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21 * @file ats/ats_api_scheduling.c
22 * @brief automatic transport selection and outbound bandwidth determination
23 * @author Christian Grothoff
24 * @author Matthias Wachs
27 * - we could avoid a linear scan over the
28 * active addresses in some cases, so if
29 * there is need, we can still optimize here
30 * - we might want to split off the logic to
31 * determine LAN vs. WAN, as it has nothing
32 * to do with accessing the ATS service.
35 #include "gnunet_ats_service.h"
39 * How frequently do we scan the interfaces for changes to the addresses?
41 #define INTERFACE_PROCESSING_INTERVAL GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 2)
43 #define LOG(kind,...) GNUNET_log_from(kind, "ats-scheduling-api", __VA_ARGS__)
46 * Session ID we use if there is no session / slot.
52 * Information we track per address, incoming or outgoing. It also
53 * doesn't matter if we have a session, any address that ATS is
54 * allowed to suggest right now should be tracked.
56 struct GNUNET_ATS_AddressRecord
60 * Scheduling handle this address record belongs to.
62 struct GNUNET_ATS_SchedulingHandle *sh;
67 struct GNUNET_HELLO_Address *address;
70 * Session handle. NULL if we have an address but no
71 * active session for this address.
73 struct GNUNET_ATS_Session *session;
76 * Performance data about the address.
78 struct GNUNET_ATS_PropertiesNBO properties;
81 * Which slot (index) in the session array does
82 * this record correspond to?
83 * FIXME: a linear search on this is really crappy!
84 * Maybe switch to a 64-bit global counter and be
85 * done with it? Or does that then cause too much
86 * trouble on the ATS-service side?
91 * We're about to destroy this address record, just ATS does
92 * not know this yet. Once ATS confirms its destruction,
100 * Handle to the ATS subsystem for bandwidth/transport scheduling information.
102 struct GNUNET_ATS_SchedulingHandle
108 const struct GNUNET_CONFIGURATION_Handle *cfg;
111 * Callback to invoke on suggestions.
113 GNUNET_ATS_AddressSuggestionCallback suggest_cb;
116 * Closure for @e suggest_cb.
118 void *suggest_cb_cls;
121 * Message queue for sending requests to the ATS service.
123 struct GNUNET_MQ_Handle *mq;
126 * Array of session objects (we need to translate them to numbers and back
127 * for the protocol; the offset in the array is the session number on the
128 * network). Index 0 is always NULL and reserved to represent the NULL pointer.
129 * Unused entries are also NULL.
131 struct GNUNET_ATS_AddressRecord **session_array;
134 * Task to trigger reconnect.
136 struct GNUNET_SCHEDULER_Task *task;
139 * Reconnect backoff delay.
141 struct GNUNET_TIME_Relative backoff;
144 * Size of the @e session_array.
146 unsigned int session_array_size;
152 * Re-establish the connection to the ATS service.
154 * @param sh handle to use to re-connect.
157 reconnect (struct GNUNET_ATS_SchedulingHandle *sh);
161 * Re-establish the connection to the ATS service.
163 * @param cls handle to use to re-connect.
166 reconnect_task (void *cls)
168 struct GNUNET_ATS_SchedulingHandle *sh = cls;
176 * Disconnect from ATS and then reconnect.
178 * @param sh our handle
181 force_reconnect (struct GNUNET_ATS_SchedulingHandle *sh)
185 GNUNET_MQ_destroy (sh->mq);
188 sh->suggest_cb (sh->suggest_cb_cls,
190 GNUNET_BANDWIDTH_ZERO,
191 GNUNET_BANDWIDTH_ZERO);
192 sh->backoff = GNUNET_TIME_STD_BACKOFF (sh->backoff);
193 sh->task = GNUNET_SCHEDULER_add_delayed (sh->backoff,
200 * Find the session object corresponding to the given session ID.
202 * @param sh our handle
203 * @param session_id current session ID
204 * @param peer peer the session belongs to
205 * @return the session object (or NULL)
207 static struct GNUNET_ATS_AddressRecord *
208 find_session (struct GNUNET_ATS_SchedulingHandle *sh,
210 const struct GNUNET_PeerIdentity *peer)
212 struct GNUNET_ATS_AddressRecord *ar;
214 if (session_id >= sh->session_array_size)
221 ar = sh->session_array[session_id];
227 if (NULL == ar->address)
229 /* address was destroyed in the meantime, this can happen
230 as we communicate asynchronously with the ATS service. */
233 if (0 != memcmp (peer,
235 sizeof (struct GNUNET_PeerIdentity)))
245 * Get an available session ID.
247 * @param sh our handle
248 * @return an unused slot, but never NOT_FOUND (0)
251 find_empty_session_slot (struct GNUNET_ATS_SchedulingHandle *sh)
256 GNUNET_assert (0 != sh->session_array_size);
258 while ( ( (NOT_FOUND == off) ||
259 (NULL != sh->session_array[off % sh->session_array_size]) ) &&
260 (i < sh->session_array_size) )
265 if ( (NOT_FOUND != off % sh->session_array_size) &&
266 (NULL == sh->session_array[off % sh->session_array_size]) )
268 i = sh->session_array_size;
269 GNUNET_array_grow (sh->session_array,
270 sh->session_array_size,
271 sh->session_array_size * 2);
277 * Get the ID for the given session object.
279 * @param sh our handle
280 * @param session session object
281 * @param address the address we are looking for
282 * @return the session id or NOT_FOUND for error
285 find_session_id (struct GNUNET_ATS_SchedulingHandle *sh,
286 struct GNUNET_ATS_Session *session,
287 const struct GNUNET_HELLO_Address *address)
296 for (i = 1; i < sh->session_array_size; i++)
297 if ( (NULL != sh->session_array[i]) &&
298 (GNUNET_NO == sh->session_array[i]->in_destroy) &&
299 ( (session == sh->session_array[i]->session) ||
300 (NULL == sh->session_array[i]->session) ) &&
301 (0 == memcmp (&address->peer,
302 &sh->session_array[i]->address->peer,
303 sizeof (struct GNUNET_PeerIdentity))) &&
304 (0 == GNUNET_HELLO_address_cmp (address,
305 sh->session_array[i]->address)) )
312 * Release the session slot from the session table (ATS service is
313 * also done using it).
315 * @param sh our handle
316 * @param session_id identifies session that is no longer valid
319 release_session (struct GNUNET_ATS_SchedulingHandle *sh,
322 struct GNUNET_ATS_AddressRecord *ar;
324 if (NOT_FOUND == session_id)
326 if (session_id >= sh->session_array_size)
329 force_reconnect (sh);
332 /* this slot should have been removed from remove_session before */
333 ar = sh->session_array[session_id];
334 if (NULL != ar->session)
337 force_reconnect (sh);
340 GNUNET_HELLO_address_free (ar->address);
342 sh->session_array[session_id] = NULL;
347 * Type of a function to call when we receive a session release
348 * message from the service.
350 * @param cls the `struct GNUNET_ATS_SchedulingHandle`
351 * @param srm message received
354 handle_ats_session_release (void *cls,
355 const struct GNUNET_ATS_SessionReleaseMessage *srm)
357 struct GNUNET_ATS_SchedulingHandle *sh = cls;
359 /* Note: peer field in srm not necessary right now,
360 but might be good to have in the future */
362 ntohl (srm->session_id));
367 * Type of a function to call when we receive a address suggestion
368 * message from the service.
370 * @param cls the `struct GNUNET_ATS_SchedulingHandle`
371 * @param m message received
374 handle_ats_address_suggestion (void *cls,
375 const struct AddressSuggestionMessage *m)
377 struct GNUNET_ATS_SchedulingHandle *sh = cls;
378 struct GNUNET_ATS_AddressRecord *ar;
381 session_id = ntohl (m->session_id);
385 force_reconnect (sh);
388 ar = find_session (sh,
394 force_reconnect (sh);
397 if (NULL == sh->suggest_cb)
399 if (GNUNET_YES == ar->in_destroy)
401 /* ignore suggestion, as this address is dying, unless BW is 0,
402 in that case signal 'disconnect' via BW 0 */
403 if ( (0 == ntohl (m->bandwidth_out.value__)) &&
404 (0 == ntohl (m->bandwidth_in.value__)) )
406 LOG (GNUNET_ERROR_TYPE_DEBUG,
407 "ATS suggests disconnect from peer `%s' with BW %u/%u\n",
408 GNUNET_i2s (&ar->address->peer),
409 (unsigned int) ntohl (m->bandwidth_out.value__),
410 (unsigned int) ntohl (m->bandwidth_in.value__));
411 sh->suggest_cb (sh->suggest_cb_cls,
420 if ( (NULL == ar->session) &&
421 (GNUNET_HELLO_address_check_option (ar->address,
422 GNUNET_HELLO_ADDRESS_INFO_INBOUND)) )
427 sh->backoff = GNUNET_TIME_UNIT_ZERO;
428 LOG (GNUNET_ERROR_TYPE_DEBUG,
429 "ATS suggests address slot %u for peer `%s' using plugin %s\n",
431 GNUNET_i2s (&ar->address->peer),
432 ar->address->transport_name);
433 sh->suggest_cb (sh->suggest_cb_cls,
443 * We encountered an error handling the MQ to the
444 * ATS service. Reconnect.
446 * @param cls the `struct GNUNET_ATS_SchedulingHandle`
447 * @param error details about the error
450 error_handler (void *cls,
451 enum GNUNET_MQ_Error error)
453 struct GNUNET_ATS_SchedulingHandle *sh = cls;
455 LOG (GNUNET_ERROR_TYPE_DEBUG,
456 "ATS connection died (code %d), reconnecting\n",
458 force_reconnect (sh);
463 * Generate and transmit the `struct AddressAddMessage` for the given
466 * @param sh the scheduling handle to use for transmission
467 * @param ar the address to inform the ATS service about
470 send_add_address_message (struct GNUNET_ATS_SchedulingHandle *sh,
471 const struct GNUNET_ATS_AddressRecord *ar)
473 struct GNUNET_MQ_Envelope *ev;
474 struct AddressAddMessage *m;
480 return; /* disconnected, skip for now */
481 GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != ar->properties.scope);
482 namelen = strlen (ar->address->transport_name) + 1;
483 msize = ar->address->address_length + namelen;
484 ev = GNUNET_MQ_msg_extra (m, msize, GNUNET_MESSAGE_TYPE_ATS_ADDRESS_ADD);
485 m->peer = ar->address->peer;
486 m->address_length = htons (ar->address->address_length);
487 m->address_local_info = htonl ((uint32_t) ar->address->local_info);
488 m->plugin_name_length = htons (namelen);
489 m->session_id = htonl (ar->slot);
490 m->properties = ar->properties;
492 LOG (GNUNET_ERROR_TYPE_DEBUG,
493 "Adding address for peer `%s', plugin `%s', session %p slot %u\n",
494 GNUNET_i2s (&ar->address->peer),
495 ar->address->transport_name,
500 ar->address->address,
501 ar->address->address_length);
502 if (NULL != ar->address->transport_name)
503 GNUNET_memcpy (&pm[ar->address->address_length],
504 ar->address->transport_name,
506 GNUNET_MQ_send (sh->mq, ev);
511 * Re-establish the connection to the ATS service.
513 * @param sh handle to use to re-connect.
516 reconnect (struct GNUNET_ATS_SchedulingHandle *sh)
518 struct GNUNET_MQ_MessageHandler handlers[] = {
519 GNUNET_MQ_hd_fixed_size (ats_session_release,
520 GNUNET_MESSAGE_TYPE_ATS_SESSION_RELEASE,
521 struct GNUNET_ATS_SessionReleaseMessage,
523 GNUNET_MQ_hd_fixed_size (ats_address_suggestion,
524 GNUNET_MESSAGE_TYPE_ATS_ADDRESS_SUGGESTION,
525 struct AddressSuggestionMessage,
527 GNUNET_MQ_handler_end ()
529 struct GNUNET_MQ_Envelope *ev;
530 struct ClientStartMessage *init;
532 struct GNUNET_ATS_AddressRecord *ar;
534 GNUNET_assert (NULL == sh->mq);
535 sh->mq = GNUNET_CLIENT_connecT (sh->cfg,
543 force_reconnect (sh);
546 ev = GNUNET_MQ_msg (init,
547 GNUNET_MESSAGE_TYPE_ATS_START);
548 init->start_flag = htonl (START_FLAG_SCHEDULING);
549 GNUNET_MQ_send (sh->mq, ev);
552 for (i=0;i<sh->session_array_size;i++)
554 ar = sh->session_array[i];
557 send_add_address_message (sh, ar);
565 * Initialize the ATS subsystem.
567 * @param cfg configuration to use
568 * @param suggest_cb notification to call whenever the suggestation changed
569 * @param suggest_cb_cls closure for @a suggest_cb
570 * @return ats context
572 struct GNUNET_ATS_SchedulingHandle *
573 GNUNET_ATS_scheduling_init (const struct GNUNET_CONFIGURATION_Handle *cfg,
574 GNUNET_ATS_AddressSuggestionCallback suggest_cb,
575 void *suggest_cb_cls)
577 struct GNUNET_ATS_SchedulingHandle *sh;
579 sh = GNUNET_new (struct GNUNET_ATS_SchedulingHandle);
581 sh->suggest_cb = suggest_cb;
582 sh->suggest_cb_cls = suggest_cb_cls;
583 GNUNET_array_grow (sh->session_array,
584 sh->session_array_size,
592 * Client is done with ATS scheduling, release resources.
594 * @param sh handle to release
597 GNUNET_ATS_scheduling_done (struct GNUNET_ATS_SchedulingHandle *sh)
599 struct GNUNET_ATS_AddressRecord *ar;
604 GNUNET_MQ_destroy (sh->mq);
607 if (NULL != sh->task)
609 GNUNET_SCHEDULER_cancel (sh->task);
612 for (i=0;i<sh->session_array_size;i++)
614 if (NULL != (ar = sh->session_array[i]))
616 GNUNET_HELLO_address_free (ar->address);
618 sh->session_array[i] = NULL;
621 GNUNET_array_grow (sh->session_array,
622 sh->session_array_size,
629 * We have a new address ATS should know. Addresses have to be added
630 * with this function before they can be: updated, set in use and
634 * @param address the address
635 * @param session session handle, can be NULL
636 * @param prop performance data for the address
637 * @return handle to the address representation inside ATS, NULL
638 * on error (i.e. ATS knows this exact address already)
640 struct GNUNET_ATS_AddressRecord *
641 GNUNET_ATS_address_add (struct GNUNET_ATS_SchedulingHandle *sh,
642 const struct GNUNET_HELLO_Address *address,
643 struct GNUNET_ATS_Session *session,
644 const struct GNUNET_ATS_Properties *prop)
646 struct GNUNET_ATS_AddressRecord *ar;
653 /* we need a valid address */
657 GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != prop->scope);
658 namelen = strlen (address->transport_name) + 1;
659 msize = address->address_length + namelen;
660 if ((msize + sizeof (struct AddressUpdateMessage) >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
661 (address->address_length >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
662 (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE) )
664 /* address too large for us, this should not happen */
674 /* Already existing, nothing todo, but this should not happen */
678 s = find_empty_session_slot (sh);
679 ar = GNUNET_new (struct GNUNET_ATS_AddressRecord);
682 ar->session = session;
683 ar->address = GNUNET_HELLO_address_copy (address);
684 GNUNET_ATS_properties_hton (&ar->properties,
686 sh->session_array[s] = ar;
687 send_add_address_message (sh, ar);
693 * An address was used to initiate a session.
695 * @param ar address record to update information for
696 * @param session session handle
699 GNUNET_ATS_address_add_session (struct GNUNET_ATS_AddressRecord *ar,
700 struct GNUNET_ATS_Session *session)
702 GNUNET_break (NULL == ar->session);
703 ar->session = session;
708 * A session was destroyed, disassociate it from the
709 * given address record. If this was an incoming
710 * addess, destroy the address as well.
712 * @param ar address record to update information for
713 * @param session session handle
714 * @return #GNUNET_YES if the @a ar was destroyed because
715 * it was an incoming address,
716 * #GNUNET_NO if the @ar was kept because we can
717 * use it still to establish a new session
720 GNUNET_ATS_address_del_session (struct GNUNET_ATS_AddressRecord *ar,
721 struct GNUNET_ATS_Session *session)
723 GNUNET_assert (session == ar->session);
725 if (GNUNET_HELLO_address_check_option (ar->address,
726 GNUNET_HELLO_ADDRESS_INFO_INBOUND))
728 GNUNET_ATS_address_destroy (ar);
736 * We have updated performance statistics for a given address. Note
737 * that this function can be called for addresses that are currently
738 * in use as well as addresses that are valid but not actively in use.
739 * Furthermore, the peer may not even be connected to us right now (in
740 * which case the call may be ignored or the information may be stored
741 * for later use). Update bandwidth assignments.
743 * @param ar address record to update information for
744 * @param prop performance data for the address
747 GNUNET_ATS_address_update (struct GNUNET_ATS_AddressRecord *ar,
748 const struct GNUNET_ATS_Properties *prop)
750 struct GNUNET_ATS_SchedulingHandle *sh = ar->sh;
751 struct GNUNET_MQ_Envelope *ev;
752 struct AddressUpdateMessage *m;
754 LOG (GNUNET_ERROR_TYPE_DEBUG,
755 "Updating address for peer `%s', plugin `%s', session %p slot %u\n",
756 GNUNET_i2s (&ar->address->peer),
757 ar->address->transport_name,
760 GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != prop->scope);
761 GNUNET_ATS_properties_hton (&ar->properties,
764 return; /* disconnected, skip for now */
765 ev = GNUNET_MQ_msg (m, GNUNET_MESSAGE_TYPE_ATS_ADDRESS_UPDATE);
766 m->session_id = htonl (ar->slot);
767 m->peer = ar->address->peer;
768 m->properties = ar->properties;
769 GNUNET_MQ_send (sh->mq,
775 * An address got destroyed, stop using it as a valid address.
777 * @param ar address to destroy
780 GNUNET_ATS_address_destroy (struct GNUNET_ATS_AddressRecord *ar)
782 struct GNUNET_ATS_SchedulingHandle *sh = ar->sh;
783 struct GNUNET_MQ_Envelope *ev;
784 struct AddressDestroyedMessage *m;
786 LOG (GNUNET_ERROR_TYPE_DEBUG,
787 "Deleting address for peer `%s', plugin `%s', slot %u session %p\n",
788 GNUNET_i2s (&ar->address->peer),
789 ar->address->transport_name,
792 GNUNET_break (NULL == ar->session);
794 ar->in_destroy = GNUNET_YES;
797 ev = GNUNET_MQ_msg (m, GNUNET_MESSAGE_TYPE_ATS_ADDRESS_DESTROYED);
798 m->session_id = htonl (ar->slot);
799 m->peer = ar->address->peer;
800 GNUNET_MQ_send (sh->mq, ev);
804 /* end of ats_api_scheduling.c */