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_CONNECTION_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       GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
 394       GNUNET_free (th);
 395       return 0;
 396     }
 397 #if DEBUG_TRANSPORT
 398   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 399               "Ready to transmit %u bytes to transport service\n", size);
 400 #endif
 401   cbuf = buf;
 402   ret = 0;
 403   h->network_handle = NULL;
 404   h->transmission_scheduled = GNUNET_NO;
 405   do
 406     {
 407       th = h->connect_ready_head;
 408       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
 409         {
 410           /* remove existing time out task (only applies if
 411              this is not the first iteration of the loop) */
 412           GNUNET_SCHEDULER_cancel (h->sched,
 413                                    th->notify_delay_task);
 414           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 415         }
 416       GNUNET_assert (th->notify_size <= size);
 417       if (th->next != NULL)
 418         th->next->prev = NULL;
 419       h->connect_ready_head = th->next;
 420       if (NULL != (n = th->neighbour))
 421         {
 422           GNUNET_assert (n->transmit_handle == th);
 423           n->transmit_handle = NULL;
 424         }
 425       ret += th->notify (th->notify_cls, size, &cbuf[ret]);
 426       GNUNET_free (th);
 427       if (n != NULL)
 428         n->last_sent += ret;
 429       size -= ret;
 430     }
 431   while ((h->connect_ready_head != NULL) &&
 432          (h->connect_ready_head->notify_size <= size));
 433   if (h->connect_ready_head != NULL)
 434     schedule_transmission (h);
 435 #if DEBUG_TRANSPORT
 436   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 437               "Transmitting %u bytes to transport service\n", ret);
 438 #endif
 439   return ret;
 440 }
 441
 442
 443 /**
 444  * Schedule the task to send one message from the
 445  * connect_ready list to the service.
 446  */
 447 static void
 448 schedule_transmission (struct GNUNET_TRANSPORT_Handle *h)
 449 {
 450   struct GNUNET_TRANSPORT_TransmitHandle *th;
 451
 452   GNUNET_assert (NULL == h->network_handle);
 453   if (h->client == NULL)
 454     {
 455       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 456                   "Could not yet schedule transmission: we are not yet connected to the transport service!\n");
 457       return; /* not yet connected */
 458     }
 459   th = h->connect_ready_head;
 460   if (th == NULL)
 461     return; /* no request pending */
 462   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
 463     {
 464       /* remove existing time out task, will be integrated
 465          with transmit_ready notification! */
 466       GNUNET_SCHEDULER_cancel (h->sched,
 467                                th->notify_delay_task);
 468       th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 469     }
 470   h->transmission_scheduled = GNUNET_YES;
 471   h->network_handle = GNUNET_CLIENT_notify_transmit_ready (h->client,
 472                                                            th->notify_size,
 473                                                            GNUNET_TIME_absolute_get_remaining
 474                                                            (th->timeout),
 475                                                            &transport_notify_ready,
 476                                                            h);
 477   GNUNET_assert (NULL != h->network_handle);
 478 }
 479
 480
 481 /**
 482  * Insert the given transmit handle in the given sorted
 483  * doubly linked list based on timeout.
 484  *
 485  * @param head pointer to the head of the linked list
 486  * @param th element to insert into the list
 487  */
 488 static void
 489 insert_transmit_handle (struct GNUNET_TRANSPORT_TransmitHandle **head,
 490                         struct GNUNET_TRANSPORT_TransmitHandle *th)
 491 {
 492   struct GNUNET_TRANSPORT_TransmitHandle *pos;
 493   struct GNUNET_TRANSPORT_TransmitHandle *prev;
 494
 495   pos = *head;
 496   prev = NULL;
 497   while ((pos != NULL) && (pos->timeout.value < th->timeout.value))
 498     {
 499       prev = pos;
 500       pos = pos->next;
 501     }
 502   if (prev == NULL)
 503     {
 504       th->next = *head;
 505       if (th->next != NULL)
 506         th->next->prev = th;
 507       *head = th;
 508     }
 509   else
 510     {
 511       th->next = pos;
 512       th->prev = prev;
 513       prev->next = th;
 514       if (pos != NULL)
 515         pos->prev = th;
 516     }
 517 }
 518
 519
 520 /**
 521  * Cancel a pending notify delay task (if pending) and also remove the
 522  * given transmit handle from whatever list is on.
 523  *
 524  * @param th handle for the transmission request to manipulate
 525  */
 526 static void
 527 remove_from_any_list (struct GNUNET_TRANSPORT_TransmitHandle *th)
 528 {
 529   struct GNUNET_TRANSPORT_Handle *h;
 530
 531   h = th->handle;
 532   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
 533     {
 534       GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
 535       th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 536     }
 537   if (th->prev == NULL)
 538     {
 539       if (th == h->connect_wait_head)
 540         h->connect_wait_head = th->next;
 541       else
 542         h->connect_ready_head = th->next;
 543     }
 544   else
 545     {
 546       th->prev->next = th->next;
 547     }
 548   if (th->next != NULL)
 549     th->next->prev = th->prev;
 550 }
 551
 552
 553 /**
 554  * Schedule a request to connect to the given
 555  * neighbour (and if successful, add the specified
 556  * handle to the wait list).
 557  *
 558  * @param th handle for a request to transmit once we
 559  *        have connected
 560  */
 561 static void
 562 try_connect (struct GNUNET_TRANSPORT_TransmitHandle *th);
 563
 564
 565 /**
 566  * Called when our transmit request timed out before any transport
 567  * reported success connecting to the desired peer or before the
 568  * transport was ready to receive.  Signal error and free
 569  * TransmitHandle.
 570  */
 571 static void
 572 transmit_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 573 {
 574   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
 575
 576   th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 577   if (th->neighbour != NULL)
 578     th->neighbour->transmit_handle = NULL;
 579 #if DEBUG_TRANSPORT
 580   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 581               "Request for transmission to peer `%s' timed out.\n",
 582               GNUNET_i2s(&th->target));
 583 #endif
 584   remove_from_any_list (th);
 585   th->notify (th->notify_cls, 0, NULL);
 586   GNUNET_free (th);
 587 }
 588
 589
 590
 591
 592 /**
 593  * Queue control request for transmission to the transport
 594  * service.
 595  *
 596  * @param size number of bytes to be transmitted
 597  * @param at_head request must be added to the head of the queue
 598  *        (otherwise request will be appended)
 599  * @param timeout how long this transmission can wait (at most)
 600  * @param notify function to call to get the content
 601  * @param notify_cls closure for notify
 602  */
 603 static void
 604 schedule_control_transmit (struct GNUNET_TRANSPORT_Handle *h,
 605                            size_t size,
 606                            int at_head,
 607                            struct GNUNET_TIME_Relative timeout,
 608                            GNUNET_CONNECTION_TransmitReadyNotify notify,
 609                            void *notify_cls)
 610 {
 611   struct GNUNET_TRANSPORT_TransmitHandle *th;
 612
 613   th = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_TransmitHandle));
 614   th->handle = h;
 615   th->notify = notify;
 616   th->notify_cls = notify_cls;
 617   th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 618   th->notify_size = size;
 619   th->notify_delay_task
 620     = GNUNET_SCHEDULER_add_delayed (h->sched,
 621                                     GNUNET_NO,
 622                                     GNUNET_SCHEDULER_PRIORITY_KEEP,
 623                                     GNUNET_SCHEDULER_NO_TASK,
 624                                     timeout,
 625                                     &transmit_timeout, th);
 626   if (at_head)
 627     {
 628       th->next = h->connect_ready_head;
 629       h->connect_ready_head = th;
 630       if (th->next != NULL)
 631         th->next->prev = th;
 632     }
 633   else
 634     {
 635       insert_transmit_handle (&h->connect_ready_head, th);
 636     }
 637   if (GNUNET_NO == h->transmission_scheduled)
 638     schedule_transmission (h);
 639 }
 640
 641
 642 /**
 643  * Update the quota values for the given neighbour now.
 644  */
 645 static void
 646 update_quota (struct NeighbourList *n)
 647 {
 648   struct GNUNET_TIME_Relative delta;
 649   uint64_t allowed;
 650   uint64_t remaining;
 651
 652   delta = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
 653   allowed = delta.value * n->quota_out;
 654   if (n->last_sent < allowed)
 655     {
 656       remaining = allowed - n->last_sent;
 657       if (n->quota_out > 0)
 658         remaining /= n->quota_out;
 659       else
 660         remaining = 0;
 661       if (remaining > MAX_BANDWIDTH_CARRY)
 662         remaining = MAX_BANDWIDTH_CARRY;
 663       n->last_sent = 0;
 664       n->last_quota_update = GNUNET_TIME_absolute_get ();
 665       n->last_quota_update.value -= remaining;
 666     }
 667   else
 668     {
 669       n->last_sent -= allowed;
 670       n->last_quota_update = GNUNET_TIME_absolute_get ();
 671     }
 672 }
 673
 674
 675 struct SetQuotaContext
 676 {
 677   struct GNUNET_TRANSPORT_Handle *handle;
 678
 679   struct GNUNET_PeerIdentity target;
 680
 681   GNUNET_SCHEDULER_Task cont;
 682
 683   void *cont_cls;
 684
 685   struct GNUNET_TIME_Absolute timeout;
 686
 687   uint32_t quota_in;
 688 };
 689
 690
 691 static size_t
 692 send_set_quota (void *cls, size_t size, void *buf)
 693 {
 694   struct SetQuotaContext *sqc = cls;
 695   struct QuotaSetMessage *msg;
 696
 697   if (buf == NULL)
 698     {
 699       GNUNET_SCHEDULER_add_continuation (sqc->handle->sched,
 700                                          GNUNET_NO,
 701                                          sqc->cont,
 702                                          sqc->cont_cls,
 703                                          GNUNET_SCHEDULER_REASON_TIMEOUT);
 704       GNUNET_free (sqc);
 705       return 0;
 706     }
 707 #if DEBUG_TRANSPORT
 708   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 709               "Transmitting `%s' request with respect to `%4s'.\n",
 710               "SET_QUOTA", GNUNET_i2s (&sqc->target));
 711 #endif
 712   GNUNET_assert (size >= sizeof (struct QuotaSetMessage));
 713   msg = buf;
 714   msg->header.size = htons (sizeof (struct QuotaSetMessage));
 715   msg->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SET_QUOTA);
 716   msg->quota_in = htonl (sqc->quota_in);
 717   memcpy (&msg->peer, &sqc->target, sizeof (struct GNUNET_PeerIdentity));
 718   if (sqc->cont != NULL)
 719     GNUNET_SCHEDULER_add_continuation (sqc->handle->sched,
 720                                        GNUNET_NO,
 721                                        sqc->cont,
 722                                        sqc->cont_cls,
 723                                        GNUNET_SCHEDULER_REASON_PREREQ_DONE);
 724   GNUNET_free (sqc);
 725   return sizeof (struct QuotaSetMessage);
 726 }
 727
 728
 729 /**
 730  * Set the share of incoming bandwidth for the given
 731  * peer to the specified amount.
 732  *
 733  * @param handle connection to transport service
 734  * @param target who's bandwidth quota is being changed
 735  * @param quota_in incoming bandwidth quota in bytes per ms; 0 can
 736  *        be used to force all traffic to be discarded
 737  * @param quota_out outgoing bandwidth quota in bytes per ms; 0 can
 738  *        be used to force all traffic to be discarded
 739  * @param timeout how long to wait until signaling failure if
 740  *        we can not communicate the quota change
 741  * @param cont continuation to call when done, will be called
 742  *        either with reason "TIMEOUT" or with reason "PREREQ_DONE"
 743  * @param cont_cls closure for continuation
 744  */
 745 void
 746 GNUNET_TRANSPORT_set_quota (struct GNUNET_TRANSPORT_Handle *handle,
 747                             const struct GNUNET_PeerIdentity *target,
 748                             uint32_t quota_in,
 749                             uint32_t quota_out,
 750                             struct GNUNET_TIME_Relative timeout,
 751                             GNUNET_SCHEDULER_Task cont, void *cont_cls)
 752 {
 753   struct NeighbourList *n;
 754   struct SetQuotaContext *sqc;
 755
 756   n = find_neighbour (handle, target);
 757   if (n != NULL)
 758     {
 759       update_quota (n);
 760       if (n->quota_out < quota_out)
 761         n->last_quota_update = GNUNET_TIME_absolute_get ();
 762       n->quota_out = quota_out;
 763     }
 764   sqc = GNUNET_malloc (sizeof (struct SetQuotaContext));
 765   sqc->handle = handle;
 766   sqc->target = *target;
 767   sqc->cont = cont;
 768   sqc->cont_cls = cont_cls;
 769   sqc->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 770   sqc->quota_in = quota_in;
 771   schedule_control_transmit (handle,
 772                              sizeof (struct QuotaSetMessage),
 773                              GNUNET_NO, timeout, &send_set_quota, sqc);
 774 }
 775
 776
 777 /**
 778  * A "get_hello" request has timed out.  Signal the client
 779  * and clean up.
 780  */
 781 static void
 782 hello_wait_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 783 {
 784   struct HelloWaitList *hwl = cls;
 785   struct HelloWaitList *pos;
 786   struct HelloWaitList *prev;
 787
 788   hwl->task = GNUNET_SCHEDULER_NO_TASK;
 789   if (GNUNET_TIME_absolute_get_remaining (hwl->timeout).value > 0)
 790     {
 791 #if DEBUG_TRANSPORT
 792       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 793                   _("First attempt to obtain `%s' from transport service failed, will try again for %llums.\n"),
 794                   "HELLO",
 795                   GNUNET_TIME_absolute_get_remaining (hwl->timeout).value);
 796 #endif
 797       hwl->task = GNUNET_SCHEDULER_add_delayed (hwl->handle->sched,
 798                                                 GNUNET_YES,
 799                                                 GNUNET_SCHEDULER_PRIORITY_KEEP,
 800                                                 GNUNET_SCHEDULER_NO_TASK,
 801                                                 GNUNET_TIME_absolute_get_remaining (hwl->timeout),
 802                                                 &hello_wait_timeout, hwl);
 803       return;
 804     }
 805   /* signal timeout */
 806   GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 807               _("Timeout trying to obtain `%s' from transport service.\n"),
 808               "HELLO");
 809   prev = NULL;
 810   pos = hwl->handle->hwl_head;
 811   while (pos != hwl)
 812     {
 813       GNUNET_assert (pos != NULL);
 814       prev = pos;
 815       pos = pos->next;
 816     }
 817   if (prev == NULL)
 818     hwl->handle->hwl_head = hwl->next;
 819   else
 820     prev->next = hwl->next;
 821   if (hwl->rec != NULL)
 822     hwl->rec (hwl->rec_cls, GNUNET_TIME_UNIT_ZERO, NULL, NULL);
 823   GNUNET_free (hwl);
 824 }
 825
 826
 827 /**
 828  * Obtain the HELLO message for this peer.
 829  *
 830  * @param handle connection to transport service
 831  * @param timeout how long to wait for the HELLO
 832  * @param rec function to call with the HELLO, sender will be our peer
 833  *            identity; message and sender will be NULL on timeout
 834  *            (handshake with transport service pending/failed).
 835  *             cost estimate will be 0.
 836  * @param rec_cls closure for rec
 837  */
 838 void
 839 GNUNET_TRANSPORT_get_hello (struct GNUNET_TRANSPORT_Handle *handle,
 840                             struct GNUNET_TIME_Relative timeout,
 841                             GNUNET_TRANSPORT_ReceiveCallback rec,
 842                             void *rec_cls)
 843 {
 844   struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded pk;
 845   struct GNUNET_PeerIdentity me;
 846   struct HelloWaitList *hwl;
 847
 848   if (handle->my_hello == NULL)
 849     {
 850       hwl = GNUNET_malloc (sizeof (struct HelloWaitList));
 851       hwl->next = handle->hwl_head;
 852       handle->hwl_head = hwl;
 853       hwl->handle = handle;
 854       hwl->rec = rec;
 855       hwl->rec_cls = rec_cls;
 856       hwl->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 857       hwl->task = GNUNET_SCHEDULER_add_delayed (handle->sched,
 858                                                 GNUNET_YES,
 859                                                 GNUNET_SCHEDULER_PRIORITY_KEEP,
 860                                                 GNUNET_SCHEDULER_NO_TASK,
 861                                                 timeout,
 862                                                 &hello_wait_timeout, hwl);
 863       return;
 864     }
 865   GNUNET_assert (GNUNET_OK == GNUNET_HELLO_get_key (handle->my_hello, &pk));
 866   GNUNET_CRYPTO_hash (&pk,
 867                       sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
 868                       &me.hashPubKey);
 869
 870   rec (rec_cls,
 871        GNUNET_TIME_UNIT_ZERO,
 872        &me, (const struct GNUNET_MessageHeader *) handle->my_hello);
 873 }
 874
 875
 876 static size_t
 877 send_hello (void *cls, size_t size, void *buf)
 878 {
 879   struct GNUNET_MessageHeader *hello = cls;
 880   uint16_t msize;
 881
 882   if (buf == NULL)
 883     {
 884 #if DEBUG_TRANSPORT
 885       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 886                   "Timeout while trying to transmit `%s' request.\n",
 887                   "HELLO");
 888 #endif
 889       GNUNET_free (hello);
 890       return 0;
 891     }
 892 #if DEBUG_TRANSPORT
 893   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 894               "Transmitting `%s' request.\n", "HELLO");
 895 #endif
 896   msize = ntohs (hello->size);
 897   GNUNET_assert (size >= msize);
 898   memcpy (buf, hello, msize);
 899   GNUNET_free (hello);
 900   return msize;
 901 }
 902
 903
 904 /**
 905  * Offer the transport service the HELLO of another peer.  Note that
 906  * the transport service may just ignore this message if the HELLO is
 907  * malformed or useless due to our local configuration.
 908  *
 909  * @param handle connection to transport service
 910  * @param hello the hello message
 911  */
 912 void
 913 GNUNET_TRANSPORT_offer_hello (struct GNUNET_TRANSPORT_Handle *handle,
 914                               const struct GNUNET_MessageHeader *hello)
 915 {
 916   struct GNUNET_MessageHeader *hc;
 917   uint16_t size;
 918
 919   if (handle->client == NULL)
 920     {
 921 #if DEBUG_TRANSPORT
 922       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 923                   "Not connected to transport service, dropping offered HELLO\n");
 924 #endif
 925       return;
 926     }
 927   GNUNET_break (ntohs (hello->type) == GNUNET_MESSAGE_TYPE_HELLO);
 928   size = ntohs (hello->size);
 929   GNUNET_break (size >= sizeof (struct GNUNET_MessageHeader));
 930   hc = GNUNET_malloc (size);
 931   memcpy (hc, hello, size);
 932   schedule_control_transmit (handle,
 933                              size,
 934                              GNUNET_NO, OFFER_HELLO_TIMEOUT, &send_hello, hc);
 935 }
 936
 937
 938 /**
 939  * Function we use for handling incoming messages.
 940  */
 941 static void demultiplexer (void *cls, const struct GNUNET_MessageHeader *msg);
 942
 943
 944 static size_t
 945 send_start (void *cls, size_t size, void *buf)
 946 {
 947   struct GNUNET_MessageHeader *s = buf;
 948
 949   if (buf == NULL)
 950     {
 951 #if DEBUG_TRANSPORT
 952       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 953                   "Timeout while trying to transmit `%s' request.\n",
 954                   "START");
 955 #endif
 956       return 0;
 957     }
 958 #if DEBUG_TRANSPORT
 959   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 960               "Transmitting `%s' request.\n", "START");
 961 #endif
 962   GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
 963   s->size = htons (sizeof (struct GNUNET_MessageHeader));
 964   s->type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_START);
 965   return sizeof (struct GNUNET_MessageHeader);
 966 }
 967
 968
 969 /**
 970  * We're ready to transmit the request that the transport service
 971  * should connect to a new peer.  In addition to sending the
 972  * request, schedule the next phase for the transmission processing
 973  * that caused the connect request in the first place.
 974  */
 975 static size_t
 976 request_connect (void *cls, size_t size, void *buf)
 977 {
 978   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
 979   struct TryConnectMessage *tcm;
 980   struct GNUNET_TRANSPORT_Handle *h;
 981
 982   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_TASK);
 983   h = th->handle;
 984   if (buf == NULL)
 985     {
 986 #if DEBUG_TRANSPORT
 987       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 988                   "Failed to transmit `%s' request for `%4s' to service.\n",
 989                   "TRY_CONNECT",
 990                   GNUNET_i2s(&th->target));
 991 #endif
 992       th->notify (th->notify_cls, 0, NULL);
 993       GNUNET_free (th);
 994       return 0;
 995     }
 996 #if DEBUG_TRANSPORT
 997   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 998               "Transmitting `%s' message for `%4s'.\n",
 999               "TRY_CONNECT", GNUNET_i2s (&th->target));
1000 #endif
1001   GNUNET_assert (size >= sizeof (struct TryConnectMessage));
1002   tcm = buf;
1003   tcm->header.size = htons (sizeof (struct TryConnectMessage));
1004   tcm->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_TRY_CONNECT);
1005   tcm->reserved = htonl (0);
1006   memcpy (&tcm->peer, &th->target, sizeof (struct GNUNET_PeerIdentity));
1007   th->notify_delay_task
1008     = GNUNET_SCHEDULER_add_delayed (h->sched,
1009                                     GNUNET_NO,
1010                                     GNUNET_SCHEDULER_PRIORITY_KEEP,
1011                                     GNUNET_SCHEDULER_NO_TASK,
1012                                     GNUNET_TIME_absolute_get_remaining
1013                                     (th->timeout),
1014                                     &transmit_timeout, th);
1015   insert_transmit_handle (&h->connect_wait_head, th);
1016   return sizeof (struct TryConnectMessage);
1017 }
1018
1019
1020 /**
1021  * Schedule a request to connect to the given
1022  * neighbour (and if successful, add the specified
1023  * handle to the wait list).
1024  *
1025  * @param th handle for a request to transmit once we
1026  *        have connected
1027  */
1028 static void
1029 try_connect (struct GNUNET_TRANSPORT_TransmitHandle *th)
1030 {
1031   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_TASK);
1032   schedule_control_transmit (th->handle,
1033                              sizeof (struct TryConnectMessage),
1034                              GNUNET_NO,
1035                              GNUNET_TIME_absolute_get_remaining (th->timeout),
1036                              &request_connect, th);
1037 }
1038
1039
1040 /**
1041  * Task for delayed attempts to reconnect to a peer.
1042  *
1043  * @param cls must be a transmit handle that determines the peer
1044  *        to which we will try to connect
1045  * @param tc scheduler information about why we were triggered (not used)
1046  */
1047 static void
1048 try_connect_task (void *cls,
1049                   const struct GNUNET_SCHEDULER_TaskContext *tc)
1050 {
1051   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
1052
1053   th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1054   try_connect (th);
1055 }
1056
1057
1058 /**
1059  * Remove neighbour from our list.  Will automatically
1060  * trigger a re-connect attempt if we have messages pending
1061  * for this peer.
1062  *
1063  * @param h our state
1064  * @param peer the peer to remove
1065  */
1066 static void
1067 remove_neighbour (struct GNUNET_TRANSPORT_Handle *h,
1068                   const struct GNUNET_PeerIdentity *peer)
1069 {
1070   struct NeighbourList *prev;
1071   struct NeighbourList *pos;
1072   struct GNUNET_TRANSPORT_TransmitHandle *th;
1073
1074 #if DEBUG_TRANSPORT
1075   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1076               "Removing neighbour `%s' from list of connected peers.\n",
1077               GNUNET_i2s (peer));
1078 #endif
1079   prev = NULL;
1080   pos = h->neighbours;
1081   while ((pos != NULL) &&
1082          (0 != memcmp (peer,
1083                        &pos->id,
1084                        sizeof (struct GNUNET_PeerIdentity))))
1085     {
1086       prev = pos;
1087       pos = pos->next;
1088     }
1089   if (pos == NULL)
1090     {
1091       GNUNET_break (0);
1092       return;
1093     }
1094   if (prev == NULL)
1095     h->neighbours = pos->next;
1096   else
1097     prev->next = pos->next;
1098   if (NULL != (th = pos->transmit_handle))
1099     {
1100       pos->transmit_handle = NULL;
1101       th->neighbour = NULL;
1102       remove_from_any_list (th);
1103       if (GNUNET_TIME_absolute_get_remaining (th->timeout).value <= CONNECT_RETRY_TIMEOUT.value)
1104         {
1105           /* signal error */
1106           GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == th->notify_delay_task);
1107           transmit_timeout (th, NULL);
1108         }
1109       else
1110         {
1111           GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1112                       _("Connection with `%4s' failed, will keep trying for %llu ms to deliver message\n"),
1113                       GNUNET_i2s (peer),
1114                       GNUNET_TIME_absolute_get_remaining (th->timeout).value);
1115           /* try again in a bit */
1116           GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == th->notify_delay_task);
1117           th->notify_delay_task
1118             = GNUNET_SCHEDULER_add_delayed (h->sched,
1119                                             GNUNET_NO,
1120                                             GNUNET_SCHEDULER_PRIORITY_KEEP,
1121                                             GNUNET_SCHEDULER_NO_TASK,
1122                                             CONNECT_RETRY_TIMEOUT,
1123                                             &try_connect_task,
1124                                             th);
1125         }
1126     }
1127   if (h->nc_cb != NULL)
1128     h->nd_cb (h->cls, peer);
1129   GNUNET_free (pos);
1130 }
1131
1132
1133 /**
1134  * Try again to connect to transport service.
1135  */
1136 static void
1137 reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1138 {
1139   struct GNUNET_TRANSPORT_Handle *h = cls;
1140   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1141   struct NeighbourList *n;
1142
1143   /* Forget about all neighbours that we used to be connected
1144      to */
1145   while (NULL != (n = h->neighbours))
1146     remove_neighbour (h, &n->id);
1147 #if DEBUG_TRANSPORT
1148   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connecting to transport service.\n");
1149 #endif
1150   GNUNET_assert (h->client == NULL);
1151   h->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
1152   h->client = GNUNET_CLIENT_connect (h->sched, "transport", h->cfg);
1153   GNUNET_assert (h->client != NULL);
1154   /* make sure we don't send "START" twice,
1155      remove existing entry from queue (if present) */
1156   pos = h->connect_ready_head;
1157   while (pos != NULL)
1158     {
1159       if (pos->notify == &send_start)
1160         {
1161           if (pos->prev == NULL)
1162             h->connect_ready_head = pos->next;
1163           else
1164             pos->prev->next = pos->next;
1165           if (pos->next != NULL)
1166             pos->next->prev = pos->prev;
1167           GNUNET_assert (pos->neighbour == NULL);
1168           GNUNET_free (pos);
1169           break;
1170         }
1171       pos = pos->next;
1172     }
1173   schedule_control_transmit (h,
1174                              sizeof (struct GNUNET_MessageHeader),
1175                              GNUNET_YES,
1176                              GNUNET_TIME_UNIT_FOREVER_REL,
1177                              &send_start, NULL);
1178   GNUNET_CLIENT_receive (h->client,
1179                          &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL);
1180 }
1181
1182
1183 /**
1184  * Function that will schedule the job that will try
1185  * to connect us again to the client.
1186  */
1187 static void
1188 schedule_reconnect (struct GNUNET_TRANSPORT_Handle *h)
1189 {
1190 #if DEBUG_TRANSPORT
1191   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1192               "Scheduling task to reconnect to transport service in %llu ms.\n",
1193               h->reconnect_delay.value);
1194 #endif
1195   GNUNET_assert (h->client == NULL);
1196   GNUNET_assert (h->reconnect_task == GNUNET_SCHEDULER_NO_TASK);
1197   h->reconnect_task
1198     = GNUNET_SCHEDULER_add_delayed (h->sched,
1199                                     GNUNET_NO,
1200                                     GNUNET_SCHEDULER_PRIORITY_DEFAULT,
1201                                     GNUNET_SCHEDULER_NO_TASK,
1202                                     h->reconnect_delay, &reconnect, h);
1203   h->reconnect_delay = GNUNET_TIME_UNIT_SECONDS;
1204 }
1205
1206
1207 /**
1208  * We are connected to the respective peer, check the
1209  * bandwidth limits and schedule the transmission.
1210  */
1211 static void schedule_request (struct GNUNET_TRANSPORT_TransmitHandle *th);
1212
1213
1214 /**
1215  * Function called by the scheduler when the timeout
1216  * for bandwidth availablility for the target
1217  * neighbour is reached.
1218  */
1219 static void
1220 transmit_ready (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1221 {
1222   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
1223
1224   th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1225   schedule_request (th);
1226 }
1227
1228
1229 /**
1230  * Remove the given transmit handle from the wait list.  Does NOT free
1231  * it.
1232  */
1233 static void
1234 remove_from_wait_list (struct GNUNET_TRANSPORT_TransmitHandle *th)
1235 {
1236   if (th->prev == NULL)
1237     th->handle->connect_wait_head = th->next;
1238   else
1239     th->prev->next = th->next;
1240   if (th->next != NULL)
1241     th->next->prev = th->prev;
1242 }
1243
1244
1245 /**
1246  * We are connected to the respective peer, check the
1247  * bandwidth limits and schedule the transmission.
1248  */
1249 static void
1250 schedule_request (struct GNUNET_TRANSPORT_TransmitHandle *th)
1251 {
1252   struct GNUNET_TRANSPORT_Handle *h;
1253   struct GNUNET_TIME_Relative duration;
1254   struct NeighbourList *n;
1255   uint64_t available;
1256
1257   h = th->handle;
1258   n = th->neighbour;
1259   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1260     {
1261       GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
1262       th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1263     }
1264   /* check outgoing quota */
1265   duration = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
1266   if (duration.value > MIN_QUOTA_REFRESH_TIME)
1267     {
1268       update_quota (n);
1269       duration = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
1270     }
1271   available = duration.value * n->quota_out;
1272   if (available < n->last_sent + th->notify_size)
1273     {
1274       /* calculate how much bandwidth we'd still need to
1275          accumulate and based on that how long we'll have
1276          to wait... */
1277       available = n->last_sent + th->notify_size - available;
1278       duration = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS,
1279                                                 available / n->quota_out);
1280       if (th->timeout.value <
1281           GNUNET_TIME_relative_to_absolute (duration).value)
1282         {
1283           /* signal timeout! */
1284 #if DEBUG_TRANSPORT
1285           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1286                       "Would need %llu ms before bandwidth is available for delivery to `%4s', that is too long.  Signaling timeout.\n",
1287                       duration.value,
1288                       GNUNET_i2s(&th->target));
1289 #endif
1290           remove_from_wait_list (th);
1291           th->notify (th->notify_cls, 0, NULL);
1292           GNUNET_free (th);
1293           return;
1294         }
1295 #if DEBUG_TRANSPORT
1296       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1297                   "Need more bandwidth, delaying delivery to `%4s' by %llu ms\n",
1298                   GNUNET_i2s(&th->target),
1299                   duration.value);
1300 #endif
1301       th->notify_delay_task
1302         = GNUNET_SCHEDULER_add_delayed (h->sched,
1303                                         GNUNET_NO,
1304                                         GNUNET_SCHEDULER_PRIORITY_KEEP,
1305                                         GNUNET_SCHEDULER_NO_TASK,
1306                                         duration, &transmit_ready, th);
1307       return;
1308     }
1309 #if DEBUG_TRANSPORT
1310   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1311               "Bandwidth available for transmission to `%4s'\n",
1312               GNUNET_i2s (&n->id));
1313 #endif
1314   if (GNUNET_NO == n->transmit_ok)
1315     {
1316       /* we may be ready, but transport service is not;
1317          wait for SendOkMessage or timeout */
1318 #if DEBUG_TRANSPORT
1319       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1320                   "Need to wait for transport service `%s' message\n",
1321                   "SEND_OK");
1322 #endif
1323       th->notify_delay_task
1324         = GNUNET_SCHEDULER_add_delayed (h->sched,
1325                                         GNUNET_NO,
1326                                         GNUNET_SCHEDULER_PRIORITY_KEEP,
1327                                         GNUNET_SCHEDULER_NO_TASK,
1328                                         GNUNET_TIME_absolute_get_remaining
1329                                         (th->timeout), &transmit_timeout, th);
1330       return;
1331     }
1332   n->transmit_ok = GNUNET_NO;
1333   remove_from_wait_list (th);
1334 #if DEBUG_TRANSPORT
1335   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Moving message for `%4s' to ready list\n",
1336               GNUNET_i2s(&n->id));
1337 #endif
1338   insert_transmit_handle (&h->connect_ready_head, th);
1339   if (GNUNET_NO == h->transmission_scheduled)
1340     schedule_transmission (h);
1341 }
1342
1343
1344 /**
1345  * Add neighbour to our list
1346  */
1347 static void
1348 add_neighbour (struct GNUNET_TRANSPORT_Handle *h,
1349                uint32_t quota_out,
1350                struct GNUNET_TIME_Relative latency,
1351                const struct GNUNET_PeerIdentity *pid)
1352 {
1353   struct NeighbourList *n;
1354   struct GNUNET_TRANSPORT_TransmitHandle *prev;
1355   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1356   struct GNUNET_TRANSPORT_TransmitHandle *next;
1357
1358   /* check for duplicates */
1359   if (NULL != find_neighbour (h, pid))
1360     {
1361       GNUNET_break (0);
1362       return;
1363     }
1364 #if DEBUG_TRANSPORT
1365   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1366               "Creating entry for new neighbour `%4s'.\n", GNUNET_i2s (pid));
1367 #endif
1368   n = GNUNET_malloc (sizeof (struct NeighbourList));
1369   n->id = *pid;
1370   n->last_quota_update = GNUNET_TIME_absolute_get ();
1371   n->quota_out = quota_out;
1372   n->next = h->neighbours;
1373   n->transmit_ok = GNUNET_YES;
1374   h->neighbours = n;
1375   if (h->nc_cb != NULL)
1376     h->nc_cb (h->cls, &n->id, latency);
1377   prev = NULL;
1378   pos = h->connect_wait_head;
1379   while (pos != NULL)
1380     {
1381       next = pos->next;
1382       if (0 == memcmp (pid,
1383                        &pos->target, sizeof (struct GNUNET_PeerIdentity)))
1384         {
1385           pos->neighbour = n;
1386           GNUNET_assert (NULL == n->transmit_handle);
1387           n->transmit_handle = pos;
1388           if (prev == NULL)
1389             h->connect_wait_head = next;
1390           else
1391             prev->next = next;
1392           if (GNUNET_YES == n->received_ack)
1393             {
1394 #if DEBUG_TRANSPORT
1395               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1396                           "Found pending request for `%4s' will trigger it now.\n",
1397                           GNUNET_i2s (&pos->target));
1398 #endif
1399               if (pos->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1400                 {
1401                   GNUNET_SCHEDULER_cancel (h->sched, pos->notify_delay_task);
1402                   pos->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1403                 }
1404               schedule_request (pos);
1405             }
1406           else
1407             {
1408 #if DEBUG_TRANSPORT
1409               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1410                           "Found pending request for `%4s' but still need `%s' before proceeding.\n",
1411                           GNUNET_i2s (&pos->target),
1412                           "ACK");
1413 #endif
1414             }
1415           break;
1416         }
1417       prev = pos;
1418       pos = next;
1419     }
1420 }
1421
1422
1423 /**
1424  * Connect to the transport service.  Note that the connection may
1425  * complete (or fail) asynchronously.
1426  *
1427
1428  * @param sched scheduler to use
1429  * @param cfg configuration to use
1430  * @param cls closure for the callbacks
1431  * @param rec receive function to call
1432  * @param nc function to call on connect events
1433  * @param dc function to call on disconnect events
1434  */
1435 struct GNUNET_TRANSPORT_Handle *
1436 GNUNET_TRANSPORT_connect (struct GNUNET_SCHEDULER_Handle *sched,
1437                           const struct GNUNET_CONFIGURATION_Handle *cfg,
1438                           void *cls,
1439                           GNUNET_TRANSPORT_ReceiveCallback rec,
1440                           GNUNET_TRANSPORT_NotifyConnect nc,
1441                           GNUNET_TRANSPORT_NotifyDisconnect nd)
1442 {
1443   struct GNUNET_TRANSPORT_Handle *ret;
1444
1445   GNUNET_ARM_start_service ("peerinfo",
1446                             cfg, sched, START_SERVICE_TIMEOUT, NULL, NULL);
1447   GNUNET_ARM_start_service ("transport",
1448                             cfg, sched, START_SERVICE_TIMEOUT, NULL, NULL);
1449   ret = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_Handle));
1450   ret->sched = sched;
1451   ret->cfg = cfg;
1452   ret->cls = cls;
1453   ret->rec = rec;
1454   ret->nc_cb = nc;
1455   ret->nd_cb = nd;
1456   ret->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
1457   schedule_reconnect (ret);
1458   return ret;
1459 }
1460
1461
1462 /**
1463  * These stop activities must be run in a fresh
1464  * scheduler that is NOT in shutdown mode.
1465  */
1466 static void
1467 stop_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1468 {
1469   struct GNUNET_TRANSPORT_Handle *handle = cls;
1470   GNUNET_ARM_stop_service ("transport",
1471                            handle->cfg,
1472                            tc->sched, STOP_SERVICE_TIMEOUT, NULL, NULL);
1473   GNUNET_ARM_stop_service ("peerinfo",
1474                            handle->cfg,
1475                            tc->sched, STOP_SERVICE_TIMEOUT, NULL, NULL);
1476 }
1477
1478
1479 /**
1480  * Disconnect from the transport service.
1481  */
1482 void
1483 GNUNET_TRANSPORT_disconnect (struct GNUNET_TRANSPORT_Handle *handle)
1484 {
1485   struct GNUNET_TRANSPORT_TransmitHandle *th;
1486   struct NeighbourList *n;
1487   struct HelloWaitList *hwl;
1488   struct GNUNET_CLIENT_Connection *client;
1489
1490 #if DEBUG_TRANSPORT
1491   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transport disconnect called!\n");
1492 #endif
1493   while (NULL != (th = handle->connect_ready_head))
1494     {
1495       handle->connect_ready_head = th->next;
1496       th->notify (th->notify_cls, 0, NULL);
1497       GNUNET_free (th);
1498     }
1499   while (NULL != (th = handle->connect_wait_head))
1500     {
1501       handle->connect_wait_head = th->next;
1502       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1503         {
1504           GNUNET_SCHEDULER_cancel (handle->sched, th->notify_delay_task);
1505           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1506         }
1507       th->notify (th->notify_cls, 0, NULL);
1508       GNUNET_free (th);
1509     }
1510   while (NULL != (n = handle->neighbours))
1511     {
1512       handle->neighbours = n->next;
1513       GNUNET_free (n);
1514     }
1515   while (NULL != (hwl = handle->hwl_head))
1516     {
1517       handle->hwl_head = hwl->next;
1518       GNUNET_SCHEDULER_cancel (handle->sched, hwl->task);
1519       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1520                   _("Disconnect while trying to obtain `%s' from transport service.\n"),
1521                   "HELLO");
1522       if (hwl->rec != NULL)
1523         hwl->rec (hwl->rec_cls, GNUNET_TIME_UNIT_ZERO, NULL, NULL);
1524       GNUNET_free (hwl);
1525     }
1526   if (handle->reconnect_task != GNUNET_SCHEDULER_NO_TASK)
1527     {
1528       GNUNET_SCHEDULER_cancel (handle->sched, handle->reconnect_task);
1529       handle->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
1530     }
1531   GNUNET_free_non_null (handle->my_hello);
1532   handle->my_hello = NULL;
1533   GNUNET_SCHEDULER_run (&stop_task, handle);
1534   if (NULL != (client = handle->client))
1535     {
1536 #if DEBUG_TRANSPORT
1537       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1538                   "Disconnecting from transport service for good.\n");
1539 #endif
1540       handle->client = NULL;
1541       GNUNET_CLIENT_disconnect (client);
1542     }
1543   if (client == NULL)
1544     GNUNET_free (handle);
1545 }
1546
1547
1548 /**
1549  * Type of a function to call when we receive a message
1550  * from the service.
1551  *
1552  * @param cls closure
1553  * @param msg message received, NULL on timeout or fatal error
1554  */
1555 static void
1556 demultiplexer (void *cls, const struct GNUNET_MessageHeader *msg)
1557 {
1558   struct GNUNET_TRANSPORT_Handle *h = cls;
1559   const struct DisconnectInfoMessage *dim;
1560   const struct ConnectInfoMessage *cim;
1561   const struct InboundMessage *im;
1562   const struct GNUNET_MessageHeader *imm;
1563   const struct SendOkMessage *okm;
1564   struct HelloWaitList *hwl;
1565   struct NeighbourList *n;
1566   struct GNUNET_PeerIdentity me;
1567   struct GNUNET_TRANSPORT_TransmitHandle *th;
1568   uint16_t size;
1569
1570   if ((msg == NULL) || (h->client == NULL))
1571     {
1572       if (h->client != NULL)
1573         {
1574 #if DEBUG_TRANSPORT
1575           GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1576                       "Error receiving from transport service, disconnecting temporarily.\n");
1577 #endif
1578           if (h->network_handle != NULL)
1579             {
1580               GNUNET_CONNECTION_notify_transmit_ready_cancel (h->network_handle);
1581               h->network_handle = NULL;
1582               h->transmission_scheduled = GNUNET_NO;
1583               th = h->connect_ready_head;
1584               /* add timeout again, we cancelled the transmit_ready task! */
1585               GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_TASK);
1586               th->notify_delay_task
1587                 = GNUNET_SCHEDULER_add_delayed (h->sched,
1588                                                 GNUNET_NO,
1589                                                 GNUNET_SCHEDULER_PRIORITY_KEEP,
1590                                                 GNUNET_SCHEDULER_NO_TASK,
1591                                                 GNUNET_TIME_absolute_get_remaining(th->timeout),
1592                                                 &transmit_timeout,
1593                                                 th);
1594             }
1595           GNUNET_CLIENT_disconnect (h->client);
1596           h->client = NULL;
1597           schedule_reconnect (h);
1598         }
1599       else
1600         {
1601           /* shutdown initiated from 'GNUNET_TRANSPORT_disconnect',
1602              finish clean up work! */
1603           GNUNET_free (h);
1604         }
1605       return;
1606     }
1607   GNUNET_CLIENT_receive (h->client,
1608                          &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL);
1609   size = ntohs (msg->size);
1610   switch (ntohs (msg->type))
1611     {
1612     case GNUNET_MESSAGE_TYPE_HELLO:
1613       if (GNUNET_OK !=
1614           GNUNET_HELLO_get_id ((const struct GNUNET_HELLO_Message *) msg,
1615                                &me))
1616         {
1617           GNUNET_break (0);
1618           break;
1619         }
1620 #if DEBUG_TRANSPORT
1621       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1622                   "Receiving (my own) `%s' message, I am `%4s'.\n",
1623                   "HELLO", GNUNET_i2s (&me));
1624 #endif
1625       GNUNET_free_non_null (h->my_hello);
1626       h->my_hello = NULL;
1627       if (size < sizeof (struct GNUNET_MessageHeader))
1628         {
1629           GNUNET_break (0);
1630           break;
1631         }
1632       h->my_hello = GNUNET_malloc (size);
1633       memcpy (h->my_hello, msg, size);
1634       while (NULL != (hwl = h->hwl_head))
1635         {
1636           h->hwl_head = hwl->next;
1637           GNUNET_SCHEDULER_cancel (h->sched, hwl->task);
1638           GNUNET_TRANSPORT_get_hello (h,
1639                                       GNUNET_TIME_UNIT_ZERO,
1640                                       hwl->rec, hwl->rec_cls);
1641           GNUNET_free (hwl);
1642         }
1643       break;
1644     case GNUNET_MESSAGE_TYPE_TRANSPORT_CONNECT:
1645       if (size != sizeof (struct ConnectInfoMessage))
1646         {
1647           GNUNET_break (0);
1648           break;
1649         }
1650       cim = (const struct ConnectInfoMessage *) msg;
1651 #if DEBUG_TRANSPORT
1652       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1653                   "Receiving `%s' message for `%4s'.\n",
1654                   "CONNECT", GNUNET_i2s (&cim->id));
1655 #endif
1656       add_neighbour (h,
1657                      ntohl (cim->quota_out),
1658                      GNUNET_TIME_relative_ntoh (cim->latency), &cim->id);
1659       break;
1660     case GNUNET_MESSAGE_TYPE_TRANSPORT_DISCONNECT:
1661       if (size != sizeof (struct DisconnectInfoMessage))
1662         {
1663           GNUNET_break (0);
1664           break;
1665         }
1666       dim = (const struct DisconnectInfoMessage *) msg;
1667 #if DEBUG_TRANSPORT
1668       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1669                   "Receiving `%s' message for `%4s'.\n",
1670                   "DISCONNECT", GNUNET_i2s (&dim->peer));
1671 #endif
1672       remove_neighbour (h, &dim->peer);
1673       break;
1674     case GNUNET_MESSAGE_TYPE_TRANSPORT_SEND_OK:
1675       if (size != sizeof (struct SendOkMessage))
1676         {
1677           GNUNET_break (0);
1678           break;
1679         }
1680       okm = (const struct SendOkMessage *) msg;
1681 #if DEBUG_TRANSPORT
1682       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1683                   "Receiving `%s' message, transmission %s.\n", "SEND_OK",
1684                   ntohl(okm->success) == GNUNET_OK ? "succeeded" : "failed");
1685 #endif
1686       n = find_neighbour (h, &okm->peer);
1687       GNUNET_assert (n != NULL);
1688       n->transmit_ok = GNUNET_YES;
1689       if (n->transmit_handle != NULL)
1690         {
1691 #if DEBUG_TRANSPORT
1692           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1693                       "Processing pending message for `%4s'\n",
1694                       GNUNET_i2s(&n->id));
1695 #endif
1696           GNUNET_SCHEDULER_cancel (h->sched,
1697                                    n->transmit_handle->notify_delay_task);
1698           n->transmit_handle->notify_delay_task =
1699             GNUNET_SCHEDULER_NO_TASK;
1700           GNUNET_assert (GNUNET_YES == n->received_ack);
1701           schedule_request (n->transmit_handle);
1702         }
1703       break;
1704     case GNUNET_MESSAGE_TYPE_TRANSPORT_RECV:
1705 #if DEBUG_TRANSPORT
1706       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1707                   "Receiving `%s' message.\n", "RECV");
1708 #endif
1709       if (size <
1710           sizeof (struct InboundMessage) +
1711           sizeof (struct GNUNET_MessageHeader))
1712         {
1713           GNUNET_break (0);
1714           break;
1715         }
1716       im = (const struct InboundMessage *) msg;
1717       imm = (const struct GNUNET_MessageHeader *) &im[1];
1718       if (ntohs (imm->size) + sizeof (struct InboundMessage) != size)
1719         {
1720           GNUNET_break (0);
1721           break;
1722         }
1723       switch (ntohs (imm->type))
1724         {
1725         case GNUNET_MESSAGE_TYPE_TRANSPORT_ACK:
1726 #if DEBUG_TRANSPORT
1727           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1728                       "Receiving `%s' message from `%4s'.\n",
1729                       "ACK", GNUNET_i2s (&im->peer));
1730 #endif
1731           n = find_neighbour (h, &im->peer);
1732           if (n == NULL)
1733             {
1734               GNUNET_break (0);
1735               break;
1736             }
1737           if (n->received_ack == GNUNET_NO)
1738             {
1739               n->received_ack = GNUNET_YES;
1740               if (NULL != n->transmit_handle)
1741                 {
1742 #if DEBUG_TRANSPORT
1743                   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1744                               "Peer connected, scheduling delayed message for deliverery now.\n");
1745 #endif
1746                   schedule_request (n->transmit_handle);
1747                 }
1748             }
1749           break;
1750         default:
1751 #if DEBUG_TRANSPORT
1752           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1753                       "Received message of type %u from `%4s'.\n",
1754                       ntohs (imm->type), GNUNET_i2s (&im->peer));
1755 #endif
1756           if (h->rec != NULL)
1757             h->rec (h->cls,
1758                     GNUNET_TIME_relative_ntoh (im->latency), &im->peer, imm);
1759           break;
1760         }
1761       break;
1762     default:
1763       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1764                   _
1765                   ("Received unexpected message of type %u in %s:%u\n"),
1766                   ntohs (msg->type), __FILE__, __LINE__);
1767       GNUNET_break (0);
1768       break;
1769     }
1770 }
1771
1772
1773 struct ClientTransmitWrapper
1774 {
1775   GNUNET_CONNECTION_TransmitReadyNotify notify;
1776   void *notify_cls;
1777   struct GNUNET_TRANSPORT_TransmitHandle *th;
1778 };
1779
1780
1781 /**
1782  * Transmit message of a client destined for another
1783  * peer to the service.
1784  */
1785 static size_t
1786 client_notify_wrapper (void *cls, size_t size, void *buf)
1787 {
1788   struct ClientTransmitWrapper *ctw = cls;
1789   struct OutboundMessage *obm;
1790   struct GNUNET_MessageHeader *hdr;
1791   size_t ret;
1792
1793   if (size == 0)
1794     {
1795 #if DEBUG_TRANSPORT
1796       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1797                   "Transmission request could not be satisfied.\n");
1798 #endif
1799       ret = ctw->notify (ctw->notify_cls, 0, NULL);
1800       GNUNET_assert (ret == 0);
1801       GNUNET_free (ctw);
1802       return 0;
1803     }
1804   GNUNET_assert (size >= sizeof (struct OutboundMessage));
1805   obm = buf;
1806   ret = ctw->notify (ctw->notify_cls,
1807                      size - sizeof (struct OutboundMessage),
1808                      (void *) &obm[1]);
1809   if (ret == 0)
1810     {
1811       /* Need to reset flag, no SEND means no SEND_OK! */
1812       ctw->th->neighbour->transmit_ok = GNUNET_YES;
1813       GNUNET_free (ctw);
1814       return 0;
1815     }
1816   GNUNET_assert (ret >= sizeof (struct GNUNET_MessageHeader));
1817   hdr = (struct GNUNET_MessageHeader *) &obm[1];
1818   GNUNET_assert (ntohs (hdr->size) == ret);
1819   GNUNET_assert (ret + sizeof (struct OutboundMessage) <
1820                  GNUNET_SERVER_MAX_MESSAGE_SIZE);
1821 #if DEBUG_TRANSPORT
1822   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1823               "Transmitting `%s' message with data for `%4s'\n",
1824               "SEND", GNUNET_i2s (&ctw->th->target));
1825 #endif
1826   ret += sizeof (struct OutboundMessage);
1827   obm->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SEND);
1828   obm->header.size = htons (ret);
1829   obm->priority = htonl (ctw->th->priority);
1830   obm->peer = ctw->th->target;
1831   GNUNET_free (ctw);
1832   return ret;
1833 }
1834
1835
1836
1837 /**
1838  * Check if we could queue a message of the given size for
1839  * transmission.  The transport service will take both its
1840  * internal buffers and bandwidth limits imposed by the
1841  * other peer into consideration when answering this query.
1842  *
1843  * @param handle connection to transport service
1844  * @param target who should receive the message
1845  * @param size how big is the message we want to transmit?
1846  * @param priority how important is the message?
1847  * @param timeout after how long should we give up (and call
1848  *        notify with buf NULL and size 0)?
1849  * @param notify function to call when we are ready to
1850  *        send such a message
1851  * @param notify_cls closure for notify
1852  * @return NULL if someone else is already waiting to be notified
1853  *         non-NULL if the notify callback was queued (can be used to cancel
1854  *         using GNUNET_TRANSPORT_notify_transmit_ready_cancel)
1855  */
1856 struct GNUNET_TRANSPORT_TransmitHandle *
1857 GNUNET_TRANSPORT_notify_transmit_ready (struct GNUNET_TRANSPORT_Handle
1858                                         *handle,
1859                                         const struct GNUNET_PeerIdentity
1860                                         *target, size_t size,
1861                                         unsigned int priority,
1862                                         struct GNUNET_TIME_Relative timeout,
1863                                         GNUNET_CONNECTION_TransmitReadyNotify
1864                                         notify, void *notify_cls)
1865 {
1866   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1867   struct GNUNET_TRANSPORT_TransmitHandle *th;
1868   struct NeighbourList *n;
1869   struct ClientTransmitWrapper *ctw;
1870
1871   if (size + sizeof (struct OutboundMessage) >=
1872       GNUNET_SERVER_MAX_MESSAGE_SIZE)
1873     {
1874       GNUNET_break (0);
1875       return NULL;
1876     }
1877 #if DEBUG_TRANSPORT
1878   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1879               "Asking transport service for transmission of %u bytes to peer `%4s'.\n",
1880               size, GNUNET_i2s (target));
1881 #endif
1882   n = find_neighbour (handle, target);
1883   if ( (n != NULL) &&
1884        (n->transmit_handle != NULL) )
1885     return NULL; /* already have a request pending for this peer! */
1886   ctw = GNUNET_malloc (sizeof (struct ClientTransmitWrapper));
1887   th = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_TransmitHandle));
1888   ctw->notify = notify;
1889   ctw->notify_cls = notify_cls;
1890   ctw->th = th;
1891   th->handle = handle;
1892   th->neighbour = n;
1893   th->target = *target;
1894   th->notify = &client_notify_wrapper;
1895   th->notify_cls = ctw;
1896   th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
1897   th->notify_size = size + sizeof (struct OutboundMessage);
1898   th->priority = priority;
1899   if (NULL == n)
1900     {
1901       pos = handle->connect_wait_head;
1902       while (pos != NULL)
1903         {
1904           GNUNET_assert (0 != memcmp (target,
1905                                       &pos->target,
1906                                       sizeof (struct GNUNET_PeerIdentity)));
1907           pos = pos->next;
1908         }
1909 #if DEBUG_TRANSPORT
1910       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1911                   "Will now try to connect to `%4s'.\n", GNUNET_i2s (target));
1912 #endif
1913       try_connect (th);
1914       return th;
1915     }
1916
1917 #if DEBUG_TRANSPORT
1918   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1919               "Transmission request queued for transmission to transport service.\n");
1920 #endif
1921   GNUNET_assert (NULL == n->transmit_handle);
1922   n->transmit_handle = th;
1923   if (GNUNET_YES != n->received_ack)
1924     {
1925 #if DEBUG_TRANSPORT
1926       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1927                   "Connection to `%4s' is not yet confirmed connected, scheduling timeout (%llu ms) only.\n",
1928                   GNUNET_i2s (target), timeout.value);
1929 #endif
1930       th->notify_delay_task
1931         = GNUNET_SCHEDULER_add_delayed (handle->sched,
1932                                         GNUNET_NO,
1933                                         GNUNET_SCHEDULER_PRIORITY_KEEP,
1934                                         GNUNET_SCHEDULER_NO_TASK,
1935                                         timeout, &transmit_timeout, th);
1936       return th;
1937     }
1938
1939 #if DEBUG_TRANSPORT
1940   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1941               "Peer `%4s' is ready to receive, scheduling message for delivery now.\n",
1942               GNUNET_i2s (target));
1943 #endif
1944   schedule_request (th);
1945   return th;
1946 }
1947
1948
1949 /**
1950  * Cancel the specified transmission-ready
1951  * notification.
1952  */
1953 void
1954 GNUNET_TRANSPORT_notify_transmit_ready_cancel (struct
1955                                                GNUNET_TRANSPORT_TransmitHandle
1956                                                *th)
1957 {
1958   struct GNUNET_TRANSPORT_Handle *h;
1959
1960 #if DEBUG_TRANSPORT
1961   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1962               "Transmission request of %u bytes to `%4s' was cancelled.\n",
1963               th->notify_size - sizeof(struct OutboundMessage),
1964               GNUNET_i2s (&th->target));
1965 #endif
1966   GNUNET_assert (th->notify == &client_notify_wrapper);
1967   remove_from_any_list (th);
1968   h = th->handle;
1969   if ((h->connect_ready_head == NULL) && (h->network_handle != NULL))
1970     {
1971       GNUNET_CONNECTION_notify_transmit_ready_cancel (h->network_handle);
1972       h->network_handle = NULL;
1973       h->transmission_scheduled = GNUNET_NO;
1974     }
1975   GNUNET_free (th->notify_cls);
1976   GNUNET_free (th);
1977 }
1978
1979
1980 /* end of transport_api.c */