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

   1 /*
   2     net.c -- most of the network code
   3     Copyright (C) 2014-2017 Guus Sliepen <guus@meshlink.io>
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License along
  16     with this program; if not, write to the Free Software Foundation, Inc.,
  17     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #include "system.h"
  21
  22 #include "utils.h"
  23 #include "conf.h"
  24 #include "connection.h"
  25 #include "graph.h"
  26 #include "logger.h"
  27 #include "meshlink_internal.h"
  28 #include "meta.h"
  29 #include "net.h"
  30 #include "netutl.h"
  31 #include "protocol.h"
  32 #include "sptps.h"
  33 #include "xalloc.h"
  34
  35 #include <assert.h>
  36
  37 #if !defined(min)
  38 static inline int min(int a, int b) {
  39         return a < b ? a : b;
  40 }
  41 #endif
  42
  43 static const int default_timeout = 5;
  44 static const int default_interval = 60;
  45
  46 /*
  47   Terminate a connection:
  48   - Mark it as inactive
  49   - Remove the edge representing this connection
  50   - Kill it with fire
  51   - Check if we need to retry making an outgoing connection
  52 */
  53 void terminate_connection(meshlink_handle_t *mesh, connection_t *c, bool report) {
  54         logger(mesh, MESHLINK_INFO, "Closing connection with %s", c->name);
  55
  56         c->status.active = false;
  57
  58         if(c->node && c->node->connection == c) {
  59                 c->node->connection = NULL;
  60         }
  61
  62         if(c->edge) {
  63                 if(report) {
  64                         send_del_edge(mesh, mesh->everyone, c->edge, 0);
  65                 }
  66
  67                 edge_del(mesh, c->edge);
  68                 c->edge = NULL;
  69
  70                 /* Run MST and SSSP algorithms */
  71
  72                 graph(mesh);
  73
  74                 /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
  75
  76                 if(report && c->node && !c->node->status.reachable) {
  77                         edge_t *e;
  78                         e = lookup_edge(c->node, mesh->self);
  79
  80                         if(e) {
  81                                 send_del_edge(mesh, mesh->everyone, e, 0);
  82                                 edge_del(mesh, e);
  83                         }
  84                 }
  85         }
  86
  87         outgoing_t *outgoing = c->outgoing;
  88         connection_del(mesh, c);
  89
  90         /* Check if this was our outgoing connection */
  91
  92         if(outgoing) {
  93                 do_outgoing_connection(mesh, outgoing);
  94         }
  95 }
  96
  97 /*
  98   Check if the other end is active.
  99   If we have sent packets, but didn't receive any,
 100   then possibly the other end is dead. We send a
 101   PING request over the meta connection. If the other
 102   end does not reply in time, we consider them dead
 103   and close the connection.
 104 */
 105 static void timeout_handler(event_loop_t *loop, void *data) {
 106         assert(data);
 107
 108         meshlink_handle_t *mesh = loop->data;
 109         logger(mesh, MESHLINK_DEBUG, "timeout_handler()");
 110
 111         for list_each(connection_t, c, mesh->connections) {
 112                 int pingtimeout = c->node ? mesh->dev_class_traits[c->node->devclass].pingtimeout : default_timeout;
 113                 int pinginterval = c->node ? mesh->dev_class_traits[c->node->devclass].pinginterval : default_interval;
 114
 115                 if(c->outgoing && c->outgoing->timeout < 5) {
 116                         pingtimeout = 1;
 117                 }
 118
 119                 // Also make sure that if outstanding key requests for the UDP counterpart of a connection has timed out, we restart it.
 120                 if(c->node) {
 121                         if(c->node->status.waitingforkey && c->node->last_req_key + pingtimeout <= mesh->loop.now.tv_sec) {
 122                                 send_req_key(mesh, c->node);
 123                         }
 124                 }
 125
 126                 if(c->status.active && c->last_key_renewal + 3600 < mesh->loop.now.tv_sec) {
 127                         if(!sptps_force_kex(&c->sptps)) {
 128                                 logger(mesh, MESHLINK_ERROR, "SPTPS key renewal for connection with %s failed", c->name);
 129                                 terminate_connection(mesh, c, true);
 130                                 continue;
 131                         } else {
 132                                 c->last_key_renewal = mesh->loop.now.tv_sec;
 133                         }
 134                 }
 135
 136                 if(c->last_ping_time + pingtimeout <= mesh->loop.now.tv_sec) {
 137                         if(c->status.active) {
 138                                 if(c->status.pinged) {
 139                                         logger(mesh, MESHLINK_INFO, "%s didn't respond to PING in %ld seconds", c->name, (long)mesh->loop.now.tv_sec - c->last_ping_time);
 140                                 } else if(c->last_ping_time + pinginterval <= mesh->loop.now.tv_sec) {
 141                                         send_ping(mesh, c);
 142                                         continue;
 143                                 } else {
 144                                         continue;
 145                                 }
 146                         } else {
 147                                 if(c->status.connecting) {
 148                                         logger(mesh, MESHLINK_WARNING, "Timeout while connecting to %s", c->name);
 149                                 } else {
 150                                         logger(mesh, MESHLINK_WARNING, "Timeout from %s during authentication", c->name);
 151                                 }
 152                         }
 153
 154                         terminate_connection(mesh, c, c->status.active);
 155                 }
 156         }
 157
 158         timeout_set(&mesh->loop, data, &(struct timespec) {
 159                 1, prng(mesh, TIMER_FUDGE)
 160         });
 161 }
 162
 163 // devclass asc, last_successfull_connection desc
 164 static int node_compare_devclass_asc_lsc_desc(const void *a, const void *b) {
 165         const node_t *na = a, *nb = b;
 166
 167         if(na->devclass < nb->devclass) {
 168                 return -1;
 169         }
 170
 171         if(na->devclass > nb->devclass) {
 172                 return 1;
 173         }
 174
 175         if(na->last_successfull_connection == nb->last_successfull_connection) {
 176                 return 0;
 177         }
 178
 179         if(na->last_successfull_connection == 0 || na->last_successfull_connection > nb->last_successfull_connection) {
 180                 return -1;
 181         }
 182
 183         if(nb->last_successfull_connection == 0 || na->last_successfull_connection < nb->last_successfull_connection) {
 184                 return 1;
 185         }
 186
 187         if(na < nb) {
 188                 return -1;
 189         }
 190
 191         if(na > nb) {
 192                 return 1;
 193         }
 194
 195         return 0;
 196 }
 197
 198 // last_successfull_connection desc
 199 static int node_compare_lsc_desc(const void *a, const void *b) {
 200         const node_t *na = a, *nb = b;
 201
 202         if(na->last_successfull_connection == nb->last_successfull_connection) {
 203                 return 0;
 204         }
 205
 206         if(na->last_successfull_connection == 0 || na->last_successfull_connection > nb->last_successfull_connection) {
 207                 return -1;
 208         }
 209
 210         if(nb->last_successfull_connection == 0 || na->last_successfull_connection < nb->last_successfull_connection) {
 211                 return 1;
 212         }
 213
 214         if(na < nb) {
 215                 return -1;
 216         }
 217
 218         if(na > nb) {
 219                 return 1;
 220         }
 221
 222         return 0;
 223 }
 224
 225 // devclass desc
 226 static int node_compare_devclass_desc(const void *a, const void *b) {
 227         const node_t *na = a, *nb = b;
 228
 229         if(na->devclass < nb->devclass) {
 230                 return -1;
 231         }
 232
 233         if(na->devclass > nb->devclass) {
 234                 return 1;
 235         }
 236
 237         if(na < nb) {
 238                 return -1;
 239         }
 240
 241         if(na > nb) {
 242                 return 1;
 243         }
 244
 245         return 0;
 246 }
 247
 248
 249 /*
 250
 251 autoconnect()
 252 {
 253         timeout = 5
 254
 255         // find the best one for initial connect
 256
 257         if cur < min
 258                 newcon =
 259                         first from nodes
 260                                 where dclass <= my.dclass and !connection and (timestamp - last_retry) > retry_timeout
 261                                 order by dclass asc, last_connection desc
 262                 if newcon
 263                         timeout = 0
 264                         goto connect
 265
 266
 267         // find better nodes to connect to: in case we have less than min connections within [BACKBONE, i] and there are nodes which we are not connected to within the range
 268
 269         if min <= cur < max
 270                 j = 0
 271                 for i = BACKBONE to my.dclass
 272                         j += count(from connections where node.dclass = i)
 273                         if j < min
 274                                 newcon =
 275                                         first from nodes
 276                                                 where dclass = i and !connection and (timestamp - last_retry) > retry_timeout
 277                                                 order by last_connection desc
 278                                 if newcon
 279                                         goto connect
 280                         else
 281                                 break
 282
 283
 284         // heal partitions
 285
 286         if min <= cur < max
 287                 newcon =
 288                         first from nodes
 289                                 where dclass <= my.dclass and !reachable and (timestamp - last_retry) > retry_timeout
 290                                 order by dclass asc, last_connection desc
 291                 if newcon
 292                         goto connect
 293
 294
 295         // connect
 296
 297 connect:
 298         if newcon
 299                 connect newcon
 300
 301
 302         // disconnect outgoing connections in case we have more than min connections within [BACKBONE, i] and there are nodes which we are connected to within the range [i, PORTABLE]
 303
 304         if min < cur <= max
 305                 j = 0
 306                 for i = BACKBONE to my.dclass
 307                         j += count(from connections where node.dclass = i)
 308                         if min < j
 309                                 delcon =
 310                                         first from nodes
 311                                                 where dclass >= i and outgoing_connection
 312                                                 order by dclass desc
 313                                 if disconnect
 314                                         goto disconnect
 315                                 else
 316                                         break
 317
 318
 319         // disconnect connections in case we have more than enough connections
 320
 321         if max < cur
 322                 delcon =
 323                         first from nodes
 324                                 where outgoing_connection
 325                                 order by dclass desc
 326                 goto disconnect
 327
 328         // disconnect
 329
 330 disconnect
 331         if delcon
 332                 disconnect delcon
 333
 334
 335         // next iteration
 336         next (timeout, autoconnect)
 337
 338 }
 339
 340 */
 341
 342
 343 static void periodic_handler(event_loop_t *loop, void *data) {
 344         meshlink_handle_t *mesh = loop->data;
 345
 346         /* Check if there are too many contradicting ADD_EDGE and DEL_EDGE messages.
 347            This usually only happens when another node has the same Name as this node.
 348            If so, sleep for a short while to prevent a storm of contradicting messages.
 349         */
 350
 351         if(mesh->contradicting_del_edge > 100 && mesh->contradicting_add_edge > 100) {
 352                 logger(mesh, MESHLINK_WARNING, "Possible node with same Name as us! Sleeping %d seconds.", mesh->sleeptime);
 353                 struct timespec ts = {mesh->sleeptime, 0};
 354                 clock_nanosleep(CLOCK_MONOTONIC, 0, &ts, NULL);
 355                 mesh->sleeptime *= 2;
 356
 357                 if(mesh->sleeptime < 0) {
 358                         mesh->sleeptime = 3600;
 359                 }
 360         } else {
 361                 mesh->sleeptime /= 2;
 362
 363                 if(mesh->sleeptime < 10) {
 364                         mesh->sleeptime = 10;
 365                 }
 366         }
 367
 368         mesh->contradicting_add_edge = 0;
 369         mesh->contradicting_del_edge = 0;
 370
 371         int timeout = default_timeout;
 372
 373         /* Check if we need to make or break connections. */
 374
 375         if(mesh->nodes->count > 1) {
 376
 377                 logger(mesh, MESHLINK_DEBUG, "--- autoconnect begin ---");
 378
 379                 int retry_timeout = min(mesh->nodes->count * default_timeout, 60);
 380
 381                 logger(mesh, MESHLINK_DEBUG, "* devclass = %d", mesh->devclass);
 382                 logger(mesh, MESHLINK_DEBUG, "* nodes = %d", mesh->nodes->count);
 383                 logger(mesh, MESHLINK_DEBUG, "* retry_timeout = %d", retry_timeout);
 384
 385
 386                 // connect disconnect nodes
 387
 388                 node_t *connect_to = NULL;
 389                 node_t *disconnect_from = NULL;
 390
 391
 392                 // get cur_connects
 393
 394                 unsigned int cur_connects = 0;
 395
 396                 for list_each(connection_t, c, mesh->connections) {
 397                         if(c->status.active) {
 398                                 cur_connects += 1;
 399                         }
 400                 }
 401
 402                 logger(mesh, MESHLINK_DEBUG, "* cur_connects = %d", cur_connects);
 403                 logger(mesh, MESHLINK_DEBUG, "* outgoings = %d", mesh->outgoings->count);
 404
 405                 // get min_connects and max_connects
 406
 407                 unsigned int min_connects = mesh->dev_class_traits[mesh->devclass].min_connects;
 408                 unsigned int max_connects = mesh->dev_class_traits[mesh->devclass].max_connects;
 409
 410                 logger(mesh, MESHLINK_DEBUG, "* min_connects = %d", min_connects);
 411                 logger(mesh, MESHLINK_DEBUG, "* max_connects = %d", max_connects);
 412
 413                 // find the best one for initial connect
 414
 415                 if(cur_connects < min_connects) {
 416                         splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_asc_lsc_desc, NULL);
 417
 418                         for splay_each(node_t, n, mesh->nodes) {
 419                                 logger(mesh, MESHLINK_DEBUG, "* %s->devclass = %d", n->name, n->devclass);
 420
 421                                 if(n != mesh->self && n->devclass <= mesh->devclass && !n->connection && !n->status.blacklisted && (n->last_connect_try == 0 || (mesh->loop.now.tv_sec - n->last_connect_try) > retry_timeout)) {
 422                                         splay_insert(nodes, n);
 423                                 }
 424                         }
 425
 426                         if(nodes->head) {
 427                                 //timeout = 0;
 428                                 connect_to = (node_t *)nodes->head->data;
 429
 430                                 logger(mesh, MESHLINK_DEBUG, "* found best one for initial connect: %s", connect_to->name);
 431                         } else {
 432                                 logger(mesh, MESHLINK_DEBUG, "* could not find node for initial connect");
 433                         }
 434
 435                         splay_delete_tree(nodes);
 436                 }
 437
 438
 439                 // find better nodes to connect to
 440
 441                 if(!connect_to && min_connects <= cur_connects && cur_connects < max_connects) {
 442                         unsigned int connects = 0;
 443
 444                         for(dev_class_t devclass = 0; devclass <= mesh->devclass; ++devclass) {
 445                                 for list_each(connection_t, c, mesh->connections) {
 446                                         if(c->status.active && c->node && c->node->devclass == devclass) {
 447                                                 connects += 1;
 448                                         }
 449                                 }
 450
 451                                 if(connects < min_connects) {
 452                                         splay_tree_t *nodes = splay_alloc_tree(node_compare_lsc_desc, NULL);
 453
 454                                         for splay_each(node_t, n, mesh->nodes) {
 455                                                 if(n != mesh->self && n->devclass == devclass && !n->connection && !n->status.blacklisted && (n->last_connect_try == 0 || (mesh->loop.now.tv_sec - n->last_connect_try) > retry_timeout)) {
 456                                                         splay_insert(nodes, n);
 457                                                 }
 458                                         }
 459
 460                                         if(nodes->head) {
 461                                                 logger(mesh, MESHLINK_DEBUG, "* found better node");
 462                                                 connect_to = (node_t *)nodes->head->data;
 463
 464                                                 splay_delete_tree(nodes);
 465                                                 break;
 466                                         }
 467
 468                                         splay_delete_tree(nodes);
 469                                 } else {
 470                                         break;
 471                                 }
 472                         }
 473
 474                         if(!connect_to) {
 475                                 logger(mesh, MESHLINK_DEBUG, "* could not find better nodes");
 476                         }
 477                 }
 478
 479
 480                 // heal partitions
 481
 482                 if(!connect_to && min_connects <= cur_connects && cur_connects < max_connects) {
 483                         splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_asc_lsc_desc, NULL);
 484
 485                         for splay_each(node_t, n, mesh->nodes) {
 486                                 if(n != mesh->self && n->devclass <= mesh->devclass && !n->status.reachable && !n->status.blacklisted && (n->last_connect_try == 0 || (mesh->loop.now.tv_sec - n->last_connect_try) > retry_timeout)) {
 487                                         splay_insert(nodes, n);
 488                                 }
 489                         }
 490
 491                         if(nodes->head) {
 492                                 logger(mesh, MESHLINK_DEBUG, "* try to heal partition");
 493                                 connect_to = (node_t *)nodes->head->data;
 494                         } else {
 495                                 logger(mesh, MESHLINK_DEBUG, "* could not find nodes for partition healing");
 496                         }
 497
 498                         splay_delete_tree(nodes);
 499                 }
 500
 501
 502                 // perform connect
 503
 504                 if(connect_to && !connect_to->connection) {
 505                         connect_to->last_connect_try = mesh->loop.now.tv_sec;
 506                         logger(mesh, MESHLINK_DEBUG, "Autoconnect trying to connect to %s", connect_to->name);
 507
 508                         /* check if there is already a connection attempt to this node */
 509                         bool skip = false;
 510
 511                         for list_each(outgoing_t, outgoing, mesh->outgoings) {
 512                                 if(outgoing->node == connect_to) {
 513                                         logger(mesh, MESHLINK_DEBUG, "* skip autoconnect since it is an outgoing connection already");
 514                                         skip = true;
 515                                         break;
 516                                 }
 517                         }
 518
 519                         if(!connect_to->status.reachable && !node_read_public_key(mesh, connect_to)) {
 520                                 logger(mesh, MESHLINK_DEBUG, "* skip autoconnect since we don't know this node's public key");
 521                                 skip = true;
 522                         }
 523
 524                         if(!skip) {
 525                                 logger(mesh, MESHLINK_DEBUG, "Autoconnecting to %s", connect_to->name);
 526                                 outgoing_t *outgoing = xzalloc(sizeof(outgoing_t));
 527                                 outgoing->node = connect_to;
 528                                 list_insert_tail(mesh->outgoings, outgoing);
 529                                 setup_outgoing_connection(mesh, outgoing);
 530                         }
 531                 }
 532
 533
 534                 // disconnect suboptimal outgoing connections
 535
 536                 if(min_connects < cur_connects /*&& cur_connects <= max_connects*/) {
 537                         unsigned int connects = 0;
 538
 539                         for(dev_class_t devclass = 0; devclass <= mesh->devclass; ++devclass) {
 540                                 for list_each(connection_t, c, mesh->connections) {
 541                                         if(c->status.active && c->node && c->node->devclass == devclass) {
 542                                                 connects += 1;
 543                                         }
 544                                 }
 545
 546                                 if(min_connects < connects) {
 547                                         splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_desc, NULL);
 548
 549                                         for list_each(connection_t, c, mesh->connections) {
 550                                                 if(c->outgoing && c->node && c->node->devclass >= devclass) {
 551                                                         splay_insert(nodes, c->node);
 552                                                 }
 553                                         }
 554
 555                                         if(nodes->head) {
 556                                                 logger(mesh, MESHLINK_DEBUG, "* disconnect suboptimal outgoing connection");
 557                                                 disconnect_from = (node_t *)nodes->head->data;
 558                                         }
 559
 560                                         splay_delete_tree(nodes);
 561                                         break;
 562                                 }
 563                         }
 564
 565                         if(!disconnect_from) {
 566                                 logger(mesh, MESHLINK_DEBUG, "* no suboptimal outgoing connections");
 567                         }
 568                 }
 569
 570
 571                 // disconnect connections (too many connections)
 572
 573                 if(!disconnect_from && max_connects < cur_connects) {
 574                         splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_desc, NULL);
 575
 576                         for list_each(connection_t, c, mesh->connections) {
 577                                 if(c->status.active && c->node) {
 578                                         splay_insert(nodes, c->node);
 579                                 }
 580                         }
 581
 582                         if(nodes->head) {
 583                                 logger(mesh, MESHLINK_DEBUG, "* disconnect connection (too many connections)");
 584
 585                                 //timeout = 0;
 586                                 disconnect_from = (node_t *)nodes->head->data;
 587                         } else {
 588                                 logger(mesh, MESHLINK_DEBUG, "* no node we want to disconnect, even though we have too many connections");
 589                         }
 590
 591                         splay_delete_tree(nodes);
 592                 }
 593
 594
 595                 // perform disconnect
 596
 597                 if(disconnect_from && disconnect_from->connection) {
 598                         logger(mesh, MESHLINK_DEBUG, "Autodisconnecting from %s", disconnect_from->connection->name);
 599                         list_delete(mesh->outgoings, disconnect_from->connection->outgoing);
 600                         disconnect_from->connection->outgoing = NULL;
 601                         terminate_connection(mesh, disconnect_from->connection, disconnect_from->connection->status.active);
 602                 }
 603
 604                 // reduce timeout if we don't have enough connections + outgoings
 605                 if(cur_connects + mesh->outgoings->count < 3) {
 606                         timeout = 1;
 607                 }
 608
 609                 // done!
 610
 611                 logger(mesh, MESHLINK_DEBUG, "--- autoconnect end ---");
 612         }
 613
 614         for splay_each(node_t, n, mesh->nodes) {
 615                 if(n->status.dirty) {
 616                         if(!node_write_config(mesh, n)) {
 617                                 logger(mesh, MESHLINK_DEBUG, "Could not update %s", n->name);
 618                         }
 619
 620                         n->status.dirty = false;
 621                 }
 622
 623                 if(n->status.validkey && n->last_req_key + 3600 < mesh->loop.now.tv_sec) {
 624                         logger(mesh, MESHLINK_DEBUG, "SPTPS key renewal for node %s", n->name);
 625
 626                         if(!sptps_force_kex(&n->sptps)) {
 627                                 logger(mesh, MESHLINK_ERROR, "SPTPS key renewal for node %s failed", n->name);
 628                                 n->status.validkey = false;
 629                                 sptps_stop(&n->sptps);
 630                                 n->status.waitingforkey = false;
 631                                 n->last_req_key = 0;
 632                         } else {
 633                                 n->last_req_key = mesh->loop.now.tv_sec;
 634                         }
 635                 }
 636         }
 637
 638         timeout_set(&mesh->loop, data, &(struct timespec) {
 639                 timeout, prng(mesh, TIMER_FUDGE)
 640         });
 641 }
 642
 643 void handle_meta_connection_data(meshlink_handle_t *mesh, connection_t *c) {
 644         if(!receive_meta(mesh, c)) {
 645                 terminate_connection(mesh, c, c->status.active);
 646                 return;
 647         }
 648 }
 649
 650 void retry(meshlink_handle_t *mesh) {
 651         /* Reset the reconnection timers for all outgoing connections */
 652         for list_each(outgoing_t, outgoing, mesh->outgoings) {
 653                 outgoing->timeout = 0;
 654
 655                 if(outgoing->ev.cb) {
 656                         timeout_set(&mesh->loop, &outgoing->ev, &(struct timespec) {
 657                                 0, 0
 658                         });
 659                 }
 660         }
 661
 662         /* For active connections, check if their addresses are still valid.
 663          * If yes, reset their ping timers, otherwise terminate them. */
 664         for list_each(connection_t, c, mesh->connections) {
 665                 if(!c->status.active) {
 666                         continue;
 667                 }
 668
 669                 if(!c->status.pinged) {
 670                         c->last_ping_time = 0;
 671                 }
 672
 673                 sockaddr_t sa;
 674                 socklen_t salen = sizeof(sa);
 675
 676                 if(getsockname(c->socket, &sa.sa, &salen)) {
 677                         continue;
 678                 }
 679
 680                 switch(sa.sa.sa_family) {
 681                 case AF_INET:
 682                         sa.in.sin_port = 0;
 683                         break;
 684
 685                 case AF_INET6:
 686                         sa.in6.sin6_port = 0;
 687                         break;
 688
 689                 default:
 690                         continue;
 691                 }
 692
 693                 int sock = socket(sa.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 694
 695                 if(sock != -1) {
 696                         continue;
 697                 }
 698
 699                 if(bind(sock, &sa.sa, salen) && errno == EADDRNOTAVAIL) {
 700                         logger(mesh, MESHLINK_DEBUG, "Local address for connection to %s no longer valid, terminating", c->name);
 701                         terminate_connection(mesh, c, c->status.active);
 702                 }
 703
 704                 closesocket(sock);
 705         }
 706
 707         /* Kick the ping timeout handler */
 708         timeout_set(&mesh->loop, &mesh->pingtimer, &(struct timespec) {
 709                 0, 0
 710         });
 711 }
 712
 713 /*
 714   this is where it all happens...
 715 */
 716 void main_loop(meshlink_handle_t *mesh) {
 717         timeout_add(&mesh->loop, &mesh->pingtimer, timeout_handler, &mesh->pingtimer, &(struct timespec) {
 718                 1, prng(mesh, TIMER_FUDGE)
 719         });
 720         timeout_add(&mesh->loop, &mesh->periodictimer, periodic_handler, &mesh->periodictimer, &(struct timespec) {
 721                 0, 0
 722         });
 723
 724         //Add signal handler
 725         mesh->datafromapp.signum = 0;
 726         signal_add(&mesh->loop, &mesh->datafromapp, meshlink_send_from_queue, mesh, mesh->datafromapp.signum);
 727
 728         if(!event_loop_run(&mesh->loop, &mesh->mutex)) {
 729                 logger(mesh, MESHLINK_ERROR, "Error while waiting for input: %s", strerror(errno));
 730                 call_error_cb(mesh, MESHLINK_ENETWORK);
 731         }
 732
 733         signal_del(&mesh->loop, &mesh->datafromapp);
 734         timeout_del(&mesh->loop, &mesh->periodictimer);
 735         timeout_del(&mesh->loop, &mesh->pingtimer);
 736 }