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Diffstat (limited to 'src/transport/transport_api.c')
| -rw-r--r-- | src/transport/transport_api.c | 1337 |
1 files changed, 1337 insertions, 0 deletions
diff --git a/src/transport/transport_api.c b/src/transport/transport_api.c new file mode 100644 index 0000000..9ff5cec --- /dev/null +++ b/src/transport/transport_api.c @@ -0,0 +1,1337 @@ +/* + This file is part of GNUnet. + (C) 2009, 2010, 2011 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 + * + * TODO: + * - adjust testcases to use new 'try connect' style (should be easy, breaks API compatibility!) + * - adjust core service to use new 'try connect' style (should be MUCH nicer there as well!) + * - test test test + */ +#include "platform.h" +#include "gnunet_constants.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" + +#define LOG(kind,...) GNUNET_log_from (kind, "transport-api",__VA_ARGS__) + +/** + * How large to start with for the hashmap of neighbours. + */ +#define STARTING_NEIGHBOURS_SIZE 16 + +/** + * Handle for a message that should be transmitted to the service. + * Used for both control messages and normal messages. + */ +struct GNUNET_TRANSPORT_TransmitHandle +{ + + /** + * We keep all requests in a DLL. + */ + struct GNUNET_TRANSPORT_TransmitHandle *next; + + /** + * We keep all requests in a DLL. + */ + struct GNUNET_TRANSPORT_TransmitHandle *prev; + + /** + * Neighbour for this handle, NULL for control messages. + */ + struct Neighbour *neighbour; + + /** + * Function to call when notify_size bytes are available + * for transmission. + */ + GNUNET_CONNECTION_TransmitReadyNotify notify; + + /** + * Closure for notify. + */ + void *notify_cls; + + /** + * Timeout for this request, 0 for control messages. + */ + struct GNUNET_TIME_Absolute timeout; + + /** + * Task to trigger request timeout if the request is stalled due to + * congestion. + */ + GNUNET_SCHEDULER_TaskIdentifier timeout_task; + + /** + * How many bytes is our notify callback waiting for? + */ + size_t notify_size; + + /** + * How important is this message? Not used for control messages. + */ + uint32_t priority; + +}; + + +/** + * Entry in hash table of all of our current neighbours. + */ +struct Neighbour +{ + /** + * Overall transport handle. + */ + struct GNUNET_TRANSPORT_Handle *h; + + /** + * Active transmit handle or NULL. + */ + struct GNUNET_TRANSPORT_TransmitHandle *th; + + /** + * Identity of this neighbour. + */ + struct GNUNET_PeerIdentity id; + + /** + * Outbound bandwidh tracker. + */ + struct GNUNET_BANDWIDTH_Tracker out_tracker; + + /** + * Entry in our readyness heap (which is sorted by 'next_ready' + * value). NULL if there is no pending transmission request for + * this neighbour or if we're waiting for 'is_ready' to become + * true AFTER the 'out_tracker' suggested that this peer's quota + * has been satisfied (so once 'is_ready' goes to GNUNET_YES, + * we should immediately go back into the heap). + */ + struct GNUNET_CONTAINER_HeapNode *hn; + + /** + * Is this peer currently ready to receive a message? + */ + int is_ready; + +}; + + +/** + * Linked list of functions to call whenever our HELLO is updated. + */ +struct GNUNET_TRANSPORT_GetHelloHandle +{ + + /** + * This is a doubly linked list. + */ + struct GNUNET_TRANSPORT_GetHelloHandle *next; + + /** + * This is a doubly linked list. + */ + struct GNUNET_TRANSPORT_GetHelloHandle *prev; + + /** + * 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 GNUNET_TRANSPORT_TransmitHandle *control_head; + + /** + * Tail of DLL of control messages. + */ + struct GNUNET_TRANSPORT_TransmitHandle *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 *cth; + + /** + * Linked list of pending requests for our HELLO. + */ + struct GNUNET_TRANSPORT_GetHelloHandle *hwl_head; + + /** + * Linked list of pending requests for our HELLO. + */ + struct GNUNET_TRANSPORT_GetHelloHandle *hwl_tail; + + /** + * My configuration. + */ + const struct GNUNET_CONFIGURATION_Handle *cfg; + + /** + * Hash map of the current connected neighbours of this peer. + * Maps peer identities to 'struct Neighbour' entries. + */ + struct GNUNET_CONTAINER_MultiHashMap *neighbours; + + /** + * Heap sorting peers with pending messages by the timestamps that + * specify when we could next send a message to the respective peer. + * Excludes control messages (which can always go out immediately). + * Maps time stamps to 'struct Neighbour' entries. + */ + struct GNUNET_CONTAINER_Heap *ready_heap; + + /** + * Peer identity as assumed by this process, or all zeros. + */ + struct GNUNET_PeerIdentity self; + + /** + * 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. In use if there are no control + * messages and the smallest entry in the 'ready_heap' has a time + * stamp in the future. + */ + GNUNET_SCHEDULER_TaskIdentifier quota_task; + + /** + * Delay until we try to reconnect. + */ + struct GNUNET_TIME_Relative reconnect_delay; + + /** + * Should we check that 'self' matches what the service thinks? + * (if GNUNET_NO, then 'self' is all zeros!). + */ + int check_self; +}; + + +/** + * Schedule the task to send one message, either from the control + * list or the peer message queues to the service. + * + * @param h transport service to schedule a transmission for + */ +static void +schedule_transmission (struct GNUNET_TRANSPORT_Handle *h); + + +/** + * Function that will schedule the job that will try + * to connect us again to the client. + * + * @param h transport service to reconnect + */ +static void +disconnect_and_schedule_reconnect (struct GNUNET_TRANSPORT_Handle *h); + + +/** + * 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 Neighbour * +neighbour_find (struct GNUNET_TRANSPORT_Handle *h, + const struct GNUNET_PeerIdentity *peer) +{ + return GNUNET_CONTAINER_multihashmap_get (h->neighbours, &peer->hashPubKey); +} + + +/** + * Add neighbour to our list + * + * @return NULL if this API is currently disconnecting from the service + */ +static struct Neighbour * +neighbour_add (struct GNUNET_TRANSPORT_Handle *h, + const struct GNUNET_PeerIdentity *pid) +{ + struct Neighbour *n; + +#if DEBUG_TRANSPORT_API + LOG (GNUNET_ERROR_TYPE_DEBUG, "Creating entry for neighbour `%4s'.\n", + GNUNET_i2s (pid)); +#endif + n = GNUNET_malloc (sizeof (struct Neighbour)); + n->id = *pid; + n->h = h; + n->is_ready = GNUNET_YES; + GNUNET_BANDWIDTH_tracker_init (&n->out_tracker, + GNUNET_CONSTANTS_DEFAULT_BW_IN_OUT, + MAX_BANDWIDTH_CARRY_S); + GNUNET_assert (GNUNET_OK == + GNUNET_CONTAINER_multihashmap_put (h->neighbours, + &pid->hashPubKey, n, + GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)); + return n; +} + + +/** + * Iterator over hash map entries, for deleting state of a neighbour. + * + * @param cls the 'struct GNUNET_TRANSPORT_Handle*' + * @param key peer identity + * @param value value in the hash map, the neighbour entry to delete + * @return GNUNET_YES if we should continue to + * iterate, + * GNUNET_NO if not. + */ +static int +neighbour_delete (void *cls, const GNUNET_HashCode * key, void *value) +{ + struct GNUNET_TRANSPORT_Handle *handle = cls; + struct Neighbour *n = value; + + if (NULL != handle->nd_cb) + handle->nd_cb (handle->cls, &n->id); + GNUNET_assert (NULL == n->th); + GNUNET_assert (NULL == n->hn); + GNUNET_assert (GNUNET_YES == + GNUNET_CONTAINER_multihashmap_remove (handle->neighbours, key, + n)); + GNUNET_free (n); + return GNUNET_YES; +} + + +/** + * 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; + const struct QuotaSetMessage *qm; + const struct GNUNET_ATS_Information *ats; + struct GNUNET_TRANSPORT_GetHelloHandle *hwl; + struct GNUNET_TRANSPORT_GetHelloHandle *next_hwl; + struct Neighbour *n; + struct GNUNET_PeerIdentity me; + uint16_t size; + uint32_t ats_count; + + GNUNET_assert (h->client != NULL); + if (msg == NULL) + { +#if DEBUG_TRANSPORT_API + LOG (GNUNET_ERROR_TYPE_INFO, + "Error receiving from transport service, disconnecting temporarily.\n"); +#endif + disconnect_and_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_API + 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; + ats_count = ntohl (cim->ats_count); + if (size != + sizeof (struct ConnectInfoMessage) + + ats_count * sizeof (struct GNUNET_ATS_Information)) + { + GNUNET_break (0); + break; + } + ats = (const struct GNUNET_ATS_Information *) &cim[1]; +#if DEBUG_TRANSPORT_API + 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) + { + GNUNET_break (0); + break; + } + n = neighbour_add (h, &cim->id); + if (h->nc_cb != NULL) + h->nc_cb (h->cls, &n->id, ats, ats_count); + break; + case GNUNET_MESSAGE_TYPE_TRANSPORT_DISCONNECT: + if (size != sizeof (struct DisconnectInfoMessage)) + { + GNUNET_break (0); + break; + } + dim = (const struct DisconnectInfoMessage *) msg; + GNUNET_break (ntohl (dim->reserved) == 0); +#if DEBUG_TRANSPORT_API_DISCONNECT + LOG (GNUNET_ERROR_TYPE_DEBUG, "Receiving `%s' message for `%4s'.\n", + "DISCONNECT", GNUNET_i2s (&dim->peer)); +#endif + n = neighbour_find (h, &dim->peer); + if (n == NULL) + { + GNUNET_break (0); + break; + } + neighbour_delete (h, &dim->peer.hashPubKey, 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_API + 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); + if (n == NULL) + break; + GNUNET_break (GNUNET_NO == n->is_ready); + n->is_ready = GNUNET_YES; + if ((n->th != NULL) && (n->hn == NULL)) + { + GNUNET_assert (GNUNET_SCHEDULER_NO_TASK != n->th->timeout_task); + GNUNET_SCHEDULER_cancel (n->th->timeout_task); + n->th->timeout_task = GNUNET_SCHEDULER_NO_TASK; + /* we've been waiting for this (congestion, not quota, + * caused delayed transmission) */ + n->hn = GNUNET_CONTAINER_heap_insert (h->ready_heap, n, 0); + schedule_transmission (h); + } + break; + case GNUNET_MESSAGE_TYPE_TRANSPORT_RECV: +#if DEBUG_TRANSPORT_API + 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; + ats_count = ntohl (im->ats_count); + ats = (const struct GNUNET_ATS_Information *) &im[1]; + imm = (const struct GNUNET_MessageHeader *) &ats[ats_count]; + if (ntohs (imm->size) + sizeof (struct InboundMessage) + + ats_count * sizeof (struct GNUNET_ATS_Information) != size) + { + GNUNET_break (0); + break; + } +#if DEBUG_TRANSPORT_API + 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 (h->rec != NULL) + h->rec (h->cls, &im->peer, imm, ats, ats_count); + break; + case GNUNET_MESSAGE_TYPE_TRANSPORT_SET_QUOTA: +#if DEBUG_TRANSPORT_API + LOG (GNUNET_ERROR_TYPE_DEBUG, "Receiving `%s' message.\n", "SET_QUOTA"); +#endif + if (size != sizeof (struct QuotaSetMessage)) + { + GNUNET_break (0); + break; + } + qm = (const struct QuotaSetMessage *) msg; + n = neighbour_find (h, &qm->peer); + if (n == NULL) + break; + GNUNET_BANDWIDTH_tracker_update_quota (&n->out_tracker, qm->quota); + break; + default: + LOG (GNUNET_ERROR_TYPE_ERROR, + _("Received unexpected message of type %u in %s:%u\n"), + ntohs (msg->type), __FILE__, __LINE__); + GNUNET_break (0); + break; + } +} + + +/** + * A transmission request could not be satisfied because of + * network congestion. Notify the initiator and clean up. + * + * @param cls the 'struct GNUNET_TRANSPORT_TransmitHandle' + * @param tc scheduler context + */ +static void +timeout_request_due_to_congestion (void *cls, + const struct GNUNET_SCHEDULER_TaskContext + *tc) +{ + struct GNUNET_TRANSPORT_TransmitHandle *th = cls; + struct Neighbour *n = th->neighbour; + + n->th->timeout_task = GNUNET_SCHEDULER_NO_TASK; + GNUNET_assert (th == n->th); + GNUNET_assert (NULL == n->hn); + n->th = NULL; + th->notify (th->notify_cls, 0, NULL); + GNUNET_free (th); +} + + +/** + * 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 GNUNET_TRANSPORT_TransmitHandle *th; + struct Neighbour *n; + char *cbuf; + struct OutboundMessage obm; + size_t ret; + size_t nret; + size_t mret; + + GNUNET_assert (NULL != h->client); + h->cth = NULL; + if (NULL == buf) + { + /* transmission failed */ + disconnect_and_schedule_reconnect (h); + return 0; + } + + cbuf = buf; + ret = 0; + /* first send control messages */ + while ((NULL != (th = h->control_head)) && (th->notify_size <= size)) + { + GNUNET_CONTAINER_DLL_remove (h->control_head, h->control_tail, th); + nret = th->notify (th->notify_cls, size, &cbuf[ret]); +#if DEBUG_TRANSPORT_API + LOG (GNUNET_ERROR_TYPE_DEBUG, "Added %u bytes of control message at %u\n", + nret, ret); +#endif + GNUNET_free (th); + ret += nret; + size -= nret; + } + + /* then, if possible and no control messages pending, send data messages */ + while ((NULL == h->control_head) && + (NULL != (n = GNUNET_CONTAINER_heap_peek (h->ready_heap)))) + { + if (GNUNET_YES != n->is_ready) + { + /* peer not ready, wait for notification! */ + GNUNET_assert (n == GNUNET_CONTAINER_heap_remove_root (h->ready_heap)); + n->hn = NULL; + GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == n->th->timeout_task); + n->th->timeout_task = + GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_absolute_get_remaining + (n->th->timeout), + &timeout_request_due_to_congestion, + n->th); + continue; + } + th = n->th; + if (th->notify_size + sizeof (struct OutboundMessage) > size) + break; /* does not fit */ + if (GNUNET_BANDWIDTH_tracker_get_delay + (&n->out_tracker, th->notify_size).rel_value > 0) + break; /* too early */ + GNUNET_assert (n == GNUNET_CONTAINER_heap_remove_root (h->ready_heap)); + n->hn = NULL; + n->th = NULL; + n->is_ready = GNUNET_NO; + 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 (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); + } + GNUNET_free (th); + } + /* if there are more pending messages, try to schedule those */ + schedule_transmission (h); +#if DEBUG_TRANSPORT_API + 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. + * + * @param cls transport service to schedule a transmission for + * @param tc scheduler context + */ +static void +schedule_transmission_task (void *cls, + const struct GNUNET_SCHEDULER_TaskContext *tc) +{ + struct GNUNET_TRANSPORT_Handle *h = cls; + size_t size; + struct GNUNET_TRANSPORT_TransmitHandle *th; + struct Neighbour *n; + + h->quota_task = GNUNET_SCHEDULER_NO_TASK; + GNUNET_assert (NULL != h->client); + /* destroy all requests that have timed out */ + while ((NULL != (n = GNUNET_CONTAINER_heap_peek (h->ready_heap))) && + (GNUNET_TIME_absolute_get_remaining (n->th->timeout).rel_value == 0)) + { + /* notify client that the request could not be satisfied within + * the given time constraints */ + th = n->th; + n->th = NULL; + GNUNET_assert (n == GNUNET_CONTAINER_heap_remove_root (h->ready_heap)); + n->hn = NULL; +#if DEBUG_TRANSPORT_API + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Signalling timeout for transmission to peer %s due to congestion\n", + GNUNET_i2s (&n->id)); +#endif + GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL)); + GNUNET_free (th); + } + if (NULL != h->cth) + return; + if (NULL != h->control_head) + { + size = h->control_head->notify_size; + } + else + { + n = GNUNET_CONTAINER_heap_peek (h->ready_heap); + if (NULL == n) + return; /* no pending messages */ + size = n->th->notify_size + sizeof (struct OutboundMessage); + } +#if DEBUG_TRANSPORT_API + LOG (GNUNET_ERROR_TYPE_DEBUG, "Calling notify_transmit_ready\n"); +#endif + h->cth = + GNUNET_CLIENT_notify_transmit_ready (h->client, size, + GNUNET_TIME_UNIT_FOREVER_REL, + GNUNET_NO, &transport_notify_ready, + h); + GNUNET_assert (NULL != h->cth); +} + + +/** + * Schedule the task to send one message, either from the control + * list or the peer message queues to the service. + * + * @param h transport service to schedule a transmission for + */ +static void +schedule_transmission (struct GNUNET_TRANSPORT_Handle *h) +{ + struct GNUNET_TIME_Relative delay; + struct Neighbour *n; + + GNUNET_assert (NULL != h->client); + if (h->quota_task != GNUNET_SCHEDULER_NO_TASK) + { + GNUNET_SCHEDULER_cancel (h->quota_task); + h->quota_task = GNUNET_SCHEDULER_NO_TASK; + } + if (NULL != h->control_head) + delay = GNUNET_TIME_UNIT_ZERO; + else if (NULL != (n = GNUNET_CONTAINER_heap_peek (h->ready_heap))) + delay = + GNUNET_BANDWIDTH_tracker_get_delay (&n->out_tracker, + n->th->notify_size); + else + return; /* no work to be done */ +#if DEBUG_TRANSPORT_API + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Scheduling next transmission to service in %llu ms\n", + (unsigned long long) delay.rel_value); +#endif + h->quota_task = + GNUNET_SCHEDULER_add_delayed (delay, &schedule_transmission_task, h); +} + + +/** + * 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 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, + GNUNET_CONNECTION_TransmitReadyNotify notify, + void *notify_cls) +{ + struct GNUNET_TRANSPORT_TransmitHandle *th; + +#if DEBUG_TRANSPORT_API + LOG (GNUNET_ERROR_TYPE_DEBUG, "Control transmit of %u bytes requested\n", + size); +#endif + th = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_TransmitHandle)); + th->notify = notify; + th->notify_cls = notify_cls; + th->notify_size = size; + GNUNET_CONTAINER_DLL_insert_tail (h->control_head, h->control_tail, th); + schedule_transmission (h); +} + + +/** + * 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_TRANSPORT_Handle *h = cls; + struct StartMessage s; + uint32_t options; + + if (buf == NULL) + { + /* Can only be shutdown, just give up */ +#if DEBUG_TRANSPORT_API + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Shutdown while trying to transmit `%s' request.\n", "START"); +#endif + return 0; + } +#if DEBUG_TRANSPORT_API + LOG (GNUNET_ERROR_TYPE_DEBUG, "Transmitting `%s' request.\n", "START"); +#endif + GNUNET_assert (size >= sizeof (struct StartMessage)); + s.header.size = htons (sizeof (struct StartMessage)); + s.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_START); + options = 0; + if (h->check_self) + options |= 1; + if (h->rec != NULL) + options |= 2; + s.options = htonl (options); + s.self = h->self; + memcpy (buf, &s, sizeof (struct StartMessage)); + GNUNET_CLIENT_receive (h->client, &demultiplexer, h, + GNUNET_TIME_UNIT_FOREVER_REL); + return sizeof (struct StartMessage); +} + + +/** + * 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; + + h->reconnect_task = GNUNET_SCHEDULER_NO_TASK; + if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0) + { + /* shutdown, just give up */ + return; + } +#if DEBUG_TRANSPORT_API + LOG (GNUNET_ERROR_TYPE_DEBUG, "Connecting to transport service.\n"); +#endif + GNUNET_assert (h->client == NULL); + GNUNET_assert (h->control_head == NULL); + GNUNET_assert (h->control_tail == NULL); + h->client = GNUNET_CLIENT_connect ("transport", h->cfg); + GNUNET_assert (h->client != NULL); + schedule_control_transmit (h, sizeof (struct StartMessage), &send_start, h); +} + + +/** + * Function that will schedule the job that will try + * to connect us again to the client. + * + * @param h transport service to reconnect + */ +static void +disconnect_and_schedule_reconnect (struct GNUNET_TRANSPORT_Handle *h) +{ + struct GNUNET_TRANSPORT_TransmitHandle *th; + + GNUNET_assert (h->reconnect_task == GNUNET_SCHEDULER_NO_TASK); + if (NULL != h->cth) + { + GNUNET_CLIENT_notify_transmit_ready_cancel (h->cth); + h->cth = NULL; + } + if (NULL != h->client) + { + GNUNET_CLIENT_disconnect (h->client, GNUNET_YES); + h->client = NULL; + } + /* Forget about all neighbours that we used to be connected to */ + GNUNET_CONTAINER_multihashmap_iterate (h->neighbours, &neighbour_delete, h); + if (h->quota_task != GNUNET_SCHEDULER_NO_TASK) + { + GNUNET_SCHEDULER_cancel (h->quota_task); + h->quota_task = GNUNET_SCHEDULER_NO_TASK; + } + while ((NULL != (th = h->control_head))) + { + GNUNET_CONTAINER_DLL_remove (h->control_head, h->control_tail, th); + th->notify (th->notify_cls, 0, NULL); + GNUNET_free (th); + } +#if DEBUG_TRANSPORT_API + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Scheduling task to reconnect to transport service in %llu ms.\n", + h->reconnect_delay.rel_value); +#endif + h->reconnect_task = + GNUNET_SCHEDULER_add_delayed (h->reconnect_delay, &reconnect, h); + if (h->reconnect_delay.rel_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); + } +} + + +/** + * Send REQUEST_CONNECT message to the service. + * + * @param cls the 'struct GNUNET_PeerIdentity' + * @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_try_connect (void *cls, size_t size, void *buf) +{ + struct GNUNET_PeerIdentity *pid = cls; + struct TransportRequestConnectMessage msg; + + if (buf == NULL) + { + GNUNET_free (pid); + return 0; + } +#if DEBUG_TRANSPORT_API + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Transmitting `%s' request with respect to `%4s'.\n", "REQUEST_CONNECT", + GNUNET_i2s (pid)); +#endif + GNUNET_assert (size >= sizeof (struct TransportRequestConnectMessage)); + msg.header.size = htons (sizeof (struct TransportRequestConnectMessage)); + msg.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_REQUEST_CONNECT); + msg.reserved = htonl (0); + msg.peer = *pid; + memcpy (buf, &msg, sizeof (msg)); + GNUNET_free (pid); + return sizeof (struct TransportRequestConnectMessage); +} + + +/** + * Ask the transport service to establish a connection to + * the given peer. + * + * @param handle connection to transport service + * @param target who we should try to connect to + */ +void +GNUNET_TRANSPORT_try_connect (struct GNUNET_TRANSPORT_Handle *handle, + const struct GNUNET_PeerIdentity *target) +{ + struct GNUNET_PeerIdentity *pid; + + if (NULL == handle->client) + return; + pid = GNUNET_malloc (sizeof (struct GNUNET_PeerIdentity)); + *pid = *target; + schedule_control_transmit (handle, + sizeof (struct TransportRequestConnectMessage), + &send_try_connect, pid); +} + + +/** + * 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 *msg = cls; + uint16_t ssize; + + if (buf == NULL) + { +#if DEBUG_TRANSPORT_TIMEOUT + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Timeout while trying to transmit `%s' request.\n", "HELLO"); +#endif + GNUNET_free (msg); + return 0; + } +#if DEBUG_TRANSPORT_API + LOG (GNUNET_ERROR_TYPE_DEBUG, "Transmitting `%s' request.\n", "HELLO"); +#endif + ssize = ntohs (msg->size); + GNUNET_assert (size >= ssize); + memcpy (buf, msg, ssize); + GNUNET_free (msg); + return ssize; +} + + +/** + * 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 + * @param cont continuation to call when HELLO has been sent + * @param cls closure for continuation + * + */ +void +GNUNET_TRANSPORT_offer_hello (struct GNUNET_TRANSPORT_Handle *handle, + const struct GNUNET_MessageHeader *hello, + GNUNET_SCHEDULER_Task cont, void *cls) +{ + uint16_t size; + struct GNUNET_PeerIdentity peer; + struct GNUNET_MessageHeader *msg; + + if (NULL == handle->client) + return; + 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; + } + msg = GNUNET_malloc (size); + memcpy (msg, hello, size); +#if DEBUG_TRANSPORT_API + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Offering `%s' message of `%4s' to transport for validation.\n", "HELLO", + GNUNET_i2s (&peer)); +#endif + schedule_control_transmit (handle, size, &send_hello, msg); +} + + +/** + * 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 + * @return handle to cancel the operation + */ +struct GNUNET_TRANSPORT_GetHelloHandle * +GNUNET_TRANSPORT_get_hello (struct GNUNET_TRANSPORT_Handle *handle, + GNUNET_TRANSPORT_HelloUpdateCallback rec, + void *rec_cls) +{ + struct GNUNET_TRANSPORT_GetHelloHandle *hwl; + + hwl = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_GetHelloHandle)); + hwl->rec = rec; + hwl->rec_cls = rec_cls; + hwl->handle = handle; + GNUNET_CONTAINER_DLL_insert (handle->hwl_head, handle->hwl_tail, hwl); + if (handle->my_hello != NULL) + rec (rec_cls, (const struct GNUNET_MessageHeader *) handle->my_hello); + return hwl; +} + + +/** + * Stop receiving updates about changes to our HELLO message. + * + * @param ghh handle to cancel + */ +void +GNUNET_TRANSPORT_get_hello_cancel (struct GNUNET_TRANSPORT_GetHelloHandle *ghh) +{ + struct GNUNET_TRANSPORT_Handle *handle = ghh->handle; + + GNUNET_CONTAINER_DLL_remove (handle->hwl_head, handle->hwl_tail, ghh); + GNUNET_free (ghh); +} + + +/** + * Connect to the transport service. Note that the connection may + * complete (or fail) asynchronously. + * + * @param cfg configuration to use + * @param self our own identity (API should check that it matches + * the identity found by transport), or NULL (no check) + * @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 (const struct GNUNET_CONFIGURATION_Handle *cfg, + const struct GNUNET_PeerIdentity *self, 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)); + if (self != NULL) + { + ret->self = *self; + ret->check_self = GNUNET_YES; + } + ret->cfg = cfg; + ret->cls = cls; + ret->rec = rec; + ret->nc_cb = nc; + ret->nd_cb = nd; + ret->reconnect_delay = GNUNET_TIME_UNIT_ZERO; + ret->neighbours = + GNUNET_CONTAINER_multihashmap_create (STARTING_NEIGHBOURS_SIZE); + ret->ready_heap = + GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN); + ret->reconnect_task = GNUNET_SCHEDULER_add_now (&reconnect, ret); + return ret; +} + + +/** + * Disconnect from the transport service. + * + * @param handle handle to the service as returned from GNUNET_TRANSPORT_connect + */ +void +GNUNET_TRANSPORT_disconnect (struct GNUNET_TRANSPORT_Handle *handle) +{ +#if DEBUG_TRANSPORT_API + LOG (GNUNET_ERROR_TYPE_DEBUG, "Transport disconnect called!\n"); +#endif + /* this disconnects all neighbours... */ + if (handle->reconnect_task == GNUNET_SCHEDULER_NO_TASK) + disconnect_and_schedule_reconnect (handle); + /* and now we stop trying to connect again... */ + if (handle->reconnect_task != GNUNET_SCHEDULER_NO_TASK) + { + GNUNET_SCHEDULER_cancel (handle->reconnect_task); + handle->reconnect_task = GNUNET_SCHEDULER_NO_TASK; + } + GNUNET_CONTAINER_multihashmap_destroy (handle->neighbours); + handle->neighbours = NULL; + if (handle->quota_task != GNUNET_SCHEDULER_NO_TASK) + { + GNUNET_SCHEDULER_cancel (handle->quota_task); + handle->quota_task = GNUNET_SCHEDULER_NO_TASK; + } + GNUNET_free_non_null (handle->my_hello); + handle->my_hello = NULL; + GNUNET_assert (handle->hwl_head == NULL); + GNUNET_assert (handle->hwl_tail == NULL); + GNUNET_CONTAINER_heap_destroy (handle->ready_heap); + handle->ready_heap = NULL; + GNUNET_free (handle); +} + + +/** + * 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, uint32_t priority, + struct GNUNET_TIME_Relative timeout, + GNUNET_CONNECTION_TransmitReadyNotify + notify, void *notify_cls) +{ + struct Neighbour *n; + struct GNUNET_TRANSPORT_TransmitHandle *th; + struct GNUNET_TIME_Relative delay; + + n = neighbour_find (handle, target); + if (NULL == n) + { + /* use GNUNET_TRANSPORT_try_connect first, only use this function + * once a connection has been established */ + GNUNET_assert (0); + return NULL; + } + if (NULL != n->th) + { + /* attempt to send two messages at the same time to the same peer */ + GNUNET_assert (0); + return NULL; + } + GNUNET_assert (NULL == n->hn); + th = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_TransmitHandle)); + th->neighbour = n; + th->notify = notify; + th->notify_cls = notify_cls; + th->timeout = GNUNET_TIME_relative_to_absolute (timeout); + th->notify_size = size; + th->priority = priority; + n->th = th; + /* calculate when our transmission should be ready */ + delay = GNUNET_BANDWIDTH_tracker_get_delay (&n->out_tracker, size); + if (delay.rel_value > timeout.rel_value) + delay.rel_value = 0; /* notify immediately (with failure) */ +#if DEBUG_TRANSPORT_API + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Bandwidth tracker allows next transmission to peer %s in %llu ms\n", + GNUNET_i2s (target), (unsigned long long) delay.rel_value); +#endif + n->hn = GNUNET_CONTAINER_heap_insert (handle->ready_heap, n, delay.rel_value); + schedule_transmission (handle); + return th; +} + + +/** + * Cancel the specified transmission-ready notification. + * + * @param th handle returned from GNUNET_TRANSPORT_notify_transmit_ready + */ +void +GNUNET_TRANSPORT_notify_transmit_ready_cancel (struct + GNUNET_TRANSPORT_TransmitHandle + *th) +{ + struct Neighbour *n; + + GNUNET_assert (NULL == th->next); + GNUNET_assert (NULL == th->prev); + n = th->neighbour; + GNUNET_assert (th == n->th); + n->th = NULL; + if (n->hn != NULL) + { + GNUNET_CONTAINER_heap_remove_node (n->hn); + n->hn = NULL; + } + else + { + GNUNET_assert (GNUNET_SCHEDULER_NO_TASK != th->timeout_task); + GNUNET_SCHEDULER_cancel (th->timeout_task); + th->timeout_task = GNUNET_SCHEDULER_NO_TASK; + } + GNUNET_free (th); +} + + +/* end of transport_api.c */ |