src/transport/gnunet-service-transport_neighbours.c

   1 /*
   2      This file is part of GNUnet.
   3      (C) 2010-2013 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 /**
  41  * Size of the neighbour hash map.
  42  */
  43 #define NEIGHBOUR_TABLE_SIZE 256
  44
  45 /**
  46  * Time we give plugin to transmit DISCONNECT message before the
  47  * neighbour entry self-destructs.
  48  */
  49 #define DISCONNECT_SENT_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 100)
  50
  51 /**
  52  * How often must a peer violate bandwidth quotas before we start
  53  * to simply drop its messages?
  54  */
  55 #define QUOTA_VIOLATION_DROP_THRESHOLD 10
  56
  57 /**
  58  * How long are we willing to wait for a response from ATS before timing out?
  59  */
  60 #define ATS_RESPONSE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 5000)
  61
  62 /**
  63  * How long are we willing to wait for an ACK from the other peer before
  64  * giving up on our connect operation?
  65  */
  66 #define SETUP_CONNECTION_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 15)
  67
  68 /**
  69  * How long are we willing to wait for a successful reconnect if
  70  * an existing connection went down?  Much shorter than the
  71  * usual SETUP_CONNECTION_TIMEOUT as we do not inform the
  72  * higher layers about the disconnect during this period.
  73  */
  74 #define FAST_RECONNECT_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 1)
  75
  76 /**
  77  * How long are we willing to wait for a response from the blacklist
  78  * subsystem before timing out?
  79  */
  80 #define BLACKLIST_RESPONSE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 500)
  81
  82 /**
  83  * Interval to send utilization data
  84  */
  85 #define UTIL_TRANSMISSION_INTERVAL GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 1)
  86
  87 GNUNET_NETWORK_STRUCT_BEGIN
  88
  89 /**
  90  * Message a peer sends to another to indicate that it intends to
  91  * setup a connection/session for data exchange.  A 'SESSION_CONNECT'
  92  * should be answered with a 'SESSION_CONNECT_ACK' with the same body
  93  * to confirm.  A 'SESSION_CONNECT_ACK' should then be followed with
  94  * a 'SESSION_ACK'.  Once the 'SESSION_ACK' is received, both peers
  95  * should be connected.
  96  */
  97 struct SessionConnectMessage
  98 {
  99   /**
 100    * Header of type #GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_CONNECT
 101    * or #GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_CONNECT_ACK
 102    */
 103   struct GNUNET_MessageHeader header;
 104
 105   /**
 106    * Always zero.
 107    */
 108   uint32_t reserved GNUNET_PACKED;
 109
 110   /**
 111    * Absolute time at the sender.  Only the most recent connect
 112    * message implies which session is preferred by the sender.
 113    */
 114   struct GNUNET_TIME_AbsoluteNBO timestamp;
 115
 116 };
 117
 118
 119 /**
 120  * Message a peer sends to another when connected to indicate that a
 121  * session is in use and the peer is still alive or to respond to a keep alive.
 122  * A peer sends a message with type #GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_KEEPALIVE
 123  * to request a message with #GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_KEEPALIVE_RESPONSE.
 124  * When the keep alive response with type is received, transport service
 125  * will call the respective plugin to update the session timeout
 126  */
 127 struct SessionKeepAliveMessage
 128 {
 129   /**
 130    * Header of type #GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_KEEPALIVE or
 131    * #GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_KEEPALIVE_RESPONSE.
 132    */
 133   struct GNUNET_MessageHeader header;
 134
 135   /**
 136    * A nonce to identify the session the keep alive is used for
 137    */
 138   uint32_t nonce GNUNET_PACKED;
 139 };
 140
 141 /**
 142  * Message we send to the other peer to notify him that we intentionally
 143  * are disconnecting (to reduce timeouts).  This is just a friendly
 144  * notification, peers must not rely on always receiving disconnect
 145  * messages.
 146  */
 147 struct SessionDisconnectMessage
 148 {
 149   /**
 150    * Header of type #GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_DISCONNECT
 151    */
 152   struct GNUNET_MessageHeader header;
 153
 154   /**
 155    * Always zero.
 156    */
 157   uint32_t reserved GNUNET_PACKED;
 158
 159   /**
 160    * Purpose of the signature.  Extends over the timestamp.
 161    * Purpose should be #GNUNET_SIGNATURE_PURPOSE_TRANSPORT_DISCONNECT.
 162    */
 163   struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
 164
 165   /**
 166    * Absolute time at the sender.  Only the most recent connect
 167    * message implies which session is preferred by the sender.
 168    */
 169   struct GNUNET_TIME_AbsoluteNBO timestamp;
 170
 171   /**
 172    * Public key of the sender.
 173    */
 174   struct GNUNET_CRYPTO_EddsaPublicKey public_key;
 175
 176   /**
 177    * Signature of the peer that sends us the disconnect.  Only
 178    * valid if the timestamp is AFTER the timestamp from the
 179    * corresponding 'CONNECT' message.
 180    */
 181   struct GNUNET_CRYPTO_EddsaSignature signature;
 182
 183 };
 184
 185 GNUNET_NETWORK_STRUCT_END
 186
 187
 188 /**
 189  * For each neighbour we keep a list of messages
 190  * that we still want to transmit to the neighbour.
 191  */
 192 struct MessageQueue
 193 {
 194
 195   /**
 196    * This is a doubly linked list.
 197    */
 198   struct MessageQueue *next;
 199
 200   /**
 201    * This is a doubly linked list.
 202    */
 203   struct MessageQueue *prev;
 204
 205   /**
 206    * Function to call once we're done.
 207    */
 208   GST_NeighbourSendContinuation cont;
 209
 210   /**
 211    * Closure for @e cont
 212    */
 213   void *cont_cls;
 214
 215   /**
 216    * The message(s) we want to transmit, GNUNET_MessageHeader(s)
 217    * stuck together in memory.  Allocated at the end of this struct.
 218    */
 219   const char *message_buf;
 220
 221   /**
 222    * Size of the message buf
 223    */
 224   size_t message_buf_size;
 225
 226   /**
 227    * At what time should we fail?
 228    */
 229   struct GNUNET_TIME_Absolute timeout;
 230
 231 };
 232
 233
 234
 235
 236 /**
 237  * A possible address we could use to communicate with a neighbour.
 238  */
 239 struct NeighbourAddress
 240 {
 241
 242   /**
 243    * Active session for this address.
 244    */
 245   struct Session *session;
 246
 247   /**
 248    * Network-level address information.
 249    */
 250   struct GNUNET_HELLO_Address *address;
 251
 252   /**
 253    * Timestamp of the 'SESSION_CONNECT' message we sent to the other
 254    * peer for this address.  Use to check that the ACK is in response
 255    * to our most recent 'CONNECT'.
 256    */
 257   struct GNUNET_TIME_Absolute connect_timestamp;
 258
 259   /**
 260    * Inbound bandwidth from ATS for this address.
 261    */
 262   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in;
 263
 264   /**
 265    * Outbound bandwidth from ATS for this address.
 266    */
 267   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out;
 268
 269   /**
 270    * Did we tell ATS that this is our 'active' address?
 271    */
 272   int ats_active;
 273
 274   /**
 275    * The current nonce sent in the last keep alive messages
 276    */
 277   uint32_t keep_alive_nonce;
 278 };
 279
 280
 281 /**
 282  * Entry in neighbours.
 283  */
 284 struct NeighbourMapEntry
 285 {
 286
 287   /**
 288    * Head of list of messages we would like to send to this peer;
 289    * must contain at most one message per client.
 290    */
 291   struct MessageQueue *messages_head;
 292
 293   /**
 294    * Tail of list of messages we would like to send to this peer; must
 295    * contain at most one message per client.
 296    */
 297   struct MessageQueue *messages_tail;
 298
 299   /**
 300    * Are we currently trying to send a message? If so, which one?
 301    */
 302   struct MessageQueue *is_active;
 303
 304   /**
 305    * Primary address we currently use to communicate with the neighbour.
 306    */
 307   struct NeighbourAddress primary_address;
 308
 309   /**
 310    * Alternative address currently under consideration for communicating
 311    * with the neighbour.
 312    */
 313   struct NeighbourAddress alternative_address;
 314
 315   /**
 316    * Identity of this neighbour.
 317    */
 318   struct GNUNET_PeerIdentity id;
 319
 320   /**
 321    * Main task that drives this peer (timeouts, keepalives, etc.).
 322    * Always runs the 'master_task'.
 323    */
 324   GNUNET_SCHEDULER_TaskIdentifier task;
 325
 326   /**
 327    * At what time should we sent the next keep-alive message?
 328    */
 329   struct GNUNET_TIME_Absolute keep_alive_time;
 330
 331   /**
 332    * At what time did we sent the last keep-alive message?  Used
 333    * to calculate round-trip time ("latency").
 334    */
 335   struct GNUNET_TIME_Absolute last_keep_alive_time;
 336
 337   /**
 338    * Timestamp we should include in our next CONNECT_ACK message.
 339    * (only valid if 'send_connect_ack' is #GNUNET_YES).  Used to build
 340    * our CONNECT_ACK message.
 341    */
 342   struct GNUNET_TIME_Absolute connect_ack_timestamp;
 343
 344   /**
 345    * ATS address suggest handle
 346    */
 347   struct GNUNET_ATS_SuggestHandle *suggest_handle;
 348
 349   /**
 350    * Time where we should cut the connection (timeout) if we don't
 351    * make progress in the state machine (or get a KEEPALIVE_RESPONSE
 352    * if we are in S_CONNECTED).
 353    */
 354   struct GNUNET_TIME_Absolute timeout;
 355
 356   /**
 357    * Latest calculated latency value
 358    */
 359   struct GNUNET_TIME_Relative latency;
 360
 361   /**
 362    * Tracker for inbound bandwidth.
 363    */
 364   struct GNUNET_BANDWIDTH_Tracker in_tracker;
 365
 366   /**
 367    * How often has the other peer (recently) violated the inbound
 368    * traffic limit?  Incremented by 10 per violation, decremented by 1
 369    * per non-violation (for each time interval).
 370    */
 371   unsigned int quota_violation_count;
 372
 373   /**
 374    * The current state of the peer.
 375    */
 376   enum GNUNET_TRANSPORT_PeerState state;
 377
 378   /**
 379    * Did we sent an KEEP_ALIVE message and are we expecting a response?
 380    */
 381   int expect_latency_response;
 382
 383   /**
 384    * Flag to set if we still need to send a CONNECT_ACK message to the other peer
 385    * (once we have an address to use and the peer has been allowed by our
 386    * blacklist).  Set to 1 if we need to send a CONNECT_ACK.  Set to 2 if we
 387    * did send a CONNECT_ACK and should go to 'S_CONNECTED' upon receiving
 388    * a 'SESSION_ACK' (regardless of what our own state machine might say).
 389    */
 390   int send_connect_ack;
 391
 392   /**
 393    * Tracking utilization of outbound bandwidth
 394    */
 395   uint32_t util_payload_bytes_sent;
 396
 397   /**
 398    * Tracking utilization of inbound bandwidth
 399    */
 400   uint32_t util_payload_bytes_recv;
 401
 402   /**
 403    * Tracking utilization of outbound bandwidth
 404    */
 405   uint32_t util_total_bytes_sent;
 406
 407   /**
 408    * Tracking utilization of inbound bandwidth
 409    */
 410   uint32_t util_total_bytes_recv;
 411
 412   /**
 413    * Date of last utilization transmission
 414    */
 415   struct GNUNET_TIME_Absolute last_util_transmission;
 416 };
 417
 418
 419 /**
 420  * Context for blacklist checks and the #handle_test_blacklist_cont()
 421  * function.  Stores information about ongoing blacklist checks.
 422  */
 423 struct BlackListCheckContext
 424 {
 425
 426   /**
 427    * We keep blacklist checks in a DLL.
 428    */
 429   struct BlackListCheckContext *next;
 430
 431   /**
 432    * We keep blacklist checks in a DLL.
 433    */
 434   struct BlackListCheckContext *prev;
 435
 436   /**
 437    * Address that is being checked.
 438    */
 439   struct NeighbourAddress na;
 440
 441   /**
 442    * Handle to the ongoing blacklist check.
 443    */
 444   struct GST_BlacklistCheck *bc;
 445 };
 446
 447
 448 /**
 449  * Hash map from peer identities to the respective 'struct NeighbourMapEntry'.
 450  */
 451 static struct GNUNET_CONTAINER_MultiPeerMap *neighbours;
 452
 453 /**
 454  * We keep blacklist checks in a DLL so that we can find
 455  * the 'sessions' in their 'struct NeighbourAddress' if
 456  * a session goes down.
 457  */
 458 static struct BlackListCheckContext *bc_head;
 459
 460 /**
 461  * We keep blacklist checks in a DLL.
 462  */
 463 static struct BlackListCheckContext *bc_tail;
 464
 465 /**
 466  * List of pending blacklist checks: head
 467  */
 468 static struct BlacklistCheckSwitchContext *pending_bc_head;
 469
 470 /**
 471  * List of pending blacklist checks: tail
 472  */
 473 static struct BlacklistCheckSwitchContext *pending_bc_tail;
 474
 475 /**
 476  * Closure for #connect_notify_cb, #disconnect_notify_cb and #neighbour_change_cb
 477  */
 478 static void *callback_cls;
 479
 480 /**
 481  * Function to call when we connected to a neighbour.
 482  */
 483 static NotifyConnect connect_notify_cb;
 484
 485 /**
 486  * Function to call when we disconnected from a neighbour.
 487  */
 488 static GNUNET_TRANSPORT_NotifyDisconnect disconnect_notify_cb;
 489
 490 /**
 491  * Function to call when a neighbour changed address, state or bandwidth.
 492  */
 493 static GNUNET_TRANSPORT_NeighbourChangeCallback neighbour_change_cb;
 494
 495 /**
 496  * counter for connected neighbours
 497  */
 498 static unsigned int neighbours_connected;
 499
 500 /**
 501  * Number of bytes we have currently queued for transmission.
 502  */
 503 static unsigned long long bytes_in_send_queue;
 504
 505 /**
 506  * Task transmitting utilization data
 507  */
 508 static GNUNET_SCHEDULER_TaskIdentifier util_transmission_tk;
 509
 510
 511 static struct GNUNET_CONTAINER_MultiPeerMap *registered_quota_notifications;
 512
 513 /**
 514  * Lookup a neighbour entry in the neighbours hash map.
 515  *
 516  * @param pid identity of the peer to look up
 517  * @return the entry, NULL if there is no existing record
 518  */
 519 static struct NeighbourMapEntry *
 520 lookup_neighbour (const struct GNUNET_PeerIdentity *pid)
 521 {
 522   if (NULL == neighbours)
 523     return NULL;
 524   return GNUNET_CONTAINER_multipeermap_get (neighbours, pid);
 525 }
 526
 527
 528 /**
 529  * Test if we're connected to the given peer.
 530  *
 531  * @param n neighbour entry of peer to test
 532  * @return #GNUNET_YES if we are connected, #GNUNET_NO if not
 533  */
 534 static int
 535 test_connected (struct NeighbourMapEntry *n)
 536 {
 537   if (NULL == n)
 538     return GNUNET_NO;
 539   return GNUNET_TRANSPORT_is_connected (n->state);
 540 }
 541
 542 /**
 543  * Send information about a new outbound quota to our clients.
 544  *
 545  * @param target affected peer
 546  * @param quota new quota
 547  */
 548 static void
 549 send_outbound_quota (const struct GNUNET_PeerIdentity *target,
 550                      struct GNUNET_BANDWIDTH_Value32NBO quota)
 551 {
 552   struct QuotaSetMessage q_msg;
 553
 554   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 555               "Sending outbound quota of %u Bps for peer `%s' to all clients\n",
 556               ntohl (quota.value__), GNUNET_i2s (target));
 557   q_msg.header.size = htons (sizeof (struct QuotaSetMessage));
 558   q_msg.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SET_QUOTA);
 559   q_msg.quota = quota;
 560   q_msg.peer = (*target);
 561   GST_clients_broadcast (&q_msg.header, GNUNET_NO);
 562 }
 563
 564
 565 /**
 566  * We don't need a given neighbour address any more.
 567  * Release its resources and give appropriate notifications
 568  * to ATS and other subsystems.
 569  *
 570  * @param na address we are done with; @a na itself must NOT be 'free'd, only the contents!
 571  */
 572 static void
 573 free_address (struct NeighbourAddress *na)
 574 {
 575   if (GNUNET_YES == na->ats_active)
 576   {
 577     GST_validation_set_address_use (na->address, na->session, GNUNET_NO);
 578     GNUNET_ATS_address_in_use (GST_ats, na->address, na->session, GNUNET_NO);
 579   }
 580
 581   na->ats_active = GNUNET_NO;
 582   na->keep_alive_nonce = 0;
 583   if (NULL != na->address)
 584   {
 585     GNUNET_HELLO_address_free (na->address);
 586     na->address = NULL;
 587   }
 588   na->session = NULL;
 589 }
 590
 591
 592 /**
 593  * Set net state for this neighbour and notify monitoring
 594  *
 595  * @param n the respective neighbour
 596  * @param s the new state
 597  */
 598 static void
 599 set_state (struct NeighbourMapEntry *n, enum GNUNET_TRANSPORT_PeerState s)
 600 {
 601   n->state = s;
 602   GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Neighbour `%s' changed state to %s\n",
 603       GNUNET_i2s (&n->id),
 604       GNUNET_TRANSPORT_ps2s(s));
 605   neighbour_change_cb (callback_cls,
 606       &n->id,
 607       n->primary_address.address,
 608       n->state, n->timeout,
 609       n->primary_address.bandwidth_in,
 610       n->primary_address.bandwidth_out);
 611
 612 }
 613
 614 /**
 615  * Set net state and state timeout for this neighbour and notify monitoring
 616  *
 617  * @param n the respective neighbour
 618  * @param s the new state
 619  * @param timeout the new timeout
 620  */
 621 static void
 622 set_state_and_timeout (struct NeighbourMapEntry *n,
 623     enum GNUNET_TRANSPORT_PeerState s,
 624     struct GNUNET_TIME_Absolute timeout)
 625 {
 626   n->state = s;
 627   n->timeout = timeout;
 628   GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Neighbour `%s' changed state to %s with timeout %s\n",
 629       GNUNET_i2s (&n->id),
 630       GNUNET_TRANSPORT_ps2s(s),
 631       GNUNET_STRINGS_absolute_time_to_string (timeout));
 632   neighbour_change_cb (callback_cls,
 633       &n->id,
 634       n->primary_address.address,
 635       n->state, n->timeout,
 636       n->primary_address.bandwidth_in,
 637       n->primary_address.bandwidth_out);
 638 }
 639
 640
 641 /**
 642  * Set new state timeout for this neighbour and notify monitoring
 643  *
 644  * @param n the respective neighbour
 645  * @param timeout the new timeout
 646  */
 647 static void
 648 set_timeout (struct NeighbourMapEntry *n,
 649     struct GNUNET_TIME_Absolute timeout)
 650 {
 651   n->timeout = timeout;
 652   GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Neighbour `%s' changed timeout %s\n",
 653       GNUNET_i2s (&n->id),
 654       GNUNET_STRINGS_absolute_time_to_string (timeout));
 655   neighbour_change_cb (callback_cls,
 656       &n->id,
 657       n->primary_address.address,
 658       n->state, n->timeout,
 659       n->primary_address.bandwidth_in,
 660       n->primary_address.bandwidth_out);
 661 }
 662
 663
 664 /**
 665  * Initialize the alternative address of a neighbour
 666  *
 667  * @param n the neighbour
 668  * @param address address of the other peer, NULL if other peer
 669  *                       connected to us
 670  * @param session session to use (or NULL, in which case an
 671  *        address must be setup)
 672  * @param bandwidth_in inbound quota to be used when connection is up
 673  * @param bandwidth_out outbound quota to be used when connection is up
 674  */
 675 static void
 676 set_alternative_address (struct NeighbourMapEntry *n,
 677              const struct GNUNET_HELLO_Address *address,
 678              struct Session *session,
 679              struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in,
 680              struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out)
 681 {
 682   struct GNUNET_TRANSPORT_PluginFunctions *papi;
 683   if (NULL == (papi = GST_plugins_find (address->transport_name)))
 684   {
 685     GNUNET_break (0);
 686     return;
 687   }
 688   if (session == n->alternative_address.session)
 689   {
 690     n->alternative_address.bandwidth_in = bandwidth_in;
 691     n->alternative_address.bandwidth_out = bandwidth_out;
 692     return;
 693   }
 694   free_address (&n->alternative_address);
 695   if (NULL == session)
 696     session = papi->get_session (papi->cls, address);
 697   if (NULL == session)
 698   {
 699     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 700                 "Failed to obtain new session for peer `%s' and  address '%s'\n",
 701                 GNUNET_i2s (&address->peer), GST_plugins_a2s (address));
 702     GNUNET_ATS_address_destroyed (GST_ats, address, NULL);
 703     return;
 704   }
 705
 706   GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Neighbour `%s' configured alternative address %s\n",
 707       GNUNET_i2s (&n->id),
 708       GST_plugins_a2s(address));
 709
 710   n->alternative_address.address = GNUNET_HELLO_address_copy (address);
 711   n->alternative_address.bandwidth_in = bandwidth_in;
 712   n->alternative_address.bandwidth_out = bandwidth_out;
 713   n->alternative_address.session = session;
 714   n->alternative_address.ats_active = GNUNET_NO;
 715   n->alternative_address.keep_alive_nonce = 0;
 716 }
 717
 718
 719 /**
 720  * Initialize the primary address of a neighbour
 721  *
 722  * @param n the neighbour
 723  * @param address address of the other peer, NULL if other peer
 724  *                       connected to us
 725  * @param session session to use (or NULL, in which case an
 726  *        address must be setup)
 727  * @param bandwidth_in inbound quota to be used when connection is up
 728  * @param bandwidth_out outbound quota to be used when connection is up
 729  * @param is_active #GNUNET_YES to mark this as the active address with ATS
 730  */
 731 static void
 732 set_primary_address (struct NeighbourMapEntry *n,
 733              const struct GNUNET_HELLO_Address *address,
 734              struct Session *session,
 735              struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in,
 736              struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out,
 737              int is_active)
 738 {
 739   struct GNUNET_TRANSPORT_PluginFunctions *papi;
 740
 741   if (NULL == (papi = GST_plugins_find (address->transport_name)))
 742   {
 743     GNUNET_break (0);
 744     return;
 745   }
 746   if (session == n->primary_address.session)
 747   {
 748     n->primary_address.bandwidth_in = bandwidth_in;
 749     n->primary_address.bandwidth_out = bandwidth_out;
 750     if (is_active != n->primary_address.ats_active)
 751     {
 752       n->primary_address.ats_active = is_active;
 753       GNUNET_ATS_address_in_use (GST_ats, n->primary_address.address, n->primary_address.session, is_active);
 754       GST_validation_set_address_use (n->primary_address.address, n->primary_address.session, is_active);
 755     }
 756     if (GNUNET_YES == is_active)
 757     {
 758       GST_neighbours_set_incoming_quota (&address->peer, bandwidth_in);
 759       send_outbound_quota (&address->peer, bandwidth_out);
 760     }
 761     return;
 762   }
 763   free_address (&n->primary_address);
 764   if (NULL == session)
 765     session = papi->get_session (papi->cls, address);
 766   if (NULL == session)
 767   {
 768     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 769                 "Failed to obtain new session for peer `%s' and  address '%s'\n",
 770                 GNUNET_i2s (&address->peer), GST_plugins_a2s (address));
 771     GNUNET_ATS_address_destroyed (GST_ats, address, NULL);
 772     return;
 773   }
 774
 775   n->primary_address.address = GNUNET_HELLO_address_copy (address);
 776   n->primary_address.bandwidth_in = bandwidth_in;
 777   n->primary_address.bandwidth_out = bandwidth_out;
 778   n->primary_address.session = session;
 779   n->primary_address.ats_active = is_active;
 780   n->primary_address.keep_alive_nonce = 0;
 781   if (GNUNET_YES == is_active)
 782   {
 783     /* Telling ATS about new session */
 784     GNUNET_ATS_address_in_use (GST_ats, n->primary_address.address, n->primary_address.session, GNUNET_YES);
 785     GST_validation_set_address_use (n->primary_address.address, n->primary_address.session, GNUNET_YES);
 786     GST_neighbours_set_incoming_quota (&address->peer, bandwidth_in);
 787     send_outbound_quota (&address->peer, bandwidth_out);
 788   }
 789
 790   GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Neighbour `%s' switched to address `%s'\n",
 791       GNUNET_i2s (&n->id),
 792       GST_plugins_a2s(address));
 793
 794   neighbour_change_cb (callback_cls,
 795       &n->id,
 796       n->primary_address.address,
 797       n->state, n->timeout,
 798       n->primary_address.bandwidth_in,
 799       n->primary_address.bandwidth_out);
 800 }
 801
 802 #if 0
 803 TODO: Implement this
 804 /**
 805  * Clear the primary address of a neighbour since this primary address is not
 806  * valid anymore and notify monitoring about it
 807  *
 808  * @param n the neighbour
 809  */
 810 static void
 811 unset_primary_address (struct NeighbourMapEntry *n)
 812 {
 813
 814 }
 815
 816 #endif
 817
 818
 819 /**
 820  * Free a neighbour map entry.
 821  *
 822  * @param n entry to free
 823  * @param keep_sessions #GNUNET_NO to tell plugin to terminate sessions,
 824  *                      #GNUNET_YES to keep all sessions
 825  */
 826 static void
 827 free_neighbour (struct NeighbourMapEntry *n,
 828                 int keep_sessions)
 829 {
 830   struct MessageQueue *mq;
 831   struct GNUNET_TRANSPORT_PluginFunctions *papi;
 832   struct GNUNET_HELLO_Address *backup_primary;
 833
 834   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 835               "Freeing neighbour state of peer `%s'\n",
 836               GNUNET_i2s (&n->id));
 837   n->is_active = NULL; /* always free'd by its own continuation! */
 838
 839   /* fail messages currently in the queue */
 840   while (NULL != (mq = n->messages_head))
 841   {
 842     GNUNET_CONTAINER_DLL_remove (n->messages_head, n->messages_tail, mq);
 843     if (NULL != mq->cont)
 844       mq->cont (mq->cont_cls, GNUNET_SYSERR, mq->message_buf_size, 0);
 845     GNUNET_free (mq);
 846   }
 847   /* It is too late to send other peer disconnect notifications, but at
 848      least internally we need to get clean... */
 849   if (GNUNET_YES == test_connected (n))
 850   {
 851     GNUNET_STATISTICS_set (GST_stats,
 852                            gettext_noop ("# peers connected"),
 853                            --neighbours_connected,
 854                            GNUNET_NO);
 855     disconnect_notify_cb (callback_cls, &n->id);
 856   }
 857   /* Mark peer as disconnected */
 858   set_state (n, GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED);
 859
 860   if (NULL != n->primary_address.address)
 861   {
 862     backup_primary = GNUNET_HELLO_address_copy (n->primary_address.address);
 863   }
 864   else
 865     backup_primary = NULL;
 866
 867   /* free addresses and mark as unused */
 868   free_address (&n->primary_address);
 869   free_address (&n->alternative_address);
 870
 871   /* FIXME: Note that if we are switching between two TCP sessions to
 872      the same peer, we might want to selectively kill only one of
 873      them! Killing all sessions like this seems to be very, very
 874      wrong. */
 875
 876   /* cut transport-level connection */
 877   if ((GNUNET_NO == keep_sessions) &&
 878       (NULL != backup_primary) &&
 879       (NULL != (papi = GST_plugins_find (backup_primary->transport_name))))
 880     papi->disconnect_peer (papi->cls, &n->id);
 881
 882   GNUNET_free_non_null (backup_primary);
 883
 884   GNUNET_assert (GNUNET_YES ==
 885                  GNUNET_CONTAINER_multipeermap_remove (neighbours,
 886                                                        &n->id, n));
 887
 888   // FIXME-ATS-API: we might want to be more specific about
 889   // which states we do this from in the future (ATS should
 890   // have given us a 'suggest_address' handle, and if we have
 891   // such a handle, we should cancel the operation here!
 892   if (NULL != n->suggest_handle)
 893   {
 894     GNUNET_ATS_suggest_address_cancel (GST_ats, &n->id);
 895     n->suggest_handle = NULL;
 896   }
 897
 898   if (GNUNET_SCHEDULER_NO_TASK != n->task)
 899   {
 900     GNUNET_SCHEDULER_cancel (n->task);
 901     n->task = GNUNET_SCHEDULER_NO_TASK;
 902   }
 903   /* free rest of memory */
 904   GNUNET_free (n);
 905 }
 906
 907
 908 /**
 909  * Transmit a message using the current session of the given
 910  * neighbour.
 911  *
 912  * @param n entry for the recipient
 913  * @param msgbuf buffer to transmit
 914  * @param msgbuf_size number of bytes in @a msgbuf buffer
 915  * @param priority transmission priority
 916  * @param timeout transmission timeout
 917  * @param use_keepalive_timeout #GNUNET_YES to use plugin-specific keep-alive
 918  *        timeout (@a timeout is ignored in that case), #GNUNET_NO otherwise
 919  * @param cont continuation to call when finished (can be NULL)
 920  * @param cont_cls closure for @a cont
 921  * @return timeout (copy of @a timeout or a calculated one if
 922  *         @a use_keepalive_timeout is #GNUNET_YES.
 923  */
 924 static struct GNUNET_TIME_Relative
 925 send_with_session (struct NeighbourMapEntry *n,
 926                    const char *msgbuf, size_t msgbuf_size,
 927                    uint32_t priority,
 928                    struct GNUNET_TIME_Relative timeout,
 929                    unsigned int use_keepalive_timeout,
 930                    GNUNET_TRANSPORT_TransmitContinuation cont,
 931                    void *cont_cls)
 932 {
 933   struct GNUNET_TRANSPORT_PluginFunctions *papi;
 934   struct GNUNET_TIME_Relative result = GNUNET_TIME_UNIT_FOREVER_REL;
 935
 936   GNUNET_assert (n->primary_address.session != NULL);
 937   if ( ((NULL == (papi = GST_plugins_find (n->primary_address.address->transport_name)) ||
 938          (-1 == papi->send (papi->cls,
 939                             n->primary_address.session,
 940                             msgbuf, msgbuf_size,
 941                             priority,
 942                             (result = (GNUNET_NO == use_keepalive_timeout) ? timeout :
 943                                 GNUNET_TIME_relative_divide (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT,
 944                                                              papi->query_keepalive_factor (papi->cls))),
 945                             cont, cont_cls)))) &&
 946        (NULL != cont))
 947     cont (cont_cls, &n->id, GNUNET_SYSERR, msgbuf_size, 0);
 948   GST_neighbours_notify_data_sent (&n->id,
 949       n->primary_address.address, n->primary_address.session, msgbuf_size);
 950   GNUNET_break (NULL != papi);
 951   return result;
 952 }
 953
 954
 955 /**
 956  * Master task run for every neighbour.  Performs all of the time-related
 957  * activities (keep alive, send next message, disconnect if idle, finish
 958  * clean up after disconnect).
 959  *
 960  * @param cls the `struct NeighbourMapEntry` for which we are running
 961  * @param tc scheduler context (unused)
 962  */
 963 static void
 964 master_task (void *cls,
 965              const struct GNUNET_SCHEDULER_TaskContext *tc);
 966
 967
 968 /**
 969  * Function called when the 'DISCONNECT' message has been sent by the
 970  * plugin.  Frees the neighbour --- if the entry still exists.
 971  *
 972  * @param cls NULL
 973  * @param target identity of the neighbour that was disconnected
 974  * @param result #GNUNET_OK if the disconnect got out successfully
 975  * @param payload bytes payload
 976  * @param physical bytes physical
 977  */
 978 static void
 979 send_disconnect_cont (void *cls, const struct GNUNET_PeerIdentity *target,
 980                       int result, size_t payload, size_t physical)
 981 {
 982   struct NeighbourMapEntry *n;
 983
 984   n = lookup_neighbour (target);
 985   if (NULL == n)
 986     return; /* already gone */
 987   if (GNUNET_TRANSPORT_PS_DISCONNECT != n->state)
 988     return; /* have created a fresh entry since */
 989   if (GNUNET_SCHEDULER_NO_TASK != n->task)
 990     GNUNET_SCHEDULER_cancel (n->task);
 991   n->task = GNUNET_SCHEDULER_add_now (&master_task, n);
 992 }
 993
 994
 995 /**
 996  * Transmit a DISCONNECT message to the other peer.
 997  *
 998  * @param n neighbour to send DISCONNECT message.
 999  */
1000 static void
1001 send_disconnect (struct NeighbourMapEntry *n)
1002 {
1003   struct SessionDisconnectMessage disconnect_msg;
1004
1005   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1006               "Sending DISCONNECT message to peer `%4s'\n",
1007               GNUNET_i2s (&n->id));
1008   disconnect_msg.header.size = htons (sizeof (struct SessionDisconnectMessage));
1009   disconnect_msg.header.type =
1010       htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_DISCONNECT);
1011   disconnect_msg.reserved = htonl (0);
1012   disconnect_msg.purpose.size =
1013       htonl (sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
1014              sizeof (struct GNUNET_CRYPTO_EddsaPublicKey) +
1015              sizeof (struct GNUNET_TIME_AbsoluteNBO));
1016   disconnect_msg.purpose.purpose =
1017       htonl (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_DISCONNECT);
1018   disconnect_msg.timestamp =
1019       GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get ());
1020   disconnect_msg.public_key = GST_my_identity.public_key;
1021   GNUNET_assert (GNUNET_OK ==
1022                  GNUNET_CRYPTO_eddsa_sign (GST_my_private_key,
1023                                          &disconnect_msg.purpose,
1024                                          &disconnect_msg.signature));
1025
1026   (void) send_with_session (n,
1027                             (const char *) &disconnect_msg, sizeof (disconnect_msg),
1028                             UINT32_MAX, GNUNET_TIME_UNIT_FOREVER_REL,
1029                             GNUNET_NO, &send_disconnect_cont, NULL);
1030   GNUNET_STATISTICS_update (GST_stats,
1031                             gettext_noop
1032                             ("# DISCONNECT messages sent"), 1,
1033                             GNUNET_NO);
1034 }
1035
1036
1037 /**
1038  * Disconnect from the given neighbour, clean up the record.
1039  *
1040  * @param n neighbour to disconnect from
1041  */
1042 static void
1043 disconnect_neighbour (struct NeighbourMapEntry *n)
1044 {
1045   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1046               "Disconnecting from peer %s in state %s\n",
1047               GNUNET_i2s (&n->id),
1048               GNUNET_TRANSPORT_ps2s (n->state));
1049   /* depending on state, notify neighbour and/or upper layers of this peer
1050      about disconnect */
1051   switch (n->state)
1052   {
1053   case GNUNET_TRANSPORT_PS_NOT_CONNECTED:
1054   case GNUNET_TRANSPORT_PS_INIT_ATS:
1055   case GNUNET_TRANSPORT_PS_INIT_BLACKLIST:
1056     /* other peer is completely unaware of us, no need to send DISCONNECT */
1057     set_state (n, GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED);
1058     free_neighbour (n, GNUNET_NO);
1059     return;
1060   case GNUNET_TRANSPORT_PS_CONNECT_SENT:
1061     send_disconnect (n);
1062     set_state (n, GNUNET_TRANSPORT_PS_DISCONNECT);
1063     break;
1064   case GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST_INBOUND:
1065   case GNUNET_TRANSPORT_PS_CONNECT_RECV_ATS:
1066   case GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST:
1067     /* we never ACK'ed the other peer's request, no need to send DISCONNECT */
1068     set_state (n, GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED);
1069     free_neighbour (n, GNUNET_NO);
1070     return;
1071   case GNUNET_TRANSPORT_PS_CONNECT_RECV_ACK:
1072     /* we DID ACK the other peer's request, must send DISCONNECT */
1073     send_disconnect (n);
1074     set_state (n, GNUNET_TRANSPORT_PS_DISCONNECT);
1075     break;
1076   case GNUNET_TRANSPORT_PS_CONNECTED:
1077   case GNUNET_TRANSPORT_PS_RECONNECT_BLACKLIST:
1078   case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
1079   case GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_BLACKLIST:
1080   case GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_CONNECT_SENT:
1081     /* we are currently connected, need to send disconnect and do
1082        internal notifications and update statistics */
1083     send_disconnect (n);
1084     GNUNET_STATISTICS_set (GST_stats,
1085                            gettext_noop ("# peers connected"),
1086                            --neighbours_connected,
1087                            GNUNET_NO);
1088     disconnect_notify_cb (callback_cls, &n->id);
1089     set_state (n, GNUNET_TRANSPORT_PS_DISCONNECT);
1090     break;
1091   case GNUNET_TRANSPORT_PS_RECONNECT_ATS:
1092     /* ATS address request timeout, disconnect without sending disconnect message */
1093     GNUNET_STATISTICS_set (GST_stats,
1094                            gettext_noop ("# peers connected"),
1095                            --neighbours_connected,
1096                            GNUNET_NO);
1097     disconnect_notify_cb (callback_cls, &n->id);
1098     set_state (n, GNUNET_TRANSPORT_PS_DISCONNECT);
1099     break;
1100   case GNUNET_TRANSPORT_PS_DISCONNECT:
1101     /* already disconnected, ignore */
1102     break;
1103   case GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED:
1104     /* already cleaned up, how did we get here!? */
1105     GNUNET_assert (0);
1106     break;
1107   default:
1108     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1109                 "Unhandled state `%s'\n",
1110                 GNUNET_TRANSPORT_ps2s (n->state));
1111     GNUNET_break (0);
1112     break;
1113   }
1114   /* schedule timeout to clean up */
1115   if (GNUNET_SCHEDULER_NO_TASK != n->task)
1116     GNUNET_SCHEDULER_cancel (n->task);
1117   n->task = GNUNET_SCHEDULER_add_delayed (DISCONNECT_SENT_TIMEOUT,
1118                                           &master_task, n);
1119 }
1120
1121
1122 /**
1123  * We're done with our transmission attempt, continue processing.
1124  *
1125  * @param cls the `struct MessageQueue` of the message
1126  * @param receiver intended receiver
1127  * @param success whether it worked or not
1128  * @param size_payload bytes payload sent
1129  * @param physical bytes sent on wire
1130  */
1131 static void
1132 transmit_send_continuation (void *cls,
1133                             const struct GNUNET_PeerIdentity *receiver,
1134                             int success, size_t size_payload, size_t physical)
1135 {
1136   struct MessageQueue *mq = cls;
1137   struct NeighbourMapEntry *n;
1138
1139   if (NULL == (n = lookup_neighbour (receiver)))
1140   {
1141     GNUNET_free (mq);
1142     return; /* disconnect or other error while transmitting, can happen */
1143   }
1144   if (n->is_active == mq)
1145   {
1146     /* this is still "our" neighbour, remove us from its queue
1147        and allow it to send the next message now */
1148     n->is_active = NULL;
1149     if (GNUNET_SCHEDULER_NO_TASK != n->task)
1150       GNUNET_SCHEDULER_cancel (n->task);
1151     n->task = GNUNET_SCHEDULER_add_now (&master_task, n);
1152   }
1153   if (bytes_in_send_queue < mq->message_buf_size)
1154   {
1155     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1156                 "Bytes_in_send_queue `%u', Message_size %u, result: %s, payload %u, on wire %u\n",
1157                 bytes_in_send_queue, mq->message_buf_size,
1158                 (GNUNET_OK == success) ? "OK" : "FAIL",
1159                 size_payload, physical);
1160     GNUNET_break (0);
1161   }
1162
1163
1164   GNUNET_break (size_payload == mq->message_buf_size);
1165   bytes_in_send_queue -= mq->message_buf_size;
1166   GNUNET_STATISTICS_set (GST_stats,
1167                         gettext_noop
1168                          ("# bytes in message queue for other peers"),
1169                          bytes_in_send_queue, GNUNET_NO);
1170   if (GNUNET_OK == success)
1171     GNUNET_STATISTICS_update (GST_stats,
1172                               gettext_noop
1173                               ("# messages transmitted to other peers"),
1174                               1, GNUNET_NO);
1175   else
1176     GNUNET_STATISTICS_update (GST_stats,
1177                               gettext_noop
1178                               ("# transmission failures for messages to other peers"),
1179                               1, GNUNET_NO);
1180   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1181               "Sending message to `%s' of type %u was a %s\n",
1182               GNUNET_i2s (receiver),
1183               ntohs (((struct GNUNET_MessageHeader *) mq->message_buf)->type),
1184               (success == GNUNET_OK) ? "success" : "FAILURE");
1185   if (NULL != mq->cont)
1186     mq->cont (mq->cont_cls, success, size_payload, physical);
1187   GNUNET_free (mq);
1188 }
1189
1190
1191 /**
1192  * Check the message list for the given neighbour and if we can
1193  * send a message, do so.  This function should only be called
1194  * if the connection is at least generally ready for transmission.
1195  * While we will only send one message at a time, no bandwidth
1196  * quota management is performed here.  If a message was given to
1197  * the plugin, the continuation will automatically re-schedule
1198  * the 'master' task once the next message might be transmitted.
1199  *
1200  * @param n target peer for which to transmit
1201  */
1202 static void
1203 try_transmission_to_peer (struct NeighbourMapEntry *n)
1204 {
1205   struct MessageQueue *mq;
1206   struct GNUNET_TIME_Relative timeout;
1207
1208   if (NULL == n->primary_address.address)
1209   {
1210     /* no address, why are we here? */
1211     GNUNET_break (0);
1212     return;
1213   }
1214   if ((0 == n->primary_address.address->address_length) &&
1215       (NULL == n->primary_address.session))
1216   {
1217     /* no address, why are we here? */
1218     GNUNET_break (0);
1219     return;
1220   }
1221   if (NULL != n->is_active)
1222   {
1223     /* transmission already pending */
1224     return;
1225   }
1226
1227   /* timeout messages from the queue that are past their due date */
1228   while (NULL != (mq = n->messages_head))
1229   {
1230     timeout = GNUNET_TIME_absolute_get_remaining (mq->timeout);
1231     if (timeout.rel_value_us > 0)
1232       break;
1233     GNUNET_STATISTICS_update (GST_stats,
1234                               gettext_noop
1235                               ("# messages timed out while in transport queue"),
1236                               1, GNUNET_NO);
1237     GNUNET_CONTAINER_DLL_remove (n->messages_head, n->messages_tail, mq);
1238     n->is_active = mq;
1239     transmit_send_continuation (mq, &n->id,
1240                                 GNUNET_SYSERR,
1241                                 mq->message_buf_size, 0);     /* timeout */
1242   }
1243   if (NULL == mq)
1244     return;                     /* no more messages */
1245   GNUNET_CONTAINER_DLL_remove (n->messages_head, n->messages_tail, mq);
1246   n->is_active = mq;
1247   (void) send_with_session (n,
1248                             mq->message_buf, mq->message_buf_size,
1249                             0 /* priority */, timeout, GNUNET_NO,
1250                             &transmit_send_continuation, mq);
1251 }
1252
1253
1254 /**
1255  * Send keepalive message to the neighbour.  Must only be called
1256  * if we are on 'connected' state or while trying to switch addresses.
1257  * Will internally determine if a keepalive is truly needed (so can
1258  * always be called).
1259  *
1260  * @param n neighbour that went idle and needs a keepalive
1261  */
1262 static void
1263 send_keepalive (struct NeighbourMapEntry *n)
1264 {
1265   struct SessionKeepAliveMessage m;
1266   struct GNUNET_TIME_Relative timeout;
1267   uint32_t nonce;
1268
1269   GNUNET_assert ((GNUNET_TRANSPORT_PS_CONNECTED == n->state) ||
1270                  (GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_BLACKLIST == n->state) ||
1271                  (GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_CONNECT_SENT));
1272   if (GNUNET_TIME_absolute_get_remaining (n->keep_alive_time).rel_value_us > 0)
1273     return; /* no keepalive needed at this time */
1274
1275   nonce = 0; /* 0 indicates 'not set' */
1276   while (0 == nonce)
1277     nonce = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1278
1279   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1280       "Sending keep alive to peer `%s' with nonce %u\n",
1281       GNUNET_i2s (&n->id), nonce);
1282
1283   m.header.size = htons (sizeof (struct SessionKeepAliveMessage));
1284   m.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_KEEPALIVE);
1285   m.nonce = htonl (nonce);
1286
1287   timeout = send_with_session (n,
1288                                (const void *) &m, sizeof (m),
1289                                UINT32_MAX /* priority */,
1290                                GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_YES,
1291                                NULL, NULL);
1292   GNUNET_STATISTICS_update (GST_stats, gettext_noop ("# keepalives sent"), 1,
1293                             GNUNET_NO);
1294   n->primary_address.keep_alive_nonce = nonce;
1295   n->expect_latency_response = GNUNET_YES;
1296   n->last_keep_alive_time = GNUNET_TIME_absolute_get ();
1297   n->keep_alive_time = GNUNET_TIME_relative_to_absolute (timeout);
1298
1299 }
1300
1301
1302 /**
1303  * Keep the connection to the given neighbour alive longer,
1304  * we received a KEEPALIVE (or equivalent); send a response.
1305  *
1306  * @param neighbour neighbour to keep alive (by sending keep alive response)
1307  * @param m the keep alive message containing the nonce to respond to
1308  */
1309 void
1310 GST_neighbours_keepalive (const struct GNUNET_PeerIdentity *neighbour,
1311     const struct GNUNET_MessageHeader *m)
1312 {
1313   struct NeighbourMapEntry *n;
1314   const struct SessionKeepAliveMessage *msg_in;
1315   struct SessionKeepAliveMessage msg;
1316
1317   if (sizeof (struct SessionKeepAliveMessage) != ntohs (m->size))
1318     return;
1319
1320   msg_in = (struct SessionKeepAliveMessage *) m;
1321   if (NULL == (n = lookup_neighbour (neighbour)))
1322   {
1323     GNUNET_STATISTICS_update (GST_stats,
1324                               gettext_noop
1325                               ("# KEEPALIVE messages discarded (peer unknown)"),
1326                               1, GNUNET_NO);
1327     return;
1328   }
1329   if (NULL == n->primary_address.session)
1330   {
1331     GNUNET_STATISTICS_update (GST_stats,
1332                               gettext_noop
1333                               ("# KEEPALIVE messages discarded (no session)"),
1334                               1, GNUNET_NO);
1335     return;
1336   }
1337
1338   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1339       "Received keep alive request from peer `%s' with nonce %u\n",
1340       GNUNET_i2s (&n->id), ntohl (msg_in->nonce));
1341
1342   /* send reply to allow neighbour to measure latency */
1343   msg.header.size = htons (sizeof (struct SessionKeepAliveMessage));
1344   msg.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_KEEPALIVE_RESPONSE);
1345   msg.nonce = msg_in->nonce;
1346   (void) send_with_session(n,
1347                            (const void *) &msg, sizeof (struct SessionKeepAliveMessage),
1348                            UINT32_MAX /* priority */,
1349                            GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_YES,
1350                            NULL, NULL);
1351 }
1352
1353
1354 /**
1355  * We received a KEEP_ALIVE_RESPONSE message and use this to calculate
1356  * latency to this peer.  Pass the updated information (existing ats
1357  * plus calculated latency) to ATS.
1358  *
1359  * @param neighbour neighbour to keep alive
1360  * @param m the message containing the keep alive response
1361  */
1362 void
1363 GST_neighbours_keepalive_response (const struct GNUNET_PeerIdentity *neighbour,
1364     const struct GNUNET_MessageHeader *m)
1365 {
1366   struct NeighbourMapEntry *n;
1367   const struct SessionKeepAliveMessage *msg;
1368   struct GNUNET_TRANSPORT_PluginFunctions *papi;
1369   uint32_t latency;
1370   struct GNUNET_ATS_Information ats;
1371
1372   if (sizeof (struct SessionKeepAliveMessage) != ntohs (m->size))
1373     return;
1374
1375   msg = (const struct SessionKeepAliveMessage *) m;
1376   if (NULL == (n = lookup_neighbour (neighbour)))
1377   {
1378     GNUNET_STATISTICS_update (GST_stats,
1379                               gettext_noop
1380                               ("# KEEPALIVE_RESPONSE messages discarded (not connected)"),
1381                               1, GNUNET_NO);
1382     return;
1383   }
1384   if ( (GNUNET_TRANSPORT_PS_CONNECTED != n->state) ||
1385        (GNUNET_YES != n->expect_latency_response) )
1386   {
1387     GNUNET_STATISTICS_update (GST_stats,
1388                               gettext_noop
1389                               ("# KEEPALIVE_RESPONSE messages discarded (not expected)"),
1390                               1, GNUNET_NO);
1391     return;
1392   }
1393   if (NULL == n->primary_address.address)
1394   {
1395     GNUNET_STATISTICS_update (GST_stats,
1396                               gettext_noop
1397                               ("# KEEPALIVE_RESPONSE messages discarded (address changed)"),
1398                               1, GNUNET_NO);
1399     return;
1400   }
1401   if (n->primary_address.keep_alive_nonce != ntohl (msg->nonce))
1402   {
1403     GNUNET_STATISTICS_update (GST_stats,
1404                               gettext_noop
1405                               ("# KEEPALIVE_RESPONSE messages discarded (wrong nonce)"),
1406                               1, GNUNET_NO);
1407     return;
1408   }
1409   else
1410   {
1411     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1412         "Received keep alive response from peer `%s' for session %p\n",
1413         GNUNET_i2s (&n->id), n->primary_address.session);
1414
1415   }
1416
1417   /* Update session timeout here */
1418   if (NULL != (papi = GST_plugins_find (n->primary_address.address->transport_name)))
1419   {
1420     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1421         "Updating session for peer `%s' for session %p\n",
1422         GNUNET_i2s (&n->id), n->primary_address.session);
1423     papi->update_session_timeout (papi->cls, &n->id, n->primary_address.session);
1424   }
1425   else
1426   {
1427     GNUNET_break (0);
1428   }
1429
1430   n->primary_address.keep_alive_nonce = 0;
1431   n->expect_latency_response = GNUNET_NO;
1432   n->latency = GNUNET_TIME_absolute_get_duration (n->last_keep_alive_time);
1433   set_timeout (n, GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT));
1434
1435   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1436               "Latency for peer `%s' is %s\n",
1437               GNUNET_i2s (&n->id),
1438               GNUNET_STRINGS_relative_time_to_string (n->latency,
1439                                                       GNUNET_YES));
1440   /* append latency */
1441   ats.type = htonl (GNUNET_ATS_QUALITY_NET_DELAY);
1442   if (n->latency.rel_value_us > UINT32_MAX)
1443     latency = UINT32_MAX;
1444   else
1445     latency = n->latency.rel_value_us;
1446   ats.value = htonl (latency);
1447   GST_ats_update_metrics (&n->id, n->primary_address.address,
1448       n->primary_address.session, &ats, 1);
1449 }
1450
1451
1452 /**
1453  * We have received a message from the given sender.  How long should
1454  * we delay before receiving more?  (Also used to keep the peer marked
1455  * as live).
1456  *
1457  * @param sender sender of the message
1458  * @param size size of the message
1459  * @param do_forward set to #GNUNET_YES if the message should be forwarded to clients
1460  *                   #GNUNET_NO if the neighbour is not connected or violates the quota,
1461  *                   #GNUNET_SYSERR if the connection is not fully up yet
1462  * @return how long to wait before reading more from this sender
1463  */
1464 struct GNUNET_TIME_Relative
1465 GST_neighbours_calculate_receive_delay (const struct GNUNET_PeerIdentity
1466                                         *sender, ssize_t size, int *do_forward)
1467 {
1468   struct NeighbourMapEntry *n;
1469   struct GNUNET_TIME_Relative ret;
1470
1471   if (NULL == neighbours)
1472   {
1473     *do_forward = GNUNET_NO;
1474     return GNUNET_TIME_UNIT_FOREVER_REL; /* This can happen during shutdown */
1475   }
1476   if (NULL == (n = lookup_neighbour (sender)))
1477   {
1478     GST_neighbours_try_connect (sender);
1479     if (NULL == (n = lookup_neighbour (sender)))
1480     {
1481       GNUNET_STATISTICS_update (GST_stats,
1482                                 gettext_noop
1483                                 ("# messages discarded due to lack of neighbour record"),
1484                                 1, GNUNET_NO);
1485       *do_forward = GNUNET_NO;
1486       return GNUNET_TIME_UNIT_ZERO;
1487     }
1488   }
1489   if (! test_connected (n))
1490   {
1491     *do_forward = GNUNET_SYSERR;
1492     return GNUNET_TIME_UNIT_ZERO;
1493   }
1494   if (GNUNET_YES == GNUNET_BANDWIDTH_tracker_consume (&n->in_tracker, size))
1495   {
1496     n->quota_violation_count++;
1497     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1498                 "Bandwidth quota (%u b/s) violation detected (total of %u).\n",
1499                 n->in_tracker.available_bytes_per_s__,
1500                 n->quota_violation_count);
1501     /* Discount 32k per violation */
1502     GNUNET_BANDWIDTH_tracker_consume (&n->in_tracker, -32 * 1024);
1503   }
1504   else
1505   {
1506     if (n->quota_violation_count > 0)
1507     {
1508       /* try to add 32k back */
1509       GNUNET_BANDWIDTH_tracker_consume (&n->in_tracker, 32 * 1024);
1510       n->quota_violation_count--;
1511     }
1512   }
1513   if (n->quota_violation_count > QUOTA_VIOLATION_DROP_THRESHOLD)
1514   {
1515     GNUNET_STATISTICS_update (GST_stats,
1516                               gettext_noop
1517                               ("# bandwidth quota violations by other peers"),
1518                               1, GNUNET_NO);
1519     *do_forward = GNUNET_NO;
1520     return GNUNET_CONSTANTS_QUOTA_VIOLATION_TIMEOUT;
1521   }
1522   *do_forward = GNUNET_YES;
1523   ret = GNUNET_BANDWIDTH_tracker_get_delay (&n->in_tracker, 32 * 1024);
1524   if (ret.rel_value_us > 0)
1525   {
1526     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1527                 "Throttling read (%llu bytes excess at %u b/s), waiting %s before reading more.\n",
1528                 (unsigned long long) n->in_tracker.
1529                 consumption_since_last_update__,
1530                 (unsigned int) n->in_tracker.available_bytes_per_s__,
1531                 GNUNET_STRINGS_relative_time_to_string (ret, GNUNET_YES));
1532     GNUNET_STATISTICS_update (GST_stats,
1533                               gettext_noop ("# ms throttling suggested"),
1534                               (int64_t) ret.rel_value_us / 1000LL,
1535                               GNUNET_NO);
1536   }
1537   return ret;
1538 }
1539
1540
1541 /**
1542  * Transmit a message to the given target using the active connection.
1543  *
1544  * @param target destination
1545  * @param msg message to send
1546  * @param msg_size number of bytes in msg
1547  * @param timeout when to fail with timeout
1548  * @param cont function to call when done
1549  * @param cont_cls closure for 'cont'
1550  */
1551 void
1552 GST_neighbours_send (const struct GNUNET_PeerIdentity *target, const void *msg,
1553                      size_t msg_size, struct GNUNET_TIME_Relative timeout,
1554                      GST_NeighbourSendContinuation cont, void *cont_cls)
1555 {
1556   struct NeighbourMapEntry *n;
1557   struct MessageQueue *mq;
1558
1559   /* All ove these cases should never happen; they are all API violations.
1560      But we check anyway, just to be sure. */
1561   if (NULL == (n = lookup_neighbour (target)))
1562   {
1563     GNUNET_break (0);
1564     if (NULL != cont)
1565       cont (cont_cls, GNUNET_SYSERR, msg_size, 0);
1566     return;
1567   }
1568   if (GNUNET_YES != test_connected (n))
1569   {
1570     GNUNET_break (0);
1571     if (NULL != cont)
1572       cont (cont_cls, GNUNET_SYSERR, msg_size, 0);
1573     return;
1574   }
1575   bytes_in_send_queue += msg_size;
1576   GNUNET_STATISTICS_set (GST_stats,
1577                          gettext_noop
1578                          ("# bytes in message queue for other peers"),
1579                          bytes_in_send_queue, GNUNET_NO);
1580   mq = GNUNET_malloc (sizeof (struct MessageQueue) + msg_size);
1581   mq->cont = cont;
1582   mq->cont_cls = cont_cls;
1583   memcpy (&mq[1], msg, msg_size);
1584   mq->message_buf = (const char *) &mq[1];
1585   mq->message_buf_size = msg_size;
1586   mq->timeout = GNUNET_TIME_relative_to_absolute (timeout);
1587   GNUNET_CONTAINER_DLL_insert_tail (n->messages_head, n->messages_tail, mq);
1588   if ( (NULL != n->is_active) ||
1589        ( (NULL == n->primary_address.session) && (NULL == n->primary_address.address)) )
1590     return;
1591   if (GNUNET_SCHEDULER_NO_TASK != n->task)
1592     GNUNET_SCHEDULER_cancel (n->task);
1593   n->task = GNUNET_SCHEDULER_add_now (&master_task, n);
1594 }
1595
1596
1597 /**
1598  * Send a SESSION_CONNECT message via the given address.
1599  *
1600  * @param na address to use
1601  */
1602 static void
1603 send_session_connect (struct NeighbourAddress *na)
1604 {
1605   struct GNUNET_TRANSPORT_PluginFunctions *papi;
1606   struct SessionConnectMessage connect_msg;
1607
1608   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1609               "Sending SESSION_CONNECT message to peer %s\n",
1610               GNUNET_i2s (&na->address->peer));
1611   if (NULL == (papi = GST_plugins_find (na->address->transport_name)))
1612   {
1613     GNUNET_break (0);
1614     return;
1615   }
1616   if (NULL == na->session)
1617     na->session = papi->get_session (papi->cls, na->address);
1618   if (NULL == na->session)
1619   {
1620     GNUNET_break (0);
1621     return;
1622   }
1623   GNUNET_STATISTICS_update (GST_stats,
1624                             gettext_noop
1625                             ("# SESSION_CONNECT messages sent"),
1626                             1, GNUNET_NO);
1627   na->connect_timestamp = GNUNET_TIME_absolute_get ();
1628   connect_msg.header.size = htons (sizeof (struct SessionConnectMessage));
1629   connect_msg.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_CONNECT);
1630   connect_msg.reserved = htonl (0);
1631   connect_msg.timestamp = GNUNET_TIME_absolute_hton (na->connect_timestamp);
1632   if (-1 ==
1633       papi->send (papi->cls,
1634                   na->session,
1635                   (const char *) &connect_msg, sizeof (struct SessionConnectMessage),
1636                   UINT_MAX,
1637                   GNUNET_TIME_UNIT_FOREVER_REL,
1638                   NULL, NULL))
1639   {
1640     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1641                 _("Failed to transmit CONNECT message via plugin to %s\n"),
1642                 GST_plugins_a2s (na->address));
1643   }
1644   GST_neighbours_notify_data_sent (&na->address->peer,
1645                                    na->address,
1646                                    na->session,
1647                                    sizeof (struct SessionConnectMessage));
1648
1649 }
1650
1651
1652 /**
1653  * Send a SESSION_CONNECT_ACK message via the given address.
1654  *
1655  * @param address address to use
1656  * @param session session to use
1657  * @param timestamp timestamp to use for the ACK message
1658  */
1659 static void
1660 send_session_connect_ack_message (const struct GNUNET_HELLO_Address *address,
1661                                   struct Session *session,
1662                                   struct GNUNET_TIME_Absolute timestamp)
1663 {
1664   struct GNUNET_TRANSPORT_PluginFunctions *papi;
1665   struct SessionConnectMessage connect_msg;
1666
1667   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1668               "Sending CONNECT_ACK to peer `%s'\n",
1669               GNUNET_i2s (&address->peer));
1670   if (NULL == (papi = GST_plugins_find (address->transport_name)))
1671   {
1672     GNUNET_break (0);
1673     return;
1674   }
1675   if (NULL == session)
1676     session = papi->get_session (papi->cls, address);
1677   if (NULL == session)
1678   {
1679     GNUNET_break (0);
1680     return;
1681   }
1682   GNUNET_STATISTICS_update (GST_stats,
1683                             gettext_noop
1684                             ("# CONNECT_ACK messages sent"),
1685                             1, GNUNET_NO);
1686   connect_msg.header.size = htons (sizeof (struct SessionConnectMessage));
1687   connect_msg.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_CONNECT_ACK);
1688   connect_msg.reserved = htonl (0);
1689   connect_msg.timestamp = GNUNET_TIME_absolute_hton (timestamp);
1690   (void) papi->send (papi->cls,
1691                      session,
1692                      (const char *) &connect_msg, sizeof (struct SessionConnectMessage),
1693                      UINT_MAX,
1694                      GNUNET_TIME_UNIT_FOREVER_REL,
1695                      NULL, NULL);
1696
1697 }
1698
1699 struct QuotaNotificationRequest
1700 {
1701   struct GNUNET_PeerIdentity peer;
1702   struct Session *session;
1703   char *plugin;
1704 };
1705
1706 struct QNR_LookContext
1707 {
1708   struct GNUNET_PeerIdentity peer;
1709   struct Session *session;
1710   const char *plugin;
1711
1712   struct QuotaNotificationRequest *res;
1713 };
1714
1715 static int
1716 find_notification_request (void *cls, const struct GNUNET_PeerIdentity *key, void *value)
1717 {
1718   struct QNR_LookContext *qnr_ctx = cls;
1719   struct QuotaNotificationRequest *qnr = value;
1720
1721   if ((qnr->session == qnr_ctx->session) &&
1722       (0 == memcmp (&qnr->peer, &qnr_ctx->peer, sizeof (struct GNUNET_PeerIdentity))) &&
1723       (0 == strcmp(qnr_ctx->plugin, qnr->plugin)))
1724   {
1725     qnr_ctx->res = value;
1726     return GNUNET_NO;
1727   }
1728   return GNUNET_YES;
1729 }
1730
1731 void
1732 GST_neighbours_register_quota_notification(void *cls,
1733     const struct GNUNET_PeerIdentity *peer, const char *plugin,
1734     struct Session *session)
1735 {
1736   struct QuotaNotificationRequest *qnr;
1737   struct QNR_LookContext qnr_ctx;
1738
1739   if (NULL == registered_quota_notifications)
1740   {
1741     return; /* init or shutdown */
1742   }
1743
1744   qnr_ctx.peer = (*peer);
1745   qnr_ctx.plugin = plugin;
1746   qnr_ctx.session = session;
1747   qnr_ctx.res = NULL;
1748
1749   GNUNET_CONTAINER_multipeermap_get_multiple (registered_quota_notifications,
1750       peer, &find_notification_request, &qnr_ctx);
1751   if (NULL != qnr_ctx.res)
1752   {
1753     GNUNET_break(0);
1754     return;
1755   }
1756
1757   qnr = GNUNET_new (struct QuotaNotificationRequest);
1758   qnr->peer =  (*peer);
1759   qnr->plugin = GNUNET_strdup (plugin);
1760   qnr->session = session;
1761
1762   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1763       "Adding notification for peer `%s' plugin `%s' session %p \n",
1764       GNUNET_i2s (peer), plugin, session);
1765
1766   GNUNET_CONTAINER_multipeermap_put (registered_quota_notifications, peer,
1767       qnr, GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
1768 }
1769
1770
1771 void
1772 GST_neighbours_unregister_quota_notification(void *cls,
1773     const struct GNUNET_PeerIdentity *peer, const char *plugin, struct Session *session)
1774 {
1775   struct QNR_LookContext qnr_ctx;
1776
1777   if (NULL == registered_quota_notifications)
1778   {
1779     return; /* init or shutdown */
1780   }
1781
1782   qnr_ctx.peer = (*peer);
1783   qnr_ctx.plugin = plugin;
1784   qnr_ctx.session = session;
1785   qnr_ctx.res = NULL;
1786
1787   GNUNET_CONTAINER_multipeermap_iterate (registered_quota_notifications,
1788       &find_notification_request, &qnr_ctx);
1789   if (NULL == qnr_ctx.res)
1790   {
1791     GNUNET_break(0);
1792     return;
1793   }
1794
1795   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1796       "Removing notification for peer `%s' plugin `%s' session %p \n",
1797       GNUNET_i2s (peer), plugin, session);
1798
1799   GNUNET_CONTAINER_multipeermap_remove (registered_quota_notifications, peer,
1800       qnr_ctx.res);
1801   GNUNET_free (qnr_ctx.res->plugin);
1802   GNUNET_free (qnr_ctx.res);
1803 }
1804
1805 static int
1806 notification_cb(void *cls, const struct GNUNET_PeerIdentity *key, void *value)
1807 {
1808   /* struct NeighbourMapEntry *n = cls; */
1809   struct QuotaNotificationRequest *qnr = value;
1810   struct GNUNET_TRANSPORT_PluginFunctions *papi;
1811   struct GNUNET_TIME_Relative delay;
1812   int do_forward;
1813
1814   papi = GST_plugins_find(qnr->plugin);
1815   if (NULL == papi)
1816   {
1817     GNUNET_break (0);
1818     return GNUNET_OK;
1819   }
1820
1821   delay = GST_neighbours_calculate_receive_delay (key, 0, &do_forward);
1822   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1823       "New inbound delay for peer `%s' is %llu ms\n", GNUNET_i2s (key),
1824       delay.rel_value_us / 1000);
1825
1826   if (NULL != papi->update_inbound_delay)
1827     papi->update_inbound_delay (papi->cls, key, qnr->session, delay);
1828   return GNUNET_OK;
1829 }
1830
1831 static
1832 int
1833 free_notification_cb(void *cls, const struct GNUNET_PeerIdentity *key,
1834     void *value)
1835 {
1836   /* struct NeighbourMapEntry *n = cls; */
1837   struct QuotaNotificationRequest *qnr = value;
1838
1839   GNUNET_CONTAINER_multipeermap_remove (registered_quota_notifications, key,
1840       qnr);
1841   GNUNET_free(qnr->plugin);
1842   GNUNET_free(qnr);
1843
1844   return GNUNET_OK;
1845 }
1846
1847 static void
1848 inbound_bw_tracker_update(void *cls)
1849 {
1850   struct NeighbourMapEntry *n = cls;
1851
1852   /* Quota was updated, tell plugins to update the time to receive next */
1853   GNUNET_CONTAINER_multipeermap_get_multiple (registered_quota_notifications,
1854       &n->id, &notification_cb, n);
1855 }
1856
1857
1858 /**
1859  * Create a fresh entry in the neighbour map for the given peer
1860  *
1861  * @param peer peer to create an entry for
1862  * @return new neighbour map entry
1863  */
1864 static struct NeighbourMapEntry *
1865 setup_neighbour (const struct GNUNET_PeerIdentity *peer)
1866 {
1867   struct NeighbourMapEntry *n;
1868
1869   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1870               "Creating new neighbour entry for `%s'\n",
1871               GNUNET_i2s (peer));
1872   n = GNUNET_new (struct NeighbourMapEntry);
1873   n->id = *peer;
1874   n->latency = GNUNET_TIME_UNIT_FOREVER_REL;
1875   n->last_util_transmission = GNUNET_TIME_absolute_get();
1876   n->util_payload_bytes_recv = 0;
1877   n->util_payload_bytes_sent = 0;
1878   n->util_total_bytes_recv = 0;
1879   n->util_total_bytes_sent = 0;
1880   GNUNET_BANDWIDTH_tracker_init (&n->in_tracker, &inbound_bw_tracker_update, n,
1881                                  GNUNET_CONSTANTS_DEFAULT_BW_IN_OUT,
1882                                  MAX_BANDWIDTH_CARRY_S);
1883   n->task = GNUNET_SCHEDULER_add_now (&master_task, n);
1884   set_state_and_timeout (n, GNUNET_TRANSPORT_PS_NOT_CONNECTED, GNUNET_TIME_UNIT_FOREVER_ABS);
1885   GNUNET_assert (GNUNET_OK ==
1886                  GNUNET_CONTAINER_multipeermap_put (neighbours,
1887                                                     &n->id, n,
1888                                                     GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
1889   return n;
1890 }
1891
1892
1893 /**
1894  * Check if the two given addresses are the same.
1895  * Actually only checks if the sessions are non-NULL
1896  * (which they should be) and then if they are identical;
1897  * the actual addresses don't matter if the session
1898  * pointers match anyway, and we must have session pointers
1899  * at this time.
1900  *
1901  * @param a1 first address to compare
1902  * @param a2 other address to compare
1903  * @return #GNUNET_NO if the addresses do not match, #GNUNET_YES if they do match
1904  */
1905 static int
1906 address_matches (const struct NeighbourAddress *a1,
1907                  const struct NeighbourAddress *a2)
1908 {
1909   if ( (NULL == a1->session) ||
1910        (NULL == a2->session) )
1911   {
1912     GNUNET_break (0);
1913     return 0;
1914   }
1915   return (a1->session == a2->session) ? GNUNET_YES : GNUNET_NO;
1916 }
1917
1918
1919 /* We received a address suggestion after requesting an address in
1920  * try_connect or after receiving a connect, switch to address
1921  */
1922 static void
1923 address_suggest_cont (void *cls,
1924     const struct GNUNET_PeerIdentity *peer,
1925     const struct GNUNET_HELLO_Address *address, struct Session *session,
1926     struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out,
1927     struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in,
1928     const struct GNUNET_ATS_Information *ats, uint32_t ats_count)
1929 {
1930   GST_neighbours_switch_to_address(peer, address, session, ats, ats_count,
1931       bandwidth_in, bandwidth_out);
1932 }
1933
1934
1935 struct BlacklistCheckSwitchContext
1936 {
1937   struct BlacklistCheckSwitchContext *prev;
1938   struct BlacklistCheckSwitchContext *next;
1939
1940
1941   struct GST_BlacklistCheck *blc;
1942
1943   struct GNUNET_HELLO_Address *address;
1944   struct Session *session;
1945   struct GNUNET_ATS_Information *ats;
1946   uint32_t ats_count;
1947
1948   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in;
1949   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out;
1950 };
1951
1952 /**
1953  * Black list check result for try_connect call
1954  * If connection to the peer is allowed request adddress and
1955  *
1956  * @param cls blc_ctx bl context
1957  * @param peer the peer
1958  * @param result the result
1959  */
1960 static void
1961 try_connect_bl_check_cont (void *cls,
1962     const struct GNUNET_PeerIdentity *peer, int result)
1963 {
1964   struct BlacklistCheckSwitchContext *blc_ctx = cls;
1965   struct NeighbourMapEntry *n;
1966
1967   GNUNET_CONTAINER_DLL_remove (pending_bc_head, pending_bc_tail, blc_ctx);
1968   GNUNET_free (blc_ctx);
1969
1970   if (GNUNET_OK != result)
1971   {
1972     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1973         _("Blacklisting disapproved to connect to peer `%s'\n"),
1974         GNUNET_i2s (peer));
1975     return;
1976   }
1977   n = setup_neighbour (peer);
1978   set_state_and_timeout (n, GNUNET_TRANSPORT_PS_INIT_ATS,
1979       GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
1980
1981   GNUNET_ATS_reset_backoff (GST_ats, peer);
1982   n->suggest_handle = GNUNET_ATS_suggest_address (GST_ats, peer,
1983       &address_suggest_cont, n);
1984 }
1985
1986
1987
1988 /**
1989  * Try to create a connection to the given target (eventually).
1990  *
1991  * @param target peer to try to connect to
1992  */
1993 void
1994 GST_neighbours_try_connect (const struct GNUNET_PeerIdentity *target)
1995 {
1996   struct NeighbourMapEntry *n;
1997   struct GST_BlacklistCheck *blc;
1998   struct BlacklistCheckSwitchContext *blc_ctx;
1999
2000   if (NULL == neighbours)
2001   {
2002     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2003                 "Asked to connect to peer `%s' during shutdown\n",
2004                 GNUNET_i2s (target));
2005     return; /* during shutdown, do nothing */
2006   }
2007   n = lookup_neighbour (target);
2008   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2009               "Asked to connect to peer `%s' (state: %s)\n",
2010               GNUNET_i2s (target),
2011               (NULL != n) ? GNUNET_TRANSPORT_ps2s(n->state) : "NEW PEER");
2012   if (NULL != n)
2013   {
2014     switch (n->state)
2015     {
2016     case GNUNET_TRANSPORT_PS_NOT_CONNECTED:
2017       /* this should not be possible */
2018       GNUNET_break (0);
2019       free_neighbour (n, GNUNET_NO);
2020       break;
2021     case GNUNET_TRANSPORT_PS_INIT_ATS:
2022     case GNUNET_TRANSPORT_PS_INIT_BLACKLIST:
2023     case GNUNET_TRANSPORT_PS_CONNECT_SENT:
2024     case GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST_INBOUND:
2025     case GNUNET_TRANSPORT_PS_CONNECT_RECV_ATS:
2026     case GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST:
2027     case GNUNET_TRANSPORT_PS_CONNECT_RECV_ACK:
2028       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2029                   "Ignoring request to try to connect to `%s', already trying!\n",
2030                   GNUNET_i2s (target));
2031       return; /* already trying */
2032     case GNUNET_TRANSPORT_PS_CONNECTED:
2033     case GNUNET_TRANSPORT_PS_RECONNECT_ATS:
2034     case GNUNET_TRANSPORT_PS_RECONNECT_BLACKLIST:
2035     case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
2036     case GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_BLACKLIST:
2037     case GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_CONNECT_SENT:
2038       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2039                   "Ignoring request to try to connect, already connected to `%s'!\n",
2040                   GNUNET_i2s (target));
2041       return; /* already connected */
2042     case GNUNET_TRANSPORT_PS_DISCONNECT:
2043       /* get rid of remains, ready to re-try immediately */
2044       free_neighbour (n, GNUNET_NO);
2045       break;
2046     case GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED:
2047       /* should not be possible */
2048       GNUNET_assert (0);
2049     default:
2050       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2051                   "Unhandled state `%s'\n",
2052                   GNUNET_TRANSPORT_ps2s (n->state));
2053       GNUNET_break (0);
2054       free_neighbour (n, GNUNET_NO);
2055       break;
2056     }
2057   }
2058
2059   /* Do blacklist check if connecting to this peer is allowed */
2060   blc_ctx = GNUNET_new (struct BlacklistCheckSwitchContext);
2061   GNUNET_CONTAINER_DLL_insert (pending_bc_head, pending_bc_tail, blc_ctx);
2062
2063   if (NULL != (blc = GST_blacklist_test_allowed (target, NULL,
2064         &try_connect_bl_check_cont, blc_ctx)))
2065   {
2066     blc_ctx->blc = blc;
2067   }
2068 }
2069
2070
2071 /**
2072  * Function called with the result of a blacklist check.
2073  *
2074  * @param cls closure with the `struct BlackListCheckContext`
2075  * @param peer peer this check affects
2076  * @param result #GNUNET_OK if the address is allowed
2077  */
2078 static void
2079 handle_test_blacklist_cont (void *cls,
2080                             const struct GNUNET_PeerIdentity *peer,
2081                             int result)
2082 {
2083   struct BlackListCheckContext *bcc = cls;
2084   struct NeighbourMapEntry *n;
2085
2086   bcc->bc = NULL;
2087   GNUNET_CONTAINER_DLL_remove (bc_head,
2088                                bc_tail,
2089                                bcc);
2090   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2091               "Connection to new address of peer `%s' based on blacklist is `%s'\n",
2092               GNUNET_i2s (peer),
2093               (GNUNET_OK == result) ? "allowed" : "FORBIDDEN");
2094   if (GNUNET_OK == result)
2095   {
2096     GST_ats_add_address (bcc->na.address, bcc->na.session, NULL, 0);
2097   }
2098   else
2099   {
2100     /* Blacklist disagreed on connecting to a peer with this address
2101      * Destroy address because we are not allowed to use it
2102      */
2103     if (NULL != bcc->na.session)
2104       GNUNET_ATS_address_destroyed (GST_ats, bcc->na.address, bcc->na.session);
2105     GNUNET_ATS_address_destroyed (GST_ats, bcc->na.address, NULL);
2106   }
2107   if (NULL == (n = lookup_neighbour (peer)))
2108   {
2109     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2110                 "No neighbor entry for peer `%s', ignoring blacklist result\n",
2111                 GNUNET_i2s (peer));
2112     goto cleanup; /* nobody left to care about new address */
2113   }
2114   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2115               "Received blacklist result for peer `%s' in state %s/%d\n",
2116               GNUNET_i2s (peer),
2117               GNUNET_TRANSPORT_ps2s (n->state),
2118               n->send_connect_ack);
2119   switch (n->state)
2120   {
2121   case GNUNET_TRANSPORT_PS_NOT_CONNECTED:
2122     /* this should not be possible */
2123     GNUNET_break (0);
2124     free_neighbour (n, GNUNET_NO);
2125     break;
2126   case GNUNET_TRANSPORT_PS_INIT_ATS:
2127     /* waiting on ATS suggestion; still, pass address to ATS as a
2128        possibility */
2129     break;
2130   case GNUNET_TRANSPORT_PS_INIT_BLACKLIST:
2131     /* check if the address the blacklist was fine with matches
2132        ATS suggestion, if so, we can move on! */
2133     if ( (GNUNET_OK == result) &&
2134          (1 == n->send_connect_ack) )
2135     {
2136       n->send_connect_ack = 2;
2137       send_session_connect_ack_message (bcc->na.address,
2138                                         bcc->na.session,
2139                                         n->connect_ack_timestamp);
2140     }
2141     if (GNUNET_YES != address_matches (&bcc->na, &n->primary_address))
2142     {
2143       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2144                   "Blacklist result for peer %s is for non-primary address, ignored\n",
2145                   GNUNET_i2s (peer));
2146       break; /* result for an address we currently don't care about */
2147     }
2148     if (GNUNET_OK == result)
2149     {
2150       set_state_and_timeout (n, GNUNET_TRANSPORT_PS_CONNECT_SENT,
2151           GNUNET_TIME_relative_to_absolute (SETUP_CONNECTION_TIMEOUT));
2152       send_session_connect (&n->primary_address);
2153     }
2154     else
2155     {
2156       free_address (&n->primary_address);
2157       set_state_and_timeout (n, GNUNET_TRANSPORT_PS_INIT_ATS,
2158           GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
2159     }
2160     break;
2161   case GNUNET_TRANSPORT_PS_CONNECT_SENT:
2162     /* waiting on CONNECT_ACK, send ACK if one is pending */
2163     if ( (GNUNET_OK == result) &&
2164          (1 == n->send_connect_ack) )
2165     {
2166       n->send_connect_ack = 2;
2167       send_session_connect_ack_message (n->primary_address.address,
2168                                         n->primary_address.session,
2169                                         n->connect_ack_timestamp);
2170     }
2171     break;
2172   case GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST_INBOUND:
2173     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_CONNECT_RECV_ATS,
2174         GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
2175     GNUNET_ATS_reset_backoff (GST_ats, peer);
2176     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2177                 "Suggesting address for peer %s to ATS\n",
2178                 GNUNET_i2s (peer));
2179     n->suggest_handle = GNUNET_ATS_suggest_address (GST_ats, peer,
2180         &address_suggest_cont, n);
2181     break;
2182   case GNUNET_TRANSPORT_PS_CONNECT_RECV_ATS:
2183     /* waiting on ATS suggestion, don't care about blacklist */
2184     break;
2185   case GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST:
2186     if (GNUNET_YES != address_matches (&bcc->na, &n->primary_address))
2187     {
2188       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2189                   "Blacklist result ignored, as it is not for our primary address\n");
2190       break; /* result for an address we currently don't care about */
2191     }
2192     if (GNUNET_OK == result)
2193     {
2194       set_state_and_timeout (n, GNUNET_TRANSPORT_PS_CONNECT_RECV_ACK,
2195           GNUNET_TIME_relative_to_absolute (SETUP_CONNECTION_TIMEOUT));
2196       send_session_connect_ack_message (bcc->na.address,
2197                                         bcc->na.session,
2198                                         n->connect_ack_timestamp);
2199       if (1 == n->send_connect_ack)
2200         n->send_connect_ack = 2;
2201     }
2202     else
2203     {
2204       struct GNUNET_TRANSPORT_PluginFunctions *plugin;
2205
2206       plugin = GST_plugins_find (bcc->na.address->transport_name);
2207       if ( (NULL != plugin) &&
2208            (NULL != bcc->na.session) )
2209       {
2210         plugin->disconnect_session (plugin->cls,
2211                                     bcc->na.session);
2212         break;
2213       }
2214       GNUNET_break (NULL != plugin);
2215       free_address (&n->primary_address);
2216       set_state_and_timeout (n, GNUNET_TRANSPORT_PS_INIT_ATS,
2217           GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
2218       GNUNET_ATS_reset_backoff (GST_ats, peer);
2219     }
2220     break;
2221   case GNUNET_TRANSPORT_PS_CONNECT_RECV_ACK:
2222     /* waiting on SESSION_ACK, send ACK if one is pending */
2223     if ( (GNUNET_OK == result) &&
2224          (1 == n->send_connect_ack) )
2225     {
2226       n->send_connect_ack = 2;
2227       send_session_connect_ack_message (n->primary_address.address,
2228                                         n->primary_address.session,
2229                                         n->connect_ack_timestamp);
2230     }
2231     break;
2232   case GNUNET_TRANSPORT_PS_CONNECTED:
2233     /* already connected, don't care about blacklist */
2234     break;
2235   case GNUNET_TRANSPORT_PS_RECONNECT_ATS:
2236     /* still waiting on ATS suggestion, don't care about blacklist */
2237     break;
2238   case GNUNET_TRANSPORT_PS_RECONNECT_BLACKLIST:
2239     if ( (GNUNET_OK == result) &&
2240          (1 == n->send_connect_ack) )
2241     {
2242       n->send_connect_ack = 2;
2243       send_session_connect_ack_message (bcc->na.address,
2244                                         bcc->na.session,
2245                                         n->connect_ack_timestamp);
2246     }
2247     if (GNUNET_YES != address_matches (&bcc->na, &n->primary_address))
2248     {
2249       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2250                   "Blacklist result ignored, as it is not for our primary address\n");
2251       break; /* result for an address we currently don't care about */
2252     }
2253     if (GNUNET_OK == result)
2254     {
2255       set_state_and_timeout (n, GNUNET_TRANSPORT_PS_RECONNECT_SENT, GNUNET_TIME_relative_to_absolute (FAST_RECONNECT_TIMEOUT));
2256       send_session_connect (&n->primary_address);
2257     }
2258     else
2259     {
2260       set_state_and_timeout (n, GNUNET_TRANSPORT_PS_RECONNECT_ATS, GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
2261     }
2262     break;
2263   case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
2264     /* waiting on CONNECT_ACK, don't care about blacklist */
2265     if ( (GNUNET_OK == result) &&
2266          (1 == n->send_connect_ack) )
2267     {
2268       n->send_connect_ack = 2;
2269       send_session_connect_ack_message (n->primary_address.address,
2270                                         n->primary_address.session,
2271                                         n->connect_ack_timestamp);
2272     }
2273     break;
2274   case GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_BLACKLIST:
2275     if (GNUNET_YES != address_matches (&bcc->na, &n->alternative_address))
2276     {
2277       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2278                   "Blacklist result ignored, as it is not for our primary address\n");
2279       break; /* result for an address we currently don't care about */
2280     }
2281     if (GNUNET_OK == result)
2282     {
2283       send_session_connect (&n->alternative_address);
2284       set_state (n, GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_CONNECT_SENT);
2285     }
2286     else
2287     {
2288       set_state(n, GNUNET_TRANSPORT_PS_CONNECTED);
2289       free_address (&n->alternative_address);
2290     }
2291     break;
2292   case GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_CONNECT_SENT:
2293     /* waiting on CONNECT_ACK, don't care about blacklist */
2294     if ( (GNUNET_OK == result) &&
2295          (1 == n->send_connect_ack) )
2296     {
2297       n->send_connect_ack = 2;
2298       send_session_connect_ack_message (n->primary_address.address,
2299                                         n->primary_address.session,
2300                                         n->connect_ack_timestamp);
2301     }
2302     break;
2303   case GNUNET_TRANSPORT_PS_DISCONNECT:
2304     /* Nothing to do here, ATS will already do what can be done */
2305     break;
2306   case GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED:
2307     /* should not be possible */
2308     GNUNET_assert (0);
2309     break;
2310   default:
2311     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2312                 "Unhandled state `%s'\n",
2313                 GNUNET_TRANSPORT_ps2s (n->state));
2314     GNUNET_break (0);
2315     free_neighbour (n, GNUNET_NO);
2316     break;
2317   }
2318  cleanup:
2319   GNUNET_HELLO_address_free (bcc->na.address);
2320   GNUNET_free (bcc);
2321 }
2322
2323
2324 /**
2325  * We want to know if connecting to a particular peer via
2326  * a particular address is allowed.  Check it!
2327  *
2328  * @param peer identity of the peer to switch the address for
2329  * @param ts time at which the check was initiated
2330  * @param address address of the other peer, NULL if other peer
2331  *                       connected to us
2332  * @param session session to use (or NULL)
2333  */
2334 static void
2335 check_blacklist (const struct GNUNET_PeerIdentity *peer,
2336                  struct GNUNET_TIME_Absolute ts,
2337                  const struct GNUNET_HELLO_Address *address,
2338                  struct Session *session)
2339 {
2340   struct BlackListCheckContext *bcc;
2341   struct GST_BlacklistCheck *bc;
2342
2343   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2344               "Checking peer `%s' against blacklist\n",
2345               GNUNET_i2s (peer));
2346   bcc = GNUNET_new (struct BlackListCheckContext);
2347   bcc->na.address = GNUNET_HELLO_address_copy (address);
2348   bcc->na.session = session;
2349   bcc->na.connect_timestamp = ts;
2350   GNUNET_CONTAINER_DLL_insert (bc_head,
2351                                bc_tail,
2352                                bcc);
2353   if (NULL != (bc = GST_blacklist_test_allowed (peer,
2354                                                 address->transport_name,
2355                                                 &handle_test_blacklist_cont, bcc)))
2356     bcc->bc = bc;
2357   /* if NULL == bc, 'cont' was already called and 'bcc' already free'd, so
2358      we must only store 'bc' if 'bc' is non-NULL... */
2359 }
2360
2361
2362 /**
2363  * We received a 'SESSION_CONNECT' message from the other peer.
2364  * Consider switching to it.
2365  *
2366  * @param message possibly a 'struct SessionConnectMessage' (check format)
2367  * @param peer identity of the peer to switch the address for
2368  * @param address address of the other peer, NULL if other peer
2369  *                       connected to us
2370  * @param session session to use (or NULL)
2371  * @return #GNUNET_OK if the message was fine, #GNUNET_SYSERR on serious error
2372  */
2373 int
2374 GST_neighbours_handle_connect (const struct GNUNET_MessageHeader *message,
2375                                const struct GNUNET_PeerIdentity *peer,
2376                                const struct GNUNET_HELLO_Address *address,
2377                                struct Session *session)
2378 {
2379   const struct SessionConnectMessage *scm;
2380   struct NeighbourMapEntry *n;
2381   struct GNUNET_TIME_Absolute ts;
2382
2383   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2384               "Received CONNECT message from peer `%s'\n",
2385               GNUNET_i2s (peer));
2386   if (ntohs (message->size) != sizeof (struct SessionConnectMessage))
2387   {
2388     GNUNET_break_op (0);
2389     return GNUNET_SYSERR;
2390   }
2391   GNUNET_STATISTICS_update (GST_stats,
2392                             gettext_noop
2393                             ("# CONNECT messages received"),
2394                             1, GNUNET_NO);
2395   if (NULL == neighbours)
2396   {
2397     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2398                 _("CONNECT request from peer `%s' ignored due impending shutdown\n"),
2399                 GNUNET_i2s (peer));
2400     return GNUNET_OK; /* we're shutting down */
2401   }
2402   scm = (const struct SessionConnectMessage *) message;
2403   GNUNET_break_op (0 == ntohl (scm->reserved));
2404   ts = GNUNET_TIME_absolute_ntoh (scm->timestamp);
2405   n = lookup_neighbour (peer);
2406   if (NULL == n)
2407     n = setup_neighbour (peer);
2408   n->send_connect_ack = 1;
2409   n->connect_ack_timestamp = ts;
2410
2411   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2412               "Received SESSION_CONNECT for peer `%s' in state %s/%d\n",
2413               GNUNET_i2s (peer),
2414               GNUNET_TRANSPORT_ps2s (n->state),
2415               n->send_connect_ack);
2416   switch (n->state)
2417   {
2418   case GNUNET_TRANSPORT_PS_NOT_CONNECTED:
2419     /* Do a blacklist check for the new address */
2420     set_state (n, GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST_INBOUND);
2421     check_blacklist (peer, ts, address, session);
2422     break;
2423   case GNUNET_TRANSPORT_PS_INIT_ATS:
2424     /* CONNECT message takes priority over us asking ATS for address */
2425     set_state (n, GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST_INBOUND);
2426     /* fallthrough */
2427   case GNUNET_TRANSPORT_PS_INIT_BLACKLIST:
2428   case GNUNET_TRANSPORT_PS_CONNECT_SENT:
2429   case GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST_INBOUND:
2430   case GNUNET_TRANSPORT_PS_CONNECT_RECV_ATS:
2431   case GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST:
2432   case GNUNET_TRANSPORT_PS_CONNECT_RECV_ACK:
2433     /* It can never hurt to have an alternative address in the above cases,
2434        see if it is allowed */
2435     check_blacklist (peer, ts, address, session);
2436     break;
2437   case GNUNET_TRANSPORT_PS_CONNECTED:
2438     /* we are already connected and can thus send the ACK immediately;
2439        still, it can never hurt to have an alternative address, so also
2440        tell ATS  about it */
2441     GNUNET_assert (NULL != n->primary_address.address);
2442     GNUNET_assert (NULL != n->primary_address.session);
2443     n->send_connect_ack = 0;
2444     send_session_connect_ack_message (n->primary_address.address,
2445                                       n->primary_address.session, ts);
2446     check_blacklist (peer, ts, address, session);
2447     break;
2448   case GNUNET_TRANSPORT_PS_RECONNECT_ATS:
2449   case GNUNET_TRANSPORT_PS_RECONNECT_BLACKLIST:
2450   case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
2451     /* It can never hurt to have an alternative address in the above cases,
2452        see if it is allowed */
2453     check_blacklist (peer, ts, address, session);
2454     break;
2455   case GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_BLACKLIST:
2456   case GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_CONNECT_SENT:
2457     /* we are already connected and can thus send the ACK immediately;
2458        still, it can never hurt to have an alternative address, so also
2459        tell ATS  about it */
2460     GNUNET_assert (NULL != n->primary_address.address);
2461     GNUNET_assert (NULL != n->primary_address.session);
2462     n->send_connect_ack = 0;
2463     send_session_connect_ack_message (n->primary_address.address,
2464                                       n->primary_address.session, ts);
2465     check_blacklist (peer, ts, address, session);
2466     break;
2467   case GNUNET_TRANSPORT_PS_DISCONNECT:
2468     /* get rid of remains without terminating sessions, ready to re-try */
2469     free_neighbour (n, GNUNET_YES);
2470     n = setup_neighbour (peer);
2471     set_state (n, GNUNET_TRANSPORT_PS_CONNECT_RECV_ATS);
2472     GNUNET_ATS_reset_backoff (GST_ats, peer);
2473     break;
2474   case GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED:
2475     /* should not be possible */
2476     GNUNET_assert (0);
2477     break;
2478   default:
2479     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2480                 "Unhandled state `%s'\n",
2481                 GNUNET_TRANSPORT_ps2s (n->state));
2482     GNUNET_break (0);
2483     return GNUNET_SYSERR;
2484   }
2485   return GNUNET_OK;
2486 }
2487
2488 static void
2489 switch_address_bl_check_cont (void *cls,
2490     const struct GNUNET_PeerIdentity *peer, int result)
2491 {
2492   struct BlacklistCheckSwitchContext *blc_ctx = cls;
2493   struct GNUNET_TRANSPORT_PluginFunctions *papi;
2494   struct NeighbourMapEntry *n;
2495
2496   if ( (NULL == (n = lookup_neighbour (peer))) || (result == GNUNET_NO) ||
2497        (NULL == (papi = GST_plugins_find (blc_ctx->address->transport_name))) )
2498   {
2499     if (NULL == n)
2500     {
2501       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2502                   "Peer %s is unknown, suggestion ignored\n",
2503                   GNUNET_i2s (peer));
2504     }
2505     if (result == GNUNET_NO)
2506     {
2507       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2508           "Blacklist denied to switch to suggested address `%s' session %p for peer `%s'\n",
2509           GST_plugins_a2s (blc_ctx->address),
2510           blc_ctx->session,
2511           GNUNET_i2s (&blc_ctx->address->peer));
2512     }
2513     /* Delete address (or session if existing) in ATS */
2514     GNUNET_ATS_address_destroyed (GST_ats, blc_ctx->address, blc_ctx->session);
2515
2516     GNUNET_CONTAINER_DLL_remove (pending_bc_head, pending_bc_tail, blc_ctx);
2517     GNUNET_HELLO_address_free(blc_ctx->address);
2518     GNUNET_free_non_null (blc_ctx->ats);
2519     GNUNET_free (blc_ctx);
2520     return;
2521   }
2522
2523   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2524       "Blacklist accepted to switch to suggested address `%s' session %p for peer `%s'\n",
2525       GST_plugins_a2s (blc_ctx->address),
2526       blc_ctx->session,
2527       GNUNET_i2s (&blc_ctx->address->peer));
2528
2529   if (NULL == blc_ctx->session)
2530   {
2531     blc_ctx->session = papi->get_session (papi->cls, blc_ctx->address);
2532     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2533                 "Obtained new session for peer `%s' and  address '%s': %p\n",
2534                 GNUNET_i2s (&blc_ctx->address->peer), GST_plugins_a2s (blc_ctx->address), blc_ctx->session);
2535   }
2536   if (NULL == blc_ctx->session)
2537   {
2538     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2539                 "Failed to obtain new session for peer `%s' and  address '%s'\n",
2540                 GNUNET_i2s (&blc_ctx->address->peer),
2541                 GST_plugins_a2s (blc_ctx->address));
2542     GNUNET_ATS_address_destroyed (GST_ats, blc_ctx->address, NULL);
2543     return;
2544   }
2545   switch (n->state)
2546   {
2547   case GNUNET_TRANSPORT_PS_NOT_CONNECTED:
2548     GNUNET_break (0);
2549     free_neighbour (n, GNUNET_NO);
2550     return;
2551   case GNUNET_TRANSPORT_PS_INIT_ATS:
2552     set_primary_address (n, blc_ctx->address, blc_ctx->session,
2553         blc_ctx->bandwidth_in, blc_ctx->bandwidth_out, GNUNET_NO);
2554     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_INIT_BLACKLIST,
2555         GNUNET_TIME_relative_to_absolute (BLACKLIST_RESPONSE_TIMEOUT));
2556     check_blacklist (&n->id, n->connect_ack_timestamp,
2557                      blc_ctx->address, blc_ctx->session);
2558     break;
2559   case GNUNET_TRANSPORT_PS_INIT_BLACKLIST:
2560     /* ATS suggests a different address, switch again */
2561     set_primary_address (n, blc_ctx->address, blc_ctx->session,
2562         blc_ctx->bandwidth_in, blc_ctx->bandwidth_out, GNUNET_NO);
2563     set_timeout (n, GNUNET_TIME_relative_to_absolute (BLACKLIST_RESPONSE_TIMEOUT));
2564     check_blacklist (&n->id, n->connect_ack_timestamp,
2565                      blc_ctx->address, blc_ctx->session);
2566     break;
2567   case GNUNET_TRANSPORT_PS_CONNECT_SENT:
2568     /* ATS suggests a different address, switch again */
2569     set_primary_address (n, blc_ctx->address, blc_ctx->session,
2570         blc_ctx->bandwidth_in, blc_ctx->bandwidth_out, GNUNET_NO);
2571     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_INIT_BLACKLIST,
2572         GNUNET_TIME_relative_to_absolute (BLACKLIST_RESPONSE_TIMEOUT));
2573     check_blacklist (&n->id, n->connect_ack_timestamp,
2574                      blc_ctx->address, blc_ctx->session);
2575     break;
2576   case GNUNET_TRANSPORT_PS_CONNECT_RECV_ATS:
2577     set_primary_address (n, blc_ctx->address, blc_ctx->session,
2578         blc_ctx->bandwidth_in, blc_ctx->bandwidth_out, GNUNET_NO);
2579     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST,
2580         GNUNET_TIME_relative_to_absolute (BLACKLIST_RESPONSE_TIMEOUT));
2581     check_blacklist (&n->id, n->connect_ack_timestamp,
2582         blc_ctx->address, blc_ctx->session);
2583     break;
2584   case GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST_INBOUND:
2585     set_timeout (n, GNUNET_TIME_relative_to_absolute (BLACKLIST_RESPONSE_TIMEOUT));
2586     check_blacklist (&n->id, n->connect_ack_timestamp,
2587         blc_ctx->address, blc_ctx->session);
2588     break;
2589   case GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST:
2590   case GNUNET_TRANSPORT_PS_CONNECT_RECV_ACK:
2591     /* ATS asks us to switch while we were trying to connect; switch to new
2592        address and check blacklist again */
2593     set_primary_address (n, blc_ctx->address, blc_ctx->session,
2594         blc_ctx->bandwidth_in, blc_ctx->bandwidth_out, GNUNET_NO);
2595     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST,
2596         GNUNET_TIME_relative_to_absolute (BLACKLIST_RESPONSE_TIMEOUT));
2597     check_blacklist (&n->id, n->connect_ack_timestamp,
2598         blc_ctx->address, blc_ctx->session);
2599     break;
2600   case GNUNET_TRANSPORT_PS_CONNECTED:
2601     GNUNET_assert (NULL != n->primary_address.address);
2602     GNUNET_assert (NULL != n->primary_address.session);
2603     if (n->primary_address.session == blc_ctx->session)
2604     {
2605       /* not an address change, just a quota change */
2606       set_primary_address (n, blc_ctx->address, blc_ctx->session,
2607           blc_ctx->bandwidth_in, blc_ctx->bandwidth_out, GNUNET_YES);
2608       break;
2609     }
2610     /* ATS asks us to switch a life connection; see if we can get
2611        a CONNECT_ACK on it before we actually do this! */
2612     set_state (n, GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_BLACKLIST);
2613     set_alternative_address (n, blc_ctx->address, blc_ctx->session,
2614         blc_ctx->bandwidth_in, blc_ctx->bandwidth_out);
2615     check_blacklist (&n->id, GNUNET_TIME_absolute_get (),
2616         blc_ctx->address, blc_ctx->session);
2617     break;
2618   case GNUNET_TRANSPORT_PS_RECONNECT_ATS:
2619     set_primary_address (n, blc_ctx->address, blc_ctx->session,
2620         blc_ctx->bandwidth_in, blc_ctx->bandwidth_out, GNUNET_NO);
2621     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_RECONNECT_BLACKLIST,
2622         GNUNET_TIME_relative_to_absolute (BLACKLIST_RESPONSE_TIMEOUT));
2623     check_blacklist (&n->id, n->connect_ack_timestamp,
2624         blc_ctx->address, blc_ctx->session);
2625     break;
2626   case GNUNET_TRANSPORT_PS_RECONNECT_BLACKLIST:
2627     /* ATS asks us to switch while we were trying to reconnect; switch to new
2628        address and check blacklist again */
2629     set_primary_address (n, blc_ctx->address, blc_ctx->session,
2630         blc_ctx->bandwidth_in, blc_ctx->bandwidth_out, GNUNET_NO);
2631     set_timeout (n, GNUNET_TIME_relative_to_absolute (BLACKLIST_RESPONSE_TIMEOUT));
2632     check_blacklist (&n->id, n->connect_ack_timestamp,
2633         blc_ctx->address, blc_ctx->session);
2634     break;
2635   case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
2636     /* ATS asks us to switch while we were trying to reconnect; switch to new
2637        address and check blacklist again */
2638     set_primary_address (n, blc_ctx->address, blc_ctx->session,
2639         blc_ctx->bandwidth_in, blc_ctx->bandwidth_out, GNUNET_NO);
2640     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_RECONNECT_BLACKLIST,
2641         GNUNET_TIME_relative_to_absolute (BLACKLIST_RESPONSE_TIMEOUT));
2642     check_blacklist (&n->id, n->connect_ack_timestamp,
2643         blc_ctx->address, blc_ctx->session);
2644     break;
2645   case GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_BLACKLIST:
2646     if (n->primary_address.session == blc_ctx->session)
2647     {
2648       /* ATS switches back to still-active session */
2649       set_state(n, GNUNET_TRANSPORT_PS_CONNECTED);
2650       free_address (&n->alternative_address);
2651       break;
2652     }
2653     /* ATS asks us to switch a life connection, update blacklist check */
2654     set_primary_address (n, blc_ctx->address, blc_ctx->session,
2655         blc_ctx->bandwidth_in, blc_ctx->bandwidth_out, GNUNET_NO);
2656     check_blacklist (&n->id, GNUNET_TIME_absolute_get (),
2657         blc_ctx->address, blc_ctx->session);
2658     break;
2659   case GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_CONNECT_SENT:
2660     if (n->primary_address.session == blc_ctx->session)
2661     {
2662       /* ATS switches back to still-active session */
2663       free_address (&n->alternative_address);
2664       set_state (n, GNUNET_TRANSPORT_PS_CONNECTED);
2665       break;
2666     }
2667     /* ATS asks us to switch a life connection, update blacklist check */
2668     set_state (n, GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_BLACKLIST);
2669     set_alternative_address (n, blc_ctx->address, blc_ctx->session,
2670         blc_ctx->bandwidth_in, blc_ctx->bandwidth_out);
2671     check_blacklist (&n->id, GNUNET_TIME_absolute_get (),
2672         blc_ctx->address, blc_ctx->session);
2673     break;
2674   case GNUNET_TRANSPORT_PS_DISCONNECT:
2675     /* not going to switch addresses while disconnecting */
2676     return;
2677   case GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED:
2678     GNUNET_assert (0);
2679     break;
2680   default:
2681     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2682                 "Unhandled state `%s'\n",
2683                 GNUNET_TRANSPORT_ps2s (n->state));
2684     GNUNET_break (0);
2685     break;
2686   }
2687
2688   GNUNET_CONTAINER_DLL_remove (pending_bc_head, pending_bc_tail, blc_ctx);
2689   GNUNET_HELLO_address_free(blc_ctx->address);
2690   GNUNET_free_non_null (blc_ctx->ats);
2691   GNUNET_free (blc_ctx);
2692   return;
2693 }
2694
2695
2696 /**
2697  * For the given peer, switch to this address.
2698  *
2699  * Before accepting this addresses and actively using it, a blacklist check
2700  * is performed. If this blacklist check fails the address will be destroyed.
2701  *
2702  * @param peer identity of the peer to switch the address for
2703  * @param address address of the other peer,
2704  * @param session session to use or NULL if transport should initiate a session
2705  * @param ats performance data
2706  * @param ats_count number of entries in ats
2707  * @param bandwidth_in inbound quota to be used when connection is up,
2708  *      0 to disconnect from peer
2709  * @param bandwidth_out outbound quota to be used when connection is up,
2710  *      0 to disconnect from peer
2711  */
2712 void
2713 GST_neighbours_switch_to_address (const struct GNUNET_PeerIdentity *peer,
2714                                   const struct GNUNET_HELLO_Address *address,
2715                                   struct Session *session,
2716                                   const struct GNUNET_ATS_Information *ats,
2717                                   uint32_t ats_count,
2718                                   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in,
2719                                   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out)
2720 {
2721   struct NeighbourMapEntry *n;
2722   struct GST_BlacklistCheck *blc;
2723   struct GNUNET_TRANSPORT_PluginFunctions *papi;
2724   struct BlacklistCheckSwitchContext *blc_ctx;
2725   int c;
2726
2727   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2728               "ATS has decided on an address for peer %s\n",
2729               GNUNET_i2s (peer));
2730   GNUNET_assert (NULL != address->transport_name);
2731   if (NULL == (n = lookup_neighbour (peer)))
2732   {
2733     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2734                 "Peer %s is unknown, suggestion ignored\n",
2735                 GNUNET_i2s (peer));
2736     return;
2737   }
2738
2739   /* Obtain an session for this address from plugin */
2740   if (NULL == (papi = GST_plugins_find (address->transport_name)))
2741   {
2742     /* we don't have the plugin for this address */
2743     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2744                 "Plugin `%s' is unknown, suggestion for peer %s ignored\n",
2745                 address->transport_name,
2746                 GNUNET_i2s (peer));
2747     GNUNET_ATS_address_destroyed (GST_ats, address, NULL);
2748     return;
2749   }
2750   if ((NULL == session) &&
2751       (GNUNET_HELLO_address_check_option (address, GNUNET_HELLO_ADDRESS_INFO_INBOUND)))
2752   {
2753     /* This is a inbound address and we do not have a session to use! */
2754     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2755                 "Inbound address without session `%s'! Destroying address...\n",
2756                 GST_plugins_a2s (address));
2757     GNUNET_ATS_address_destroyed (GST_ats, address, NULL);
2758     return;
2759   }
2760
2761   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2762     "ATS tells us to switch to %s address '%s' session %p for "
2763     "peer `%s' in state %s/%d (quota in/out %u %u )\n",
2764     GNUNET_HELLO_address_check_option (address,
2765         GNUNET_HELLO_ADDRESS_INFO_INBOUND) ? "inbound" : "",
2766     GST_plugins_a2s (address), session, GNUNET_i2s (peer),
2767     GNUNET_TRANSPORT_ps2s (n->state), n->send_connect_ack,
2768     ntohl (bandwidth_in.value__), ntohl (bandwidth_out.value__));
2769
2770   /* Perform blacklist check */
2771   blc_ctx = GNUNET_new (struct BlacklistCheckSwitchContext);
2772   blc_ctx->address = GNUNET_HELLO_address_copy (address);
2773   blc_ctx->session = session;
2774   blc_ctx->bandwidth_in = bandwidth_in;
2775   blc_ctx->bandwidth_out = bandwidth_out;
2776   blc_ctx->ats_count = ats_count;
2777   blc_ctx->ats = NULL;
2778   if (ats_count > 0)
2779   {
2780     blc_ctx->ats = GNUNET_malloc (ats_count * sizeof (struct GNUNET_ATS_Information));
2781     for (c = 0; c < ats_count; c++)
2782     {
2783       blc_ctx->ats[c].type = ats[c].type;
2784       blc_ctx->ats[c].value = ats[c].value;
2785     }
2786   }
2787
2788   GNUNET_CONTAINER_DLL_insert (pending_bc_head, pending_bc_tail, blc_ctx);
2789   if (NULL != (blc = GST_blacklist_test_allowed (peer, address->transport_name,
2790       &switch_address_bl_check_cont, blc_ctx)))
2791   {
2792     blc_ctx->blc = blc;
2793   }
2794 }
2795
2796
2797 static int
2798 send_utilization_data (void *cls,
2799                        const struct GNUNET_PeerIdentity *key,
2800                        void *value)
2801 {
2802   struct NeighbourMapEntry *n = value;
2803   struct GNUNET_ATS_Information atsi[4];
2804   uint32_t bps_pl_in;
2805   uint32_t bps_pl_out;
2806   uint32_t bps_in;
2807   uint32_t bps_out;
2808   struct GNUNET_TIME_Relative delta;
2809
2810   delta = GNUNET_TIME_absolute_get_difference (n->last_util_transmission,
2811                                                GNUNET_TIME_absolute_get ());
2812
2813   bps_pl_in = 0;
2814
2815   if ((0 != n->util_payload_bytes_recv) && (0 != delta.rel_value_us))
2816     bps_pl_in =  (1000LL * 1000LL *  n->util_payload_bytes_recv) / (delta.rel_value_us);
2817   bps_pl_out = 0;
2818   if ((0 != n->util_payload_bytes_sent) && (0 != delta.rel_value_us))
2819     bps_pl_out = (1000LL * 1000LL * n->util_payload_bytes_sent) / delta.rel_value_us;
2820   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2821               "`%s' payload: received %u Bytes/s, sent %u Bytes/s\n",
2822               GNUNET_i2s (key),
2823               bps_pl_in,
2824               bps_pl_out);
2825   bps_in = 0;
2826   if ((0 != n->util_total_bytes_recv) && (0 != delta.rel_value_us))
2827     bps_in =  (1000LL * 1000LL *  n->util_total_bytes_recv) / (delta.rel_value_us);
2828   bps_out = 0;
2829   if ((0 != n->util_total_bytes_sent) && (0 != delta.rel_value_us))
2830     bps_out = (1000LL * 1000LL * n->util_total_bytes_sent) / delta.rel_value_us;
2831
2832
2833   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2834               "`%s' total: received %u Bytes/s, sent %u Bytes/s\n",
2835               GNUNET_i2s (key),
2836               bps_in,
2837               bps_out);
2838   atsi[0].type = htonl (GNUNET_ATS_UTILIZATION_OUT);
2839   atsi[0].value = htonl (bps_out);
2840   atsi[1].type = htonl (GNUNET_ATS_UTILIZATION_IN);
2841   atsi[1].value = htonl (bps_in);
2842
2843   atsi[2].type = htonl (GNUNET_ATS_UTILIZATION_PAYLOAD_OUT);
2844   atsi[2].value = htonl (bps_pl_out);
2845   atsi[3].type = htonl (GNUNET_ATS_UTILIZATION_PAYLOAD_IN);
2846   atsi[3].value = htonl (bps_pl_in);
2847
2848   GST_ats_update_metrics (key, n->primary_address.address,
2849       n->primary_address.session, atsi, 4);
2850   n->util_payload_bytes_recv = 0;
2851   n->util_payload_bytes_sent = 0;
2852   n->util_total_bytes_recv = 0;
2853   n->util_total_bytes_sent = 0;
2854   n->last_util_transmission = GNUNET_TIME_absolute_get();
2855   return GNUNET_OK;
2856 }
2857
2858
2859 /**
2860  * Task transmitting utilization in a regular interval
2861  *
2862  * @param cls the 'struct NeighbourMapEntry' for which we are running
2863  * @param tc scheduler context (unused)
2864  */
2865 static void
2866 utilization_transmission (void *cls,
2867                           const struct GNUNET_SCHEDULER_TaskContext *tc)
2868 {
2869   util_transmission_tk = GNUNET_SCHEDULER_NO_TASK;
2870
2871   if (0 < GNUNET_CONTAINER_multipeermap_size (neighbours))
2872     GNUNET_CONTAINER_multipeermap_iterate (neighbours, send_utilization_data, NULL);
2873
2874   util_transmission_tk = GNUNET_SCHEDULER_add_delayed (UTIL_TRANSMISSION_INTERVAL,
2875       utilization_transmission, NULL);
2876
2877 }
2878
2879
2880 void
2881 GST_neighbours_notify_data_recv (const struct GNUNET_PeerIdentity *peer,
2882                                  const struct GNUNET_HELLO_Address *address,
2883                                  struct Session *session,
2884                                  const struct GNUNET_MessageHeader *message)
2885 {
2886   struct NeighbourMapEntry *n;
2887
2888   n = lookup_neighbour (peer);
2889   if (NULL == n)
2890     return;
2891   n->util_total_bytes_recv += ntohs(message->size);
2892 }
2893
2894
2895 void
2896 GST_neighbours_notify_payload_recv (const struct GNUNET_PeerIdentity *peer,
2897                                     const struct GNUNET_HELLO_Address *address,
2898                                     struct Session *session,
2899                                     const struct GNUNET_MessageHeader *message)
2900 {
2901   struct NeighbourMapEntry *n;
2902   n = lookup_neighbour (peer);
2903   if (NULL == n)
2904     return;
2905   n->util_payload_bytes_recv += ntohs(message->size);
2906 }
2907
2908
2909 void
2910 GST_neighbours_notify_data_sent (const struct GNUNET_PeerIdentity *peer,
2911                                  const struct GNUNET_HELLO_Address *address,
2912                                  struct Session *session,
2913                                  size_t size)
2914 {
2915   struct NeighbourMapEntry *n;
2916   n = lookup_neighbour (peer);
2917   if (NULL == n)
2918       return;
2919   if (n->primary_address.session != session)
2920     return;
2921   n->util_total_bytes_sent += size;
2922 }
2923
2924
2925 void
2926 GST_neighbours_notify_payload_sent (const struct GNUNET_PeerIdentity *peer,
2927                                     size_t size)
2928 {
2929   struct NeighbourMapEntry *n;
2930   n = lookup_neighbour (peer);
2931   if (NULL == n)
2932     return;
2933   n->util_payload_bytes_sent += size;
2934 }
2935
2936
2937 /**
2938  * Master task run for every neighbour.  Performs all of the time-related
2939  * activities (keep alive, send next message, disconnect if idle, finish
2940  * clean up after disconnect).
2941  *
2942  * @param cls the 'struct NeighbourMapEntry' for which we are running
2943  * @param tc scheduler context (unused)
2944  */
2945 static void
2946 master_task (void *cls,
2947              const struct GNUNET_SCHEDULER_TaskContext *tc)
2948 {
2949   struct NeighbourMapEntry *n = cls;
2950   struct GNUNET_TIME_Relative delay;
2951
2952   n->task = GNUNET_SCHEDULER_NO_TASK;
2953   delay = GNUNET_TIME_absolute_get_remaining (n->timeout);
2954   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2955               "Master task runs for neighbour `%s' in state %s with timeout in %s\n",
2956               GNUNET_i2s (&n->id),
2957               GNUNET_TRANSPORT_ps2s(n->state),
2958               GNUNET_STRINGS_relative_time_to_string (delay,
2959                                                       GNUNET_YES));
2960   switch (n->state)
2961   {
2962   case GNUNET_TRANSPORT_PS_NOT_CONNECTED:
2963     /* invalid state for master task, clean up */
2964     GNUNET_break (0);
2965     free_neighbour (n, GNUNET_NO);
2966     return;
2967   case GNUNET_TRANSPORT_PS_INIT_ATS:
2968     if (0 == delay.rel_value_us)
2969     {
2970       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2971                   "Connection to `%s' timed out waiting for ATS to provide address\n",
2972                   GNUNET_i2s (&n->id));
2973       free_neighbour (n, GNUNET_NO);
2974       return;
2975     }
2976     break;
2977   case GNUNET_TRANSPORT_PS_INIT_BLACKLIST:
2978     if (0 == delay.rel_value_us)
2979     {
2980       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2981                   "Connection to `%s' timed out waiting for BLACKLIST to approve address\n",
2982                   GNUNET_i2s (&n->id));
2983       free_neighbour (n, GNUNET_NO);
2984       return;
2985     }
2986     break;
2987   case GNUNET_TRANSPORT_PS_CONNECT_SENT:
2988     if (0 == delay.rel_value_us)
2989     {
2990       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2991                   "Connection to `%s' timed out waiting for other peer to send CONNECT_ACK\n",
2992                   GNUNET_i2s (&n->id));
2993       /* We could not send to this address, delete address and session */
2994       if (NULL != n->primary_address.session)
2995         GNUNET_ATS_address_destroyed (GST_ats,
2996             n->primary_address.address, n->primary_address.session);
2997       GNUNET_ATS_address_destroyed (GST_ats,
2998           n->primary_address.address, NULL);
2999       disconnect_neighbour (n);
3000       return;
3001     }
3002     break;
3003   case GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST_INBOUND:
3004     if (0 == delay.rel_value_us)
3005     {
3006       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3007                   "Connection to `%s' timed out waiting BLACKLIST to approve address to use for received CONNECT\n",
3008                   GNUNET_i2s (&n->id));
3009       free_neighbour (n, GNUNET_NO);
3010       return;
3011     }
3012     break;
3013   case GNUNET_TRANSPORT_PS_CONNECT_RECV_ATS:
3014     if (0 == delay.rel_value_us)
3015     {
3016       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3017                   "Connection to `%s' timed out waiting ATS to provide address to use for CONNECT_ACK\n",
3018                   GNUNET_i2s (&n->id));
3019       free_neighbour (n, GNUNET_NO);
3020       return;
3021     }
3022     break;
3023   case GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST:
3024     if (0 == delay.rel_value_us)
3025     {
3026       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3027                   "Connection to `%s' timed out waiting BLACKLIST to approve address to use for CONNECT_ACK\n",
3028                   GNUNET_i2s (&n->id));
3029       free_neighbour (n, GNUNET_NO);
3030       return;
3031     }
3032     break;
3033   case GNUNET_TRANSPORT_PS_CONNECT_RECV_ACK:
3034     if (0 == delay.rel_value_us)
3035     {
3036       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3037                   "Connection to `%s' timed out waiting for other peer to send SESSION_ACK\n",
3038                   GNUNET_i2s (&n->id));
3039       disconnect_neighbour (n);
3040       return;
3041     }
3042     break;
3043   case GNUNET_TRANSPORT_PS_CONNECTED:
3044     if (0 == delay.rel_value_us)
3045     {
3046       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3047                   "Connection to `%s' timed out, missing KEEPALIVE_RESPONSEs\n",
3048                   GNUNET_i2s (&n->id));
3049       disconnect_neighbour (n);
3050       return;
3051     }
3052     try_transmission_to_peer (n);
3053     send_keepalive (n);
3054     break;
3055   case GNUNET_TRANSPORT_PS_RECONNECT_ATS:
3056     if (0 == delay.rel_value_us)
3057     {
3058       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3059                   "Connection to `%s' timed out, waiting for ATS replacement address\n",
3060                   GNUNET_i2s (&n->id));
3061       disconnect_neighbour (n);
3062       return;
3063     }
3064     break;
3065   case GNUNET_TRANSPORT_PS_RECONNECT_BLACKLIST:
3066     if (0 == delay.rel_value_us)
3067     {
3068       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3069                   "Connection to `%s' timed out, waiting for BLACKLIST to approve replacement address\n",
3070                   GNUNET_i2s (&n->id));
3071       disconnect_neighbour (n);
3072       return;
3073     }
3074     break;
3075   case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
3076     if (0 == delay.rel_value_us)
3077     {
3078       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3079                   "Connection to `%s' timed out, waiting for other peer to CONNECT_ACK replacement address\n",
3080                   GNUNET_i2s (&n->id));
3081       disconnect_neighbour (n);
3082       return;
3083     }
3084     break;
3085   case GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_BLACKLIST:
3086     if (0 == delay.rel_value_us)
3087     {
3088       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3089                   "Connection to `%s' timed out, missing KEEPALIVE_RESPONSEs\n",
3090                   GNUNET_i2s (&n->id));
3091       disconnect_neighbour (n);
3092       return;
3093     }
3094     try_transmission_to_peer (n);
3095     send_keepalive (n);
3096     break;
3097   case GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_CONNECT_SENT:
3098     if (0 == delay.rel_value_us)
3099     {
3100       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3101                   "Connection to `%s' timed out, missing KEEPALIVE_RESPONSEs (after trying to CONNECT on alternative address)\n",
3102                   GNUNET_i2s (&n->id));
3103       disconnect_neighbour (n);
3104       return;
3105     }
3106     try_transmission_to_peer (n);
3107     send_keepalive (n);
3108     break;
3109   case GNUNET_TRANSPORT_PS_DISCONNECT:
3110     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3111                 "Cleaning up connection to `%s' after sending DISCONNECT\n",
3112                 GNUNET_i2s (&n->id));
3113     free_neighbour (n, GNUNET_NO);
3114     return;
3115   case GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED:
3116     /* how did we get here!? */
3117     GNUNET_assert (0);
3118     break;
3119   default:
3120     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3121                 "Unhandled state `%s'\n",
3122                 GNUNET_TRANSPORT_ps2s (n->state));
3123     GNUNET_break (0);
3124     break;
3125   }
3126   if ( (GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_CONNECT_SENT == n->state) ||
3127        (GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_BLACKLIST == n->state) ||
3128        (GNUNET_TRANSPORT_PS_CONNECTED == n->state) )
3129   {
3130     /* if we are *now* in one of these three states, we're sending
3131        keep alive messages, so we need to consider the keepalive
3132        delay, not just the connection timeout */
3133     delay = GNUNET_TIME_relative_min (GNUNET_TIME_absolute_get_remaining (n->keep_alive_time),
3134                                       delay);
3135   }
3136   if (GNUNET_SCHEDULER_NO_TASK == n->task)
3137     n->task = GNUNET_SCHEDULER_add_delayed (delay,
3138                                             &master_task,
3139                                             n);
3140 }
3141
3142
3143 /**
3144  * Send a SESSION_ACK message to the neighbour to confirm that we
3145  * got his CONNECT_ACK.
3146  *
3147  * @param n neighbour to send the SESSION_ACK to
3148  */
3149 static void
3150 send_session_ack_message (struct NeighbourMapEntry *n)
3151 {
3152   struct GNUNET_MessageHeader msg;
3153
3154   msg.size = htons (sizeof (struct GNUNET_MessageHeader));
3155   msg.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_ACK);
3156   (void) send_with_session(n,
3157                            (const char *) &msg, sizeof (struct GNUNET_MessageHeader),
3158                            UINT32_MAX, GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_NO,
3159                            NULL, NULL);
3160 }
3161
3162
3163 /**
3164  * We received a 'SESSION_CONNECT_ACK' message from the other peer.
3165  * Consider switching to it.
3166  *
3167  * @param message possibly a 'struct SessionConnectMessage' (check format)
3168  * @param peer identity of the peer to switch the address for
3169  * @param address address of the other peer, NULL if other peer
3170  *                       connected to us
3171  * @param session session to use (or NULL)
3172  * @return #GNUNET_OK if the message was fine, #GNUNET_SYSERR on serious error
3173  */
3174 int
3175 GST_neighbours_handle_connect_ack (const struct GNUNET_MessageHeader *message,
3176                                    const struct GNUNET_PeerIdentity *peer,
3177                                    const struct GNUNET_HELLO_Address *address,
3178                                    struct Session *session)
3179 {
3180   const struct SessionConnectMessage *scm;
3181   struct GNUNET_TIME_Absolute ts;
3182   struct NeighbourMapEntry *n;
3183
3184   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3185               "Received CONNECT_ACK message from peer `%s'\n",
3186               GNUNET_i2s (peer));
3187
3188   if (ntohs (message->size) != sizeof (struct SessionConnectMessage))
3189   {
3190     GNUNET_break_op (0);
3191     return GNUNET_SYSERR;
3192   }
3193   GNUNET_STATISTICS_update (GST_stats,
3194                             gettext_noop
3195                             ("# CONNECT_ACK messages received"),
3196                             1, GNUNET_NO);
3197   scm = (const struct SessionConnectMessage *) message;
3198   GNUNET_break_op (ntohl (scm->reserved) == 0);
3199   if (NULL == (n = lookup_neighbour (peer)))
3200   {
3201     GNUNET_STATISTICS_update (GST_stats,
3202                               gettext_noop
3203                               ("# unexpected CONNECT_ACK messages (no peer)"),
3204                               1, GNUNET_NO);
3205     return GNUNET_SYSERR;
3206   }
3207   ts = GNUNET_TIME_absolute_ntoh (scm->timestamp);
3208   switch (n->state)
3209   {
3210   case GNUNET_TRANSPORT_PS_NOT_CONNECTED:
3211     GNUNET_break (0);
3212     free_neighbour (n, GNUNET_NO);
3213     return GNUNET_SYSERR;
3214   case GNUNET_TRANSPORT_PS_INIT_ATS:
3215   case GNUNET_TRANSPORT_PS_INIT_BLACKLIST:
3216     GNUNET_STATISTICS_update (GST_stats,
3217                               gettext_noop
3218                               ("# unexpected CONNECT_ACK messages (not ready)"),
3219                               1, GNUNET_NO);
3220     break;
3221   case GNUNET_TRANSPORT_PS_CONNECT_SENT:
3222     if (ts.abs_value_us != n->primary_address.connect_timestamp.abs_value_us)
3223     {
3224       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
3225                   "CONNECT_ACK ignored as the timestamp does not match our CONNECT request\n");
3226       return GNUNET_OK;
3227     }
3228     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_CONNECTED, GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT));
3229     GNUNET_STATISTICS_set (GST_stats,
3230                            gettext_noop ("# peers connected"),
3231                            ++neighbours_connected,
3232                            GNUNET_NO);
3233     connect_notify_cb (callback_cls, &n->id,
3234                        n->primary_address.bandwidth_in,
3235                        n->primary_address.bandwidth_out);
3236     /* Tell ATS that the outbound session we created to send CONNECT was successful */
3237     GST_ats_add_address (n->primary_address.address,
3238                          n->primary_address.session,
3239                          NULL, 0);
3240     set_primary_address (n,
3241                  n->primary_address.address,
3242                  n->primary_address.session,
3243                  n->primary_address.bandwidth_in,
3244                  n->primary_address.bandwidth_out,
3245                  GNUNET_YES);
3246     send_session_ack_message (n);
3247     break;
3248   case GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST_INBOUND:
3249   case GNUNET_TRANSPORT_PS_CONNECT_RECV_ATS:
3250   case GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST:
3251   case GNUNET_TRANSPORT_PS_CONNECT_RECV_ACK:
3252     GNUNET_STATISTICS_update (GST_stats,
3253                               gettext_noop
3254                               ("# unexpected CONNECT_ACK messages (not ready)"),
3255                               1, GNUNET_NO);
3256     break;
3257   case GNUNET_TRANSPORT_PS_CONNECTED:
3258     /* duplicate CONNECT_ACK, let's answer by duplciate SESSION_ACK just in case */
3259     send_session_ack_message (n);
3260     break;
3261   case GNUNET_TRANSPORT_PS_RECONNECT_ATS:
3262   case GNUNET_TRANSPORT_PS_RECONNECT_BLACKLIST:
3263     /* we didn't expect any CONNECT_ACK, as we are waiting for ATS
3264        to give us a new address... */
3265     GNUNET_STATISTICS_update (GST_stats,
3266                               gettext_noop
3267                               ("# unexpected CONNECT_ACK messages (waiting on ATS)"),
3268                               1, GNUNET_NO);
3269     break;
3270   case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
3271     /* new address worked; go back to connected! */
3272     set_state (n, GNUNET_TRANSPORT_PS_CONNECTED);
3273     send_session_ack_message (n);
3274     break;
3275   case GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_BLACKLIST:
3276     /* duplicate CONNECT_ACK, let's answer by duplciate SESSION_ACK just in case */
3277     send_session_ack_message (n);
3278     break;
3279   case GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_CONNECT_SENT:
3280     /* new address worked; adopt it and go back to connected! */
3281     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_CONNECTED, GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT));
3282     GNUNET_break (GNUNET_NO == n->alternative_address.ats_active);
3283
3284     GST_ats_add_address (n->alternative_address.address,
3285                          n->alternative_address.session,
3286                          NULL, 0);
3287     set_primary_address (n, n->alternative_address.address,
3288         n->alternative_address.session, n->alternative_address.bandwidth_in,
3289         n->alternative_address.bandwidth_out, GNUNET_YES);
3290
3291     free_address (&n->alternative_address);
3292     send_session_ack_message (n);
3293     break;
3294   case GNUNET_TRANSPORT_PS_DISCONNECT:
3295     GNUNET_STATISTICS_update (GST_stats,
3296                               gettext_noop
3297                               ("# unexpected CONNECT_ACK messages (disconnecting)"),
3298                               1, GNUNET_NO);
3299     return GNUNET_SYSERR;
3300   case GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED:
3301     GNUNET_assert (0);
3302     break;
3303   default:
3304     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3305                 "Unhandled state `%s'\n",
3306                 GNUNET_TRANSPORT_ps2s (n->state));
3307     GNUNET_break (0);
3308     return GNUNET_SYSERR;
3309   }
3310   return GNUNET_OK;
3311 }
3312
3313
3314 /**
3315  * A session was terminated. Take note; if needed, try to get
3316  * an alternative address from ATS.
3317  *
3318  * @param peer identity of the peer where the session died
3319  * @param session session that is gone
3320  * @return #GNUNET_YES if this was a session used, #GNUNET_NO if
3321  *        this session was not in use
3322  */
3323 int
3324 GST_neighbours_session_terminated (const struct GNUNET_PeerIdentity *peer,
3325                                    struct Session *session)
3326 {
3327   struct NeighbourMapEntry *n;
3328   struct BlackListCheckContext *bcc;
3329   struct BlackListCheckContext *bcc_next;
3330
3331   /* make sure to cancel all ongoing blacklist checks involving 'session' */
3332   bcc_next = bc_head;
3333   while (NULL != (bcc = bcc_next))
3334   {
3335     bcc_next = bcc->next;
3336     if (bcc->na.session == session)
3337     {
3338       if (NULL != bcc->bc)
3339         GST_blacklist_test_cancel (bcc->bc);
3340       GNUNET_HELLO_address_free (bcc->na.address);
3341       GNUNET_CONTAINER_DLL_remove (bc_head,
3342                                    bc_tail,
3343                                    bcc);
3344       GNUNET_free (bcc);
3345     }
3346   }
3347   if (NULL == (n = lookup_neighbour (peer)))
3348     return GNUNET_NO; /* can't affect us */
3349   if (session != n->primary_address.session)
3350   {
3351     if (session == n->alternative_address.session)
3352     {
3353       if ( (GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_BLACKLIST == n->state) ||
3354            (GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_CONNECT_SENT == n->state) )
3355         set_state (n, GNUNET_TRANSPORT_PS_CONNECTED);
3356       else
3357         GNUNET_break (0);
3358       free_address (&n->alternative_address);
3359     }
3360     return GNUNET_NO; /* doesn't affect us further */
3361   }
3362
3363   n->expect_latency_response = GNUNET_NO;
3364   switch (n->state)
3365   {
3366   case GNUNET_TRANSPORT_PS_NOT_CONNECTED:
3367     GNUNET_break (0);
3368     free_neighbour (n, GNUNET_NO);
3369     return GNUNET_YES;
3370   case GNUNET_TRANSPORT_PS_INIT_ATS:
3371     GNUNET_break (0);
3372     free_neighbour (n, GNUNET_NO);
3373     return GNUNET_YES;
3374   case GNUNET_TRANSPORT_PS_INIT_BLACKLIST:
3375   case GNUNET_TRANSPORT_PS_CONNECT_SENT:
3376     free_address (&n->primary_address);
3377     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_INIT_ATS, GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
3378     break;
3379   case GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST_INBOUND:
3380   case GNUNET_TRANSPORT_PS_CONNECT_RECV_ATS:
3381   case GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST:
3382   case GNUNET_TRANSPORT_PS_CONNECT_RECV_ACK:
3383     /* error on inbound session; free neighbour entirely */
3384     free_address (&n->primary_address);
3385     free_neighbour (n, GNUNET_NO);
3386     return GNUNET_YES;
3387   case GNUNET_TRANSPORT_PS_CONNECTED:
3388     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_INIT_ATS, GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
3389     free_address (&n->primary_address);
3390     break;
3391   case GNUNET_TRANSPORT_PS_RECONNECT_ATS:
3392     /* we don't have an address, how can it go down? */
3393     GNUNET_break (0);
3394     break;
3395   case GNUNET_TRANSPORT_PS_RECONNECT_BLACKLIST:
3396   case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
3397     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_RECONNECT_ATS, GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
3398     break;
3399   case GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_BLACKLIST:
3400     /* primary went down while we were checking secondary against
3401        blacklist, adopt secondary as primary */
3402     free_address (&n->primary_address);
3403     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_RECONNECT_BLACKLIST, GNUNET_TIME_relative_to_absolute (FAST_RECONNECT_TIMEOUT));
3404     n->primary_address = n->alternative_address;
3405     memset (&n->alternative_address, 0, sizeof (struct NeighbourAddress));
3406     break;
3407   case GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_CONNECT_SENT:
3408     /* primary went down while we were waiting for CONNECT_ACK on secondary;
3409        secondary as primary */
3410     free_address (&n->primary_address);
3411     n->primary_address = n->alternative_address;
3412     memset (&n->alternative_address, 0, sizeof (struct NeighbourAddress));
3413     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_RECONNECT_SENT, GNUNET_TIME_relative_to_absolute (FAST_RECONNECT_TIMEOUT));
3414     break;
3415   case GNUNET_TRANSPORT_PS_DISCONNECT:
3416     free_address (&n->primary_address);
3417     break;
3418   case GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED:
3419     /* neighbour was freed and plugins told to terminate session */
3420     return GNUNET_NO;
3421     break;
3422   default:
3423     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3424                 "Unhandled state `%s'\n",
3425                 GNUNET_TRANSPORT_ps2s (n->state));
3426     GNUNET_break (0);
3427     break;
3428   }
3429   if (GNUNET_SCHEDULER_NO_TASK != n->task)
3430     GNUNET_SCHEDULER_cancel (n->task);
3431   n->task = GNUNET_SCHEDULER_add_now (&master_task, n);
3432   return GNUNET_YES;
3433 }
3434
3435
3436 /**
3437  * We received a 'SESSION_ACK' message from the other peer.
3438  * If we sent a 'CONNECT_ACK' last, this means we are now
3439  * connected.  Otherwise, do nothing.
3440  *
3441  * @param message possibly a 'struct SessionConnectMessage' (check format)
3442  * @param peer identity of the peer to switch the address for
3443  * @param address address of the other peer, NULL if other peer
3444  *                       connected to us
3445  * @param session session to use (or NULL)
3446  * @return #GNUNET_OK if the message was fine, #GNUNET_SYSERR on serious error
3447  */
3448 int
3449 GST_neighbours_handle_session_ack (const struct GNUNET_MessageHeader *message,
3450                                    const struct GNUNET_PeerIdentity *peer,
3451                                    const struct GNUNET_HELLO_Address *address,
3452                                    struct Session *session)
3453 {
3454   struct NeighbourMapEntry *n;
3455
3456   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3457               "Received SESSION_ACK message from peer `%s'\n",
3458               GNUNET_i2s (peer));
3459   if (ntohs (message->size) != sizeof (struct GNUNET_MessageHeader))
3460   {
3461     GNUNET_break_op (0);
3462     return GNUNET_SYSERR;
3463   }
3464   GNUNET_STATISTICS_update (GST_stats,
3465                             gettext_noop
3466                             ("# SESSION_ACK messages received"),
3467                             1, GNUNET_NO);
3468   if (NULL == (n = lookup_neighbour (peer)))
3469   {
3470     GNUNET_break_op (0);
3471     return GNUNET_SYSERR;
3472   }
3473   /* check if we are in a plausible state for having sent
3474      a CONNECT_ACK.  If not, return, otherwise break */
3475   if ( ( (GNUNET_TRANSPORT_PS_CONNECT_RECV_ACK != n->state) &&
3476          (GNUNET_TRANSPORT_PS_CONNECT_SENT != n->state) ) ||
3477        (2 != n->send_connect_ack) )
3478   {
3479     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3480                 "Received SESSION_ACK message from peer `%s' in state %s/%d\n",
3481                 GNUNET_i2s (peer),
3482                 GNUNET_TRANSPORT_ps2s (n->state),
3483                 n->send_connect_ack);
3484     GNUNET_STATISTICS_update (GST_stats,
3485                               gettext_noop ("# unexpected SESSION_ACK messages"), 1,
3486                               GNUNET_NO);
3487     return GNUNET_OK;
3488   }
3489   set_state_and_timeout (n, GNUNET_TRANSPORT_PS_CONNECTED, GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT));
3490   GNUNET_STATISTICS_set (GST_stats,
3491                          gettext_noop ("# peers connected"),
3492                          ++neighbours_connected,
3493                          GNUNET_NO);
3494   connect_notify_cb (callback_cls, &n->id,
3495                      n->primary_address.bandwidth_in,
3496                      n->primary_address.bandwidth_out);
3497
3498   GST_ats_add_address (n->primary_address.address,
3499                        n->primary_address.session,
3500                        NULL, 0);
3501   set_primary_address (n,
3502                n->primary_address.address,
3503                n->primary_address.session,
3504                n->primary_address.bandwidth_in,
3505                n->primary_address.bandwidth_out,
3506                GNUNET_YES);
3507   return GNUNET_OK;
3508 }
3509
3510
3511 /**
3512  * Test if we're connected to the given peer.
3513  *
3514  * @param target peer to test
3515  * @return #GNUNET_YES if we are connected, #GNUNET_NO if not
3516  */
3517 int
3518 GST_neighbours_test_connected (const struct GNUNET_PeerIdentity *target)
3519 {
3520   return test_connected (lookup_neighbour (target));
3521 }
3522
3523 /**
3524  * Change the incoming quota for the given peer.
3525  *
3526  * @param neighbour identity of peer to change qutoa for
3527  * @param quota new quota
3528  */
3529 void
3530 GST_neighbours_set_incoming_quota (const struct GNUNET_PeerIdentity *neighbour,
3531                                    struct GNUNET_BANDWIDTH_Value32NBO quota)
3532 {
3533   struct NeighbourMapEntry *n;
3534
3535   if (NULL == (n = lookup_neighbour (neighbour)))
3536   {
3537     GNUNET_STATISTICS_update (GST_stats,
3538                               gettext_noop
3539                               ("# SET QUOTA messages ignored (no such peer)"),
3540                               1, GNUNET_NO);
3541     return;
3542   }
3543   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3544               "Setting inbound quota of %u Bps for peer `%s' to all clients\n",
3545               ntohl (quota.value__), GNUNET_i2s (&n->id));
3546   GNUNET_BANDWIDTH_tracker_update_quota (&n->in_tracker, quota);
3547   if (0 != ntohl (quota.value__))
3548     return;
3549   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3550               "Disconnecting peer `%4s' due to SET_QUOTA\n",
3551               GNUNET_i2s (&n->id));
3552   if (GNUNET_YES == test_connected (n))
3553     GNUNET_STATISTICS_update (GST_stats,
3554                               gettext_noop ("# disconnects due to quota of 0"),
3555                               1, GNUNET_NO);
3556   disconnect_neighbour (n);
3557 }
3558
3559
3560 /**
3561  * We received a disconnect message from the given peer,
3562  * validate and process.
3563  *
3564  * @param peer sender of the message
3565  * @param msg the disconnect message
3566  */
3567 void
3568 GST_neighbours_handle_disconnect_message (const struct GNUNET_PeerIdentity *peer,
3569                                           const struct GNUNET_MessageHeader *msg)
3570 {
3571   struct NeighbourMapEntry *n;
3572   const struct SessionDisconnectMessage *sdm;
3573
3574   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3575               "Received DISCONNECT message from peer `%s'\n",
3576               GNUNET_i2s (peer));
3577   if (ntohs (msg->size) != sizeof (struct SessionDisconnectMessage))
3578   {
3579     // GNUNET_break_op (0);
3580     GNUNET_STATISTICS_update (GST_stats,
3581                               gettext_noop
3582                               ("# disconnect messages ignored (old format)"), 1,
3583                               GNUNET_NO);
3584     return;
3585   }
3586   GNUNET_STATISTICS_update (GST_stats,
3587                             gettext_noop
3588                             ("# DISCONNECT messages received"),
3589                             1, GNUNET_NO);
3590   sdm = (const struct SessionDisconnectMessage *) msg;
3591   if (NULL == (n = lookup_neighbour (peer)))
3592     return;                     /* gone already */
3593   if (GNUNET_TIME_absolute_ntoh (sdm->timestamp).abs_value_us <= n->connect_ack_timestamp.abs_value_us)
3594   {
3595     GNUNET_STATISTICS_update (GST_stats,
3596                               gettext_noop
3597                               ("# disconnect messages ignored (timestamp)"), 1,
3598                               GNUNET_NO);
3599     return;
3600   }
3601   if (0 != memcmp (peer, &sdm->public_key, sizeof (struct GNUNET_PeerIdentity)))
3602   {
3603     GNUNET_break_op (0);
3604     return;
3605   }
3606   if (ntohl (sdm->purpose.size) !=
3607       sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
3608       sizeof (struct GNUNET_CRYPTO_EddsaPublicKey) +
3609       sizeof (struct GNUNET_TIME_AbsoluteNBO))
3610   {
3611     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
3612                 "%s message from peer `%s' has invalid size \n",
3613                 "DISCONNECT",
3614                 GNUNET_i2s (peer));
3615     GNUNET_break_op (0);
3616     return;
3617   }
3618   if (GNUNET_OK !=
3619       GNUNET_CRYPTO_eddsa_verify
3620       (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_DISCONNECT, &sdm->purpose,
3621        &sdm->signature, &sdm->public_key))
3622   {
3623     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
3624                 "%s message from peer `%s' cannot be verified \n",
3625                 "DISCONNECT",
3626                 GNUNET_i2s (peer));
3627     GNUNET_break_op (0);
3628     return;
3629   }
3630   if (GNUNET_YES == test_connected (n))
3631     GNUNET_STATISTICS_update (GST_stats,
3632                               gettext_noop
3633                               ("# other peer asked to disconnect from us"), 1,
3634                               GNUNET_NO);
3635   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3636               "Disconnecting by request from peer %s\n",
3637               GNUNET_i2s (peer));
3638   disconnect_neighbour (n);
3639 }
3640
3641
3642 /**
3643  * Closure for the neighbours_iterate function.
3644  */
3645 struct IteratorContext
3646 {
3647   /**
3648    * Function to call on each connected neighbour.
3649    */
3650   GST_NeighbourIterator cb;
3651
3652   /**
3653    * Closure for 'cb'.
3654    */
3655   void *cb_cls;
3656 };
3657
3658
3659 /**
3660  * Call the callback from the closure for each neighbour.
3661  *
3662  * @param cls the `struct IteratorContext`
3663  * @param key the hash of the public key of the neighbour
3664  * @param value the `struct NeighbourMapEntry`
3665  * @return #GNUNET_OK (continue to iterate)
3666  */
3667 static int
3668 neighbours_iterate (void *cls,
3669                     const struct GNUNET_PeerIdentity *key,
3670                     void *value)
3671 {
3672   struct IteratorContext *ic = cls;
3673   struct NeighbourMapEntry *n = value;
3674   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in;
3675   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out;
3676
3677
3678   if (NULL != n->primary_address.address)
3679   {
3680     bandwidth_in = n->primary_address.bandwidth_in;
3681     bandwidth_out = n->primary_address.bandwidth_out;
3682   }
3683   else
3684   {
3685     bandwidth_in = GNUNET_CONSTANTS_DEFAULT_BW_IN_OUT;
3686     bandwidth_out = GNUNET_CONSTANTS_DEFAULT_BW_IN_OUT;
3687   }
3688   ic->cb (ic->cb_cls,
3689           &n->id,
3690           n->primary_address.address,
3691           n->state,
3692           n->timeout,
3693           bandwidth_in, bandwidth_out);
3694   return GNUNET_OK;
3695 }
3696
3697
3698 /**
3699  * Iterate over all connected neighbours.
3700  *
3701  * @param cb function to call
3702  * @param cb_cls closure for cb
3703  */
3704 void
3705 GST_neighbours_iterate (GST_NeighbourIterator cb, void *cb_cls)
3706 {
3707   struct IteratorContext ic;
3708
3709   if (NULL == neighbours)
3710     return; /* can happen during shutdown */
3711   ic.cb = cb;
3712   ic.cb_cls = cb_cls;
3713   GNUNET_CONTAINER_multipeermap_iterate (neighbours, &neighbours_iterate, &ic);
3714 }
3715
3716
3717 /**
3718  * If we have an active connection to the given target, it must be shutdown.
3719  *
3720  * @param target peer to disconnect from
3721  */
3722 void
3723 GST_neighbours_force_disconnect (const struct GNUNET_PeerIdentity *target)
3724 {
3725   struct NeighbourMapEntry *n;
3726
3727   if (NULL == (n = lookup_neighbour (target)))
3728     return;  /* not active */
3729   if (GNUNET_YES == test_connected (n))
3730     GNUNET_STATISTICS_update (GST_stats,
3731                               gettext_noop
3732                               ("# disconnected from peer upon explicit request"), 1,
3733                               GNUNET_NO);
3734   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3735               "Forced disconnect from peer %s\n",
3736               GNUNET_i2s (target));
3737   disconnect_neighbour (n);
3738 }
3739
3740
3741 /**
3742  * Obtain current latency information for the given neighbour.
3743  *
3744  * @param peer to get the latency for
3745  * @return observed latency of the address, FOREVER if the
3746  *         the connection is not up
3747  */
3748 struct GNUNET_TIME_Relative
3749 GST_neighbour_get_latency (const struct GNUNET_PeerIdentity *peer)
3750 {
3751   struct NeighbourMapEntry *n;
3752
3753   n = lookup_neighbour (peer);
3754   if (NULL == n)
3755     return GNUNET_TIME_UNIT_FOREVER_REL;
3756   switch (n->state)
3757   {
3758   case GNUNET_TRANSPORT_PS_CONNECTED:
3759   case GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_CONNECT_SENT:
3760   case GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_BLACKLIST:
3761   case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
3762   case GNUNET_TRANSPORT_PS_RECONNECT_ATS:
3763   case GNUNET_TRANSPORT_PS_RECONNECT_BLACKLIST:
3764     return n->latency;
3765   case GNUNET_TRANSPORT_PS_NOT_CONNECTED:
3766   case GNUNET_TRANSPORT_PS_INIT_BLACKLIST:
3767   case GNUNET_TRANSPORT_PS_INIT_ATS:
3768   case GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST_INBOUND:
3769   case GNUNET_TRANSPORT_PS_CONNECT_RECV_ATS:
3770   case GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST:
3771   case GNUNET_TRANSPORT_PS_CONNECT_RECV_ACK:
3772   case GNUNET_TRANSPORT_PS_CONNECT_SENT:
3773   case GNUNET_TRANSPORT_PS_DISCONNECT:
3774   case GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED:
3775     return GNUNET_TIME_UNIT_FOREVER_REL;
3776   default:
3777     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3778                 "Unhandled state `%s'\n",
3779                 GNUNET_TRANSPORT_ps2s (n->state));
3780     GNUNET_break (0);
3781     break;
3782   }
3783   return GNUNET_TIME_UNIT_FOREVER_REL;
3784 }
3785
3786
3787 /**
3788  * Obtain current address information for the given neighbour.
3789  *
3790  * @param peer
3791  * @return address currently used
3792  */
3793 struct GNUNET_HELLO_Address *
3794 GST_neighbour_get_current_address (const struct GNUNET_PeerIdentity *peer)
3795 {
3796   struct NeighbourMapEntry *n;
3797
3798   n = lookup_neighbour (peer);
3799   if (NULL == n)
3800     return NULL;
3801   return n->primary_address.address;
3802 }
3803
3804
3805 /**
3806  * Initialize the neighbours subsystem.
3807  *
3808  * @param cls closure for callbacks
3809  * @param connect_cb function to call if we connect to a peer
3810  * @param disconnect_cb function to call if we disconnect from a peer
3811  * @param peer_address_cb function to call if we change an active address
3812  *                   of a neighbour
3813  * @param max_fds maximum number of fds to use
3814  */
3815 void
3816 GST_neighbours_start (void *cls,
3817                       NotifyConnect connect_cb,
3818                       GNUNET_TRANSPORT_NotifyDisconnect disconnect_cb,
3819                       GNUNET_TRANSPORT_NeighbourChangeCallback peer_address_cb,
3820                       unsigned int max_fds)
3821 {
3822   callback_cls = cls;
3823   connect_notify_cb = connect_cb;
3824   disconnect_notify_cb = disconnect_cb;
3825   neighbour_change_cb = peer_address_cb;
3826   neighbours = GNUNET_CONTAINER_multipeermap_create (NEIGHBOUR_TABLE_SIZE, GNUNET_NO);
3827   registered_quota_notifications = GNUNET_CONTAINER_multipeermap_create (NEIGHBOUR_TABLE_SIZE, GNUNET_NO);
3828   util_transmission_tk = GNUNET_SCHEDULER_add_delayed (UTIL_TRANSMISSION_INTERVAL,
3829       utilization_transmission, NULL);
3830 }
3831
3832
3833 /**
3834  * Disconnect from the given neighbour.
3835  *
3836  * @param cls unused
3837  * @param key hash of neighbour's public key (not used)
3838  * @param value the 'struct NeighbourMapEntry' of the neighbour
3839  * @return #GNUNET_OK (continue to iterate)
3840  */
3841 static int
3842 disconnect_all_neighbours (void *cls,
3843                            const struct GNUNET_PeerIdentity *key,
3844                            void *value)
3845 {
3846   struct NeighbourMapEntry *n = value;
3847
3848   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3849               "Disconnecting peer `%4s', %s\n",
3850               GNUNET_i2s (&n->id), "SHUTDOWN_TASK");
3851   free_neighbour (n, GNUNET_NO);
3852   return GNUNET_OK;
3853 }
3854
3855
3856 /**
3857  * Cleanup the neighbours subsystem.
3858  */
3859 void
3860 GST_neighbours_stop ()
3861 {
3862   struct BlacklistCheckSwitchContext *cur;
3863   struct BlacklistCheckSwitchContext *next;
3864
3865   if (NULL == neighbours)
3866     return;
3867   if (GNUNET_SCHEDULER_NO_TASK != util_transmission_tk)
3868   {
3869     GNUNET_SCHEDULER_cancel (util_transmission_tk);
3870     util_transmission_tk = GNUNET_SCHEDULER_NO_TASK;
3871   }
3872
3873   GNUNET_CONTAINER_multipeermap_iterate (neighbours,
3874                                          &disconnect_all_neighbours,
3875                                          NULL);
3876   GNUNET_CONTAINER_multipeermap_destroy (neighbours);
3877
3878   next = pending_bc_head;
3879   for (cur = next; NULL != cur; cur = next )
3880   {
3881     next = cur->next;
3882     GNUNET_CONTAINER_DLL_remove (pending_bc_head, pending_bc_tail, cur);
3883
3884     if (NULL != cur->blc)
3885     {
3886       GST_blacklist_test_cancel (cur->blc);
3887       cur->blc = NULL;
3888     }
3889     if (NULL != cur->address)
3890       GNUNET_HELLO_address_free (cur->address);
3891     GNUNET_free_non_null (cur->ats);
3892     GNUNET_free (cur);
3893   }
3894
3895   GNUNET_CONTAINER_multipeermap_iterate (registered_quota_notifications,
3896       &free_notification_cb, NULL);
3897   GNUNET_CONTAINER_multipeermap_destroy (registered_quota_notifications);
3898   registered_quota_notifications = NULL;
3899
3900   neighbours = NULL;
3901   callback_cls = NULL;
3902   connect_notify_cb = NULL;
3903   disconnect_notify_cb = NULL;
3904   neighbour_change_cb = NULL;
3905 }
3906
3907
3908 /* end of file gnunet-service-transport_neighbours.c */