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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"
32 * Message in linked list we should send to the ATS service. The
33 * actual binary message follows this struct.
41 struct PendingMessage *next;
46 struct PendingMessage *prev;
49 * Size of the message.
54 * Is this the 'ATS_START' message?
61 * Information we track per session.
66 * Identity of the peer (just needed for error checking).
68 struct GNUNET_PeerIdentity peer;
73 struct Session *session;
76 * Set to GNUNET_YES if the slot is used.
83 * Handle to the ATS subsystem for bandwidth/transport scheduling information.
85 struct GNUNET_ATS_SchedulingHandle
91 const struct GNUNET_CONFIGURATION_Handle *cfg;
94 * Callback to invoke on suggestions.
96 GNUNET_ATS_AddressSuggestionCallback suggest_cb;
99 * Closure for 'suggest_cb'.
101 void *suggest_cb_cls;
104 * Connection to ATS service.
106 struct GNUNET_CLIENT_Connection *client;
109 * Head of list of messages for the ATS service.
111 struct PendingMessage *pending_head;
114 * Tail of list of messages for the ATS service
116 struct PendingMessage *pending_tail;
119 * Current request for transmission to ATS.
121 struct GNUNET_CLIENT_TransmitHandle *th;
124 * Array of session objects (we need to translate them to numbers and back
125 * for the protocol; the offset in the array is the session number on the
126 * network). Index 0 is always NULL and reserved to represent the NULL pointer.
127 * Unused entries are also NULL.
129 struct SessionRecord *session_array;
132 * Task to trigger reconnect.
134 GNUNET_SCHEDULER_TaskIdentifier task;
137 * Size of the session array.
139 unsigned int session_array_size;
142 * Should we reconnect to ATS due to some serious error?
149 * Re-establish the connection to the ATS service.
151 * @param sh handle to use to re-connect.
154 reconnect (struct GNUNET_ATS_SchedulingHandle *sh);
158 * Re-establish the connection to the ATS service.
160 * @param cls handle to use to re-connect.
161 * @param tc scheduler context
164 reconnect_task (void *cls,
165 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);
185 sh->task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
186 &reconnect_task, sh);
191 * Transmit messages from the message queue to the service
192 * (if there are any, and if we are not already trying).
194 * @param sh handle to use
197 do_transmit (struct GNUNET_ATS_SchedulingHandle *sh);
201 * Type of a function to call when we receive a message
204 * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
205 * @param msg message received, NULL on timeout or fatal error
208 process_ats_message (void *cls,
209 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,
225 struct GNUNET_ATS_SchedulingHandle *sh = cls;
226 struct PendingMessage *p;
231 if ( (size == 0) || (buf == NULL))
233 force_reconnect (sh);
238 while ( (NULL != (p = sh->pending_head)) &&
241 memcpy (&cbuf[ret], &p[1], p->size);
244 GNUNET_CONTAINER_DLL_remove (sh->pending_head,
247 if (GNUNET_YES == p->is_init)
248 GNUNET_CLIENT_receive (sh->client,
249 &process_ats_message, sh,
250 GNUNET_TIME_UNIT_FOREVER_REL);
259 * Transmit messages from the message queue to the service
260 * (if there are any, and if we are not already trying).
262 * @param sh handle to use
265 do_transmit (struct GNUNET_ATS_SchedulingHandle *sh)
267 struct PendingMessage *p;
271 if (NULL == (p = sh->pending_head))
273 if (NULL == sh->client)
274 return; /* currently reconnecting */
275 sh->th = GNUNET_CLIENT_notify_transmit_ready (sh->client,
277 GNUNET_TIME_UNIT_FOREVER_REL,
279 &transmit_message_to_ats, sh);
284 * Find the session object corresponding to the given session ID.
286 * @param sh our handle
287 * @param session_id current session ID
288 * @param peer peer the session belongs to
289 * @return the session object (or NULL)
291 static struct Session*
292 find_session (struct GNUNET_ATS_SchedulingHandle *sh,
294 const struct GNUNET_PeerIdentity *peer)
296 if (session_id >= sh->session_array_size)
303 if (0 != memcmp (peer,
304 &sh->session_array[session_id].peer,
305 sizeof (struct GNUNET_PeerIdentity)))
308 sh->reconnect = GNUNET_YES;
311 return sh->session_array[session_id].session;
316 * Get the ID for the given session object. If we do not have an ID for
317 * the given session object, allocate one.
319 * @param sh our handle
320 * @param session session object
321 * @param peer peer the session belongs to
322 * @return the session id
325 get_session_id (struct GNUNET_ATS_SchedulingHandle *sh,
326 struct Session *session,
327 const struct GNUNET_PeerIdentity *peer)
335 for (i=1;i<sh->session_array_size;i++)
337 if (session == sh->session_array[i].session)
339 GNUNET_assert (0 == memcmp (peer,
340 &sh->session_array[i].peer,
341 sizeof (struct GNUNET_PeerIdentity)));
345 (sh->session_array[i].slot_used == GNUNET_NO) )
350 f = sh->session_array_size;
351 GNUNET_array_grow (sh->session_array,
352 sh->session_array_size,
353 sh->session_array_size * 2);
355 GNUNET_assert (f > 0);
356 sh->session_array[f].session = session;
357 sh->session_array[f].peer = *peer;
358 sh->session_array[f].slot_used = GNUNET_YES;
364 * Remove the session of the given session ID from the session
365 * table (it is no longer valid).
367 * @param sh our handle
368 * @param session_id identifies session that is no longer valid
369 * @param peer peer the session belongs to
372 remove_session (struct GNUNET_ATS_SchedulingHandle *sh,
374 const struct GNUNET_PeerIdentity *peer)
378 GNUNET_assert (session_id < sh->session_array_size);
379 GNUNET_assert (GNUNET_YES == sh->session_array[session_id].slot_used);
380 GNUNET_assert (0 == memcmp (peer,
381 &sh->session_array[session_id].peer,
382 sizeof (struct GNUNET_PeerIdentity)));
383 sh->session_array[session_id].session = NULL;
388 * Release the session slot from the session table (ATS service is
389 * also done using it).
391 * @param sh our handle
392 * @param session_id identifies session that is no longer valid
393 * @param peer peer the session belongs to
396 release_session (struct GNUNET_ATS_SchedulingHandle *sh,
398 const struct GNUNET_PeerIdentity *peer)
400 if (session_id >= sh->session_array_size)
403 sh->reconnect = GNUNET_YES;
406 if (0 != memcmp (peer,
407 &sh->session_array[session_id].peer,
408 sizeof (struct GNUNET_PeerIdentity)))
411 sh->reconnect = GNUNET_YES;
414 sh->session_array[session_id].slot_used = GNUNET_NO;
415 memset (&sh->session_array[session_id].peer,
417 sizeof (struct GNUNET_PeerIdentity));
422 process_release_message (struct GNUNET_ATS_SchedulingHandle *sh,
423 const struct SessionReleaseMessage *srm)
426 ntohl (srm->session_id),
432 * Type of a function to call when we receive a message
435 * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
436 * @param msg message received, NULL on timeout or fatal error
439 process_ats_message (void *cls,
440 const struct GNUNET_MessageHeader *msg)
442 struct GNUNET_ATS_SchedulingHandle *sh = cls;
443 const struct AddressSuggestionMessage *m;
444 const struct GNUNET_ATS_Information *atsi;
446 const char *plugin_name;
447 uint16_t address_length;
448 uint16_t plugin_name_length;
453 force_reconnect (sh);
456 if ( (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_ATS_SESSION_RELEASE) &&
457 (ntohs (msg->size) == sizeof (struct SessionReleaseMessage)) )
459 process_release_message (sh,
460 (const struct SessionReleaseMessage*) msg);
461 GNUNET_CLIENT_receive (sh->client,
462 &process_ats_message, sh,
463 GNUNET_TIME_UNIT_FOREVER_REL);
464 if (GNUNET_YES == sh->reconnect)
465 force_reconnect (sh);
468 if ( (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_ATS_ADDRESS_SUGGESTION) ||
469 (ntohs (msg->size) <= sizeof (struct AddressSuggestionMessage)) )
472 force_reconnect (sh);
475 m = (const struct AddressSuggestionMessage*) msg;
476 ats_count = ntohl (m->ats_count);
477 address_length = ntohs (m->address_length);
478 atsi = (const struct GNUNET_ATS_Information*) &m[1];
479 address = (const char*) &atsi[ats_count];
480 plugin_name = &address[address_length];
481 plugin_name_length = ntohs (m->plugin_name_length);
482 if ( (address_length +
484 ats_count * sizeof (struct GNUNET_ATS_Information) +
485 sizeof (struct AddressSuggestionMessage) != ntohs (msg->size)) ||
486 (ats_count > GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_ATS_Information)) ||
487 (plugin_name[plugin_name_length - 1] != '\0') )
490 force_reconnect (sh);
493 sh->suggest_cb (sh->suggest_cb_cls,
496 address, address_length,
497 find_session (sh, ntohl (m->session_id), &m->peer),
502 GNUNET_CLIENT_receive (sh->client,
503 &process_ats_message, sh,
504 GNUNET_TIME_UNIT_FOREVER_REL);
505 if (GNUNET_YES == sh->reconnect)
506 force_reconnect (sh);
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 PendingMessage *p;
519 struct ClientStartMessage *init;
521 GNUNET_assert (NULL == sh->client);
522 sh->client = GNUNET_CLIENT_connect ("ats", sh->cfg);
523 GNUNET_assert (NULL != sh->client);
524 if ( (NULL == (p = sh->pending_head)) ||
525 (GNUNET_YES != p->is_init) )
527 p = GNUNET_malloc (sizeof (struct PendingMessage) +
528 sizeof (struct ClientStartMessage));
529 p->size = sizeof (struct ClientStartMessage);
530 p->is_init = GNUNET_YES;
531 init = (struct ClientStartMessage *) &p[1];
532 init->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_START);
533 init->header.size = htons (sizeof (struct ClientStartMessage));
534 init->start_flag = htonl (START_FLAG_SCHEDULING);
535 GNUNET_CONTAINER_DLL_insert (sh->pending_head,
544 * Initialize the ATS subsystem.
546 * @param cfg configuration to use
547 * @param suggest_cb notification to call whenever the suggestation changed
548 * @param suggest_cb_cls closure for 'suggest_cb'
549 * @return ats context
551 struct GNUNET_ATS_SchedulingHandle *
552 GNUNET_ATS_scheduling_init (const struct GNUNET_CONFIGURATION_Handle *cfg,
553 GNUNET_ATS_AddressSuggestionCallback suggest_cb,
554 void *suggest_cb_cls)
556 struct GNUNET_ATS_SchedulingHandle *sh;
558 sh = GNUNET_malloc (sizeof (struct GNUNET_ATS_SchedulingHandle));
560 sh->suggest_cb = suggest_cb;
561 sh->suggest_cb_cls = suggest_cb_cls;
562 GNUNET_array_grow (sh->session_array,
563 sh->session_array_size,
571 * Client is done with ATS scheduling, release resources.
573 * @param sh handle to release
576 GNUNET_ATS_scheduling_done (struct GNUNET_ATS_SchedulingHandle *sh)
578 struct PendingMessage *p;
580 while (NULL != (p = sh->pending_head))
582 GNUNET_CONTAINER_DLL_remove (sh->pending_head,
587 if (NULL != sh->client)
589 GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
592 if (GNUNET_SCHEDULER_NO_TASK != sh->task)
594 GNUNET_SCHEDULER_cancel (sh->task);
595 sh->task = GNUNET_SCHEDULER_NO_TASK;
597 GNUNET_array_grow (sh->session_array,
598 sh->session_array_size,
605 * We would like to establish a new connection with a peer. ATS
606 * should suggest a good address to begin with.
609 * @param peer identity of the peer we need an address for
612 GNUNET_ATS_suggest_address (struct GNUNET_ATS_SchedulingHandle *sh,
613 const struct GNUNET_PeerIdentity *peer)
615 struct PendingMessage *p;
616 struct RequestAddressMessage *m;
618 p = GNUNET_malloc (sizeof (struct PendingMessage) +
619 sizeof (struct RequestAddressMessage));
620 p->size = sizeof (struct RequestAddressMessage);
621 p->is_init = GNUNET_NO;
622 m = (struct RequestAddressMessage*) &p[1];
623 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_REQUEST_ADDRESS);
624 m->header.size = htons (sizeof (struct RequestAddressMessage));
625 m->reserved = htonl (0);
627 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head,
635 * We have updated performance statistics for a given address. Note
636 * that this function can be called for addresses that are currently
637 * in use as well as addresses that are valid but not actively in use.
638 * Furthermore, the peer may not even be connected to us right now (in
639 * which case the call may be ignored or the information may be stored
640 * for later use). Update bandwidth assignments.
643 * @param peer identity of the new peer
644 * @param plugin_name name of the transport plugin
645 * @param plugin_addr address (if available)
646 * @param plugin_addr_len number of bytes in plugin_addr
647 * @param session session handle (if available)
648 * @param ats performance data for the address
649 * @param ats_count number of performance records in 'ats'
652 GNUNET_ATS_address_update (struct GNUNET_ATS_SchedulingHandle *sh,
653 const struct GNUNET_PeerIdentity *peer,
654 const char *plugin_name,
655 const void *plugin_addr, size_t plugin_addr_len,
656 struct Session *session,
657 const struct GNUNET_ATS_Information *ats,
660 struct PendingMessage *p;
661 struct AddressUpdateMessage *m;
662 struct GNUNET_ATS_Information *am;
667 namelen = (plugin_name == NULL) ? 0 : strlen (plugin_name) + 1;
668 msize = sizeof (struct AddressUpdateMessage) + plugin_addr_len +
669 ats_count * sizeof (struct GNUNET_ATS_Information) + namelen;
670 if ( (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
671 (plugin_addr_len >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
672 (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
673 (ats_count >= GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_ATS_Information)) )
678 p = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
680 p->is_init = GNUNET_NO;
681 m = (struct AddressUpdateMessage*) &p[1];
682 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_ADDRESS_UPDATE);
683 m->header.size = htons (msize);
684 m->ats_count = htonl (ats_count);
686 m->address_length = htons (plugin_addr_len);
687 m->plugin_name_length = htons (namelen);
688 m->session_id = htonl (get_session_id (sh, session, peer));
689 am = (struct GNUNET_ATS_Information*) &m[1];
690 memcpy (am, ats, ats_count * sizeof (struct GNUNET_ATS_Information));
691 pm = (char *) &am[ats_count];
692 memcpy (pm, plugin_addr, plugin_addr_len);
693 memcpy (&pm[plugin_addr_len], plugin_name, namelen);
694 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head,
702 * A session got destroyed, stop including it as a valid address.
705 * @param peer identity of the peer
706 * @param plugin_name name of the transport plugin
707 * @param plugin_addr address (if available)
708 * @param plugin_addr_len number of bytes in plugin_addr
709 * @param session session handle that is no longer valid
712 GNUNET_ATS_address_destroyed (struct GNUNET_ATS_SchedulingHandle *sh,
713 const struct GNUNET_PeerIdentity *peer,
714 const char *plugin_name,
715 const void *plugin_addr,
716 size_t plugin_addr_len,
717 struct Session *session)
719 struct PendingMessage *p;
720 struct AddressDestroyedMessage *m;
726 namelen = (plugin_name == NULL) ? 0 : strlen (plugin_name) + 1;
727 msize = sizeof (struct AddressDestroyedMessage) + plugin_addr_len +
729 if ( (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
730 (plugin_addr_len >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
731 (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE) )
736 p = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
738 p->is_init = GNUNET_NO;
739 m = (struct AddressDestroyedMessage*) &p[1];
740 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_ADDRESS_DESTROYED);
741 m->header.size = htons (msize);
742 m->reserved = htonl (0);
744 m->address_length = htons (plugin_addr_len);
745 m->plugin_name_length = htons (namelen);
746 m->session_id = htonl (session_id = get_session_id (sh, session, peer));
748 memcpy (pm, plugin_addr, plugin_addr_len);
749 memcpy (&pm[plugin_addr_len], plugin_name, namelen);
750 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head,
754 remove_session (sh, session_id, peer);
757 /* end of ats_api_scheduling.c */