/**
- * Destroy a connection.
+ * Destroy a connection, part of the internal implementation. Called
+ * only from #GCC_destroy_from_core() or #GCC_destroy_from_tunnel().
*
* @param cc connection to destroy
*/
-void
+static void
GCC_destroy (struct CadetConnection *cc)
{
- struct GNUNET_MQ_Envelope *env = NULL;
-
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Destroying %s\n",
GCC_2s (cc));
- if (CADET_CONNECTION_SENDING_CREATE != cc->state)
- {
- struct GNUNET_CADET_ConnectionDestroyMessage *destroy_msg;
-
- /* Need to notify next hop that we are down. */
- env = GNUNET_MQ_msg (destroy_msg,
- GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY);
- destroy_msg->cid = cc->cid;
- }
if (NULL != cc->mq_man)
{
GCP_request_mq_cancel (cc->mq_man,
- env);
+ NULL);
cc->mq_man = NULL;
}
if (NULL != cc->task)
}
+
+/**
+ * Destroy a connection, called when the CORE layer is already done
+ * (i.e. has received a BROKEN message), but if we still have to
+ * communicate the destruction of the connection to the tunnel (if one
+ * exists).
+ *
+ * @param cc connection to destroy
+ */
+void
+GCC_destroy_without_core (struct CadetConnection *cc)
+{
+ if (NULL != cc->ct)
+ {
+ GCT_connection_lost (cc->ct);
+ cc->ct = NULL;
+ }
+ GCC_destroy (cc);
+}
+
+
+/**
+ * Destroy a connection, called if the tunnel association with the
+ * connection was already broken, but we still need to notify the CORE
+ * layer about the breakage.
+ *
+ * @param cc connection to destroy
+ */
+void
+GCC_destroy_without_tunnel (struct CadetConnection *cc)
+{
+ cc->ct = NULL;
+ if ( (CADET_CONNECTION_SENDING_CREATE != cc->state) &&
+ (NULL != cc->mq_man) )
+ {
+ struct GNUNET_MQ_Envelope *env;
+ struct GNUNET_CADET_ConnectionDestroyMessage *destroy_msg;
+
+ /* Need to notify next hop that we are down. */
+ env = GNUNET_MQ_msg (destroy_msg,
+ GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY);
+ destroy_msg->cid = cc->cid;
+ GCP_request_mq_cancel (cc->mq_man,
+ env);
+ cc->mq_man = NULL;
+ }
+ GCC_destroy (cc);
+}
+
+
/**
* Return the tunnel associated with this connection.
*
* @param ct which tunnel uses this connection
* @param ready_cb function to call when ready to transmit
* @param ready_cb_cls closure for @a cb
- * @return handle to the connection
+ * @return handle to the connection, NULL if we already have
+ * a connection that takes precedence on @a path
*/
struct CadetConnection *
GCC_create_inbound (struct CadetPeer *destination,
GCC_ReadyCallback ready_cb,
void *ready_cb_cls)
{
+ struct CadetConnection *cc;
+ unsigned int off;
+
+ off = GCPP_find_peer (path,
+ destination);
+ GNUNET_assert (UINT_MAX != off);
+ cc = GCPP_get_connection (path,
+ destination,
+ off);
+ if (NULL != cc)
+ {
+ int cmp;
+
+ cmp = memcmp (cid,
+ &cc->cid,
+ sizeof (*cid));
+ if (0 == cmp)
+ {
+ /* Two peers picked the SAME random connection identifier at the
+ same time for the same path? Must be malicious. Drop
+ connection (existing and inbound), even if it is the only
+ one. */
+ GNUNET_break_op (0);
+ GCT_connection_lost (cc->ct);
+ GCC_destroy_without_tunnel (cc);
+ return NULL;
+ }
+ if (0 < cmp)
+ {
+ /* drop existing */
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Got two connections on %s, dropping my existing %s\n",
+ GCPP_2s (path),
+ GCC_2s (cc));
+ GCT_connection_lost (cc->ct);
+ GCC_destroy_without_tunnel (cc);
+ }
+ else
+ {
+ /* keep existing */
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Got two connections on %s, keeping my existing %s\n",
+ GCPP_2s (path),
+ GCC_2s (cc));
+ return NULL;
+ }
+ }
+
return connection_create (destination,
path,
ct,
/**
- * Destroy a connection.
+ * Destroy a connection, called when the CORE layer is already done
+ * (i.e. has received a BROKEN message), but if we still have to
+ * communicate the destruction of the connection to the tunnel (if one
+ * exists).
*
* @param cc connection to destroy
*/
void
-GCC_destroy (struct CadetConnection *cc);
+GCC_destroy_without_core (struct CadetConnection *cc);
+
+
+/**
+ * Destroy a connection, called if the tunnel association with the
+ * connection was already broken, but we still need to notify the CORE
+ * layer about the breakage.
+ *
+ * @param cc connection to destroy
+ */
+void
+GCC_destroy_without_tunnel (struct CadetConnection *cc);
/**
* @param ct which tunnel uses this connection
* @param ready_cb function to call when ready to transmit
* @param ready_cb_cls closure for @a cb
- * @return handle to the connection
+ * @return handle to the connection, NULL if we already have
+ * a connection that takes precedence on @a path
*/
struct CadetConnection *
GCC_create_inbound (struct CadetPeer *destination,
GNUNET_sh2s (&msg->cid.connection_of_tunnel));
path = GCPP_get_path_from_route (path_length - 1,
pids);
- GCT_add_inbound_connection (GCP_get_tunnel (origin,
- GNUNET_YES),
- &msg->cid,
- path);
+ if (GNUNET_OK !=
+ GCT_add_inbound_connection (GCP_get_tunnel (origin,
+ GNUNET_YES),
+ &msg->cid,
+ path))
+ {
+ /* Send back BROKEN: duplicate connection on the same path,
+ we will use the other one. */
+ struct GNUNET_MQ_Envelope *env;
+ struct GNUNET_CADET_ConnectionBrokenMessage *bm;
+
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Received CADET_CONNECTION_CREATE from %s for %s, but %s already has a connection. Sending BROKEN\n",
+ GCP_2s (sender),
+ GNUNET_sh2s (&msg->cid.connection_of_tunnel),
+ GCPP_2s (path));
+ env = GNUNET_MQ_msg (bm,
+ GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN);
+ bm->cid = msg->cid;
+ bm->peer1 = my_full_id;
+ GCP_send_ooo (sender,
+ env);
+ return;
+ }
return;
}
/* We are merely a hop on the way, check if we can support the route */
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Received CONNECTION_BROKEN for connection %s. Destroying it.\n",
GNUNET_sh2s (&msg->cid.connection_of_tunnel));
- GCC_destroy (cc);
+ GCC_destroy_without_core (cc);
/* FIXME: also destroy the path up to the specified link! */
return;
"Received CONNECTION_DESTROY for connection %s. Destroying connection.\n",
GNUNET_sh2s (&msg->cid.connection_of_tunnel));
- GCC_destroy (cc);
+ GCC_destroy_without_core (cc);
return;
}
* @author Christian Grothoff
*
* TODO:
- * - BUG: currently only allowing one unique connection per path,
- * but need to allow 2 in case WE are establishing one from A to B
- * while at the same time B establishes one to A.
- * Also, must not ASSERT if B establishes a 2nd one to us.
- * Need to have some reasonable tie-breaking to only keep ONE.
* - path desirability score calculations are not done
*/
#include "platform.h"
}
+/**
+ * We lost a connection, remove it from our list and clean up
+ * the connection object itself.
+ *
+ * @param ct binding of connection to tunnel of the connection that was lost.
+ */
+void
+GCT_connection_lost (struct CadetTConnection *ct)
+{
+ struct CadetTunnel *t = ct->t;
+
+ GNUNET_CONTAINER_DLL_remove (t->connection_head,
+ t->connection_tail,
+ ct);
+ GNUNET_free (ct);
+}
+
+
/**
* This tunnel is no longer used, destroy it.
*
GNUNET_assert (0 == GNUNET_CONTAINER_multihashmap32_size (t->channels));
while (NULL != (ct = t->connection_head))
{
+ struct CadetConnection *cc;
+
GNUNET_assert (ct->t == t);
- GNUNET_CONTAINER_DLL_remove (t->connection_head,
- t->connection_tail,
- ct);
- GCC_destroy (ct->cc);
- GNUNET_free (ct);
+ cc = ct->cc;
+ GCT_connection_lost (ct);
+ GCC_destroy_without_tunnel (cc);
}
while (NULL != (tq = t->tq_head))
{
* @param t a tunnel
* @param cid connection identifer to use for the connection
* @param path path to use for the connection
+ * @return #GNUNET_OK on success,
+ * #GNUNET_SYSERR on failure (duplicate connection)
*/
-void
+int
GCT_add_inbound_connection (struct CadetTunnel *t,
const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid,
struct CadetPeerPath *path)
cid,
&connection_ready_cb,
ct);
+ if (NULL == ct->cc)
+ {
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Tunnel %s refused inbound connection %s (duplicate)\n",
+ GCT_2s (t),
+ GCC_2s (ct->cc));
+ GNUNET_free (ct);
+ return GNUNET_SYSERR;
+ }
/* FIXME: schedule job to kill connection (and path?) if it takes
too long to get ready! (And track performance data on how long
other connections took with the tunnel!)
"Tunnel %s has new connection %s\n",
GCT_2s (t),
GCC_2s (ct->cc));
+ return GNUNET_OK;
}
* @param t a tunnel
* @param cid connection identifer to use for the connection
* @param path path to use for the connection
+ * @return #GNUNET_OK on success,
+ * #GNUNET_SYSERR on failure (duplicate connection)
*/
-void
+int
GCT_add_inbound_connection (struct CadetTunnel *t,
const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid,
struct CadetPeerPath *path);
+/**
+ * We lost a connection, remove it from our list and clean up
+ * the connection object itself.
+ *
+ * @param ct binding of connection to tunnel of the connection that was lost.
+ */
+void
+GCT_connection_lost (struct CadetTConnection *ct);
+
+
/**
* Return the peer to which this tunnel goes.
*
projects / oweals / gnunet.git / commitdiff