_till_retry = 5;
  41 int udp_rcvbuf = 1024 * 1024;
  42 int udp_sndbuf = 1024 * 1024;
  43 bool udp_rcvbuf_warnings;
  44 bool udp_sndbuf_warnings;
  45 int max_connection_burst = 10;
  46 int fwmark;
  47
  48 listen_socket_t listen_socket[MAXSOCKETS];
  49 int listen_sockets;
  50 #ifndef HAVE_WINDOWS
  51 io_t unix_socket;
  52 #endif
  53
  54 static void free_outgoing(outgoing_t *outgoing) {
  55         timeout_del(&outgoing->ev);
  56         free(outgoing);
  57 }
  58
  59 list_t outgoing_list = {
  60         .head = NULL,
  61         .tail = NULL,
  62         .count = 0,
  63         .delete = (list_action_t)free_outgoing,
  64 };
  65
  66 /* Setup sockets */
  67
  68 static void configure_tcp(connection_t *c) {
  69         int option;
  70
  71 #ifdef O_NONBLOCK
  72         int flags = fcntl(c->socket, F_GETFL);
  73
  74         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
  75                 logger(DEBUG_ALWAYS, LOG_ERR, "fcntl for %s fd %d: %s", c->hostname, c->socket, strerror(errno));
  76         }
  77
  78 #elif defined(WIN32)
  79         unsigned long arg = 1;
  80
  81         if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
  82                 logger(DEBUG_ALWAYS, LOG_ERR, "ioctlsocket for %s fd %d: %s", c->hostname, c->socket, sockstrerror(sockerrno));
  83         }
  84
  85 #endif
  86
  87 #if defined(TCP_NODELAY)
  88         option = 1;
  89         setsockopt(c->socket, IPPROTO_TCP, TCP_NODELAY, (void *)&option, sizeof(option));
  90 #endif
  91
  92 #if defined(IP_TOS) && defined(IPTOS_LOWDELAY)
  93         option = IPTOS_LOWDELAY;
  94         setsockopt(c->socket, IPPROTO_IP, IP_TOS, (void *)&option, sizeof(option));
  95 #endif
  96
  97 #if defined(IPV6_TCLASS) && defined(IPTOS_LOWDELAY)
  98         option = IPTOS_LOWDELAY;
  99         setsockopt(c->socket, IPPROTO_IPV6, IPV6_TCLASS, (void *)&option, sizeof(option));
 100 #endif
 101
 102 #if defined(SO_MARK)
 103
 104         if(fwmark) {
 105                 setsockopt(c->socket, SOL_SOCKET, SO_MARK, (void *)&fwmark, sizeof(fwmark));
 106         }
 107
 108 #endif
 109 }
 110
 111 static bool bind_to_interface(int sd) {
 112         char *iface;
 113
 114 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 115         struct ifreq ifr;
 116         int status;
 117 #endif /* defined(SOL_SOCKET) && defined(SO_BINDTODEVICE) */
 118
 119         if(!get_config_string(lookup_config(&config_tree, "BindToInterface"), &iface)) {
 120                 return true;
 121         }
 122
 123 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 124         memset(&ifr, 0, sizeof(ifr));
 125         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 126         ifr.ifr_ifrn.ifrn_name[IFNAMSIZ - 1] = 0;
 127
 128         status = setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr));
 129
 130         if(status) {
 131                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
 132                        sockstrerror(sockerrno));
 133                 return false;
 134         }
 135
 136 #else /* if !defined(SOL_SOCKET) || !defined(SO_BINDTODEVICE) */
 137         (void)sd;
 138         logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform", "BindToInterface");
 139 #endif
 140
 141         return true;
 142 }
 143
 144 static bool bind_to_address(connection_t *c) {
 145         int s = -1;
 146
 147         for(int i = 0; i < listen_sockets && listen_socket[i].bindto; i++) {
 148                 if(listen_socket[i].sa.sa.sa_family != c->address.sa.sa_family) {
 149                         continue;
 150                 }
 151
 152                 if(s >= 0) {
 153                         return false;
 154                 }
 155
 156                 s = i;
 157         }
 158
 159         if(s < 0) {
 160                 return false;
 161         }
 162
 163         sockaddr_t sa = listen_socket[s].sa;
 164
 165         if(sa.sa.sa_family == AF_INET) {
 166                 sa.in.sin_port = 0;
 167         } else if(sa.sa.sa_family == AF_INET6) {
 168                 sa.in6.sin6_port = 0;
 169         }
 170
 171         if(bind(c->socket, &sa.sa, SALEN(sa.sa))) {
 172                 logger(DEBUG_CONNECTIONS, LOG_WARNING, "Can't bind outgoing socket: %s", sockstrerror(sockerrno));
 173                 return false;
 174         }
 175
 176         return true;
 177 }
 178
 179 static bool try_bind(int nfd, const sockaddr_t *sa, const char *type) {
 180         if(!bind(nfd, &sa->sa, SALEN(sa->sa))) {
 181                 return true;
 182         }
 183
 184         closesocket(nfd);
 185         char *addrstr = sockaddr2hostname(sa);
 186         logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/%s: %s", addrstr, type, sockstrerror(sockerrno));
 187         free(addrstr);
 188         return false;
 189 }
 190
 191 int setup_listen_socket(const sockaddr_t *sa) {
 192         int nfd;
 193         int option;
 194         char *iface;
 195
 196         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 197
 198         if(nfd < 0) {
 199                 logger(DEBUG_STATUS, LOG_ERR, "Creating metasocket failed: %s", sockstrerror(sockerrno));
 200                 return -1;
 201         }
 202
 203 #ifdef FD_CLOEXEC
 204         fcntl(nfd, F_SETFD, FD_CLOEXEC);
 205 #endif
 206
 207         /* Optimize TCP settings */
 208
 209         option = 1;
 210         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
 211
 212 #if defined(IPV6_V6ONLY)
 213
 214         if(sa->sa.sa_family == AF_INET6) {
 215                 setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
 216         }
 217
 218 #else
 219 #warning IPV6_V6ONLY not defined
 220 #endif
 221
 222 #if defined(SO_MARK)
 223
 224         if(fwmark) {
 225                 setsockopt(nfd, SOL_SOCKET, SO_MARK, (void *)&fwmark, sizeof(fwmark));
 226         }
 227
 228 #endif
 229
 230         if(get_config_string
 231                         (lookup_config(&config_tree, "BindToInterface"), &iface)) {
 232 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
 233                 struct ifreq ifr;
 234
 235                 memset(&ifr, 0, sizeof(ifr));
 236                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 237                 ifr.ifr_ifrn.ifrn_name[IFNAMSIZ - 1] = 0;
 238
 239                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr))) {
 240                         closesocket(nfd);
 241                         logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
 242                                sockstrerror(sockerrno));
 243                         return -1;
 244                 }
 245
 246 #else
 247                 logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform", "BindToInterface");
 248 #endif
 249         }
 250
 251         if(!try_bind(nfd, sa, "tcp")) {
 252                 return -1;
 253         }
 254
 255         if(listen(nfd, 3)) {
 256                 closesocket(nfd);
 257                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "listen", sockstrerror(sockerrno));
 258                 return -1;
 259         }
 260
 261         return nfd;
 262 }
 263
 264 static void set_udp_buffer(int nfd, int type, const char *name, int size, bool warnings) {
 265         if(!size) {
 266                 return;
 267         }
 268
 269         if(setsockopt(nfd, SOL_SOCKET, type, (void *)&size, sizeof(size))) {
 270                 logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP %s to %i: %s", name, size, sockstrerror(sockerrno));
 271                 return;
 272         }
 273
 274         if(!warnings) {
 275                 return;
 276         }
 277
 278         // The system may cap the requested buffer size.
 279         // Read back the value and check if it is now as requested.
 280         int actual = -1;
 281         socklen_t optlen = sizeof(actual);
 282
 283         if(getsockopt(nfd, SOL_SOCKET, type, (void *)&actual, &optlen)) {
 284                 logger(DEBUG_ALWAYS, LOG_WARNING, "Can't read back UDP %s: %s", name, sockstrerror(sockerrno));
 285         } else if(optlen != sizeof(actual)) {
 286                 logger(DEBUG_ALWAYS, LOG_WARNING, "Can't read back UDP %s: unexpected returned optlen %d", name, (int)optlen);
 287         } else if(actual < size) {
 288                 logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP %s to %i, the system set it to %i instead", name, size, actual);
 289         }
 290 }
 291
 292 int setup_vpn_in_socket(const sockaddr_t *sa) {
 293         int nfd;
 294         int option;
 295
 296         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 297
 298         if(nfd < 0) {
 299                 logger(DEBUG_ALWAYS, LOG_ERR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
 300                 return -1;
 301         }
 302
 303 #ifdef FD_CLOEXEC
 304         fcntl(nfd, F_SETFD, FD_CLOEXEC);
 305 #endif
 306
 307 #ifdef O_NONBLOCK
 308         {
 309                 int flags = fcntl(nfd, F_GETFL);
 310
 311                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
 312                         closesocket(nfd);
 313                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "fcntl",
 314                                strerror(errno));
 315                         return -1;
 316                 }
 317         }
 318 #elif defined(WIN32)
 319         {
 320                 unsigned long arg = 1;
 321
 322                 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
 323                         closesocket(nfd);
 324                         logger(DEBUG_ALWAYS, LOG_ERR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
 325                         return -1;
 326                 }
 327         }
 328 #endif
 329
 330         option = 1;
 331         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
 332         setsockopt(nfd, SOL_SOCKET, SO_BROADCAST, (void *)&option, sizeof(option));
 333
 334         set_udp_buffer(nfd, SO_RCVBUF, "SO_RCVBUF", udp_rcvbuf, udp_rcvbuf_warnings);
 335         set_udp_buffer(nfd, SO_SNDBUF, "SO_SNDBUF", udp_sndbuf, udp_sndbuf_warnings);
 336
 337 #if defined(IPV6_V6ONLY)
 338
 339         if(sa->sa.sa_family == AF_INET6) {
 340                 setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
 341         }
 342
 343 #endif
 344
 345 #if defined(IP_DONTFRAG) && !defined(IP_DONTFRAGMENT)
 346 #define IP_DONTFRAGMENT IP_DONTFRAG
 347 #endif
 348
 349 #if defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 350
 351         if(myself->options & OPTION_PMTU_DISCOVERY) {
 352                 option = IP_PMTUDISC_DO;
 353                 setsockopt(nfd, IPPROTO_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
 354         }
 355
 356 #elif defined(IP_DONTFRAGMENT)
 357
 358         if(myself->options & OPTION_PMTU_DISCOVERY) {
 359                 option = 1;
 360                 setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, (void *)&option, sizeof(option));
 361         }
 362
 363 #endif
 364
 365 #if defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 366
 367         if(myself->options & OPTION_PMTU_DISCOVERY) {
 368                 option = IPV6_PMTUDISC_DO;
 369                 setsockopt(nfd, IPPROTO_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
 370         }
 371
 372 #elif defined(IPV6_DONTFRAG)
 373
 374         if(myself->options & OPTION_PMTU_DISCOVERY) {
 375                 option = 1;
 376                 setsockopt(nfd, IPPROTO_IPV6, IPV6_DONTFRAG, (void *)&option, sizeof(option));
 377         }
 378
 379 #endif
 380
 381 #if defined(SO_MARK)
 382
 383         if(fwmark) {
 384                 setsockopt(nfd, SOL_SOCKET, SO_MARK, (void *)&fwmark, sizeof(fwmark));
 385         }
 386
 387 #endif
 388
 389         if(!bind_to_interface(nfd)) {
 390                 closesocket(nfd);
 391                 return -1;
 392         }
 393
 394         if(!try_bind(nfd, sa, "udp")) {
 395                 return -1;
 396         }
 397
 398         return nfd;
 399 } /* int setup_vpn_in_socket */
 400
 401 static void retry_outgoing_handler(void *data) {
 402         setup_outgoing_connection(data, true);
 403 }
 404
 405 void retry_outgoing(outgoing_t *outgoing) {
 406         outgoing->timeout += 5;
 407
 408         if(outgoing->timeout > maxtimeout) {
 409                 outgoing->timeout = maxtimeout;
 410         }
 411
 412         timeout_add(&outgoing->ev, retry_outgoing_handler, outgoing, &(struct timeval) {
 413                 outgoing->timeout, jitter()
 414         });
 415
 416         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Trying to re-establish outgoing connection in %d seconds", outgoing->timeout);
 417 }
 418
 419 void finish_connecting(connection_t *c) {
 420         logger(DEBUG_CONNECTIONS, LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
 421
 422         c->last_ping_time = now.tv_sec;
 423         c->status.connecting = false;
 424
 425         send_id(c);
 426 }
 427
 428 static void do_outgoing_pipe(connection_t *c, const char *command) {
 429 #ifndef HAVE_WINDOWS
 430         int fd[2];
 431
 432         if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
 433                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not create socketpair: %s", sockstrerror(sockerrno));
 434                 return;
 435         }
 436
 437         if(fork()) {
 438                 c->socket = fd[0];
 439                 close(fd[1]);
 440                 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Using proxy %s", command);
 441                 return;
 442         }
 443
 444         close(0);
 445         close(1);
 446         close(fd[0]);
 447         dup2(fd[1], 0);
 448         dup2(fd[1], 1);
 449         close(fd[1]);
 450
 451         // Other filedescriptors should be closed automatically by CLOEXEC
 452
 453         char *host = NULL;
 454         char *port = NULL;
 455
 456         sockaddr2str(&c->address, &host, &port);
 457         setenv("REMOTEADDRESS", host, true);
 458         setenv("REMOTEPORT", port, true);
 459         setenv("NODE", c->name, true);
 460         setenv("NAME", myself->name, true);
 461
 462         if(netname) {
 463                 setenv("NETNAME", netname, true);
 464         }
 465
 466         int result = system(command);
 467
 468         if(result < 0) {
 469                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not execute %s: %s", command, strerror(errno));
 470         } else if(result) {
 471                 logger(DEBUG_ALWAYS, LOG_ERR, "%s exited with non-zero status %d", command, result);
 472         }
 473
 474         exit(result);
 475 #else
 476         (void)c;
 477         (void)command;
 478         logger(DEBUG_ALWAYS, LOG_ERR, "Proxy type exec not supported on this platform!");
 479         return;
 480 #endif
 481 }
 482
 483 static void handle_meta_write(connection_t *c) {
 484         if(c->outbuf.len <= c->outbuf.offset) {
 485                 return;
 486         }
 487
 488         ssize_t outlen = send(c->socket, c->outbuf.data + c->outbuf.offset, c->outbuf.len - c->outbuf.offset, 0);
 489
 490         if(outlen <= 0) {
 491                 if(!sockerrno || sockerrno == EPIPE) {
 492                         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection closed by %s (%s)", c->name, c->hostname);
 493                 } else if(sockwouldblock(sockerrno)) {
 494                         logger(DEBUG_META, LOG_DEBUG, "Sending %d bytes to %s (%s) would block", c->outbuf.len - c->outbuf.offset, c->name, c->hostname);
 495                         return;
 496                 } else {
 497                         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));
 498                 }
 499
 500                 terminate_connection(c, c->edge);
 501                 return;
 502         }
 503
 504         buffer_read(&c->outbuf, outlen);
 505
 506         if(!c->outbuf.len) {
 507                 io_set(&c->io, IO_READ);
 508         }
 509 }
 510
 511 static void handle_meta_io(void *data, int flags) {
 512         connection_t *c = data;
 513
 514         if(c->status.connecting) {
 515                 /*
 516                    The event loop does not protect against spurious events. Verify that we are actually connected
 517                    by issuing an empty send() call.
 518
 519                    Note that the behavior of send() on potentially unconnected sockets differ between platforms:
 520                    +------------+-----------+-------------+-----------+
 521                    |   Event    |   POSIX   |    Linux    |  Windows  |
 522                    +------------+-----------+-------------+-----------+
 523                    | Spurious   | ENOTCONN  | EWOULDBLOCK | ENOTCONN  |
 524                    | Failed     | ENOTCONN  | (cause)     | ENOTCONN  |
 525                    | Successful | (success) | (success)   | (success) |
 526                    +------------+-----------+-------------+-----------+
 527                 */
 528                 if(send(c->socket, NULL, 0, 0) != 0) {
 529                         if(sockwouldblock(sockerrno)) {
 530                                 return;
 531                         }
 532
 533                         int socket_error;
 534
 535                         if(!socknotconn(sockerrno)) {
 536                                 socket_error = sockerrno;
 537                         } else {
 538                                 socklen_t len = sizeof(socket_error);
 539                                 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, (void *)&socket_error, &len);
 540                         }
 541
 542                         if(socket_error) {
 543                                 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Error while connecting to %s (%s): %s", c->name, c->hostname, sockstrerror(socket_error));
 544                                 terminate_connection(c, false);
 545                         }
 546
 547                         return;
 548                 }
 549
 550                 c->status.connecting = false;
 551                 finish_connecting(c);
 552         }
 553
 554         if(flags & IO_WRITE) {
 555                 handle_meta_write(c);
 556         } else {
 557                 handle_meta_connection_data(c);
 558         }
 559 }
 560
 561 bool do_outgoing_connection(outgoing_t *outgoing) {
 562         const sockaddr_t *sa;
 563         struct addrinfo *proxyai = NULL;
 564         int result;
 565
 566 begin:
 567         sa = get_recent_address(outgoing->node->address_cache);
 568
 569         if(!sa) {
 570                 logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not set up a meta connection to %s", outgoing->node->name);
 571                 retry_outgoing(outgoing);
 572                 return false;
 573         }
 574
 575         connection_t *c = new_connection();
 576         c->outgoing = outgoing;
 577         memcpy(&c->address, sa, SALEN(sa->sa));
 578         c->hostname = sockaddr2hostname(&c->address);
 579
 580         logger(DEBUG_CONNECTIONS, LOG_INFO, "Trying to connect to %s (%s)", outgoing->node->name, c->hostname);
 581
 582         if(!proxytype) {
 583                 c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 584                 configure_tcp(c);
 585         } else if(proxytype == PROXY_EXEC) {
 586                 do_outgoing_pipe(c, proxyhost);
 587         } else {
 588                 proxyai = str2addrinfo(proxyhost, proxyport, SOCK_STREAM);
 589
 590                 if(!proxyai) {
 591                         free_connection(c);
 592                         goto begin;
 593                 }
 594
 595                 logger(DEBUG_CONNECTIONS, LOG_INFO, "Using proxy at %s port %s", proxyhost, proxyport);
 596                 c->socket = socket(proxyai->ai_family, SOCK_STREAM, IPPROTO_TCP);
 597                 configure_tcp(c);
 598         }
 599
 600         if(c->socket == -1) {
 601                 logger(DEBUG_CONNECTIONS, LOG_ERR, "Creating socket for %s failed: %s", c->hostname, sockstrerror(sockerrno));
 602                 free_connection(c);
 603                 goto begin;
 604         }
 605
 606 #ifdef FD_CLOEXEC
 607         fcntl(c->socket, F_SETFD, FD_CLOEXEC);
 608 #endif
 609
 610         if(proxytype != PROXY_EXEC) {
 611 #if defined(IPV6_V6ONLY)
 612                 int option = 1;
 613
 614                 if(c->address.sa.sa_family == AF_INET6) {
 615                         setsockopt(c->socket, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
 616                 }
 617
 618 #endif
 619
 620                 bind_to_interface(c->socket);
 621                 bind_to_address(c);
 622         }
 623
 624         /* Connect */
 625
 626         if(!proxytype) {
 627                 result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
 628         } else if(proxytype == PROXY_EXEC) {
 629                 result = 0;
 630         } else {
 631                 if(!proxyai) {
 632                         abort();
 633                 }
 634
 635                 result = connect(c->socket, proxyai->ai_addr, proxyai->ai_addrlen);
 636                 freeaddrinfo(proxyai);
 637         }
 638
 639         if(result == -1 && !sockinprogress(sockerrno)) {
 640                 logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not connect to %s (%s): %s", outgoing->node->name, c->hostname, sockstrerror(sockerrno));
 641                 free_connection(c);
 642
 643                 goto begin;
 644         }
 645
 646         /* Now that there is a working socket, fill in the rest and register this connection. */
 647
 648         c->last_ping_time = time(NULL);
 649         c->status.connecting = true;
 650         c->name = xstrdup(outgoing->node->name);
 651         c->outmaclength = myself->connection->outmaclength;
 652         c->last_ping_time = now.tv_sec;
 653
 654         connection_add(c);
 655
 656         io_add(&c->io, handle_meta_io, c, c->socket, IO_READ | IO_WRITE);
 657
 658         return true;
 659 }
 660
 661 void setup_outgoing_connection(outgoing_t *outgoing, bool verbose) {
 662         (void)verbose;
 663         timeout_del(&outgoing->ev);
 664
 665         node_t *n = outgoing->node;
 666
 667         if(!n->address_cache) {
 668                 n->address_cache = open_address_cache(n);
 669         }
 670
 671         if(n->connection) {
 672                 logger(DEBUG_CONNECTIONS, LOG_INFO, "Already connected to %s", n->name);
 673
 674                 if(!n->connection->outgoing) {
 675                         n->connection->outgoing = outgoing;
 676                         return;
 677                 } else {
 678                         goto remove;
 679                 }
 680         }
 681
 682         do_outgoing_connection(outgoing);
 683         return;
 684
 685 remove:
 686         list_delete(&outgoing_list, outgoing);
 687 }
 688
 689 /*
 690   accept a new tcp connect and create a
 691   new connection
 692 */
 693 void handle_new_meta_connection(void *data, int flags) {
 694         (void)flags;
 695         listen_socket_t *l = data;
 696         connection_t *c;
 697         sockaddr_t sa;
 698         int fd;
 699         socklen_t len = sizeof(sa);
 700
 701         fd = accept(l->tcp.fd, &sa.sa, &len);
 702
 703         if(fd < 0) {
 704                 logger(DEBUG_ALWAYS, LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
 705                 return;
 706         }
 707
 708         sockaddrunmap(&sa);
 709
 710         // Check if we get many connections from the same host
 711
 712         static sockaddr_t prev_sa;
 713
 714         if(!sockaddrcmp_noport(&sa, &prev_sa)) {
 715                 static time_t samehost_burst;
 716                 static time_t samehost_burst_time;
 717
 718                 if(now.tv_sec - samehost_burst_time > samehost_burst) {
 719                         samehost_burst = 0;
 720                 } else {
 721                         samehost_burst -= now.tv_sec - samehost_burst_time;
 722                 }
 723
 724                 samehost_burst_time = now.tv_sec;
 725                 samehost_burst++;
 726
 727                 if(samehost_burst > max_connection_burst) {
 728                         tarpit(fd);
 729                         return;
 730                 }
 731         }
 732
 733         memcpy(&prev_sa, &sa, sizeof(sa));
 734
 735         // Check if we get many connections from different hosts
 736
 737         static time_t connection_burst;
 738         static time_t connection_burst_time;
 739
 740         if(now.tv_sec - connection_burst_time > connection_burst) {
 741                 connection_burst = 0;
 742         } else {
 743                 connection_burst -= now.tv_sec - connection_burst_time;
 744         }
 745
 746         connection_burst_time = now.tv_sec;
 747         connection_burst++;
 748
 749         if(connection_burst >= max_connection_burst) {
 750                 connection_burst = max_connection_burst;
 751                 tarpit(fd);
 752                 return;
 753         }
 754
 755         // Accept the new connection
 756
 757         c = new_connection();
 758         c->name = xstrdup("<unknown>");
 759         c->outmaclength = myself->connection->outmaclength;
 760
 761         c->address = sa;
 762         c->hostname = sockaddr2hostname(&sa);
 763         c->socket = fd;
 764         c->last_ping_time = now.tv_sec;
 765
 766         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection from %s", c->hostname);
 767
 768         io_add(&c->io, handle_meta_io, c, c->socket, IO_READ);
 769
 770         configure_tcp(c);
 771
 772         connection_add(c);
 773
 774         c->allow_request = ID;
 775 }
 776
 777 #ifndef HAVE_WINDOWS
 778 /*
 779   accept a new UNIX socket connection
 780 */
 781 void handle_new_unix_connection(void *data, int flags) {
 782         (void)flags;
 783         io_t *io = data;
 784         connection_t *c;
 785         sockaddr_t sa;
 786         int fd;
 787         socklen_t len = sizeof(sa);
 788
 789         fd = accept(io->fd, &sa.sa, &len);
 790
 791         if(fd < 0) {
 792                 logger(DEBUG_ALWAYS, LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
 793                 return;
 794         }
 795
 796         sockaddrunmap(&sa);
 797
 798         c = new_connection();
 799         c->name = xstrdup("<control>");
 800         c->address = sa;
 801         c->hostname = xstrdup("localhost port unix");
 802         c->socket = fd;
 803         c->last_ping_time = now.tv_sec;
 804
 805         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection from %s", c->hostname);
 806
 807         io_add(&c->io, handle_meta_io, c, c->socket, IO_READ);
 808
 809         connection_add(c);
 810
 811         c->allow_request = ID;
 812 }
 813 #endif
 814
 815 void try_outgoing_connections(void) {
 816         /* If there is no outgoing list yet, create one. Otherwise, mark all outgoings as deleted. */
 817
 818         for list_each(outgoing_t, outgoing, &outgoing_list) {
 819                 outgoing->timeout = -1;
 820         }
 821
 822         /* Make sure there is one outgoing_t in the list for each ConnectTo. */
 823
 824         for(config_t *cfg = lookup_config(&config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(&config_tree, cfg)) {
 825                 char *name;
 826                 get_config_string(cfg, &name);
 827
 828                 if(!check_id(name)) {
 829                         logger(DEBUG_ALWAYS, LOG_ERR,
 830                                "Invalid name for outgoing connection in %s line %d",
 831                                cfg->file, cfg->line);
 832                         free(name);
 833                         continue;
 834                 }
 835
 836                 if(!strcmp(name, myself->name)) {
 837                         free(name);
 838                         continue;
 839                 }
 840
 841                 bool found = false;
 842
 843                 for list_each(outgoing_t, outgoing, &outgoing_list) {
 844                         if(!strcmp(outgoing->node->name, name)) {
 845                                 found = true;
 846                                 outgoing->timeout = 0;
 847                                 break;
 848                         }
 849                 }
 850
 851                 if(!found) {
 852                         outgoing_t *outgoing = xzalloc(sizeof(*outgoing));
 853                         node_t *n = lookup_node(name);
 854
 855                         if(!n) {
 856                                 n = new_node();
 857                                 n->name = xstrdup(name);
 858                                 node_add(n);
 859                         }
 860
 861                         free(name);
 862
 863                         outgoing->node = n;
 864                         list_insert_tail(&outgoing_list, outgoing);
 865                         setup_outgoing_connection(outgoing, true);
 866                 }
 867         }
 868
 869         /* Terminate any connections whose outgoing_t is to be deleted. */
 870
 871         for list_each(connection_t, c, &connection_list) {
 872                 if(c->outgoing && c->outgoing->timeout == -1) {
 873                         c->outgoing = NULL;
 874                         logger(DEBUG_CONNECTIONS, LOG_INFO, "No more outgoing connection to %s", c->name);
 875                         terminate_connection(c, c->edge);
 876                 }
 877         }
 878
 879         /* Delete outgoing_ts for which there is no ConnectTo. */
 880
 881         for list_each(outgoing_t, outgoing, &outgoing_list)
 882                 if(outgoing->timeout == -1) {
 883                         list_delete_node(&outgoing_list, node);
 884                 }
 885 }