/* This file is part of GNUnet. (C) 2001-2013 Christian Grothoff (and other contributing authors) GNUnet is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GNUnet is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNUnet; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /** * @file mesh/gnunet-service-mesh_connection.c * @brief GNUnet MESH service connection handling * @author Bartlomiej Polot */ #include "platform.h" #include "gnunet_util_lib.h" #include "gnunet_statistics_service.h" #include "gnunet-service-mesh_connection.h" #include "gnunet-service-mesh_peer.h" #include "gnunet-service-mesh_tunnel.h" #include "gnunet-service-mesh_channel.h" #include "mesh_protocol_enc.h" #include "mesh_path.h" #define MESH_MAX_POLL_TIME GNUNET_TIME_relative_multiply (\ GNUNET_TIME_UNIT_MINUTES,\ 10) #define MESH_RETRANSMIT_TIME GNUNET_TIME_UNIT_SECONDS #define MESH_RETRANSMIT_MARGIN 4 #define LOG(level, ...) GNUNET_log_from (level,"mesh-con",__VA_ARGS__) /******************************************************************************/ /******************************** STRUCTS **********************************/ /******************************************************************************/ /** * Struct containing info about a queued transmission to this peer */ struct MeshPeerQueue { /** * DLL next */ struct MeshPeerQueue *next; /** * DLL previous */ struct MeshPeerQueue *prev; /** * Peer this transmission is directed to. */ struct MeshPeer *peer; /** * Connection this message belongs to. */ struct MeshConnection *c; /** * Is FWD in c? */ int fwd; /** * Channel this message belongs to, if known. */ struct MeshChannel *ch; /** * Pointer to info stucture used as cls. */ void *cls; /** * Type of message */ uint16_t type; /** * Size of the message */ size_t size; }; /** * Struct to encapsulate all the Flow Control information to a peer to which * we are directly connected (on a core level). */ struct MeshFlowControl { /** * Connection this controls. */ struct MeshConnection *c; /** * How many messages are in the queue on this connection. */ unsigned int queue_n; /** * How many messages do we accept in the queue. */ unsigned int queue_max; /** * Next ID to use. */ uint32_t next_pid; /** * ID of the last packet sent towards the peer. */ uint32_t last_pid_sent; /** * ID of the last packet received from the peer. */ uint32_t last_pid_recv; /** * Last ACK sent to the peer (peer can't send more than this PID). */ uint32_t last_ack_sent; /** * Last ACK sent towards the origin (for traffic towards leaf node). */ uint32_t last_ack_recv; /** * Task to poll the peer in case of a lost ACK causes stall. */ GNUNET_SCHEDULER_TaskIdentifier poll_task; /** * How frequently to poll for ACKs. */ struct GNUNET_TIME_Relative poll_time; }; /** * Struct containing all information regarding a connection to a peer. */ struct MeshConnection { /** * Tunnel this connection is part of. */ struct MeshTunnel3 *t; /** * Flow control information for traffic fwd. */ struct MeshFlowControl fwd_fc; /** * Flow control information for traffic bck. */ struct MeshFlowControl bck_fc; /** * ID of the connection. */ struct GNUNET_HashCode id; /** * State of the connection. */ enum MeshConnectionState state; /** * Path being used for the tunnel. */ struct MeshPeerPath *path; /** * Position of the local peer in the path. */ unsigned int own_pos; /** * Task to keep the used paths alive at the owner, * time tunnel out on all the other peers. */ GNUNET_SCHEDULER_TaskIdentifier fwd_maintenance_task; /** * Task to keep the used paths alive at the destination, * time tunnel out on all the other peers. */ GNUNET_SCHEDULER_TaskIdentifier bck_maintenance_task; /** * Pending message count. */ int pending_messages; /** * Destroy flag: if true, destroy on last message. */ int destroy; }; /******************************************************************************/ /******************************* GLOBALS ***********************************/ /******************************************************************************/ /** * Global handle to the statistics service. */ extern struct GNUNET_STATISTICS_Handle *stats; /** * Connections known, indexed by cid (MeshConnection). */ static struct GNUNET_CONTAINER_MultiHashMap *connections; /** * How many connections are we willing to maintain. * Local connections are always allowed, even if there are more connections than max. */ static unsigned long long max_connections; /** * How many messages *in total* are we willing to queue, divide by number of * connections to get connection queue size. */ static unsigned long long max_msgs_queue; /** * How often to send path keepalives. Paths timeout after 4 missed. */ static struct GNUNET_TIME_Relative refresh_connection_time; /******************************************************************************/ /******************************** STATIC ***********************************/ /******************************************************************************/ #if 0 // avoid compiler warning for unused static function static void fc_debug (struct MeshFlowControl *fc) { LOG (GNUNET_ERROR_TYPE_DEBUG, " IN: %u/%u\n", fc->last_pid_recv, fc->last_ack_sent); LOG (GNUNET_ERROR_TYPE_DEBUG, " OUT: %u/%u\n", fc->last_pid_sent, fc->last_ack_recv); LOG (GNUNET_ERROR_TYPE_DEBUG, " QUEUE: %u/%u\n", fc->queue_n, fc->queue_max); } static void connection_debug (struct MeshConnection *c) { if (NULL == c) { LOG (GNUNET_ERROR_TYPE_DEBUG, "*** DEBUG NULL CONNECTION ***\n"); return; } LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s:%X\n", peer2s (c->t->peer), GNUNET_h2s (&c->id)); LOG (GNUNET_ERROR_TYPE_DEBUG, " state: %u, pending msgs: %u\n", c->state, c->pending_messages); LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD FC\n"); fc_debug (&c->fwd_fc); LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK FC\n"); fc_debug (&c->bck_fc); } #endif /** * Get string description for tunnel state. * * @param s Tunnel state. * * @return String representation. */ static const char * GMC_state2s (enum MeshConnectionState s) { switch (s) { case MESH_CONNECTION_NEW: return "MESH_CONNECTION_NEW"; case MESH_CONNECTION_SENT: return "MESH_CONNECTION_SENT"; case MESH_CONNECTION_ACK: return "MESH_CONNECTION_ACK"; case MESH_CONNECTION_READY: return "MESH_CONNECTION_READY"; default: return "MESH_CONNECTION_STATE_ERROR"; } } /** * Initialize a Flow Control structure to the initial state. * * @param fc Flow Control structure to initialize. */ static void fc_init (struct MeshFlowControl *fc) { fc->next_pid = 0; fc->last_pid_sent = (uint32_t) -1; /* Next (expected) = 0 */ fc->last_pid_recv = (uint32_t) -1; fc->last_ack_sent = (uint32_t) 0; fc->last_ack_recv = (uint32_t) 0; fc->poll_task = GNUNET_SCHEDULER_NO_TASK; fc->poll_time = GNUNET_TIME_UNIT_SECONDS; fc->queue_n = 0; fc->queue_max = (max_msgs_queue / max_connections) + 1; } /** * Find a connection. * * @param cid Connection ID. */ static struct MeshConnection * connection_get (const struct GNUNET_HashCode *cid) { return GNUNET_CONTAINER_multihashmap_get (connections, cid); } /** * Send an ACK informing the predecessor about the available buffer space. * * Note that for fwd ack, the FWD mean forward *traffic* (root->dest), * the ACK itself goes "back" (dest->root). * * @param c Connection on which to send the ACK. * @param buffer How much space free to advertise? * @param fwd Is this FWD ACK? (Going dest->owner) */ static void connection_send_ack (struct MeshConnection *c, unsigned int buffer, int fwd) { struct MeshFlowControl *next_fc; struct MeshFlowControl *prev_fc; struct GNUNET_MESH_ACK msg; uint32_t ack; int delta; next_fc = fwd ? &c->fwd_fc : &c->bck_fc; prev_fc = fwd ? &c->bck_fc : &c->fwd_fc; LOG (GNUNET_ERROR_TYPE_DEBUG, "connection send %s ack on %s\n", fwd ? "FWD" : "BCK", GNUNET_h2s (&c->id)); /* Check if we need to transmit the ACK */ if (prev_fc->last_ack_sent - prev_fc->last_pid_recv > 3) { LOG (GNUNET_ERROR_TYPE_DEBUG, "Not sending ACK, buffer > 3\n"); LOG (GNUNET_ERROR_TYPE_DEBUG, " last pid recv: %u, last ack sent: %u\n", prev_fc->last_pid_recv, prev_fc->last_ack_sent); return; } /* Ok, ACK might be necessary, what PID to ACK? */ delta = next_fc->queue_max - next_fc->queue_n; ack = prev_fc->last_pid_recv + delta; LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK %u\n", ack); LOG (GNUNET_ERROR_TYPE_DEBUG, " last pid %u, last ack %u, qmax %u, q %u\n", prev_fc->last_pid_recv, prev_fc->last_ack_sent, next_fc->queue_max, next_fc->queue_n); if (ack == prev_fc->last_ack_sent) { LOG (GNUNET_ERROR_TYPE_DEBUG, "Not sending FWD ACK, not needed\n"); return; } prev_fc->last_ack_sent = ack; /* Build ACK message and send on connection */ msg.header.size = htons (sizeof (msg)); msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_ACK); msg.ack = htonl (ack); msg.cid = c->id; send_prebuilt_message_connection (&msg.header, c, NULL, !fwd); } /** * Sends a CONNECTION ACK message in reponse to a received CONNECTION_CREATE * directed to us. * * @param connection Connection to confirm. * @param fwd Is this a fwd ACK? (First is bck (SYNACK), second is fwd (ACK)) */ static void send_connection_ack (struct MeshConnection *connection, int fwd) { struct MeshTunnel3 *t; t = connection->t; LOG (GNUNET_ERROR_TYPE_DEBUG, "Send connection ack\n"); queue_add (NULL, GNUNET_MESSAGE_TYPE_MESH_CONNECTION_ACK, sizeof (struct GNUNET_MESH_ConnectionACK), connection, NULL, fwd); if (MESH_TUNNEL_NEW == t->state) tunnel_change_state (t, MESH_TUNNEL_WAITING); if (MESH_CONNECTION_READY != connection->state) connection_change_state (connection, MESH_CONNECTION_SENT); } /** * Sends a CREATE CONNECTION message for a path to a peer. * Changes the connection and tunnel states if necessary. * * @param connection Connection to create. */ static void send_connection_create (struct MeshConnection *connection) { struct MeshTunnel3 *t; t = connection->t; LOG (GNUNET_ERROR_TYPE_DEBUG, "Send connection create\n"); queue_add (NULL, GNUNET_MESSAGE_TYPE_MESH_CONNECTION_CREATE, sizeof (struct GNUNET_MESH_ConnectionCreate) + (connection->path->length * sizeof (struct GNUNET_PeerIdentity)), connection, NULL, GNUNET_YES); if (NULL != t && (MESH_TUNNEL_SEARCHING == t->state || MESH_TUNNEL_NEW == t->state)) tunnel_change_state (t, MESH_TUNNEL_WAITING); if (MESH_CONNECTION_NEW == connection->state) connection_change_state (connection, MESH_CONNECTION_SENT); } static void connection_change_state (struct MeshConnection* c, enum MeshConnectionState state) { LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s state was %s\n", GNUNET_h2s (&c->id), GMC_state2s (c->state)); LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s state is now %s\n", GNUNET_h2s (&c->id), GMC_state2s (state)); c->state = state; } /** * Send keepalive packets for a connection. * * @param c Connection to keep alive.. * @param fwd Is this a FWD keepalive? (owner -> dest). */ static void connection_keepalive (struct MeshConnection *c, int fwd) { struct GNUNET_MESH_ConnectionKeepAlive *msg; size_t size = sizeof (struct GNUNET_MESH_ConnectionKeepAlive); char cbuf[size]; uint16_t type; type = fwd ? GNUNET_MESSAGE_TYPE_MESH_FWD_KEEPALIVE : GNUNET_MESSAGE_TYPE_MESH_BCK_KEEPALIVE; LOG (GNUNET_ERROR_TYPE_DEBUG, "sending %s keepalive for connection %s[%d]\n", fwd ? "FWD" : "BCK", peer2s (c->t->peer), c->id); msg = (struct GNUNET_MESH_ConnectionKeepAlive *) cbuf; msg->header.size = htons (size); msg->header.type = htons (type); msg->cid = c->id; send_prebuilt_message_connection (&msg->header, c, NULL, fwd); } /** * Send CONNECTION_{CREATE/ACK} packets for a connection. * * @param c Connection for which to send the message. * @param fwd If GNUNET_YES, send CREATE, otherwise send ACK. */ static void connection_recreate (struct MeshConnection *c, int fwd) { LOG (GNUNET_ERROR_TYPE_DEBUG, "sending connection recreate\n"); if (fwd) send_connection_create (c); else send_connection_ack (c, GNUNET_NO); } /** * Generic connection timer management. * Depending on the role of the peer in the connection will send the * appropriate message (build or keepalive) * * @param c Conncetion to maintain. * @param fwd Is FWD? */ static void connection_maintain (struct MeshConnection *c, int fwd) { if (MESH_TUNNEL_SEARCHING == c->t->state) { /* TODO DHT GET with RO_BART */ return; } switch (c->state) { case MESH_CONNECTION_NEW: GNUNET_break (0); case MESH_CONNECTION_SENT: connection_recreate (c, fwd); break; case MESH_CONNECTION_READY: connection_keepalive (c, fwd); break; default: break; } } static void connection_fwd_keepalive (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct MeshConnection *c = cls; c->fwd_maintenance_task = GNUNET_SCHEDULER_NO_TASK; if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) return; connection_maintain (c, GNUNET_YES); c->fwd_maintenance_task = GNUNET_SCHEDULER_add_delayed (refresh_connection_time, &connection_fwd_keepalive, c); } static void connection_bck_keepalive (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct MeshConnection *c = cls; c->bck_maintenance_task = GNUNET_SCHEDULER_NO_TASK; if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) return; connection_maintain (c, GNUNET_NO); c->bck_maintenance_task = GNUNET_SCHEDULER_add_delayed (refresh_connection_time, &connection_bck_keepalive, c); } /** * Get the first transmittable message for a connection. * * @param c Connection. * @param fwd Is this FWD? * * @return First transmittable message. */ static struct MeshPeerQueue * connection_get_first_message (struct MeshConnection *c, int fwd) { struct MeshPeerQueue *q; struct MeshPeer *p; p = connection_get_hop (c, fwd); for (q = p->queue_head; NULL != q; q = q->next) { if (q->c != c) continue; if (queue_is_sendable (q)) return q; } return NULL; } /** * @brief Re-initiate traffic on this connection if necessary. * * Check if there is traffic queued towards this peer * and the core transmit handle is NULL (traffic was stalled). * If so, call core tmt rdy. * * @param c Connection on which initiate traffic. * @param fwd Is this about fwd traffic? */ static void connection_unlock_queue (struct MeshConnection *c, int fwd) { struct MeshPeer *peer; struct MeshPeerQueue *q; size_t size; LOG (GNUNET_ERROR_TYPE_DEBUG, "connection_unlock_queue %s on %s\n", fwd ? "FWD" : "BCK", GNUNET_h2s (&c->id)); if (GMC_is_terminal (c, fwd)) { LOG (GNUNET_ERROR_TYPE_DEBUG, " is terminal!\n"); return; } peer = connection_get_hop (c, fwd); if (NULL != peer->core_transmit) { LOG (GNUNET_ERROR_TYPE_DEBUG, " already unlocked!\n"); return; /* Already unlocked */ } q = connection_get_first_message (c, fwd); if (NULL == q) { LOG (GNUNET_ERROR_TYPE_DEBUG, " queue empty!\n"); return; /* Nothing to transmit */ } size = q->size; peer->core_transmit = GNUNET_CORE_notify_transmit_ready (core_handle, GNUNET_NO, 0, GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_PEER_resolve2 (peer->id), size, &queue_send, peer); } /** * Cancel all transmissions that belong to a certain connection. * * @param c Connection which to cancel. * @param fwd Cancel fwd traffic? */ static void connection_cancel_queues (struct MeshConnection *c, int fwd) { struct MeshPeerQueue *q; struct MeshPeerQueue *next; struct MeshFlowControl *fc; struct MeshPeer *peer; if (NULL == c) { GNUNET_break (0); return; } fc = fwd ? &c->fwd_fc : &c->bck_fc; peer = connection_get_hop (c, fwd); for (q = peer->queue_head; NULL != q; q = next) { next = q->next; if (q->c == c) { LOG (GNUNET_ERROR_TYPE_DEBUG, "connection_cancel_queue %s\n", GNUNET_MESH_DEBUG_M2S (q->type)); queue_destroy (q, GNUNET_YES); } } if (NULL == peer->queue_head) { if (NULL != peer->core_transmit) { GNUNET_CORE_notify_transmit_ready_cancel (peer->core_transmit); peer->core_transmit = NULL; } if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task) { GNUNET_SCHEDULER_cancel (fc->poll_task); fc->poll_task = GNUNET_SCHEDULER_NO_TASK; } } } /** * Function called if a connection has been stalled for a while, * possibly due to a missed ACK. Poll the neighbor about its ACK status. * * @param cls Closure (poll ctx). * @param tc TaskContext. */ static void connection_poll (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct MeshFlowControl *fc = cls; struct GNUNET_MESH_Poll msg; struct MeshConnection *c; fc->poll_task = GNUNET_SCHEDULER_NO_TASK; if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) { return; } c = fc->c; LOG (GNUNET_ERROR_TYPE_DEBUG, " *** Polling!\n"); LOG (GNUNET_ERROR_TYPE_DEBUG, " *** connection [%X]\n", GNUNET_h2s (&c->id)); LOG (GNUNET_ERROR_TYPE_DEBUG, " *** %s\n", fc == &c->fwd_fc ? "FWD" : "BCK"); msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_POLL); msg.header.size = htons (sizeof (msg)); LOG (GNUNET_ERROR_TYPE_DEBUG, " *** pid (%u)!\n", fc->last_pid_sent); send_prebuilt_message_connection (&msg.header, c, NULL, fc == &c->fwd_fc); fc->poll_time = GNUNET_TIME_STD_BACKOFF (fc->poll_time); fc->poll_task = GNUNET_SCHEDULER_add_delayed (fc->poll_time, &connection_poll, fc); } /** * Get the previous hop in a connection * * @param c Connection. * * @return Previous peer in the connection. */ static struct MeshPeer * connection_get_prev_hop (struct MeshConnection *c) { GNUNET_PEER_Id id; if (0 == c->own_pos || c->path->length < 2) id = c->path->peers[0]; else id = c->path->peers[c->own_pos - 1]; return peer_get_short (id); } /** * Get the next hop in a connection * * @param c Connection. * * @return Next peer in the connection. */ static struct MeshPeer * connection_get_next_hop (struct MeshConnection *c) { GNUNET_PEER_Id id; if ((c->path->length - 1) == c->own_pos || c->path->length < 2) id = c->path->peers[c->path->length - 1]; else id = c->path->peers[c->own_pos + 1]; return peer_get_short (id); } /** * Get the hop in a connection. * * @param c Connection. * @param fwd Next hop? * * @return Next peer in the connection. */ static struct MeshPeer * connection_get_hop (struct MeshConnection *c, int fwd) { if (fwd) return connection_get_next_hop (c); return connection_get_prev_hop (c); } /** * Timeout function due to lack of keepalive/traffic from the owner. * Destroys connection if called. * * @param cls Closure (connection to destroy). * @param tc TaskContext. */ static void connection_fwd_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct MeshConnection *c = cls; c->fwd_maintenance_task = GNUNET_SCHEDULER_NO_TASK; if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) return; LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s[%X] FWD timed out. Destroying.\n", peer2s (c->t->peer), c->id); if (GMC_is_origin (c, GNUNET_YES)) /* If local, leave. */ return; GMC_destroy (c); } /** * Timeout function due to lack of keepalive/traffic from the destination. * Destroys connection if called. * * @param cls Closure (connection to destroy). * @param tc TaskContext */ static void connection_bck_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct MeshConnection *c = cls; c->bck_maintenance_task = GNUNET_SCHEDULER_NO_TASK; if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) return; LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s[%X] FWD timed out. Destroying.\n", peer2s (c->t->peer), c->id); if (GMC_is_origin (c, GNUNET_NO)) /* If local, leave. */ return; GMC_destroy (c); } /** * Resets the connection timeout task, some other message has done the * task's job. * - For the first peer on the direction this means to send * a keepalive or a path confirmation message (either create or ACK). * - For all other peers, this means to destroy the connection, * due to lack of activity. * Starts the tiemout if no timeout was running (connection just created). * * @param c Connection whose timeout to reset. * @param fwd Is this forward? * * TODO use heap to improve efficiency of scheduler. */ static void connection_reset_timeout (struct MeshConnection *c, int fwd) { GNUNET_SCHEDULER_TaskIdentifier *ti; GNUNET_SCHEDULER_Task f; ti = fwd ? &c->fwd_maintenance_task : &c->bck_maintenance_task; if (GNUNET_SCHEDULER_NO_TASK != *ti) GNUNET_SCHEDULER_cancel (*ti); if (GMC_is_origin (c, fwd)) /* Endpoint */ { f = fwd ? &connection_fwd_keepalive : &connection_bck_keepalive; *ti = GNUNET_SCHEDULER_add_delayed (refresh_connection_time, f, c); } else /* Relay */ { struct GNUNET_TIME_Relative delay; delay = GNUNET_TIME_relative_multiply (refresh_connection_time, 4); f = fwd ? &connection_fwd_timeout : &connection_bck_timeout; *ti = GNUNET_SCHEDULER_add_delayed (delay, f, c); } } /** * */ static void register_neighbors (struct MeshConnection *c) { struct MeshPeer *peer; peer = connection_get_next_hop (c); if (GNUNET_NO == GMP_is_neighbor (peer)) { GMC_destroy (c); return NULL; } GMP_add_connection (peer, c); peer = connection_get_prev_hop (c); if (GNUNET_NO == GMP_is_neighbor (peer)) { GMC_destroy (c); return NULL; } GMP_add_connection (peer, c); } /** * */ static void unregister_neighbors (struct MeshConnection *c) { struct MeshPeer *peer; peer = connection_get_next_hop (c); GMP_remove_connection (peer, c); peer = connection_get_prev_hop (c); GMP_remove_connection (peer, c); } /******************************************************************************/ /******************************** API ***********************************/ /******************************************************************************/ /** * Core handler for connection creation. * * @param cls Closure (unused). * @param peer Sender (neighbor). * @param message Message. * * @return GNUNET_OK to keep the connection open, * GNUNET_SYSERR to close it (signal serious error) */ int GMC_handle_create (void *cls, const struct GNUNET_PeerIdentity *peer, const struct GNUNET_MessageHeader *message) { struct GNUNET_MESH_ConnectionCreate *msg; struct GNUNET_PeerIdentity *id; struct GNUNET_HashCode *cid; struct MeshPeerPath *path; struct MeshPeer *dest_peer; struct MeshPeer *orig_peer; struct MeshConnection *c; unsigned int own_pos; uint16_t size; uint16_t i; LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n"); LOG (GNUNET_ERROR_TYPE_DEBUG, "Received a connection create msg\n"); /* Check size */ size = ntohs (message->size); if (size < sizeof (struct GNUNET_MESH_ConnectionCreate)) { GNUNET_break_op (0); return GNUNET_OK; } /* Calculate hops */ size -= sizeof (struct GNUNET_MESH_ConnectionCreate); if (size % sizeof (struct GNUNET_PeerIdentity)) { GNUNET_break_op (0); return GNUNET_OK; } size /= sizeof (struct GNUNET_PeerIdentity); if (1 > size) { GNUNET_break_op (0); return GNUNET_OK; } LOG (GNUNET_ERROR_TYPE_DEBUG, " path has %u hops.\n", size); /* Get parameters */ msg = (struct GNUNET_MESH_ConnectionCreate *) message; cid = &msg->cid; id = (struct GNUNET_PeerIdentity *) &msg[1]; LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s (%s).\n", GNUNET_h2s (cid), GNUNET_i2s (id)); /* Create connection */ c = connection_get (cid); if (NULL == c) { LOG (GNUNET_ERROR_TYPE_DEBUG, " Creating connection\n"); c = connection_new (cid); if (NULL == c) return GNUNET_OK; connection_reset_timeout (c, GNUNET_YES); /* Create path */ LOG (GNUNET_ERROR_TYPE_DEBUG, " Creating path...\n"); path = path_new (size); own_pos = 0; for (i = 0; i < size; i++) { LOG (GNUNET_ERROR_TYPE_DEBUG, " ... adding %s\n", GNUNET_i2s (&id[i])); path->peers[i] = GNUNET_PEER_intern (&id[i]); if (path->peers[i] == my_short_id) own_pos = i; } if (own_pos == 0 && path->peers[own_pos] != myid) { /* create path: self not found in path through self */ GNUNET_break_op (0); path_destroy (path); GMC_destroy (c); return GNUNET_OK; } LOG (GNUNET_ERROR_TYPE_DEBUG, " Own position: %u\n", own_pos); path_add_to_peers (path, GNUNET_NO); c->path = path_duplicate (path); c->own_pos = own_pos; } else { path = NULL; } if (MESH_CONNECTION_NEW == c->state) connection_change_state (c, MESH_CONNECTION_SENT); /* Remember peers */ dest_peer = peer_get (&id[size - 1]); orig_peer = peer_get (&id[0]); /* Is it a connection to us? */ if (c->own_pos == size - 1) { LOG (GNUNET_ERROR_TYPE_DEBUG, " It's for us!\n"); peer_add_path_to_origin (orig_peer, path, GNUNET_YES); if (NULL == orig_peer->tunnel) { orig_peer->tunnel = tunnel_new (); orig_peer->tunnel->peer = orig_peer; } GMT_add_connection (orig_peer->tunnel, c); if (MESH_TUNNEL_NEW == GMT_get_state (c->t)) GMT_change_state (c->t, MESH_TUNNEL_WAITING); send_connection_ack (c, GNUNET_NO); if (MESH_CONNECTION_SENT == c->state) connection_change_state (c, MESH_CONNECTION_ACK); /* Keep tunnel alive in direction dest->owner*/ connection_reset_timeout (c, GNUNET_NO); } else { /* It's for somebody else! Retransmit. */ LOG (GNUNET_ERROR_TYPE_DEBUG, " Retransmitting.\n"); peer_add_path (dest_peer, path_duplicate (path), GNUNET_NO); peer_add_path_to_origin (orig_peer, path, GNUNET_NO); send_prebuilt_message_connection (message, c, NULL, GNUNET_YES); } return GNUNET_OK; } /** * Core handler for path confirmations. * * @param cls closure * @param message message * @param peer peer identity this notification is about * * @return GNUNET_OK to keep the connection open, * GNUNET_SYSERR to close it (signal serious error) */ int GMC_handle_confirm (void *cls, const struct GNUNET_PeerIdentity *peer, const struct GNUNET_MessageHeader *message) { struct GNUNET_MESH_ConnectionACK *msg; struct MeshConnection *c; struct MeshPeerPath *p; struct MeshPeer *pi; int fwd; LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n"); LOG (GNUNET_ERROR_TYPE_DEBUG, "Received a connection ACK msg\n"); msg = (struct GNUNET_MESH_ConnectionACK *) message; LOG (GNUNET_ERROR_TYPE_DEBUG, " on connection %s\n", GNUNET_h2s (&msg->cid)); c = connection_get (&msg->cid); if (NULL == c) { GNUNET_STATISTICS_update (stats, "# control on unknown connection", 1, GNUNET_NO); LOG (GNUNET_ERROR_TYPE_DEBUG, " don't know the connection!\n"); return GNUNET_OK; } LOG (GNUNET_ERROR_TYPE_DEBUG, " via peer %s\n", GNUNET_i2s (peer)); pi = peer_get (peer); if (connection_get_next_hop (c) == pi) { LOG (GNUNET_ERROR_TYPE_DEBUG, " SYNACK\n"); fwd = GNUNET_NO; if (MESH_CONNECTION_SENT == c->state) connection_change_state (c, MESH_CONNECTION_ACK); } else if (connection_get_prev_hop (c) == pi) { LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK\n"); fwd = GNUNET_YES; connection_change_state (c, MESH_CONNECTION_READY); } else { GNUNET_break_op (0); return GNUNET_OK; } connection_reset_timeout (c, fwd); /* Add path to peers? */ p = c->path; if (NULL != p) { path_add_to_peers (p, GNUNET_YES); } else { GNUNET_break (0); } /* Message for us as creator? */ if (connection_is_origin (c, GNUNET_YES)) { LOG (GNUNET_ERROR_TYPE_DEBUG, " Connection (SYN)ACK for us!\n"); connection_change_state (c, MESH_CONNECTION_READY); if (MESH_TUNNEL_READY != c->t->state) tunnel_change_state (c->t, MESH_TUNNEL_READY); send_connection_ack (c, GNUNET_YES); tunnel_send_queued_data (c->t, GNUNET_YES); if (3 <= tunnel_count_connections (c->t) && NULL != c->t->peer->dhtget) { GNUNET_DHT_get_stop (c->t->peer->dhtget); c->t->peer->dhtget = NULL; } return GNUNET_OK; } /* Message for us as destination? */ if (GMC_is_terminal (c, GNUNET_YES)) { LOG (GNUNET_ERROR_TYPE_DEBUG, " Connection ACK for us!\n"); GMC_change_state (c, MESH_CONNECTION_READY); GMT_change_state (c->t, MESH_TUNNEL_READY); GMT_send_queued_data (c->t, GNUNET_NO); return GNUNET_OK; } LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n"); GMC_send_prebuilt_message (message, c, NULL, fwd); return GNUNET_OK; } /** * Core handler for notifications of broken paths * * @param cls Closure (unused). * @param peer Peer identity of sending neighbor. * @param message Message. * * @return GNUNET_OK to keep the connection open, * GNUNET_SYSERR to close it (signal serious error) */ int GMC_handle_broken (void *cls, const struct GNUNET_PeerIdentity *peer, const struct GNUNET_MessageHeader *message) { struct GNUNET_MESH_ConnectionBroken *msg; struct MeshConnection *c; LOG (GNUNET_ERROR_TYPE_DEBUG, "Received a CONNECTION BROKEN msg from %s\n", GNUNET_i2s (peer)); msg = (struct GNUNET_MESH_ConnectionBroken *) message; LOG (GNUNET_ERROR_TYPE_DEBUG, " regarding %s\n", GNUNET_i2s (&msg->peer1)); LOG (GNUNET_ERROR_TYPE_DEBUG, " regarding %s\n", GNUNET_i2s (&msg->peer2)); c = connection_get (&msg->cid); if (NULL == c) { GNUNET_break_op (0); return GNUNET_OK; } tunnel_notify_connection_broken (c->t, GNUNET_PEER_search (&msg->peer1), GNUNET_PEER_search (&msg->peer2)); return GNUNET_OK; } /** * Core handler for tunnel destruction * * @param cls Closure (unused). * @param peer Peer identity of sending neighbor. * @param message Message. * * @return GNUNET_OK to keep the connection open, * GNUNET_SYSERR to close it (signal serious error) */ int GMC_handle_destroy (void *cls, const struct GNUNET_PeerIdentity *peer, const struct GNUNET_MessageHeader *message) { struct GNUNET_MESH_ConnectionDestroy *msg; struct MeshConnection *c; GNUNET_PEER_Id id; int fwd; msg = (struct GNUNET_MESH_ConnectionDestroy *) message; LOG (GNUNET_ERROR_TYPE_DEBUG, "Got a CONNECTION DESTROY message from %s\n", GNUNET_i2s (peer)); LOG (GNUNET_ERROR_TYPE_DEBUG, " for connection %s\n", GNUNET_h2s (&msg->cid)); c = connection_get (&msg->cid); if (NULL == c) { /* Probably already got the message from another path, * destroyed the tunnel and retransmitted to children. * Safe to ignore. */ GNUNET_STATISTICS_update (stats, "# control on unknown tunnel", 1, GNUNET_NO); return GNUNET_OK; } id = GNUNET_PEER_search (peer); if (id == GMP_get_short_id (connection_get_prev_hop (c))) fwd = GNUNET_YES; else if (id == GMP_get_short_id (connection_get_next_hop (c))) fwd = GNUNET_NO; else { GNUNET_break_op (0); return GNUNET_OK; } GMC_send_prebuilt_message (message, c, NULL, fwd); c->destroy = GNUNET_YES; return GNUNET_OK; } /** * Generic handler for mesh network encrypted traffic. * * @param peer Peer identity this notification is about. * @param message Encrypted message. * @param fwd Is this FWD traffic? GNUNET_YES : GNUNET_NO; * * @return GNUNET_OK to keep the connection open, * GNUNET_SYSERR to close it (signal serious error) */ static int handle_mesh_encrypted (const struct GNUNET_PeerIdentity *peer, const struct GNUNET_MESH_Encrypted *msg, int fwd) { struct MeshConnection *c; struct MeshTunnel3 *t; struct MeshPeer *neighbor; struct MeshFlowControl *fc; uint32_t pid; uint32_t ttl; uint16_t type; size_t size; /* Check size */ size = ntohs (msg->header.size); if (size < sizeof (struct GNUNET_MESH_Encrypted) + sizeof (struct GNUNET_MessageHeader)) { GNUNET_break_op (0); return GNUNET_OK; } type = ntohs (msg->header.type); LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n"); LOG (GNUNET_ERROR_TYPE_DEBUG, "got a %s message from %s\n", GNUNET_MESH_DEBUG_M2S (type), GNUNET_i2s (peer)); /* Check connection */ c = connection_get (&msg->cid); if (NULL == c) { GNUNET_STATISTICS_update (stats, "# unknown connection", 1, GNUNET_NO); LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING connection unknown\n"); return GNUNET_OK; } t = c->t; fc = fwd ? &c->bck_fc : &c->fwd_fc; /* Check if origin is as expected */ neighbor = connection_get_hop (c, !fwd); if (GNUNET_PEER_search (peer) != GMP_get_short_id (neighbor)) { GNUNET_break_op (0); return GNUNET_OK; } /* Check PID */ pid = ntohl (msg->pid); if (GMC_is_pid_bigger (pid, fc->last_ack_sent)) { GNUNET_STATISTICS_update (stats, "# unsolicited message", 1, GNUNET_NO); LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING Received PID %u, (prev %u), ACK %u\n", pid, fc->last_pid_recv, fc->last_ack_sent); return GNUNET_OK; } if (GNUNET_NO == GMC_is_pid_bigger (pid, fc->last_pid_recv)) { GNUNET_STATISTICS_update (stats, "# duplicate PID", 1, GNUNET_NO); LOG (GNUNET_ERROR_TYPE_DEBUG, " Pid %u not expected (%u+), dropping!\n", pid, fc->last_pid_recv + 1); return GNUNET_OK; } if (MESH_CONNECTION_SENT == c->state) connection_change_state (c, MESH_CONNECTION_READY); connection_reset_timeout (c, fwd); fc->last_pid_recv = pid; /* Is this message for us? */ if (GMC_is_terminal (c, fwd)) { size_t dsize = size - sizeof (struct GNUNET_MESH_Encrypted); char cbuf[dsize]; struct GNUNET_MessageHeader *msgh; unsigned int off; /* TODO signature verification */ LOG (GNUNET_ERROR_TYPE_DEBUG, " message for us!\n"); GNUNET_STATISTICS_update (stats, "# messages received", 1, GNUNET_NO); fc->last_pid_recv = pid; tunnel_decrypt (t, cbuf, &msg[1], dsize, msg->iv, fwd); off = 0; while (off < dsize) { msgh = (struct GNUNET_MessageHeader *) &cbuf[off]; handle_decrypted (t, msgh, fwd); off += ntohs (msgh->size); } send_ack (c, NULL, fwd); return GNUNET_OK; } /* Message not for us: forward to next hop */ LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n"); ttl = ntohl (msg->ttl); LOG (GNUNET_ERROR_TYPE_DEBUG, " ttl: %u\n", ttl); if (ttl == 0) { GNUNET_STATISTICS_update (stats, "# TTL drops", 1, GNUNET_NO); LOG (GNUNET_ERROR_TYPE_WARNING, " TTL is 0, DROPPING!\n"); send_ack (c, NULL, fwd); return GNUNET_OK; } GNUNET_STATISTICS_update (stats, "# messages forwarded", 1, GNUNET_NO); send_prebuilt_message_connection (&msg->header, c, NULL, fwd); return GNUNET_OK; } /** * Core handler for mesh network traffic going orig->dest. * * @param cls Closure (unused). * @param message Message received. * @param peer Peer who sent the message. * * @return GNUNET_OK to keep the connection open, * GNUNET_SYSERR to close it (signal serious error) */ int GMC_handle_fwd (void *cls, const struct GNUNET_PeerIdentity *peer, const struct GNUNET_MessageHeader *message) { return handle_mesh_encrypted (peer, (struct GNUNET_MESH_Encrypted *)message, GNUNET_YES); } /** * Core handler for mesh network traffic going dest->orig. * * @param cls Closure (unused). * @param message Message received. * @param peer Peer who sent the message. * * @return GNUNET_OK to keep the connection open, * GNUNET_SYSERR to close it (signal serious error) */ int GMC_handle_bck (void *cls, const struct GNUNET_PeerIdentity *peer, const struct GNUNET_MessageHeader *message) { return handle_mesh_encrypted (peer, (struct GNUNET_MESH_Encrypted *)message, GNUNET_NO); } /** * Core handler for mesh network traffic point-to-point acks. * * @param cls closure * @param message message * @param peer peer identity this notification is about * * @return GNUNET_OK to keep the connection open, * GNUNET_SYSERR to close it (signal serious error) */ int GMC_handle_ack (void *cls, const struct GNUNET_PeerIdentity *peer, const struct GNUNET_MessageHeader *message) { struct GNUNET_MESH_ACK *msg; struct MeshConnection *c; struct MeshFlowControl *fc; GNUNET_PEER_Id id; uint32_t ack; int fwd; LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n"); LOG (GNUNET_ERROR_TYPE_DEBUG, "Got an ACK packet from %s!\n", GNUNET_i2s (peer)); msg = (struct GNUNET_MESH_ACK *) message; c = connection_get (&msg->cid); if (NULL == c) { GNUNET_STATISTICS_update (stats, "# ack on unknown connection", 1, GNUNET_NO); return GNUNET_OK; } /* Is this a forward or backward ACK? */ id = GNUNET_PEER_search (peer); if (GMP_get_short_id (connection_get_next_hop (c)) == id) { LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD ACK\n"); fc = &c->fwd_fc; fwd = GNUNET_YES; } else if (GMP_get_short_id (connection_get_prev_hop (c)) == id) { LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK ACK\n"); fc = &c->bck_fc; fwd = GNUNET_NO; } else { GNUNET_break_op (0); return GNUNET_OK; } ack = ntohl (msg->ack); LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK %u (was %u)\n", ack, fc->last_ack_recv); if (GMC_is_pid_bigger (ack, fc->last_ack_recv)) fc->last_ack_recv = ack; /* Cancel polling if the ACK is big enough. */ if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task && GMC_is_pid_bigger (fc->last_ack_recv, fc->last_pid_sent)) { LOG (GNUNET_ERROR_TYPE_DEBUG, " Cancel poll\n"); GNUNET_SCHEDULER_cancel (fc->poll_task); fc->poll_task = GNUNET_SCHEDULER_NO_TASK; fc->poll_time = GNUNET_TIME_UNIT_SECONDS; } connection_unlock_queue (c, fwd); return GNUNET_OK; } /** * Core handler for mesh network traffic point-to-point ack polls. * * @param cls closure * @param message message * @param peer peer identity this notification is about * * @return GNUNET_OK to keep the connection open, * GNUNET_SYSERR to close it (signal serious error) */ int GMC_handle_poll (void *cls, const struct GNUNET_PeerIdentity *peer, const struct GNUNET_MessageHeader *message) { struct GNUNET_MESH_Poll *msg; struct MeshConnection *c; struct MeshFlowControl *fc; GNUNET_PEER_Id id; uint32_t pid; int fwd; LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n"); LOG (GNUNET_ERROR_TYPE_DEBUG, "Got a POLL packet from %s!\n", GNUNET_i2s (peer)); msg = (struct GNUNET_MESH_Poll *) message; c = connection_get (&msg->cid); if (NULL == c) { GNUNET_STATISTICS_update (stats, "# poll on unknown connection", 1, GNUNET_NO); GNUNET_break_op (0); return GNUNET_OK; } /* Is this a forward or backward ACK? * Note: a poll should never be needed in a loopback case, * since there is no possiblility of packet loss there, so * this way of discerining FWD/BCK should not be a problem. */ id = GNUNET_PEER_search (peer); if (GMP_get_short_id (connection_get_next_hop (c)) == id) { LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD ACK\n"); fc = &c->fwd_fc; } else if (GMP_get_short_id (connection_get_prev_hop (c)) == id) { LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK ACK\n"); fc = &c->bck_fc; } else { GNUNET_break_op (0); return GNUNET_OK; } pid = ntohl (msg->pid); LOG (GNUNET_ERROR_TYPE_DEBUG, " PID %u, OLD %u\n", pid, fc->last_pid_recv); fc->last_pid_recv = pid; fwd = fc == &c->fwd_fc; send_ack (c, NULL, fwd); return GNUNET_OK; } /** * Core handler for mesh keepalives. * * @param cls closure * @param message message * @param peer peer identity this notification is about * @return GNUNET_OK to keep the connection open, * GNUNET_SYSERR to close it (signal serious error) * * TODO: Check who we got this from, to validate route. */ int GMC_handle_keepalive (void *cls, const struct GNUNET_PeerIdentity *peer, const struct GNUNET_MessageHeader *message) { struct GNUNET_MESH_ConnectionKeepAlive *msg; struct MeshConnection *c; struct MeshPeer *neighbor; int fwd; msg = (struct GNUNET_MESH_ConnectionKeepAlive *) message; LOG (GNUNET_ERROR_TYPE_DEBUG, "got a keepalive packet from %s\n", GNUNET_i2s (peer)); c = connection_get (&msg->cid); if (NULL == c) { GNUNET_STATISTICS_update (stats, "# keepalive on unknown connection", 1, GNUNET_NO); return GNUNET_OK; } fwd = GNUNET_MESSAGE_TYPE_MESH_FWD_KEEPALIVE == ntohs (message->type) ? GNUNET_YES : GNUNET_NO; /* Check if origin is as expected */ neighbor = connection_get_hop (c, fwd); if (GNUNET_PEER_search (peer) != GMP_get_short_id (neighbor)) { GNUNET_break_op (0); return GNUNET_OK; } connection_change_state (c, MESH_CONNECTION_READY); connection_reset_timeout (c, fwd); if (GMC_is_terminal (c, fwd)) return GNUNET_OK; GNUNET_STATISTICS_update (stats, "# keepalives forwarded", 1, GNUNET_NO); GMC_send_prebuilt_message (message, c, NULL, fwd); return GNUNET_OK; } /** * Send an ACK on the appropriate connection/channel, depending on * the direction and the position of the peer. * * @param c Which connection to send the hop-by-hop ACK. * @param ch Channel, if any. * @param fwd Is this a fwd ACK? (will go dest->root) */ void GMC_send_ack (struct MeshConnection *c, struct MeshChannel *ch, int fwd) { unsigned int buffer; LOG (GNUNET_ERROR_TYPE_DEBUG, "send ack %s on %p %p\n", fwd ? "FWD" : "BCK", c, ch); if (NULL == c || GMC_is_terminal (c, fwd)) { struct MeshTunnel3 *t; LOG (GNUNET_ERROR_TYPE_DEBUG, " getting from all connections\n"); t = (NULL == c) ? GMCH_get_tunnel (ch) : GMC_get_tunnel (c); buffer = GMT_get_buffer (t, fwd); } else { LOG (GNUNET_ERROR_TYPE_DEBUG, " getting from one connection\n"); buffer = GMC_get_buffer (c, fwd); } LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer available: %u\n", buffer); if ( (NULL != ch && GMCH_is_origin (ch, fwd)) || (NULL != c && GMC_is_origin (c, fwd)) ) { LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on channel...\n"); if (0 < buffer) { GNUNET_assert (NULL != ch); LOG (GNUNET_ERROR_TYPE_DEBUG, " really sending!\n"); send_local_ack (ch, fwd); } } else if (NULL == c) { LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on all connections\n"); GNUNET_assert (NULL != ch); channel_send_connections_ack (ch, buffer, fwd); } else { LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on connection\n"); connection_send_ack (c, buffer, fwd); } } /** * Initialize the connections subsystem * * @param c Configuration handle. */ void GMC_init (const struct GNUNET_CONFIGURATION_Handle *c) { if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_number (c, "MESH", "MAX_MSGS_QUEUE", &max_msgs_queue)) { LOG_config_invalid (GNUNET_ERROR_TYPE_ERROR, "MESH", "MAX_MSGS_QUEUE", "MISSING"); GNUNET_SCHEDULER_shutdown (); return; } if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_number (c, "MESH", "MAX_CONNECTIONS", &max_connections)) { LOG_config_invalid (GNUNET_ERROR_TYPE_ERROR, "MESH", "MAX_CONNECTIONS", "MISSING"); GNUNET_SCHEDULER_shutdown (); return; } if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_time (c, "MESH", "REFRESH_CONNECTION_TIME", &refresh_connection_time)) { LOG_config_invalid (GNUNET_ERROR_TYPE_ERROR, "MESH", "REFRESH_CONNECTION_TIME", "MISSING"); GNUNET_SCHEDULER_shutdown (); return; } connections = GNUNET_CONTAINER_multihashmap_create (1024, GNUNET_YES); } /** * Shut down the connections subsystem. */ void GMC_shutdown (void) { } struct MeshConnection * GMC_new (const struct GNUNET_HashCode *cid, struct MeshTunnel3 *t, struct MeshPeerPath *p, unsigned int own_pos) { struct MeshConnection *c; c = GNUNET_new (struct MeshConnection); c->id = *cid; GNUNET_CONTAINER_multihashmap_put (connections, &c->id, c, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST); fc_init (&c->fwd_fc); fc_init (&c->bck_fc); c->fwd_fc.c = c; c->bck_fc.c = c; c->t = t; if (own_pos > p->length - 1) { GNUNET_break (0); GMC_destroy (c); return NULL; } c->own_pos = own_pos; c->path = p; if (0 == own_pos) { c->fwd_maintenance_task = GNUNET_SCHEDULER_add_delayed (refresh_connection_time, &connection_fwd_keepalive, c); } register_neighbors (c); return c; } void GMC_destroy (struct MeshConnection *c) { struct MeshPeer *peer; if (NULL == c) return; LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying connection %s\n", GNUNET_h2s (&c->id)); /* Cancel all traffic */ connection_cancel_queues (c, GNUNET_YES); connection_cancel_queues (c, GNUNET_NO); /* Cancel maintainance task (keepalive/timeout) */ if (GNUNET_SCHEDULER_NO_TASK != c->fwd_maintenance_task) GNUNET_SCHEDULER_cancel (c->fwd_maintenance_task); if (GNUNET_SCHEDULER_NO_TASK != c->bck_maintenance_task) GNUNET_SCHEDULER_cancel (c->bck_maintenance_task); /* Unregister from neighbors */ unregister_neighbors (c); /* Delete */ GNUNET_STATISTICS_update (stats, "# connections", -1, GNUNET_NO); GMT_remove_connection (c->t, c); GNUNET_free (c); } /** * Get the connection ID. * * @param c Connection to get the ID from. * * @return ID of the connection. */ const struct GNUNET_HashCode * GMC_get_id (const struct MeshConnection *c) { return &c->id; } /** * Get the connection state. * * @param c Connection to get the state from. * * @return state of the connection. */ enum MeshConnectionState GMC_get_state (const struct MeshConnection *c) { return c->state; } /** * Get the connection tunnel. * * @param c Connection to get the tunnel from. * * @return tunnel of the connection. */ struct MeshTunnel3 * GMC_get_tunnel (const struct MeshConnection *c) { return c->t; } /** * Get free buffer space in a connection. * * @param c Connection. * @param fwd Is query about FWD traffic? * * @return Free buffer space [0 - max_msgs_queue/max_connections] */ unsigned int GMC_get_buffer (struct MeshConnection *c, int fwd) { struct MeshFlowControl *fc; fc = fwd ? &c->fwd_fc : &c->bck_fc; return (fc->queue_max - fc->queue_n); } /** * Get messages queued in a connection. * * @param c Connection. * @param fwd Is query about FWD traffic? * * @return Number of messages queued. */ unsigned int GMC_get_qn (struct MeshConnection *c, int fwd) { struct MeshFlowControl *fc; fc = fwd ? &c->fwd_fc : &c->bck_fc; return fc->queue_n; } /** * Notify other peers on a connection of a broken link. Mark connections * to destroy after all traffic has been sent. * * @param c Connection on which there has been a disconnection. * @param peer Peer that disconnected. * @param my_full_id My ID (to send to other peers). */ void GMC_notify_broken (struct MeshConnection *c, struct MeshPeer *peer, struct GNUNET_PeerIdentity *my_full_id) { struct GNUNET_MESH_ConnectionBroken msg; int fwd; fwd = peer == connection_get_prev_hop (c); connection_cancel_queues (c, !fwd); if (GMC_is_terminal (c, fwd)) { /* Local shutdown, no one to notify about this. */ GMC_destroy (c); return; } msg.header.size = htons (sizeof (struct GNUNET_MESH_ConnectionBroken)); msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CONNECTION_BROKEN); msg.cid = c->id; msg.peer1 = *my_full_id; msg.peer2 = *GMP_get_id (peer); GMC_send_prebuilt_message (&msg.header, c, NULL, fwd); c->destroy = GNUNET_YES; return; } /** * Is this peer the first one on the connection? * * @param c Connection. * @param fwd Is this about fwd traffic? * * @return GNUNET_YES if origin, GNUNET_NO if relay/terminal. */ int GMC_is_origin (struct MeshConnection *c, int fwd) { if (!fwd && c->path->length - 1 == c->own_pos ) return GNUNET_YES; if (fwd && 0 == c->own_pos) return GNUNET_YES; return GNUNET_NO; } /** * Is this peer the last one on the connection? * * @param c Connection. * @param fwd Is this about fwd traffic? * Note that the ROOT is the terminal for BCK traffic! * * @return GNUNET_YES if terminal, GNUNET_NO if relay/origin. */ int GMC_is_terminal (struct MeshConnection *c, int fwd) { return GMC_is_origin (c, !fwd); } /** * Sends an already built message on a connection, properly registering * all used resources. * * @param message Message to send. Function makes a copy of it. * If message is not hop-by-hop, decrements TTL of copy. * @param c Connection on which this message is transmitted. * @param ch Channel on which this message is transmitted, or NULL. * @param fwd Is this a fwd message? */ void GMC_send_prebuilt_message (const struct GNUNET_MessageHeader *message, struct MeshConnection *c, struct MeshChannel *ch, int fwd) { void *data; size_t size; uint16_t type; size = ntohs (message->size); data = GNUNET_malloc (size); memcpy (data, message, size); type = ntohs (message->type); LOG (GNUNET_ERROR_TYPE_DEBUG, "Send %s (%u) on connection %s\n", GNUNET_MESH_DEBUG_M2S (type), size, GNUNET_h2s (&c->id)); switch (type) { struct GNUNET_MESH_Encrypted *emsg; struct GNUNET_MESH_ACK *amsg; struct GNUNET_MESH_Poll *pmsg; struct GNUNET_MESH_ConnectionDestroy *dmsg; struct GNUNET_MESH_ConnectionBroken *bmsg; uint32_t ttl; case GNUNET_MESSAGE_TYPE_MESH_FWD: case GNUNET_MESSAGE_TYPE_MESH_BCK: emsg = (struct GNUNET_MESH_Encrypted *) data; ttl = ntohl (emsg->ttl); if (0 == ttl) { GNUNET_break_op (0); return; } emsg->cid = c->id; emsg->ttl = htonl (ttl - 1); emsg->pid = htonl (fwd ? c->fwd_fc.next_pid++ : c->bck_fc.next_pid++); LOG (GNUNET_ERROR_TYPE_DEBUG, " pid %u\n", ntohl (emsg->pid)); break; case GNUNET_MESSAGE_TYPE_MESH_ACK: amsg = (struct GNUNET_MESH_ACK *) data; amsg->cid = c->id; LOG (GNUNET_ERROR_TYPE_DEBUG, " ack %u\n", ntohl (amsg->ack)); break; case GNUNET_MESSAGE_TYPE_MESH_POLL: pmsg = (struct GNUNET_MESH_Poll *) data; pmsg->cid = c->id; pmsg->pid = htonl (fwd ? c->fwd_fc.last_pid_sent : c->bck_fc.last_pid_sent); LOG (GNUNET_ERROR_TYPE_DEBUG, " poll %u\n", ntohl (pmsg->pid)); break; case GNUNET_MESSAGE_TYPE_MESH_TUNNEL_DESTROY: dmsg = (struct GNUNET_MESH_ConnectionDestroy *) data; dmsg->cid = c->id; dmsg->reserved = 0; break; case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_BROKEN: bmsg = (struct GNUNET_MESH_ConnectionBroken *) data; bmsg->cid = c->id; bmsg->reserved = 0; break; case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_CREATE: case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_ACK: break; default: GNUNET_break (0); } GMP_queue_add (data, type, size, c, ch, fwd); } /** * Send a message to all peers in this connection that the connection * is no longer valid. * * If some peer should not receive the message, it should be zero'ed out * before calling this function. * * @param c The connection whose peers to notify. */ void GMC_send_destroy (struct MeshConnection *c) { struct GNUNET_MESH_ConnectionDestroy msg; if (GNUNET_YES == c->destroy) return; msg.header.size = htons (sizeof (msg)); msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_TUNNEL_DESTROY);; msg.cid = c->id; LOG (GNUNET_ERROR_TYPE_DEBUG, " sending connection destroy for connection %s\n", GNUNET_h2s (&c->id)); if (GNUNET_NO == GMC_is_terminal (c, GNUNET_YES)) GMC_send_prebuilt_message (&msg.header, c, NULL, GNUNET_YES); if (GNUNET_NO == GMC_is_terminal (c, GNUNET_NO)) GMC_send_prebuilt_message (&msg.header, c, NULL, GNUNET_NO); c->destroy = GNUNET_YES; }