src/transport/transport_api.c

   1 /*
   2      This file is part of GNUnet.
   3      (C) 2009 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 2, 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/transport_api.c
  23  * @brief library to access the low-level P2P IO service
  24  * @author Christian Grothoff
  25  *
  26  * TODO:
  27  * - set_quota with low bandwidth should cause peer
  28  *   disconnects (currently never does that) (MINOR)
  29  */
  30 #include "platform.h"
  31 #include "gnunet_client_lib.h"
  32 #include "gnunet_arm_service.h"
  33 #include "gnunet_hello_lib.h"
  34 #include "gnunet_protocols.h"
  35 #include "gnunet_server_lib.h"
  36 #include "gnunet_time_lib.h"
  37 #include "gnunet_transport_service.h"
  38 #include "transport.h"
  39
  40 /**
  41  * After how long do we give up on transmitting a HELLO
  42  * to the service?
  43  */
  44 #define OFFER_HELLO_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 30)
  45
  46 /**
  47  * After how long do we give automatically retry an unsuccessful
  48  * CONNECT request?
  49  */
  50 #define CONNECT_RETRY_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 750)
  51
  52 /**
  53  * How long should ARM wait when starting up the
  54  * transport service before reporting back?
  55  */
  56 #define START_SERVICE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
  57
  58 /**
  59  * How long should ARM wait when stopping the
  60  * transport service before reporting back?
  61  */
  62 #define STOP_SERVICE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
  63
  64 /**
  65  * Entry in linked list of all of our current neighbours.
  66  */
  67 struct NeighbourList
  68 {
  69
  70   /**
  71    * This is a linked list.
  72    */
  73   struct NeighbourList *next;
  74
  75   /**
  76    * Active transmit handle, can be NULL.  Used to move
  77    * from ready to wait list on disconnect and to block
  78    * two transmissions to the same peer from being scheduled
  79    * at the same time.
  80    */
  81   struct GNUNET_TRANSPORT_TransmitHandle *transmit_handle;
  82
  83
  84   /**
  85    * Identity of this neighbour.
  86    */
  87   struct GNUNET_PeerIdentity id;
  88
  89   /**
  90    * At what time did we reset last_sent last?
  91    */
  92   struct GNUNET_TIME_Absolute last_quota_update;
  93
  94   /**
  95    * How many bytes have we sent since the "last_quota_update"
  96    * timestamp?
  97    */
  98   uint64_t last_sent;
  99
 100   /**
 101    * Quota for outbound traffic to the neighbour in bytes/ms.
 102    */
 103   uint32_t quota_out;
 104
 105   /**
 106    * Set to GNUNET_YES if we are currently allowed to
 107    * transmit a message to the transport service for this
 108    * peer, GNUNET_NO otherwise.
 109    */
 110   int transmit_ok;
 111
 112   /**
 113    * Set to GNUNET_YES if we have received an ACK for the
 114    * given peer.  Peers that receive our HELLO always respond
 115    * with an ACK to let us know that we are successfully
 116    * communicating.  Note that a PING can not be used for this
 117    * since PINGs are only send if a HELLO address requires
 118    * confirmation (and also, PINGs are not passed to the
 119    * transport API itself).
 120    */
 121   int received_ack;
 122
 123 };
 124
 125
 126 /**
 127  * Linked list of requests from clients for our HELLO
 128  * that were deferred.
 129  */
 130 struct HelloWaitList
 131 {
 132
 133   /**
 134    * This is a linked list.
 135    */
 136   struct HelloWaitList *next;
 137
 138   /**
 139    * Reference back to our transport handle.
 140    */
 141   struct GNUNET_TRANSPORT_Handle *handle;
 142
 143   /**
 144    * Callback to call once we got our HELLO.
 145    */
 146   GNUNET_TRANSPORT_ReceiveCallback rec;
 147
 148   /**
 149    * Closure for rec.
 150    */
 151   void *rec_cls;
 152
 153   /**
 154    * When to time out (call rec with NULL).
 155    */
 156   struct GNUNET_TIME_Absolute timeout;
 157
 158   /**
 159    * Timeout task (used to trigger timeout,
 160    * cancel if we get the HELLO in time).
 161    */
 162   GNUNET_SCHEDULER_TaskIdentifier task;
 163
 164
 165 };
 166
 167
 168 /**
 169  * Opaque handle for a transmission-ready request.
 170  */
 171 struct GNUNET_TRANSPORT_TransmitHandle
 172 {
 173
 174   /**
 175    * We keep the transmit handles that are waiting for
 176    * a transport-level connection in a doubly linked list.
 177    */
 178   struct GNUNET_TRANSPORT_TransmitHandle *next;
 179
 180   /**
 181    * We keep the transmit handles that are waiting for
 182    * a transport-level connection in a doubly linked list.
 183    */
 184   struct GNUNET_TRANSPORT_TransmitHandle *prev;
 185
 186   /**
 187    * Handle of the main transport data structure.
 188    */
 189   struct GNUNET_TRANSPORT_Handle *handle;
 190
 191   /**
 192    * Neighbour for this handle, can be NULL if the service
 193    * is not yet connected to the target.
 194    */
 195   struct NeighbourList *neighbour;
 196
 197   /**
 198    * Which peer is this transmission going to be for?  All
 199    * zeros if it is control-traffic to the service.
 200    */
 201   struct GNUNET_PeerIdentity target;
 202
 203   /**
 204    * Function to call when notify_size bytes are available
 205    * for transmission.
 206    */
 207   GNUNET_NETWORK_TransmitReadyNotify notify;
 208
 209   /**
 210    * Closure for notify.
 211    */
 212   void *notify_cls;
 213
 214   /**
 215    * transmit_ready task Id.  The task is used to introduce the
 216    * artificial delay that may be required to maintain the bandwidth
 217    * limits.  Later, this will be the ID of the "transmit_timeout"
 218    * task which is used to signal a timeout if the transmission could
 219    * not be done in a timely fashion.
 220    */
 221   GNUNET_SCHEDULER_TaskIdentifier notify_delay_task;
 222
 223   /**
 224    * Timeout for this request.
 225    */
 226   struct GNUNET_TIME_Absolute timeout;
 227
 228   /**
 229    * How many bytes is our notify callback waiting for?
 230    */
 231   size_t notify_size;
 232
 233   /**
 234    * How important is this message?
 235    */
 236   unsigned int priority;
 237
 238 };
 239
 240
 241 /**
 242  * Handle for the transport service (includes all of the
 243  * state for the transport service).
 244  */
 245 struct GNUNET_TRANSPORT_Handle
 246 {
 247
 248   /**
 249    * Closure for the callbacks.
 250    */
 251   void *cls;
 252
 253   /**
 254    * Function to call for received data.
 255    */
 256   GNUNET_TRANSPORT_ReceiveCallback rec;
 257
 258   /**
 259    * function to call on connect events
 260    */
 261   GNUNET_TRANSPORT_NotifyConnect nc_cb;
 262
 263   /**
 264    * function to call on disconnect events
 265    */
 266   GNUNET_TRANSPORT_NotifyDisconnect nd_cb;
 267
 268   /**
 269    * The current HELLO message for this peer.  Updated
 270    * whenever transports change their addresses.
 271    */
 272   struct GNUNET_HELLO_Message *my_hello;
 273
 274   /**
 275    * My client connection to the transport service.
 276    */
 277   struct GNUNET_CLIENT_Connection *client;
 278
 279   /**
 280    * Handle to our registration with the client for notification.
 281    */
 282   struct GNUNET_NETWORK_TransmitHandle *network_handle;
 283
 284   /**
 285    * Linked list of transmit handles that are waiting for the
 286    * transport to connect to the respective peer.  When we
 287    * receive notification that the transport connected to a
 288    * peer, we go over this list and check if someone has already
 289    * requested a transmission to the new peer; if so, we trigger
 290    * the next step.
 291    */
 292   struct GNUNET_TRANSPORT_TransmitHandle *connect_wait_head;
 293
 294   /**
 295    * Linked list of transmit handles that are waiting for the
 296    * transport to be ready for transmission to the respective
 297    * peer.  When we
 298    * receive notification that the transport disconnected from
 299    * a peer, we go over this list and move the entry back to
 300    * the connect_wait list.
 301    */
 302   struct GNUNET_TRANSPORT_TransmitHandle *connect_ready_head;
 303
 304   /**
 305    * Linked list of pending requests for our HELLO.
 306    */
 307   struct HelloWaitList *hwl_head;
 308
 309   /**
 310    * My scheduler.
 311    */
 312   struct GNUNET_SCHEDULER_Handle *sched;
 313
 314   /**
 315    * My configuration.
 316    */
 317   struct GNUNET_CONFIGURATION_Handle *cfg;
 318
 319   /**
 320    * Linked list of the current neighbours of this peer.
 321    */
 322   struct NeighbourList *neighbours;
 323
 324   /**
 325    * ID of the task trying to reconnect to the
 326    * service.
 327    */
 328   GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
 329
 330   /**
 331    * Delay until we try to reconnect.
 332    */
 333   struct GNUNET_TIME_Relative reconnect_delay;
 334
 335   /**
 336    * Do we currently have a transmission pending?
 337    * (schedule transmission was called but has not
 338    * yet succeeded)?
 339    */
 340   int transmission_scheduled;
 341 };
 342
 343
 344 static struct NeighbourList *
 345 find_neighbour (struct GNUNET_TRANSPORT_Handle *h,
 346                 const struct GNUNET_PeerIdentity *peer)
 347 {
 348   struct NeighbourList *pos;
 349
 350   pos = h->neighbours;
 351   while ((pos != NULL) &&
 352          (0 != memcmp (peer, &pos->id, sizeof (struct GNUNET_PeerIdentity))))
 353     pos = pos->next;
 354   return pos;
 355 }
 356
 357
 358 /**
 359  * Schedule the task to send one message from the
 360  * connect_ready list to the service.
 361  */
 362 static void schedule_transmission (struct GNUNET_TRANSPORT_Handle *h);
 363
 364
 365 /**
 366  * Transmit message to client...
 367  */
 368 static size_t
 369 transport_notify_ready (void *cls, size_t size, void *buf)
 370 {
 371   struct GNUNET_TRANSPORT_Handle *h = cls;
 372   struct GNUNET_TRANSPORT_TransmitHandle *th;
 373   struct NeighbourList *n;
 374   size_t ret;
 375   char *cbuf;
 376
 377   h->network_handle = NULL;
 378   h->transmission_scheduled = GNUNET_NO;
 379   if (buf == NULL)
 380     {
 381 #if DEBUG_TRANSPORT
 382       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 383                   "Could not transmit to transport service, cancelling pending requests\n");
 384 #endif
 385       th = h->connect_ready_head;
 386       if (th->next != NULL)
 387         th->next->prev = NULL;
 388       h->connect_ready_head = th->next;
 389       if (NULL != (n = th->neighbour))
 390         {
 391           GNUNET_assert (n->transmit_handle == th);
 392           n->transmit_handle = NULL;
 393         }
 394       GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
 395       GNUNET_free (th);
 396       return 0;
 397     }
 398 #if DEBUG_TRANSPORT
 399   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 400               "Ready to transmit %u bytes to transport service\n", size);
 401 #endif
 402   cbuf = buf;
 403   ret = 0;
 404   h->network_handle = NULL;
 405   h->transmission_scheduled = GNUNET_NO;
 406   do
 407     {
 408       th = h->connect_ready_head;
 409       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
 410         {
 411           /* remove existing time out task (only applies if
 412              this is not the first iteration of the loop) */
 413           GNUNET_SCHEDULER_cancel (h->sched,
 414                                    th->notify_delay_task);
 415           th->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
 416         }
 417       GNUNET_assert (th->notify_size <= size);
 418       if (th->next != NULL)
 419         th->next->prev = NULL;
 420       h->connect_ready_head = th->next;
 421       if (NULL != (n = th->neighbour))
 422         {
 423           GNUNET_assert (n->transmit_handle == th);
 424           n->transmit_handle = NULL;
 425         }
 426       ret += th->notify (th->notify_cls, size, &cbuf[ret]);
 427       GNUNET_free (th);
 428       if (n != NULL)
 429         n->last_sent += ret;
 430       size -= ret;
 431     }
 432   while ((h->connect_ready_head != NULL) &&
 433          (h->connect_ready_head->notify_size <= size));
 434   if (h->connect_ready_head != NULL)
 435     schedule_transmission (h);
 436 #if DEBUG_TRANSPORT
 437   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 438               "Transmitting %u bytes to transport service\n", ret);
 439 #endif
 440   return ret;
 441 }
 442
 443
 444 /**
 445  * Schedule the task to send one message from the
 446  * connect_ready list to the service.
 447  */
 448 static void
 449 schedule_transmission (struct GNUNET_TRANSPORT_Handle *h)
 450 {
 451   struct GNUNET_TRANSPORT_TransmitHandle *th;
 452
 453   GNUNET_assert (NULL == h->network_handle);
 454   if (h->client == NULL)
 455     {
 456       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 457                   "Could not yet schedule transmission: we are not yet connected to the transport service!\n");
 458       return; /* not yet connected */
 459     }
 460   th = h->connect_ready_head;
 461   if (th == NULL)
 462     return; /* no request pending */
 463   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
 464     {
 465       /* remove existing time out task, will be integrated
 466          with transmit_ready notification! */
 467       GNUNET_SCHEDULER_cancel (h->sched,
 468                                th->notify_delay_task);
 469       th->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
 470     }
 471   h->transmission_scheduled = GNUNET_YES;
 472   h->network_handle = GNUNET_CLIENT_notify_transmit_ready (h->client,
 473                                                            th->notify_size,
 474                                                            GNUNET_TIME_absolute_get_remaining
 475                                                            (th->timeout),
 476                                                            &transport_notify_ready,
 477                                                            h);
 478   GNUNET_assert (NULL != h->network_handle);
 479 }
 480
 481
 482 /**
 483  * Insert the given transmit handle in the given sorted
 484  * doubly linked list based on timeout.
 485  *
 486  * @param head pointer to the head of the linked list
 487  * @param th element to insert into the list
 488  */
 489 static void
 490 insert_transmit_handle (struct GNUNET_TRANSPORT_TransmitHandle **head,
 491                         struct GNUNET_TRANSPORT_TransmitHandle *th)
 492 {
 493   struct GNUNET_TRANSPORT_TransmitHandle *pos;
 494   struct GNUNET_TRANSPORT_TransmitHandle *prev;
 495
 496   pos = *head;
 497   prev = NULL;
 498   while ((pos != NULL) && (pos->timeout.value < th->timeout.value))
 499     {
 500       prev = pos;
 501       pos = pos->next;
 502     }
 503   if (prev == NULL)
 504     {
 505       th->next = *head;
 506       if (th->next != NULL)
 507         th->next->prev = th;
 508       *head = th;
 509     }
 510   else
 511     {
 512       th->next = pos;
 513       th->prev = prev;
 514       prev->next = th;
 515       if (pos != NULL)
 516         pos->prev = th;
 517     }
 518 }
 519
 520
 521 /**
 522  * Cancel a pending notify delay task (if pending) and also remove the
 523  * given transmit handle from whatever list is on.
 524  *
 525  * @param th handle for the transmission request to manipulate
 526  */
 527 static void
 528 remove_from_any_list (struct GNUNET_TRANSPORT_TransmitHandle *th)
 529 {
 530   struct GNUNET_TRANSPORT_Handle *h;
 531
 532   h = th->handle;
 533   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
 534     {
 535       GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
 536       th->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
 537     }
 538   if (th->prev == NULL)
 539     {
 540       if (th == h->connect_wait_head)
 541         h->connect_wait_head = th->next;
 542       else
 543         h->connect_ready_head = th->next;
 544     }
 545   else
 546     {
 547       th->prev->next = th->next;
 548     }
 549   if (th->next != NULL)
 550     th->next->prev = th->prev;
 551 }
 552
 553
 554 /**
 555  * Schedule a request to connect to the given
 556  * neighbour (and if successful, add the specified
 557  * handle to the wait list).
 558  *
 559  * @param th handle for a request to transmit once we
 560  *        have connected
 561  */
 562 static void
 563 try_connect (struct GNUNET_TRANSPORT_TransmitHandle *th);
 564
 565
 566 /**
 567  * Called when our transmit request timed out before any transport
 568  * reported success connecting to the desired peer or before the
 569  * transport was ready to receive.  Signal error and free
 570  * TransmitHandle.
 571  */
 572 static void
 573 transmit_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 574 {
 575   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
 576
 577   th->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
 578   if (th->neighbour != NULL)
 579     th->neighbour->transmit_handle = NULL;
 580 #if DEBUG_TRANSPORT
 581   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 582               "Request for transmission to peer `%s' timed out.\n",
 583               GNUNET_i2s(&th->target));
 584 #endif
 585   remove_from_any_list (th);
 586   th->notify (th->notify_cls, 0, NULL);
 587   GNUNET_free (th);
 588 }
 589
 590
 591
 592
 593 /**
 594  * Queue control request for transmission to the transport
 595  * service.
 596  *
 597  * @param size number of bytes to be transmitted
 598  * @param at_head request must be added to the head of the queue
 599  *        (otherwise request will be appended)
 600  * @param timeout how long this transmission can wait (at most)
 601  * @param notify function to call to get the content
 602  * @param notify_cls closure for notify
 603  */
 604 static void
 605 schedule_control_transmit (struct GNUNET_TRANSPORT_Handle *h,
 606                            size_t size,
 607                            int at_head,
 608                            struct GNUNET_TIME_Relative timeout,
 609                            GNUNET_NETWORK_TransmitReadyNotify notify,
 610                            void *notify_cls)
 611 {
 612   struct GNUNET_TRANSPORT_TransmitHandle *th;
 613
 614   th = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_TransmitHandle));
 615   th->handle = h;
 616   th->notify = notify;
 617   th->notify_cls = notify_cls;
 618   th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 619   th->notify_size = size;
 620   th->notify_delay_task
 621     = GNUNET_SCHEDULER_add_delayed (h->sched,
 622                                     GNUNET_NO,
 623                                     GNUNET_SCHEDULER_PRIORITY_KEEP,
 624                                     GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
 625                                     timeout,
 626                                     &transmit_timeout, th);
 627   if (at_head)
 628     {
 629       th->next = h->connect_ready_head;
 630       h->connect_ready_head = th;
 631       if (th->next != NULL)
 632         th->next->prev = th;
 633     }
 634   else
 635     {
 636       insert_transmit_handle (&h->connect_ready_head, th);
 637     }
 638   if (GNUNET_NO == h->transmission_scheduled)
 639     schedule_transmission (h);
 640 }
 641
 642
 643 /**
 644  * Update the quota values for the given neighbour now.
 645  */
 646 static void
 647 update_quota (struct NeighbourList *n)
 648 {
 649   struct GNUNET_TIME_Relative delta;
 650   uint64_t allowed;
 651   uint64_t remaining;
 652
 653   delta = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
 654   allowed = delta.value * n->quota_out;
 655   if (n->last_sent < allowed)
 656     {
 657       remaining = allowed - n->last_sent;
 658       if (n->quota_out > 0)
 659         remaining /= n->quota_out;
 660       else
 661         remaining = 0;
 662       if (remaining > MAX_BANDWIDTH_CARRY)
 663         remaining = MAX_BANDWIDTH_CARRY;
 664       n->last_sent = 0;
 665       n->last_quota_update = GNUNET_TIME_absolute_get ();
 666       n->last_quota_update.value -= remaining;
 667     }
 668   else
 669     {
 670       n->last_sent -= allowed;
 671       n->last_quota_update = GNUNET_TIME_absolute_get ();
 672     }
 673 }
 674
 675
 676 struct SetQuotaContext
 677 {
 678   struct GNUNET_TRANSPORT_Handle *handle;
 679
 680   struct GNUNET_PeerIdentity target;
 681
 682   GNUNET_SCHEDULER_Task cont;
 683
 684   void *cont_cls;
 685
 686   struct GNUNET_TIME_Absolute timeout;
 687
 688   uint32_t quota_in;
 689 };
 690
 691
 692 static size_t
 693 send_set_quota (void *cls, size_t size, void *buf)
 694 {
 695   struct SetQuotaContext *sqc = cls;
 696   struct QuotaSetMessage *msg;
 697
 698   if (buf == NULL)
 699     {
 700       GNUNET_SCHEDULER_add_continuation (sqc->handle->sched,
 701                                          GNUNET_NO,
 702                                          sqc->cont,
 703                                          sqc->cont_cls,
 704                                          GNUNET_SCHEDULER_REASON_TIMEOUT);
 705       GNUNET_free (sqc);
 706       return 0;
 707     }
 708 #if DEBUG_TRANSPORT
 709   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 710               "Transmitting `%s' request with respect to `%4s'.\n",
 711               "SET_QUOTA", GNUNET_i2s (&sqc->target));
 712 #endif
 713   GNUNET_assert (size >= sizeof (struct QuotaSetMessage));
 714   msg = buf;
 715   msg->header.size = htons (sizeof (struct QuotaSetMessage));
 716   msg->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SET_QUOTA);
 717   msg->quota_in = htonl (sqc->quota_in);
 718   memcpy (&msg->peer, &sqc->target, sizeof (struct GNUNET_PeerIdentity));
 719   if (sqc->cont != NULL)
 720     GNUNET_SCHEDULER_add_continuation (sqc->handle->sched,
 721                                        GNUNET_NO,
 722                                        sqc->cont,
 723                                        sqc->cont_cls,
 724                                        GNUNET_SCHEDULER_REASON_PREREQ_DONE);
 725   GNUNET_free (sqc);
 726   return sizeof (struct QuotaSetMessage);
 727 }
 728
 729
 730 /**
 731  * Set the share of incoming bandwidth for the given
 732  * peer to the specified amount.
 733  *
 734  * @param handle connection to transport service
 735  * @param target who's bandwidth quota is being changed
 736  * @param quota_in incoming bandwidth quota in bytes per ms; 0 can
 737  *        be used to force all traffic to be discarded
 738  * @param quota_out outgoing bandwidth quota in bytes per ms; 0 can
 739  *        be used to force all traffic to be discarded
 740  * @param timeout how long to wait until signaling failure if
 741  *        we can not communicate the quota change
 742  * @param cont continuation to call when done, will be called
 743  *        either with reason "TIMEOUT" or with reason "PREREQ_DONE"
 744  * @param cont_cls closure for continuation
 745  */
 746 void
 747 GNUNET_TRANSPORT_set_quota (struct GNUNET_TRANSPORT_Handle *handle,
 748                             const struct GNUNET_PeerIdentity *target,
 749                             uint32_t quota_in,
 750                             uint32_t quota_out,
 751                             struct GNUNET_TIME_Relative timeout,
 752                             GNUNET_SCHEDULER_Task cont, void *cont_cls)
 753 {
 754   struct NeighbourList *n;
 755   struct SetQuotaContext *sqc;
 756
 757   n = find_neighbour (handle, target);
 758   if (n != NULL)
 759     {
 760       update_quota (n);
 761       if (n->quota_out < quota_out)
 762         n->last_quota_update = GNUNET_TIME_absolute_get ();
 763       n->quota_out = quota_out;
 764     }
 765   sqc = GNUNET_malloc (sizeof (struct SetQuotaContext));
 766   sqc->handle = handle;
 767   sqc->target = *target;
 768   sqc->cont = cont;
 769   sqc->cont_cls = cont_cls;
 770   sqc->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 771   sqc->quota_in = quota_in;
 772   schedule_control_transmit (handle,
 773                              sizeof (struct QuotaSetMessage),
 774                              GNUNET_NO, timeout, &send_set_quota, sqc);
 775 }
 776
 777
 778 /**
 779  * A "get_hello" request has timed out.  Signal the client
 780  * and clean up.
 781  */
 782 static void
 783 hello_wait_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 784 {
 785   struct HelloWaitList *hwl = cls;
 786   struct HelloWaitList *pos;
 787   struct HelloWaitList *prev;
 788
 789   prev = NULL;
 790   pos = hwl->handle->hwl_head;
 791   while (pos != hwl)
 792     {
 793       GNUNET_assert (pos != NULL);
 794       prev = pos;
 795       pos = pos->next;
 796     }
 797   if (prev == NULL)
 798     hwl->handle->hwl_head = hwl->next;
 799   else
 800     prev->next = hwl->next;
 801   GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 802               _("Timeout trying to obtain `%s' from transport service.\n"),
 803               "HELLO");
 804   /* signal timeout */
 805   if (hwl->rec != NULL)
 806     hwl->rec (hwl->rec_cls, GNUNET_TIME_UNIT_ZERO, NULL, NULL);
 807   GNUNET_free (hwl);
 808 }
 809
 810
 811 /**
 812  * Obtain the HELLO message for this peer.
 813  *
 814  * @param handle connection to transport service
 815  * @param timeout how long to wait for the HELLO
 816  * @param rec function to call with the HELLO, sender will be our peer
 817  *            identity; message and sender will be NULL on timeout
 818  *            (handshake with transport service pending/failed).
 819  *             cost estimate will be 0.
 820  * @param rec_cls closure for rec
 821  */
 822 void
 823 GNUNET_TRANSPORT_get_hello (struct GNUNET_TRANSPORT_Handle *handle,
 824                             struct GNUNET_TIME_Relative timeout,
 825                             GNUNET_TRANSPORT_ReceiveCallback rec,
 826                             void *rec_cls)
 827 {
 828   struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded pk;
 829   struct GNUNET_PeerIdentity me;
 830   struct HelloWaitList *hwl;
 831
 832   if (handle->my_hello == NULL)
 833     {
 834       hwl = GNUNET_malloc (sizeof (struct HelloWaitList));
 835       hwl->next = handle->hwl_head;
 836       handle->hwl_head = hwl;
 837       hwl->handle = handle;
 838       hwl->rec = rec;
 839       hwl->rec_cls = rec_cls;
 840       hwl->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 841       hwl->task = GNUNET_SCHEDULER_add_delayed (handle->sched,
 842                                                 GNUNET_YES,
 843                                                 GNUNET_SCHEDULER_PRIORITY_KEEP,
 844                                                 GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
 845                                                 timeout,
 846                                                 &hello_wait_timeout, hwl);
 847       return;
 848     }
 849   GNUNET_assert (GNUNET_OK == GNUNET_HELLO_get_key (handle->my_hello, &pk));
 850   GNUNET_CRYPTO_hash (&pk,
 851                       sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
 852                       &me.hashPubKey);
 853
 854   rec (rec_cls,
 855        GNUNET_TIME_UNIT_ZERO,
 856        &me, (const struct GNUNET_MessageHeader *) handle->my_hello);
 857 }
 858
 859
 860 static size_t
 861 send_hello (void *cls, size_t size, void *buf)
 862 {
 863   struct GNUNET_MessageHeader *hello = cls;
 864   uint16_t msize;
 865
 866   if (buf == NULL)
 867     {
 868 #if DEBUG_TRANSPORT
 869       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 870                   "Timeout while trying to transmit `%s' request.\n",
 871                   "HELLO");
 872 #endif
 873       GNUNET_free (hello);
 874       return 0;
 875     }
 876 #if DEBUG_TRANSPORT
 877   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 878               "Transmitting `%s' request.\n", "HELLO");
 879 #endif
 880   msize = ntohs (hello->size);
 881   GNUNET_assert (size >= msize);
 882   memcpy (buf, hello, msize);
 883   GNUNET_free (hello);
 884   return msize;
 885 }
 886
 887
 888 /**
 889  * Offer the transport service the HELLO of another peer.  Note that
 890  * the transport service may just ignore this message if the HELLO is
 891  * malformed or useless due to our local configuration.
 892  *
 893  * @param handle connection to transport service
 894  * @param hello the hello message
 895  */
 896 void
 897 GNUNET_TRANSPORT_offer_hello (struct GNUNET_TRANSPORT_Handle *handle,
 898                               const struct GNUNET_MessageHeader *hello)
 899 {
 900   struct GNUNET_MessageHeader *hc;
 901   uint16_t size;
 902
 903   if (handle->client == NULL)
 904     {
 905 #if DEBUG_TRANSPORT
 906       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 907                   "Not connected to transport service, dropping offered HELLO\n");
 908 #endif
 909       return;
 910     }
 911   GNUNET_break (ntohs (hello->type) == GNUNET_MESSAGE_TYPE_HELLO);
 912   size = ntohs (hello->size);
 913   GNUNET_break (size >= sizeof (struct GNUNET_MessageHeader));
 914   hc = GNUNET_malloc (size);
 915   memcpy (hc, hello, size);
 916   schedule_control_transmit (handle,
 917                              size,
 918                              GNUNET_NO, OFFER_HELLO_TIMEOUT, &send_hello, hc);
 919 }
 920
 921
 922 /**
 923  * Function we use for handling incoming messages.
 924  */
 925 static void demultiplexer (void *cls, const struct GNUNET_MessageHeader *msg);
 926
 927
 928 static size_t
 929 send_start (void *cls, size_t size, void *buf)
 930 {
 931   struct GNUNET_MessageHeader *s = buf;
 932
 933   if (buf == NULL)
 934     {
 935 #if DEBUG_TRANSPORT
 936       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 937                   "Timeout while trying to transmit `%s' request.\n",
 938                   "START");
 939 #endif
 940       return 0;
 941     }
 942 #if DEBUG_TRANSPORT
 943   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 944               "Transmitting `%s' request.\n", "START");
 945 #endif
 946   GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
 947   s->size = htons (sizeof (struct GNUNET_MessageHeader));
 948   s->type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_START);
 949   return sizeof (struct GNUNET_MessageHeader);
 950 }
 951
 952
 953 /**
 954  * We're ready to transmit the request that the transport service
 955  * should connect to a new peer.  In addition to sending the
 956  * request, schedule the next phase for the transmission processing
 957  * that caused the connect request in the first place.
 958  */
 959 static size_t
 960 request_connect (void *cls, size_t size, void *buf)
 961 {
 962   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
 963   struct TryConnectMessage *tcm;
 964   struct GNUNET_TRANSPORT_Handle *h;
 965
 966   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_PREREQUISITE_TASK);
 967   h = th->handle;
 968   if (buf == NULL)
 969     {
 970 #if DEBUG_TRANSPORT
 971       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 972                   "Failed to transmit `%s' request for `%4s' to service.\n",
 973                   "TRY_CONNECT",
 974                   GNUNET_i2s(&th->target));
 975 #endif
 976       th->notify (th->notify_cls, 0, NULL);
 977       GNUNET_free (th);
 978       return 0;
 979     }
 980 #if DEBUG_TRANSPORT
 981   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 982               "Transmitting `%s' message for `%4s'.\n",
 983               "TRY_CONNECT", GNUNET_i2s (&th->target));
 984 #endif
 985   GNUNET_assert (size >= sizeof (struct TryConnectMessage));
 986   tcm = buf;
 987   tcm->header.size = htons (sizeof (struct TryConnectMessage));
 988   tcm->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_TRY_CONNECT);
 989   tcm->reserved = htonl (0);
 990   memcpy (&tcm->peer, &th->target, sizeof (struct GNUNET_PeerIdentity));
 991   th->notify_delay_task
 992     = GNUNET_SCHEDULER_add_delayed (h->sched,
 993                                     GNUNET_NO,
 994                                     GNUNET_SCHEDULER_PRIORITY_KEEP,
 995                                     GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
 996                                     GNUNET_TIME_absolute_get_remaining
 997                                     (th->timeout),
 998                                     &transmit_timeout, th);
 999   insert_transmit_handle (&h->connect_wait_head, th);
1000   return sizeof (struct TryConnectMessage);
1001 }
1002
1003
1004 /**
1005  * Schedule a request to connect to the given
1006  * neighbour (and if successful, add the specified
1007  * handle to the wait list).
1008  *
1009  * @param th handle for a request to transmit once we
1010  *        have connected
1011  */
1012 static void
1013 try_connect (struct GNUNET_TRANSPORT_TransmitHandle *th)
1014 {
1015   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_PREREQUISITE_TASK);
1016   schedule_control_transmit (th->handle,
1017                              sizeof (struct TryConnectMessage),
1018                              GNUNET_NO,
1019                              GNUNET_TIME_absolute_get_remaining (th->timeout),
1020                              &request_connect, th);
1021 }
1022
1023
1024 /**
1025  * Task for delayed attempts to reconnect to a peer.
1026  *
1027  * @param cls must be a transmit handle that determines the peer
1028  *        to which we will try to connect
1029  * @param tc scheduler information about why we were triggered (not used)
1030  */
1031 static void
1032 try_connect_task (void *cls,
1033                   const struct GNUNET_SCHEDULER_TaskContext *tc)
1034 {
1035   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
1036
1037   th->notify_delay_task
1038     = GNUNET_SCHEDULER_add_delayed (th->handle->sched,
1039                                     GNUNET_NO,
1040                                     GNUNET_SCHEDULER_PRIORITY_KEEP,
1041                                     GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
1042                                     GNUNET_TIME_absolute_get_remaining
1043                                     (th->timeout), &transmit_timeout, th);
1044   try_connect (th);
1045 }
1046
1047
1048 /**
1049  * Remove neighbour from our list.  Will automatically
1050  * trigger a re-connect attempt if we have messages pending
1051  * for this peer.
1052  *
1053  * @param h our state
1054  * @param peer the peer to remove
1055  */
1056 static void
1057 remove_neighbour (struct GNUNET_TRANSPORT_Handle *h,
1058                   const struct GNUNET_PeerIdentity *peer)
1059 {
1060   struct NeighbourList *prev;
1061   struct NeighbourList *pos;
1062   struct GNUNET_TRANSPORT_TransmitHandle *th;
1063
1064   prev = NULL;
1065   pos = h->neighbours;
1066   while ((pos != NULL) &&
1067          (0 != memcmp (peer,
1068                        &pos->id,
1069                        sizeof (struct GNUNET_PeerIdentity))))
1070     {
1071       prev = pos;
1072       pos = pos->next;
1073     }
1074   if (pos == NULL)
1075     {
1076       GNUNET_break (0);
1077       return;
1078     }
1079   if (prev == NULL)
1080     h->neighbours = pos->next;
1081   else
1082     prev->next = pos->next;
1083   if (NULL != (th = pos->transmit_handle))
1084     {
1085       pos->transmit_handle = NULL;
1086       th->neighbour = NULL;
1087       remove_from_any_list (th);
1088       if (GNUNET_TIME_absolute_get_remaining (th->timeout).value > CONNECT_RETRY_TIMEOUT.value)
1089         {
1090           /* signal error */
1091           GNUNET_SCHEDULER_cancel (h->sched,
1092                                    th->notify_delay_task);
1093           transmit_timeout (th, NULL);
1094         }
1095       else
1096         {
1097           /* try again in a bit */
1098           GNUNET_SCHEDULER_cancel (h->sched,
1099                                    th->notify_delay_task);
1100           th->notify_delay_task
1101             = GNUNET_SCHEDULER_add_delayed (h->sched,
1102                                             GNUNET_NO,
1103                                             GNUNET_SCHEDULER_PRIORITY_KEEP,
1104                                             GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
1105                                             CONNECT_RETRY_TIMEOUT,
1106                                             &try_connect_task,
1107                                             th);
1108         }
1109     }
1110   if (h->nc_cb != NULL)
1111     h->nd_cb (h->cls, peer);
1112   GNUNET_free (pos);
1113 }
1114
1115
1116 /**
1117  * Try again to connect to transport service.
1118  */
1119 static void
1120 reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1121 {
1122   struct GNUNET_TRANSPORT_Handle *h = cls;
1123   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1124   struct NeighbourList *n;
1125
1126   /* Forget about all neighbours that we used to be connected
1127      to */
1128   while (NULL != (n = h->neighbours))
1129     remove_neighbour (h, &n->id);
1130 #if DEBUG_TRANSPORT
1131   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connecting to transport service.\n");
1132 #endif
1133   GNUNET_assert (h->client == NULL);
1134   h->reconnect_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1135   h->client = GNUNET_CLIENT_connect (h->sched, "transport", h->cfg);
1136   GNUNET_assert (h->client != NULL);
1137   /* make sure we don't send "START" twice,
1138      remove existing entry from queue (if present) */
1139   pos = h->connect_ready_head;
1140   while (pos != NULL)
1141     {
1142       if (pos->notify == &send_start)
1143         {
1144           if (pos->prev == NULL)
1145             h->connect_ready_head = pos->next;
1146           else
1147             pos->prev->next = pos->next;
1148           if (pos->next != NULL)
1149             pos->next->prev = pos->prev;
1150           GNUNET_assert (pos->neighbour == NULL);
1151           GNUNET_free (pos);
1152           break;
1153         }
1154       pos = pos->next;
1155     }
1156   schedule_control_transmit (h,
1157                              sizeof (struct GNUNET_MessageHeader),
1158                              GNUNET_YES,
1159                              GNUNET_TIME_UNIT_FOREVER_REL, &send_start, NULL);
1160   GNUNET_CLIENT_receive (h->client,
1161                          &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL);
1162 }
1163
1164
1165 /**
1166  * Function that will schedule the job that will try
1167  * to connect us again to the client.
1168  */
1169 static void
1170 schedule_reconnect (struct GNUNET_TRANSPORT_Handle *h)
1171 {
1172 #if DEBUG_TRANSPORT
1173   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1174               "Scheduling task to reconnect to transport service in %llu ms.\n",
1175               h->reconnect_delay.value);
1176 #endif
1177   GNUNET_assert (h->client == NULL);
1178   GNUNET_assert (h->reconnect_task == GNUNET_SCHEDULER_NO_PREREQUISITE_TASK);
1179   h->reconnect_task
1180     = GNUNET_SCHEDULER_add_delayed (h->sched,
1181                                     GNUNET_NO,
1182                                     GNUNET_SCHEDULER_PRIORITY_DEFAULT,
1183                                     GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
1184                                     h->reconnect_delay, &reconnect, h);
1185   h->reconnect_delay = GNUNET_TIME_UNIT_SECONDS;
1186 }
1187
1188
1189 /**
1190  * We are connected to the respective peer, check the
1191  * bandwidth limits and schedule the transmission.
1192  */
1193 static void schedule_request (struct GNUNET_TRANSPORT_TransmitHandle *th);
1194
1195
1196 /**
1197  * Function called by the scheduler when the timeout
1198  * for bandwidth availablility for the target
1199  * neighbour is reached.
1200  */
1201 static void
1202 transmit_ready (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1203 {
1204   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
1205
1206   th->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1207   schedule_request (th);
1208 }
1209
1210
1211 /**
1212  * Remove the given transmit handle from the wait list.  Does NOT free
1213  * it.
1214  */
1215 static void
1216 remove_from_wait_list (struct GNUNET_TRANSPORT_TransmitHandle *th)
1217 {
1218   if (th->prev == NULL)
1219     th->handle->connect_wait_head = th->next;
1220   else
1221     th->prev->next = th->next;
1222   if (th->next != NULL)
1223     th->next->prev = th->prev;
1224 }
1225
1226
1227 /**
1228  * We are connected to the respective peer, check the
1229  * bandwidth limits and schedule the transmission.
1230  */
1231 static void
1232 schedule_request (struct GNUNET_TRANSPORT_TransmitHandle *th)
1233 {
1234   struct GNUNET_TRANSPORT_Handle *h;
1235   struct GNUNET_TIME_Relative duration;
1236   struct NeighbourList *n;
1237   uint64_t available;
1238
1239   h = th->handle;
1240   n = th->neighbour;
1241   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
1242     {
1243       GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
1244       th->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1245     }
1246   /* check outgoing quota */
1247   duration = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
1248   if (duration.value > MIN_QUOTA_REFRESH_TIME)
1249     {
1250       update_quota (n);
1251       duration = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
1252     }
1253   available = duration.value * n->quota_out;
1254   if (available < n->last_sent + th->notify_size)
1255     {
1256       /* calculate how much bandwidth we'd still need to
1257          accumulate and based on that how long we'll have
1258          to wait... */
1259       available = n->last_sent + th->notify_size - available;
1260       duration = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS,
1261                                                 available / n->quota_out);
1262       if (th->timeout.value <
1263           GNUNET_TIME_relative_to_absolute (duration).value)
1264         {
1265           /* signal timeout! */
1266 #if DEBUG_TRANSPORT
1267           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1268                       "Would need %llu ms before bandwidth is available for delivery to `%4s', that is too long.  Signaling timeout.\n",
1269                       duration.value,
1270                       GNUNET_i2s(&th->target));
1271 #endif
1272           remove_from_wait_list (th);
1273           th->notify (th->notify_cls, 0, NULL);
1274           GNUNET_free (th);
1275           return;
1276         }
1277 #if DEBUG_TRANSPORT
1278       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1279                   "Need more bandwidth, delaying delivery to `%4s' by %llu ms\n",
1280                   GNUNET_i2s(&th->target),
1281                   duration.value);
1282 #endif
1283       th->notify_delay_task
1284         = GNUNET_SCHEDULER_add_delayed (h->sched,
1285                                         GNUNET_NO,
1286                                         GNUNET_SCHEDULER_PRIORITY_KEEP,
1287                                         GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
1288                                         duration, &transmit_ready, th);
1289       return;
1290     }
1291 #if DEBUG_TRANSPORT
1292   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1293               "Bandwidth available for transmission to `%4s'\n",
1294               GNUNET_i2s (&n->id));
1295 #endif
1296   if (GNUNET_NO == n->transmit_ok)
1297     {
1298       /* we may be ready, but transport service is not;
1299          wait for SendOkMessage or timeout */
1300 #if DEBUG_TRANSPORT
1301       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1302                   "Need to wait for transport service `%s' message\n",
1303                   "SEND_OK");
1304 #endif
1305       th->notify_delay_task
1306         = GNUNET_SCHEDULER_add_delayed (h->sched,
1307                                         GNUNET_NO,
1308                                         GNUNET_SCHEDULER_PRIORITY_KEEP,
1309                                         GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
1310                                         GNUNET_TIME_absolute_get_remaining
1311                                         (th->timeout), &transmit_timeout, th);
1312       return;
1313     }
1314   n->transmit_ok = GNUNET_NO;
1315   remove_from_wait_list (th);
1316 #if DEBUG_TRANSPORT
1317   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Moving message for `%4s' to ready list\n",
1318               GNUNET_i2s(&n->id));
1319 #endif
1320   insert_transmit_handle (&h->connect_ready_head, th);
1321   if (GNUNET_NO == h->transmission_scheduled)
1322     schedule_transmission (h);
1323 }
1324
1325
1326 /**
1327  * Add neighbour to our list
1328  */
1329 static void
1330 add_neighbour (struct GNUNET_TRANSPORT_Handle *h,
1331                uint32_t quota_out,
1332                struct GNUNET_TIME_Relative latency,
1333                const struct GNUNET_PeerIdentity *pid)
1334 {
1335   struct NeighbourList *n;
1336   struct GNUNET_TRANSPORT_TransmitHandle *prev;
1337   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1338   struct GNUNET_TRANSPORT_TransmitHandle *next;
1339
1340   /* check for duplicates */
1341   if (NULL != find_neighbour (h, pid))
1342     {
1343       GNUNET_break (0);
1344       return;
1345     }
1346 #if DEBUG_TRANSPORT
1347   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1348               "Creating entry for new neighbour `%4s'.\n", GNUNET_i2s (pid));
1349 #endif
1350   n = GNUNET_malloc (sizeof (struct NeighbourList));
1351   n->id = *pid;
1352   n->last_quota_update = GNUNET_TIME_absolute_get ();
1353   n->quota_out = quota_out;
1354   n->next = h->neighbours;
1355   n->transmit_ok = GNUNET_YES;
1356   h->neighbours = n;
1357   if (h->nc_cb != NULL)
1358     h->nc_cb (h->cls, &n->id, latency);
1359   prev = NULL;
1360   pos = h->connect_wait_head;
1361   while (pos != NULL)
1362     {
1363       next = pos->next;
1364       if (0 == memcmp (pid,
1365                        &pos->target, sizeof (struct GNUNET_PeerIdentity)))
1366         {
1367           pos->neighbour = n;
1368           GNUNET_assert (NULL == n->transmit_handle);
1369           n->transmit_handle = pos;
1370           if (prev == NULL)
1371             h->connect_wait_head = next;
1372           else
1373             prev->next = next;
1374           if (GNUNET_YES == n->received_ack)
1375             {
1376 #if DEBUG_TRANSPORT
1377               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1378                           "Found pending request for `%4s' will trigger it now.\n",
1379                           GNUNET_i2s (&pos->target));
1380 #endif
1381               if (pos->notify_delay_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
1382                 {
1383                   GNUNET_SCHEDULER_cancel (h->sched, pos->notify_delay_task);
1384                   pos->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1385                 }
1386               schedule_request (pos);
1387             }
1388           else
1389             {
1390 #if DEBUG_TRANSPORT
1391               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1392                           "Found pending request for `%4s' but still need `%s' before proceeding.\n",
1393                           GNUNET_i2s (&pos->target),
1394                           "ACK");
1395 #endif
1396             }
1397           break;
1398         }
1399       prev = pos;
1400       pos = next;
1401     }
1402 }
1403
1404
1405 /**
1406  * Connect to the transport service.  Note that the connection may
1407  * complete (or fail) asynchronously.
1408  *
1409
1410  * @param sched scheduler to use
1411  * @param cfg configuration to use
1412  * @param cls closure for the callbacks
1413  * @param rec receive function to call
1414  * @param nc function to call on connect events
1415  * @param dc function to call on disconnect events
1416  */
1417 struct GNUNET_TRANSPORT_Handle *
1418 GNUNET_TRANSPORT_connect (struct GNUNET_SCHEDULER_Handle *sched,
1419                           struct GNUNET_CONFIGURATION_Handle *cfg,
1420                           void *cls,
1421                           GNUNET_TRANSPORT_ReceiveCallback rec,
1422                           GNUNET_TRANSPORT_NotifyConnect nc,
1423                           GNUNET_TRANSPORT_NotifyDisconnect nd)
1424 {
1425   struct GNUNET_TRANSPORT_Handle *ret;
1426
1427   GNUNET_ARM_start_service ("peerinfo",
1428                             cfg, sched, START_SERVICE_TIMEOUT, NULL, NULL);
1429   GNUNET_ARM_start_service ("transport",
1430                             cfg, sched, START_SERVICE_TIMEOUT, NULL, NULL);
1431   ret = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_Handle));
1432   ret->sched = sched;
1433   ret->cfg = cfg;
1434   ret->cls = cls;
1435   ret->rec = rec;
1436   ret->nc_cb = nc;
1437   ret->nd_cb = nd;
1438   ret->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
1439   schedule_reconnect (ret);
1440   return ret;
1441 }
1442
1443
1444 /**
1445  * These stop activities must be run in a fresh
1446  * scheduler that is NOT in shutdown mode.
1447  */
1448 static void
1449 stop_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1450 {
1451   struct GNUNET_TRANSPORT_Handle *handle = cls;
1452   GNUNET_ARM_stop_service ("transport",
1453                            handle->cfg,
1454                            tc->sched, STOP_SERVICE_TIMEOUT, NULL, NULL);
1455   GNUNET_ARM_stop_service ("peerinfo",
1456                            handle->cfg,
1457                            tc->sched, STOP_SERVICE_TIMEOUT, NULL, NULL);
1458 }
1459
1460
1461 /**
1462  * Disconnect from the transport service.
1463  */
1464 void
1465 GNUNET_TRANSPORT_disconnect (struct GNUNET_TRANSPORT_Handle *handle)
1466 {
1467   struct GNUNET_TRANSPORT_TransmitHandle *th;
1468   struct NeighbourList *n;
1469   struct HelloWaitList *hwl;
1470   struct GNUNET_CLIENT_Connection *client;
1471
1472 #if DEBUG_TRANSPORT
1473   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transport disconnect called!\n");
1474 #endif
1475   while (NULL != (th = handle->connect_ready_head))
1476     {
1477       handle->connect_ready_head = th->next;
1478       th->notify (th->notify_cls, 0, NULL);
1479       GNUNET_free (th);
1480     }
1481   while (NULL != (th = handle->connect_wait_head))
1482     {
1483       handle->connect_wait_head = th->next;
1484       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
1485         {
1486           GNUNET_SCHEDULER_cancel (handle->sched, th->notify_delay_task);
1487           th->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1488         }
1489       th->notify (th->notify_cls, 0, NULL);
1490       GNUNET_free (th);
1491     }
1492   while (NULL != (n = handle->neighbours))
1493     {
1494       handle->neighbours = n->next;
1495       GNUNET_free (n);
1496     }
1497   while (NULL != (hwl = handle->hwl_head))
1498     {
1499       handle->hwl_head = hwl->next;
1500       GNUNET_SCHEDULER_cancel (handle->sched, hwl->task);
1501       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1502                   _("Disconnect while trying to obtain `%s' from transport service.\n"),
1503                   "HELLO");
1504       if (hwl->rec != NULL)
1505         hwl->rec (hwl->rec_cls, GNUNET_TIME_UNIT_ZERO, NULL, NULL);
1506       GNUNET_free (hwl);
1507     }
1508   if (handle->reconnect_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
1509     {
1510       GNUNET_SCHEDULER_cancel (handle->sched, handle->reconnect_task);
1511       handle->reconnect_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1512     }
1513   GNUNET_free_non_null (handle->my_hello);
1514   handle->my_hello = NULL;
1515   GNUNET_SCHEDULER_run (&stop_task, handle);
1516   if (NULL != (client = handle->client))
1517     {
1518 #if DEBUG_TRANSPORT
1519       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1520                   "Disconnecting from transport service for good.\n");
1521 #endif
1522       handle->client = NULL;
1523       GNUNET_CLIENT_disconnect (client);
1524     }
1525   if (client == NULL)
1526     GNUNET_free (handle);
1527 }
1528
1529
1530 /**
1531  * Type of a function to call when we receive a message
1532  * from the service.
1533  *
1534  * @param cls closure
1535  * @param msg message received, NULL on timeout or fatal error
1536  */
1537 static void
1538 demultiplexer (void *cls, const struct GNUNET_MessageHeader *msg)
1539 {
1540   struct GNUNET_TRANSPORT_Handle *h = cls;
1541   const struct DisconnectInfoMessage *dim;
1542   const struct ConnectInfoMessage *cim;
1543   const struct InboundMessage *im;
1544   const struct GNUNET_MessageHeader *imm;
1545   const struct SendOkMessage *okm;
1546   struct HelloWaitList *hwl;
1547   struct NeighbourList *n;
1548   struct GNUNET_PeerIdentity me;
1549   struct GNUNET_TRANSPORT_TransmitHandle *th;
1550   uint16_t size;
1551
1552   if ((msg == NULL) || (h->client == NULL))
1553     {
1554       if (h->client != NULL)
1555         {
1556 #if DEBUG_TRANSPORT
1557           GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1558                       "Error receiving from transport service, disconnecting temporarily.\n");
1559 #endif
1560           if (h->network_handle != NULL)
1561             {
1562               GNUNET_NETWORK_notify_transmit_ready_cancel (h->network_handle);
1563               h->network_handle = NULL;
1564               h->transmission_scheduled = GNUNET_NO;
1565               th = h->connect_ready_head;
1566               /* add timeout again, we cancelled the transmit_ready task! */
1567               GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_PREREQUISITE_TASK);
1568               th->notify_delay_task
1569                 = GNUNET_SCHEDULER_add_delayed (h->sched,
1570                                                 GNUNET_NO,
1571                                                 GNUNET_SCHEDULER_PRIORITY_KEEP,
1572                                                 GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
1573                                                 GNUNET_TIME_absolute_get_remaining(th->timeout),
1574                                                 &transmit_timeout,
1575                                                 th);
1576             }
1577           GNUNET_CLIENT_disconnect (h->client);
1578           h->client = NULL;
1579           schedule_reconnect (h);
1580         }
1581       else
1582         {
1583           /* shutdown initiated from 'GNUNET_TRANSPORT_disconnect',
1584              finish clean up work! */
1585           GNUNET_free (h);
1586         }
1587       return;
1588     }
1589   GNUNET_CLIENT_receive (h->client,
1590                          &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL);
1591   size = ntohs (msg->size);
1592   switch (ntohs (msg->type))
1593     {
1594     case GNUNET_MESSAGE_TYPE_HELLO:
1595       if (GNUNET_OK !=
1596           GNUNET_HELLO_get_id ((const struct GNUNET_HELLO_Message *) msg,
1597                                &me))
1598         {
1599           GNUNET_break (0);
1600           break;
1601         }
1602 #if DEBUG_TRANSPORT
1603       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1604                   "Receiving (my own) `%s' message, I am `%4s'.\n",
1605                   "HELLO", GNUNET_i2s (&me));
1606 #endif
1607       GNUNET_free_non_null (h->my_hello);
1608       h->my_hello = NULL;
1609       if (size < sizeof (struct GNUNET_MessageHeader))
1610         {
1611           GNUNET_break (0);
1612           break;
1613         }
1614       h->my_hello = GNUNET_malloc (size);
1615       memcpy (h->my_hello, msg, size);
1616       while (NULL != (hwl = h->hwl_head))
1617         {
1618           h->hwl_head = hwl->next;
1619           GNUNET_SCHEDULER_cancel (h->sched, hwl->task);
1620           GNUNET_TRANSPORT_get_hello (h,
1621                                       GNUNET_TIME_UNIT_ZERO,
1622                                       hwl->rec, hwl->rec_cls);
1623           GNUNET_free (hwl);
1624         }
1625       break;
1626     case GNUNET_MESSAGE_TYPE_TRANSPORT_CONNECT:
1627       if (size != sizeof (struct ConnectInfoMessage))
1628         {
1629           GNUNET_break (0);
1630           break;
1631         }
1632       cim = (const struct ConnectInfoMessage *) msg;
1633 #if DEBUG_TRANSPORT
1634       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1635                   "Receiving `%s' message for `%4s'.\n",
1636                   "CONNECT", GNUNET_i2s (&cim->id));
1637 #endif
1638       add_neighbour (h,
1639                      ntohl (cim->quota_out),
1640                      GNUNET_TIME_relative_ntoh (cim->latency), &cim->id);
1641       break;
1642     case GNUNET_MESSAGE_TYPE_TRANSPORT_DISCONNECT:
1643       if (size != sizeof (struct DisconnectInfoMessage))
1644         {
1645           GNUNET_break (0);
1646           break;
1647         }
1648       dim = (const struct DisconnectInfoMessage *) msg;
1649 #if DEBUG_TRANSPORT
1650       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1651                   "Receiving `%s' message for `%4s'.\n",
1652                   "DISCONNECT", GNUNET_i2s (&dim->peer));
1653 #endif
1654       remove_neighbour (h, &dim->peer);
1655       break;
1656     case GNUNET_MESSAGE_TYPE_TRANSPORT_SEND_OK:
1657       if (size != sizeof (struct SendOkMessage))
1658         {
1659           GNUNET_break (0);
1660           break;
1661         }
1662       okm = (const struct SendOkMessage *) msg;
1663 #if DEBUG_TRANSPORT
1664       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1665                   "Receiving `%s' message, transmission %s.\n", "SEND_OK",
1666                   ntohl(okm->success) == GNUNET_OK ? "succeeded" : "failed");
1667 #endif
1668       /* FIXME: need to check status code and change action accordingly,
1669          especially if the error was for CONNECT */
1670       n = find_neighbour (h, &okm->peer);
1671       GNUNET_assert (n != NULL);
1672       n->transmit_ok = GNUNET_YES;
1673       if (n->transmit_handle != NULL)
1674         {
1675 #if DEBUG_TRANSPORT
1676           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1677                       "Processing pending message\n");
1678 #endif
1679           GNUNET_SCHEDULER_cancel (h->sched,
1680                                    n->transmit_handle->notify_delay_task);
1681           n->transmit_handle->notify_delay_task =
1682             GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1683           GNUNET_assert (GNUNET_YES == n->received_ack);
1684           schedule_request (n->transmit_handle);
1685         }
1686       break;
1687     case GNUNET_MESSAGE_TYPE_TRANSPORT_RECV:
1688 #if DEBUG_TRANSPORT
1689       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1690                   "Receiving `%s' message.\n", "RECV");
1691 #endif
1692       if (size <
1693           sizeof (struct InboundMessage) +
1694           sizeof (struct GNUNET_MessageHeader))
1695         {
1696           GNUNET_break (0);
1697           break;
1698         }
1699       im = (const struct InboundMessage *) msg;
1700       imm = (const struct GNUNET_MessageHeader *) &im[1];
1701       if (ntohs (imm->size) + sizeof (struct InboundMessage) != size)
1702         {
1703           GNUNET_break (0);
1704           break;
1705         }
1706       switch (ntohs (imm->type))
1707         {
1708         case GNUNET_MESSAGE_TYPE_TRANSPORT_ACK:
1709 #if DEBUG_TRANSPORT
1710           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1711                       "Receiving `%s' message from `%4s'.\n",
1712                       "ACK", GNUNET_i2s (&im->peer));
1713 #endif
1714           n = find_neighbour (h, &im->peer);
1715           if (n == NULL)
1716             {
1717               GNUNET_break (0);
1718               break;
1719             }
1720           if (n->received_ack == GNUNET_NO)
1721             {
1722               n->received_ack = GNUNET_YES;
1723               if (NULL != n->transmit_handle)
1724                 {
1725 #if DEBUG_TRANSPORT
1726                   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1727                               "Peer connected, scheduling delayed message for deliverery now.\n");
1728 #endif
1729                   schedule_request (n->transmit_handle);
1730                 }
1731             }
1732           break;
1733         default:
1734 #if DEBUG_TRANSPORT
1735           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1736                       "Received message of type %u from `%4s'.\n",
1737                       ntohs (imm->type), GNUNET_i2s (&im->peer));
1738 #endif
1739           if (h->rec != NULL)
1740             h->rec (h->cls,
1741                     GNUNET_TIME_relative_ntoh (im->latency), &im->peer, imm);
1742           break;
1743         }
1744       break;
1745     default:
1746       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1747                   _
1748                   ("Received unexpected message of type %u in %s:%u\n"),
1749                   ntohs (msg->type), __FILE__, __LINE__);
1750       GNUNET_break (0);
1751       break;
1752     }
1753 }
1754
1755
1756 struct ClientTransmitWrapper
1757 {
1758   GNUNET_NETWORK_TransmitReadyNotify notify;
1759   void *notify_cls;
1760   struct GNUNET_TRANSPORT_TransmitHandle *th;
1761 };
1762
1763
1764 /**
1765  * Transmit message of a client destined for another
1766  * peer to the service.
1767  */
1768 static size_t
1769 client_notify_wrapper (void *cls, size_t size, void *buf)
1770 {
1771   struct ClientTransmitWrapper *ctw = cls;
1772   struct OutboundMessage *obm;
1773   struct GNUNET_MessageHeader *hdr;
1774   size_t ret;
1775
1776   if (size == 0)
1777     {
1778 #if DEBUG_TRANSPORT
1779       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1780                   "Transmission request could not be satisfied.\n");
1781 #endif
1782       ret = ctw->notify (ctw->notify_cls, 0, NULL);
1783       GNUNET_assert (ret == 0);
1784       GNUNET_free (ctw);
1785       return 0;
1786     }
1787   GNUNET_assert (size >= sizeof (struct OutboundMessage));
1788   obm = buf;
1789   ret = ctw->notify (ctw->notify_cls,
1790                      size - sizeof (struct OutboundMessage),
1791                      (void *) &obm[1]);
1792   if (ret == 0)
1793     {
1794       /* Need to reset flag, no SEND means no SEND_OK! */
1795       ctw->th->neighbour->transmit_ok = GNUNET_YES;
1796       GNUNET_free (ctw);
1797       return 0;
1798     }
1799   GNUNET_assert (ret >= sizeof (struct GNUNET_MessageHeader));
1800   hdr = (struct GNUNET_MessageHeader *) &obm[1];
1801   GNUNET_assert (ntohs (hdr->size) == ret);
1802   GNUNET_assert (ret + sizeof (struct OutboundMessage) <
1803                  GNUNET_SERVER_MAX_MESSAGE_SIZE);
1804 #if DEBUG_TRANSPORT
1805   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1806               "Transmitting `%s' message with data for `%4s'\n",
1807               "SEND", GNUNET_i2s (&ctw->th->target));
1808 #endif
1809   ret += sizeof (struct OutboundMessage);
1810   obm->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SEND);
1811   obm->header.size = htons (ret);
1812   obm->priority = htonl (ctw->th->priority);
1813   obm->peer = ctw->th->target;
1814   GNUNET_free (ctw);
1815   return ret;
1816 }
1817
1818
1819
1820 /**
1821  * Check if we could queue a message of the given size for
1822  * transmission.  The transport service will take both its
1823  * internal buffers and bandwidth limits imposed by the
1824  * other peer into consideration when answering this query.
1825  *
1826  * @param handle connection to transport service
1827  * @param target who should receive the message
1828  * @param size how big is the message we want to transmit?
1829  * @param priority how important is the message?
1830  * @param timeout after how long should we give up (and call
1831  *        notify with buf NULL and size 0)?
1832  * @param notify function to call when we are ready to
1833  *        send such a message
1834  * @param notify_cls closure for notify
1835  * @return NULL if someone else is already waiting to be notified
1836  *         non-NULL if the notify callback was queued (can be used to cancel
1837  *         using GNUNET_TRANSPORT_notify_transmit_ready_cancel)
1838  */
1839 struct GNUNET_TRANSPORT_TransmitHandle *
1840 GNUNET_TRANSPORT_notify_transmit_ready (struct GNUNET_TRANSPORT_Handle
1841                                         *handle,
1842                                         const struct GNUNET_PeerIdentity
1843                                         *target, size_t size,
1844                                         unsigned int priority,
1845                                         struct GNUNET_TIME_Relative timeout,
1846                                         GNUNET_NETWORK_TransmitReadyNotify
1847                                         notify, void *notify_cls)
1848 {
1849   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1850   struct GNUNET_TRANSPORT_TransmitHandle *th;
1851   struct NeighbourList *n;
1852   struct ClientTransmitWrapper *ctw;
1853
1854   if (size + sizeof (struct OutboundMessage) >=
1855       GNUNET_SERVER_MAX_MESSAGE_SIZE)
1856     {
1857       GNUNET_break (0);
1858       return NULL;
1859     }
1860 #if DEBUG_TRANSPORT
1861   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1862               "Asking transport service for transmission of %u bytes to peer `%4s'.\n",
1863               size, GNUNET_i2s (target));
1864 #endif
1865   n = find_neighbour (handle, target);
1866   if ( (n != NULL) &&
1867        (n->transmit_handle != NULL) )
1868     return NULL; /* already have a request pending for this peer! */
1869   ctw = GNUNET_malloc (sizeof (struct ClientTransmitWrapper));
1870   th = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_TransmitHandle));
1871   ctw->notify = notify;
1872   ctw->notify_cls = notify_cls;
1873   ctw->th = th;
1874   th->handle = handle;
1875   th->neighbour = n;
1876   th->target = *target;
1877   th->notify = &client_notify_wrapper;
1878   th->notify_cls = ctw;
1879   th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
1880   th->notify_size = size + sizeof (struct OutboundMessage);
1881   th->priority = priority;
1882   if (NULL == n)
1883     {
1884       pos = handle->connect_wait_head;
1885       while (pos != NULL)
1886         {
1887           GNUNET_assert (0 != memcmp (target,
1888                                       &pos->target,
1889                                       sizeof (struct GNUNET_PeerIdentity)));
1890           pos = pos->next;
1891         }
1892 #if DEBUG_TRANSPORT
1893       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1894                   "Will now try to connect to `%4s'.\n", GNUNET_i2s (target));
1895 #endif
1896       try_connect (th);
1897       return th;
1898     }
1899
1900 #if DEBUG_TRANSPORT
1901   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1902               "Transmission request queued for transmission to transport service.\n");
1903 #endif
1904   GNUNET_assert (NULL == n->transmit_handle);
1905   n->transmit_handle = th;
1906   if (GNUNET_YES != n->received_ack)
1907     {
1908 #if DEBUG_TRANSPORT
1909       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1910                   "Connection to `%4s' is not yet confirmed connected, scheduling timeout (%llu ms) only.\n",
1911                   GNUNET_i2s (target), timeout.value);
1912 #endif
1913       th->notify_delay_task
1914         = GNUNET_SCHEDULER_add_delayed (handle->sched,
1915                                         GNUNET_NO,
1916                                         GNUNET_SCHEDULER_PRIORITY_KEEP,
1917                                         GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
1918                                         timeout, &transmit_timeout, th);
1919       return th;
1920     }
1921
1922 #if DEBUG_TRANSPORT
1923   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1924               "Peer `%4s' is ready to receive, scheduling message for delivery now.\n",
1925               GNUNET_i2s (target));
1926 #endif
1927   schedule_request (th);
1928   return th;
1929 }
1930
1931
1932 /**
1933  * Cancel the specified transmission-ready
1934  * notification.
1935  */
1936 void
1937 GNUNET_TRANSPORT_notify_transmit_ready_cancel (struct
1938                                                GNUNET_TRANSPORT_TransmitHandle
1939                                                *th)
1940 {
1941   struct GNUNET_TRANSPORT_Handle *h;
1942
1943 #if DEBUG_TRANSPORT
1944   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1945               "Transmission request of %u bytes to `%4s' was cancelled.\n",
1946               th->notify_size - sizeof(struct OutboundMessage),
1947               GNUNET_i2s (&th->target));
1948 #endif
1949   GNUNET_assert (th->notify == &client_notify_wrapper);
1950   remove_from_any_list (th);
1951   h = th->handle;
1952   if ((h->connect_ready_head == NULL) && (h->network_handle != NULL))
1953     {
1954       GNUNET_NETWORK_notify_transmit_ready_cancel (h->network_handle);
1955       h->network_handle = NULL;
1956       h->transmission_scheduled = GNUNET_NO;
1957     }
1958   GNUNET_free (th->notify_cls);
1959   GNUNET_free (th);
1960 }
1961
1962
1963 /* end of transport_api.c */