src/transport/transport_api.c

   1 /*
   2      This file is part of GNUnet.
   3      (C) 2009 Christian Grothoff (and other contributing authors)
   4
   5      GNUnet is free software; you can redistribute it and/or modify
   6      it under the terms of the GNU General Public License as published
   7      by the Free Software Foundation; either version 2, or (at your
   8      option) any later version.
   9
  10      GNUnet is distributed in the hope that it will be useful, but
  11      WITHOUT ANY WARRANTY; without even the implied warranty of
  12      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13      General Public License for more details.
  14
  15      You should have received a copy of the GNU General Public License
  16      along with GNUnet; see the file COPYING.  If not, write to the
  17      Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18      Boston, MA 02111-1307, USA.
  19 */
  20
  21 /**
  22  * @file transport/transport_api.c
  23  * @brief library to access the low-level P2P IO service
  24  * @author Christian Grothoff
  25  *
  26  * TODO:
  27  * - set_quota with low bandwidth should cause peer
  28  *   disconnects (currently never does that) (MINOR)
  29  */
  30 #include "platform.h"
  31 #include "gnunet_client_lib.h"
  32 #include "gnunet_arm_service.h"
  33 #include "gnunet_hello_lib.h"
  34 #include "gnunet_protocols.h"
  35 #include "gnunet_server_lib.h"
  36 #include "gnunet_time_lib.h"
  37 #include "gnunet_transport_service.h"
  38 #include "transport.h"
  39
  40 /**
  41  * After how long do we give up on transmitting a HELLO
  42  * to the service?
  43  */
  44 #define OFFER_HELLO_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 30)
  45
  46 /**
  47  * How long should ARM wait when starting up the
  48  * transport service before reporting back?
  49  */
  50 #define START_SERVICE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
  51
  52 /**
  53  * How long should ARM wait when stopping the
  54  * transport service before reporting back?
  55  */
  56 #define STOP_SERVICE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
  57
  58 /**
  59  * Entry in linked list of all of our current neighbours.
  60  */
  61 struct NeighbourList
  62 {
  63
  64   /**
  65    * This is a linked list.
  66    */
  67   struct NeighbourList *next;
  68
  69   /**
  70    * Active transmit handle, can be NULL.  Used to move
  71    * from ready to wait list on disconnect and to block
  72    * two transmissions to the same peer from being scheduled
  73    * at the same time.
  74    */
  75   struct GNUNET_TRANSPORT_TransmitHandle *transmit_handle;
  76
  77
  78   /**
  79    * Identity of this neighbour.
  80    */
  81   struct GNUNET_PeerIdentity id;
  82
  83   /**
  84    * At what time did we reset last_sent last?
  85    */
  86   struct GNUNET_TIME_Absolute last_quota_update;
  87
  88   /**
  89    * How many bytes have we sent since the "last_quota_update"
  90    * timestamp?
  91    */
  92   uint64_t last_sent;
  93
  94   /**
  95    * Global quota for outbound traffic to the neighbour in bytes/ms.
  96    */
  97   uint32_t quota_out;
  98
  99   /**
 100    * Set to GNUNET_YES if we are currently allowed to
 101    * transmit a message to the transport service for this
 102    * peer, GNUNET_NO otherwise.
 103    */
 104   int transmit_ok;
 105
 106   /**
 107    * Set to GNUNET_YES if we have received an ACK for the
 108    * given peer.  Peers that receive our HELLO always respond
 109    * with an ACK to let us know that we are successfully
 110    * communicating.  Note that a PING can not be used for this
 111    * since PINGs are only send if a HELLO address requires
 112    * confirmation (and also, PINGs are not passed to the
 113    * transport API itself).
 114    */
 115   int received_ack;
 116
 117 };
 118
 119
 120 /**
 121  * Linked list of requests from clients for our HELLO
 122  * that were deferred.
 123  */
 124 struct HelloWaitList
 125 {
 126
 127   /**
 128    * This is a linked list.
 129    */
 130   struct HelloWaitList *next;
 131
 132   /**
 133    * Reference back to our transport handle.
 134    */
 135   struct GNUNET_TRANSPORT_Handle *handle;
 136
 137   /**
 138    * Callback to call once we got our HELLO.
 139    */
 140   GNUNET_TRANSPORT_ReceiveCallback rec;
 141
 142   /**
 143    * Closure for rec.
 144    */
 145   void *rec_cls;
 146
 147   /**
 148    * When to time out (call rec with NULL).
 149    */
 150   struct GNUNET_TIME_Absolute timeout;
 151
 152   /**
 153    * Timeout task (used to trigger timeout,
 154    * cancel if we get the HELLO in time).
 155    */
 156   GNUNET_SCHEDULER_TaskIdentifier task;
 157
 158
 159 };
 160
 161
 162 /**
 163  * Opaque handle for a transmission-ready request.
 164  */
 165 struct GNUNET_TRANSPORT_TransmitHandle
 166 {
 167
 168   /**
 169    * We keep the transmit handles that are waiting for
 170    * a transport-level connection in a doubly linked list.
 171    */
 172   struct GNUNET_TRANSPORT_TransmitHandle *next;
 173
 174   /**
 175    * We keep the transmit handles that are waiting for
 176    * a transport-level connection in a doubly linked list.
 177    */
 178   struct GNUNET_TRANSPORT_TransmitHandle *prev;
 179
 180   /**
 181    * Handle of the main transport data structure.
 182    */
 183   struct GNUNET_TRANSPORT_Handle *handle;
 184
 185   /**
 186    * Neighbour for this handle, can be NULL if the service
 187    * is not yet connected to the target.
 188    */
 189   struct NeighbourList *neighbour;
 190
 191   /**
 192    * Which peer is this transmission going to be for?  All
 193    * zeros if it is control-traffic to the service.
 194    */
 195   struct GNUNET_PeerIdentity target;
 196
 197   /**
 198    * Function to call when notify_size bytes are available
 199    * for transmission.
 200    */
 201   GNUNET_NETWORK_TransmitReadyNotify notify;
 202
 203   /**
 204    * Closure for notify.
 205    */
 206   void *notify_cls;
 207
 208   /**
 209    * transmit_ready task Id.  The task is used to introduce
 210    * the artificial delay that may be required to maintain
 211    * the bandwidth limits.
 212    */
 213   GNUNET_SCHEDULER_TaskIdentifier notify_delay_task;
 214
 215   /**
 216    * Timeout for this request.
 217    */
 218   struct GNUNET_TIME_Absolute timeout;
 219
 220   /**
 221    * How many bytes is our notify callback waiting for?
 222    */
 223   size_t notify_size;
 224
 225 };
 226
 227
 228 /**
 229  * Handle for the transport service (includes all of the
 230  * state for the transport service).
 231  */
 232 struct GNUNET_TRANSPORT_Handle
 233 {
 234
 235   /**
 236    * Closure for the callbacks.
 237    */
 238   void *cls;
 239
 240   /**
 241    * Function to call for received data.
 242    */
 243   GNUNET_TRANSPORT_ReceiveCallback rec;
 244
 245   /**
 246    * function to call on connect events
 247    */
 248   GNUNET_TRANSPORT_NotifyConnect nc_cb;
 249
 250   /**
 251    * function to call on disconnect events
 252    */
 253   GNUNET_TRANSPORT_NotifyDisconnect nd_cb;
 254
 255   /**
 256    * The current HELLO message for this peer.  Updated
 257    * whenever transports change their addresses.
 258    */
 259   struct GNUNET_HELLO_Message *my_hello;
 260
 261   /**
 262    * My client connection to the transport service.
 263    */
 264   struct GNUNET_CLIENT_Connection *client;
 265
 266   /**
 267    * Handle to our registration with the client for notification.
 268    */
 269   struct GNUNET_NETWORK_TransmitHandle *network_handle;
 270
 271   /**
 272    * Linked list of transmit handles that are waiting for the
 273    * transport to connect to the respective peer.  When we
 274    * receive notification that the transport connected to a
 275    * peer, we go over this list and check if someone has already
 276    * requested a transmission to the new peer; if so, we trigger
 277    * the next step.
 278    */
 279   struct GNUNET_TRANSPORT_TransmitHandle *connect_wait_head;
 280
 281   /**
 282    * Linked list of transmit handles that are waiting for the
 283    * transport to be ready for transmission to the respective
 284    * peer.  When we
 285    * receive notification that the transport disconnected from
 286    * a peer, we go over this list and move the entry back to
 287    * the connect_wait list.
 288    */
 289   struct GNUNET_TRANSPORT_TransmitHandle *connect_ready_head;
 290
 291   /**
 292    * Linked list of pending requests for our HELLO.
 293    */
 294   struct HelloWaitList *hwl_head;
 295
 296   /**
 297    * My scheduler.
 298    */
 299   struct GNUNET_SCHEDULER_Handle *sched;
 300
 301   /**
 302    * My configuration.
 303    */
 304   struct GNUNET_CONFIGURATION_Handle *cfg;
 305
 306   /**
 307    * Linked list of the current neighbours of this peer.
 308    */
 309   struct NeighbourList *neighbours;
 310
 311   /**
 312    * ID of the task trying to reconnect to the
 313    * service.
 314    */
 315   GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
 316
 317   /**
 318    * Delay until we try to reconnect.
 319    */
 320   struct GNUNET_TIME_Relative reconnect_delay;
 321
 322   /**
 323    * Do we currently have a transmission pending?
 324    * (schedule transmission was called but has not
 325    * yet succeeded)?
 326    */
 327   int transmission_scheduled;
 328 };
 329
 330
 331 static struct NeighbourList *
 332 find_neighbour (struct GNUNET_TRANSPORT_Handle *h,
 333                 const struct GNUNET_PeerIdentity *peer)
 334 {
 335   struct NeighbourList *pos;
 336
 337   pos = h->neighbours;
 338   while ((pos != NULL) &&
 339          (0 != memcmp (peer, &pos->id, sizeof (struct GNUNET_PeerIdentity))))
 340     pos = pos->next;
 341   return pos;
 342 }
 343
 344
 345 /**
 346  * Schedule the task to send one message from the
 347  * connect_ready list to the service.
 348  */
 349 static void schedule_transmission (struct GNUNET_TRANSPORT_Handle *h);
 350
 351
 352 /**
 353  * Transmit message to client...
 354  */
 355 static size_t
 356 transport_notify_ready (void *cls, size_t size, void *buf)
 357 {
 358   struct GNUNET_TRANSPORT_Handle *h = cls;
 359   struct GNUNET_TRANSPORT_TransmitHandle *th;
 360   struct NeighbourList *n;
 361   size_t ret;
 362   char *cbuf;
 363
 364   h->network_handle = NULL;
 365   h->transmission_scheduled = GNUNET_NO;
 366   if (buf == NULL)
 367     {
 368 #if DEBUG_TRANSPORT
 369       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 370                   "Could not transmit to transport service, cancelling pending requests\n");
 371 #endif
 372       th = h->connect_ready_head;
 373       if (th->next != NULL)
 374         th->next->prev = NULL;
 375       h->connect_ready_head = th->next;
 376       if (NULL != (n = th->neighbour))
 377         {
 378           GNUNET_assert (n->transmit_handle == th);
 379           n->transmit_handle = NULL;
 380         }
 381       GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
 382       GNUNET_free (th);
 383       return 0;
 384     }
 385 #if DEBUG_TRANSPORT
 386   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 387               "Ready to transmit %u bytes to transport service\n", size);
 388 #endif
 389   cbuf = buf;
 390   ret = 0;
 391   h->network_handle = NULL;
 392   h->transmission_scheduled = GNUNET_NO;
 393   do
 394     {
 395       th = h->connect_ready_head;
 396       GNUNET_assert (th->notify_size <= size);
 397       if (th->next != NULL)
 398         th->next->prev = NULL;
 399       h->connect_ready_head = th->next;
 400       if (NULL != (n = th->neighbour))
 401         {
 402           GNUNET_assert (n->transmit_handle == th);
 403           n->transmit_handle = NULL;
 404         }
 405       ret += th->notify (th->notify_cls, size, &cbuf[ret]);
 406       GNUNET_free (th);
 407       if (n != NULL)
 408         n->last_sent += ret;
 409       size -= ret;
 410     }
 411   while ((h->connect_ready_head != NULL) &&
 412          (h->connect_ready_head->notify_size <= size));
 413   if (h->connect_ready_head != NULL)
 414     schedule_transmission (h);
 415 #if DEBUG_TRANSPORT
 416   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 417               "Transmitting %u bytes to transport service\n", ret);
 418 #endif
 419   return ret;
 420 }
 421
 422
 423 /**
 424  * Schedule the task to send one message from the
 425  * connect_ready list to the service.
 426  */
 427 static void
 428 schedule_transmission (struct GNUNET_TRANSPORT_Handle *h)
 429 {
 430   struct GNUNET_TRANSPORT_TransmitHandle *th;
 431
 432   GNUNET_assert (NULL == h->network_handle);
 433   if (h->client == NULL)
 434     return; /* not yet connected */
 435   th = h->connect_ready_head;
 436   if (th == NULL)
 437     return; /* no request pending */
 438   h->transmission_scheduled = GNUNET_YES;
 439   h->network_handle = GNUNET_CLIENT_notify_transmit_ready (h->client,
 440                                                            th->notify_size,
 441                                                            GNUNET_TIME_absolute_get_remaining
 442                                                            (th->timeout),
 443                                                            &transport_notify_ready,
 444                                                            h);
 445   GNUNET_assert (NULL != h->network_handle);
 446 }
 447
 448
 449 /**
 450  * Insert the given transmit handle in the given sorted
 451  * doubly linked list based on timeout.
 452  *
 453  * @param head pointer to the head of the linked list
 454  * @param th element to insert into the list
 455  */
 456 static void
 457 insert_transmit_handle (struct GNUNET_TRANSPORT_TransmitHandle **head,
 458                         struct GNUNET_TRANSPORT_TransmitHandle *th)
 459 {
 460   struct GNUNET_TRANSPORT_TransmitHandle *pos;
 461   struct GNUNET_TRANSPORT_TransmitHandle *prev;
 462
 463   pos = *head;
 464   prev = NULL;
 465   while ((pos != NULL) && (pos->timeout.value < th->timeout.value))
 466     {
 467       prev = pos;
 468       pos = pos->next;
 469     }
 470   if (prev == NULL)
 471     {
 472       th->next = *head;
 473       if (th->next != NULL)
 474         th->next->prev = th;
 475       *head = th;
 476     }
 477   else
 478     {
 479       th->next = pos;
 480       th->prev = prev;
 481       prev->next = th;
 482       if (pos != NULL)
 483         pos->prev = th;
 484     }
 485 }
 486
 487
 488 /**
 489  * Queue control request for transmission to the transport
 490  * service.
 491  *
 492  * @param size number of bytes to be transmitted
 493  * @param at_head request must be added to the head of the queue
 494  *        (otherwise request will be appended)
 495  * @param timeout how long this transmission can wait (at most)
 496  * @param notify function to call to get the content
 497  * @param notify_cls closure for notify
 498  */
 499 static void
 500 schedule_control_transmit (struct GNUNET_TRANSPORT_Handle *h,
 501                            size_t size,
 502                            int at_head,
 503                            struct GNUNET_TIME_Relative timeout,
 504                            GNUNET_NETWORK_TransmitReadyNotify notify,
 505                            void *notify_cls)
 506 {
 507   struct GNUNET_TRANSPORT_TransmitHandle *th;
 508
 509   th = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_TransmitHandle));
 510   th->handle = h;
 511   th->notify = notify;
 512   th->notify_cls = notify_cls;
 513   th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 514   th->notify_size = size;
 515   if (at_head)
 516     {
 517       th->next = h->connect_ready_head;
 518       h->connect_ready_head = th;
 519       if (th->next != NULL)
 520         th->next->prev = th;
 521     }
 522   else
 523     {
 524       insert_transmit_handle (&h->connect_ready_head, th);
 525     }
 526   if (GNUNET_NO == h->transmission_scheduled)
 527     schedule_transmission (h);
 528 }
 529
 530
 531 /**
 532  * Update the quota values for the given neighbour now.
 533  */
 534 static void
 535 update_quota (struct NeighbourList *n)
 536 {
 537   struct GNUNET_TIME_Relative delta;
 538   uint64_t allowed;
 539   uint64_t remaining;
 540
 541   delta = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
 542   allowed = delta.value * n->quota_out;
 543   if (n->last_sent < allowed)
 544     {
 545       remaining = allowed - n->last_sent;
 546       if (n->quota_out > 0)
 547         remaining /= n->quota_out;
 548       else
 549         remaining = 0;
 550       if (remaining > MAX_BANDWIDTH_CARRY)
 551         remaining = MAX_BANDWIDTH_CARRY;
 552       n->last_sent = 0;
 553       n->last_quota_update = GNUNET_TIME_absolute_get ();
 554       n->last_quota_update.value -= remaining;
 555     }
 556   else
 557     {
 558       n->last_sent -= allowed;
 559       n->last_quota_update = GNUNET_TIME_absolute_get ();
 560     }
 561 }
 562
 563
 564 struct SetQuotaContext
 565 {
 566   struct GNUNET_TRANSPORT_Handle *handle;
 567
 568   struct GNUNET_PeerIdentity target;
 569
 570   GNUNET_SCHEDULER_Task cont;
 571
 572   void *cont_cls;
 573
 574   struct GNUNET_TIME_Absolute timeout;
 575
 576   uint32_t quota_in;
 577 };
 578
 579
 580 static size_t
 581 send_set_quota (void *cls, size_t size, void *buf)
 582 {
 583   struct SetQuotaContext *sqc = cls;
 584   struct QuotaSetMessage *msg;
 585
 586   if (buf == NULL)
 587     {
 588       GNUNET_SCHEDULER_add_continuation (sqc->handle->sched,
 589                                          GNUNET_NO,
 590                                          sqc->cont,
 591                                          sqc->cont_cls,
 592                                          GNUNET_SCHEDULER_REASON_TIMEOUT);
 593       GNUNET_free (sqc);
 594       return 0;
 595     }
 596 #if DEBUG_TRANSPORT
 597   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 598               "Transmitting `%s' request with respect to `%4s'.\n",
 599               "SET_QUOTA", GNUNET_i2s (&sqc->target));
 600 #endif
 601   GNUNET_assert (size >= sizeof (struct QuotaSetMessage));
 602   msg = buf;
 603   msg->header.size = htons (sizeof (struct QuotaSetMessage));
 604   msg->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SET_QUOTA);
 605   msg->quota_in = htonl (sqc->quota_in);
 606   memcpy (&msg->peer, &sqc->target, sizeof (struct GNUNET_PeerIdentity));
 607   if (sqc->cont != NULL)
 608     GNUNET_SCHEDULER_add_continuation (sqc->handle->sched,
 609                                        GNUNET_NO,
 610                                        sqc->cont,
 611                                        sqc->cont_cls,
 612                                        GNUNET_SCHEDULER_REASON_PREREQ_DONE);
 613   GNUNET_free (sqc);
 614   return sizeof (struct QuotaSetMessage);
 615 }
 616
 617
 618 /**
 619  * Set the share of incoming bandwidth for the given
 620  * peer to the specified amount.
 621  *
 622  * @param handle connection to transport service
 623  * @param target who's bandwidth quota is being changed
 624  * @param quota_in incoming bandwidth quota in bytes per ms; 0 can
 625  *        be used to force all traffic to be discarded
 626  * @param quota_out outgoing bandwidth quota in bytes per ms; 0 can
 627  *        be used to force all traffic to be discarded
 628  * @param timeout how long to wait until signaling failure if
 629  *        we can not communicate the quota change
 630  * @param cont continuation to call when done, will be called
 631  *        either with reason "TIMEOUT" or with reason "PREREQ_DONE"
 632  * @param cont_cls closure for continuation
 633  */
 634 void
 635 GNUNET_TRANSPORT_set_quota (struct GNUNET_TRANSPORT_Handle *handle,
 636                             const struct GNUNET_PeerIdentity *target,
 637                             uint32_t quota_in,
 638                             uint32_t quota_out,
 639                             struct GNUNET_TIME_Relative timeout,
 640                             GNUNET_SCHEDULER_Task cont, void *cont_cls)
 641 {
 642   struct NeighbourList *n;
 643   struct SetQuotaContext *sqc;
 644
 645   n = find_neighbour (handle, target);
 646   if (n != NULL)
 647     {
 648       update_quota (n);
 649       if (n->quota_out < quota_out)
 650         n->last_quota_update = GNUNET_TIME_absolute_get ();
 651       n->quota_out = quota_out;
 652     }
 653   sqc = GNUNET_malloc (sizeof (struct SetQuotaContext));
 654   sqc->handle = handle;
 655   sqc->target = *target;
 656   sqc->cont = cont;
 657   sqc->cont_cls = cont_cls;
 658   sqc->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 659   sqc->quota_in = quota_in;
 660   schedule_control_transmit (handle,
 661                              sizeof (struct QuotaSetMessage),
 662                              GNUNET_NO, timeout, &send_set_quota, sqc);
 663 }
 664
 665
 666 /**
 667  * A "get_hello" request has timed out.  Signal the client
 668  * and clean up.
 669  */
 670 static void
 671 hello_wait_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 672 {
 673   struct HelloWaitList *hwl = cls;
 674   struct HelloWaitList *pos;
 675   struct HelloWaitList *prev;
 676
 677   prev = NULL;
 678   pos = hwl->handle->hwl_head;
 679   while (pos != hwl)
 680     {
 681       GNUNET_assert (pos != NULL);
 682       prev = pos;
 683       pos = pos->next;
 684     }
 685   if (prev == NULL)
 686     hwl->handle->hwl_head = hwl->next;
 687   else
 688     prev->next = hwl->next;
 689   GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 690               _("Timeout trying to obtain `%s' from transport service.\n"),
 691               "HELLO");
 692   /* signal timeout */
 693   if (hwl->rec != NULL)
 694     hwl->rec (hwl->rec_cls, GNUNET_TIME_UNIT_ZERO, NULL, NULL);
 695   GNUNET_free (hwl);
 696 }
 697
 698
 699 /**
 700  * Obtain the HELLO message for this peer.
 701  *
 702  * @param handle connection to transport service
 703  * @param timeout how long to wait for the HELLO
 704  * @param rec function to call with the HELLO, sender will be our peer
 705  *            identity; message and sender will be NULL on timeout
 706  *            (handshake with transport service pending/failed).
 707  *             cost estimate will be 0.
 708  * @param rec_cls closure for rec
 709  */
 710 void
 711 GNUNET_TRANSPORT_get_hello (struct GNUNET_TRANSPORT_Handle *handle,
 712                             struct GNUNET_TIME_Relative timeout,
 713                             GNUNET_TRANSPORT_ReceiveCallback rec,
 714                             void *rec_cls)
 715 {
 716   struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded pk;
 717   struct GNUNET_PeerIdentity me;
 718   struct HelloWaitList *hwl;
 719
 720   if (handle->my_hello == NULL)
 721     {
 722       hwl = GNUNET_malloc (sizeof (struct HelloWaitList));
 723       hwl->next = handle->hwl_head;
 724       handle->hwl_head = hwl;
 725       hwl->handle = handle;
 726       hwl->rec = rec;
 727       hwl->rec_cls = rec_cls;
 728       hwl->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 729       hwl->task = GNUNET_SCHEDULER_add_delayed (handle->sched,
 730                                                 GNUNET_YES,
 731                                                 GNUNET_SCHEDULER_PRIORITY_KEEP,
 732                                                 GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
 733                                                 timeout,
 734                                                 &hello_wait_timeout, hwl);
 735       return;
 736     }
 737   GNUNET_assert (GNUNET_OK == GNUNET_HELLO_get_key (handle->my_hello, &pk));
 738   GNUNET_CRYPTO_hash (&pk,
 739                       sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
 740                       &me.hashPubKey);
 741
 742   rec (rec_cls,
 743        GNUNET_TIME_UNIT_ZERO,
 744        &me, (const struct GNUNET_MessageHeader *) handle->my_hello);
 745 }
 746
 747
 748 static size_t
 749 send_hello (void *cls, size_t size, void *buf)
 750 {
 751   struct GNUNET_MessageHeader *hello = cls;
 752   uint16_t msize;
 753
 754   if (buf == NULL)
 755     {
 756 #if DEBUG_TRANSPORT
 757       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 758                   "Timeout while trying to transmit `%s' request.\n",
 759                   "HELLO");
 760 #endif
 761       GNUNET_free (hello);
 762       return 0;
 763     }
 764 #if DEBUG_TRANSPORT
 765   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 766               "Transmitting `%s' request.\n", "HELLO");
 767 #endif
 768   msize = ntohs (hello->size);
 769   GNUNET_assert (size >= msize);
 770   memcpy (buf, hello, msize);
 771   GNUNET_free (hello);
 772   return msize;
 773 }
 774
 775
 776 /**
 777  * Offer the transport service the HELLO of another peer.  Note that
 778  * the transport service may just ignore this message if the HELLO is
 779  * malformed or useless due to our local configuration.
 780  *
 781  * @param handle connection to transport service
 782  * @param hello the hello message
 783  */
 784 void
 785 GNUNET_TRANSPORT_offer_hello (struct GNUNET_TRANSPORT_Handle *handle,
 786                               const struct GNUNET_MessageHeader *hello)
 787 {
 788   struct GNUNET_MessageHeader *hc;
 789   uint16_t size;
 790
 791   if (handle->client == NULL)
 792     {
 793 #if DEBUG_TRANSPORT
 794       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 795                   "Not connected to transport service, dropping offered HELLO\n");
 796 #endif
 797       return;
 798     }
 799   GNUNET_break (ntohs (hello->type) == GNUNET_MESSAGE_TYPE_HELLO);
 800   size = ntohs (hello->size);
 801   GNUNET_break (size >= sizeof (struct GNUNET_MessageHeader));
 802   hc = GNUNET_malloc (size);
 803   memcpy (hc, hello, size);
 804   schedule_control_transmit (handle,
 805                              size,
 806                              GNUNET_NO, OFFER_HELLO_TIMEOUT, &send_hello, hc);
 807 }
 808
 809
 810 /**
 811  * Function we use for handling incoming messages.
 812  */
 813 static void demultiplexer (void *cls, const struct GNUNET_MessageHeader *msg);
 814
 815
 816 static size_t
 817 send_start (void *cls, size_t size, void *buf)
 818 {
 819   struct GNUNET_MessageHeader *s = buf;
 820
 821   if (buf == NULL)
 822     {
 823 #if DEBUG_TRANSPORT
 824       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 825                   "Timeout while trying to transmit `%s' request.\n",
 826                   "START");
 827 #endif
 828       return 0;
 829     }
 830 #if DEBUG_TRANSPORT
 831   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 832               "Transmitting `%s' request.\n", "START");
 833 #endif
 834   GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
 835   s->size = htons (sizeof (struct GNUNET_MessageHeader));
 836   s->type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_START);
 837   return sizeof (struct GNUNET_MessageHeader);
 838 }
 839
 840
 841 /**
 842  * Try again to connect to transport service.
 843  */
 844 static void
 845 reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 846 {
 847   struct GNUNET_TRANSPORT_Handle *h = cls;
 848   struct GNUNET_TRANSPORT_TransmitHandle *pos;
 849   struct NeighbourList *n;
 850
 851   while (NULL != (n = h->neighbours))
 852     {
 853       h->neighbours = n->next;
 854       pos = n->transmit_handle;
 855       if (pos != NULL)
 856         {
 857           pos->neighbour = NULL;
 858           pos->next = h->connect_wait_head;
 859           h->connect_wait_head = pos;
 860           if (pos->next != NULL)
 861             pos->next->prev = pos;
 862           pos->prev = NULL;
 863         }
 864       GNUNET_free (n);
 865     }
 866   h->connect_ready_head = NULL;
 867 #if DEBUG_TRANSPORT
 868   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connecting to transport service.\n");
 869 #endif
 870   GNUNET_assert (h->client == NULL);
 871   h->reconnect_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
 872   h->client = GNUNET_CLIENT_connect (h->sched, "transport", h->cfg);
 873   GNUNET_assert (h->client != NULL);
 874   /* make sure we don't send "START" twice,
 875      remove existing entry from queue (if present) */
 876   pos = h->connect_ready_head;
 877   while (pos != NULL)
 878     {
 879       if (pos->notify == &send_start)
 880         {
 881           if (pos->prev == NULL)
 882             h->connect_ready_head = pos->next;
 883           else
 884             pos->prev->next = pos->next;
 885           if (pos->next != NULL)
 886             pos->next->prev = pos->prev;
 887           GNUNET_assert (pos->neighbour == NULL);
 888           GNUNET_free (pos);
 889           break;
 890         }
 891       pos = pos->next;
 892     }
 893   schedule_control_transmit (h,
 894                              sizeof (struct GNUNET_MessageHeader),
 895                              GNUNET_YES,
 896                              GNUNET_TIME_UNIT_FOREVER_REL, &send_start, NULL);
 897   GNUNET_CLIENT_receive (h->client,
 898                          &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL);
 899 }
 900
 901
 902 /**
 903  * Function that will schedule the job that will try
 904  * to connect us again to the client.
 905  */
 906 static void
 907 schedule_reconnect (struct GNUNET_TRANSPORT_Handle *h)
 908 {
 909 #if DEBUG_TRANSPORT
 910   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 911               "Scheduling task to reconnect to transport service in %llu ms.\n",
 912               h->reconnect_delay.value);
 913 #endif
 914   GNUNET_assert (h->client == NULL);
 915   GNUNET_assert (h->reconnect_task == GNUNET_SCHEDULER_NO_PREREQUISITE_TASK);
 916   h->reconnect_task
 917     = GNUNET_SCHEDULER_add_delayed (h->sched,
 918                                     GNUNET_NO,
 919                                     GNUNET_SCHEDULER_PRIORITY_DEFAULT,
 920                                     GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
 921                                     h->reconnect_delay, &reconnect, h);
 922   h->reconnect_delay = GNUNET_TIME_UNIT_SECONDS;
 923 }
 924
 925
 926 /**
 927  * Remove the given transmit handle from the wait list.  Does NOT free
 928  * it.
 929  */
 930 static void
 931 remove_from_wait_list (struct GNUNET_TRANSPORT_TransmitHandle *th)
 932 {
 933   if (th->prev == NULL)
 934     th->handle->connect_wait_head = th->next;
 935   else
 936     th->prev->next = th->next;
 937   if (th->next != NULL)
 938     th->next->prev = th->prev;
 939 }
 940
 941
 942 /**
 943  * We are connected to the respective peer, check the
 944  * bandwidth limits and schedule the transmission.
 945  */
 946 static void schedule_request (struct GNUNET_TRANSPORT_TransmitHandle *th);
 947
 948
 949 /**
 950  * Function called by the scheduler when the timeout
 951  * for bandwidth availablility for the target
 952  * neighbour is reached.
 953  */
 954 static void
 955 transmit_ready (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 956 {
 957   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
 958
 959   th->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
 960   schedule_request (th);
 961 }
 962
 963
 964 /**
 965  * Called when our transmit request timed out before any transport
 966  * reported success connecting to the desired peer or before the
 967  * transport was ready to receive.  Signal error and free
 968  * TransmitHandle.
 969  */
 970 static void
 971 transmit_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 972 {
 973   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
 974
 975   if (th->neighbour != NULL)
 976     th->neighbour->transmit_handle = NULL;
 977 #if DEBUG_TRANSPORT
 978   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 979               "Request for transmission to peer `%s' timed out.\n",
 980               GNUNET_i2s(&th->target));
 981 #endif
 982   th->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
 983   remove_from_wait_list (th);
 984   th->notify (th->notify_cls, 0, NULL);
 985   GNUNET_free (th);
 986 }
 987
 988
 989 /**
 990  * We are connected to the respective peer, check the
 991  * bandwidth limits and schedule the transmission.
 992  */
 993 static void
 994 schedule_request (struct GNUNET_TRANSPORT_TransmitHandle *th)
 995 {
 996   struct GNUNET_TRANSPORT_Handle *h;
 997   struct GNUNET_TIME_Relative duration;
 998   struct NeighbourList *n;
 999   uint64_t available;
1000
1001   h = th->handle;
1002   n = th->neighbour;
1003   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
1004     {
1005       GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
1006       th->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1007     }
1008   /* check outgoing quota */
1009   duration = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
1010   if (duration.value > MIN_QUOTA_REFRESH_TIME)
1011     {
1012       update_quota (n);
1013       duration = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
1014     }
1015   available = duration.value * n->quota_out;
1016   if (available < n->last_sent + th->notify_size)
1017     {
1018       /* calculate how much bandwidth we'd still need to
1019          accumulate and based on that how long we'll have
1020          to wait... */
1021       available = n->last_sent + th->notify_size - available;
1022       duration = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS,
1023                                                 available / n->quota_out);
1024       if (th->timeout.value <
1025           GNUNET_TIME_relative_to_absolute (duration).value)
1026         {
1027           /* signal timeout! */
1028 #if DEBUG_TRANSPORT
1029           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1030                       "Would need %llu ms before bandwidth is available for delivery to `%4s', that is too long.  Signaling timeout.\n",
1031                       duration.value,
1032                       GNUNET_i2s(&th->target));
1033 #endif
1034           remove_from_wait_list (th);
1035           th->notify (th->notify_cls, 0, NULL);
1036           GNUNET_free (th);
1037           return;
1038         }
1039 #if DEBUG_TRANSPORT
1040       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1041                   "Need more bandwidth, delaying delivery to `%4s' by %llu ms\n",
1042                   GNUNET_i2s(&th->target),
1043                   duration.value);
1044 #endif
1045       th->notify_delay_task
1046         = GNUNET_SCHEDULER_add_delayed (h->sched,
1047                                         GNUNET_NO,
1048                                         GNUNET_SCHEDULER_PRIORITY_KEEP,
1049                                         GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
1050                                         duration, &transmit_ready, th);
1051       return;
1052     }
1053 #if DEBUG_TRANSPORT
1054   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1055               "Bandwidth available for transmission to `%4s'\n",
1056               GNUNET_i2s (&n->id));
1057 #endif
1058   if (GNUNET_NO == n->transmit_ok)
1059     {
1060       /* we may be ready, but transport service is not;
1061          wait for SendOkMessage or timeout */
1062 #if DEBUG_TRANSPORT
1063       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1064                   "Need to wait for transport service `%s' message\n",
1065                   "SEND_OK");
1066 #endif
1067       th->notify_delay_task
1068         = GNUNET_SCHEDULER_add_delayed (h->sched,
1069                                         GNUNET_NO,
1070                                         GNUNET_SCHEDULER_PRIORITY_KEEP,
1071                                         GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
1072                                         GNUNET_TIME_absolute_get_remaining
1073                                         (th->timeout), &transmit_timeout, th);
1074       return;
1075     }
1076   n->transmit_ok = GNUNET_NO;
1077   remove_from_wait_list (th);
1078 #if DEBUG_TRANSPORT
1079   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Moving message for `%4s' to ready list\n",
1080               GNUNET_i2s(&n->id));
1081 #endif
1082   insert_transmit_handle (&h->connect_ready_head, th);
1083   if (GNUNET_NO == h->transmission_scheduled)
1084     schedule_transmission (h);
1085 }
1086
1087
1088 /**
1089  * Add neighbour to our list
1090  */
1091 static void
1092 add_neighbour (struct GNUNET_TRANSPORT_Handle *h,
1093                uint32_t quota_out,
1094                struct GNUNET_TIME_Relative latency,
1095                const struct GNUNET_PeerIdentity *pid)
1096 {
1097   struct NeighbourList *n;
1098   struct GNUNET_TRANSPORT_TransmitHandle *prev;
1099   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1100   struct GNUNET_TRANSPORT_TransmitHandle *next;
1101
1102   /* check for duplicates */
1103   if (NULL != find_neighbour (h, pid))
1104     {
1105       GNUNET_break (0);
1106       return;
1107     }
1108 #if DEBUG_TRANSPORT
1109   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1110               "Creating entry for new neighbour `%4s'.\n", GNUNET_i2s (pid));
1111 #endif
1112   n = GNUNET_malloc (sizeof (struct NeighbourList));
1113   n->id = *pid;
1114   n->last_quota_update = GNUNET_TIME_absolute_get ();
1115   n->quota_out = quota_out;
1116   n->next = h->neighbours;
1117   n->transmit_ok = GNUNET_YES;
1118   h->neighbours = n;
1119   if (h->nc_cb != NULL)
1120     h->nc_cb (h->cls, &n->id, latency);
1121   prev = NULL;
1122   pos = h->connect_wait_head;
1123   while (pos != NULL)
1124     {
1125       next = pos->next;
1126       if (0 == memcmp (pid,
1127                        &pos->target, sizeof (struct GNUNET_PeerIdentity)))
1128         {
1129           pos->neighbour = n;
1130           GNUNET_assert (NULL == n->transmit_handle);
1131           n->transmit_handle = pos;
1132           if (prev == NULL)
1133             h->connect_wait_head = next;
1134           else
1135             prev->next = next;
1136           if (GNUNET_YES == n->received_ack)
1137             {
1138 #if DEBUG_TRANSPORT
1139               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1140                           "Found pending request for `%4s' will trigger it now.\n",
1141                           GNUNET_i2s (&pos->target));
1142 #endif
1143               if (pos->notify_delay_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
1144                 {
1145                   GNUNET_SCHEDULER_cancel (h->sched, pos->notify_delay_task);
1146                   pos->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1147                 }
1148               schedule_request (pos);
1149             }
1150           else
1151             {
1152 #if DEBUG_TRANSPORT
1153               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1154                           "Found pending request for `%4s' but still need `%s' before proceeding.\n",
1155                           GNUNET_i2s (&pos->target),
1156                           "ACK");
1157 #endif
1158             }
1159           break;
1160         }
1161       prev = pos;
1162       pos = next;
1163     }
1164 }
1165
1166
1167 /**
1168  * Connect to the transport service.  Note that the connection may
1169  * complete (or fail) asynchronously.
1170  *
1171
1172  * @param sched scheduler to use
1173  * @param cfg configuration to use
1174  * @param cls closure for the callbacks
1175  * @param rec receive function to call
1176  * @param nc function to call on connect events
1177  * @param dc function to call on disconnect events
1178  */
1179 struct GNUNET_TRANSPORT_Handle *
1180 GNUNET_TRANSPORT_connect (struct GNUNET_SCHEDULER_Handle *sched,
1181                           struct GNUNET_CONFIGURATION_Handle *cfg,
1182                           void *cls,
1183                           GNUNET_TRANSPORT_ReceiveCallback rec,
1184                           GNUNET_TRANSPORT_NotifyConnect nc,
1185                           GNUNET_TRANSPORT_NotifyDisconnect nd)
1186 {
1187   struct GNUNET_TRANSPORT_Handle *ret;
1188
1189   GNUNET_ARM_start_service ("peerinfo",
1190                             cfg, sched, START_SERVICE_TIMEOUT, NULL, NULL);
1191   GNUNET_ARM_start_service ("transport",
1192                             cfg, sched, START_SERVICE_TIMEOUT, NULL, NULL);
1193   ret = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_Handle));
1194   ret->sched = sched;
1195   ret->cfg = cfg;
1196   ret->cls = cls;
1197   ret->rec = rec;
1198   ret->nc_cb = nc;
1199   ret->nd_cb = nd;
1200   ret->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
1201   schedule_reconnect (ret);
1202   return ret;
1203 }
1204
1205
1206 /**
1207  * These stop activities must be run in a fresh
1208  * scheduler that is NOT in shutdown mode.
1209  */
1210 static void
1211 stop_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1212 {
1213   struct GNUNET_TRANSPORT_Handle *handle = cls;
1214   GNUNET_ARM_stop_service ("transport",
1215                            handle->cfg,
1216                            tc->sched, STOP_SERVICE_TIMEOUT, NULL, NULL);
1217   GNUNET_ARM_stop_service ("peerinfo",
1218                            handle->cfg,
1219                            tc->sched, STOP_SERVICE_TIMEOUT, NULL, NULL);
1220 }
1221
1222
1223 /**
1224  * Disconnect from the transport service.
1225  */
1226 void
1227 GNUNET_TRANSPORT_disconnect (struct GNUNET_TRANSPORT_Handle *handle)
1228 {
1229   struct GNUNET_TRANSPORT_TransmitHandle *th;
1230   struct NeighbourList *n;
1231   struct HelloWaitList *hwl;
1232   struct GNUNET_CLIENT_Connection *client;
1233
1234 #if DEBUG_TRANSPORT
1235   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transport disconnect called!\n");
1236 #endif
1237   while (NULL != (th = handle->connect_ready_head))
1238     {
1239       handle->connect_ready_head = th->next;
1240       th->notify (th->notify_cls, 0, NULL);
1241       GNUNET_free (th);
1242     }
1243
1244   while (NULL != (th = handle->connect_wait_head))
1245     {
1246       handle->connect_wait_head = th->next;
1247       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
1248         {
1249           GNUNET_SCHEDULER_cancel (handle->sched, th->notify_delay_task);
1250           th->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1251         }
1252       th->notify (th->notify_cls, 0, NULL);
1253       GNUNET_free (th);
1254     }
1255   while (NULL != (n = handle->neighbours))
1256     {
1257       handle->neighbours = n->next;
1258       GNUNET_free (n);
1259     }
1260   while (NULL != (hwl = handle->hwl_head))
1261     {
1262       handle->hwl_head = hwl->next;
1263       GNUNET_SCHEDULER_cancel (handle->sched, hwl->task);
1264       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1265                   _("Disconnect while trying to obtain `%s' from transport service.\n"),
1266                   "HELLO");
1267       if (hwl->rec != NULL)
1268         hwl->rec (hwl->rec_cls, GNUNET_TIME_UNIT_ZERO, NULL, NULL);
1269       GNUNET_free (hwl);
1270     }
1271   if (handle->reconnect_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
1272     {
1273       GNUNET_SCHEDULER_cancel (handle->sched, handle->reconnect_task);
1274       handle->reconnect_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1275     }
1276   GNUNET_free_non_null (handle->my_hello);
1277   handle->my_hello = NULL;
1278   GNUNET_SCHEDULER_run (&stop_task, handle);
1279   if (NULL != (client = handle->client))
1280     {
1281 #if DEBUG_TRANSPORT
1282       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1283                   "Disconnecting from transport service for good.\n");
1284 #endif
1285       handle->client = NULL;
1286       GNUNET_CLIENT_disconnect (client);
1287     }
1288   if (client == NULL)
1289     GNUNET_free (handle);
1290 }
1291
1292
1293 /**
1294  * We're ready to transmit the request that the transport service
1295  * should connect to a new peer.  In addition to sending the
1296  * request, schedule the next phase for the transmission processing
1297  * that caused the connect request in the first place.
1298  */
1299 static size_t
1300 request_connect (void *cls, size_t size, void *buf)
1301 {
1302   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
1303   struct TryConnectMessage *tcm;
1304   struct GNUNET_TRANSPORT_Handle *h;
1305
1306   h = th->handle;
1307   if (buf == NULL)
1308     {
1309 #if DEBUG_TRANSPORT
1310       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1311                   "Failed to transmit `%s' request for `%4s' to service.\n",
1312                   "TRY_CONNECT",
1313                   GNUNET_i2s(&th->target));
1314 #endif
1315       th->notify (th->notify_cls, 0, NULL);
1316       GNUNET_free (th);
1317       return 0;
1318     }
1319 #if DEBUG_TRANSPORT
1320   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1321               "Transmitting `%s' message for `%4s'.\n",
1322               "TRY_CONNECT", GNUNET_i2s (&th->target));
1323 #endif
1324   GNUNET_assert (size >= sizeof (struct TryConnectMessage));
1325   tcm = buf;
1326   tcm->header.size = htons (sizeof (struct TryConnectMessage));
1327   tcm->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_TRY_CONNECT);
1328   tcm->reserved = htonl (0);
1329   memcpy (&tcm->peer, &th->target, sizeof (struct GNUNET_PeerIdentity));
1330   th->notify_delay_task
1331     = GNUNET_SCHEDULER_add_delayed (h->sched,
1332                                     GNUNET_NO,
1333                                     GNUNET_SCHEDULER_PRIORITY_KEEP,
1334                                     GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
1335                                     GNUNET_TIME_absolute_get_remaining
1336                                     (th->timeout), &transmit_timeout, th);
1337   insert_transmit_handle (&h->connect_wait_head, th);
1338   return sizeof (struct TryConnectMessage);
1339 }
1340
1341
1342 /**
1343  * Schedule a request to connect to the given
1344  * neighbour (and if successful, add the specified
1345  * handle to the wait list).
1346  */
1347 static void
1348 try_connect (struct GNUNET_TRANSPORT_TransmitHandle *th)
1349 {
1350   schedule_control_transmit (th->handle,
1351                              sizeof (struct TryConnectMessage),
1352                              GNUNET_NO,
1353                              GNUNET_TIME_absolute_get_remaining (th->timeout),
1354                              &request_connect, th);
1355 }
1356
1357
1358 /**
1359  * Cancel a pending notify transmit task
1360  * and also remove the given transmit handle
1361  * from whatever list is on.
1362  */
1363 static void
1364 remove_from_any_list (struct GNUNET_TRANSPORT_TransmitHandle *th)
1365 {
1366   struct GNUNET_TRANSPORT_Handle *h;
1367
1368   h = th->handle;
1369   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
1370     {
1371       GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
1372       th->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1373     }
1374   if (th->prev == NULL)
1375     {
1376       if (th == h->connect_wait_head)
1377         h->connect_wait_head = th->next;
1378       else
1379         h->connect_ready_head = th->next;
1380     }
1381   else
1382     th->prev->next = th->next;
1383   if (th->next != NULL)
1384     th->next->prev = th->prev;
1385 }
1386
1387
1388 /**
1389  * Remove neighbour from our list
1390  */
1391 static void
1392 remove_neighbour (struct GNUNET_TRANSPORT_Handle *h,
1393                   const struct GNUNET_PeerIdentity *peer)
1394 {
1395   struct NeighbourList *prev;
1396   struct NeighbourList *pos;
1397   struct GNUNET_TRANSPORT_TransmitHandle *th;
1398
1399   prev = NULL;
1400   pos = h->neighbours;
1401   while ((pos != NULL) &&
1402          (0 != memcmp (peer, &pos->id, sizeof (struct GNUNET_PeerIdentity))))
1403     {
1404       prev = pos;
1405       pos = pos->next;
1406     }
1407   if (pos == NULL)
1408     {
1409       GNUNET_break (0);
1410       return;
1411     }
1412   if (prev == NULL)
1413     h->neighbours = pos->next;
1414   else
1415     prev->next = pos->next;
1416   if (NULL != (th = pos->transmit_handle))
1417     {
1418       pos->transmit_handle = NULL;
1419       th->neighbour = NULL;
1420       remove_from_any_list (th);
1421       try_connect (th);
1422     }
1423   if (h->nc_cb != NULL)
1424     h->nd_cb (h->cls, peer);
1425   GNUNET_free (pos);
1426 }
1427
1428
1429 /**
1430  * Type of a function to call when we receive a message
1431  * from the service.
1432  *
1433  * @param cls closure
1434  * @param msg message received, NULL on timeout or fatal error
1435  */
1436 static void
1437 demultiplexer (void *cls, const struct GNUNET_MessageHeader *msg)
1438 {
1439   struct GNUNET_TRANSPORT_Handle *h = cls;
1440   const struct DisconnectInfoMessage *dim;
1441   const struct ConnectInfoMessage *cim;
1442   const struct InboundMessage *im;
1443   const struct GNUNET_MessageHeader *imm;
1444   const struct SendOkMessage *okm;
1445   struct HelloWaitList *hwl;
1446   struct NeighbourList *n;
1447   struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded pkey;
1448   struct GNUNET_PeerIdentity me;
1449   uint16_t size;
1450
1451   if ((msg == NULL) || (h->client == NULL))
1452     {
1453       if (h->client != NULL)
1454         {
1455 #if DEBUG_TRANSPORT
1456           GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1457                       "Error receiving from transport service, disconnecting temporarily.\n");
1458 #endif
1459           if (h->network_handle != NULL)
1460             {
1461               GNUNET_NETWORK_notify_transmit_ready_cancel (h->network_handle);
1462               h->network_handle = NULL;
1463               h->transmission_scheduled = GNUNET_NO;
1464             }
1465           GNUNET_CLIENT_disconnect (h->client);
1466           h->client = NULL;
1467           schedule_reconnect (h);
1468         }
1469       else
1470         {
1471           /* shutdown initiated from 'GNUNET_TRANSPORT_disconnect',
1472              finish clean up work! */
1473           GNUNET_free (h);
1474         }
1475       return;
1476     }
1477   GNUNET_CLIENT_receive (h->client,
1478                          &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL);
1479   size = ntohs (msg->size);
1480   switch (ntohs (msg->type))
1481     {
1482     case GNUNET_MESSAGE_TYPE_HELLO:
1483       if (GNUNET_OK !=
1484           GNUNET_HELLO_get_key ((const struct GNUNET_HELLO_Message *) msg,
1485                                 &pkey))
1486         {
1487           GNUNET_break (0);
1488           break;
1489         }
1490       GNUNET_CRYPTO_hash (&pkey,
1491                           sizeof (struct
1492                                   GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
1493                           &me.hashPubKey);
1494 #if DEBUG_TRANSPORT
1495       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1496                   "Receiving (my own) `%s' message, I am `%4s'.\n",
1497                   "HELLO", GNUNET_i2s (&me));
1498 #endif
1499       GNUNET_free_non_null (h->my_hello);
1500       h->my_hello = NULL;
1501       if (size < sizeof (struct GNUNET_MessageHeader))
1502         {
1503           GNUNET_break (0);
1504           break;
1505         }
1506       h->my_hello = GNUNET_malloc (size);
1507       memcpy (h->my_hello, msg, size);
1508       while (NULL != (hwl = h->hwl_head))
1509         {
1510           h->hwl_head = hwl->next;
1511           GNUNET_SCHEDULER_cancel (h->sched, hwl->task);
1512           GNUNET_TRANSPORT_get_hello (h,
1513                                       GNUNET_TIME_UNIT_ZERO,
1514                                       hwl->rec, hwl->rec_cls);
1515           GNUNET_free (hwl);
1516         }
1517       break;
1518     case GNUNET_MESSAGE_TYPE_TRANSPORT_CONNECT:
1519       if (size != sizeof (struct ConnectInfoMessage))
1520         {
1521           GNUNET_break (0);
1522           break;
1523         }
1524       cim = (const struct ConnectInfoMessage *) msg;
1525 #if DEBUG_TRANSPORT
1526       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1527                   "Receiving `%s' message for `%4s'.\n",
1528                   "CONNECT", GNUNET_i2s (&cim->id));
1529 #endif
1530       add_neighbour (h,
1531                      ntohl (cim->quota_out),
1532                      GNUNET_TIME_relative_ntoh (cim->latency), &cim->id);
1533       break;
1534     case GNUNET_MESSAGE_TYPE_TRANSPORT_DISCONNECT:
1535       if (size != sizeof (struct DisconnectInfoMessage))
1536         {
1537           GNUNET_break (0);
1538           break;
1539         }
1540       dim = (const struct DisconnectInfoMessage *) msg;
1541 #if DEBUG_TRANSPORT
1542       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1543                   "Receiving `%s' message for `%4s'.\n",
1544                   "DISCONNECT", GNUNET_i2s (&dim->peer));
1545 #endif
1546       remove_neighbour (h, &dim->peer);
1547       break;
1548     case GNUNET_MESSAGE_TYPE_TRANSPORT_SEND_OK:
1549       if (size != sizeof (struct SendOkMessage))
1550         {
1551           GNUNET_break (0);
1552           break;
1553         }
1554       okm = (const struct SendOkMessage *) msg;
1555 #if DEBUG_TRANSPORT
1556       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1557                   "Receiving `%s' message, transmission %s.\n", "SEND_OK",
1558                   ntohl(okm->success) == GNUNET_OK ? "succeeded" : "failed");
1559 #endif
1560       n = find_neighbour (h, &okm->peer);
1561       GNUNET_assert (n != NULL);
1562       n->transmit_ok = GNUNET_YES;
1563       if (n->transmit_handle != NULL)
1564         {
1565 #if DEBUG_TRANSPORT
1566           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1567                       "Processing pending message\n");
1568 #endif
1569           GNUNET_SCHEDULER_cancel (h->sched,
1570                                    n->transmit_handle->notify_delay_task);
1571           n->transmit_handle->notify_delay_task =
1572             GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1573           GNUNET_assert (GNUNET_YES == n->received_ack);
1574           schedule_request (n->transmit_handle);
1575         }
1576       break;
1577     case GNUNET_MESSAGE_TYPE_TRANSPORT_RECV:
1578 #if DEBUG_TRANSPORT
1579       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1580                   "Receiving `%s' message.\n", "RECV");
1581 #endif
1582       if (size <
1583           sizeof (struct InboundMessage) +
1584           sizeof (struct GNUNET_MessageHeader))
1585         {
1586           GNUNET_break (0);
1587           break;
1588         }
1589       im = (const struct InboundMessage *) msg;
1590       imm = (const struct GNUNET_MessageHeader *) &im[1];
1591       if (ntohs (imm->size) + sizeof (struct InboundMessage) != size)
1592         {
1593           GNUNET_break (0);
1594           break;
1595         }
1596       switch (ntohs (imm->type))
1597         {
1598         case GNUNET_MESSAGE_TYPE_TRANSPORT_ACK:
1599 #if DEBUG_TRANSPORT
1600           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1601                       "Receiving `%s' message from `%4s'.\n",
1602                       "ACK", GNUNET_i2s (&im->peer));
1603 #endif
1604           n = find_neighbour (h, &im->peer);
1605           if (n == NULL)
1606             {
1607               GNUNET_break (0);
1608               break;
1609             }
1610           if (n->received_ack == GNUNET_NO)
1611             {
1612               n->received_ack = GNUNET_YES;
1613               if (NULL != n->transmit_handle)
1614                 {
1615 #if DEBUG_TRANSPORT
1616                   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1617                               "Peer connected, scheduling delayed message for deliverery now.\n");
1618 #endif
1619                   schedule_request (n->transmit_handle);
1620                 }
1621             }
1622           break;
1623         default:
1624 #if DEBUG_TRANSPORT
1625           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1626                       "Received message of type %u from `%4s'.\n",
1627                       ntohs (imm->type), GNUNET_i2s (&im->peer));
1628 #endif
1629           if (h->rec != NULL)
1630             h->rec (h->cls,
1631                     GNUNET_TIME_relative_ntoh (im->latency), &im->peer, imm);
1632           break;
1633         }
1634       break;
1635     default:
1636       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1637                   _
1638                   ("Received unexpected message of type %u in %s:%u\n"),
1639                   ntohs (msg->type), __FILE__, __LINE__);
1640       GNUNET_break (0);
1641       break;
1642     }
1643 }
1644
1645
1646 struct ClientTransmitWrapper
1647 {
1648   GNUNET_NETWORK_TransmitReadyNotify notify;
1649   void *notify_cls;
1650   struct GNUNET_TRANSPORT_TransmitHandle *th;
1651 };
1652
1653
1654 /**
1655  * Transmit message of a client destined for another
1656  * peer to the service.
1657  */
1658 static size_t
1659 client_notify_wrapper (void *cls, size_t size, void *buf)
1660 {
1661   struct ClientTransmitWrapper *ctw = cls;
1662   struct OutboundMessage *obm;
1663   struct GNUNET_MessageHeader *hdr;
1664   size_t ret;
1665
1666   if (size == 0)
1667     {
1668 #if DEBUG_TRANSPORT
1669       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1670                   "Transmission request could not be satisfied.\n");
1671 #endif
1672       ret = ctw->notify (ctw->notify_cls, 0, NULL);
1673       GNUNET_assert (ret == 0);
1674       GNUNET_free (ctw);
1675       return 0;
1676     }
1677   GNUNET_assert (size >= sizeof (struct OutboundMessage));
1678   obm = buf;
1679   ret = ctw->notify (ctw->notify_cls,
1680                      size - sizeof (struct OutboundMessage),
1681                      (void *) &obm[1]);
1682   if (ret == 0)
1683     {
1684       /* Need to reset flag, no SEND means no SEND_OK! */
1685       ctw->th->neighbour->transmit_ok = GNUNET_YES;
1686       GNUNET_free (ctw);
1687       return 0;
1688     }
1689   GNUNET_assert (ret >= sizeof (struct GNUNET_MessageHeader));
1690   hdr = (struct GNUNET_MessageHeader *) &obm[1];
1691   GNUNET_assert (ntohs (hdr->size) == ret);
1692   GNUNET_assert (ret + sizeof (struct OutboundMessage) <
1693                  GNUNET_SERVER_MAX_MESSAGE_SIZE);
1694 #if DEBUG_TRANSPORT
1695   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1696               "Transmitting `%s' message with data for `%4s'\n",
1697               "SEND", GNUNET_i2s (&ctw->th->target));
1698 #endif
1699   ret += sizeof (struct OutboundMessage);
1700   obm->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SEND);
1701   obm->header.size = htons (ret);
1702   obm->reserved = htonl (0);
1703   obm->peer = ctw->th->target;
1704   GNUNET_free (ctw);
1705   return ret;
1706 }
1707
1708
1709
1710 /**
1711  * Check if we could queue a message of the given size for
1712  * transmission.  The transport service will take both its
1713  * internal buffers and bandwidth limits imposed by the
1714  * other peer into consideration when answering this query.
1715  *
1716  * @param handle connection to transport service
1717  * @param target who should receive the message
1718  * @param size how big is the message we want to transmit?
1719  * @param timeout after how long should we give up (and call
1720  *        notify with buf NULL and size 0)?
1721  * @param notify function to call when we are ready to
1722  *        send such a message
1723  * @param notify_cls closure for notify
1724  * @return NULL if someone else is already waiting to be notified
1725  *         non-NULL if the notify callback was queued (can be used to cancel
1726  *         using GNUNET_TRANSPORT_notify_transmit_ready_cancel)
1727  */
1728 struct GNUNET_TRANSPORT_TransmitHandle *
1729 GNUNET_TRANSPORT_notify_transmit_ready (struct GNUNET_TRANSPORT_Handle
1730                                         *handle,
1731                                         const struct GNUNET_PeerIdentity
1732                                         *target, size_t size,
1733                                         struct GNUNET_TIME_Relative timeout,
1734                                         GNUNET_NETWORK_TransmitReadyNotify
1735                                         notify, void *notify_cls)
1736 {
1737   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1738   struct GNUNET_TRANSPORT_TransmitHandle *th;
1739   struct NeighbourList *n;
1740   struct ClientTransmitWrapper *ctw;
1741
1742   if (size + sizeof (struct OutboundMessage) >=
1743       GNUNET_SERVER_MAX_MESSAGE_SIZE)
1744     {
1745       GNUNET_break (0);
1746       return NULL;
1747     }
1748 #if DEBUG_TRANSPORT
1749   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1750               "Asking transport service for transmission of %u bytes to peer `%4s'.\n",
1751               size, GNUNET_i2s (target));
1752 #endif
1753   n = find_neighbour (handle, target);
1754   ctw = GNUNET_malloc (sizeof (struct ClientTransmitWrapper));
1755   th = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_TransmitHandle));
1756   ctw->notify = notify;
1757   ctw->notify_cls = notify_cls;
1758   ctw->th = th;
1759   th->handle = handle;
1760   th->target = *target;
1761   th->notify = &client_notify_wrapper;
1762   th->notify_cls = ctw;
1763   th->notify_size = size + sizeof (struct OutboundMessage);
1764   th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
1765   th->neighbour = n;
1766   if (NULL == n)
1767     {
1768       pos = handle->connect_wait_head;
1769       while (pos != NULL)
1770         {
1771           GNUNET_assert (0 != memcmp (target,
1772                                       &pos->target,
1773                                       sizeof (struct GNUNET_PeerIdentity)));
1774           pos = pos->next;
1775         }
1776 #if DEBUG_TRANSPORT
1777       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1778                   "Will now try to connect to `%4s'.\n", GNUNET_i2s (target));
1779 #endif
1780       try_connect (th);
1781       return th;
1782     }
1783
1784 #if DEBUG_TRANSPORT
1785   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1786               "Transmission request queued for transmission to transport service.\n");
1787 #endif
1788   GNUNET_assert (NULL == n->transmit_handle);
1789   n->transmit_handle = th;
1790   if (GNUNET_YES != n->received_ack)
1791     {
1792 #if DEBUG_TRANSPORT
1793       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1794                   "Connection to `%4s' is not yet confirmed connected, scheduling timeout (%llu ms) only.\n",
1795                   GNUNET_i2s (target), timeout.value);
1796 #endif
1797       th->notify_delay_task
1798         = GNUNET_SCHEDULER_add_delayed (handle->sched,
1799                                         GNUNET_NO,
1800                                         GNUNET_SCHEDULER_PRIORITY_KEEP,
1801                                         GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
1802                                         timeout, &transmit_timeout, th);
1803       return th;
1804     }
1805
1806 #if DEBUG_TRANSPORT
1807   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1808               "Peer `%4s' is ready to receive, scheduling message for delivery now.\n",
1809               GNUNET_i2s (target));
1810 #endif
1811   schedule_request (th);
1812   return th;
1813 }
1814
1815
1816 /**
1817  * Cancel the specified transmission-ready
1818  * notification.
1819  */
1820 void
1821 GNUNET_TRANSPORT_notify_transmit_ready_cancel (struct
1822                                                GNUNET_TRANSPORT_TransmitHandle
1823                                                *th)
1824 {
1825   struct GNUNET_TRANSPORT_Handle *h;
1826
1827 #if DEBUG_TRANSPORT
1828   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1829               "Transmission request of %u bytes to `%4s' was cancelled.\n",
1830               th->notify_size - sizeof(struct OutboundMessage),
1831               GNUNET_i2s (&th->target));
1832 #endif
1833   GNUNET_assert (th->notify == &client_notify_wrapper);
1834   remove_from_any_list (th);
1835   h = th->handle;
1836   if ((h->connect_ready_head == NULL) && (h->network_handle != NULL))
1837     {
1838       GNUNET_NETWORK_notify_transmit_ready_cancel (h->network_handle);
1839       h->network_handle = NULL;
1840       h->transmission_scheduled = GNUNET_NO;
1841     }
1842   GNUNET_free (th->notify_cls);
1843   GNUNET_free (th);
1844 }
1845
1846
1847 /* end of transport_api.c */