*/
struct GNUNET_DHT_GetHandle *dhtget;
- /**
- * Provided callback to call when a path is found.
- */
- GCD_search_callback callback;
-
- /**
- * Provided closure.
- */
- void *cls;
-
};
static struct GNUNET_TIME_Relative announce_delay;
-
/**
* Function to process paths received for a new peer addition. The recorded
* paths form the initial tunnel, which can be optimized later.
size_t size,
const void *data)
{
- struct GCD_search_handle *h = cls;
const struct GNUNET_HELLO_Message *hello = data;
- struct CadetPeerPath *p;
struct CadetPeer *peer;
- p = GCPP_path_from_dht (get_path,
+ GCPP_try_path_from_dht (get_path,
get_path_length,
put_path,
put_path_length);
- h->callback (h->cls,
- p);
- GCPP_path_destroy (p);
-
if ( (size >= sizeof (struct GNUNET_HELLO_Message)) &&
(ntohs (hello->header.size) == size) &&
(size == GNUNET_HELLO_size (hello)) )
* Search DHT for paths to @a peeR_id
*
* @param peer_id peer to search for
- * @param callback function to call with results
- * @param callback_cls closure for @a callback
* @return handle to abort search
*/
struct GCD_search_handle *
-GCD_search (const struct GNUNET_PeerIdentity *peer_id,
- GCD_search_callback callback,
- void *callback_cls)
+GCD_search (const struct GNUNET_PeerIdentity *peer_id)
{
struct GNUNET_HashCode phash;
struct GCD_search_handle *h;
sizeof (*peer_id));
h = GNUNET_new (struct GCD_search_handle);
- h->callback = callback;
- h->cls = callback_cls;
h->dhtget = GNUNET_DHT_get_start (dht_handle, /* handle */
GNUNET_BLOCK_TYPE_DHT_HELLO, /* type */
&phash, /* key to search */
struct GCD_search_handle;
-/**
- * Callback called on each path found over the DHT.
- *
- * @param cls Closure.
- * @param path An unchecked, unoptimized path to the target node.
- * After callback will no longer be valid, unless #GCPP_acquire() is called!
- */
-typedef void
-(*GCD_search_callback) (void *cls,
- struct CadetPeerPath *path);
-
-
/**
* Initialize the DHT subsystem.
*
void
GCD_init (const struct GNUNET_CONFIGURATION_Handle *c);
+
/**
* Shut down the DHT subsystem.
*/
* Search DHT for paths to @a peeR_id
*
* @param peer_id peer to search for
- * @param callback function to call with results
- * @param callback_cls closure for @a callback
* @return handle to abort search
*/
struct GCD_search_handle *
-GCD_search (const struct GNUNET_PeerIdentity *peer_id,
- GCD_search_callback callback,
- void *callback_cls);
+GCD_search (const struct GNUNET_PeerIdentity *peer_id);
/**
* @brief Information we track per path.
* @author Bartlomiej Polot
* @author Christian Grothoff
+ *
+ * TODO:
+ * - path desirability score calculations are not done
+ * (and will be tricky to have during path changes)
*/
#include "platform.h"
#include "gnunet-service-cadet-new_peer.h"
};
-
/**
* Return how much we like keeping the path. This is an aggregate
* score based on various factors, including the age of the path
GNUNET_CONTAINER_HeapCostType
GCPP_get_desirability (const struct CadetPeerPath *path)
{
- GNUNET_break (0);
- return 0;
-}
-
-
-/**
- * The given peer @a cp used to own this @a path. However, it is no
- * longer interested in maintaining it, so the path should be
- * discarded or shortened (in case a previous peer on the path finds
- * the path desirable).
- *
- * @param path the path that is being released
- * @param node entry in the heap of @a cp where this path is anchored
- * should be used for updates to the desirability of this path
- */
-void
-GCPP_acquire (struct CadetPeerPath *path,
- struct GNUNET_CONTAINER_HeapNode *node)
-{
- GNUNET_assert (NULL == path->hn);
- path->hn = node;
+ return path->desirability;
}
/* see if new peer at the end likes this path any better */
entry = &path->entries[path->entries_length - 1];
path->hn = GCP_attach_path (entry->peer,
- path);
+ path,
+ path->entries_length);
if (NULL != path->hn)
return; /* yep, got attached, we are done. */
}
/**
- * Create a peer path based on the result of a DHT lookup.
- * If we already know this path, or one that is longer,
- * simply return NULL.
+ * Closure for #find_peer_at() and #check_match().
+ */
+struct CheckMatchContext
+{
+
+ /**
+ * Set to a matching path, if any.
+ */
+ struct CadetPeerPath *match;
+
+ /**
+ * Array the combined paths.
+ */
+ struct CadetPeer **cpath;
+
+};
+
+
+/**
+ * Check if the given path is identical on all of the
+ * hops until @a off, and not longer than @a off. If the
+ * @a path matches, store it in `match`.
*
- * FIXME: change API completely!
- * Should in here create path transiently, then call
- * callback, and then do path destroy (if applicable)
- * without returning in the middle.
+ * @param cls the `struct CheckMatchContext` to check against
+ * @param path the path to check
+ * @param off offset to check at
+ * @return #GNUNET_YES (continue to iterate), or if found #GNUNET_NO
+ */
+static int
+check_match (void *cls,
+ struct CadetPeerPath *path,
+ unsigned int off)
+{
+ struct CheckMatchContext *cm_ctx = cls;
+
+ if (path->entries_length > off)
+ return GNUNET_YES; /* too long, cannot be useful */
+ for (unsigned int i=0;i<off;i++)
+ if (cm_ctx->cpath[i] !=
+ GCPP_get_peer_at_offset (path,
+ i))
+ return GNUNET_YES; /* missmatch, ignore */
+ cm_ctx->match = path;
+ return GNUNET_NO; /* match, we are done! */
+}
+
+
+/**
+ * Extend path @a path by the @a num_peers from the @a peers
+ * array, assuming the owners past the current owner want it.
*
- * FIXME: also need to nicely handle case that this path
- * extends (lengthens!) an existing path.
+ * @param path path to extend
+ * @param peers list of peers beyond the end of @a path
+ * @param num_peers length of the @a peers array
+ */
+static void
+extend_path (struct CadetPeerPath *path,
+ struct CadetPeer **peers,
+ unsigned int num_peers)
+{
+ unsigned int old_len = path->entries_length;
+ struct GNUNET_CONTAINER_HeapNode *hn;
+ int i;
+
+ /* If we extend an existing path, detach it from the
+ old owner and re-attach to the new one */
+ hn = NULL;
+ for (i=num_peers-1;i>=0;i--)
+ {
+ /* FIXME: note that path->desirability is used, but not yet updated here! */
+ hn = GCP_attach_path (peers[i],
+ path,
+ old_len + (unsigned int) i);
+ if (NULL != hn)
+ break;
+ }
+ if (NULL == hn)
+ return; /* none of the peers is interested in this path */
+ GCP_detach_path (path->entries[old_len-1].peer,
+ path,
+ path->hn);
+ path->hn = hn;
+ GNUNET_array_grow (path->entries,
+ path->entries_length,
+ old_len + i);
+ for (;i >= 0;i--)
+ {
+ struct CadetPeerPathEntry *entry = &path->entries[old_len + i];
+
+ entry->peer = peers[i];
+ entry->path = path;
+ GCP_path_entry_add (entry->peer,
+ entry,
+ old_len + i);
+ }
+}
+
+
+/**
+ * Create a peer path based on the result of a DHT lookup. If we
+ * already know this path, or one that is longer, simply return NULL.
+ * Otherwise, we try to extend an existing path, or create a new one
+ * if applicable.
*
* @param get_path path of the get request
* @param get_path_length lenght of @a get_path
* @param put_path_length length of the @a put_path
* @return a path through the network
*/
-struct CadetPeerPath *
-GCPP_path_from_dht (const struct GNUNET_PeerIdentity *get_path,
- unsigned int get_path_length,
- const struct GNUNET_PeerIdentity *put_path,
- unsigned int put_path_length)
+void
+GCPP_try_path_from_dht (const struct GNUNET_PeerIdentity *get_path,
+ unsigned int get_path_length,
+ const struct GNUNET_PeerIdentity *put_path,
+ unsigned int put_path_length)
{
+ struct CheckMatchContext cm_ctx;
+ struct CadetPeer *cpath[get_path_length + put_path_length];
struct CadetPeerPath *path;
+ struct GNUNET_CONTAINER_HeapNode *hn;
+ int i;
+
+ /* precompute 'cpath' so we can avoid doing the lookups lots of times */
+ for (unsigned int off=0;off<get_path_length + put_path_length;off++)
+ {
+ const struct GNUNET_PeerIdentity *pid;
+
+ pid = (off < get_path_length)
+ ? &get_path[get_path_length - off]
+ : &put_path[get_path_length + put_path_length - off];
+ cpath[off] = GCP_get (pid,
+ GNUNET_YES);
+ }
+ /* First figure out if this path is a subset of an existing path, an
+ extension of an existing path, or a new path. */
+ cm_ctx.cpath = cpath;
+ cm_ctx.match = NULL;
+ for (i=get_path_length + put_path_length-1;i>=0;i--)
+ {
+ GCP_iterate_paths_at (cpath[i],
+ (unsigned int) i,
+ &check_match,
+ &cm_ctx);
+ if (NULL != cm_ctx.match)
+ {
+ if (i == get_path_length + put_path_length - 1)
+ {
+ /* Existing path includes this one, nothing to do! */
+ return;
+ }
+ if (cm_ctx.match->entries_length == i + 1)
+ {
+ /* Existing path ends in the middle of new path, extend it! */
+ extend_path (cm_ctx.match,
+ &cpath[i],
+ get_path_length + put_path_length - i);
+ return;
+ }
+ }
+ }
+
+ /* No match at all, create completely new path */
path = GNUNET_new (struct CadetPeerPath);
- path->entries_length = get_path_length + put_path_length;
+
+ /* First, try to attach it */
+ hn = NULL;
+ for (i=get_path_length + put_path_length-1;i>=0;i--)
+ {
+ path->entries_length = i;
+ /* FIXME: note that path->desirability is used, but not yet initialized here! */
+ hn = GCP_attach_path (cpath[i],
+ path,
+ (unsigned int) i);
+ if (NULL != hn)
+ break;
+ }
+ if (NULL == hn)
+ {
+ /* None of the peers on the path care about it. */
+ GNUNET_free (path);
+ return;
+ }
+ path->hn = hn;
+ path->entries_length = i;
path->entries = GNUNET_new_array (path->entries_length,
struct CadetPeerPathEntry);
- for (unsigned int i=0;i<get_path_length + put_path_length;i++)
+ for (;i>=0;i--)
{
struct CadetPeerPathEntry *entry = &path->entries[i];
- const struct GNUNET_PeerIdentity *pid;
- pid = (i < get_path_length) ? &get_path[get_path_length - i] : &put_path[path->entries_length - i];
- entry->peer = GCP_get (pid,
- GNUNET_YES);
+ entry->peer = cpath[i];
entry->path = path;
GCP_path_entry_add (entry->peer,
entry,
i);
}
- GNUNET_break (0);
- return NULL;
-}
-
-
-/**
- * Destroy a path, we no longer need it.
- *
- * @param p path to destroy.
- */
-void
-GCPP_path_destroy (struct CadetPeerPath *path)
-{
- if (NULL != path->hn)
- return; /* path was attached, to be kept! */
- path_destroy (path);
}
#include "gnunet-service-cadet-new.h"
/**
- * Create a peer path based on the result of a DHT lookup.
- * If we already know this path, or one that is longer,
- * simply return NULL.
+ * Create a peer path based on the result of a DHT lookup. If we
+ * already know this path, or one that is longer, simply return NULL.
+ * Otherwise, we try to extend an existing path, or create a new one
+ * if applicable.
*
* @param get_path path of the get request
* @param get_path_length lenght of @a get_path
* @param put_path path of the put request
* @param put_path_length length of the @a put_path
- * @return a path through the network
- */
-struct CadetPeerPath *
-GCPP_path_from_dht (const struct GNUNET_PeerIdentity *get_path,
- unsigned int get_path_length,
- const struct GNUNET_PeerIdentity *put_path,
- unsigned int put_path_length);
-
-
-/**
- * Destroy a path, we no longer need it.
- *
- * @param path path to destroy.
*/
void
-GCPP_path_destroy (struct CadetPeerPath *path);
+GCPP_try_path_from_dht (const struct GNUNET_PeerIdentity *get_path,
+ unsigned int get_path_length,
+ const struct GNUNET_PeerIdentity *put_path,
+ unsigned int put_path_length);
/**
GCPP_get_desirability (const struct CadetPeerPath *path);
-/**
- * The given peer @a cp used to own this @a path. However, it is no
- * longer interested in maintaining it, so the path should be
- * discarded or shortened (in case a previous peer on the path finds
- * the path desirable).
- *
- * @param path the path that is being released
- * @param node entry in the heap of @a cp where this path is anchored
- * should be used for updates to the desirability of this path
- */
-void
-GCPP_acquire (struct CadetPeerPath *path,
- struct GNUNET_CONTAINER_HeapNode *node);
-
-
/**
* The given peer @a cp used to own this @a path. However, it is no
* longer interested in maintaining it, so the path should be
* has plenty of paths, return NULL.
*
* @param cp peer to which the @a path leads to
- * @param path a path looking for an owner
+ * @param path a path looking for an owner; may not be fully initialized yet!
+ * @param off offset of @a cp in @a path
* @return NULL if this peer does not care to become a new owner,
* otherwise the node in the peer's path heap for the @a path.
*/
struct GNUNET_CONTAINER_HeapNode *
GCP_attach_path (struct CadetPeer *cp,
- struct CadetPeerPath *path)
+ struct CadetPeerPath *path,
+ unsigned int off)
{
GNUNET_CONTAINER_HeapCostType desirability;
struct CadetPeerPath *root;
GNUNET_CONTAINER_HeapCostType root_desirability;
struct GNUNET_CONTAINER_HeapNode *hn;
+ /* FIXME: desirability is not yet initialized; tricky! */
desirability = GCPP_get_desirability (path);
if (GNUNET_NO ==
GNUNET_CONTAINER_heap_peek2 (cp->path_heap,
/**
- * Function called when the DHT finds a @a path to the peer (@a cls).
+ * This peer can no longer own @a path as the path
+ * has been extended and a peer further down the line
+ * is now the new owner.
*
- * @param cls the `struct CadetPeer`
- * @param path the path that was found
+ * @param cp old owner of the @a path
+ * @param path path where the ownership is lost
+ * @param hn note in @a cp's path heap that must be deleted
*/
-static void
-dht_result_cb (void *cls,
- struct CadetPeerPath *path)
+void
+GCP_detach_path (struct CadetPeer *cp,
+ struct CadetPeerPath *path,
+ struct GNUNET_CONTAINER_HeapNode *hn)
{
- struct CadetPeer *cp = cls;
- struct GNUNET_CONTAINER_HeapNode *hn;
-
- hn = GCP_attach_path (cp,
- path);
- if (NULL == hn)
- return;
- GCPP_acquire (path,
- hn);
+ GNUNET_assert (path ==
+ GNUNET_CONTAINER_heap_remove_node (hn));
}
if ( (NULL == cp->search_h) &&
(DESIRED_CONNECTIONS_PER_TUNNEL < cp->num_paths) )
cp->search_h
- = GCD_search (&cp->pid,
- &dht_result_cb,
- cp);
+ = GCD_search (&cp->pid);
}
else
{
}
+/**
+ * Iterate over the paths to @a peer where
+ * @a peer is at distance @a dist from us.
+ *
+ * @param peer Peer to get path info.
+ * @param dist desired distance of @a peer to us on the path
+ * @param callback Function to call for every path.
+ * @param callback_cls Closure for @a callback.
+ * @return Number of iterated paths.
+ */
+unsigned int
+GCP_iterate_paths_at (struct CadetPeer *peer,
+ unsigned int dist,
+ GCP_PathIterator callback,
+ void *callback_cls)
+{
+ unsigned int ret = 0;
+
+ if (dist<peer->path_dll_length)
+ return 0;
+ for (struct CadetPeerPathEntry *pe = peer->path_heads[dist];
+ NULL != pe;
+ pe = pe->next)
+ {
+ if (GNUNET_NO ==
+ callback (callback_cls,
+ pe->path,
+ dist))
+ return ret;
+ ret++;
+ }
+ return ret;
+}
+
+
/**
* Get the tunnel towards a peer.
*
void *callback_cls);
+/**
+ * Iterate over the paths to @a peer where
+ * @a peer is at distance @a dist from us.
+ *
+ * @param peer Peer to get path info.
+ * @param dist desired distance of @a peer to us on the path
+ * @param callback Function to call for every path.
+ * @param callback_cls Closure for @a callback.
+ * @return Number of iterated paths.
+ */
+unsigned int
+GCP_iterate_paths_at (struct CadetPeer *peer,
+ unsigned int dist,
+ GCP_PathIterator callback,
+ void *callback_cls);
+
+
/**
* Remove an entry from the DLL of all of the paths that this peer is on.
*
* has plenty of paths, return NULL.
*
* @param cp peer to which the @a path leads to
- * @param path a path looking for an owner
+ * @param path a path looking for an owner; may not be fully initialized yet!
+ * @param off offset of @a cp in @a path
* @return NULL if this peer does not care to become a new owner,
* otherwise the node in the peer's path heap for the @a path.
*/
struct GNUNET_CONTAINER_HeapNode *
GCP_attach_path (struct CadetPeer *cp,
- struct CadetPeerPath *path);
+ struct CadetPeerPath *path,
+ unsigned int off);
+
+
+/**
+ * This peer can no longer own @a path as the path
+ * has been extended and a peer further down the line
+ * is now the new owner.
+ *
+ * @param cp old owner of the @a path
+ * @param path path where the ownership is lost
+ * @param hn note in @a cp's path heap that must be deleted
+ */
+void
+GCP_detach_path (struct CadetPeer *cp,
+ struct CadetPeerPath *path,
+ struct GNUNET_CONTAINER_HeapNode *hn);
/**
projects / oweals / gnunet.git / commitdiff