/*
This file is part of GNUnet.
- (C) 2009, 2010 Christian Grothoff (and other contributing authors)
+ (C) 2009-2013 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
Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.
*/
-
/**
* @file gns/gns_api.c
* @brief library to access the GNS service
* @author Martin Schanzenbach
+ * @author Christian Grothoff
*/
-
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_constants.h"
#include "gnunet_hello_lib.h"
#include "gnunet_protocols.h"
#include "gnunet_dht_service.h"
+#include "gns.h"
+#include "gnunet_gns_service.h"
-#define DEBUG_GNS_API GNUNET_EXTRA_LOGGING
-
-#define LOG(kind,...) GNUNET_log_from (kind, "gns-api",__VA_ARGS__)
/**
- * Handle to a Lookup request
+ * Handle to a lookup request
*/
-struct GNUNET_GNS_LookupHandle
+struct GNUNET_GNS_LookupRequest
{
/**
- * Iterator to call on data receipt
+ * DLL
+ */
+ struct GNUNET_GNS_LookupRequest *next;
+
+ /**
+ * DLL
+ */
+ struct GNUNET_GNS_LookupRequest *prev;
+
+ /**
+ * handle to gns
+ */
+ struct GNUNET_GNS_Handle *gns_handle;
+
+ /**
+ * processor to call on lookup result
*/
- GNUNET_GNS_LookupIterator iter;
+ GNUNET_GNS_LookupResultProcessor lookup_proc;
/**
- * Closure for the iterator callback
+ * processor closure
*/
- void *iter_cls;
+ void *proc_cls;
+
+ /**
+ * request id
+ */
+ uint32_t r_id;
+
+};
+
+/**
+ * Entry in our list of messages to be (re-)transmitted.
+ */
+struct PendingMessage
+{
/**
- * Main handle to this GNS api
+ * This is a doubly-linked list.
*/
- struct GNUNET_GNS_Handle *gns_handle;
+ struct PendingMessage *prev;
/**
- * Key that this get request is for
+ * This is a doubly-linked list.
*/
- GNUNET_HashCode key;
+ struct PendingMessage *next;
/**
- * Unique identifier for this request (for key collisions).
+ * Size of the message.
*/
- uint64_t unique_id;
+ size_t size;
+
+ /**
+ * request id
+ */
+ uint32_t r_id;
+
+ /**
+ * This message has been transmitted. GNUNET_NO if the message is
+ * in the "pending" DLL, GNUNET_YES if it has been transmitted to
+ * the service via the current client connection.
+ */
+ int transmitted;
};
* Currently pending transmission request (or NULL).
*/
struct GNUNET_CLIENT_TransmitHandle *th;
+
+ /**
+ * Head of linked list of shorten messages we would like to transmit.
+ */
+ struct PendingMessage *pending_head;
- GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
+ /**
+ * Tail of linked list of shorten messages we would like to transmit.
+ */
+ struct PendingMessage *pending_tail;
+
+ /**
+ * Head of linked list of lookup messages we would like to transmit.
+ */
+ struct GNUNET_GNS_LookupRequest *lookup_head;
/**
- * How quickly should we retry? Used for exponential back-off on
- * connect-errors.
+ * Tail of linked list of lookup messages we would like to transmit.
*/
- struct GNUNET_TIME_Relative retry_time;
+ struct GNUNET_GNS_LookupRequest *lookup_tail;
/**
- * Generator for unique ids.
+ * Reconnect task
*/
- uint64_t uid_gen;
+ GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
+
+ /**
+ * How long do we wait until we try to reconnect?
+ */
+ struct GNUNET_TIME_Relative reconnect_backoff;
+ /**
+ * Request Id generator. Incremented by one for each request.
+ */
+ uint32_t r_id_gen;
+
/**
* Did we start our receive loop yet?
*/
int in_receive;
+
};
/**
- * Try to (re)connect to the GNS service.
+ * Try to send messages from list of messages to send
+ * @param handle GNS_Handle
+ */
+static void
+process_pending_messages (struct GNUNET_GNS_Handle *handle);
+
+
+/**
+ * Reconnect to GNS service.
*
- * @return GNUNET_YES on success, GNUNET_NO on failure.
+ * @param handle the handle to the GNS service
*/
-static int
-try_connect (struct GNUNET_GNS_Handle *handle)
+static void
+reconnect (struct GNUNET_GNS_Handle *handle)
{
- if (handle->client != NULL)
- return GNUNET_OK;
- handle->in_receive = GNUNET_NO;
+ GNUNET_assert (NULL == handle->client);
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Trying to connect to GNS\n");
handle->client = GNUNET_CLIENT_connect ("gns", handle->cfg);
- if (handle->client == NULL)
- {
- LOG (GNUNET_ERROR_TYPE_WARNING,
- _("Failed to connect to the GNS service!\n"));
- return GNUNET_NO;
- }
- return GNUNET_YES;
+ GNUNET_assert (NULL != handle->client);
+ process_pending_messages (handle);
}
+
/**
- * Try reconnecting to the GNS service.
+ * Reconnect to GNS
*
- * @param cls GNUNET_GNS_Handle
- * @param tc scheduler context
+ * @param cls the handle
+ * @param tc task context
*/
static void
-try_reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
struct GNUNET_GNS_Handle *handle = cls;
-#if DEBUG_DHT
- LOG (GNUNET_ERROR_TYPE_DEBUG, "Reconnecting with GNS %p\n", handle);
-#endif
- handle->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
- if (handle->retry_time.rel_value < GNUNET_CONSTANTS_SERVICE_RETRY.rel_value)
- handle->retry_time = GNUNET_CONSTANTS_SERVICE_RETRY;
- else
- handle->retry_time = GNUNET_TIME_relative_multiply (handle->retry_time, 2);
- if (handle->retry_time.rel_value > GNUNET_CONSTANTS_SERVICE_TIMEOUT.rel_value)
- handle->retry_time = GNUNET_CONSTANTS_SERVICE_TIMEOUT;
handle->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
- if (GNUNET_YES != try_connect (handle))
+ reconnect (handle);
+}
+
+
+/**
+ * Disconnect from service and then reconnect.
+ *
+ * @param handle our handle
+ */
+static void
+force_reconnect (struct GNUNET_GNS_Handle *handle)
+{
+ struct GNUNET_GNS_LookupRequest *lh;
+ struct PendingMessage *p;
+
+ GNUNET_CLIENT_disconnect (handle->client);
+ handle->client = NULL;
+ handle->in_receive = GNUNET_NO;
+ for (lh = handle->lookup_head; NULL != lh; lh = lh->next)
{
-#if DEBUG_DHT
- LOG (GNUNET_ERROR_TYPE_DEBUG, "GNS reconnect failed(!)\n");
-#endif
- return;
+ p = (struct PendingMessage *) &lh[1];
+ if (GNUNET_NO == p->transmitted)
+ continue;
+ p->transmitted = GNUNET_NO;
+ GNUNET_CONTAINER_DLL_insert (handle->pending_head,
+ handle->pending_tail,
+ p);
}
- GNUNET_CONTAINER_multihashmap_iterate (handle->active_requests,
- &add_request_to_pending, handle);
- process_pending_messages (handle);
+ handle->reconnect_backoff = GNUNET_TIME_STD_BACKOFF (handle->reconnect_backoff);
+ handle->reconnect_task = GNUNET_SCHEDULER_add_delayed (handle->reconnect_backoff,
+ &reconnect_task,
+ handle);
}
/**
- * Try reconnecting to the GNS service.
+ * Transmit the next pending message, called by notify_transmit_ready
*
- * @param handle handle to gns to (possibly) disconnect and reconnect
+ * @param cls the closure
+ * @param size size of pending data
+ * @param buf buffer with pending data
+ * @return size data transmitted
+ */
+static size_t
+transmit_pending (void *cls, size_t size, void *buf);
+
+
+/**
+ * Handler for messages received from the GNS service
+ *
+ * @param cls the 'struct GNUNET_GNS_Handle'
+ * @param msg the incoming message
*/
static void
-do_disconnect (struct GNUNET_GNS_Handle *handle)
+process_message (void *cls, const struct GNUNET_MessageHeader *msg);
+
+
+/**
+ * Try to send messages from list of messages to send
+ *
+ * @param handle the GNS handle
+ */
+static void
+process_pending_messages (struct GNUNET_GNS_Handle *handle)
{
- if (handle->client == NULL)
- return;
- GNUNET_assert (handle->reconnect_task == GNUNET_SCHEDULER_NO_TASK);
+ struct PendingMessage *p = handle->pending_head;
+
+ if (NULL == handle->client)
+ return; /* wait for reconnect */
if (NULL != handle->th)
- GNUNET_CLIENT_notify_transmit_ready_cancel (handle->th);
+ return; /* transmission request already pending */
+
+ while ((NULL != p) && (p->transmitted == GNUNET_YES))
+ p = p->next;
+ if (NULL == p)
+ return; /* no messages pending */
+
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Trying to transmit %u bytes\n",
+ (unsigned int) p->size);
+ handle->th =
+ GNUNET_CLIENT_notify_transmit_ready (handle->client,
+ p->size,
+ GNUNET_TIME_UNIT_FOREVER_REL,
+ GNUNET_NO, &transmit_pending,
+ handle);
+ GNUNET_break (NULL != handle->th);
+}
+
+
+/**
+ * Transmit the next pending message, called by notify_transmit_ready
+ *
+ * @param cls the closure
+ * @param size size of pending data
+ * @param buf buffer with pending data
+ * @return size data transmitted
+ */
+static size_t
+transmit_pending (void *cls, size_t size, void *buf)
+{
+ struct GNUNET_GNS_Handle *handle = cls;
+ char *cbuf = buf;
+ struct PendingMessage *p;
+ size_t tsize;
+
handle->th = NULL;
+ if ((0 == size) || (NULL == buf))
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Transmission to GNS service failed!\n");
+ force_reconnect (handle);
+ return 0;
+ }
+ if (NULL == (p = handle->pending_head))
+ return 0;
+
+ tsize = 0;
+ while ((NULL != (p = handle->pending_head)) && (p->size <= size))
+ {
+ memcpy (&cbuf[tsize], &p[1], p->size);
+ tsize += p->size;
+ size -= p->size;
+ p->transmitted = GNUNET_YES;
+ GNUNET_CONTAINER_DLL_remove (handle->pending_head,
+ handle->pending_tail,
+ p);
+ if (GNUNET_YES != handle->in_receive)
+ {
+ GNUNET_CLIENT_receive (handle->client, &process_message, handle,
+ GNUNET_TIME_UNIT_FOREVER_REL);
+ handle->in_receive = GNUNET_YES;
+ }
+ }
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Disconnecting from GNS service, will try to reconnect in %llu ms\n",
- (unsigned long long) handle->retry_time.rel_value);
- GNUNET_CLIENT_disconnect (handle->client, GNUNET_NO);
- handle->client = NULL;
- handle->reconnect_task =
- GNUNET_SCHEDULER_add_delayed (handle->retry_time, &try_reconnect, handle);
+ "Sending %u bytes\n",
+ (unsigned int) tsize);
+ process_pending_messages (handle);
+ return tsize;
+}
+
+
+/**
+ * Process a given reply to the lookup request
+ *
+ * @param qe a queue entry
+ * @param msg the lookup message received
+ */
+static void
+process_lookup_reply (struct GNUNET_GNS_LookupRequest *qe,
+ const struct GNUNET_GNS_ClientLookupResultMessage *msg)
+{
+ struct GNUNET_GNS_Handle *handle = qe->gns_handle;
+ struct PendingMessage *p = (struct PendingMessage *) &qe[1];
+ uint32_t rd_count = ntohl (msg->rd_count);
+ struct GNUNET_NAMESTORE_RecordData rd[rd_count];
+ size_t mlen;
+
+ if (GNUNET_YES != p->transmitted)
+ {
+ /* service send reply to query we never managed to send!? */
+ GNUNET_break (0);
+ force_reconnect (handle);
+ return;
+ }
+ mlen = ntohs (msg->header.size);
+ mlen -= sizeof (struct GNUNET_GNS_ClientLookupResultMessage);
+ if (GNUNET_SYSERR == GNUNET_NAMESTORE_records_deserialize (mlen,
+ (const char*) &msg[1],
+ rd_count,
+ rd))
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+ _("Failed to serialize lookup reply from GNS service!\n"));
+ qe->lookup_proc (qe->proc_cls, 0, NULL);
+ }
+ else
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Received lookup reply from GNS service (%u records)\n",
+ (unsigned int) rd_count);
+ qe->lookup_proc (qe->proc_cls, rd_count, rd);
+ }
+ GNUNET_CONTAINER_DLL_remove (handle->lookup_head, handle->lookup_tail, qe);
+ GNUNET_free (qe);
+}
+
+
+/**
+ * Handler for messages received from the GNS service
+ *
+ * @param cls the 'struct GNUNET_GNS_Handle'
+ * @param msg the incoming message
+ */
+static void
+process_message (void *cls, const struct GNUNET_MessageHeader *msg)
+{
+ struct GNUNET_GNS_Handle *handle = cls;
+ struct GNUNET_GNS_LookupRequest *lr;
+ const struct GNUNET_GNS_ClientLookupResultMessage *lookup_msg;
+ uint32_t r_id;
+
+ if (NULL == msg)
+ {
+ force_reconnect (handle);
+ return;
+ }
+ switch (ntohs (msg->type))
+ {
+ case GNUNET_MESSAGE_TYPE_GNS_LOOKUP_RESULT:
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Got LOOKUP_RESULT msg\n");
+ if (ntohs (msg->size) < sizeof (struct GNUNET_GNS_ClientLookupResultMessage))
+ {
+ GNUNET_break (0);
+ force_reconnect (handle);
+ return;
+ }
+ lookup_msg = (const struct GNUNET_GNS_ClientLookupResultMessage *) msg;
+ r_id = ntohl (lookup_msg->id);
+ for (lr = handle->lookup_head; NULL != lr; lr = lr->next)
+ if (lr->r_id == r_id)
+ {
+ process_lookup_reply(lr, lookup_msg);
+ break;
+ }
+ break;
+ default:
+ GNUNET_break (0);
+ force_reconnect (handle);
+ return;
+ }
+ GNUNET_CLIENT_receive (handle->client, &process_message, handle,
+ GNUNET_TIME_UNIT_FOREVER_REL);
}
* @return handle to the GNS service, or NULL on error
*/
struct GNUNET_GNS_Handle *
-GNUNET_GNS_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
- unsigned int ht_len)
+GNUNET_GNS_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
{
struct GNUNET_GNS_Handle *handle;
- handle = GNUNET_malloc (sizeof (struct GNUNET_GNS_Handle));
+ handle = GNUNET_new (struct GNUNET_GNS_Handle);
handle->cfg = cfg;
- handle->uid_gen =
- GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK, UINT64_MAX);
- handle->active_requests = GNUNET_CONTAINER_multihashmap_create (ht_len);
- if (GNUNET_NO == try_connect (handle))
- {
- GNUNET_GNS_disconnect (handle);
- return NULL;
- }
+ reconnect (handle);
return handle;
}
void
GNUNET_GNS_disconnect (struct GNUNET_GNS_Handle *handle)
{
- /* disco from GNS */
+ GNUNET_CLIENT_disconnect (handle->client);
+ if (GNUNET_SCHEDULER_NO_TASK != handle->reconnect_task)
+ {
+ GNUNET_SCHEDULER_cancel (handle->reconnect_task);
+ handle->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
+ }
+ GNUNET_assert (NULL == handle->lookup_head);
+ GNUNET_free (handle);
}
/**
- * Add a new record to the GNS.
+ * Cancel pending lookup request
*
- * @param handle handle to GNS service
- * @param key the key to store under
- * @param desired_replication_level estimate of how many
- * nearest peers this request should reach
- * @param options routing options for this message
- * @param type type of the value
- * @param size number of bytes in data; must be less than 64k
- * @param data the data to store
- * @param exp desired expiration time for the value
- * @param timeout how long to wait for transmission of this request
- * @param cont continuation to call when done (transmitting request to service)
- * @param cont_cls closure for cont
+ * @param lr the lookup request to cancel
*/
void
-GNUNET_GNS_add_record (struct GNUNET_GNS_Handle *handle, const GNUNET_HashCode * key,
- uint32_t desired_replication_level,
- enum GNUNET_DHT_RouteOption options,
- enum GNUNET_BLOCK_Type type, size_t size, const char *data,
- struct GNUNET_TIME_Absolute exp,
- struct GNUNET_TIME_Relative timeout, GNUNET_SCHEDULER_Task cont,
- void *cont_cls)
+GNUNET_GNS_lookup_cancel (struct GNUNET_GNS_LookupRequest *lr)
{
- /* add record to local db, dht; sign etc */
+ struct PendingMessage *p = (struct PendingMessage*) &lr[1];
+
+ GNUNET_assert (NULL != lr->gns_handle);
+ if (GNUNET_NO == p->transmitted)
+ GNUNET_CONTAINER_DLL_remove (lr->gns_handle->pending_head,
+ lr->gns_handle->pending_tail,
+ p);
+ GNUNET_CONTAINER_DLL_remove (lr->gns_handle->lookup_head,
+ lr->gns_handle->lookup_tail,
+ lr);
+ GNUNET_free (lr);
}
* Perform an asynchronous Lookup operation on the GNS.
*
* @param handle handle to the GNS service
- * @param timeout how long to wait for transmission of this request to the service
- * @param type expected type of the response object
- * @param key the key to look up
- * @param desired_replication_level estimate of how many
- nearest peers this request should reach
- * @param options routing options for this message
- * @param xquery extended query data (can be NULL, depending on type)
- * @param xquery_size number of bytes in xquery
- * @param iter function to call on each result
- * @param iter_cls closure for iter
- * @return handle to stop the async get
+ * @param name the name to look up
+ * @param zone the zone to start the resolution in
+ * @param type the record type to look up
+ * @param only_cached GNUNET_YES to only check locally not DHT for performance
+ * @param shorten_key the private key of the shorten zone (can be NULL)
+ * @param proc processor to call on result
+ * @param proc_cls closure for processor
+ * @return handle to the get request
*/
-struct GNUNET_GNS_LookupHandle *
-GNUNET_GNS_lookup_start (struct GNUNET_GNS_Handle *handle,
- struct GNUNET_TIME_Relative timeout,
- enum GNUNET_BLOCK_Type type, const GNUNET_HashCode * key,
- uint32_t desired_replication_level,
- enum GNUNET_DHT_RouteOption options, const void *xquery,
- size_t xquery_size, GNUNET_GNS_LookupIterator iter,
- void *iter_cls)
+struct GNUNET_GNS_LookupRequest*
+GNUNET_GNS_lookup (struct GNUNET_GNS_Handle *handle,
+ const char *name,
+ const struct GNUNET_CRYPTO_EccPublicKey *zone,
+ int type,
+ int only_cached,
+ const struct GNUNET_CRYPTO_EccPrivateKey *shorten_key,
+ GNUNET_GNS_LookupResultProcessor proc,
+ void *proc_cls)
{
- /* look for local entries, start dht lookup, return lookup_handle */
-}
+ /* IPC to shorten gns names, return shorten_handle */
+ struct GNUNET_GNS_ClientLookupMessage *lookup_msg;
+ struct GNUNET_GNS_LookupRequest *lr;
+ size_t msize;
+ struct PendingMessage *pending;
-
-/**
- * Stop async GNS lookup.
- *
- * @param lookup_handle handle to the GNS lookup operation to stop
- */
-void
-GNUNET_GNS_lookup_stop (struct GNUNET_GNS_LookupHandle *lookup_handle)
-{
- struct GNUNET_DHT_Handle *handle;
- /* TODO Stop dht lookups */
+ if (NULL == name)
+ {
+ GNUNET_break (0);
+ return NULL;
+ }
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Trying to lookup `%s' in GNS\n",
+ name);
+ msize = sizeof (struct GNUNET_GNS_ClientLookupMessage)
+ + strlen (name) + 1;
+ if (msize > UINT16_MAX)
+ {
+ GNUNET_break (0);
+ return NULL;
+ }
+ lr = GNUNET_malloc (sizeof (struct GNUNET_GNS_LookupRequest) +
+ sizeof (struct PendingMessage) + msize);
+ lr->gns_handle = handle;
+ lr->lookup_proc = proc;
+ lr->proc_cls = proc_cls;
+ lr->r_id = handle->r_id_gen++;
+ pending = (struct PendingMessage *)&lr[1];
+ pending->size = msize;
+ pending->r_id = lr->r_id;
+ GNUNET_CONTAINER_DLL_insert_tail (handle->lookup_head,
+ handle->lookup_tail, lr);
+
+ lookup_msg = (struct GNUNET_GNS_ClientLookupMessage *) &pending[1];
+ lookup_msg->header.type = htons (GNUNET_MESSAGE_TYPE_GNS_LOOKUP);
+ lookup_msg->header.size = htons (msize);
+ lookup_msg->id = htonl (lr->r_id);
+ lookup_msg->only_cached = htonl (only_cached);
+ lookup_msg->zone = *zone;
+ lookup_msg->type = htonl (type);
+ if (NULL != shorten_key)
+ {
+ lookup_msg->have_key = htonl (GNUNET_YES);
+ lookup_msg->shorten_key = *shorten_key;
+ }
+ memcpy (&lookup_msg[1], name, strlen (name) + 1);
+ GNUNET_CONTAINER_DLL_insert_tail (handle->pending_head,
+ handle->pending_tail,
+ pending);
+ process_pending_messages (handle);
+ return lr;
}