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22 * @file peerinfo/peerinfo_api.c
23 * @brief API to access peerinfo service
24 * @author Christian Grothoff
27 #include "gnunet_util_lib.h"
28 #include "gnunet_protocols.h"
31 #define LOG(kind,...) GNUNET_log_from (kind, "peerinfo-api",__VA_ARGS__)
35 * Entry in the transmission queue to PEERINFO service. We use
36 * the same structure for queueing 'iteration' requests and
37 * actual 'add' messages.
39 struct GNUNET_PEERINFO_AddContext
42 * This is a linked list.
44 struct GNUNET_PEERINFO_AddContext *next;
47 * This is a linked list.
49 struct GNUNET_PEERINFO_AddContext *prev;
52 * Handle to the PEERINFO service.
54 struct GNUNET_PEERINFO_Handle *h;
57 * Function to call after request has been transmitted, or NULL.
59 GNUNET_PEERINFO_Continuation cont;
62 * Closure for @e cont.
67 * Number of bytes of the request message (follows after this struct).
75 * Context for an iteration request.
77 struct GNUNET_PEERINFO_IteratorContext
83 struct GNUNET_PEERINFO_IteratorContext *next;
88 struct GNUNET_PEERINFO_IteratorContext *prev;
91 * Handle to the PEERINFO service.
93 struct GNUNET_PEERINFO_Handle *h;
96 * Function to call with the results.
98 GNUNET_PEERINFO_Processor callback;
101 * Closure for @e callback.
106 * Our entry in the transmission queue.
108 struct GNUNET_PEERINFO_AddContext *ac;
111 * Task responsible for timeout.
113 struct GNUNET_SCHEDULER_Task *timeout_task;
116 * Timeout for the operation.
118 struct GNUNET_TIME_Absolute timeout;
121 * Peer we are interested in (only valid if iteration was restricted to one peer).
123 struct GNUNET_PeerIdentity peer;
131 * Set to #GNUNET_YES if we are currently receiving replies from the
134 int request_transmitted;
140 * Handle to the peerinfo service.
142 struct GNUNET_PEERINFO_Handle
147 const struct GNUNET_CONFIGURATION_Handle *cfg;
150 * Connection to the service.
152 struct GNUNET_CLIENT_Connection *client;
155 * Head of transmission queue.
157 struct GNUNET_PEERINFO_AddContext *ac_head;
160 * Tail of transmission queue.
162 struct GNUNET_PEERINFO_AddContext *ac_tail;
165 * Handle for the current transmission request, or NULL if none is pending.
167 struct GNUNET_CLIENT_TransmitHandle *th;
170 * Head of iterator DLL.
172 struct GNUNET_PEERINFO_IteratorContext *ic_head;
175 * Tail of iterator DLL.
177 struct GNUNET_PEERINFO_IteratorContext *ic_tail;
180 * ID for a reconnect task.
182 struct GNUNET_SCHEDULER_Task *r_task;
185 * Are we now receiving?
193 * Connect to the peerinfo service.
195 * @param cfg configuration to use
196 * @return NULL on error (configuration related, actual connection
197 * establishment may happen asynchronously).
199 struct GNUNET_PEERINFO_Handle *
200 GNUNET_PEERINFO_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
202 struct GNUNET_PEERINFO_Handle *h;
204 h = GNUNET_new (struct GNUNET_PEERINFO_Handle);
205 h->client = GNUNET_CLIENT_connect ("peerinfo", cfg);
212 * Disconnect from the peerinfo service. Note that all iterators must
213 * have completed or have been cancelled by the time this function is
214 * called (otherwise, calling this function is a serious error).
215 * Furthermore, if #GNUNET_PEERINFO_add_peer() operations are still
216 * pending, they will be cancelled silently on disconnect.
218 * @param h handle to disconnect
221 GNUNET_PEERINFO_disconnect (struct GNUNET_PEERINFO_Handle *h)
223 struct GNUNET_PEERINFO_AddContext *ac;
224 struct GNUNET_PEERINFO_IteratorContext *ic;
226 while (NULL != (ic = h->ic_head))
228 GNUNET_break (GNUNET_YES == ic->request_transmitted);
229 ic->request_transmitted = GNUNET_NO;
230 GNUNET_PEERINFO_iterate_cancel (ic);
232 while (NULL != (ac = h->ac_head))
234 GNUNET_CONTAINER_DLL_remove (h->ac_head, h->ac_tail, ac);
235 if (NULL != ac->cont)
236 ac->cont (ac->cont_cls,
237 _("aborted due to explicit disconnect request"));
242 GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
245 if (NULL != h->client)
247 GNUNET_CLIENT_disconnect (h->client);
250 if (NULL != h->r_task)
252 GNUNET_SCHEDULER_cancel (h->r_task);
260 * Check if we have a request pending in the transmission queue and are
261 * able to transmit it right now. If so, schedule transmission.
263 * @param h handle to the service
266 trigger_transmit (struct GNUNET_PEERINFO_Handle *h);
270 * Close the existing connection to PEERINFO and reconnect.
272 * @param h handle to the service
275 reconnect (struct GNUNET_PEERINFO_Handle *h);
279 * Task scheduled to re-try connecting to the peerinfo service.
281 * @param cls the `struct GNUNET_PEERINFO_Handle *`
284 reconnect_task (void *cls)
286 struct GNUNET_PEERINFO_Handle *h = cls;
294 * Close the existing connection to PEERINFO and reconnect.
296 * @param h handle to the service
299 reconnect (struct GNUNET_PEERINFO_Handle *h)
301 if (NULL != h->r_task)
303 GNUNET_SCHEDULER_cancel (h->r_task);
308 GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
311 if (NULL != h->client)
313 GNUNET_CLIENT_disconnect (h->client);
316 h->in_receive = GNUNET_NO;
317 h->client = GNUNET_CLIENT_connect ("peerinfo", h->cfg);
318 if (NULL == h->client)
321 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
326 trigger_transmit (h);
331 * Transmit the request at the head of the transmission queue
332 * and trigger continuation (if any).
334 * @param cls the `struct GNUNET_PEERINFO_Handle *` (with the queue)
335 * @param size size of @a buf (0 on error)
336 * @param buf where to copy the message
337 * @return number of bytes copied to @a buf
340 do_transmit (void *cls,
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",
357 GNUNET_CONTAINER_DLL_remove (h->ac_head, h->ac_tail, ac);
359 if (NULL != ac->cont)
360 ac->cont (ac->cont_cls,
361 _("failed to transmit request (service down?)"));
368 /* change in head of queue (i.e. cancel + add), try again */
369 trigger_transmit (h);
372 LOG (GNUNET_ERROR_TYPE_DEBUG,
373 "Transmitting request of size %u to `%s' service.\n",
376 memcpy (buf, &ac[1], ret);
377 GNUNET_CONTAINER_DLL_remove (h->ac_head, h->ac_tail, ac);
378 trigger_transmit (h);
379 if (NULL != ac->cont)
380 ac->cont (ac->cont_cls, NULL);
387 * Check if we have a request pending in the transmission queue and are
388 * able to transmit it right now. If so, schedule transmission.
390 * @param h handle to the service
393 trigger_transmit (struct GNUNET_PEERINFO_Handle *h)
395 struct GNUNET_PEERINFO_AddContext *ac;
397 if (NULL == (ac = h->ac_head))
398 return; /* no requests queued */
400 return; /* request already pending */
401 if (NULL == h->client)
403 /* disconnected, try to reconnect */
408 GNUNET_CLIENT_notify_transmit_ready (h->client,
410 GNUNET_TIME_UNIT_FOREVER_REL,
417 * Add a host to the persistent list. This method operates in
418 * semi-reliable mode: if the transmission is not completed by
419 * the time #GNUNET_PEERINFO_disconnect() is called, it will be
420 * aborted. Furthermore, if a second HELLO is added for the
421 * same peer before the first one was transmitted, PEERINFO may
422 * merge the two HELLOs prior to transmission to the service.
424 * @param h handle to the peerinfo service
425 * @param hello the verified (!) HELLO message
426 * @param cont continuation to call when done, NULL is allowed
427 * @param cont_cls closure for @a cont
428 * @return handle to cancel add operation; all pending
429 * 'add' operations will be cancelled automatically
430 * on disconnect, so it is not necessary to keep this
431 * handle (unless @a cont is NULL and at some point
432 * calling @a cont must be prevented)
434 struct GNUNET_PEERINFO_AddContext *
435 GNUNET_PEERINFO_add_peer (struct GNUNET_PEERINFO_Handle *h,
436 const struct GNUNET_HELLO_Message *hello,
437 GNUNET_PEERINFO_Continuation cont,
440 uint16_t hs = GNUNET_HELLO_size (hello);
441 struct GNUNET_PEERINFO_AddContext *ac;
442 struct GNUNET_PeerIdentity peer;
444 GNUNET_assert (GNUNET_OK == GNUNET_HELLO_get_id (hello, &peer));
445 LOG (GNUNET_ERROR_TYPE_DEBUG,
446 "Adding peer `%s' to PEERINFO database (%u bytes of HELLO)\n",
449 ac = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_AddContext) + hs);
453 ac->cont_cls = cont_cls;
454 memcpy (&ac[1], hello, hs);
455 GNUNET_CONTAINER_DLL_insert_tail (h->ac_head, h->ac_tail, ac);
456 trigger_transmit (h);
462 * Cancel pending 'add' operation. Must only be called before
463 * either 'cont' or #GNUNET_PEERINFO_disconnect() are invoked.
465 * @param ac handle for the add operation to cancel
468 GNUNET_PEERINFO_add_peer_cancel (struct GNUNET_PEERINFO_AddContext *ac)
470 struct GNUNET_PEERINFO_Handle *h = ac->h;
472 GNUNET_CONTAINER_DLL_remove (h->ac_head, h->ac_tail, ac);
478 * Type of a function to call when we receive a message from the
479 * service. Call the iterator with the result and (if applicable)
480 * continue to receive more messages or trigger processing the next
481 * event (if applicable).
484 * @param msg message received, NULL on timeout or fatal error
487 peerinfo_handler (void *cls,
488 const struct GNUNET_MessageHeader *msg)
490 struct GNUNET_PEERINFO_Handle *h = cls;
491 struct GNUNET_PEERINFO_IteratorContext *ic = h->ic_head;
492 const struct InfoMessage *im;
493 const struct GNUNET_HELLO_Message *hello;
494 GNUNET_PEERINFO_Processor cb;
495 struct GNUNET_PeerIdentity id;
499 h->in_receive = GNUNET_NO;
502 /* peerinfo service died, signal error */
506 cb_cls = ic->callback_cls;
507 GNUNET_PEERINFO_iterate_cancel (ic);
515 cb (cb_cls, NULL, NULL,
516 _("Failed to receive response from `PEERINFO' service."));
521 /* didn't expect a response, reconnect */
525 ic->request_transmitted = GNUNET_NO;
527 cb_cls = ic->callback_cls;
528 if (GNUNET_MESSAGE_TYPE_PEERINFO_INFO_END == ntohs (msg->type))
530 /* normal end of list of peers, signal end, process next pending request */
531 LOG (GNUNET_ERROR_TYPE_DEBUG,
532 "Received end of list of peers from `%s' service\n",
534 GNUNET_PEERINFO_iterate_cancel (ic);
535 trigger_transmit (h);
536 if ( (GNUNET_NO == h->in_receive) &&
537 (NULL != h->ic_head) )
539 h->in_receive = GNUNET_YES;
540 GNUNET_CLIENT_receive (h->client,
543 GNUNET_TIME_absolute_get_remaining (h->ic_head->timeout));
546 cb (cb_cls, NULL, NULL, NULL);
550 ms = ntohs (msg->size);
551 if ((ms < sizeof (struct InfoMessage)) ||
552 (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_PEERINFO_INFO))
554 /* malformed message */
556 GNUNET_PEERINFO_iterate_cancel (ic);
559 cb (cb_cls, NULL, NULL,
560 _("Received invalid message from `PEERINFO' service."));
563 im = (const struct InfoMessage *) msg;
564 GNUNET_break (0 == ntohl (im->reserved));
565 if ( (GNUNET_YES == ic->have_peer) &&
566 (0 != memcmp (&ic->peer,
568 sizeof (struct GNUNET_PeerIdentity))) )
570 /* bogus message (from a different iteration call?); out of sequence! */
571 LOG (GNUNET_ERROR_TYPE_ERROR,
572 "Received HELLO for peer `%s', expected peer `%s'\n",
573 GNUNET_i2s (&im->peer),
574 GNUNET_i2s (&ic->peer));
577 GNUNET_PEERINFO_iterate_cancel (ic);
583 _("Received invalid message from `PEERINFO' service."));
587 if (ms > sizeof (struct InfoMessage) + sizeof (struct GNUNET_MessageHeader))
589 hello = (const struct GNUNET_HELLO_Message *) &im[1];
590 if (ms != sizeof (struct InfoMessage) + GNUNET_HELLO_size (hello))
592 /* malformed message */
594 GNUNET_PEERINFO_iterate_cancel (ic);
600 _("Received invalid message from `PEERINFO' service."));
603 if (GNUNET_OK != GNUNET_HELLO_get_id (hello, &id))
605 /* malformed message */
607 GNUNET_PEERINFO_iterate_cancel (ic);
613 _("Received invalid message from `PEERINFO' service."));
616 if (0 != memcmp (&im->peer,
618 sizeof (struct GNUNET_PeerIdentity)))
620 /* malformed message */
622 GNUNET_PEERINFO_iterate_cancel (ic);
628 _("Received invalid message from `PEERINFO' service."));
633 /* normal data message */
634 LOG (GNUNET_ERROR_TYPE_DEBUG,
635 "Received %u bytes of `%s' information about peer `%s' from `%s' service\n",
636 (hello == NULL) ? 0 : (unsigned int) GNUNET_HELLO_size (hello),
638 GNUNET_i2s (&im->peer),
640 h->in_receive = GNUNET_YES;
641 GNUNET_CLIENT_receive (h->client,
644 GNUNET_TIME_absolute_get_remaining (ic->timeout));
654 * We've transmitted the iteration request. Now get ready to process
655 * the results (or handle transmission error).
657 * @param cls the `struct GNUNET_PEERINFO_IteratorContext *`
658 * @param emsg error message, NULL if transmission worked
661 iterator_start_receive (void *cls,
664 struct GNUNET_PEERINFO_IteratorContext *ic = cls;
665 struct GNUNET_PEERINFO_Handle *h = ic->h;
666 GNUNET_PEERINFO_Processor cb;
673 cb_cls = ic->callback_cls;
674 GNUNET_PEERINFO_iterate_cancel (ic);
677 cb (cb_cls, NULL, NULL, emsg);
680 LOG (GNUNET_ERROR_TYPE_DEBUG,
681 "Waiting for response from `%s' service.\n",
683 ic->request_transmitted = GNUNET_YES;
684 if (GNUNET_NO == h->in_receive)
686 h->in_receive = GNUNET_YES;
687 GNUNET_CLIENT_receive (h->client,
690 GNUNET_TIME_absolute_get_remaining (ic->timeout));
696 * Peerinfo iteration request has timed out.
698 * @param cls the `struct GNUNET_PEERINFO_IteratorContext *`
701 signal_timeout (void *cls)
703 struct GNUNET_PEERINFO_IteratorContext *ic = cls;
704 GNUNET_PEERINFO_Processor cb;
707 ic->timeout_task = NULL;
709 cb_cls = ic->callback_cls;
710 GNUNET_PEERINFO_iterate_cancel (ic);
715 _("Timeout transmitting iteration request to `PEERINFO' service."));
720 * Call a method for each known matching host. The callback method
721 * will be invoked once for each matching host and then finally once
722 * with a NULL pointer. After that final invocation, the iterator
723 * context must no longer be used.
725 * Instead of calling this function with `peer == NULL` it is often
726 * better to use #GNUNET_PEERINFO_notify().
728 * @param h handle to the peerinfo service
729 * @param include_friend_only include HELLO messages for friends only
730 * @param peer restrict iteration to this peer only (can be NULL)
731 * @param timeout how long to wait until timing out
732 * @param callback the method to call for each peer
733 * @param callback_cls closure for @a callback
734 * @return iterator context
736 struct GNUNET_PEERINFO_IteratorContext *
737 GNUNET_PEERINFO_iterate (struct GNUNET_PEERINFO_Handle *h,
738 int include_friend_only,
739 const struct GNUNET_PeerIdentity *peer,
740 struct GNUNET_TIME_Relative timeout,
741 GNUNET_PEERINFO_Processor callback,
744 struct ListAllPeersMessage *lapm;
745 struct ListPeerMessage *lpm;
746 struct GNUNET_PEERINFO_IteratorContext *ic;
747 struct GNUNET_PEERINFO_AddContext *ac;
749 ic = GNUNET_new (struct GNUNET_PEERINFO_IteratorContext);
752 LOG (GNUNET_ERROR_TYPE_DEBUG,
753 "Requesting list of peers from PEERINFO service\n");
755 GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_AddContext) +
756 sizeof (struct ListAllPeersMessage));
757 ac->size = sizeof (struct ListAllPeersMessage);
758 lapm = (struct ListAllPeersMessage *) &ac[1];
759 lapm->header.size = htons (sizeof (struct ListAllPeersMessage));
760 lapm->header.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_GET_ALL);
761 lapm->include_friend_only = htonl (include_friend_only);
765 LOG (GNUNET_ERROR_TYPE_DEBUG,
766 "Requesting information on peer `%4s' from PEERINFO service\n",
769 GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_AddContext) +
770 sizeof (struct ListPeerMessage));
771 ac->size = sizeof (struct ListPeerMessage);
772 lpm = (struct ListPeerMessage *) &ac[1];
773 lpm->header.size = htons (sizeof (struct ListPeerMessage));
774 lpm->header.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_GET);
775 lpm->include_friend_only = htonl (include_friend_only);
776 memcpy (&lpm->peer, peer, sizeof (struct GNUNET_PeerIdentity));
777 ic->have_peer = GNUNET_YES;
782 ic->callback = callback;
783 ic->callback_cls = callback_cls;
784 ic->timeout = GNUNET_TIME_relative_to_absolute (timeout);
786 GNUNET_SCHEDULER_add_delayed (timeout, &signal_timeout, ic);
787 ac->cont = &iterator_start_receive;
789 GNUNET_CONTAINER_DLL_insert_tail (h->ac_head,
792 GNUNET_CONTAINER_DLL_insert_tail (h->ic_head,
795 trigger_transmit (h);
801 * Cancel an iteration over peer information.
803 * @param ic context of the iterator to cancel
806 GNUNET_PEERINFO_iterate_cancel (struct GNUNET_PEERINFO_IteratorContext *ic)
808 struct GNUNET_PEERINFO_Handle *h;
811 if (NULL != ic->timeout_task)
813 GNUNET_SCHEDULER_cancel (ic->timeout_task);
814 ic->timeout_task = NULL;
817 if (GNUNET_YES == ic->request_transmitted)
818 return; /* need to finish processing */
819 GNUNET_CONTAINER_DLL_remove (h->ic_head,
824 GNUNET_CONTAINER_DLL_remove (h->ac_head,
827 GNUNET_free (ic->ac);
833 /* end of peerinfo_api.c */