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3 (C) 2001 - 2011 Christian Grothoff (and other contributing authors)
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13 General Public License for more details.
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22 * @file mesh/mesh_tree_tree.h
23 * @brief Tunnel tree handling functions
24 * @author Bartlomiej Polot
29 /******************************************************************************/
30 /************************ DATA STRUCTURES ****************************/
31 /******************************************************************************/
34 * Information regarding a possible path to reach a single peer
42 struct MeshPeerPath *next;
43 struct MeshPeerPath *prev;
46 * List of all the peers that form the path from origin to target.
48 GNUNET_PEER_Id *peers;
51 * Number of peers (hops) in the path
59 * Node of path tree for a tunnel
61 struct MeshTunnelTreeNode
64 * Tunnel this node belongs to (and therefore tree)
69 * Peer this node describes
74 * Parent node in the tree
76 struct MeshTunnelTreeNode *parent;
81 struct MeshTunnelTreeNode *next;
86 struct MeshTunnelTreeNode *prev;
91 struct MeshTunnelTreeNode *children_head;
96 struct MeshTunnelTreeNode *children_tail;
99 * Status of the peer in the tunnel
101 enum MeshPeerState status;
106 * Tree to reach all peers in the tunnel
108 struct MeshTunnelTree
111 * How often to refresh the path
113 struct GNUNET_TIME_Relative refresh;
116 * Tunnel this path belongs to
118 struct MeshTunnel *t;
121 * Root node of peer tree
123 struct MeshTunnelTreeNode *root;
126 * Node that represents our position in the tree (for non local tunnels)
128 struct MeshTunnelTreeNode *me;
131 * Cache of all peers and the first hop to them.
132 * Indexed by PeerIdentity, contains a pointer to the PeerIdentity
135 struct GNUNET_CONTAINER_MultiHashMap *first_hops;
140 /******************************************************************************/
141 /************************* FUNCTIONS *****************************/
142 /******************************************************************************/
147 * @param lenght How many hops will the path have.
149 * @return A newly allocated path with a peer array of the specified length.
151 struct MeshPeerPath *
152 path_new (unsigned int length);
158 * @param p the path to invert
161 path_invert (struct MeshPeerPath *p);
165 * Find the first peer whom to send a packet to go down this path
167 * @param t The tunnel tree to use
168 * @param peer The peerinfo of the peer we are trying to reach
170 * @return peerinfo of the peer who is the first hop in the tunnel
173 struct GNUNET_PeerIdentity *
174 path_get_first_hop (struct MeshTunnelTree *t,
175 GNUNET_PEER_Id peer);
179 * Get the length of a path
181 * @param p The path to measure, with the local peer at any point of it
183 * @return Number of hops to reach destination
184 * UINT_MAX in case the peer is not in the path
187 path_get_length (struct MeshPeerPath *p);
191 * Get the cost of the path relative to the already built tunnel tree
193 * @param t The tunnel tree to which compare
194 * @param path The individual path to reach a peer
196 * @return Number of hops to reach destination, UINT_MAX in case the peer is not
200 path_get_cost (struct MeshTunnelTree *t,
201 struct MeshPeerPath *path);
205 * Destroy the path and free any allocated resources linked to it
207 * @param p the path to destroy
209 * @return GNUNET_OK on success
212 path_destroy (struct MeshPeerPath *p);
215 /******************************************************************************/
218 * Method called whenever a node has been marked as disconnected.
220 * @param node peer identity the tunnel stopped working with
222 typedef void (*MeshNodeDisconnectCB) (const struct MeshTunnelTreeNode * node);
226 * Create a new tunnel tree associated to a tunnel
228 * @param t Tunnel this tree will represent
229 * @param peer A short peer id of the root of the tree
231 * @return A newly allocated and initialized tunnel tree
233 struct MeshTunnelTree *
234 tree_new (struct MeshTunnel *t, GNUNET_PEER_Id peer);
238 * Recursively find the given peer in the tree.
240 * @param parent Parent node where to start looking.
241 * @param peer Short ID of peer to find.
243 * @return Pointer to the node of the peer. NULL if not found.
245 struct MeshTunnelTreeNode *
246 tree_find_peer (struct MeshTunnelTreeNode *parent,
247 GNUNET_PEER_Id peer);
251 * Delete the current path to the peer, including all now unused relays.
252 * The destination peer is NOT destroyed, it is returned in order to either set
253 * a new path to it or destroy it explicitly, taking care of it's child nodes.
255 * @param t Tunnel tree where to delete the path from.
256 * @param peer Destination peer whose path we want to remove.
257 * @param cb Callback to use to notify about which peers are going to be
260 * @return pointer to the pathless node.
261 * NULL when not found
263 struct MeshTunnelTreeNode *
264 tree_del_path (struct MeshTunnelTree *t,
266 MeshNodeDisconnectCB cb);
270 * Return a newly allocated individual path to reach a peer from the local peer,
271 * according to the path tree of some tunnel.
273 * @param t Tunnel from which to read the path tree
274 * @param peer Destination peer to whom we want a path
276 * @return A newly allocated individual path to reach the destination peer.
277 * Path must be destroyed afterwards.
279 struct MeshPeerPath *
280 tree_get_path_to_peer(struct MeshTunnelTree *t,
281 GNUNET_PEER_Id peer);
285 * Integrate a stand alone path into the tunnel tree.
287 * @param t Tunnel where to add the new path.
288 * @param p Path to be integrated.
289 * @param cb Callback to use to notify about peers temporarily disconnecting
291 * @return GNUNET_OK in case of success.
292 * GNUNET_SYSERR in case of error.
295 tree_add_path (struct MeshTunnelTree *t,
296 const struct MeshPeerPath *p,
297 MeshNodeDisconnectCB cb);
301 * Print the tree on stderr
306 tree_debug(struct MeshTunnelTree *t);
310 * Destroy the whole tree and free all used memory and Peer_Ids
312 * @param t Tree to be destroyed
315 tree_destroy (struct MeshTunnelTree *t);