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3 (C) 2001, 2002, 2004, 2005, 2007, 2009, 2010, 2012 Christian Grothoff (and other contributing authors)
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22 * @file peerinfo/peerinfo_api.c
23 * @brief API to access peerinfo service
24 * @author Christian Grothoff
27 #include "gnunet_client_lib.h"
28 #include "gnunet_container_lib.h"
29 #include "gnunet_peerinfo_service.h"
30 #include "gnunet_protocols.h"
31 #include "gnunet_time_lib.h"
34 #define LOG(kind,...) GNUNET_log_from (kind, "peerinfo-api",__VA_ARGS__)
38 * Entry in the transmission queue to PEERINFO service. We use
39 * the same structure for queueing 'iteration' requests and
40 * actual 'add' messages.
42 struct GNUNET_PEERINFO_AddContext
45 * This is a linked list.
47 struct GNUNET_PEERINFO_AddContext *next;
50 * This is a linked list.
52 struct GNUNET_PEERINFO_AddContext *prev;
55 * Handle to the PEERINFO service.
57 struct GNUNET_PEERINFO_Handle *h;
60 * Function to call after request has been transmitted, or NULL.
62 GNUNET_PEERINFO_Continuation cont;
70 * Number of bytes of the request message (follows after this struct).
78 * Context for an iteration request.
80 struct GNUNET_PEERINFO_IteratorContext
86 struct GNUNET_PEERINFO_IteratorContext *next;
91 struct GNUNET_PEERINFO_IteratorContext *prev;
94 * Handle to the PEERINFO service.
96 struct GNUNET_PEERINFO_Handle *h;
99 * Function to call with the results.
101 GNUNET_PEERINFO_Processor callback;
104 * Closure for 'callback'.
109 * Our entry in the transmission queue.
111 struct GNUNET_PEERINFO_AddContext *ac;
114 * Task responsible for timeout.
116 GNUNET_SCHEDULER_TaskIdentifier timeout_task;
119 * Timeout for the operation.
121 struct GNUNET_TIME_Absolute timeout;
124 * Peer we are interested in (only valid if iteration was restricted to one peer).
126 struct GNUNET_PeerIdentity peer;
134 * Set to GNUNET_YES if we are currently receiving replies from the
137 int request_transmitted;
143 * Handle to the peerinfo service.
145 struct GNUNET_PEERINFO_Handle
150 const struct GNUNET_CONFIGURATION_Handle *cfg;
153 * Connection to the service.
155 struct GNUNET_CLIENT_Connection *client;
158 * Head of transmission queue.
160 struct GNUNET_PEERINFO_AddContext *ac_head;
163 * Tail of transmission queue.
165 struct GNUNET_PEERINFO_AddContext *ac_tail;
168 * Handle for the current transmission request, or NULL if none is pending.
170 struct GNUNET_CLIENT_TransmitHandle *th;
173 * Head of iterator DLL.
175 struct GNUNET_PEERINFO_IteratorContext *ic_head;
178 * Tail of iterator DLL.
180 struct GNUNET_PEERINFO_IteratorContext *ic_tail;
183 * ID for a reconnect task.
185 GNUNET_SCHEDULER_TaskIdentifier r_task;
188 * Are we now receiving?
196 * Connect to the peerinfo service.
198 * @param cfg configuration to use
199 * @return NULL on error (configuration related, actual connection
200 * establishment may happen asynchronously).
202 struct GNUNET_PEERINFO_Handle *
203 GNUNET_PEERINFO_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
205 struct GNUNET_PEERINFO_Handle *h;
207 h = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_Handle));
208 h->client = GNUNET_CLIENT_connect ("peerinfo", cfg);
215 * Disconnect from the peerinfo service. Note that all iterators must
216 * have completed or have been cancelled by the time this function is
217 * called (otherwise, calling this function is a serious error).
218 * Furthermore, if 'GNUNET_PEERINFO_add_peer' operations are still
219 * pending, they will be cancelled silently on disconnect.
221 * @param h handle to disconnect
224 GNUNET_PEERINFO_disconnect (struct GNUNET_PEERINFO_Handle *h)
226 struct GNUNET_PEERINFO_AddContext *ac;
227 struct GNUNET_PEERINFO_IteratorContext *ic;
229 while (NULL != (ic = h->ic_head))
231 GNUNET_break (GNUNET_YES == ic->request_transmitted);
232 ic->request_transmitted = GNUNET_NO;
233 GNUNET_PEERINFO_iterate_cancel (ic);
235 while (NULL != (ac = h->ac_head))
237 GNUNET_CONTAINER_DLL_remove (h->ac_head, h->ac_tail, ac);
238 if (NULL != ac->cont)
239 ac->cont (ac->cont_cls, _("aborted due to explicit disconnect request"));
244 GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
247 if (NULL != h->client)
249 GNUNET_CLIENT_disconnect (h->client);
252 if (GNUNET_SCHEDULER_NO_TASK != h->r_task)
254 GNUNET_SCHEDULER_cancel (h->r_task);
255 h->r_task = GNUNET_SCHEDULER_NO_TASK;
262 * Check if we have a request pending in the transmission queue and are
263 * able to transmit it right now. If so, schedule transmission.
265 * @param h handle to the service
268 trigger_transmit (struct GNUNET_PEERINFO_Handle *h);
272 * Close the existing connection to PEERINFO and reconnect.
274 * @param h handle to the service
277 reconnect (struct GNUNET_PEERINFO_Handle *h);
281 * Task scheduled to re-try connecting to the peerinfo service.
283 * @param cls the 'struct GNUNET_PEERINFO_Handle'
284 * @param tc scheduler context
287 reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
289 struct GNUNET_PEERINFO_Handle *h = cls;
291 h->r_task = GNUNET_SCHEDULER_NO_TASK;
297 * Close the existing connection to PEERINFO and reconnect.
299 * @param h handle to the service
302 reconnect (struct GNUNET_PEERINFO_Handle *h)
304 if (GNUNET_SCHEDULER_NO_TASK != h->r_task)
306 GNUNET_SCHEDULER_cancel (h->r_task);
307 h->r_task = GNUNET_SCHEDULER_NO_TASK;
311 GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
314 if (NULL != h->client)
316 GNUNET_CLIENT_disconnect (h->client);
319 h->in_receive = GNUNET_NO;
320 h->client = GNUNET_CLIENT_connect ("peerinfo", h->cfg);
321 if (NULL == h->client)
324 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, &reconnect_task,
328 trigger_transmit (h);
333 * Transmit the request at the head of the transmission queue
334 * and trigger continuation (if any).
336 * @param cls the 'struct GNUNET_PEERINFO_Handle' (with the queue)
337 * @param size size of the buffer (0 on error)
338 * @param buf where to copy the message
339 * @return number of bytes copied to buf
342 do_transmit (void *cls, size_t size, void *buf)
344 struct GNUNET_PEERINFO_Handle *h = cls;
345 struct GNUNET_PEERINFO_AddContext *ac = h->ac_head;
350 return 0; /* request was cancelled in the meantime */
353 /* peerinfo service died */
354 LOG (GNUNET_ERROR_TYPE_DEBUG | GNUNET_ERROR_TYPE_BULK,
355 "Failed to transmit message to `%s' service.\n", "PEERINFO");
356 GNUNET_CONTAINER_DLL_remove (h->ac_head, h->ac_tail, ac);
358 if (NULL != ac->cont)
359 ac->cont (ac->cont_cls, _("failed to transmit request (service down?)"));
366 /* change in head of queue (i.e. cancel + add), try again */
367 trigger_transmit (h);
370 LOG (GNUNET_ERROR_TYPE_DEBUG,
371 "Transmitting request of size %u to `%s' service.\n", ret, "PEERINFO");
372 memcpy (buf, &ac[1], ret);
373 GNUNET_CONTAINER_DLL_remove (h->ac_head, h->ac_tail, ac);
374 trigger_transmit (h);
375 if (NULL != ac->cont)
376 ac->cont (ac->cont_cls, NULL);
383 * Check if we have a request pending in the transmission queue and are
384 * able to transmit it right now. If so, schedule transmission.
386 * @param h handle to the service
389 trigger_transmit (struct GNUNET_PEERINFO_Handle *h)
391 struct GNUNET_PEERINFO_AddContext *ac;
393 if (NULL == (ac = h->ac_head))
394 return; /* no requests queued */
396 return; /* request already pending */
397 if (GNUNET_YES == h->in_receive)
398 return; /* still reading replies from last request */
399 if (NULL == h->client)
401 /* disconnected, try to reconnect */
406 GNUNET_CLIENT_notify_transmit_ready (h->client, ac->size,
407 GNUNET_TIME_UNIT_FOREVER_REL,
414 * Add a host to the persistent list. This method operates in
415 * semi-reliable mode: if the transmission is not completed by
416 * the time 'GNUNET_PEERINFO_disconnect' is called, it will be
417 * aborted. Furthermore, if a second HELLO is added for the
418 * same peer before the first one was transmitted, PEERINFO may
419 * merge the two HELLOs prior to transmission to the service.
421 * @param h handle to the peerinfo service
422 * @param hello the verified (!) HELLO message
423 * @param cont continuation to call when done, NULL is allowed
424 * @param cont_cls closure for 'cont'
425 * @return handle to cancel add operation; all pending
426 * 'add' operations will be cancelled automatically
427 * on disconnect, so it is not necessary to keep this
428 * handle (unless 'cont' is NULL and at some point
429 * calling 'cont' must be prevented)
431 struct GNUNET_PEERINFO_AddContext *
432 GNUNET_PEERINFO_add_peer (struct GNUNET_PEERINFO_Handle *h,
433 const struct GNUNET_HELLO_Message *hello,
434 GNUNET_PEERINFO_Continuation cont,
437 uint16_t hs = GNUNET_HELLO_size (hello);
438 struct GNUNET_PEERINFO_AddContext *ac;
439 struct GNUNET_PeerIdentity peer;
441 GNUNET_assert (GNUNET_OK == GNUNET_HELLO_get_id (hello, &peer));
442 LOG (GNUNET_ERROR_TYPE_DEBUG,
443 "Adding peer `%s' to PEERINFO database (%u bytes of `%s')\n",
444 GNUNET_i2s (&peer), hs, "HELLO");
445 ac = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_AddContext) + hs);
449 ac->cont_cls = cont_cls;
450 memcpy (&ac[1], hello, hs);
451 GNUNET_CONTAINER_DLL_insert_tail (h->ac_head, h->ac_tail, ac);
452 trigger_transmit (h);
458 * Cancel pending 'add' operation. Must only be called before
459 * either 'cont' or 'GNUNET_PEERINFO_disconnect' are invoked.
461 * @param ac handle for the add operation to cancel
464 GNUNET_PEERINFO_add_peer_cancel (struct GNUNET_PEERINFO_AddContext *ac)
466 struct GNUNET_PEERINFO_Handle *h = ac->h;
468 GNUNET_CONTAINER_DLL_remove (h->ac_head, h->ac_tail, ac);
474 * Type of a function to call when we receive a message from the
475 * service. Call the iterator with the result and (if applicable)
476 * continue to receive more messages or trigger processing the next
477 * event (if applicable).
480 * @param msg message received, NULL on timeout or fatal error
483 peerinfo_handler (void *cls, const struct GNUNET_MessageHeader *msg)
485 struct GNUNET_PEERINFO_Handle *h = cls;
486 struct GNUNET_PEERINFO_IteratorContext *ic = h->ic_head;
487 const struct InfoMessage *im;
488 const struct GNUNET_HELLO_Message *hello;
489 GNUNET_PEERINFO_Processor cb;
490 struct GNUNET_PeerIdentity id;
494 GNUNET_assert (NULL != ic);
495 h->in_receive = GNUNET_NO;
496 ic->request_transmitted = GNUNET_NO;
498 cb_cls = ic->callback_cls;
501 /* peerinfo service died, signal error */
502 GNUNET_PEERINFO_iterate_cancel (ic);
505 cb (cb_cls, NULL, NULL,
506 _("Failed to receive response from `PEERINFO' service."));
510 if (GNUNET_MESSAGE_TYPE_PEERINFO_INFO_END == ntohs (msg->type))
512 /* normal end of list of peers, signal end, process next pending request */
513 LOG (GNUNET_ERROR_TYPE_DEBUG,
514 "Received end of list of peers from `%s' service\n", "PEERINFO");
515 GNUNET_PEERINFO_iterate_cancel (ic);
516 trigger_transmit (h);
517 if (GNUNET_NO == h->in_receive)
519 h->in_receive = GNUNET_YES;
520 GNUNET_CLIENT_receive (h->client, &peerinfo_handler, h,
521 GNUNET_TIME_absolute_get_remaining (ic->timeout));
524 cb (cb_cls, NULL, NULL, NULL);
528 ms = ntohs (msg->size);
529 if ((ms < sizeof (struct InfoMessage)) ||
530 (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_PEERINFO_INFO))
532 /* malformed message */
534 GNUNET_PEERINFO_iterate_cancel (ic);
537 cb (cb_cls, NULL, NULL,
538 _("Received invalid message from `PEERINFO' service."));
541 im = (const struct InfoMessage *) msg;
542 GNUNET_break (0 == ntohl (im->reserved));
543 if ( (GNUNET_YES == ic->have_peer) &&
544 (0 != memcmp (&ic->peer, &im->peer, sizeof (struct GNUNET_PeerIdentity))) )
546 /* bogus message (from a different iteration call?); out of sequence! */
547 LOG (GNUNET_ERROR_TYPE_ERROR,
548 "Received HELLO for peer `%s', expected peer `%s'\n",
549 GNUNET_h2s (&im->peer.hashPubKey),
550 GNUNET_i2s (&ic->peer));
553 GNUNET_PEERINFO_iterate_cancel (ic);
556 cb (cb_cls, NULL, NULL,
557 _("Received invalid message from `PEERINFO' service."));
561 if (ms > sizeof (struct InfoMessage) + sizeof (struct GNUNET_MessageHeader))
563 hello = (const struct GNUNET_HELLO_Message *) &im[1];
564 if (ms != sizeof (struct InfoMessage) + GNUNET_HELLO_size (hello))
566 /* malformed message */
568 GNUNET_PEERINFO_iterate_cancel (ic);
571 cb (cb_cls, NULL, NULL,
572 _("Received invalid message from `PEERINFO' service."));
575 if (GNUNET_OK != GNUNET_HELLO_get_id (hello, &id))
577 /* malformed message */
579 GNUNET_PEERINFO_iterate_cancel (ic);
582 cb (cb_cls, NULL, NULL,
583 _("Received invalid message from `PEERINFO' service."));
586 if (0 != memcmp (&im->peer, &id, sizeof (struct GNUNET_PeerIdentity)))
588 /* malformed message */
590 GNUNET_PEERINFO_iterate_cancel (ic);
593 cb (cb_cls, NULL, NULL,
594 _("Received invalid message from `PEERINFO' service."));
599 /* normal data message */
600 LOG (GNUNET_ERROR_TYPE_DEBUG,
601 "Received %u bytes of `%s' information about peer `%s' from `%s' service\n",
602 (hello == NULL) ? 0 : (unsigned int) GNUNET_HELLO_size (hello), "HELLO",
603 GNUNET_i2s (&im->peer), "PEERINFO");
604 h->in_receive = GNUNET_YES;
605 GNUNET_CLIENT_receive (h->client, &peerinfo_handler, h,
606 GNUNET_TIME_absolute_get_remaining (ic->timeout));
608 cb (cb_cls, &im->peer, hello, NULL);
613 * We've transmitted the iteration request. Now get ready to process
614 * the results (or handle transmission error).
616 * @param cls the 'struct GNUNET_PEERINFO_IteratorContext'
617 * @param emsg error message, NULL if transmission worked
620 iterator_start_receive (void *cls, const char *emsg)
622 struct GNUNET_PEERINFO_IteratorContext *ic = cls;
623 struct GNUNET_PEERINFO_Handle *h = ic->h;
624 GNUNET_PEERINFO_Processor cb;
631 cb_cls = ic->callback_cls;
632 GNUNET_PEERINFO_iterate_cancel (ic);
635 cb (cb_cls, NULL, NULL, emsg);
638 LOG (GNUNET_ERROR_TYPE_DEBUG, "Waiting for response from `%s' service.\n",
640 ic->request_transmitted = GNUNET_YES;
641 if (GNUNET_NO == h->in_receive)
643 h->in_receive = GNUNET_YES;
644 GNUNET_CLIENT_receive (h->client, &peerinfo_handler, h,
645 GNUNET_TIME_absolute_get_remaining (ic->timeout));
651 * Peerinfo iteration request has timed out.
653 * @param cls the 'struct GNUNET_PEERINFO_IteratorContext*'
654 * @param tc scheduler context
657 signal_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
659 struct GNUNET_PEERINFO_IteratorContext *ic = cls;
660 GNUNET_PEERINFO_Processor cb;
663 ic->timeout_task = GNUNET_SCHEDULER_NO_TASK;
665 cb_cls = ic->callback_cls;
666 GNUNET_PEERINFO_iterate_cancel (ic);
668 cb (cb_cls, NULL, NULL,
669 _("Timeout transmitting iteration request to `PEERINFO' service."));
674 * Call a method for each known matching host and change its trust
675 * value. The callback method will be invoked once for each matching
676 * host and then finally once with a NULL pointer. After that final
677 * invocation, the iterator context must no longer be used.
679 * Instead of calling this function with 'peer == NULL' it is often
680 * better to use 'GNUNET_PEERINFO_notify'.
682 * @param h handle to the peerinfo service
683 * @param peer restrict iteration to this peer only (can be NULL)
684 * @param timeout how long to wait until timing out
685 * @param callback the method to call for each peer
686 * @param callback_cls closure for callback
687 * @return iterator context
689 struct GNUNET_PEERINFO_IteratorContext *
690 GNUNET_PEERINFO_iterate (struct GNUNET_PEERINFO_Handle *h,
691 const struct GNUNET_PeerIdentity *peer,
692 struct GNUNET_TIME_Relative timeout,
693 GNUNET_PEERINFO_Processor callback, void *callback_cls)
695 struct GNUNET_MessageHeader *lapm;
696 struct ListPeerMessage *lpm;
697 struct GNUNET_PEERINFO_IteratorContext *ic;
698 struct GNUNET_PEERINFO_AddContext *ac;
700 ic = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_IteratorContext));
703 LOG (GNUNET_ERROR_TYPE_DEBUG,
704 "Requesting list of peers from PEERINFO service\n");
706 GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_AddContext) +
707 sizeof (struct GNUNET_MessageHeader));
708 ac->size = sizeof (struct GNUNET_MessageHeader);
709 lapm = (struct GNUNET_MessageHeader *) &ac[1];
710 lapm->size = htons (sizeof (struct GNUNET_MessageHeader));
711 lapm->type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_GET_ALL);
715 LOG (GNUNET_ERROR_TYPE_DEBUG,
716 "Requesting information on peer `%4s' from PEERINFO service\n",
719 GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_AddContext) +
720 sizeof (struct ListPeerMessage));
721 ac->size = sizeof (struct ListPeerMessage);
722 lpm = (struct ListPeerMessage *) &ac[1];
723 lpm->header.size = htons (sizeof (struct ListPeerMessage));
724 lpm->header.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_GET);
725 memcpy (&lpm->peer, peer, sizeof (struct GNUNET_PeerIdentity));
726 ic->have_peer = GNUNET_YES;
731 ic->callback = callback;
732 ic->callback_cls = callback_cls;
733 ic->timeout = GNUNET_TIME_relative_to_absolute (timeout);
735 GNUNET_SCHEDULER_add_delayed (timeout, &signal_timeout, ic);
736 ac->cont = &iterator_start_receive;
738 GNUNET_CONTAINER_DLL_insert_tail (h->ac_head, h->ac_tail, ac);
739 GNUNET_CONTAINER_DLL_insert_tail (h->ic_head,
742 trigger_transmit (h);
748 * Cancel an iteration over peer information.
750 * @param ic context of the iterator to cancel
753 GNUNET_PEERINFO_iterate_cancel (struct GNUNET_PEERINFO_IteratorContext *ic)
755 struct GNUNET_PEERINFO_Handle *h;
758 if (GNUNET_SCHEDULER_NO_TASK != ic->timeout_task)
760 GNUNET_SCHEDULER_cancel (ic->timeout_task);
761 ic->timeout_task = GNUNET_SCHEDULER_NO_TASK;
764 if (GNUNET_YES == ic->request_transmitted)
765 return; /* need to finish processing */
766 GNUNET_CONTAINER_DLL_remove (h->ic_head,
771 GNUNET_CONTAINER_DLL_remove (h->ac_head, h->ac_tail, ic->ac);
772 GNUNET_free (ic->ac);
778 /* end of peerinfo_api.c */