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3 (C) 2010,2011 Christian Grothoff (and other contributing authors)
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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 #include "gnunet_ats_service.h"
30 #define DEBUG_ATS GNUNET_EXTRA_LOGGING
33 * Message in linked list we should send to the ATS service. The
34 * actual binary message follows this struct.
42 struct PendingMessage *next;
47 struct PendingMessage *prev;
50 * Size of the message.
55 * Is this the 'ATS_START' message?
62 * Information we track per session.
67 * Identity of the peer (just needed for error checking).
69 struct GNUNET_PeerIdentity peer;
74 struct Session *session;
77 * Set to GNUNET_YES if the slot is used.
84 * Handle to the ATS subsystem for bandwidth/transport scheduling information.
86 struct GNUNET_ATS_SchedulingHandle
92 const struct GNUNET_CONFIGURATION_Handle *cfg;
95 * Callback to invoke on suggestions.
97 GNUNET_ATS_AddressSuggestionCallback suggest_cb;
100 * Closure for 'suggest_cb'.
102 void *suggest_cb_cls;
105 * Connection to ATS service.
107 struct GNUNET_CLIENT_Connection *client;
110 * Head of list of messages for the ATS service.
112 struct PendingMessage *pending_head;
115 * Tail of list of messages for the ATS service
117 struct PendingMessage *pending_tail;
120 * Current request for transmission to ATS.
122 struct GNUNET_CLIENT_TransmitHandle *th;
125 * Array of session objects (we need to translate them to numbers and back
126 * for the protocol; the offset in the array is the session number on the
127 * network). Index 0 is always NULL and reserved to represent the NULL pointer.
128 * Unused entries are also NULL.
130 struct SessionRecord *session_array;
133 * Task to trigger reconnect.
135 GNUNET_SCHEDULER_TaskIdentifier task;
138 * Size of the session array.
140 unsigned int session_array_size;
143 * Should we reconnect to ATS due to some serious error?
150 * Re-establish the connection to the ATS service.
152 * @param sh handle to use to re-connect.
155 reconnect (struct GNUNET_ATS_SchedulingHandle *sh);
159 * Re-establish the connection to the ATS service.
161 * @param cls handle to use to re-connect.
162 * @param tc scheduler context
165 reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
167 struct GNUNET_ATS_SchedulingHandle *sh = cls;
169 sh->task = GNUNET_SCHEDULER_NO_TASK;
175 * Disconnect from ATS and then reconnect.
177 * @param sh our handle
180 force_reconnect (struct GNUNET_ATS_SchedulingHandle *sh)
182 sh->reconnect = GNUNET_NO;
183 GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
186 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, &reconnect_task,
192 * Transmit messages from the message queue to the service
193 * (if there are any, and if we are not already trying).
195 * @param sh handle to use
198 do_transmit (struct GNUNET_ATS_SchedulingHandle *sh);
202 * Type of a function to call when we receive a message
205 * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
206 * @param msg message received, NULL on timeout or fatal error
209 process_ats_message (void *cls, const struct GNUNET_MessageHeader *msg);
213 * We can now transmit a message to ATS. Do it.
215 * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
216 * @param size number of bytes we can transmit to ATS
217 * @param buf where to copy the messages
218 * @return number of bytes copied into buf
221 transmit_message_to_ats (void *cls, size_t size, void *buf)
223 struct GNUNET_ATS_SchedulingHandle *sh = cls;
224 struct PendingMessage *p;
229 if ((size == 0) || (buf == NULL))
231 force_reconnect (sh);
236 while ((NULL != (p = sh->pending_head)) && (p->size <= size))
238 memcpy (&cbuf[ret], &p[1], p->size);
241 GNUNET_CONTAINER_DLL_remove (sh->pending_head, sh->pending_tail, p);
242 if (GNUNET_YES == p->is_init)
243 GNUNET_CLIENT_receive (sh->client, &process_ats_message, sh,
244 GNUNET_TIME_UNIT_FOREVER_REL);
253 * Transmit messages from the message queue to the service
254 * (if there are any, and if we are not already trying).
256 * @param sh handle to use
259 do_transmit (struct GNUNET_ATS_SchedulingHandle *sh)
261 struct PendingMessage *p;
265 if (NULL == (p = sh->pending_head))
267 if (NULL == sh->client)
268 return; /* currently reconnecting */
270 GNUNET_CLIENT_notify_transmit_ready (sh->client, p->size,
271 GNUNET_TIME_UNIT_FOREVER_REL,
272 GNUNET_NO, &transmit_message_to_ats,
278 * Find the session object corresponding to the given session ID.
280 * @param sh our handle
281 * @param session_id current session ID
282 * @param peer peer the session belongs to
283 * @return the session object (or NULL)
285 static struct Session *
286 find_session (struct GNUNET_ATS_SchedulingHandle *sh, uint32_t session_id,
287 const struct GNUNET_PeerIdentity *peer)
290 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Find session %u from peer %s in %p\n",
291 (unsigned int) session_id, GNUNET_i2s (peer), sh);
293 if (session_id >= sh->session_array_size)
300 if (sh->session_array[session_id].session == NULL)
303 memcmp (peer, &sh->session_array[session_id].peer,
304 sizeof (struct GNUNET_PeerIdentity)));
309 memcmp (peer, &sh->session_array[session_id].peer,
310 sizeof (struct GNUNET_PeerIdentity)))
313 sh->reconnect = GNUNET_YES;
316 return sh->session_array[session_id].session;
321 * Get the ID for the given session object. If we do not have an ID for
322 * the given session object, allocate one.
324 * @param sh our handle
325 * @param session session object
326 * @param peer peer the session belongs to
327 * @return the session id
330 get_session_id (struct GNUNET_ATS_SchedulingHandle *sh, struct Session *session,
331 const struct GNUNET_PeerIdentity *peer)
337 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
338 "Get session ID for session %p from peer %s in %p\n", session,
339 GNUNET_i2s (peer), sh);
344 for (i = 1; i < sh->session_array_size; i++)
346 if (session == sh->session_array[i].session)
349 memcmp (peer, &sh->session_array[i].peer,
350 sizeof (struct GNUNET_PeerIdentity)));
353 if ((f == 0) && (sh->session_array[i].slot_used == GNUNET_NO))
358 f = sh->session_array_size;
359 GNUNET_array_grow (sh->session_array, sh->session_array_size,
360 sh->session_array_size * 2);
362 GNUNET_assert (f > 0);
363 sh->session_array[f].session = session;
364 sh->session_array[f].peer = *peer;
365 sh->session_array[f].slot_used = GNUNET_YES;
367 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
368 "Assigning session ID %u for session %p of peer %s in %p\n", f,
369 session, GNUNET_i2s (peer), sh);
376 * Remove the session of the given session ID from the session
377 * table (it is no longer valid).
379 * @param sh our handle
380 * @param session_id identifies session that is no longer valid
381 * @param peer peer the session belongs to
384 remove_session (struct GNUNET_ATS_SchedulingHandle *sh, uint32_t session_id,
385 const struct GNUNET_PeerIdentity *peer)
388 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
389 "Remove sessionID %u from peer %s in %p\n",
390 (unsigned int) session_id, GNUNET_i2s (peer), sh);
394 GNUNET_assert (session_id < sh->session_array_size);
395 GNUNET_assert (GNUNET_YES == sh->session_array[session_id].slot_used);
397 memcmp (peer, &sh->session_array[session_id].peer,
398 sizeof (struct GNUNET_PeerIdentity)));
399 sh->session_array[session_id].session = NULL;
404 * Release the session slot from the session table (ATS service is
405 * also done using it).
407 * @param sh our handle
408 * @param session_id identifies session that is no longer valid
409 * @param peer peer the session belongs to
412 release_session (struct GNUNET_ATS_SchedulingHandle *sh, uint32_t session_id,
413 const struct GNUNET_PeerIdentity *peer)
416 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
417 "Release sessionID %u from peer %s in %p\n",
418 (unsigned int) session_id, GNUNET_i2s (peer), sh);
420 if (session_id >= sh->session_array_size)
423 sh->reconnect = GNUNET_YES;
427 /* this slot should have been removed from remove_session before */
428 GNUNET_assert (sh->session_array[session_id].session == NULL);
431 memcmp (peer, &sh->session_array[session_id].peer,
432 sizeof (struct GNUNET_PeerIdentity)))
435 sh->reconnect = GNUNET_YES;
438 sh->session_array[session_id].slot_used = GNUNET_NO;
439 memset (&sh->session_array[session_id].peer, 0,
440 sizeof (struct GNUNET_PeerIdentity));
445 process_release_message (struct GNUNET_ATS_SchedulingHandle *sh,
446 const struct SessionReleaseMessage *srm)
448 release_session (sh, ntohl (srm->session_id), &srm->peer);
453 * Type of a function to call when we receive a message
456 * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
457 * @param msg message received, NULL on timeout or fatal error
460 process_ats_message (void *cls, const struct GNUNET_MessageHeader *msg)
462 struct GNUNET_ATS_SchedulingHandle *sh = cls;
463 const struct AddressSuggestionMessage *m;
464 const struct GNUNET_ATS_Information *atsi;
465 const char *plugin_address;
466 const char *plugin_name;
467 uint16_t plugin_address_length;
468 uint16_t plugin_name_length;
470 struct GNUNET_HELLO_Address address;
475 force_reconnect (sh);
478 if ((ntohs (msg->type) == GNUNET_MESSAGE_TYPE_ATS_SESSION_RELEASE) &&
479 (ntohs (msg->size) == sizeof (struct SessionReleaseMessage)))
481 process_release_message (sh, (const struct SessionReleaseMessage *) msg);
482 GNUNET_CLIENT_receive (sh->client, &process_ats_message, sh,
483 GNUNET_TIME_UNIT_FOREVER_REL);
484 if (GNUNET_YES == sh->reconnect)
485 force_reconnect (sh);
488 if ((ntohs (msg->type) != GNUNET_MESSAGE_TYPE_ATS_ADDRESS_SUGGESTION) ||
489 (ntohs (msg->size) <= sizeof (struct AddressSuggestionMessage)))
492 force_reconnect (sh);
495 m = (const struct AddressSuggestionMessage *) msg;
496 ats_count = ntohl (m->ats_count);
497 plugin_address_length = ntohs (m->address_length);
498 atsi = (const struct GNUNET_ATS_Information *) &m[1];
499 plugin_address = (const char *) &atsi[ats_count];
500 plugin_name = &plugin_address[plugin_address_length];
501 plugin_name_length = ntohs (m->plugin_name_length);
502 if ((plugin_address_length + plugin_name_length +
503 ats_count * sizeof (struct GNUNET_ATS_Information) +
504 sizeof (struct AddressSuggestionMessage) != ntohs (msg->size)) ||
506 GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_ATS_Information))
507 || (plugin_name[plugin_name_length - 1] != '\0'))
510 force_reconnect (sh);
513 uint32_t session_id = ntohl (m->session_id);
519 s = find_session (sh, session_id, &m->peer);
523 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
524 "ATS tries to use outdated session `%s'\n",
525 GNUNET_i2s (&m->peer));
527 GNUNET_CLIENT_receive (sh->client, &process_ats_message, sh,
528 GNUNET_TIME_UNIT_FOREVER_REL);
532 address.peer = m->peer;
533 address.address = plugin_address;
534 address.address_length = plugin_address_length;
535 address.transport_name = plugin_name;
537 if ((s == NULL) && (0 == address.address_length))
539 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
540 "ATS returned invalid address for peer `%s' transport `%s' address length %i, session_id %i\n",
541 GNUNET_i2s (&address.peer), address.transport_name,
542 plugin_address_length, session_id);
544 GNUNET_CLIENT_receive (sh->client, &process_ats_message, sh,
545 GNUNET_TIME_UNIT_FOREVER_REL);
549 sh->suggest_cb (sh->suggest_cb_cls, &address, s, m->bandwidth_out,
550 m->bandwidth_in, atsi, ats_count);
552 GNUNET_CLIENT_receive (sh->client, &process_ats_message, sh,
553 GNUNET_TIME_UNIT_FOREVER_REL);
554 if (GNUNET_YES == sh->reconnect)
555 force_reconnect (sh);
560 * Re-establish the connection to the ATS service.
562 * @param sh handle to use to re-connect.
565 reconnect (struct GNUNET_ATS_SchedulingHandle *sh)
567 struct PendingMessage *p;
568 struct ClientStartMessage *init;
570 GNUNET_assert (NULL == sh->client);
571 sh->client = GNUNET_CLIENT_connect ("ats", sh->cfg);
572 GNUNET_assert (NULL != sh->client);
573 if ((NULL == (p = sh->pending_head)) || (GNUNET_YES != p->is_init))
575 p = GNUNET_malloc (sizeof (struct PendingMessage) +
576 sizeof (struct ClientStartMessage));
577 p->size = sizeof (struct ClientStartMessage);
578 p->is_init = GNUNET_YES;
579 init = (struct ClientStartMessage *) &p[1];
580 init->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_START);
581 init->header.size = htons (sizeof (struct ClientStartMessage));
582 init->start_flag = htonl (START_FLAG_SCHEDULING);
583 GNUNET_CONTAINER_DLL_insert (sh->pending_head, sh->pending_tail, p);
590 * Initialize the ATS subsystem.
592 * @param cfg configuration to use
593 * @param suggest_cb notification to call whenever the suggestation changed
594 * @param suggest_cb_cls closure for 'suggest_cb'
595 * @return ats context
597 struct GNUNET_ATS_SchedulingHandle *
598 GNUNET_ATS_scheduling_init (const struct GNUNET_CONFIGURATION_Handle *cfg,
599 GNUNET_ATS_AddressSuggestionCallback suggest_cb,
600 void *suggest_cb_cls)
602 struct GNUNET_ATS_SchedulingHandle *sh;
604 sh = GNUNET_malloc (sizeof (struct GNUNET_ATS_SchedulingHandle));
606 sh->suggest_cb = suggest_cb;
607 sh->suggest_cb_cls = suggest_cb_cls;
608 GNUNET_array_grow (sh->session_array, sh->session_array_size, 4);
615 * Client is done with ATS scheduling, release resources.
617 * @param sh handle to release
620 GNUNET_ATS_scheduling_done (struct GNUNET_ATS_SchedulingHandle *sh)
622 struct PendingMessage *p;
624 while (NULL != (p = sh->pending_head))
626 GNUNET_CONTAINER_DLL_remove (sh->pending_head, sh->pending_tail, p);
629 if (NULL != sh->client)
631 GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
634 if (GNUNET_SCHEDULER_NO_TASK != sh->task)
636 GNUNET_SCHEDULER_cancel (sh->task);
637 sh->task = GNUNET_SCHEDULER_NO_TASK;
639 GNUNET_array_grow (sh->session_array, sh->session_array_size, 0);
645 * We would like to establish a new connection with a peer. ATS
646 * should suggest a good address to begin with.
649 * @param peer identity of the peer we need an address for
652 GNUNET_ATS_suggest_address (struct GNUNET_ATS_SchedulingHandle *sh,
653 const struct GNUNET_PeerIdentity *peer)
655 struct PendingMessage *p;
656 struct RequestAddressMessage *m;
658 p = GNUNET_malloc (sizeof (struct PendingMessage) +
659 sizeof (struct RequestAddressMessage));
660 p->size = sizeof (struct RequestAddressMessage);
661 p->is_init = GNUNET_NO;
662 m = (struct RequestAddressMessage *) &p[1];
663 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_REQUEST_ADDRESS);
664 m->header.size = htons (sizeof (struct RequestAddressMessage));
665 m->reserved = htonl (0);
667 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head, sh->pending_tail, p);
673 * We would like to stop receiving address updates for this peer
676 * @param peer identity of the peer
679 GNUNET_ATS_suggest_address_cancel (struct GNUNET_ATS_SchedulingHandle *sh,
680 const struct GNUNET_PeerIdentity *peer)
682 struct PendingMessage *p;
683 struct RequestAddressMessage *m;
685 p = GNUNET_malloc (sizeof (struct PendingMessage) +
686 sizeof (struct RequestAddressMessage));
687 p->size = sizeof (struct RequestAddressMessage);
688 p->is_init = GNUNET_NO;
689 m = (struct RequestAddressMessage *) &p[1];
690 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_REQUEST_ADDRESS_CANCEL);
691 m->header.size = htons (sizeof (struct RequestAddressMessage));
692 m->reserved = htonl (0);
694 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head, sh->pending_tail, p);
699 * We have updated performance statistics for a given address. Note
700 * that this function can be called for addresses that are currently
701 * in use as well as addresses that are valid but not actively in use.
702 * Furthermore, the peer may not even be connected to us right now (in
703 * which case the call may be ignored or the information may be stored
704 * for later use). Update bandwidth assignments.
707 * @param address the address
708 * @param session session handle (if available)
709 * @param ats performance data for the address
710 * @param ats_count number of performance records in 'ats'
713 GNUNET_ATS_address_update (struct GNUNET_ATS_SchedulingHandle *sh,
714 const struct GNUNET_HELLO_Address *address,
715 struct Session *session,
716 const struct GNUNET_ATS_Information *ats,
719 struct PendingMessage *p;
720 struct AddressUpdateMessage *m;
721 struct GNUNET_ATS_Information *am;
727 (address->transport_name ==
728 NULL) ? 0 : strlen (address->transport_name) + 1;
730 sizeof (struct AddressUpdateMessage) + address->address_length +
731 ats_count * sizeof (struct GNUNET_ATS_Information) + namelen;
732 if ((msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
733 (address->address_length >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
734 (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
736 GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_ATS_Information)))
742 p = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
744 p->is_init = GNUNET_NO;
745 m = (struct AddressUpdateMessage *) &p[1];
746 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_ADDRESS_UPDATE);
747 m->header.size = htons (msize);
748 m->ats_count = htonl (ats_count);
749 m->peer = address->peer;
750 m->address_length = htons (address->address_length);
751 m->plugin_name_length = htons (namelen);
752 m->session_id = htonl (get_session_id (sh, session, &address->peer));
753 am = (struct GNUNET_ATS_Information *) &m[1];
754 memcpy (am, ats, ats_count * sizeof (struct GNUNET_ATS_Information));
755 pm = (char *) &am[ats_count];
756 memcpy (pm, address->address, address->address_length);
757 memcpy (&pm[address->address_length], address->transport_name, namelen);
758 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head, sh->pending_tail, p);
764 * An address is now in use or not used any more.
767 * @param address the address
768 * @param session session handle
769 * @param in_use GNUNET_YES if this address is now used, GNUNET_NO
770 * if address is not used any more
773 GNUNET_ATS_address_in_use (struct GNUNET_ATS_SchedulingHandle *sh,
774 const struct GNUNET_HELLO_Address *address,
775 struct Session *session, int in_use)
777 struct PendingMessage *p;
778 struct AddressUseMessage *m;
783 GNUNET_assert (NULL != address);
785 (address->transport_name ==
786 NULL) ? 0 : strlen (address->transport_name) + 1;
787 msize = sizeof (struct AddressUseMessage) + address->address_length + namelen;
788 if ((msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
789 (address->address_length >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
790 (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE))
796 p = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
798 p->is_init = GNUNET_NO;
799 m = (struct AddressUseMessage *) &p[1];
800 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_ADDRESS_IN_USE);
801 m->header.size = htons (msize);
802 m->peer = address->peer;
803 m->in_use = htons (in_use);
804 m->address_length = htons (address->address_length);
805 m->plugin_name_length = htons (namelen);
806 m->session_id = htonl (get_session_id (sh, session, &address->peer));
808 memcpy (pm, address->address, address->address_length);
809 memcpy (&pm[address->address_length], address->transport_name, namelen);
810 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head, sh->pending_tail, p);
816 * A session got destroyed, stop including it as a valid address.
819 * @param address the address
820 * @param session session handle that is no longer valid
823 GNUNET_ATS_address_destroyed (struct GNUNET_ATS_SchedulingHandle *sh,
824 const struct GNUNET_HELLO_Address *address,
825 struct Session *session)
827 struct PendingMessage *p;
828 struct AddressDestroyedMessage *m;
834 GNUNET_assert (address->transport_name != NULL);
835 namelen = strlen (address->transport_name) + 1;
836 GNUNET_assert (namelen > 1);
838 sizeof (struct AddressDestroyedMessage) + address->address_length +
840 if ((msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
841 (address->address_length >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
842 (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE))
848 p = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
850 p->is_init = GNUNET_NO;
851 m = (struct AddressDestroyedMessage *) &p[1];
852 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_ADDRESS_DESTROYED);
853 m->header.size = htons (msize);
854 m->reserved = htonl (0);
855 m->peer = address->peer;
856 m->address_length = htons (address->address_length);
857 m->plugin_name_length = htons (namelen);
858 session_id = get_session_id (sh, session, &address->peer);
859 m->session_id = htonl (session_id);
861 memcpy (pm, address->address, address->address_length);
862 memcpy (&pm[address->address_length], address->transport_name, namelen);
863 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head, sh->pending_tail, p);
865 remove_session (sh, session_id, &address->peer);
868 /* end of ats_api_scheduling.c */