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22 * @file mesh/mesh_tunnel_tree.c
23 * @brief Tunnel tree handling functions
24 * @author Bartlomiej Polot
28 #include "mesh_tunnel_tree.h"
30 #define MESH_TREE_DEBUG GNUNET_YES
36 * @param lenght How many hops will the path have.
38 * @return A newly allocated path with a peer array of the specified length.
41 path_new (unsigned int length)
43 struct MeshPeerPath *p;
45 p = GNUNET_malloc (sizeof(struct MeshPeerPath));
49 p->peers = GNUNET_malloc (length * sizeof(GNUNET_PEER_Id));
58 * @param p the path to invert
61 path_invert (struct MeshPeerPath *path)
66 for (i = 0; i < path->length / 2; i++)
69 path->peers[i] = path->peers[path->length - i - 1];
70 path->peers[path->length - i - 1] = aux;
76 * Duplicate a path, incrementing short peer's rc.
78 * @param p The path to duplicate.
81 path_duplicate (struct MeshPeerPath *path)
83 struct MeshPeerPath *aux;
86 aux = path_new(path->length);
87 memcpy (aux->peers, path->peers, path->length * sizeof(GNUNET_PEER_Id));
88 for (i = 0; i < path->length; i++)
89 GNUNET_PEER_change_rc(path->peers[i], 1);
95 * Find the first peer whom to send a packet to go down this path
97 * @param t The tunnel tree to use
98 * @param peer The peerinfo of the peer we are trying to reach
100 * @return peerinfo of the peer who is the first hop in the tunnel
103 struct GNUNET_PeerIdentity *
104 path_get_first_hop (struct MeshTunnelTree *t, GNUNET_PEER_Id peer)
106 struct GNUNET_PeerIdentity id;
107 struct GNUNET_PeerIdentity *r;
109 GNUNET_PEER_resolve (peer, &id);
110 r = GNUNET_CONTAINER_multihashmap_get (t->first_hops, &id.hashPubKey);
111 GNUNET_break (NULL != r);
118 * Get the length of a path
120 * @param path The path to measure, with the local peer at any point of it
122 * @return Number of hops to reach destination
123 * UINT_MAX in case the peer is not in the path
126 path_get_length (struct MeshPeerPath *path)
135 * Get the cost of the path relative to the already built tunnel tree
137 * @param t The tunnel tree to which compare
138 * @param path The individual path to reach a peer
140 * @return Number of hops to reach destination, UINT_MAX in case the peer is not
143 * TODO: remove dummy implementation, look into the tunnel tree
146 path_get_cost (struct MeshTunnelTree *t, struct MeshPeerPath *path)
148 return path_get_length (path);
153 * Destroy the path and free any allocated resources linked to it
155 * @param p the path to destroy
157 * @return GNUNET_OK on success
160 path_destroy (struct MeshPeerPath *p)
164 GNUNET_PEER_decrement_rcs (p->peers, p->length);
165 GNUNET_free (p->peers);
173 * Allocates and initializes a new node.
174 * Sets ID and parent of the new node and inserts it in the DLL of the parent
176 * @param parent Node that will be the parent from the new node, NULL for root
177 * @param peer Short Id of the new node
179 * @return Newly allocated node
181 static struct MeshTunnelTreeNode *
182 tree_node_new(struct MeshTunnelTreeNode *parent, GNUNET_PEER_Id peer)
184 struct MeshTunnelTreeNode *node;
186 node = GNUNET_malloc(sizeof(struct MeshTunnelTreeNode));
188 GNUNET_PEER_change_rc(peer, 1);
189 node->parent = parent;
191 GNUNET_CONTAINER_DLL_insert(parent->children_head,
192 parent->children_tail,
200 tree_node_debug(struct MeshTunnelTreeNode *n, uint16_t level)
202 struct MeshTunnelTreeNode *c;
205 for (i = 0; i < level; i++)
206 fprintf(stderr, " ");
207 if (n->status == MESH_PEER_READY)
208 fprintf(stderr, "#");
209 if (n->status == MESH_PEER_SEARCHING)
210 fprintf(stderr, "+");
211 if (n->status == MESH_PEER_RELAY)
212 fprintf(stderr, "-");
213 if (n->status == MESH_PEER_RECONNECTING)
214 fprintf(stderr, "*");
216 fprintf(stderr, "%u [%p] ", n->peer, n);
217 if (NULL != n->parent)
218 fprintf(stderr, "(-> %u)\n", n->parent->peer);
220 fprintf(stderr, "(root)\n");
221 for (c = n->children_head; NULL != c; c = c->next)
222 tree_node_debug(c, level + 1);
227 * Destroys and frees the node and all children
229 * @param n Parent node to be destroyed
232 tree_node_destroy (struct MeshTunnelTreeNode *parent)
234 struct MeshTunnelTreeNode *n;
235 struct MeshTunnelTreeNode *next;
237 n = parent->children_head;
241 tree_node_destroy(n);
244 GNUNET_PEER_change_rc(parent->peer, -1);
245 if (NULL != parent->parent)
246 GNUNET_CONTAINER_DLL_remove(parent->parent->children_head,
247 parent->parent->children_tail,
255 * Create a new tunnel tree associated to a tunnel
257 * @param t Tunnel this tree will represent
258 * @param peer A short peer id of the root of the tree
260 * @return A newly allocated and initialized tunnel tree
262 struct MeshTunnelTree *
263 tree_new (struct MeshTunnel *t, GNUNET_PEER_Id peer)
265 struct MeshTunnelTree *tree;
267 tree = GNUNET_malloc(sizeof (struct MeshTunnelTree));
268 tree->first_hops = GNUNET_CONTAINER_multihashmap_create(32);
269 tree->root = tree_node_new(NULL, peer);
270 tree->root->status = MESH_PEER_ROOT;
279 * Recursively find the given peer in the tree.
281 * @param t Tunnel where to look for the peer.
282 * @param peer Peer to find
284 * @return Pointer to the node of the peer. NULL if not found.
286 struct MeshTunnelTreeNode *
287 tree_find_peer (struct MeshTunnelTreeNode *parent, GNUNET_PEER_Id peer_id)
289 struct MeshTunnelTreeNode *n;
290 struct MeshTunnelTreeNode *r;
292 if (parent->peer == peer_id)
294 for (n = parent->children_head; NULL != n; n = n->next)
296 r = tree_find_peer (n, peer_id);
305 * Recusively mark peer and children as disconnected, notify client
307 * @param tree Tree this node belongs to
308 * @param parent Node to be clean, potentially with children
309 * @param cb Callback to use to notify about disconnected peers.
312 tree_mark_peers_disconnected (struct MeshTunnelTree *tree,
313 struct MeshTunnelTreeNode *parent,
314 MeshNodeDisconnectCB cb)
316 struct GNUNET_PeerIdentity *pi;
317 struct GNUNET_PeerIdentity id;
318 struct MeshTunnelTreeNode *n;
320 for (n = parent->children_head; NULL != n; n = n->next)
322 tree_mark_peers_disconnected (tree, n, cb);
324 if (MESH_PEER_READY == parent->status && NULL != cb)
328 parent->status = MESH_PEER_RECONNECTING;
330 /* Remove and free info about first hop */
331 GNUNET_PEER_resolve(parent->peer, &id);
332 pi = GNUNET_CONTAINER_multihashmap_get(tree->first_hops, &id.hashPubKey);
333 GNUNET_CONTAINER_multihashmap_remove_all(tree->first_hops, &id.hashPubKey);
340 * Recusively update the info about what is the first hop to reach the node
342 * @param tree Tree this nodes belongs to
343 * @param parent Node to be start updating
344 * @param hop If known, ID of the first hop.
345 * If not known, NULL to find out and pass on children.
348 tree_update_first_hops (struct MeshTunnelTree *tree,
349 struct MeshTunnelTreeNode *parent,
350 struct GNUNET_PeerIdentity *hop)
352 struct GNUNET_PeerIdentity pi;
353 struct GNUNET_PeerIdentity *copy;
354 struct GNUNET_PeerIdentity id;
355 struct MeshTunnelTreeNode *n;
358 GNUNET_PEER_resolve(parent->peer, &id);
359 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
360 "tree: Finding first hop for %s.\n",
365 struct MeshTunnelTreeNode *aux;
366 struct MeshTunnelTreeNode *old;
369 while (aux != tree->me)
372 GNUNET_PEER_resolve(old->peer, &id);
373 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
374 "tree: ... its not %s.\n",
379 GNUNET_assert(NULL != aux);
382 GNUNET_PEER_resolve(old->peer, &id);
383 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
388 GNUNET_PEER_resolve(old->peer, hop);
390 copy = GNUNET_malloc(sizeof(struct GNUNET_PeerIdentity));
392 GNUNET_PEER_resolve(parent->peer, &id);
393 GNUNET_CONTAINER_multihashmap_put(
397 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST);
399 for (n = parent->children_head; NULL != n; n = n->next)
401 tree_update_first_hops (tree, n, hop);
407 * Delete the current path to the peer, including all now unused relays.
408 * The destination peer is NOT destroyed, it is returned in order to either set
409 * a new path to it or destroy it explicitly, taking care of it's child nodes.
411 * @param t Tunnel tree where to delete the path from.
412 * @param peer Destination peer whose path we want to remove.
413 * @param cb Callback to use to notify about disconnected peers.
415 * @return pointer to the pathless node.
416 * NULL when not found
418 struct MeshTunnelTreeNode *
419 tree_del_path (struct MeshTunnelTree *t, GNUNET_PEER_Id peer_id,
420 MeshNodeDisconnectCB cb)
422 struct MeshTunnelTreeNode *parent;
423 struct MeshTunnelTreeNode *node;
424 struct MeshTunnelTreeNode *n;
427 struct GNUNET_PeerIdentity id;
428 GNUNET_PEER_resolve(peer_id, &id);
429 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
430 "tree: Deleting path to %s.\n",
433 if (peer_id == t->root->peer)
436 for (n = t->disconnected_head; NULL != n; n = n->next)
438 if (n->peer == peer_id)
440 /* Was already pathless, waiting for reconnection */
441 GNUNET_CONTAINER_DLL_remove (t->disconnected_head,
442 t->disconnected_tail,
447 n = tree_find_peer (t->root, peer_id);
453 GNUNET_CONTAINER_DLL_remove(parent->children_head, parent->children_tail, n);
456 while (MESH_PEER_RELAY == parent->status && NULL == parent->children_head)
459 GNUNET_PEER_resolve(parent->peer, &id);
460 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
461 "tree: Deleting node %s.\n",
465 tree_node_destroy(parent);
469 GNUNET_PEER_resolve(parent->peer, &id);
470 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
471 "tree: Not deleted peer %s.\n",
475 tree_mark_peers_disconnected (t, node, cb);
482 * Return a newly allocated individual path to reach a peer from the local peer,
483 * according to the path tree of some tunnel.
485 * @param t Tunnel from which to read the path tree
486 * @param peer_info Destination peer to whom we want a path
488 * @return A newly allocated individual path to reach the destination peer.
489 * Path must be destroyed afterwards.
491 struct MeshPeerPath *
492 tree_get_path_to_peer(struct MeshTunnelTree *t, GNUNET_PEER_Id peer)
494 struct MeshTunnelTreeNode *n;
495 struct MeshPeerPath *p;
496 GNUNET_PEER_Id myid = t->me->peer;
498 n = tree_find_peer(t->me, peer);
501 /* Building the path (inverted!) */
502 while (n->peer != myid)
504 GNUNET_array_append(p->peers, p->length, n->peer);
505 GNUNET_PEER_change_rc(n->peer, 1);
507 GNUNET_assert(NULL != n);
509 GNUNET_array_append(p->peers, p->length, myid);
510 GNUNET_PEER_change_rc(myid, 1);
520 * Integrate a stand alone path into the tunnel tree.
521 * If the peer toward which the new path is already in the tree, the peer
522 * and its children will be maked as disconnected and the callback
523 * will be called on each one of them. They will be maked as online only after
524 * receiving a PATH ACK for the new path for each one of them, so the caller
525 * should take care of sending a new CREATE PATH message for each disconnected
528 * @param t Tunnel where to add the new path.
529 * @param p Path to be integrated.
530 * @param cb Callback to use to notify about peers temporarily disconnecting
532 * @return GNUNET_OK in case of success.
533 * GNUNET_SYSERR in case of error.
536 * - go backwards on path looking for each peer in the present tree
537 * - do not disconnect peers until new path is created & connected
540 tree_add_path (struct MeshTunnelTree *t,
541 const struct MeshPeerPath *p,
542 MeshNodeDisconnectCB cb)
544 struct MeshTunnelTreeNode *parent;
545 struct MeshTunnelTreeNode *oldnode;
546 struct MeshTunnelTreeNode *n;
547 struct MeshTunnelTreeNode *c;
548 struct GNUNET_PeerIdentity id;
551 // int oldnode_is_me;
555 GNUNET_PEER_resolve(p->peers[p->length - 1], &id);
556 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
557 "tree: Adding path [%u] towards peer %s.\n",
566 GNUNET_assert(0 != p->length);
567 parent = n = t->root;
568 if (n->peer != p->peers[0])
571 return GNUNET_SYSERR;
575 oldnode = tree_del_path (t, p->peers[p->length - 1], cb);
576 /* Look for the first node that is not already present in the tree
578 * Assuming that the tree is somewhat balanced, O(log n * log N).
579 * - Length of the path is expected to be log N (size of whole network).
580 * - Each level of the tree is expected to have log n children (size of tree).
582 me = t->root->peer == myid ? 0 : -1;
583 for (i = 1; i < p->length; i++)
586 GNUNET_PEER_resolve(p->peers[i], &id);
587 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
588 "tree: Looking for peer %s.\n",
592 if (p->peers[i] == myid)
594 for (c = n->children_head; NULL != c; c = c->next)
596 if (c->peer == p->peers[i])
599 GNUNET_PEER_resolve(parent->peer, &id);
600 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
601 "tree: Found in children of %s.\n",
608 /* If we couldn't find a child equal to path[i], we have reached the end
609 * of the common path. */
614 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
615 "tree: All childen visited.\n");
617 /* Add the rest of the path as a branch from parent. */
618 while (i < p->length)
621 GNUNET_PEER_resolve(p->peers[i], &id);
622 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
623 "tree: Adding peer %s.\n",
625 GNUNET_PEER_resolve(parent->peer, &id);
626 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
631 if (i == p->length - 1 && NULL != oldnode)
634 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
635 "tree: Putting old node into place.\n");
637 oldnode->parent = parent;
638 GNUNET_CONTAINER_DLL_insert(parent->children_head,
639 parent->children_tail,
641 tree_update_first_hops (t, oldnode, NULL);
647 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "tree: Creating new node.\n");
649 n = tree_node_new(parent, p->peers[i]);
651 n->status = MESH_PEER_RELAY;
656 n->status = MESH_PEER_SEARCHING;
658 /* Add info about first hop into hashmap. */
659 if (-1 != me && me < p->length - 1)
662 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
663 "MESH: finding first hop (own pos %d/%u)\n",
666 GNUNET_PEER_resolve (p->peers[me + 1], &id);
667 tree_update_first_hops(t,
668 tree_find_peer(t->root, p->peers[p->length - 1]),
672 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "tree: New node added.\n");
679 * Notifies a tree that a connection it might be using is broken.
680 * Marks all peers down the paths as disconnected and notifies the client.
682 * @param t Tree to use.
683 * @param p1 Short id of one of the peers (order unimportant)
684 * @param p2 Short id of one of the peers (order unimportant)
685 * @param cb Function to call for every peer that is marked as disconnected.
687 * @return Short ID of the first disconnected peer in the tree.
690 tree_notify_connection_broken (struct MeshTunnelTree *t,
693 MeshNodeDisconnectCB cb)
695 struct MeshTunnelTreeNode *n;
696 struct MeshTunnelTreeNode *c;
698 n = tree_find_peer(t->me, p1);
701 if (NULL != n->parent && n->parent->peer == p2)
703 tree_mark_peers_disconnected(t, n, cb);
704 GNUNET_CONTAINER_DLL_remove(n->parent->children_head,
705 n->parent->children_tail,
707 GNUNET_CONTAINER_DLL_insert(t->disconnected_head,
708 t->disconnected_tail,
712 for (c = n->children_head; NULL != c; c = c->next)
716 tree_mark_peers_disconnected(t, c, cb);
717 GNUNET_CONTAINER_DLL_remove(n->children_head,
720 GNUNET_CONTAINER_DLL_insert(t->disconnected_head,
721 t->disconnected_tail,
731 * Deletes a peer from a tunnel, liberating all unused resources on the path to
732 * it. It shouldn't have children, if it has they will be destroyed as well.
733 * If the tree is not local and no longer has any paths, the root node will be
734 * destroyed and marked as NULL.
736 * @param t Tunnel tree to use.
737 * @param peer Short ID of the peer to remove from the tunnel tree.
738 * @param cb Callback to notify client of disconnected peers.
740 * @return GNUNET_OK or GNUNET_SYSERR
743 tree_del_peer (struct MeshTunnelTree *t,
745 MeshNodeDisconnectCB cb)
747 struct MeshTunnelTreeNode *n;
749 n = tree_del_path(t, peer, cb);
751 return GNUNET_SYSERR;
752 GNUNET_break_op (NULL == n->children_head);
753 tree_node_destroy(n);
754 if (NULL == t->root->children_head && t->me != t->root)
756 tree_node_destroy (t->root);
764 * Print the tree on stderr
769 tree_debug(struct MeshTunnelTree *t)
771 tree_node_debug(t->root, 0);
776 * Iterator over hash map peer entries and frees all data in it.
777 * Used prior to destroying a hashmap. Makes you miss anonymous functions in C.
780 * @param key current key code (will no longer contain valid data!!)
781 * @param value value in the hash map (treated as void *)
782 * @return GNUNET_YES if we should continue to iterate, GNUNET_NO if not.
785 iterate_free (void *cls, const GNUNET_HashCode * key, void *value)
793 * Destroy the whole tree and free all used memory and Peer_Ids
795 * @param t Tree to be destroyed
798 tree_destroy (struct MeshTunnelTree *t)
800 tree_node_destroy(t->root);
801 GNUNET_CONTAINER_multihashmap_iterate(t->first_hops, &iterate_free, NULL);
802 GNUNET_CONTAINER_multihashmap_destroy(t->first_hops);