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, 500)
  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 /**
  88  * State describing which kind a reply this neighbour should send
  89  */
  90 enum GST_ACK_State
  91 {
  92   /**
  93    * We did not receive a SYN message for this neighbour
  94    */
  95   ACK_UNDEFINED = 0,
  96
  97   /* The neighbour received a SYN message and has to send a SYN_ACK
  98    * as reply */
  99   ACK_SEND_SYN_ACK = 1,
 100
 101   /* The neighbour sent a SYN_ACK message and has to send a ACK
 102    * as reply */
 103   ACK_SEND_ACK = 2
 104 };
 105
 106
 107 GNUNET_NETWORK_STRUCT_BEGIN
 108
 109 /**
 110  * Message a peer sends to another to indicate that it intends to
 111  * setup a connection/session for data exchange.  A 'SESSION_SYN'
 112  * should be answered with a 'SESSION_SYN_ACK' with the same body
 113  * to confirm.  A 'SESSION_SYN_ACK' should then be followed with
 114  * a 'ACK'.  Once the 'ACK' is received, both peers
 115  * should be connected.
 116  */
 117 struct TransportSynMessage
 118 {
 119   /**
 120    * Header of type #GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_SYN
 121    * or #GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_SYN_ACK
 122    */
 123   struct GNUNET_MessageHeader header;
 124
 125   /**
 126    * Always zero.
 127    */
 128   uint32_t reserved GNUNET_PACKED;
 129
 130   /**
 131    * Absolute time at the sender.  Only the most recent connect
 132    * message implies which session is preferred by the sender.
 133    */
 134   struct GNUNET_TIME_AbsoluteNBO timestamp;
 135
 136 };
 137
 138
 139 /**
 140  * Message a peer sends to another when connected to indicate that a
 141  * session is in use and the peer is still alive or to respond to a keep alive.
 142  * A peer sends a message with type #GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_KEEPALIVE
 143  * to request a message with #GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_KEEPALIVE_RESPONSE.
 144  * When the keep alive response with type is received, transport service
 145  * will call the respective plugin to update the session timeout
 146  */
 147 struct SessionKeepAliveMessage
 148 {
 149   /**
 150    * Header of type #GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_KEEPALIVE or
 151    * #GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_KEEPALIVE_RESPONSE.
 152    */
 153   struct GNUNET_MessageHeader header;
 154
 155   /**
 156    * A nonce to identify the session the keep alive is used for
 157    */
 158   uint32_t nonce GNUNET_PACKED;
 159 };
 160
 161 /**
 162  * Message we send to the other peer to notify him that we intentionally
 163  * are disconnecting (to reduce timeouts).  This is just a friendly
 164  * notification, peers must not rely on always receiving disconnect
 165  * messages.
 166  */
 167 struct SessionDisconnectMessage
 168 {
 169   /**
 170    * Header of type #GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_DISCONNECT
 171    */
 172   struct GNUNET_MessageHeader header;
 173
 174   /**
 175    * Always zero.
 176    */
 177   uint32_t reserved GNUNET_PACKED;
 178
 179   /**
 180    * Purpose of the signature.  Extends over the timestamp.
 181    * Purpose should be #GNUNET_SIGNATURE_PURPOSE_TRANSPORT_DISCONNECT.
 182    */
 183   struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
 184
 185   /**
 186    * Absolute time at the sender.  Only the most recent connect
 187    * message implies which session is preferred by the sender.
 188    */
 189   struct GNUNET_TIME_AbsoluteNBO timestamp;
 190
 191   /**
 192    * Public key of the sender.
 193    */
 194   struct GNUNET_CRYPTO_EddsaPublicKey public_key;
 195
 196   /**
 197    * Signature of the peer that sends us the disconnect.  Only
 198    * valid if the timestamp is AFTER the timestamp from the
 199    * corresponding 'SYN' message.
 200    */
 201   struct GNUNET_CRYPTO_EddsaSignature signature;
 202
 203 };
 204
 205 GNUNET_NETWORK_STRUCT_END
 206
 207
 208 /**
 209  * For each neighbour we keep a list of messages
 210  * that we still want to transmit to the neighbour.
 211  */
 212 struct MessageQueue
 213 {
 214
 215   /**
 216    * This is a doubly linked list.
 217    */
 218   struct MessageQueue *next;
 219
 220   /**
 221    * This is a doubly linked list.
 222    */
 223   struct MessageQueue *prev;
 224
 225   /**
 226    * Function to call once we're done.
 227    */
 228   GST_NeighbourSendContinuation cont;
 229
 230   /**
 231    * Closure for @e cont
 232    */
 233   void *cont_cls;
 234
 235   /**
 236    * The message(s) we want to transmit, GNUNET_MessageHeader(s)
 237    * stuck together in memory.  Allocated at the end of this struct.
 238    */
 239   const char *message_buf;
 240
 241   /**
 242    * Size of the message buf
 243    */
 244   size_t message_buf_size;
 245
 246   /**
 247    * At what time should we fail?
 248    */
 249   struct GNUNET_TIME_Absolute timeout;
 250
 251 };
 252
 253
 254
 255
 256 /**
 257  * A possible address we could use to communicate with a neighbour.
 258  */
 259 struct NeighbourAddress
 260 {
 261
 262   /**
 263    * Active session for this address.
 264    */
 265   struct Session *session;
 266
 267   /**
 268    * Network-level address information.
 269    */
 270   struct GNUNET_HELLO_Address *address;
 271
 272   /**
 273    * Timestamp of the 'SESSION_CONNECT' message we sent to the other
 274    * peer for this address.  Use to check that the ACK is in response
 275    * to our most recent 'SYN'.
 276    */
 277   struct GNUNET_TIME_Absolute connect_timestamp;
 278
 279   /**
 280    * Inbound bandwidth from ATS for this address.
 281    */
 282   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in;
 283
 284   /**
 285    * Outbound bandwidth from ATS for this address.
 286    */
 287   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out;
 288
 289   /**
 290    * Did we tell ATS that this is our 'active' address?
 291    */
 292   int ats_active;
 293
 294   /**
 295    * The current nonce sent in the last keep alive messages
 296    */
 297   uint32_t keep_alive_nonce;
 298 };
 299
 300 /**
 301  * Entry in neighbours.
 302  */
 303 struct NeighbourMapEntry
 304 {
 305
 306   /**
 307    * Head of list of messages we would like to send to this peer;
 308    * must contain at most one message per client.
 309    */
 310   struct MessageQueue *messages_head;
 311
 312   /**
 313    * Tail of list of messages we would like to send to this peer; must
 314    * contain at most one message per client.
 315    */
 316   struct MessageQueue *messages_tail;
 317
 318   /**
 319    * Are we currently trying to send a message? If so, which one?
 320    */
 321   struct MessageQueue *is_active;
 322
 323   /**
 324    * Primary address we currently use to communicate with the neighbour.
 325    */
 326   struct NeighbourAddress primary_address;
 327
 328   /**
 329    * Alternative address currently under consideration for communicating
 330    * with the neighbour.
 331    */
 332   struct NeighbourAddress alternative_address;
 333
 334   /**
 335    * Identity of this neighbour.
 336    */
 337   struct GNUNET_PeerIdentity id;
 338
 339   /**
 340    * Main task that drives this peer (timeouts, keepalives, etc.).
 341    * Always runs the 'master_task'.
 342    */
 343   GNUNET_SCHEDULER_TaskIdentifier task;
 344
 345   /**
 346    * Task to disconnect neighbour after we received a DISCONNECT message
 347    */
 348   GNUNET_SCHEDULER_TaskIdentifier delayed_disconnect_task;
 349
 350   /**
 351    * At what time should we sent the next keep-alive message?
 352    */
 353   struct GNUNET_TIME_Absolute keep_alive_time;
 354
 355   /**
 356    * At what time did we sent the last keep-alive message?  Used
 357    * to calculate round-trip time ("latency").
 358    */
 359   struct GNUNET_TIME_Absolute last_keep_alive_time;
 360
 361   /**
 362    * Timestamp we should include in our next SYN_ACK message.
 363    * (only valid if 'send_connect_ack' is #GNUNET_YES).  Used to build
 364    * our SYN_ACK message.
 365    */
 366   struct GNUNET_TIME_Absolute connect_ack_timestamp;
 367
 368   /**
 369    * ATS address suggest handle
 370    */
 371   struct GNUNET_ATS_SuggestHandle *suggest_handle;
 372
 373   /**
 374    * Time where we should cut the connection (timeout) if we don't
 375    * make progress in the state machine (or get a KEEPALIVE_RESPONSE
 376    * if we are in S_CONNECTED).
 377    */
 378   struct GNUNET_TIME_Absolute timeout;
 379
 380   /**
 381    * Latest calculated latency value
 382    */
 383   struct GNUNET_TIME_Relative latency;
 384
 385   /**
 386    * Tracker for inbound bandwidth.
 387    */
 388   struct GNUNET_BANDWIDTH_Tracker in_tracker;
 389
 390   /**
 391    * How often has the other peer (recently) violated the inbound
 392    * traffic limit?  Incremented by 10 per violation, decremented by 1
 393    * per non-violation (for each time interval).
 394    */
 395   unsigned int quota_violation_count;
 396
 397   /**
 398    * The current state of the peer.
 399    */
 400   enum GNUNET_TRANSPORT_PeerState state;
 401
 402   /**
 403    * Did we sent an KEEP_ALIVE message and are we expecting a response?
 404    */
 405   int expect_latency_response;
 406
 407   /**
 408    * When a peer wants to connect we have to reply to the 1st SYN message
 409    * with a SYN_ACK message. But sometime we cannot send this message
 410    * immediately since we do not have an address and then we have to remember
 411    * to send this message as soon as we have an address.
 412    *
 413    * Flag to set if we still need to send a SYN_ACK message to the other peer
 414    * (once we have an address to use and the peer has been allowed by our
 415    * blacklist).  Initially set to #ACK_UNDEFINED. Set to #ACK_SEND_SYN_ACK
 416    * if we need to send a SYN_ACK.  Set to #ACK_SEND_ACK if we did
 417    * send a SYN_ACK and should go to 'S_CONNECTED' upon receiving a
 418    * 'ACK' (regardless of what our own state machine might say).
 419    */
 420   enum GST_ACK_State ack_state;
 421
 422   /**
 423    * Tracking utilization of outbound bandwidth
 424    */
 425   uint32_t util_payload_bytes_sent;
 426
 427   /**
 428    * Tracking utilization of inbound bandwidth
 429    */
 430   uint32_t util_payload_bytes_recv;
 431
 432   /**
 433    * Tracking utilization of outbound bandwidth
 434    */
 435   uint32_t util_total_bytes_sent;
 436
 437   /**
 438    * Tracking utilization of inbound bandwidth
 439    */
 440   uint32_t util_total_bytes_recv;
 441
 442   /**
 443    * Date of last utilization transmission
 444    */
 445   struct GNUNET_TIME_Absolute last_util_transmission;
 446 };
 447
 448
 449 /**
 450  * Context for blacklist checks and the #try_connect_bl_check_cont()
 451  * function.  Stores information about ongoing blacklist checks.
 452  */
 453 struct BlackListCheckContext
 454 {
 455
 456   /**
 457    * We keep blacklist checks in a DLL.
 458    */
 459   struct BlackListCheckContext *next;
 460
 461   /**
 462    * We keep blacklist checks in a DLL.
 463    */
 464   struct BlackListCheckContext *prev;
 465
 466   /**
 467    * Address that is being checked.
 468    */
 469   struct NeighbourAddress na;
 470
 471   /**
 472    * Handle to the ongoing blacklist check.
 473    */
 474   struct GST_BlacklistCheck *bc;
 475 };
 476
 477
 478 /**
 479  * Hash map from peer identities to the respective 'struct NeighbourMapEntry'.
 480  */
 481 static struct GNUNET_CONTAINER_MultiPeerMap *neighbours;
 482
 483 /**
 484  * We keep blacklist checks in a DLL so that we can find
 485  * the 'sessions' in their 'struct NeighbourAddress' if
 486  * a session goes down.
 487  */
 488 static struct BlackListCheckContext *bc_head;
 489
 490 /**
 491  * We keep blacklist checks in a DLL.
 492  */
 493 static struct BlackListCheckContext *bc_tail;
 494
 495 /**
 496  * List of pending blacklist checks: head
 497  */
 498 static struct BlacklistCheckSwitchContext *pending_bc_head;
 499
 500 /**
 501  * List of pending blacklist checks: tail
 502  */
 503 static struct BlacklistCheckSwitchContext *pending_bc_tail;
 504
 505 /**
 506  * Closure for #connect_notify_cb, #disconnect_notify_cb and #neighbour_change_cb
 507  */
 508 static void *callback_cls;
 509
 510 /**
 511  * Function to call when we connected to a neighbour.
 512  */
 513 static NotifyConnect connect_notify_cb;
 514
 515 /**
 516  * Function to call when we disconnected from a neighbour.
 517  */
 518 static GNUNET_TRANSPORT_NotifyDisconnect disconnect_notify_cb;
 519
 520 /**
 521  * Function to call when a neighbour changed address, state or bandwidth.
 522  */
 523 static GNUNET_TRANSPORT_NeighbourChangeCallback neighbour_change_cb;
 524
 525 /**
 526  * counter for connected neighbours
 527  */
 528 static unsigned int neighbours_connected;
 529
 530 /**
 531  * Number of bytes we have currently queued for transmission.
 532  */
 533 static unsigned long long bytes_in_send_queue;
 534
 535 /**
 536  * Task transmitting utilization data
 537  */
 538 static GNUNET_SCHEDULER_TaskIdentifier util_transmission_tk;
 539
 540
 541 static struct GNUNET_CONTAINER_MultiPeerMap *registered_quota_notifications;
 542
 543 static char *
 544 print_ack_state (enum GST_ACK_State s)
 545 {
 546   switch (s) {
 547     case ACK_UNDEFINED:
 548       return "UNDEFINED";
 549     case ACK_SEND_SYN_ACK:
 550       return "SEND_SYN_ACK";
 551     case ACK_SEND_ACK:
 552       return "SEND_ACK";
 553     default:
 554       GNUNET_break (0);
 555       return "N/A";
 556   }
 557 }
 558
 559 /**
 560  * Lookup a neighbour entry in the neighbours hash map.
 561  *
 562  * @param pid identity of the peer to look up
 563  * @return the entry, NULL if there is no existing record
 564  */
 565 static struct NeighbourMapEntry *
 566 lookup_neighbour (const struct GNUNET_PeerIdentity *pid)
 567 {
 568   if (NULL == neighbours)
 569     return NULL;
 570   return GNUNET_CONTAINER_multipeermap_get (neighbours, pid);
 571 }
 572
 573
 574 /**
 575  * Test if we're connected to the given peer.
 576  *
 577  * @param n neighbour entry of peer to test
 578  * @return #GNUNET_YES if we are connected, #GNUNET_NO if not
 579  */
 580 static int
 581 test_connected (struct NeighbourMapEntry *n)
 582 {
 583   if (NULL == n)
 584     return GNUNET_NO;
 585   return GNUNET_TRANSPORT_is_connected (n->state);
 586 }
 587
 588 /**
 589  * Send information about a new outbound quota to our clients.
 590  *
 591  * @param target affected peer
 592  * @param quota new quota
 593  */
 594 static void
 595 send_outbound_quota (const struct GNUNET_PeerIdentity *target,
 596                      struct GNUNET_BANDWIDTH_Value32NBO quota)
 597 {
 598   struct QuotaSetMessage q_msg;
 599
 600   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 601               "Sending outbound quota of %u Bps for peer `%s' to all clients\n",
 602               ntohl (quota.value__), GNUNET_i2s (target));
 603   q_msg.header.size = htons (sizeof (struct QuotaSetMessage));
 604   q_msg.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SET_QUOTA);
 605   q_msg.quota = quota;
 606   q_msg.peer = (*target);
 607   GST_clients_broadcast (&q_msg.header, GNUNET_NO);
 608 }
 609
 610
 611 /**
 612  * We don't need a given neighbour address any more.
 613  * Release its resources and give appropriate notifications
 614  * to ATS and other subsystems.
 615  *
 616  * @param na address we are done with; @a na itself must NOT be 'free'd, only the contents!
 617  */
 618 static void
 619 free_address (struct NeighbourAddress *na)
 620 {
 621   if (GNUNET_YES == na->ats_active)
 622   {
 623     GST_validation_set_address_use (na->address, na->session, GNUNET_NO);
 624     GNUNET_ATS_address_in_use (GST_ats, na->address, na->session, GNUNET_NO);
 625   }
 626
 627   na->bandwidth_in = GNUNET_BANDWIDTH_value_init (0);
 628   na->bandwidth_out = GNUNET_BANDWIDTH_value_init (0);
 629   na->ats_active = GNUNET_NO;
 630   na->keep_alive_nonce = 0;
 631   if (NULL != na->address)
 632   {
 633     GNUNET_HELLO_address_free (na->address);
 634     na->address = NULL;
 635   }
 636   na->session = NULL;
 637 }
 638
 639
 640 /**
 641  * Set net state for this neighbour and notify monitoring
 642  *
 643  * @param n the respective neighbour
 644  * @param s the new state
 645  */
 646 static void
 647 set_state (struct NeighbourMapEntry *n, enum GNUNET_TRANSPORT_PeerState s)
 648 {
 649   n->state = s;
 650   GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Neighbour `%s' changed state to %s\n",
 651       GNUNET_i2s (&n->id),
 652       GNUNET_TRANSPORT_ps2s(s));
 653   neighbour_change_cb (callback_cls,
 654       &n->id,
 655       n->primary_address.address,
 656       n->state, n->timeout,
 657       n->primary_address.bandwidth_in,
 658       n->primary_address.bandwidth_out);
 659 }
 660
 661
 662 /**
 663  * Set net state and state timeout for this neighbour and notify monitoring
 664  *
 665  * @param n the respective neighbour
 666  * @param s the new state
 667  * @param timeout the new timeout
 668  */
 669 static void
 670 set_state_and_timeout (struct NeighbourMapEntry *n,
 671     enum GNUNET_TRANSPORT_PeerState s,
 672     struct GNUNET_TIME_Absolute timeout)
 673 {
 674   n->state = s;
 675   n->timeout = timeout;
 676   GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Neighbour `%s' changed state to %s with timeout %s\n",
 677       GNUNET_i2s (&n->id),
 678       GNUNET_TRANSPORT_ps2s(s),
 679       GNUNET_STRINGS_absolute_time_to_string (timeout));
 680   neighbour_change_cb (callback_cls,
 681       &n->id,
 682       n->primary_address.address,
 683       n->state, n->timeout,
 684       n->primary_address.bandwidth_in,
 685       n->primary_address.bandwidth_out);
 686 }
 687
 688
 689 /**
 690  * Set new state timeout for this neighbour and notify monitoring
 691  *
 692  * @param n the respective neighbour
 693  * @param timeout the new timeout
 694  */
 695 static void
 696 set_timeout (struct NeighbourMapEntry *n,
 697     struct GNUNET_TIME_Absolute timeout)
 698 {
 699   n->timeout = timeout;
 700   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Neighbour `%s' changed timeout %s\n",
 701       GNUNET_i2s (&n->id),
 702       GNUNET_STRINGS_absolute_time_to_string (timeout));
 703   neighbour_change_cb (callback_cls,
 704       &n->id,
 705       n->primary_address.address,
 706       n->state, n->timeout,
 707       n->primary_address.bandwidth_in,
 708       n->primary_address.bandwidth_out);
 709 }
 710
 711
 712 /**
 713  * Initialize the alternative address of a neighbour
 714  *
 715  * @param n the neighbour
 716  * @param address address of the other peer, NULL if other peer
 717  *                       connected to us
 718  * @param session session to use (or NULL, in which case an
 719  *        address must be setup)
 720  * @param bandwidth_in inbound quota to be used when connection is up
 721  * @param bandwidth_out outbound quota to be used when connection is up
 722  */
 723 static void
 724 set_alternative_address (struct NeighbourMapEntry *n,
 725              const struct GNUNET_HELLO_Address *address,
 726              struct Session *session,
 727              struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in,
 728              struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out)
 729 {
 730   struct GNUNET_TRANSPORT_PluginFunctions *papi;
 731   if (NULL == (papi = GST_plugins_find (address->transport_name)))
 732   {
 733     GNUNET_break (0);
 734     return;
 735   }
 736   if (session == n->alternative_address.session)
 737   {
 738     n->alternative_address.bandwidth_in = bandwidth_in;
 739     n->alternative_address.bandwidth_out = bandwidth_out;
 740     return;
 741   }
 742   free_address (&n->alternative_address);
 743   if (NULL == session)
 744     session = papi->get_session (papi->cls, address);
 745   if (NULL == session)
 746   {
 747     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 748                 "Failed to obtain new session for peer `%s' and  address '%s'\n",
 749                 GNUNET_i2s (&address->peer), GST_plugins_a2s (address));
 750     GNUNET_ATS_address_destroyed (GST_ats, address, NULL);
 751     return;
 752   }
 753
 754   GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Neighbour `%s' configured alternative address %s\n",
 755       GNUNET_i2s (&n->id),
 756       GST_plugins_a2s(address));
 757
 758   n->alternative_address.address = GNUNET_HELLO_address_copy (address);
 759   n->alternative_address.bandwidth_in = bandwidth_in;
 760   n->alternative_address.bandwidth_out = bandwidth_out;
 761   n->alternative_address.session = session;
 762   n->alternative_address.ats_active = GNUNET_NO;
 763   n->alternative_address.keep_alive_nonce = 0;
 764 }
 765
 766
 767 /**
 768  * Initialize the primary address of a neighbour
 769  *
 770  * @param n the neighbour
 771  * @param address address of the other peer, NULL if other peer
 772  *                       connected to us
 773  * @param session session to use (or NULL, in which case an
 774  *        address must be setup)
 775  * @param bandwidth_in inbound quota to be used when connection is up
 776  * @param bandwidth_out outbound quota to be used when connection is up
 777  * @param is_active #GNUNET_YES to mark this as the active address with ATS
 778  */
 779 static void
 780 set_primary_address (struct NeighbourMapEntry *n,
 781              const struct GNUNET_HELLO_Address *address,
 782              struct Session *session,
 783              struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in,
 784              struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out,
 785              int is_active)
 786 {
 787   struct GNUNET_TRANSPORT_PluginFunctions *papi;
 788
 789   if (NULL == (papi = GST_plugins_find (address->transport_name)))
 790   {
 791     GNUNET_break (0);
 792     return;
 793   }
 794   if (session == n->primary_address.session)
 795   {
 796     n->primary_address.bandwidth_in = bandwidth_in;
 797     n->primary_address.bandwidth_out = bandwidth_out;
 798     if (is_active != n->primary_address.ats_active)
 799     {
 800       n->primary_address.ats_active = is_active;
 801       GNUNET_ATS_address_in_use (GST_ats, n->primary_address.address, n->primary_address.session, is_active);
 802       GST_validation_set_address_use (n->primary_address.address, n->primary_address.session, is_active);
 803     }
 804     if (GNUNET_YES == is_active)
 805     {
 806       GST_neighbours_set_incoming_quota (&address->peer, bandwidth_in);
 807       send_outbound_quota (&address->peer, bandwidth_out);
 808     }
 809     return;
 810   }
 811   free_address (&n->primary_address);
 812   if (NULL == session)
 813     session = papi->get_session (papi->cls, address);
 814   if (NULL == session)
 815   {
 816     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 817                 "Failed to obtain new session for peer `%s' and  address '%s'\n",
 818                 GNUNET_i2s (&address->peer), GST_plugins_a2s (address));
 819     GNUNET_ATS_address_destroyed (GST_ats, address, NULL);
 820     return;
 821   }
 822
 823   n->primary_address.address = GNUNET_HELLO_address_copy (address);
 824   n->primary_address.bandwidth_in = bandwidth_in;
 825   n->primary_address.bandwidth_out = bandwidth_out;
 826   n->primary_address.session = session;
 827   n->primary_address.ats_active = is_active;
 828   n->primary_address.keep_alive_nonce = 0;
 829   if (GNUNET_YES == is_active)
 830   {
 831     /* Telling ATS about new session */
 832     GNUNET_ATS_address_in_use (GST_ats, n->primary_address.address, n->primary_address.session, GNUNET_YES);
 833     GST_validation_set_address_use (n->primary_address.address, n->primary_address.session, GNUNET_YES);
 834     GST_neighbours_set_incoming_quota (&address->peer, bandwidth_in);
 835     send_outbound_quota (&address->peer, bandwidth_out);
 836   }
 837
 838   GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Neighbour `%s' switched to address `%s'\n",
 839       GNUNET_i2s (&n->id),
 840       GST_plugins_a2s(address));
 841
 842   neighbour_change_cb (callback_cls,
 843       &n->id,
 844       n->primary_address.address,
 845       n->state, n->timeout,
 846       n->primary_address.bandwidth_in,
 847       n->primary_address.bandwidth_out);
 848 }
 849
 850 /**
 851  * Clear the primary address of a neighbour since this address is not
 852  * valid anymore and notify monitoring about it
 853  *
 854  * @param n the neighbour
 855  */
 856 static void
 857 unset_primary_address (struct NeighbourMapEntry *n)
 858 {
 859   /* Unset primary address */
 860   free_address (&n->primary_address);
 861
 862   /* Notify monitoring about it */
 863   neighbour_change_cb (callback_cls,
 864       &n->id,
 865       NULL,
 866       n->state, n->timeout,
 867       n->primary_address.bandwidth_in,
 868       n->primary_address.bandwidth_out);
 869 }
 870
 871 /**
 872  * Clear the alternative address of a neighbour since this address is not
 873  * valid anymore
 874  *
 875  * @param n the neighbour
 876  */
 877 static void
 878 unset_alternative_address (struct NeighbourMapEntry *n)
 879 {
 880   /* Unset primary address */
 881   free_address (&n->alternative_address);
 882 }
 883
 884 /**
 885  * Free a neighbour map entry.
 886  *
 887  * @param n entry to free
 888  * @param keep_sessions #GNUNET_NO to tell plugin to terminate sessions,
 889  *                      #GNUNET_YES to keep all sessions
 890  */
 891 static void
 892 free_neighbour (struct NeighbourMapEntry *n,
 893                 int keep_sessions)
 894 {
 895   struct MessageQueue *mq;
 896   struct GNUNET_TRANSPORT_PluginFunctions *papi;
 897   struct GNUNET_HELLO_Address *backup_primary;
 898
 899   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 900               "Freeing neighbour state of peer `%s'\n",
 901               GNUNET_i2s (&n->id));
 902   n->is_active = NULL; /* always free'd by its own continuation! */
 903
 904   /* fail messages currently in the queue */
 905   while (NULL != (mq = n->messages_head))
 906   {
 907     GNUNET_CONTAINER_DLL_remove (n->messages_head, n->messages_tail, mq);
 908     if (NULL != mq->cont)
 909       mq->cont (mq->cont_cls, GNUNET_SYSERR, mq->message_buf_size, 0);
 910     GNUNET_free (mq);
 911   }
 912   /* It is too late to send other peer disconnect notifications, but at
 913      least internally we need to get clean... */
 914   if (GNUNET_YES == test_connected (n))
 915   {
 916     GNUNET_STATISTICS_set (GST_stats,
 917                            gettext_noop ("# peers connected"),
 918                            --neighbours_connected,
 919                            GNUNET_NO);
 920     disconnect_notify_cb (callback_cls, &n->id);
 921   }
 922
 923   /* Mark peer as disconnected */
 924   set_state (n, GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED);
 925
 926   if (NULL != n->primary_address.address)
 927     backup_primary = GNUNET_HELLO_address_copy (n->primary_address.address);
 928   else
 929     backup_primary = NULL;
 930
 931   /* free addresses and mark as unused */
 932   unset_primary_address (n);
 933   free_address (&n->alternative_address);
 934
 935   /* cut all transport-level connection for this peer */
 936   if ((GNUNET_NO == keep_sessions) &&
 937       (NULL != backup_primary) &&
 938       (NULL != (papi = GST_plugins_find (backup_primary->transport_name))))
 939     papi->disconnect_peer (papi->cls, &n->id);
 940
 941   if (NULL != backup_primary)
 942     GNUNET_HELLO_address_free (backup_primary);
 943   GNUNET_assert (GNUNET_YES ==
 944                  GNUNET_CONTAINER_multipeermap_remove (neighbours,
 945                                                        &n->id, n));
 946
 947   /* Cancel address requests for this peer */
 948   if (NULL != n->suggest_handle)
 949   {
 950     GNUNET_ATS_suggest_address_cancel (GST_ats, &n->id);
 951     n->suggest_handle = NULL;
 952   }
 953
 954   /* Cancel the disconnect task */
 955   if (GNUNET_SCHEDULER_NO_TASK != n->delayed_disconnect_task)
 956   {
 957     GNUNET_SCHEDULER_cancel (n->delayed_disconnect_task);
 958     n->delayed_disconnect_task = GNUNET_SCHEDULER_NO_TASK;
 959   }
 960
 961   /* Cancel the master task */
 962   if (GNUNET_SCHEDULER_NO_TASK != n->task)
 963   {
 964     GNUNET_SCHEDULER_cancel (n->task);
 965     n->task = GNUNET_SCHEDULER_NO_TASK;
 966   }
 967   /* free rest of memory */
 968   GNUNET_free (n);
 969 }
 970
 971
 972 /**
 973  * Transmit a message using the current session of the given
 974  * neighbour.
 975  *
 976  * @param n entry for the recipient
 977  * @param msgbuf buffer to transmit
 978  * @param msgbuf_size number of bytes in @a msgbuf buffer
 979  * @param priority transmission priority
 980  * @param timeout transmission timeout
 981  * @param use_keepalive_timeout #GNUNET_YES to use plugin-specific keep-alive
 982  *        timeout (@a timeout is ignored in that case), #GNUNET_NO otherwise
 983  * @param cont continuation to call when finished (can be NULL)
 984  * @param cont_cls closure for @a cont
 985  * @return timeout (copy of @a timeout or a calculated one if
 986  *         @a use_keepalive_timeout is #GNUNET_YES.
 987  */
 988 static struct GNUNET_TIME_Relative
 989 send_with_session (struct NeighbourMapEntry *n,
 990                    const char *msgbuf, size_t msgbuf_size,
 991                    uint32_t priority,
 992                    struct GNUNET_TIME_Relative timeout,
 993                    unsigned int use_keepalive_timeout,
 994                    GNUNET_TRANSPORT_TransmitContinuation cont,
 995                    void *cont_cls)
 996 {
 997   struct GNUNET_TRANSPORT_PluginFunctions *papi;
 998   struct GNUNET_TIME_Relative result = GNUNET_TIME_UNIT_FOREVER_REL;
 999
1000   GNUNET_assert (n->primary_address.session != NULL);
1001   if ( ((NULL == (papi = GST_plugins_find (n->primary_address.address->transport_name)) ||
1002          (-1 == papi->send (papi->cls,
1003                             n->primary_address.session,
1004                             msgbuf, msgbuf_size,
1005                             priority,
1006                             (result = (GNUNET_NO == use_keepalive_timeout) ? timeout :
1007                                 GNUNET_TIME_relative_divide (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT,
1008                                                              papi->query_keepalive_factor (papi->cls))),
1009                             cont, cont_cls)))) &&
1010        (NULL != cont))
1011     cont (cont_cls, &n->id, GNUNET_SYSERR, msgbuf_size, 0);
1012   GST_neighbours_notify_data_sent (&n->id,
1013       n->primary_address.address, n->primary_address.session, msgbuf_size);
1014   GNUNET_break (NULL != papi);
1015   return result;
1016 }
1017
1018
1019 /**
1020  * Master task run for every neighbour.  Performs all of the time-related
1021  * activities (keep alive, send next message, disconnect if idle, finish
1022  * clean up after disconnect).
1023  *
1024  * @param cls the `struct NeighbourMapEntry` for which we are running
1025  * @param tc scheduler context (unused)
1026  */
1027 static void
1028 master_task (void *cls,
1029              const struct GNUNET_SCHEDULER_TaskContext *tc);
1030
1031
1032 /**
1033  * Function called when the 'DISCONNECT' message has been sent by the
1034  * plugin.  Frees the neighbour --- if the entry still exists.
1035  *
1036  * @param cls NULL
1037  * @param target identity of the neighbour that was disconnected
1038  * @param result #GNUNET_OK if the disconnect got out successfully
1039  * @param payload bytes payload
1040  * @param physical bytes physical
1041  */
1042 static void
1043 send_disconnect_cont (void *cls, const struct GNUNET_PeerIdentity *target,
1044                       int result, size_t payload, size_t physical)
1045 {
1046   struct NeighbourMapEntry *n;
1047
1048   n = lookup_neighbour (target);
1049   if (NULL == n)
1050     return; /* already gone */
1051   if (GNUNET_TRANSPORT_PS_DISCONNECT != n->state)
1052     return; /* have created a fresh entry since */
1053   if (GNUNET_SCHEDULER_NO_TASK != n->task)
1054     GNUNET_SCHEDULER_cancel (n->task);
1055   n->task = GNUNET_SCHEDULER_add_now (&master_task, n);
1056 }
1057
1058
1059 /**
1060  * Transmit a DISCONNECT message to the other peer.
1061  *
1062  * @param n neighbour to send DISCONNECT message.
1063  */
1064 static void
1065 send_disconnect (struct NeighbourMapEntry *n)
1066 {
1067   struct SessionDisconnectMessage disconnect_msg;
1068
1069   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1070               "Sending DISCONNECT message to peer `%4s'\n",
1071               GNUNET_i2s (&n->id));
1072   disconnect_msg.header.size = htons (sizeof (struct SessionDisconnectMessage));
1073   disconnect_msg.header.type =
1074       htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_DISCONNECT);
1075   disconnect_msg.reserved = htonl (0);
1076   disconnect_msg.purpose.size =
1077       htonl (sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
1078              sizeof (struct GNUNET_CRYPTO_EddsaPublicKey) +
1079              sizeof (struct GNUNET_TIME_AbsoluteNBO));
1080   disconnect_msg.purpose.purpose =
1081       htonl (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_DISCONNECT);
1082   disconnect_msg.timestamp =
1083       GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get ());
1084   disconnect_msg.public_key = GST_my_identity.public_key;
1085   GNUNET_assert (GNUNET_OK ==
1086                  GNUNET_CRYPTO_eddsa_sign (GST_my_private_key,
1087                                          &disconnect_msg.purpose,
1088                                          &disconnect_msg.signature));
1089
1090   (void) send_with_session (n, (const char *) &disconnect_msg,
1091       sizeof (disconnect_msg), UINT32_MAX, GNUNET_TIME_UNIT_FOREVER_REL,
1092       GNUNET_NO, &send_disconnect_cont, NULL );
1093   GNUNET_STATISTICS_update (GST_stats,
1094                             gettext_noop
1095                             ("# DISCONNECT messages sent"), 1,
1096                             GNUNET_NO);
1097 }
1098
1099
1100 /**
1101  * Disconnect from the given neighbour, clean up the record.
1102  *
1103  * @param n neighbour to disconnect from
1104  */
1105 static void
1106 disconnect_neighbour (struct NeighbourMapEntry *n)
1107 {
1108   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1109               "Disconnecting from peer %s in state %s\n",
1110               GNUNET_i2s (&n->id),
1111               GNUNET_TRANSPORT_ps2s (n->state));
1112   /* depending on state, notify neighbour and/or upper layers of this peer
1113      about disconnect */
1114   switch (n->state)
1115   {
1116   case GNUNET_TRANSPORT_PS_NOT_CONNECTED:
1117   case GNUNET_TRANSPORT_PS_INIT_ATS:
1118     /* other peer is completely unaware of us, no need to send DISCONNECT */
1119     free_neighbour (n, GNUNET_NO);
1120     return;
1121   case GNUNET_TRANSPORT_PS_SYN_SENT:
1122     send_disconnect (n);
1123     set_state (n, GNUNET_TRANSPORT_PS_DISCONNECT);
1124     break;
1125   case GNUNET_TRANSPORT_PS_SYN_RECV_ATS:
1126     /* we never ACK'ed the other peer's request, no need to send DISCONNECT */
1127     free_neighbour (n, GNUNET_NO);
1128     return;
1129   case GNUNET_TRANSPORT_PS_SYN_RECV_ACK:
1130     /* we DID ACK the other peer's request, must send DISCONNECT */
1131     send_disconnect (n);
1132     set_state (n, GNUNET_TRANSPORT_PS_DISCONNECT);
1133     break;
1134   case GNUNET_TRANSPORT_PS_SWITCH_SYN_SENT:
1135   case GNUNET_TRANSPORT_PS_CONNECTED:
1136   case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
1137     /* we are currently connected, need to send disconnect and do
1138        internal notifications and update statistics */
1139     send_disconnect (n);
1140     GNUNET_STATISTICS_set (GST_stats,
1141                            gettext_noop ("# peers connected"),
1142                            --neighbours_connected,
1143                            GNUNET_NO);
1144     disconnect_notify_cb (callback_cls, &n->id);
1145     set_state (n, GNUNET_TRANSPORT_PS_DISCONNECT);
1146     break;
1147   case GNUNET_TRANSPORT_PS_RECONNECT_ATS:
1148     /* Disconnecting while waiting for an ATS address to reconnect,
1149      * cannot send DISCONNECT */
1150     free_neighbour (n, GNUNET_NO);
1151     return;
1152   case GNUNET_TRANSPORT_PS_DISCONNECT:
1153     /* already disconnected, ignore */
1154     break;
1155   case GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED:
1156     /* already cleaned up, how did we get here!? */
1157     GNUNET_assert (0);
1158     break;
1159   default:
1160     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1161                 "Unhandled state `%s'\n",
1162                 GNUNET_TRANSPORT_ps2s (n->state));
1163     GNUNET_break (0);
1164     break;
1165   }
1166   /* schedule timeout to clean up */
1167   if (GNUNET_SCHEDULER_NO_TASK != n->task)
1168     GNUNET_SCHEDULER_cancel (n->task);
1169   n->task = GNUNET_SCHEDULER_add_delayed (DISCONNECT_SENT_TIMEOUT,
1170                                           &master_task, n);
1171 }
1172
1173
1174 /**
1175  * We're done with our transmission attempt, continue processing.
1176  *
1177  * @param cls the `struct MessageQueue` of the message
1178  * @param receiver intended receiver
1179  * @param success whether it worked or not
1180  * @param size_payload bytes payload sent
1181  * @param physical bytes sent on wire
1182  */
1183 static void
1184 transmit_send_continuation (void *cls,
1185                             const struct GNUNET_PeerIdentity *receiver,
1186                             int success, size_t size_payload, size_t physical)
1187 {
1188   struct MessageQueue *mq = cls;
1189   struct NeighbourMapEntry *n;
1190
1191   if (NULL == (n = lookup_neighbour (receiver)))
1192   {
1193     GNUNET_free (mq);
1194     return; /* disconnect or other error while transmitting, can happen */
1195   }
1196   if (n->is_active == mq)
1197   {
1198     /* this is still "our" neighbour, remove us from its queue
1199        and allow it to send the next message now */
1200     n->is_active = NULL;
1201     if (GNUNET_SCHEDULER_NO_TASK != n->task)
1202       GNUNET_SCHEDULER_cancel (n->task);
1203     n->task = GNUNET_SCHEDULER_add_now (&master_task, n);
1204   }
1205   if (bytes_in_send_queue < mq->message_buf_size)
1206   {
1207     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1208                 "Bytes_in_send_queue `%u', Message_size %u, result: %s, payload %u, on wire %u\n",
1209                 bytes_in_send_queue, mq->message_buf_size,
1210                 (GNUNET_OK == success) ? "OK" : "FAIL",
1211                 size_payload, physical);
1212     GNUNET_break (0);
1213   }
1214
1215
1216   GNUNET_break (size_payload == mq->message_buf_size);
1217   bytes_in_send_queue -= mq->message_buf_size;
1218   GNUNET_STATISTICS_set (GST_stats,
1219                         gettext_noop
1220                          ("# bytes in message queue for other peers"),
1221                          bytes_in_send_queue, GNUNET_NO);
1222   if (GNUNET_OK == success)
1223     GNUNET_STATISTICS_update (GST_stats,
1224                               gettext_noop
1225                               ("# messages transmitted to other peers"),
1226                               1, GNUNET_NO);
1227   else
1228     GNUNET_STATISTICS_update (GST_stats,
1229                               gettext_noop
1230                               ("# transmission failures for messages to other peers"),
1231                               1, GNUNET_NO);
1232   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1233               "Sending message to `%s' of type %u with %u bytes was a %s\n",
1234               GNUNET_i2s (receiver),
1235               ntohs (((struct GNUNET_MessageHeader *) mq->message_buf)->type),
1236               mq->message_buf_size,
1237               (success == GNUNET_OK) ? "success" : "FAILURE");
1238   if (NULL != mq->cont)
1239     mq->cont (mq->cont_cls, success, size_payload, physical);
1240   GNUNET_free (mq);
1241 }
1242
1243
1244 /**
1245  * Check the message list for the given neighbour and if we can
1246  * send a message, do so.  This function should only be called
1247  * if the connection is at least generally ready for transmission.
1248  * While we will only send one message at a time, no bandwidth
1249  * quota management is performed here.  If a message was given to
1250  * the plugin, the continuation will automatically re-schedule
1251  * the 'master' task once the next message might be transmitted.
1252  *
1253  * @param n target peer for which to transmit
1254  */
1255 static void
1256 try_transmission_to_peer (struct NeighbourMapEntry *n)
1257 {
1258   struct MessageQueue *mq;
1259   struct GNUNET_TIME_Relative timeout;
1260
1261   if (NULL == n->primary_address.address)
1262   {
1263     /* no address, why are we here? */
1264     GNUNET_break (0);
1265     return;
1266   }
1267   if ((0 == n->primary_address.address->address_length) &&
1268       (NULL == n->primary_address.session))
1269   {
1270     /* no address, why are we here? */
1271     GNUNET_break (0);
1272     return;
1273   }
1274   if (NULL != n->is_active)
1275   {
1276     /* transmission already pending */
1277     return;
1278   }
1279
1280   /* timeout messages from the queue that are past their due date */
1281   while (NULL != (mq = n->messages_head))
1282   {
1283     timeout = GNUNET_TIME_absolute_get_remaining (mq->timeout);
1284     if (timeout.rel_value_us > 0)
1285       break;
1286     GNUNET_STATISTICS_update (GST_stats,
1287                               gettext_noop
1288                               ("# messages timed out while in transport queue"),
1289                               1, GNUNET_NO);
1290     GNUNET_CONTAINER_DLL_remove (n->messages_head, n->messages_tail, mq);
1291     n->is_active = mq;
1292     transmit_send_continuation (mq, &n->id,
1293                                 GNUNET_SYSERR,
1294                                 mq->message_buf_size, 0);     /* timeout */
1295   }
1296   if (NULL == mq)
1297     return;                     /* no more messages */
1298   GNUNET_CONTAINER_DLL_remove (n->messages_head, n->messages_tail, mq);
1299   n->is_active = mq;
1300
1301   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1302       "Giving message with %u bytes to plugin session %p\n",
1303       mq->message_buf_size, n->primary_address.session);
1304
1305   (void) send_with_session (n,
1306                             mq->message_buf, mq->message_buf_size,
1307                             0 /* priority */, timeout, GNUNET_NO,
1308                             &transmit_send_continuation, mq);
1309 }
1310
1311
1312 /**
1313  * Send keepalive message to the neighbour.  Must only be called
1314  * if we are on 'connected' state or while trying to switch addresses.
1315  * Will internally determine if a keepalive is truly needed (so can
1316  * always be called).
1317  *
1318  * @param n neighbour that went idle and needs a keepalive
1319  */
1320 static void
1321 send_keepalive (struct NeighbourMapEntry *n)
1322 {
1323   struct SessionKeepAliveMessage m;
1324   struct GNUNET_TIME_Relative timeout;
1325   uint32_t nonce;
1326
1327   GNUNET_assert ((GNUNET_TRANSPORT_PS_CONNECTED == n->state) ||
1328                  (GNUNET_TRANSPORT_PS_SWITCH_SYN_SENT));
1329   if (GNUNET_TIME_absolute_get_remaining (n->keep_alive_time).rel_value_us > 0)
1330     return; /* no keepalive needed at this time */
1331
1332   nonce = 0; /* 0 indicates 'not set' */
1333   while (0 == nonce)
1334     nonce = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1335
1336   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1337       "Sending keep alive to peer `%s' with nonce %u\n",
1338       GNUNET_i2s (&n->id), nonce);
1339
1340   m.header.size = htons (sizeof (struct SessionKeepAliveMessage));
1341   m.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_KEEPALIVE);
1342   m.nonce = htonl (nonce);
1343
1344   timeout = send_with_session (n,
1345                                (const void *) &m, sizeof (m),
1346                                UINT32_MAX /* priority */,
1347                                GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_YES,
1348                                NULL, NULL);
1349   GNUNET_STATISTICS_update (GST_stats, gettext_noop ("# keepalives sent"), 1,
1350                             GNUNET_NO);
1351   n->primary_address.keep_alive_nonce = nonce;
1352   n->expect_latency_response = GNUNET_YES;
1353   n->last_keep_alive_time = GNUNET_TIME_absolute_get ();
1354   n->keep_alive_time = GNUNET_TIME_relative_to_absolute (timeout);
1355
1356 }
1357
1358
1359 /**
1360  * Keep the connection to the given neighbour alive longer,
1361  * we received a KEEPALIVE (or equivalent); send a response.
1362  *
1363  * @param neighbour neighbour to keep alive (by sending keep alive response)
1364  * @param m the keep alive message containing the nonce to respond to
1365  */
1366 void
1367 GST_neighbours_keepalive (const struct GNUNET_PeerIdentity *neighbour,
1368     const struct GNUNET_MessageHeader *m)
1369 {
1370   struct NeighbourMapEntry *n;
1371   const struct SessionKeepAliveMessage *msg_in;
1372   struct SessionKeepAliveMessage msg;
1373
1374   if (sizeof (struct SessionKeepAliveMessage) != ntohs (m->size))
1375     return;
1376
1377   msg_in = (struct SessionKeepAliveMessage *) m;
1378   if (NULL == (n = lookup_neighbour (neighbour)))
1379   {
1380     GNUNET_STATISTICS_update (GST_stats,
1381                               gettext_noop
1382                               ("# KEEPALIVE messages discarded (peer unknown)"),
1383                               1, GNUNET_NO);
1384     return;
1385   }
1386   if (NULL == n->primary_address.session)
1387   {
1388     GNUNET_STATISTICS_update (GST_stats,
1389                               gettext_noop
1390                               ("# KEEPALIVE messages discarded (no session)"),
1391                               1, GNUNET_NO);
1392     return;
1393   }
1394
1395   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1396       "Received keep alive request from peer `%s' with nonce %u\n",
1397       GNUNET_i2s (&n->id), ntohl (msg_in->nonce));
1398
1399   /* send reply to allow neighbour to measure latency */
1400   msg.header.size = htons (sizeof (struct SessionKeepAliveMessage));
1401   msg.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_KEEPALIVE_RESPONSE);
1402   msg.nonce = msg_in->nonce;
1403   (void) send_with_session(n,
1404                            (const void *) &msg, sizeof (struct SessionKeepAliveMessage),
1405                            UINT32_MAX /* priority */,
1406                            GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_YES,
1407                            NULL, NULL);
1408 }
1409
1410
1411 /**
1412  * We received a KEEP_ALIVE_RESPONSE message and use this to calculate
1413  * latency to this peer.  Pass the updated information (existing ats
1414  * plus calculated latency) to ATS.
1415  *
1416  * @param neighbour neighbour to keep alive
1417  * @param m the message containing the keep alive response
1418  */
1419 void
1420 GST_neighbours_keepalive_response (const struct GNUNET_PeerIdentity *neighbour,
1421     const struct GNUNET_MessageHeader *m)
1422 {
1423   struct NeighbourMapEntry *n;
1424   const struct SessionKeepAliveMessage *msg;
1425   struct GNUNET_TRANSPORT_PluginFunctions *papi;
1426   uint32_t latency;
1427   struct GNUNET_ATS_Information ats;
1428
1429   if (sizeof (struct SessionKeepAliveMessage) != ntohs (m->size))
1430     return;
1431
1432   msg = (const struct SessionKeepAliveMessage *) m;
1433   if (NULL == (n = lookup_neighbour (neighbour)))
1434   {
1435     GNUNET_STATISTICS_update (GST_stats,
1436                               gettext_noop
1437                               ("# KEEPALIVE_RESPONSE messages discarded (not connected)"),
1438                               1, GNUNET_NO);
1439     return;
1440   }
1441   if ( (GNUNET_TRANSPORT_PS_CONNECTED != n->state) ||
1442        (GNUNET_YES != n->expect_latency_response) )
1443   {
1444     GNUNET_STATISTICS_update (GST_stats,
1445                               gettext_noop
1446                               ("# KEEPALIVE_RESPONSE messages discarded (not expected)"),
1447                               1, GNUNET_NO);
1448     return;
1449   }
1450   if (NULL == n->primary_address.address)
1451   {
1452     GNUNET_STATISTICS_update (GST_stats,
1453                               gettext_noop
1454                               ("# KEEPALIVE_RESPONSE messages discarded (address changed)"),
1455                               1, GNUNET_NO);
1456     return;
1457   }
1458   if (n->primary_address.keep_alive_nonce != ntohl (msg->nonce))
1459   {
1460     GNUNET_STATISTICS_update (GST_stats,
1461                               gettext_noop
1462                               ("# KEEPALIVE_RESPONSE messages discarded (wrong nonce)"),
1463                               1, GNUNET_NO);
1464     return;
1465   }
1466   else
1467   {
1468     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1469         "Received keep alive response from peer `%s' for session %p\n",
1470         GNUNET_i2s (&n->id), n->primary_address.session);
1471
1472   }
1473
1474   /* Update session timeout here */
1475   if (NULL != (papi = GST_plugins_find (n->primary_address.address->transport_name)))
1476   {
1477     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1478         "Updating session for peer `%s' for session %p\n",
1479         GNUNET_i2s (&n->id), n->primary_address.session);
1480     papi->update_session_timeout (papi->cls, &n->id, n->primary_address.session);
1481   }
1482   else
1483   {
1484     GNUNET_break (0);
1485   }
1486
1487   n->primary_address.keep_alive_nonce = 0;
1488   n->expect_latency_response = GNUNET_NO;
1489   n->latency = GNUNET_TIME_absolute_get_duration (n->last_keep_alive_time);
1490   set_timeout (n, GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT));
1491
1492   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1493               "Latency for peer `%s' is %s\n",
1494               GNUNET_i2s (&n->id),
1495               GNUNET_STRINGS_relative_time_to_string (n->latency,
1496                                                       GNUNET_YES));
1497   /* append latency */
1498   ats.type = htonl (GNUNET_ATS_QUALITY_NET_DELAY);
1499   if (n->latency.rel_value_us > UINT32_MAX)
1500     latency = UINT32_MAX;
1501   else
1502     latency = n->latency.rel_value_us;
1503   ats.value = htonl (latency);
1504   GST_ats_update_metrics (&n->id, n->primary_address.address,
1505       n->primary_address.session, &ats, 1);
1506 }
1507
1508
1509 /**
1510  * We have received a message from the given sender.  How long should
1511  * we delay before receiving more?  (Also used to keep the peer marked
1512  * as live).
1513  *
1514  * @param sender sender of the message
1515  * @param size size of the message
1516  * @param do_forward set to #GNUNET_YES if the message should be forwarded to clients
1517  *                   #GNUNET_NO if the neighbour is not connected or violates the quota,
1518  *                   #GNUNET_SYSERR if the connection is not fully up yet
1519  * @return how long to wait before reading more from this sender
1520  */
1521 struct GNUNET_TIME_Relative
1522 GST_neighbours_calculate_receive_delay (const struct GNUNET_PeerIdentity
1523                                         *sender, ssize_t size, int *do_forward)
1524 {
1525   struct NeighbourMapEntry *n;
1526   struct GNUNET_TIME_Relative ret;
1527
1528   if (NULL == neighbours)
1529   {
1530     *do_forward = GNUNET_NO;
1531     return GNUNET_TIME_UNIT_FOREVER_REL; /* This can happen during shutdown */
1532   }
1533   if (NULL == (n = lookup_neighbour (sender)))
1534   {
1535     GST_neighbours_try_connect (sender);
1536     if (NULL == (n = lookup_neighbour (sender)))
1537     {
1538       GNUNET_STATISTICS_update (GST_stats,
1539                                 gettext_noop
1540                                 ("# messages discarded due to lack of neighbour record"),
1541                                 1, GNUNET_NO);
1542       *do_forward = GNUNET_NO;
1543       return GNUNET_TIME_UNIT_ZERO;
1544     }
1545   }
1546   if (! test_connected (n))
1547   {
1548     *do_forward = GNUNET_SYSERR;
1549     return GNUNET_TIME_UNIT_ZERO;
1550   }
1551   if (GNUNET_YES == GNUNET_BANDWIDTH_tracker_consume (&n->in_tracker, size))
1552   {
1553     n->quota_violation_count++;
1554     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1555                 "Bandwidth quota (%u b/s) violation detected (total of %u).\n",
1556                 n->in_tracker.available_bytes_per_s__,
1557                 n->quota_violation_count);
1558     /* Discount 32k per violation */
1559     GNUNET_BANDWIDTH_tracker_consume (&n->in_tracker, -32 * 1024);
1560   }
1561   else
1562   {
1563     if (n->quota_violation_count > 0)
1564     {
1565       /* try to add 32k back */
1566       GNUNET_BANDWIDTH_tracker_consume (&n->in_tracker, 32 * 1024);
1567       n->quota_violation_count--;
1568     }
1569   }
1570   if (n->quota_violation_count > QUOTA_VIOLATION_DROP_THRESHOLD)
1571   {
1572     GNUNET_STATISTICS_update (GST_stats,
1573                               gettext_noop
1574                               ("# bandwidth quota violations by other peers"),
1575                               1, GNUNET_NO);
1576     *do_forward = GNUNET_NO;
1577     return GNUNET_CONSTANTS_QUOTA_VIOLATION_TIMEOUT;
1578   }
1579   *do_forward = GNUNET_YES;
1580   ret = GNUNET_BANDWIDTH_tracker_get_delay (&n->in_tracker, 32 * 1024);
1581   if (ret.rel_value_us > 0)
1582   {
1583     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1584                 "Throttling read (%llu bytes excess at %u b/s), waiting %s before reading more.\n",
1585                 (unsigned long long) n->in_tracker.
1586                 consumption_since_last_update__,
1587                 (unsigned int) n->in_tracker.available_bytes_per_s__,
1588                 GNUNET_STRINGS_relative_time_to_string (ret, GNUNET_YES));
1589     GNUNET_STATISTICS_update (GST_stats,
1590                               gettext_noop ("# ms throttling suggested"),
1591                               (int64_t) ret.rel_value_us / 1000LL,
1592                               GNUNET_NO);
1593   }
1594   return ret;
1595 }
1596
1597
1598 /**
1599  * Transmit a message to the given target using the active connection.
1600  *
1601  * @param target destination
1602  * @param msg message to send
1603  * @param msg_size number of bytes in msg
1604  * @param timeout when to fail with timeout
1605  * @param cont function to call when done
1606  * @param cont_cls closure for 'cont'
1607  */
1608 void
1609 GST_neighbours_send (const struct GNUNET_PeerIdentity *target, const void *msg,
1610                      size_t msg_size, struct GNUNET_TIME_Relative timeout,
1611                      GST_NeighbourSendContinuation cont, void *cont_cls)
1612 {
1613   struct NeighbourMapEntry *n;
1614   struct MessageQueue *mq;
1615
1616   /* All ove these cases should never happen; they are all API violations.
1617      But we check anyway, just to be sure. */
1618   if (NULL == (n = lookup_neighbour (target)))
1619   {
1620     GNUNET_break (0);
1621     if (NULL != cont)
1622       cont (cont_cls, GNUNET_SYSERR, msg_size, 0);
1623     return;
1624   }
1625   if (GNUNET_YES != test_connected (n))
1626   {
1627     GNUNET_break (0);
1628     if (NULL != cont)
1629       cont (cont_cls, GNUNET_SYSERR, msg_size, 0);
1630     return;
1631   }
1632   bytes_in_send_queue += msg_size;
1633   GNUNET_STATISTICS_set (GST_stats,
1634                          gettext_noop
1635                          ("# bytes in message queue for other peers"),
1636                          bytes_in_send_queue, GNUNET_NO);
1637   mq = GNUNET_malloc (sizeof (struct MessageQueue) + msg_size);
1638   mq->cont = cont;
1639   mq->cont_cls = cont_cls;
1640   memcpy (&mq[1], msg, msg_size);
1641   mq->message_buf = (const char *) &mq[1];
1642   mq->message_buf_size = msg_size;
1643   mq->timeout = GNUNET_TIME_relative_to_absolute (timeout);
1644
1645   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Enqueueing %u bytes to send to peer %s\n",
1646       msg_size, GNUNET_i2s (target));
1647
1648   GNUNET_CONTAINER_DLL_insert_tail (n->messages_head, n->messages_tail, mq);
1649   if (GNUNET_SCHEDULER_NO_TASK != n->task)
1650     GNUNET_SCHEDULER_cancel (n->task);
1651   n->task = GNUNET_SCHEDULER_add_now (&master_task, n);
1652 }
1653
1654 static void
1655 send_session_connect_cont (void *cls,
1656                       const struct GNUNET_PeerIdentity *target,
1657                       int result,
1658                       size_t size_payload,
1659                       size_t size_on_wire)
1660 {
1661   struct NeighbourMapEntry *n;
1662
1663   n = lookup_neighbour (target);
1664   if (NULL == n)
1665   {
1666     /* SYN continuation was called after neighbor was freed,
1667      * for example due to a time out for the state or the session
1668      * used was already terminated: nothing to do here... */
1669     return;
1670   }
1671
1672   if ( (GNUNET_TRANSPORT_PS_SYN_SENT != n->state) &&
1673        (GNUNET_TRANSPORT_PS_RECONNECT_SENT != n->state) &&
1674        (GNUNET_TRANSPORT_PS_SWITCH_SYN_SENT != n->state))
1675   {
1676     /* SYN continuation was called after neighbor changed state,
1677      * for example due to a time out for the state or the session
1678      * used was already terminated: nothing to do here... */
1679     return;
1680   }
1681   if (GNUNET_OK == result)
1682     return;
1683
1684   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1685             _("Failed to send SYN message to peer `%s' using address `%s' session %p\n"),
1686             GNUNET_i2s (target),
1687             GST_plugins_a2s (n->primary_address.address),
1688             n->primary_address.session);
1689
1690   switch (n->state) {
1691   case GNUNET_TRANSPORT_PS_SYN_SENT:
1692     /* Remove address and request and additional one */
1693     GNUNET_ATS_address_destroyed (GST_ats, n->primary_address.address,
1694         n->primary_address.session);
1695     GNUNET_ATS_address_destroyed (GST_ats, n->primary_address.address, NULL );
1696     unset_primary_address (n);
1697     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_INIT_ATS,
1698         GNUNET_TIME_relative_to_absolute (FAST_RECONNECT_TIMEOUT));
1699     break;
1700   case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
1701     /* Remove address and request and additional one */
1702     GNUNET_ATS_address_destroyed (GST_ats, n->primary_address.address,
1703         n->primary_address.session);
1704     GNUNET_ATS_address_destroyed (GST_ats, n->primary_address.address, NULL );
1705     unset_primary_address (n);
1706     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_RECONNECT_ATS,
1707         GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
1708     break;
1709   case GNUNET_TRANSPORT_PS_SWITCH_SYN_SENT:
1710     /* Remove address and request and go back to primary address */
1711     GNUNET_STATISTICS_update (GST_stats, gettext_noop
1712         ("# Failed attempts to switch addresses (failed to send SYN CONT)"), 1, GNUNET_NO);
1713     GNUNET_ATS_address_destroyed (GST_ats, n->alternative_address.address,
1714         n->alternative_address.session);
1715     GNUNET_ATS_address_destroyed (GST_ats, n->alternative_address.address,
1716         NULL );
1717     unset_alternative_address (n);
1718     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_CONNECTED,
1719         GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
1720     break;
1721   default:
1722     disconnect_neighbour (n);
1723     break;
1724   }
1725 }
1726
1727 /**
1728  * Send a SYN message via the given address.
1729  *
1730  * @param na address to use
1731  */
1732 static void
1733 send_syn (struct NeighbourAddress *na)
1734 {
1735   struct GNUNET_TRANSPORT_PluginFunctions *papi;
1736   struct TransportSynMessage connect_msg;
1737   struct NeighbourMapEntry *n;
1738
1739   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1740               "Sending SYN message to peer `%s'\n",
1741               GNUNET_i2s (&na->address->peer));
1742
1743   if (NULL == (papi = GST_plugins_find (na->address->transport_name)))
1744   {
1745     GNUNET_break (0);
1746     return;
1747   }
1748   if (NULL == na->session)
1749     na->session = papi->get_session (papi->cls, na->address);
1750   if (NULL == na->session)
1751   {
1752     GNUNET_break (0);
1753     return;
1754   }
1755   GNUNET_STATISTICS_update (GST_stats,
1756                             gettext_noop
1757                             ("# SYN messages sent"),
1758                             1, GNUNET_NO);
1759   na->connect_timestamp = GNUNET_TIME_absolute_get ();
1760   connect_msg.header.size = htons (sizeof (struct TransportSynMessage));
1761   connect_msg.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_SYN);
1762   connect_msg.reserved = htonl (0);
1763   connect_msg.timestamp = GNUNET_TIME_absolute_hton (na->connect_timestamp);
1764   if (-1 ==
1765       papi->send (papi->cls,
1766                   na->session,
1767                   (const char *) &connect_msg, sizeof (struct TransportSynMessage),
1768                   UINT_MAX,
1769                   SETUP_CONNECTION_TIMEOUT,
1770                   send_session_connect_cont, NULL))
1771   {
1772     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1773                 _("Failed to transmit SYN message via plugin to %s\n"),
1774                 GST_plugins_a2s (na->address));
1775
1776     n = lookup_neighbour (&na->address->peer);
1777     if (NULL == n)
1778     {
1779       GNUNET_break (0);
1780       return;
1781     }
1782
1783     switch (n->state) {
1784       case GNUNET_TRANSPORT_PS_SYN_SENT:
1785         /* Remove address and request and additional one */
1786         unset_primary_address (n);
1787         set_state_and_timeout (n, GNUNET_TRANSPORT_PS_INIT_ATS,
1788           GNUNET_TIME_relative_to_absolute (FAST_RECONNECT_TIMEOUT));
1789         /* Hard failure to send the SYN message with this address:
1790            Destroy address and session */
1791         break;
1792       case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
1793         /* Remove address and request and additional one */
1794         unset_primary_address (n);
1795         set_state_and_timeout (n, GNUNET_TRANSPORT_PS_RECONNECT_ATS,
1796           GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
1797         break;
1798       case GNUNET_TRANSPORT_PS_SWITCH_SYN_SENT:
1799         GNUNET_STATISTICS_update (GST_stats, gettext_noop
1800             ("# Failed attempts to switch addresses (failed to send SYN)"), 1, GNUNET_NO);
1801         /* Remove address and request and additional one */
1802         unset_alternative_address (n);
1803         set_state_and_timeout (n, GNUNET_TRANSPORT_PS_CONNECTED,
1804           GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
1805         break;
1806       default:
1807         disconnect_neighbour (n);
1808         break;
1809     }
1810     GNUNET_ATS_address_destroyed (GST_ats, na->address, na->session);
1811     GNUNET_ATS_address_destroyed (GST_ats, na->address, NULL);
1812   }
1813   GST_neighbours_notify_data_sent (&na->address->peer,
1814                                    na->address,
1815                                    na->session,
1816                                    sizeof (struct TransportSynMessage));
1817 }
1818
1819
1820 static void
1821 send_session_connect_ack_cont (void *cls,
1822                       const struct GNUNET_PeerIdentity *target,
1823                       int result,
1824                       size_t size_payload,
1825                       size_t size_on_wire)
1826 {
1827   struct NeighbourMapEntry *n;
1828
1829   n = lookup_neighbour (target);
1830   if (NULL == n)
1831   {
1832     /* SYN_ACK continuation was called after neighbor was freed,
1833      * for example due to a time out for the state or the session
1834      * used was already terminated: nothing to do here... */
1835     return;
1836   }
1837
1838   if (GNUNET_TRANSPORT_PS_SYN_RECV_ACK != n->state)
1839   {
1840     /* SYN_ACK continuation was called after neighbor changed state,
1841      * for example due to a time out for the state or the session
1842      * used was already terminated: nothing to do here... */
1843     return;
1844   }
1845   if (GNUNET_OK == result)
1846     return;
1847
1848   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1849             _("Failed to send SYN_ACK message to peer `%s' using address `%s' session %p\n"),
1850             GNUNET_i2s (target),
1851             GST_plugins_a2s (n->primary_address.address),
1852             n->primary_address.session);
1853
1854   /* Failed to send SYN_ACK message with this address */
1855   GNUNET_ATS_address_destroyed (GST_ats, n->primary_address.address,
1856       n->primary_address.session);
1857   GNUNET_ATS_address_destroyed (GST_ats, n->primary_address.address,
1858       NULL);
1859
1860   /* Remove address and request and additional one */
1861   unset_primary_address (n);
1862   n->ack_state = ACK_SEND_SYN_ACK;
1863   set_state_and_timeout (n, GNUNET_TRANSPORT_PS_SYN_RECV_ATS,
1864       GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
1865   return;
1866 }
1867
1868
1869 /**
1870  * Send a SYN_ACK message via the given address.
1871  *
1872  * @param address address to use
1873  * @param session session to use
1874  * @param timestamp timestamp to use for the ACK message
1875  * @return GNUNET_SYSERR if sending immediately failed, GNUNET_OK otherwise
1876  */
1877 static void
1878 send_connect_ack_message (const struct GNUNET_HELLO_Address *address,
1879                                   struct Session *session,
1880                                   struct GNUNET_TIME_Absolute timestamp)
1881 {
1882   struct GNUNET_TRANSPORT_PluginFunctions *papi;
1883   struct TransportSynMessage connect_msg;
1884   struct NeighbourMapEntry *n;
1885
1886   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1887               "Sending SYN_ACK to peer `%s'\n",
1888               GNUNET_i2s (&address->peer));
1889
1890   if (NULL == (papi = GST_plugins_find (address->transport_name)))
1891   {
1892     GNUNET_break (0);
1893     return;
1894   }
1895   if (NULL == session)
1896     session = papi->get_session (papi->cls, address);
1897   if (NULL == session)
1898   {
1899     GNUNET_break (0);
1900     return;
1901   }
1902   GNUNET_STATISTICS_update (GST_stats,
1903                             gettext_noop
1904                             ("# SYN_ACK messages sent"),
1905                             1, GNUNET_NO);
1906   connect_msg.header.size = htons (sizeof (struct TransportSynMessage));
1907   connect_msg.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_SYN_ACK);
1908   connect_msg.reserved = htonl (0);
1909   connect_msg.timestamp = GNUNET_TIME_absolute_hton (timestamp);
1910
1911   if (GNUNET_SYSERR == papi->send (papi->cls,
1912                      session,
1913                      (const char *) &connect_msg, sizeof (struct TransportSynMessage),
1914                      UINT_MAX,
1915                      GNUNET_TIME_UNIT_FOREVER_REL,
1916                      send_session_connect_ack_cont, NULL))
1917   {
1918     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1919                 _("Failed to transmit SYN_ACK message via plugin to %s\n"),
1920                 GST_plugins_a2s (address));
1921
1922     n = lookup_neighbour (&address->peer);
1923     if (NULL == n)
1924     {
1925       GNUNET_break (0);
1926       return;
1927     }
1928     /* Hard failure to send the SYN_ACK message with this address:
1929        Destroy session (and address)  */
1930     if (GNUNET_YES == GNUNET_HELLO_address_check_option(address,
1931         GNUNET_HELLO_ADDRESS_INFO_INBOUND))
1932     {
1933       GNUNET_ATS_address_destroyed (GST_ats, address, session);
1934       GNUNET_ATS_address_destroyed (GST_ats, address, NULL);
1935     }
1936     else
1937       GNUNET_ATS_address_destroyed (GST_ats, address, session);
1938
1939     /* Remove address and request and additional one */
1940     unset_primary_address (n);
1941     n->ack_state = ACK_SEND_SYN_ACK;
1942     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_SYN_RECV_ATS,
1943         GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
1944     return;
1945   }
1946
1947 }
1948
1949 struct QuotaNotificationRequest
1950 {
1951   struct GNUNET_PeerIdentity peer;
1952   struct Session *session;
1953   char *plugin;
1954 };
1955
1956 struct QNR_LookContext
1957 {
1958   struct GNUNET_PeerIdentity peer;
1959   struct Session *session;
1960   const char *plugin;
1961
1962   struct QuotaNotificationRequest *res;
1963 };
1964
1965 static int
1966 find_notification_request (void *cls, const struct GNUNET_PeerIdentity *key, void *value)
1967 {
1968   struct QNR_LookContext *qnr_ctx = cls;
1969   struct QuotaNotificationRequest *qnr = value;
1970
1971   if ((qnr->session == qnr_ctx->session) &&
1972       (0 == memcmp (&qnr->peer, &qnr_ctx->peer, sizeof (struct GNUNET_PeerIdentity))) &&
1973       (0 == strcmp(qnr_ctx->plugin, qnr->plugin)))
1974   {
1975     qnr_ctx->res = value;
1976     return GNUNET_NO;
1977   }
1978   return GNUNET_YES;
1979 }
1980
1981 void
1982 GST_neighbours_register_quota_notification(void *cls,
1983     const struct GNUNET_PeerIdentity *peer, const char *plugin,
1984     struct Session *session)
1985 {
1986   struct QuotaNotificationRequest *qnr;
1987   struct QNR_LookContext qnr_ctx;
1988
1989   if (NULL == registered_quota_notifications)
1990   {
1991     return; /* init or shutdown */
1992   }
1993
1994   qnr_ctx.peer = (*peer);
1995   qnr_ctx.plugin = plugin;
1996   qnr_ctx.session = session;
1997   qnr_ctx.res = NULL;
1998
1999   GNUNET_CONTAINER_multipeermap_get_multiple (registered_quota_notifications,
2000       peer, &find_notification_request, &qnr_ctx);
2001   if (NULL != qnr_ctx.res)
2002   {
2003     GNUNET_break(0);
2004     return;
2005   }
2006
2007   qnr = GNUNET_new (struct QuotaNotificationRequest);
2008   qnr->peer =  (*peer);
2009   qnr->plugin = GNUNET_strdup (plugin);
2010   qnr->session = session;
2011
2012   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2013       "Adding notification for peer `%s' plugin `%s' session %p \n",
2014       GNUNET_i2s (peer), plugin, session);
2015
2016   GNUNET_CONTAINER_multipeermap_put (registered_quota_notifications, peer,
2017       qnr, GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
2018 }
2019
2020
2021 void
2022 GST_neighbours_unregister_quota_notification(void *cls,
2023     const struct GNUNET_PeerIdentity *peer, const char *plugin, struct Session *session)
2024 {
2025   struct QNR_LookContext qnr_ctx;
2026
2027   if (NULL == registered_quota_notifications)
2028   {
2029     return; /* init or shutdown */
2030   }
2031
2032   qnr_ctx.peer = (*peer);
2033   qnr_ctx.plugin = plugin;
2034   qnr_ctx.session = session;
2035   qnr_ctx.res = NULL;
2036
2037   GNUNET_CONTAINER_multipeermap_iterate (registered_quota_notifications,
2038       &find_notification_request, &qnr_ctx);
2039   if (NULL == qnr_ctx.res)
2040   {
2041     GNUNET_break(0);
2042     return;
2043   }
2044
2045   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2046       "Removing notification for peer `%s' plugin `%s' session %p \n",
2047       GNUNET_i2s (peer), plugin, session);
2048
2049   GNUNET_CONTAINER_multipeermap_remove (registered_quota_notifications, peer,
2050       qnr_ctx.res);
2051   GNUNET_free (qnr_ctx.res->plugin);
2052   GNUNET_free (qnr_ctx.res);
2053 }
2054
2055 static int
2056 notification_cb(void *cls, const struct GNUNET_PeerIdentity *key, void *value)
2057 {
2058   /* struct NeighbourMapEntry *n = cls; */
2059   struct QuotaNotificationRequest *qnr = value;
2060   struct GNUNET_TRANSPORT_PluginFunctions *papi;
2061   struct GNUNET_TIME_Relative delay;
2062   int do_forward;
2063
2064   papi = GST_plugins_find(qnr->plugin);
2065   if (NULL == papi)
2066   {
2067     GNUNET_break (0);
2068     return GNUNET_OK;
2069   }
2070
2071   delay = GST_neighbours_calculate_receive_delay (key, 0, &do_forward);
2072   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2073       "New inbound delay for peer `%s' is %llu ms\n", GNUNET_i2s (key),
2074       delay.rel_value_us / 1000);
2075
2076   if (NULL != papi->update_inbound_delay)
2077     papi->update_inbound_delay (papi->cls, key, qnr->session, delay);
2078   return GNUNET_OK;
2079 }
2080
2081 static int
2082 free_notification_cb(void *cls, const struct GNUNET_PeerIdentity *key,
2083     void *value)
2084 {
2085   /* struct NeighbourMapEntry *n = cls; */
2086   struct QuotaNotificationRequest *qnr = value;
2087
2088   GNUNET_break (GNUNET_OK == GNUNET_CONTAINER_multipeermap_remove (registered_quota_notifications, key,
2089       qnr));
2090   GNUNET_free(qnr->plugin);
2091   GNUNET_free(qnr);
2092
2093   return GNUNET_OK;
2094 }
2095
2096 static void
2097 inbound_bw_tracker_update(void *cls)
2098 {
2099   struct NeighbourMapEntry *n = cls;
2100
2101   /* Quota was updated, tell plugins to update the time to receive next */
2102   GNUNET_CONTAINER_multipeermap_get_multiple (registered_quota_notifications,
2103       &n->id, &notification_cb, n);
2104 }
2105
2106
2107 /**
2108  * Create a fresh entry in the neighbour map for the given peer
2109  *
2110  * @param peer peer to create an entry for
2111  * @return new neighbour map entry
2112  */
2113 static struct NeighbourMapEntry *
2114 setup_neighbour (const struct GNUNET_PeerIdentity *peer)
2115 {
2116   struct NeighbourMapEntry *n;
2117
2118   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2119               "Creating new neighbour entry for `%s'\n",
2120               GNUNET_i2s (peer));
2121   n = GNUNET_new (struct NeighbourMapEntry);
2122   n->id = *peer;
2123   n->ack_state = ACK_UNDEFINED;
2124   n->latency = GNUNET_TIME_UNIT_FOREVER_REL;
2125   n->last_util_transmission = GNUNET_TIME_absolute_get();
2126   n->util_payload_bytes_recv = 0;
2127   n->util_payload_bytes_sent = 0;
2128   n->util_total_bytes_recv = 0;
2129   n->util_total_bytes_sent = 0;
2130   GNUNET_BANDWIDTH_tracker_init (&n->in_tracker, &inbound_bw_tracker_update, n,
2131                                  GNUNET_CONSTANTS_DEFAULT_BW_IN_OUT,
2132                                  MAX_BANDWIDTH_CARRY_S);
2133   n->task = GNUNET_SCHEDULER_add_now (&master_task, n);
2134   set_state_and_timeout (n, GNUNET_TRANSPORT_PS_NOT_CONNECTED, GNUNET_TIME_UNIT_FOREVER_ABS);
2135   GNUNET_assert (GNUNET_OK ==
2136                  GNUNET_CONTAINER_multipeermap_put (neighbours,
2137                                                     &n->id, n,
2138                                                     GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
2139   return n;
2140 }
2141
2142 /* We received a address suggestion after requesting an address in
2143  * try_connect or after receiving a connect, switch to address
2144  */
2145 static void
2146 address_suggest_cont (void *cls,
2147     const struct GNUNET_PeerIdentity *peer,
2148     const struct GNUNET_HELLO_Address *address, struct Session *session,
2149     struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out,
2150     struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in,
2151     const struct GNUNET_ATS_Information *ats, uint32_t ats_count)
2152 {
2153   GST_neighbours_switch_to_address(peer, address, session, ats, ats_count,
2154       bandwidth_in, bandwidth_out);
2155 }
2156
2157
2158 struct BlacklistCheckSwitchContext
2159 {
2160   struct BlacklistCheckSwitchContext *prev;
2161   struct BlacklistCheckSwitchContext *next;
2162
2163
2164   struct GST_BlacklistCheck *blc;
2165
2166   struct GNUNET_HELLO_Address *address;
2167   struct Session *session;
2168   struct GNUNET_ATS_Information *ats;
2169   uint32_t ats_count;
2170
2171   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in;
2172   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out;
2173 };
2174
2175
2176 /**
2177  * Black list check result for try_connect call
2178  * If connection to the peer is allowed request adddress and
2179  *
2180  * @param cls blc_ctx bl context
2181  * @param peer the peer
2182  * @param result the result
2183  */
2184 static void
2185 try_connect_bl_check_cont (void *cls,
2186                            const struct GNUNET_PeerIdentity *peer,
2187                            int result)
2188 {
2189   struct BlacklistCheckSwitchContext *blc_ctx = cls;
2190   struct NeighbourMapEntry *n;
2191
2192   GNUNET_CONTAINER_DLL_remove (pending_bc_head,
2193                                pending_bc_tail,
2194                                blc_ctx);
2195   GNUNET_free (blc_ctx);
2196   if (GNUNET_OK != result)
2197   {
2198     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2199                 _("Blacklisting disapproved to connect to peer `%s'\n"),
2200                 GNUNET_i2s (peer));
2201     return;
2202   }
2203
2204   /* Setup a new neighbour */
2205   if (NULL != lookup_neighbour(peer))
2206     return; /* The neighbor was created in the meantime while waited for BL clients */
2207
2208   n = setup_neighbour (peer);
2209
2210   /* Request address suggestions for this peer */
2211   set_state_and_timeout (n,
2212                          GNUNET_TRANSPORT_PS_INIT_ATS,
2213                          GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
2214   GNUNET_ATS_reset_backoff (GST_ats, peer);
2215   n->suggest_handle = GNUNET_ATS_suggest_address (GST_ats,
2216                                                   peer,
2217                                                   &address_suggest_cont, n);
2218 }
2219
2220
2221
2222 /**
2223  * Try to create a connection to the given target (eventually).
2224  *
2225  * @param target peer to try to connect to
2226  */
2227 void
2228 GST_neighbours_try_connect (const struct GNUNET_PeerIdentity *target)
2229 {
2230   struct NeighbourMapEntry *n;
2231   struct GST_BlacklistCheck *blc;
2232   struct BlacklistCheckSwitchContext *blc_ctx;
2233
2234   if (NULL == neighbours)
2235   {
2236     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2237                 "Asked to connect to peer `%s' during shutdown\n",
2238                 GNUNET_i2s (target));
2239     return; /* during shutdown, do nothing */
2240   }
2241   n = lookup_neighbour (target);
2242   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2243               "Asked to connect to peer `%s' (state: %s)\n",
2244               GNUNET_i2s (target),
2245               (NULL != n) ? GNUNET_TRANSPORT_ps2s(n->state) : "NEW PEER");
2246   if (NULL != n)
2247   {
2248     switch (n->state)
2249     {
2250     case GNUNET_TRANSPORT_PS_NOT_CONNECTED:
2251       /* this should not be possible */
2252       GNUNET_break (0);
2253       free_neighbour (n, GNUNET_NO);
2254       break;
2255     case GNUNET_TRANSPORT_PS_INIT_ATS:
2256     case GNUNET_TRANSPORT_PS_SYN_SENT:
2257     case GNUNET_TRANSPORT_PS_SYN_RECV_ATS:
2258     case GNUNET_TRANSPORT_PS_SYN_RECV_ACK:
2259       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2260                   "Ignoring request to try to connect to `%s', already trying!\n",
2261                   GNUNET_i2s (target));
2262       return; /* already trying */
2263     case GNUNET_TRANSPORT_PS_CONNECTED:
2264     case GNUNET_TRANSPORT_PS_RECONNECT_ATS:
2265     case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
2266     case GNUNET_TRANSPORT_PS_SWITCH_SYN_SENT:
2267       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2268                   "Ignoring request to try to connect, already connected to `%s'!\n",
2269                   GNUNET_i2s (target));
2270       return; /* already connected */
2271     case GNUNET_TRANSPORT_PS_DISCONNECT:
2272       /* get rid of remains, ready to re-try immediately */
2273       free_neighbour (n, GNUNET_NO);
2274       break;
2275     case GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED:
2276       /* should not be possible */
2277       GNUNET_assert (0);
2278       return;
2279     default:
2280       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2281                   "Unhandled state `%s'\n",
2282                   GNUNET_TRANSPORT_ps2s (n->state));
2283       GNUNET_break (0);
2284       free_neighbour (n, GNUNET_NO);
2285       break;
2286     }
2287   }
2288
2289   /* Do blacklist check if connecting to this peer is allowed */
2290   blc_ctx = GNUNET_new (struct BlacklistCheckSwitchContext);
2291   GNUNET_CONTAINER_DLL_insert (pending_bc_head, pending_bc_tail, blc_ctx);
2292
2293   if (NULL != (blc = GST_blacklist_test_allowed (target, NULL,
2294         &try_connect_bl_check_cont, blc_ctx)))
2295   {
2296     blc_ctx->blc = blc;
2297   }
2298 }
2299
2300
2301 /**
2302  * We received a 'SYN' message from the other peer.
2303  * Consider switching to it.
2304  *
2305  * @param message possibly a 'struct TransportSynMessage' (check format)
2306  * @param peer identity of the peer to switch the address for
2307  * @return #GNUNET_OK if the message was fine, #GNUNET_SYSERR on serious error
2308  */
2309 int
2310 GST_neighbours_handle_session_syn (const struct GNUNET_MessageHeader *message,
2311                                const struct GNUNET_PeerIdentity *peer)
2312 {
2313   const struct TransportSynMessage *scm;
2314   struct NeighbourMapEntry *n;
2315   struct GNUNET_TIME_Absolute ts;
2316
2317   if (ntohs (message->size) != sizeof (struct TransportSynMessage))
2318   {
2319     GNUNET_break_op (0);
2320     return GNUNET_SYSERR;
2321   }
2322   GNUNET_STATISTICS_update (GST_stats,
2323                             gettext_noop
2324                             ("# SYN messages received"),
2325                             1, GNUNET_NO);
2326   if (NULL == neighbours)
2327   {
2328     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2329                 _("SYN request from peer `%s' ignored due impending shutdown\n"),
2330                 GNUNET_i2s (peer));
2331     return GNUNET_OK; /* we're shutting down */
2332   }
2333   scm = (const struct TransportSynMessage *) message;
2334   GNUNET_break_op (0 == ntohl (scm->reserved));
2335   ts = GNUNET_TIME_absolute_ntoh (scm->timestamp);
2336   n = lookup_neighbour (peer);
2337   if (NULL == n)
2338   {
2339     /* This is a new neighbour and set to not connected */
2340     n = setup_neighbour (peer);
2341   }
2342
2343   /* Remember this SYN message in neighbour */
2344   n->ack_state = ACK_SEND_SYN_ACK;
2345   n->connect_ack_timestamp = ts;
2346
2347   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2348               "Received SYN for peer `%s' in state %s/%s\n",
2349               GNUNET_i2s (peer),
2350               GNUNET_TRANSPORT_ps2s (n->state),
2351               print_ack_state (n->ack_state));
2352
2353   switch (n->state)
2354   {
2355   case GNUNET_TRANSPORT_PS_NOT_CONNECTED:
2356     /* Request an address from ATS to send SYN_ACK to this peer */
2357     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_SYN_RECV_ATS,
2358         GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
2359     if (NULL == n->suggest_handle)
2360       GNUNET_ATS_suggest_address (GST_ats, peer, address_suggest_cont, n);
2361     break;
2362   case GNUNET_TRANSPORT_PS_INIT_ATS:
2363     /* SYN message takes priority over us asking ATS for address:
2364      * Wait for ATS to suggest an address and send SYN_ACK */
2365     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_SYN_RECV_ATS,
2366         GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
2367     break;
2368   case GNUNET_TRANSPORT_PS_SYN_RECV_ATS:
2369     /* We already wait for an address to send an SYN_ACK */
2370     break;
2371   case GNUNET_TRANSPORT_PS_SYN_SENT:
2372   case GNUNET_TRANSPORT_PS_SYN_RECV_ACK:
2373     /* Send ACK immediately */
2374     n->ack_state = ACK_SEND_ACK;
2375     send_connect_ack_message (n->primary_address.address,
2376                               n->primary_address.session, ts);
2377     break;
2378   case GNUNET_TRANSPORT_PS_CONNECTED:
2379     /* we are already connected and can thus send the ACK immediately */
2380     GNUNET_assert (NULL != n->primary_address.address);
2381     GNUNET_assert (NULL != n->primary_address.session);
2382     n->ack_state = ACK_SEND_ACK;
2383     send_connect_ack_message (n->primary_address.address,
2384                               n->primary_address.session, ts);
2385     break;
2386   case GNUNET_TRANSPORT_PS_RECONNECT_ATS:
2387     /* We wait for ATS address suggestion */
2388     break;
2389   case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
2390     /* We received a SYN message while waiting for a SYN_ACK in fast
2391      * reconnect. Send SYN_ACK immediately */
2392     n->ack_state = ACK_SEND_ACK;
2393     send_connect_ack_message (n->primary_address.address,
2394         n->primary_address.session, n->connect_ack_timestamp);
2395     break;
2396   case GNUNET_TRANSPORT_PS_SWITCH_SYN_SENT:
2397     /* We are already connected and can thus send the ACK immediately;
2398        still, it can never hurt to have an alternative address, so also
2399        tell ATS  about it */
2400     GNUNET_assert (NULL != n->primary_address.address);
2401     GNUNET_assert (NULL != n->primary_address.session);
2402     n->ack_state = ACK_SEND_ACK;
2403     send_connect_ack_message (n->primary_address.address,
2404         n->primary_address.session, ts);
2405     break;
2406   case GNUNET_TRANSPORT_PS_DISCONNECT:
2407     /* Get rid of remains without terminating sessions, ready to re-try */
2408     free_neighbour (n, GNUNET_YES);
2409     n = setup_neighbour (peer);
2410     /* Remember the SYN time stamp for ACK message */
2411     n->ack_state = ACK_SEND_SYN_ACK;
2412     n->connect_ack_timestamp = ts;
2413     /* Request an address for the peer */
2414     GNUNET_ATS_suggest_address (GST_ats, peer, address_suggest_cont, n);
2415     GNUNET_ATS_reset_backoff (GST_ats, peer);
2416     set_state (n, GNUNET_TRANSPORT_PS_SYN_RECV_ATS);
2417     break;
2418   case GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED:
2419     /* should not be possible */
2420     GNUNET_assert (0);
2421     break;
2422   default:
2423     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2424                 "Unhandled state `%s'\n",
2425                 GNUNET_TRANSPORT_ps2s (n->state));
2426     GNUNET_break (0);
2427     return GNUNET_SYSERR;
2428   }
2429   return GNUNET_OK;
2430 }
2431
2432 static void
2433 switch_address_bl_check_cont (void *cls,
2434     const struct GNUNET_PeerIdentity *peer, int result)
2435 {
2436   struct BlacklistCheckSwitchContext *blc_ctx = cls;
2437   struct GNUNET_TRANSPORT_PluginFunctions *papi;
2438   struct NeighbourMapEntry *n;
2439
2440   papi = GST_plugins_find (blc_ctx->address->transport_name);
2441
2442   if ( (NULL == (n = lookup_neighbour (peer))) || (result == GNUNET_NO) ||
2443        (NULL == (papi)) )
2444   {
2445     if (NULL == n)
2446     {
2447       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2448                   "Peer %s is unknown, suggestion ignored\n",
2449                   GNUNET_i2s (peer));
2450     }
2451     if (result == GNUNET_NO)
2452     {
2453       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2454           "Blacklist denied to switch to suggested address `%s' session %p for peer `%s'\n",
2455           GST_plugins_a2s (blc_ctx->address),
2456           blc_ctx->session,
2457           GNUNET_i2s (&blc_ctx->address->peer));
2458     }
2459     if (NULL == papi)
2460     {
2461       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2462           "Plugin `%s' for suggested address `%s' session %p for peer `%s' is not available\n",
2463           blc_ctx->address->transport_name,
2464           GST_plugins_a2s (blc_ctx->address),
2465           blc_ctx->session,
2466           GNUNET_i2s (&blc_ctx->address->peer));
2467     }
2468
2469     /* This address is blacklisted, delete address and session (if existing) in ATS */
2470     GNUNET_ATS_address_destroyed (GST_ats, blc_ctx->address, blc_ctx->session);
2471
2472     if ( (GNUNET_YES == (GNUNET_HELLO_address_check_option (blc_ctx->address,
2473           GNUNET_HELLO_ADDRESS_INFO_INBOUND))) && (NULL != blc_ctx->session))
2474     {
2475       /* This is an inbound address, destroy full  address */
2476       GNUNET_ATS_address_destroyed (GST_ats, blc_ctx->address, NULL );
2477     }
2478
2479     /* Remove blacklist check and clean up */
2480     GNUNET_CONTAINER_DLL_remove (pending_bc_head, pending_bc_tail, blc_ctx);
2481     GNUNET_HELLO_address_free (blc_ctx->address);
2482     GNUNET_free_non_null (blc_ctx->ats);
2483     GNUNET_free (blc_ctx);
2484     return;
2485   }
2486
2487   if (NULL == blc_ctx->session)
2488   {
2489     blc_ctx->session = papi->get_session (papi->cls, blc_ctx->address);
2490     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2491                 "Obtained new session for peer `%s' and  address '%s': %p\n",
2492                 GNUNET_i2s (&blc_ctx->address->peer), GST_plugins_a2s (blc_ctx->address), blc_ctx->session);
2493   }
2494   if (NULL == blc_ctx->session)
2495   {
2496     /* No session could be obtained, remove blacklist check and clean up */
2497     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2498                 "Failed to obtain new session for peer `%s' and  address '%s'\n",
2499                 GNUNET_i2s (&blc_ctx->address->peer),
2500                 GST_plugins_a2s (blc_ctx->address));
2501     /* Delete address in ATS */
2502     GNUNET_ATS_address_destroyed (GST_ats, blc_ctx->address, NULL);
2503
2504     GNUNET_CONTAINER_DLL_remove (pending_bc_head, pending_bc_tail, blc_ctx);
2505     GNUNET_HELLO_address_free (blc_ctx->address);
2506     GNUNET_free_non_null (blc_ctx->ats);
2507     GNUNET_free (blc_ctx);
2508     return;
2509   }
2510
2511   if ( (NULL != n->primary_address.address) &&
2512        (0 == GNUNET_HELLO_address_cmp(blc_ctx->address, n->primary_address.address)) )
2513   {
2514     if (blc_ctx->session == n->primary_address.session)
2515     {
2516       /* This address is already primary, update only quotas */
2517       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2518           "Updating quota for peer `%s' address `%s' session %p\n",
2519           GNUNET_i2s (&blc_ctx->address->peer),
2520           GST_plugins_a2s (blc_ctx->address),
2521           blc_ctx->session);
2522
2523       set_primary_address (n, blc_ctx->address, blc_ctx->session,
2524           blc_ctx->bandwidth_in, blc_ctx->bandwidth_out, GNUNET_NO);
2525
2526       GNUNET_CONTAINER_DLL_remove (pending_bc_head, pending_bc_tail, blc_ctx);
2527       GNUNET_HELLO_address_free(blc_ctx->address);
2528       GNUNET_free_non_null (blc_ctx->ats);
2529       GNUNET_free (blc_ctx);
2530
2531       return;
2532     }
2533   }
2534
2535   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2536       "Peer `%s' switches to address `%s' session %p\n",
2537       GNUNET_i2s (&blc_ctx->address->peer),
2538       GST_plugins_a2s (blc_ctx->address),
2539       blc_ctx->session);
2540
2541   switch (n->state)
2542   {
2543   case GNUNET_TRANSPORT_PS_NOT_CONNECTED:
2544     GNUNET_break (0);
2545     free_neighbour (n, GNUNET_NO);
2546     return;
2547   case GNUNET_TRANSPORT_PS_INIT_ATS:
2548     /* We requested an address and ATS suggests one:
2549      * set primary address and send SYN message*/
2550     set_primary_address (n, blc_ctx->address, blc_ctx->session,
2551         blc_ctx->bandwidth_in, blc_ctx->bandwidth_out, GNUNET_NO);
2552     if ( (ACK_SEND_SYN_ACK == n->ack_state) )
2553     {
2554       /* Send pending SYN_ACK message */
2555       n->ack_state = ACK_SEND_ACK;
2556       send_connect_ack_message (n->primary_address.address,
2557           n->primary_address.session, n->connect_ack_timestamp);
2558     }
2559     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_SYN_SENT,
2560         GNUNET_TIME_relative_to_absolute (SETUP_CONNECTION_TIMEOUT));
2561     send_syn (&n->primary_address);
2562     break;
2563   case GNUNET_TRANSPORT_PS_SYN_SENT:
2564     /* ATS suggested a new address while waiting for an SYN_ACK:
2565      * Switch and send new SYN */
2566     /* ATS suggests a different address, switch again */
2567     set_primary_address (n, blc_ctx->address, blc_ctx->session,
2568         blc_ctx->bandwidth_in, blc_ctx->bandwidth_out, GNUNET_NO);
2569     if (ACK_SEND_SYN_ACK == n->ack_state)
2570     {
2571       /* Send pending SYN_ACK message */
2572       n->ack_state = ACK_SEND_ACK;
2573       send_connect_ack_message (n->primary_address.address,
2574           n->primary_address.session, n->connect_ack_timestamp);
2575     }
2576     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_SYN_SENT,
2577         GNUNET_TIME_relative_to_absolute (SETUP_CONNECTION_TIMEOUT));
2578     send_syn (&n->primary_address);
2579     break;
2580   case GNUNET_TRANSPORT_PS_SYN_RECV_ATS:
2581     /* We requested an address and ATS suggests one:
2582      * set primary address and send SYN_ACK message*/
2583     set_primary_address (n, blc_ctx->address, blc_ctx->session,
2584         blc_ctx->bandwidth_in, blc_ctx->bandwidth_out, GNUNET_NO);
2585     /* Send an ACK message as a response to the SYN msg */
2586     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_SYN_RECV_ACK,
2587         GNUNET_TIME_relative_to_absolute (SETUP_CONNECTION_TIMEOUT));
2588     send_connect_ack_message (n->primary_address.address,
2589                               n->primary_address.session,
2590                               n->connect_ack_timestamp);
2591     if ( (ACK_SEND_SYN_ACK == n->ack_state) ||
2592          (ACK_UNDEFINED == n->ack_state) )
2593       n->ack_state = ACK_SEND_ACK;
2594     break;
2595   case GNUNET_TRANSPORT_PS_SYN_RECV_ACK:
2596     /* ATS asks us to switch while we were trying to connect; switch to new
2597        address and check blacklist again */
2598     if ( (ACK_SEND_SYN_ACK == n->ack_state) )
2599     {
2600       n->ack_state = ACK_SEND_ACK;
2601       send_connect_ack_message (n->primary_address.address,
2602           n->primary_address.session, n->connect_ack_timestamp);
2603     }
2604     set_primary_address (n, blc_ctx->address, blc_ctx->session,
2605         blc_ctx->bandwidth_in, blc_ctx->bandwidth_out, GNUNET_NO);
2606     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_SYN_RECV_ACK,
2607         GNUNET_TIME_relative_to_absolute (SETUP_CONNECTION_TIMEOUT));
2608     break;
2609   case GNUNET_TRANSPORT_PS_CONNECTED:
2610     GNUNET_assert (NULL != n->primary_address.address);
2611     GNUNET_assert (NULL != n->primary_address.session);
2612     if (n->primary_address.session == blc_ctx->session)
2613     {
2614       /* not an address change, just a quota change */
2615       set_primary_address (n, blc_ctx->address, blc_ctx->session,
2616           blc_ctx->bandwidth_in, blc_ctx->bandwidth_out, GNUNET_YES);
2617       break;
2618     }
2619     /* ATS asks us to switch a life connection; see if we can get
2620        a SYN_ACK on it before we actually do this! */
2621     set_alternative_address (n, blc_ctx->address, blc_ctx->session,
2622         blc_ctx->bandwidth_in, blc_ctx->bandwidth_out);
2623     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_SWITCH_SYN_SENT,
2624         GNUNET_TIME_relative_to_absolute (SETUP_CONNECTION_TIMEOUT));
2625     GNUNET_STATISTICS_update (GST_stats, gettext_noop
2626         ("# Attempts to switch addresses"), 1, GNUNET_NO);
2627     send_syn (&n->alternative_address);
2628     break;
2629   case GNUNET_TRANSPORT_PS_RECONNECT_ATS:
2630     set_primary_address (n, blc_ctx->address, blc_ctx->session,
2631         blc_ctx->bandwidth_in, blc_ctx->bandwidth_out, GNUNET_NO);
2632     if ( (ACK_SEND_SYN_ACK == n->ack_state) )
2633     {
2634       /* Send pending SYN_ACK message */
2635       n->ack_state = ACK_SEND_ACK;
2636       send_connect_ack_message (n->primary_address.address,
2637           n->primary_address.session, n->connect_ack_timestamp);
2638     }
2639     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_RECONNECT_SENT,
2640         GNUNET_TIME_relative_to_absolute (FAST_RECONNECT_TIMEOUT));
2641     send_syn (&n->primary_address);
2642     break;
2643   case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
2644     /* ATS asks us to switch while we were trying to reconnect; switch to new
2645        address and send SYN again */
2646     set_primary_address (n, blc_ctx->address, blc_ctx->session,
2647         blc_ctx->bandwidth_in, blc_ctx->bandwidth_out, GNUNET_NO);
2648     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_RECONNECT_SENT,
2649         GNUNET_TIME_relative_to_absolute (FAST_RECONNECT_TIMEOUT));
2650     send_syn (&n->primary_address);
2651     break;
2652   case GNUNET_TRANSPORT_PS_SWITCH_SYN_SENT:
2653     if ( (0 == GNUNET_HELLO_address_cmp(n->primary_address.address,
2654         blc_ctx->address) && n->primary_address.session == blc_ctx->session) )
2655     {
2656       /* ATS switches back to still-active session */
2657       free_address (&n->alternative_address);
2658       set_state (n, GNUNET_TRANSPORT_PS_CONNECTED);
2659       break;
2660     }
2661     /* ATS asks us to switch a life connection, send */
2662     set_alternative_address (n, blc_ctx->address, blc_ctx->session,
2663         blc_ctx->bandwidth_in, blc_ctx->bandwidth_out);
2664     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_SWITCH_SYN_SENT,
2665         GNUNET_TIME_relative_to_absolute (SETUP_CONNECTION_TIMEOUT));
2666     send_syn (&n->alternative_address);
2667     break;
2668   case GNUNET_TRANSPORT_PS_DISCONNECT:
2669     /* not going to switch addresses while disconnecting */
2670     return;
2671   case GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED:
2672     GNUNET_assert (0);
2673     break;
2674   default:
2675     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2676                 "Unhandled state `%s'\n",
2677                 GNUNET_TRANSPORT_ps2s (n->state));
2678     GNUNET_break (0);
2679     break;
2680   }
2681
2682   GNUNET_CONTAINER_DLL_remove (pending_bc_head, pending_bc_tail, blc_ctx);
2683   GNUNET_HELLO_address_free(blc_ctx->address);
2684   GNUNET_free_non_null (blc_ctx->ats);
2685   GNUNET_free (blc_ctx);
2686   return;
2687 }
2688
2689
2690 /**
2691  * For the given peer, switch to this address.
2692  *
2693  * Before accepting this addresses and actively using it, a blacklist check
2694  * is performed. If this blacklist check fails the address will be destroyed.
2695  *
2696  * @param peer identity of the peer to switch the address for
2697  * @param address address of the other peer,
2698  * @param session session to use or NULL if transport should initiate a session
2699  * @param ats performance data
2700  * @param ats_count number of entries in ats
2701  * @param bandwidth_in inbound quota to be used when connection is up,
2702  *      0 to disconnect from peer
2703  * @param bandwidth_out outbound quota to be used when connection is up,
2704  *      0 to disconnect from peer
2705  */
2706 void
2707 GST_neighbours_switch_to_address (const struct GNUNET_PeerIdentity *peer,
2708                                   const struct GNUNET_HELLO_Address *address,
2709                                   struct Session *session,
2710                                   const struct GNUNET_ATS_Information *ats,
2711                                   uint32_t ats_count,
2712                                   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in,
2713                                   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out)
2714 {
2715   struct NeighbourMapEntry *n;
2716   struct GST_BlacklistCheck *blc;
2717   struct BlacklistCheckSwitchContext *blc_ctx;
2718   int c;
2719
2720   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2721               "ATS has decided on an address for peer %s\n",
2722               GNUNET_i2s (peer));
2723   GNUNET_assert (NULL != address->transport_name);
2724   if (NULL == (n = lookup_neighbour (peer)))
2725   {
2726     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2727                 "Peer %s is unknown, suggestion ignored\n",
2728                 GNUNET_i2s (peer));
2729     return;
2730   }
2731
2732   /* Check if plugin is available */
2733   if (NULL == (GST_plugins_find (address->transport_name)))
2734   {
2735     /* we don't have the plugin for this address */
2736     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2737                 "Plugin `%s' is unknown, suggestion for peer %s ignored\n",
2738                 address->transport_name,
2739                 GNUNET_i2s (peer));
2740     GNUNET_ATS_address_destroyed (GST_ats, address, NULL);
2741     return;
2742   }
2743   if ((NULL == session) &&
2744       (GNUNET_HELLO_address_check_option (address, GNUNET_HELLO_ADDRESS_INFO_INBOUND)))
2745   {
2746     /* This is a inbound address and we do not have a session to use! */
2747     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2748                 "Inbound address without session `%s'! Destroying address...\n",
2749                 GST_plugins_a2s (address));
2750     GNUNET_ATS_address_destroyed (GST_ats, address, NULL);
2751     return;
2752   }
2753
2754   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2755     "ATS suggests %s address '%s' session %p for "
2756     "peer `%s' in state %s/%s \n",
2757     GNUNET_HELLO_address_check_option (address,
2758         GNUNET_HELLO_ADDRESS_INFO_INBOUND) ? "inbound" : "outbound",
2759     GST_plugins_a2s (address), session, GNUNET_i2s (peer),
2760     GNUNET_TRANSPORT_ps2s (n->state), print_ack_state (n->ack_state));
2761
2762   /* Perform blacklist check */
2763   blc_ctx = GNUNET_new (struct BlacklistCheckSwitchContext);
2764   blc_ctx->address = GNUNET_HELLO_address_copy (address);
2765   blc_ctx->session = session;
2766   blc_ctx->bandwidth_in = bandwidth_in;
2767   blc_ctx->bandwidth_out = bandwidth_out;
2768   blc_ctx->ats_count = ats_count;
2769   blc_ctx->ats = NULL;
2770   if (ats_count > 0)
2771   {
2772     blc_ctx->ats = GNUNET_malloc (ats_count * sizeof (struct GNUNET_ATS_Information));
2773     for (c = 0; c < ats_count; c++)
2774     {
2775       blc_ctx->ats[c].type = ats[c].type;
2776       blc_ctx->ats[c].value = ats[c].value;
2777     }
2778   }
2779
2780   GNUNET_CONTAINER_DLL_insert (pending_bc_head, pending_bc_tail, blc_ctx);
2781   if (NULL != (blc = GST_blacklist_test_allowed (peer, address->transport_name,
2782       &switch_address_bl_check_cont, blc_ctx)))
2783   {
2784     blc_ctx->blc = blc;
2785   }
2786 }
2787
2788
2789 static int
2790 send_utilization_data (void *cls,
2791                        const struct GNUNET_PeerIdentity *key,
2792                        void *value)
2793 {
2794   struct NeighbourMapEntry *n = value;
2795   struct GNUNET_ATS_Information atsi[4];
2796   uint32_t bps_pl_in;
2797   uint32_t bps_pl_out;
2798   uint32_t bps_in;
2799   uint32_t bps_out;
2800   struct GNUNET_TIME_Relative delta;
2801
2802   delta = GNUNET_TIME_absolute_get_difference (n->last_util_transmission,
2803                                                GNUNET_TIME_absolute_get ());
2804
2805   bps_pl_in = 0;
2806
2807   if ((0 != n->util_payload_bytes_recv) && (0 != delta.rel_value_us))
2808     bps_pl_in =  (1000LL * 1000LL *  n->util_payload_bytes_recv) / (delta.rel_value_us);
2809   bps_pl_out = 0;
2810   if ((0 != n->util_payload_bytes_sent) && (0 != delta.rel_value_us))
2811     bps_pl_out = (1000LL * 1000LL * n->util_payload_bytes_sent) / delta.rel_value_us;
2812   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2813               "`%s' payload: received %u Bytes/s, sent %u Bytes/s\n",
2814               GNUNET_i2s (key),
2815               bps_pl_in,
2816               bps_pl_out);
2817   bps_in = 0;
2818   if ((0 != n->util_total_bytes_recv) && (0 != delta.rel_value_us))
2819     bps_in =  (1000LL * 1000LL *  n->util_total_bytes_recv) / (delta.rel_value_us);
2820   bps_out = 0;
2821   if ((0 != n->util_total_bytes_sent) && (0 != delta.rel_value_us))
2822     bps_out = (1000LL * 1000LL * n->util_total_bytes_sent) / delta.rel_value_us;
2823
2824
2825   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2826               "`%s' total: received %u Bytes/s, sent %u Bytes/s\n",
2827               GNUNET_i2s (key),
2828               bps_in,
2829               bps_out);
2830   atsi[0].type = htonl (GNUNET_ATS_UTILIZATION_OUT);
2831   atsi[0].value = htonl (bps_out);
2832   atsi[1].type = htonl (GNUNET_ATS_UTILIZATION_IN);
2833   atsi[1].value = htonl (bps_in);
2834
2835   atsi[2].type = htonl (GNUNET_ATS_UTILIZATION_PAYLOAD_OUT);
2836   atsi[2].value = htonl (bps_pl_out);
2837   atsi[3].type = htonl (GNUNET_ATS_UTILIZATION_PAYLOAD_IN);
2838   atsi[3].value = htonl (bps_pl_in);
2839
2840   GST_ats_update_metrics (key, n->primary_address.address,
2841       n->primary_address.session, atsi, 4);
2842   n->util_payload_bytes_recv = 0;
2843   n->util_payload_bytes_sent = 0;
2844   n->util_total_bytes_recv = 0;
2845   n->util_total_bytes_sent = 0;
2846   n->last_util_transmission = GNUNET_TIME_absolute_get();
2847   return GNUNET_OK;
2848 }
2849
2850
2851 /**
2852  * Task transmitting utilization in a regular interval
2853  *
2854  * @param cls the 'struct NeighbourMapEntry' for which we are running
2855  * @param tc scheduler context (unused)
2856  */
2857 static void
2858 utilization_transmission (void *cls,
2859                           const struct GNUNET_SCHEDULER_TaskContext *tc)
2860 {
2861   util_transmission_tk = GNUNET_SCHEDULER_NO_TASK;
2862
2863   if (0 < GNUNET_CONTAINER_multipeermap_size (neighbours))
2864     GNUNET_CONTAINER_multipeermap_iterate (neighbours, send_utilization_data, NULL);
2865
2866   util_transmission_tk = GNUNET_SCHEDULER_add_delayed (UTIL_TRANSMISSION_INTERVAL,
2867       utilization_transmission, NULL);
2868
2869 }
2870
2871
2872 void
2873 GST_neighbours_notify_data_recv (const struct GNUNET_PeerIdentity *peer,
2874                                  const struct GNUNET_HELLO_Address *address,
2875                                  struct Session *session,
2876                                  const struct GNUNET_MessageHeader *message)
2877 {
2878   struct NeighbourMapEntry *n;
2879
2880   n = lookup_neighbour (peer);
2881   if (NULL == n)
2882     return;
2883   n->util_total_bytes_recv += ntohs(message->size);
2884 }
2885
2886
2887 void
2888 GST_neighbours_notify_payload_recv (const struct GNUNET_PeerIdentity *peer,
2889                                     const struct GNUNET_HELLO_Address *address,
2890                                     struct Session *session,
2891                                     const struct GNUNET_MessageHeader *message)
2892 {
2893   struct NeighbourMapEntry *n;
2894   n = lookup_neighbour (peer);
2895   if (NULL == n)
2896     return;
2897   n->util_payload_bytes_recv += ntohs(message->size);
2898 }
2899
2900
2901 void
2902 GST_neighbours_notify_data_sent (const struct GNUNET_PeerIdentity *peer,
2903                                  const struct GNUNET_HELLO_Address *address,
2904                                  struct Session *session,
2905                                  size_t size)
2906 {
2907   struct NeighbourMapEntry *n;
2908   n = lookup_neighbour (peer);
2909   if (NULL == n)
2910       return;
2911   if (n->primary_address.session != session)
2912     return;
2913   n->util_total_bytes_sent += size;
2914 }
2915
2916
2917 void
2918 GST_neighbours_notify_payload_sent (const struct GNUNET_PeerIdentity *peer,
2919                                     size_t size)
2920 {
2921   struct NeighbourMapEntry *n;
2922   n = lookup_neighbour (peer);
2923   if (NULL == n)
2924     return;
2925   n->util_payload_bytes_sent += size;
2926 }
2927
2928
2929 /**
2930  * Master task run for every neighbour.  Performs all of the time-related
2931  * activities (keep alive, send next message, disconnect if idle, finish
2932  * clean up after disconnect).
2933  *
2934  * @param cls the 'struct NeighbourMapEntry' for which we are running
2935  * @param tc scheduler context (unused)
2936  */
2937 static void
2938 master_task (void *cls,
2939              const struct GNUNET_SCHEDULER_TaskContext *tc)
2940 {
2941   struct NeighbourMapEntry *n = cls;
2942   struct GNUNET_TIME_Relative delay;
2943
2944   n->task = GNUNET_SCHEDULER_NO_TASK;
2945   delay = GNUNET_TIME_absolute_get_remaining (n->timeout);
2946   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2947               "Master task runs for neighbour `%s' in state %s with timeout in %s\n",
2948               GNUNET_i2s (&n->id),
2949               GNUNET_TRANSPORT_ps2s(n->state),
2950               GNUNET_STRINGS_relative_time_to_string (delay,
2951                                                       GNUNET_YES));
2952   switch (n->state)
2953   {
2954   case GNUNET_TRANSPORT_PS_NOT_CONNECTED:
2955     /* invalid state for master task, clean up */
2956     GNUNET_break (0);
2957     free_neighbour (n, GNUNET_NO);
2958     return;
2959   case GNUNET_TRANSPORT_PS_INIT_ATS:
2960     if (0 == delay.rel_value_us)
2961     {
2962       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2963                   "Connection to `%s' timed out waiting for ATS to provide address\n",
2964                   GNUNET_i2s (&n->id));
2965       free_neighbour (n, GNUNET_NO);
2966       return;
2967     }
2968     break;
2969   case GNUNET_TRANSPORT_PS_SYN_SENT:
2970     if (0 == delay.rel_value_us)
2971     {
2972       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2973                   "Connection to `%s' timed out waiting for other peer to send SYN_ACK\n",
2974                   GNUNET_i2s (&n->id));
2975       /* We could not send to this address, delete address and session */
2976       if (NULL != n->primary_address.session)
2977         GNUNET_ATS_address_destroyed (GST_ats, n->primary_address.address,
2978             n->primary_address.session);
2979       GNUNET_ATS_address_destroyed (GST_ats, n->primary_address.address, NULL);
2980
2981       /* Remove address and request and additional one */
2982       unset_primary_address (n);
2983       set_state_and_timeout (n, GNUNET_TRANSPORT_PS_INIT_ATS,
2984           GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
2985       return;
2986     }
2987     break;
2988   case GNUNET_TRANSPORT_PS_SYN_RECV_ATS:
2989     if (0 == delay.rel_value_us)
2990     {
2991       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2992                   "Connection to `%s' timed out waiting ATS to provide address to use for SYN_ACK\n",
2993                   GNUNET_i2s (&n->id));
2994       free_neighbour (n, GNUNET_NO);
2995       return;
2996     }
2997     break;
2998   case GNUNET_TRANSPORT_PS_SYN_RECV_ACK:
2999     if (0 == delay.rel_value_us)
3000     {
3001       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
3002                   "Connection to `%s' timed out waiting for other peer to send ACK\n",
3003                   GNUNET_i2s (&n->id));
3004       disconnect_neighbour (n);
3005       return;
3006     }
3007     break;
3008   case GNUNET_TRANSPORT_PS_CONNECTED:
3009     if (0 == delay.rel_value_us)
3010     {
3011       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
3012                   "Connection to `%s' timed out, missing KEEPALIVE_RESPONSEs\n",
3013                   GNUNET_i2s (&n->id));
3014       disconnect_neighbour (n);
3015       return;
3016     }
3017     try_transmission_to_peer (n);
3018     send_keepalive (n);
3019     break;
3020   case GNUNET_TRANSPORT_PS_RECONNECT_ATS:
3021     if (0 == delay.rel_value_us)
3022     {
3023       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
3024                   "Connection to `%s' timed out, waiting for ATS replacement address\n",
3025                   GNUNET_i2s (&n->id));
3026       disconnect_neighbour (n);
3027       return;
3028     }
3029     break;
3030   case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
3031     if (0 == delay.rel_value_us)
3032     {
3033       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
3034                   "Connection to `%s' timed out, waiting for other peer to SYN_ACK replacement address\n",
3035                   GNUNET_i2s (&n->id));
3036       disconnect_neighbour (n);
3037       return;
3038     }
3039     break;
3040   case GNUNET_TRANSPORT_PS_SWITCH_SYN_SENT:
3041     if (0 == delay.rel_value_us)
3042     {
3043       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
3044                   "Connection to `%s' timed out, missing KEEPALIVE_RESPONSEs (after trying to SYN on alternative address)\n",
3045                   GNUNET_i2s (&n->id));
3046       GNUNET_STATISTICS_update (GST_stats, gettext_noop
3047           ("# Failed attempts to switch addresses (no response)"), 1, GNUNET_NO);
3048       disconnect_neighbour (n);
3049       return;
3050     }
3051     try_transmission_to_peer (n);
3052     send_keepalive (n);
3053     break;
3054   case GNUNET_TRANSPORT_PS_DISCONNECT:
3055     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
3056                 "Cleaning up connection to `%s' after sending DISCONNECT\n",
3057                 GNUNET_i2s (&n->id));
3058     free_neighbour (n, GNUNET_NO);
3059     return;
3060   case GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED:
3061     /* how did we get here!? */
3062     GNUNET_assert (0);
3063     break;
3064   default:
3065     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3066                 "Unhandled state `%s'\n",
3067                 GNUNET_TRANSPORT_ps2s (n->state));
3068     GNUNET_break (0);
3069     break;
3070   }
3071   if ( (GNUNET_TRANSPORT_PS_SWITCH_SYN_SENT == n->state) ||
3072        (GNUNET_TRANSPORT_PS_CONNECTED == n->state) )
3073   {
3074     /* if we are *now* in one of the two states, we're sending
3075        keep alive messages, so we need to consider the keepalive
3076        delay, not just the connection timeout */
3077     delay = GNUNET_TIME_relative_min (GNUNET_TIME_absolute_get_remaining (n->keep_alive_time),
3078                                       delay);
3079   }
3080   if (GNUNET_SCHEDULER_NO_TASK == n->task)
3081     n->task = GNUNET_SCHEDULER_add_delayed (delay,
3082                                             &master_task,
3083                                             n);
3084 }
3085
3086
3087 /**
3088  * Send a ACK message to the neighbour to confirm that we
3089  * got his SYN_ACK.
3090  *
3091  * @param n neighbour to send the ACK to
3092  */
3093 static void
3094 send_session_ack_message (struct NeighbourMapEntry *n)
3095 {
3096   struct GNUNET_MessageHeader msg;
3097
3098   GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Sending ACK message to peer `%s'\n",
3099               GNUNET_i2s (&n->id));
3100
3101   msg.size = htons (sizeof (struct GNUNET_MessageHeader));
3102   msg.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_ACK);
3103   (void) send_with_session(n,
3104                            (const char *) &msg, sizeof (struct GNUNET_MessageHeader),
3105                            UINT32_MAX, GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_NO,
3106                            NULL, NULL);
3107 }
3108
3109
3110 /**
3111  * We received a 'SESSION_SYN_ACK' message from the other peer.
3112  * Consider switching to it.
3113  *
3114  * @param message possibly a 'struct SessionConnectMessage' (check format)
3115  * @param peer identity of the peer to switch the address for
3116  * @param address address of the other peer, NULL if other peer
3117  *                       connected to us
3118  * @param session session to use (or NULL)
3119  * @return #GNUNET_OK if the message was fine, #GNUNET_SYSERR on serious error
3120  */
3121 int
3122 GST_neighbours_handle_session_syn_ack (const struct GNUNET_MessageHeader *message,
3123                                    const struct GNUNET_PeerIdentity *peer,
3124                                    const struct GNUNET_HELLO_Address *address,
3125                                    struct Session *session)
3126 {
3127   const struct TransportSynMessage *scm;
3128   struct GNUNET_TIME_Absolute ts;
3129   struct NeighbourMapEntry *n;
3130
3131   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
3132               "Received SYN_ACK message from peer `%s'\n",
3133               GNUNET_i2s (peer));
3134
3135   if (ntohs (message->size) != sizeof (struct TransportSynMessage))
3136   {
3137     GNUNET_break_op (0);
3138     return GNUNET_SYSERR;
3139   }
3140   GNUNET_STATISTICS_update (GST_stats,
3141                             gettext_noop
3142                             ("# SYN_ACK messages received"),
3143                             1, GNUNET_NO);
3144   scm = (const struct TransportSynMessage *) message;
3145   GNUNET_break_op (ntohl (scm->reserved) == 0);
3146   if (NULL == (n = lookup_neighbour (peer)))
3147   {
3148     GNUNET_STATISTICS_update (GST_stats,
3149                               gettext_noop
3150                               ("# unexpected SYN_ACK messages (no peer)"),
3151                               1, GNUNET_NO);
3152     return GNUNET_SYSERR;
3153   }
3154   ts = GNUNET_TIME_absolute_ntoh (scm->timestamp);
3155   switch (n->state)
3156   {
3157   case GNUNET_TRANSPORT_PS_NOT_CONNECTED:
3158     GNUNET_break (0);
3159     free_neighbour (n, GNUNET_NO);
3160     return GNUNET_SYSERR;
3161   case GNUNET_TRANSPORT_PS_INIT_ATS:
3162     GNUNET_STATISTICS_update (GST_stats,
3163                               gettext_noop
3164                               ("# unexpected SYN_ACK messages (not ready)"),
3165                               1, GNUNET_NO);
3166     break;
3167   case GNUNET_TRANSPORT_PS_SYN_SENT:
3168     if (ts.abs_value_us != n->primary_address.connect_timestamp.abs_value_us)
3169     {
3170       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
3171                   "SYN_ACK ignored as the timestamp does not match our SYN request\n");
3172       return GNUNET_OK;
3173     }
3174     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_CONNECTED,
3175         GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT));
3176     GNUNET_STATISTICS_set (GST_stats,
3177                            gettext_noop ("# peers connected"),
3178                            ++neighbours_connected,
3179                            GNUNET_NO);
3180     connect_notify_cb (callback_cls, &n->id,
3181                        n->primary_address.bandwidth_in,
3182                        n->primary_address.bandwidth_out);
3183     /* Tell ATS that the outbound session we created to send SYN was successful */
3184     GST_ats_add_address (n->primary_address.address,
3185                          n->primary_address.session,
3186                          NULL, 0);
3187     set_primary_address (n,
3188                  n->primary_address.address,
3189                  n->primary_address.session,
3190                  n->primary_address.bandwidth_in,
3191                  n->primary_address.bandwidth_out,
3192                  GNUNET_YES);
3193     send_session_ack_message (n);
3194     break;
3195   case GNUNET_TRANSPORT_PS_SYN_RECV_ATS:
3196   case GNUNET_TRANSPORT_PS_SYN_RECV_ACK:
3197     GNUNET_STATISTICS_update (GST_stats,
3198                               gettext_noop
3199                               ("# unexpected SYN_ACK messages (not ready)"),
3200                               1, GNUNET_NO);
3201     break;
3202   case GNUNET_TRANSPORT_PS_CONNECTED:
3203     /* duplicate SYN_ACK, let's answer by duplicate ACK just in case */
3204     send_session_ack_message (n);
3205     break;
3206   case GNUNET_TRANSPORT_PS_RECONNECT_ATS:
3207     /* we didn't expect any SYN_ACK, as we are waiting for ATS
3208        to give us a new address... */
3209     GNUNET_STATISTICS_update (GST_stats,
3210                               gettext_noop
3211                               ("# unexpected SYN_ACK messages (waiting on ATS)"),
3212                               1, GNUNET_NO);
3213     break;
3214   case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
3215     /* Reconnecting with new address address worked; go back to connected! */
3216     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_CONNECTED,
3217         GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT));
3218     send_session_ack_message (n);
3219     break;
3220   case GNUNET_TRANSPORT_PS_SWITCH_SYN_SENT:
3221     /* new address worked; adopt it and go back to connected! */
3222     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_CONNECTED,
3223         GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT));
3224     GNUNET_break (GNUNET_NO == n->alternative_address.ats_active);
3225
3226     /* Notify about session... perhaps we obtained it */
3227     GST_ats_add_address (n->alternative_address.address,
3228         n->alternative_address.session, NULL, 0);
3229     /* Set primary addresses */
3230     set_primary_address (n, n->alternative_address.address,
3231         n->alternative_address.session, n->alternative_address.bandwidth_in,
3232         n->alternative_address.bandwidth_out, GNUNET_YES);
3233     GNUNET_STATISTICS_update (GST_stats, gettext_noop
3234         ("# Successful attempts to switch addresses"), 1, GNUNET_NO);
3235
3236     free_address (&n->alternative_address);
3237     send_session_ack_message (n);
3238     break;
3239   case GNUNET_TRANSPORT_PS_DISCONNECT:
3240     GNUNET_STATISTICS_update (GST_stats,
3241                               gettext_noop
3242                               ("# unexpected SYN_ACK messages (disconnecting)"),
3243                               1, GNUNET_NO);
3244     return GNUNET_SYSERR;
3245   case GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED:
3246     GNUNET_assert (0);
3247     break;
3248   default:
3249     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3250                 "Unhandled state `%s'\n",
3251                 GNUNET_TRANSPORT_ps2s (n->state));
3252     GNUNET_break (0);
3253     return GNUNET_SYSERR;
3254   }
3255   return GNUNET_OK;
3256 }
3257
3258
3259 /**
3260  * A session was terminated. Take note; if needed, try to get
3261  * an alternative address from ATS.
3262  *
3263  * @param peer identity of the peer where the session died
3264  * @param session session that is gone
3265  * @return #GNUNET_YES if this was a session used, #GNUNET_NO if
3266  *        this session was not in use
3267  */
3268 int
3269 GST_neighbours_session_terminated (const struct GNUNET_PeerIdentity *peer,
3270                                    struct Session *session)
3271 {
3272   struct NeighbourMapEntry *n;
3273   struct BlackListCheckContext *bcc;
3274   struct BlackListCheckContext *bcc_next;
3275
3276   /* make sure to cancel all ongoing blacklist checks involving 'session' */
3277   bcc_next = bc_head;
3278   while (NULL != (bcc = bcc_next))
3279   {
3280     bcc_next = bcc->next;
3281     if (bcc->na.session == session)
3282     {
3283       if (NULL != bcc->bc)
3284         GST_blacklist_test_cancel (bcc->bc);
3285       GNUNET_HELLO_address_free (bcc->na.address);
3286       GNUNET_CONTAINER_DLL_remove (bc_head,
3287                                    bc_tail,
3288                                    bcc);
3289       GNUNET_free (bcc);
3290     }
3291   }
3292   if (NULL == (n = lookup_neighbour (peer)))
3293     return GNUNET_NO; /* can't affect us */
3294   if (session != n->primary_address.session)
3295   {
3296     /* Free alternative address */
3297     if (session == n->alternative_address.session)
3298     {
3299       if ( (GNUNET_TRANSPORT_PS_SWITCH_SYN_SENT == n->state) )
3300         set_state (n, GNUNET_TRANSPORT_PS_CONNECTED);
3301       free_address (&n->alternative_address);
3302     }
3303     return GNUNET_NO; /* doesn't affect us further */
3304   }
3305
3306   n->expect_latency_response = GNUNET_NO;
3307   /* The session for neighbour's primary address died */
3308   switch (n->state)
3309   {
3310   case GNUNET_TRANSPORT_PS_NOT_CONNECTED:
3311     GNUNET_break (0);
3312     free_neighbour (n, GNUNET_NO);
3313     return GNUNET_YES;
3314   case GNUNET_TRANSPORT_PS_INIT_ATS:
3315     GNUNET_break (0);
3316     free_neighbour (n, GNUNET_NO);
3317     return GNUNET_YES;
3318   case GNUNET_TRANSPORT_PS_SYN_SENT:
3319     /* The session used to send the SYN terminated:
3320      * this implies a connect error*/
3321     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
3322                 "Failed to send SYN in %s with `%s' %p: session terminated\n",
3323                 "CONNECT_SENT",
3324                 GST_plugins_a2s (n->primary_address.address),
3325                 n->primary_address.session,
3326                 GNUNET_i2s (peer));
3327
3328     /* Destroy the address since it cannot be used */
3329     GNUNET_ATS_address_destroyed (GST_ats, n->primary_address.address, NULL);
3330     unset_primary_address (n);
3331     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_INIT_ATS,
3332         GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
3333     break;
3334   case GNUNET_TRANSPORT_PS_SYN_RECV_ATS:
3335   case GNUNET_TRANSPORT_PS_SYN_RECV_ACK:
3336     /* error on inbound session; free neighbour entirely */
3337     free_address (&n->primary_address);
3338     free_neighbour (n, GNUNET_NO);
3339     return GNUNET_YES;
3340   case GNUNET_TRANSPORT_PS_CONNECTED:
3341     /* Our primary connection died, try a fast reconnect */
3342     unset_primary_address (n);
3343     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_RECONNECT_ATS,
3344         GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
3345     break;
3346   case GNUNET_TRANSPORT_PS_RECONNECT_ATS:
3347     /* we don't have an address, how can it go down? */
3348     GNUNET_break (0);
3349     break;
3350   case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
3351     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
3352                 "Failed to send SYN in %s with `%s' %p: session terminated\n",
3353                 "RECONNECT_SENT",
3354                 GST_plugins_a2s (n->primary_address.address),
3355                 n->primary_address.session,
3356                 GNUNET_i2s (peer));
3357
3358     /* Destroy the address since it cannot be used */
3359     GNUNET_ATS_address_destroyed (GST_ats, n->primary_address.address, NULL);
3360     unset_primary_address (n);
3361     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_RECONNECT_ATS,
3362         GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT));
3363     break;
3364   case GNUNET_TRANSPORT_PS_SWITCH_SYN_SENT:
3365     /* primary went down while we were waiting for SYN_ACK on secondary;
3366        secondary as primary */
3367
3368     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
3369         "Connection `%s' %p to peer `%s' was terminated while switching, "
3370         "switching to alternative address `%s' %p\n",
3371         GST_plugins_a2s (n->primary_address.address),
3372         n->primary_address.session,
3373         GNUNET_i2s (peer),
3374         GST_plugins_a2s (n->alternative_address.address),
3375         n->alternative_address.session);
3376
3377     /* Destroy the inbound address since it cannot be used */
3378     if (GNUNET_YES
3379         == GNUNET_HELLO_address_check_option (n->primary_address.address,
3380             GNUNET_HELLO_ADDRESS_INFO_INBOUND))
3381       GNUNET_ATS_address_destroyed (GST_ats, n->primary_address.address, NULL);
3382     free_address (&n->primary_address);
3383
3384
3385     n->primary_address = n->alternative_address;
3386     memset (&n->alternative_address, 0, sizeof (struct NeighbourAddress));
3387     set_state_and_timeout (n, GNUNET_TRANSPORT_PS_RECONNECT_SENT,
3388         GNUNET_TIME_relative_to_absolute (FAST_RECONNECT_TIMEOUT));
3389     break;
3390   case GNUNET_TRANSPORT_PS_DISCONNECT:
3391     free_address (&n->primary_address);
3392     break;
3393   case GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED:
3394     /* neighbour was freed and plugins told to terminate session */
3395     return GNUNET_NO;
3396     break;
3397   default:
3398     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3399                 "Unhandled state `%s'\n",
3400                 GNUNET_TRANSPORT_ps2s (n->state));
3401     GNUNET_break (0);
3402     break;
3403   }
3404   if (GNUNET_SCHEDULER_NO_TASK != n->task)
3405     GNUNET_SCHEDULER_cancel (n->task);
3406   n->task = GNUNET_SCHEDULER_add_now (&master_task, n);
3407   return GNUNET_YES;
3408 }
3409
3410
3411 /**
3412  * We received a 'ACK' message from the other peer.
3413  * If we sent a 'SYN_ACK' last, this means we are now
3414  * connected.  Otherwise, do nothing.
3415  *
3416  * @param message possibly a 'struct SessionConnectMessage' (check format)
3417  * @param peer identity of the peer to switch the address for
3418  * @param address address of the other peer, NULL if other peer
3419  *                       connected to us
3420  * @param session session to use (or NULL)
3421  * @return #GNUNET_OK if the message was fine, #GNUNET_SYSERR on serious error
3422  */
3423 int
3424 GST_neighbours_handle_session_ack (const struct GNUNET_MessageHeader *message,
3425                                    const struct GNUNET_PeerIdentity *peer,
3426                                    const struct GNUNET_HELLO_Address *address,
3427                                    struct Session *session)
3428 {
3429   struct NeighbourMapEntry *n;
3430
3431   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3432               "Received ACK message from peer `%s'\n",
3433               GNUNET_i2s (peer));
3434   if (ntohs (message->size) != sizeof (struct GNUNET_MessageHeader))
3435   {
3436     GNUNET_break_op (0);
3437     return GNUNET_SYSERR;
3438   }
3439   GNUNET_STATISTICS_update (GST_stats,
3440                             gettext_noop
3441                             ("# ACK messages received"),
3442                             1, GNUNET_NO);
3443   if (NULL == (n = lookup_neighbour (peer)))
3444   {
3445     GNUNET_break_op (0);
3446     return GNUNET_SYSERR;
3447   }
3448
3449   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
3450               "Received %s for peer `%s' in state %s/%s\n",
3451               "ACK",
3452               GNUNET_i2s (peer),
3453               GNUNET_TRANSPORT_ps2s (n->state),
3454               print_ack_state (n->ack_state));
3455
3456   /* Check if we are in a plausible state for having sent
3457      a SYN_ACK.  If not, return, otherwise break.
3458
3459      The remote peers sends a ACK as a response for a SYN_ACK
3460      message.
3461
3462      We expect a ACK:
3463      - If a remote peer has sent a SYN, we responded with a SYN_ACK and
3464      now wait for the ACK to finally be connected
3465      - If we sent a SYN_ACK to this peer before */
3466
3467   if (   (GNUNET_TRANSPORT_PS_SYN_RECV_ACK != n->state) &&
3468          (ACK_SEND_ACK != n->ack_state))
3469   {
3470     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
3471                 "Received unexpected ACK message from peer `%s' in state %s/%s\n",
3472                 GNUNET_i2s (peer),
3473                 GNUNET_TRANSPORT_ps2s (n->state),
3474                 print_ack_state (n->ack_state));
3475
3476     GNUNET_STATISTICS_update (GST_stats,
3477                               gettext_noop ("# unexpected ACK messages"), 1,
3478                               GNUNET_NO);
3479     return GNUNET_OK;
3480   }
3481
3482   /* We are connected */
3483   if (GNUNET_NO == GST_neighbours_test_connected(&n->id))
3484   {
3485     /* Notify about connection */
3486     connect_notify_cb (callback_cls, &n->id,
3487                      n->primary_address.bandwidth_in,
3488                      n->primary_address.bandwidth_out);\
3489
3490      GNUNET_STATISTICS_set (GST_stats,
3491                             gettext_noop ("# peers connected"),
3492                             ++neighbours_connected,
3493                             GNUNET_NO);
3494   }
3495
3496   if (GNUNET_TRANSPORT_PS_SWITCH_SYN_SENT == n->state)
3497   {
3498     /* We tried to switch addresses while being connect. We explicitly wait
3499      * for a SYN_ACK before going to GNUNET_TRANSPORT_PS_CONNECTED,
3500      * so we do not want to set the address as in use! */
3501     return GNUNET_OK;
3502   }
3503
3504   set_state_and_timeout (n, GNUNET_TRANSPORT_PS_CONNECTED,
3505     GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT));
3506
3507   /* Add session to ATS since no session was given (NULL) and we may have
3508    * obtained a new session */
3509   GST_ats_add_address (n->primary_address.address, n->primary_address.session,
3510       NULL, 0);
3511
3512   /* Set primary address to used */
3513   set_primary_address (n,
3514                n->primary_address.address,
3515                n->primary_address.session,
3516                n->primary_address.bandwidth_in,
3517                n->primary_address.bandwidth_out,
3518                GNUNET_YES);
3519   return GNUNET_OK;
3520 }
3521
3522
3523 /**
3524  * Test if we're connected to the given peer.
3525  *
3526  * @param target peer to test
3527  * @return #GNUNET_YES if we are connected, #GNUNET_NO if not
3528  */
3529 int
3530 GST_neighbours_test_connected (const struct GNUNET_PeerIdentity *target)
3531 {
3532   return test_connected (lookup_neighbour (target));
3533 }
3534
3535 /**
3536  * Change the incoming quota for the given peer.
3537  *
3538  * @param neighbour identity of peer to change qutoa for
3539  * @param quota new quota
3540  */
3541 void
3542 GST_neighbours_set_incoming_quota (const struct GNUNET_PeerIdentity *neighbour,
3543                                    struct GNUNET_BANDWIDTH_Value32NBO quota)
3544 {
3545   struct NeighbourMapEntry *n;
3546
3547   if (NULL == (n = lookup_neighbour (neighbour)))
3548   {
3549     GNUNET_STATISTICS_update (GST_stats,
3550                               gettext_noop
3551                               ("# SET QUOTA messages ignored (no such peer)"),
3552                               1, GNUNET_NO);
3553     return;
3554   }
3555   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3556               "Setting inbound quota of %u Bps for peer `%s' to all clients\n",
3557               ntohl (quota.value__), GNUNET_i2s (&n->id));
3558   GNUNET_BANDWIDTH_tracker_update_quota (&n->in_tracker, quota);
3559   if (0 != ntohl (quota.value__))
3560     return;
3561   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
3562               "Disconnecting peer `%4s' due to SET_QUOTA\n",
3563               GNUNET_i2s (&n->id));
3564   if (GNUNET_YES == test_connected (n))
3565     GNUNET_STATISTICS_update (GST_stats,
3566                               gettext_noop ("# disconnects due to quota of 0"),
3567                               1, GNUNET_NO);
3568   disconnect_neighbour (n);
3569 }
3570
3571 void delayed_disconnect (void *cls,
3572     const struct GNUNET_SCHEDULER_TaskContext* tc)
3573 {
3574   struct NeighbourMapEntry *n = cls;
3575
3576   n->delayed_disconnect_task = GNUNET_SCHEDULER_NO_TASK;
3577   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
3578               "Disconnecting by request from peer %s\n",
3579               GNUNET_i2s (&n->id));
3580
3581   if (NULL != n->primary_address.address)
3582     GNUNET_ATS_address_destroyed (GST_ats, n->primary_address.address,
3583         n->primary_address.session);
3584
3585   free_neighbour (n, GNUNET_NO);
3586 }
3587
3588
3589 /**
3590  * We received a disconnect message from the given peer,
3591  * validate and process.
3592  *
3593  * @param peer sender of the message
3594  * @param msg the disconnect message
3595  */
3596 void
3597 GST_neighbours_handle_disconnect_message (const struct GNUNET_PeerIdentity *peer,
3598                                           const struct GNUNET_MessageHeader *msg)
3599 {
3600   struct NeighbourMapEntry *n;
3601   const struct SessionDisconnectMessage *sdm;
3602
3603   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
3604               "Received DISCONNECT message from peer `%s'\n",
3605               GNUNET_i2s (peer));
3606   if (ntohs (msg->size) != sizeof (struct SessionDisconnectMessage))
3607   {
3608     GNUNET_break_op (0);
3609     GNUNET_STATISTICS_update (GST_stats,
3610                               gettext_noop
3611                               ("# disconnect messages ignored (malformed)"), 1,
3612                               GNUNET_NO);
3613     return;
3614   }
3615   GNUNET_STATISTICS_update (GST_stats,
3616                             gettext_noop
3617                             ("# DISCONNECT messages received"),
3618                             1, GNUNET_NO);
3619   sdm = (const struct SessionDisconnectMessage *) msg;
3620   if (NULL == (n = lookup_neighbour (peer)))
3621     return;                     /* gone already */
3622   if (GNUNET_TIME_absolute_ntoh (sdm->timestamp).abs_value_us <= n->connect_ack_timestamp.abs_value_us)
3623   {
3624     GNUNET_STATISTICS_update (GST_stats,
3625                               gettext_noop
3626                               ("# disconnect messages ignored (timestamp)"), 1,
3627                               GNUNET_NO);
3628     return;
3629   }
3630   if (0 != memcmp (peer, &sdm->public_key, sizeof (struct GNUNET_PeerIdentity)))
3631   {
3632     GNUNET_break_op (0);
3633     return;
3634   }
3635   if (ntohl (sdm->purpose.size) !=
3636       sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
3637       sizeof (struct GNUNET_CRYPTO_EddsaPublicKey) +
3638       sizeof (struct GNUNET_TIME_AbsoluteNBO))
3639   {
3640     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
3641                 "%s message from peer `%s' has invalid size \n",
3642                 "DISCONNECT",
3643                 GNUNET_i2s (peer));
3644     GNUNET_break_op (0);
3645     return;
3646   }
3647   if (GNUNET_OK !=
3648       GNUNET_CRYPTO_eddsa_verify
3649       (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_DISCONNECT, &sdm->purpose,
3650        &sdm->signature, &sdm->public_key))
3651   {
3652     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
3653                 "%s message from peer `%s' cannot be verified \n",
3654                 "DISCONNECT",
3655                 GNUNET_i2s (peer));
3656     GNUNET_break_op (0);
3657     return;
3658   }
3659   n->delayed_disconnect_task = GNUNET_SCHEDULER_add_now (&delayed_disconnect, n);
3660 }
3661
3662
3663 /**
3664  * Closure for the neighbours_iterate function.
3665  */
3666 struct IteratorContext
3667 {
3668   /**
3669    * Function to call on each connected neighbour.
3670    */
3671   GST_NeighbourIterator cb;
3672
3673   /**
3674    * Closure for 'cb'.
3675    */
3676   void *cb_cls;
3677 };
3678
3679
3680 /**
3681  * Call the callback from the closure for each neighbour.
3682  *
3683  * @param cls the `struct IteratorContext`
3684  * @param key the hash of the public key of the neighbour
3685  * @param value the `struct NeighbourMapEntry`
3686  * @return #GNUNET_OK (continue to iterate)
3687  */
3688 static int
3689 neighbours_iterate (void *cls,
3690                     const struct GNUNET_PeerIdentity *key,
3691                     void *value)
3692 {
3693   struct IteratorContext *ic = cls;
3694   struct NeighbourMapEntry *n = value;
3695   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in;
3696   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out;
3697
3698
3699   if (NULL != n->primary_address.address)
3700   {
3701     bandwidth_in = n->primary_address.bandwidth_in;
3702     bandwidth_out = n->primary_address.bandwidth_out;
3703   }
3704   else
3705   {
3706     bandwidth_in = GNUNET_CONSTANTS_DEFAULT_BW_IN_OUT;
3707     bandwidth_out = GNUNET_CONSTANTS_DEFAULT_BW_IN_OUT;
3708   }
3709   ic->cb (ic->cb_cls,
3710           &n->id,
3711           n->primary_address.address,
3712           n->state,
3713           n->timeout,
3714           bandwidth_in, bandwidth_out);
3715   return GNUNET_OK;
3716 }
3717
3718
3719 /**
3720  * Iterate over all connected neighbours.
3721  *
3722  * @param cb function to call
3723  * @param cb_cls closure for cb
3724  */
3725 void
3726 GST_neighbours_iterate (GST_NeighbourIterator cb, void *cb_cls)
3727 {
3728   struct IteratorContext ic;
3729
3730   if (NULL == neighbours)
3731     return; /* can happen during shutdown */
3732   ic.cb = cb;
3733   ic.cb_cls = cb_cls;
3734   GNUNET_CONTAINER_multipeermap_iterate (neighbours, &neighbours_iterate, &ic);
3735 }
3736
3737
3738 /**
3739  * If we have an active connection to the given target, it must be shutdown.
3740  *
3741  * @param target peer to disconnect from
3742  */
3743 void
3744 GST_neighbours_force_disconnect (const struct GNUNET_PeerIdentity *target)
3745 {
3746   struct NeighbourMapEntry *n;
3747
3748   if (NULL == (n = lookup_neighbour (target)))
3749     return;  /* not active */
3750   if (GNUNET_YES == test_connected (n))
3751     GNUNET_STATISTICS_update (GST_stats,
3752                               gettext_noop
3753                               ("# disconnected from peer upon explicit request"), 1,
3754                               GNUNET_NO);
3755   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
3756               "Forced disconnect from peer %s\n",
3757               GNUNET_i2s (target));
3758   disconnect_neighbour (n);
3759 }
3760
3761
3762 /**
3763  * Obtain current latency information for the given neighbour.
3764  *
3765  * @param peer to get the latency for
3766  * @return observed latency of the address, FOREVER if the
3767  *         the connection is not up
3768  */
3769 struct GNUNET_TIME_Relative
3770 GST_neighbour_get_latency (const struct GNUNET_PeerIdentity *peer)
3771 {
3772   struct NeighbourMapEntry *n;
3773
3774   n = lookup_neighbour (peer);
3775   if (NULL == n)
3776     return GNUNET_TIME_UNIT_FOREVER_REL;
3777   switch (n->state)
3778   {
3779   case GNUNET_TRANSPORT_PS_CONNECTED:
3780   case GNUNET_TRANSPORT_PS_SWITCH_SYN_SENT:
3781   case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
3782   case GNUNET_TRANSPORT_PS_RECONNECT_ATS:
3783     return n->latency;
3784   case GNUNET_TRANSPORT_PS_NOT_CONNECTED:
3785   case GNUNET_TRANSPORT_PS_INIT_ATS:
3786   case GNUNET_TRANSPORT_PS_SYN_RECV_ATS:
3787   case GNUNET_TRANSPORT_PS_SYN_RECV_ACK:
3788   case GNUNET_TRANSPORT_PS_SYN_SENT:
3789   case GNUNET_TRANSPORT_PS_DISCONNECT:
3790   case GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED:
3791     return GNUNET_TIME_UNIT_FOREVER_REL;
3792   default:
3793     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3794                 "Unhandled state `%s'\n",
3795                 GNUNET_TRANSPORT_ps2s (n->state));
3796     GNUNET_break (0);
3797     break;
3798   }
3799   return GNUNET_TIME_UNIT_FOREVER_REL;
3800 }
3801
3802
3803 /**
3804  * Obtain current address information for the given neighbour.
3805  *
3806  * @param peer
3807  * @return address currently used
3808  */
3809 struct GNUNET_HELLO_Address *
3810 GST_neighbour_get_current_address (const struct GNUNET_PeerIdentity *peer)
3811 {
3812   struct NeighbourMapEntry *n;
3813
3814   n = lookup_neighbour (peer);
3815   if (NULL == n)
3816     return NULL;
3817   return n->primary_address.address;
3818 }
3819
3820
3821 /**
3822  * Initialize the neighbours subsystem.
3823  *
3824  * @param cls closure for callbacks
3825  * @param connect_cb function to call if we connect to a peer
3826  * @param disconnect_cb function to call if we disconnect from a peer
3827  * @param peer_address_cb function to call if we change an active address
3828  *                   of a neighbour
3829  * @param max_fds maximum number of fds to use
3830  */
3831 void
3832 GST_neighbours_start (void *cls,
3833                       NotifyConnect connect_cb,
3834                       GNUNET_TRANSPORT_NotifyDisconnect disconnect_cb,
3835                       GNUNET_TRANSPORT_NeighbourChangeCallback peer_address_cb,
3836                       unsigned int max_fds)
3837 {
3838   callback_cls = cls;
3839   connect_notify_cb = connect_cb;
3840   disconnect_notify_cb = disconnect_cb;
3841   neighbour_change_cb = peer_address_cb;
3842   neighbours = GNUNET_CONTAINER_multipeermap_create (NEIGHBOUR_TABLE_SIZE, GNUNET_NO);
3843   registered_quota_notifications = GNUNET_CONTAINER_multipeermap_create (NEIGHBOUR_TABLE_SIZE, GNUNET_NO);
3844   util_transmission_tk = GNUNET_SCHEDULER_add_delayed (UTIL_TRANSMISSION_INTERVAL,
3845       utilization_transmission, NULL);
3846 }
3847
3848
3849 /**
3850  * Disconnect from the given neighbour.
3851  *
3852  * @param cls unused
3853  * @param key hash of neighbour's public key (not used)
3854  * @param value the 'struct NeighbourMapEntry' of the neighbour
3855  * @return #GNUNET_OK (continue to iterate)
3856  */
3857 static int
3858 disconnect_all_neighbours (void *cls,
3859                            const struct GNUNET_PeerIdentity *key,
3860                            void *value)
3861 {
3862   struct NeighbourMapEntry *n = value;
3863
3864   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3865               "Disconnecting peer `%4s', %s\n",
3866               GNUNET_i2s (&n->id), "SHUTDOWN_TASK");
3867   free_neighbour (n, GNUNET_NO);
3868   return GNUNET_OK;
3869 }
3870
3871
3872 /**
3873  * Cleanup the neighbours subsystem.
3874  */
3875 void
3876 GST_neighbours_stop ()
3877 {
3878   struct BlacklistCheckSwitchContext *cur;
3879   struct BlacklistCheckSwitchContext *next;
3880
3881   if (NULL == neighbours)
3882     return;
3883   if (GNUNET_SCHEDULER_NO_TASK != util_transmission_tk)
3884   {
3885     GNUNET_SCHEDULER_cancel (util_transmission_tk);
3886     util_transmission_tk = GNUNET_SCHEDULER_NO_TASK;
3887   }
3888
3889   GNUNET_CONTAINER_multipeermap_iterate (neighbours, &disconnect_all_neighbours,
3890       NULL );
3891   GNUNET_CONTAINER_multipeermap_destroy (neighbours);
3892
3893   next = pending_bc_head;
3894   for (cur = next; NULL != cur; cur = next )
3895   {
3896     next = cur->next;
3897     GNUNET_CONTAINER_DLL_remove (pending_bc_head, pending_bc_tail, cur);
3898
3899     if (NULL != cur->blc)
3900     {
3901       GST_blacklist_test_cancel (cur->blc);
3902       cur->blc = NULL;
3903     }
3904     if (NULL != cur->address)
3905       GNUNET_HELLO_address_free (cur->address);
3906     GNUNET_free_non_null (cur->ats);
3907     GNUNET_free (cur);
3908   }
3909
3910   GNUNET_CONTAINER_multipeermap_iterate (registered_quota_notifications,
3911       &free_notification_cb, NULL);
3912   GNUNET_CONTAINER_multipeermap_destroy (registered_quota_notifications);
3913   registered_quota_notifications = NULL;
3914
3915   neighbours = NULL;
3916   callback_cls = NULL;
3917   connect_notify_cb = NULL;
3918   disconnect_notify_cb = NULL;
3919   neighbour_change_cb = NULL;
3920 }
3921
3922
3923 /* end of file gnunet-service-transport_neighbours.c */