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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;
145 * Re-establish the connection to the ATS service.
147 * @param sh handle to use to re-connect.
150 reconnect (struct GNUNET_ATS_SchedulingHandle *sh);
155 * Re-establish the connection to the ATS service.
157 * @param cls handle to use to re-connect.
158 * @param tc scheduler context
161 reconnect_task (void *cls,
162 const struct GNUNET_SCHEDULER_TaskContext *tc)
164 struct GNUNET_ATS_SchedulingHandle *sh = cls;
166 sh->task = GNUNET_SCHEDULER_NO_TASK;
172 * Transmit messages from the message queue to the service
173 * (if there are any, and if we are not already trying).
175 * @param sh handle to use
178 do_transmit (struct GNUNET_ATS_SchedulingHandle *sh);
182 * Type of a function to call when we receive a message
185 * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
186 * @param msg message received, NULL on timeout or fatal error
189 process_ats_message (void *cls,
190 const struct GNUNET_MessageHeader *msg);
194 * We can now transmit a message to ATS. Do it.
196 * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
197 * @param size number of bytes we can transmit to ATS
198 * @param buf where to copy the messages
199 * @return number of bytes copied into buf
202 transmit_message_to_ats (void *cls,
206 struct GNUNET_ATS_SchedulingHandle *sh = cls;
207 struct PendingMessage *p;
214 while ( (NULL != (p = sh->pending_head)) &&
217 memcpy (&cbuf[ret], &p[1], p->size);
220 GNUNET_CONTAINER_DLL_remove (sh->pending_head,
223 if (GNUNET_YES == p->is_init)
224 GNUNET_CLIENT_receive (sh->client,
225 &process_ats_message, sh,
226 GNUNET_TIME_UNIT_FOREVER_REL);
235 * Transmit messages from the message queue to the service
236 * (if there are any, and if we are not already trying).
238 * @param sh handle to use
241 do_transmit (struct GNUNET_ATS_SchedulingHandle *sh)
243 struct PendingMessage *p;
247 if (NULL == (p = sh->pending_head))
249 if (NULL == sh->client)
250 return; /* currently reconnecting */
251 sh->th = GNUNET_CLIENT_notify_transmit_ready (sh->client,
253 GNUNET_TIME_UNIT_FOREVER_REL,
255 &transmit_message_to_ats, sh);
260 * Find the session object corresponding to the given session ID.
262 * @param sh our handle
263 * @param session_id current session ID
264 * @param peer peer the session belongs to
265 * @return the session object (or NULL)
267 static struct Session*
268 find_session (struct GNUNET_ATS_SchedulingHandle *sh,
270 const struct GNUNET_PeerIdentity *peer)
272 if (session_id >= sh->session_array_size)
279 GNUNET_assert (0 == memcmp (peer,
280 &sh->session_array[session_id].peer,
281 sizeof (struct GNUNET_PeerIdentity)));
282 return sh->session_array[session_id].session;
287 * Get the ID for the given session object. If we do not have an ID for
288 * the given session object, allocate one.
290 * @param sh our handle
291 * @param session session object
292 * @param peer peer the session belongs to
293 * @return the session id
296 get_session_id (struct GNUNET_ATS_SchedulingHandle *sh,
297 struct Session *session,
298 const struct GNUNET_PeerIdentity *peer)
306 for (i=1;i<sh->session_array_size;i++)
308 if (session == sh->session_array[i].session)
310 GNUNET_assert (0 == memcmp (peer,
311 &sh->session_array[i].peer,
312 sizeof (struct GNUNET_PeerIdentity)));
316 (sh->session_array[i].session == NULL) )
321 f = sh->session_array_size;
322 GNUNET_array_grow (sh->session_array,
323 sh->session_array_size,
324 sh->session_array_size * 2);
326 GNUNET_assert (f > 0);
327 sh->session_array[f].session = session;
328 sh->session_array[f].peer = *peer;
329 sh->session_array[f].slot_used = GNUNET_YES;
335 * Remove the session of the given session ID from the session
336 * table (it is no longer valid).
338 * @param sh our handle
339 * @param session_id identifies session that is no longer valid
340 * @param peer peer the session belongs to
343 remove_session (struct GNUNET_ATS_SchedulingHandle *sh,
345 const struct GNUNET_PeerIdentity *peer)
347 GNUNET_assert (session_id < sh->session_array_size);
348 GNUNET_assert (0 == memcmp (peer,
349 &sh->session_array[session_id].peer,
350 sizeof (struct GNUNET_PeerIdentity)));
351 sh->session_array[session_id].session = NULL;
356 * Release the session slot from the session table (ATS service is
357 * also done using it).
359 * @param sh our handle
360 * @param session_id identifies session that is no longer valid
361 * @param peer peer the session belongs to
364 release_session (struct GNUNET_ATS_SchedulingHandle *sh,
366 const struct GNUNET_PeerIdentity *peer)
368 GNUNET_assert (session_id < sh->session_array_size);
369 GNUNET_assert (0 == memcmp (peer,
370 &sh->session_array[session_id].peer,
371 sizeof (struct GNUNET_PeerIdentity)));
372 sh->session_array[session_id].slot_used = GNUNET_NO;
373 memset (&sh->session_array[session_id].peer,
375 sizeof (struct GNUNET_PeerIdentity));
380 process_release_message (struct GNUNET_ATS_SchedulingHandle *sh,
381 const struct SessionReleaseMessage *srm)
384 ntohl (srm->session_id),
390 * Type of a function to call when we receive a message
393 * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
394 * @param msg message received, NULL on timeout or fatal error
397 process_ats_message (void *cls,
398 const struct GNUNET_MessageHeader *msg)
400 struct GNUNET_ATS_SchedulingHandle *sh = cls;
401 const struct AddressSuggestionMessage *m;
402 const struct GNUNET_ATS_Information *atsi;
404 const char *plugin_name;
405 uint16_t address_length;
406 uint16_t plugin_name_length;
411 GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
413 sh->task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
414 &reconnect_task, sh);
417 if ( (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_ATS_SESSION_RELEASE) &&
418 (ntohs (msg->size) == sizeof (struct SessionReleaseMessage)) )
420 process_release_message (sh,
421 (const struct SessionReleaseMessage*) msg);
422 GNUNET_CLIENT_receive (sh->client,
423 &process_ats_message, sh,
424 GNUNET_TIME_UNIT_FOREVER_REL);
427 if ( (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_ATS_ADDRESS_SUGGESTION) ||
428 (ntohs (msg->size) <= sizeof (struct AddressSuggestionMessage)) )
431 GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
433 sh->task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
434 &reconnect_task, sh);
437 m = (const struct AddressSuggestionMessage*) msg;
438 ats_count = ntohl (m->ats_count);
439 address_length = ntohs (m->address_length);
440 atsi = (const struct GNUNET_ATS_Information*) &m[1];
441 address = (const char*) &atsi[ats_count];
442 plugin_name = &address[address_length];
443 plugin_name_length = ntohs (m->plugin_name_length);
444 if ( (address_length +
446 ats_count * sizeof (struct GNUNET_ATS_Information) +
447 sizeof (struct AddressSuggestionMessage) != ntohs (msg->size)) ||
448 (ats_count > GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_ATS_Information)) ||
449 (plugin_name[plugin_name_length - 1] != '\0') )
452 GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
454 sh->task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
455 &reconnect_task, sh);
458 sh->suggest_cb (sh->suggest_cb_cls,
461 address, address_length,
462 find_session (sh, ntohl (m->session_id), &m->peer),
467 GNUNET_CLIENT_receive (sh->client,
468 &process_ats_message, sh,
469 GNUNET_TIME_UNIT_FOREVER_REL);
474 * Re-establish the connection to the ATS service.
476 * @param sh handle to use to re-connect.
479 reconnect (struct GNUNET_ATS_SchedulingHandle *sh)
481 struct PendingMessage *p;
482 struct ClientStartMessage *init;
484 GNUNET_assert (NULL == sh->client);
485 sh->client = GNUNET_CLIENT_connect ("ats", sh->cfg);
486 GNUNET_assert (NULL != sh->client);
487 if ( (NULL == (p = sh->pending_head)) ||
488 (GNUNET_YES != p->is_init) )
490 p = GNUNET_malloc (sizeof (struct PendingMessage) +
491 sizeof (struct ClientStartMessage));
492 p->size = sizeof (struct ClientStartMessage);
493 p->is_init = GNUNET_YES;
494 init = (struct ClientStartMessage *) &p[1];
495 init->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_START);
496 init->header.size = htons (sizeof (struct ClientStartMessage));
497 init->start_flag = htonl (START_FLAG_SCHEDULING);
498 GNUNET_CONTAINER_DLL_insert (sh->pending_head,
507 * Initialize the ATS subsystem.
509 * @param cfg configuration to use
510 * @param suggest_cb notification to call whenever the suggestation changed
511 * @param suggest_cb_cls closure for 'suggest_cb'
512 * @return ats context
514 struct GNUNET_ATS_SchedulingHandle *
515 GNUNET_ATS_scheduling_init (const struct GNUNET_CONFIGURATION_Handle *cfg,
516 GNUNET_ATS_AddressSuggestionCallback suggest_cb,
517 void *suggest_cb_cls)
519 struct GNUNET_ATS_SchedulingHandle *sh;
521 sh = GNUNET_malloc (sizeof (struct GNUNET_ATS_SchedulingHandle));
523 sh->suggest_cb = suggest_cb;
524 sh->suggest_cb_cls = suggest_cb_cls;
525 GNUNET_array_grow (sh->session_array,
526 sh->session_array_size,
534 * Client is done with ATS scheduling, release resources.
536 * @param sh handle to release
539 GNUNET_ATS_scheduling_done (struct GNUNET_ATS_SchedulingHandle *sh)
541 struct PendingMessage *p;
543 while (NULL != (p = sh->pending_head))
545 GNUNET_CONTAINER_DLL_remove (sh->pending_head,
550 if (NULL != sh->client)
552 GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
555 if (GNUNET_SCHEDULER_NO_TASK != sh->task)
557 GNUNET_SCHEDULER_cancel (sh->task);
558 sh->task = GNUNET_SCHEDULER_NO_TASK;
560 GNUNET_array_grow (sh->session_array,
561 sh->session_array_size,
568 * We would like to establish a new connection with a peer. ATS
569 * should suggest a good address to begin with.
572 * @param peer identity of the peer we need an address for
575 GNUNET_ATS_suggest_address (struct GNUNET_ATS_SchedulingHandle *sh,
576 const struct GNUNET_PeerIdentity *peer)
578 struct PendingMessage *p;
579 struct RequestAddressMessage *m;
581 p = GNUNET_malloc (sizeof (struct PendingMessage) +
582 sizeof (struct RequestAddressMessage));
583 p->size = sizeof (struct RequestAddressMessage);
584 p->is_init = GNUNET_NO;
585 m = (struct RequestAddressMessage*) &p[1];
586 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_REQUEST_ADDRESS);
587 m->header.size = htons (sizeof (struct RequestAddressMessage));
588 m->reserved = htonl (0);
590 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head,
598 * We have updated performance statistics for a given address. Note
599 * that this function can be called for addresses that are currently
600 * in use as well as addresses that are valid but not actively in use.
601 * Furthermore, the peer may not even be connected to us right now (in
602 * which case the call may be ignored or the information may be stored
603 * for later use). Update bandwidth assignments.
606 * @param peer identity of the new peer
607 * @param plugin_name name of the transport plugin
608 * @param plugin_addr address (if available)
609 * @param plugin_addr_len number of bytes in plugin_addr
610 * @param session session handle (if available)
611 * @param ats performance data for the address
612 * @param ats_count number of performance records in 'ats'
615 GNUNET_ATS_address_update (struct GNUNET_ATS_SchedulingHandle *sh,
616 const struct GNUNET_PeerIdentity *peer,
617 const char *plugin_name,
618 const void *plugin_addr, size_t plugin_addr_len,
619 struct Session *session,
620 const struct GNUNET_ATS_Information *ats,
623 struct PendingMessage *p;
624 struct AddressUpdateMessage *m;
625 struct GNUNET_ATS_Information *am;
630 namelen = (plugin_name == NULL) ? 0 : strlen (plugin_name) + 1;
631 msize = sizeof (struct AddressUpdateMessage) + plugin_addr_len +
632 ats_count * sizeof (struct GNUNET_ATS_Information) + namelen;
633 if ( (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
634 (plugin_addr_len >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
635 (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
636 (ats_count >= GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_ATS_Information)) )
641 p = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
643 p->is_init = GNUNET_NO;
644 m = (struct AddressUpdateMessage*) &p[1];
645 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_ADDRESS_UPDATE);
646 m->header.size = htons (msize);
647 m->ats_count = htonl (ats_count);
649 m->address_length = htons (plugin_addr_len);
650 m->plugin_name_length = htons (namelen);
651 m->session_id = htonl (get_session_id (sh, session, peer));
652 am = (struct GNUNET_ATS_Information*) &m[1];
653 memcpy (am, ats, ats_count * sizeof (struct GNUNET_ATS_Information));
654 pm = (char *) &am[ats_count];
655 memcpy (pm, plugin_addr, plugin_addr_len);
656 memcpy (&pm[plugin_addr_len], plugin_name, namelen);
657 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head,
665 * A session got destroyed, stop including it as a valid address.
668 * @param peer identity of the peer
669 * @param plugin_name name of the transport plugin
670 * @param plugin_addr address (if available)
671 * @param plugin_addr_len number of bytes in plugin_addr
672 * @param session session handle that is no longer valid
675 GNUNET_ATS_address_destroyed (struct GNUNET_ATS_SchedulingHandle *sh,
676 const struct GNUNET_PeerIdentity *peer,
677 const char *plugin_name,
678 const void *plugin_addr,
679 size_t plugin_addr_len,
680 struct Session *session)
682 struct PendingMessage *p;
683 struct AddressDestroyedMessage *m;
689 namelen = (plugin_name == NULL) ? 0 : strlen (plugin_name) + 1;
690 msize = sizeof (struct AddressDestroyedMessage) + plugin_addr_len +
692 if ( (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
693 (plugin_addr_len >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
694 (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE) )
699 p = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
701 p->is_init = GNUNET_NO;
702 m = (struct AddressDestroyedMessage*) &p[1];
703 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_ADDRESS_DESTROYED);
704 m->header.size = htons (msize);
705 m->reserved = htonl (0);
707 m->address_length = htons (plugin_addr_len);
708 m->plugin_name_length = htons (namelen);
709 m->session_id = htonl (session_id = get_session_id (sh, session, peer));
711 memcpy (pm, plugin_addr, plugin_addr_len);
712 memcpy (&pm[plugin_addr_len], plugin_name, namelen);
713 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head,
717 remove_session (sh, session_id, peer);
720 /* end of ats_api_scheduling.c */