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  * Obtain the HELLO message for this peer.
 779  *
 780  * @param handle connection to transport service
 781  * @param timeout how long to wait for the HELLO
 782  * @param rec function to call with the HELLO, sender will be our peer
 783  *            identity; message and sender will be NULL on timeout
 784  *            (handshake with transport service pending/failed).
 785  *             cost estimate will be 0.
 786  * @param rec_cls closure for rec
 787  */
 788 void
 789 GNUNET_TRANSPORT_get_hello (struct GNUNET_TRANSPORT_Handle *handle,
 790                             GNUNET_TRANSPORT_HelloUpdateCallback rec,
 791                             void *rec_cls)
 792 {
 793   struct HelloWaitList *hwl;
 794
 795   hwl = GNUNET_malloc (sizeof (struct HelloWaitList));
 796   hwl->next = handle->hwl_head;
 797   handle->hwl_head = hwl;
 798   hwl->handle = handle;
 799   hwl->rec = rec;
 800   hwl->rec_cls = rec_cls;
 801   if (handle->my_hello == NULL)
 802     return;
 803   rec (rec_cls, (const struct GNUNET_MessageHeader *) handle->my_hello);
 804 }
 805
 806
 807
 808 /**
 809  * Stop receiving updates about changes to our HELLO message.
 810  *
 811  * @param handle connection to transport service
 812  * @param rec function previously registered to be called with the HELLOs
 813  * @param rec_cls closure for rec
 814  */
 815 void
 816 GNUNET_TRANSPORT_get_hello_cancel (struct GNUNET_TRANSPORT_Handle *handle,
 817                                    GNUNET_TRANSPORT_HelloUpdateCallback rec,
 818                                    void *rec_cls)
 819 {
 820   struct HelloWaitList *pos;
 821   struct HelloWaitList *prev;
 822
 823   prev = NULL;
 824   pos = handle->hwl_head;
 825   while (pos != NULL)
 826     {
 827       if ( (pos->rec == rec) &&
 828            (pos->rec_cls == rec_cls) )
 829         break;
 830       prev = pos;
 831       pos = pos->next;
 832     }
 833   GNUNET_break (pos != NULL);
 834   if (pos == NULL)
 835     return;
 836   if (prev == NULL)
 837     handle->hwl_head = pos->next;
 838   else
 839     prev->next = pos->next;
 840   GNUNET_free (pos);
 841 }
 842
 843
 844 static size_t
 845 send_hello (void *cls, size_t size, void *buf)
 846 {
 847   struct GNUNET_MessageHeader *hello = cls;
 848   uint16_t msize;
 849
 850   if (buf == NULL)
 851     {
 852 #if DEBUG_TRANSPORT
 853       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 854                   "Timeout while trying to transmit `%s' request.\n",
 855                   "HELLO");
 856 #endif
 857       GNUNET_free (hello);
 858       return 0;
 859     }
 860 #if DEBUG_TRANSPORT
 861   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 862               "Transmitting `%s' request.\n", "HELLO");
 863 #endif
 864   msize = ntohs (hello->size);
 865   GNUNET_assert (size >= msize);
 866   memcpy (buf, hello, msize);
 867   GNUNET_free (hello);
 868   return msize;
 869 }
 870
 871
 872 /**
 873  * Offer the transport service the HELLO of another peer.  Note that
 874  * the transport service may just ignore this message if the HELLO is
 875  * malformed or useless due to our local configuration.
 876  *
 877  * @param handle connection to transport service
 878  * @param hello the hello message
 879  */
 880 void
 881 GNUNET_TRANSPORT_offer_hello (struct GNUNET_TRANSPORT_Handle *handle,
 882                               const struct GNUNET_MessageHeader *hello)
 883 {
 884   struct GNUNET_MessageHeader *hc;
 885   uint16_t size;
 886
 887   if (handle->client == NULL)
 888     {
 889 #if DEBUG_TRANSPORT
 890       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 891                   "Not connected to transport service, dropping offered HELLO\n");
 892 #endif
 893       return;
 894     }
 895   GNUNET_break (ntohs (hello->type) == GNUNET_MESSAGE_TYPE_HELLO);
 896   size = ntohs (hello->size);
 897   GNUNET_break (size >= sizeof (struct GNUNET_MessageHeader));
 898   hc = GNUNET_malloc (size);
 899   memcpy (hc, hello, size);
 900   schedule_control_transmit (handle,
 901                              size,
 902                              GNUNET_NO, OFFER_HELLO_TIMEOUT, &send_hello, hc);
 903 }
 904
 905
 906 /**
 907  * Function we use for handling incoming messages.
 908  */
 909 static void demultiplexer (void *cls, const struct GNUNET_MessageHeader *msg);
 910
 911
 912 static size_t
 913 send_start (void *cls, size_t size, void *buf)
 914 {
 915   struct GNUNET_MessageHeader *s = buf;
 916
 917   if (buf == NULL)
 918     {
 919 #if DEBUG_TRANSPORT
 920       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 921                   "Timeout while trying to transmit `%s' request.\n",
 922                   "START");
 923 #endif
 924       return 0;
 925     }
 926 #if DEBUG_TRANSPORT
 927   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 928               "Transmitting `%s' request.\n", "START");
 929 #endif
 930   GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
 931   s->size = htons (sizeof (struct GNUNET_MessageHeader));
 932   s->type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_START);
 933   return sizeof (struct GNUNET_MessageHeader);
 934 }
 935
 936
 937 /**
 938  * We're ready to transmit the request that the transport service
 939  * should connect to a new peer.  In addition to sending the
 940  * request, schedule the next phase for the transmission processing
 941  * that caused the connect request in the first place.
 942  */
 943 static size_t
 944 request_connect (void *cls, size_t size, void *buf)
 945 {
 946   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
 947   struct TryConnectMessage *tcm;
 948   struct GNUNET_TRANSPORT_Handle *h;
 949   struct NeighbourList *n;
 950
 951   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_TASK);
 952   h = th->handle;
 953
 954   n = find_neighbour(h, &th->target);
 955
 956   if (n != NULL)
 957     {
 958 #if DEBUG_TRANSPORT
 959       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 960                   "Asked to TRY_CONNECT to already connected peer!\n");
 961 #endif
 962       return GNUNET_YES;
 963     }
 964
 965
 966   if (buf == NULL)
 967     {
 968 #if DEBUG_TRANSPORT
 969       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 970                   "Failed to transmit `%s' request for `%4s' to service.\n",
 971                   "TRY_CONNECT", GNUNET_i2s (&th->target));
 972 #endif
 973       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
 974         {
 975           GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
 976           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 977         }
 978       if (NULL != th->notify)
 979         GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
 980       GNUNET_free (th);
 981       return 0;
 982     }
 983 #if DEBUG_TRANSPORT
 984   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 985               "Transmitting `%s' message for `%4s' (need connection in %llu ms).\n",
 986               "TRY_CONNECT", GNUNET_i2s (&th->target),
 987               GNUNET_TIME_absolute_get_remaining (th->timeout).value);
 988 #endif
 989   GNUNET_assert (size >= sizeof (struct TryConnectMessage));
 990   tcm = buf;
 991   tcm->header.size = htons (sizeof (struct TryConnectMessage));
 992   tcm->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_TRY_CONNECT);
 993   tcm->reserved = htonl (0);
 994   memcpy (&tcm->peer, &th->target, sizeof (struct GNUNET_PeerIdentity));
 995   th->notify_delay_task
 996     = GNUNET_SCHEDULER_add_delayed (h->sched,
 997                                     GNUNET_TIME_absolute_get_remaining
 998                                     (th->timeout),
 999                                     &peer_transmit_timeout, th);
1000   insert_transmit_handle (&h->connect_wait_head, th);
1001   return sizeof (struct TryConnectMessage);
1002 }
1003
1004
1005 /**
1006  * Schedule a request to connect to the given
1007  * neighbour (and if successful, add the specified
1008  * handle to the wait list).
1009  *
1010  * @param th handle for a request to transmit once we
1011  *        have connected
1012  */
1013 static void
1014 try_connect (struct GNUNET_TRANSPORT_TransmitHandle *th)
1015 {
1016   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_TASK);
1017   schedule_control_transmit (th->handle,
1018                              sizeof (struct TryConnectMessage),
1019                              GNUNET_NO,
1020                              GNUNET_TIME_absolute_get_remaining (th->timeout),
1021                              &request_connect, th);
1022 }
1023
1024
1025 /**
1026  * Task for delayed attempts to reconnect to a peer.
1027  *
1028  * @param cls must be a transmit handle that determines the peer
1029  *        to which we will try to connect
1030  * @param tc scheduler information about why we were triggered (not used)
1031  */
1032 static void
1033 try_connect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1034 {
1035   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
1036
1037   th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1038   try_connect (th);
1039 }
1040
1041
1042 /**
1043  * Remove neighbour from our list.  Will automatically
1044  * trigger a re-connect attempt if we have messages pending
1045  * for this peer.
1046  *
1047  * @param h our state
1048  * @param peer the peer to remove
1049  */
1050 static void
1051 remove_neighbour (struct GNUNET_TRANSPORT_Handle *h,
1052                   const struct GNUNET_PeerIdentity *peer)
1053 {
1054   struct NeighbourList *prev;
1055   struct NeighbourList *pos;
1056   struct GNUNET_TRANSPORT_TransmitHandle *th;
1057
1058 #if DEBUG_TRANSPORT
1059   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1060               "Removing neighbour `%s' from list of connected peers.\n",
1061               GNUNET_i2s (peer));
1062 #endif
1063   prev = NULL;
1064   pos = h->neighbours;
1065   while ((pos != NULL) &&
1066          (0 != memcmp (peer, &pos->id, sizeof (struct GNUNET_PeerIdentity))))
1067     {
1068       prev = pos;
1069       pos = pos->next;
1070     }
1071   if (pos == NULL)
1072     {
1073       GNUNET_break (0);
1074       return;
1075     }
1076   if (prev == NULL)
1077     h->neighbours = pos->next;
1078   else
1079     prev->next = pos->next;
1080   if (NULL != (th = pos->transmit_handle))
1081     {
1082       pos->transmit_handle = NULL;
1083       th->neighbour = NULL;
1084       remove_from_any_list (th);
1085       if (GNUNET_TIME_absolute_get_remaining (th->timeout).value <=
1086           CONNECT_RETRY_TIMEOUT.value)
1087         {
1088           /* signal error */
1089           GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1090                       _
1091                       ("Connection with `%4s' failed and timeout was in the past, giving up on message delivery.\n"),
1092                       GNUNET_i2s (peer));
1093           GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == th->notify_delay_task);
1094           peer_transmit_timeout (th, NULL);
1095         }
1096       else
1097         {
1098           GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1099                       _
1100                       ("Connection with `%4s' failed, will keep trying for %llu ms to deliver message\n"),
1101                       GNUNET_i2s (peer),
1102                       GNUNET_TIME_absolute_get_remaining (th->timeout).value);
1103           /* try again in a bit */
1104           GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == th->notify_delay_task);
1105           th->notify_delay_task
1106             = GNUNET_SCHEDULER_add_delayed (h->sched,
1107                                             CONNECT_RETRY_TIMEOUT,
1108                                             &try_connect_task, th);
1109         }
1110     }
1111   if (h->nc_cb != NULL)
1112     h->nd_cb (h->cls, peer);
1113   GNUNET_free (pos);
1114 }
1115
1116
1117 /**
1118  * Try again to connect to transport service.
1119  */
1120 static void
1121 reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1122 {
1123   struct GNUNET_TRANSPORT_Handle *h = cls;
1124   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1125   struct NeighbourList *n;
1126
1127   /* Forget about all neighbours that we used to be connected
1128      to */
1129   while (NULL != (n = h->neighbours))
1130     remove_neighbour (h, &n->id);
1131 #if DEBUG_TRANSPORT
1132   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connecting to transport service.\n");
1133 #endif
1134   GNUNET_assert (h->client == NULL);
1135   h->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
1136   h->client = GNUNET_CLIENT_connect (h->sched, "transport", h->cfg);
1137   GNUNET_assert (h->client != NULL);
1138   /* make sure we don't send "START" twice,
1139      remove existing entry from queue (if present) */
1140   pos = h->connect_ready_head;
1141   while (pos != NULL)
1142     {
1143       if (pos->notify == &send_start)
1144         {
1145           if (pos->prev == NULL)
1146             h->connect_ready_head = pos->next;
1147           else
1148             pos->prev->next = pos->next;
1149           if (pos->next != NULL)
1150             pos->next->prev = pos->prev;
1151           GNUNET_assert (pos->neighbour == NULL);
1152           if (GNUNET_SCHEDULER_NO_TASK != pos->notify_delay_task)
1153             {
1154               GNUNET_SCHEDULER_cancel (h->sched, pos->notify_delay_task);
1155               pos->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1156             }
1157           GNUNET_free (pos);
1158           break;
1159         }
1160       pos = pos->next;
1161     }
1162   schedule_control_transmit (h,
1163                              sizeof (struct GNUNET_MessageHeader),
1164                              GNUNET_YES,
1165                              GNUNET_TIME_UNIT_FOREVER_REL, &send_start, NULL);
1166   GNUNET_CLIENT_receive (h->client,
1167                          &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL);
1168 }
1169
1170
1171 /**
1172  * Function that will schedule the job that will try
1173  * to connect us again to the client.
1174  */
1175 static void
1176 schedule_reconnect (struct GNUNET_TRANSPORT_Handle *h)
1177 {
1178 #if DEBUG_TRANSPORT
1179   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1180               "Scheduling task to reconnect to transport service in %llu ms.\n",
1181               h->reconnect_delay.value);
1182 #endif
1183   GNUNET_assert (h->client == NULL);
1184   GNUNET_assert (h->reconnect_task == GNUNET_SCHEDULER_NO_TASK);
1185   h->reconnect_task
1186     = GNUNET_SCHEDULER_add_delayed (h->sched,
1187                                     h->reconnect_delay, &reconnect, h);
1188   h->reconnect_delay = GNUNET_TIME_UNIT_SECONDS;
1189 }
1190
1191
1192 /**
1193  * We are connected to the respective peer, check the
1194  * bandwidth limits and schedule the transmission.
1195  */
1196 static void schedule_request (struct GNUNET_TRANSPORT_TransmitHandle *th);
1197
1198
1199 /**
1200  * Function called by the scheduler when the timeout
1201  * for bandwidth availablility for the target
1202  * neighbour is reached.
1203  */
1204 static void
1205 transmit_ready (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1206 {
1207   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
1208
1209   th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1210   schedule_request (th);
1211 }
1212
1213
1214 /**
1215  * Remove the given transmit handle from the wait list.  Does NOT free
1216  * it.
1217  */
1218 static void
1219 remove_from_wait_list (struct GNUNET_TRANSPORT_TransmitHandle *th)
1220 {
1221   if (th->prev == NULL)
1222     th->handle->connect_wait_head = th->next;
1223   else
1224     th->prev->next = th->next;
1225   if (th->next != NULL)
1226     th->next->prev = th->prev;
1227 }
1228
1229
1230 /**
1231  * We are connected to the respective peer, check the
1232  * bandwidth limits and schedule the transmission.
1233  */
1234 static void
1235 schedule_request (struct GNUNET_TRANSPORT_TransmitHandle *th)
1236 {
1237   struct GNUNET_TRANSPORT_Handle *h;
1238   struct GNUNET_TIME_Relative duration;
1239   struct NeighbourList *n;
1240   uint64_t available;
1241
1242   h = th->handle;
1243   n = th->neighbour;
1244   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1245     {
1246       GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
1247       th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1248     }
1249   /* check outgoing quota */
1250   duration = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
1251   if (duration.value > MIN_QUOTA_REFRESH_TIME)
1252     {
1253       update_quota (n);
1254       duration = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
1255     }
1256   available = duration.value * n->quota_out;
1257   if (available < n->last_sent + th->notify_size)
1258     {
1259       /* calculate how much bandwidth we'd still need to
1260          accumulate and based on that how long we'll have
1261          to wait... */
1262       available = n->last_sent + th->notify_size - available;
1263       duration = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS,
1264                                                 available / n->quota_out);
1265       if (th->timeout.value <
1266           GNUNET_TIME_relative_to_absolute (duration).value)
1267         {
1268           /* signal timeout! */
1269 #if DEBUG_TRANSPORT
1270           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1271                       "Would need %llu ms before bandwidth is available for delivery to `%4s', that is too long.  Signaling timeout.\n",
1272                       duration.value, GNUNET_i2s (&th->target));
1273 #endif
1274           remove_from_wait_list (th);
1275           if (NULL != th->notify)
1276             GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
1277           GNUNET_free (th);
1278           return;
1279         }
1280 #if DEBUG_TRANSPORT
1281       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1282                   "Need more bandwidth, delaying delivery to `%4s' by %llu ms\n",
1283                   GNUNET_i2s (&th->target), duration.value);
1284 #endif
1285       th->notify_delay_task
1286         = GNUNET_SCHEDULER_add_delayed (h->sched,
1287                                         duration, &transmit_ready, th);
1288       return;
1289     }
1290 #if DEBUG_TRANSPORT
1291   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1292               "Bandwidth available for transmission to `%4s'\n",
1293               GNUNET_i2s (&n->id));
1294 #endif
1295   if (GNUNET_NO == n->transmit_ok)
1296     {
1297       /* we may be ready, but transport service is not;
1298          wait for SendOkMessage or timeout */
1299 #if DEBUG_TRANSPORT
1300       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1301                   "Need to wait for transport service `%s' message\n",
1302                   "SEND_OK");
1303 #endif
1304       th->notify_delay_task
1305         = GNUNET_SCHEDULER_add_delayed (h->sched,
1306                                         GNUNET_TIME_absolute_get_remaining
1307                                         (th->timeout), &peer_transmit_timeout,
1308                                         th);
1309       return;
1310     }
1311   n->transmit_ok = GNUNET_NO;
1312   remove_from_wait_list (th);
1313 #if DEBUG_TRANSPORT
1314   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1315               "Moving message for `%4s' to ready list\n",
1316               GNUNET_i2s (&n->id));
1317 #endif
1318   insert_transmit_handle (&h->connect_ready_head, th);
1319   if (GNUNET_NO == h->transmission_scheduled)
1320     schedule_transmission (h);
1321 }
1322
1323
1324 /**
1325  * Add neighbour to our list
1326  */
1327 static void
1328 add_neighbour (struct GNUNET_TRANSPORT_Handle *h,
1329                uint32_t quota_out,
1330                struct GNUNET_TIME_Relative latency,
1331                uint16_t distance,
1332                const struct GNUNET_PeerIdentity *pid)
1333 {
1334   struct NeighbourList *n;
1335   struct GNUNET_TRANSPORT_TransmitHandle *prev;
1336   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1337   struct GNUNET_TRANSPORT_TransmitHandle *next;
1338
1339   /* check for duplicates */
1340   if (NULL != find_neighbour (h, pid))
1341     {
1342       GNUNET_break (0);
1343       return;
1344     }
1345 #if DEBUG_TRANSPORT
1346   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1347               "Creating entry for new neighbour `%4s'.\n", GNUNET_i2s (pid));
1348 #endif
1349   n = GNUNET_malloc (sizeof (struct NeighbourList));
1350   n->id = *pid;
1351   n->last_quota_update = GNUNET_TIME_absolute_get ();
1352   n->quota_out = quota_out;
1353   n->next = h->neighbours;
1354   n->transmit_ok = GNUNET_YES;
1355   h->neighbours = n;
1356   if (h->nc_cb != NULL)
1357     h->nc_cb (h->cls, &n->id, latency, distance);
1358   prev = NULL;
1359   pos = h->connect_wait_head;
1360   while (pos != NULL)
1361     {
1362       next = pos->next;
1363       if (0 == memcmp (pid,
1364                        &pos->target, sizeof (struct GNUNET_PeerIdentity)))
1365         {
1366           pos->neighbour = n;
1367           GNUNET_assert (NULL == n->transmit_handle);
1368           n->transmit_handle = pos;
1369           if (prev == NULL)
1370             h->connect_wait_head = next;
1371           else
1372             prev->next = next;
1373 #if ACK
1374           if (GNUNET_YES == n->received_ack)
1375             {
1376 #endif
1377 #if DEBUG_TRANSPORT
1378               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1379                           "Found pending request for `%4s' will trigger it now.\n",
1380                           GNUNET_i2s (&pos->target));
1381 #endif
1382               if (pos->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1383                 {
1384                   GNUNET_SCHEDULER_cancel (h->sched, pos->notify_delay_task);
1385                   pos->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1386                 }
1387               schedule_request (pos);
1388 #if ACK
1389             }
1390 #endif
1391
1392           break;
1393         }
1394       prev = pos;
1395       pos = next;
1396     }
1397 }
1398
1399
1400 /**
1401  * Connect to the transport service.  Note that the connection may
1402  * complete (or fail) asynchronously.
1403  *
1404
1405  * @param sched scheduler to use
1406  * @param cfg configuration to use
1407  * @param cls closure for the callbacks
1408  * @param rec receive function to call
1409  * @param nc function to call on connect events
1410  * @param nd function to call on disconnect events
1411  */
1412 struct GNUNET_TRANSPORT_Handle *
1413 GNUNET_TRANSPORT_connect (struct GNUNET_SCHEDULER_Handle *sched,
1414                           const struct GNUNET_CONFIGURATION_Handle *cfg,
1415                           void *cls,
1416                           GNUNET_TRANSPORT_ReceiveCallback rec,
1417                           GNUNET_TRANSPORT_NotifyConnect nc,
1418                           GNUNET_TRANSPORT_NotifyDisconnect nd)
1419 {
1420   struct GNUNET_TRANSPORT_Handle *ret;
1421
1422   GNUNET_ARM_start_services (cfg, sched, "peerinfo", "transport", NULL);
1423   ret = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_Handle));
1424   ret->sched = sched;
1425   ret->cfg = cfg;
1426   ret->cls = cls;
1427   ret->rec = rec;
1428   ret->nc_cb = nc;
1429   ret->nd_cb = nd;
1430   ret->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
1431   schedule_reconnect (ret);
1432   return ret;
1433 }
1434
1435
1436 /**
1437  * Disconnect from the transport service.
1438  */
1439 void
1440 GNUNET_TRANSPORT_disconnect (struct GNUNET_TRANSPORT_Handle *handle)
1441 {
1442   struct GNUNET_TRANSPORT_TransmitHandle *th;
1443   struct NeighbourList *n;
1444   struct HelloWaitList *hwl;
1445   struct GNUNET_CLIENT_Connection *client;
1446
1447 #if DEBUG_TRANSPORT
1448   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transport disconnect called!\n");
1449 #endif
1450   while (NULL != (th = handle->connect_ready_head))
1451     {
1452       handle->connect_ready_head = th->next;
1453       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1454         {
1455           GNUNET_SCHEDULER_cancel (handle->sched, th->notify_delay_task);
1456           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1457         }
1458       if (NULL != th->notify)
1459         GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
1460       GNUNET_free (th);
1461     }
1462   while (NULL != (th = handle->connect_wait_head))
1463     {
1464       handle->connect_wait_head = th->next;
1465       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1466         {
1467           GNUNET_SCHEDULER_cancel (handle->sched, th->notify_delay_task);
1468           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1469         }
1470       if (NULL != th->notify)
1471         GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
1472       GNUNET_free (th);
1473     }
1474   while (NULL != (n = handle->neighbours))
1475     {
1476       handle->neighbours = n->next;
1477       if (NULL != (th = n->transmit_handle))
1478         {
1479           if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1480             {
1481               GNUNET_SCHEDULER_cancel (handle->sched, th->notify_delay_task);
1482               th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1483             }
1484           if (NULL != th->notify)
1485             GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
1486           GNUNET_free (th);
1487         }
1488       GNUNET_free (n);
1489     }
1490   while (NULL != (hwl = handle->hwl_head))
1491     {
1492       handle->hwl_head = hwl->next;
1493       GNUNET_SCHEDULER_cancel (handle->sched, hwl->task);
1494       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1495                   _
1496                   ("Disconnect while notification for `%s' still registered.\n"),
1497                   "HELLO");
1498       if (hwl->rec != NULL)
1499         hwl->rec (hwl->rec_cls, NULL);
1500       GNUNET_free (hwl);
1501     }
1502   if (handle->reconnect_task != GNUNET_SCHEDULER_NO_TASK)
1503     {
1504       GNUNET_SCHEDULER_cancel (handle->sched, handle->reconnect_task);
1505       handle->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
1506     }
1507   GNUNET_free_non_null (handle->my_hello);
1508   handle->my_hello = NULL;
1509   GNUNET_ARM_stop_services (handle->cfg, handle->sched, "transport",
1510                             "peerinfo", NULL);
1511   if (NULL != handle->network_handle)
1512     {
1513       GNUNET_CLIENT_notify_transmit_ready_cancel (handle->network_handle);
1514       handle->network_handle = NULL;
1515     }
1516   if (NULL != (client = handle->client))
1517     {
1518 #if DEBUG_TRANSPORT
1519       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1520                   "Disconnecting from transport service for good.\n");
1521 #endif
1522       handle->client = NULL;
1523       GNUNET_CLIENT_disconnect (client);
1524     }
1525   GNUNET_free (handle);
1526 }
1527
1528
1529 /**
1530  * Type of a function to call when we receive a message
1531  * from the service.
1532  *
1533  * @param cls closure
1534  * @param msg message received, NULL on timeout or fatal error
1535  */
1536 static void
1537 demultiplexer (void *cls, const struct GNUNET_MessageHeader *msg)
1538 {
1539   struct GNUNET_TRANSPORT_Handle *h = cls;
1540   const struct DisconnectInfoMessage *dim;
1541   const struct ConnectInfoMessage *cim;
1542   const struct InboundMessage *im;
1543   const struct GNUNET_MessageHeader *imm;
1544   const struct SendOkMessage *okm;
1545   struct HelloWaitList *hwl;
1546   struct HelloWaitList *next_hwl;
1547   struct NeighbourList *n;
1548   struct GNUNET_PeerIdentity me;
1549   struct GNUNET_TRANSPORT_TransmitHandle *th;
1550
1551   struct GNUNET_TRANSPORT_TransmitHandle *prev;
1552   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1553   struct GNUNET_TRANSPORT_TransmitHandle *next;
1554   uint16_t size;
1555
1556   if ((msg == NULL) || (h->client == NULL))
1557     {
1558       if (h->client != NULL)
1559         {
1560 #if DEBUG_TRANSPORT
1561           GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1562                       "Error receiving from transport service, disconnecting temporarily.\n");
1563 #endif
1564           if (h->network_handle != NULL)
1565             {
1566               GNUNET_CLIENT_notify_transmit_ready_cancel (h->network_handle);
1567               h->network_handle = NULL;
1568               h->transmission_scheduled = GNUNET_NO;
1569               th = h->connect_ready_head;
1570               /* add timeout again, we cancelled the transmit_ready task! */
1571               GNUNET_assert (th->notify_delay_task ==
1572                              GNUNET_SCHEDULER_NO_TASK);
1573               th->notify_delay_task =
1574                 GNUNET_SCHEDULER_add_delayed (h->sched,
1575                                               GNUNET_TIME_absolute_get_remaining
1576                                               (th->timeout),
1577                                               &peer_transmit_timeout, th);
1578             }
1579           GNUNET_CLIENT_disconnect (h->client);
1580           h->client = NULL;
1581           schedule_reconnect (h);
1582         }
1583       else
1584         {
1585           /* shutdown initiated from 'GNUNET_TRANSPORT_disconnect',
1586              finish clean up work! */
1587           GNUNET_free (h);
1588         }
1589       return;
1590     }
1591   GNUNET_CLIENT_receive (h->client,
1592                          &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL);
1593   size = ntohs (msg->size);
1594   switch (ntohs (msg->type))
1595     {
1596     case GNUNET_MESSAGE_TYPE_HELLO:
1597       if (GNUNET_OK !=
1598           GNUNET_HELLO_get_id ((const struct GNUNET_HELLO_Message *) msg,
1599                                &me))
1600         {
1601           GNUNET_break (0);
1602           break;
1603         }
1604 #if DEBUG_TRANSPORT
1605       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1606                   "Receiving (my own) `%s' message, I am `%4s'.\n",
1607                   "HELLO", GNUNET_i2s (&me));
1608 #endif
1609       GNUNET_free_non_null (h->my_hello);
1610       h->my_hello = NULL;
1611       if (size < sizeof (struct GNUNET_MessageHeader))
1612         {
1613           GNUNET_break (0);
1614           break;
1615         }
1616       h->my_hello = GNUNET_malloc (size);
1617       memcpy (h->my_hello, msg, size);
1618       hwl = h->hwl_head;
1619       while (NULL != hwl)
1620         {
1621           next_hwl = hwl->next;
1622           hwl->rec (hwl->rec_cls,
1623                     (const struct GNUNET_MessageHeader *) h->my_hello);
1624           hwl = next_hwl;
1625         }
1626       break;
1627     case GNUNET_MESSAGE_TYPE_TRANSPORT_CONNECT:
1628       if (size != sizeof (struct ConnectInfoMessage))
1629         {
1630           GNUNET_break (0);
1631           break;
1632         }
1633       cim = (const struct ConnectInfoMessage *) msg;
1634 #if DEBUG_TRANSPORT
1635       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1636                   "Receiving `%s' message for `%4s'.\n",
1637                   "CONNECT", GNUNET_i2s (&cim->id));
1638 #endif
1639       if (find_neighbour(h, &cim->id) == NULL)
1640         {
1641 #if DEBUG_TRANSPORT
1642               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1643                           "Don't know neighbor, adding!\n");
1644 #endif
1645           add_neighbour (h,
1646                          ntohl (cim->quota_out),
1647                          GNUNET_TIME_relative_ntoh (cim->latency), ntohs(cim->distance), &cim->id);
1648         }
1649       else
1650         {
1651 #if DEBUG_TRANSPORT
1652               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1653                           "Do know neighbor, scheduling transmission!\n");
1654 #endif
1655           n = find_neighbour(h, &cim->id);
1656           GNUNET_assert(n != NULL);
1657           n->received_ack = GNUNET_YES;
1658           if (NULL != n->transmit_handle)
1659             {
1660 #if DEBUG_TRANSPORT
1661               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1662                           "Peer connected, scheduling delayed message for delivery now.\n");
1663 #endif
1664               schedule_request (n->transmit_handle);
1665             }
1666           else
1667             {
1668 #if DEBUG_TRANSPORT
1669               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1670                           "Transmit handle is null... Checking for pending stuff(?)\n");
1671 #endif
1672               prev = NULL;
1673               pos = h->connect_wait_head;
1674               while (pos != NULL)
1675                 {
1676                   next = pos->next;
1677                   if (0 == memcmp (&cim->id,
1678                                    &pos->target, sizeof (struct GNUNET_PeerIdentity)))
1679                     {
1680                       pos->neighbour = n;
1681                       GNUNET_assert (NULL == n->transmit_handle);
1682                       n->transmit_handle = pos;
1683                       if (prev == NULL)
1684                         h->connect_wait_head = next;
1685                       else
1686                         prev->next = next;
1687 #if ACK
1688                         if (GNUNET_YES == n->received_ack)
1689                           {
1690 #endif
1691   #if DEBUG_TRANSPORT
1692                           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1693                                       "Found pending request for `%4s' will trigger it now.\n",
1694                                       GNUNET_i2s (&pos->target));
1695   #endif
1696                           if (pos->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1697                             {
1698                               GNUNET_SCHEDULER_cancel (h->sched, pos->notify_delay_task);
1699                               pos->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1700                             }
1701                           schedule_request (pos);
1702 #if ACK
1703                           }
1704 #endif
1705
1706                       break;
1707                     }
1708                   prev = pos;
1709                   pos = next;
1710                 }
1711           }
1712         }
1713
1714       break;
1715     case GNUNET_MESSAGE_TYPE_TRANSPORT_DISCONNECT:
1716       if (size != sizeof (struct DisconnectInfoMessage))
1717         {
1718           GNUNET_break (0);
1719           break;
1720         }
1721       dim = (const struct DisconnectInfoMessage *) msg;
1722 #if DEBUG_TRANSPORT
1723       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1724                   "Receiving `%s' message for `%4s'.\n",
1725                   "DISCONNECT", GNUNET_i2s (&dim->peer));
1726 #endif
1727       remove_neighbour (h, &dim->peer);
1728       break;
1729     case GNUNET_MESSAGE_TYPE_TRANSPORT_SEND_OK:
1730       if (size != sizeof (struct SendOkMessage))
1731         {
1732           GNUNET_break (0);
1733           break;
1734         }
1735       okm = (const struct SendOkMessage *) msg;
1736 #if DEBUG_TRANSPORT
1737       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1738                   "Receiving `%s' message, transmission %s.\n", "SEND_OK",
1739                   ntohl (okm->success) == GNUNET_OK ? "succeeded" : "failed");
1740 #endif
1741       n = find_neighbour (h, &okm->peer);
1742       GNUNET_assert (n != NULL);
1743       n->transmit_ok = GNUNET_YES;
1744       if (n->transmit_handle != NULL)
1745         {
1746 #if DEBUG_TRANSPORT
1747           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1748                       "Processing pending message for `%4s'\n",
1749                       GNUNET_i2s (&n->id));
1750 #endif
1751           GNUNET_SCHEDULER_cancel (h->sched,
1752                                    n->transmit_handle->notify_delay_task);
1753           n->transmit_handle->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1754           GNUNET_assert (GNUNET_YES == n->received_ack);
1755           schedule_request (n->transmit_handle);
1756         }
1757       break;
1758     case GNUNET_MESSAGE_TYPE_TRANSPORT_RECV:
1759 #if DEBUG_TRANSPORT
1760       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1761                   "Receiving `%s' message.\n", "RECV");
1762 #endif
1763       if (size <
1764           sizeof (struct InboundMessage) +
1765           sizeof (struct GNUNET_MessageHeader))
1766         {
1767           GNUNET_break (0);
1768           break;
1769         }
1770       im = (const struct InboundMessage *) msg;
1771       imm = (const struct GNUNET_MessageHeader *) &im[1];
1772       if (ntohs (imm->size) + sizeof (struct InboundMessage) != size)
1773         {
1774           GNUNET_break (0);
1775           break;
1776         }
1777       switch (ntohs (imm->type))
1778         {
1779         case GNUNET_MESSAGE_TYPE_TRANSPORT_ACK:
1780 #if DEBUG_TRANSPORT
1781           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1782                       "Receiving `%s' message from `%4s'.\n",
1783                       "ACK", GNUNET_i2s (&im->peer));
1784 #endif
1785           n = find_neighbour (h, &im->peer);
1786           if (n == NULL)
1787             {
1788               GNUNET_break (0);
1789               break;
1790             }
1791           if (n->received_ack == GNUNET_NO)
1792             {
1793               n->received_ack = GNUNET_YES;
1794               if (NULL != n->transmit_handle)
1795                 {
1796 #if DEBUG_TRANSPORT
1797                   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1798                               "Peer connected, scheduling delayed message for delivery now.\n");
1799 #endif
1800                   schedule_request (n->transmit_handle);
1801                 }
1802             }
1803           break;
1804         default:
1805 #if DEBUG_TRANSPORT
1806           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1807                       "Received message of type %u from `%4s'.\n",
1808                       ntohs (imm->type), GNUNET_i2s (&im->peer));
1809 #endif
1810           if (h->rec != NULL)
1811             h->rec (h->cls, &im->peer, imm,
1812                     GNUNET_TIME_relative_ntoh (im->latency), ntohs(im->distance));
1813           break;
1814         }
1815       break;
1816     default:
1817       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1818                   _
1819                   ("Received unexpected message of type %u in %s:%u\n"),
1820                   ntohs (msg->type), __FILE__, __LINE__);
1821       GNUNET_break (0);
1822       break;
1823     }
1824 }
1825
1826
1827 struct ClientTransmitWrapper
1828 {
1829   GNUNET_CONNECTION_TransmitReadyNotify notify;
1830   void *notify_cls;
1831   struct GNUNET_TRANSPORT_TransmitHandle *th;
1832 };
1833
1834
1835 /**
1836  * Transmit message of a client destined for another
1837  * peer to the service.
1838  */
1839 static size_t
1840 client_notify_wrapper (void *cls, size_t size, void *buf)
1841 {
1842   struct ClientTransmitWrapper *ctw = cls;
1843   struct OutboundMessage *obm;
1844   struct GNUNET_MessageHeader *hdr;
1845   size_t ret;
1846
1847   if (size == 0)
1848     {
1849 #if DEBUG_TRANSPORT
1850       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1851                   "Transmission request could not be satisfied.\n");
1852 #endif
1853       if (NULL != ctw->notify)
1854         GNUNET_assert (0 == ctw->notify (ctw->notify_cls, 0, NULL));
1855       GNUNET_free (ctw);
1856       return 0;
1857     }
1858   GNUNET_assert (size >= sizeof (struct OutboundMessage));
1859   obm = buf;
1860   if (ctw->notify != NULL)
1861     ret = ctw->notify (ctw->notify_cls,
1862                        size - sizeof (struct OutboundMessage),
1863                        (void *) &obm[1]);
1864   else
1865     ret = 0;
1866   if (ret == 0)
1867     {
1868       /* Need to reset flag, no SEND means no SEND_OK! */
1869       ctw->th->neighbour->transmit_ok = GNUNET_YES;
1870       GNUNET_free (ctw);
1871       return 0;
1872     }
1873   GNUNET_assert (ret >= sizeof (struct GNUNET_MessageHeader));
1874   hdr = (struct GNUNET_MessageHeader *) &obm[1];
1875   GNUNET_assert (ntohs (hdr->size) == ret);
1876   GNUNET_assert (ret + sizeof (struct OutboundMessage) <
1877                  GNUNET_SERVER_MAX_MESSAGE_SIZE);
1878 #if DEBUG_TRANSPORT
1879   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1880               "Transmitting `%s' message with data for `%4s'\n",
1881               "SEND", GNUNET_i2s (&ctw->th->target));
1882 #endif
1883   ret += sizeof (struct OutboundMessage);
1884   obm->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SEND);
1885   obm->header.size = htons (ret);
1886   obm->priority = htonl (ctw->th->priority);
1887   obm->peer = ctw->th->target;
1888   GNUNET_free (ctw);
1889   return ret;
1890 }
1891
1892
1893
1894 /**
1895  * Check if we could queue a message of the given size for
1896  * transmission.  The transport service will take both its
1897  * internal buffers and bandwidth limits imposed by the
1898  * other peer into consideration when answering this query.
1899  *
1900  * @param handle connection to transport service
1901  * @param target who should receive the message
1902  * @param size how big is the message we want to transmit?
1903  * @param priority how important is the message?
1904  * @param timeout after how long should we give up (and call
1905  *        notify with buf NULL and size 0)?
1906  * @param notify function to call when we are ready to
1907  *        send such a message
1908  * @param notify_cls closure for notify
1909  * @return NULL if someone else is already waiting to be notified
1910  *         non-NULL if the notify callback was queued (can be used to cancel
1911  *         using GNUNET_TRANSPORT_notify_transmit_ready_cancel)
1912  */
1913 struct GNUNET_TRANSPORT_TransmitHandle *
1914 GNUNET_TRANSPORT_notify_transmit_ready (struct GNUNET_TRANSPORT_Handle
1915                                         *handle,
1916                                         const struct GNUNET_PeerIdentity
1917                                         *target, size_t size,
1918                                         unsigned int priority,
1919                                         struct GNUNET_TIME_Relative timeout,
1920                                         GNUNET_CONNECTION_TransmitReadyNotify
1921                                         notify, void *notify_cls)
1922 {
1923   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1924   struct GNUNET_TRANSPORT_TransmitHandle *th;
1925   struct NeighbourList *n;
1926   struct ClientTransmitWrapper *ctw;
1927
1928   if (size + sizeof (struct OutboundMessage) >=
1929       GNUNET_SERVER_MAX_MESSAGE_SIZE)
1930     {
1931       GNUNET_break (0);
1932       return NULL;
1933     }
1934 #if DEBUG_TRANSPORT
1935   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1936               "Asking transport service for transmission of %u bytes to peer `%4s'.\n",
1937               size, GNUNET_i2s (target));
1938 #endif
1939   n = find_neighbour (handle, target);
1940   if ((n != NULL) && (n->transmit_handle != NULL))
1941     return NULL;                /* already have a request pending for this peer! */
1942   ctw = GNUNET_malloc (sizeof (struct ClientTransmitWrapper));
1943   th = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_TransmitHandle));
1944   ctw->notify = notify;
1945   ctw->notify_cls = notify_cls;
1946   ctw->th = th;
1947   th->handle = handle;
1948   th->neighbour = n;
1949   th->target = *target;
1950   th->notify = &client_notify_wrapper;
1951   th->notify_cls = ctw;
1952   th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
1953   th->notify_size = size + sizeof (struct OutboundMessage);
1954   th->priority = priority;
1955   if (NULL == n)
1956     {
1957       pos = handle->connect_wait_head;
1958       while (pos != NULL)
1959         {
1960           GNUNET_assert (0 != memcmp (target,
1961                                       &pos->target,
1962                                       sizeof (struct GNUNET_PeerIdentity)));
1963           pos = pos->next;
1964         }
1965 #if DEBUG_TRANSPORT
1966       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1967                   "Will now try to connect to `%4s'.\n", GNUNET_i2s (target));
1968 #endif
1969       try_connect (th);
1970       return th;
1971     }
1972
1973 #if DEBUG_TRANSPORT
1974   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1975               "Transmission request queued for transmission to transport service.\n");
1976 #endif
1977   GNUNET_assert (NULL == n->transmit_handle);
1978   n->transmit_handle = th;
1979   if (GNUNET_YES != n->transmit_ok)
1980     {
1981 #if DEBUG_TRANSPORT
1982       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1983                   "Connection to `%4s' is not yet confirmed connected, scheduling timeout (%llu ms) only.\n",
1984                   GNUNET_i2s (target), timeout.value);
1985 #endif
1986       th->notify_delay_task
1987         = GNUNET_SCHEDULER_add_delayed (handle->sched,
1988                                         timeout, &peer_transmit_timeout, th);
1989       return th;
1990     }
1991
1992 #if DEBUG_TRANSPORT
1993   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1994               "Peer `%4s' is ready to receive, scheduling message for delivery now.\n",
1995               GNUNET_i2s (target));
1996 #endif
1997   th->notify_delay_task
1998     = GNUNET_SCHEDULER_add_now (handle->sched, &transmit_ready, th);
1999   return th;
2000 }
2001
2002
2003 /**
2004  * Cancel the specified transmission-ready notification.
2005  */
2006 void
2007 GNUNET_TRANSPORT_notify_transmit_ready_cancel (struct
2008                                                GNUNET_TRANSPORT_TransmitHandle
2009                                                *th)
2010 {
2011   struct GNUNET_TRANSPORT_Handle *h;
2012
2013 #if DEBUG_TRANSPORT
2014   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2015               "Transmission request of %u bytes to `%4s' was cancelled.\n",
2016               th->notify_size - sizeof (struct OutboundMessage),
2017               GNUNET_i2s (&th->target));
2018 #endif
2019   GNUNET_assert (th->notify == &client_notify_wrapper);
2020   remove_from_any_list (th);
2021   h = th->handle;
2022   if ((h->connect_ready_head == NULL) && (h->network_handle != NULL))
2023     {
2024       GNUNET_CLIENT_notify_transmit_ready_cancel (h->network_handle);
2025       h->network_handle = NULL;
2026       h->transmission_scheduled = GNUNET_NO;
2027     }
2028   GNUNET_free (th->notify_cls);
2029   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_TASK);
2030   GNUNET_free (th);
2031 }
2032
2033
2034 /* end of transport_api.c */