/* This file is part of GNUnet. Copyright (C) 2012-2014 GNUnet e.V. 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ /** * @author Florian Dold * @file util/mq.c * @brief general purpose request queue */ #include "platform.h" #include "gnunet_util_lib.h" #define LOG(kind,...) GNUNET_log_from (kind, "mq",__VA_ARGS__) struct GNUNET_MQ_Envelope { /** * Messages are stored in a linked list. * Each queue has its own list of envelopes. */ struct GNUNET_MQ_Envelope *next; /** * Messages are stored in a linked list * Each queue has its own list of envelopes. */ struct GNUNET_MQ_Envelope *prev; /** * Actual allocated message header, * usually points to the end of the containing GNUNET_MQ_Envelope */ struct GNUNET_MessageHeader *mh; /** * Queue the message is queued in, NULL if message is not queued. */ struct GNUNET_MQ_Handle *parent_queue; /** * Called after the message was sent irrevocably. */ GNUNET_MQ_NotifyCallback sent_cb; /** * Closure for @e send_cb */ void *sent_cls; }; /** * Handle to a message queue. */ struct GNUNET_MQ_Handle { /** * Handlers array, or NULL if the queue should not receive messages */ struct GNUNET_MQ_MessageHandler *handlers; /** * Actual implementation of message sending, * called when a message is added */ GNUNET_MQ_SendImpl send_impl; /** * Implementation-dependent queue destruction function */ GNUNET_MQ_DestroyImpl destroy_impl; /** * Implementation-dependent send cancel function */ GNUNET_MQ_CancelImpl cancel_impl; /** * Implementation-specific state */ void *impl_state; /** * Callback will be called when an error occurs. */ GNUNET_MQ_ErrorHandler error_handler; /** * Closure for the error handler. */ void *error_handler_cls; /** * Linked list of messages pending to be sent */ struct GNUNET_MQ_Envelope *envelope_head; /** * Linked list of messages pending to be sent */ struct GNUNET_MQ_Envelope *envelope_tail; /** * Message that is currently scheduled to be * sent. Not the head of the message queue, as the implementation * needs to know if sending has been already scheduled or not. */ struct GNUNET_MQ_Envelope *current_envelope; /** * Map of associations, lazily allocated */ struct GNUNET_CONTAINER_MultiHashMap32 *assoc_map; /** * Task scheduled during #GNUNET_MQ_impl_send_continue. */ struct GNUNET_SCHEDULER_Task *continue_task; /** * Next id that should be used for the @e assoc_map, * initialized lazily to a random value together with * @e assoc_map */ uint32_t assoc_id; /** * Number of entries we have in the envelope-DLL. */ unsigned int queue_length; }; /** * Implementation-specific state for connection to * client (MQ for server). */ struct ServerClientSocketState { /** * Handle of the client that connected to the server. */ struct GNUNET_SERVER_Client *client; /** * Active transmission request to the client. */ struct GNUNET_SERVER_TransmitHandle *th; }; /** * Implementation-specific state for connection to * service (MQ for clients). */ struct ClientConnectionState { /** * Did we call receive alread alreadyy? */ int receive_active; /** * Do we also want to receive? */ int receive_requested; /** * Connection to the service. */ struct GNUNET_CLIENT_Connection *connection; /** * Active transmission request (or NULL). */ struct GNUNET_CLIENT_TransmitHandle *th; }; /** * Call the message message handler that was registered * for the type of the given message in the given message queue. * * This function is indended to be used for the implementation * of message queues. * * @param mq message queue with the handlers * @param mh message to dispatch */ void GNUNET_MQ_inject_message (struct GNUNET_MQ_Handle *mq, const struct GNUNET_MessageHeader *mh) { const struct GNUNET_MQ_MessageHandler *handler; int handled = GNUNET_NO; uint16_t ms = ntohs (mh->size); if (NULL == mq->handlers) goto done; for (handler = mq->handlers; NULL != handler->cb; handler++) { if (handler->type == ntohs (mh->type)) { handled = GNUNET_YES; if ( (handler->expected_size > ms) || ( (handler->expected_size != ms) && (NULL == handler->mv) ) ) { /* Too small, or not an exact size and no 'mv' handler to check rest */ GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Received malformed message of type %u\n", (unsigned int) handler->type); GNUNET_MQ_inject_error (mq, GNUNET_MQ_ERROR_MALFORMED); break; } if ( (NULL == handler->mv) || (GNUNET_OK == handler->mv (handler->cls, mh)) ) { /* message well-formed, pass to handler */ handler->cb (handler->cls, mh); } else { /* Message rejected by check routine */ GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Received malformed message of type %u\n", (unsigned int) handler->type); GNUNET_MQ_inject_error (mq, GNUNET_MQ_ERROR_MALFORMED); } break; } } done: if (GNUNET_NO == handled) LOG (GNUNET_ERROR_TYPE_DEBUG, "No handler for message of type %d\n", ntohs (mh->type)); } /** * Call the error handler of a message queue with the given * error code. If there is no error handler, log a warning. * * This function is intended to be used by the implementation * of message queues. * * @param mq message queue * @param error the error type */ void GNUNET_MQ_inject_error (struct GNUNET_MQ_Handle *mq, enum GNUNET_MQ_Error error) { if (NULL == mq->error_handler) { LOG (GNUNET_ERROR_TYPE_WARNING, "Got error %d, but no handler installed\n", (int) error); return; } mq->error_handler (mq->error_handler_cls, error); } /** * Discard the message queue message, free all * allocated resources. Must be called in the event * that a message is created but should not actually be sent. * * @param mqm the message to discard */ void GNUNET_MQ_discard (struct GNUNET_MQ_Envelope *mqm) { GNUNET_assert (NULL == mqm->parent_queue); GNUNET_free (mqm); } /** * Obtain the current length of the message queue. * * @param mq queue to inspect * @return number of queued, non-transmitted messages */ unsigned int GNUNET_MQ_get_length (struct GNUNET_MQ_Handle *mq) { return mq->queue_length; } /** * Send a message with the given message queue. * May only be called once per message. * * @param mq message queue * @param ev the envelope with the message to send. */ void GNUNET_MQ_send (struct GNUNET_MQ_Handle *mq, struct GNUNET_MQ_Envelope *ev) { GNUNET_assert (NULL != mq); GNUNET_assert (NULL == ev->parent_queue); ev->parent_queue = mq; /* is the implementation busy? queue it! */ if (NULL != mq->current_envelope) { GNUNET_CONTAINER_DLL_insert_tail (mq->envelope_head, mq->envelope_tail, ev); mq->queue_length++; return; } mq->current_envelope = ev; mq->send_impl (mq, ev->mh, mq->impl_state); } /** * Send a copy of a message with the given message queue. * Can be called repeatedly on the same envelope. * * @param mq message queue * @param ev the envelope with the message to send. */ void GNUNET_MQ_send_copy (struct GNUNET_MQ_Handle *mq, const struct GNUNET_MQ_Envelope *ev) { struct GNUNET_MQ_Envelope *env; uint16_t msize; msize = ntohs (ev->mh->size); env = GNUNET_malloc (sizeof (struct GNUNET_MQ_Envelope) + msize); env->mh = (struct GNUNET_MessageHeader *) &env[1]; env->sent_cb = ev->sent_cb; env->sent_cls = ev->sent_cls; GNUNET_memcpy (&env[1], ev->mh, msize); GNUNET_MQ_send (mq, env); } /** * Task run to call the send implementation for the next queued * message, if any. Only useful for implementing message queues, * results in undefined behavior if not used carefully. * * @param cls message queue to send the next message with */ static void impl_send_continue (void *cls) { struct GNUNET_MQ_Handle *mq = cls; struct GNUNET_MQ_Envelope *current_envelope; mq->continue_task = NULL; /* call is only valid if we're actually currently sending * a message */ current_envelope = mq->current_envelope; GNUNET_assert (NULL != current_envelope); current_envelope->parent_queue = NULL; if (NULL == mq->envelope_head) { mq->current_envelope = NULL; } else { mq->current_envelope = mq->envelope_head; GNUNET_CONTAINER_DLL_remove (mq->envelope_head, mq->envelope_tail, mq->current_envelope); mq->queue_length--; mq->send_impl (mq, mq->current_envelope->mh, mq->impl_state); } if (NULL != current_envelope->sent_cb) current_envelope->sent_cb (current_envelope->sent_cls); GNUNET_free (current_envelope); } /** * Call the send implementation for the next queued message, if any. * Only useful for implementing message queues, results in undefined * behavior if not used carefully. * * @param mq message queue to send the next message with */ void GNUNET_MQ_impl_send_continue (struct GNUNET_MQ_Handle *mq) { GNUNET_assert (NULL == mq->continue_task); mq->continue_task = GNUNET_SCHEDULER_add_now (&impl_send_continue, mq); } /** * Create a message queue for the specified handlers. * * @param send function the implements sending messages * @param destroy function that implements destroying the queue * @param cancel function that implements canceling a message * @param impl_state for the queue, passed to 'send' and 'destroy' * @param handlers array of message handlers * @param error_handler handler for read and write errors * @param error_handler_cls closure for @a error_handler * @return a new message queue */ struct GNUNET_MQ_Handle * GNUNET_MQ_queue_for_callbacks (GNUNET_MQ_SendImpl send, GNUNET_MQ_DestroyImpl destroy, GNUNET_MQ_CancelImpl cancel, void *impl_state, const struct GNUNET_MQ_MessageHandler *handlers, GNUNET_MQ_ErrorHandler error_handler, void *error_handler_cls) { struct GNUNET_MQ_Handle *mq; unsigned int i; mq = GNUNET_new (struct GNUNET_MQ_Handle); mq->send_impl = send; mq->destroy_impl = destroy; mq->cancel_impl = cancel; if (NULL != handlers) { for (i=0;NULL != handlers[i].cb; i++) ; mq->handlers = GNUNET_new_array (i + 1, struct GNUNET_MQ_MessageHandler); GNUNET_memcpy (mq->handlers, handlers, i * sizeof (struct GNUNET_MQ_MessageHandler)); } mq->error_handler = error_handler; mq->error_handler_cls = error_handler_cls; mq->impl_state = impl_state; return mq; } /** * Change the closure argument in all of the `handlers` of the * @a mq. * * @param mq to modify * @param handlers_cls new closure to use */ void GNUNET_MQ_set_handlers_closure (struct GNUNET_MQ_Handle *mq, void *handlers_cls) { unsigned int i; if (NULL == mq->handlers) return; for (i=0;NULL != mq->handlers[i].cb; i++) mq->handlers[i].cls = handlers_cls; } /** * Get the message that should currently be sent. * Fails if there is no current message. * Only useful for implementing message queues, * results in undefined behavior if not used carefully. * * @param mq message queue with the current message * @return message to send, never NULL */ const struct GNUNET_MessageHeader * GNUNET_MQ_impl_current (struct GNUNET_MQ_Handle *mq) { if (NULL == mq->current_envelope) GNUNET_assert (0); if (NULL == mq->current_envelope->mh) GNUNET_assert (0); return mq->current_envelope->mh; } /** * Get the implementation state associated with the * message queue. * * While the GNUNET_MQ_Impl* callbacks receive the * implementation state, continuations that are scheduled * by the implementation function often only have one closure * argument, with this function it is possible to get at the * implementation state when only passing the GNUNET_MQ_Handle * as closure. * * @param mq message queue with the current message * @return message to send, never NULL */ void * GNUNET_MQ_impl_state (struct GNUNET_MQ_Handle *mq) { return mq->impl_state; } struct GNUNET_MQ_Envelope * GNUNET_MQ_msg_ (struct GNUNET_MessageHeader **mhp, uint16_t size, uint16_t type) { struct GNUNET_MQ_Envelope *mqm; mqm = GNUNET_malloc (sizeof *mqm + size); mqm->mh = (struct GNUNET_MessageHeader *) &mqm[1]; mqm->mh->size = htons (size); mqm->mh->type = htons (type); if (NULL != mhp) *mhp = mqm->mh; return mqm; } /** * Create a new envelope by copying an existing message. * * @param hdr header of the message to copy * @return envelope containing @a hdr */ struct GNUNET_MQ_Envelope * GNUNET_MQ_msg_copy (const struct GNUNET_MessageHeader *hdr) { struct GNUNET_MQ_Envelope *mqm; uint16_t size = ntohs (hdr->size); mqm = GNUNET_malloc (sizeof (*mqm) + size); mqm->mh = (struct GNUNET_MessageHeader *) &mqm[1]; GNUNET_memcpy (mqm->mh, hdr, size); return mqm; } /** * Implementation of the #GNUNET_MQ_msg_nested_mh macro. * * @param mhp pointer to the message header pointer that will be changed to allocate at * the newly allocated space for the message. * @param base_size size of the data before the nested message * @param type type of the message in the envelope * @param nested_mh the message to append to the message after base_size */ struct GNUNET_MQ_Envelope * GNUNET_MQ_msg_nested_mh_ (struct GNUNET_MessageHeader **mhp, uint16_t base_size, uint16_t type, const struct GNUNET_MessageHeader *nested_mh) { struct GNUNET_MQ_Envelope *mqm; uint16_t size; if (NULL == nested_mh) return GNUNET_MQ_msg_ (mhp, base_size, type); size = base_size + ntohs (nested_mh->size); /* check for uint16_t overflow */ if (size < base_size) return NULL; mqm = GNUNET_MQ_msg_ (mhp, size, type); GNUNET_memcpy ((char *) mqm->mh + base_size, nested_mh, ntohs (nested_mh->size)); return mqm; } /** * Transmit a queued message to the session's client. * * @param cls consensus session * @param size number of bytes available in @a buf * @param buf where the callee should write the message * @return number of bytes written to @a buf */ static size_t transmit_queued (void *cls, size_t size, void *buf) { struct GNUNET_MQ_Handle *mq = cls; struct ServerClientSocketState *state = GNUNET_MQ_impl_state (mq); const struct GNUNET_MessageHeader *msg = GNUNET_MQ_impl_current (mq); size_t msg_size; GNUNET_assert (NULL != buf); msg_size = ntohs (msg->size); GNUNET_assert (size >= msg_size); GNUNET_memcpy (buf, msg, msg_size); state->th = NULL; GNUNET_MQ_impl_send_continue (mq); return msg_size; } static void server_client_destroy_impl (struct GNUNET_MQ_Handle *mq, void *impl_state) { struct ServerClientSocketState *state = impl_state; if (NULL != state->th) { GNUNET_SERVER_notify_transmit_ready_cancel (state->th); state->th = NULL; } GNUNET_assert (NULL != mq); GNUNET_assert (NULL != state); GNUNET_SERVER_client_drop (state->client); GNUNET_free (state); } static void server_client_send_impl (struct GNUNET_MQ_Handle *mq, const struct GNUNET_MessageHeader *msg, void *impl_state) { struct ServerClientSocketState *state = impl_state; GNUNET_assert (NULL != mq); state->th = GNUNET_SERVER_notify_transmit_ready (state->client, ntohs (msg->size), GNUNET_TIME_UNIT_FOREVER_REL, &transmit_queued, mq); } struct GNUNET_MQ_Handle * GNUNET_MQ_queue_for_server_client (struct GNUNET_SERVER_Client *client) { struct GNUNET_MQ_Handle *mq; struct ServerClientSocketState *scss; mq = GNUNET_new (struct GNUNET_MQ_Handle); scss = GNUNET_new (struct ServerClientSocketState); mq->impl_state = scss; scss->client = client; GNUNET_SERVER_client_keep (client); mq->send_impl = &server_client_send_impl; mq->destroy_impl = &server_client_destroy_impl; return mq; } /** * Type of a function to call when we receive a message * from the service. * * @param cls closure * @param msg message received, NULL on timeout or fatal error */ static void handle_client_message (void *cls, const struct GNUNET_MessageHeader *msg) { struct GNUNET_MQ_Handle *mq = cls; struct ClientConnectionState *state; state = mq->impl_state; if (NULL == msg) { GNUNET_MQ_inject_error (mq, GNUNET_MQ_ERROR_READ); return; } GNUNET_CLIENT_receive (state->connection, &handle_client_message, mq, GNUNET_TIME_UNIT_FOREVER_REL); GNUNET_MQ_inject_message (mq, msg); } /** * Transmit a queued message to the session's client. * * @param cls consensus session * @param size number of bytes available in @a buf * @param buf where the callee should write the message * @return number of bytes written to buf */ static size_t connection_client_transmit_queued (void *cls, size_t size, void *buf) { struct GNUNET_MQ_Handle *mq = cls; const struct GNUNET_MessageHeader *msg; struct ClientConnectionState *state = mq->impl_state; size_t msg_size; GNUNET_assert (NULL != mq); state->th = NULL; msg = GNUNET_MQ_impl_current (mq); if (NULL == buf) { GNUNET_MQ_inject_error (mq, GNUNET_MQ_ERROR_READ); return 0; } if ( (GNUNET_YES == state->receive_requested) && (GNUNET_NO == state->receive_active) ) { state->receive_active = GNUNET_YES; GNUNET_CLIENT_receive (state->connection, &handle_client_message, mq, GNUNET_TIME_UNIT_FOREVER_REL); } msg_size = ntohs (msg->size); GNUNET_assert (size >= msg_size); GNUNET_memcpy (buf, msg, msg_size); state->th = NULL; GNUNET_MQ_impl_send_continue (mq); return msg_size; } static void connection_client_destroy_impl (struct GNUNET_MQ_Handle *mq, void *impl_state) { struct ClientConnectionState *state = impl_state; if (NULL != state->th) { GNUNET_CLIENT_notify_transmit_ready_cancel (state->th); state->th = NULL; } GNUNET_CLIENT_disconnect (state->connection); GNUNET_free (impl_state); } static void connection_client_send_impl (struct GNUNET_MQ_Handle *mq, const struct GNUNET_MessageHeader *msg, void *impl_state) { struct ClientConnectionState *state = impl_state; GNUNET_assert (NULL != state); GNUNET_assert (NULL == state->th); state->th = GNUNET_CLIENT_notify_transmit_ready (state->connection, ntohs (msg->size), GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_NO, &connection_client_transmit_queued, mq); GNUNET_assert (NULL != state->th); } static void connection_client_cancel_impl (struct GNUNET_MQ_Handle *mq, void *impl_state) { struct ClientConnectionState *state = impl_state; GNUNET_assert (NULL != state->th); GNUNET_CLIENT_notify_transmit_ready_cancel (state->th); state->th = NULL; } struct GNUNET_MQ_Handle * GNUNET_MQ_queue_for_connection_client (struct GNUNET_CLIENT_Connection *connection, const struct GNUNET_MQ_MessageHandler *handlers, GNUNET_MQ_ErrorHandler error_handler, void *error_handler_cls) { struct GNUNET_MQ_Handle *mq; struct ClientConnectionState *state; unsigned int i; mq = GNUNET_new (struct GNUNET_MQ_Handle); if (NULL != handlers) { for (i=0;NULL != handlers[i].cb; i++) ; mq->handlers = GNUNET_new_array (i + 1, struct GNUNET_MQ_MessageHandler); GNUNET_memcpy (mq->handlers, handlers, i * sizeof (struct GNUNET_MQ_MessageHandler)); } mq->error_handler = error_handler; mq->error_handler_cls = error_handler_cls; state = GNUNET_new (struct ClientConnectionState); state->connection = connection; mq->impl_state = state; mq->send_impl = &connection_client_send_impl; mq->destroy_impl = &connection_client_destroy_impl; mq->cancel_impl = &connection_client_cancel_impl; if (NULL != handlers) state->receive_requested = GNUNET_YES; return mq; } /** * Associate the assoc_data in mq with a unique request id. * * @param mq message queue, id will be unique for the queue * @param assoc_data to associate */ uint32_t GNUNET_MQ_assoc_add (struct GNUNET_MQ_Handle *mq, void *assoc_data) { uint32_t id; if (NULL == mq->assoc_map) { mq->assoc_map = GNUNET_CONTAINER_multihashmap32_create (8); mq->assoc_id = 1; } id = mq->assoc_id++; GNUNET_CONTAINER_multihashmap32_put (mq->assoc_map, id, assoc_data, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY); return id; } void * GNUNET_MQ_assoc_get (struct GNUNET_MQ_Handle *mq, uint32_t request_id) { if (NULL == mq->assoc_map) return NULL; return GNUNET_CONTAINER_multihashmap32_get (mq->assoc_map, request_id); } void * GNUNET_MQ_assoc_remove (struct GNUNET_MQ_Handle *mq, uint32_t request_id) { void *val; if (NULL == mq->assoc_map) return NULL; val = GNUNET_CONTAINER_multihashmap32_get (mq->assoc_map, request_id); GNUNET_CONTAINER_multihashmap32_remove_all (mq->assoc_map, request_id); return val; } void GNUNET_MQ_notify_sent (struct GNUNET_MQ_Envelope *mqm, GNUNET_MQ_NotifyCallback cb, void *cls) { mqm->sent_cb = cb; mqm->sent_cls = cls; } void GNUNET_MQ_destroy (struct GNUNET_MQ_Handle *mq) { if (NULL != mq->destroy_impl) { mq->destroy_impl (mq, mq->impl_state); } if (NULL != mq->continue_task) { GNUNET_SCHEDULER_cancel (mq->continue_task); mq->continue_task = NULL; } while (NULL != mq->envelope_head) { struct GNUNET_MQ_Envelope *ev; ev = mq->envelope_head; ev->parent_queue = NULL; GNUNET_CONTAINER_DLL_remove (mq->envelope_head, mq->envelope_tail, ev); mq->queue_length--; GNUNET_MQ_discard (ev); } GNUNET_assert (0 == mq->queue_length); if (NULL != mq->current_envelope) { /* we can only discard envelopes that * are not queued! */ mq->current_envelope->parent_queue = NULL; GNUNET_MQ_discard (mq->current_envelope); mq->current_envelope = NULL; } if (NULL != mq->assoc_map) { GNUNET_CONTAINER_multihashmap32_destroy (mq->assoc_map); mq->assoc_map = NULL; } GNUNET_free_non_null (mq->handlers); GNUNET_free (mq); } const struct GNUNET_MessageHeader * GNUNET_MQ_extract_nested_mh_ (const struct GNUNET_MessageHeader *mh, uint16_t base_size) { uint16_t whole_size; uint16_t nested_size; const struct GNUNET_MessageHeader *nested_msg; whole_size = ntohs (mh->size); GNUNET_assert (whole_size >= base_size); nested_size = whole_size - base_size; if (0 == nested_size) return NULL; if (nested_size < sizeof (struct GNUNET_MessageHeader)) { GNUNET_break_op (0); return NULL; } nested_msg = (const struct GNUNET_MessageHeader *) ((char *) mh + base_size); if (ntohs (nested_msg->size) != nested_size) { GNUNET_break_op (0); return NULL; } return nested_msg; } /** * Cancel sending the message. Message must have been sent with * #GNUNET_MQ_send before. May not be called after the notify sent * callback has been called * * @param ev queued envelope to cancel */ void GNUNET_MQ_send_cancel (struct GNUNET_MQ_Envelope *ev) { struct GNUNET_MQ_Handle *mq = ev->parent_queue; GNUNET_assert (NULL != mq); GNUNET_assert (NULL != mq->cancel_impl); if (mq->current_envelope == ev) { // complex case, we already started with transmitting // the message mq->cancel_impl (mq, mq->impl_state); // continue sending the next message, if any if (NULL == mq->envelope_head) { mq->current_envelope = NULL; } else { mq->current_envelope = mq->envelope_head; GNUNET_CONTAINER_DLL_remove (mq->envelope_head, mq->envelope_tail, mq->current_envelope); mq->queue_length--; mq->send_impl (mq, mq->current_envelope->mh, mq->impl_state); } } else { // simple case, message is still waiting in the queue GNUNET_CONTAINER_DLL_remove (mq->envelope_head, mq->envelope_tail, ev); mq->queue_length--; } ev->parent_queue = NULL; ev->mh = NULL; GNUNET_free (ev); } /* end of mq.c */