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 "xalloc.h"
  33
  34 #include <assert.h>
  35
  36 #if !defined(min)
  37 static inline int min(int a, int b) {
  38         return a < b ? a : b;
  39 }
  40 #endif
  41
  42 /*
  43   Terminate a connection:
  44   - Mark it as inactive
  45   - Remove the edge representing this connection
  46   - Kill it with fire
  47   - Check if we need to retry making an outgoing connection
  48 */
  49 void terminate_connection(meshlink_handle_t *mesh, connection_t *c, bool report) {
  50         logger(mesh, MESHLINK_INFO, "Closing connection with %s", c->name);
  51
  52         c->status.active = false;
  53
  54         if(c->node && c->node->connection == c) {
  55                 c->node->connection = NULL;
  56         }
  57
  58         if(c->edge) {
  59                 if(report) {
  60                         send_del_edge(mesh, mesh->everyone, c->edge, 0);
  61                 }
  62
  63                 edge_del(mesh, c->edge);
  64                 c->edge = NULL;
  65
  66                 /* Run MST and SSSP algorithms */
  67
  68                 graph(mesh);
  69
  70                 /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
  71
  72                 if(report && c->node && !c->node->status.reachable) {
  73                         edge_t *e;
  74                         e = lookup_edge(c->node, mesh->self);
  75
  76                         if(e) {
  77                                 send_del_edge(mesh, mesh->everyone, e, 0);
  78                                 edge_del(mesh, e);
  79                         }
  80                 }
  81         }
  82
  83         outgoing_t *outgoing = c->outgoing;
  84         connection_del(mesh, c);
  85
  86         /* Check if this was our outgoing connection */
  87
  88         if(outgoing) {
  89                 do_outgoing_connection(mesh, outgoing);
  90         }
  91
  92 #ifndef HAVE_MINGW
  93         /* Clean up dead proxy processes */
  94
  95         while(waitpid(-1, NULL, WNOHANG) > 0);
  96
  97 #endif
  98 }
  99
 100 /*
 101   Check if the other end is active.
 102   If we have sent packets, but didn't receive any,
 103   then possibly the other end is dead. We send a
 104   PING request over the meta connection. If the other
 105   end does not reply in time, we consider them dead
 106   and close the connection.
 107 */
 108 static void timeout_handler(event_loop_t *loop, void *data) {
 109         meshlink_handle_t *mesh = loop->data;
 110         logger(mesh, MESHLINK_DEBUG, "timeout_handler()");
 111
 112         for list_each(connection_t, c, mesh->connections) {
 113                 // Also make sure that if outstanding key requests for the UDP counterpart of a connection has timed out, we restart it.
 114                 if(c->node) {
 115                         if(c->node->status.waitingforkey && c->node->last_req_key + mesh->pingtimeout <= mesh->loop.now.tv_sec) {
 116                                 send_req_key(mesh, c->node);
 117                         }
 118                 }
 119
 120                 if(c->last_ping_time + mesh->pingtimeout <= mesh->loop.now.tv_sec) {
 121                         if(c->status.active) {
 122                                 if(c->status.pinged) {
 123                                         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);
 124                                 } else if(c->last_ping_time + mesh->pinginterval <= mesh->loop.now.tv_sec) {
 125                                         send_ping(mesh, c);
 126                                         continue;
 127                                 } else {
 128                                         continue;
 129                                 }
 130                         } else {
 131                                 if(c->status.connecting) {
 132                                         logger(mesh, MESHLINK_WARNING, "Timeout while connecting to %s", c->name);
 133                                 } else {
 134                                         logger(mesh, MESHLINK_WARNING, "Timeout from %s during authentication", c->name);
 135                                 }
 136                         }
 137
 138                         terminate_connection(mesh, c, c->status.active);
 139                 }
 140         }
 141
 142         timeout_set(&mesh->loop, data, &(struct timeval) {
 143                 mesh->pingtimeout, rand() % 100000
 144         });
 145 }
 146
 147 // devclass asc, last_successfull_connection desc
 148 static int node_compare_devclass_asc_lsc_desc(const void *a, const void *b) {
 149         const node_t *na = a, *nb = b;
 150
 151         if(na->devclass < nb->devclass) {
 152                 return -1;
 153         }
 154
 155         if(na->devclass > nb->devclass) {
 156                 return 1;
 157         }
 158
 159         if(na->last_successfull_connection == nb->last_successfull_connection) {
 160                 return 0;
 161         }
 162
 163         if(na->last_successfull_connection == 0 || na->last_successfull_connection > nb->last_successfull_connection) {
 164                 return -1;
 165         }
 166
 167         if(nb->last_successfull_connection == 0 || na->last_successfull_connection < nb->last_successfull_connection) {
 168                 return 1;
 169         }
 170
 171         if(na < nb) {
 172                 return -1;
 173         }
 174
 175         if(na > nb) {
 176                 return 1;
 177         }
 178
 179         return 0;
 180 }
 181
 182 // last_successfull_connection desc
 183 static int node_compare_lsc_desc(const void *a, const void *b) {
 184         const node_t *na = a, *nb = b;
 185
 186         if(na->last_successfull_connection == nb->last_successfull_connection) {
 187                 return 0;
 188         }
 189
 190         if(na->last_successfull_connection == 0 || na->last_successfull_connection > nb->last_successfull_connection) {
 191                 return -1;
 192         }
 193
 194         if(nb->last_successfull_connection == 0 || na->last_successfull_connection < nb->last_successfull_connection) {
 195                 return 1;
 196         }
 197
 198         if(na < nb) {
 199                 return -1;
 200         }
 201
 202         if(na > nb) {
 203                 return 1;
 204         }
 205
 206         return 0;
 207 }
 208
 209 // devclass desc
 210 static int node_compare_devclass_desc(const void *a, const void *b) {
 211         const node_t *na = a, *nb = b;
 212
 213         if(na->devclass < nb->devclass) {
 214                 return -1;
 215         }
 216
 217         if(na->devclass > nb->devclass) {
 218                 return 1;
 219         }
 220
 221         if(na < nb) {
 222                 return -1;
 223         }
 224
 225         if(na > nb) {
 226                 return 1;
 227         }
 228
 229         return 0;
 230 }
 231
 232
 233 /*
 234
 235 autoconnect()
 236 {
 237         timeout = 5
 238
 239         // find the best one for initial connect
 240
 241         if cur < min
 242                 newcon =
 243                         first from nodes
 244                                 where dclass <= my.dclass and !connection and (timestamp - last_retry) > retry_timeout
 245                                 order by dclass asc, last_connection desc
 246                 if newcon
 247                         timeout = 0
 248                         goto connect
 249
 250
 251         // 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
 252
 253         if min <= cur < max
 254                 j = 0
 255                 for i = BACKBONE to my.dclass
 256                         j += count(from connections where node.dclass = i)
 257                         if j < min
 258                                 newcon =
 259                                         first from nodes
 260                                                 where dclass = i and !connection and (timestamp - last_retry) > retry_timeout
 261                                                 order by last_connection desc
 262                                 if newcon
 263                                         goto connect
 264                         else
 265                                 break
 266
 267
 268         // heal partitions
 269
 270         if min <= cur < max
 271                 newcon =
 272                         first from nodes
 273                                 where dclass <= my.dclass and !reachable and (timestamp - last_retry) > retry_timeout
 274                                 order by dclass asc, last_connection desc
 275                 if newcon
 276                         goto connect
 277
 278
 279         // connect
 280
 281 connect:
 282         if newcon
 283                 connect newcon
 284
 285
 286         // 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]
 287
 288         if min < cur <= max
 289                 j = 0
 290                 for i = BACKBONE to my.dclass
 291                         j += count(from connections where node.dclass = i)
 292                         if min < j
 293                                 delcon =
 294                                         first from nodes
 295                                                 where dclass >= i and outgoing_connection
 296                                                 order by dclass desc
 297                                 if disconnect
 298                                         goto disconnect
 299                                 else
 300                                         break
 301
 302
 303         // disconnect connections in case we have more than enough connections
 304
 305         if max < cur
 306                 delcon =
 307                         first from nodes
 308                                 where outgoing_connection
 309                                 order by dclass desc
 310                 goto disconnect
 311
 312         // disconnect
 313
 314 disconnect
 315         if delcon
 316                 disconnect delcon
 317
 318
 319         // next iteration
 320         next (timeout, autoconnect)
 321
 322 }
 323
 324 */
 325
 326
 327 static void periodic_handler(event_loop_t *loop, void *data) {
 328         meshlink_handle_t *mesh = loop->data;
 329
 330         /* Check if there are too many contradicting ADD_EDGE and DEL_EDGE messages.
 331            This usually only happens when another node has the same Name as this node.
 332            If so, sleep for a short while to prevent a storm of contradicting messages.
 333         */
 334
 335         if(mesh->contradicting_del_edge > 100 && mesh->contradicting_add_edge > 100) {
 336                 logger(mesh, MESHLINK_WARNING, "Possible node with same Name as us! Sleeping %d seconds.", mesh->sleeptime);
 337                 usleep(mesh->sleeptime * 1000000LL);
 338                 mesh->sleeptime *= 2;
 339
 340                 if(mesh->sleeptime < 0) {
 341                         mesh->sleeptime = 3600;
 342                 }
 343         } else {
 344                 mesh->sleeptime /= 2;
 345
 346                 if(mesh->sleeptime < 10) {
 347                         mesh->sleeptime = 10;
 348                 }
 349         }
 350
 351         mesh->contradicting_add_edge = 0;
 352         mesh->contradicting_del_edge = 0;
 353
 354         int timeout = 5;
 355
 356         /* Check if we need to make or break connections. */
 357
 358         if(mesh->nodes->count > 1) {
 359
 360                 logger(mesh, MESHLINK_DEBUG, "--- autoconnect begin ---");
 361
 362                 int retry_timeout = min(mesh->nodes->count * 5, 60);
 363
 364                 logger(mesh, MESHLINK_DEBUG, "* devclass = %d", mesh->devclass);
 365                 logger(mesh, MESHLINK_DEBUG, "* nodes = %d", mesh->nodes->count);
 366                 logger(mesh, MESHLINK_DEBUG, "* retry_timeout = %d", retry_timeout);
 367
 368
 369                 // connect disconnect nodes
 370
 371                 node_t *connect_to = NULL;
 372                 node_t *disconnect_from = NULL;
 373
 374
 375                 // get cur_connects
 376
 377                 unsigned int cur_connects = 0;
 378
 379                 for list_each(connection_t, c, mesh->connections) {
 380                         if(c->status.active) {
 381                                 cur_connects += 1;
 382                         }
 383                 }
 384
 385                 logger(mesh, MESHLINK_DEBUG, "* cur_connects = %d", cur_connects);
 386                 logger(mesh, MESHLINK_DEBUG, "* outgoings = %d", mesh->outgoings->count);
 387
 388                 // get min_connects and max_connects
 389
 390                 assert(mesh->devclass >= 0 && mesh->devclass <= _DEV_CLASS_MAX);
 391
 392                 unsigned int min_connects = dev_class_traits[mesh->devclass].min_connects;
 393                 unsigned int max_connects = dev_class_traits[mesh->devclass].max_connects;
 394
 395                 logger(mesh, MESHLINK_DEBUG, "* min_connects = %d", min_connects);
 396                 logger(mesh, MESHLINK_DEBUG, "* max_connects = %d", max_connects);
 397
 398
 399                 // find the best one for initial connect
 400
 401                 if(cur_connects < min_connects) {
 402                         splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_asc_lsc_desc, NULL);
 403
 404                         for splay_each(node_t, n, mesh->nodes) {
 405                                 logger(mesh, MESHLINK_DEBUG, "* n->devclass = %d", n->devclass);
 406
 407                                 if(n != mesh->self && n->devclass <= mesh->devclass && !n->connection && !n->status.blacklisted && (n->last_connect_try == 0 || (time(NULL) - n->last_connect_try) > retry_timeout)) {
 408                                         splay_insert(nodes, n);
 409                                 }
 410                         }
 411
 412                         if(nodes->head) {
 413                                 logger(mesh, MESHLINK_DEBUG, "* found best one for initial connect");
 414
 415                                 //timeout = 0;
 416                                 connect_to = (node_t *)nodes->head->data;
 417                         } else {
 418                                 logger(mesh, MESHLINK_DEBUG, "* could not find node for initial connect");
 419                         }
 420
 421                         splay_free_tree(nodes);
 422                 }
 423
 424
 425                 // find better nodes to connect to
 426
 427                 if(!connect_to && min_connects <= cur_connects && cur_connects < max_connects) {
 428                         unsigned int connects = 0;
 429
 430                         for(unsigned int devclass = 0; devclass <= mesh->devclass; ++devclass) {
 431                                 for list_each(connection_t, c, mesh->connections) {
 432                                         if(c->status.active && c->node && c->node->devclass == devclass) {
 433                                                 connects += 1;
 434                                         }
 435                                 }
 436
 437                                 if(connects < min_connects) {
 438                                         splay_tree_t *nodes = splay_alloc_tree(node_compare_lsc_desc, NULL);
 439
 440                                         for splay_each(node_t, n, mesh->nodes) {
 441                                                 if(n != mesh->self && n->devclass == devclass && !n->connection && !n->status.blacklisted && (n->last_connect_try == 0 || (time(NULL) - n->last_connect_try) > retry_timeout)) {
 442                                                         splay_insert(nodes, n);
 443                                                 }
 444                                         }
 445
 446                                         if(nodes->head) {
 447                                                 logger(mesh, MESHLINK_DEBUG, "* found better node");
 448                                                 connect_to = (node_t *)nodes->head->data;
 449
 450                                                 splay_free_tree(nodes);
 451                                                 break;
 452                                         }
 453
 454                                         splay_free_tree(nodes);
 455                                 } else {
 456                                         break;
 457                                 }
 458                         }
 459
 460                         if(!connect_to) {
 461                                 logger(mesh, MESHLINK_DEBUG, "* could not find better nodes");
 462                         }
 463                 }
 464
 465
 466                 // heal partitions
 467
 468                 if(!connect_to && min_connects <= cur_connects && cur_connects < max_connects) {
 469                         splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_asc_lsc_desc, NULL);
 470
 471                         for splay_each(node_t, n, mesh->nodes) {
 472                                 if(n != mesh->self && n->devclass <= mesh->devclass && !n->status.reachable && !n->status.blacklisted && (n->last_connect_try == 0 || (time(NULL) - n->last_connect_try) > retry_timeout)) {
 473                                         splay_insert(nodes, n);
 474                                 }
 475                         }
 476
 477                         if(nodes->head) {
 478                                 logger(mesh, MESHLINK_DEBUG, "* try to heal partition");
 479                                 connect_to = (node_t *)nodes->head->data;
 480                         } else {
 481                                 logger(mesh, MESHLINK_DEBUG, "* could not find nodes for partition healing");
 482                         }
 483
 484                         splay_free_tree(nodes);
 485                 }
 486
 487
 488                 // perform connect
 489
 490                 if(connect_to && !connect_to->connection) {
 491                         connect_to->last_connect_try = time(NULL);
 492                         logger(mesh, MESHLINK_DEBUG, "Autoconnect trying to connect to %s", connect_to->name);
 493
 494                         /* check if there is already a connection attempt to this node */
 495                         bool found = false;
 496
 497                         for list_each(outgoing_t, outgoing, mesh->outgoings) {
 498                                 if(!strcmp(outgoing->name, connect_to->name)) {
 499                                         found = true;
 500                                         break;
 501                                 }
 502                         }
 503
 504                         if(!found) {
 505                                 logger(mesh, MESHLINK_DEBUG, "Autoconnecting to %s", connect_to->name);
 506                                 outgoing_t *outgoing = xzalloc(sizeof(outgoing_t));
 507                                 outgoing->mesh = mesh;
 508                                 outgoing->name = xstrdup(connect_to->name);
 509                                 list_insert_tail(mesh->outgoings, outgoing);
 510                                 setup_outgoing_connection(mesh, outgoing);
 511                         } else {
 512                                 logger(mesh, MESHLINK_DEBUG, "* skip autoconnect since it is an outgoing connection already");
 513                         }
 514                 }
 515
 516
 517                 // disconnect suboptimal outgoing connections
 518
 519                 if(min_connects < cur_connects /*&& cur_connects <= max_connects*/) {
 520                         unsigned int connects = 0;
 521
 522                         for(unsigned int devclass = 0; devclass <= mesh->devclass; ++devclass) {
 523                                 for list_each(connection_t, c, mesh->connections) {
 524                                         if(c->status.active && c->node && c->node->devclass == devclass) {
 525                                                 connects += 1;
 526                                         }
 527                                 }
 528
 529                                 if(min_connects < connects) {
 530                                         splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_desc, NULL);
 531
 532                                         for list_each(connection_t, c, mesh->connections) {
 533                                                 if(c->outgoing && c->node && c->node->devclass >= devclass) {
 534                                                         splay_insert(nodes, c->node);
 535                                                 }
 536                                         }
 537
 538                                         if(nodes->head) {
 539                                                 logger(mesh, MESHLINK_DEBUG, "* disconnect suboptimal outgoing connection");
 540                                                 disconnect_from = (node_t *)nodes->head->data;
 541                                         }
 542
 543                                         splay_free_tree(nodes);
 544                                         break;
 545                                 }
 546                         }
 547
 548                         if(!disconnect_from) {
 549                                 logger(mesh, MESHLINK_DEBUG, "* no suboptimal outgoing connections");
 550                         }
 551                 }
 552
 553
 554                 // disconnect connections (too many connections)
 555
 556                 if(!disconnect_from && max_connects < cur_connects) {
 557                         splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_desc, NULL);
 558
 559                         for list_each(connection_t, c, mesh->connections) {
 560                                 if(c->status.active && c->node) {
 561                                         splay_insert(nodes, c->node);
 562                                 }
 563                         }
 564
 565                         if(nodes->head) {
 566                                 logger(mesh, MESHLINK_DEBUG, "* disconnect connection (too many connections)");
 567
 568                                 //timeout = 0;
 569                                 disconnect_from = (node_t *)nodes->head->data;
 570                         } else {
 571                                 logger(mesh, MESHLINK_DEBUG, "* no node we want to disconnect, even though we have too many connections");
 572                         }
 573
 574                         splay_free_tree(nodes);
 575                 }
 576
 577
 578                 // perform disconnect
 579
 580                 if(disconnect_from && disconnect_from->connection) {
 581                         logger(mesh, MESHLINK_DEBUG, "Autodisconnecting from %s", disconnect_from->connection->name);
 582                         list_delete(mesh->outgoings, disconnect_from->connection->outgoing);
 583                         disconnect_from->connection->outgoing = NULL;
 584                         terminate_connection(mesh, disconnect_from->connection, disconnect_from->connection->status.active);
 585                 }
 586
 587
 588                 // done!
 589
 590                 logger(mesh, MESHLINK_DEBUG, "--- autoconnect end ---");
 591         }
 592
 593         timeout_set(&mesh->loop, data, &(struct timeval) {
 594                 timeout, rand() % 100000
 595         });
 596 }
 597
 598 void handle_meta_connection_data(meshlink_handle_t *mesh, connection_t *c) {
 599         if(!receive_meta(mesh, c)) {
 600                 terminate_connection(mesh, c, c->status.active);
 601                 return;
 602         }
 603 }
 604
 605 void retry(meshlink_handle_t *mesh) {
 606         /* Reset the reconnection timers for all outgoing connections */
 607         for list_each(outgoing_t, outgoing, mesh->outgoings) {
 608                 outgoing->timeout = 0;
 609
 610                 if(outgoing->ev.cb)
 611                         timeout_set(&mesh->loop, &outgoing->ev, &(struct timeval) {
 612                         0, 0
 613                 });
 614         }
 615
 616         /* Check for outgoing connections that are in progress, and reset their ping timers */
 617         for list_each(connection_t, c, mesh->connections) {
 618                 if(c->outgoing && !c->node) {
 619                         c->last_ping_time = 0;
 620                 }
 621         }
 622
 623         /* Kick the ping timeout handler */
 624         timeout_set(&mesh->loop, &mesh->pingtimer, &(struct timeval) {
 625                 0, 0
 626         });
 627 }
 628
 629 /*
 630   this is where it all happens...
 631 */
 632 int main_loop(meshlink_handle_t *mesh) {
 633         timeout_add(&mesh->loop, &mesh->pingtimer, timeout_handler, &mesh->pingtimer, &(struct timeval) {
 634                 mesh->pingtimeout, rand() % 100000
 635         });
 636         timeout_add(&mesh->loop, &mesh->periodictimer, periodic_handler, &mesh->periodictimer, &(struct timeval) {
 637                 0, 0
 638         });
 639
 640         //Add signal handler
 641         mesh->datafromapp.signum = 0;
 642         signal_add(&(mesh->loop), &(mesh->datafromapp), (signal_cb_t)meshlink_send_from_queue, mesh, mesh->datafromapp.signum);
 643
 644         if(!event_loop_run(&(mesh->loop), &(mesh->mesh_mutex))) {
 645                 logger(mesh, MESHLINK_ERROR, "Error while waiting for input: %s", strerror(errno));
 646                 return 1;
 647         }
 648
 649         timeout_del(&mesh->loop, &mesh->periodictimer);
 650         timeout_del(&mesh->loop, &mesh->pingtimer);
 651
 652         return 0;
 653 }