/**
* Return a newly allocated individual path to reach a peer from the local peer,
* according to the path tree of some tunnel.
*
* @param t Tunnel from which to read the path tree.
* @param peer Short ID of the destination peer to whom we want a path.
*
* @return A newly allocated individual path to reach the destination peer.
* Path must be destroyed afterwards.
*/
struct MeshPeerPath *
tree_get_path_to_peer (struct MeshTunnelTree *t, GNUNET_PEER_Id peer)
{
struct MeshTunnelTreeNode *n;
struct MeshPeerPath *p;
n = tree_find_peer (t, peer);
if (NULL == n)
{
GNUNET_break (0);
return NULL;
}
p = path_new (0);
/* Building the path (inverted!) */
while (n->peer != 1)
{
GNUNET_array_append (p->peers, p->length, n->peer);
GNUNET_PEER_change_rc (n->peer, 1);
n = n->parent;
if (NULL == n)
{
GNUNET_break (0);
path_destroy (p);
return NULL;
}
}
GNUNET_array_append (p->peers, p->length, 1);
GNUNET_PEER_change_rc (1, 1);
path_invert (p);
return p;
}
/**
* Destroys and frees the node and all children
*
* @param parent Parent node to be destroyed
*/
static void
tree_node_destroy (struct MeshTunnelTreeNode *parent)
{
struct MeshTunnelTreeNode *n;
struct MeshTunnelTreeNode *next;
#if MESH_TREE_DEBUG
struct GNUNET_PeerIdentity id;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree: Destroying node %u\n",
parent->peer);
GNUNET_PEER_resolve (parent->peer, &id);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree: (%s)\n", GNUNET_i2s (&id));
#endif
n = parent->children_head;
while (NULL != n)
{
next = n->next;
tree_node_destroy (n);
n = next;
}
GNUNET_PEER_change_rc (parent->peer, -1);
if (NULL != parent->parent)
GNUNET_CONTAINER_DLL_remove (parent->parent->children_head,
parent->parent->children_tail, parent);
GNUNET_free (parent);
}
/**
* Duplicate a path, incrementing short peer's rc.
*
* @param path The path to duplicate.
*/
struct MeshPeerPath *
path_duplicate (struct MeshPeerPath *path)
{
struct MeshPeerPath *aux;
unsigned int i;
aux = path_new (path->length);
memcpy (aux->peers, path->peers, path->length * sizeof (GNUNET_PEER_Id));
for (i = 0; i < path->length; i++)
GNUNET_PEER_change_rc (path->peers[i], 1);
return aux;
}
/**
* Builds a path from a PeerIdentity array.
*
* @param peers PeerIdentity array.
* @param size Size of the @c peers array.
* @param myid ID of local peer, to find @c own_pos.
* @param own_pos Output parameter: own position in the path.
*
* @return Fixed and shortened path.
*/
struct CadetPeerPath *
path_build_from_peer_ids (struct GNUNET_PeerIdentity *peers,
unsigned int size,
GNUNET_PEER_Id myid,
unsigned int *own_pos)
{
struct CadetPeerPath *path;
GNUNET_PEER_Id shortid;
unsigned int i;
unsigned int j;
unsigned int offset;
/* Create path */
LOG (GNUNET_ERROR_TYPE_DEBUG, " Creating path...\n");
path = path_new (size);
*own_pos = 0;
offset = 0;
for (i = 0; i < size; i++)
{
LOG (GNUNET_ERROR_TYPE_DEBUG, " - %u: taking %s\n",
i, GNUNET_i2s (&peers[i]));
shortid = GNUNET_PEER_intern (&peers[i]);
/* Check for loops / duplicates */
for (j = 0; j < i - offset; j++)
{
if (path->peers[j] == shortid)
{
LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists at pos %u\n", j);
offset = i - j;
LOG (GNUNET_ERROR_TYPE_DEBUG, " offset now %u\n", offset);
GNUNET_PEER_change_rc (shortid, -1);
}
}
LOG (GNUNET_ERROR_TYPE_DEBUG, " storing at %u\n", i - offset);
path->peers[i - offset] = shortid;
if (path->peers[i - offset] == myid)
*own_pos = i - offset;
}
path->length -= offset;
if (path->peers[*own_pos] != myid)
{
/* create path: self not found in path through self */
GNUNET_break_op (0);
path_destroy (path);
return NULL;
}
return path;
}
/**
* Allocates and initializes a new node.
* Sets ID and parent of the new node and inserts it in the DLL of the parent
*
* @param parent Node that will be the parent from the new node, NULL for root
* @param peer Short Id of the new node
*
* @return Newly allocated node
*/
static struct MeshTunnelTreeNode *
tree_node_new (struct MeshTunnelTreeNode *parent, GNUNET_PEER_Id peer)
{
struct MeshTunnelTreeNode *node;
node = GNUNET_malloc (sizeof (struct MeshTunnelTreeNode));
node->peer = peer;
GNUNET_PEER_change_rc (peer, 1);
node->parent = parent;
if (NULL != parent)
GNUNET_CONTAINER_DLL_insert (parent->children_head, parent->children_tail,
node);
return node;
}
static int
check ()
{
int i;
GNUNET_PEER_Id pid;
struct GNUNET_PeerIdentity res;
struct GNUNET_PeerIdentity zero;
GNUNET_PEER_Id ids[] = { 1, 2, 3 };
GNUNET_assert (0 == GNUNET_PEER_intern (NULL));
/* Insert Peers into PeerEntry table and hashmap */
for (i = 0; i < NUMBER_OF_PEERS; i++)
{
pid = GNUNET_PEER_intern (&pidArr[i]);
if (pid != (i + 1))
{
FPRINTF (stderr, "%s", "Unexpected Peer ID returned by intern function\n");
return 1;
}
}
/* Referencing the first 3 peers once again */
for (i = 0; i < 3; i++)
{
pid = GNUNET_PEER_intern (&pidArr[i]);
if (pid != (i + 1))
{
FPRINTF (stderr, "%s", "Unexpected Peer ID returned by intern function\n");
return 1;
}
}
/* Dereferencing the first 3 peers once [decrementing their reference count] */
GNUNET_PEER_decrement_rcs (ids, 3);
/* re-referencing the first 3 peers using the change_rc function */
for (i = 1; i <= 3; i++)
GNUNET_PEER_change_rc (i, 1);
/* Removing the second Peer from the PeerEntry hash map */
GNUNET_PEER_change_rc (2, -2);
/* convert the pid of the first PeerEntry into that of the third */
GNUNET_PEER_resolve (1, &res);
GNUNET_assert (0 == memcmp (&res, &pidArr[0], sizeof (res)));
/*
* Attempt to convert pid = 0 (which is reserved)
* into a peer identity object, the peer identity memory
* is expected to be set to zero
*/
memset (&zero, 0, sizeof (struct GNUNET_PeerIdentity));
GNUNET_log_skip (1, GNUNET_YES);
GNUNET_PEER_resolve (0, &res);
GNUNET_assert (0 == memcmp (&res, &zero, sizeof (res)));
/* Removing peer entries 1 and 3 from table using the list decrement function */
/* If count = 0, nothing should be done whatsoever */
GNUNET_PEER_decrement_rcs (ids, 0);
ids[1] = 3;
GNUNET_PEER_decrement_rcs (ids, 2);
GNUNET_PEER_decrement_rcs (ids, 2);
return 0;
}