/* 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 "mesh_path.h" #include "mesh_protocol_enc.h" #include "mesh_enc.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" #define LOG(level, ...) GNUNET_log_from (level,"mesh-con",__VA_ARGS__) #define MESH_MAX_POLL_TIME GNUNET_TIME_relative_multiply (\ GNUNET_TIME_UNIT_MINUTES,\ 10) #define AVG_MSGS 32 /******************************************************************************/ /******************************** STRUCTS **********************************/ /******************************************************************************/ /** * 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; }; /** * Keep a record of the last messages sent on this connection. */ struct MeshConnectionPerformance { /** * Circular buffer for storing measurements. */ double usecsperbyte[AVG_MSGS]; /** * Running average of @c usecsperbyte. */ double avg; /** * How many values of @c usecsperbyte are valid. */ uint16_t size; /** * Index of the next "free" position in @c usecsperbyte. */ uint16_t idx; }; /** * 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; /** * Measure connection performance on the endpoint. */ struct MeshConnectionPerformance *perf; /** * 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; /** * Local peer own ID (memory efficient handle). */ extern GNUNET_PEER_Id myid; /** * Local peer own ID (full value). */ extern struct GNUNET_PeerIdentity my_full_id; /** * 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), GMC_2s (c)); 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); } static void connection_change_state (struct MeshConnection* c, enum MeshConnectionState state) { LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s state was %s\n", GMC_2s (c), GMC_state2s (c->state)); LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s state is now %s\n", GMC_2s (c), GMC_state2s (state)); c->state = state; } /** * Send an ACK on the connection, informing the predecessor about * the available buffer space. Should not be called in case the peer * is origin (no predecessor). * * 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 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; /* If origin, there is no connection to send ACKs. Wrong function! */ if (GMC_is_origin (c, fwd)) { GNUNET_break (0); return; } 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", GMC_2s (c)); /* Check if we need to transmit the ACK */ delta = prev_fc->last_ack_sent - prev_fc->last_pid_recv; if (3 < delta && buffer < delta) { 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? */ ack = prev_fc->last_pid_recv + buffer; 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; GMC_send_prebuilt_message (&msg.header, c, NULL, !fwd); } /** * Callback called when a queued message is sent. * * Calculates the average time and connection packet tracking. * * @param cls Closure. * @param c Connection this message was on. * @param type Type of message sent. * @param fwd Was this a FWD going message? * @param size Size of the message. * @param wait Time spent waiting for core (only the time for THIS message) */ static void message_sent (void *cls, struct MeshConnection *c, uint16_t type, int fwd, size_t size, struct GNUNET_TIME_Relative wait) { struct MeshConnectionPerformance *p; struct MeshFlowControl *fc; double usecsperbyte; fc = fwd ? &c->fwd_fc : &c->bck_fc; LOG (GNUNET_ERROR_TYPE_DEBUG, "! sent %s\n", GNUNET_MESH_DEBUG_M2S (type)); LOG (GNUNET_ERROR_TYPE_DEBUG, "! Q_N- %p %u\n", fc, fc->queue_n); c->pending_messages--; if (GNUNET_YES == c->destroy && 0 == c->pending_messages) { LOG (GNUNET_ERROR_TYPE_DEBUG, "! destroying connection!\n"); GMC_destroy (c); return; } /* Send ACK if needed, after accounting for sent ID in fc->queue_n */ switch (type) { case GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED: fc->last_pid_sent++; fc->queue_n--; LOG (GNUNET_ERROR_TYPE_DEBUG, "! accounting pid %u\n", fc->last_pid_sent); GMC_send_ack (c, fwd); break; default: break; } LOG (GNUNET_ERROR_TYPE_DEBUG, "! message sent!\n"); if (NULL == c->perf) return; /* Only endpoints are interested in timing. */ p = c->perf; usecsperbyte = ((double) wait.rel_value_us) / size; if (p->size == AVG_MSGS) { /* Array is full. Substract oldest value, add new one and store. */ p->avg -= (p->usecsperbyte[p->idx] / AVG_MSGS); p->usecsperbyte[p->idx] = usecsperbyte; p->avg += (p->usecsperbyte[p->idx] / AVG_MSGS); } else { /* Array not yet full. Add current value to avg and store. */ p->usecsperbyte[p->idx] = usecsperbyte; p->avg *= p->size; p->avg += p->usecsperbyte[p->idx]; p->size++; p->avg /= p->size; } p->idx = (p->idx + 1) % AVG_MSGS; // if (NULL != c->t) // { // c->t->pending_messages--; // if (GNUNET_YES == c->t->destroy && 0 == t->pending_messages) // { // LOG (GNUNET_ERROR_TYPE_DEBUG, "* destroying tunnel!\n"); // GMT_destroy (c->t); // } // } } /** * Get the previous hop in a connection * * @param c Connection. * * @return Previous peer in the connection. */ static struct MeshPeer * get_prev_hop (const 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 GMP_get_short (id); } /** * Get the next hop in a connection * * @param c Connection. * * @return Next peer in the connection. */ static struct MeshPeer * get_next_hop (const 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 GMP_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 * get_hop (struct MeshConnection *c, int fwd) { if (fwd) return get_next_hop (c); return get_prev_hop (c); } /** * Is traffic coming from this sender 'FWD' traffic? * * @param c Connection to check. * @param sender Peer identity of neighbor. * * @return GNUNET_YES in case the sender is the 'prev' hop and therefore * the traffic is 'FWD'. GNUNET_NO for BCK. GNUNET_SYSERR for errors. */ static int is_fwd (const struct MeshConnection *c, const struct GNUNET_PeerIdentity *sender) { GNUNET_PEER_Id id; id = GNUNET_PEER_search (sender); if (GMP_get_short_id (get_prev_hop (c)) == id) return GNUNET_YES; if (GMP_get_short_id (get_next_hop (c)) == id) return GNUNET_NO; GNUNET_break (0); return GNUNET_SYSERR; } /** * Sends a CONNECTION ACK message in reponse to a received CONNECTION_CREATE * or a first CONNECTION_ACK directed to us. * * @param connection Connection to confirm. * @param fwd Should we send it FWD? * (First (~SYNACK) goes BCK, second (~ACK) goes FWD) */ 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"); GMP_queue_add (get_hop (connection, fwd), NULL, GNUNET_MESSAGE_TYPE_MESH_CONNECTION_ACK, sizeof (struct GNUNET_MESH_ConnectionACK), connection, NULL, fwd, &message_sent, NULL); if (MESH_TUNNEL3_NEW == GMT_get_state (t)) GMT_change_state (t, MESH_TUNNEL3_WAITING); if (MESH_CONNECTION_READY != connection->state) connection_change_state (connection, MESH_CONNECTION_SENT); } /** * Send a notification that a connection is broken. * * @param c Connection that is broken. * @param id1 Peer that has disconnected. * @param id2 Peer that has disconnected. * @param fwd Direction towards which to send it. */ static void send_broken (struct MeshConnection *c, const struct GNUNET_PeerIdentity *id1, const struct GNUNET_PeerIdentity *id2, int fwd) { struct GNUNET_MESH_ConnectionBroken msg; 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 = *id1; msg.peer2 = *id2; GMC_send_prebuilt_message (&msg.header, c, NULL, fwd); } /** * 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]\n", fwd ? "FWD" : "BCK", GMC_2s (c)); msg = (struct GNUNET_MESH_ConnectionKeepAlive *) cbuf; msg->header.size = htons (size); msg->header.type = htons (type); msg->cid = c->id; GMC_send_prebuilt_message (&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) GMC_send_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_TUNNEL3_SEARCHING == GMT_get_state (c->t)) { /* 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); } /** * @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; LOG (GNUNET_ERROR_TYPE_DEBUG, "connection_unlock_queue %s on %s\n", fwd ? "FWD" : "BCK", GMC_2s (c)); if (GMC_is_terminal (c, fwd)) { LOG (GNUNET_ERROR_TYPE_DEBUG, " is terminal!\n"); return; } peer = get_hop (c, fwd); GMP_queue_unlock (peer, c); } /** * Cancel all transmissions that belong to a certain connection. * * If the connection is scheduled for destruction and no more messages are left, * the connection will be destroyed by the continuation call. * * @param c Connection which to cancel. Might be destroyed during this call. * @param fwd Cancel fwd traffic? */ static void connection_cancel_queues (struct MeshConnection *c, int fwd) { struct MeshFlowControl *fc; struct MeshPeer *peer; if (NULL == c) { GNUNET_break (0); return; } fc = fwd ? &c->fwd_fc : &c->bck_fc; if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task) { GNUNET_SCHEDULER_cancel (fc->poll_task); fc->poll_task = GNUNET_SCHEDULER_NO_TASK; } peer = get_hop (c, fwd); GMP_queue_cancel (peer, c); } /** * 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 [%s]\n", GMC_2s (c)); 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); GMC_send_prebuilt_message (&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); } /** * 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", GMT_2s (c->t), 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", GMT_2s (c->t), 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); } } /** * Add the connection to the list of both neighbors. * * @param c Connection. */ static void register_neighbors (struct MeshConnection *c) { struct MeshPeer *peer; peer = get_next_hop (c); if (GNUNET_NO == GMP_is_neighbor (peer)) { GMC_destroy (c); return; } GMP_add_connection (peer, c); peer = get_prev_hop (c); if (GNUNET_NO == GMP_is_neighbor (peer)) { GMC_destroy (c); return; } GMP_add_connection (peer, c); } /** * Remove the connection from the list of both neighbors. * * @param c Connection. */ static void unregister_neighbors (struct MeshConnection *c) { struct MeshPeer *peer; peer = get_next_hop (c); GMP_remove_connection (peer, c); peer = get_prev_hop (c); GMP_remove_connection (peer, c); } /** * Bind the connection to the peer and the tunnel to that peer. * * If the peer has no tunnel, create one. Update tunnel and connection * data structres to reflect new status. * * @param c Connection. * @param peer Peer. */ static void add_to_peer (struct MeshConnection *c, struct MeshPeer *peer) { GMP_add_tunnel (peer); c->t = GMP_get_tunnel (peer); GMT_add_connection (c->t, 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) { /* 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] == myid) 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); return GNUNET_OK; } LOG (GNUNET_ERROR_TYPE_DEBUG, " Own position: %u\n", own_pos); GMP_add_path_to_all (path, GNUNET_NO); LOG (GNUNET_ERROR_TYPE_DEBUG, " Creating connection\n"); c = GMC_new (cid, NULL, path_duplicate (path), own_pos); if (NULL == c) return GNUNET_OK; connection_reset_timeout (c, GNUNET_YES); } else { path = NULL; } if (MESH_CONNECTION_NEW == c->state) connection_change_state (c, MESH_CONNECTION_SENT); /* Remember peers */ dest_peer = GMP_get (&id[size - 1]); orig_peer = GMP_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"); GMP_add_path_to_origin (orig_peer, path, GNUNET_YES); add_to_peer (c, orig_peer); if (MESH_TUNNEL3_NEW == GMT_get_state (c->t)) GMT_change_state (c->t, MESH_TUNNEL3_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"); GMP_add_path (dest_peer, path_duplicate (path), GNUNET_NO); GMP_add_path_to_origin (orig_peer, path, GNUNET_NO); GMC_send_prebuilt_message (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 = GMP_get (peer); if (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 (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) { GMP_add_path_to_all (p, GNUNET_YES); } else { GNUNET_break (0); } /* Message for us as creator? */ if (GMC_is_origin (c, GNUNET_YES)) { LOG (GNUNET_ERROR_TYPE_DEBUG, " Connection (SYN)ACK for us!\n"); connection_change_state (c, MESH_CONNECTION_READY); GMT_change_state (c->t, MESH_TUNNEL3_READY); send_connection_ack (c, GNUNET_YES); GMT_send_queued_data (c->t, GNUNET_YES); 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"); connection_change_state (c, MESH_CONNECTION_READY); GMT_change_state (c->t, MESH_TUNNEL3_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 id 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* id, const struct GNUNET_MessageHeader* message) { struct GNUNET_MESH_ConnectionBroken *msg; struct MeshConnection *c; int fwd; LOG (GNUNET_ERROR_TYPE_DEBUG, "Received a CONNECTION BROKEN msg from %s\n", GNUNET_i2s (id)); 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; } fwd = is_fwd (c, id); connection_cancel_queues (c, !fwd); if (GMC_is_terminal (c, fwd)) { if (0 < c->pending_messages) c->destroy = GNUNET_YES; else GMC_destroy (c); } else { GMC_send_prebuilt_message (message, c, NULL, fwd); c->destroy = GNUNET_YES; } 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; 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; } fwd = is_fwd (c, peer); if (GNUNET_SYSERR == fwd) { 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 msg Encrypted message. * * @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) { struct MeshConnection *c; struct MeshPeer *neighbor; struct MeshFlowControl *fc; GNUNET_PEER_Id peer_id; uint32_t pid; uint32_t ttl; uint16_t type; size_t size; int fwd; /* 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; } /* Check if origin is as expected */ neighbor = get_prev_hop (c); peer_id = GNUNET_PEER_search (peer); if (peer_id == GMP_get_short_id (neighbor)) { fwd = GNUNET_YES; } else { neighbor = get_next_hop (c); if (peer_id == GMP_get_short_id (neighbor)) { fwd = GNUNET_NO; } else { /* Unexpected peer sending traffic on a connection. */ GNUNET_break_op (0); return GNUNET_OK; } } /* Check PID */ fc = fwd ? &c->bck_fc : &c->fwd_fc; 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 || MESH_CONNECTION_ACK == 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)) { /* TODO signature verification */ LOG (GNUNET_ERROR_TYPE_DEBUG, " message for us!\n"); GNUNET_STATISTICS_update (stats, "# messages received", 1, GNUNET_NO); if (NULL == c->t) { GNUNET_break (0); return GNUNET_OK; } fc->last_pid_recv = pid; GMT_handle_encrypted (c->t, msg, fwd); GMC_send_ack (c, 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"); GMC_send_ack (c, fwd); return GNUNET_OK; } GNUNET_STATISTICS_update (stats, "# messages forwarded", 1, GNUNET_NO); GMC_send_prebuilt_message (&msg->header, c, NULL, fwd); return GNUNET_OK; } /** * Core handler for encrypted mesh network traffic (channel mgmt, data). * * @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_encrypted (void *cls, const struct GNUNET_PeerIdentity *peer, const struct GNUNET_MessageHeader *message) { return handle_mesh_encrypted (peer, (struct GNUNET_MESH_Encrypted *)message); } /** * 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 (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 (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 (get_next_hop (c)) == id) { LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD ACK\n"); fc = &c->fwd_fc; } else if (GMP_get_short_id (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; GMC_send_ack (c, 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 = 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 fwd Is this a fwd ACK? (will go dest->root) */ void GMC_send_ack (struct MeshConnection *c, int fwd) { unsigned int buffer; LOG (GNUNET_ERROR_TYPE_DEBUG, "GMC send %s ACK on %s\n", fwd ? "FWD" : "BCK", GMC_2s (c)); if (NULL == c) { GNUNET_break (0); return; } /* Get available buffer space */ if (GMC_is_terminal (c, fwd)) { LOG (GNUNET_ERROR_TYPE_DEBUG, " getting from all channels\n"); buffer = GMT_get_buffer (c->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); /* Send available buffer space */ if (GMC_is_origin (c, fwd)) { GNUNET_assert (NULL != c->t); LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on channels...\n"); if (0 < buffer) { LOG (GNUNET_ERROR_TYPE_DEBUG, " really sending!\n"); GMT_unchoke_channels (c->t, fwd); } } else { LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on connection\n"); send_ack (c, buffer, fwd); } } /** * Initialize the connections subsystem * * @param c Configuration handle. */ void GMC_init (const struct GNUNET_CONFIGURATION_Handle *c) { LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n"); if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_number (c, "MESH", "MAX_MSGS_QUEUE", &max_msgs_queue)) { GNUNET_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)) { GNUNET_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)) { GNUNET_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) { GNUNET_CONTAINER_multihashmap_destroy (connections); } 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) { if (NULL == c) return; if (2 == c->destroy) /* cancel queues -> GMP_queue_cancel -> q_destroy -> */ return; /* -> message_sent -> GMC_destroy. Don't loop. */ c->destroy = 2; LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying connection %s\n", GMC_2s (c)); /* 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); if (NULL != c->t) 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 path. * * @param c Connection to get the path from. * * @return path used by the connection. */ const struct MeshPeerPath * GMC_get_path (const struct MeshConnection *c) { return c->path; } /** * 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 how many messages have we allowed to send to us from a direction. * * @param c Connection. * @param fwd Are we asking about traffic from FWD (BCK messages)? * * @return last_ack_sent - last_pid_recv */ unsigned int GMC_get_allowed (struct MeshConnection *c, int fwd) { struct MeshFlowControl *fc; fc = fwd ? &c->fwd_fc : &c->bck_fc; if (GMC_is_pid_bigger(fc->last_pid_recv, fc->last_ack_sent)) { return 0; } return (fc->last_ack_sent - fc->last_pid_recv); } /** * 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; } /** * Allow the connection to advertise a buffer of the given size. * * The connection will send an @c fwd ACK message (so: in direction !fwd) * allowing up to last_pid_recv + buffer. * * @param c Connection. * @param buffer How many more messages the connection can accept. * @param fwd Is this about FWD traffic? (The ack will go dest->root). */ void GMC_allow (struct MeshConnection *c, unsigned int buffer, int fwd) { send_ack (c, buffer, fwd); } /** * 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. */ void GMC_notify_broken (struct MeshConnection *c, struct MeshPeer *peer) { int fwd; fwd = peer == get_prev_hop (c); if (GNUNET_YES == GMC_is_terminal (c, fwd)) { /* Local shutdown, no one to notify about this. */ GMC_destroy (c); return; } send_broken (c, &my_full_id, GMP_get_id (peer), fwd); connection_cancel_queues (c, !fwd); /* Connection will have at least one pending message * (the one we just scheduled), so no point in checking whether to * destroy immediately. */ 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); } /** * See if we are allowed to send by the next hop in the given direction. * * @param c Connection. * @param fwd Is this about fwd traffic? * * @return GNUNET_YES in case it's OK. */ int GMC_is_sendable (struct MeshConnection *c, int fwd) { struct MeshFlowControl *fc; fc = fwd ? &c->fwd_fc : &c->bck_fc; if (GMC_is_pid_bigger (fc->last_ack_recv, fc->last_pid_sent)) return GNUNET_YES; return GNUNET_NO; } /** * 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) { struct MeshFlowControl *fc; void *data; size_t size; uint16_t type; int droppable; 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, GMC_2s (c)); fc = fwd ? &c->fwd_fc : &c->bck_fc; droppable = GNUNET_YES; 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_ENCRYPTED: 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, " Q_N+ %p %u\n", fc, fc->queue_n); fc->queue_n++; LOG (GNUNET_ERROR_TYPE_DEBUG, "pid %u\n", ntohl (emsg->pid)); LOG (GNUNET_ERROR_TYPE_DEBUG, "last pid %u\n", fc->last_pid_sent); LOG (GNUNET_ERROR_TYPE_DEBUG, " ack %u\n", fc->last_ack_recv); if (GMC_is_pid_bigger (fc->last_pid_sent + 1, fc->last_ack_recv)) { GMC_start_poll (c, fwd); } 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)); droppable = GNUNET_NO; 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)); droppable = GNUNET_NO; break; case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_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); } if (fc->queue_n > fc->queue_max && droppable) { GNUNET_STATISTICS_update (stats, "# messages dropped (buffer full)", 1, GNUNET_NO); GNUNET_break (0); LOG (GNUNET_ERROR_TYPE_DEBUG, "queue full: %u/%u\n", fc->queue_n, fc->queue_max); if (GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED == type) fc->queue_n--; return; /* Drop this message */ } c->pending_messages++; GMP_queue_add (get_hop (c, fwd), data, type, size, c, ch, fwd, &message_sent, NULL); } /** * Sends a CREATE CONNECTION message for a path to a peer. * Changes the connection and tunnel states if necessary. * * @param connection Connection to create. */ void GMC_send_create (struct MeshConnection *connection) { enum MeshTunnel3State state; size_t size; size = sizeof (struct GNUNET_MESH_ConnectionCreate); size += connection->path->length * sizeof (struct GNUNET_PeerIdentity); LOG (GNUNET_ERROR_TYPE_DEBUG, "Send connection create\n"); GMP_queue_add (get_next_hop (connection), NULL, GNUNET_MESSAGE_TYPE_MESH_CONNECTION_CREATE, size, connection, NULL, GNUNET_YES, &message_sent, NULL); state = GMT_get_state (connection->t); if (MESH_TUNNEL3_SEARCHING == state || MESH_TUNNEL3_NEW == state) GMT_change_state (connection->t, MESH_TUNNEL3_WAITING); if (MESH_CONNECTION_NEW == connection->state) connection_change_state (connection, MESH_CONNECTION_SENT); } /** * 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_CONNECTION_DESTROY);; msg.cid = c->id; LOG (GNUNET_ERROR_TYPE_DEBUG, " sending connection destroy for connection %s\n", GMC_2s (c)); 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; } /** * @brief Start a polling timer for the connection. * * When a neighbor does not accept more traffic on the connection it could be * caused by a simple congestion or by a lost ACK. Polling enables to check * for the lastest ACK status for a connection. * * @param c Connection. * @param fwd Should we poll in the FWD direction? */ void GMC_start_poll (struct MeshConnection *c, int fwd) { struct MeshFlowControl *fc; fc = fwd ? &c->fwd_fc : &c->bck_fc; if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task) { return; } fc->poll_task = GNUNET_SCHEDULER_add_delayed (fc->poll_time, &connection_poll, fc); } /** * @brief Stop polling a connection for ACKs. * * Once we have enough ACKs for future traffic, polls are no longer necessary. * * @param c Connection. * @param fwd Should we stop the poll in the FWD direction? */ void GMC_stop_poll (struct MeshConnection *c, int fwd) { struct MeshFlowControl *fc; fc = fwd ? &c->fwd_fc : &c->bck_fc; if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task) { GNUNET_SCHEDULER_cancel (fc->poll_task); fc->poll_task = GNUNET_SCHEDULER_NO_TASK; } } /** * Get a (static) string for a connection. * * @param c Connection. */ const char * GMC_2s (struct MeshConnection *c) { if (NULL != c->t) { static char buf[128]; sprintf (buf, "%s (->%s)", GNUNET_h2s (&c->id), GMT_2s (c->t)); return buf; } return GNUNET_h2s (&c->id); }