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Diffstat (limited to 'src/peerinfo/peerinfo_api.c')
| -rw-r--r-- | src/peerinfo/peerinfo_api.c | 661 |
1 files changed, 661 insertions, 0 deletions
diff --git a/src/peerinfo/peerinfo_api.c b/src/peerinfo/peerinfo_api.c new file mode 100644 index 0000000..4c5d795 --- /dev/null +++ b/src/peerinfo/peerinfo_api.c @@ -0,0 +1,661 @@ +/* + This file is part of GNUnet. + (C) 2001, 2002, 2004, 2005, 2007, 2009, 2010 Christian Grothoff (and other contributing authors) + + GNUnet is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published + by the Free Software Foundation; either version 3, or (at your + option) any later version. + + GNUnet is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with GNUnet; see the file COPYING. If not, write to the + Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. +*/ + +/** + * @file peerinfo/peerinfo_api.c + * @brief API to access peerinfo service + * @author Christian Grothoff + */ +#include "platform.h" +#include "gnunet_client_lib.h" +#include "gnunet_container_lib.h" +#include "gnunet_peerinfo_service.h" +#include "gnunet_protocols.h" +#include "gnunet_time_lib.h" +#include "peerinfo.h" + +#define LOG(kind,...) GNUNET_log_from (kind, "nse-api",__VA_ARGS__) + +/** + * Function to call after transmission has succeeded. + * + * @param cls closure + * @param success GNUNET_OK if transmission worked, GNUNET_SYSERR on error + */ +typedef void (*TransmissionContinuation) (void *cls, int success); + + +/** + * Entry in the transmission queue to PEERINFO service. + */ +struct TransmissionQueueEntry +{ + /** + * This is a linked list. + */ + struct TransmissionQueueEntry *next; + + /** + * This is a linked list. + */ + struct TransmissionQueueEntry *prev; + + /** + * Function to call after request has been transmitted, or NULL (in which + * case we must consider sending the next entry immediately). + */ + TransmissionContinuation cont; + + /** + * Closure for 'cont'. + */ + void *cont_cls; + + /** + * Timeout for the operation. + */ + struct GNUNET_TIME_Absolute timeout; + + /** + * Number of bytes of the request message (follows after this struct). + */ + size_t size; + +}; + + +/** + * Handle to the peerinfo service. + */ +struct GNUNET_PEERINFO_Handle +{ + /** + * Our configuration. + */ + const struct GNUNET_CONFIGURATION_Handle *cfg; + + /** + * Connection to the service. + */ + struct GNUNET_CLIENT_Connection *client; + + /** + * Head of transmission queue. + */ + struct TransmissionQueueEntry *tq_head; + + /** + * Tail of transmission queue. + */ + struct TransmissionQueueEntry *tq_tail; + + /** + * Handle for the current transmission request, or NULL if none is pending. + */ + struct GNUNET_CLIENT_TransmitHandle *th; + + /** + * ID for a reconnect task. + */ + GNUNET_SCHEDULER_TaskIdentifier r_task; + + /** + * Set to GNUNET_YES if we are currently receiving replies from the + * service. + */ + int in_receive; + +}; + + +/** + * Connect to the peerinfo service. + * + * @param cfg configuration to use + * @return NULL on error (configuration related, actual connection + * establishment may happen asynchronously). + */ +struct GNUNET_PEERINFO_Handle * +GNUNET_PEERINFO_connect (const struct GNUNET_CONFIGURATION_Handle *cfg) +{ + struct GNUNET_PEERINFO_Handle *ret; + + ret = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_Handle)); + ret->client = GNUNET_CLIENT_connect ("peerinfo", cfg); + ret->cfg = cfg; + return ret; +} + + +/** + * Disconnect from the peerinfo service. Note that all iterators must + * have completed or have been cancelled by the time this function is + * called (otherwise, calling this function is a serious error). + * Furthermore, if 'GNUNET_PEERINFO_add_peer' operations are still + * pending, they will be cancelled silently on disconnect. + * + * @param h handle to disconnect + */ +void +GNUNET_PEERINFO_disconnect (struct GNUNET_PEERINFO_Handle *h) +{ + struct TransmissionQueueEntry *tqe; + + while (NULL != (tqe = h->tq_head)) + { + GNUNET_CONTAINER_DLL_remove (h->tq_head, h->tq_tail, tqe); + if (tqe->cont != NULL) + tqe->cont (tqe->cont_cls, GNUNET_SYSERR); + GNUNET_free (tqe); + } + if (h->th != NULL) + { + GNUNET_CLIENT_notify_transmit_ready_cancel (h->th); + h->th = NULL; + } + if (NULL != h->client) + { + GNUNET_CLIENT_disconnect (h->client, GNUNET_NO); + h->client = NULL; + } + if (GNUNET_SCHEDULER_NO_TASK != h->r_task) + { + GNUNET_SCHEDULER_cancel (h->r_task); + h->r_task = GNUNET_SCHEDULER_NO_TASK; + } + GNUNET_free (h); +} + + +/** + * Check if we have a request pending in the transmission queue and are + * able to transmit it right now. If so, schedule transmission. + * + * @param h handle to the service + */ +static void +trigger_transmit (struct GNUNET_PEERINFO_Handle *h); + + +/** + * Close the existing connection to PEERINFO and reconnect. + * + * @param h handle to the service + */ +static void +reconnect (struct GNUNET_PEERINFO_Handle *h); + +/** + * Task scheduled to re-try connecting to the peerinfo service. + * + * @param cls the 'struct GNUNET_PEERINFO_Handle' + * @param tc scheduler context + */ +static void +reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) +{ + struct GNUNET_PEERINFO_Handle *h = cls; + + h->r_task = GNUNET_SCHEDULER_NO_TASK; + reconnect (h); +} + + +/** + * Close the existing connection to PEERINFO and reconnect. + * + * @param h handle to the service + */ +static void +reconnect (struct GNUNET_PEERINFO_Handle *h) +{ + if (h->r_task != GNUNET_SCHEDULER_NO_TASK) + { + GNUNET_SCHEDULER_cancel (h->r_task); + h->r_task = GNUNET_SCHEDULER_NO_TASK; + } + if (NULL != h->th) + { + GNUNET_CLIENT_notify_transmit_ready_cancel (h->th); + h->th = NULL; + } + if (NULL != h->client) + { + GNUNET_CLIENT_disconnect (h->client, GNUNET_SYSERR); + h->client = NULL; + } + h->client = GNUNET_CLIENT_connect ("peerinfo", h->cfg); + if (NULL == h->client) + { + h->r_task = + GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, &reconnect_task, + h); + return; + } + trigger_transmit (h); +} + + +/** + * Transmit the request at the head of the transmission queue + * and trigger continuation (if any). + * + * @param cls the 'struct GNUNET_PEERINFO_Handle' (with the queue) + * @param size size of the buffer (0 on error) + * @param buf where to copy the message + * @return number of bytes copied to buf + */ +static size_t +do_transmit (void *cls, size_t size, void *buf) +{ + struct GNUNET_PEERINFO_Handle *h = cls; + struct TransmissionQueueEntry *tqe = h->tq_head; + size_t ret; + + h->th = NULL; + if (tqe == NULL) + return 0; + if (buf == NULL) + { +#if DEBUG_PEERINFO + LOG (GNUNET_ERROR_TYPE_DEBUG | GNUNET_ERROR_TYPE_BULK, + _("Failed to transmit message to `%s' service.\n"), "PEERINFO"); +#endif + GNUNET_CONTAINER_DLL_remove (h->tq_head, h->tq_tail, tqe); + reconnect (h); + if (tqe->cont != NULL) + tqe->cont (tqe->cont_cls, GNUNET_SYSERR); + GNUNET_free (tqe); + return 0; + } + ret = tqe->size; + GNUNET_assert (size >= ret); + memcpy (buf, &tqe[1], ret); +#if DEBUG_PEERINFO + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Transmitting request of size %u to `%s' service.\n", ret, "PEERINFO"); +#endif + GNUNET_CONTAINER_DLL_remove (h->tq_head, h->tq_tail, tqe); + if (tqe->cont != NULL) + tqe->cont (tqe->cont_cls, GNUNET_OK); + else + trigger_transmit (h); + GNUNET_free (tqe); + return ret; +} + + +/** + * Check if we have a request pending in the transmission queue and are + * able to transmit it right now. If so, schedule transmission. + * + * @param h handle to the service + */ +static void +trigger_transmit (struct GNUNET_PEERINFO_Handle *h) +{ + struct TransmissionQueueEntry *tqe; + + if (NULL == (tqe = h->tq_head)) + return; + if (h->th != NULL) + return; + if (h->in_receive == GNUNET_YES) + return; + if (NULL == h->client) + { + reconnect (h); + return; + } + h->th = + GNUNET_CLIENT_notify_transmit_ready (h->client, tqe->size, + GNUNET_TIME_absolute_get_remaining + (tqe->timeout), GNUNET_YES, + &do_transmit, h); +} + + +/** + * Add a host to the persistent list. This method operates in + * semi-reliable mode: if the transmission is not completed by + * the time 'GNUNET_PEERINFO_disconnect' is called, it will be + * aborted. Furthermore, if a second HELLO is added for the + * same peer before the first one was transmitted, PEERINFO may + * merge the two HELLOs prior to transmission to the service. + * + * @param h handle to the peerinfo service + * @param hello the verified (!) HELLO message + */ +void +GNUNET_PEERINFO_add_peer (struct GNUNET_PEERINFO_Handle *h, + const struct GNUNET_HELLO_Message *hello) +{ + uint16_t hs = GNUNET_HELLO_size (hello); + struct TransmissionQueueEntry *tqe; + +#if DEBUG_PEERINFO + struct GNUNET_PeerIdentity peer; + + GNUNET_assert (GNUNET_OK == GNUNET_HELLO_get_id (hello, &peer)); + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Adding peer `%s' to PEERINFO database (%u bytes of `%s')\n", + GNUNET_i2s (&peer), hs, "HELLO"); +#endif + tqe = GNUNET_malloc (sizeof (struct TransmissionQueueEntry) + hs); + tqe->size = hs; + tqe->timeout = GNUNET_TIME_UNIT_FOREVER_ABS; + memcpy (&tqe[1], hello, hs); + GNUNET_CONTAINER_DLL_insert_after (h->tq_head, h->tq_tail, h->tq_tail, tqe); + trigger_transmit (h); +} + + +/** + * Context for an iteration request. + */ +struct GNUNET_PEERINFO_IteratorContext +{ + /** + * Handle to the PEERINFO service. + */ + struct GNUNET_PEERINFO_Handle *h; + + /** + * Function to call with the results. + */ + GNUNET_PEERINFO_Processor callback; + + /** + * Closure for 'callback'. + */ + void *callback_cls; + + /** + * Our entry in the transmission queue. + */ + struct TransmissionQueueEntry *tqe; + + /** + * Task responsible for timeout. + */ + GNUNET_SCHEDULER_TaskIdentifier timeout_task; + + /** + * Timeout for the operation. + */ + struct GNUNET_TIME_Absolute timeout; + + /** + * Are we now receiving? + */ + int in_receive; +}; + + +/** + * Type of a function to call when we receive a message + * from the service. + * + * @param cls closure + * @param msg message received, NULL on timeout or fatal error + */ +static void +peerinfo_handler (void *cls, const struct GNUNET_MessageHeader *msg) +{ + struct GNUNET_PEERINFO_IteratorContext *ic = cls; + const struct InfoMessage *im; + const struct GNUNET_HELLO_Message *hello; + uint16_t ms; + + ic->h->in_receive = GNUNET_NO; + if (msg == NULL) + { + reconnect (ic->h); + if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK) + GNUNET_SCHEDULER_cancel (ic->timeout_task); + if (ic->callback != NULL) + ic->callback (ic->callback_cls, NULL, NULL, + _("Failed to receive response from `PEERINFO' service.")); + GNUNET_free (ic); + return; + } + if (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_PEERINFO_INFO_END) + { +#if DEBUG_PEERINFO + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Received end of list of peers from `%s' service\n", "PEERINFO"); +#endif + trigger_transmit (ic->h); + if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK) + GNUNET_SCHEDULER_cancel (ic->timeout_task); + if (ic->callback != NULL) + ic->callback (ic->callback_cls, NULL, NULL, NULL); + GNUNET_free (ic); + return; + } + ms = ntohs (msg->size); + if ((ms < sizeof (struct InfoMessage)) || + (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_PEERINFO_INFO)) + { + GNUNET_break (0); + reconnect (ic->h); + if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK) + GNUNET_SCHEDULER_cancel (ic->timeout_task); + if (ic->callback != NULL) + ic->callback (ic->callback_cls, NULL, NULL, + _("Received invalid message from `PEERINFO' service.\n")); + GNUNET_free (ic); + return; + } + im = (const struct InfoMessage *) msg; + GNUNET_break (0 == ntohl (im->reserved)); + hello = NULL; + if (ms > sizeof (struct InfoMessage) + sizeof (struct GNUNET_MessageHeader)) + { + hello = (const struct GNUNET_HELLO_Message *) &im[1]; + if (ms != sizeof (struct InfoMessage) + GNUNET_HELLO_size (hello)) + { + GNUNET_break (0); + reconnect (ic->h); + if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK) + GNUNET_SCHEDULER_cancel (ic->timeout_task); + if (ic->callback != NULL) + ic->callback (ic->callback_cls, NULL, NULL, + _("Received invalid message from `PEERINFO' service.\n")); + GNUNET_free (ic); + return; + } + } +#if DEBUG_PEERINFO + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Received %u bytes of `%s' information about peer `%s' from `%s' service\n", + (hello == NULL) ? 0 : (unsigned int) GNUNET_HELLO_size (hello), "HELLO", + GNUNET_i2s (&im->peer), "PEERINFO"); +#endif + ic->h->in_receive = GNUNET_YES; + if (ic->callback != NULL) + ic->callback (ic->callback_cls, &im->peer, hello, NULL); + GNUNET_CLIENT_receive (ic->h->client, &peerinfo_handler, ic, + GNUNET_TIME_absolute_get_remaining (ic->timeout)); +} + + +/** + * We've transmitted the iteration request. Now get ready to process + * the results (or handle transmission error). + * + * @param cls the 'struct GNUNET_PEERINFO_IteratorContext' + * @param transmit_success GNUNET_OK if transmission worked + */ +static void +iterator_start_receive (void *cls, int transmit_success) +{ + struct GNUNET_PEERINFO_IteratorContext *ic = cls; + + if (GNUNET_OK != transmit_success) + { + if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK) + { + GNUNET_SCHEDULER_cancel (ic->timeout_task); + ic->timeout_task = GNUNET_SCHEDULER_NO_TASK; + } + reconnect (ic->h); + if (ic->callback != NULL) + ic->callback (ic->callback_cls, NULL, NULL, + _ + ("Failed to transmit iteration request to `PEERINFO' service\n")); + GNUNET_free (ic); + return; + } +#if DEBUG_PEERINFO + LOG (GNUNET_ERROR_TYPE_DEBUG, "Waiting for response from `%s' service.\n", + "PEERINFO"); +#endif + ic->h->in_receive = GNUNET_YES; + ic->in_receive = GNUNET_YES; + ic->tqe = NULL; + GNUNET_CLIENT_receive (ic->h->client, &peerinfo_handler, ic, + GNUNET_TIME_absolute_get_remaining (ic->timeout)); +} + + +/** + * Peerinfo iteration request has timed out. + * + * @param cls the 'struct GNUNET_PEERINFO_IteratorContext*' + * @param tc scheduler context + */ +static void +signal_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) +{ + struct GNUNET_PEERINFO_IteratorContext *ic = cls; + + ic->timeout_task = GNUNET_SCHEDULER_NO_TASK; + if (!ic->in_receive) + GNUNET_CONTAINER_DLL_remove (ic->h->tq_head, ic->h->tq_tail, ic->tqe); + else + reconnect (ic->h); + ic->callback (ic->callback_cls, NULL, NULL, + _ + ("Timeout transmitting iteration request to `PEERINFO' service.\n")); + ic->callback = NULL; + GNUNET_free_non_null (ic->tqe); + GNUNET_free (ic); +} + + +/** + * Call a method for each known matching host and change its trust + * value. The callback method will be invoked once for each matching + * host and then finally once with a NULL pointer. After that final + * invocation, the iterator context must no longer be used. + * + * Instead of calling this function with 'peer == NULL' it is often + * better to use 'GNUNET_PEERINFO_notify'. + * + * @param h handle to the peerinfo service + * @param peer restrict iteration to this peer only (can be NULL) + * @param timeout how long to wait until timing out + * @param callback the method to call for each peer + * @param callback_cls closure for callback + * @return iterator context + */ +struct GNUNET_PEERINFO_IteratorContext * +GNUNET_PEERINFO_iterate (struct GNUNET_PEERINFO_Handle *h, + const struct GNUNET_PeerIdentity *peer, + struct GNUNET_TIME_Relative timeout, + GNUNET_PEERINFO_Processor callback, void *callback_cls) +{ + struct GNUNET_MessageHeader *lapm; + struct ListPeerMessage *lpm; + struct GNUNET_PEERINFO_IteratorContext *ic; + struct TransmissionQueueEntry *tqe; + + if (peer == NULL) + { +#if DEBUG_PEERINFO + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Requesting list of peers from PEERINFO service\n"); +#endif + tqe = + GNUNET_malloc (sizeof (struct TransmissionQueueEntry) + + sizeof (struct GNUNET_MessageHeader)); + tqe->size = sizeof (struct GNUNET_MessageHeader); + lapm = (struct GNUNET_MessageHeader *) &tqe[1]; + lapm->size = htons (sizeof (struct GNUNET_MessageHeader)); + lapm->type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_GET_ALL); + } + else + { +#if DEBUG_PEERINFO + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Requesting information on peer `%4s' from PEERINFO service\n", + GNUNET_i2s (peer)); +#endif + tqe = + GNUNET_malloc (sizeof (struct TransmissionQueueEntry) + + sizeof (struct ListPeerMessage)); + tqe->size = sizeof (struct ListPeerMessage); + lpm = (struct ListPeerMessage *) &tqe[1]; + lpm->header.size = htons (sizeof (struct ListPeerMessage)); + lpm->header.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_GET); + memcpy (&lpm->peer, peer, sizeof (struct GNUNET_PeerIdentity)); + } + ic = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_IteratorContext)); + ic->h = h; + ic->tqe = tqe; + ic->callback = callback; + ic->callback_cls = callback_cls; + ic->timeout = GNUNET_TIME_relative_to_absolute (timeout); + ic->timeout_task = + GNUNET_SCHEDULER_add_delayed (timeout, &signal_timeout, ic); + tqe->timeout = ic->timeout; + tqe->cont = &iterator_start_receive; + tqe->cont_cls = ic; + tqe->timeout = ic->timeout; + GNUNET_CONTAINER_DLL_insert_after (h->tq_head, h->tq_tail, h->tq_tail, tqe); + trigger_transmit (h); + return ic; +} + + +/** + * Cancel an iteration over peer information. + * + * @param ic context of the iterator to cancel + */ +void +GNUNET_PEERINFO_iterate_cancel (struct GNUNET_PEERINFO_IteratorContext *ic) +{ + if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK) + { + GNUNET_SCHEDULER_cancel (ic->timeout_task); + ic->timeout_task = GNUNET_SCHEDULER_NO_TASK; + } + ic->callback = NULL; + if (GNUNET_YES == ic->in_receive) + return; /* need to finish processing */ + GNUNET_CONTAINER_DLL_remove (ic->h->tq_head, ic->h->tq_tail, ic->tqe); + GNUNET_free (ic->tqe); + GNUNET_free (ic); +} + + +/* end of peerinfo_api.c */ |