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3 (C) 2001, 2002, 2004, 2005, 2007, 2009, 2010 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, "nse-api",__VA_ARGS__)
37 * Function to call after transmission has succeeded.
40 * @param success GNUNET_OK if transmission worked, GNUNET_SYSERR on error
42 typedef void (*TransmissionContinuation) (void *cls, int success);
46 * Entry in the transmission queue to PEERINFO service.
48 struct TransmissionQueueEntry
51 * This is a linked list.
53 struct TransmissionQueueEntry *next;
56 * This is a linked list.
58 struct TransmissionQueueEntry *prev;
61 * Function to call after request has been transmitted, or NULL (in which
62 * case we must consider sending the next entry immediately).
64 TransmissionContinuation cont;
72 * Timeout for the operation.
74 struct GNUNET_TIME_Absolute timeout;
77 * Number of bytes of the request message (follows after this struct).
85 * Handle to the peerinfo service.
87 struct GNUNET_PEERINFO_Handle
92 const struct GNUNET_CONFIGURATION_Handle *cfg;
95 * Connection to the service.
97 struct GNUNET_CLIENT_Connection *client;
100 * Head of transmission queue.
102 struct TransmissionQueueEntry *tq_head;
105 * Tail of transmission queue.
107 struct TransmissionQueueEntry *tq_tail;
110 * Handle for the current transmission request, or NULL if none is pending.
112 struct GNUNET_CLIENT_TransmitHandle *th;
115 * ID for a reconnect task.
117 GNUNET_SCHEDULER_TaskIdentifier r_task;
120 * Set to GNUNET_YES if we are currently receiving replies from the
129 * Connect to the peerinfo service.
131 * @param cfg configuration to use
132 * @return NULL on error (configuration related, actual connection
133 * establishment may happen asynchronously).
135 struct GNUNET_PEERINFO_Handle *
136 GNUNET_PEERINFO_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
138 struct GNUNET_PEERINFO_Handle *ret;
140 ret = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_Handle));
141 ret->client = GNUNET_CLIENT_connect ("peerinfo", cfg);
148 * Disconnect from the peerinfo service. Note that all iterators must
149 * have completed or have been cancelled by the time this function is
150 * called (otherwise, calling this function is a serious error).
151 * Furthermore, if 'GNUNET_PEERINFO_add_peer' operations are still
152 * pending, they will be cancelled silently on disconnect.
154 * @param h handle to disconnect
157 GNUNET_PEERINFO_disconnect (struct GNUNET_PEERINFO_Handle *h)
159 struct TransmissionQueueEntry *tqe;
161 while (NULL != (tqe = h->tq_head))
163 GNUNET_CONTAINER_DLL_remove (h->tq_head, h->tq_tail, tqe);
164 if (tqe->cont != NULL)
165 tqe->cont (tqe->cont_cls, GNUNET_SYSERR);
170 GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
173 if (NULL != h->client)
175 GNUNET_CLIENT_disconnect (h->client, GNUNET_NO);
178 if (GNUNET_SCHEDULER_NO_TASK != h->r_task)
180 GNUNET_SCHEDULER_cancel (h->r_task);
181 h->r_task = GNUNET_SCHEDULER_NO_TASK;
188 * Check if we have a request pending in the transmission queue and are
189 * able to transmit it right now. If so, schedule transmission.
191 * @param h handle to the service
194 trigger_transmit (struct GNUNET_PEERINFO_Handle *h);
198 * Close the existing connection to PEERINFO and reconnect.
200 * @param h handle to the service
203 reconnect (struct GNUNET_PEERINFO_Handle *h);
206 * Task scheduled to re-try connecting to the peerinfo service.
208 * @param cls the 'struct GNUNET_PEERINFO_Handle'
209 * @param tc scheduler context
212 reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
214 struct GNUNET_PEERINFO_Handle *h = cls;
216 h->r_task = GNUNET_SCHEDULER_NO_TASK;
222 * Close the existing connection to PEERINFO and reconnect.
224 * @param h handle to the service
227 reconnect (struct GNUNET_PEERINFO_Handle *h)
229 if (h->r_task != GNUNET_SCHEDULER_NO_TASK)
231 GNUNET_SCHEDULER_cancel (h->r_task);
232 h->r_task = GNUNET_SCHEDULER_NO_TASK;
236 GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
239 if (NULL != h->client)
241 GNUNET_CLIENT_disconnect (h->client, GNUNET_SYSERR);
244 h->client = GNUNET_CLIENT_connect ("peerinfo", h->cfg);
245 if (NULL == h->client)
248 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, &reconnect_task,
252 trigger_transmit (h);
257 * Transmit the request at the head of the transmission queue
258 * and trigger continuation (if any).
260 * @param cls the 'struct GNUNET_PEERINFO_Handle' (with the queue)
261 * @param size size of the buffer (0 on error)
262 * @param buf where to copy the message
263 * @return number of bytes copied to buf
266 do_transmit (void *cls, size_t size, void *buf)
268 struct GNUNET_PEERINFO_Handle *h = cls;
269 struct TransmissionQueueEntry *tqe = h->tq_head;
278 LOG (GNUNET_ERROR_TYPE_DEBUG | GNUNET_ERROR_TYPE_BULK,
279 _("Failed to transmit message to `%s' service.\n"), "PEERINFO");
281 GNUNET_CONTAINER_DLL_remove (h->tq_head, h->tq_tail, tqe);
283 if (tqe->cont != NULL)
284 tqe->cont (tqe->cont_cls, GNUNET_SYSERR);
289 GNUNET_assert (size >= ret);
290 memcpy (buf, &tqe[1], ret);
292 LOG (GNUNET_ERROR_TYPE_DEBUG,
293 "Transmitting request of size %u to `%s' service.\n", ret, "PEERINFO");
295 GNUNET_CONTAINER_DLL_remove (h->tq_head, h->tq_tail, tqe);
296 if (tqe->cont != NULL)
297 tqe->cont (tqe->cont_cls, GNUNET_OK);
299 trigger_transmit (h);
306 * Check if we have a request pending in the transmission queue and are
307 * able to transmit it right now. If so, schedule transmission.
309 * @param h handle to the service
312 trigger_transmit (struct GNUNET_PEERINFO_Handle *h)
314 struct TransmissionQueueEntry *tqe;
316 if (NULL == (tqe = h->tq_head))
320 if (h->in_receive == GNUNET_YES)
322 if (NULL == h->client)
328 GNUNET_CLIENT_notify_transmit_ready (h->client, tqe->size,
329 GNUNET_TIME_absolute_get_remaining
330 (tqe->timeout), GNUNET_YES,
336 * Add a host to the persistent list. This method operates in
337 * semi-reliable mode: if the transmission is not completed by
338 * the time 'GNUNET_PEERINFO_disconnect' is called, it will be
339 * aborted. Furthermore, if a second HELLO is added for the
340 * same peer before the first one was transmitted, PEERINFO may
341 * merge the two HELLOs prior to transmission to the service.
343 * @param h handle to the peerinfo service
344 * @param hello the verified (!) HELLO message
347 GNUNET_PEERINFO_add_peer (struct GNUNET_PEERINFO_Handle *h,
348 const struct GNUNET_HELLO_Message *hello)
350 uint16_t hs = GNUNET_HELLO_size (hello);
351 struct TransmissionQueueEntry *tqe;
354 struct GNUNET_PeerIdentity peer;
356 GNUNET_assert (GNUNET_OK == GNUNET_HELLO_get_id (hello, &peer));
357 LOG (GNUNET_ERROR_TYPE_DEBUG,
358 "Adding peer `%s' to PEERINFO database (%u bytes of `%s')\n",
359 GNUNET_i2s (&peer), hs, "HELLO");
361 tqe = GNUNET_malloc (sizeof (struct TransmissionQueueEntry) + hs);
363 tqe->timeout = GNUNET_TIME_UNIT_FOREVER_ABS;
364 memcpy (&tqe[1], hello, hs);
365 GNUNET_CONTAINER_DLL_insert_after (h->tq_head, h->tq_tail, h->tq_tail, tqe);
366 trigger_transmit (h);
371 * Context for an iteration request.
373 struct GNUNET_PEERINFO_IteratorContext
376 * Handle to the PEERINFO service.
378 struct GNUNET_PEERINFO_Handle *h;
381 * Function to call with the results.
383 GNUNET_PEERINFO_Processor callback;
386 * Closure for 'callback'.
391 * Our entry in the transmission queue.
393 struct TransmissionQueueEntry *tqe;
396 * Task responsible for timeout.
398 GNUNET_SCHEDULER_TaskIdentifier timeout_task;
401 * Timeout for the operation.
403 struct GNUNET_TIME_Absolute timeout;
406 * Are we now receiving?
413 * Type of a function to call when we receive a message
417 * @param msg message received, NULL on timeout or fatal error
420 peerinfo_handler (void *cls, const struct GNUNET_MessageHeader *msg)
422 struct GNUNET_PEERINFO_IteratorContext *ic = cls;
423 const struct InfoMessage *im;
424 const struct GNUNET_HELLO_Message *hello;
427 ic->h->in_receive = GNUNET_NO;
431 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
432 GNUNET_SCHEDULER_cancel (ic->timeout_task);
433 if (ic->callback != NULL)
434 ic->callback (ic->callback_cls, NULL, NULL,
435 _("Failed to receive response from `PEERINFO' service."));
439 if (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_PEERINFO_INFO_END)
442 LOG (GNUNET_ERROR_TYPE_DEBUG,
443 "Received end of list of peers from `%s' service\n", "PEERINFO");
445 trigger_transmit (ic->h);
446 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
447 GNUNET_SCHEDULER_cancel (ic->timeout_task);
448 if (ic->callback != NULL)
449 ic->callback (ic->callback_cls, NULL, NULL, NULL);
453 ms = ntohs (msg->size);
454 if ((ms < sizeof (struct InfoMessage)) ||
455 (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_PEERINFO_INFO))
459 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
460 GNUNET_SCHEDULER_cancel (ic->timeout_task);
461 if (ic->callback != NULL)
462 ic->callback (ic->callback_cls, NULL, NULL,
463 _("Received invalid message from `PEERINFO' service.\n"));
467 im = (const struct InfoMessage *) msg;
468 GNUNET_break (0 == ntohl (im->reserved));
470 if (ms > sizeof (struct InfoMessage) + sizeof (struct GNUNET_MessageHeader))
472 hello = (const struct GNUNET_HELLO_Message *) &im[1];
473 if (ms != sizeof (struct InfoMessage) + GNUNET_HELLO_size (hello))
477 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
478 GNUNET_SCHEDULER_cancel (ic->timeout_task);
479 if (ic->callback != NULL)
480 ic->callback (ic->callback_cls, NULL, NULL,
481 _("Received invalid message from `PEERINFO' service.\n"));
487 LOG (GNUNET_ERROR_TYPE_DEBUG,
488 "Received %u bytes of `%s' information about peer `%s' from `%s' service\n",
489 (hello == NULL) ? 0 : (unsigned int) GNUNET_HELLO_size (hello), "HELLO",
490 GNUNET_i2s (&im->peer), "PEERINFO");
492 ic->h->in_receive = GNUNET_YES;
493 if (ic->callback != NULL)
494 ic->callback (ic->callback_cls, &im->peer, hello, NULL);
495 GNUNET_CLIENT_receive (ic->h->client, &peerinfo_handler, ic,
496 GNUNET_TIME_absolute_get_remaining (ic->timeout));
501 * We've transmitted the iteration request. Now get ready to process
502 * the results (or handle transmission error).
504 * @param cls the 'struct GNUNET_PEERINFO_IteratorContext'
505 * @param transmit_success GNUNET_OK if transmission worked
508 iterator_start_receive (void *cls, int transmit_success)
510 struct GNUNET_PEERINFO_IteratorContext *ic = cls;
512 if (GNUNET_OK != transmit_success)
514 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
516 GNUNET_SCHEDULER_cancel (ic->timeout_task);
517 ic->timeout_task = GNUNET_SCHEDULER_NO_TASK;
520 if (ic->callback != NULL)
521 ic->callback (ic->callback_cls, NULL, NULL,
523 ("Failed to transmit iteration request to `PEERINFO' service"));
528 LOG (GNUNET_ERROR_TYPE_DEBUG, "Waiting for response from `%s' service.\n",
531 ic->h->in_receive = GNUNET_YES;
532 ic->in_receive = GNUNET_YES;
534 GNUNET_CLIENT_receive (ic->h->client, &peerinfo_handler, ic,
535 GNUNET_TIME_absolute_get_remaining (ic->timeout));
540 * Peerinfo iteration request has timed out.
542 * @param cls the 'struct GNUNET_PEERINFO_IteratorContext*'
543 * @param tc scheduler context
546 signal_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
548 struct GNUNET_PEERINFO_IteratorContext *ic = cls;
550 ic->timeout_task = GNUNET_SCHEDULER_NO_TASK;
552 GNUNET_CONTAINER_DLL_remove (ic->h->tq_head, ic->h->tq_tail, ic->tqe);
555 ic->callback (ic->callback_cls, NULL, NULL,
557 ("Timeout transmitting iteration request to `PEERINFO' service.\n"));
559 GNUNET_free_non_null (ic->tqe);
565 * Call a method for each known matching host and change its trust
566 * value. The callback method will be invoked once for each matching
567 * host and then finally once with a NULL pointer. After that final
568 * invocation, the iterator context must no longer be used.
570 * Instead of calling this function with 'peer == NULL' it is often
571 * better to use 'GNUNET_PEERINFO_notify'.
573 * @param h handle to the peerinfo service
574 * @param peer restrict iteration to this peer only (can be NULL)
575 * @param timeout how long to wait until timing out
576 * @param callback the method to call for each peer
577 * @param callback_cls closure for callback
578 * @return iterator context
580 struct GNUNET_PEERINFO_IteratorContext *
581 GNUNET_PEERINFO_iterate (struct GNUNET_PEERINFO_Handle *h,
582 const struct GNUNET_PeerIdentity *peer,
583 struct GNUNET_TIME_Relative timeout,
584 GNUNET_PEERINFO_Processor callback, void *callback_cls)
586 struct GNUNET_MessageHeader *lapm;
587 struct ListPeerMessage *lpm;
588 struct GNUNET_PEERINFO_IteratorContext *ic;
589 struct TransmissionQueueEntry *tqe;
594 LOG (GNUNET_ERROR_TYPE_DEBUG,
595 "Requesting list of peers from PEERINFO service\n");
598 GNUNET_malloc (sizeof (struct TransmissionQueueEntry) +
599 sizeof (struct GNUNET_MessageHeader));
600 tqe->size = sizeof (struct GNUNET_MessageHeader);
601 lapm = (struct GNUNET_MessageHeader *) &tqe[1];
602 lapm->size = htons (sizeof (struct GNUNET_MessageHeader));
603 lapm->type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_GET_ALL);
608 LOG (GNUNET_ERROR_TYPE_DEBUG,
609 "Requesting information on peer `%4s' from PEERINFO service\n",
613 GNUNET_malloc (sizeof (struct TransmissionQueueEntry) +
614 sizeof (struct ListPeerMessage));
615 tqe->size = sizeof (struct ListPeerMessage);
616 lpm = (struct ListPeerMessage *) &tqe[1];
617 lpm->header.size = htons (sizeof (struct ListPeerMessage));
618 lpm->header.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_GET);
619 memcpy (&lpm->peer, peer, sizeof (struct GNUNET_PeerIdentity));
621 ic = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_IteratorContext));
624 ic->callback = callback;
625 ic->callback_cls = callback_cls;
626 ic->timeout = GNUNET_TIME_relative_to_absolute (timeout);
628 GNUNET_SCHEDULER_add_delayed (timeout, &signal_timeout, ic);
629 tqe->timeout = ic->timeout;
630 tqe->cont = &iterator_start_receive;
632 tqe->timeout = ic->timeout;
633 GNUNET_CONTAINER_DLL_insert_after (h->tq_head, h->tq_tail, h->tq_tail, tqe);
634 trigger_transmit (h);
640 * Cancel an iteration over peer information.
642 * @param ic context of the iterator to cancel
645 GNUNET_PEERINFO_iterate_cancel (struct GNUNET_PEERINFO_IteratorContext *ic)
647 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
649 GNUNET_SCHEDULER_cancel (ic->timeout_task);
650 ic->timeout_task = GNUNET_SCHEDULER_NO_TASK;
653 if (GNUNET_YES == ic->in_receive)
654 return; /* need to finish processing */
655 GNUNET_CONTAINER_DLL_remove (ic->h->tq_head, ic->h->tq_tail, ic->tqe);
656 GNUNET_free (ic->tqe);
661 /* end of peerinfo_api.c */