/* This file is part of GNUnet. (C) 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. */ #include "platform.h" #include "gnunet_util_lib.h" #include "gnunet_statistics_service.h" #include "mesh.h" #include "mesh_protocol.h" #include "gnunet-service-mesh_channel.h" #include "gnunet-service-mesh_local.h" #include "gnunet-service-mesh_tunnel.h" #include "gnunet-service-mesh_peer.h" #define LOG(level, ...) GNUNET_log_from(level,"mesh-chn",__VA_ARGS__) #define MESH_RETRANSMIT_TIME GNUNET_TIME_relative_multiply(\ GNUNET_TIME_UNIT_MILLISECONDS, 250) #define MESH_RETRANSMIT_MARGIN 4 /** * All the states a connection can be in. */ enum MeshChannelState { /** * Uninitialized status, should never appear in operation. */ MESH_CHANNEL_NEW, /** * Connection create message sent, waiting for ACK. */ MESH_CHANNEL_SENT, /** * Connection confirmed, ready to carry traffic. */ MESH_CHANNEL_READY, }; /** * Info holder for channel messages in queues. */ struct MeshChannelQueue { /** * Tunnel Queue. */ struct MeshTunnel3Queue *tq; /** * Message type (DATA/DATA_ACK) */ uint16_t type; /** * Message copy (for DATAs, to start retransmission timer) */ struct MeshReliableMessage *copy; /** * Reliability (for DATA_ACKs, to access rel->ack_q) */ struct MeshChannelReliability *rel; }; /** * Info needed to retry a message in case it gets lost. */ struct MeshReliableMessage { /** * Double linked list, FIFO style */ struct MeshReliableMessage *next; struct MeshReliableMessage *prev; /** * Type of message (payload, channel management). */ int16_t type; /** * Tunnel Reliability queue this message is in. */ struct MeshChannelReliability *rel; /** * ID of the message (ACK needed to free) */ uint32_t mid; /** * Tunnel Queue. */ struct MeshChannelQueue *chq; /** * When was this message issued (to calculate ACK delay) */ struct GNUNET_TIME_Absolute timestamp; /* struct GNUNET_MESH_Data with payload */ }; /** * Info about the traffic state for a client in a channel. */ struct MeshChannelReliability { /** * Channel this is about. */ struct MeshChannel *ch; /** * DLL of messages sent and not yet ACK'd. */ struct MeshReliableMessage *head_sent; struct MeshReliableMessage *tail_sent; /** * DLL of messages received out of order. */ struct MeshReliableMessage *head_recv; struct MeshReliableMessage *tail_recv; /** * Messages received. */ unsigned int n_recv; /** * Next MID to use for outgoing traffic. */ uint32_t mid_send; /** * Next MID expected for incoming traffic. */ uint32_t mid_recv; /** * Handle for queued unique data CREATE, DATA_ACK. */ struct MeshChannelQueue *uniq; /** * Can we send data to the client? */ int client_ready; /** * Can the client send data to us? */ int client_allowed; /** * Task to resend/poll in case no ACK is received. */ GNUNET_SCHEDULER_TaskIdentifier retry_task; /** * Counter for exponential backoff. */ struct GNUNET_TIME_Relative retry_timer; /** * How long does it usually take to get an ACK. */ struct GNUNET_TIME_Relative expected_delay; }; /** * Struct containing all information regarding a channel to a remote client. */ struct MeshChannel { /** * Tunnel this channel is in. */ struct MeshTunnel3 *t; /** * Destination port of the channel. */ uint32_t port; /** * Global channel number ( < GNUNET_MESH_LOCAL_CHANNEL_ID_CLI) */ MESH_ChannelNumber gid; /** * Local tunnel number for root (owner) client. * ( >= GNUNET_MESH_LOCAL_CHANNEL_ID_CLI or 0 ) */ MESH_ChannelNumber lid_root; /** * Local tunnel number for local destination clients (incoming number) * ( >= GNUNET_MESH_LOCAL_CHANNEL_ID_SERV or 0). */ MESH_ChannelNumber lid_dest; /** * Channel state. */ enum MeshChannelState state; /** * Is the tunnel bufferless (minimum latency)? */ int nobuffer; /** * Is the tunnel reliable? */ int reliable; /** * Last time the channel was used */ struct GNUNET_TIME_Absolute timestamp; /** * Client owner of the tunnel, if any */ struct MeshClient *root; /** * Client destination of the tunnel, if any. */ struct MeshClient *dest; /** * Flag to signal the destruction of the channel. * If this is set GNUNET_YES the channel will be destroyed * when the queue is empty. */ int destroy; /** * Total (reliable) messages pending ACK for this channel. */ unsigned int pending_messages; /** * Reliability data. * Only present (non-NULL) at the owner of a tunnel. */ struct MeshChannelReliability *root_rel; /** * Reliability data. * Only present (non-NULL) at the destination of a tunnel. */ struct MeshChannelReliability *dest_rel; }; /******************************************************************************/ /******************************* 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; /******************************************************************************/ /******************************** STATIC ***********************************/ /******************************************************************************/ /** * Destroy a reliable message after it has been acknowledged, either by * direct mid ACK or bitfield. Updates the appropriate data structures and * timers and frees all memory. * * @param copy Message that is no longer needed: remote peer got it. * @param update_time Is the timing information relevant? * If this message is ACK in a batch the timing information * is skewed by the retransmission, count only for the * retransmitted message. */ static int rel_message_free (struct MeshReliableMessage *copy, int update_time); /** * send a channel create message. * * @param ch Channel for which to send. */ static void send_create (struct MeshChannel *ch); /** * Confirm we got a channel create, FWD ack. * * @param ch The channel to confirm. * @param fwd Should we send a FWD ACK? (going dest->root) * @param reaction This ACK is a reaction to a duplicate CREATE, don't save. */ static void send_ack (struct MeshChannel *ch, int fwd, int reaction); /** * Test if the channel is loopback: both root and dest are on the local peer. * * @param ch Channel to test. * * @return #GNUNET_YES if channel is loopback, #GNUNET_NO otherwise. */ static int is_loopback (const struct MeshChannel *ch) { if (NULL != ch->t) return GMT_is_loopback (ch->t); return (NULL != ch->root && NULL != ch->dest); } /** * Save a copy of the data message for later retransmission. * * @param msg Message to copy. * @param mid Message ID. * @param rel Reliability data for retransmission. */ static struct MeshReliableMessage * copy_message (const struct GNUNET_MESH_Data *msg, uint32_t mid, struct MeshChannelReliability *rel) { struct MeshReliableMessage *copy; uint16_t size; size = ntohs (msg->header.size); copy = GNUNET_malloc (sizeof (*copy) + size); copy->mid = mid; copy->rel = rel; copy->type = GNUNET_MESSAGE_TYPE_MESH_DATA; memcpy (©[1], msg, size); return copy; } /** * We have received a message out of order, or the client is not ready. * Buffer it until we receive an ACK from the client or the missing * message from the channel. * * @param msg Message to buffer (MUST be of type MESH_DATA). * @param rel Reliability data to the corresponding direction. */ static void add_buffered_data (const struct GNUNET_MESH_Data *msg, struct MeshChannelReliability *rel) { struct MeshReliableMessage *copy; struct MeshReliableMessage *prev; uint32_t mid; mid = ntohl (msg->mid); LOG (GNUNET_ERROR_TYPE_DEBUG, "add_buffered_data %u\n", mid); rel->n_recv++; // FIXME do something better than O(n), although n < 64... // FIXME start from the end (most messages are the latest ones) for (prev = rel->head_recv; NULL != prev; prev = prev->next) { LOG (GNUNET_ERROR_TYPE_DEBUG, " prev %u\n", prev->mid); if (prev->mid == mid) { LOG (GNUNET_ERROR_TYPE_DEBUG, " already there!\n"); return; } else if (GM_is_pid_bigger (prev->mid, mid)) { LOG (GNUNET_ERROR_TYPE_DEBUG, " bingo!\n"); copy = copy_message (msg, mid, rel); GNUNET_CONTAINER_DLL_insert_before (rel->head_recv, rel->tail_recv, prev, copy); return; } } copy = copy_message (msg, mid, rel); LOG (GNUNET_ERROR_TYPE_DEBUG, " insert at tail!\n"); GNUNET_CONTAINER_DLL_insert_tail (rel->head_recv, rel->tail_recv, copy); LOG (GNUNET_ERROR_TYPE_DEBUG, "add_buffered_data END\n"); } /** * Add a destination client to a channel, initializing all data structures * in the channel and the client. * * @param ch Channel to which add the destination. * @param c Client which to add to the channel. */ static void add_destination (struct MeshChannel *ch, struct MeshClient *c) { if (NULL != ch->dest) { GNUNET_break (0); return; } /* Assign local id as destination */ ch->lid_dest = GML_get_next_chid (c); /* Store in client's hashmap */ GML_channel_add (c, ch->lid_dest, ch); GNUNET_break (NULL == ch->dest_rel); ch->dest_rel = GNUNET_new (struct MeshChannelReliability); ch->dest_rel->ch = ch; ch->dest_rel->expected_delay.rel_value_us = 0; ch->dest_rel->retry_timer = MESH_RETRANSMIT_TIME; ch->dest = c; } /** * Set options in a channel, extracted from a bit flag field. * * @param ch Channel to set options to. * @param options Bit array in host byte order. */ static void channel_set_options (struct MeshChannel *ch, uint32_t options) { ch->nobuffer = (options & GNUNET_MESH_OPTION_NOBUFFER) != 0 ? GNUNET_YES : GNUNET_NO; ch->reliable = (options & GNUNET_MESH_OPTION_RELIABLE) != 0 ? GNUNET_YES : GNUNET_NO; } /** * Get a bit flag field with the options of a channel. * * @param ch Channel to get options from. * * @return Bit array in host byte order. */ static uint32_t channel_get_options (struct MeshChannel *ch) { uint32_t options; options = 0; if (ch->nobuffer) options |= GNUNET_MESH_OPTION_NOBUFFER; if (ch->reliable) options |= GNUNET_MESH_OPTION_RELIABLE; return options; } /** * Notify the destination client that a new incoming channel was created. * * @param ch Channel that was created. */ static void send_client_create (struct MeshChannel *ch) { uint32_t opt; if (NULL == ch->dest) return; opt = 0; opt |= GNUNET_YES == ch->reliable ? GNUNET_MESH_OPTION_RELIABLE : 0; opt |= GNUNET_YES == ch->nobuffer ? GNUNET_MESH_OPTION_NOBUFFER : 0; GML_send_channel_create (ch->dest, ch->lid_dest, ch->port, opt, GMT_get_destination (ch->t)); } /** * Send data to a client. * * If the client is ready, send directly, otherwise buffer while listening * for a local ACK. * * @param ch Channel * @param msg Message. * @param fwd Is this a fwd (root->dest) message? */ static void send_client_data (struct MeshChannel *ch, const struct GNUNET_MESH_Data *msg, int fwd) { if (fwd) { if (ch->dest_rel->client_ready) GML_send_data (ch->dest, msg, ch->lid_dest); else add_buffered_data (msg, ch->dest_rel); } else { if (ch->root_rel->client_ready) GML_send_data (ch->root, msg, ch->lid_root); else add_buffered_data (msg, ch->root_rel); } } /** * Send a buffered message to the client, for in order delivery or * as result of client ACK. * * @param ch Channel on which to empty the message buffer. * @param c Client to send to. * @param fwd Is this to send FWD data?. */ static void send_client_buffered_data (struct MeshChannel *ch, struct MeshClient *c, int fwd) { struct MeshReliableMessage *copy; struct MeshChannelReliability *rel; LOG (GNUNET_ERROR_TYPE_DEBUG, "send_buffered_data\n"); rel = fwd ? ch->dest_rel : ch->root_rel; if (GNUNET_NO == rel->client_ready) { LOG (GNUNET_ERROR_TYPE_DEBUG, "client not ready\n"); return; } copy = rel->head_recv; /* We never buffer channel management messages */ if (NULL != copy) { if (copy->mid == rel->mid_recv || GNUNET_NO == ch->reliable) { struct GNUNET_MESH_Data *msg = (struct GNUNET_MESH_Data *) ©[1]; LOG (GNUNET_ERROR_TYPE_DEBUG, " have %u! now expecting %u\n", copy->mid, rel->mid_recv + 1); send_client_data (ch, msg, fwd); rel->n_recv--; rel->mid_recv++; GNUNET_CONTAINER_DLL_remove (rel->head_recv, rel->tail_recv, copy); LOG (GNUNET_ERROR_TYPE_DEBUG, " COPYFREE RECV %p\n", copy); GNUNET_free (copy); } else { LOG (GNUNET_ERROR_TYPE_DEBUG, " reliable && don't have %u, next is %u\n", rel->mid_recv, copy->mid); return; } } LOG (GNUNET_ERROR_TYPE_DEBUG, "send_buffered_data END\n"); } /** * Allow a client to send more data. * * In case the client was already allowed to send data, do nothing. * * @param ch Channel. * @param fwd Is this a FWD ACK? (FWD ACKs are sent to root) */ static void send_client_ack (struct MeshChannel *ch, int fwd) { struct MeshChannelReliability *rel = fwd ? ch->root_rel : ch->dest_rel; struct MeshClient *c = fwd ? ch->root : ch->dest; if (NULL == c) { GNUNET_break (GNUNET_NO != ch->destroy); return; } LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %s ack to client on channel %s\n", GM_f2s (fwd), GMCH_2s (ch)); if (NULL == rel) { GNUNET_break (0); return; } if (GNUNET_YES == rel->client_allowed) { LOG (GNUNET_ERROR_TYPE_DEBUG, " already allowed\n"); return; } rel->client_allowed = GNUNET_YES; GML_send_ack (c, fwd ? ch->lid_root : ch->lid_dest); } /** * Notify the root that the destination rejected the channel. * * @param ch Rejected channel. */ static void send_client_nack (struct MeshChannel *ch) { if (NULL == ch->root) { GNUNET_break (0); return; } GML_send_channel_nack (ch->root, ch->lid_root); } /** * We haven't received an ACK after a certain time: restransmit the message. * * @param cls Closure (MeshChannelReliability with the message to restransmit) * @param tc TaskContext. */ static void channel_retransmit_message (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct MeshChannelReliability *rel = cls; struct MeshReliableMessage *copy; struct MeshChannel *ch; struct GNUNET_MESH_Data *payload; int fwd; rel->retry_task = GNUNET_SCHEDULER_NO_TASK; if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) return; ch = rel->ch; copy = rel->head_sent; if (NULL == copy) { GNUNET_break (0); return; } payload = (struct GNUNET_MESH_Data *) ©[1]; fwd = (rel == ch->root_rel); /* Message not found in the queue that we are going to use. */ LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! RETRANSMIT %u\n", copy->mid); GMCH_send_prebuilt_message (&payload->header, ch, fwd, copy); GNUNET_STATISTICS_update (stats, "# data retransmitted", 1, GNUNET_NO); } /** * We haven't received an Channel ACK after a certain time: resend the CREATE. * * @param cls Closure (MeshChannelReliability of the channel to recreate) * @param tc TaskContext. */ static void channel_recreate (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct MeshChannelReliability *rel = cls; rel->retry_task = GNUNET_SCHEDULER_NO_TASK; if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) return; LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! RE-CREATE\n"); GNUNET_STATISTICS_update (stats, "# data retransmitted", 1, GNUNET_NO); if (rel == rel->ch->root_rel) { send_create (rel->ch); } else if (rel == rel->ch->dest_rel) { send_ack (rel->ch, GNUNET_YES, GNUNET_NO); } else { GNUNET_break (0); } } /** * Message has been sent: start retransmission timer. * * @param cls Closure (queue structure). * @param t Tunnel. * @param q Queue handler (no longer valid). * @param type Type of message. * @param size Size of the message. */ static void ch_message_sent (void *cls, struct MeshTunnel3 *t, struct MeshTunnel3Queue *q, uint16_t type, size_t size) { struct MeshChannelQueue *chq = cls; struct MeshReliableMessage *copy = chq->copy; struct MeshChannelReliability *rel; LOG (GNUNET_ERROR_TYPE_DEBUG, "channel message sent callback %s\n", GM_m2s (chq->type)); switch (chq->type) { case GNUNET_MESSAGE_TYPE_MESH_DATA: LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SENT DATA MID %u\n", copy->mid); GNUNET_assert (chq == copy->chq); copy->timestamp = GNUNET_TIME_absolute_get (); rel = copy->rel; if (GNUNET_SCHEDULER_NO_TASK == rel->retry_task) { LOG (GNUNET_ERROR_TYPE_DEBUG, "!! scheduling retry in 4 * %s\n", GNUNET_STRINGS_relative_time_to_string (rel->expected_delay, GNUNET_YES)); if (0 != rel->expected_delay.rel_value_us) { LOG (GNUNET_ERROR_TYPE_DEBUG, "!! delay != 0\n"); rel->retry_timer = GNUNET_TIME_relative_multiply (rel->expected_delay, MESH_RETRANSMIT_MARGIN); } else { LOG (GNUNET_ERROR_TYPE_DEBUG, "!! delay reset\n"); rel->retry_timer = MESH_RETRANSMIT_TIME; } LOG (GNUNET_ERROR_TYPE_DEBUG, "!! using delay %s\n", GNUNET_STRINGS_relative_time_to_string (rel->retry_timer, GNUNET_NO)); rel->retry_task = GNUNET_SCHEDULER_add_delayed (rel->retry_timer, &channel_retransmit_message, rel); } else { LOG (GNUNET_ERROR_TYPE_DEBUG, "!! retry task %u\n", rel->retry_task); } copy->chq = NULL; break; case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK: case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE: case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK: LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SENT %s\n", GM_m2s (chq->type)); rel = chq->rel; GNUNET_assert (rel->uniq == chq); rel->uniq = NULL; if (MESH_CHANNEL_READY != rel->ch->state && GNUNET_MESSAGE_TYPE_MESH_DATA_ACK != type && GNUNET_NO == rel->ch->destroy) { GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == rel->retry_task); LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! STD BACKOFF %s\n", GNUNET_STRINGS_relative_time_to_string (rel->retry_timer, GNUNET_NO)); rel->retry_timer = GNUNET_TIME_STD_BACKOFF (rel->retry_timer); rel->retry_task = GNUNET_SCHEDULER_add_delayed (rel->retry_timer, &channel_recreate, rel); } break; default: GNUNET_break (0); } GNUNET_free (chq); } /** * send a channel create message. * * @param ch Channel for which to send. */ static void send_create (struct MeshChannel *ch) { struct GNUNET_MESH_ChannelCreate msgcc; msgcc.header.size = htons (sizeof (msgcc)); msgcc.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE); msgcc.chid = htonl (ch->gid); msgcc.port = htonl (ch->port); msgcc.opt = htonl (channel_get_options (ch)); GMCH_send_prebuilt_message (&msgcc.header, ch, GNUNET_YES, NULL); } /** * Confirm we got a channel create or FWD ack. * * @param ch The channel to confirm. * @param fwd Should we send a FWD ACK? (going dest->root) * @param reaction This ACK is a reaction to a duplicate CREATE, don't save. */ static void send_ack (struct MeshChannel *ch, int fwd, int reaction) { struct GNUNET_MESH_ChannelManage msg; msg.header.size = htons (sizeof (msg)); msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK); LOG (GNUNET_ERROR_TYPE_DEBUG, " sending channel %s ack for channel %s\n", GM_f2s (fwd), GMCH_2s (ch)); msg.chid = htonl (ch->gid); GMCH_send_prebuilt_message (&msg.header, ch, !fwd, reaction ? &msg : NULL); } /** * Send a message and don't keep any info about it: we won't need to cancel it * or resend it. * * @param msg Header of the message to fire away. * @param ch Channel on which the message should go. * @param force Is this a forced (undroppable) message? */ static void fire_and_forget (const struct GNUNET_MessageHeader *msg, struct MeshChannel *ch, int force) { GNUNET_break (NULL == GMT_send_prebuilt_message (msg, ch->t, NULL, force, NULL, NULL)); } /** * Notify that a channel create didn't succeed. * * @param ch The channel to reject. */ static void send_nack (struct MeshChannel *ch) { struct GNUNET_MESH_ChannelManage msg; msg.header.size = htons (sizeof (msg)); msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_NACK); LOG (GNUNET_ERROR_TYPE_DEBUG, " sending channel NACK for channel %s\n", GMCH_2s (ch)); msg.chid = htonl (ch->gid); GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_NO, NULL); } /** * Notify a client that the channel is no longer valid. * * @param ch Channel that is destroyed. * @param local_only Should we avoid sending it to other peers? */ static void send_destroy (struct MeshChannel *ch, int local_only) { struct GNUNET_MESH_ChannelManage msg; msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY); msg.header.size = htons (sizeof (msg)); msg.chid = htonl (ch->gid); /* If root is not NULL, notify. * If it's NULL, check lid_root. When a local destroy comes in, root * is set to NULL but lid_root is left untouched. In this case, do nothing, * the client is the one who reuqested the channel to be destroyed. */ if (NULL != ch->root) GML_send_channel_destroy (ch->root, ch->lid_root); else if (0 == ch->lid_root && GNUNET_NO == local_only) GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_NO, NULL); if (NULL != ch->dest) GML_send_channel_destroy (ch->dest, ch->lid_dest); else if (0 == ch->lid_dest && GNUNET_NO == local_only) GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_YES, NULL); } /** * Destroy all reliable messages queued for a channel, * during a channel destruction. * Frees the reliability structure itself. * * @param rel Reliability data for a channel. */ static void channel_rel_free_all (struct MeshChannelReliability *rel) { struct MeshReliableMessage *copy; struct MeshReliableMessage *next; if (NULL == rel) return; for (copy = rel->head_recv; NULL != copy; copy = next) { next = copy->next; GNUNET_CONTAINER_DLL_remove (rel->head_recv, rel->tail_recv, copy); LOG (GNUNET_ERROR_TYPE_DEBUG, " COPYFREE BATCH RECV %p\n", copy); GNUNET_break (NULL == copy->chq); GNUNET_free (copy); } for (copy = rel->head_sent; NULL != copy; copy = next) { next = copy->next; GNUNET_CONTAINER_DLL_remove (rel->head_sent, rel->tail_sent, copy); LOG (GNUNET_ERROR_TYPE_DEBUG, " COPYFREE BATCH %p\n", copy); if (NULL != copy->chq) { if (NULL != copy->chq->tq) { GMT_cancel (copy->chq->tq); /* ch_message_sent will free copy->q */ } else { GNUNET_free (copy->chq); GNUNET_break (0); } } GNUNET_free (copy); } if (NULL != rel->uniq && NULL != rel->uniq->tq) { GMT_cancel (rel->uniq->tq); /* ch_message_sent is called freeing uniq */ } if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task) { GNUNET_SCHEDULER_cancel (rel->retry_task); rel->retry_task = GNUNET_SCHEDULER_NO_TASK; } GNUNET_free (rel); } /** * Mark future messages as ACK'd. * * @param rel Reliability data. * @param msg DataACK message with a bitfield of future ACK'd messages. */ static void channel_rel_free_sent (struct MeshChannelReliability *rel, const struct GNUNET_MESH_DataACK *msg) { struct MeshReliableMessage *copy; struct MeshReliableMessage *next; uint64_t bitfield; uint64_t mask; uint32_t mid; uint32_t target; unsigned int i; bitfield = msg->futures; mid = ntohl (msg->mid); LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! free_sent_reliable %u %llX\n", mid, bitfield); LOG (GNUNET_ERROR_TYPE_DEBUG, " rel %p, head %p\n", rel, rel->head_sent); for (i = 0, copy = rel->head_sent; i < 64 && NULL != copy && 0 != bitfield; i++) { LOG (GNUNET_ERROR_TYPE_DEBUG, " trying bit %u (mid %u)\n", i, mid + i + 1); mask = 0x1LL << i; if (0 == (bitfield & mask)) continue; LOG (GNUNET_ERROR_TYPE_DEBUG, " set!\n"); /* Bit was set, clear the bit from the bitfield */ bitfield &= ~mask; /* The i-th bit was set. Do we have that copy? */ /* Skip copies with mid < target */ target = mid + i + 1; LOG (GNUNET_ERROR_TYPE_DEBUG, " target %u\n", target); while (NULL != copy && GM_is_pid_bigger (target, copy->mid)) copy = copy->next; /* Did we run out of copies? (previously freed, it's ok) */ if (NULL == copy) { LOG (GNUNET_ERROR_TYPE_DEBUG, "run out of copies...\n"); return; } /* Did we overshoot the target? (previously freed, it's ok) */ if (GM_is_pid_bigger (copy->mid, target)) { LOG (GNUNET_ERROR_TYPE_DEBUG, " next copy %u\n", copy->mid); continue; } /* Now copy->mid == target, free it */ next = copy->next; GNUNET_break (GNUNET_YES != rel_message_free (copy, GNUNET_YES)); copy = next; } LOG (GNUNET_ERROR_TYPE_DEBUG, "free_sent_reliable END\n"); } /** * Destroy a reliable message after it has been acknowledged, either by * direct mid ACK or bitfield. Updates the appropriate data structures and * timers and frees all memory. * * @param copy Message that is no longer needed: remote peer got it. * @param update_time Is the timing information relevant? * If this message is ACK in a batch the timing information * is skewed by the retransmission, count only for the * retransmitted message. * * @return #GNUNET_YES if channel was destroyed as a result of the call, * #GNUNET_NO otherwise. */ static int rel_message_free (struct MeshReliableMessage *copy, int update_time) { struct MeshChannelReliability *rel; struct GNUNET_TIME_Relative time; rel = copy->rel; LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Freeing %u\n", copy->mid); if (update_time) { time = GNUNET_TIME_absolute_get_duration (copy->timestamp); if (0 == rel->expected_delay.rel_value_us) rel->expected_delay = time; else { rel->expected_delay.rel_value_us *= 7; rel->expected_delay.rel_value_us += time.rel_value_us; rel->expected_delay.rel_value_us /= 8; } LOG (GNUNET_ERROR_TYPE_INFO, "!!! took %s, new delay %s\n", GNUNET_STRINGS_relative_time_to_string (time, GNUNET_NO), GNUNET_STRINGS_relative_time_to_string (rel->expected_delay, GNUNET_NO)); rel->retry_timer = rel->expected_delay; } else { LOG (GNUNET_ERROR_TYPE_INFO, "!!! batch free, ignoring timing\n"); } rel->ch->pending_messages--; if (NULL != copy->chq) { GMT_cancel (copy->chq->tq); /* copy->q is set to NULL by ch_message_sent */ } GNUNET_CONTAINER_DLL_remove (rel->head_sent, rel->tail_sent, copy); LOG (GNUNET_ERROR_TYPE_DEBUG, " COPYFREE %p\n", copy); GNUNET_free (copy); if (GNUNET_NO != rel->ch->destroy && 0 == rel->ch->pending_messages) { struct MeshTunnel3 *t = rel->ch->t; GMCH_destroy (rel->ch); GMT_destroy_if_empty (t); return GNUNET_YES; } return GNUNET_NO; } /** * Channel was ACK'd by remote peer, mark as ready and cancel retransmission. * * @param ch Channel to mark as ready. * @param fwd Was the ACK message a FWD ACK? (dest->root, SYNACK) */ static void channel_confirm (struct MeshChannel *ch, int fwd) { struct MeshChannelReliability *rel; enum MeshChannelState oldstate; rel = fwd ? ch->root_rel : ch->dest_rel; if (NULL == rel) { GNUNET_break (GNUNET_NO != ch->destroy); return; } LOG (GNUNET_ERROR_TYPE_DEBUG, " channel confirm %s %s\n", GM_f2s (fwd), GMCH_2s (ch)); oldstate = ch->state; ch->state = MESH_CHANNEL_READY; if (MESH_CHANNEL_READY != oldstate || GNUNET_YES == is_loopback (ch)) { rel->client_ready = GNUNET_YES; rel->expected_delay = rel->retry_timer; LOG (GNUNET_ERROR_TYPE_DEBUG, " !! retry timer confirm %s\n", GNUNET_STRINGS_relative_time_to_string (rel->retry_timer, GNUNET_NO)); if (GMT_get_connections_buffer (ch->t) > 0 || GMT_is_loopback (ch->t)) send_client_ack (ch, fwd); if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task) { GNUNET_SCHEDULER_cancel (rel->retry_task); rel->retry_task = GNUNET_SCHEDULER_NO_TASK; } else if (NULL != rel->uniq) { GMT_cancel (rel->uniq->tq); /* ch_message_sent will free and NULL uniq */ } else { if (GNUNET_NO == is_loopback (ch)) { /* We SHOULD have been trying to retransmit this! */ GNUNET_break (0); } } } /* In case of a FWD ACK (SYNACK) send a BCK ACK (ACK). */ if (GNUNET_YES == fwd) send_ack (ch, GNUNET_NO, GNUNET_NO); } /** * Save a copy to retransmit in case it gets lost. * * Initializes all needed callbacks and timers. * * @param ch Channel this message goes on. * @param msg Message to copy. * @param fwd Is this fwd traffic? */ static struct MeshReliableMessage * channel_save_copy (struct MeshChannel *ch, const struct GNUNET_MessageHeader *msg, int fwd) { struct MeshChannelReliability *rel; struct MeshReliableMessage *copy; uint32_t mid; uint16_t type; uint16_t size; rel = fwd ? ch->root_rel : ch->dest_rel; mid = rel->mid_send - 1; type = ntohs (msg->type); size = ntohs (msg->size); LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SAVE %u %s\n", mid, GM_m2s (type)); copy = GNUNET_malloc (sizeof (struct MeshReliableMessage) + size); LOG (GNUNET_ERROR_TYPE_DEBUG, " at %p\n", copy); copy->mid = mid; copy->rel = rel; copy->type = type; memcpy (©[1], msg, size); GNUNET_CONTAINER_DLL_insert_tail (rel->head_sent, rel->tail_sent, copy); ch->pending_messages++; return copy; } /** * Create a new channel. * * @param t Tunnel this channel is in. * @param owner Client that owns the channel, NULL for foreign channels. * @param lid_root Local ID for root client. * * @return A new initialized channel. NULL on error. */ static struct MeshChannel * channel_new (struct MeshTunnel3 *t, struct MeshClient *owner, MESH_ChannelNumber lid_root) { struct MeshChannel *ch; ch = GNUNET_new (struct MeshChannel); ch->root = owner; ch->lid_root = lid_root; ch->t = t; GNUNET_STATISTICS_update (stats, "# channels", 1, GNUNET_NO); if (NULL != owner) { ch->gid = GMT_get_next_chid (t); GML_channel_add (owner, lid_root, ch); } GMT_add_channel (t, ch); return ch; } /** * Handle a loopback message: call the appropriate handler for the message type. * * @param ch Channel this message is on. * @param msgh Message header. * @param fwd Is this FWD traffic? */ void handle_loopback (struct MeshChannel *ch, const struct GNUNET_MessageHeader *msgh, int fwd) { uint16_t type; type = ntohs (msgh->type); LOG (GNUNET_ERROR_TYPE_DEBUG, "Loopback %s %s message!\n", GM_f2s (fwd), GM_m2s (type)); switch (type) { case GNUNET_MESSAGE_TYPE_MESH_DATA: /* Don't send hop ACK, wait for client to ACK */ LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SEND loopback %u (%u)\n", ntohl (((struct GNUNET_MESH_Data *) msgh)->mid), ntohs (msgh->size)); GMCH_handle_data (ch, (struct GNUNET_MESH_Data *) msgh, fwd); break; case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK: GMCH_handle_data_ack (ch, (struct GNUNET_MESH_DataACK *) msgh, fwd); break; case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE: GMCH_handle_create (ch->t, (struct GNUNET_MESH_ChannelCreate *) msgh); break; case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK: GMCH_handle_ack (ch, (struct GNUNET_MESH_ChannelManage *) msgh, fwd); break; case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_NACK: GMCH_handle_nack (ch); break; case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY: GMCH_handle_destroy (ch, (struct GNUNET_MESH_ChannelManage *) msgh, fwd); break; default: GNUNET_break_op (0); LOG (GNUNET_ERROR_TYPE_DEBUG, "end-to-end message not known (%u)\n", ntohs (msgh->type)); } } /******************************************************************************/ /******************************** API ***********************************/ /******************************************************************************/ /** * Destroy a channel and free all resources. * * @param ch Channel to destroy. */ void GMCH_destroy (struct MeshChannel *ch) { struct MeshClient *c; if (NULL == ch) return; if (2 == ch->destroy) return; /* recursive call */ ch->destroy = 2; LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying channel %s:%u\n", GMT_2s (ch->t), ch->gid); GMCH_debug (ch); c = ch->root; if (NULL != c) { GML_channel_remove (c, ch->lid_root, ch); } c = ch->dest; if (NULL != c) { GML_channel_remove (c, ch->lid_dest, ch); } channel_rel_free_all (ch->root_rel); channel_rel_free_all (ch->dest_rel); GMT_remove_channel (ch->t, ch); GNUNET_STATISTICS_update (stats, "# channels", -1, GNUNET_NO); GNUNET_free (ch); } /** * Get the channel's public ID. * * @param ch Channel. * * @return ID used to identify the channel with the remote peer. */ MESH_ChannelNumber GMCH_get_id (const struct MeshChannel *ch) { return ch->gid; } /** * Get the channel tunnel. * * @param ch Channel to get the tunnel from. * * @return tunnel of the channel. */ struct MeshTunnel3 * GMCH_get_tunnel (const struct MeshChannel *ch) { return ch->t; } /** * Get free buffer space towards the client on a specific channel. * * @param ch Channel. * @param fwd Is query about FWD traffic? * * @return Free buffer space [0 - 64] */ unsigned int GMCH_get_buffer (struct MeshChannel *ch, int fwd) { struct MeshChannelReliability *rel; rel = fwd ? ch->dest_rel : ch->root_rel; /* If rel is NULL it means that the end is not yet created, * most probably is a loopback channel at the point of sending * the ChannelCreate to itself. */ if (NULL == rel) return 64; return (64 - rel->n_recv); } /** * Get flow control status of end point: is client allow to send? * * @param ch Channel. * @param fwd Is query about FWD traffic? (Request root status). * * @return #GNUNET_YES if client is allowed to send us data. */ int GMCH_get_allowed (struct MeshChannel *ch, int fwd) { struct MeshChannelReliability *rel; rel = fwd ? ch->root_rel : ch->dest_rel; if (NULL == rel) { /* Probably shutting down: root/dest NULL'ed to mark disconnection */ GNUNET_break (GNUNET_NO != ch->destroy); return 0; } return rel->client_allowed; } /** * Is the root client for this channel on this peer? * * @param ch Channel. * @param fwd Is this for fwd traffic? * * @return #GNUNET_YES in case it is. */ int GMCH_is_origin (struct MeshChannel *ch, int fwd) { struct MeshClient *c; c = fwd ? ch->root : ch->dest; return NULL != c; } /** * Is the destination client for this channel on this peer? * * @param ch Channel. * @param fwd Is this for fwd traffic? * * @return #GNUNET_YES in case it is. */ int GMCH_is_terminal (struct MeshChannel *ch, int fwd) { struct MeshClient *c; c = fwd ? ch->dest : ch->root; return NULL != c; } /** * Send an end-to-end ACK message for the most recent in-sequence payload. * * If channel is not reliable, do nothing. * * @param ch Channel this is about. * @param fwd Is for FWD traffic? (ACK dest->owner) */ void GMCH_send_data_ack (struct MeshChannel *ch, int fwd) { struct GNUNET_MESH_DataACK msg; struct MeshChannelReliability *rel; struct MeshReliableMessage *copy; unsigned int delta; uint64_t mask; uint32_t ack; if (GNUNET_NO == ch->reliable) { return; } rel = fwd ? ch->dest_rel : ch->root_rel; ack = rel->mid_recv - 1; LOG (GNUNET_ERROR_TYPE_INFO, "=> DATA_ACK for %u\n", ack); msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_DATA_ACK); msg.header.size = htons (sizeof (msg)); msg.chid = htonl (ch->gid); msg.futures = 0; for (copy = rel->head_recv; NULL != copy; copy = copy->next) { if (copy->type != GNUNET_MESSAGE_TYPE_MESH_DATA) { LOG (GNUNET_ERROR_TYPE_DEBUG, "!! Type %s, expected DATA\n", GM_m2s (copy->type)); continue; } if (copy->mid == ack + 1) { ack++; continue; } delta = copy->mid - (ack + 1); if (63 < delta) break; mask = 0x1LL << delta; msg.futures |= mask; LOG (GNUNET_ERROR_TYPE_DEBUG, " !! setting bit for %u (delta %u) (%llX) -> %llX\n", copy->mid, delta, mask, msg.futures); } msg.mid = htonl (ack); LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! ACK for %u, futures %llX\n", ack, msg.futures); GMCH_send_prebuilt_message (&msg.header, ch, !fwd, NULL); LOG (GNUNET_ERROR_TYPE_DEBUG, "send_data_ack END\n"); } /** * Allow a client to send us more data, in case it was choked. * * @param ch Channel. * @param fwd Is this about FWD traffic? (Root client). */ void GMCH_allow_client (struct MeshChannel *ch, int fwd) { struct MeshChannelReliability *rel; unsigned int buffer; LOG (GNUNET_ERROR_TYPE_DEBUG, "GMCH allow\n"); if (MESH_CHANNEL_READY != ch->state) { LOG (GNUNET_ERROR_TYPE_DEBUG, " channel not ready yet!\n"); return; } if (GNUNET_YES == ch->reliable) { rel = fwd ? ch->root_rel : ch->dest_rel; if (NULL == rel) { GNUNET_break (GNUNET_NO != ch->destroy); return; } if (NULL != rel->head_sent) { if (64 <= rel->mid_send - rel->head_sent->mid) { LOG (GNUNET_ERROR_TYPE_DEBUG, " too big MID gap! Wait for ACK.\n"); return; } else LOG (GNUNET_ERROR_TYPE_DEBUG, " gap ok: %u - %u\n", rel->head_sent->mid, rel->mid_send); } else { LOG (GNUNET_ERROR_TYPE_DEBUG, " head sent is NULL\n"); } } if (is_loopback (ch)) buffer = GMCH_get_buffer (ch, fwd); else buffer = GMT_get_connections_buffer (ch->t); if (0 == buffer) { LOG (GNUNET_ERROR_TYPE_DEBUG, " no buffer space.\n"); return; } LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space %u, allowing\n", buffer); send_client_ack (ch, fwd); } /** * Log channel info. * * @param ch Channel. */ void GMCH_debug (struct MeshChannel *ch) { if (NULL == ch) { LOG (GNUNET_ERROR_TYPE_DEBUG, "*** DEBUG NULL CHANNEL ***\n"); return; } LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %s:%X (%p)\n", GMT_2s (ch->t), ch->gid, ch); LOG (GNUNET_ERROR_TYPE_DEBUG, " root %p/%p\n", ch->root, ch->root_rel); if (NULL != ch->root) { LOG (GNUNET_ERROR_TYPE_DEBUG, " cli %s\n", GML_2s (ch->root)); LOG (GNUNET_ERROR_TYPE_DEBUG, " ready %s\n", ch->root_rel->client_ready ? "YES" : "NO"); LOG (GNUNET_ERROR_TYPE_DEBUG, " id %X\n", ch->lid_root); } LOG (GNUNET_ERROR_TYPE_DEBUG, " dest %p/%p\n", ch->dest, ch->dest_rel); if (NULL != ch->dest) { LOG (GNUNET_ERROR_TYPE_DEBUG, " cli %s\n", GML_2s (ch->dest)); LOG (GNUNET_ERROR_TYPE_DEBUG, " ready %s\n", ch->dest_rel->client_ready ? "YES" : "NO"); LOG (GNUNET_ERROR_TYPE_DEBUG, " id %X\n", ch->lid_dest); } } /** * Handle an ACK given by a client. * * Mark client as ready and send him any buffered data we could have for him. * * @param ch Channel. * @param fwd Is this a "FWD ACK"? (FWD ACKs are sent by dest and go BCK) */ void GMCH_handle_local_ack (struct MeshChannel *ch, int fwd) { struct MeshChannelReliability *rel; struct MeshClient *c; rel = fwd ? ch->dest_rel : ch->root_rel; c = fwd ? ch->dest : ch->root; rel->client_ready = GNUNET_YES; send_client_buffered_data (ch, c, fwd); if (is_loopback (ch)) { unsigned int buffer; buffer = GMCH_get_buffer (ch, fwd); if (0 < buffer) GMCH_allow_client (ch, fwd); return; } GMT_send_connection_acks (ch->t); } /** * Handle data given by a client. * * Check whether the client is allowed to send in this tunnel, save if channel * is reliable and send an ACK to the client if there is still buffer space * in the tunnel. * * @param ch Channel. * @param c Client which sent the data. * @param message Message. * @param fwd Is this a FWD data? * * @return GNUNET_OK if everything goes well, GNUNET_SYSERR in case of en error. */ int GMCH_handle_local_data (struct MeshChannel *ch, struct MeshClient *c, struct GNUNET_MessageHeader *message, int fwd) { struct MeshChannelReliability *rel; struct GNUNET_MESH_Data *payload; size_t size = ntohs (message->size); uint16_t p2p_size = sizeof(struct GNUNET_MESH_Data) + size; unsigned char cbuf[p2p_size]; /* Is the client in the channel? */ if ( !( (fwd && ch->root == c) || (!fwd && ch->dest == c) ) ) { GNUNET_break_op (0); return GNUNET_SYSERR; } rel = fwd ? ch->root_rel : ch->dest_rel; if (GNUNET_NO == rel->client_allowed) { GNUNET_break_op (0); return GNUNET_SYSERR; } rel->client_allowed = GNUNET_NO; /* Ok, everything is correct, send the message. */ payload = (struct GNUNET_MESH_Data *) cbuf; payload->mid = htonl (rel->mid_send); rel->mid_send++; memcpy (&payload[1], message, size); payload->header.size = htons (p2p_size); payload->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_DATA); payload->chid = htonl (ch->gid); LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on channel...\n"); GMCH_send_prebuilt_message (&payload->header, ch, fwd, NULL); if (is_loopback (ch)) { if (GMCH_get_buffer (ch, fwd) > 0) GMCH_allow_client (ch, fwd); return GNUNET_OK; } if (GMT_get_connections_buffer (ch->t) > 0) { GMCH_allow_client (ch, fwd); } return GNUNET_OK; } /** * Handle a channel destroy requested by a client. * * Destroy the channel and the tunnel in case this was the last channel. * * @param ch Channel. * @param c Client that requested the destruction (to avoid notifying him). * @param is_root Is the request coming from root? */ void GMCH_handle_local_destroy (struct MeshChannel *ch, struct MeshClient *c, int is_root) { struct MeshTunnel3 *t; ch->destroy = GNUNET_YES; /* Cleanup after the tunnel */ if (GNUNET_NO == is_root && c == ch->dest) { LOG (GNUNET_ERROR_TYPE_DEBUG, " Client %s is destination.\n", GML_2s (c)); GML_client_delete_channel (c, ch, ch->lid_dest); ch->dest = NULL; } if (GNUNET_YES == is_root && c == ch->root) { LOG (GNUNET_ERROR_TYPE_DEBUG, " Client %s is owner.\n", GML_2s (c)); GML_client_delete_channel (c, ch, ch->lid_root); ch->root = NULL; } t = ch->t; send_destroy (ch, GNUNET_NO); if (0 == ch->pending_messages) { GMCH_destroy (ch); GMT_destroy_if_empty (t); } } /** * Handle a channel create requested by a client. * * Create the channel and the tunnel in case this was the first0 channel. * * @param c Client that requested the creation (will be the root). * @param msg Create Channel message. * * @return GNUNET_OK if everything went fine, GNUNET_SYSERR otherwise. */ int GMCH_handle_local_create (struct MeshClient *c, struct GNUNET_MESH_ChannelMessage *msg) { struct MeshChannel *ch; struct MeshTunnel3 *t; struct MeshPeer *peer; MESH_ChannelNumber chid; LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s:%u\n", GNUNET_i2s (&msg->peer), ntohl (msg->port)); chid = ntohl (msg->channel_id); /* Sanity check for duplicate channel IDs */ if (NULL != GML_channel_get (c, chid)) { GNUNET_break (0); return GNUNET_SYSERR; } peer = GMP_get (&msg->peer); GMP_add_tunnel (peer); t = GMP_get_tunnel (peer); if (GMP_get_short_id (peer) == myid) { GMT_change_cstate (t, MESH_TUNNEL3_READY); } else { /* FIXME change to a tunnel API, eliminate ch <-> peer connection */ GMP_connect (peer); } /* Create channel */ ch = channel_new (t, c, chid); if (NULL == ch) { GNUNET_break (0); return GNUNET_SYSERR; } ch->port = ntohl (msg->port); channel_set_options (ch, ntohl (msg->opt)); /* In unreliable channels, we'll use the DLL to buffer BCK data */ ch->root_rel = GNUNET_new (struct MeshChannelReliability); ch->root_rel->ch = ch; ch->root_rel->retry_timer = MESH_RETRANSMIT_TIME; ch->root_rel->expected_delay.rel_value_us = 0; LOG (GNUNET_ERROR_TYPE_DEBUG, "CREATED CHANNEL %s\n", GMCH_2s (ch)); send_create (ch); return GNUNET_OK; } /** * Handler for mesh network payload traffic. * * @param ch Channel for the message. * @param msg Unencryted data message. * @param fwd Is this message fwd? This only is meaningful in loopback channels. * #GNUNET_YES if message is FWD on the respective channel (loopback) * #GNUNET_NO if message is BCK on the respective channel (loopback) * #GNUNET_SYSERR if message on a one-ended channel (remote) */ void GMCH_handle_data (struct MeshChannel *ch, const struct GNUNET_MESH_Data *msg, int fwd) { struct MeshChannelReliability *rel; struct MeshClient *c; uint32_t mid; /* If this is a remote (non-loopback) channel, find 'fwd'. */ if (GNUNET_SYSERR == fwd) { if (is_loopback (ch)) { /* It is a loopback channel after all... */ GNUNET_break (0); return; } fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO; } /* Initialize FWD/BCK data */ c = fwd ? ch->dest : ch->root; rel = fwd ? ch->dest_rel : ch->root_rel; if (NULL == c) { GNUNET_break (GNUNET_NO != ch->destroy); return; } if (MESH_CHANNEL_READY != ch->state) { if (GNUNET_NO == fwd) { /* If we are the root, this means the other peer has sent traffic before * receiving our ACK. Even if the SYNACK goes missing, no traffic should * be sent before the ACK. */ GNUNET_break_op (0); return; } /* If we are the dest, this means that the SYNACK got to the root but * the ACK went missing. Treat this as an ACK. */ channel_confirm (ch, GNUNET_NO); } GNUNET_STATISTICS_update (stats, "# data received", 1, GNUNET_NO); mid = ntohl (msg->mid); LOG (GNUNET_ERROR_TYPE_DEBUG, "!! got mid %u\n", mid); if (GNUNET_NO == ch->reliable || ( !GM_is_pid_bigger (rel->mid_recv, mid) && GM_is_pid_bigger (rel->mid_recv + 64, mid) ) ) { LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! RECV %u (%u)\n", mid, ntohs (msg->header.size)); if (GNUNET_YES == ch->reliable) { /* Is this the exact next expected messasge? */ if (mid == rel->mid_recv) { LOG (GNUNET_ERROR_TYPE_DEBUG, "as expected\n"); rel->mid_recv++; send_client_data (ch, msg, fwd); } else { LOG (GNUNET_ERROR_TYPE_DEBUG, "save for later\n"); add_buffered_data (msg, rel); } } else { /* Tunnel is unreliable: send to clients directly */ /* FIXME: accept Out Of Order traffic */ rel->mid_recv = mid + 1; send_client_data (ch, msg, fwd); } } else { GNUNET_break_op (GM_is_pid_bigger (rel->mid_recv, mid)); LOG (GNUNET_ERROR_TYPE_WARNING, "MID %u not expected (%u - %u), dropping!\n", mid, rel->mid_recv, rel->mid_recv + 63); } GMCH_send_data_ack (ch, fwd); } /** * Handler for mesh network traffic end-to-end ACKs. * * @param ch Channel on which we got this message. * @param msg Data message. * @param fwd Is this message fwd? This only is meaningful in loopback channels. * #GNUNET_YES if message is FWD on the respective channel (loopback) * #GNUNET_NO if message is BCK on the respective channel (loopback) * #GNUNET_SYSERR if message on a one-ended channel (remote) */ void GMCH_handle_data_ack (struct MeshChannel *ch, const struct GNUNET_MESH_DataACK *msg, int fwd) { struct MeshChannelReliability *rel; struct MeshReliableMessage *copy; struct MeshReliableMessage *next; uint32_t ack; int work; /* If this is a remote (non-loopback) channel, find 'fwd'. */ if (GNUNET_SYSERR == fwd) { if (is_loopback (ch)) { /* It is a loopback channel after all... */ GNUNET_break (0); return; } /* Inverted: if message came 'FWD' is a 'BCK ACK'. */ fwd = (NULL != ch->dest) ? GNUNET_NO : GNUNET_YES; } ack = ntohl (msg->mid); LOG (GNUNET_ERROR_TYPE_INFO, "<= %s ACK %u\n", GM_f2s (fwd), ack); if (GNUNET_YES == fwd) { rel = ch->root_rel; } else { rel = ch->dest_rel; } if (NULL == rel) { GNUNET_break_op (GNUNET_NO != ch->destroy); return; } /* Free ACK'd copies: no need to retransmit those anymore FIXME refactor */ for (work = GNUNET_NO, copy = rel->head_sent; copy != NULL; copy = next) { if (GM_is_pid_bigger (copy->mid, ack)) { LOG (GNUNET_ERROR_TYPE_DEBUG, " head %u, out!\n", copy->mid); channel_rel_free_sent (rel, msg); break; } work = GNUNET_YES; LOG (GNUNET_ERROR_TYPE_DEBUG, " id %u\n", copy->mid); next = copy->next; if (GNUNET_YES == rel_message_free (copy, GNUNET_YES)) return; } /* ACK client if needed and possible */ GMCH_allow_client (ch, fwd); /* If some message was free'd, update the retransmission delay */ if (GNUNET_YES == work) { if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task) { GNUNET_SCHEDULER_cancel (rel->retry_task); rel->retry_task = GNUNET_SCHEDULER_NO_TASK; if (NULL != rel->head_sent && NULL == rel->head_sent->chq) { struct GNUNET_TIME_Absolute new_target; struct GNUNET_TIME_Relative delay; delay = GNUNET_TIME_relative_multiply (rel->retry_timer, MESH_RETRANSMIT_MARGIN); new_target = GNUNET_TIME_absolute_add (rel->head_sent->timestamp, delay); delay = GNUNET_TIME_absolute_get_remaining (new_target); rel->retry_task = GNUNET_SCHEDULER_add_delayed (delay, &channel_retransmit_message, rel); } } else { /* Work was done but no task was pending? Shouldn't happen! */ GNUNET_break (0); } } } /** * Handler for channel create messages. * * Does not have fwd parameter because it's always 'FWD': channel is incoming. * * @param t Tunnel this channel will be in. * @param msg Channel crate message. */ struct MeshChannel * GMCH_handle_create (struct MeshTunnel3 *t, const struct GNUNET_MESH_ChannelCreate *msg) { MESH_ChannelNumber chid; struct MeshChannel *ch; struct MeshClient *c; int new_channel; int reaction; reaction = GNUNET_NO; chid = ntohl (msg->chid); ch = GMT_get_channel (t, chid); if (NULL == ch) { /* Create channel */ ch = channel_new (t, NULL, 0); ch->gid = chid; channel_set_options (ch, ntohl (msg->opt)); new_channel = GNUNET_YES; } else { new_channel = GNUNET_NO; } if (GNUNET_YES == new_channel || GMT_is_loopback (t)) { /* Find a destination client */ ch->port = ntohl (msg->port); LOG (GNUNET_ERROR_TYPE_DEBUG, " port %u\n", ch->port); c = GML_client_get_by_port (ch->port); if (NULL == c) { LOG (GNUNET_ERROR_TYPE_DEBUG, " no client has port registered\n"); if (is_loopback (ch)) { LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback: destroy on handler\n"); send_nack (ch); } else { LOG (GNUNET_ERROR_TYPE_DEBUG, " not loopback: destroy now\n"); send_nack (ch); GMCH_destroy (ch); } return NULL; } else { LOG (GNUNET_ERROR_TYPE_DEBUG, " client %p has port registered\n", c); } add_destination (ch, c); if (GNUNET_YES == ch->reliable) LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Reliable\n"); else LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Not Reliable\n"); send_client_create (ch); ch->state = MESH_CHANNEL_SENT; } else { LOG (GNUNET_ERROR_TYPE_DEBUG, " duplicate create channel\n"); reaction = GNUNET_YES; if (GNUNET_SCHEDULER_NO_TASK != ch->dest_rel->retry_task) { LOG (GNUNET_ERROR_TYPE_DEBUG, " clearing retry task\n"); /* we were waiting to re-send our 'SYNACK', wait no more! */ GNUNET_SCHEDULER_cancel (ch->dest_rel->retry_task); ch->dest_rel->retry_task = GNUNET_SCHEDULER_NO_TASK; } } send_ack (ch, GNUNET_YES, reaction); return ch; } /** * Handler for channel NACK messages. * * NACK messages always go dest -> root, no need for 'fwd' or 'msg' parameter. * * @param ch Channel. */ void GMCH_handle_nack (struct MeshChannel *ch) { send_client_nack (ch); GMCH_destroy (ch); } /** * Handler for channel ack messages. * * @param ch Channel. * @param msg Message. * @param fwd Is this message fwd? This only is meaningful in loopback channels. * #GNUNET_YES if message is FWD on the respective channel (loopback) * #GNUNET_NO if message is BCK on the respective channel (loopback) * #GNUNET_SYSERR if message on a one-ended channel (remote) */ void GMCH_handle_ack (struct MeshChannel *ch, const struct GNUNET_MESH_ChannelManage *msg, int fwd) { /* If this is a remote (non-loopback) channel, find 'fwd'. */ if (GNUNET_SYSERR == fwd) { if (is_loopback (ch)) { /* It is a loopback channel after all... */ GNUNET_break (0); return; } fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO; } channel_confirm (ch, !fwd); } /** * Handler for channel destroy messages. * * @param ch Channel to be destroyed of. * @param msg Message. * @param fwd Is this message fwd? This only is meaningful in loopback channels. * #GNUNET_YES if message is FWD on the respective channel (loopback) * #GNUNET_NO if message is BCK on the respective channel (loopback) * #GNUNET_SYSERR if message on a one-ended channel (remote) */ void GMCH_handle_destroy (struct MeshChannel *ch, const struct GNUNET_MESH_ChannelManage *msg, int fwd) { struct MeshTunnel3 *t; /* If this is a remote (non-loopback) channel, find 'fwd'. */ if (GNUNET_SYSERR == fwd) { if (is_loopback (ch)) { /* It is a loopback channel after all... */ GNUNET_break (0); return; } fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO; } GMCH_debug (ch); if ( (fwd && NULL == ch->dest) || (!fwd && NULL == ch->root) ) { /* Not for us (don't destroy twice a half-open loopback channel) */ return; } t = ch->t; send_destroy (ch, GNUNET_YES); GMCH_destroy (ch); GMT_destroy_if_empty (t); } /** * Sends an already built message on a channel. * * If the channel is on a loopback tunnel, notifies the appropriate destination * client locally. * * On a normal channel passes the message to the tunnel for encryption and * sending on a connection. * * This function DOES NOT save the message for retransmission. * * @param message Message to send. Function makes a copy of it. * @param ch Channel on which this message is transmitted. * @param fwd Is this a fwd message? * @param existing_copy This is a retransmission, don't save a copy. */ void GMCH_send_prebuilt_message (const struct GNUNET_MessageHeader *message, struct MeshChannel *ch, int fwd, void *existing_copy) { struct MeshChannelQueue *chq; uint16_t type; type = ntohs (message->type); LOG (GNUNET_ERROR_TYPE_INFO, "=> %s %s on channel %s\n", GM_m2s (type), GM_f2s (fwd), GMCH_2s (ch)); if (GMT_is_loopback (ch->t)) { handle_loopback (ch, message, fwd); return; } switch (type) { struct GNUNET_MESH_Data *payload; case GNUNET_MESSAGE_TYPE_MESH_DATA: payload = (struct GNUNET_MESH_Data *) message; LOG (GNUNET_ERROR_TYPE_INFO, "=> %s %u\n", GM_m2s (type), ntohl (payload->mid)); if (GNUNET_YES == ch->reliable) { chq = GNUNET_new (struct MeshChannelQueue); chq->type = type; if (NULL == existing_copy) chq->copy = channel_save_copy (ch, message, fwd); else { chq->copy = (struct MeshReliableMessage *) existing_copy; if (NULL != chq->copy->chq) { /* Last retransmission was queued but not yet sent! * This retransmission was scheduled by a ch_message_sent which * followed a very fast RTT, so the tiny delay made the * retransmission function to execute before the previous * retransmitted message even had a chance to leave the peer. * Cancel this message and wait until the pending * retransmission leaves the peer and ch_message_sent starts * the timer for the next one. */ GNUNET_free (chq); LOG (GNUNET_ERROR_TYPE_DEBUG, " exisitng copy not yet transmitted!\n"); return; } LOG (GNUNET_ERROR_TYPE_DEBUG, " using existing copy: %p {r:%p q:%p t:%u}\n", existing_copy, chq->copy->rel, chq->copy->chq, chq->copy->type); } LOG (GNUNET_ERROR_TYPE_DEBUG, " new chq: %p\n", chq); chq->copy->chq = chq; chq->tq = GMT_send_prebuilt_message (message, ch->t, NULL, NULL != existing_copy, &ch_message_sent, chq); /* q itself is stored in copy */ GNUNET_assert (NULL != chq->tq || GNUNET_NO != ch->destroy); } else { fire_and_forget (message, ch, GNUNET_NO); } break; case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK: if (GNUNET_YES == fwd || NULL != existing_copy) { /* BCK ACK (going FWD) is just a response for a SYNACK, don't keep*/ fire_and_forget (message, ch, GNUNET_YES); return; } /* fall-trough */ case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK: case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE: chq = GNUNET_new (struct MeshChannelQueue); chq->type = type; chq->rel = fwd ? ch->root_rel : ch->dest_rel; if (NULL != chq->rel->uniq) { if (NULL != chq->rel->uniq->tq) { GMT_cancel (chq->rel->uniq->tq); /* ch_message_sent is called, freeing and NULLing uniq */ } else { GNUNET_break (0); GNUNET_free (chq->rel->uniq); } } chq->tq = GMT_send_prebuilt_message (message, ch->t, NULL, GNUNET_YES, &ch_message_sent, chq); if (NULL == chq->tq) { GNUNET_break (0); GNUNET_free (chq); chq = NULL; return; } chq->rel->uniq = chq; break; case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY: case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_NACK: fire_and_forget (message, ch, GNUNET_YES); break; default: GNUNET_break (0); LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s unknown!\n", GM_m2s (type)); fire_and_forget (message, ch, GNUNET_YES); } } /** * Get the static string for identification of the channel. * * @param ch Channel. * * @return Static string with the channel IDs. */ const char * GMCH_2s (const struct MeshChannel *ch) { static char buf[64]; if (NULL == ch) return "(NULL Channel)"; sprintf (buf, "%s:%u gid:%X (%X / %X)", GMT_2s (ch->t), ch->port, ch->gid, ch->lid_root, ch->lid_dest); return buf; }