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    * Identity of this neighbour.
  85    */
  86   struct GNUNET_PeerIdentity id;
  87
  88   /**
  89    * At what time did we reset last_sent last?
  90    */
  91   struct GNUNET_TIME_Absolute last_quota_update;
  92
  93   /**
  94    * How many bytes have we sent since the "last_quota_update"
  95    * timestamp?
  96    */
  97   uint64_t last_sent;
  98
  99   /**
 100    * Quota for outbound traffic to the neighbour in bytes/ms.
 101    */
 102   uint32_t quota_out;
 103
 104   /**
 105    * Set to GNUNET_YES if we are currently allowed to
 106    * transmit a message to the transport service for this
 107    * peer, GNUNET_NO otherwise.
 108    */
 109   int transmit_ok;
 110
 111   /**
 112    * Set to GNUNET_YES if we have received an ACK for the
 113    * given peer.  Peers that receive our HELLO always respond
 114    * with an ACK to let us know that we are successfully
 115    * communicating.  Note that a PING can not be used for this
 116    * since PINGs are only send if a HELLO address requires
 117    * confirmation (and also, PINGs are not passed to the
 118    * transport API itself).
 119    */
 120   int received_ack;
 121
 122 };
 123
 124
 125 /**
 126  * Linked list of requests from clients for our HELLO
 127  * that were deferred.
 128  */
 129 struct HelloWaitList
 130 {
 131
 132   /**
 133    * This is a linked list.
 134    */
 135   struct HelloWaitList *next;
 136
 137   /**
 138    * Reference back to our transport handle.
 139    */
 140   struct GNUNET_TRANSPORT_Handle *handle;
 141
 142   /**
 143    * Callback to call once we got our HELLO.
 144    */
 145   GNUNET_TRANSPORT_ReceiveCallback rec;
 146
 147   /**
 148    * Closure for rec.
 149    */
 150   void *rec_cls;
 151
 152   /**
 153    * When to time out (call rec with NULL).
 154    */
 155   struct GNUNET_TIME_Absolute timeout;
 156
 157   /**
 158    * Timeout task (used to trigger timeout,
 159    * cancel if we get the HELLO in time).
 160    */
 161   GNUNET_SCHEDULER_TaskIdentifier task;
 162
 163
 164 };
 165
 166
 167 /**
 168  * Opaque handle for a transmission-ready request.
 169  */
 170 struct GNUNET_TRANSPORT_TransmitHandle
 171 {
 172
 173   /**
 174    * We keep the transmit handles that are waiting for
 175    * a transport-level connection in a doubly linked list.
 176    */
 177   struct GNUNET_TRANSPORT_TransmitHandle *next;
 178
 179   /**
 180    * We keep the transmit handles that are waiting for
 181    * a transport-level connection in a doubly linked list.
 182    */
 183   struct GNUNET_TRANSPORT_TransmitHandle *prev;
 184
 185   /**
 186    * Handle of the main transport data structure.
 187    */
 188   struct GNUNET_TRANSPORT_Handle *handle;
 189
 190   /**
 191    * Neighbour for this handle, can be NULL if the service
 192    * is not yet connected to the target.
 193    */
 194   struct NeighbourList *neighbour;
 195
 196   /**
 197    * Which peer is this transmission going to be for?  All
 198    * zeros if it is control-traffic to the service.
 199    */
 200   struct GNUNET_PeerIdentity target;
 201
 202   /**
 203    * Function to call when notify_size bytes are available
 204    * for transmission.
 205    */
 206   GNUNET_CONNECTION_TransmitReadyNotify notify;
 207
 208   /**
 209    * Closure for notify.
 210    */
 211   void *notify_cls;
 212
 213   /**
 214    * transmit_ready task Id.  The task is used to introduce the
 215    * artificial delay that may be required to maintain the bandwidth
 216    * limits.  Later, this will be the ID of the "transmit_timeout"
 217    * task which is used to signal a timeout if the transmission could
 218    * not be done in a timely fashion.
 219    */
 220   GNUNET_SCHEDULER_TaskIdentifier notify_delay_task;
 221
 222   /**
 223    * Timeout for this request.
 224    */
 225   struct GNUNET_TIME_Absolute timeout;
 226
 227   /**
 228    * How many bytes is our notify callback waiting for?
 229    */
 230   size_t notify_size;
 231
 232   /**
 233    * How important is this message?
 234    */
 235   unsigned int priority;
 236
 237 };
 238
 239
 240 /**
 241  * Handle for the transport service (includes all of the
 242  * state for the transport service).
 243  */
 244 struct GNUNET_TRANSPORT_Handle
 245 {
 246
 247   /**
 248    * Closure for the callbacks.
 249    */
 250   void *cls;
 251
 252   /**
 253    * Function to call for received data.
 254    */
 255   GNUNET_TRANSPORT_ReceiveCallback rec;
 256
 257   /**
 258    * function to call on connect events
 259    */
 260   GNUNET_TRANSPORT_NotifyConnect nc_cb;
 261
 262   /**
 263    * function to call on disconnect events
 264    */
 265   GNUNET_TRANSPORT_NotifyDisconnect nd_cb;
 266
 267   /**
 268    * The current HELLO message for this peer.  Updated
 269    * whenever transports change their addresses.
 270    */
 271   struct GNUNET_HELLO_Message *my_hello;
 272
 273   /**
 274    * My client connection to the transport service.
 275    */
 276   struct GNUNET_CLIENT_Connection *client;
 277
 278   /**
 279    * Handle to our registration with the client for notification.
 280    */
 281   struct GNUNET_CLIENT_TransmitHandle *network_handle;
 282
 283   /**
 284    * Linked list of transmit handles that are waiting for the
 285    * transport to connect to the respective peer.  When we
 286    * receive notification that the transport connected to a
 287    * peer, we go over this list and check if someone has already
 288    * requested a transmission to the new peer; if so, we trigger
 289    * the next step.
 290    */
 291   struct GNUNET_TRANSPORT_TransmitHandle *connect_wait_head;
 292
 293   /**
 294    * Linked list of transmit handles that are waiting for the
 295    * transport to be ready for transmission to the respective
 296    * peer.  When we
 297    * receive notification that the transport disconnected from
 298    * a peer, we go over this list and move the entry back to
 299    * the connect_wait list.
 300    */
 301   struct GNUNET_TRANSPORT_TransmitHandle *connect_ready_head;
 302
 303   /**
 304    * Linked list of pending requests for our HELLO.
 305    */
 306   struct HelloWaitList *hwl_head;
 307
 308   /**
 309    * My scheduler.
 310    */
 311   struct GNUNET_SCHEDULER_Handle *sched;
 312
 313   /**
 314    * My configuration.
 315    */
 316   const struct GNUNET_CONFIGURATION_Handle *cfg;
 317
 318   /**
 319    * Linked list of the current neighbours of this peer.
 320    */
 321   struct NeighbourList *neighbours;
 322
 323   /**
 324    * ID of the task trying to reconnect to the
 325    * service.
 326    */
 327   GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
 328
 329   /**
 330    * Delay until we try to reconnect.
 331    */
 332   struct GNUNET_TIME_Relative reconnect_delay;
 333
 334   /**
 335    * Do we currently have a transmission pending?
 336    * (schedule transmission was called but has not
 337    * yet succeeded)?
 338    */
 339   int transmission_scheduled;
 340 };
 341
 342
 343 static struct NeighbourList *
 344 find_neighbour (struct GNUNET_TRANSPORT_Handle *h,
 345                 const struct GNUNET_PeerIdentity *peer)
 346 {
 347   struct NeighbourList *pos;
 348
 349   pos = h->neighbours;
 350   while ((pos != NULL) &&
 351          (0 != memcmp (peer, &pos->id, sizeof (struct GNUNET_PeerIdentity))))
 352     pos = pos->next;
 353   return pos;
 354 }
 355
 356
 357 /**
 358  * Schedule the task to send one message from the
 359  * connect_ready list to the service.
 360  */
 361 static void schedule_transmission (struct GNUNET_TRANSPORT_Handle *h);
 362
 363
 364 /**
 365  * Transmit message to client...
 366  */
 367 static size_t
 368 transport_notify_ready (void *cls, size_t size, void *buf)
 369 {
 370   struct GNUNET_TRANSPORT_Handle *h = cls;
 371   struct GNUNET_TRANSPORT_TransmitHandle *th;
 372   struct NeighbourList *n;
 373   size_t ret;
 374   char *cbuf;
 375
 376   h->network_handle = NULL;
 377   h->transmission_scheduled = GNUNET_NO;
 378   if (buf == NULL)
 379     {
 380 #if DEBUG_TRANSPORT
 381       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 382                   "Could not transmit to transport service, cancelling pending requests\n");
 383 #endif
 384       th = h->connect_ready_head;
 385       if (th->next != NULL)
 386         th->next->prev = NULL;
 387       h->connect_ready_head = th->next;
 388       if (NULL != (n = th->neighbour))
 389         {
 390           GNUNET_assert (n->transmit_handle == th);
 391           n->transmit_handle = NULL;
 392         }
 393       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
 394         {
 395           GNUNET_SCHEDULER_cancel (h->sched,
 396                                    th->notify_delay_task);
 397           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 398         }
 399       GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
 400       GNUNET_free (th);
 401       if (h->connect_ready_head != NULL) schedule_transmission (h); /* FIXME: is this ok? */
 402       return 0;
 403     }
 404 #if DEBUG_TRANSPORT
 405   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 406               "Ready to transmit %u bytes to transport service\n", size);
 407 #endif
 408   cbuf = buf;
 409   ret = 0;
 410   h->network_handle = NULL;
 411   h->transmission_scheduled = GNUNET_NO;
 412   do
 413     {
 414       th = h->connect_ready_head;
 415       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
 416         {
 417           GNUNET_SCHEDULER_cancel (h->sched,
 418                                    th->notify_delay_task);
 419           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 420         }
 421       GNUNET_assert (th->notify_size <= size);
 422       if (th->next != NULL)
 423         th->next->prev = NULL;
 424       h->connect_ready_head = th->next;
 425       if (NULL != (n = th->neighbour))
 426         {
 427           GNUNET_assert (n->transmit_handle == th);
 428           n->transmit_handle = NULL;
 429         }
 430       ret += th->notify (th->notify_cls, size, &cbuf[ret]);
 431       GNUNET_free (th);
 432       if (n != NULL)
 433         n->last_sent += ret;
 434       size -= ret;
 435     }
 436   while ((h->connect_ready_head != NULL) &&
 437          (h->connect_ready_head->notify_size <= size));
 438   if (h->connect_ready_head != NULL)
 439     schedule_transmission (h);
 440 #if DEBUG_TRANSPORT
 441   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 442               "Transmitting %u bytes to transport service\n", ret);
 443 #endif
 444   return ret;
 445 }
 446
 447
 448 /**
 449  * Schedule the task to send one message from the
 450  * connect_ready list to the service.
 451  */
 452 static void
 453 schedule_transmission (struct GNUNET_TRANSPORT_Handle *h)
 454 {
 455   struct GNUNET_TRANSPORT_TransmitHandle *th;
 456
 457   GNUNET_assert (NULL == h->network_handle);
 458   if (h->client == NULL)
 459     {
 460       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 461                   "Could not yet schedule transmission: we are not yet connected to the transport service!\n");
 462       return; /* not yet connected */
 463     }
 464   th = h->connect_ready_head;
 465   if (th == NULL)
 466     return; /* no request pending */
 467   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
 468     {
 469       /* remove existing time out task, will be integrated
 470          with transmit_ready notification! */
 471       GNUNET_SCHEDULER_cancel (h->sched,
 472                                th->notify_delay_task);
 473       th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 474     }
 475   h->transmission_scheduled = GNUNET_YES;
 476   h->network_handle = GNUNET_CLIENT_notify_transmit_ready (h->client,
 477                                                            th->notify_size,
 478                                                            GNUNET_TIME_absolute_get_remaining
 479                                                            (th->timeout),
 480                                                            GNUNET_NO,
 481                                                            &transport_notify_ready,
 482                                                            h);
 483   GNUNET_assert (NULL != h->network_handle);
 484 }
 485
 486
 487 /**
 488  * Insert the given transmit handle in the given sorted
 489  * doubly linked list based on timeout.
 490  *
 491  * @param head pointer to the head of the linked list
 492  * @param th element to insert into the list
 493  */
 494 static void
 495 insert_transmit_handle (struct GNUNET_TRANSPORT_TransmitHandle **head,
 496                         struct GNUNET_TRANSPORT_TransmitHandle *th)
 497 {
 498   struct GNUNET_TRANSPORT_TransmitHandle *pos;
 499   struct GNUNET_TRANSPORT_TransmitHandle *prev;
 500
 501   pos = *head;
 502   prev = NULL;
 503   while ((pos != NULL) && (pos->timeout.value < th->timeout.value))
 504     {
 505       prev = pos;
 506       pos = pos->next;
 507     }
 508   if (prev == NULL)
 509     {
 510       th->next = *head;
 511       if (th->next != NULL)
 512         th->next->prev = th;
 513       *head = th;
 514     }
 515   else
 516     {
 517       th->next = pos;
 518       th->prev = prev;
 519       prev->next = th;
 520       if (pos != NULL)
 521         pos->prev = th;
 522     }
 523 }
 524
 525
 526 /**
 527  * Cancel a pending notify delay task (if pending) and also remove the
 528  * given transmit handle from whatever list is on.
 529  *
 530  * @param th handle for the transmission request to manipulate
 531  */
 532 static void
 533 remove_from_any_list (struct GNUNET_TRANSPORT_TransmitHandle *th)
 534 {
 535   struct GNUNET_TRANSPORT_Handle *h;
 536
 537   h = th->handle;
 538   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
 539     {
 540       GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
 541       th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 542     }
 543   if (th->prev == NULL)
 544     {
 545       if (th == h->connect_wait_head)
 546         h->connect_wait_head = th->next;
 547       else
 548         h->connect_ready_head = th->next;
 549     }
 550   else
 551     {
 552       th->prev->next = th->next;
 553     }
 554   if (th->next != NULL)
 555     th->next->prev = th->prev;
 556 }
 557
 558
 559 /**
 560  * Schedule a request to connect to the given
 561  * neighbour (and if successful, add the specified
 562  * handle to the wait list).
 563  *
 564  * @param th handle for a request to transmit once we
 565  *        have connected
 566  */
 567 static void
 568 try_connect (struct GNUNET_TRANSPORT_TransmitHandle *th);
 569
 570
 571 /**
 572  * Called when our transmit request timed out before any transport
 573  * reported success connecting to the desired peer or before the
 574  * transport was ready to receive.  Signal error and free
 575  * TransmitHandle.
 576  */
 577 static void
 578 peer_transmit_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 579 {
 580   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
 581
 582   th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 583   if (th->neighbour != NULL)
 584     th->neighbour->transmit_handle = NULL;
 585 #if DEBUG_TRANSPORT
 586   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 587               "Request for transmission to peer `%s' timed out.\n",
 588               GNUNET_i2s(&th->target));
 589 #endif
 590   remove_from_any_list (th);
 591   th->notify (th->notify_cls, 0, NULL);
 592   GNUNET_free (th);
 593 }
 594
 595
 596
 597
 598 /**
 599  * Queue control request for transmission to the transport
 600  * service.
 601  *
 602  * @param h handle to the transport service
 603  * @param size number of bytes to be transmitted
 604  * @param at_head request must be added to the head of the queue
 605  *        (otherwise request will be appended)
 606  * @param timeout how long this transmission can wait (at most)
 607  * @param notify function to call to get the content
 608  * @param notify_cls closure for notify
 609  */
 610 static void
 611 schedule_control_transmit (struct GNUNET_TRANSPORT_Handle *h,
 612                            size_t size,
 613                            int at_head,
 614                            struct GNUNET_TIME_Relative timeout,
 615                            GNUNET_CONNECTION_TransmitReadyNotify notify,
 616                            void *notify_cls)
 617 {
 618   struct GNUNET_TRANSPORT_TransmitHandle *th;
 619
 620 #if DEBUG_TRANSPORT
 621   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 622               "Control transmit of %u bytes within %llums requested\n",
 623               size,
 624               (unsigned long long) timeout.value);
 625 #endif
 626   th = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_TransmitHandle));
 627   th->handle = h;
 628   th->notify = notify;
 629   th->notify_cls = notify_cls;
 630   th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 631   th->notify_size = size;
 632   th->notify_delay_task
 633     = GNUNET_SCHEDULER_add_delayed (h->sched,
 634                                     timeout,
 635                                     &peer_transmit_timeout, th);
 636   if (at_head)
 637     {
 638       th->next = h->connect_ready_head;
 639       h->connect_ready_head = th;
 640       if (th->next != NULL)
 641         th->next->prev = th;
 642     }
 643   else
 644     {
 645       insert_transmit_handle (&h->connect_ready_head, th);
 646     }
 647   if (GNUNET_NO == h->transmission_scheduled)
 648     schedule_transmission (h);
 649 }
 650
 651
 652 /**
 653  * Update the quota values for the given neighbour now.
 654  */
 655 static void
 656 update_quota (struct NeighbourList *n)
 657 {
 658   struct GNUNET_TIME_Relative delta;
 659   uint64_t allowed;
 660   uint64_t remaining;
 661
 662   delta = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
 663   allowed = delta.value * n->quota_out;
 664   if (n->last_sent < allowed)
 665     {
 666       remaining = allowed - n->last_sent;
 667       if (n->quota_out > 0)
 668         remaining /= n->quota_out;
 669       else
 670         remaining = 0;
 671       if (remaining > MAX_BANDWIDTH_CARRY)
 672         remaining = MAX_BANDWIDTH_CARRY;
 673       n->last_sent = 0;
 674       n->last_quota_update = GNUNET_TIME_absolute_get ();
 675       n->last_quota_update.value -= remaining;
 676     }
 677   else
 678     {
 679       n->last_sent -= allowed;
 680       n->last_quota_update = GNUNET_TIME_absolute_get ();
 681     }
 682 }
 683
 684
 685 struct SetQuotaContext
 686 {
 687   struct GNUNET_TRANSPORT_Handle *handle;
 688
 689   struct GNUNET_PeerIdentity target;
 690
 691   GNUNET_SCHEDULER_Task cont;
 692
 693   void *cont_cls;
 694
 695   struct GNUNET_TIME_Absolute timeout;
 696
 697   uint32_t quota_in;
 698 };
 699
 700
 701 static size_t
 702 send_set_quota (void *cls, size_t size, void *buf)
 703 {
 704   struct SetQuotaContext *sqc = cls;
 705   struct QuotaSetMessage *msg;
 706
 707   if (buf == NULL)
 708     {
 709       GNUNET_SCHEDULER_add_continuation (sqc->handle->sched,
 710                                          sqc->cont,
 711                                          sqc->cont_cls,
 712                                          GNUNET_SCHEDULER_REASON_TIMEOUT);
 713       GNUNET_free (sqc);
 714       return 0;
 715     }
 716 #if DEBUG_TRANSPORT
 717   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 718               "Transmitting `%s' request with respect to `%4s'.\n",
 719               "SET_QUOTA", GNUNET_i2s (&sqc->target));
 720 #endif
 721   GNUNET_assert (size >= sizeof (struct QuotaSetMessage));
 722   msg = buf;
 723   msg->header.size = htons (sizeof (struct QuotaSetMessage));
 724   msg->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SET_QUOTA);
 725   msg->quota_in = htonl (sqc->quota_in);
 726   memcpy (&msg->peer, &sqc->target, sizeof (struct GNUNET_PeerIdentity));
 727   if (sqc->cont != NULL)
 728     GNUNET_SCHEDULER_add_continuation (sqc->handle->sched,
 729                                        sqc->cont,
 730                                        sqc->cont_cls,
 731                                        GNUNET_SCHEDULER_REASON_PREREQ_DONE);
 732   GNUNET_free (sqc);
 733   return sizeof (struct QuotaSetMessage);
 734 }
 735
 736
 737 /**
 738  * Set the share of incoming bandwidth for the given
 739  * peer to the specified amount.
 740  *
 741  * @param handle connection to transport service
 742  * @param target who's bandwidth quota is being changed
 743  * @param quota_in incoming bandwidth quota in bytes per ms; 0 can
 744  *        be used to force all traffic to be discarded
 745  * @param quota_out outgoing bandwidth quota in bytes per ms; 0 can
 746  *        be used to force all traffic to be discarded
 747  * @param timeout how long to wait until signaling failure if
 748  *        we can not communicate the quota change
 749  * @param cont continuation to call when done, will be called
 750  *        either with reason "TIMEOUT" or with reason "PREREQ_DONE"
 751  * @param cont_cls closure for continuation
 752  */
 753 void
 754 GNUNET_TRANSPORT_set_quota (struct GNUNET_TRANSPORT_Handle *handle,
 755                             const struct GNUNET_PeerIdentity *target,
 756                             uint32_t quota_in,
 757                             uint32_t quota_out,
 758                             struct GNUNET_TIME_Relative timeout,
 759                             GNUNET_SCHEDULER_Task cont, void *cont_cls)
 760 {
 761   struct NeighbourList *n;
 762   struct SetQuotaContext *sqc;
 763
 764   n = find_neighbour (handle, target);
 765   if (n != NULL)
 766     {
 767       update_quota (n);
 768       if (n->quota_out < quota_out)
 769         n->last_quota_update = GNUNET_TIME_absolute_get ();
 770       n->quota_out = quota_out;
 771     }
 772   sqc = GNUNET_malloc (sizeof (struct SetQuotaContext));
 773   sqc->handle = handle;
 774   sqc->target = *target;
 775   sqc->cont = cont;
 776   sqc->cont_cls = cont_cls;
 777   sqc->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 778   sqc->quota_in = quota_in;
 779   schedule_control_transmit (handle,
 780                              sizeof (struct QuotaSetMessage),
 781                              GNUNET_NO, timeout, &send_set_quota, sqc);
 782 }
 783
 784
 785 /**
 786  * A "get_hello" request has timed out.  Signal the client
 787  * and clean up.
 788  */
 789 static void
 790 hello_wait_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 791 {
 792   struct HelloWaitList *hwl = cls;
 793   struct HelloWaitList *pos;
 794   struct HelloWaitList *prev;
 795
 796   hwl->task = GNUNET_SCHEDULER_NO_TASK;
 797   if (GNUNET_TIME_absolute_get_remaining (hwl->timeout).value > 0)
 798     {
 799 #if DEBUG_TRANSPORT
 800       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 801                   _("First attempt to obtain `%s' from transport service failed, will try again for %llums.\n"),
 802                   "HELLO",
 803                   GNUNET_TIME_absolute_get_remaining (hwl->timeout).value);
 804 #endif
 805       hwl->task = GNUNET_SCHEDULER_add_delayed (hwl->handle->sched,
 806                                                 GNUNET_TIME_absolute_get_remaining (hwl->timeout),
 807                                                 &hello_wait_timeout, hwl);
 808       return;
 809     }
 810   /* signal timeout */
 811   GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 812               _("Timeout trying to obtain `%s' from transport service.\n"),
 813               "HELLO");
 814   prev = NULL;
 815   pos = hwl->handle->hwl_head;
 816   while (pos != hwl)
 817     {
 818       GNUNET_assert (pos != NULL);
 819       prev = pos;
 820       pos = pos->next;
 821     }
 822   if (prev == NULL)
 823     hwl->handle->hwl_head = hwl->next;
 824   else
 825     prev->next = hwl->next;
 826   if (hwl->rec != NULL)
 827     hwl->rec (hwl->rec_cls, GNUNET_TIME_UNIT_ZERO, NULL, NULL);
 828   GNUNET_free (hwl);
 829 }
 830
 831
 832 /**
 833  * Obtain the HELLO message for this peer.
 834  *
 835  * @param handle connection to transport service
 836  * @param timeout how long to wait for the HELLO
 837  * @param rec function to call with the HELLO, sender will be our peer
 838  *            identity; message and sender will be NULL on timeout
 839  *            (handshake with transport service pending/failed).
 840  *             cost estimate will be 0.
 841  * @param rec_cls closure for rec
 842  */
 843 void
 844 GNUNET_TRANSPORT_get_hello (struct GNUNET_TRANSPORT_Handle *handle,
 845                             struct GNUNET_TIME_Relative timeout,
 846                             GNUNET_TRANSPORT_ReceiveCallback rec,
 847                             void *rec_cls)
 848 {
 849   struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded pk;
 850   struct GNUNET_PeerIdentity me;
 851   struct HelloWaitList *hwl;
 852
 853   if (handle->my_hello == NULL)
 854     {
 855       hwl = GNUNET_malloc (sizeof (struct HelloWaitList));
 856       hwl->next = handle->hwl_head;
 857       handle->hwl_head = hwl;
 858       hwl->handle = handle;
 859       hwl->rec = rec;
 860       hwl->rec_cls = rec_cls;
 861       hwl->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 862       hwl->task = GNUNET_SCHEDULER_add_delayed (handle->sched,
 863                                                 timeout,
 864                                                 &hello_wait_timeout, hwl);
 865       return;
 866     }
 867   GNUNET_assert (GNUNET_OK == GNUNET_HELLO_get_key (handle->my_hello, &pk));
 868   GNUNET_CRYPTO_hash (&pk,
 869                       sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
 870                       &me.hashPubKey);
 871
 872   rec (rec_cls,
 873        GNUNET_TIME_UNIT_ZERO,
 874        &me, (const struct GNUNET_MessageHeader *) handle->my_hello);
 875 }
 876
 877
 878 static size_t
 879 send_hello (void *cls, size_t size, void *buf)
 880 {
 881   struct GNUNET_MessageHeader *hello = cls;
 882   uint16_t msize;
 883
 884   if (buf == NULL)
 885     {
 886 #if DEBUG_TRANSPORT
 887       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 888                   "Timeout while trying to transmit `%s' request.\n",
 889                   "HELLO");
 890 #endif
 891       GNUNET_free (hello);
 892       return 0;
 893     }
 894 #if DEBUG_TRANSPORT
 895   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 896               "Transmitting `%s' request.\n", "HELLO");
 897 #endif
 898   msize = ntohs (hello->size);
 899   GNUNET_assert (size >= msize);
 900   memcpy (buf, hello, msize);
 901   GNUNET_free (hello);
 902   return msize;
 903 }
 904
 905
 906 /**
 907  * Offer the transport service the HELLO of another peer.  Note that
 908  * the transport service may just ignore this message if the HELLO is
 909  * malformed or useless due to our local configuration.
 910  *
 911  * @param handle connection to transport service
 912  * @param hello the hello message
 913  */
 914 void
 915 GNUNET_TRANSPORT_offer_hello (struct GNUNET_TRANSPORT_Handle *handle,
 916                               const struct GNUNET_MessageHeader *hello)
 917 {
 918   struct GNUNET_MessageHeader *hc;
 919   uint16_t size;
 920
 921   if (handle->client == NULL)
 922     {
 923 #if DEBUG_TRANSPORT
 924       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 925                   "Not connected to transport service, dropping offered HELLO\n");
 926 #endif
 927       return;
 928     }
 929   GNUNET_break (ntohs (hello->type) == GNUNET_MESSAGE_TYPE_HELLO);
 930   size = ntohs (hello->size);
 931   GNUNET_break (size >= sizeof (struct GNUNET_MessageHeader));
 932   hc = GNUNET_malloc (size);
 933   memcpy (hc, hello, size);
 934   schedule_control_transmit (handle,
 935                              size,
 936                              GNUNET_NO, OFFER_HELLO_TIMEOUT, &send_hello, hc);
 937 }
 938
 939
 940 /**
 941  * Function we use for handling incoming messages.
 942  */
 943 static void demultiplexer (void *cls, const struct GNUNET_MessageHeader *msg);
 944
 945
 946 static size_t
 947 send_start (void *cls, size_t size, void *buf)
 948 {
 949   struct GNUNET_MessageHeader *s = buf;
 950
 951   if (buf == NULL)
 952     {
 953 #if DEBUG_TRANSPORT
 954       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 955                   "Timeout while trying to transmit `%s' request.\n",
 956                   "START");
 957 #endif
 958       return 0;
 959     }
 960 #if DEBUG_TRANSPORT
 961   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 962               "Transmitting `%s' request.\n", "START");
 963 #endif
 964   GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
 965   s->size = htons (sizeof (struct GNUNET_MessageHeader));
 966   s->type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_START);
 967   return sizeof (struct GNUNET_MessageHeader);
 968 }
 969
 970
 971 /**
 972  * We're ready to transmit the request that the transport service
 973  * should connect to a new peer.  In addition to sending the
 974  * request, schedule the next phase for the transmission processing
 975  * that caused the connect request in the first place.
 976  */
 977 static size_t
 978 request_connect (void *cls, size_t size, void *buf)
 979 {
 980   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
 981   struct TryConnectMessage *tcm;
 982   struct GNUNET_TRANSPORT_Handle *h;
 983
 984   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_TASK);
 985   h = th->handle;
 986   if (buf == NULL)
 987     {
 988 #if DEBUG_TRANSPORT
 989       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 990                   "Failed to transmit `%s' request for `%4s' to service.\n",
 991                   "TRY_CONNECT",
 992                   GNUNET_i2s(&th->target));
 993 #endif
 994       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
 995         {
 996           GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
 997           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 998         }
 999       th->notify (th->notify_cls, 0, NULL);
1000       GNUNET_free (th);
1001       return 0;
1002     }
1003 #if DEBUG_TRANSPORT
1004   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1005               "Transmitting `%s' message for `%4s' (need connection in %llu ms).\n",
1006               "TRY_CONNECT", GNUNET_i2s (&th->target),
1007               GNUNET_TIME_absolute_get_remaining (th->timeout).value);
1008 #endif
1009   GNUNET_assert (size >= sizeof (struct TryConnectMessage));
1010   tcm = buf;
1011   tcm->header.size = htons (sizeof (struct TryConnectMessage));
1012   tcm->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_TRY_CONNECT);
1013   tcm->reserved = htonl (0);
1014   memcpy (&tcm->peer, &th->target, sizeof (struct GNUNET_PeerIdentity));
1015   th->notify_delay_task
1016     = GNUNET_SCHEDULER_add_delayed (h->sched,
1017                                     GNUNET_TIME_absolute_get_remaining
1018                                     (th->timeout),
1019                                     &peer_transmit_timeout, th);
1020   insert_transmit_handle (&h->connect_wait_head, th);
1021   return sizeof (struct TryConnectMessage);
1022 }
1023
1024
1025 /**
1026  * Schedule a request to connect to the given
1027  * neighbour (and if successful, add the specified
1028  * handle to the wait list).
1029  *
1030  * @param th handle for a request to transmit once we
1031  *        have connected
1032  */
1033 static void
1034 try_connect (struct GNUNET_TRANSPORT_TransmitHandle *th)
1035 {
1036   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_TASK);
1037   schedule_control_transmit (th->handle,
1038                              sizeof (struct TryConnectMessage),
1039                              GNUNET_NO,
1040                              GNUNET_TIME_absolute_get_remaining (th->timeout),
1041                              &request_connect, th);
1042 }
1043
1044
1045 /**
1046  * Task for delayed attempts to reconnect to a peer.
1047  *
1048  * @param cls must be a transmit handle that determines the peer
1049  *        to which we will try to connect
1050  * @param tc scheduler information about why we were triggered (not used)
1051  */
1052 static void
1053 try_connect_task (void *cls,
1054                   const struct GNUNET_SCHEDULER_TaskContext *tc)
1055 {
1056   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
1057
1058   th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1059   try_connect (th);
1060 }
1061
1062
1063 /**
1064  * Remove neighbour from our list.  Will automatically
1065  * trigger a re-connect attempt if we have messages pending
1066  * for this peer.
1067  *
1068  * @param h our state
1069  * @param peer the peer to remove
1070  */
1071 static void
1072 remove_neighbour (struct GNUNET_TRANSPORT_Handle *h,
1073                   const struct GNUNET_PeerIdentity *peer)
1074 {
1075   struct NeighbourList *prev;
1076   struct NeighbourList *pos;
1077   struct GNUNET_TRANSPORT_TransmitHandle *th;
1078
1079 #if DEBUG_TRANSPORT
1080   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1081               "Removing neighbour `%s' from list of connected peers.\n",
1082               GNUNET_i2s (peer));
1083 #endif
1084   prev = NULL;
1085   pos = h->neighbours;
1086   while ((pos != NULL) &&
1087          (0 != memcmp (peer,
1088                        &pos->id,
1089                        sizeof (struct GNUNET_PeerIdentity))))
1090     {
1091       prev = pos;
1092       pos = pos->next;
1093     }
1094   if (pos == NULL)
1095     {
1096       GNUNET_break (0);
1097       return;
1098     }
1099   if (prev == NULL)
1100     h->neighbours = pos->next;
1101   else
1102     prev->next = pos->next;
1103   if (NULL != (th = pos->transmit_handle))
1104     {
1105       pos->transmit_handle = NULL;
1106       th->neighbour = NULL;
1107       remove_from_any_list (th);
1108       if (GNUNET_TIME_absolute_get_remaining (th->timeout).value <= CONNECT_RETRY_TIMEOUT.value)
1109         {
1110           /* signal error */
1111           GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1112                       _("Connection with `%4s' failed and timeout was in the past, giving up on message delivery.\n"),
1113                       GNUNET_i2s (peer));
1114           GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == th->notify_delay_task);
1115           peer_transmit_timeout (th, NULL);
1116         }
1117       else
1118         {
1119           GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1120                       _("Connection with `%4s' failed, will keep trying for %llu ms to deliver message\n"),
1121                       GNUNET_i2s (peer),
1122                       GNUNET_TIME_absolute_get_remaining (th->timeout).value);
1123           /* try again in a bit */
1124           GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == th->notify_delay_task);
1125           th->notify_delay_task
1126             = GNUNET_SCHEDULER_add_delayed (h->sched,
1127                                             CONNECT_RETRY_TIMEOUT,
1128                                             &try_connect_task,
1129                                             th);
1130         }
1131     }
1132   if (h->nc_cb != NULL)
1133     h->nd_cb (h->cls, peer);
1134   GNUNET_free (pos);
1135 }
1136
1137
1138 /**
1139  * Try again to connect to transport service.
1140  */
1141 static void
1142 reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1143 {
1144   struct GNUNET_TRANSPORT_Handle *h = cls;
1145   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1146   struct NeighbourList *n;
1147
1148   /* Forget about all neighbours that we used to be connected
1149      to */
1150   while (NULL != (n = h->neighbours))
1151     remove_neighbour (h, &n->id);
1152 #if DEBUG_TRANSPORT
1153   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connecting to transport service.\n");
1154 #endif
1155   GNUNET_assert (h->client == NULL);
1156   h->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
1157   h->client = GNUNET_CLIENT_connect (h->sched, "transport", h->cfg);
1158   GNUNET_assert (h->client != NULL);
1159   /* make sure we don't send "START" twice,
1160      remove existing entry from queue (if present) */
1161   pos = h->connect_ready_head;
1162   while (pos != NULL)
1163     {
1164       if (pos->notify == &send_start)
1165         {
1166           if (pos->prev == NULL)
1167             h->connect_ready_head = pos->next;
1168           else
1169             pos->prev->next = pos->next;
1170           if (pos->next != NULL)
1171             pos->next->prev = pos->prev;
1172           GNUNET_assert (pos->neighbour == NULL);
1173           if (GNUNET_SCHEDULER_NO_TASK != pos->notify_delay_task)
1174             {
1175               GNUNET_SCHEDULER_cancel (h->sched,
1176                                        pos->notify_delay_task);
1177               pos->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1178             }
1179           GNUNET_free (pos);
1180           break;
1181         }
1182       pos = pos->next;
1183     }
1184   schedule_control_transmit (h,
1185                              sizeof (struct GNUNET_MessageHeader),
1186                              GNUNET_YES,
1187                              GNUNET_TIME_UNIT_FOREVER_REL,
1188                              &send_start, NULL);
1189   GNUNET_CLIENT_receive (h->client,
1190                          &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL);
1191 }
1192
1193
1194 /**
1195  * Function that will schedule the job that will try
1196  * to connect us again to the client.
1197  */
1198 static void
1199 schedule_reconnect (struct GNUNET_TRANSPORT_Handle *h)
1200 {
1201 #if DEBUG_TRANSPORT
1202   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1203               "Scheduling task to reconnect to transport service in %llu ms.\n",
1204               h->reconnect_delay.value);
1205 #endif
1206   GNUNET_assert (h->client == NULL);
1207   GNUNET_assert (h->reconnect_task == GNUNET_SCHEDULER_NO_TASK);
1208   h->reconnect_task
1209     = GNUNET_SCHEDULER_add_delayed (h->sched,
1210                                     h->reconnect_delay, &reconnect, h);
1211   h->reconnect_delay = GNUNET_TIME_UNIT_SECONDS;
1212 }
1213
1214
1215 /**
1216  * We are connected to the respective peer, check the
1217  * bandwidth limits and schedule the transmission.
1218  */
1219 static void schedule_request (struct GNUNET_TRANSPORT_TransmitHandle *th);
1220
1221
1222 /**
1223  * Function called by the scheduler when the timeout
1224  * for bandwidth availablility for the target
1225  * neighbour is reached.
1226  */
1227 static void
1228 transmit_ready (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1229 {
1230   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
1231
1232   th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1233   schedule_request (th);
1234 }
1235
1236
1237 /**
1238  * Remove the given transmit handle from the wait list.  Does NOT free
1239  * it.
1240  */
1241 static void
1242 remove_from_wait_list (struct GNUNET_TRANSPORT_TransmitHandle *th)
1243 {
1244   if (th->prev == NULL)
1245     th->handle->connect_wait_head = th->next;
1246   else
1247     th->prev->next = th->next;
1248   if (th->next != NULL)
1249     th->next->prev = th->prev;
1250 }
1251
1252
1253 /**
1254  * We are connected to the respective peer, check the
1255  * bandwidth limits and schedule the transmission.
1256  */
1257 static void
1258 schedule_request (struct GNUNET_TRANSPORT_TransmitHandle *th)
1259 {
1260   struct GNUNET_TRANSPORT_Handle *h;
1261   struct GNUNET_TIME_Relative duration;
1262   struct NeighbourList *n;
1263   uint64_t available;
1264
1265   h = th->handle;
1266   n = th->neighbour;
1267   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1268     {
1269       GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
1270       th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1271     }
1272   /* check outgoing quota */
1273   duration = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
1274   if (duration.value > MIN_QUOTA_REFRESH_TIME)
1275     {
1276       update_quota (n);
1277       duration = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
1278     }
1279   available = duration.value * n->quota_out;
1280   if (available < n->last_sent + th->notify_size)
1281     {
1282       /* calculate how much bandwidth we'd still need to
1283          accumulate and based on that how long we'll have
1284          to wait... */
1285       available = n->last_sent + th->notify_size - available;
1286       duration = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS,
1287                                                 available / n->quota_out);
1288       if (th->timeout.value <
1289           GNUNET_TIME_relative_to_absolute (duration).value)
1290         {
1291           /* signal timeout! */
1292 #if DEBUG_TRANSPORT
1293           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1294                       "Would need %llu ms before bandwidth is available for delivery to `%4s', that is too long.  Signaling timeout.\n",
1295                       duration.value,
1296                       GNUNET_i2s(&th->target));
1297 #endif
1298           remove_from_wait_list (th);
1299           th->notify (th->notify_cls, 0, NULL);
1300           GNUNET_free (th);
1301           return;
1302         }
1303 #if DEBUG_TRANSPORT
1304       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1305                   "Need more bandwidth, delaying delivery to `%4s' by %llu ms\n",
1306                   GNUNET_i2s(&th->target),
1307                   duration.value);
1308 #endif
1309       th->notify_delay_task
1310         = GNUNET_SCHEDULER_add_delayed (h->sched,
1311                                         duration, &transmit_ready, th);
1312       return;
1313     }
1314 #if DEBUG_TRANSPORT
1315   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1316               "Bandwidth available for transmission to `%4s'\n",
1317               GNUNET_i2s (&n->id));
1318 #endif
1319   if (GNUNET_NO == n->transmit_ok)
1320     {
1321       /* we may be ready, but transport service is not;
1322          wait for SendOkMessage or timeout */
1323 #if DEBUG_TRANSPORT
1324       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1325                   "Need to wait for transport service `%s' message\n",
1326                   "SEND_OK");
1327 #endif
1328       th->notify_delay_task
1329         = GNUNET_SCHEDULER_add_delayed (h->sched,
1330                                         GNUNET_TIME_absolute_get_remaining
1331                                         (th->timeout), &peer_transmit_timeout, th);
1332       return;
1333     }
1334   n->transmit_ok = GNUNET_NO;
1335   remove_from_wait_list (th);
1336 #if DEBUG_TRANSPORT
1337   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Moving message for `%4s' to ready list\n",
1338               GNUNET_i2s(&n->id));
1339 #endif
1340   insert_transmit_handle (&h->connect_ready_head, th);
1341   if (GNUNET_NO == h->transmission_scheduled)
1342     schedule_transmission (h);
1343 }
1344
1345
1346 /**
1347  * Add neighbour to our list
1348  */
1349 static void
1350 add_neighbour (struct GNUNET_TRANSPORT_Handle *h,
1351                uint32_t quota_out,
1352                struct GNUNET_TIME_Relative latency,
1353                const struct GNUNET_PeerIdentity *pid)
1354 {
1355   struct NeighbourList *n;
1356   struct GNUNET_TRANSPORT_TransmitHandle *prev;
1357   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1358   struct GNUNET_TRANSPORT_TransmitHandle *next;
1359
1360   /* check for duplicates */
1361   if (NULL != find_neighbour (h, pid))
1362     {
1363       GNUNET_break (0);
1364       return;
1365     }
1366 #if DEBUG_TRANSPORT
1367   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1368               "Creating entry for new neighbour `%4s'.\n", GNUNET_i2s (pid));
1369 #endif
1370   n = GNUNET_malloc (sizeof (struct NeighbourList));
1371   n->id = *pid;
1372   n->last_quota_update = GNUNET_TIME_absolute_get ();
1373   n->quota_out = quota_out;
1374   n->next = h->neighbours;
1375   n->transmit_ok = GNUNET_YES;
1376   h->neighbours = n;
1377   if (h->nc_cb != NULL)
1378     h->nc_cb (h->cls, &n->id, latency);
1379   prev = NULL;
1380   pos = h->connect_wait_head;
1381   while (pos != NULL)
1382     {
1383       next = pos->next;
1384       if (0 == memcmp (pid,
1385                        &pos->target, sizeof (struct GNUNET_PeerIdentity)))
1386         {
1387           pos->neighbour = n;
1388           GNUNET_assert (NULL == n->transmit_handle);
1389           n->transmit_handle = pos;
1390           if (prev == NULL)
1391             h->connect_wait_head = next;
1392           else
1393             prev->next = next;
1394           if (GNUNET_YES == n->received_ack)
1395             {
1396 #if DEBUG_TRANSPORT
1397               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1398                           "Found pending request for `%4s' will trigger it now.\n",
1399                           GNUNET_i2s (&pos->target));
1400 #endif
1401               if (pos->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1402                 {
1403                   GNUNET_SCHEDULER_cancel (h->sched, pos->notify_delay_task);
1404                   pos->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1405                 }
1406               schedule_request (pos);
1407             }
1408           else
1409             {
1410 #if DEBUG_TRANSPORT
1411               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1412                           "Found pending request for `%4s' but still need `%s' before proceeding.\n",
1413                           GNUNET_i2s (&pos->target),
1414                           "ACK");
1415 #endif
1416             }
1417           break;
1418         }
1419       prev = pos;
1420       pos = next;
1421     }
1422 }
1423
1424
1425 /**
1426  * Connect to the transport service.  Note that the connection may
1427  * complete (or fail) asynchronously.
1428  *
1429
1430  * @param sched scheduler to use
1431  * @param cfg configuration to use
1432  * @param cls closure for the callbacks
1433  * @param rec receive function to call
1434  * @param nc function to call on connect events
1435  * @param nd function to call on disconnect events
1436  */
1437 struct GNUNET_TRANSPORT_Handle *
1438 GNUNET_TRANSPORT_connect (struct GNUNET_SCHEDULER_Handle *sched,
1439                           const struct GNUNET_CONFIGURATION_Handle *cfg,
1440                           void *cls,
1441                           GNUNET_TRANSPORT_ReceiveCallback rec,
1442                           GNUNET_TRANSPORT_NotifyConnect nc,
1443                           GNUNET_TRANSPORT_NotifyDisconnect nd)
1444 {
1445   struct GNUNET_TRANSPORT_Handle *ret;
1446
1447   GNUNET_ARM_start_services (cfg, sched, "peerinfo", "transport", NULL);
1448   ret = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_Handle));
1449   ret->sched = sched;
1450   ret->cfg = cfg;
1451   ret->cls = cls;
1452   ret->rec = rec;
1453   ret->nc_cb = nc;
1454   ret->nd_cb = nd;
1455   ret->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
1456   schedule_reconnect (ret);
1457   return ret;
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,
1474               "Transport disconnect called!\n");
1475 #endif
1476   while (NULL != (th = handle->connect_ready_head))
1477     {
1478       handle->connect_ready_head = th->next;
1479       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1480         {
1481           GNUNET_SCHEDULER_cancel (handle->sched, th->notify_delay_task);
1482           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1483         }
1484       th->notify (th->notify_cls, 0, NULL);
1485       GNUNET_free (th);
1486     }
1487   while (NULL != (th = handle->connect_wait_head))
1488     {
1489       handle->connect_wait_head = th->next;
1490       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1491         {
1492           GNUNET_SCHEDULER_cancel (handle->sched, th->notify_delay_task);
1493           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1494         }
1495       th->notify (th->notify_cls, 0, NULL);
1496       GNUNET_free (th);
1497     }
1498   while (NULL != (n = handle->neighbours))
1499     {
1500       handle->neighbours = n->next;
1501       GNUNET_free (n);
1502     }
1503   while (NULL != (hwl = handle->hwl_head))
1504     {
1505       handle->hwl_head = hwl->next;
1506       GNUNET_SCHEDULER_cancel (handle->sched, hwl->task);
1507       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1508                   _("Disconnect while trying to obtain `%s' from transport service.\n"),
1509                   "HELLO");
1510       if (hwl->rec != NULL)
1511         hwl->rec (hwl->rec_cls, GNUNET_TIME_UNIT_ZERO, NULL, NULL);
1512       GNUNET_free (hwl);
1513     }
1514   if (handle->reconnect_task != GNUNET_SCHEDULER_NO_TASK)
1515     {
1516       GNUNET_SCHEDULER_cancel (handle->sched, handle->reconnect_task);
1517       handle->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
1518     }
1519   GNUNET_free_non_null (handle->my_hello);
1520   handle->my_hello = NULL;
1521   GNUNET_ARM_stop_services (handle->cfg, handle->sched, "transport", "peerinfo", NULL);
1522   if (NULL != handle->network_handle)
1523     {
1524       GNUNET_CLIENT_notify_transmit_ready_cancel (handle->network_handle);
1525       handle->network_handle = NULL;
1526     }
1527   if (NULL != (client = handle->client))
1528     {
1529 #if DEBUG_TRANSPORT
1530       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1531                   "Disconnecting from transport service for good.\n");
1532 #endif
1533       handle->client = NULL;
1534       GNUNET_CLIENT_disconnect (client);
1535     }
1536   GNUNET_free (handle);
1537 }
1538
1539
1540 /**
1541  * Type of a function to call when we receive a message
1542  * from the service.
1543  *
1544  * @param cls closure
1545  * @param msg message received, NULL on timeout or fatal error
1546  */
1547 static void
1548 demultiplexer (void *cls, const struct GNUNET_MessageHeader *msg)
1549 {
1550   struct GNUNET_TRANSPORT_Handle *h = cls;
1551   const struct DisconnectInfoMessage *dim;
1552   const struct ConnectInfoMessage *cim;
1553   const struct InboundMessage *im;
1554   const struct GNUNET_MessageHeader *imm;
1555   const struct SendOkMessage *okm;
1556   struct HelloWaitList *hwl;
1557   struct NeighbourList *n;
1558   struct GNUNET_PeerIdentity me;
1559   struct GNUNET_TRANSPORT_TransmitHandle *th;
1560   uint16_t size;
1561
1562   if ((msg == NULL) || (h->client == NULL))
1563     {
1564       if (h->client != NULL)
1565         {
1566 #if DEBUG_TRANSPORT
1567           GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1568                       "Error receiving from transport service, disconnecting temporarily.\n");
1569 #endif
1570           if (h->network_handle != NULL)
1571             {
1572               GNUNET_CLIENT_notify_transmit_ready_cancel (h->network_handle);
1573               h->network_handle = NULL;
1574               h->transmission_scheduled = GNUNET_NO;
1575               th = h->connect_ready_head;
1576               /* add timeout again, we cancelled the transmit_ready task! */
1577               GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_TASK);
1578               th->notify_delay_task
1579                 = GNUNET_SCHEDULER_add_delayed (h->sched,
1580                                                 GNUNET_TIME_absolute_get_remaining(th->timeout),
1581                                                 &peer_transmit_timeout,
1582                                                 th);
1583             }
1584           GNUNET_CLIENT_disconnect (h->client);
1585           h->client = NULL;
1586           schedule_reconnect (h);
1587         }
1588       else
1589         {
1590           /* shutdown initiated from 'GNUNET_TRANSPORT_disconnect',
1591              finish clean up work! */
1592           GNUNET_free (h);
1593         }
1594       return;
1595     }
1596   GNUNET_CLIENT_receive (h->client,
1597                          &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL);
1598   size = ntohs (msg->size);
1599   switch (ntohs (msg->type))
1600     {
1601     case GNUNET_MESSAGE_TYPE_HELLO:
1602       if (GNUNET_OK !=
1603           GNUNET_HELLO_get_id ((const struct GNUNET_HELLO_Message *) msg,
1604                                &me))
1605         {
1606           GNUNET_break (0);
1607           break;
1608         }
1609 #if DEBUG_TRANSPORT
1610       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1611                   "Receiving (my own) `%s' message, I am `%4s'.\n",
1612                   "HELLO", GNUNET_i2s (&me));
1613 #endif
1614       GNUNET_free_non_null (h->my_hello);
1615       h->my_hello = NULL;
1616       if (size < sizeof (struct GNUNET_MessageHeader))
1617         {
1618           GNUNET_break (0);
1619           break;
1620         }
1621       h->my_hello = GNUNET_malloc (size);
1622       memcpy (h->my_hello, msg, size);
1623       while (NULL != (hwl = h->hwl_head))
1624         {
1625           h->hwl_head = hwl->next;
1626           GNUNET_SCHEDULER_cancel (h->sched, hwl->task);
1627           GNUNET_TRANSPORT_get_hello (h,
1628                                       GNUNET_TIME_UNIT_ZERO,
1629                                       hwl->rec, hwl->rec_cls);
1630           GNUNET_free (hwl);
1631         }
1632       break;
1633     case GNUNET_MESSAGE_TYPE_TRANSPORT_CONNECT:
1634       if (size != sizeof (struct ConnectInfoMessage))
1635         {
1636           GNUNET_break (0);
1637           break;
1638         }
1639       cim = (const struct ConnectInfoMessage *) msg;
1640 #if DEBUG_TRANSPORT
1641       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1642                   "Receiving `%s' message for `%4s'.\n",
1643                   "CONNECT", GNUNET_i2s (&cim->id));
1644 #endif
1645       add_neighbour (h,
1646                      ntohl (cim->quota_out),
1647                      GNUNET_TIME_relative_ntoh (cim->latency), &cim->id);
1648       break;
1649     case GNUNET_MESSAGE_TYPE_TRANSPORT_DISCONNECT:
1650       if (size != sizeof (struct DisconnectInfoMessage))
1651         {
1652           GNUNET_break (0);
1653           break;
1654         }
1655       dim = (const struct DisconnectInfoMessage *) msg;
1656 #if DEBUG_TRANSPORT
1657       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1658                   "Receiving `%s' message for `%4s'.\n",
1659                   "DISCONNECT", GNUNET_i2s (&dim->peer));
1660 #endif
1661       remove_neighbour (h, &dim->peer);
1662       break;
1663     case GNUNET_MESSAGE_TYPE_TRANSPORT_SEND_OK:
1664       if (size != sizeof (struct SendOkMessage))
1665         {
1666           GNUNET_break (0);
1667           break;
1668         }
1669       okm = (const struct SendOkMessage *) msg;
1670 #if DEBUG_TRANSPORT
1671       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1672                   "Receiving `%s' message, transmission %s.\n", "SEND_OK",
1673                   ntohl(okm->success) == GNUNET_OK ? "succeeded" : "failed");
1674 #endif
1675       n = find_neighbour (h, &okm->peer);
1676       GNUNET_assert (n != NULL);
1677       n->transmit_ok = GNUNET_YES;
1678       if (n->transmit_handle != NULL)
1679         {
1680 #if DEBUG_TRANSPORT
1681           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1682                       "Processing pending message for `%4s'\n",
1683                       GNUNET_i2s(&n->id));
1684 #endif
1685           GNUNET_SCHEDULER_cancel (h->sched,
1686                                    n->transmit_handle->notify_delay_task);
1687           n->transmit_handle->notify_delay_task =
1688             GNUNET_SCHEDULER_NO_TASK;
1689           GNUNET_assert (GNUNET_YES == n->received_ack);
1690           schedule_request (n->transmit_handle);
1691         }
1692       break;
1693     case GNUNET_MESSAGE_TYPE_TRANSPORT_RECV:
1694 #if DEBUG_TRANSPORT
1695       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1696                   "Receiving `%s' message.\n", "RECV");
1697 #endif
1698       if (size <
1699           sizeof (struct InboundMessage) +
1700           sizeof (struct GNUNET_MessageHeader))
1701         {
1702           GNUNET_break (0);
1703           break;
1704         }
1705       im = (const struct InboundMessage *) msg;
1706       imm = (const struct GNUNET_MessageHeader *) &im[1];
1707       if (ntohs (imm->size) + sizeof (struct InboundMessage) != size)
1708         {
1709           GNUNET_break (0);
1710           break;
1711         }
1712       switch (ntohs (imm->type))
1713         {
1714         case GNUNET_MESSAGE_TYPE_TRANSPORT_ACK:
1715 #if DEBUG_TRANSPORT
1716           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1717                       "Receiving `%s' message from `%4s'.\n",
1718                       "ACK", GNUNET_i2s (&im->peer));
1719 #endif
1720           n = find_neighbour (h, &im->peer);
1721           if (n == NULL)
1722             {
1723               GNUNET_break (0);
1724               break;
1725             }
1726           if (n->received_ack == GNUNET_NO)
1727             {
1728               n->received_ack = GNUNET_YES;
1729               if (NULL != n->transmit_handle)
1730                 {
1731 #if DEBUG_TRANSPORT
1732                   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1733                               "Peer connected, scheduling delayed message for deliverery now.\n");
1734 #endif
1735                   schedule_request (n->transmit_handle);
1736                 }
1737             }
1738           break;
1739         default:
1740 #if DEBUG_TRANSPORT
1741           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1742                       "Received message of type %u from `%4s'.\n",
1743                       ntohs (imm->type), GNUNET_i2s (&im->peer));
1744 #endif
1745           if (h->rec != NULL)
1746             h->rec (h->cls,
1747                     GNUNET_TIME_relative_ntoh (im->latency), &im->peer, imm);
1748           break;
1749         }
1750       break;
1751     default:
1752       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1753                   _
1754                   ("Received unexpected message of type %u in %s:%u\n"),
1755                   ntohs (msg->type), __FILE__, __LINE__);
1756       GNUNET_break (0);
1757       break;
1758     }
1759 }
1760
1761
1762 struct ClientTransmitWrapper
1763 {
1764   GNUNET_CONNECTION_TransmitReadyNotify notify;
1765   void *notify_cls;
1766   struct GNUNET_TRANSPORT_TransmitHandle *th;
1767 };
1768
1769
1770 /**
1771  * Transmit message of a client destined for another
1772  * peer to the service.
1773  */
1774 static size_t
1775 client_notify_wrapper (void *cls, size_t size, void *buf)
1776 {
1777   struct ClientTransmitWrapper *ctw = cls;
1778   struct OutboundMessage *obm;
1779   struct GNUNET_MessageHeader *hdr;
1780   size_t ret;
1781
1782   if (size == 0)
1783     {
1784 #if DEBUG_TRANSPORT
1785       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1786                   "Transmission request could not be satisfied.\n");
1787 #endif
1788       ret = ctw->notify (ctw->notify_cls, 0, NULL);
1789       GNUNET_assert (ret == 0);
1790       GNUNET_free (ctw);
1791       return 0;
1792     }
1793   GNUNET_assert (size >= sizeof (struct OutboundMessage));
1794   obm = buf;
1795   ret = ctw->notify (ctw->notify_cls,
1796                      size - sizeof (struct OutboundMessage),
1797                      (void *) &obm[1]);
1798   if (ret == 0)
1799     {
1800       /* Need to reset flag, no SEND means no SEND_OK! */
1801       ctw->th->neighbour->transmit_ok = GNUNET_YES;
1802       GNUNET_free (ctw);
1803       return 0;
1804     }
1805   GNUNET_assert (ret >= sizeof (struct GNUNET_MessageHeader));
1806   hdr = (struct GNUNET_MessageHeader *) &obm[1];
1807   GNUNET_assert (ntohs (hdr->size) == ret);
1808   GNUNET_assert (ret + sizeof (struct OutboundMessage) <
1809                  GNUNET_SERVER_MAX_MESSAGE_SIZE);
1810 #if DEBUG_TRANSPORT
1811   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1812               "Transmitting `%s' message with data for `%4s'\n",
1813               "SEND", GNUNET_i2s (&ctw->th->target));
1814 #endif
1815   ret += sizeof (struct OutboundMessage);
1816   obm->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SEND);
1817   obm->header.size = htons (ret);
1818   obm->priority = htonl (ctw->th->priority);
1819   obm->peer = ctw->th->target;
1820   GNUNET_free (ctw);
1821   return ret;
1822 }
1823
1824
1825
1826 /**
1827  * Check if we could queue a message of the given size for
1828  * transmission.  The transport service will take both its
1829  * internal buffers and bandwidth limits imposed by the
1830  * other peer into consideration when answering this query.
1831  *
1832  * @param handle connection to transport service
1833  * @param target who should receive the message
1834  * @param size how big is the message we want to transmit?
1835  * @param priority how important is the message?
1836  * @param timeout after how long should we give up (and call
1837  *        notify with buf NULL and size 0)?
1838  * @param notify function to call when we are ready to
1839  *        send such a message
1840  * @param notify_cls closure for notify
1841  * @return NULL if someone else is already waiting to be notified
1842  *         non-NULL if the notify callback was queued (can be used to cancel
1843  *         using GNUNET_TRANSPORT_notify_transmit_ready_cancel)
1844  */
1845 struct GNUNET_TRANSPORT_TransmitHandle *
1846 GNUNET_TRANSPORT_notify_transmit_ready (struct GNUNET_TRANSPORT_Handle
1847                                         *handle,
1848                                         const struct GNUNET_PeerIdentity
1849                                         *target, size_t size,
1850                                         unsigned int priority,
1851                                         struct GNUNET_TIME_Relative timeout,
1852                                         GNUNET_CONNECTION_TransmitReadyNotify
1853                                         notify, void *notify_cls)
1854 {
1855   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1856   struct GNUNET_TRANSPORT_TransmitHandle *th;
1857   struct NeighbourList *n;
1858   struct ClientTransmitWrapper *ctw;
1859
1860   if (size + sizeof (struct OutboundMessage) >=
1861       GNUNET_SERVER_MAX_MESSAGE_SIZE)
1862     {
1863       GNUNET_break (0);
1864       return NULL;
1865     }
1866 #if DEBUG_TRANSPORT
1867   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1868               "Asking transport service for transmission of %u bytes to peer `%4s'.\n",
1869               size, GNUNET_i2s (target));
1870 #endif
1871   n = find_neighbour (handle, target);
1872   if ( (n != NULL) &&
1873        (n->transmit_handle != NULL) )
1874     return NULL; /* already have a request pending for this peer! */
1875   ctw = GNUNET_malloc (sizeof (struct ClientTransmitWrapper));
1876   th = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_TransmitHandle));
1877   ctw->notify = notify;
1878   ctw->notify_cls = notify_cls;
1879   ctw->th = th;
1880   th->handle = handle;
1881   th->neighbour = n;
1882   th->target = *target;
1883   th->notify = &client_notify_wrapper;
1884   th->notify_cls = ctw;
1885   th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
1886   th->notify_size = size + sizeof (struct OutboundMessage);
1887   th->priority = priority;
1888   if (NULL == n)
1889     {
1890       pos = handle->connect_wait_head;
1891       while (pos != NULL)
1892         {
1893           GNUNET_assert (0 != memcmp (target,
1894                                       &pos->target,
1895                                       sizeof (struct GNUNET_PeerIdentity)));
1896           pos = pos->next;
1897         }
1898 #if DEBUG_TRANSPORT
1899       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1900                   "Will now try to connect to `%4s'.\n", GNUNET_i2s (target));
1901 #endif
1902       try_connect (th);
1903       return th;
1904     }
1905
1906 #if DEBUG_TRANSPORT
1907   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1908               "Transmission request queued for transmission to transport service.\n");
1909 #endif
1910   GNUNET_assert (NULL == n->transmit_handle);
1911   n->transmit_handle = th;
1912   if (GNUNET_YES != n->received_ack)
1913     {
1914 #if DEBUG_TRANSPORT
1915       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1916                   "Connection to `%4s' is not yet confirmed connected, scheduling timeout (%llu ms) only.\n",
1917                   GNUNET_i2s (target), timeout.value);
1918 #endif
1919       th->notify_delay_task
1920         = GNUNET_SCHEDULER_add_delayed (handle->sched,
1921                                         timeout, &peer_transmit_timeout, th);
1922       return th;
1923     }
1924
1925 #if DEBUG_TRANSPORT
1926   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1927               "Peer `%4s' is ready to receive, scheduling message for delivery now.\n",
1928               GNUNET_i2s (target));
1929 #endif
1930   th->notify_delay_task
1931     = GNUNET_SCHEDULER_add_now (handle->sched,
1932                                 &transmit_ready, th);
1933   return th;
1934 }
1935
1936
1937 /**
1938  * Cancel the specified transmission-ready notification.
1939  */
1940 void
1941 GNUNET_TRANSPORT_notify_transmit_ready_cancel (struct
1942                                                GNUNET_TRANSPORT_TransmitHandle
1943                                                *th)
1944 {
1945   struct GNUNET_TRANSPORT_Handle *h;
1946
1947 #if DEBUG_TRANSPORT
1948   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1949               "Transmission request of %u bytes to `%4s' was cancelled.\n",
1950               th->notify_size - sizeof(struct OutboundMessage),
1951               GNUNET_i2s (&th->target));
1952 #endif
1953   GNUNET_assert (th->notify == &client_notify_wrapper);
1954   remove_from_any_list (th);
1955   h = th->handle;
1956   if ((h->connect_ready_head == NULL) && (h->network_handle != NULL))
1957     {
1958       GNUNET_CLIENT_notify_transmit_ready_cancel (h->network_handle);
1959       h->network_handle = NULL;
1960       h->transmission_scheduled = GNUNET_NO;
1961     }
1962   GNUNET_free (th->notify_cls);
1963   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_TASK);
1964   GNUNET_free (th);
1965 }
1966
1967
1968 /* end of transport_api.c */