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  * TODO:
  27  * - TEST, TEST, TEST...
  28  */
  29 #include "platform.h"
  30 #include "gnunet_ats_service.h"
  31 #include "gnunet-service-transport_neighbours.h"
  32 #include "gnunet-service-transport_plugins.h"
  33 #include "gnunet-service-transport_validation.h"
  34 #include "gnunet-service-transport_clients.h"
  35 #include "gnunet-service-transport.h"
  36 #include "gnunet_peerinfo_service.h"
  37 #include "gnunet-service-transport_blacklist.h"
  38 #include "gnunet_constants.h"
  39 #include "transport.h"
  40
  41
  42
  43 /**
  44  * Size of the neighbour hash map.
  45  */
  46 #define NEIGHBOUR_TABLE_SIZE 256
  47
  48 /**
  49  * Time we give plugin to transmit DISCONNECT message before the
  50  * neighbour entry self-destructs.
  51  */
  52 #define DISCONNECT_SENT_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 100)
  53
  54 /**
  55  * How often must a peer violate bandwidth quotas before we start
  56  * to simply drop its messages?
  57  */
  58 #define QUOTA_VIOLATION_DROP_THRESHOLD 10
  59
  60 /**
  61  * How often do we send KEEPALIVE messages to each of our neighbours and measure
  62  * the latency with this neighbour?
  63  * (idle timeout is 5 minutes or 300 seconds, so with 100s interval we
  64  * send 3 keepalives in each interval, so 3 messages would need to be
  65  * lost in a row for a disconnect).
  66  */
  67 #define KEEPALIVE_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 100)
  68
  69 /**
  70  * How long are we willing to wait for a response from ATS before timing out?
  71  */
  72 #define ATS_RESPONSE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 5000)
  73
  74 /**
  75  * How long are we willing to wait for an ACK from the other peer before
  76  * giving up on our connect operation?
  77  */
  78 #define SETUP_CONNECTION_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 15)
  79
  80 /**
  81  * How long are we willing to wait for a successful reconnect if
  82  * an existing connection went down?  Much shorter than the
  83  * usual SETUP_CONNECTION_TIMEOUT as we do not inform the
  84  * higher layers about the disconnect during this period.
  85  */
  86 #define FAST_RECONNECT_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 1)
  87
  88 /**
  89  * How long are we willing to wait for a response from the blacklist
  90  * subsystem before timing out?
  91  */
  92 #define BLACKLIST_RESPONSE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 500)
  93
  94 /**
  95  * Interval to send utilization data
  96  */
  97 #define UTIL_TRANSMISSION_INTERVAL GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 1)
  98
  99 GNUNET_NETWORK_STRUCT_BEGIN
 100
 101 /**
 102  * Message a peer sends to another to indicate that it intends to
 103  * setup a connection/session for data exchange.  A 'SESSION_CONNECT'
 104  * should be answered with a 'SESSION_CONNECT_ACK' with the same body
 105  * to confirm.  A 'SESSION_CONNECT_ACK' should then be followed with
 106  * a 'SESSION_ACK'.  Once the 'SESSION_ACK' is received, both peers
 107  * should be connected.
 108  */
 109 struct SessionConnectMessage
 110 {
 111   /**
 112    * Header of type #GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_CONNECT
 113    * or #GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_CONNECT_ACK
 114    */
 115   struct GNUNET_MessageHeader header;
 116
 117   /**
 118    * Always zero.
 119    */
 120   uint32_t reserved GNUNET_PACKED;
 121
 122   /**
 123    * Absolute time at the sender.  Only the most recent connect
 124    * message implies which session is preferred by the sender.
 125    */
 126   struct GNUNET_TIME_AbsoluteNBO timestamp;
 127
 128 };
 129
 130
 131 /**
 132  * Message we send to the other peer to notify him that we intentionally
 133  * are disconnecting (to reduce timeouts).  This is just a friendly
 134  * notification, peers must not rely on always receiving disconnect
 135  * messages.
 136  */
 137 struct SessionDisconnectMessage
 138 {
 139   /**
 140    * Header of type #GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_DISCONNECT
 141    */
 142   struct GNUNET_MessageHeader header;
 143
 144   /**
 145    * Always zero.
 146    */
 147   uint32_t reserved GNUNET_PACKED;
 148
 149   /**
 150    * Purpose of the signature.  Extends over the timestamp.
 151    * Purpose should be #GNUNET_SIGNATURE_PURPOSE_TRANSPORT_DISCONNECT.
 152    */
 153   struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
 154
 155   /**
 156    * Absolute time at the sender.  Only the most recent connect
 157    * message implies which session is preferred by the sender.
 158    */
 159   struct GNUNET_TIME_AbsoluteNBO timestamp;
 160
 161   /**
 162    * Public key of the sender.
 163    */
 164   struct GNUNET_CRYPTO_EddsaPublicKey public_key;
 165
 166   /**
 167    * Signature of the peer that sends us the disconnect.  Only
 168    * valid if the timestamp is AFTER the timestamp from the
 169    * corresponding 'CONNECT' message.
 170    */
 171   struct GNUNET_CRYPTO_EddsaSignature signature;
 172
 173 };
 174
 175 GNUNET_NETWORK_STRUCT_END
 176
 177
 178 /**
 179  * For each neighbour we keep a list of messages
 180  * that we still want to transmit to the neighbour.
 181  */
 182 struct MessageQueue
 183 {
 184
 185   /**
 186    * This is a doubly linked list.
 187    */
 188   struct MessageQueue *next;
 189
 190   /**
 191    * This is a doubly linked list.
 192    */
 193   struct MessageQueue *prev;
 194
 195   /**
 196    * Function to call once we're done.
 197    */
 198   GST_NeighbourSendContinuation cont;
 199
 200   /**
 201    * Closure for @e cont
 202    */
 203   void *cont_cls;
 204
 205   /**
 206    * The message(s) we want to transmit, GNUNET_MessageHeader(s)
 207    * stuck together in memory.  Allocated at the end of this struct.
 208    */
 209   const char *message_buf;
 210
 211   /**
 212    * Size of the message buf
 213    */
 214   size_t message_buf_size;
 215
 216   /**
 217    * At what time should we fail?
 218    */
 219   struct GNUNET_TIME_Absolute timeout;
 220
 221 };
 222
 223
 224 /**
 225  * Possible state of a neighbour.  Initially, we are #S_NOT_CONNECTED.
 226  *
 227  * Then, there are two main paths. If we receive a CONNECT message, we
 228  * first run a check against the blacklist (#S_CONNECT_RECV_BLACKLIST_INBOUND).
 229  * If this check is successful, we give the inbound address to ATS.
 230  * After the check we ask ATS for a suggestion (S_CONNECT_RECV_ATS).
 231  * If ATS makes a suggestion, we ALSO give that suggestion to the blacklist
 232  * (#S_CONNECT_RECV_BLACKLIST).  Once the blacklist approves the
 233  * address we got from ATS, we send our CONNECT_ACK and go to
 234  * #S_CONNECT_RECV_ACK.  If we receive a SESSION_ACK, we go to
 235  * #S_CONNECTED (and notify everyone about the new connection).  If the
 236  * operation times out, we go to #S_DISCONNECT.
 237  *
 238  * The other case is where we transmit a CONNECT message first.  We
 239  * start with #S_INIT_ATS.  If we get an address, we enter
 240  * #S_INIT_BLACKLIST and check the blacklist.  If the blacklist is OK
 241  * with the connection, we actually send the CONNECT message and go to
 242  * state S_CONNECT_SENT.  Once we receive a CONNECT_ACK, we go to
 243  * #S_CONNECTED (and notify everyone about the new connection and send
 244  * back a SESSION_ACK).  If the operation times out, we go to
 245  * #S_DISCONNECT.
 246  *
 247  * If the session is in trouble (i.e. transport-level disconnect or
 248  * timeout), we go to #S_RECONNECT_ATS where we ask ATS for a new
 249  * address (we don't notify anyone about the disconnect yet).  Once we
 250  * have a new address, we go to #S_RECONNECT_BLACKLIST to check the new
 251  * address against the blacklist.  If the blacklist approves, we enter
 252  * #S_RECONNECT_SENT and send a CONNECT message.  If we receive a
 253  * CONNECT_ACK, we go to #S_CONNECTED and nobody noticed that we had
 254  * trouble; we also send a SESSION_ACK at this time just in case.  If
 255  * the operation times out, we go to S_DISCONNECT (and notify everyone
 256  * about the lost connection).
 257  *
 258  * If ATS decides to switch addresses while we have a normal
 259  * connection, we go to #S_CONNECTED_SWITCHING_BLACKLIST to check the
 260  * new address against the blacklist.  If the blacklist approves, we
 261  * go to #S_CONNECTED_SWITCHING_CONNECT_SENT and send a
 262  * SESSION_CONNECT.  If we get a SESSION_ACK back, we switch the
 263  * primary connection to the suggested alternative from ATS, go back
 264  * to #S_CONNECTED and send a SESSION_ACK to the other peer just to be
 265  * sure.  If the operation times out (or the blacklist disapproves),
 266  * we go to #S_CONNECTED (and notify ATS that the given alternative
 267  * address is "invalid").
 268  *
 269  * Once a session is in #S_DISCONNECT, it is cleaned up and then goes
 270  * to (#S_DISCONNECT_FINISHED).  If we receive an explicit disconnect
 271  * request, we can go from any state to #S_DISCONNECT, possibly after
 272  * generating disconnect notifications.
 273  *
 274  * Note that it is quite possible that while we are in any of these
 275  * states, we could receive a 'CONNECT' request from the other peer.
 276  * We then enter a 'weird' state where we pursue our own primary state
 277  * machine (as described above), but with the 'send_connect_ack' flag
 278  * set to 1.  If our state machine allows us to send a 'CONNECT_ACK'
 279  * (because we have an acceptable address), we send the 'CONNECT_ACK'
 280  * and set the 'send_connect_ack' to 2.  If we then receive a
 281  * 'SESSION_ACK', we go to #S_CONNECTED (and reset 'send_connect_ack'
 282  * to 0).
 283  *
 284  */
 285 enum State
 286 {
 287   /**
 288    * fresh peer or completely disconnected
 289    */
 290   S_NOT_CONNECTED = 0,
 291
 292   /**
 293    * Asked to initiate connection, trying to get address from ATS
 294    */
 295   S_INIT_ATS,
 296
 297   /**
 298    * Asked to initiate connection, trying to get address approved
 299    * by blacklist.
 300    */
 301   S_INIT_BLACKLIST,
 302
 303   /**
 304    * Sent CONNECT message to other peer, waiting for CONNECT_ACK
 305    */
 306   S_CONNECT_SENT,
 307
 308   /**
 309    * Received a CONNECT, do a blacklist check for inbound address
 310    */
 311   S_CONNECT_RECV_BLACKLIST_INBOUND,
 312
 313   /**
 314    * Received a CONNECT, asking ATS about address suggestions.
 315    */
 316   S_CONNECT_RECV_ATS,
 317
 318   /**
 319    * Received CONNECT from other peer, got an address, checking with blacklist.
 320    */
 321   S_CONNECT_RECV_BLACKLIST,
 322
 323   /**
 324    * CONNECT request from other peer was SESSION_ACK'ed, waiting for
 325    * SESSION_ACK.
 326    */
 327   S_CONNECT_RECV_ACK,
 328
 329   /**
 330    * Got our CONNECT_ACK/SESSION_ACK, connection is up.
 331    */
 332   S_CONNECTED,
 333
 334   /**
 335    * Connection got into trouble, rest of the system still believes
 336    * it to be up, but we're getting a new address from ATS.
 337    */
 338   S_RECONNECT_ATS,
 339
 340   /**
 341    * Connection got into trouble, rest of the system still believes
 342    * it to be up; we are checking the new address against the blacklist.
 343    */
 344   S_RECONNECT_BLACKLIST,
 345
 346   /**
 347    * Sent CONNECT over new address (either by ATS telling us to switch
 348    * addresses or from RECONNECT_ATS); if this fails, we need to tell
 349    * the rest of the system about a disconnect.
 350    */
 351   S_RECONNECT_SENT,
 352
 353   /**
 354    * We have some primary connection, but ATS suggested we switch
 355    * to some alternative; we're now checking the alternative against
 356    * the blacklist.
 357    */
 358   S_CONNECTED_SWITCHING_BLACKLIST,
 359
 360   /**
 361    * We have some primary connection, but ATS suggested we switch
 362    * to some alternative; we now sent a CONNECT message for the
 363    * alternative session to the other peer and waiting for a
 364    * CONNECT_ACK to make this our primary connection.
 365    */
 366   S_CONNECTED_SWITCHING_CONNECT_SENT,
 367
 368   /**
 369    * Disconnect in progress (we're sending the DISCONNECT message to the
 370    * other peer; after that is finished, the state will be cleaned up).
 371    */
 372   S_DISCONNECT,
 373
 374   /**
 375    * We're finished with the disconnect; and are cleaning up the state
 376    * now!  We put the struct into this state when we are really in the
 377    * task that calls 'free' on it and are about to remove the record
 378    * from the map.  We should never find a 'struct NeighbourMapEntry'
 379    * in this state in the map.  Accessing a 'struct NeighbourMapEntry'
 380    * in this state virtually always means using memory that has been
 381    * freed (the exception being the cleanup code in #free_neighbour()).
 382    */
 383   S_DISCONNECT_FINISHED
 384 };
 385
 386
 387 /**
 388  * A possible address we could use to communicate with a neighbour.
 389  */
 390 struct NeighbourAddress
 391 {
 392
 393   /**
 394    * Active session for this address.
 395    */
 396   struct Session *session;
 397
 398   /**
 399    * Network-level address information.
 400    */
 401   struct GNUNET_HELLO_Address *address;
 402
 403   /**
 404    * Timestamp of the 'SESSION_CONNECT' message we sent to the other
 405    * peer for this address.  Use to check that the ACK is in response
 406    * to our most recent 'CONNECT'.
 407    */
 408   struct GNUNET_TIME_Absolute connect_timestamp;
 409
 410   /**
 411    * Inbound bandwidth from ATS for this address.
 412    */
 413   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in;
 414
 415   /**
 416    * Outbound bandwidth from ATS for this address.
 417    */
 418   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out;
 419
 420   /**
 421    * Did we tell ATS that this is our 'active' address?
 422    */
 423   int ats_active;
 424
 425 };
 426
 427
 428 /**
 429  * Entry in neighbours.
 430  */
 431 struct NeighbourMapEntry
 432 {
 433
 434   /**
 435    * Head of list of messages we would like to send to this peer;
 436    * must contain at most one message per client.
 437    */
 438   struct MessageQueue *messages_head;
 439
 440   /**
 441    * Tail of list of messages we would like to send to this peer; must
 442    * contain at most one message per client.
 443    */
 444   struct MessageQueue *messages_tail;
 445
 446   /**
 447    * Are we currently trying to send a message? If so, which one?
 448    */
 449   struct MessageQueue *is_active;
 450
 451   /**
 452    * Primary address we currently use to communicate with the neighbour.
 453    */
 454   struct NeighbourAddress primary_address;
 455
 456   /**
 457    * Alternative address currently under consideration for communicating
 458    * with the neighbour.
 459    */
 460   struct NeighbourAddress alternative_address;
 461
 462   /**
 463    * Identity of this neighbour.
 464    */
 465   struct GNUNET_PeerIdentity id;
 466
 467   /**
 468    * Main task that drives this peer (timeouts, keepalives, etc.).
 469    * Always runs the 'master_task'.
 470    */
 471   GNUNET_SCHEDULER_TaskIdentifier task;
 472
 473   /**
 474    * At what time should we sent the next keep-alive message?
 475    */
 476   struct GNUNET_TIME_Absolute keep_alive_time;
 477
 478   /**
 479    * At what time did we sent the last keep-alive message?  Used
 480    * to calculate round-trip time ("latency").
 481    */
 482   struct GNUNET_TIME_Absolute last_keep_alive_time;
 483
 484   /**
 485    * Timestamp we should include in our next CONNECT_ACK message.
 486    * (only valid if 'send_connect_ack' is GNUNET_YES).  Used to build
 487    * our CONNECT_ACK message.
 488    */
 489   struct GNUNET_TIME_Absolute connect_ack_timestamp;
 490
 491   /**
 492    * ATS address suggest handle
 493    */
 494   struct GNUNET_ATS_SuggestHandle *suggest_handle;
 495
 496   /**
 497    * Time where we should cut the connection (timeout) if we don't
 498    * make progress in the state machine (or get a KEEPALIVE_RESPONSE
 499    * if we are in S_CONNECTED).
 500    */
 501   struct GNUNET_TIME_Absolute timeout;
 502
 503   /**
 504    * Latest calculated latency value
 505    */
 506   struct GNUNET_TIME_Relative latency;
 507
 508   /**
 509    * Tracker for inbound bandwidth.
 510    */
 511   struct GNUNET_BANDWIDTH_Tracker in_tracker;
 512
 513   /**
 514    * How often has the other peer (recently) violated the inbound
 515    * traffic limit?  Incremented by 10 per violation, decremented by 1
 516    * per non-violation (for each time interval).
 517    */
 518   unsigned int quota_violation_count;
 519
 520   /**
 521    * The current state of the peer.
 522    */
 523   enum State state;
 524
 525   /**
 526    * Did we sent an KEEP_ALIVE message and are we expecting a response?
 527    */
 528   int expect_latency_response;
 529
 530   /**
 531    * Flag to set if we still need to send a CONNECT_ACK message to the other peer
 532    * (once we have an address to use and the peer has been allowed by our
 533    * blacklist).  Set to 1 if we need to send a CONNECT_ACK.  Set to 2 if we
 534    * did send a CONNECT_ACK and should go to 'S_CONNECTED' upon receiving
 535    * a 'SESSION_ACK' (regardless of what our own state machine might say).
 536    */
 537   int send_connect_ack;
 538
 539   /**
 540    * Tracking utilization of outbound bandwidth
 541    */
 542   uint32_t util_payload_bytes_sent;
 543
 544   /**
 545    * Tracking utilization of inbound bandwidth
 546    */
 547   uint32_t util_payload_bytes_recv;
 548
 549   /**
 550    * Tracking utilization of outbound bandwidth
 551    */
 552   uint32_t util_total_bytes_sent;
 553
 554   /**
 555    * Tracking utilization of inbound bandwidth
 556    */
 557   uint32_t util_total_bytes_recv;
 558
 559   /**
 560    * Date of last utilization transmission
 561    */
 562   struct GNUNET_TIME_Absolute last_util_transmission;
 563 };
 564
 565
 566 /**
 567  * Context for blacklist checks and the 'handle_test_blacklist_cont'
 568  * function.  Stores information about ongoing blacklist checks.
 569  */
 570 struct BlackListCheckContext
 571 {
 572
 573   /**
 574    * We keep blacklist checks in a DLL.
 575    */
 576   struct BlackListCheckContext *next;
 577
 578   /**
 579    * We keep blacklist checks in a DLL.
 580    */
 581   struct BlackListCheckContext *prev;
 582
 583   /**
 584    * Address that is being checked.
 585    */
 586   struct NeighbourAddress na;
 587
 588   /**
 589    * Handle to the ongoing blacklist check.
 590    */
 591   struct GST_BlacklistCheck *bc;
 592 };
 593
 594
 595 /**
 596  * Hash map from peer identities to the respective 'struct NeighbourMapEntry'.
 597  */
 598 static struct GNUNET_CONTAINER_MultiPeerMap *neighbours;
 599
 600 /**
 601  * We keep blacklist checks in a DLL so that we can find
 602  * the 'sessions' in their 'struct NeighbourAddress' if
 603  * a session goes down.
 604  */
 605 static struct BlackListCheckContext *bc_head;
 606
 607 /**
 608  * We keep blacklist checks in a DLL.
 609  */
 610 static struct BlackListCheckContext *bc_tail;
 611
 612 /**
 613  * Closure for #connect_notify_cb, #disconnect_notify_cb and #address_change_cb
 614  */
 615 static void *callback_cls;
 616
 617 /**
 618  * Function to call when we connected to a neighbour.
 619  */
 620 static NotifyConnect connect_notify_cb;
 621
 622 /**
 623  * Function to call when we disconnected from a neighbour.
 624  */
 625 static GNUNET_TRANSPORT_NotifyDisconnect disconnect_notify_cb;
 626
 627 /**
 628  * Function to call when we changed an active address of a neighbour.
 629  */
 630 static GNUNET_TRANSPORT_PeerIterateCallback address_change_cb;
 631
 632 /**
 633  * counter for connected neighbours
 634  */
 635 static unsigned int neighbours_connected;
 636
 637 /**
 638  * Number of bytes we have currently queued for transmission.
 639  */
 640 static unsigned long long bytes_in_send_queue;
 641
 642 /**
 643  * Task transmitting utilization data
 644  */
 645 static GNUNET_SCHEDULER_TaskIdentifier util_transmission_tk;
 646
 647
 648 /**
 649  * Lookup a neighbour entry in the neighbours hash map.
 650  *
 651  * @param pid identity of the peer to look up
 652  * @return the entry, NULL if there is no existing record
 653  */
 654 static struct NeighbourMapEntry *
 655 lookup_neighbour (const struct GNUNET_PeerIdentity *pid)
 656 {
 657   if (NULL == neighbours)
 658     return NULL;
 659   return GNUNET_CONTAINER_multipeermap_get (neighbours, pid);
 660 }
 661
 662
 663 static const char *
 664 print_state (int state)
 665 {
 666
 667   switch (state)
 668   {
 669   case S_NOT_CONNECTED:
 670     return "S_NOT_CONNECTED";
 671   case S_INIT_ATS:
 672     return "S_INIT_ATS";
 673   case S_INIT_BLACKLIST:
 674     return "S_INIT_BLACKLIST";
 675   case S_CONNECT_SENT:
 676     return "S_CONNECT_SENT";
 677   case S_CONNECT_RECV_BLACKLIST_INBOUND:
 678     return "S_CONNECT_RECV_BLACKLIST_INBOUND";
 679   case S_CONNECT_RECV_ATS:
 680     return "S_CONNECT_RECV_ATS";
 681   case S_CONNECT_RECV_BLACKLIST:
 682     return "S_CONNECT_RECV_BLACKLIST";
 683   case S_CONNECT_RECV_ACK:
 684     return "S_CONNECT_RECV_ACK";
 685   case S_CONNECTED:
 686     return "S_CONNECTED";
 687   case S_RECONNECT_ATS:
 688     return "S_RECONNECT_ATS";
 689   case S_RECONNECT_BLACKLIST:
 690     return "S_RECONNECT_BLACKLIST";
 691   case S_RECONNECT_SENT:
 692     return "S_RECONNECT_SENT";
 693   case S_CONNECTED_SWITCHING_BLACKLIST:
 694     return "S_CONNECTED_SWITCHING_BLACKLIST";
 695   case S_CONNECTED_SWITCHING_CONNECT_SENT:
 696     return "S_CONNECTED_SWITCHING_CONNECT_SENT";
 697   case S_DISCONNECT:
 698     return "S_DISCONNECT";
 699   case S_DISCONNECT_FINISHED:
 700     return "S_DISCONNECT_FINISHED";
 701   default:
 702     GNUNET_break (0);
 703     return "UNDEFINED";
 704   }
 705 }
 706
 707 /**
 708  * Test if we're connected to the given peer.
 709  *
 710  * @param n neighbour entry of peer to test
 711  * @return #GNUNET_YES if we are connected, #GNUNET_NO if not
 712  */
 713 static int
 714 test_connected (struct NeighbourMapEntry *n)
 715 {
 716   if (NULL == n)
 717     return GNUNET_NO;
 718   switch (n->state)
 719   {
 720   case S_NOT_CONNECTED:
 721   case S_INIT_ATS:
 722   case S_INIT_BLACKLIST:
 723   case S_CONNECT_SENT:
 724   case S_CONNECT_RECV_BLACKLIST_INBOUND:
 725   case S_CONNECT_RECV_ATS:
 726   case S_CONNECT_RECV_BLACKLIST:
 727   case S_CONNECT_RECV_ACK:
 728     return GNUNET_NO;
 729   case S_CONNECTED:
 730   case S_RECONNECT_ATS:
 731   case S_RECONNECT_BLACKLIST:
 732   case S_RECONNECT_SENT:
 733   case S_CONNECTED_SWITCHING_BLACKLIST:
 734   case S_CONNECTED_SWITCHING_CONNECT_SENT:
 735     return GNUNET_YES;
 736   case S_DISCONNECT:
 737   case S_DISCONNECT_FINISHED:
 738     return GNUNET_NO;
 739   default:
 740     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 741                 "Unhandled state `%s' \n",
 742                 print_state (n->state));
 743     GNUNET_break (0);
 744     break;
 745   }
 746   return GNUNET_SYSERR;
 747 }
 748
 749 /**
 750  * Send information about a new outbound quota to our clients.
 751  *
 752  * @param target affected peer
 753  * @param quota new quota
 754  */
 755 static void
 756 send_outbound_quota (const struct GNUNET_PeerIdentity *target,
 757                      struct GNUNET_BANDWIDTH_Value32NBO quota)
 758 {
 759   struct QuotaSetMessage q_msg;
 760
 761   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 762               "Sending outbound quota of %u Bps for peer `%s' to all clients\n",
 763               ntohl (quota.value__), GNUNET_i2s (target));
 764   q_msg.header.size = htons (sizeof (struct QuotaSetMessage));
 765   q_msg.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SET_QUOTA);
 766   q_msg.quota = quota;
 767   q_msg.peer = (*target);
 768   GST_clients_broadcast (&q_msg.header, GNUNET_NO);
 769 }
 770
 771
 772 /**
 773  * We don't need a given neighbour address any more.
 774  * Release its resources and give appropriate notifications
 775  * to ATS and other subsystems.
 776  *
 777  * @param na address we are done with; @a na itself must NOT be 'free'd, only the contents!
 778  */
 779 static void
 780 free_address (struct NeighbourAddress *na)
 781 {
 782   if (GNUNET_YES == na->ats_active)
 783   {
 784     GST_validation_set_address_use (na->address, na->session, GNUNET_NO, __LINE__);
 785     GNUNET_ATS_address_in_use (GST_ats, na->address, na->session, GNUNET_NO);
 786     address_change_cb (callback_cls, &na->address->peer, NULL);
 787   }
 788
 789   na->ats_active = GNUNET_NO;
 790   if (NULL != na->address)
 791   {
 792     GNUNET_HELLO_address_free (na->address);
 793     na->address = NULL;
 794   }
 795   na->session = NULL;
 796 }
 797
 798
 799 /**
 800  * Initialize the 'struct NeighbourAddress'.
 801  *
 802  * @param na neighbour address to initialize
 803  * @param address address of the other peer, NULL if other peer
 804  *                       connected to us
 805  * @param session session to use (or NULL, in which case an
 806  *        address must be setup)
 807  * @param bandwidth_in inbound quota to be used when connection is up
 808  * @param bandwidth_out outbound quota to be used when connection is up
 809  * @param is_active #GNUNET_YES to mark this as the active address with ATS
 810  */
 811 static void
 812 set_address (struct NeighbourAddress *na,
 813              const struct GNUNET_HELLO_Address *address,
 814              struct Session *session,
 815              struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in,
 816              struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out,
 817              int is_active)
 818 {
 819   struct GNUNET_TRANSPORT_PluginFunctions *papi;
 820
 821   if (NULL == (papi = GST_plugins_find (address->transport_name)))
 822   {
 823     GNUNET_break (0);
 824     return;
 825   }
 826   if (session == na->session)
 827   {
 828     na->bandwidth_in = bandwidth_in;
 829     na->bandwidth_out = bandwidth_out;
 830     if (is_active != na->ats_active)
 831     {
 832       na->ats_active = is_active;
 833       GNUNET_ATS_address_in_use (GST_ats, na->address, na->session, is_active);
 834       GST_validation_set_address_use (na->address, na->session, is_active,  __LINE__);
 835       if (is_active)
 836         address_change_cb (callback_cls, &address->peer, address);
 837     }
 838     if (GNUNET_YES == is_active)
 839     {
 840       /* FIXME: is this the right place to set quotas? */
 841       GST_neighbours_set_incoming_quota (&address->peer, bandwidth_in);
 842       send_outbound_quota (&address->peer, bandwidth_out);
 843     }
 844     return;
 845   }
 846   free_address (na);
 847   if (NULL == session)
 848     session = papi->get_session (papi->cls, address);
 849   if (NULL == session)
 850   {
 851     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 852                 "Failed to obtain new session for peer `%s' and  address '%s'\n",
 853                 GNUNET_i2s (&address->peer), GST_plugins_a2s (address));
 854     GNUNET_ATS_address_destroyed (GST_ats, address, NULL);
 855     return;
 856   }
 857   na->address = GNUNET_HELLO_address_copy (address);
 858   na->bandwidth_in = bandwidth_in;
 859   na->bandwidth_out = bandwidth_out;
 860   na->session = session;
 861   na->ats_active = is_active;
 862   if (GNUNET_YES == is_active)
 863   {
 864     /* Telling ATS about new session */
 865     GNUNET_ATS_address_in_use (GST_ats, na->address, na->session, GNUNET_YES);
 866     GST_validation_set_address_use (na->address, na->session, GNUNET_YES,  __LINE__);
 867     address_change_cb (callback_cls, &address->peer, address);
 868     /* FIXME: is this the right place to set quotas? */
 869     GST_neighbours_set_incoming_quota (&address->peer, bandwidth_in);
 870     send_outbound_quota (&address->peer, bandwidth_out);
 871   }
 872 }
 873
 874
 875 /**
 876  * Free a neighbour map entry.
 877  *
 878  * @param n entry to free
 879  * @param keep_sessions #GNUNET_NO to tell plugin to terminate sessions,
 880  *                      #GNUNET_YES to keep all sessions
 881  */
 882 static void
 883 free_neighbour (struct NeighbourMapEntry *n, int keep_sessions)
 884 {
 885   struct MessageQueue *mq;
 886   struct GNUNET_TRANSPORT_PluginFunctions *papi;
 887   struct GNUNET_HELLO_Address *backup_primary;
 888
 889   n->is_active = NULL; /* always free'd by its own continuation! */
 890
 891   /* fail messages currently in the queue */
 892   while (NULL != (mq = n->messages_head))
 893   {
 894     GNUNET_CONTAINER_DLL_remove (n->messages_head, n->messages_tail, mq);
 895     if (NULL != mq->cont)
 896       mq->cont (mq->cont_cls, GNUNET_SYSERR, mq->message_buf_size, 0);
 897     GNUNET_free (mq);
 898   }
 899   /* It is too late to send other peer disconnect notifications, but at
 900      least internally we need to get clean... */
 901   if (GNUNET_YES == test_connected (n))
 902   {
 903     GNUNET_STATISTICS_set (GST_stats,
 904                            gettext_noop ("# peers connected"),
 905                            --neighbours_connected,
 906                            GNUNET_NO);
 907     disconnect_notify_cb (callback_cls, &n->id);
 908   }
 909   n->state = S_DISCONNECT_FINISHED;
 910
 911   if (NULL != n->primary_address.address)
 912   {
 913     backup_primary = GNUNET_HELLO_address_copy (n->primary_address.address);
 914   }
 915   else
 916     backup_primary = NULL;
 917
 918   /* free addresses and mark as unused */
 919   free_address (&n->primary_address);
 920   free_address (&n->alternative_address);
 921
 922   /* FIXME: Note that if we are switching between two TCP sessions to
 923      the same peer, we might want to selectively kill only one of
 924      them! Killing all sessions like this seems to be very, very
 925      wrong. */
 926
 927   /* cut transport-level connection */
 928   if ((GNUNET_NO == keep_sessions) &&
 929       (NULL != backup_primary) &&
 930       (NULL != (papi = GST_plugins_find (backup_primary->transport_name))))
 931     papi->disconnect_peer (papi->cls, &n->id);
 932
 933   GNUNET_free_non_null (backup_primary);
 934
 935   GNUNET_assert (GNUNET_YES ==
 936                  GNUNET_CONTAINER_multipeermap_remove (neighbours,
 937                                                        &n->id, n));
 938
 939   // FIXME-ATS-API: we might want to be more specific about
 940   // which states we do this from in the future (ATS should
 941   // have given us a 'suggest_address' handle, and if we have
 942   // such a handle, we should cancel the operation here!
 943   if (NULL != n->suggest_handle)
 944   {
 945     GNUNET_ATS_suggest_address_cancel (GST_ats, &n->id);
 946     n->suggest_handle = NULL;
 947   }
 948
 949   if (GNUNET_SCHEDULER_NO_TASK != n->task)
 950   {
 951     GNUNET_SCHEDULER_cancel (n->task);
 952     n->task = GNUNET_SCHEDULER_NO_TASK;
 953   }
 954   /* free rest of memory */
 955   GNUNET_free (n);
 956 }
 957
 958
 959 /**
 960  * Transmit a message using the current session of the given
 961  * neighbour.
 962  *
 963  * @param n entry for the recipient
 964  * @param msgbuf buffer to transmit
 965  * @param msgbuf_size number of bytes in buffer
 966  * @param priority transmission priority
 967  * @param timeout transmission timeout
 968  * @param cont continuation to call when finished (can be NULL)
 969  * @param cont_cls closure for cont
 970  */
 971 static void
 972 send_with_session (struct NeighbourMapEntry *n,
 973                    const char *msgbuf, size_t msgbuf_size,
 974                    uint32_t priority,
 975                    struct GNUNET_TIME_Relative timeout,
 976                    GNUNET_TRANSPORT_TransmitContinuation cont,
 977                    void *cont_cls)
 978 {
 979   struct GNUNET_TRANSPORT_PluginFunctions *papi;
 980
 981   GNUNET_assert (n->primary_address.session != NULL);
 982   if ( ((NULL == (papi = GST_plugins_find (n->primary_address.address->transport_name)) ||
 983          (-1 == papi->send (papi->cls,
 984                             n->primary_address.session,
 985                             msgbuf, msgbuf_size,
 986                             priority,
 987                             timeout,
 988                             cont, cont_cls)))) &&
 989        (NULL != cont))
 990     cont (cont_cls, &n->id, GNUNET_SYSERR, msgbuf_size, 0);
 991   GST_neighbours_notify_data_sent (&n->id,
 992       n->primary_address.address, n->primary_address.session, msgbuf_size);
 993   GNUNET_break (NULL != papi);
 994 }
 995
 996
 997 /**
 998  * Master task run for every neighbour.  Performs all of the time-related
 999  * activities (keep alive, send next message, disconnect if idle, finish
1000  * clean up after disconnect).
1001  *
1002  * @param cls the 'struct NeighbourMapEntry' for which we are running
1003  * @param tc scheduler context (unused)
1004  */
1005 static void
1006 master_task (void *cls,
1007              const struct GNUNET_SCHEDULER_TaskContext *tc);
1008
1009
1010 /**
1011  * Function called when the 'DISCONNECT' message has been sent by the
1012  * plugin.  Frees the neighbour --- if the entry still exists.
1013  *
1014  * @param cls NULL
1015  * @param target identity of the neighbour that was disconnected
1016  * @param result #GNUNET_OK if the disconnect got out successfully
1017  * @param payload bytes payload
1018  * @param physical bytes physical
1019  */
1020 static void
1021 send_disconnect_cont (void *cls, const struct GNUNET_PeerIdentity *target,
1022                       int result, size_t payload, size_t physical)
1023 {
1024   struct NeighbourMapEntry *n;
1025
1026   n = lookup_neighbour (target);
1027   if (NULL == n)
1028     return; /* already gone */
1029   if (S_DISCONNECT != n->state)
1030     return; /* have created a fresh entry since */
1031   if (GNUNET_SCHEDULER_NO_TASK != n->task)
1032     GNUNET_SCHEDULER_cancel (n->task);
1033   n->task = GNUNET_SCHEDULER_add_now (&master_task, n);
1034 }
1035
1036
1037 /**
1038  * Transmit a DISCONNECT message to the other peer.
1039  *
1040  * @param n neighbour to send DISCONNECT message.
1041  */
1042 static void
1043 send_disconnect (struct NeighbourMapEntry *n)
1044 {
1045   struct SessionDisconnectMessage disconnect_msg;
1046
1047   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1048               "Sending DISCONNECT message to peer `%4s'\n",
1049               GNUNET_i2s (&n->id));
1050   disconnect_msg.header.size = htons (sizeof (struct SessionDisconnectMessage));
1051   disconnect_msg.header.type =
1052       htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_DISCONNECT);
1053   disconnect_msg.reserved = htonl (0);
1054   disconnect_msg.purpose.size =
1055       htonl (sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
1056              sizeof (struct GNUNET_CRYPTO_EddsaPublicKey) +
1057              sizeof (struct GNUNET_TIME_AbsoluteNBO));
1058   disconnect_msg.purpose.purpose =
1059       htonl (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_DISCONNECT);
1060   disconnect_msg.timestamp =
1061       GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get ());
1062   disconnect_msg.public_key = GST_my_identity.public_key;
1063   GNUNET_assert (GNUNET_OK ==
1064                  GNUNET_CRYPTO_eddsa_sign (GST_my_private_key,
1065                                          &disconnect_msg.purpose,
1066                                          &disconnect_msg.signature));
1067
1068   send_with_session (n,
1069                      (const char *) &disconnect_msg, sizeof (disconnect_msg),
1070                      UINT32_MAX, GNUNET_TIME_UNIT_FOREVER_REL,
1071                      &send_disconnect_cont, NULL);
1072   GNUNET_STATISTICS_update (GST_stats,
1073                             gettext_noop
1074                             ("# DISCONNECT messages sent"), 1,
1075                             GNUNET_NO);
1076 }
1077
1078
1079 /**
1080  * Disconnect from the given neighbour, clean up the record.
1081  *
1082  * @param n neighbour to disconnect from
1083  */
1084 static void
1085 disconnect_neighbour (struct NeighbourMapEntry *n)
1086 {
1087   /* depending on state, notify neighbour and/or upper layers of this peer
1088      about disconnect */
1089   switch (n->state)
1090   {
1091   case S_NOT_CONNECTED:
1092   case S_INIT_ATS:
1093   case S_INIT_BLACKLIST:
1094     /* other peer is completely unaware of us, no need to send DISCONNECT */
1095     n->state = S_DISCONNECT_FINISHED;
1096     free_neighbour (n, GNUNET_NO);
1097     return;
1098   case S_CONNECT_SENT:
1099     send_disconnect (n);
1100     n->state = S_DISCONNECT;
1101     break;
1102   case S_CONNECT_RECV_BLACKLIST_INBOUND:
1103   case S_CONNECT_RECV_ATS:
1104   case S_CONNECT_RECV_BLACKLIST:
1105     /* we never ACK'ed the other peer's request, no need to send DISCONNECT */
1106     n->state = S_DISCONNECT_FINISHED;
1107     free_neighbour (n, GNUNET_NO);
1108     return;
1109   case S_CONNECT_RECV_ACK:
1110     /* we DID ACK the other peer's request, must send DISCONNECT */
1111     send_disconnect (n);
1112     n->state = S_DISCONNECT;
1113     break;
1114   case S_CONNECTED:
1115   case S_RECONNECT_BLACKLIST:
1116   case S_RECONNECT_SENT:
1117   case S_CONNECTED_SWITCHING_BLACKLIST:
1118   case S_CONNECTED_SWITCHING_CONNECT_SENT:
1119     /* we are currently connected, need to send disconnect and do
1120        internal notifications and update statistics */
1121     send_disconnect (n);
1122     GNUNET_STATISTICS_set (GST_stats,
1123                            gettext_noop ("# peers connected"),
1124                            --neighbours_connected,
1125                            GNUNET_NO);
1126     disconnect_notify_cb (callback_cls, &n->id);
1127     n->state = S_DISCONNECT;
1128     break;
1129   case S_RECONNECT_ATS:
1130     /* ATS address request timeout, disconnect without sending disconnect message */
1131     GNUNET_STATISTICS_set (GST_stats,
1132                            gettext_noop ("# peers connected"),
1133                            --neighbours_connected,
1134                            GNUNET_NO);
1135     disconnect_notify_cb (callback_cls, &n->id);
1136     n->state = S_DISCONNECT;
1137     break;
1138   case S_DISCONNECT:
1139     /* already disconnected, ignore */
1140     break;
1141   case S_DISCONNECT_FINISHED:
1142     /* already cleaned up, how did we get here!? */
1143     GNUNET_assert (0);
1144     break;
1145   default:
1146     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1147                 "Unhandled state `%s'\n",
1148                 print_state (n->state));
1149     GNUNET_break (0);
1150     break;
1151   }
1152   /* schedule timeout to clean up */
1153   if (GNUNET_SCHEDULER_NO_TASK != n->task)
1154     GNUNET_SCHEDULER_cancel (n->task);
1155   n->task = GNUNET_SCHEDULER_add_delayed (DISCONNECT_SENT_TIMEOUT,
1156                                           &master_task, n);
1157 }
1158
1159
1160 /**
1161  * We're done with our transmission attempt, continue processing.
1162  *
1163  * @param cls the 'struct MessageQueue' of the message
1164  * @param receiver intended receiver
1165  * @param success whether it worked or not
1166  * @param size_payload bytes payload sent
1167  * @param physical bytes sent on wire
1168  */
1169 static void
1170 transmit_send_continuation (void *cls,
1171                             const struct GNUNET_PeerIdentity *receiver,
1172                             int success, size_t size_payload, size_t physical)
1173 {
1174   struct MessageQueue *mq = cls;
1175   struct NeighbourMapEntry *n;
1176
1177   if (NULL == (n = lookup_neighbour (receiver)))
1178   {
1179     GNUNET_free (mq);
1180     return; /* disconnect or other error while transmitting, can happen */
1181   }
1182   if (n->is_active == mq)
1183   {
1184     /* this is still "our" neighbour, remove us from its queue
1185        and allow it to send the next message now */
1186     n->is_active = NULL;
1187     if (GNUNET_SCHEDULER_NO_TASK != n->task)
1188       GNUNET_SCHEDULER_cancel (n->task);
1189     n->task = GNUNET_SCHEDULER_add_now (&master_task, n);
1190   }
1191   if (bytes_in_send_queue < mq->message_buf_size)
1192   {
1193       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1194                   "Bytes_in_send_queue `%u', Message_size %u, result: %s, payload %u, on wire %u\n",
1195                   bytes_in_send_queue, mq->message_buf_size,
1196                   (GNUNET_OK == success) ? "OK" : "FAIL",
1197                   size_payload, physical);
1198       GNUNET_break (0);
1199   }
1200
1201
1202   GNUNET_break (size_payload == mq->message_buf_size);
1203   bytes_in_send_queue -= mq->message_buf_size;
1204   GNUNET_STATISTICS_set (GST_stats,
1205                         gettext_noop
1206                          ("# bytes in message queue for other peers"),
1207                          bytes_in_send_queue, GNUNET_NO);
1208   if (GNUNET_OK == success)
1209     GNUNET_STATISTICS_update (GST_stats,
1210                               gettext_noop
1211                               ("# messages transmitted to other peers"),
1212                               1, GNUNET_NO);
1213   else
1214     GNUNET_STATISTICS_update (GST_stats,
1215                               gettext_noop
1216                               ("# transmission failures for messages to other peers"),
1217                               1, GNUNET_NO);
1218   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1219               "Sending message to `%s' of type %u was a %s\n",
1220               GNUNET_i2s (receiver),
1221               ntohs (((struct GNUNET_MessageHeader *) mq->message_buf)->type),
1222               (success == GNUNET_OK) ? "success" : "FAILURE");
1223   if (NULL != mq->cont)
1224     mq->cont (mq->cont_cls, success, size_payload, physical);
1225   GNUNET_free (mq);
1226 }
1227
1228
1229 /**
1230  * Check the message list for the given neighbour and if we can
1231  * send a message, do so.  This function should only be called
1232  * if the connection is at least generally ready for transmission.
1233  * While we will only send one message at a time, no bandwidth
1234  * quota management is performed here.  If a message was given to
1235  * the plugin, the continuation will automatically re-schedule
1236  * the 'master' task once the next message might be transmitted.
1237  *
1238  * @param n target peer for which to transmit
1239  */
1240 static void
1241 try_transmission_to_peer (struct NeighbourMapEntry *n)
1242 {
1243   struct MessageQueue *mq;
1244   struct GNUNET_TIME_Relative timeout;
1245
1246   if (NULL == n->primary_address.address)
1247   {
1248     /* no address, why are we here? */
1249     GNUNET_break (0);
1250     return;
1251   }
1252   if ((0 == n->primary_address.address->address_length) &&
1253       (NULL == n->primary_address.session))
1254   {
1255     /* no address, why are we here? */
1256     GNUNET_break (0);
1257     return;
1258   }
1259   if (NULL != n->is_active)
1260   {
1261     /* transmission already pending */
1262     return;
1263   }
1264
1265   /* timeout messages from the queue that are past their due date */
1266   while (NULL != (mq = n->messages_head))
1267   {
1268     timeout = GNUNET_TIME_absolute_get_remaining (mq->timeout);
1269     if (timeout.rel_value_us > 0)
1270       break;
1271     GNUNET_STATISTICS_update (GST_stats,
1272                               gettext_noop
1273                               ("# messages timed out while in transport queue"),
1274                               1, GNUNET_NO);
1275     GNUNET_CONTAINER_DLL_remove (n->messages_head, n->messages_tail, mq);
1276     n->is_active = mq;
1277     transmit_send_continuation (mq, &n->id, GNUNET_SYSERR, mq->message_buf_size, 0);     /* timeout */
1278   }
1279   if (NULL == mq)
1280     return;                     /* no more messages */
1281   GNUNET_CONTAINER_DLL_remove (n->messages_head, n->messages_tail, mq);
1282   n->is_active = mq;
1283   send_with_session (n,
1284                      mq->message_buf, mq->message_buf_size,
1285                      0 /* priority */, timeout,
1286                      &transmit_send_continuation, mq);
1287 }
1288
1289
1290 /**
1291  * Send keepalive message to the neighbour.  Must only be called
1292  * if we are on 'connected' state or while trying to switch addresses.
1293  * Will internally determine if a keepalive is truly needed (so can
1294  * always be called).
1295  *
1296  * @param n neighbour that went idle and needs a keepalive
1297  */
1298 static void
1299 send_keepalive (struct NeighbourMapEntry *n)
1300 {
1301   struct GNUNET_MessageHeader m;
1302
1303   GNUNET_assert ((S_CONNECTED == n->state) ||
1304                  (S_CONNECTED_SWITCHING_BLACKLIST == n->state) ||
1305                  (S_CONNECTED_SWITCHING_CONNECT_SENT));
1306   if (GNUNET_TIME_absolute_get_remaining (n->keep_alive_time).rel_value_us > 0)
1307     return; /* no keepalive needed at this time */
1308   m.size = htons (sizeof (struct GNUNET_MessageHeader));
1309   m.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_KEEPALIVE);
1310   send_with_session (n,
1311                      (const void *) &m, sizeof (m),
1312                      UINT32_MAX /* priority */,
1313                      KEEPALIVE_FREQUENCY,
1314                      NULL, NULL);
1315   GNUNET_STATISTICS_update (GST_stats, gettext_noop ("# keepalives sent"), 1,
1316                             GNUNET_NO);
1317   n->expect_latency_response = GNUNET_YES;
1318   n->last_keep_alive_time = GNUNET_TIME_absolute_get ();
1319   n->keep_alive_time = GNUNET_TIME_relative_to_absolute (KEEPALIVE_FREQUENCY);
1320 }
1321
1322
1323 /**
1324  * Keep the connection to the given neighbour alive longer,
1325  * we received a KEEPALIVE (or equivalent); send a response.
1326  *
1327  * @param neighbour neighbour to keep alive (by sending keep alive response)
1328  */
1329 void
1330 GST_neighbours_keepalive (const struct GNUNET_PeerIdentity *neighbour)
1331 {
1332   struct NeighbourMapEntry *n;
1333   struct GNUNET_MessageHeader m;
1334
1335   if (NULL == (n = lookup_neighbour (neighbour)))
1336   {
1337     GNUNET_STATISTICS_update (GST_stats,
1338                               gettext_noop
1339                               ("# KEEPALIVE messages discarded (peer unknown)"),
1340                               1, GNUNET_NO);
1341     return;
1342   }
1343   if (NULL == n->primary_address.session)
1344   {
1345     GNUNET_STATISTICS_update (GST_stats,
1346                               gettext_noop
1347                               ("# KEEPALIVE messages discarded (no session)"),
1348                               1, GNUNET_NO);
1349     return;
1350   }
1351   /* send reply to allow neighbour to measure latency */
1352   m.size = htons (sizeof (struct GNUNET_MessageHeader));
1353   m.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_KEEPALIVE_RESPONSE);
1354   send_with_session(n,
1355                     (const void *) &m, sizeof (m),
1356                     UINT32_MAX /* priority */,
1357                     KEEPALIVE_FREQUENCY,
1358                     NULL, NULL);
1359 }
1360
1361
1362 /**
1363  * We received a KEEP_ALIVE_RESPONSE message and use this to calculate
1364  * latency to this peer.  Pass the updated information (existing ats
1365  * plus calculated latency) to ATS.
1366  *
1367  * @param neighbour neighbour to keep alive
1368  */
1369 void
1370 GST_neighbours_keepalive_response (const struct GNUNET_PeerIdentity *neighbour)
1371 {
1372   struct NeighbourMapEntry *n;
1373   uint32_t latency;
1374   struct GNUNET_ATS_Information ats;
1375
1376   if (NULL == (n = lookup_neighbour (neighbour)))
1377   {
1378     GNUNET_STATISTICS_update (GST_stats,
1379                               gettext_noop
1380                               ("# KEEPALIVE_RESPONSE messages discarded (not connected)"),
1381                               1, GNUNET_NO);
1382     return;
1383   }
1384   if ( (S_CONNECTED != n->state) ||
1385        (GNUNET_YES != n->expect_latency_response) )
1386   {
1387     GNUNET_STATISTICS_update (GST_stats,
1388                               gettext_noop
1389                               ("# KEEPALIVE_RESPONSE messages discarded (not expected)"),
1390                               1, GNUNET_NO);
1391     return;
1392   }
1393   n->expect_latency_response = GNUNET_NO;
1394   n->latency = GNUNET_TIME_absolute_get_duration (n->last_keep_alive_time);
1395   n->timeout = GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT);
1396   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1397               "Latency for peer `%s' is %s\n",
1398               GNUNET_i2s (&n->id),
1399               GNUNET_STRINGS_relative_time_to_string (n->latency,
1400                                                       GNUNET_YES));
1401   /* append latency */
1402   ats.type = htonl (GNUNET_ATS_QUALITY_NET_DELAY);
1403   if (n->latency.rel_value_us > UINT32_MAX)
1404     latency = UINT32_MAX;
1405   else
1406     latency = n->latency.rel_value_us;
1407   ats.value = htonl (latency);
1408   GST_ats_update_metrics (&n->id,
1409                                                                                           n->primary_address.address,
1410                                                                                         n->primary_address.session,
1411                                                                                         &ats, 1);
1412 }
1413
1414
1415 /**
1416  * We have received a message from the given sender.  How long should
1417  * we delay before receiving more?  (Also used to keep the peer marked
1418  * as live).
1419  *
1420  * @param sender sender of the message
1421  * @param size size of the message
1422  * @param do_forward set to GNUNET_YES if the message should be forwarded to clients
1423  *                   GNUNET_NO if the neighbour is not connected or violates the quota,
1424  *                   GNUNET_SYSERR if the connection is not fully up yet
1425  * @return how long to wait before reading more from this sender
1426  */
1427 struct GNUNET_TIME_Relative
1428 GST_neighbours_calculate_receive_delay (const struct GNUNET_PeerIdentity
1429                                         *sender, ssize_t size, int *do_forward)
1430 {
1431   struct NeighbourMapEntry *n;
1432   struct GNUNET_TIME_Relative ret;
1433
1434   if (NULL == neighbours)
1435   {
1436     *do_forward = GNUNET_NO;
1437     return GNUNET_TIME_UNIT_FOREVER_REL; /* This can happen during shutdown */
1438   }
1439   if (NULL == (n = lookup_neighbour (sender)))
1440   {
1441     GST_neighbours_try_connect (sender);
1442     if (NULL == (n = lookup_neighbour (sender)))
1443     {
1444       GNUNET_STATISTICS_update (GST_stats,
1445                                 gettext_noop
1446                                 ("# messages discarded due to lack of neighbour record"),
1447                                 1, GNUNET_NO);
1448       *do_forward = GNUNET_NO;
1449       return GNUNET_TIME_UNIT_ZERO;
1450     }
1451   }
1452   if (! test_connected (n))
1453   {
1454     *do_forward = GNUNET_SYSERR;
1455     return GNUNET_TIME_UNIT_ZERO;
1456   }
1457   if (GNUNET_YES == GNUNET_BANDWIDTH_tracker_consume (&n->in_tracker, size))
1458   {
1459     n->quota_violation_count++;
1460     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1461                 "Bandwidth quota (%u b/s) violation detected (total of %u).\n",
1462                 n->in_tracker.available_bytes_per_s__,
1463                 n->quota_violation_count);
1464     /* Discount 32k per violation */
1465     GNUNET_BANDWIDTH_tracker_consume (&n->in_tracker, -32 * 1024);
1466   }
1467   else
1468   {
1469     if (n->quota_violation_count > 0)
1470     {
1471       /* try to add 32k back */
1472       GNUNET_BANDWIDTH_tracker_consume (&n->in_tracker, 32 * 1024);
1473       n->quota_violation_count--;
1474     }
1475   }
1476   if (n->quota_violation_count > QUOTA_VIOLATION_DROP_THRESHOLD)
1477   {
1478     GNUNET_STATISTICS_update (GST_stats,
1479                               gettext_noop
1480                               ("# bandwidth quota violations by other peers"),
1481                               1, GNUNET_NO);
1482     *do_forward = GNUNET_NO;
1483     return GNUNET_CONSTANTS_QUOTA_VIOLATION_TIMEOUT;
1484   }
1485   *do_forward = GNUNET_YES;
1486   ret = GNUNET_BANDWIDTH_tracker_get_delay (&n->in_tracker, 32 * 1024);
1487   if (ret.rel_value_us > 0)
1488   {
1489     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1490                 "Throttling read (%llu bytes excess at %u b/s), waiting %s before reading more.\n",
1491                 (unsigned long long) n->in_tracker.
1492                 consumption_since_last_update__,
1493                 (unsigned int) n->in_tracker.available_bytes_per_s__,
1494                 GNUNET_STRINGS_relative_time_to_string (ret, GNUNET_YES));
1495     GNUNET_STATISTICS_update (GST_stats,
1496                               gettext_noop ("# ms throttling suggested"),
1497                               (int64_t) ret.rel_value_us / 1000LL,
1498                               GNUNET_NO);
1499   }
1500   return ret;
1501 }
1502
1503
1504 /**
1505  * Transmit a message to the given target using the active connection.
1506  *
1507  * @param target destination
1508  * @param msg message to send
1509  * @param msg_size number of bytes in msg
1510  * @param timeout when to fail with timeout
1511  * @param cont function to call when done
1512  * @param cont_cls closure for 'cont'
1513  */
1514 void
1515 GST_neighbours_send (const struct GNUNET_PeerIdentity *target, const void *msg,
1516                      size_t msg_size, struct GNUNET_TIME_Relative timeout,
1517                      GST_NeighbourSendContinuation cont, void *cont_cls)
1518 {
1519   struct NeighbourMapEntry *n;
1520   struct MessageQueue *mq;
1521
1522   /* All ove these cases should never happen; they are all API violations.
1523      But we check anyway, just to be sure. */
1524   if (NULL == (n = lookup_neighbour (target)))
1525   {
1526     GNUNET_break (0);
1527     if (NULL != cont)
1528       cont (cont_cls, GNUNET_SYSERR, msg_size, 0);
1529     return;
1530   }
1531   if (GNUNET_YES != test_connected (n))
1532   {
1533     GNUNET_break (0);
1534     if (NULL != cont)
1535       cont (cont_cls, GNUNET_SYSERR, msg_size, 0);
1536     return;
1537   }
1538   bytes_in_send_queue += msg_size;
1539   GNUNET_STATISTICS_set (GST_stats,
1540                          gettext_noop
1541                          ("# bytes in message queue for other peers"),
1542                          bytes_in_send_queue, GNUNET_NO);
1543   mq = GNUNET_malloc (sizeof (struct MessageQueue) + msg_size);
1544   mq->cont = cont;
1545   mq->cont_cls = cont_cls;
1546   memcpy (&mq[1], msg, msg_size);
1547   mq->message_buf = (const char *) &mq[1];
1548   mq->message_buf_size = msg_size;
1549   mq->timeout = GNUNET_TIME_relative_to_absolute (timeout);
1550   GNUNET_CONTAINER_DLL_insert_tail (n->messages_head, n->messages_tail, mq);
1551   if ( (NULL != n->is_active) ||
1552        ( (NULL == n->primary_address.session) && (NULL == n->primary_address.address)) )
1553     return;
1554   if (GNUNET_SCHEDULER_NO_TASK != n->task)
1555     GNUNET_SCHEDULER_cancel (n->task);
1556   n->task = GNUNET_SCHEDULER_add_now (&master_task, n);
1557 }
1558
1559
1560 /**
1561  * Send a SESSION_CONNECT message via the given address.
1562  *
1563  * @param na address to use
1564  */
1565 static void
1566 send_session_connect (struct NeighbourAddress *na)
1567 {
1568   struct GNUNET_TRANSPORT_PluginFunctions *papi;
1569   struct SessionConnectMessage connect_msg;
1570
1571   if (NULL == (papi = GST_plugins_find (na->address->transport_name)))
1572   {
1573     GNUNET_break (0);
1574     return;
1575   }
1576   if (NULL == na->session)
1577     na->session = papi->get_session (papi->cls, na->address);
1578   if (NULL == na->session)
1579   {
1580     GNUNET_break (0);
1581     return;
1582   }
1583   GNUNET_STATISTICS_update (GST_stats,
1584                             gettext_noop
1585                             ("# SESSION_CONNECT messages sent"),
1586                             1, GNUNET_NO);
1587   na->connect_timestamp = GNUNET_TIME_absolute_get ();
1588   connect_msg.header.size = htons (sizeof (struct SessionConnectMessage));
1589   connect_msg.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_CONNECT);
1590   connect_msg.reserved = htonl (0);
1591   connect_msg.timestamp = GNUNET_TIME_absolute_hton (na->connect_timestamp);
1592   if (-1 ==
1593       papi->send (papi->cls,
1594                   na->session,
1595                   (const char *) &connect_msg, sizeof (struct SessionConnectMessage),
1596                   UINT_MAX,
1597                   GNUNET_TIME_UNIT_FOREVER_REL,
1598                   NULL, NULL))
1599   {
1600     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1601                 _("Failed to transmit CONNECT message via plugin to %s\n"),
1602                 GST_plugins_a2s (na->address));
1603   }
1604   GST_neighbours_notify_data_sent (&na->address->peer,
1605                                    na->address,
1606                                    na->session,
1607                                    sizeof (struct SessionConnectMessage));
1608
1609 }
1610
1611
1612 /**
1613  * Send a SESSION_CONNECT_ACK message via the given address.
1614  *
1615  * @param address address to use
1616  * @param session session to use
1617  * @param timestamp timestamp to use for the ACK message
1618  */
1619 static void
1620 send_session_connect_ack_message (const struct GNUNET_HELLO_Address *address,
1621                                   struct Session *session,
1622                                   struct GNUNET_TIME_Absolute timestamp)
1623 {
1624   struct GNUNET_TRANSPORT_PluginFunctions *papi;
1625   struct SessionConnectMessage connect_msg;
1626
1627   if (NULL == (papi = GST_plugins_find (address->transport_name)))
1628   {
1629     GNUNET_break (0);
1630     return;
1631   }
1632   if (NULL == session)
1633     session = papi->get_session (papi->cls, address);
1634   if (NULL == session)
1635   {
1636     GNUNET_break (0);
1637     return;
1638   }
1639   GNUNET_STATISTICS_update (GST_stats,
1640                             gettext_noop
1641                             ("# CONNECT_ACK messages sent"),
1642                             1, GNUNET_NO);
1643   connect_msg.header.size = htons (sizeof (struct SessionConnectMessage));
1644   connect_msg.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_CONNECT_ACK);
1645   connect_msg.reserved = htonl (0);
1646   connect_msg.timestamp = GNUNET_TIME_absolute_hton (timestamp);
1647   (void) papi->send (papi->cls,
1648                      session,
1649                      (const char *) &connect_msg, sizeof (struct SessionConnectMessage),
1650                      UINT_MAX,
1651                      GNUNET_TIME_UNIT_FOREVER_REL,
1652                      NULL, NULL);
1653
1654 }
1655
1656
1657 /**
1658  * Create a fresh entry in the neighbour map for the given peer
1659  *
1660  * @param peer peer to create an entry for
1661  * @return new neighbour map entry
1662  */
1663 static struct NeighbourMapEntry *
1664 setup_neighbour (const struct GNUNET_PeerIdentity *peer)
1665 {
1666   struct NeighbourMapEntry *n;
1667
1668   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1669               "Creating new neighbour entry for `%s'\n",
1670               GNUNET_i2s (peer));
1671   n = GNUNET_new (struct NeighbourMapEntry);
1672   n->id = *peer;
1673   n->state = S_NOT_CONNECTED;
1674   n->latency = GNUNET_TIME_UNIT_FOREVER_REL;
1675   n->last_util_transmission = GNUNET_TIME_absolute_get();
1676   n->util_payload_bytes_recv = 0;
1677   n->util_payload_bytes_sent = 0;
1678   n->util_total_bytes_recv = 0;
1679   n->util_total_bytes_sent = 0;
1680   GNUNET_BANDWIDTH_tracker_init (&n->in_tracker,
1681                                  GNUNET_CONSTANTS_DEFAULT_BW_IN_OUT,
1682                                  MAX_BANDWIDTH_CARRY_S);
1683   n->task = GNUNET_SCHEDULER_add_now (&master_task, n);
1684   GNUNET_assert (GNUNET_OK ==
1685                  GNUNET_CONTAINER_multipeermap_put (neighbours,
1686                                                     &n->id, n,
1687                                                     GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
1688   return n;
1689 }
1690
1691
1692 /**
1693  * Check if the two given addresses are the same.
1694  * Actually only checks if the sessions are non-NULL
1695  * (which they should be) and then if they are identical;
1696  * the actual addresses don't matter if the session
1697  * pointers match anyway, and we must have session pointers
1698  * at this time.
1699  *
1700  * @param a1 first address to compare
1701  * @param a2 other address to compare
1702  * @return #GNUNET_NO if the addresses do not match, #GNUNET_YES if they do match
1703  */
1704 static int
1705 address_matches (const struct NeighbourAddress *a1,
1706                  const struct NeighbourAddress *a2)
1707 {
1708   if ( (NULL == a1->session) ||
1709        (NULL == a2->session) )
1710   {
1711     GNUNET_break (0);
1712     return 0;
1713   }
1714   return (a1->session == a2->session) ? GNUNET_YES : GNUNET_NO;
1715 }
1716
1717
1718 /**
1719  * Try to create a connection to the given target (eventually).
1720  *
1721  * @param target peer to try to connect to
1722  */
1723 void
1724 GST_neighbours_try_connect (const struct GNUNET_PeerIdentity *target)
1725 {
1726   struct NeighbourMapEntry *n;
1727
1728   if (NULL == neighbours)
1729   {
1730     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1731                 "Asked to connect to peer `%s' during shutdown\n",
1732                 GNUNET_i2s (target));
1733     return; /* during shutdown, do nothing */
1734   }
1735   if (0 == memcmp (target,
1736                    &GST_my_identity, sizeof (struct GNUNET_PeerIdentity)))
1737   {
1738     /* refuse to connect to myself */
1739     /* FIXME: can this happen? Is this not an API violation? */
1740     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1741                 "Refusing to try to connect to myself.\n");
1742     return;
1743   }
1744   n = lookup_neighbour (target);
1745   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1746               "Asked to connect to peer `%s' (state: %s)\n",
1747               GNUNET_i2s (target),
1748               (NULL != n) ? print_state(n->state) : "UNKNOWN PEER");
1749   if (NULL != n)
1750   {
1751     switch (n->state)
1752     {
1753     case S_NOT_CONNECTED:
1754       /* this should not be possible */
1755       GNUNET_break (0);
1756       free_neighbour (n, GNUNET_NO);
1757       break;
1758     case S_INIT_ATS:
1759     case S_INIT_BLACKLIST:
1760     case S_CONNECT_SENT:
1761     case S_CONNECT_RECV_BLACKLIST_INBOUND:
1762     case S_CONNECT_RECV_ATS:
1763     case S_CONNECT_RECV_BLACKLIST:
1764     case S_CONNECT_RECV_ACK:
1765       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1766                   "Ignoring request to try to connect to `%s', already trying!\n",
1767                   GNUNET_i2s (target));
1768       return; /* already trying */
1769     case S_CONNECTED:
1770     case S_RECONNECT_ATS:
1771     case S_RECONNECT_BLACKLIST:
1772     case S_RECONNECT_SENT:
1773     case S_CONNECTED_SWITCHING_BLACKLIST:
1774     case S_CONNECTED_SWITCHING_CONNECT_SENT:
1775       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1776                   "Ignoring request to try to connect, already connected to `%s'!\n",
1777                   GNUNET_i2s (target));
1778       return; /* already connected */
1779     case S_DISCONNECT:
1780       /* get rid of remains, ready to re-try immediately */
1781       free_neighbour (n, GNUNET_NO);
1782       break;
1783     case S_DISCONNECT_FINISHED:
1784       /* should not be possible */
1785       GNUNET_assert (0);
1786     default:
1787       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1788                   "Unhandled state `%s'\n",
1789                   print_state (n->state));
1790       GNUNET_break (0);
1791       free_neighbour (n, GNUNET_NO);
1792       break;
1793     }
1794   }
1795   n = setup_neighbour (target);
1796   n->state = S_INIT_ATS;
1797   n->timeout = GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT);
1798
1799   GNUNET_ATS_reset_backoff (GST_ats, target);
1800   n->suggest_handle = GNUNET_ATS_suggest_address (GST_ats, target);
1801 }
1802
1803
1804 /**
1805  * Function called with the result of a blacklist check.
1806  *
1807  * @param cls closure with the 'struct BlackListCheckContext'
1808  * @param peer peer this check affects
1809  * @param result #GNUNET_OK if the address is allowed
1810  */
1811 static void
1812 handle_test_blacklist_cont (void *cls,
1813                             const struct GNUNET_PeerIdentity *peer,
1814                             int result)
1815 {
1816   struct BlackListCheckContext *bcc = cls;
1817   struct NeighbourMapEntry *n;
1818
1819   bcc->bc = NULL;
1820   GNUNET_CONTAINER_DLL_remove (bc_head,
1821                                bc_tail,
1822                                bcc);
1823   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1824               "Connection to new address of peer `%s' based on blacklist is `%s'\n",
1825               GNUNET_i2s (peer),
1826               (GNUNET_OK == result) ? "allowed" : "FORBIDDEN");
1827   if (GNUNET_OK == result)
1828     GST_ats_add_address (bcc->na.address, bcc->na.session);
1829   if (NULL == (n = lookup_neighbour (peer)))
1830     goto cleanup; /* nobody left to care about new address */
1831   switch (n->state)
1832   {
1833   case S_NOT_CONNECTED:
1834     /* this should not be possible */
1835     GNUNET_break (0);
1836     free_neighbour (n, GNUNET_NO);
1837     break;
1838   case S_INIT_ATS:
1839     /* waiting on ATS suggestion; still, pass address to ATS as a
1840        possibility */
1841     break;
1842   case S_INIT_BLACKLIST:
1843     /* check if the address the blacklist was fine with matches
1844        ATS suggestion, if so, we can move on! */
1845     if ( (GNUNET_OK == result) &&
1846          (1 == n->send_connect_ack) )
1847     {
1848       n->send_connect_ack = 2;
1849       send_session_connect_ack_message (bcc->na.address,
1850                                         bcc->na.session,
1851                                         n->connect_ack_timestamp);
1852     }
1853     if (GNUNET_YES != address_matches (&bcc->na, &n->primary_address))
1854       break; /* result for an address we currently don't care about */
1855     if (GNUNET_OK == result)
1856     {
1857       n->timeout = GNUNET_TIME_relative_to_absolute (SETUP_CONNECTION_TIMEOUT);
1858       n->state = S_CONNECT_SENT;
1859       send_session_connect (&n->primary_address);
1860     }
1861     else
1862     {
1863       // FIXME: should also possibly destroy session with plugin!?
1864       GNUNET_ATS_address_destroyed (GST_ats,
1865                                     bcc->na.address,
1866                                     NULL);
1867       free_address (&n->primary_address);
1868       n->state = S_INIT_ATS;
1869       n->timeout = GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT);
1870       // FIXME: do we need to ask ATS again for suggestions?
1871       n->suggest_handle = GNUNET_ATS_suggest_address (GST_ats, &n->id);
1872     }
1873     break;
1874   case S_CONNECT_SENT:
1875     /* waiting on CONNECT_ACK, send ACK if one is pending */
1876     if ( (GNUNET_OK == result) &&
1877          (1 == n->send_connect_ack) )
1878     {
1879       n->send_connect_ack = 2;
1880       send_session_connect_ack_message (n->primary_address.address,
1881                                         n->primary_address.session,
1882                                         n->connect_ack_timestamp);
1883     }
1884     break;
1885   case S_CONNECT_RECV_BLACKLIST_INBOUND:
1886     n->state = S_CONNECT_RECV_ATS;
1887     n->timeout = GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT);
1888     GNUNET_ATS_reset_backoff (GST_ats, peer);
1889     n->suggest_handle = GNUNET_ATS_suggest_address (GST_ats, peer);
1890     break;
1891   case S_CONNECT_RECV_ATS:
1892     /* waiting on ATS suggestion, don't care about blacklist */
1893     break;
1894   case S_CONNECT_RECV_BLACKLIST:
1895     if (GNUNET_YES != address_matches (&bcc->na, &n->primary_address))
1896     {
1897       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1898                   "Blacklist result ignored, as it is not for our primary address\n");
1899       break; /* result for an address we currently don't care about */
1900     }
1901     if (GNUNET_OK == result)
1902     {
1903       n->timeout = GNUNET_TIME_relative_to_absolute (SETUP_CONNECTION_TIMEOUT);
1904       n->state = S_CONNECT_RECV_ACK;
1905       send_session_connect_ack_message (bcc->na.address,
1906                                         bcc->na.session,
1907                                         n->connect_ack_timestamp);
1908       if (1 == n->send_connect_ack)
1909         n->send_connect_ack = 2;
1910     }
1911     else
1912     {
1913       struct GNUNET_TRANSPORT_PluginFunctions *plugin;
1914
1915       plugin = GST_plugins_find (bcc->na.address->transport_name);
1916       if ( (NULL != plugin) &&
1917            (NULL != bcc->na.session) )
1918       {
1919         plugin->disconnect_session (plugin->cls,
1920                                     bcc->na.session);
1921         break;
1922       }
1923       GNUNET_break (NULL != plugin);
1924       GNUNET_ATS_address_destroyed (GST_ats,
1925                                     bcc->na.address,
1926                                     NULL);
1927       free_address (&n->primary_address);
1928       n->state = S_INIT_ATS;
1929       n->timeout = GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT);
1930       // FIXME: do we need to ask ATS again for suggestions?
1931       GNUNET_ATS_reset_backoff (GST_ats, peer);
1932       n->suggest_handle = GNUNET_ATS_suggest_address (GST_ats, &n->id);
1933     }
1934     break;
1935   case S_CONNECT_RECV_ACK:
1936     /* waiting on SESSION_ACK, send ACK if one is pending */
1937     if ( (GNUNET_OK == result) &&
1938          (1 == n->send_connect_ack) )
1939     {
1940       n->send_connect_ack = 2;
1941       send_session_connect_ack_message (n->primary_address.address,
1942                                         n->primary_address.session,
1943                                         n->connect_ack_timestamp);
1944     }
1945     break;
1946   case S_CONNECTED:
1947     /* already connected, don't care about blacklist */
1948     break;
1949   case S_RECONNECT_ATS:
1950     /* still waiting on ATS suggestion, don't care about blacklist */
1951     break;
1952   case S_RECONNECT_BLACKLIST:
1953     if ( (GNUNET_OK == result) &&
1954          (1 == n->send_connect_ack) )
1955     {
1956       n->send_connect_ack = 2;
1957       send_session_connect_ack_message (bcc->na.address,
1958                                         bcc->na.session,
1959                                         n->connect_ack_timestamp);
1960     }
1961     if (GNUNET_YES != address_matches (&bcc->na, &n->primary_address))
1962       break; /* result for an address we currently don't care about */
1963     if (GNUNET_OK == result)
1964     {
1965       send_session_connect (&n->primary_address);
1966       n->timeout = GNUNET_TIME_relative_to_absolute (FAST_RECONNECT_TIMEOUT);
1967       n->state = S_RECONNECT_SENT;
1968     }
1969     else
1970     {
1971       GNUNET_ATS_address_destroyed (GST_ats,
1972                                     bcc->na.address,
1973                                     NULL);
1974       n->state = S_RECONNECT_ATS;
1975       n->timeout = GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT);
1976       // FIXME: do we need to ask ATS again for suggestions?
1977       n->suggest_handle = GNUNET_ATS_suggest_address (GST_ats, &n->id);
1978     }
1979     break;
1980   case S_RECONNECT_SENT:
1981     /* waiting on CONNECT_ACK, don't care about blacklist */
1982     if ( (GNUNET_OK == result) &&
1983          (1 == n->send_connect_ack) )
1984     {
1985       n->send_connect_ack = 2;
1986       send_session_connect_ack_message (n->primary_address.address,
1987                                         n->primary_address.session,
1988                                         n->connect_ack_timestamp);
1989     }
1990     break;
1991   case S_CONNECTED_SWITCHING_BLACKLIST:
1992     if (GNUNET_YES != address_matches (&bcc->na, &n->alternative_address))
1993       break; /* result for an address we currently don't care about */
1994     if (GNUNET_OK == result)
1995     {
1996       send_session_connect (&n->alternative_address);
1997       n->state = S_CONNECTED_SWITCHING_CONNECT_SENT;
1998     }
1999     else
2000     {
2001       GNUNET_ATS_address_destroyed (GST_ats,
2002                                     bcc->na.address,
2003                                     NULL);
2004       free_address (&n->alternative_address);
2005       n->state = S_CONNECTED;
2006     }
2007     break;
2008   case S_CONNECTED_SWITCHING_CONNECT_SENT:
2009     /* waiting on CONNECT_ACK, don't care about blacklist */
2010     if ( (GNUNET_OK == result) &&
2011          (1 == n->send_connect_ack) )
2012     {
2013       n->send_connect_ack = 2;
2014       send_session_connect_ack_message (n->primary_address.address,
2015                                         n->primary_address.session,
2016                                         n->connect_ack_timestamp);
2017     }
2018     break;
2019   case S_DISCONNECT:
2020     /* Nothing to do here, ATS will already do what can be done */
2021     break;
2022   case S_DISCONNECT_FINISHED:
2023     /* should not be possible */
2024     GNUNET_assert (0);
2025     break;
2026   default:
2027     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2028                 "Unhandled state `%s'\n",
2029                 print_state (n->state));
2030     GNUNET_break (0);
2031     free_neighbour (n, GNUNET_NO);
2032     break;
2033   }
2034  cleanup:
2035   GNUNET_HELLO_address_free (bcc->na.address);
2036   GNUNET_free (bcc);
2037 }
2038
2039
2040 /**
2041  * We want to know if connecting to a particular peer via
2042  * a particular address is allowed.  Check it!
2043  *
2044  * @param peer identity of the peer to switch the address for
2045  * @param ts time at which the check was initiated
2046  * @param address address of the other peer, NULL if other peer
2047  *                       connected to us
2048  * @param session session to use (or NULL)
2049  */
2050 static void
2051 check_blacklist (const struct GNUNET_PeerIdentity *peer,
2052                  struct GNUNET_TIME_Absolute ts,
2053                  const struct GNUNET_HELLO_Address *address,
2054                  struct Session *session)
2055 {
2056   struct BlackListCheckContext *bcc;
2057   struct GST_BlacklistCheck *bc;
2058
2059   bcc = GNUNET_new (struct BlackListCheckContext);
2060   bcc->na.address = GNUNET_HELLO_address_copy (address);
2061   bcc->na.session = session;
2062   bcc->na.connect_timestamp = ts;
2063   GNUNET_CONTAINER_DLL_insert (bc_head,
2064                                bc_tail,
2065                                bcc);
2066   if (NULL != (bc = GST_blacklist_test_allowed (peer,
2067                                                 address->transport_name,
2068                                                 &handle_test_blacklist_cont, bcc)))
2069     bcc->bc = bc;
2070   /* if NULL == bc, 'cont' was already called and 'bcc' already free'd, so
2071      we must only store 'bc' if 'bc' is non-NULL... */
2072 }
2073
2074
2075 /**
2076  * We received a 'SESSION_CONNECT' message from the other peer.
2077  * Consider switching to it.
2078  *
2079  * @param message possibly a 'struct SessionConnectMessage' (check format)
2080  * @param peer identity of the peer to switch the address for
2081  * @param address address of the other peer, NULL if other peer
2082  *                       connected to us
2083  * @param session session to use (or NULL)
2084  * @return #GNUNET_OK if the message was fine, #GNUNET_SYSERR on serious error
2085  */
2086 int
2087 GST_neighbours_handle_connect (const struct GNUNET_MessageHeader *message,
2088                                const struct GNUNET_PeerIdentity *peer,
2089                                const struct GNUNET_HELLO_Address *address,
2090                                struct Session *session)
2091 {
2092   const struct SessionConnectMessage *scm;
2093   struct NeighbourMapEntry *n;
2094   struct GNUNET_TIME_Absolute ts;
2095
2096   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2097               "Received CONNECT message from peer `%s'\n",
2098               GNUNET_i2s (peer));
2099   if (ntohs (message->size) != sizeof (struct SessionConnectMessage))
2100   {
2101     GNUNET_break_op (0);
2102     return GNUNET_SYSERR;
2103   }
2104   GNUNET_STATISTICS_update (GST_stats,
2105                             gettext_noop
2106                             ("# CONNECT messages received"),
2107                             1, GNUNET_NO);
2108   if (NULL == neighbours)
2109   {
2110     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2111                 _("CONNECT request from peer `%s' ignored due impending shutdown\n"),
2112                 GNUNET_i2s (peer));
2113     return GNUNET_OK; /* we're shutting down */
2114   }
2115   scm = (const struct SessionConnectMessage *) message;
2116   GNUNET_break_op (0 == ntohl (scm->reserved));
2117   ts = GNUNET_TIME_absolute_ntoh (scm->timestamp);
2118   n = lookup_neighbour (peer);
2119   if (NULL == n)
2120     n = setup_neighbour (peer);
2121   n->send_connect_ack = 1;
2122   n->connect_ack_timestamp = ts;
2123
2124   switch (n->state)
2125   {
2126   case S_NOT_CONNECTED:
2127     n->state = S_CONNECT_RECV_BLACKLIST_INBOUND;
2128     /* Do a blacklist check for the new address */
2129     check_blacklist (peer, ts, address, session);
2130     break;
2131   case S_INIT_ATS:
2132     /* CONNECT message takes priority over us asking ATS for address */
2133     n->state = S_CONNECT_RECV_BLACKLIST_INBOUND;
2134     /* fallthrough */
2135   case S_INIT_BLACKLIST:
2136   case S_CONNECT_SENT:
2137   case S_CONNECT_RECV_BLACKLIST_INBOUND:
2138   case S_CONNECT_RECV_ATS:
2139   case S_CONNECT_RECV_BLACKLIST:
2140   case S_CONNECT_RECV_ACK:
2141     /* It can never hurt to have an alternative address in the above cases,
2142        see if it is allowed */
2143     check_blacklist (peer, ts, address, session);
2144     break;
2145   case S_CONNECTED:
2146     /* we are already connected and can thus send the ACK immediately;
2147        still, it can never hurt to have an alternative address, so also
2148        tell ATS  about it */
2149     GNUNET_assert (NULL != n->primary_address.address);
2150     GNUNET_assert (NULL != n->primary_address.session);
2151     n->send_connect_ack = 0;
2152     send_session_connect_ack_message (n->primary_address.address,
2153                                       n->primary_address.session, ts);
2154     check_blacklist (peer, ts, address, session);
2155     break;
2156   case S_RECONNECT_ATS:
2157   case S_RECONNECT_BLACKLIST:
2158   case S_RECONNECT_SENT:
2159     /* It can never hurt to have an alternative address in the above cases,
2160        see if it is allowed */
2161     check_blacklist (peer, ts, address, session);
2162     break;
2163   case S_CONNECTED_SWITCHING_BLACKLIST:
2164   case S_CONNECTED_SWITCHING_CONNECT_SENT:
2165     /* we are already connected and can thus send the ACK immediately;
2166        still, it can never hurt to have an alternative address, so also
2167        tell ATS  about it */
2168     GNUNET_assert (NULL != n->primary_address.address);
2169     GNUNET_assert (NULL != n->primary_address.session);
2170     n->send_connect_ack = 0;
2171     send_session_connect_ack_message (n->primary_address.address,
2172                                       n->primary_address.session, ts);
2173     check_blacklist (peer, ts, address, session);
2174     break;
2175   case S_DISCONNECT:
2176     /* get rid of remains without terminating sessions, ready to re-try */
2177     free_neighbour (n, GNUNET_YES);
2178     n = setup_neighbour (peer);
2179     n->state = S_CONNECT_RECV_ATS;
2180     GNUNET_ATS_reset_backoff (GST_ats, peer);
2181     n->suggest_handle = GNUNET_ATS_suggest_address (GST_ats, peer);
2182     break;
2183   case S_DISCONNECT_FINISHED:
2184     /* should not be possible */
2185     GNUNET_assert (0);
2186     break;
2187   default:
2188     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2189                 "Unhandled state `%s'\n",
2190                 print_state (n->state));
2191     GNUNET_break (0);
2192     return GNUNET_SYSERR;
2193   }
2194   return GNUNET_OK;
2195 }
2196
2197
2198 /**
2199  * For an existing neighbour record, set the active connection to
2200  * use the given address.
2201  *
2202  * @param peer identity of the peer to switch the address for
2203  * @param address address of the other peer, NULL if other peer
2204  *                       connected to us
2205  * @param session session to use (or NULL)
2206  * @param ats performance data
2207  * @param ats_count number of entries in ats
2208  * @param bandwidth_in inbound quota to be used when connection is up,
2209  *      0 to disconnect from peer
2210  * @param bandwidth_out outbound quota to be used when connection is up,
2211  *      0 to disconnect from peer
2212  */
2213 void
2214 GST_neighbours_switch_to_address (const struct GNUNET_PeerIdentity *peer,
2215                                   const struct GNUNET_HELLO_Address *address,
2216                                   struct Session *session,
2217                                   const struct GNUNET_ATS_Information *ats,
2218                                   uint32_t ats_count,
2219                                   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in,
2220                                   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out)
2221 {
2222   struct NeighbourMapEntry *n;
2223   struct GNUNET_TRANSPORT_PluginFunctions *papi;
2224
2225   GNUNET_assert (address->transport_name != NULL);
2226   if (NULL == (n = lookup_neighbour (peer)))
2227     return;
2228
2229   /* Obtain an session for this address from plugin */
2230   if (NULL == (papi = GST_plugins_find (address->transport_name)))
2231   {
2232     /* we don't have the plugin for this address */
2233     GNUNET_ATS_address_destroyed (GST_ats, address, NULL);
2234     return;
2235   }
2236   if ((NULL == session) && (0 == address->address_length))
2237   {
2238     GNUNET_break (0);
2239     if (strlen (address->transport_name) > 0)
2240       GNUNET_ATS_address_destroyed (GST_ats, address, NULL);
2241     return;
2242   }
2243
2244   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2245               "ATS tells us to switch to address '%s' session %p for "
2246               "peer `%s' in state %s/%d (quota in/out %u %u )\n",
2247               (address->address_length != 0) ? GST_plugins_a2s (address): "<inbound>",
2248               session,
2249               GNUNET_i2s (peer),
2250               print_state (n->state),
2251               n->send_connect_ack,
2252               ntohl (bandwidth_in.value__),
2253               ntohl (bandwidth_out.value__));
2254
2255   if (NULL == session)
2256   {
2257     session = papi->get_session (papi->cls, address);
2258     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2259                 "Obtained new session for peer `%s' and  address '%s': %p\n",
2260                 GNUNET_i2s (&address->peer), GST_plugins_a2s (address), session);
2261   }
2262   if (NULL == session)
2263   {
2264     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2265                 "Failed to obtain new session for peer `%s' and  address '%s'\n",
2266                 GNUNET_i2s (&address->peer), GST_plugins_a2s (address));
2267     GNUNET_ATS_address_destroyed (GST_ats, address, NULL);
2268     return;
2269   }
2270   switch (n->state)
2271   {
2272   case S_NOT_CONNECTED:
2273     GNUNET_break (0);
2274     free_neighbour (n, GNUNET_NO);
2275     return;
2276   case S_INIT_ATS:
2277     set_address (&n->primary_address,
2278                  address, session, bandwidth_in, bandwidth_out, GNUNET_NO);
2279     n->state = S_INIT_BLACKLIST;
2280     n->timeout = GNUNET_TIME_relative_to_absolute (BLACKLIST_RESPONSE_TIMEOUT);
2281     check_blacklist (&n->id,
2282                      n->connect_ack_timestamp,
2283                      address, session);
2284     break;
2285   case S_INIT_BLACKLIST:
2286     /* ATS suggests a different address, switch again */
2287     set_address (&n->primary_address,
2288                  address, session, bandwidth_in, bandwidth_out, GNUNET_NO);
2289     n->timeout = GNUNET_TIME_relative_to_absolute (BLACKLIST_RESPONSE_TIMEOUT);
2290     check_blacklist (&n->id,
2291                      n->connect_ack_timestamp,
2292                      address, session);
2293     break;
2294   case S_CONNECT_SENT:
2295     /* ATS suggests a different address, switch again */
2296     set_address (&n->primary_address,
2297                  address, session, bandwidth_in, bandwidth_out, GNUNET_NO);
2298     n->state = S_INIT_BLACKLIST;
2299     n->timeout = GNUNET_TIME_relative_to_absolute (BLACKLIST_RESPONSE_TIMEOUT);
2300     check_blacklist (&n->id,
2301                      n->connect_ack_timestamp,
2302                      address, session);
2303     break;
2304   case S_CONNECT_RECV_ATS:
2305     set_address (&n->primary_address,
2306                  address, session, bandwidth_in, bandwidth_out, GNUNET_NO);
2307     n->state = S_CONNECT_RECV_BLACKLIST;
2308     n->timeout = GNUNET_TIME_relative_to_absolute (BLACKLIST_RESPONSE_TIMEOUT);
2309     check_blacklist (&n->id,
2310                      n->connect_ack_timestamp,
2311                      address, session);
2312     break;
2313   case S_CONNECT_RECV_BLACKLIST_INBOUND:
2314     n->timeout = GNUNET_TIME_relative_to_absolute (BLACKLIST_RESPONSE_TIMEOUT);
2315     check_blacklist (&n->id,
2316                      n->connect_ack_timestamp,
2317                      address, session);
2318     break;
2319   case S_CONNECT_RECV_BLACKLIST:
2320   case S_CONNECT_RECV_ACK:
2321     /* ATS asks us to switch while we were trying to connect; switch to new
2322        address and check blacklist again */
2323     set_address (&n->primary_address,
2324                  address, session, bandwidth_in, bandwidth_out, GNUNET_NO);
2325     n->timeout = GNUNET_TIME_relative_to_absolute (BLACKLIST_RESPONSE_TIMEOUT);
2326     check_blacklist (&n->id,
2327                      n->connect_ack_timestamp,
2328                      address, session);
2329     break;
2330   case S_CONNECTED:
2331     GNUNET_assert (NULL != n->primary_address.address);
2332     GNUNET_assert (NULL != n->primary_address.session);
2333     if (n->primary_address.session == session)
2334     {
2335       /* not an address change, just a quota change */
2336       set_address (&n->primary_address,
2337                    address, session, bandwidth_in, bandwidth_out, GNUNET_YES);
2338       break;
2339     }
2340     /* ATS asks us to switch a life connection; see if we can get
2341        a CONNECT_ACK on it before we actually do this! */
2342     set_address (&n->alternative_address,
2343                  address, session, bandwidth_in, bandwidth_out, GNUNET_NO);
2344     n->state = S_CONNECTED_SWITCHING_BLACKLIST;
2345     check_blacklist (&n->id,
2346                      GNUNET_TIME_absolute_get (),
2347                      address, session);
2348     break;
2349   case S_RECONNECT_ATS:
2350     set_address (&n->primary_address,
2351                  address, session, bandwidth_in, bandwidth_out, GNUNET_NO);
2352     n->state = S_RECONNECT_BLACKLIST;
2353     n->timeout = GNUNET_TIME_relative_to_absolute (BLACKLIST_RESPONSE_TIMEOUT);
2354     check_blacklist (&n->id,
2355                      n->connect_ack_timestamp,
2356                      address, session);
2357     break;
2358   case S_RECONNECT_BLACKLIST:
2359     /* ATS asks us to switch while we were trying to reconnect; switch to new
2360        address and check blacklist again */
2361     set_address (&n->primary_address,
2362                  address, session, bandwidth_in, bandwidth_out, GNUNET_NO);
2363     n->timeout = GNUNET_TIME_relative_to_absolute (BLACKLIST_RESPONSE_TIMEOUT);
2364     check_blacklist (&n->id,
2365                      n->connect_ack_timestamp,
2366                      address, session);
2367     break;
2368   case S_RECONNECT_SENT:
2369     /* ATS asks us to switch while we were trying to reconnect; switch to new
2370        address and check blacklist again */
2371     set_address (&n->primary_address,
2372                  address, session, bandwidth_in, bandwidth_out, GNUNET_NO);
2373     n->state = S_RECONNECT_BLACKLIST;
2374     n->timeout = GNUNET_TIME_relative_to_absolute (BLACKLIST_RESPONSE_TIMEOUT);
2375     check_blacklist (&n->id,
2376                      n->connect_ack_timestamp,
2377                      address, session);
2378     break;
2379   case S_CONNECTED_SWITCHING_BLACKLIST:
2380     if (n->primary_address.session == session)
2381     {
2382       /* ATS switches back to still-active session */
2383       free_address (&n->alternative_address);
2384       n->state = S_CONNECTED;
2385       break;
2386     }
2387     /* ATS asks us to switch a life connection, update blacklist check */
2388     set_address (&n->alternative_address,
2389                  address, session, bandwidth_in, bandwidth_out, GNUNET_NO);
2390     check_blacklist (&n->id,
2391                      GNUNET_TIME_absolute_get (),
2392                      address, session);
2393     break;
2394   case S_CONNECTED_SWITCHING_CONNECT_SENT:
2395     if (n->primary_address.session == session)
2396     {
2397       /* ATS switches back to still-active session */
2398       free_address (&n->alternative_address);
2399       n->state = S_CONNECTED;
2400       break;
2401     }
2402     /* ATS asks us to switch a life connection, update blacklist check */
2403     set_address (&n->alternative_address,
2404                  address, session, bandwidth_in, bandwidth_out, GNUNET_NO);
2405     n->state = S_CONNECTED_SWITCHING_BLACKLIST;
2406     check_blacklist (&n->id,
2407                      GNUNET_TIME_absolute_get (),
2408                      address, session);
2409     break;
2410   case S_DISCONNECT:
2411     /* not going to switch addresses while disconnecting */
2412     return;
2413   case S_DISCONNECT_FINISHED:
2414     GNUNET_assert (0);
2415     break;
2416   default:
2417     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2418                 "Unhandled state `%s'\n",
2419                 print_state (n->state));
2420     GNUNET_break (0);
2421     break;
2422   }
2423 }
2424
2425
2426 static int
2427 send_utilization_data (void *cls,
2428                        const struct GNUNET_PeerIdentity *key,
2429                        void *value)
2430 {
2431   struct NeighbourMapEntry *n = value;
2432   struct GNUNET_ATS_Information atsi[4];
2433   uint32_t bps_pl_in;
2434   uint32_t bps_pl_out;
2435   uint32_t bps_in;
2436   uint32_t bps_out;
2437   struct GNUNET_TIME_Relative delta;
2438
2439   delta = GNUNET_TIME_absolute_get_difference (n->last_util_transmission,
2440                                                GNUNET_TIME_absolute_get ());
2441
2442   bps_pl_in = 0;
2443
2444   if ((0 != n->util_payload_bytes_recv) && (0 != delta.rel_value_us))
2445     bps_pl_in =  (1000LL * 1000LL *  n->util_payload_bytes_recv) / (delta.rel_value_us);
2446   bps_pl_out = 0;
2447   if ((0 != n->util_payload_bytes_sent) && (0 != delta.rel_value_us))
2448     bps_pl_out = (1000LL * 1000LL * n->util_payload_bytes_sent) / delta.rel_value_us;
2449   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2450               "`%s' payload: received %u Bytes/s, sent %u Bytes/s\n",
2451               GNUNET_i2s (key),
2452               bps_pl_in,
2453               bps_pl_out);
2454   bps_in = 0;
2455   if ((0 != n->util_total_bytes_recv) && (0 != delta.rel_value_us))
2456     bps_in =  (1000LL * 1000LL *  n->util_total_bytes_recv) / (delta.rel_value_us);
2457   bps_out = 0;
2458   if ((0 != n->util_total_bytes_sent) && (0 != delta.rel_value_us))
2459     bps_out = (1000LL * 1000LL * n->util_total_bytes_sent) / delta.rel_value_us;
2460
2461
2462   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2463               "`%s' total: received %u Bytes/s, sent %u Bytes/s\n",
2464               GNUNET_i2s (key),
2465               bps_in,
2466               bps_out);
2467   atsi[0].type = htonl (GNUNET_ATS_UTILIZATION_OUT);
2468   atsi[0].value = htonl (bps_out);
2469   atsi[1].type = htonl (GNUNET_ATS_UTILIZATION_IN);
2470   atsi[1].value = htonl (bps_in);
2471
2472   atsi[2].type = htonl (GNUNET_ATS_UTILIZATION_PAYLOAD_OUT);
2473   atsi[2].value = htonl (bps_pl_out);
2474   atsi[3].type = htonl (GNUNET_ATS_UTILIZATION_PAYLOAD_IN);
2475   atsi[3].value = htonl (bps_pl_in);
2476
2477   GST_ats_update_metrics (key, n->primary_address.address,
2478       n->primary_address.session, atsi, 4);
2479   n->util_payload_bytes_recv = 0;
2480   n->util_payload_bytes_sent = 0;
2481   n->util_total_bytes_recv = 0;
2482   n->util_total_bytes_sent = 0;
2483   n->last_util_transmission = GNUNET_TIME_absolute_get();
2484   return GNUNET_OK;
2485 }
2486
2487
2488 /**
2489  * Task transmitting utilization in a regular interval
2490  *
2491  * @param cls the 'struct NeighbourMapEntry' for which we are running
2492  * @param tc scheduler context (unused)
2493  */
2494 static void
2495 utilization_transmission (void *cls,
2496                           const struct GNUNET_SCHEDULER_TaskContext *tc)
2497 {
2498   util_transmission_tk = GNUNET_SCHEDULER_NO_TASK;
2499
2500   if (0 < GNUNET_CONTAINER_multipeermap_size (neighbours))
2501     GNUNET_CONTAINER_multipeermap_iterate (neighbours, send_utilization_data, NULL);
2502
2503   util_transmission_tk = GNUNET_SCHEDULER_add_delayed (UTIL_TRANSMISSION_INTERVAL,
2504       utilization_transmission, NULL);
2505
2506 }
2507
2508
2509 void
2510 GST_neighbours_notify_data_recv (const struct GNUNET_PeerIdentity *peer,
2511                                  const struct GNUNET_HELLO_Address *address,
2512                                  struct Session *session,
2513                                  const struct GNUNET_MessageHeader *message)
2514 {
2515   struct NeighbourMapEntry *n;
2516
2517   n = lookup_neighbour (peer);
2518   if (NULL == n)
2519     return;
2520   n->util_total_bytes_recv += ntohs(message->size);
2521 }
2522
2523
2524 void
2525 GST_neighbours_notify_payload_recv (const struct GNUNET_PeerIdentity *peer,
2526                                     const struct GNUNET_HELLO_Address *address,
2527                                     struct Session *session,
2528                                     const struct GNUNET_MessageHeader *message)
2529 {
2530   struct NeighbourMapEntry *n;
2531   n = lookup_neighbour (peer);
2532   if (NULL == n)
2533     return;
2534   n->util_payload_bytes_recv += ntohs(message->size);
2535 }
2536
2537
2538 void
2539 GST_neighbours_notify_data_sent (const struct GNUNET_PeerIdentity *peer,
2540                                  const struct GNUNET_HELLO_Address *address,
2541                                  struct Session *session,
2542                                  size_t size)
2543 {
2544   struct NeighbourMapEntry *n;
2545   n = lookup_neighbour (peer);
2546   if (NULL == n)
2547       return;
2548   if (n->primary_address.session != session)
2549     return;
2550   n->util_total_bytes_sent += size;
2551 }
2552
2553
2554 void
2555 GST_neighbours_notify_payload_sent (const struct GNUNET_PeerIdentity *peer,
2556                                     size_t size)
2557 {
2558   struct NeighbourMapEntry *n;
2559   n = lookup_neighbour (peer);
2560   if (NULL == n)
2561     return;
2562   n->util_payload_bytes_sent += size;
2563 }
2564
2565
2566 /**
2567  * Master task run for every neighbour.  Performs all of the time-related
2568  * activities (keep alive, send next message, disconnect if idle, finish
2569  * clean up after disconnect).
2570  *
2571  * @param cls the 'struct NeighbourMapEntry' for which we are running
2572  * @param tc scheduler context (unused)
2573  */
2574 static void
2575 master_task (void *cls,
2576              const struct GNUNET_SCHEDULER_TaskContext *tc)
2577 {
2578   struct NeighbourMapEntry *n = cls;
2579   struct GNUNET_TIME_Relative delay;
2580
2581   n->task = GNUNET_SCHEDULER_NO_TASK;
2582   delay = GNUNET_TIME_absolute_get_remaining (n->timeout);
2583   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2584               "Master task runs for neighbour `%s' in state %s with timeout in %s\n",
2585               GNUNET_i2s (&n->id),
2586               print_state(n->state),
2587               GNUNET_STRINGS_relative_time_to_string (delay,
2588                                                       GNUNET_YES));
2589   switch (n->state)
2590   {
2591   case S_NOT_CONNECTED:
2592     /* invalid state for master task, clean up */
2593     GNUNET_break (0);
2594     n->state = S_DISCONNECT_FINISHED;
2595     free_neighbour (n, GNUNET_NO);
2596     return;
2597   case S_INIT_ATS:
2598     if (0 == delay.rel_value_us)
2599     {
2600       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2601                   "Connection to `%s' timed out waiting for ATS to provide address\n",
2602                   GNUNET_i2s (&n->id));
2603       n->state = S_DISCONNECT_FINISHED;
2604       free_neighbour (n, GNUNET_NO);
2605       return;
2606     }
2607     break;
2608   case S_INIT_BLACKLIST:
2609     if (0 == delay.rel_value_us)
2610     {
2611       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2612                   "Connection to `%s' timed out waiting for BLACKLIST to approve address\n",
2613                   GNUNET_i2s (&n->id));
2614       n->state = S_DISCONNECT_FINISHED;
2615       free_neighbour (n, GNUNET_NO);
2616       return;
2617     }
2618     break;
2619   case S_CONNECT_SENT:
2620     if (0 == delay.rel_value_us)
2621     {
2622       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2623                   "Connection to `%s' timed out waiting for other peer to send CONNECT_ACK\n",
2624                   GNUNET_i2s (&n->id));
2625       disconnect_neighbour (n);
2626       return;
2627     }
2628     break;
2629   case S_CONNECT_RECV_BLACKLIST_INBOUND:
2630     if (0 == delay.rel_value_us)
2631     {
2632       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2633                   "Connection to `%s' timed out waiting BLACKLIST to approve address to use for received CONNECT\n",
2634                   GNUNET_i2s (&n->id));
2635       n->state = S_DISCONNECT_FINISHED;
2636       free_neighbour (n, GNUNET_NO);
2637       return;
2638     }
2639     break;
2640   case S_CONNECT_RECV_ATS:
2641     if (0 == delay.rel_value_us)
2642     {
2643       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2644                   "Connection to `%s' timed out waiting ATS to provide address to use for CONNECT_ACK\n",
2645                   GNUNET_i2s (&n->id));
2646       n->state = S_DISCONNECT_FINISHED;
2647       free_neighbour (n, GNUNET_NO);
2648       return;
2649     }
2650     break;
2651   case S_CONNECT_RECV_BLACKLIST:
2652     if (0 == delay.rel_value_us)
2653     {
2654       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2655                   "Connection to `%s' timed out waiting BLACKLIST to approve address to use for CONNECT_ACK\n",
2656                   GNUNET_i2s (&n->id));
2657       n->state = S_DISCONNECT_FINISHED;
2658       free_neighbour (n, GNUNET_NO);
2659       return;
2660     }
2661     break;
2662   case S_CONNECT_RECV_ACK:
2663     if (0 == delay.rel_value_us)
2664     {
2665       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2666                   "Connection to `%s' timed out waiting for other peer to send SESSION_ACK\n",
2667                   GNUNET_i2s (&n->id));
2668       disconnect_neighbour (n);
2669       return;
2670     }
2671     break;
2672   case S_CONNECTED:
2673     if (0 == delay.rel_value_us)
2674     {
2675       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2676                   "Connection to `%s' timed out, missing KEEPALIVE_RESPONSEs\n",
2677                   GNUNET_i2s (&n->id));
2678       disconnect_neighbour (n);
2679       return;
2680     }
2681     try_transmission_to_peer (n);
2682     send_keepalive (n);
2683     break;
2684   case S_RECONNECT_ATS:
2685     if (0 == delay.rel_value_us)
2686     {
2687       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2688                   "Connection to `%s' timed out, waiting for ATS replacement address\n",
2689                   GNUNET_i2s (&n->id));
2690       disconnect_neighbour (n);
2691       return;
2692     }
2693     break;
2694   case S_RECONNECT_BLACKLIST:
2695     if (0 == delay.rel_value_us)
2696     {
2697       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2698                   "Connection to `%s' timed out, waiting for BLACKLIST to approve replacement address\n",
2699                   GNUNET_i2s (&n->id));
2700       disconnect_neighbour (n);
2701       return;
2702     }
2703     break;
2704   case S_RECONNECT_SENT:
2705     if (0 == delay.rel_value_us)
2706     {
2707       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2708                   "Connection to `%s' timed out, waiting for other peer to CONNECT_ACK replacement address\n",
2709                   GNUNET_i2s (&n->id));
2710       disconnect_neighbour (n);
2711       return;
2712     }
2713     break;
2714   case S_CONNECTED_SWITCHING_BLACKLIST:
2715     if (0 == delay.rel_value_us)
2716     {
2717       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2718                   "Connection to `%s' timed out, missing KEEPALIVE_RESPONSEs\n",
2719                   GNUNET_i2s (&n->id));
2720       disconnect_neighbour (n);
2721       return;
2722     }
2723     try_transmission_to_peer (n);
2724     send_keepalive (n);
2725     break;
2726   case S_CONNECTED_SWITCHING_CONNECT_SENT:
2727     if (0 == delay.rel_value_us)
2728     {
2729       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2730                   "Connection to `%s' timed out, missing KEEPALIVE_RESPONSEs (after trying to CONNECT on alternative address)\n",
2731                   GNUNET_i2s (&n->id));
2732       disconnect_neighbour (n);
2733       return;
2734     }
2735     try_transmission_to_peer (n);
2736     send_keepalive (n);
2737     break;
2738   case S_DISCONNECT:
2739     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2740                 "Cleaning up connection to `%s' after sending DISCONNECT\n",
2741                 GNUNET_i2s (&n->id));
2742     free_neighbour (n, GNUNET_NO);
2743     return;
2744   case S_DISCONNECT_FINISHED:
2745     /* how did we get here!? */
2746     GNUNET_assert (0);
2747     break;
2748   default:
2749     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2750                 "Unhandled state `%s'\n",
2751                 print_state (n->state));
2752     GNUNET_break (0);
2753     break;
2754   }
2755   if ( (S_CONNECTED_SWITCHING_CONNECT_SENT == n->state) ||
2756        (S_CONNECTED_SWITCHING_BLACKLIST == n->state) ||
2757        (S_CONNECTED == n->state) )
2758   {
2759     /* if we are *now* in one of these three states, we're sending
2760        keep alive messages, so we need to consider the keepalive
2761        delay, not just the connection timeout */
2762     delay = GNUNET_TIME_relative_min (GNUNET_TIME_absolute_get_remaining (n->keep_alive_time),
2763                                       delay);
2764   }
2765   if (GNUNET_SCHEDULER_NO_TASK == n->task)
2766     n->task = GNUNET_SCHEDULER_add_delayed (delay,
2767                                             &master_task,
2768                                             n);
2769 }
2770
2771
2772 /**
2773  * Send a SESSION_ACK message to the neighbour to confirm that we
2774  * got his CONNECT_ACK.
2775  *
2776  * @param n neighbour to send the SESSION_ACK to
2777  */
2778 static void
2779 send_session_ack_message (struct NeighbourMapEntry *n)
2780 {
2781   struct GNUNET_MessageHeader msg;
2782
2783   msg.size = htons (sizeof (struct GNUNET_MessageHeader));
2784   msg.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_ACK);
2785   (void) send_with_session(n,
2786                            (const char *) &msg, sizeof (struct GNUNET_MessageHeader),
2787                            UINT32_MAX, GNUNET_TIME_UNIT_FOREVER_REL,
2788                            NULL, NULL);
2789 }
2790
2791
2792 /**
2793  * We received a 'SESSION_CONNECT_ACK' message from the other peer.
2794  * Consider switching to it.
2795  *
2796  * @param message possibly a 'struct SessionConnectMessage' (check format)
2797  * @param peer identity of the peer to switch the address for
2798  * @param address address of the other peer, NULL if other peer
2799  *                       connected to us
2800  * @param session session to use (or NULL)
2801  * @return #GNUNET_OK if the message was fine, #GNUNET_SYSERR on serious error
2802  */
2803 int
2804 GST_neighbours_handle_connect_ack (const struct GNUNET_MessageHeader *message,
2805                                    const struct GNUNET_PeerIdentity *peer,
2806                                    const struct GNUNET_HELLO_Address *address,
2807                                    struct Session *session)
2808 {
2809   const struct SessionConnectMessage *scm;
2810   struct GNUNET_TIME_Absolute ts;
2811   struct NeighbourMapEntry *n;
2812
2813   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2814               "Received CONNECT_ACK message from peer `%s'\n",
2815               GNUNET_i2s (peer));
2816
2817   if (ntohs (message->size) != sizeof (struct SessionConnectMessage))
2818   {
2819     GNUNET_break_op (0);
2820     return GNUNET_SYSERR;
2821   }
2822   GNUNET_STATISTICS_update (GST_stats,
2823                             gettext_noop
2824                             ("# CONNECT_ACK messages received"),
2825                             1, GNUNET_NO);
2826   scm = (const struct SessionConnectMessage *) message;
2827   GNUNET_break_op (ntohl (scm->reserved) == 0);
2828   if (NULL == (n = lookup_neighbour (peer)))
2829   {
2830     GNUNET_STATISTICS_update (GST_stats,
2831                               gettext_noop
2832                               ("# unexpected CONNECT_ACK messages (no peer)"),
2833                               1, GNUNET_NO);
2834     return GNUNET_SYSERR;
2835   }
2836   ts = GNUNET_TIME_absolute_ntoh (scm->timestamp);
2837   switch (n->state)
2838   {
2839   case S_NOT_CONNECTED:
2840     GNUNET_break (0);
2841     free_neighbour (n, GNUNET_NO);
2842     return GNUNET_SYSERR;
2843   case S_INIT_ATS:
2844   case S_INIT_BLACKLIST:
2845     GNUNET_STATISTICS_update (GST_stats,
2846                               gettext_noop
2847                               ("# unexpected CONNECT_ACK messages (not ready)"),
2848                               1, GNUNET_NO);
2849     break;
2850   case S_CONNECT_SENT:
2851     if (ts.abs_value_us != n->primary_address.connect_timestamp.abs_value_us)
2852     {
2853       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2854                   "CONNECT_ACK ignored as the timestamp does not match our CONNECT request\n");
2855       return GNUNET_OK;
2856     }
2857     n->state = S_CONNECTED;
2858     n->timeout = GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT);
2859     GNUNET_STATISTICS_set (GST_stats,
2860                            gettext_noop ("# peers connected"),
2861                            ++neighbours_connected,
2862                            GNUNET_NO);
2863     connect_notify_cb (callback_cls, &n->id,
2864                        n->primary_address.bandwidth_in,
2865                        n->primary_address.bandwidth_out);
2866     /* Tell ATS that the outbound session we created to send CONNECT was successfull */
2867     GST_ats_add_address (n->primary_address.address, n->primary_address.session);
2868     set_address (&n->primary_address,
2869                  n->primary_address.address,
2870                  n->primary_address.session,
2871                  n->primary_address.bandwidth_in,
2872                  n->primary_address.bandwidth_out,
2873                  GNUNET_YES);
2874     send_session_ack_message (n);
2875     break;
2876   case S_CONNECT_RECV_BLACKLIST_INBOUND:
2877   case S_CONNECT_RECV_ATS:
2878   case S_CONNECT_RECV_BLACKLIST:
2879   case S_CONNECT_RECV_ACK:
2880     GNUNET_STATISTICS_update (GST_stats,
2881                               gettext_noop
2882                               ("# unexpected CONNECT_ACK messages (not ready)"),
2883                               1, GNUNET_NO);
2884     break;
2885   case S_CONNECTED:
2886     /* duplicate CONNECT_ACK, let's answer by duplciate SESSION_ACK just in case */
2887     send_session_ack_message (n);
2888     break;
2889   case S_RECONNECT_ATS:
2890   case S_RECONNECT_BLACKLIST:
2891     /* we didn't expect any CONNECT_ACK, as we are waiting for ATS
2892        to give us a new address... */
2893     GNUNET_STATISTICS_update (GST_stats,
2894                               gettext_noop
2895                               ("# unexpected CONNECT_ACK messages (waiting on ATS)"),
2896                               1, GNUNET_NO);
2897     break;
2898   case S_RECONNECT_SENT:
2899     /* new address worked; go back to connected! */
2900     n->state = S_CONNECTED;
2901     send_session_ack_message (n);
2902     break;
2903   case S_CONNECTED_SWITCHING_BLACKLIST:
2904     /* duplicate CONNECT_ACK, let's answer by duplciate SESSION_ACK just in case */
2905     send_session_ack_message (n);
2906     break;
2907   case S_CONNECTED_SWITCHING_CONNECT_SENT:
2908     /* new address worked; adopt it and go back to connected! */
2909     n->state = S_CONNECTED;
2910     n->timeout = GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT);
2911     GNUNET_break (GNUNET_NO == n->alternative_address.ats_active);
2912
2913     GST_ats_add_address (n->alternative_address.address, n->alternative_address.session);
2914     set_address (&n->primary_address,
2915                  n->alternative_address.address,
2916                  n->alternative_address.session,
2917                  n->alternative_address.bandwidth_in,
2918                  n->alternative_address.bandwidth_out,
2919                  GNUNET_YES);
2920     free_address (&n->alternative_address);
2921     send_session_ack_message (n);
2922     break;
2923   case S_DISCONNECT:
2924     GNUNET_STATISTICS_update (GST_stats,
2925                               gettext_noop
2926                               ("# unexpected CONNECT_ACK messages (disconnecting)"),
2927                               1, GNUNET_NO);
2928     return GNUNET_SYSERR;
2929   case S_DISCONNECT_FINISHED:
2930     GNUNET_assert (0);
2931     break;
2932   default:
2933     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2934                 "Unhandled state `%s'\n",
2935                 print_state (n->state));
2936     GNUNET_break (0);
2937     return GNUNET_SYSERR;
2938   }
2939   return GNUNET_OK;
2940 }
2941
2942
2943 /**
2944  * A session was terminated. Take note; if needed, try to get
2945  * an alternative address from ATS.
2946  *
2947  * @param peer identity of the peer where the session died
2948  * @param session session that is gone
2949  * @return #GNUNET_YES if this was a session used, #GNUNET_NO if
2950  *        this session was not in use
2951  */
2952 int
2953 GST_neighbours_session_terminated (const struct GNUNET_PeerIdentity *peer,
2954                                    struct Session *session)
2955 {
2956   struct NeighbourMapEntry *n;
2957   struct BlackListCheckContext *bcc;
2958   struct BlackListCheckContext *bcc_next;
2959
2960   /* make sure to cancel all ongoing blacklist checks involving 'session' */
2961   bcc_next = bc_head;
2962   while (NULL != (bcc = bcc_next))
2963   {
2964     bcc_next = bcc->next;
2965     if (bcc->na.session == session)
2966     {
2967       if (NULL != bcc->bc)
2968         GST_blacklist_test_cancel (bcc->bc);
2969       GNUNET_HELLO_address_free (bcc->na.address);
2970       GNUNET_CONTAINER_DLL_remove (bc_head,
2971                                    bc_tail,
2972                                    bcc);
2973       GNUNET_free (bcc);
2974     }
2975   }
2976   if (NULL == (n = lookup_neighbour (peer)))
2977     return GNUNET_NO; /* can't affect us */
2978   if (session != n->primary_address.session)
2979   {
2980     if (session == n->alternative_address.session)
2981     {
2982       free_address (&n->alternative_address);
2983       if ( (S_CONNECTED_SWITCHING_BLACKLIST == n->state) ||
2984            (S_CONNECTED_SWITCHING_CONNECT_SENT == n->state) )
2985         n->state = S_CONNECTED;
2986       else
2987         GNUNET_break (0);
2988     }
2989     return GNUNET_NO; /* doesn't affect us further */
2990   }
2991
2992   n->expect_latency_response = GNUNET_NO;
2993   switch (n->state)
2994   {
2995   case S_NOT_CONNECTED:
2996     GNUNET_break (0);
2997     free_neighbour (n, GNUNET_NO);
2998     return GNUNET_YES;
2999   case S_INIT_ATS:
3000     GNUNET_break (0);
3001     free_neighbour (n, GNUNET_NO);
3002     return GNUNET_YES;
3003   case S_INIT_BLACKLIST:
3004   case S_CONNECT_SENT:
3005     free_address (&n->primary_address);
3006     n->state = S_INIT_ATS;
3007     n->timeout = GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT);
3008     // FIXME: need to ask ATS for suggestions again?
3009     n->suggest_handle = GNUNET_ATS_suggest_address (GST_ats, &n->id);
3010     break;
3011   case S_CONNECT_RECV_BLACKLIST_INBOUND:
3012   case S_CONNECT_RECV_ATS:
3013   case S_CONNECT_RECV_BLACKLIST:
3014   case S_CONNECT_RECV_ACK:
3015     /* error on inbound session; free neighbour entirely */
3016     free_address (&n->primary_address);
3017     free_neighbour (n, GNUNET_NO);
3018     return GNUNET_YES;
3019   case S_CONNECTED:
3020     free_address (&n->primary_address);
3021     n->state = S_RECONNECT_ATS;
3022     n->timeout = GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT);
3023     /* FIXME: is this ATS call needed? */
3024     n->suggest_handle = GNUNET_ATS_suggest_address (GST_ats, &n->id);
3025     break;
3026   case S_RECONNECT_ATS:
3027     /* we don't have an address, how can it go down? */
3028     GNUNET_break (0);
3029     break;
3030   case S_RECONNECT_BLACKLIST:
3031   case S_RECONNECT_SENT:
3032     n->state = S_RECONNECT_ATS;
3033     n->timeout = GNUNET_TIME_relative_to_absolute (ATS_RESPONSE_TIMEOUT);
3034     // FIXME: need to ask ATS for suggestions again?
3035     n->suggest_handle = GNUNET_ATS_suggest_address (GST_ats, &n->id);
3036     break;
3037   case S_CONNECTED_SWITCHING_BLACKLIST:
3038     /* primary went down while we were checking secondary against
3039        blacklist, adopt secondary as primary */
3040     free_address (&n->primary_address);
3041     n->primary_address = n->alternative_address;
3042     memset (&n->alternative_address, 0, sizeof (struct NeighbourAddress));
3043     n->timeout = GNUNET_TIME_relative_to_absolute (FAST_RECONNECT_TIMEOUT);
3044     n->state = S_RECONNECT_BLACKLIST;
3045     break;
3046   case S_CONNECTED_SWITCHING_CONNECT_SENT:
3047     /* primary went down while we were waiting for CONNECT_ACK on secondary;
3048        secondary as primary */
3049     free_address (&n->primary_address);
3050     n->primary_address = n->alternative_address;
3051     memset (&n->alternative_address, 0, sizeof (struct NeighbourAddress));
3052     n->timeout = GNUNET_TIME_relative_to_absolute (FAST_RECONNECT_TIMEOUT);
3053     n->state = S_RECONNECT_SENT;
3054     break;
3055   case S_DISCONNECT:
3056     free_address (&n->primary_address);
3057     break;
3058   case S_DISCONNECT_FINISHED:
3059     /* neighbour was freed and plugins told to terminate session */
3060     return GNUNET_NO;
3061     break;
3062   default:
3063     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3064                 "Unhandled state `%s'\n",
3065                 print_state (n->state));
3066     GNUNET_break (0);
3067     break;
3068   }
3069   if (GNUNET_SCHEDULER_NO_TASK != n->task)
3070     GNUNET_SCHEDULER_cancel (n->task);
3071   n->task = GNUNET_SCHEDULER_add_now (&master_task, n);
3072   return GNUNET_YES;
3073 }
3074
3075
3076 /**
3077  * We received a 'SESSION_ACK' message from the other peer.
3078  * If we sent a 'CONNECT_ACK' last, this means we are now
3079  * connected.  Otherwise, do nothing.
3080  *
3081  * @param message possibly a 'struct SessionConnectMessage' (check format)
3082  * @param peer identity of the peer to switch the address for
3083  * @param address address of the other peer, NULL if other peer
3084  *                       connected to us
3085  * @param session session to use (or NULL)
3086  * @return #GNUNET_OK if the message was fine, #GNUNET_SYSERR on serious error
3087  */
3088 int
3089 GST_neighbours_handle_session_ack (const struct GNUNET_MessageHeader *message,
3090                                    const struct GNUNET_PeerIdentity *peer,
3091                                    const struct GNUNET_HELLO_Address *address,
3092                                    struct Session *session)
3093 {
3094   struct NeighbourMapEntry *n;
3095
3096   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3097               "Received SESSION_ACK message from peer `%s'\n",
3098               GNUNET_i2s (peer));
3099   if (ntohs (message->size) != sizeof (struct GNUNET_MessageHeader))
3100   {
3101     GNUNET_break_op (0);
3102     return GNUNET_SYSERR;
3103   }
3104   GNUNET_STATISTICS_update (GST_stats,
3105                             gettext_noop
3106                             ("# SESSION_ACK messages received"),
3107                             1, GNUNET_NO);
3108   if (NULL == (n = lookup_neighbour (peer)))
3109     return GNUNET_SYSERR;
3110   /* check if we are in a plausible state for having sent
3111      a CONNECT_ACK.  If not, return, otherwise break */
3112   if ( ( (S_CONNECT_RECV_ACK != n->state) &&
3113          (S_CONNECT_SENT != n->state) ) ||
3114        (2 != n->send_connect_ack) )
3115   {
3116     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3117                 "Received SESSION_ACK message from peer `%s' in state %s/%d\n",
3118                 GNUNET_i2s (peer),
3119                 print_state (n->state),
3120                 n->send_connect_ack);
3121     GNUNET_STATISTICS_update (GST_stats,
3122                               gettext_noop ("# unexpected SESSION_ACK messages"), 1,
3123                               GNUNET_NO);
3124     return GNUNET_SYSERR;
3125   }
3126   n->state = S_CONNECTED;
3127   n->timeout = GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT);
3128   GNUNET_STATISTICS_set (GST_stats,
3129                          gettext_noop ("# peers connected"),
3130                          ++neighbours_connected,
3131                          GNUNET_NO);
3132   connect_notify_cb (callback_cls, &n->id,
3133                      n->primary_address.bandwidth_in,
3134                      n->primary_address.bandwidth_out);
3135
3136   GST_ats_add_address (n->primary_address.address, n->primary_address.session);
3137   set_address (&n->primary_address,
3138                n->primary_address.address,
3139                n->primary_address.session,
3140                n->primary_address.bandwidth_in,
3141                n->primary_address.bandwidth_out,
3142                GNUNET_YES);
3143   return GNUNET_OK;
3144 }
3145
3146
3147 /**
3148  * Test if we're connected to the given peer.
3149  *
3150  * @param target peer to test
3151  * @return #GNUNET_YES if we are connected, #GNUNET_NO if not
3152  */
3153 int
3154 GST_neighbours_test_connected (const struct GNUNET_PeerIdentity *target)
3155 {
3156   return test_connected (lookup_neighbour (target));
3157 }
3158
3159
3160 /**
3161  * Change the incoming quota for the given peer.
3162  *
3163  * @param neighbour identity of peer to change qutoa for
3164  * @param quota new quota
3165  */
3166 void
3167 GST_neighbours_set_incoming_quota (const struct GNUNET_PeerIdentity *neighbour,
3168                                    struct GNUNET_BANDWIDTH_Value32NBO quota)
3169 {
3170   struct NeighbourMapEntry *n;
3171
3172   if (NULL == (n = lookup_neighbour (neighbour)))
3173   {
3174     GNUNET_STATISTICS_update (GST_stats,
3175                               gettext_noop
3176                               ("# SET QUOTA messages ignored (no such peer)"),
3177                               1, GNUNET_NO);
3178     return;
3179   }
3180   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3181               "Setting inbound quota of %u Bps for peer `%s' to all clients\n",
3182               ntohl (quota.value__), GNUNET_i2s (&n->id));
3183   GNUNET_BANDWIDTH_tracker_update_quota (&n->in_tracker, quota);
3184   if (0 != ntohl (quota.value__))
3185     return;
3186   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Disconnecting peer `%4s' due to `%s'\n",
3187               GNUNET_i2s (&n->id), "SET_QUOTA");
3188   if (GNUNET_YES == test_connected (n))
3189     GNUNET_STATISTICS_update (GST_stats,
3190                               gettext_noop ("# disconnects due to quota of 0"),
3191                               1, GNUNET_NO);
3192   disconnect_neighbour (n);
3193 }
3194
3195
3196 /**
3197  * We received a disconnect message from the given peer,
3198  * validate and process.
3199  *
3200  * @param peer sender of the message
3201  * @param msg the disconnect message
3202  */
3203 void
3204 GST_neighbours_handle_disconnect_message (const struct GNUNET_PeerIdentity
3205                                           *peer,
3206                                           const struct GNUNET_MessageHeader
3207                                           *msg)
3208 {
3209   struct NeighbourMapEntry *n;
3210   const struct SessionDisconnectMessage *sdm;
3211
3212   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3213               "Received DISCONNECT message from peer `%s'\n",
3214               GNUNET_i2s (peer));
3215   if (ntohs (msg->size) != sizeof (struct SessionDisconnectMessage))
3216   {
3217     // GNUNET_break_op (0);
3218     GNUNET_STATISTICS_update (GST_stats,
3219                               gettext_noop
3220                               ("# disconnect messages ignored (old format)"), 1,
3221                               GNUNET_NO);
3222     return;
3223   }
3224   GNUNET_STATISTICS_update (GST_stats,
3225                             gettext_noop
3226                             ("# DISCONNECT messages received"),
3227                             1, GNUNET_NO);
3228   sdm = (const struct SessionDisconnectMessage *) msg;
3229   if (NULL == (n = lookup_neighbour (peer)))
3230     return;                     /* gone already */
3231   if (GNUNET_TIME_absolute_ntoh (sdm->timestamp).abs_value_us <= n->connect_ack_timestamp.abs_value_us)
3232   {
3233     GNUNET_STATISTICS_update (GST_stats,
3234                               gettext_noop
3235                               ("# disconnect messages ignored (timestamp)"), 1,
3236                               GNUNET_NO);
3237     return;
3238   }
3239   if (0 != memcmp (peer, &sdm->public_key, sizeof (struct GNUNET_PeerIdentity)))
3240   {
3241     GNUNET_break_op (0);
3242     return;
3243   }
3244   if (ntohl (sdm->purpose.size) !=
3245       sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
3246       sizeof (struct GNUNET_CRYPTO_EddsaPublicKey) +
3247       sizeof (struct GNUNET_TIME_AbsoluteNBO))
3248   {
3249     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
3250                 "%s message from peer `%s' has invalid size \n",
3251                 "DISCONNECT",
3252                 GNUNET_i2s (peer));
3253     GNUNET_break_op (0);
3254     return;
3255   }
3256   if (GNUNET_OK !=
3257       GNUNET_CRYPTO_eddsa_verify
3258       (GNUNET_MESSAGE_TYPE_TRANSPORT_SESSION_DISCONNECT, &sdm->purpose,
3259        &sdm->signature, &sdm->public_key))
3260   {
3261     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
3262                 "%s message from peer `%s' cannot be verified \n",
3263                 "DISCONNECT",
3264                 GNUNET_i2s (peer));
3265     GNUNET_break_op (0);
3266     return;
3267   }
3268   if (GNUNET_YES == test_connected (n))
3269     GNUNET_STATISTICS_update (GST_stats,
3270                               gettext_noop
3271                               ("# other peer asked to disconnect from us"), 1,
3272                               GNUNET_NO);
3273   disconnect_neighbour (n);
3274 }
3275
3276
3277 /**
3278  * Closure for the neighbours_iterate function.
3279  */
3280 struct IteratorContext
3281 {
3282   /**
3283    * Function to call on each connected neighbour.
3284    */
3285   GST_NeighbourIterator cb;
3286
3287   /**
3288    * Closure for 'cb'.
3289    */
3290   void *cb_cls;
3291 };
3292
3293
3294 /**
3295  * Call the callback from the closure for each connected neighbour.
3296  *
3297  * @param cls the `struct IteratorContext`
3298  * @param key the hash of the public key of the neighbour
3299  * @param value the `struct NeighbourMapEntry`
3300  * @return #GNUNET_OK (continue to iterate)
3301  */
3302 static int
3303 neighbours_iterate (void *cls,
3304                     const struct GNUNET_PeerIdentity *key,
3305                     void *value)
3306 {
3307   struct IteratorContext *ic = cls;
3308   struct NeighbourMapEntry *n = value;
3309   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in;
3310   struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out;
3311
3312   if (GNUNET_YES != test_connected (n))
3313     return GNUNET_OK;
3314
3315   if (NULL != n->primary_address.address)
3316   {
3317     bandwidth_in = n->primary_address.bandwidth_in;
3318     bandwidth_out = n->primary_address.bandwidth_out;
3319   }
3320   else
3321   {
3322     bandwidth_in = GNUNET_CONSTANTS_DEFAULT_BW_IN_OUT;
3323     bandwidth_out = GNUNET_CONSTANTS_DEFAULT_BW_IN_OUT;
3324   }
3325   ic->cb (ic->cb_cls, &n->id,
3326           n->primary_address.address,
3327           bandwidth_in, bandwidth_out);
3328   return GNUNET_OK;
3329 }
3330
3331
3332 /**
3333  * Iterate over all connected neighbours.
3334  *
3335  * @param cb function to call
3336  * @param cb_cls closure for cb
3337  */
3338 void
3339 GST_neighbours_iterate (GST_NeighbourIterator cb, void *cb_cls)
3340 {
3341   struct IteratorContext ic;
3342
3343   if (NULL == neighbours)
3344     return; /* can happen during shutdown */
3345   ic.cb = cb;
3346   ic.cb_cls = cb_cls;
3347   GNUNET_CONTAINER_multipeermap_iterate (neighbours, &neighbours_iterate, &ic);
3348 }
3349
3350
3351 /**
3352  * If we have an active connection to the given target, it must be shutdown.
3353  *
3354  * @param target peer to disconnect from
3355  */
3356 void
3357 GST_neighbours_force_disconnect (const struct GNUNET_PeerIdentity *target)
3358 {
3359   struct NeighbourMapEntry *n;
3360
3361   if (NULL == (n = lookup_neighbour (target)))
3362     return;  /* not active */
3363   if (GNUNET_YES == test_connected (n))
3364     GNUNET_STATISTICS_update (GST_stats,
3365                               gettext_noop
3366                               ("# disconnected from peer upon explicit request"), 1,
3367                               GNUNET_NO);
3368   disconnect_neighbour (n);
3369 }
3370
3371
3372 /**
3373  * Obtain current latency information for the given neighbour.
3374  *
3375  * @param peer to get the latency for
3376  * @return observed latency of the address, FOREVER if the
3377  *         the connection is not up
3378  */
3379 struct GNUNET_TIME_Relative
3380 GST_neighbour_get_latency (const struct GNUNET_PeerIdentity *peer)
3381 {
3382   struct NeighbourMapEntry *n;
3383
3384   n = lookup_neighbour (peer);
3385   if (NULL == n)
3386     return GNUNET_TIME_UNIT_FOREVER_REL;
3387   switch (n->state)
3388   {
3389   case S_CONNECTED:
3390   case S_CONNECTED_SWITCHING_CONNECT_SENT:
3391   case S_CONNECTED_SWITCHING_BLACKLIST:
3392   case S_RECONNECT_SENT:
3393   case S_RECONNECT_ATS:
3394   case S_RECONNECT_BLACKLIST:
3395     return n->latency;
3396   case S_NOT_CONNECTED:
3397   case S_INIT_BLACKLIST:
3398   case S_INIT_ATS:
3399   case S_CONNECT_RECV_BLACKLIST_INBOUND:
3400   case S_CONNECT_RECV_ATS:
3401   case S_CONNECT_RECV_BLACKLIST:
3402   case S_CONNECT_RECV_ACK:
3403   case S_CONNECT_SENT:
3404   case S_DISCONNECT:
3405   case S_DISCONNECT_FINISHED:
3406     return GNUNET_TIME_UNIT_FOREVER_REL;
3407   default:
3408     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3409                 "Unhandled state `%s'\n",
3410                 print_state (n->state));
3411     GNUNET_break (0);
3412     break;
3413   }
3414   return GNUNET_TIME_UNIT_FOREVER_REL;
3415 }
3416
3417
3418 /**
3419  * Obtain current address information for the given neighbour.
3420  *
3421  * @param peer
3422  * @return address currently used
3423  */
3424 struct GNUNET_HELLO_Address *
3425 GST_neighbour_get_current_address (const struct GNUNET_PeerIdentity *peer)
3426 {
3427   struct NeighbourMapEntry *n;
3428
3429   n = lookup_neighbour (peer);
3430   if (NULL == n)
3431     return NULL;
3432   return n->primary_address.address;
3433 }
3434
3435
3436 /**
3437  * Initialize the neighbours subsystem.
3438  *
3439  * @param cls closure for callbacks
3440  * @param connect_cb function to call if we connect to a peer
3441  * @param disconnect_cb function to call if we disconnect from a peer
3442  * @param peer_address_cb function to call if we change an active address
3443  *                   of a neighbour
3444  * @param max_fds maximum number of fds to use
3445  */
3446 void
3447 GST_neighbours_start (void *cls,
3448                       NotifyConnect connect_cb,
3449                       GNUNET_TRANSPORT_NotifyDisconnect disconnect_cb,
3450                       GNUNET_TRANSPORT_PeerIterateCallback peer_address_cb,
3451                       unsigned int max_fds)
3452 {
3453   callback_cls = cls;
3454   connect_notify_cb = connect_cb;
3455   disconnect_notify_cb = disconnect_cb;
3456   address_change_cb = peer_address_cb;
3457   neighbours = GNUNET_CONTAINER_multipeermap_create (NEIGHBOUR_TABLE_SIZE, GNUNET_NO);
3458   util_transmission_tk = GNUNET_SCHEDULER_add_delayed (UTIL_TRANSMISSION_INTERVAL,
3459       utilization_transmission, NULL);
3460 }
3461
3462
3463 /**
3464  * Disconnect from the given neighbour.
3465  *
3466  * @param cls unused
3467  * @param key hash of neighbour's public key (not used)
3468  * @param value the 'struct NeighbourMapEntry' of the neighbour
3469  * @return #GNUNET_OK (continue to iterate)
3470  */
3471 static int
3472 disconnect_all_neighbours (void *cls,
3473                            const struct GNUNET_PeerIdentity *key,
3474                            void *value)
3475 {
3476   struct NeighbourMapEntry *n = value;
3477
3478   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3479               "Disconnecting peer `%4s', %s\n",
3480               GNUNET_i2s (&n->id), "SHUTDOWN_TASK");
3481   n->state = S_DISCONNECT_FINISHED;
3482   free_neighbour (n, GNUNET_NO);
3483   return GNUNET_OK;
3484 }
3485
3486
3487 /**
3488  * Cleanup the neighbours subsystem.
3489  */
3490 void
3491 GST_neighbours_stop ()
3492 {
3493   if (NULL == neighbours)
3494     return;
3495   if (GNUNET_SCHEDULER_NO_TASK != util_transmission_tk)
3496   {
3497     GNUNET_SCHEDULER_cancel (util_transmission_tk);
3498     util_transmission_tk = GNUNET_SCHEDULER_NO_TASK;
3499   }
3500
3501   GNUNET_CONTAINER_multipeermap_iterate (neighbours,
3502                                          &disconnect_all_neighbours,
3503                                          NULL);
3504   GNUNET_CONTAINER_multipeermap_destroy (neighbours);
3505   neighbours = NULL;
3506   callback_cls = NULL;
3507   connect_notify_cb = NULL;
3508   disconnect_notify_cb = NULL;
3509   address_change_cb = NULL;
3510 }
3511
3512
3513 /* end of file gnunet-service-transport_neighbours.c */