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 2, or (at your
+ 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
* @brief library to access the DHT service
* @author Christian Grothoff
* @author Nathan Evans
- *
- * TODO: Only allow a single message until confirmed as received by
- * the service. For put messages call continuation as soon as
- * receipt acknowledged (then remove), for GET or other messages
- * only call continuation when data received.
- * Add unique identifier to message types requesting data to be
- * returned.
*/
+
#include "platform.h"
-#include "gnunet_bandwidth_lib.h"
-#include "gnunet_client_lib.h"
+#include "gnunet_util_lib.h"
#include "gnunet_constants.h"
-#include "gnunet_container_lib.h"
#include "gnunet_arm_service.h"
#include "gnunet_hello_lib.h"
#include "gnunet_protocols.h"
-#include "gnunet_server_lib.h"
-#include "gnunet_time_lib.h"
#include "gnunet_dht_service.h"
#include "dht.h"
-#define DEBUG_DHT_API GNUNET_YES
+#define DEBUG_DHT_API GNUNET_EXTRA_LOGGING
-#define DEFAULT_DHT_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
+#define LOG(kind,...) GNUNET_log_from (kind, "dht-api",__VA_ARGS__)
+/**
+ * Entry in our list of messages to be (re-)transmitted.
+ */
struct PendingMessage
{
/**
- * Message that is pending
+ * This is a doubly-linked list.
+ */
+ struct PendingMessage *prev;
+
+ /**
+ * This is a doubly-linked list.
+ */
+ struct PendingMessage *next;
+
+ /**
+ * Message that is pending, allocated at the end
+ * of this struct.
*/
- struct GNUNET_MessageHeader *msg;
+ const struct GNUNET_MessageHeader *msg;
/**
- * Timeout for this message
+ * Handle to the DHT API context.
*/
- struct GNUNET_TIME_Relative timeout;
+ struct GNUNET_DHT_Handle *handle;
/**
- * Continuation to call on message send
- * or message receipt confirmation
+ * Continuation to call when the request has been
+ * transmitted (for the first time) to the service; can be NULL.
*/
- GNUNET_DHT_MessageCallback cont;
+ GNUNET_SCHEDULER_Task cont;
/**
- * Continuation closure
+ * Closure for 'cont'.
*/
void *cont_cls;
/**
- * Whether or not to await verification the message
- * was received by the service
+ * Timeout task for this message
*/
- size_t is_unique;
+ GNUNET_SCHEDULER_TaskIdentifier timeout_task;
/**
* Unique ID for this request
*/
uint64_t unique_id;
-};
-
-struct GNUNET_DHT_GetContext
-{
-
-
/**
- * Iterator to call on data receipt
+ * Free the saved message once sent, set to GNUNET_YES for messages
+ * that do not receive responses; GNUNET_NO if this pending message
+ * is aliased from a 'struct GNUNET_DHT_RouteHandle' and will be freed
+ * from there.
*/
- GNUNET_DHT_GetIterator iter;
+ int free_on_send;
/**
- * Closure for the iterator callback
+ * GNUNET_YES if this message is in our pending queue right now.
*/
- void *iter_cls;
+ int in_pending_queue;
};
+
/**
- * Handle to control a unique operation (one that is
- * expected to return results)
+ * Handle to a GET request
*/
-struct GNUNET_DHT_RouteHandle
+struct GNUNET_DHT_GetHandle
{
- /**
- * Unique identifier for this request (for key collisions)
- */
- uint64_t uid;
-
- /**
- * Key that this get request is for
- */
- GNUNET_HashCode key;
-
/**
* Iterator to call on data receipt
*/
- GNUNET_DHT_ReplyProcessor iter;
+ GNUNET_DHT_GetIterator iter;
/**
* Closure for the iterator callback
* Main handle to this DHT api
*/
struct GNUNET_DHT_Handle *dht_handle;
-};
-/**
- * Handle for a non unique request, holds callback
- * which needs to be called before we allow other
- * messages to be processed and sent to the DHT service
- */
-struct GNUNET_DHT_NonUniqueHandle
-{
/**
- * Key that this get request is for
+ * The actual message sent for this request,
+ * used for retransmitting requests on service
+ * failure/reconnect. Freed on route_stop.
*/
- GNUNET_HashCode key;
+ struct PendingMessage *message;
/**
- * Type of data get request was for
+ * Key that this get request is for
*/
- uint32_t type;
+ GNUNET_HashCode key;
/**
- * Continuation to call on service
- * confirmation of message receipt.
+ * Unique identifier for this request (for key collisions).
*/
- GNUNET_SCHEDULER_Task cont;
+ uint64_t unique_id;
- /**
- * Send continuation cls
- */
- void *cont_cls;
};
*/
struct GNUNET_DHT_Handle
{
- /**
- * Our scheduler.
- */
- struct GNUNET_SCHEDULER_Handle *sched;
/**
* Configuration to use.
struct GNUNET_CLIENT_Connection *client;
/**
- * Currently pending transmission request.
+ * Currently pending transmission request (or NULL).
*/
struct GNUNET_CLIENT_TransmitHandle *th;
/**
- * Message we are currently sending, only allow
- * a single message to be queued. If not unique
- * (typically a put request), await a confirmation
- * from the service that the message was received.
- * If unique, just fire and forget.
+ * Head of linked list of messages we would like to transmit.
*/
- struct PendingMessage *current;
+ struct PendingMessage *pending_head;
/**
- * Hash map containing the current outstanding unique requests
+ * Tail of linked list of messages we would like to transmit.
*/
- struct GNUNET_CONTAINER_MultiHashMap *outstanding_requests;
+ struct PendingMessage *pending_tail;
/**
- * Non unique handle. If set don't schedule another non
- * unique request.
+ * Hash map containing the current outstanding unique requests
+ * (values are of type 'struct GNUNET_DHT_RouteHandle').
*/
- struct GNUNET_DHT_NonUniqueHandle *non_unique_request;
+ struct GNUNET_CONTAINER_MultiHashMap *active_requests;
/**
- * Kill off the connection and any pending messages.
+ * Task for trying to reconnect.
*/
- int do_destroy;
+ GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
-};
+ /**
+ * How quickly should we retry? Used for exponential back-off on
+ * connect-errors.
+ */
+ struct GNUNET_TIME_Relative retry_time;
-static struct GNUNET_TIME_Relative default_request_timeout;
+ /**
+ * Generator for unique ids.
+ */
+ uint64_t uid_gen;
-/* Forward declaration */
-static void process_pending_message(struct GNUNET_DHT_Handle *handle);
+};
-static GNUNET_HashCode * hash_from_uid(uint64_t uid)
-{
- int count;
- int remaining;
- GNUNET_HashCode *hash;
- hash = GNUNET_malloc(sizeof(GNUNET_HashCode));
- count = 0;
-
- while (count < sizeof(GNUNET_HashCode))
- {
- remaining = sizeof(GNUNET_HashCode) - count;
- if (remaining > sizeof(uid))
- remaining = sizeof(uid);
-
- memcpy(hash, &uid, remaining);
- count += remaining;
- }
-
- return hash;
-}
/**
* Handler for messages received from the DHT service
* a demultiplexer which handles numerous message types
*
*/
-void service_message_handler (void *cls,
- const struct GNUNET_MessageHeader *msg)
-{
- struct GNUNET_DHT_Handle *handle = cls;
- struct GNUNET_DHT_Message *dht_msg = (struct GNUNET_DHT_Message *)msg;
- struct GNUNET_MessageHeader *enc_msg;
- struct GNUNET_DHT_RouteHandle *route_handle;
- GNUNET_HashCode *uid_hash;
- size_t enc_size;
- /* TODO: find out message type, handle callbacks for different types of messages.
- * Should be a non unique acknowledgment, or unique result. */
-
-#if DEBUG_DHT_API
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "`%s': Received response to message (uid %llu)\n", "DHT API", ntohl(dht_msg->unique_id));
-#endif
-
- if (ntohs(dht_msg->unique))
- {
- uid_hash = hash_from_uid(ntohl(dht_msg->unique_id));
-
- route_handle = GNUNET_CONTAINER_multihashmap_get(handle->outstanding_requests, uid_hash);
- if (route_handle == NULL) /* We have no recollection of this request */
- {
-#if DEBUG_DHT_API
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "`%s': Received response to message (uid %llu), but have no recollection of it!\n", "DHT API", ntohl(dht_msg->unique_id));
-#endif
- }
- else
- {
- enc_size = ntohs(dht_msg->header.size) - sizeof(struct GNUNET_DHT_Message);
- GNUNET_assert(enc_size > 0);
- enc_msg = (struct GNUNET_MessageHeader *)&dht_msg[1];
- route_handle->iter(route_handle->iter_cls, enc_msg);
- }
- }
- else
- {
- if (handle->current->unique_id == ntohl(dht_msg->unique_id))
- {
- handle->current->cont(handle->current->cont_cls, GNUNET_OK);
- GNUNET_free(handle->current->msg);
- handle->current = NULL;
- GNUNET_free(handle->current);
- }
- }
-
-
-}
+static void
+service_message_handler (void *cls, const struct GNUNET_MessageHeader *msg);
/**
- * Initialize the connection with the DHT service.
+ * Try to (re)connect to the DHT service.
*
- * @param cfg configuration to use
- * @param sched scheduler to use
- * @param ht_len size of the internal hash table to use for
- * processing multiple GET/FIND requests in parallel
- * @return NULL on error
+ * @return GNUNET_YES on success, GNUNET_NO on failure.
*/
-struct GNUNET_DHT_Handle *
-GNUNET_DHT_connect (struct GNUNET_SCHEDULER_Handle *sched,
- const struct GNUNET_CONFIGURATION_Handle *cfg,
- unsigned int ht_len)
+static int
+try_connect (struct GNUNET_DHT_Handle *handle)
{
- struct GNUNET_DHT_Handle *handle;
-
- handle = GNUNET_malloc(sizeof(struct GNUNET_DHT_Handle));
-
- default_request_timeout = GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 5);
- handle->cfg = cfg;
- handle->sched = sched;
-
- handle->current = NULL;
- handle->do_destroy = GNUNET_NO;
- handle->th = NULL;
-
- handle->client = GNUNET_CLIENT_connect(sched, "dht", cfg);
- handle->outstanding_requests = GNUNET_CONTAINER_multihashmap_create(ht_len);
-
+ if (handle->client != NULL)
+ return GNUNET_OK;
+ handle->client = GNUNET_CLIENT_connect ("dht", handle->cfg);
if (handle->client == NULL)
- return NULL;
-#if DEBUG_DHT_API
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "`%s': Connection to service in progress\n", "DHT API");
+ {
+ LOG (GNUNET_ERROR_TYPE_WARNING,
+ _("Failed to connect to the DHT service!\n"));
+ return GNUNET_NO;
+ }
+#if DEBUG_DHT
+ LOG (GNUNET_ERROR_TYPE_DEBUG, "Starting to process replies from DHT\n");
#endif
- GNUNET_CLIENT_receive (handle->client,
- &service_message_handler,
- handle, GNUNET_TIME_UNIT_FOREVER_REL);
-
- return handle;
+ GNUNET_CLIENT_receive (handle->client, &service_message_handler, handle,
+ GNUNET_TIME_UNIT_FOREVER_REL);
+ return GNUNET_YES;
}
/**
- * Shutdown connection with the DHT service.
+ * Add the request corresponding to the given route handle
+ * to the pending queue (if it is not already in there).
*
- * @param h connection to shut down
+ * @param cls the 'struct GNUNET_DHT_Handle*'
+ * @param key key for the request (not used)
+ * @param value the 'struct GNUNET_DHT_GetHandle*'
+ * @return GNUNET_YES (always)
*/
-void
-GNUNET_DHT_disconnect (struct GNUNET_DHT_Handle *handle)
+static int
+add_request_to_pending (void *cls, const GNUNET_HashCode * key, void *value)
{
-#if DEBUG_DHT_API
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "`%s': Called GNUNET_DHT_disconnect\n", "DHT API");
-#endif
- GNUNET_assert(handle != NULL);
-
- if (handle->th != NULL) /* We have a live transmit request in the Aether */
- {
- GNUNET_CLIENT_notify_transmit_ready_cancel (handle->th);
- handle->th = NULL;
- }
- if (handle->current != NULL) /* We are trying to send something now, clean it up */
- GNUNET_free(handle->current);
-
- if (handle->client != NULL) /* Finally, disconnect from the service */
- {
- GNUNET_CLIENT_disconnect (handle->client, GNUNET_NO);
- handle->client = NULL;
- }
+ struct GNUNET_DHT_Handle *handle = cls;
+ struct GNUNET_DHT_GetHandle *rh = value;
- GNUNET_free (handle);
+ if (GNUNET_NO == rh->message->in_pending_queue)
+ {
+ GNUNET_CONTAINER_DLL_insert (handle->pending_head, handle->pending_tail,
+ rh->message);
+ rh->message->in_pending_queue = GNUNET_YES;
+ }
+ return GNUNET_YES;
}
/**
- * Send complete (or failed), schedule next (or don't)
+ * Try to send messages from list of messages to send
+ * @param handle DHT_Handle
*/
static void
-finish (struct GNUNET_DHT_Handle *handle, int code)
-{
- /* TODO: if code is not GNUNET_OK, do something! */
- struct PendingMessage *pos = handle->current;
-
- GNUNET_assert(pos != NULL);
+process_pending_messages (struct GNUNET_DHT_Handle *handle);
- if (pos->is_unique)
- {
- if (pos->cont != NULL)
- pos->cont(pos->cont_cls, code);
-
- GNUNET_free(pos->msg);
- handle->current = NULL;
- GNUNET_free(pos);
- }
- /* Otherwise we need to wait for a response to this message! */
-}
/**
- * Transmit the next pending message, called by notify_transmit_ready
+ * Try reconnecting to the dht service.
+ *
+ * @param cls GNUNET_DHT_Handle
+ * @param tc scheduler context
*/
-static size_t
-transmit_pending (void *cls, size_t size, void *buf)
+static void
+try_reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
struct GNUNET_DHT_Handle *handle = cls;
- size_t tsize;
- if (buf == NULL)
- {
-#if DEBUG_DHT_API
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "`%s': In transmit_pending buf is NULL\n", "DHT API");
-#endif
- /* FIXME: free associated resources or summat */
- finish(handle, GNUNET_SYSERR);
- return 0;
- }
-
- handle->th = NULL;
-
- if (handle->current != NULL)
+ 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;
+ handle->client = GNUNET_CLIENT_connect ("dht", handle->cfg);
+ if (handle->client == NULL)
{
- tsize = ntohs(handle->current->msg->size);
- if (size >= tsize)
- {
-#if DEBUG_DHT_API
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "`%s': Sending message size %d\n", "DHT API", tsize);
-#endif
- memcpy(buf, handle->current->msg, tsize);
- return tsize;
- }
- else
- {
- return 0;
- }
+ LOG (GNUNET_ERROR_TYPE_DEBUG, "dht reconnect failed(!)\n");
+ return;
}
- /* Have no pending request */
- return 0;
+ GNUNET_CONTAINER_multihashmap_iterate (handle->active_requests,
+ &add_request_to_pending, handle);
+ process_pending_messages (handle);
}
/**
- * Try to (re)connect to the dht service.
+ * Try reconnecting to the DHT service.
*
- * @return GNUNET_YES on success, GNUNET_NO on failure.
+ * @param handle handle to dht to (possibly) disconnect and reconnect
*/
-static int
-try_connect (struct GNUNET_DHT_Handle *ret)
+static void
+do_disconnect (struct GNUNET_DHT_Handle *handle)
{
- if (ret->client != NULL)
- return GNUNET_OK;
- ret->client = GNUNET_CLIENT_connect (ret->sched, "dht", ret->cfg);
- if (ret->client != NULL)
- return GNUNET_YES;
-#if DEBUG_STATISTICS
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- _("Failed to connect to the dht service!\n"));
-#endif
- return GNUNET_NO;
+ if (handle->client == NULL)
+ return;
+ GNUNET_assert (handle->reconnect_task == GNUNET_SCHEDULER_NO_TASK);
+ if (NULL != handle->th)
+ GNUNET_CLIENT_notify_transmit_ready_cancel (handle->th);
+ handle->th = NULL;
+ GNUNET_CLIENT_disconnect (handle->client, GNUNET_NO);
+ handle->client = NULL;
+ handle->reconnect_task =
+ GNUNET_SCHEDULER_add_delayed (handle->retry_time, &try_reconnect, handle);
}
+/**
+ * Transmit the next pending message, called by notify_transmit_ready
+ */
+static size_t
+transmit_pending (void *cls, size_t size, void *buf);
+
+
/**
* Try to send messages from list of messages to send
*/
-static void process_pending_message(struct GNUNET_DHT_Handle *handle)
+static void
+process_pending_messages (struct GNUNET_DHT_Handle *handle)
{
+ struct PendingMessage *head;
- if (handle->current != NULL)
- return; /* action already pending */
- if (GNUNET_YES != try_connect (handle))
- {
- finish (handle, GNUNET_SYSERR);
- return;
- }
-
- /* TODO: set do_destroy somewhere's, see what needs to happen in that case! */
- if (handle->do_destroy)
- {
- //GNUNET_DHT_disconnect (handle); /* FIXME: replace with proper disconnect stuffs */
- }
-
-
- if (NULL ==
- (handle->th = GNUNET_CLIENT_notify_transmit_ready (handle->client,
- ntohs(handle->current->msg->size),
- handle->current->timeout,
- GNUNET_YES,
- &transmit_pending, handle)))
- {
-#if DEBUG_DHT_API
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Failed to transmit request to dht service.\n");
-#endif
- finish (handle, GNUNET_SYSERR);
- }
-#if DEBUG_DHT_API
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "`%s': Scheduled sending message of size %d to service\n", "DHT API", ntohs(handle->current->msg->size));
-#endif
+ if (handle->client == NULL)
+ {
+ do_disconnect (handle);
+ return;
+ }
+ if (handle->th != NULL)
+ return;
+ if (NULL == (head = handle->pending_head))
+ return;
+ handle->th =
+ GNUNET_CLIENT_notify_transmit_ready (handle->client,
+ ntohs (head->msg->size),
+ GNUNET_TIME_UNIT_FOREVER_REL,
+ GNUNET_YES, &transmit_pending,
+ handle);
+ if (NULL != handle->th)
+ return;
+ do_disconnect (handle);
}
+
/**
- * Iterator called on each result obtained from a generic route
- * operation
+ * Transmit the next pending message, called by notify_transmit_ready
*/
-void get_reply_iterator (void *cls,
- const struct GNUNET_MessageHeader *reply)
+static size_t
+transmit_pending (void *cls, size_t size, void *buf)
{
+ struct GNUNET_DHT_Handle *handle = cls;
+ struct PendingMessage *head;
+ size_t tsize;
+ handle->th = NULL;
+ if (buf == NULL)
+ {
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Transmission to DHT service failed! Reconnecting!\n");
+ do_disconnect (handle);
+ return 0;
+ }
+ if (NULL == (head = handle->pending_head))
+ return 0;
+
+ tsize = ntohs (head->msg->size);
+ if (size < tsize)
+ {
+ process_pending_messages (handle);
+ return 0;
+ }
+ memcpy (buf, head->msg, tsize);
+ GNUNET_CONTAINER_DLL_remove (handle->pending_head, handle->pending_tail,
+ head);
+ if (head->timeout_task != GNUNET_SCHEDULER_NO_TASK)
+ {
+ GNUNET_SCHEDULER_cancel (head->timeout_task);
+ head->timeout_task = GNUNET_SCHEDULER_NO_TASK;
+ }
+ if (NULL != head->cont)
+ {
+ GNUNET_SCHEDULER_add_continuation (head->cont, head->cont_cls,
+ GNUNET_SCHEDULER_REASON_PREREQ_DONE);
+ head->cont = NULL;
+ head->cont_cls = NULL;
+ }
+ head->in_pending_queue = GNUNET_NO;
+ if (GNUNET_YES == head->free_on_send)
+ GNUNET_free (head);
+ process_pending_messages (handle);
+#if DEBUG_DHT
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Forwarded request of %u bytes to DHT service\n", (unsigned int) tsize);
+#endif
+ return tsize;
}
+
/**
- * Perform an asynchronous FIND_PEER operation on the DHT.
+ * Process a given reply that might match the given
+ * request.
*
- * @param handle handle to the DHT service
- * @param key the key to look up
- * @param desired_replication_level how many peers should ultimately receive
- * this message (advisory only, target may be too high for the
- * given DHT or not hit exactly).
- * @param options options for routing
- * @param enc send the encapsulated message to a peer close to the key
- * @param iter function to call on each result, NULL if no replies are expected
- * @param iter_cls closure for iter
- * @param timeout when to abort with an error if we fail to get
- * a confirmation for the PUT from the local DHT service
- * @param cont continuation to call when done;
- * reason will be TIMEOUT on error,
- * reason will be PREREQ_DONE on success
- * @param cont_cls closure for cont
- * @return handle to stop the request
+ * @param cls the 'struct GNUNET_DHT_ClientResultMessage'
+ * @param key query of the request
+ * @param value the 'struct GNUNET_DHT_RouteHandle' of a request matching the same key
+ * @return GNUNET_YES to continue to iterate over all results,
+ * GNUNET_NO if the reply is malformed
*/
-struct GNUNET_DHT_RouteHandle *
-GNUNET_DHT_route_start (struct GNUNET_DHT_Handle *handle,
- const GNUNET_HashCode *key,
- unsigned int desired_replication_level,
- enum GNUNET_DHT_RouteOption options,
- const struct GNUNET_MessageHeader *enc,
- struct GNUNET_TIME_Relative timeout,
- GNUNET_DHT_ReplyProcessor iter,
- void *iter_cls,
- GNUNET_DHT_MessageCallback cont,
- void *cont_cls)
+static int
+process_reply (void *cls, const GNUNET_HashCode * key, void *value)
{
- struct GNUNET_DHT_RouteHandle *route_handle;
- struct PendingMessage *pending;
- struct GNUNET_DHT_Message *message;
- size_t is_unique;
+ const struct GNUNET_DHT_ClientResultMessage *dht_msg = cls;
+ struct GNUNET_DHT_GetHandle *get_handle = value;
+ const struct GNUNET_PeerIdentity *put_path;
+ const struct GNUNET_PeerIdentity *get_path;
+ uint32_t put_path_length;
+ uint32_t get_path_length;
+ size_t data_length;
size_t msize;
- GNUNET_HashCode *uid_key;
- int count;
-
- is_unique = GNUNET_YES;
- if (iter == NULL)
- is_unique = GNUNET_NO;
-
- route_handle = NULL;
-
- if (is_unique)
- {
- route_handle = GNUNET_malloc(sizeof(struct GNUNET_DHT_RouteHandle));
- memcpy(&route_handle->key, key, sizeof(GNUNET_HashCode));
- route_handle->iter = iter;
- route_handle->iter_cls = iter_cls;
- route_handle->dht_handle = handle;
- route_handle->uid = GNUNET_CRYPTO_random_u64(GNUNET_CRYPTO_QUALITY_WEAK, -1);
-
- count = 0;
- uid_key = hash_from_uid(route_handle->uid);
- /* While we have an outstanding request with the same identifier! */
- while (GNUNET_CONTAINER_multihashmap_contains(handle->outstanding_requests, uid_key) == GNUNET_YES)
- {
- GNUNET_free(uid_key);
- uid_key = hash_from_uid(route_handle->uid);
- }
- /**
- * Store based on random identifier!
- */
- GNUNET_CONTAINER_multihashmap_put(handle->outstanding_requests, uid_key, route_handle, GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
- msize = sizeof(struct GNUNET_DHT_Message) + ntohs(enc->size) + sizeof(route_handle->uid);
- GNUNET_free(uid_key);
- }
- else
- {
- msize = sizeof(struct GNUNET_DHT_Message) + ntohs(enc->size);
- }
-
- message = GNUNET_malloc(msize);
- message->header.size = htons(msize);
- message->header.type = htons(GNUNET_MESSAGE_TYPE_DHT);
- memcpy(&message->key, key, sizeof(GNUNET_HashCode));
- message->options = htons(options);
- message->desired_replication_level = htons(options);
- message->unique = htons(is_unique);
-
- pending = GNUNET_malloc(sizeof(struct PendingMessage));
- pending->msg = &message->header;
- pending->timeout = timeout;
- pending->cont = cont;
- pending->cont_cls = cont_cls;
- pending->is_unique = is_unique;
-
- GNUNET_assert(handle->current == NULL);
+ size_t meta_length;
+ const void *data;
- process_pending_message(handle);
-
- return route_handle;
+ if (dht_msg->unique_id != get_handle->unique_id)
+ {
+ /* UID mismatch */
+ LOG (GNUNET_ERROR_TYPE_DEBUG, "Ignoring reply (UID mismatch: %llu/%llu)\n",
+ dht_msg->unique_id, get_handle->unique_id);
+ return GNUNET_YES;
+ }
+ msize = ntohs (dht_msg->header.size);
+ put_path_length = ntohl (dht_msg->put_path_length);
+ get_path_length = ntohl (dht_msg->get_path_length);
+ meta_length =
+ sizeof (struct GNUNET_DHT_ClientResultMessage) +
+ sizeof (struct GNUNET_PeerIdentity) * (get_path_length + put_path_length);
+ if ((msize < meta_length) ||
+ (get_path_length >
+ GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)) ||
+ (put_path_length >
+ GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)))
+ {
+ GNUNET_break (0);
+ return GNUNET_NO;
+ }
+ data_length = msize - meta_length;
+ put_path = (const struct GNUNET_PeerIdentity *) &dht_msg[1];
+ get_path = &put_path[put_path_length];
+ data = &get_path[get_path_length];
+ get_handle->iter (get_handle->iter_cls,
+ GNUNET_TIME_absolute_ntoh (dht_msg->expiration), key,
+ get_path, get_path_length, put_path, put_path_length,
+ ntohl (dht_msg->type), data_length, data);
+ return GNUNET_YES;
}
-void
-GNUNET_DHT_route_stop (struct GNUNET_DHT_RouteHandle *fph);
-
-void dht_get_processor (void *cls,
- const struct GNUNET_MessageHeader *reply)
+/**
+ * Handler for messages received from the DHT service
+ * a demultiplexer which handles numerous message types
+ *
+ * @param cls the 'struct GNUNET_DHT_Handle'
+ * @param msg the incoming message
+ */
+static void
+service_message_handler (void *cls, const struct GNUNET_MessageHeader *msg)
{
+ struct GNUNET_DHT_Handle *handle = cls;
+ const struct GNUNET_DHT_ClientResultMessage *dht_msg;
+ if (msg == NULL)
+ {
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Error receiving data from DHT service, reconnecting\n");
+ do_disconnect (handle);
+ return;
+ }
+ if (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_DHT_CLIENT_RESULT)
+ {
+ GNUNET_break (0);
+ do_disconnect (handle);
+ return;
+ }
+ if (ntohs (msg->size) < sizeof (struct GNUNET_DHT_ClientResultMessage))
+ {
+ GNUNET_break (0);
+ do_disconnect (handle);
+ return;
+ }
+ LOG (GNUNET_ERROR_TYPE_DEBUG, "Received reply from DHT service\n");
+ dht_msg = (const struct GNUNET_DHT_ClientResultMessage *) msg;
+ GNUNET_CONTAINER_multihashmap_get_multiple (handle->active_requests,
+ &dht_msg->key, &process_reply,
+ (void *) dht_msg);
+ GNUNET_CLIENT_receive (handle->client, &service_message_handler, handle,
+ GNUNET_TIME_UNIT_FOREVER_REL);
}
+
/**
- * Perform an asynchronous GET operation on the DHT identified.
+ * Initialize the connection with the DHT service.
*
- * @param h handle to the DHT service
- * @param type expected type of the response object
- * @param key the key to look up
- * @param iter function to call on each result
- * @param iter_cls closure for iter
- * @return handle to stop the async get
+ * @param cfg configuration to use
+ * @param ht_len size of the internal hash table to use for
+ * processing multiple GET/FIND requests in parallel
+ *
+ * @return handle to the DHT service, or NULL on error
*/
-struct GNUNET_DHT_RouteHandle *
-GNUNET_DHT_get_start (struct GNUNET_DHT_Handle *handle,
- struct GNUNET_TIME_Relative timeout,
- uint32_t type,
- const GNUNET_HashCode * key,
- GNUNET_DHT_GetIterator iter,
- void *iter_cls)
+struct GNUNET_DHT_Handle *
+GNUNET_DHT_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
+ unsigned int ht_len)
{
- struct GNUNET_DHT_GetContext *get_context;
- struct GNUNET_DHT_GetMessage *get_msg;
+ struct GNUNET_DHT_Handle *handle;
- if (handle->current != NULL) /* Can't send right now, we have a pending message... */
+ handle = GNUNET_malloc (sizeof (struct GNUNET_DHT_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_DHT_disconnect (handle);
return NULL;
-
- get_context = GNUNET_malloc(sizeof(struct GNUNET_DHT_GetContext));
- get_context->iter = iter;
- get_context->iter_cls = iter_cls;
-
-#if DEBUG_DHT_API
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "`%s': Inserting pending get request with key %s\n", "DHT API", GNUNET_h2s(key));
-#endif
-
- get_msg = GNUNET_malloc(sizeof(struct GNUNET_DHT_GetMessage));
- get_msg->header.type = htons(GNUNET_MESSAGE_TYPE_DHT_GET);
- get_msg->header.size = htons(sizeof(struct GNUNET_DHT_GetMessage));
- get_msg->type = htonl(type);
-
- return GNUNET_DHT_route_start(handle, key, 0, 0, &get_msg->header, timeout, &get_reply_iterator, get_context, NULL, NULL);
-
+ }
+ return handle;
}
+/**
+ * Shutdown connection with the DHT service.
+ *
+ * @param handle handle of the DHT connection to stop
+ */
void
-GNUNET_DHT_route_stop (struct GNUNET_DHT_RouteHandle *route_handle)
+GNUNET_DHT_disconnect (struct GNUNET_DHT_Handle *handle)
{
- struct PendingMessage *pending;
- struct GNUNET_DHT_StopMessage *message;
- size_t msize;
- GNUNET_HashCode *uid_key;
-
- msize = sizeof(struct GNUNET_DHT_StopMessage);
-
- message = GNUNET_malloc(msize);
- message->header.size = htons(msize);
- message->header.type = htons(GNUNET_MESSAGE_TYPE_DHT_STOP);
- message->unique_id = htonl(route_handle->uid);
-
- pending = GNUNET_malloc(sizeof(struct PendingMessage));
- pending->msg = (struct GNUNET_MessageHeader *)message;
- pending->timeout = DEFAULT_DHT_TIMEOUT;
- pending->cont = NULL;
- pending->cont_cls = NULL;
- pending->is_unique = GNUNET_NO;
+ struct PendingMessage *pm;
- GNUNET_assert(route_handle->dht_handle->current == NULL);
-
- process_pending_message(route_handle->dht_handle);
-
- uid_key = hash_from_uid(route_handle->uid);
-
- if (GNUNET_CONTAINER_multihashmap_remove(route_handle->dht_handle->outstanding_requests, uid_key, route_handle) != GNUNET_YES)
- {
-#if DEBUG_DHT_API
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "`%s': Remove outstanding request from hashmap failed for key %s, uid %llu\n", "DHT API", GNUNET_h2s(uid_key), route_handle->uid);
-#endif
- }
-
- return;
+ GNUNET_assert (handle != NULL);
+ GNUNET_assert (0 ==
+ GNUNET_CONTAINER_multihashmap_size (handle->active_requests));
+ if (handle->th != NULL)
+ {
+ GNUNET_CLIENT_notify_transmit_ready_cancel (handle->th);
+ handle->th = NULL;
+ }
+ while (NULL != (pm = handle->pending_head))
+ {
+ GNUNET_CONTAINER_DLL_remove (handle->pending_head, handle->pending_tail,
+ pm);
+ GNUNET_assert (GNUNET_YES == pm->free_on_send);
+ if (GNUNET_SCHEDULER_NO_TASK != pm->timeout_task)
+ GNUNET_SCHEDULER_cancel (pm->timeout_task);
+ if (NULL != pm->cont)
+ GNUNET_SCHEDULER_add_continuation (pm->cont, pm->cont_cls,
+ GNUNET_SCHEDULER_REASON_TIMEOUT);
+ pm->in_pending_queue = GNUNET_NO;
+ GNUNET_free (pm);
+ }
+ if (handle->client != NULL)
+ {
+ GNUNET_CLIENT_disconnect (handle->client, GNUNET_YES);
+ handle->client = NULL;
+ }
+ if (handle->reconnect_task != GNUNET_SCHEDULER_NO_TASK)
+ GNUNET_SCHEDULER_cancel (handle->reconnect_task);
+ GNUNET_CONTAINER_multihashmap_destroy (handle->active_requests);
+ GNUNET_free (handle);
}
/**
- * Stop async DHT-get. Frees associated resources.
+ * Timeout for the transmission of a fire&forget-request. Clean it up.
*
- * @param record GET operation to stop.
+ * @param cls the 'struct PendingMessage'
+ * @param tc scheduler context
*/
-void
-GNUNET_DHT_get_stop (struct GNUNET_DHT_RouteHandle *handle)
+static void
+timeout_put_request (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
-#if OLDREMOVE
- struct GNUNET_DHT_GetMessage *get_msg;
+ struct PendingMessage *pending = cls;
struct GNUNET_DHT_Handle *handle;
- GNUNET_HashCode *uid_key;
-#endif
-
- GNUNET_DHT_route_stop(handle);
-
-#if OLDREMOVE
- uid_key = hash_from_uid(get_handle->uid);
- GNUNET_assert(GNUNET_CONTAINER_multihashmap_remove(handle->outstanding_requests, uid_key, get_handle) == GNUNET_YES);
-
- if (handle->do_destroy == GNUNET_NO)
- {
- get_msg = GNUNET_malloc(sizeof(struct GNUNET_DHT_GetMessage));
- get_msg->header.type = htons(GNUNET_MESSAGE_TYPE_DHT_GET_STOP);
- get_msg->header.size = htons(sizeof(struct GNUNET_DHT_GetMessage));
-
- }
-#endif
-#if DEBUG_DHT_API
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "`%s': Removing pending get request with key %s, uid %llu\n", "DHT API", GNUNET_h2s(&handle->key), handle->uid);
-#endif
+ handle = pending->handle;
+ GNUNET_CONTAINER_DLL_remove (handle->pending_head, handle->pending_tail,
+ pending);
+ if (pending->cont != NULL)
+ pending->cont (pending->cont_cls, tc);
+ GNUNET_free (pending);
}
/**
* Perform a PUT operation storing data in the DHT.
*
- * @param h handle to DHT service
+ * @param handle handle to DHT 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 cont continuation to call when done;
- * reason will be TIMEOUT on error,
- * reason will be PREREQ_DONE on success
+ * @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
- *
- * @return GNUNET_YES if put message is queued for transmission
*/
void
-GNUNET_DHT_put (struct GNUNET_DHT_Handle *handle,
- const GNUNET_HashCode * key,
- uint32_t type,
- uint32_t size,
- const char *data,
+GNUNET_DHT_put (struct GNUNET_DHT_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_DHT_MessageCallback cont,
+ struct GNUNET_TIME_Relative timeout, GNUNET_SCHEDULER_Task cont,
void *cont_cls)
{
- struct GNUNET_DHT_PutMessage *put_msg;
+ struct GNUNET_DHT_ClientPutMessage *put_msg;
size_t msize;
+ struct PendingMessage *pending;
- if (handle->current != NULL)
- {
- cont(cont_cls, GNUNET_SYSERR);
- return;
- }
+ msize = sizeof (struct GNUNET_DHT_ClientPutMessage) + size;
+ if ((msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
+ (size >= GNUNET_SERVER_MAX_MESSAGE_SIZE))
+ {
+ GNUNET_break (0);
+ if (NULL != cont)
+ cont (cont_cls, NULL);
+ return;
+ }
+ pending = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
+ put_msg = (struct GNUNET_DHT_ClientPutMessage *) &pending[1];
+ pending->msg = &put_msg->header;
+ pending->handle = handle;
+ pending->cont = cont;
+ pending->cont_cls = cont_cls;
+ pending->free_on_send = GNUNET_YES;
+ pending->timeout_task =
+ GNUNET_SCHEDULER_add_delayed (timeout, &timeout_put_request, pending);
+ put_msg->header.size = htons (msize);
+ put_msg->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_CLIENT_PUT);
+ put_msg->type = htonl (type);
+ put_msg->options = htonl ((uint32_t) options);
+ put_msg->desired_replication_level = htonl (desired_replication_level);
+ put_msg->expiration = GNUNET_TIME_absolute_hton (exp);
+ put_msg->key = *key;
+ memcpy (&put_msg[1], data, size);
+ GNUNET_CONTAINER_DLL_insert (handle->pending_head, handle->pending_tail,
+ pending);
+ pending->in_pending_queue = GNUNET_YES;
+ process_pending_messages (handle);
+}
-#if DEBUG_DHT_API
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "`%s': Inserting pending put request with key %s\n", "DHT API", GNUNET_h2s(key));
-#endif
- msize = sizeof(struct GNUNET_DHT_PutMessage) + size;
- put_msg = GNUNET_malloc(msize);
- put_msg->header.type = htons(GNUNET_MESSAGE_TYPE_DHT_PUT);
- put_msg->header.size = htons(msize);
- put_msg->type = htonl(type);
- memcpy(&put_msg[1], data, size);
+/**
+ * Perform an asynchronous GET operation on the DHT identified. See
+ * also "GNUNET_BLOCK_evaluate".
+ *
+ * @param handle handle to the DHT 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
+ */
+struct GNUNET_DHT_GetHandle *
+GNUNET_DHT_get_start (struct GNUNET_DHT_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_DHT_GetIterator iter,
+ void *iter_cls)
+{
+ struct GNUNET_DHT_ClientGetMessage *get_msg;
+ struct GNUNET_DHT_GetHandle *get_handle;
+ size_t msize;
+ struct PendingMessage *pending;
- GNUNET_DHT_route_start(handle, key, 0, 0, &put_msg->header, timeout, NULL, NULL, cont, cont_cls);
+ msize = sizeof (struct GNUNET_DHT_ClientGetMessage) + xquery_size;
+ if ((msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
+ (xquery_size >= GNUNET_SERVER_MAX_MESSAGE_SIZE))
+ {
+ GNUNET_break (0);
+ return NULL;
+ }
+ pending = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
+ get_msg = (struct GNUNET_DHT_ClientGetMessage *) &pending[1];
+ pending->msg = &get_msg->header;
+ pending->handle = handle;
+ pending->free_on_send = GNUNET_NO;
+ get_msg->header.size = htons (msize);
+ get_msg->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_CLIENT_GET);
+ get_msg->options = htonl ((uint32_t) options);
+ get_msg->desired_replication_level = htonl (desired_replication_level);
+ get_msg->type = htonl (type);
+ get_msg->key = *key;
+ handle->uid_gen++;
+ get_msg->unique_id = handle->uid_gen;
+ memcpy (&get_msg[1], xquery, xquery_size);
+ GNUNET_CONTAINER_DLL_insert (handle->pending_head, handle->pending_tail,
+ pending);
+ pending->in_pending_queue = GNUNET_YES;
+ get_handle = GNUNET_malloc (sizeof (struct GNUNET_DHT_GetHandle));
+ get_handle->iter = iter;
+ get_handle->iter_cls = iter_cls;
+ get_handle->message = pending;
+ get_handle->unique_id = get_msg->unique_id;
+ GNUNET_CONTAINER_multihashmap_put (handle->active_requests, key, get_handle,
+ GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
+ process_pending_messages (handle);
+ return get_handle;
+}
+
+/**
+ * Stop async DHT-get.
+ *
+ * @param get_handle handle to the GET operation to stop
+ */
+void
+GNUNET_DHT_get_stop (struct GNUNET_DHT_GetHandle *get_handle)
+{
+ struct GNUNET_DHT_Handle *handle;
+ const struct GNUNET_DHT_ClientGetMessage *get_msg;
+ struct GNUNET_DHT_ClientGetStopMessage *stop_msg;
+ struct PendingMessage *pending;
+
+ handle = get_handle->message->handle;
+ get_msg =
+ (const struct GNUNET_DHT_ClientGetMessage *) get_handle->message->msg;
+
+ /* generate STOP */
+ pending =
+ GNUNET_malloc (sizeof (struct PendingMessage) +
+ sizeof (struct GNUNET_DHT_ClientGetStopMessage));
+ stop_msg = (struct GNUNET_DHT_ClientGetStopMessage *) &pending[1];
+ pending->msg = &stop_msg->header;
+ pending->handle = handle;
+ pending->free_on_send = GNUNET_YES;
+ stop_msg->header.size =
+ htons (sizeof (struct GNUNET_DHT_ClientGetStopMessage));
+ stop_msg->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_CLIENT_GET_STOP);
+ stop_msg->reserved = htonl (0);
+ stop_msg->unique_id = get_msg->unique_id;
+ stop_msg->key = get_msg->key;
+ GNUNET_CONTAINER_DLL_insert (handle->pending_head, handle->pending_tail,
+ pending);
+ pending->in_pending_queue = GNUNET_YES;
+
+ /* remove 'GET' from active status */
+ GNUNET_assert (GNUNET_YES ==
+ GNUNET_CONTAINER_multihashmap_remove (handle->active_requests,
+ &get_msg->key,
+ get_handle));
+ if (GNUNET_YES == get_handle->message->in_pending_queue)
+ {
+ GNUNET_CONTAINER_DLL_remove (handle->pending_head, handle->pending_tail,
+ get_handle->message);
+ get_handle->message->in_pending_queue = GNUNET_NO;
+ }
+ GNUNET_free (get_handle->message);
+ GNUNET_free (get_handle);
+
+ process_pending_messages (handle);
}
+
+
+/* end of dht_api.c */