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 #include "platform.h"
  27 #include "gnunet_client_lib.h"
  28 #include "gnunet_arm_service.h"
  29 #include "gnunet_hello_lib.h"
  30 #include "gnunet_protocols.h"
  31 #include "gnunet_server_lib.h"
  32 #include "gnunet_time_lib.h"
  33 #include "gnunet_transport_service.h"
  34 #include "transport.h"
  35
  36 /**
  37  * After how long do we give up on transmitting a HELLO
  38  * to the service?
  39  */
  40 #define OFFER_HELLO_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 30)
  41
  42 /**
  43  * After how long do we automatically retry an unsuccessful
  44  * CONNECT request?
  45  */
  46 #define CONNECT_RETRY_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 750)
  47
  48 /**
  49  * How long should ARM wait when starting up the
  50  * transport service before reporting back?
  51  */
  52 #define START_SERVICE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
  53
  54 /**
  55  * How long should ARM wait when stopping the
  56  * transport service before reporting back?
  57  */
  58 #define STOP_SERVICE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
  59
  60 /**
  61  * Entry in linked list of all of our current neighbours.
  62  */
  63 struct NeighbourList
  64 {
  65
  66   /**
  67    * This is a linked list.
  68    */
  69   struct NeighbourList *next;
  70
  71   /**
  72    * Active transmit handle, can be NULL.  Used to move
  73    * from ready to wait list on disconnect and to block
  74    * two transmissions to the same peer from being scheduled
  75    * at the same time.
  76    */
  77   struct GNUNET_TRANSPORT_TransmitHandle *transmit_handle;
  78
  79   /**
  80    * Identity of this neighbour.
  81    */
  82   struct GNUNET_PeerIdentity id;
  83
  84   /**
  85    * At what time did we reset last_sent last?
  86    */
  87   struct GNUNET_TIME_Absolute last_quota_update;
  88
  89   /**
  90    * How many bytes have we sent since the "last_quota_update"
  91    * timestamp?
  92    */
  93   uint64_t last_sent;
  94
  95   /**
  96    * Quota for outbound traffic to the neighbour in bytes/ms.
  97    */
  98   uint32_t quota_out;
  99
 100   /**
 101    * Set to GNUNET_YES if we are currently allowed to
 102    * transmit a message to the transport service for this
 103    * peer, GNUNET_NO otherwise.
 104    */
 105   int transmit_ok;
 106
 107   /**
 108    * Set to GNUNET_YES if we have received an ACK for the
 109    * given peer.  Peers that receive our HELLO always respond
 110    * with an ACK to let us know that we are successfully
 111    * communicating.  Note that a PING can not be used for this
 112    * since PINGs are only send if a HELLO address requires
 113    * confirmation (and also, PINGs are not passed to the
 114    * transport API itself).
 115    */
 116   int received_ack;
 117
 118 };
 119
 120
 121 /**
 122  * Linked list of requests from clients for our HELLO
 123  * that were deferred.
 124  */
 125 struct HelloWaitList
 126 {
 127
 128   /**
 129    * This is a linked list.
 130    */
 131   struct HelloWaitList *next;
 132
 133   /**
 134    * Reference back to our transport handle.
 135    */
 136   struct GNUNET_TRANSPORT_Handle *handle;
 137
 138   /**
 139    * Callback to call once we got our HELLO.
 140    */
 141   GNUNET_TRANSPORT_HelloUpdateCallback rec;
 142
 143   /**
 144    * Closure for rec.
 145    */
 146   void *rec_cls;
 147
 148   /**
 149    * When to time out (call rec with NULL).
 150    */
 151   struct GNUNET_TIME_Absolute timeout;
 152
 153   /**
 154    * Timeout task (used to trigger timeout,
 155    * cancel if we get the HELLO in time).
 156    */
 157   GNUNET_SCHEDULER_TaskIdentifier task;
 158
 159
 160 };
 161
 162
 163 /**
 164  * Opaque handle for a transmission-ready request.
 165  */
 166 struct GNUNET_TRANSPORT_TransmitHandle
 167 {
 168
 169   /**
 170    * We keep the transmit handles that are waiting for
 171    * a transport-level connection in a doubly linked list.
 172    */
 173   struct GNUNET_TRANSPORT_TransmitHandle *next;
 174
 175   /**
 176    * We keep the transmit handles that are waiting for
 177    * a transport-level connection in a doubly linked list.
 178    */
 179   struct GNUNET_TRANSPORT_TransmitHandle *prev;
 180
 181   /**
 182    * Handle of the main transport data structure.
 183    */
 184   struct GNUNET_TRANSPORT_Handle *handle;
 185
 186   /**
 187    * Neighbour for this handle, can be NULL if the service
 188    * is not yet connected to the target.
 189    */
 190   struct NeighbourList *neighbour;
 191
 192   /**
 193    * Which peer is this transmission going to be for?  All
 194    * zeros if it is control-traffic to the service.
 195    */
 196   struct GNUNET_PeerIdentity target;
 197
 198   /**
 199    * Function to call when notify_size bytes are available
 200    * for transmission.
 201    */
 202   GNUNET_CONNECTION_TransmitReadyNotify notify;
 203
 204   /**
 205    * Closure for notify.
 206    */
 207   void *notify_cls;
 208
 209   /**
 210    * transmit_ready task Id.  The task is used to introduce the
 211    * artificial delay that may be required to maintain the bandwidth
 212    * limits.  Later, this will be the ID of the "transmit_timeout"
 213    * task which is used to signal a timeout if the transmission could
 214    * not be done in a timely fashion.
 215    */
 216   GNUNET_SCHEDULER_TaskIdentifier notify_delay_task;
 217
 218   /**
 219    * Timeout for this request.
 220    */
 221   struct GNUNET_TIME_Absolute timeout;
 222
 223   /**
 224    * How many bytes is our notify callback waiting for?
 225    */
 226   size_t notify_size;
 227
 228   /**
 229    * How important is this message?
 230    */
 231   unsigned int priority;
 232
 233 };
 234
 235
 236 /**
 237  * Handle for the transport service (includes all of the
 238  * state for the transport service).
 239  */
 240 struct GNUNET_TRANSPORT_Handle
 241 {
 242
 243   /**
 244    * Closure for the callbacks.
 245    */
 246   void *cls;
 247
 248   /**
 249    * Function to call for received data.
 250    */
 251   GNUNET_TRANSPORT_ReceiveCallback rec;
 252
 253   /**
 254    * function to call on connect events
 255    */
 256   GNUNET_TRANSPORT_NotifyConnect nc_cb;
 257
 258   /**
 259    * function to call on disconnect events
 260    */
 261   GNUNET_TRANSPORT_NotifyDisconnect nd_cb;
 262
 263   /**
 264    * The current HELLO message for this peer.  Updated
 265    * whenever transports change their addresses.
 266    */
 267   struct GNUNET_HELLO_Message *my_hello;
 268
 269   /**
 270    * My client connection to the transport service.
 271    */
 272   struct GNUNET_CLIENT_Connection *client;
 273
 274   /**
 275    * Handle to our registration with the client for notification.
 276    */
 277   struct GNUNET_CLIENT_TransmitHandle *network_handle;
 278
 279   /**
 280    * Linked list of transmit handles that are waiting for the
 281    * transport to connect to the respective peer.  When we
 282    * receive notification that the transport connected to a
 283    * peer, we go over this list and check if someone has already
 284    * requested a transmission to the new peer; if so, we trigger
 285    * the next step.
 286    */
 287   struct GNUNET_TRANSPORT_TransmitHandle *connect_wait_head;
 288
 289   /**
 290    * Linked list of transmit handles that are waiting for the
 291    * transport to be ready for transmission to the respective
 292    * peer.  When we
 293    * receive notification that the transport disconnected from
 294    * a peer, we go over this list and move the entry back to
 295    * the connect_wait list.
 296    */
 297   struct GNUNET_TRANSPORT_TransmitHandle *connect_ready_head;
 298
 299   /**
 300    * Linked list of pending requests for our HELLO.
 301    */
 302   struct HelloWaitList *hwl_head;
 303
 304   /**
 305    * My scheduler.
 306    */
 307   struct GNUNET_SCHEDULER_Handle *sched;
 308
 309   /**
 310    * My configuration.
 311    */
 312   const struct GNUNET_CONFIGURATION_Handle *cfg;
 313
 314   /**
 315    * Linked list of the current neighbours of this peer.
 316    */
 317   struct NeighbourList *neighbours;
 318
 319   /**
 320    * ID of the task trying to reconnect to the
 321    * service.
 322    */
 323   GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
 324
 325   /**
 326    * Delay until we try to reconnect.
 327    */
 328   struct GNUNET_TIME_Relative reconnect_delay;
 329
 330   /**
 331    * Do we currently have a transmission pending?
 332    * (schedule transmission was called but has not
 333    * yet succeeded)?
 334    */
 335   int transmission_scheduled;
 336 };
 337
 338
 339 static struct NeighbourList *
 340 find_neighbour (struct GNUNET_TRANSPORT_Handle *h,
 341                 const struct GNUNET_PeerIdentity *peer)
 342 {
 343   struct NeighbourList *pos;
 344
 345   pos = h->neighbours;
 346   while ((pos != NULL) &&
 347          (0 != memcmp (peer, &pos->id, sizeof (struct GNUNET_PeerIdentity))))
 348     pos = pos->next;
 349   return pos;
 350 }
 351
 352
 353 /**
 354  * Schedule the task to send one message from the
 355  * connect_ready list to the service.
 356  */
 357 static void schedule_transmission (struct GNUNET_TRANSPORT_Handle *h);
 358
 359
 360 /**
 361  * Transmit message to client...
 362  */
 363 static size_t
 364 transport_notify_ready (void *cls, size_t size, void *buf)
 365 {
 366   struct GNUNET_TRANSPORT_Handle *h = cls;
 367   struct GNUNET_TRANSPORT_TransmitHandle *th;
 368   struct NeighbourList *n;
 369   size_t ret;
 370   char *cbuf;
 371
 372   h->network_handle = NULL;
 373   h->transmission_scheduled = GNUNET_NO;
 374   if (buf == NULL)
 375     {
 376 #if DEBUG_TRANSPORT
 377       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 378                   "Could not transmit to transport service, cancelling pending requests\n");
 379 #endif
 380       th = h->connect_ready_head;
 381       if (th->next != NULL)
 382         th->next->prev = NULL;
 383       h->connect_ready_head = th->next;
 384       if (NULL != (n = th->neighbour))
 385         {
 386           GNUNET_assert (n->transmit_handle == th);
 387           n->transmit_handle = NULL;
 388         }
 389       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
 390         {
 391           GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
 392           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 393         }
 394       if (NULL != th->notify)
 395         GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
 396       GNUNET_free (th);
 397       if (h->connect_ready_head != NULL)
 398         schedule_transmission (h);      /* FIXME: is this ok? */
 399       return 0;
 400     }
 401 #if DEBUG_TRANSPORT
 402   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 403               "Ready to transmit %u bytes to transport service\n", size);
 404 #endif
 405   cbuf = buf;
 406   ret = 0;
 407   h->network_handle = NULL;
 408   h->transmission_scheduled = GNUNET_NO;
 409   while ((h->connect_ready_head != NULL) &&
 410          (h->connect_ready_head->notify_size <= size))
 411     {
 412       th = h->connect_ready_head;
 413       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
 414         {
 415           GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
 416           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 417         }
 418       GNUNET_assert (th->notify_size <= size);
 419       if (th->next != NULL)
 420         th->next->prev = NULL;
 421       h->connect_ready_head = th->next;
 422       if (NULL != (n = th->neighbour))
 423         {
 424           GNUNET_assert (n->transmit_handle == th);
 425           n->transmit_handle = NULL;
 426         }
 427       if (NULL != th->notify)
 428         ret += th->notify (th->notify_cls, size, &cbuf[ret]);
 429       GNUNET_free (th);
 430       if (n != NULL)
 431         n->last_sent += ret;
 432       size -= ret;
 433     }
 434   if (h->connect_ready_head != NULL)
 435     schedule_transmission (h);
 436 #if DEBUG_TRANSPORT
 437   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 438               "Transmitting %u bytes to transport service\n", ret);
 439 #endif
 440   return ret;
 441 }
 442
 443
 444 /**
 445  * Schedule the task to send one message from the
 446  * connect_ready list to the service.
 447  */
 448 static void
 449 schedule_transmission (struct GNUNET_TRANSPORT_Handle *h)
 450 {
 451   struct GNUNET_TRANSPORT_TransmitHandle *th;
 452
 453   GNUNET_assert (NULL == h->network_handle);
 454   if (h->client == NULL)
 455     {
 456       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 457                   "Could not yet schedule transmission: we are not yet connected to the transport service!\n");
 458       return;                   /* not yet connected */
 459     }
 460   th = h->connect_ready_head;
 461   if (th == NULL)
 462     return;                     /* no request pending */
 463   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
 464     {
 465       /* remove existing time out task, will be integrated
 466          with transmit_ready notification! */
 467       GNUNET_SCHEDULER_cancel (h->sched, 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                                                            GNUNET_NO,
 476                                                            &transport_notify_ready,
 477                                                            h);
 478   GNUNET_assert (NULL != h->network_handle);
 479 }
 480
 481
 482 /**
 483  * Insert the given transmit handle in the given sorted
 484  * doubly linked list based on timeout.
 485  *
 486  * @param head pointer to the head of the linked list
 487  * @param th element to insert into the list
 488  */
 489 static void
 490 insert_transmit_handle (struct GNUNET_TRANSPORT_TransmitHandle **head,
 491                         struct GNUNET_TRANSPORT_TransmitHandle *th)
 492 {
 493   struct GNUNET_TRANSPORT_TransmitHandle *pos;
 494   struct GNUNET_TRANSPORT_TransmitHandle *prev;
 495
 496   pos = *head;
 497   prev = NULL;
 498   while ((pos != NULL) && (pos->timeout.value < th->timeout.value))
 499     {
 500       prev = pos;
 501       pos = pos->next;
 502     }
 503   if (prev == NULL)
 504     {
 505       th->next = *head;
 506       if (th->next != NULL)
 507         th->next->prev = th;
 508       *head = th;
 509     }
 510   else
 511     {
 512       th->next = pos;
 513       th->prev = prev;
 514       prev->next = th;
 515       if (pos != NULL)
 516         pos->prev = th;
 517     }
 518 }
 519
 520
 521 /**
 522  * Cancel a pending notify delay task (if pending) and also remove the
 523  * given transmit handle from whatever list is on.
 524  *
 525  * @param th handle for the transmission request to manipulate
 526  */
 527 static void
 528 remove_from_any_list (struct GNUNET_TRANSPORT_TransmitHandle *th)
 529 {
 530   struct GNUNET_TRANSPORT_Handle *h;
 531
 532   h = th->handle;
 533   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
 534     {
 535       GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
 536       th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 537     }
 538   if (th->prev == NULL)
 539     {
 540       if (th == h->connect_wait_head)
 541         h->connect_wait_head = th->next;
 542       else
 543         h->connect_ready_head = th->next;
 544     }
 545   else
 546     {
 547       th->prev->next = th->next;
 548     }
 549   if (th->next != NULL)
 550     th->next->prev = th->prev;
 551 }
 552
 553
 554 /**
 555  * Schedule a request to connect to the given
 556  * neighbour (and if successful, add the specified
 557  * handle to the wait list).
 558  *
 559  * @param th handle for a request to transmit once we
 560  *        have connected
 561  */
 562 static void 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 peer_transmit_timeout (void *cls,
 573                        const struct GNUNET_SCHEDULER_TaskContext *tc)
 574 {
 575   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
 576
 577   th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 578   if (th->neighbour != NULL)
 579     th->neighbour->transmit_handle = NULL;
 580 #if DEBUG_TRANSPORT
 581   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 582               "Request for transmission to peer `%s' timed out.\n",
 583               GNUNET_i2s (&th->target));
 584 #endif
 585   remove_from_any_list (th);
 586   if (NULL != th->notify)
 587     th->notify (th->notify_cls, 0, NULL);
 588   GNUNET_free (th);
 589 }
 590
 591
 592
 593
 594 /**
 595  * Queue control request for transmission to the transport
 596  * service.
 597  *
 598  * @param h handle to the transport service
 599  * @param size number of bytes to be transmitted
 600  * @param at_head request must be added to the head of the queue
 601  *        (otherwise request will be appended)
 602  * @param timeout how long this transmission can wait (at most)
 603  * @param notify function to call to get the content
 604  * @param notify_cls closure for notify
 605  */
 606 static void
 607 schedule_control_transmit (struct GNUNET_TRANSPORT_Handle *h,
 608                            size_t size,
 609                            int at_head,
 610                            struct GNUNET_TIME_Relative timeout,
 611                            GNUNET_CONNECTION_TransmitReadyNotify notify,
 612                            void *notify_cls)
 613 {
 614   struct GNUNET_TRANSPORT_TransmitHandle *th;
 615
 616 #if DEBUG_TRANSPORT
 617   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 618               "Control transmit of %u bytes within %llums requested\n",
 619               size, (unsigned long long) timeout.value);
 620 #endif
 621   th = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_TransmitHandle));
 622   th->handle = h;
 623   th->notify = notify;
 624   th->notify_cls = notify_cls;
 625   th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 626   th->notify_size = size;
 627   th->notify_delay_task
 628     = GNUNET_SCHEDULER_add_delayed (h->sched,
 629                                     timeout, &peer_transmit_timeout, th);
 630   if (at_head)
 631     {
 632       th->next = h->connect_ready_head;
 633       h->connect_ready_head = th;
 634       if (th->next != NULL)
 635         th->next->prev = th;
 636     }
 637   else
 638     {
 639       insert_transmit_handle (&h->connect_ready_head, th);
 640     }
 641   if (GNUNET_NO == h->transmission_scheduled)
 642     schedule_transmission (h);
 643 }
 644
 645
 646 /**
 647  * Update the quota values for the given neighbour now.
 648  */
 649 static void
 650 update_quota (struct NeighbourList *n)
 651 {
 652   struct GNUNET_TIME_Relative delta;
 653   uint64_t allowed;
 654   uint64_t remaining;
 655
 656   delta = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
 657   allowed = delta.value * n->quota_out;
 658   if (n->last_sent < allowed)
 659     {
 660       remaining = allowed - n->last_sent;
 661       if (n->quota_out > 0)
 662         remaining /= n->quota_out;
 663       else
 664         remaining = 0;
 665       if (remaining > MAX_BANDWIDTH_CARRY)
 666         remaining = MAX_BANDWIDTH_CARRY;
 667       n->last_sent = 0;
 668       n->last_quota_update = GNUNET_TIME_absolute_get ();
 669       n->last_quota_update.value -= remaining;
 670     }
 671   else
 672     {
 673       n->last_sent -= allowed;
 674       n->last_quota_update = GNUNET_TIME_absolute_get ();
 675     }
 676 }
 677
 678
 679 struct SetQuotaContext
 680 {
 681   struct GNUNET_TRANSPORT_Handle *handle;
 682
 683   struct GNUNET_PeerIdentity target;
 684
 685   GNUNET_SCHEDULER_Task cont;
 686
 687   void *cont_cls;
 688
 689   struct GNUNET_TIME_Absolute timeout;
 690
 691   uint32_t quota_in;
 692 };
 693
 694
 695 static size_t
 696 send_set_quota (void *cls, size_t size, void *buf)
 697 {
 698   struct SetQuotaContext *sqc = cls;
 699   struct QuotaSetMessage *msg;
 700
 701   if (buf == NULL)
 702     {
 703       GNUNET_SCHEDULER_add_continuation (sqc->handle->sched,
 704                                          sqc->cont,
 705                                          sqc->cont_cls,
 706                                          GNUNET_SCHEDULER_REASON_TIMEOUT);
 707       GNUNET_free (sqc);
 708       return 0;
 709     }
 710 #if DEBUG_TRANSPORT
 711   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 712               "Transmitting `%s' request with respect to `%4s'.\n",
 713               "SET_QUOTA", GNUNET_i2s (&sqc->target));
 714 #endif
 715   GNUNET_assert (size >= sizeof (struct QuotaSetMessage));
 716   msg = buf;
 717   msg->header.size = htons (sizeof (struct QuotaSetMessage));
 718   msg->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SET_QUOTA);
 719   msg->quota_in = htonl (sqc->quota_in);
 720   memcpy (&msg->peer, &sqc->target, sizeof (struct GNUNET_PeerIdentity));
 721   if (sqc->cont != NULL)
 722     GNUNET_SCHEDULER_add_continuation (sqc->handle->sched,
 723                                        sqc->cont,
 724                                        sqc->cont_cls,
 725                                        GNUNET_SCHEDULER_REASON_PREREQ_DONE);
 726   GNUNET_free (sqc);
 727   return sizeof (struct QuotaSetMessage);
 728 }
 729
 730
 731 /**
 732  * Set the share of incoming bandwidth for the given
 733  * peer to the specified amount.
 734  *
 735  * @param handle connection to transport service
 736  * @param target who's bandwidth quota is being changed
 737  * @param quota_in incoming bandwidth quota in bytes per ms
 738  * @param quota_out outgoing bandwidth quota in bytes per ms
 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 #if 0
 782 static void
 783 hello_wait_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 784 {
 785   struct HelloWaitList *hwl = cls;
 786   struct HelloWaitList *pos;
 787   struct HelloWaitList *prev;
 788
 789   hwl->task = GNUNET_SCHEDULER_NO_TASK;
 790   if (GNUNET_TIME_absolute_get_remaining (hwl->timeout).value > 0)
 791     {
 792 #if DEBUG_TRANSPORT
 793       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 794                   _
 795                   ("First attempt to obtain `%s' from transport service failed, will try again for %llums.\n"),
 796                   "HELLO",
 797                   GNUNET_TIME_absolute_get_remaining (hwl->timeout).value);
 798 #endif
 799       hwl->task = GNUNET_SCHEDULER_add_delayed (hwl->handle->sched,
 800                                                 GNUNET_TIME_absolute_get_remaining
 801                                                 (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, NULL);
 823   GNUNET_free (hwl);
 824 }
 825 #endif
 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                             GNUNET_TRANSPORT_HelloUpdateCallback rec,
 841                             void *rec_cls)
 842 {
 843   struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded pk;
 844   struct GNUNET_PeerIdentity me;
 845   struct HelloWaitList *hwl;
 846
 847   if (handle->my_hello == NULL)
 848     {
 849       hwl = GNUNET_malloc (sizeof (struct HelloWaitList));
 850       hwl->next = handle->hwl_head;
 851       handle->hwl_head = hwl;
 852       hwl->handle = handle;
 853       hwl->rec = rec;
 854       hwl->rec_cls = rec_cls;
 855       /* hwl->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 856        * Timeout not needed, because we should notify on change.
 857        * FIXME: set up scheduler to notify on modification?
 858
 859       hwl->task = GNUNET_SCHEDULER_add_delayed (handle->sched,
 860                                                 timeout,
 861                                                 &hello_wait_timeout, hwl);
 862       */
 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, (const struct GNUNET_MessageHeader *) handle->my_hello);
 871 }
 872
 873
 874 static size_t
 875 send_hello (void *cls, size_t size, void *buf)
 876 {
 877   struct GNUNET_MessageHeader *hello = cls;
 878   uint16_t msize;
 879
 880   if (buf == NULL)
 881     {
 882 #if DEBUG_TRANSPORT
 883       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 884                   "Timeout while trying to transmit `%s' request.\n",
 885                   "HELLO");
 886 #endif
 887       GNUNET_free (hello);
 888       return 0;
 889     }
 890 #if DEBUG_TRANSPORT
 891   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 892               "Transmitting `%s' request.\n", "HELLO");
 893 #endif
 894   msize = ntohs (hello->size);
 895   GNUNET_assert (size >= msize);
 896   memcpy (buf, hello, msize);
 897   GNUNET_free (hello);
 898   return msize;
 899 }
 900
 901
 902 /**
 903  * Offer the transport service the HELLO of another peer.  Note that
 904  * the transport service may just ignore this message if the HELLO is
 905  * malformed or useless due to our local configuration.
 906  *
 907  * @param handle connection to transport service
 908  * @param hello the hello message
 909  */
 910 void
 911 GNUNET_TRANSPORT_offer_hello (struct GNUNET_TRANSPORT_Handle *handle,
 912                               const struct GNUNET_MessageHeader *hello)
 913 {
 914   struct GNUNET_MessageHeader *hc;
 915   uint16_t size;
 916
 917   if (handle->client == NULL)
 918     {
 919 #if DEBUG_TRANSPORT
 920       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 921                   "Not connected to transport service, dropping offered HELLO\n");
 922 #endif
 923       return;
 924     }
 925   GNUNET_break (ntohs (hello->type) == GNUNET_MESSAGE_TYPE_HELLO);
 926   size = ntohs (hello->size);
 927   GNUNET_break (size >= sizeof (struct GNUNET_MessageHeader));
 928   hc = GNUNET_malloc (size);
 929   memcpy (hc, hello, size);
 930   schedule_control_transmit (handle,
 931                              size,
 932                              GNUNET_NO, OFFER_HELLO_TIMEOUT, &send_hello, hc);
 933 }
 934
 935
 936 /**
 937  * Function we use for handling incoming messages.
 938  */
 939 static void demultiplexer (void *cls, const struct GNUNET_MessageHeader *msg);
 940
 941
 942 static size_t
 943 send_start (void *cls, size_t size, void *buf)
 944 {
 945   struct GNUNET_MessageHeader *s = buf;
 946
 947   if (buf == NULL)
 948     {
 949 #if DEBUG_TRANSPORT
 950       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 951                   "Timeout while trying to transmit `%s' request.\n",
 952                   "START");
 953 #endif
 954       return 0;
 955     }
 956 #if DEBUG_TRANSPORT
 957   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 958               "Transmitting `%s' request.\n", "START");
 959 #endif
 960   GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
 961   s->size = htons (sizeof (struct GNUNET_MessageHeader));
 962   s->type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_START);
 963   return sizeof (struct GNUNET_MessageHeader);
 964 }
 965
 966
 967 /**
 968  * We're ready to transmit the request that the transport service
 969  * should connect to a new peer.  In addition to sending the
 970  * request, schedule the next phase for the transmission processing
 971  * that caused the connect request in the first place.
 972  */
 973 static size_t
 974 request_connect (void *cls, size_t size, void *buf)
 975 {
 976   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
 977   struct TryConnectMessage *tcm;
 978   struct GNUNET_TRANSPORT_Handle *h;
 979
 980   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_TASK);
 981   h = th->handle;
 982   if (buf == NULL)
 983     {
 984 #if DEBUG_TRANSPORT
 985       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 986                   "Failed to transmit `%s' request for `%4s' to service.\n",
 987                   "TRY_CONNECT", GNUNET_i2s (&th->target));
 988 #endif
 989       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
 990         {
 991           GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
 992           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 993         }
 994       if (NULL != th->notify)
 995         GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
 996       GNUNET_free (th);
 997       return 0;
 998     }
 999 #if DEBUG_TRANSPORT
1000   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1001               "Transmitting `%s' message for `%4s' (need connection in %llu ms).\n",
1002               "TRY_CONNECT", GNUNET_i2s (&th->target),
1003               GNUNET_TIME_absolute_get_remaining (th->timeout).value);
1004 #endif
1005   GNUNET_assert (size >= sizeof (struct TryConnectMessage));
1006   tcm = buf;
1007   tcm->header.size = htons (sizeof (struct TryConnectMessage));
1008   tcm->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_TRY_CONNECT);
1009   tcm->reserved = htonl (0);
1010   memcpy (&tcm->peer, &th->target, sizeof (struct GNUNET_PeerIdentity));
1011   th->notify_delay_task
1012     = GNUNET_SCHEDULER_add_delayed (h->sched,
1013                                     GNUNET_TIME_absolute_get_remaining
1014                                     (th->timeout),
1015                                     &peer_transmit_timeout, th);
1016   insert_transmit_handle (&h->connect_wait_head, th);
1017   return sizeof (struct TryConnectMessage);
1018 }
1019
1020
1021 /**
1022  * Schedule a request to connect to the given
1023  * neighbour (and if successful, add the specified
1024  * handle to the wait list).
1025  *
1026  * @param th handle for a request to transmit once we
1027  *        have connected
1028  */
1029 static void
1030 try_connect (struct GNUNET_TRANSPORT_TransmitHandle *th)
1031 {
1032   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_TASK);
1033   schedule_control_transmit (th->handle,
1034                              sizeof (struct TryConnectMessage),
1035                              GNUNET_NO,
1036                              GNUNET_TIME_absolute_get_remaining (th->timeout),
1037                              &request_connect, th);
1038 }
1039
1040
1041 /**
1042  * Task for delayed attempts to reconnect to a peer.
1043  *
1044  * @param cls must be a transmit handle that determines the peer
1045  *        to which we will try to connect
1046  * @param tc scheduler information about why we were triggered (not used)
1047  */
1048 static void
1049 try_connect_task (void *cls, 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, &pos->id, sizeof (struct GNUNET_PeerIdentity))))
1083     {
1084       prev = pos;
1085       pos = pos->next;
1086     }
1087   if (pos == NULL)
1088     {
1089       GNUNET_break (0);
1090       return;
1091     }
1092   if (prev == NULL)
1093     h->neighbours = pos->next;
1094   else
1095     prev->next = pos->next;
1096   if (NULL != (th = pos->transmit_handle))
1097     {
1098       pos->transmit_handle = NULL;
1099       th->neighbour = NULL;
1100       remove_from_any_list (th);
1101       if (GNUNET_TIME_absolute_get_remaining (th->timeout).value <=
1102           CONNECT_RETRY_TIMEOUT.value)
1103         {
1104           /* signal error */
1105           GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1106                       _
1107                       ("Connection with `%4s' failed and timeout was in the past, giving up on message delivery.\n"),
1108                       GNUNET_i2s (peer));
1109           GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == th->notify_delay_task);
1110           peer_transmit_timeout (th, NULL);
1111         }
1112       else
1113         {
1114           GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1115                       _
1116                       ("Connection with `%4s' failed, will keep trying for %llu ms to deliver message\n"),
1117                       GNUNET_i2s (peer),
1118                       GNUNET_TIME_absolute_get_remaining (th->timeout).value);
1119           /* try again in a bit */
1120           GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == th->notify_delay_task);
1121           th->notify_delay_task
1122             = GNUNET_SCHEDULER_add_delayed (h->sched,
1123                                             CONNECT_RETRY_TIMEOUT,
1124                                             &try_connect_task, 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           if (GNUNET_SCHEDULER_NO_TASK != pos->notify_delay_task)
1169             {
1170               GNUNET_SCHEDULER_cancel (h->sched, pos->notify_delay_task);
1171               pos->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1172             }
1173           GNUNET_free (pos);
1174           break;
1175         }
1176       pos = pos->next;
1177     }
1178   schedule_control_transmit (h,
1179                              sizeof (struct GNUNET_MessageHeader),
1180                              GNUNET_YES,
1181                              GNUNET_TIME_UNIT_FOREVER_REL, &send_start, NULL);
1182   GNUNET_CLIENT_receive (h->client,
1183                          &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL);
1184 }
1185
1186
1187 /**
1188  * Function that will schedule the job that will try
1189  * to connect us again to the client.
1190  */
1191 static void
1192 schedule_reconnect (struct GNUNET_TRANSPORT_Handle *h)
1193 {
1194 #if DEBUG_TRANSPORT
1195   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1196               "Scheduling task to reconnect to transport service in %llu ms.\n",
1197               h->reconnect_delay.value);
1198 #endif
1199   GNUNET_assert (h->client == NULL);
1200   GNUNET_assert (h->reconnect_task == GNUNET_SCHEDULER_NO_TASK);
1201   h->reconnect_task
1202     = GNUNET_SCHEDULER_add_delayed (h->sched,
1203                                     h->reconnect_delay, &reconnect, h);
1204   h->reconnect_delay = GNUNET_TIME_UNIT_SECONDS;
1205 }
1206
1207
1208 /**
1209  * We are connected to the respective peer, check the
1210  * bandwidth limits and schedule the transmission.
1211  */
1212 static void schedule_request (struct GNUNET_TRANSPORT_TransmitHandle *th);
1213
1214
1215 /**
1216  * Function called by the scheduler when the timeout
1217  * for bandwidth availablility for the target
1218  * neighbour is reached.
1219  */
1220 static void
1221 transmit_ready (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1222 {
1223   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
1224
1225   th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1226   schedule_request (th);
1227 }
1228
1229
1230 /**
1231  * Remove the given transmit handle from the wait list.  Does NOT free
1232  * it.
1233  */
1234 static void
1235 remove_from_wait_list (struct GNUNET_TRANSPORT_TransmitHandle *th)
1236 {
1237   if (th->prev == NULL)
1238     th->handle->connect_wait_head = th->next;
1239   else
1240     th->prev->next = th->next;
1241   if (th->next != NULL)
1242     th->next->prev = th->prev;
1243 }
1244
1245
1246 /**
1247  * We are connected to the respective peer, check the
1248  * bandwidth limits and schedule the transmission.
1249  */
1250 static void
1251 schedule_request (struct GNUNET_TRANSPORT_TransmitHandle *th)
1252 {
1253   struct GNUNET_TRANSPORT_Handle *h;
1254   struct GNUNET_TIME_Relative duration;
1255   struct NeighbourList *n;
1256   uint64_t available;
1257
1258   h = th->handle;
1259   n = th->neighbour;
1260   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1261     {
1262       GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
1263       th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1264     }
1265   /* check outgoing quota */
1266   duration = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
1267   if (duration.value > MIN_QUOTA_REFRESH_TIME)
1268     {
1269       update_quota (n);
1270       duration = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
1271     }
1272   available = duration.value * n->quota_out;
1273   if (available < n->last_sent + th->notify_size)
1274     {
1275       /* calculate how much bandwidth we'd still need to
1276          accumulate and based on that how long we'll have
1277          to wait... */
1278       available = n->last_sent + th->notify_size - available;
1279       duration = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS,
1280                                                 available / n->quota_out);
1281       if (th->timeout.value <
1282           GNUNET_TIME_relative_to_absolute (duration).value)
1283         {
1284           /* signal timeout! */
1285 #if DEBUG_TRANSPORT
1286           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1287                       "Would need %llu ms before bandwidth is available for delivery to `%4s', that is too long.  Signaling timeout.\n",
1288                       duration.value, GNUNET_i2s (&th->target));
1289 #endif
1290           remove_from_wait_list (th);
1291           if (NULL != th->notify)
1292             GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
1293           GNUNET_free (th);
1294           return;
1295         }
1296 #if DEBUG_TRANSPORT
1297       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1298                   "Need more bandwidth, delaying delivery to `%4s' by %llu ms\n",
1299                   GNUNET_i2s (&th->target), duration.value);
1300 #endif
1301       th->notify_delay_task
1302         = GNUNET_SCHEDULER_add_delayed (h->sched,
1303                                         duration, &transmit_ready, th);
1304       return;
1305     }
1306 #if DEBUG_TRANSPORT
1307   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1308               "Bandwidth available for transmission to `%4s'\n",
1309               GNUNET_i2s (&n->id));
1310 #endif
1311   if (GNUNET_NO == n->transmit_ok)
1312     {
1313       /* we may be ready, but transport service is not;
1314          wait for SendOkMessage or timeout */
1315 #if DEBUG_TRANSPORT
1316       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1317                   "Need to wait for transport service `%s' message\n",
1318                   "SEND_OK");
1319 #endif
1320       th->notify_delay_task
1321         = GNUNET_SCHEDULER_add_delayed (h->sched,
1322                                         GNUNET_TIME_absolute_get_remaining
1323                                         (th->timeout), &peer_transmit_timeout,
1324                                         th);
1325       return;
1326     }
1327   n->transmit_ok = GNUNET_NO;
1328   remove_from_wait_list (th);
1329 #if DEBUG_TRANSPORT
1330   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1331               "Moving message for `%4s' to ready list\n",
1332               GNUNET_i2s (&n->id));
1333 #endif
1334   insert_transmit_handle (&h->connect_ready_head, th);
1335   if (GNUNET_NO == h->transmission_scheduled)
1336     schedule_transmission (h);
1337 }
1338
1339
1340 /**
1341  * Add neighbour to our list
1342  */
1343 static void
1344 add_neighbour (struct GNUNET_TRANSPORT_Handle *h,
1345                uint32_t quota_out,
1346                struct GNUNET_TIME_Relative latency,
1347                uint16_t distance,
1348                const struct GNUNET_PeerIdentity *pid)
1349 {
1350   struct NeighbourList *n;
1351   struct GNUNET_TRANSPORT_TransmitHandle *prev;
1352   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1353   struct GNUNET_TRANSPORT_TransmitHandle *next;
1354
1355   /* check for duplicates */
1356   if (NULL != find_neighbour (h, pid))
1357     {
1358       GNUNET_break (0);
1359       return;
1360     }
1361 #if DEBUG_TRANSPORT
1362   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1363               "Creating entry for new neighbour `%4s'.\n", GNUNET_i2s (pid));
1364 #endif
1365   n = GNUNET_malloc (sizeof (struct NeighbourList));
1366   n->id = *pid;
1367   n->last_quota_update = GNUNET_TIME_absolute_get ();
1368   n->quota_out = quota_out;
1369   n->next = h->neighbours;
1370   n->transmit_ok = GNUNET_YES;
1371   h->neighbours = n;
1372   if (h->nc_cb != NULL)
1373     h->nc_cb (h->cls, &n->id, latency, distance);
1374   prev = NULL;
1375   pos = h->connect_wait_head;
1376   while (pos != NULL)
1377     {
1378       next = pos->next;
1379       if (0 == memcmp (pid,
1380                        &pos->target, sizeof (struct GNUNET_PeerIdentity)))
1381         {
1382           pos->neighbour = n;
1383           GNUNET_assert (NULL == n->transmit_handle);
1384           n->transmit_handle = pos;
1385           if (prev == NULL)
1386             h->connect_wait_head = next;
1387           else
1388             prev->next = next;
1389           if (GNUNET_YES == n->received_ack)
1390             {
1391 #if DEBUG_TRANSPORT
1392               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1393                           "Found pending request for `%4s' will trigger it now.\n",
1394                           GNUNET_i2s (&pos->target));
1395 #endif
1396               if (pos->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1397                 {
1398                   GNUNET_SCHEDULER_cancel (h->sched, pos->notify_delay_task);
1399                   pos->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1400                 }
1401               schedule_request (pos);
1402             }
1403           else
1404             {
1405 #if DEBUG_TRANSPORT
1406               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1407                           "Found pending request for `%4s' but still need `%s' before proceeding.\n",
1408                           GNUNET_i2s (&pos->target), "ACK");
1409 #endif
1410             }
1411           break;
1412         }
1413       prev = pos;
1414       pos = next;
1415     }
1416 }
1417
1418
1419 /**
1420  * Connect to the transport service.  Note that the connection may
1421  * complete (or fail) asynchronously.
1422  *
1423
1424  * @param sched scheduler to use
1425  * @param cfg configuration to use
1426  * @param cls closure for the callbacks
1427  * @param rec receive function to call
1428  * @param nc function to call on connect events
1429  * @param nd function to call on disconnect events
1430  */
1431 struct GNUNET_TRANSPORT_Handle *
1432 GNUNET_TRANSPORT_connect (struct GNUNET_SCHEDULER_Handle *sched,
1433                           const struct GNUNET_CONFIGURATION_Handle *cfg,
1434                           void *cls,
1435                           GNUNET_TRANSPORT_ReceiveCallback rec,
1436                           GNUNET_TRANSPORT_NotifyConnect nc,
1437                           GNUNET_TRANSPORT_NotifyDisconnect nd)
1438 {
1439   struct GNUNET_TRANSPORT_Handle *ret;
1440
1441   GNUNET_ARM_start_services (cfg, sched, "peerinfo", "transport", NULL);
1442   ret = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_Handle));
1443   ret->sched = sched;
1444   ret->cfg = cfg;
1445   ret->cls = cls;
1446   ret->rec = rec;
1447   ret->nc_cb = nc;
1448   ret->nd_cb = nd;
1449   ret->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
1450   schedule_reconnect (ret);
1451   return ret;
1452 }
1453
1454
1455 /**
1456  * Disconnect from the transport service.
1457  */
1458 void
1459 GNUNET_TRANSPORT_disconnect (struct GNUNET_TRANSPORT_Handle *handle)
1460 {
1461   struct GNUNET_TRANSPORT_TransmitHandle *th;
1462   struct NeighbourList *n;
1463   struct HelloWaitList *hwl;
1464   struct GNUNET_CLIENT_Connection *client;
1465
1466 #if DEBUG_TRANSPORT
1467   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transport disconnect called!\n");
1468 #endif
1469   while (NULL != (th = handle->connect_ready_head))
1470     {
1471       handle->connect_ready_head = th->next;
1472       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1473         {
1474           GNUNET_SCHEDULER_cancel (handle->sched, th->notify_delay_task);
1475           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1476         }
1477       if (NULL != th->notify)
1478         GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
1479       GNUNET_free (th);
1480     }
1481   while (NULL != (th = handle->connect_wait_head))
1482     {
1483       handle->connect_wait_head = th->next;
1484       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1485         {
1486           GNUNET_SCHEDULER_cancel (handle->sched, th->notify_delay_task);
1487           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1488         }
1489       if (NULL != th->notify)
1490         GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
1491       GNUNET_free (th);
1492     }
1493   while (NULL != (n = handle->neighbours))
1494     {
1495       handle->neighbours = n->next;
1496       if (NULL != (th = n->transmit_handle))
1497         {
1498           if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1499             {
1500               GNUNET_SCHEDULER_cancel (handle->sched, th->notify_delay_task);
1501               th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1502             }
1503           if (NULL != th->notify)
1504             GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
1505           GNUNET_free (th);
1506         }
1507       GNUNET_free (n);
1508     }
1509   while (NULL != (hwl = handle->hwl_head))
1510     {
1511       handle->hwl_head = hwl->next;
1512       GNUNET_SCHEDULER_cancel (handle->sched, hwl->task);
1513       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1514                   _
1515                   ("Disconnect while trying to obtain `%s' from transport service.\n"),
1516                   "HELLO");
1517       if (hwl->rec != NULL)
1518         hwl->rec (hwl->rec_cls, NULL);
1519       GNUNET_free (hwl);
1520     }
1521   if (handle->reconnect_task != GNUNET_SCHEDULER_NO_TASK)
1522     {
1523       GNUNET_SCHEDULER_cancel (handle->sched, handle->reconnect_task);
1524       handle->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
1525     }
1526   GNUNET_free_non_null (handle->my_hello);
1527   handle->my_hello = NULL;
1528   GNUNET_ARM_stop_services (handle->cfg, handle->sched, "transport",
1529                             "peerinfo", NULL);
1530   if (NULL != handle->network_handle)
1531     {
1532       GNUNET_CLIENT_notify_transmit_ready_cancel (handle->network_handle);
1533       handle->network_handle = NULL;
1534     }
1535   if (NULL != (client = handle->client))
1536     {
1537 #if DEBUG_TRANSPORT
1538       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1539                   "Disconnecting from transport service for good.\n");
1540 #endif
1541       handle->client = NULL;
1542       GNUNET_CLIENT_disconnect (client);
1543     }
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_CLIENT_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 ==
1586                              GNUNET_SCHEDULER_NO_TASK);
1587               th->notify_delay_task =
1588                 GNUNET_SCHEDULER_add_delayed (h->sched,
1589                                               GNUNET_TIME_absolute_get_remaining
1590                                               (th->timeout),
1591                                               &peer_transmit_timeout, th);
1592             }
1593           GNUNET_CLIENT_disconnect (h->client);
1594           h->client = NULL;
1595           schedule_reconnect (h);
1596         }
1597       else
1598         {
1599           /* shutdown initiated from 'GNUNET_TRANSPORT_disconnect',
1600              finish clean up work! */
1601           GNUNET_free (h);
1602         }
1603       return;
1604     }
1605   GNUNET_CLIENT_receive (h->client,
1606                          &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL);
1607   size = ntohs (msg->size);
1608   switch (ntohs (msg->type))
1609     {
1610     case GNUNET_MESSAGE_TYPE_HELLO:
1611       if (GNUNET_OK !=
1612           GNUNET_HELLO_get_id ((const struct GNUNET_HELLO_Message *) msg,
1613                                &me))
1614         {
1615           GNUNET_break (0);
1616           break;
1617         }
1618 #if DEBUG_TRANSPORT
1619       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1620                   "Receiving (my own) `%s' message, I am `%4s'.\n",
1621                   "HELLO", GNUNET_i2s (&me));
1622 #endif
1623       GNUNET_free_non_null (h->my_hello);
1624       h->my_hello = NULL;
1625       if (size < sizeof (struct GNUNET_MessageHeader))
1626         {
1627           GNUNET_break (0);
1628           break;
1629         }
1630       h->my_hello = GNUNET_malloc (size);
1631       memcpy (h->my_hello, msg, size);
1632       while (NULL != (hwl = h->hwl_head))
1633         {
1634           h->hwl_head = hwl->next;
1635           GNUNET_SCHEDULER_cancel (h->sched, hwl->task);
1636           GNUNET_TRANSPORT_get_hello (h,
1637                                       hwl->rec, hwl->rec_cls);
1638           GNUNET_free (hwl);
1639         }
1640       break;
1641     case GNUNET_MESSAGE_TYPE_TRANSPORT_CONNECT:
1642       if (size != sizeof (struct ConnectInfoMessage))
1643         {
1644           GNUNET_break (0);
1645           break;
1646         }
1647       cim = (const struct ConnectInfoMessage *) msg;
1648 #if DEBUG_TRANSPORT
1649       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1650                   "Receiving `%s' message for `%4s'.\n",
1651                   "CONNECT", GNUNET_i2s (&cim->id));
1652 #endif
1653       add_neighbour (h,
1654                      ntohl (cim->quota_out),
1655                      GNUNET_TIME_relative_ntoh (cim->latency), ntohs(cim->distance), &cim->id);
1656       break;
1657     case GNUNET_MESSAGE_TYPE_TRANSPORT_DISCONNECT:
1658       if (size != sizeof (struct DisconnectInfoMessage))
1659         {
1660           GNUNET_break (0);
1661           break;
1662         }
1663       dim = (const struct DisconnectInfoMessage *) msg;
1664 #if DEBUG_TRANSPORT
1665       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1666                   "Receiving `%s' message for `%4s'.\n",
1667                   "DISCONNECT", GNUNET_i2s (&dim->peer));
1668 #endif
1669       remove_neighbour (h, &dim->peer);
1670       break;
1671     case GNUNET_MESSAGE_TYPE_TRANSPORT_SEND_OK:
1672       if (size != sizeof (struct SendOkMessage))
1673         {
1674           GNUNET_break (0);
1675           break;
1676         }
1677       okm = (const struct SendOkMessage *) msg;
1678 #if DEBUG_TRANSPORT
1679       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1680                   "Receiving `%s' message, transmission %s.\n", "SEND_OK",
1681                   ntohl (okm->success) == GNUNET_OK ? "succeeded" : "failed");
1682 #endif
1683       n = find_neighbour (h, &okm->peer);
1684       GNUNET_assert (n != NULL);
1685       n->transmit_ok = GNUNET_YES;
1686       if (n->transmit_handle != NULL)
1687         {
1688 #if DEBUG_TRANSPORT
1689           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1690                       "Processing pending message for `%4s'\n",
1691                       GNUNET_i2s (&n->id));
1692 #endif
1693           GNUNET_SCHEDULER_cancel (h->sched,
1694                                    n->transmit_handle->notify_delay_task);
1695           n->transmit_handle->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1696           GNUNET_assert (GNUNET_YES == n->received_ack);
1697           schedule_request (n->transmit_handle);
1698         }
1699       break;
1700     case GNUNET_MESSAGE_TYPE_TRANSPORT_RECV:
1701 #if DEBUG_TRANSPORT
1702       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1703                   "Receiving `%s' message.\n", "RECV");
1704 #endif
1705       if (size <
1706           sizeof (struct InboundMessage) +
1707           sizeof (struct GNUNET_MessageHeader))
1708         {
1709           GNUNET_break (0);
1710           break;
1711         }
1712       im = (const struct InboundMessage *) msg;
1713       imm = (const struct GNUNET_MessageHeader *) &im[1];
1714       if (ntohs (imm->size) + sizeof (struct InboundMessage) != size)
1715         {
1716           GNUNET_break (0);
1717           break;
1718         }
1719       switch (ntohs (imm->type))
1720         {
1721         case GNUNET_MESSAGE_TYPE_TRANSPORT_ACK:
1722 #if DEBUG_TRANSPORT
1723           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1724                       "Receiving `%s' message from `%4s'.\n",
1725                       "ACK", GNUNET_i2s (&im->peer));
1726 #endif
1727           n = find_neighbour (h, &im->peer);
1728           if (n == NULL)
1729             {
1730               GNUNET_break (0);
1731               break;
1732             }
1733           if (n->received_ack == GNUNET_NO)
1734             {
1735               n->received_ack = GNUNET_YES;
1736               if (NULL != n->transmit_handle)
1737                 {
1738 #if DEBUG_TRANSPORT
1739                   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1740                               "Peer connected, scheduling delayed message for deliverery now.\n");
1741 #endif
1742                   schedule_request (n->transmit_handle);
1743                 }
1744             }
1745           break;
1746         default:
1747 #if DEBUG_TRANSPORT
1748           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1749                       "Received message of type %u from `%4s'.\n",
1750                       ntohs (imm->type), GNUNET_i2s (&im->peer));
1751 #endif
1752           if (h->rec != NULL)
1753             h->rec (h->cls, &im->peer, imm,
1754                     GNUNET_TIME_relative_ntoh (im->latency), ntohs(im->distance));
1755           break;
1756         }
1757       break;
1758     default:
1759       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1760                   _
1761                   ("Received unexpected message of type %u in %s:%u\n"),
1762                   ntohs (msg->type), __FILE__, __LINE__);
1763       GNUNET_break (0);
1764       break;
1765     }
1766 }
1767
1768
1769 struct ClientTransmitWrapper
1770 {
1771   GNUNET_CONNECTION_TransmitReadyNotify notify;
1772   void *notify_cls;
1773   struct GNUNET_TRANSPORT_TransmitHandle *th;
1774 };
1775
1776
1777 /**
1778  * Transmit message of a client destined for another
1779  * peer to the service.
1780  */
1781 static size_t
1782 client_notify_wrapper (void *cls, size_t size, void *buf)
1783 {
1784   struct ClientTransmitWrapper *ctw = cls;
1785   struct OutboundMessage *obm;
1786   struct GNUNET_MessageHeader *hdr;
1787   size_t ret;
1788
1789   if (size == 0)
1790     {
1791 #if DEBUG_TRANSPORT
1792       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1793                   "Transmission request could not be satisfied.\n");
1794 #endif
1795       if (NULL != ctw->notify)
1796         GNUNET_assert (0 == ctw->notify (ctw->notify_cls, 0, NULL));
1797       GNUNET_free (ctw);
1798       return 0;
1799     }
1800   GNUNET_assert (size >= sizeof (struct OutboundMessage));
1801   obm = buf;
1802   if (ctw->notify != NULL)
1803     ret = ctw->notify (ctw->notify_cls,
1804                        size - sizeof (struct OutboundMessage),
1805                        (void *) &obm[1]);
1806   else
1807     ret = 0;
1808   if (ret == 0)
1809     {
1810       /* Need to reset flag, no SEND means no SEND_OK! */
1811       ctw->th->neighbour->transmit_ok = GNUNET_YES;
1812       GNUNET_free (ctw);
1813       return 0;
1814     }
1815   GNUNET_assert (ret >= sizeof (struct GNUNET_MessageHeader));
1816   hdr = (struct GNUNET_MessageHeader *) &obm[1];
1817   GNUNET_assert (ntohs (hdr->size) == ret);
1818   GNUNET_assert (ret + sizeof (struct OutboundMessage) <
1819                  GNUNET_SERVER_MAX_MESSAGE_SIZE);
1820 #if DEBUG_TRANSPORT
1821   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1822               "Transmitting `%s' message with data for `%4s'\n",
1823               "SEND", GNUNET_i2s (&ctw->th->target));
1824 #endif
1825   ret += sizeof (struct OutboundMessage);
1826   obm->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SEND);
1827   obm->header.size = htons (ret);
1828   obm->priority = htonl (ctw->th->priority);
1829   obm->peer = ctw->th->target;
1830   GNUNET_free (ctw);
1831   return ret;
1832 }
1833
1834
1835
1836 /**
1837  * Check if we could queue a message of the given size for
1838  * transmission.  The transport service will take both its
1839  * internal buffers and bandwidth limits imposed by the
1840  * other peer into consideration when answering this query.
1841  *
1842  * @param handle connection to transport service
1843  * @param target who should receive the message
1844  * @param size how big is the message we want to transmit?
1845  * @param priority how important is the message?
1846  * @param timeout after how long should we give up (and call
1847  *        notify with buf NULL and size 0)?
1848  * @param notify function to call when we are ready to
1849  *        send such a message
1850  * @param notify_cls closure for notify
1851  * @return NULL if someone else is already waiting to be notified
1852  *         non-NULL if the notify callback was queued (can be used to cancel
1853  *         using GNUNET_TRANSPORT_notify_transmit_ready_cancel)
1854  */
1855 struct GNUNET_TRANSPORT_TransmitHandle *
1856 GNUNET_TRANSPORT_notify_transmit_ready (struct GNUNET_TRANSPORT_Handle
1857                                         *handle,
1858                                         const struct GNUNET_PeerIdentity
1859                                         *target, size_t size,
1860                                         unsigned int priority,
1861                                         struct GNUNET_TIME_Relative timeout,
1862                                         GNUNET_CONNECTION_TransmitReadyNotify
1863                                         notify, void *notify_cls)
1864 {
1865   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1866   struct GNUNET_TRANSPORT_TransmitHandle *th;
1867   struct NeighbourList *n;
1868   struct ClientTransmitWrapper *ctw;
1869
1870   if (size + sizeof (struct OutboundMessage) >=
1871       GNUNET_SERVER_MAX_MESSAGE_SIZE)
1872     {
1873       GNUNET_break (0);
1874       return NULL;
1875     }
1876 #if DEBUG_TRANSPORT
1877   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1878               "Asking transport service for transmission of %u bytes to peer `%4s'.\n",
1879               size, GNUNET_i2s (target));
1880 #endif
1881   n = find_neighbour (handle, target);
1882   if ((n != NULL) && (n->transmit_handle != NULL))
1883     return NULL;                /* already have a request pending for this peer! */
1884   ctw = GNUNET_malloc (sizeof (struct ClientTransmitWrapper));
1885   th = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_TransmitHandle));
1886   ctw->notify = notify;
1887   ctw->notify_cls = notify_cls;
1888   ctw->th = th;
1889   th->handle = handle;
1890   th->neighbour = n;
1891   th->target = *target;
1892   th->notify = &client_notify_wrapper;
1893   th->notify_cls = ctw;
1894   th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
1895   th->notify_size = size + sizeof (struct OutboundMessage);
1896   th->priority = priority;
1897   if (NULL == n)
1898     {
1899       pos = handle->connect_wait_head;
1900       while (pos != NULL)
1901         {
1902           GNUNET_assert (0 != memcmp (target,
1903                                       &pos->target,
1904                                       sizeof (struct GNUNET_PeerIdentity)));
1905           pos = pos->next;
1906         }
1907 #if DEBUG_TRANSPORT
1908       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1909                   "Will now try to connect to `%4s'.\n", GNUNET_i2s (target));
1910 #endif
1911       try_connect (th);
1912       return th;
1913     }
1914
1915 #if DEBUG_TRANSPORT
1916   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1917               "Transmission request queued for transmission to transport service.\n");
1918 #endif
1919   GNUNET_assert (NULL == n->transmit_handle);
1920   n->transmit_handle = th;
1921   if (GNUNET_YES != n->received_ack)
1922     {
1923 #if DEBUG_TRANSPORT
1924       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1925                   "Connection to `%4s' is not yet confirmed connected, scheduling timeout (%llu ms) only.\n",
1926                   GNUNET_i2s (target), timeout.value);
1927 #endif
1928       th->notify_delay_task
1929         = GNUNET_SCHEDULER_add_delayed (handle->sched,
1930                                         timeout, &peer_transmit_timeout, th);
1931       return th;
1932     }
1933
1934 #if DEBUG_TRANSPORT
1935   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1936               "Peer `%4s' is ready to receive, scheduling message for delivery now.\n",
1937               GNUNET_i2s (target));
1938 #endif
1939   th->notify_delay_task
1940     = GNUNET_SCHEDULER_add_now (handle->sched, &transmit_ready, th);
1941   return th;
1942 }
1943
1944
1945 /**
1946  * Cancel the specified transmission-ready notification.
1947  */
1948 void
1949 GNUNET_TRANSPORT_notify_transmit_ready_cancel (struct
1950                                                GNUNET_TRANSPORT_TransmitHandle
1951                                                *th)
1952 {
1953   struct GNUNET_TRANSPORT_Handle *h;
1954
1955 #if DEBUG_TRANSPORT
1956   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1957               "Transmission request of %u bytes to `%4s' was cancelled.\n",
1958               th->notify_size - sizeof (struct OutboundMessage),
1959               GNUNET_i2s (&th->target));
1960 #endif
1961   GNUNET_assert (th->notify == &client_notify_wrapper);
1962   remove_from_any_list (th);
1963   h = th->handle;
1964   if ((h->connect_ready_head == NULL) && (h->network_handle != NULL))
1965     {
1966       GNUNET_CLIENT_notify_transmit_ready_cancel (h->network_handle);
1967       h->network_handle = NULL;
1968       h->transmission_scheduled = GNUNET_NO;
1969     }
1970   GNUNET_free (th->notify_cls);
1971   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_TASK);
1972   GNUNET_free (th);
1973 }
1974
1975
1976 /* end of transport_api.c */