src/transport/gnunet-service-transport_neighbours.c

   1 /*
   2      This file is part of GNUnet.
   3      (C) 2010,2011 Christian Grothoff (and other contributing authors)
   4
   5      GNUnet is free software; you can redistribute it and/or modify
   6      it under the terms of the GNU General Public License as published
   7      by the Free Software Foundation; either version 3, or (at your
   8      option) any later version.
   9
  10      GNUnet is distributed in the hope that it will be useful, but
  11      WITHOUT ANY WARRANTY; without even the implied warranty of
  12      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13      General Public License for more details.
  14
  15      You should have received a copy of the GNU General Public License
  16      along with GNUnet; see the file COPYING.  If not, write to the
  17      Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18      Boston, MA 02111-1307, USA.
  19 */
  20
  21 /**
  22  * @file transport/gnunet-service-transport_neighbours.c
  23  * @brief neighbour management
  24  * @author Christian Grothoff
  25  */
  26 #include "platform.h"
  27 #include "gnunet_ats_service.h"
  28 #include "gnunet-service-transport_neighbours.h"
  29 #include "gnunet-service-transport_plugins.h"
  30 #include "gnunet-service-transport_validation.h"
  31 #include "gnunet-service-transport_clients.h"
  32 #include "gnunet-service-transport.h"
  33 #include "gnunet_peerinfo_service.h"
  34 #include "gnunet-service-transport_blacklist.h"
  35 #include "gnunet_constants.h"
  36 #include "transport.h"
  37
  38
  39 /**
  40  * Size of the neighbour hash map.
  41  */
  42 #define NEIGHBOUR_TABLE_SIZE 256
  43
  44 /**
  45  * How often must a peer violate bandwidth quotas before we start
  46  * to simply drop its messages?
  47  */
  48 #define QUOTA_VIOLATION_DROP_THRESHOLD 10
  49
  50 /**
  51  * How often do we send KEEPALIVE messages to each of our neighbours?
  52  * (idle timeout is 5 minutes or 300 seconds, so with 90s interval we
  53  * send 3 keepalives in each interval, so 3 messages would need to be
  54  * lost in a row for a disconnect).
  55  */
  56 #define KEEPALIVE_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 90)
  57
  58
  59 #define ATS_RESPONSE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 3)
  60
  61
  62 #define SETUP_CONNECTION_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 15)
  63
  64
  65 /**
  66  * Entry in neighbours.
  67  */
  68 struct NeighbourMapEntry;
  69
  70 /**
  71  * Message a peer sends to another to indicate its
  72  * preference for communicating via a particular
  73  * session (and the desire to establish a real
  74  * connection).
  75  */
  76 struct SessionConnectMessage
  77 {
  78   /**
  79    * Header of type 'GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_CONNECT'
  80    */
  81   struct GNUNET_MessageHeader header;
  82
  83   /**
  84    * Always zero.
  85    */
  86   uint32_t reserved GNUNET_PACKED;
  87
  88   /**
  89    * Absolute time at the sender.  Only the most recent connect
  90    * message implies which session is preferred by the sender.
  91    */
  92   struct GNUNET_TIME_AbsoluteNBO timestamp;
  93
  94 };
  95
  96
  97 struct SessionDisconnectMessage
  98 {
  99   /**
 100    * Header of type 'GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_DISCONNECT'
 101    */
 102   struct GNUNET_MessageHeader header;
 103
 104   /**
 105    * Always zero.
 106    */
 107   uint32_t reserved GNUNET_PACKED;
 108
 109   /**
 110    * Purpose of the signature.  Extends over the timestamp.
 111    * Purpose should be GNUNET_SIGNATURE_PURPOSE_TRANSPORT_DISCONNECT.
 112    */
 113   struct GNUNET_CRYPTO_RsaSignaturePurpose purpose;
 114
 115   /**
 116    * Absolute time at the sender.  Only the most recent connect
 117    * message implies which session is preferred by the sender.
 118    */
 119   struct GNUNET_TIME_AbsoluteNBO timestamp;
 120
 121   /**
 122    * Public key of the sender.
 123    */
 124   struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded public_key;
 125
 126   /**
 127    * Signature of the peer that sends us the disconnect.  Only
 128    * valid if the timestamp is AFTER the timestamp from the
 129    * corresponding 'CONNECT' message.
 130    */
 131   struct GNUNET_CRYPTO_RsaSignature signature;
 132
 133 };
 134
 135
 136 /**
 137  * For each neighbour we keep a list of messages
 138  * that we still want to transmit to the neighbour.
 139  */
 140 struct MessageQueue
 141 {
 142
 143   /**
 144    * This is a doubly linked list.
 145    */
 146   struct MessageQueue *next;
 147
 148   /**
 149    * This is a doubly linked list.
 150    */
 151   struct MessageQueue *prev;
 152
 153   /**
 154    * Once this message is actively being transmitted, which
 155    * neighbour is it associated with?
 156    */
 157   struct NeighbourMapEntry *n;
 158
 159   /**
 160    * Function to call once we're done.
 161    */
 162   GST_NeighbourSendContinuation cont;
 163
 164   /**
 165    * Closure for 'cont'
 166    */
 167   void *cont_cls;
 168
 169   /**
 170    * The message(s) we want to transmit, GNUNET_MessageHeader(s)
 171    * stuck together in memory.  Allocated at the end of this struct.
 172    */
 173   const char *message_buf;
 174
 175   /**
 176    * Size of the message buf
 177    */
 178   size_t message_buf_size;
 179
 180   /**
 181    * At what time should we fail?
 182    */
 183   struct GNUNET_TIME_Absolute timeout;
 184
 185 };
 186
 187 enum State
 188 {
 189     /* fresh peer or completely disconnected */
 190     S_NOT_CONNECTED = 0,
 191     /* sent CONNECT message to other peer, waiting for CONNECT_ACK */
 192     S_CONNECT_SENT = 1,
 193     /* received CONNECT message to other peer, sending CONNECT_ACK */
 194     S_CONNECT_RECV = 4,
 195     /* sent CONNECT_ACK message to other peer, wait for ACK or payload */
 196     S_CONNECT_RECV_ACK_SENT = 8,
 197     /* received ACK or payload */
 198     S_CONNECTED = 16,
 199     /* Disconnect in progress */
 200     S_DISCONNECT = 32
 201 };
 202
 203 /**
 204  * Entry in neighbours.
 205  */
 206 struct NeighbourMapEntry
 207 {
 208
 209   /**
 210    * Head of list of messages we would like to send to this peer;
 211    * must contain at most one message per client.
 212    */
 213   struct MessageQueue *messages_head;
 214
 215   /**
 216    * Tail of list of messages we would like to send to this peer; must
 217    * contain at most one message per client.
 218    */
 219   struct MessageQueue *messages_tail;
 220
 221   /**
 222    * Performance data for the peer.
 223    */
 224   //struct GNUNET_ATS_Information *ats;
 225
 226   /**
 227    * Are we currently trying to send a message? If so, which one?
 228    */
 229   struct MessageQueue *is_active;
 230
 231   /**
 232    * Active session for communicating with the peer.
 233    */
 234   struct Session *session;
 235
 236   /**
 237    * Name of the plugin we currently use.
 238    */
 239   char *plugin_name;
 240
 241   /**
 242    * Address used for communicating with the peer, NULL for inbound connections.
 243    */
 244   void *addr;
 245
 246   /**
 247    * Number of bytes in 'addr'.
 248    */
 249   size_t addrlen;
 250
 251   /**
 252    * Identity of this neighbour.
 253    */
 254   struct GNUNET_PeerIdentity id;
 255
 256   /**
 257    * ID of task scheduled to run when this peer is about to
 258    * time out (will free resources associated with the peer).
 259    */
 260   GNUNET_SCHEDULER_TaskIdentifier timeout_task;
 261
 262   /**
 263    * ID of task scheduled to send keepalives.
 264    */
 265   GNUNET_SCHEDULER_TaskIdentifier keepalive_task;
 266
 267   /**
 268    * ID of task scheduled to run when we should try transmitting
 269    * the head of the message queue.
 270    */
 271   GNUNET_SCHEDULER_TaskIdentifier transmission_task;
 272
 273   /**
 274    * Tracker for inbound bandwidth.
 275    */
 276   struct GNUNET_BANDWIDTH_Tracker in_tracker;
 277
 278   /**
 279    * Inbound bandwidth from ATS, activated when connection is up
 280    */
 281   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in;
 282
 283   /**
 284    * Inbound bandwidth from ATS, activated when connection is up
 285    */
 286   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out;
 287
 288   /**
 289    * Timestamp of the 'SESSION_CONNECT' message we got from the other peer
 290    */
 291   struct GNUNET_TIME_Absolute connect_ts;
 292
 293   /**
 294    * Timeout for ATS
 295    * We asked ATS for a new address for this peer
 296    */
 297   GNUNET_SCHEDULER_TaskIdentifier ats_suggest;
 298
 299   /**
 300    * Task the resets the peer state after due to an pending
 301    * unsuccessful connection setup
 302    */
 303   GNUNET_SCHEDULER_TaskIdentifier state_reset;
 304
 305   /**
 306    * How often has the other peer (recently) violated the inbound
 307    * traffic limit?  Incremented by 10 per violation, decremented by 1
 308    * per non-violation (for each time interval).
 309    */
 310   unsigned int quota_violation_count;
 311
 312
 313   /**
 314    * The current state of the peer
 315    * Element of enum State
 316    */
 317   int state;
 318
 319 };
 320
 321
 322 /**
 323  * All known neighbours and their HELLOs.
 324  */
 325 static struct GNUNET_CONTAINER_MultiHashMap *neighbours;
 326
 327 /**
 328  * Closure for connect_notify_cb and disconnect_notify_cb
 329  */
 330 static void *callback_cls;
 331
 332 /**
 333  * Function to call when we connected to a neighbour.
 334  */
 335 static GNUNET_TRANSPORT_NotifyConnect connect_notify_cb;
 336
 337 /**
 338  * Function to call when we disconnected from a neighbour.
 339  */
 340 static GNUNET_TRANSPORT_NotifyDisconnect disconnect_notify_cb;
 341
 342 /**
 343  * counter for connected neighbours
 344  */
 345 static int neighbours_connected;
 346
 347 /**
 348  * Lookup a neighbour entry in the neighbours hash map.
 349  *
 350  * @param pid identity of the peer to look up
 351  * @return the entry, NULL if there is no existing record
 352  */
 353 static struct NeighbourMapEntry *
 354 lookup_neighbour (const struct GNUNET_PeerIdentity *pid)
 355 {
 356   return GNUNET_CONTAINER_multihashmap_get (neighbours, &pid->hashPubKey);
 357 }
 358
 359 #define change_state(n, state, ...) change (n, state, __LINE__)
 360
 361 static int
 362 is_connecting (struct NeighbourMapEntry * n)
 363 {
 364   if ((n->state > S_NOT_CONNECTED) && (n->state < S_CONNECTED))
 365     return GNUNET_YES;
 366   return GNUNET_NO;
 367 }
 368
 369 static int
 370 is_connected (struct NeighbourMapEntry * n)
 371 {
 372   if (n->state == S_CONNECTED)
 373     return GNUNET_YES;
 374   return GNUNET_NO;
 375 }
 376
 377 static int
 378 is_disconnecting (struct NeighbourMapEntry * n)
 379 {
 380   if (n->state == S_DISCONNECT)
 381     return GNUNET_YES;
 382   return GNUNET_NO;
 383 }
 384
 385 static const char *
 386 print_state (int state)
 387 {
 388   switch (state) {
 389     case S_CONNECTED:
 390         return "S_CONNECTED";
 391       break;
 392     case S_CONNECT_RECV:
 393       return "S_CONNECT_RECV";
 394       break;
 395     case S_CONNECT_RECV_ACK_SENT:
 396       return"S_CONNECT_RECV_ACK_SENT";
 397       break;
 398     case S_CONNECT_SENT:
 399       return "S_CONNECT_SENT";
 400       break;
 401     case S_DISCONNECT:
 402       return "S_DISCONNECT";
 403       break;
 404     case S_NOT_CONNECTED:
 405       return "S_NOT_CONNECTED";
 406       break;
 407     default:
 408       GNUNET_break (0);
 409       break;
 410   }
 411   return NULL;
 412 }
 413
 414 static int
 415 change (struct NeighbourMapEntry * n, int state, int line);
 416
 417 static void
 418 ats_suggest_cancel (void *cls,
 419     const struct GNUNET_SCHEDULER_TaskContext *tc);
 420
 421 static void
 422 reset_task (void *cls,
 423             const struct GNUNET_SCHEDULER_TaskContext *tc)
 424 {
 425   struct NeighbourMapEntry * n = cls;
 426
 427   n->state_reset = GNUNET_SCHEDULER_NO_TASK;
 428
 429 #if DEBUG_TRANSPORT
 430   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 431       "Connection to peer `%s' %s failed in state `%s', resetting connection attempt \n",
 432       GNUNET_i2s (&n->id), GST_plugins_a2s(n->plugin_name, n->addr, n->addrlen), print_state(n->state));
 433 #endif
 434   GNUNET_STATISTICS_update (GST_stats,
 435                             gettext_noop ("# failed connection attempts due to timeout"),
 436                             1,
 437                             GNUNET_NO);
 438
 439   /* resetting state */
 440   n->state = S_NOT_CONNECTED;
 441
 442   /* destroying address */
 443   GNUNET_ATS_address_destroyed (GST_ats,
 444                                 &n->id,
 445                                 n->plugin_name,
 446                                 n->addr,
 447                                 n->addrlen,
 448                                 NULL);
 449
 450   /* request new address */
 451   if (n->ats_suggest != GNUNET_SCHEDULER_NO_TASK)
 452     GNUNET_SCHEDULER_cancel(n->ats_suggest);
 453   n->ats_suggest = GNUNET_SCHEDULER_add_delayed (ATS_RESPONSE_TIMEOUT, ats_suggest_cancel, n);
 454   GNUNET_ATS_suggest_address(GST_ats, &n->id);
 455 }
 456
 457 static int
 458 change (struct NeighbourMapEntry * n, int state, int line)
 459 {
 460   char * old = strdup(print_state(n->state));
 461   char * new = strdup(print_state(state));
 462
 463   /* allowed transitions */
 464   int allowed = GNUNET_NO;
 465   switch (n->state) {
 466   case S_NOT_CONNECTED:
 467     if ((state == S_CONNECT_RECV) || (state == S_CONNECT_SENT) ||
 468         (state == S_DISCONNECT))
 469     {
 470       allowed = GNUNET_YES;
 471
 472       /* Schedule reset task */
 473       if ((state == S_CONNECT_RECV) || (state == S_CONNECT_SENT) )
 474       {
 475         GNUNET_assert (n->state_reset == GNUNET_SCHEDULER_NO_TASK);
 476         n->state_reset = GNUNET_SCHEDULER_add_delayed (SETUP_CONNECTION_TIMEOUT, &reset_task, n);
 477       }
 478
 479       break;
 480     }
 481     break;
 482   case S_CONNECT_RECV:
 483     if ((state == S_NOT_CONNECTED) || (state == S_DISCONNECT) ||
 484         (state == S_CONNECTED) || /* FIXME SENT -> RECV ISSUE!*/ (state == S_CONNECT_SENT))
 485     {
 486       if ((state == S_CONNECTED) || (state == S_DISCONNECT) || (state == S_NOT_CONNECTED))
 487       {
 488 #if DEBUG_TRANSPORT
 489         GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 490             "Removed reset task for peer `%s' %s failed in state transition `%s' -> `%s' \n",
 491             GNUNET_i2s (&n->id), GST_plugins_a2s(n->plugin_name, n->addr, n->addrlen), print_state(n->state), print_state(state));
 492 #endif
 493         GNUNET_assert (n->state_reset != GNUNET_SCHEDULER_NO_TASK);
 494         GNUNET_SCHEDULER_cancel (n->state_reset);
 495         n->state_reset = GNUNET_SCHEDULER_NO_TASK;
 496       }
 497
 498       allowed = GNUNET_YES;
 499       break;
 500     }
 501     break;
 502   case S_CONNECT_SENT:
 503     if ((state == S_NOT_CONNECTED) || (state == S_CONNECTED) ||
 504         (state == S_DISCONNECT) || /* FIXME SENT -> RECV ISSUE!*/ (state == S_CONNECT_RECV))
 505     {
 506       if ((state == S_CONNECTED) || (state == S_DISCONNECT) || (state == S_NOT_CONNECTED))
 507       {
 508 #if DEBUG_TRANSPORT
 509         GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 510             "Removed reset task for peer `%s' %s failed in state transition `%s' -> `%s' \n",
 511             GNUNET_i2s (&n->id), GST_plugins_a2s(n->plugin_name, n->addr, n->addrlen), print_state(n->state), print_state(state));
 512 #endif
 513         GNUNET_assert (n->state_reset != GNUNET_SCHEDULER_NO_TASK);
 514         GNUNET_SCHEDULER_cancel (n->state_reset);
 515         n->state_reset = GNUNET_SCHEDULER_NO_TASK;
 516       }
 517
 518       allowed = GNUNET_YES;
 519       break;
 520     }
 521     break;
 522   case S_CONNECTED:
 523     if (state == S_DISCONNECT)
 524     {
 525       allowed = GNUNET_YES;
 526       break;
 527     }
 528     break;
 529   case S_DISCONNECT:
 530     /*
 531     if (state == S_NOT_CONNECTED)
 532     {
 533       allowed = GNUNET_YES;
 534       break;
 535     }*/
 536     break;
 537   default:
 538     GNUNET_break (0);
 539     break;
 540
 541   }
 542
 543   if (allowed == GNUNET_NO)
 544   {
 545     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 546         "Illegal state transition from `%s' to `%s' in line %u \n",
 547         old, new, line);
 548     GNUNET_break (0);
 549     GNUNET_free (old);
 550     GNUNET_free (new);
 551     return GNUNET_SYSERR;
 552   }
 553
 554   n->state = state;
 555 #if DEBUG_TRANSPORT
 556   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "State for neighbour `%s' %X changed from `%s' to `%s' in line %u\n",
 557       GNUNET_i2s (&n->id), n, old, new, line);
 558 #endif
 559   GNUNET_free (old);
 560   GNUNET_free (new);
 561   return GNUNET_OK;
 562 }
 563
 564 static ssize_t
 565 send_with_plugin ( const struct GNUNET_PeerIdentity * target,
 566     const char *msgbuf,
 567     size_t msgbuf_size,
 568     uint32_t priority,
 569     struct GNUNET_TIME_Relative timeout,
 570     struct Session * session,
 571     const char * plugin_name,
 572     const void *addr,
 573     size_t addrlen,
 574     int force_address,
 575     GNUNET_TRANSPORT_TransmitContinuation cont,
 576     void *cont_cls)
 577
 578 {
 579   struct GNUNET_TRANSPORT_PluginFunctions *papi;
 580   size_t ret = GNUNET_SYSERR;
 581
 582   /* FIXME : ats returns an address with all values 0 */
 583   if (((plugin_name == NULL) && (addr == NULL) && (addrlen == 0 )) ||
 584       ((plugin_name == NULL) && (session == NULL)))
 585   {
 586     if (cont != NULL)
 587       cont (cont_cls, target, GNUNET_SYSERR);
 588     return GNUNET_SYSERR;
 589   }
 590   papi = GST_plugins_find (plugin_name);
 591   if (papi == NULL)
 592   {
 593     if (cont != NULL)
 594       cont (cont_cls, target, GNUNET_SYSERR);
 595     return GNUNET_SYSERR;
 596   }
 597
 598   ret = papi->send (papi->cls,
 599       target,
 600       msgbuf, msgbuf_size,
 601       0,
 602       timeout,
 603       session,
 604       addr, addrlen,
 605       GNUNET_YES,
 606       cont, cont_cls);
 607
 608   if (ret == -1)
 609   {
 610     if (cont != NULL)
 611       cont (cont_cls, target, GNUNET_SYSERR);
 612   }
 613   return ret;
 614 }
 615
 616 /**
 617  * Task invoked to start a transmission to another peer.
 618  *
 619  * @param cls the 'struct NeighbourMapEntry'
 620  * @param tc scheduler context
 621  */
 622 static void
 623 transmission_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
 624
 625
 626 /**
 627  * We're done with our transmission attempt, continue processing.
 628  *
 629  * @param cls the 'struct MessageQueue' of the message
 630  * @param receiver intended receiver
 631  * @param success whether it worked or not
 632  */
 633 static void
 634 transmit_send_continuation (void *cls,
 635                             const struct GNUNET_PeerIdentity *receiver,
 636                             int success)
 637 {
 638   struct MessageQueue *mq;
 639   struct NeighbourMapEntry *n;
 640
 641   mq = cls;
 642   n = mq->n;
 643   if (NULL != n)
 644   {
 645     GNUNET_assert (n->is_active == mq);
 646     n->is_active = NULL;
 647     if (success == GNUNET_YES)
 648     {
 649       GNUNET_assert (n->transmission_task == GNUNET_SCHEDULER_NO_TASK);
 650       n->transmission_task = GNUNET_SCHEDULER_add_now (&transmission_task, n);
 651     }
 652   }
 653 #if DEBUG_TRANSPORT
 654   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sending message of type %u was %s\n",
 655               ntohs (((struct GNUNET_MessageHeader *) mq->message_buf)->type),
 656               (success == GNUNET_OK) ? "successful" : "FAILED");
 657 #endif
 658   if (NULL != mq->cont)
 659     mq->cont (mq->cont_cls, success);
 660   GNUNET_free (mq);
 661 }
 662
 663
 664 /**
 665  * Check the ready list for the given neighbour and if a plugin is
 666  * ready for transmission (and if we have a message), do so!
 667  *
 668  * @param n target peer for which to transmit
 669  */
 670 static void
 671 try_transmission_to_peer (struct NeighbourMapEntry *n)
 672 {
 673   struct MessageQueue *mq;
 674   struct GNUNET_TIME_Relative timeout;
 675   ssize_t ret;
 676
 677   if (n->is_active != NULL)
 678   {
 679     GNUNET_break (0);
 680     return;                     /* transmission already pending */
 681   }
 682   if (n->transmission_task != GNUNET_SCHEDULER_NO_TASK)
 683   {
 684     GNUNET_break (0);
 685     return;                     /* currently waiting for bandwidth */
 686   }
 687   while (NULL != (mq = n->messages_head))
 688   {
 689     timeout = GNUNET_TIME_absolute_get_remaining (mq->timeout);
 690     if (timeout.rel_value > 0)
 691       break;
 692     GNUNET_CONTAINER_DLL_remove (n->messages_head, n->messages_tail, mq);
 693     n->is_active = mq;
 694     mq->n = n;
 695     transmit_send_continuation (mq, &n->id, GNUNET_SYSERR);     /* timeout */
 696   }
 697   if (NULL == mq)
 698     return;                     /* no more messages */
 699
 700   if (GST_plugins_find (n->plugin_name) == NULL)
 701   {
 702     GNUNET_break (0);
 703     return;
 704   }
 705   GNUNET_CONTAINER_DLL_remove (n->messages_head, n->messages_tail, mq);
 706   n->is_active = mq;
 707   mq->n = n;
 708
 709   if  ((n->session == NULL) && (n->addr == NULL) && (n->addrlen == 0))
 710   {
 711     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "No address for peer `%s'\n",
 712                 GNUNET_i2s (&n->id));
 713     transmit_send_continuation (mq, &n->id, GNUNET_SYSERR);
 714     GNUNET_assert (n->transmission_task == GNUNET_SCHEDULER_NO_TASK);
 715     n->transmission_task = GNUNET_SCHEDULER_add_now (&transmission_task, n);
 716     return;
 717   }
 718
 719   ret = send_with_plugin (&n->id,
 720                           mq->message_buf, mq->message_buf_size, 0,
 721                           timeout,
 722                           n->session, n->plugin_name, n->addr, n->addrlen,
 723                           GNUNET_YES,
 724                           &transmit_send_continuation, mq);
 725   if (ret == -1)
 726   {
 727     /* failure, but 'send' would not call continuation in this case,
 728      * so we need to do it here! */
 729     transmit_send_continuation (mq, &n->id, GNUNET_SYSERR);
 730   }
 731
 732 }
 733
 734
 735 /**
 736  * Task invoked to start a transmission to another peer.
 737  *
 738  * @param cls the 'struct NeighbourMapEntry'
 739  * @param tc scheduler context
 740  */
 741 static void
 742 transmission_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 743 {
 744   struct NeighbourMapEntry *n = cls;
 745   GNUNET_assert (NULL != lookup_neighbour(&n->id));
 746   n->transmission_task = GNUNET_SCHEDULER_NO_TASK;
 747   try_transmission_to_peer (n);
 748 }
 749
 750
 751 /**
 752  * Initialize the neighbours subsystem.
 753  *
 754  * @param cls closure for callbacks
 755  * @param connect_cb function to call if we connect to a peer
 756  * @param disconnect_cb function to call if we disconnect from a peer
 757  */
 758 void
 759 GST_neighbours_start (void *cls, GNUNET_TRANSPORT_NotifyConnect connect_cb,
 760                       GNUNET_TRANSPORT_NotifyDisconnect disconnect_cb)
 761 {
 762   callback_cls = cls;
 763   connect_notify_cb = connect_cb;
 764   disconnect_notify_cb = disconnect_cb;
 765   neighbours = GNUNET_CONTAINER_multihashmap_create (NEIGHBOUR_TABLE_SIZE);
 766 }
 767
 768
 769 static void
 770 send_disconnect_cont (void *cls,
 771     const struct GNUNET_PeerIdentity * target,
 772     int result)
 773 {
 774 #if DEBUG_TRANSPORT
 775   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sending DISCONNECT message to peer `%4s': %i\n",
 776               GNUNET_i2s (target), result);
 777 #endif
 778 }
 779
 780
 781 static int
 782 send_disconnect (const struct GNUNET_PeerIdentity * target,
 783                  const char *plugin_name,
 784                  const char *sender_address, uint16_t sender_address_len,
 785                  struct Session *session)
 786 {
 787   size_t ret;
 788   struct SessionDisconnectMessage disconnect_msg;
 789
 790 #if DEBUG_TRANSPORT
 791   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sending DISCONNECT message to peer `%4s'\n",
 792               GNUNET_i2s (target));
 793 #endif
 794
 795   disconnect_msg.header.size = htons (sizeof (struct SessionDisconnectMessage));
 796   disconnect_msg.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_DISCONNECT);
 797   disconnect_msg.reserved = htonl (0);
 798   disconnect_msg.purpose.size = htonl (sizeof (struct GNUNET_CRYPTO_RsaSignaturePurpose) +
 799                                        sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded) +
 800                                        sizeof (struct GNUNET_TIME_AbsoluteNBO) );
 801   disconnect_msg.purpose.purpose = htonl (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_DISCONNECT);
 802   disconnect_msg.timestamp = GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get ());
 803   disconnect_msg.public_key = GST_my_public_key;
 804   GNUNET_assert (GNUNET_OK ==
 805                  GNUNET_CRYPTO_rsa_sign (GST_my_private_key,
 806                                          &disconnect_msg.purpose,
 807                                          &disconnect_msg.signature));
 808
 809   ret = send_with_plugin(target,
 810                          (const char *) &disconnect_msg, sizeof (disconnect_msg),
 811                          UINT32_MAX, GNUNET_TIME_UNIT_FOREVER_REL,
 812                          session, plugin_name, sender_address,  sender_address_len,
 813                          GNUNET_YES, &send_disconnect_cont, NULL);
 814
 815   if (ret == GNUNET_SYSERR)
 816     return GNUNET_SYSERR;
 817
 818   GNUNET_STATISTICS_update (GST_stats,
 819                             gettext_noop ("# peers disconnected due to external request"), 1,
 820                             GNUNET_NO);
 821   return GNUNET_OK;
 822 }
 823
 824 /**
 825  * Disconnect from the given neighbour, clean up the record.
 826  *
 827  * @param n neighbour to disconnect from
 828  */
 829 static void
 830 disconnect_neighbour (struct NeighbourMapEntry *n)
 831 {
 832   struct MessageQueue *mq;
 833   int was_connected = is_connected(n);
 834
 835   /* send DISCONNECT MESSAGE */
 836   if (is_connected(n) || is_connecting(n))
 837   {
 838     if (GNUNET_OK == send_disconnect(&n->id, n->plugin_name, n->addr, n->addrlen, n->session))
 839       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sent DISCONNECT_MSG to `%s'\n",
 840                   GNUNET_i2s (&n->id));
 841     else
 842       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Could not send DISCONNECT_MSG to `%s'\n",
 843                   GNUNET_i2s (&n->id));
 844   }
 845
 846
 847   if (is_disconnecting(n))
 848     return;
 849   change_state (n, S_DISCONNECT);
 850
 851   while (NULL != (mq = n->messages_head))
 852   {
 853     GNUNET_CONTAINER_DLL_remove (n->messages_head, n->messages_tail, mq);
 854     if (NULL != mq->cont)
 855       mq->cont (mq->cont_cls, GNUNET_SYSERR);
 856     GNUNET_free (mq);
 857   }
 858   if (NULL != n->is_active)
 859   {
 860     n->is_active->n = NULL;
 861     n->is_active = NULL;
 862   }
 863   if (was_connected)
 864   {
 865     GNUNET_assert (GNUNET_SCHEDULER_NO_TASK != n->keepalive_task);
 866     GNUNET_SCHEDULER_cancel (n->keepalive_task);
 867     n->keepalive_task = GNUNET_SCHEDULER_NO_TASK;
 868     GNUNET_assert (neighbours_connected > 0);
 869     neighbours_connected--;
 870     GNUNET_STATISTICS_update (GST_stats, gettext_noop ("# peers connected"), -1,
 871                               GNUNET_NO);
 872     disconnect_notify_cb (callback_cls, &n->id);
 873   }
 874   GNUNET_assert (GNUNET_YES ==
 875                  GNUNET_CONTAINER_multihashmap_remove (neighbours,
 876                                                        &n->id.hashPubKey, n));
 877   if (GNUNET_SCHEDULER_NO_TASK != n->ats_suggest)
 878   {
 879     GNUNET_SCHEDULER_cancel (n->ats_suggest);
 880     n->ats_suggest = GNUNET_SCHEDULER_NO_TASK;
 881   }
 882   if (GNUNET_SCHEDULER_NO_TASK != n->timeout_task)
 883   {
 884     GNUNET_SCHEDULER_cancel (n->timeout_task);
 885     n->timeout_task = GNUNET_SCHEDULER_NO_TASK;
 886   }
 887   if (GNUNET_SCHEDULER_NO_TASK != n->transmission_task)
 888   {
 889     GNUNET_SCHEDULER_cancel (n->transmission_task);
 890     n->transmission_task = GNUNET_SCHEDULER_NO_TASK;
 891   }
 892   if (NULL != n->plugin_name)
 893   {
 894     GNUNET_free (n->plugin_name);
 895     n->plugin_name = NULL;
 896   }
 897   if (NULL != n->addr)
 898   {
 899     GNUNET_free (n->addr);
 900     n->addr = NULL;
 901     n->addrlen = 0;
 902   }
 903   n->session = NULL;
 904   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Deleting peer `%4s', %X\n",
 905               GNUNET_i2s (&n->id), n);
 906   GNUNET_free (n);
 907 }
 908
 909
 910 /**
 911  * Peer has been idle for too long. Disconnect.
 912  *
 913  * @param cls the 'struct NeighbourMapEntry' of the neighbour that went idle
 914  * @param tc scheduler context
 915  */
 916 static void
 917 neighbour_timeout_task (void *cls,
 918                         const struct GNUNET_SCHEDULER_TaskContext *tc)
 919 {
 920   struct NeighbourMapEntry *n = cls;
 921
 922   n->timeout_task = GNUNET_SCHEDULER_NO_TASK;
 923
 924   GNUNET_STATISTICS_update (GST_stats,
 925                             gettext_noop ("# peers disconnected due to timeout"), 1,
 926                             GNUNET_NO);
 927   disconnect_neighbour (n);
 928 }
 929
 930
 931 /**
 932  * Send another keepalive message.
 933  *
 934  * @param cls the 'struct NeighbourMapEntry' of the neighbour that went idle
 935  * @param tc scheduler context
 936  */
 937 static void
 938 neighbour_keepalive_task (void *cls,
 939                           const struct GNUNET_SCHEDULER_TaskContext *tc)
 940 {
 941   struct NeighbourMapEntry *n = cls;
 942   struct GNUNET_MessageHeader m;
 943
 944   n->keepalive_task = GNUNET_SCHEDULER_add_delayed (KEEPALIVE_FREQUENCY,
 945                                                     &neighbour_keepalive_task,
 946                                                     n);
 947   GNUNET_assert (is_connected(n));
 948   GNUNET_STATISTICS_update (GST_stats,
 949                             gettext_noop ("# keepalives sent"), 1,
 950                             GNUNET_NO);
 951   m.size = htons (sizeof (struct GNUNET_MessageHeader));
 952   m.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_KEEPALIVE);
 953
 954   send_with_plugin(&n->id, (const void *) &m,
 955                    sizeof (m),
 956                    UINT32_MAX /* priority */ ,
 957                    GNUNET_TIME_UNIT_FOREVER_REL,
 958                    n->session, n->plugin_name, n->addr, n->addrlen,
 959                    GNUNET_YES, NULL, NULL);
 960 }
 961
 962
 963 /**
 964  * Disconnect from the given neighbour.
 965  *
 966  * @param cls unused
 967  * @param key hash of neighbour's public key (not used)
 968  * @param value the 'struct NeighbourMapEntry' of the neighbour
 969  */
 970 static int
 971 disconnect_all_neighbours (void *cls, const GNUNET_HashCode * key, void *value)
 972 {
 973   struct NeighbourMapEntry *n = value;
 974
 975 #if DEBUG_TRANSPORT
 976   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Disconnecting peer `%4s', %s\n",
 977               GNUNET_i2s (&n->id), "SHUTDOWN_TASK");
 978 #endif
 979   if (is_connected(n))
 980     GNUNET_STATISTICS_update (GST_stats,
 981                               gettext_noop ("# peers disconnected due to global disconnect"), 1,
 982                               GNUNET_NO);
 983   disconnect_neighbour (n);
 984   return GNUNET_OK;
 985 }
 986
 987
 988 static void
 989 ats_suggest_cancel (void *cls,
 990     const struct GNUNET_SCHEDULER_TaskContext *tc)
 991 {
 992   struct NeighbourMapEntry *n = cls;
 993
 994   n->ats_suggest = GNUNET_SCHEDULER_NO_TASK;
 995
 996   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 997               " ATS did not suggested address to connect to peer `%s'\n",
 998               GNUNET_i2s (&n->id));
 999
1000   disconnect_neighbour(n);
1001 }
1002
1003
1004 /**
1005  * Cleanup the neighbours subsystem.
1006  */
1007 void
1008 GST_neighbours_stop ()
1009 {
1010   // This can happen during shutdown
1011   if (neighbours == NULL)
1012   {
1013     return;
1014   }
1015
1016   GNUNET_CONTAINER_multihashmap_iterate (neighbours, &disconnect_all_neighbours,
1017                                          NULL);
1018   GNUNET_CONTAINER_multihashmap_destroy (neighbours);
1019   GNUNET_assert (neighbours_connected == 0);
1020   neighbours = NULL;
1021   callback_cls = NULL;
1022   connect_notify_cb = NULL;
1023   disconnect_notify_cb = NULL;
1024 }
1025
1026
1027 /**
1028  * We tried to send a SESSION_CONNECT message to another peer.  If this
1029  * succeeded, we change the state.  If it failed, we should tell
1030  * ATS to not use this address anymore (until it is re-validated).
1031  *
1032  * @param cls the 'struct NeighbourMapEntry'
1033  * @param success GNUNET_OK on success
1034  */
1035 static void
1036 send_connect_continuation (void *cls,
1037       const struct GNUNET_PeerIdentity * target,
1038       int success)
1039
1040 {
1041   struct NeighbourMapEntry *n = cls;
1042
1043   GNUNET_assert (n != NULL);
1044   GNUNET_assert (!is_connected(n));
1045
1046   if (is_disconnecting(n))
1047     return; /* neighbour is going away */
1048
1049   if (GNUNET_YES != success)
1050   {
1051 #if DEBUG_TRANSPORT
1052     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1053               "Failed to send CONNECT_MSG to peer `%4s' with plugin `%s' address '%s' session %X, asking ATS for new address \n",
1054               GNUNET_i2s (&n->id), n->plugin_name,
1055               (n->addrlen == 0) ? "<inbound>" : GST_plugins_a2s (n->plugin_name,
1056                                                                   n->addr,
1057                                                                   n->addrlen),
1058               n->session);
1059 #endif
1060
1061     GNUNET_ATS_address_destroyed (GST_ats,
1062                                   &n->id,
1063                                   n->plugin_name,
1064                                   n->addr,
1065                                   n->addrlen,
1066                                   NULL);
1067
1068     change_state(n, S_NOT_CONNECTED);
1069
1070     if (n->ats_suggest!= GNUNET_SCHEDULER_NO_TASK)
1071       GNUNET_SCHEDULER_cancel(n->ats_suggest);
1072     n->ats_suggest = GNUNET_SCHEDULER_add_delayed (ATS_RESPONSE_TIMEOUT, ats_suggest_cancel, n);
1073     GNUNET_ATS_suggest_address(GST_ats, &n->id);
1074     return;
1075   }
1076
1077
1078 }
1079
1080
1081 /**
1082  * We tried to switch addresses with an peer already connected. If it failed,
1083  * we should tell ATS to not use this address anymore (until it is re-validated).
1084  *
1085  * @param cls the 'struct NeighbourMapEntry'
1086  * @param success GNUNET_OK on success
1087  */
1088 static void
1089 send_switch_address_continuation (void *cls,
1090       const struct GNUNET_PeerIdentity * target,
1091       int success)
1092
1093 {
1094   struct NeighbourMapEntry *n = cls;
1095
1096   GNUNET_assert (n != NULL);
1097   if (is_disconnecting(n))
1098     return; /* neighbour is going away */
1099
1100   GNUNET_assert (n->state == S_CONNECTED);
1101   if (GNUNET_YES != success)
1102   {
1103 #if DEBUG_TRANSPORT
1104     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1105               "Failed to switch connected peer `%s' to plugin `%s' address '%s' session %X, asking ATS for new address \n",
1106               GNUNET_i2s (&n->id), n->plugin_name,
1107               (n->addrlen == 0) ? "<inbound>" : GST_plugins_a2s (n->plugin_name,
1108                                                                   n->addr,
1109                                                                   n->addrlen),
1110               n->session);
1111 #endif
1112
1113     GNUNET_ATS_address_destroyed (GST_ats,
1114                                   &n->id,
1115                                   n->plugin_name,
1116                                   n->addr,
1117                                   n->addrlen,
1118                                   NULL);
1119
1120     if (n->ats_suggest != GNUNET_SCHEDULER_NO_TASK)
1121       GNUNET_SCHEDULER_cancel(n->ats_suggest);
1122     n->ats_suggest = GNUNET_SCHEDULER_add_delayed (ATS_RESPONSE_TIMEOUT, ats_suggest_cancel, n);
1123     GNUNET_ATS_suggest_address(GST_ats, &n->id);
1124     return;
1125   }
1126 }
1127
1128 /**
1129  * We tried to send a SESSION_CONNECT message to another peer.  If this
1130  * succeeded, we change the state.  If it failed, we should tell
1131  * ATS to not use this address anymore (until it is re-validated).
1132  *
1133  * @param cls the 'struct NeighbourMapEntry'
1134  * @param success GNUNET_OK on success
1135  */
1136 static void
1137 send_connect_ack_continuation (void *cls,
1138       const struct GNUNET_PeerIdentity * target,
1139       int success)
1140
1141 {
1142   struct NeighbourMapEntry *n = cls;
1143
1144   GNUNET_assert (n != NULL);
1145
1146   if (GNUNET_YES == success)
1147     return; /* sending successful */
1148
1149   /* sending failed, ask for next address  */
1150 #if DEBUG_TRANSPORT
1151     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1152               "Failed to send CONNECT_MSG to peer `%4s' with plugin `%s' address '%s' session %X, asking ATS for new address \n",
1153               GNUNET_i2s (&n->id), n->plugin_name,
1154               (n->addrlen == 0) ? "<inbound>" : GST_plugins_a2s (n->plugin_name,
1155                                                                   n->addr,
1156                                                                   n->addrlen),
1157               n->session);
1158 #endif
1159     change_state(n, S_NOT_CONNECTED);
1160
1161     GNUNET_ATS_address_destroyed (GST_ats,
1162                                   &n->id,
1163                                   n->plugin_name,
1164                                   n->addr,
1165                                   n->addrlen,
1166                                   NULL);
1167
1168     if (n->ats_suggest != GNUNET_SCHEDULER_NO_TASK)
1169       GNUNET_SCHEDULER_cancel(n->ats_suggest);
1170     n->ats_suggest = GNUNET_SCHEDULER_add_delayed (ATS_RESPONSE_TIMEOUT, ats_suggest_cancel, n);
1171     GNUNET_ATS_suggest_address(GST_ats, &n->id);
1172 }
1173
1174 /**
1175  * For an existing neighbour record, set the active connection to
1176  * the given address.
1177  *
1178  * @param peer identity of the peer to switch the address for
1179  * @param plugin_name name of transport that delivered the PONG
1180  * @param address address of the other peer, NULL if other peer
1181  *                       connected to us
1182  * @param address_len number of bytes in address
1183  * @param session session to use (or NULL)
1184  * @param ats performance data
1185  * @param ats_count number of entries in ats
1186  * @return GNUNET_YES if we are currently connected, GNUNET_NO if the
1187  *         connection is not up (yet)
1188  */
1189 int
1190 GST_neighbours_switch_to_address_3way (const struct GNUNET_PeerIdentity *peer,
1191                                   const char *plugin_name, const void *address,
1192                                   size_t address_len, struct Session *session,
1193                                   const struct GNUNET_ATS_Information
1194                                   *ats, uint32_t ats_count,
1195                                   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in,
1196                                   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out)
1197 {
1198   struct NeighbourMapEntry *n;
1199   struct SessionConnectMessage connect_msg;
1200   size_t msg_len;
1201   size_t ret;
1202
1203   // This can happen during shutdown
1204   if (neighbours == NULL)
1205   {
1206     return GNUNET_NO;
1207   }
1208   n = lookup_neighbour (peer);
1209   if (NULL == n)
1210   {
1211     if (NULL == session)
1212       GNUNET_ATS_address_destroyed (GST_ats,
1213                                     peer,
1214                                     plugin_name, address,
1215                                     address_len, NULL);
1216     return GNUNET_NO;
1217   }
1218
1219   if (n->ats_suggest != GNUNET_SCHEDULER_NO_TASK)
1220   {
1221     GNUNET_SCHEDULER_cancel(n->ats_suggest);
1222     n->ats_suggest = GNUNET_SCHEDULER_NO_TASK;
1223   }
1224
1225 #if DEBUG_TRANSPORT
1226   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1227               "ATS tells us to switch to plugin `%s' address '%s' session %X for %s peer `%s'\n",
1228               plugin_name,
1229               (address_len == 0) ? "<inbound>" : GST_plugins_a2s (plugin_name,
1230                                                                   address,
1231                                                                   address_len),
1232               session, (is_connected(n) ? "CONNECTED" : "NOT CONNECTED"),
1233               GNUNET_i2s (peer));
1234 #endif
1235
1236   // do not switch addresses just update quotas
1237   if (n != NULL)
1238   {
1239     if ((is_connected(n)) && (address_len == n->addrlen))
1240     {
1241       if ((0 == memcmp (address, n->addr, address_len)) &&
1242           (n->session == session))
1243       {
1244         struct QuotaSetMessage q_msg;
1245
1246 #if DEBUG_TRANSPORT
1247   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1248               "Sending outbound quota of %u Bps and inbound quota of %u Bps for peer `%s' to all clients\n",
1249               ntohl (n->bandwidth_out.value__),
1250               ntohl (n->bandwidth_in.value__),
1251               GNUNET_i2s (peer));
1252 #endif
1253
1254         n->bandwidth_in = bandwidth_in;
1255         n->bandwidth_out = bandwidth_out;
1256         GST_neighbours_set_incoming_quota(&n->id, n->bandwidth_in);
1257
1258         q_msg.header.size = htons (sizeof (struct QuotaSetMessage));
1259         q_msg.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SET_QUOTA);
1260         q_msg.quota = n->bandwidth_out;
1261         q_msg.peer = (*peer);
1262         GST_clients_broadcast (&q_msg.header, GNUNET_NO);
1263         return GNUNET_NO;
1264       }
1265     }
1266   }
1267
1268   GNUNET_free_non_null (n->addr);
1269   n->addr = GNUNET_malloc (address_len);
1270   memcpy (n->addr, address, address_len);
1271   n->bandwidth_in = bandwidth_in;
1272   n->bandwidth_out = bandwidth_out;
1273   n->addrlen = address_len;
1274   n->session = session;
1275   GNUNET_free_non_null (n->plugin_name);
1276   n->plugin_name = GNUNET_strdup (plugin_name);
1277   GNUNET_SCHEDULER_cancel (n->timeout_task);
1278   n->timeout_task =
1279       GNUNET_SCHEDULER_add_delayed (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT,
1280                                     &neighbour_timeout_task, n);
1281
1282   if (n->state == S_DISCONNECT)
1283   {
1284     /* We are disconnecting, nothing to do here */
1285     return GNUNET_NO;
1286   }
1287   /* We are not connected/connecting and initiate a fresh connect */
1288   if (n->state == S_NOT_CONNECTED)
1289   {
1290     msg_len = sizeof (struct SessionConnectMessage);
1291     connect_msg.header.size = htons (msg_len);
1292     connect_msg.header.type =
1293         htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_CONNECT);
1294     connect_msg.reserved = htonl (0);
1295     connect_msg.timestamp =
1296         GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get ());
1297
1298     change_state (n, S_CONNECT_SENT);
1299
1300     ret = send_with_plugin (peer, (const char *) &connect_msg, msg_len, UINT32_MAX, GNUNET_TIME_UNIT_FOREVER_REL,
1301                             session, plugin_name, address, address_len,
1302                             GNUNET_YES, &send_connect_continuation, n);
1303
1304     return GNUNET_NO;
1305   }
1306   /* We received a CONNECT message and asked ATS for an address */
1307   else if (n->state == S_CONNECT_RECV)
1308   {
1309     msg_len = sizeof (struct SessionConnectMessage);
1310     connect_msg.header.size = htons (msg_len);
1311     connect_msg.header.type =
1312       htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_CONNECT_ACK);
1313     connect_msg.reserved = htonl (0);
1314     connect_msg.timestamp = GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get ());
1315
1316     ret = send_with_plugin(&n->id, (const void *) &connect_msg, msg_len, UINT32_MAX, GNUNET_TIME_UNIT_FOREVER_REL,
1317                            session, plugin_name, address, address_len,
1318                            GNUNET_YES, &send_connect_ack_continuation, n);
1319     return GNUNET_NO;
1320   }
1321   /* connected peer is switching addresses */
1322   else if (n->state == S_CONNECTED)
1323   {
1324     msg_len = sizeof (struct SessionConnectMessage);
1325     connect_msg.header.size = htons (msg_len);
1326     connect_msg.header.type =
1327         htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_CONNECT);
1328     connect_msg.reserved = htonl (0);
1329     connect_msg.timestamp =
1330         GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get ());
1331
1332     ret = send_with_plugin (peer, (const char *) &connect_msg, msg_len, UINT32_MAX, GNUNET_TIME_UNIT_FOREVER_REL,
1333                             session, plugin_name, address, address_len,
1334                             GNUNET_YES, &send_switch_address_continuation, n);
1335     if (ret == GNUNET_SYSERR)
1336     {
1337       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1338                 "Failed to send CONNECT_MESSAGE to `%4s' using plugin `%s' address '%s' session %X\n",
1339                 GNUNET_i2s (peer), plugin_name,
1340                 (address_len == 0) ? "<inbound>" : GST_plugins_a2s (plugin_name,
1341                                                                     address,
1342                                                                     address_len),
1343                 session);
1344     }
1345     return GNUNET_NO;
1346   }
1347   else if (n->state == S_CONNECT_SENT)
1348   {
1349      return GNUNET_NO;
1350   }
1351   GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Invalid connection state to switch addresses %u \n", n->state);
1352   GNUNET_break_op (0);
1353   return GNUNET_NO;
1354 }
1355
1356
1357 /**
1358  * Create an entry in the neighbour map for the given peer
1359  *
1360  * @param peer peer to create an entry for
1361  * @return new neighbour map entry
1362  */
1363 static struct NeighbourMapEntry *
1364 setup_neighbour (const struct GNUNET_PeerIdentity *peer)
1365 {
1366   struct NeighbourMapEntry *n;
1367
1368 #if DEBUG_TRANSPORT
1369   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1370               "Unknown peer `%s', creating new neighbour\n",
1371               GNUNET_i2s (peer));
1372 #endif
1373   n = GNUNET_malloc (sizeof (struct NeighbourMapEntry));
1374   n->id = *peer;
1375   n->state = S_NOT_CONNECTED;
1376   GNUNET_BANDWIDTH_tracker_init (&n->in_tracker,
1377                                  GNUNET_CONSTANTS_DEFAULT_BW_IN_OUT,
1378                                  MAX_BANDWIDTH_CARRY_S);
1379   n->timeout_task =
1380     GNUNET_SCHEDULER_add_delayed (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT,
1381                                   &neighbour_timeout_task, n);
1382   GNUNET_assert (GNUNET_OK ==
1383                  GNUNET_CONTAINER_multihashmap_put (neighbours,
1384                                                     &n->id.hashPubKey, n,
1385                                                     GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
1386   return n;
1387 }
1388
1389
1390 /**
1391  * Try to create a connection to the given target (eventually).
1392  *
1393  * @param target peer to try to connect to
1394  */
1395 void
1396 GST_neighbours_try_connect (const struct GNUNET_PeerIdentity *target)
1397 {
1398   struct NeighbourMapEntry *n;
1399
1400   // This can happen during shutdown
1401   if (neighbours == NULL)
1402   {
1403     return;
1404   }
1405 #if DEBUG_TRANSPORT
1406   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Trying to connect to peer `%s'\n",
1407               GNUNET_i2s (target));
1408 #endif
1409   if (0 == memcmp (target, &GST_my_identity,
1410                    sizeof (struct GNUNET_PeerIdentity)))
1411   {
1412     /* my own hello */
1413     return;
1414   }
1415   n = lookup_neighbour (target);
1416
1417   if (NULL != n)
1418   {
1419     if ((is_connected(n)) || (is_connecting(n)))
1420       return;                     /* already connecting or connected */
1421     if (is_disconnecting(n))
1422       change_state (n, S_NOT_CONNECTED);
1423   }
1424
1425
1426   if (n == NULL)
1427     n = setup_neighbour (target);
1428 #if DEBUG_TRANSPORT
1429   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1430               "Asking ATS for suggested address to connect to peer `%s'\n",
1431               GNUNET_i2s (&n->id));
1432 #endif
1433
1434    GNUNET_ATS_suggest_address (GST_ats, &n->id);
1435 }
1436
1437 /**
1438  * Test if we're connected to the given peer.
1439  *
1440  * @param target peer to test
1441  * @return GNUNET_YES if we are connected, GNUNET_NO if not
1442  */
1443 int
1444 GST_neighbours_test_connected (const struct GNUNET_PeerIdentity *target)
1445 {
1446   struct NeighbourMapEntry *n;
1447
1448   // This can happen during shutdown
1449   if (neighbours == NULL)
1450   {
1451     return GNUNET_NO;
1452   }
1453
1454   n = lookup_neighbour (target);
1455
1456   if ((NULL == n) || (!is_connected(n)))
1457     return GNUNET_NO;           /* not connected */
1458   return GNUNET_YES;
1459 }
1460
1461
1462 /**
1463  * A session was terminated. Take note.
1464  *
1465  * @param peer identity of the peer where the session died
1466  * @param session session that is gone
1467  */
1468 void
1469 GST_neighbours_session_terminated (const struct GNUNET_PeerIdentity *peer,
1470                                    struct Session *session)
1471 {
1472   struct NeighbourMapEntry *n;
1473
1474   // This can happen during shutdown
1475   if (neighbours == NULL)
1476   {
1477     return;
1478   }
1479
1480 #if DEBUG_TRANSPORT
1481   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1482               "Session %X to peer `%s' ended \n",
1483               session, GNUNET_i2s (peer));
1484 #endif
1485
1486   n = lookup_neighbour (peer);
1487   if (NULL == n)
1488     return;
1489   if (session != n->session)
1490     return;                     /* doesn't affect us */
1491
1492   n->session = NULL;
1493   GNUNET_free (n->addr);
1494   n->addr = NULL;
1495   n->addrlen = 0;
1496
1497   /* not connected anymore anyway, shouldn't matter */
1498   if ((!is_connected(n)) && (!is_connecting(n)))
1499     return;
1500
1501   /* We are connected, so ask ATS to switch addresses */
1502   GNUNET_SCHEDULER_cancel (n->timeout_task);
1503   n->timeout_task =
1504       GNUNET_SCHEDULER_add_delayed (GNUNET_CONSTANTS_DISCONNECT_SESSION_TIMEOUT,
1505                                     &neighbour_timeout_task, n);
1506   /* try QUICKLY to re-establish a connection, reduce timeout! */
1507   if (n->ats_suggest != GNUNET_SCHEDULER_NO_TASK)
1508     GNUNET_SCHEDULER_cancel(n->ats_suggest);
1509   n->ats_suggest = GNUNET_SCHEDULER_add_delayed (ATS_RESPONSE_TIMEOUT, ats_suggest_cancel, n);
1510   GNUNET_ATS_suggest_address (GST_ats, peer);
1511 }
1512
1513
1514 /**
1515  * Transmit a message to the given target using the active connection.
1516  *
1517  * @param target destination
1518  * @param msg message to send
1519  * @param msg_size number of bytes in msg
1520  * @param timeout when to fail with timeout
1521  * @param cont function to call when done
1522  * @param cont_cls closure for 'cont'
1523  */
1524 void
1525 GST_neighbours_send (const struct GNUNET_PeerIdentity *target, const void *msg,
1526                      size_t msg_size, struct GNUNET_TIME_Relative timeout,
1527                      GST_NeighbourSendContinuation cont, void *cont_cls)
1528 {
1529   struct NeighbourMapEntry *n;
1530   struct MessageQueue *mq;
1531
1532   // This can happen during shutdown
1533   if (neighbours == NULL)
1534   {
1535     return;
1536   }
1537
1538   n = lookup_neighbour (target);
1539   if ((n == NULL) || (!is_connected(n)))
1540   {
1541     GNUNET_STATISTICS_update (GST_stats,
1542                               gettext_noop
1543                               ("# messages not sent (no such peer or not connected)"),
1544                               1, GNUNET_NO);
1545 #if DEBUG_TRANSPORT
1546     if (n == NULL)
1547       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1548                   "Could not send message to peer `%s': unknown neighbour",
1549                   GNUNET_i2s (target));
1550     else if (!is_connected(n))
1551       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1552                   "Could not send message to peer `%s': not connected\n",
1553                   GNUNET_i2s (target));
1554 #endif
1555     if (NULL != cont)
1556       cont (cont_cls, GNUNET_SYSERR);
1557     return;
1558   }
1559
1560   if ((n->session == NULL) && (n->addr == NULL) && (n->addrlen ==0))
1561   {
1562     GNUNET_STATISTICS_update (GST_stats,
1563                               gettext_noop
1564                               ("# messages not sent (no such peer or not connected)"),
1565                               1, GNUNET_NO);
1566 #if DEBUG_TRANSPORT
1567       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1568                   "Could not send message to peer `%s': no address available\n",
1569                   GNUNET_i2s (target));
1570 #endif
1571
1572     if (NULL != cont)
1573       cont (cont_cls, GNUNET_SYSERR);
1574     return;
1575   }
1576
1577   GNUNET_assert (msg_size >= sizeof (struct GNUNET_MessageHeader));
1578   GNUNET_STATISTICS_update (GST_stats,
1579                             gettext_noop
1580                             ("# bytes in message queue for other peers"),
1581                             msg_size, GNUNET_NO);
1582   mq = GNUNET_malloc (sizeof (struct MessageQueue) + msg_size);
1583   mq->cont = cont;
1584   mq->cont_cls = cont_cls;
1585   /* FIXME: this memcpy can be up to 7% of our total runtime! */
1586   memcpy (&mq[1], msg, msg_size);
1587   mq->message_buf = (const char *) &mq[1];
1588   mq->message_buf_size = msg_size;
1589   mq->timeout = GNUNET_TIME_relative_to_absolute (timeout);
1590   GNUNET_CONTAINER_DLL_insert_tail (n->messages_head, n->messages_tail, mq);
1591
1592   if ((GNUNET_SCHEDULER_NO_TASK == n->transmission_task) &&
1593       (NULL == n->is_active))
1594     n->transmission_task = GNUNET_SCHEDULER_add_now (&transmission_task, n);
1595 }
1596
1597
1598 /**
1599  * We have received a message from the given sender.  How long should
1600  * we delay before receiving more?  (Also used to keep the peer marked
1601  * as live).
1602  *
1603  * @param sender sender of the message
1604  * @param size size of the message
1605  * @param do_forward set to GNUNET_YES if the message should be forwarded to clients
1606  *                   GNUNET_NO if the neighbour is not connected or violates the quota,
1607  *                   GNUNET_SYSERR if the connection is not fully up yet
1608  * @return how long to wait before reading more from this sender
1609  */
1610 struct GNUNET_TIME_Relative
1611 GST_neighbours_calculate_receive_delay (const struct GNUNET_PeerIdentity
1612                                         *sender, ssize_t size, int *do_forward)
1613 {
1614   struct NeighbourMapEntry *n;
1615   struct GNUNET_TIME_Relative ret;
1616
1617   // This can happen during shutdown
1618   if (neighbours == NULL)
1619   {
1620     return GNUNET_TIME_UNIT_FOREVER_REL;
1621   }
1622
1623   n = lookup_neighbour (sender);
1624   if (n == NULL)
1625   {
1626     GST_neighbours_try_connect (sender);
1627     n = lookup_neighbour (sender);
1628     if (NULL == n)
1629     {
1630       GNUNET_STATISTICS_update (GST_stats,
1631                                 gettext_noop
1632                                 ("# messages discarded due to lack of neighbour record"),
1633                                 1, GNUNET_NO);
1634       *do_forward = GNUNET_NO;
1635       return GNUNET_TIME_UNIT_ZERO;
1636     }
1637   }
1638   if (!is_connected(n))
1639   {
1640     *do_forward = GNUNET_SYSERR;
1641     return GNUNET_TIME_UNIT_ZERO;
1642   }
1643   if (GNUNET_YES == GNUNET_BANDWIDTH_tracker_consume (&n->in_tracker, size))
1644   {
1645     n->quota_violation_count++;
1646 #if DEBUG_TRANSPORT
1647     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1648                 "Bandwidth quota (%u b/s) violation detected (total of %u).\n",
1649                 n->in_tracker.available_bytes_per_s__,
1650                 n->quota_violation_count);
1651 #endif
1652     /* Discount 32k per violation */
1653     GNUNET_BANDWIDTH_tracker_consume (&n->in_tracker, -32 * 1024);
1654   }
1655   else
1656   {
1657     if (n->quota_violation_count > 0)
1658     {
1659       /* try to add 32k back */
1660       GNUNET_BANDWIDTH_tracker_consume (&n->in_tracker, 32 * 1024);
1661       n->quota_violation_count--;
1662     }
1663   }
1664   if (n->quota_violation_count > QUOTA_VIOLATION_DROP_THRESHOLD)
1665   {
1666     GNUNET_STATISTICS_update (GST_stats,
1667                               gettext_noop
1668                               ("# bandwidth quota violations by other peers"),
1669                               1, GNUNET_NO);
1670     *do_forward = GNUNET_NO;
1671     return GNUNET_CONSTANTS_QUOTA_VIOLATION_TIMEOUT;
1672   }
1673   *do_forward = GNUNET_YES;
1674   ret = GNUNET_BANDWIDTH_tracker_get_delay (&n->in_tracker, 32 * 1024);
1675   if (ret.rel_value > 0)
1676   {
1677 #if DEBUG_TRANSPORT
1678     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1679                 "Throttling read (%llu bytes excess at %u b/s), waiting %llu ms before reading more.\n",
1680                 (unsigned long long) n->in_tracker.
1681                 consumption_since_last_update__,
1682                 (unsigned int) n->in_tracker.available_bytes_per_s__,
1683                 (unsigned long long) ret.rel_value);
1684 #endif
1685     GNUNET_STATISTICS_update (GST_stats,
1686                               gettext_noop ("# ms throttling suggested"),
1687                               (int64_t) ret.rel_value, GNUNET_NO);
1688   }
1689   return ret;
1690 }
1691
1692
1693 /**
1694  * Keep the connection to the given neighbour alive longer,
1695  * we received a KEEPALIVE (or equivalent).
1696  *
1697  * @param neighbour neighbour to keep alive
1698  */
1699 void
1700 GST_neighbours_keepalive (const struct GNUNET_PeerIdentity *neighbour)
1701 {
1702   struct NeighbourMapEntry *n;
1703
1704   // This can happen during shutdown
1705   if (neighbours == NULL)
1706   {
1707     return;
1708   }
1709
1710   n = lookup_neighbour (neighbour);
1711   if (NULL == n)
1712   {
1713     GNUNET_STATISTICS_update (GST_stats,
1714                               gettext_noop
1715                               ("# KEEPALIVE messages discarded (not connected)"),
1716                               1, GNUNET_NO);
1717     return;
1718   }
1719   GNUNET_SCHEDULER_cancel (n->timeout_task);
1720   n->timeout_task =
1721       GNUNET_SCHEDULER_add_delayed (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT,
1722                                     &neighbour_timeout_task, n);
1723 }
1724
1725
1726 /**
1727  * Change the incoming quota for the given peer.
1728  *
1729  * @param neighbour identity of peer to change qutoa for
1730  * @param quota new quota
1731  */
1732 void
1733 GST_neighbours_set_incoming_quota (const struct GNUNET_PeerIdentity *neighbour,
1734                                    struct GNUNET_BANDWIDTH_Value32NBO quota)
1735 {
1736   struct NeighbourMapEntry *n;
1737
1738   // This can happen during shutdown
1739   if (neighbours == NULL)
1740   {
1741     return;
1742   }
1743
1744   n = lookup_neighbour (neighbour);
1745   if (n == NULL)
1746   {
1747     GNUNET_STATISTICS_update (GST_stats,
1748                               gettext_noop
1749                               ("# SET QUOTA messages ignored (no such peer)"),
1750                               1, GNUNET_NO);
1751     return;
1752   }
1753   GNUNET_BANDWIDTH_tracker_update_quota (&n->in_tracker, quota);
1754   if (0 != ntohl (quota.value__))
1755     return;
1756 #if DEBUG_TRANSPORT
1757   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Disconnecting peer `%4s' due to `%s'\n",
1758               GNUNET_i2s (&n->id), "SET_QUOTA");
1759 #endif
1760   if (is_connected(n))
1761     GNUNET_STATISTICS_update (GST_stats,
1762                               gettext_noop ("# disconnects due to quota of 0"), 1,
1763                               GNUNET_NO);
1764   disconnect_neighbour (n);
1765 }
1766
1767
1768 /**
1769  * Closure for the neighbours_iterate function.
1770  */
1771 struct IteratorContext
1772 {
1773   /**
1774    * Function to call on each connected neighbour.
1775    */
1776   GST_NeighbourIterator cb;
1777
1778   /**
1779    * Closure for 'cb'.
1780    */
1781   void *cb_cls;
1782 };
1783
1784
1785 /**
1786  * Call the callback from the closure for each connected neighbour.
1787  *
1788  * @param cls the 'struct IteratorContext'
1789  * @param key the hash of the public key of the neighbour
1790  * @param value the 'struct NeighbourMapEntry'
1791  * @return GNUNET_OK (continue to iterate)
1792  */
1793 static int
1794 neighbours_iterate (void *cls, const GNUNET_HashCode * key, void *value)
1795 {
1796   struct IteratorContext *ic = cls;
1797   struct NeighbourMapEntry *n = value;
1798
1799   if (!is_connected(n))
1800     return GNUNET_OK;
1801
1802   ic->cb (ic->cb_cls, &n->id, NULL, 0, n->plugin_name, n->addr, n->addrlen);
1803   return GNUNET_OK;
1804 }
1805
1806
1807 /**
1808  * Iterate over all connected neighbours.
1809  *
1810  * @param cb function to call
1811  * @param cb_cls closure for cb
1812  */
1813 void
1814 GST_neighbours_iterate (GST_NeighbourIterator cb, void *cb_cls)
1815 {
1816   struct IteratorContext ic;
1817
1818   // This can happen during shutdown
1819   if (neighbours == NULL)
1820   {
1821     return;
1822   }
1823
1824   ic.cb = cb;
1825   ic.cb_cls = cb_cls;
1826   GNUNET_CONTAINER_multihashmap_iterate (neighbours, &neighbours_iterate, &ic);
1827 }
1828
1829 /**
1830  * If we have an active connection to the given target, it must be shutdown.
1831  *
1832  * @param target peer to disconnect from
1833  */
1834 void
1835 GST_neighbours_force_disconnect (const struct GNUNET_PeerIdentity *target)
1836 {
1837   struct NeighbourMapEntry *n;
1838
1839   // This can happen during shutdown
1840   if (neighbours == NULL)
1841   {
1842     return;
1843   }
1844
1845   n = lookup_neighbour (target);
1846   if (NULL == n)
1847     return;                     /* not active */
1848   if (is_connected(n))
1849   {
1850     send_disconnect(&n->id, n->plugin_name, n->addr, n->addrlen, n->session);
1851
1852     n = lookup_neighbour (target);
1853     if (NULL == n)
1854       return;                     /* gone already */
1855   }
1856   disconnect_neighbour (n);
1857 }
1858
1859
1860 /**
1861  * We received a disconnect message from the given peer,
1862  * validate and process.
1863  *
1864  * @param peer sender of the message
1865  * @param msg the disconnect message
1866  */
1867 void
1868 GST_neighbours_handle_disconnect_message (const struct GNUNET_PeerIdentity *peer,
1869                                           const struct GNUNET_MessageHeader *msg)
1870 {
1871   struct NeighbourMapEntry *n;
1872   const struct SessionDisconnectMessage *sdm;
1873   GNUNET_HashCode hc;
1874
1875 #if DEBUG_TRANSPORT
1876   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1877       "Received DISCONNECT message from peer `%s'\n", GNUNET_i2s (peer));
1878 #endif
1879
1880   if (ntohs (msg->size) != sizeof (struct SessionDisconnectMessage))
1881   {
1882     // GNUNET_break_op (0);
1883     GNUNET_STATISTICS_update (GST_stats,
1884                               gettext_noop ("# disconnect messages ignored (old format)"), 1,
1885                               GNUNET_NO);
1886     return;
1887   }
1888   sdm = (const struct SessionDisconnectMessage* ) msg;
1889   n = lookup_neighbour (peer);
1890   if (NULL == n)
1891     return;                     /* gone already */
1892   if (GNUNET_TIME_absolute_ntoh (sdm->timestamp).abs_value <=
1893       n->connect_ts.abs_value)
1894   {
1895     GNUNET_STATISTICS_update (GST_stats,
1896                               gettext_noop ("# disconnect messages ignored (timestamp)"), 1,
1897                               GNUNET_NO);
1898     return;
1899   }
1900   GNUNET_CRYPTO_hash (&sdm->public_key,
1901                       sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
1902                       &hc);
1903   if (0 != memcmp (peer,
1904                    &hc,
1905                    sizeof (struct GNUNET_PeerIdentity)))
1906   {
1907     GNUNET_break_op (0);
1908     return;
1909   }
1910   if (ntohl (sdm->purpose.size) !=
1911       sizeof (struct GNUNET_CRYPTO_RsaSignaturePurpose) +
1912       sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded) +
1913       sizeof (struct GNUNET_TIME_AbsoluteNBO))
1914   {
1915     GNUNET_break_op (0);
1916     return;
1917   }
1918   if (GNUNET_OK !=
1919       GNUNET_CRYPTO_rsa_verify (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_DISCONNECT,
1920                                 &sdm->purpose,
1921                                 &sdm->signature,
1922                                 &sdm->public_key))
1923   {
1924     GNUNET_break_op (0);
1925     return;
1926   }
1927   GST_neighbours_force_disconnect (peer);
1928 }
1929
1930 /**
1931  * We received a 'SESSION_CONNECT_ACK' message from the other peer.
1932  * Consider switching to it.
1933  *
1934  * @param message possibly a 'struct SessionConnectMessage' (check format)
1935  * @param peer identity of the peer to switch the address for
1936  * @param plugin_name name of transport that delivered the PONG
1937  * @param address address of the other peer, NULL if other peer
1938  *                       connected to us
1939  * @param address_len number of bytes in address
1940  * @param session session to use (or NULL)
1941  * @param ats performance data
1942  * @param ats_count number of entries in ats
1943   */
1944 void
1945 GST_neighbours_handle_connect_ack (const struct GNUNET_MessageHeader *message,
1946                                const struct GNUNET_PeerIdentity *peer,
1947                                const char *plugin_name,
1948                                const char *sender_address, uint16_t sender_address_len,
1949                                struct Session *session,
1950                                const struct GNUNET_ATS_Information *ats,
1951                                uint32_t ats_count)
1952 {
1953   const struct SessionConnectMessage *scm;
1954   struct QuotaSetMessage q_msg;
1955   struct GNUNET_MessageHeader msg;
1956   struct NeighbourMapEntry *n;
1957   size_t msg_len;
1958   size_t ret;
1959   int was_connected;
1960
1961 #if DEBUG_TRANSPORT
1962   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1963       "Received CONNECT_ACK message from peer `%s'\n", GNUNET_i2s (peer));
1964 #endif
1965
1966   if (ntohs (message->size) != sizeof (struct SessionConnectMessage))
1967   {
1968     GNUNET_break_op (0);
1969     return;
1970   }
1971
1972   scm = (const struct SessionConnectMessage *) message;
1973   GNUNET_break_op (ntohl (scm->reserved) == 0);
1974   n = lookup_neighbour (peer);
1975   if (NULL == n)
1976     n = setup_neighbour (peer);
1977 /*
1978   if (n->state != S_CONNECT_SENT)
1979   {
1980     GNUNET_break (0);
1981     send_disconnect(&n->id, n->plugin_name, n->addr, n->addrlen, n->session);
1982     return;
1983   }
1984 */
1985   if (NULL != session)
1986     GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG | GNUNET_ERROR_TYPE_BULK,
1987                      "transport-ats",
1988                      "Giving ATS session %p of plugin %s for peer %s\n",
1989                      session,
1990                      plugin_name,
1991                      GNUNET_i2s (peer));
1992   GNUNET_ATS_address_update (GST_ats,
1993                              peer,
1994                              plugin_name, sender_address, sender_address_len,
1995                              session, ats, ats_count);
1996
1997   was_connected = is_connected(n);
1998   if (!is_connected(n))
1999     change_state (n, S_CONNECTED);
2000
2001 #if DEBUG_TRANSPORT
2002   GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2003               "Setting inbound quota of %u for peer `%s' to \n",
2004               ntohl (n->bandwidth_in.value__), GNUNET_i2s (&n->id));
2005 #endif
2006   GST_neighbours_set_incoming_quota(&n->id, n->bandwidth_in);
2007
2008   /* send ACK (ACK)*/
2009   msg_len =  sizeof (msg);
2010   msg.size = htons (msg_len);
2011   msg.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_ACK);
2012
2013   ret = send_with_plugin (&n->id, (const char *) &msg, msg_len, UINT32_MAX,
2014                           GNUNET_TIME_UNIT_FOREVER_REL,
2015                           n->session, n->plugin_name, n->addr, n->addrlen,
2016                           GNUNET_YES, NULL, NULL);
2017
2018   if (ret == GNUNET_SYSERR)
2019     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2020               "Failed to send SESSION_ACK to `%4s' using plugin `%s' address '%s' session %X\n",
2021               GNUNET_i2s (&n->id), n->plugin_name,
2022               (n->addrlen == 0) ? "<inbound>" : GST_plugins_a2s (n->plugin_name,
2023                                                                  n->addr,
2024                                                                  n->addrlen),
2025               n->session);
2026
2027
2028   if (!was_connected)
2029   {
2030     if (n->keepalive_task == GNUNET_SCHEDULER_NO_TASK)
2031       n->keepalive_task = GNUNET_SCHEDULER_add_delayed (KEEPALIVE_FREQUENCY,
2032                                                         &neighbour_keepalive_task,
2033                                                         n);
2034
2035     neighbours_connected++;
2036     GNUNET_STATISTICS_update (GST_stats, gettext_noop ("# peers connected"), 1,
2037                               GNUNET_NO);
2038 #if DEBUG_TRANSPORT
2039     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2040               "Notify about connect of `%4s' using plugin `%s' address '%s' session %X LINE %u\n",
2041               GNUNET_i2s (&n->id), n->plugin_name,
2042               (n->addrlen == 0) ? "<inbound>" : GST_plugins_a2s (n->plugin_name,
2043                                                                  n->addr,
2044                                                                  n->addrlen),
2045               n->session, __LINE__);
2046 #endif
2047     connect_notify_cb (callback_cls, &n->id, ats, ats_count);
2048   }
2049
2050 #if DEBUG_TRANSPORT
2051     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2052                 "Sending outbound quota of %u Bps for peer `%s' to all clients\n",
2053                 ntohl (n->bandwidth_out.value__), GNUNET_i2s (peer));
2054 #endif
2055     q_msg.header.size = htons (sizeof (struct QuotaSetMessage));
2056     q_msg.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SET_QUOTA);
2057     q_msg.quota = n->bandwidth_out;
2058     q_msg.peer = (*peer);
2059     GST_clients_broadcast (&q_msg.header, GNUNET_NO);
2060
2061 }
2062
2063 void
2064 GST_neighbours_handle_ack (const struct GNUNET_MessageHeader *message,
2065     const struct GNUNET_PeerIdentity *peer,
2066     const char *plugin_name,
2067     const char *sender_address, uint16_t sender_address_len,
2068     struct Session *session,
2069     const struct GNUNET_ATS_Information *ats,
2070     uint32_t ats_count)
2071 {
2072   struct NeighbourMapEntry *n;
2073   struct QuotaSetMessage q_msg;
2074   int was_connected;
2075
2076 #if DEBUG_TRANSPORT
2077   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2078       "Received ACK message from peer `%s'\n", GNUNET_i2s (peer));
2079 #endif
2080
2081   if (ntohs (message->size) != sizeof (struct GNUNET_MessageHeader))
2082   {
2083     GNUNET_break_op (0);
2084     return;
2085   }
2086
2087   n = lookup_neighbour (peer);
2088   if (NULL == n)
2089   {
2090     send_disconnect(peer, plugin_name, sender_address, sender_address_len, session);
2091     GNUNET_break (0);
2092     return;
2093   }
2094
2095   if (is_connected(n))
2096     return;
2097
2098   if (NULL != session)
2099     GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG | GNUNET_ERROR_TYPE_BULK,
2100                      "transport-ats",
2101                      "Giving ATS session %p of plugin %s for peer %s\n",
2102                      session,
2103                      plugin_name,
2104                      GNUNET_i2s (peer));
2105   GNUNET_ATS_address_update (GST_ats,
2106                              peer,
2107                              plugin_name, sender_address, sender_address_len,
2108                              session, ats, ats_count);
2109
2110   was_connected = is_connected(n);
2111   change_state (n, S_CONNECTED);
2112
2113   GST_neighbours_set_incoming_quota(&n->id, n->bandwidth_in);
2114
2115   if (n->keepalive_task == GNUNET_SCHEDULER_NO_TASK)
2116     n->keepalive_task = GNUNET_SCHEDULER_add_delayed (KEEPALIVE_FREQUENCY,
2117                                                       &neighbour_keepalive_task,
2118                                                       n);
2119
2120   if (!was_connected)
2121   {
2122   neighbours_connected++;
2123   GNUNET_STATISTICS_update (GST_stats, gettext_noop ("# peers connected"), 1,
2124                             GNUNET_NO);
2125
2126 #if DEBUG_TRANSPORT
2127     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2128               "Notify about connect of `%4s' using plugin `%s' address '%s' session %X LINE %u\n",
2129               GNUNET_i2s (&n->id), n->plugin_name,
2130               (n->addrlen == 0) ? "<inbound>" : GST_plugins_a2s (n->plugin_name,
2131                                                                  n->addr,
2132                                                                  n->addrlen),
2133               n->session, __LINE__);
2134 #endif
2135   connect_notify_cb (callback_cls, &n->id, ats, ats_count);
2136   }
2137 #if DEBUG_TRANSPORT
2138   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2139               "Sending outbound quota of %u Bps for peer `%s' to all clients\n",
2140               ntohl (n->bandwidth_out.value__), GNUNET_i2s (peer));
2141 #endif
2142
2143   q_msg.header.size = htons (sizeof (struct QuotaSetMessage));
2144   q_msg.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SET_QUOTA);
2145   q_msg.quota = n->bandwidth_out;
2146   q_msg.peer = (*peer);
2147   GST_clients_broadcast (&q_msg.header, GNUNET_NO);
2148
2149 }
2150
2151 struct BlackListCheckContext
2152 {
2153   struct GNUNET_ATS_Information *ats;
2154
2155   uint32_t ats_count;
2156
2157   struct Session *session;
2158
2159   char *sender_address;
2160
2161   uint16_t sender_address_len;
2162
2163   char *plugin_name;
2164
2165   struct GNUNET_TIME_Absolute ts;
2166 };
2167
2168
2169 static void
2170 handle_connect_blacklist_cont (void *cls,
2171                                const struct GNUNET_PeerIdentity
2172                                * peer, int result)
2173 {
2174   struct NeighbourMapEntry *n;
2175   struct BlackListCheckContext * bcc = cls;
2176
2177 #if DEBUG_TRANSPORT
2178   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2179       "Blacklist check due to CONNECT message: `%s'\n", GNUNET_i2s (peer), (result == GNUNET_OK) ? "ALLOWED" : "FORBIDDEN");
2180 #endif
2181
2182   /* not allowed */
2183   if (GNUNET_OK != result)
2184   {
2185     GNUNET_free (bcc);
2186     return;
2187   }
2188
2189   n = lookup_neighbour (peer);
2190   if (NULL == n)
2191     n = setup_neighbour (peer);
2192
2193   if (bcc->ts.abs_value > n->connect_ts.abs_value)
2194   {
2195     if (NULL != bcc->session)
2196       GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG | GNUNET_ERROR_TYPE_BULK,
2197                        "transport-ats",
2198                        "Giving ATS session %p of plugin %s address `%s' for peer %s\n",
2199                        bcc->session,
2200                        bcc->plugin_name,
2201                        GST_plugins_a2s (bcc->plugin_name, bcc->sender_address, bcc->sender_address_len),
2202                        GNUNET_i2s (peer));
2203     GNUNET_ATS_address_update (GST_ats,
2204                                peer,
2205                                bcc->plugin_name, bcc->sender_address, bcc->sender_address_len,
2206                                bcc->session, bcc->ats, bcc->ats_count);
2207     n->connect_ts = bcc->ts;
2208   }
2209
2210   GNUNET_free (bcc);
2211
2212   if (n->state != S_CONNECT_RECV)
2213       change_state (n, S_CONNECT_RECV);
2214
2215   /* Ask ATS for an address to connect via that address */
2216   if (n->ats_suggest != GNUNET_SCHEDULER_NO_TASK)
2217     GNUNET_SCHEDULER_cancel(n->ats_suggest);
2218   n->ats_suggest = GNUNET_SCHEDULER_add_delayed (ATS_RESPONSE_TIMEOUT, ats_suggest_cancel, n);
2219   GNUNET_ATS_suggest_address(GST_ats, peer);
2220 }
2221
2222 /**
2223  * We received a 'SESSION_CONNECT' message from the other peer.
2224  * Consider switching to it.
2225  *
2226  * @param message possibly a 'struct SessionConnectMessage' (check format)
2227  * @param peer identity of the peer to switch the address for
2228  * @param plugin_name name of transport that delivered the PONG
2229  * @param address address of the other peer, NULL if other peer
2230  *                       connected to us
2231  * @param address_len number of bytes in address
2232  * @param session session to use (or NULL)
2233  * @param ats performance data
2234  * @param ats_count number of entries in ats (excluding 0-termination)
2235   */
2236 void
2237 GST_neighbours_handle_connect (const struct GNUNET_MessageHeader *message,
2238                                const struct GNUNET_PeerIdentity *peer,
2239                                const char *plugin_name,
2240                                const char *sender_address, uint16_t sender_address_len,
2241                                struct Session *session,
2242                                const struct GNUNET_ATS_Information *ats,
2243                                uint32_t ats_count)
2244 {
2245   const struct SessionConnectMessage *scm;
2246   struct NeighbourMapEntry * n;
2247   struct BlackListCheckContext * bcc = NULL;
2248
2249 #if DEBUG_TRANSPORT
2250   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2251       "Received CONNECT message from peer `%s'\n", GNUNET_i2s (peer));
2252 #endif
2253
2254   if (ntohs (message->size) != sizeof (struct SessionConnectMessage))
2255   {
2256     GNUNET_break_op (0);
2257     return;
2258   }
2259
2260   scm = (const struct SessionConnectMessage *) message;
2261   GNUNET_break_op (ntohl (scm->reserved) == 0);
2262
2263   n = lookup_neighbour(peer);
2264   if (n != NULL)
2265   {
2266     /* connected peer switches addresses */
2267     if (is_connected(n))
2268     {
2269       GNUNET_ATS_address_update(GST_ats, peer, plugin_name, sender_address, sender_address_len, session, ats, ats_count);
2270       return;
2271     }
2272   }
2273
2274   /* we are not connected to this peer */
2275   /* do blacklist check*/
2276   bcc = GNUNET_malloc (sizeof (struct BlackListCheckContext) +
2277             sizeof (struct GNUNET_ATS_Information) * ats_count +
2278             sender_address_len +
2279             strlen (plugin_name)+1);
2280
2281   bcc->ts = GNUNET_TIME_absolute_ntoh (scm->timestamp);
2282
2283   bcc->ats_count = ats_count;
2284   bcc->sender_address_len = sender_address_len;
2285   bcc->session = session;
2286
2287   bcc->ats = (struct GNUNET_ATS_Information *) &bcc[1];
2288   memcpy (bcc->ats, ats,sizeof (struct GNUNET_ATS_Information) * ats_count );
2289
2290   bcc->sender_address = (char *) &bcc->ats[ats_count];
2291   memcpy (bcc->sender_address, sender_address , sender_address_len);
2292
2293   bcc->plugin_name = &bcc->sender_address[sender_address_len];
2294   strcpy (bcc->plugin_name, plugin_name);
2295
2296   GST_blacklist_test_allowed (peer, plugin_name, handle_connect_blacklist_cont, bcc);
2297 }
2298
2299
2300 /* end of file gnunet-service-transport_neighbours.c */