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