/* This file is part of GNUnet. (C) 2009, 2010 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 transport/transport_api.c * @brief library to access the low-level P2P IO service * @author Christian Grothoff */ #include "platform.h" #include "gnunet_bandwidth_lib.h" #include "gnunet_client_lib.h" #include "gnunet_constants.h" #include "gnunet_container_lib.h" #include "gnunet_arm_service.h" #include "gnunet_hello_lib.h" #include "gnunet_protocols.h" #include "gnunet_server_lib.h" #include "gnunet_time_lib.h" #include "gnunet_transport_service.h" #include "transport.h" /** * After how long do we give up on transmitting a HELLO * to the service? */ #define OFFER_HELLO_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 30) /** * After how long do we automatically retry an unsuccessful * CONNECT request? */ #define CONNECT_RETRY_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 750) /** * How long should ARM wait when starting up the * transport service before reporting back? */ #define START_SERVICE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5) /** * How long should ARM wait when stopping the * transport service before reporting back? */ #define STOP_SERVICE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5) /** * What stage are we in for transmission processing? */ enum TransmitStage { /** * No active message. */ TS_NEW = 0, /** * Message in local queue, not given to service. */ TS_QUEUED = 1, /** * Message given to service, not confirmed (no SEND_OK). */ TS_TRANSMITTED = 2, /** * One message was given to service and before it was confirmed, * another one was already queued (waiting for SEND_OK to pass on * to service). */ TS_TRANSMITTED_QUEUED = 3 }; /** * Handle for a transmission-ready request. */ struct GNUNET_TRANSPORT_TransmitHandle { /** * Neighbour for this handle, NULL for control-traffic. */ struct NeighbourList *neighbour; /** * Function to call when notify_size bytes are available * for transmission. */ GNUNET_CONNECTION_TransmitReadyNotify notify; /** * Closure for notify. */ void *notify_cls; /** * transmit_ready task Id. The task is used to introduce the * artificial delay that may be required to maintain the bandwidth * limits. Later, this will be the ID of the "transmit_timeout" * task which is used to signal a timeout if the transmission could * not be done in a timely fashion. */ GNUNET_SCHEDULER_TaskIdentifier notify_delay_task; /** * Timeout for this request. */ struct GNUNET_TIME_Absolute timeout; /** * How many bytes is our notify callback waiting for? */ size_t notify_size; /** * How important is this message? */ unsigned int priority; }; /** * Handle for a control message queue entry. */ struct ControlMessage { /** * This is a doubly-linked list. */ struct ControlMessage *next; /** * This is a doubly-linked list. */ struct ControlMessage *prev; /** * Overall transport handle. */ struct GNUNET_TRANSPORT_Handle *h; /** * Function to call when notify_size bytes are available * for transmission. */ GNUNET_CONNECTION_TransmitReadyNotify notify; /** * Closure for notify. */ void *notify_cls; /** * transmit_ready task Id. The task is used to introduce the * artificial delay that may be required to maintain the bandwidth * limits. Later, this will be the ID of the "transmit_timeout" * task which is used to signal a timeout if the transmission could * not be done in a timely fashion. */ GNUNET_SCHEDULER_TaskIdentifier notify_delay_task; /** * How many bytes is our notify callback waiting for? */ size_t notify_size; }; /** * Entry in linked list of all of our current neighbours. */ struct NeighbourList { /** * This is a linked list. */ struct NeighbourList *next; /** * Overall transport handle. */ struct GNUNET_TRANSPORT_Handle *h; /** * Active transmit handle; available if 'transmit_forbidden' * is GNUNET_NO. */ struct GNUNET_TRANSPORT_TransmitHandle transmit_handle; /** * Identity of this neighbour. */ struct GNUNET_PeerIdentity id; /** * Outbound bandwidh tracker. */ struct GNUNET_BANDWIDTH_Tracker out_tracker; /** * Set to GNUNET_NO if we are currently allowed to accept a * message to the transport service for this peer, GNUNET_YES * if we have one and are waiting for transmission, GNUNET_SYSERR * if we are waiting for confirmation AND have already accepted * yet another message. */ enum TransmitStage transmit_stage; /** * Have we received a notification that this peer is connected * to us right now? */ int is_connected; }; /** * Linked list of requests from clients for our HELLO that were * deferred. */ struct HelloWaitList { /** * This is a linked list. */ struct HelloWaitList *next; /** * Reference back to our transport handle. */ struct GNUNET_TRANSPORT_Handle *handle; /** * Callback to call once we got our HELLO. */ GNUNET_TRANSPORT_HelloUpdateCallback rec; /** * Closure for rec. */ void *rec_cls; }; /** * Handle for the transport service (includes all of the * state for the transport service). */ struct GNUNET_TRANSPORT_Handle { /** * Closure for the callbacks. */ void *cls; /** * Function to call for received data. */ GNUNET_TRANSPORT_ReceiveCallback rec; /** * function to call on connect events */ GNUNET_TRANSPORT_NotifyConnect nc_cb; /** * function to call on disconnect events */ GNUNET_TRANSPORT_NotifyDisconnect nd_cb; /** * Head of DLL of control messages. */ struct ControlMessage *control_head; /** * Tail of DLL of control messages. */ struct ControlMessage *control_tail; /** * The current HELLO message for this peer. Updated * whenever transports change their addresses. */ struct GNUNET_HELLO_Message *my_hello; /** * My client connection to the transport service. */ struct GNUNET_CLIENT_Connection *client; /** * Handle to our registration with the client for notification. */ struct GNUNET_CLIENT_TransmitHandle *network_handle; /** * Linked list of pending requests for our HELLO. */ struct HelloWaitList *hwl_head; /** * My scheduler. */ struct GNUNET_SCHEDULER_Handle *sched; /** * My configuration. */ const struct GNUNET_CONFIGURATION_Handle *cfg; /** * Linked list of the current neighbours of this peer. */ struct NeighbourList *neighbours; /** * ID of the task trying to reconnect to the service. */ GNUNET_SCHEDULER_TaskIdentifier reconnect_task; /** * ID of the task trying to trigger transmission for a peer * while maintaining bandwidth quotas. */ GNUNET_SCHEDULER_TaskIdentifier quota_task; /** * Delay until we try to reconnect. */ struct GNUNET_TIME_Relative reconnect_delay; /** * Set once we are in the process of disconnecting from the * service. */ int in_disconnect; }; // FIXME: replace with hash map! /** * Get the neighbour list entry for the given peer * * @param h our context * @param peer peer to look up * @return NULL if no such peer entry exists */ static struct NeighbourList * neighbour_find (struct GNUNET_TRANSPORT_Handle *h, const struct GNUNET_PeerIdentity *peer) { struct NeighbourList *pos; pos = h->neighbours; while ((pos != NULL) && (0 != memcmp (peer, &pos->id, sizeof (struct GNUNET_PeerIdentity)))) pos = pos->next; return pos; } /** * Schedule the task to send one message, either from the control * list or the peer message queues to the service. */ static void schedule_transmission (struct GNUNET_TRANSPORT_Handle *h); /** * Function called by the scheduler when the timeout for bandwidth * availablility for the target neighbour is reached. * * @param cls the 'struct GNUNET_TRANSPORT_Handle*' * @param tc scheduler context */ static void quota_transmit_ready (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct GNUNET_TRANSPORT_Handle *h = cls; h->quota_task = GNUNET_SCHEDULER_NO_TASK; schedule_transmission (h); } /** * Figure out which transmission to a peer can be done right now. * If none can, schedule a task to call 'schedule_transmission' * whenever a peer transmission can be done in the future and * return NULL. Otherwise return the next transmission to be * performed. * * @param h handle to transport * @return NULL to wait longer before doing any peer transmissions */ static struct GNUNET_TRANSPORT_TransmitHandle * schedule_peer_transmission (struct GNUNET_TRANSPORT_Handle *h) { struct GNUNET_TRANSPORT_TransmitHandle *ret; struct GNUNET_TRANSPORT_TransmitHandle *th; struct NeighbourList *n; struct NeighbourList *next; struct GNUNET_TIME_Relative retry_time; struct GNUNET_TIME_Relative duration; if (h->quota_task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel (h->sched, h->quota_task); h->quota_task = GNUNET_SCHEDULER_NO_TASK; } retry_time = GNUNET_TIME_UNIT_FOREVER_REL; ret = NULL; next = h->neighbours; while (NULL != (n = next)) { next = n->next; if (n->transmit_stage != TS_QUEUED) continue; /* not eligible */ th = &n->transmit_handle; GNUNET_break (n == th->neighbour); /* check outgoing quota */ duration = GNUNET_BANDWIDTH_tracker_get_delay (&n->out_tracker, th->notify_size - sizeof (struct OutboundMessage)); if (th->timeout.value < duration.value) { /* signal timeout! */ #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Would need %llu ms before bandwidth is available for delivery to `%4s', that is too long. Signaling timeout.\n", duration.value, GNUNET_i2s (&n->id)); #endif if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task); th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK; } n->transmit_stage = TS_NEW; if (NULL != th->notify) GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL)); continue; } if (duration.value > 0) { #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Need more bandwidth (%u b/s allowed, %u b needed), delaying delivery to `%4s' by %llu ms\n", (unsigned int) n->out_tracker.available_bytes_per_s__, (unsigned int) th->notify_size - sizeof (struct OutboundMessage), GNUNET_i2s (&n->id), duration.value); #endif retry_time = GNUNET_TIME_relative_min (retry_time, duration); continue; } #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Have %u bytes of bandwidth available for transmission to `%4s' right now\n", th->notify_size - sizeof (struct OutboundMessage), GNUNET_i2s (&n->id)); #endif if ( (ret == NULL) || (ret->priority < th->priority) ) ret = th; } if (ret == NULL) h->quota_task = GNUNET_SCHEDULER_add_delayed (h->sched, retry_time, "a_transmit_ready, h); return ret; } /** * Transmit message(s) to service. * * @param cls handle to transport * @param size number of bytes available in buf * @param buf where to copy the message * @return number of bytes copied to buf */ static size_t transport_notify_ready (void *cls, size_t size, void *buf) { struct GNUNET_TRANSPORT_Handle *h = cls; struct ControlMessage *cm; struct GNUNET_TRANSPORT_TransmitHandle *th; struct NeighbourList *n; struct OutboundMessage obm; size_t ret; size_t mret; size_t nret; char *cbuf; h->network_handle = NULL; if (buf == NULL) { schedule_transmission (h); return 0; } #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Ready to transmit %u bytes to transport service\n", size); #endif cbuf = buf; ret = 0; while ( (NULL != (cm = h->control_head)) && (cm->notify_size <= size) ) { if (cm->notify_delay_task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel (h->sched, cm->notify_delay_task); cm->notify_delay_task = GNUNET_SCHEDULER_NO_TASK; } GNUNET_CONTAINER_DLL_remove (h->control_head, h->control_tail, cm); nret = cm->notify (cm->notify_cls, size, &cbuf[ret]); #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Added %u bytes of control message at %u\n", nret, ret); #endif GNUNET_free (cm); ret += nret; size -= nret; } while ( (NULL != (th = schedule_peer_transmission (h))) && (th->notify_size <= size) ) { if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task); th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK; } n = th->neighbour; switch (n->transmit_stage) { case TS_NEW: GNUNET_break (0); break; case TS_QUEUED: n->transmit_stage = TS_TRANSMITTED; break; case TS_TRANSMITTED: GNUNET_break (0); break; case TS_TRANSMITTED_QUEUED: GNUNET_break (0); break; default: GNUNET_break (0); } GNUNET_assert (size >= sizeof (struct OutboundMessage)); mret = th->notify (th->notify_cls, size - sizeof (struct OutboundMessage), &cbuf[ret + sizeof (struct OutboundMessage)]); GNUNET_assert (mret <= size - sizeof (struct OutboundMessage)); #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Message of %u bytes with timeout %llums constructed for `%4s'\n", (unsigned int) mret, (unsigned long long) GNUNET_TIME_absolute_get_remaining (th->timeout).value, GNUNET_i2s (&n->id)); #endif if (mret != 0) { GNUNET_assert (mret + sizeof (struct OutboundMessage) < GNUNET_SERVER_MAX_MESSAGE_SIZE); obm.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SEND); obm.header.size = htons (mret + sizeof (struct OutboundMessage)); obm.priority = htonl (th->priority); obm.timeout = GNUNET_TIME_relative_hton (GNUNET_TIME_absolute_get_remaining (th->timeout)); obm.peer = n->id; memcpy (&cbuf[ret], &obm, sizeof (struct OutboundMessage)); ret += (mret + sizeof (struct OutboundMessage)); size -= (mret + sizeof (struct OutboundMessage)); GNUNET_BANDWIDTH_tracker_consume (&n->out_tracker, mret); } else { switch (n->transmit_stage) { case TS_NEW: GNUNET_break (0); break; case TS_QUEUED: GNUNET_break (0); break; case TS_TRANSMITTED: n->transmit_stage = TS_NEW; break; case TS_TRANSMITTED_QUEUED: n->transmit_stage = TS_QUEUED; continue; default: GNUNET_break (0); } } } schedule_transmission (h); #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transmitting %u bytes to transport service\n", ret); #endif return ret; } /** * Schedule the task to send one message, either from the control * list or the peer message queues to the service. */ static void schedule_transmission (struct GNUNET_TRANSPORT_Handle *h) { size_t size; struct GNUNET_TIME_Relative timeout; struct GNUNET_TRANSPORT_TransmitHandle *th; if (NULL != h->network_handle) return; if (h->client == NULL) { GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Could not yet schedule transmission: we are not yet connected to the transport service!\n")); return; /* not yet connected */ } if (NULL != h->control_head) { size = h->control_head->notify_size; timeout = GNUNET_TIME_UNIT_FOREVER_REL; } else { th = schedule_peer_transmission (h); if (th == NULL) { /* no transmission ready right now */ #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Could not yet schedule transmission: none ready\n"); #endif return; } size = th->notify_size; timeout = GNUNET_TIME_absolute_get_remaining (th->timeout); } h->network_handle = GNUNET_CLIENT_notify_transmit_ready (h->client, size, timeout, GNUNET_NO, &transport_notify_ready, h); GNUNET_assert (NULL != h->network_handle); } /** * Called when our transmit request timed out before any transport * reported success connecting to the desired peer or before the * transport was ready to receive. Signal error and free * TransmitHandle. */ static void control_transmit_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct ControlMessage *th = cls; th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK; if (NULL != th->notify) th->notify (th->notify_cls, 0, NULL); GNUNET_CONTAINER_DLL_remove (th->h->control_head, th->h->control_tail, th); GNUNET_free (th); } /** * Queue control request for transmission to the transport * service. * * @param h handle to the transport service * @param size number of bytes to be transmitted * @param at_head request must be added to the head of the queue * (otherwise request will be appended) * @param timeout how long this transmission can wait (at most) * @param notify function to call to get the content * @param notify_cls closure for notify */ static void schedule_control_transmit (struct GNUNET_TRANSPORT_Handle *h, size_t size, int at_head, struct GNUNET_TIME_Relative timeout, GNUNET_CONNECTION_TransmitReadyNotify notify, void *notify_cls) { struct ControlMessage *th; #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Control transmit of %u bytes within %llums requested\n", size, (unsigned long long) timeout.value); #endif th = GNUNET_malloc (sizeof (struct ControlMessage)); th->h = h; th->notify = notify; th->notify_cls = notify_cls; th->notify_size = size; th->notify_delay_task = GNUNET_SCHEDULER_add_delayed (h->sched, timeout, &control_transmit_timeout, th); if (at_head) GNUNET_CONTAINER_DLL_insert (h->control_head, h->control_tail, th); else GNUNET_CONTAINER_DLL_insert_after (h->control_head, h->control_tail, h->control_tail, th); schedule_transmission (h); } struct SetQuotaContext { struct GNUNET_TRANSPORT_Handle *handle; struct GNUNET_PeerIdentity target; GNUNET_SCHEDULER_Task cont; void *cont_cls; struct GNUNET_TIME_Absolute timeout; struct GNUNET_BANDWIDTH_Value32NBO quota_in; }; /** * Send SET_QUOTA message to the service. * * @param cls the 'struct SetQuotaContext' * @param size number of bytes available in buf * @param buf where to copy the message * @return number of bytes copied to buf */ static size_t send_set_quota (void *cls, size_t size, void *buf) { struct SetQuotaContext *sqc = cls; struct QuotaSetMessage *msg; if (buf == NULL) { GNUNET_SCHEDULER_add_continuation (sqc->handle->sched, sqc->cont, sqc->cont_cls, GNUNET_SCHEDULER_REASON_TIMEOUT); GNUNET_free (sqc); return 0; } #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transmitting `%s' request with respect to `%4s'.\n", "SET_QUOTA", GNUNET_i2s (&sqc->target)); #endif GNUNET_assert (size >= sizeof (struct QuotaSetMessage)); msg = buf; msg->header.size = htons (sizeof (struct QuotaSetMessage)); msg->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SET_QUOTA); msg->quota = sqc->quota_in; memcpy (&msg->peer, &sqc->target, sizeof (struct GNUNET_PeerIdentity)); if (sqc->cont != NULL) GNUNET_SCHEDULER_add_continuation (sqc->handle->sched, sqc->cont, sqc->cont_cls, GNUNET_SCHEDULER_REASON_PREREQ_DONE); GNUNET_free (sqc); return sizeof (struct QuotaSetMessage); } /** * Set the share of incoming bandwidth for the given * peer to the specified amount. * * @param handle connection to transport service * @param target who's bandwidth quota is being changed * @param quota_in incoming bandwidth quota in bytes per ms * @param quota_out outgoing bandwidth quota in bytes per ms * @param timeout how long to wait until signaling failure if * we can not communicate the quota change * @param cont continuation to call when done, will be called * either with reason "TIMEOUT" or with reason "PREREQ_DONE" * @param cont_cls closure for continuation */ void GNUNET_TRANSPORT_set_quota (struct GNUNET_TRANSPORT_Handle *handle, const struct GNUNET_PeerIdentity *target, struct GNUNET_BANDWIDTH_Value32NBO quota_in, struct GNUNET_BANDWIDTH_Value32NBO quota_out, struct GNUNET_TIME_Relative timeout, GNUNET_SCHEDULER_Task cont, void *cont_cls) { struct NeighbourList *n; struct SetQuotaContext *sqc; n = neighbour_find (handle, target); if (n != NULL) { #if DEBUG_TRANSPORT if (ntohl (quota_out.value__) != n->out_tracker.available_bytes_per_s__) GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Quota changed from %u to %u for peer `%s'\n", (unsigned int) n->out_tracker.available_bytes_per_s__, (unsigned int) ntohl (quota_out.value__), GNUNET_i2s (target)); else GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Quota remains at %u for peer `%s'\n", (unsigned int) n->out_tracker.available_bytes_per_s__, GNUNET_i2s (target)); #endif GNUNET_BANDWIDTH_tracker_update_quota (&n->out_tracker, quota_out); } else { #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Quota changed to %u for peer `%s', but I have no such neighbour!\n", (unsigned int) ntohl (quota_out.value__), GNUNET_i2s (target)); #endif } sqc = GNUNET_malloc (sizeof (struct SetQuotaContext)); sqc->handle = handle; sqc->target = *target; sqc->cont = cont; sqc->cont_cls = cont_cls; sqc->timeout = GNUNET_TIME_relative_to_absolute (timeout); sqc->quota_in = quota_in; schedule_control_transmit (handle, sizeof (struct QuotaSetMessage), GNUNET_NO, timeout, &send_set_quota, sqc); } /** * Obtain the HELLO message for this peer. * * @param handle connection to transport service * @param rec function to call with the HELLO, sender will be our peer * identity; message and sender will be NULL on timeout * (handshake with transport service pending/failed). * cost estimate will be 0. * @param rec_cls closure for rec */ void GNUNET_TRANSPORT_get_hello (struct GNUNET_TRANSPORT_Handle *handle, GNUNET_TRANSPORT_HelloUpdateCallback rec, void *rec_cls) { struct HelloWaitList *hwl; hwl = GNUNET_malloc (sizeof (struct HelloWaitList)); hwl->next = handle->hwl_head; handle->hwl_head = hwl; hwl->handle = handle; hwl->rec = rec; hwl->rec_cls = rec_cls; if (handle->my_hello == NULL) return; rec (rec_cls, (const struct GNUNET_MessageHeader *) handle->my_hello); } /** * Stop receiving updates about changes to our HELLO message. * * @param handle connection to transport service * @param rec function previously registered to be called with the HELLOs * @param rec_cls closure for rec */ void GNUNET_TRANSPORT_get_hello_cancel (struct GNUNET_TRANSPORT_Handle *handle, GNUNET_TRANSPORT_HelloUpdateCallback rec, void *rec_cls) { struct HelloWaitList *pos; struct HelloWaitList *prev; prev = NULL; pos = handle->hwl_head; while (pos != NULL) { if ( (pos->rec == rec) && (pos->rec_cls == rec_cls) ) break; prev = pos; pos = pos->next; } GNUNET_break (pos != NULL); if (pos == NULL) return; if (prev == NULL) handle->hwl_head = pos->next; else prev->next = pos->next; GNUNET_free (pos); } /** * Send HELLO message to the service. * * @param cls the HELLO message to send * @param size number of bytes available in buf * @param buf where to copy the message * @return number of bytes copied to buf */ static size_t send_hello (void *cls, size_t size, void *buf) { struct GNUNET_MessageHeader *hello = cls; uint16_t msize; if (buf == NULL) { #if DEBUG_TRANSPORT_TIMEOUT GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Timeout while trying to transmit `%s' request.\n", "HELLO"); #endif GNUNET_free (hello); return 0; } #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transmitting `%s' request.\n", "HELLO"); #endif msize = ntohs (hello->size); GNUNET_assert (size >= msize); memcpy (buf, hello, msize); GNUNET_free (hello); return msize; } /** * Offer the transport service the HELLO of another peer. Note that * the transport service may just ignore this message if the HELLO is * malformed or useless due to our local configuration. * * @param handle connection to transport service * @param hello the hello message */ void GNUNET_TRANSPORT_offer_hello (struct GNUNET_TRANSPORT_Handle *handle, const struct GNUNET_MessageHeader *hello) { struct GNUNET_MessageHeader *hc; uint16_t size; struct GNUNET_PeerIdentity peer; GNUNET_break (ntohs (hello->type) == GNUNET_MESSAGE_TYPE_HELLO); size = ntohs (hello->size); GNUNET_break (size >= sizeof (struct GNUNET_MessageHeader)); if (GNUNET_OK != GNUNET_HELLO_get_id ((const struct GNUNET_HELLO_Message*) hello, &peer)) { GNUNET_break (0); return; } #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Offering `%s' message of `%4s' to transport for validation.\n", "HELLO", GNUNET_i2s (&peer)); #endif hc = GNUNET_malloc (size); memcpy (hc, hello, size); schedule_control_transmit (handle, size, GNUNET_NO, OFFER_HELLO_TIMEOUT, &send_hello, hc); } /** * Transmit START message to service. * * @param cls unused * @param size number of bytes available in buf * @param buf where to copy the message * @return number of bytes copied to buf */ static size_t send_start (void *cls, size_t size, void *buf) { struct GNUNET_MessageHeader *s = buf; if (buf == NULL) { /* Can only be shutdown, just give up */ #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Shutdown while trying to transmit `%s' request.\n", "START"); #endif return 0; } #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transmitting `%s' request.\n", "START"); #endif GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader)); s->size = htons (sizeof (struct GNUNET_MessageHeader)); s->type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_START); return sizeof (struct GNUNET_MessageHeader); } /** * Free neighbour. * * @param n the entry to free */ static void neighbour_free (struct NeighbourList *n) { struct GNUNET_TRANSPORT_Handle *h; struct NeighbourList *prev; struct NeighbourList *pos; h = n->h; #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Removing neighbour `%s' from list of connected peers.\n", GNUNET_i2s (&n->id)); #endif GNUNET_break (n->is_connected == GNUNET_NO); GNUNET_break (n->transmit_stage == TS_NEW); prev = NULL; pos = h->neighbours; while (pos != n) { prev = pos; pos = pos->next; } if (prev == NULL) h->neighbours = n->next; else prev->next = n->next; GNUNET_free (n); } /** * Mark neighbour as disconnected. * * @param n the entry to mark as disconnected */ static void neighbour_disconnect (struct NeighbourList *n) { struct GNUNET_TRANSPORT_Handle *h = n->h; #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Removing neighbour `%s' from list of connected peers.\n", GNUNET_i2s (&n->id)); #endif GNUNET_break (n->is_connected == GNUNET_YES); n->is_connected = GNUNET_NO; if (h->nc_cb != NULL) h->nd_cb (h->cls, &n->id); if (n->transmit_stage == TS_NEW) neighbour_free (n); } /** * Function we use for handling incoming messages. * * @param cls closure (struct GNUNET_TRANSPORT_Handle *) * @param msg message received, NULL on timeout or fatal error */ static void demultiplexer (void *cls, const struct GNUNET_MessageHeader *msg); /** * Try again to connect to transport service. * * @param cls the handle to the transport service * @param tc scheduler context */ static void reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct GNUNET_TRANSPORT_Handle *h = cls; struct ControlMessage *pos; struct NeighbourList *n; struct NeighbourList *next; h->reconnect_task = GNUNET_SCHEDULER_NO_TASK; if ( (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0) { /* shutdown, just give up */ return; } /* Forget about all neighbours that we used to be connected to */ n = h->neighbours; while (NULL != n) { #if DEBUG_TRANSPORT_DISCONNECT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Disconnecting due to reconnect being called\n"); #endif next = n->next; if (n->is_connected) neighbour_disconnect (n); n = next; } #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connecting to transport service.\n"); #endif GNUNET_assert (h->client == NULL); h->client = GNUNET_CLIENT_connect (h->sched, "transport", h->cfg); GNUNET_assert (h->client != NULL); /* make sure we don't send "START" twice, remove existing entry from queue (if present) */ pos = h->control_head; while (pos != NULL) { if (pos->notify == &send_start) { GNUNET_CONTAINER_DLL_remove (h->control_head, h->control_tail, pos); if (GNUNET_SCHEDULER_NO_TASK != pos->notify_delay_task) { GNUNET_SCHEDULER_cancel (h->sched, pos->notify_delay_task); pos->notify_delay_task = GNUNET_SCHEDULER_NO_TASK; } GNUNET_free (pos); break; } pos = pos->next; } schedule_control_transmit (h, sizeof (struct GNUNET_MessageHeader), GNUNET_YES, GNUNET_TIME_UNIT_FOREVER_REL, &send_start, NULL); GNUNET_CLIENT_receive (h->client, &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL); } /** * Function that will schedule the job that will try * to connect us again to the client. * * @param h transport service to reconnect */ static void schedule_reconnect (struct GNUNET_TRANSPORT_Handle *h) { #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Scheduling task to reconnect to transport service in %llu ms.\n", h->reconnect_delay.value); #endif GNUNET_assert (h->client == NULL); GNUNET_assert (h->reconnect_task == GNUNET_SCHEDULER_NO_TASK); h->reconnect_task = GNUNET_SCHEDULER_add_delayed (h->sched, h->reconnect_delay, &reconnect, h); if (h->reconnect_delay.value == 0) { h->reconnect_delay = GNUNET_TIME_UNIT_MILLISECONDS; } else { h->reconnect_delay = GNUNET_TIME_relative_multiply (h->reconnect_delay, 2); h->reconnect_delay = GNUNET_TIME_relative_min (GNUNET_TIME_UNIT_SECONDS, h->reconnect_delay); } } /** * Add neighbour to our list * * @return NULL if this API is currently disconnecting from the service */ static struct NeighbourList * neighbour_add (struct GNUNET_TRANSPORT_Handle *h, const struct GNUNET_PeerIdentity *pid) { struct NeighbourList *n; if (GNUNET_YES == h->in_disconnect) return NULL; /* check for duplicates */ if (NULL != (n = neighbour_find (h, pid))) { GNUNET_break (0); return n; } #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Creating entry for neighbour `%4s'.\n", GNUNET_i2s (pid)); #endif n = GNUNET_malloc (sizeof (struct NeighbourList)); n->id = *pid; GNUNET_BANDWIDTH_tracker_init (&n->out_tracker, GNUNET_CONSTANTS_DEFAULT_BW_IN_OUT, MAX_BANDWIDTH_CARRY_S); n->next = h->neighbours; n->h = h; h->neighbours = n; return n; } /** * Connect to the transport service. Note that the connection may * complete (or fail) asynchronously. * * @param sched scheduler to use * @param cfg configuration to use * @param cls closure for the callbacks * @param rec receive function to call * @param nc function to call on connect events * @param nd function to call on disconnect events */ struct GNUNET_TRANSPORT_Handle * GNUNET_TRANSPORT_connect (struct GNUNET_SCHEDULER_Handle *sched, const struct GNUNET_CONFIGURATION_Handle *cfg, void *cls, GNUNET_TRANSPORT_ReceiveCallback rec, GNUNET_TRANSPORT_NotifyConnect nc, GNUNET_TRANSPORT_NotifyDisconnect nd) { struct GNUNET_TRANSPORT_Handle *ret; ret = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_Handle)); ret->sched = sched; ret->cfg = cfg; ret->cls = cls; ret->rec = rec; ret->nc_cb = nc; ret->nd_cb = nd; ret->reconnect_delay = GNUNET_TIME_UNIT_ZERO; schedule_reconnect (ret); return ret; } /** * Disconnect from the transport service. */ void GNUNET_TRANSPORT_disconnect (struct GNUNET_TRANSPORT_Handle *handle) { struct GNUNET_TRANSPORT_TransmitHandle *th; struct NeighbourList *n; struct HelloWaitList *hwl; struct GNUNET_CLIENT_Connection *client; struct ControlMessage *cm; #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transport disconnect called!\n"); #endif handle->in_disconnect = GNUNET_YES; while (NULL != (n = handle->neighbours)) { handle->neighbours = n->next; switch (n->transmit_stage) { case TS_NEW: case TS_TRANSMITTED: /* nothing to do */ break; case TS_QUEUED: case TS_TRANSMITTED_QUEUED: th = &n->transmit_handle; if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel (handle->sched, th->notify_delay_task); th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK; } GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL)); break; default: GNUNET_break (0); } GNUNET_free (n); } while (NULL != (hwl = handle->hwl_head)) { handle->hwl_head = hwl->next; GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _ ("Disconnect while notification for `%s' still registered.\n"), "HELLO"); if (hwl->rec != NULL) hwl->rec (hwl->rec_cls, NULL); GNUNET_free (hwl); } /* Check for still scheduled control messages, cancel delay tasks if so */ /* Added because somehow a notify_delay_task is remaining scheduled and is ever so annoying */ while ( (NULL != (cm = handle->control_head))) { #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Disconnect before control message sent!\n"); #endif if (cm->notify_delay_task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel (handle->sched, cm->notify_delay_task); cm->notify_delay_task = GNUNET_SCHEDULER_NO_TASK; } GNUNET_CONTAINER_DLL_remove (handle->control_head, handle->control_tail, cm); GNUNET_free (cm); } /* end check */ if (handle->reconnect_task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel (handle->sched, handle->reconnect_task); handle->reconnect_task = GNUNET_SCHEDULER_NO_TASK; } if (handle->quota_task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel (handle->sched, handle->quota_task); handle->quota_task = GNUNET_SCHEDULER_NO_TASK; } GNUNET_free_non_null (handle->my_hello); handle->my_hello = NULL; if (NULL != handle->network_handle) { GNUNET_CLIENT_notify_transmit_ready_cancel (handle->network_handle); handle->network_handle = NULL; } if (NULL != (client = handle->client)) { #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Disconnecting from transport service for good.\n"); #endif handle->client = NULL; GNUNET_CLIENT_disconnect (client, GNUNET_NO); } GNUNET_free (handle); } /** * Function we use for handling incoming messages. * * @param cls closure (struct GNUNET_TRANSPORT_Handle *) * @param msg message received, NULL on timeout or fatal error */ static void demultiplexer (void *cls, const struct GNUNET_MessageHeader *msg) { struct GNUNET_TRANSPORT_Handle *h = cls; const struct DisconnectInfoMessage *dim; const struct ConnectInfoMessage *cim; const struct InboundMessage *im; const struct GNUNET_MessageHeader *imm; const struct SendOkMessage *okm; struct HelloWaitList *hwl; struct HelloWaitList *next_hwl; struct NeighbourList *n; struct GNUNET_PeerIdentity me; uint16_t size; if (h->client == NULL) { /* shutdown initiated from 'GNUNET_TRANSPORT_disconnect', finish clean up work! */ GNUNET_free (h); return; } if (msg == NULL) { #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Error receiving from transport service, disconnecting temporarily.\n"); #endif if (h->network_handle != NULL) { GNUNET_CLIENT_notify_transmit_ready_cancel (h->network_handle); h->network_handle = NULL; } GNUNET_CLIENT_disconnect (h->client, GNUNET_NO); h->client = NULL; schedule_reconnect (h); return; } GNUNET_CLIENT_receive (h->client, &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL); size = ntohs (msg->size); switch (ntohs (msg->type)) { case GNUNET_MESSAGE_TYPE_HELLO: if (GNUNET_OK != GNUNET_HELLO_get_id ((const struct GNUNET_HELLO_Message *) msg, &me)) { GNUNET_break (0); break; } #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Receiving (my own) `%s' message, I am `%4s'.\n", "HELLO", GNUNET_i2s (&me)); #endif GNUNET_free_non_null (h->my_hello); h->my_hello = NULL; if (size < sizeof (struct GNUNET_MessageHeader)) { GNUNET_break (0); break; } h->my_hello = GNUNET_malloc (size); memcpy (h->my_hello, msg, size); hwl = h->hwl_head; while (NULL != hwl) { next_hwl = hwl->next; hwl->rec (hwl->rec_cls, (const struct GNUNET_MessageHeader *) h->my_hello); hwl = next_hwl; } break; case GNUNET_MESSAGE_TYPE_TRANSPORT_CONNECT: if (size != sizeof (struct ConnectInfoMessage)) { GNUNET_break (0); break; } cim = (const struct ConnectInfoMessage *) msg; #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Receiving `%s' message for `%4s'.\n", "CONNECT", GNUNET_i2s (&cim->id)); #endif n = neighbour_find (h, &cim->id); if (n == NULL) n = neighbour_add (h, &cim->id); if (n == NULL) return; GNUNET_break (n->is_connected == GNUNET_NO); n->is_connected = GNUNET_YES; if (h->nc_cb != NULL) h->nc_cb (h->cls, &n->id, GNUNET_TIME_relative_ntoh (cim->latency), ntohl (cim->distance)); break; case GNUNET_MESSAGE_TYPE_TRANSPORT_DISCONNECT: if (size != sizeof (struct DisconnectInfoMessage)) { GNUNET_break (0); break; } dim = (const struct DisconnectInfoMessage *) msg; #if DEBUG_TRANSPORT_DISCONNECT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Receiving `%s' message for `%4s'.\n", "DISCONNECT", GNUNET_i2s (&dim->peer)); #endif n = neighbour_find (h, &dim->peer); GNUNET_break (n != NULL); if (n != NULL) neighbour_disconnect (n); break; case GNUNET_MESSAGE_TYPE_TRANSPORT_SEND_OK: if (size != sizeof (struct SendOkMessage)) { GNUNET_break (0); break; } okm = (const struct SendOkMessage *) msg; #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Receiving `%s' message, transmission %s.\n", "SEND_OK", ntohl (okm->success) == GNUNET_OK ? "succeeded" : "failed"); #endif n = neighbour_find (h, &okm->peer); GNUNET_assert (n != NULL); switch (n->transmit_stage) { case TS_NEW: GNUNET_break (0); break; case TS_QUEUED: GNUNET_break (0); break; case TS_TRANSMITTED: n->transmit_stage = TS_NEW; break; case TS_TRANSMITTED_QUEUED: n->transmit_stage = TS_QUEUED; schedule_transmission (h); break; default: GNUNET_break (0); } break; case GNUNET_MESSAGE_TYPE_TRANSPORT_RECV: #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Receiving `%s' message.\n", "RECV"); #endif if (size < sizeof (struct InboundMessage) + sizeof (struct GNUNET_MessageHeader)) { GNUNET_break (0); break; } im = (const struct InboundMessage *) msg; imm = (const struct GNUNET_MessageHeader *) &im[1]; if (ntohs (imm->size) + sizeof (struct InboundMessage) != size) { GNUNET_break (0); break; } #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received message of type %u from `%4s'.\n", ntohs (imm->type), GNUNET_i2s (&im->peer)); #endif n = neighbour_find (h, &im->peer); if (n == NULL) { GNUNET_break (0); break; } if (n->is_connected != GNUNET_YES) { GNUNET_break (0); break; } if (h->rec != NULL) h->rec (h->cls, &im->peer, imm, GNUNET_TIME_relative_ntoh (im->latency), ntohl(im->distance)); break; default: GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Received unexpected message of type %u in %s:%u\n"), ntohs (msg->type), __FILE__, __LINE__); GNUNET_break (0); break; } } /** * Called when our transmit request timed out before any transport * reported success connecting to the desired peer or before the * transport was ready to receive. Signal error and free * TransmitHandle. * * @param cls the 'struct GNUNET_TRANSPORT_TransmitHandle*' that is timing out * @param tc scheduler context */ static void peer_transmit_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct GNUNET_TRANSPORT_TransmitHandle *th = cls; struct NeighbourList *n; GNUNET_CONNECTION_TransmitReadyNotify notify; void *notify_cls; th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK; n = th->neighbour; #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Triggering timeout for request to transmit to `%4s' (%d)\n", GNUNET_i2s (&n->id), n->transmit_stage); #endif notify = th->notify; notify_cls = th->notify_cls; switch (n->transmit_stage) { case TS_NEW: GNUNET_break (0); break; case TS_QUEUED: n->transmit_stage = TS_NEW; if (n->is_connected == GNUNET_NO) neighbour_free (n); break; case TS_TRANSMITTED: GNUNET_break (0); break; case TS_TRANSMITTED_QUEUED: n->transmit_stage = TS_TRANSMITTED; break; default: GNUNET_break (0); } if (NULL != notify) notify (notify_cls, 0, NULL); } /** * Check if we could queue a message of the given size for * transmission. The transport service will take both its * internal buffers and bandwidth limits imposed by the * other peer into consideration when answering this query. * * @param handle connection to transport service * @param target who should receive the message * @param size how big is the message we want to transmit? * @param priority how important is the message? * @param timeout after how long should we give up (and call * notify with buf NULL and size 0)? * @param notify function to call when we are ready to * send such a message * @param notify_cls closure for notify * @return NULL if someone else is already waiting to be notified * non-NULL if the notify callback was queued (can be used to cancel * using GNUNET_TRANSPORT_notify_transmit_ready_cancel) */ struct GNUNET_TRANSPORT_TransmitHandle * GNUNET_TRANSPORT_notify_transmit_ready (struct GNUNET_TRANSPORT_Handle *handle, const struct GNUNET_PeerIdentity *target, size_t size, unsigned int priority, struct GNUNET_TIME_Relative timeout, GNUNET_CONNECTION_TransmitReadyNotify notify, void *notify_cls) { struct GNUNET_TRANSPORT_TransmitHandle *th; struct NeighbourList *n; if (size + sizeof (struct OutboundMessage) >= GNUNET_SERVER_MAX_MESSAGE_SIZE) { #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Message size is %d, max allowed is %d.\n", size + sizeof (struct OutboundMessage), GNUNET_SERVER_MAX_MESSAGE_SIZE - 1); #endif GNUNET_break (0); return NULL; } #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Asking transport service for transmission of %u bytes to peer `%4s' within %llu ms.\n", size, GNUNET_i2s (target), (unsigned long long) timeout.value); #endif n = neighbour_find (handle, target); if (n == NULL) n = neighbour_add (handle, target); if (n == NULL) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Could not create neighbour entry for peer `%s'\n", GNUNET_i2s (target)); return NULL; } switch (n->transmit_stage) { case TS_NEW: n->transmit_stage = TS_QUEUED; break; case TS_QUEUED: GNUNET_break (0); return NULL; case TS_TRANSMITTED: n->transmit_stage = TS_TRANSMITTED_QUEUED; break; case TS_TRANSMITTED_QUEUED: GNUNET_break (0); return NULL; default: GNUNET_break (0); return NULL; } th = &n->transmit_handle; th->neighbour = n; th->notify = notify; th->notify_cls = notify_cls; th->timeout = GNUNET_TIME_relative_to_absolute (timeout); th->notify_size = size + sizeof (struct OutboundMessage); th->priority = priority; th->notify_delay_task = GNUNET_SCHEDULER_add_delayed (handle->sched, timeout, &peer_transmit_timeout, th); schedule_transmission (handle); return th; } /** * Cancel the specified transmission-ready notification. */ void GNUNET_TRANSPORT_notify_transmit_ready_cancel (struct GNUNET_TRANSPORT_TransmitHandle *th) { struct NeighbourList *n; n = th->neighbour; #if DEBUG_TRANSPORT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transmission request of %u bytes to `%4s' was cancelled.\n", th->notify_size - sizeof (struct OutboundMessage), GNUNET_i2s (&n->id)); #endif switch (n->transmit_stage) { case TS_NEW: GNUNET_break (0); break; case TS_QUEUED: n->transmit_stage = TS_NEW; if (n->is_connected == GNUNET_NO) neighbour_free (n); break; case TS_TRANSMITTED: GNUNET_break (0); break; case TS_TRANSMITTED_QUEUED: n->transmit_stage = TS_TRANSMITTED; break; default: GNUNET_break (0); } } /* end of transport_api.c */