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- /*
- This file is part of GNUnet.
- (C) 2013 Christian Grothoff (and other contributing authors)
- GNUnet is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published
- by the Free Software Foundation; either version 3, or (at your
- option) any later version.
- GNUnet is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with GNUnet; see the file COPYING. If not, write to the
- Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA.
- */
- /**
- * @file util/client_manager.c
- * @brief Client manager; higher level client API with transmission queue
- * and message handler registration.
- * @author Gabor X Toth
- */
- #include <inttypes.h>
- #include "platform.h"
- #include "gnunet_util_lib.h"
- #define LOG(kind,...) GNUNET_log_from (kind, "util-client-mgr", __VA_ARGS__)
- /**
- * List of arrays of message handlers.
- */
- struct HandlersListItem
- {
- struct HandlersListItem *prev;
- struct HandlersListItem *next;
- /**
- * NULL-terminated array of handlers.
- */
- const struct GNUNET_CLIENT_MANAGER_MessageHandler *handlers;
- };
- struct MessageQueueItem
- {
- struct MessageQueueItem *prev;
- struct MessageQueueItem *next;
- struct GNUNET_MessageHeader *msg;
- };
- struct GNUNET_CLIENT_MANAGER_Connection
- {
- /**
- * Configuration to use.
- */
- const struct GNUNET_CONFIGURATION_Handle *cfg;
- /**
- * Client connection to service.
- */
- struct GNUNET_CLIENT_Connection *client;
- /**
- * Currently pending transmission request, or NULL for none.
- */
- struct GNUNET_CLIENT_TransmitHandle *client_tmit;
- /**
- * Service name to connect to.
- */
- const char *service_name;
- /**
- * Head of messages to transmit to the service.
- */
- struct MessageQueueItem *tmit_head;
- /**
- * Tail of messages to transmit to the service.
- */
- struct MessageQueueItem *tmit_tail;
- /**
- * Message handlers.
- */
- const struct GNUNET_CLIENT_MANAGER_MessageHandler *handlers;
- /**
- * Disconnect callback.
- */
- void (*disconnect_cb)(void *);
- /**
- * Disconnect closure.
- */
- void *disconnect_cls;
- /**
- * User context value.
- * @see GNUNET_CLIENT_MANAGER_set_user_context()
- * @see GNUNET_CLIENT_MANAGER_get_user_context()
- */
- void *user_ctx;
- /**
- * Last size given when user context was initialized.
- * Used for sanity check.
- */
- size_t user_ctx_size;
- /**
- * Task doing exponential back-off trying to reconnect.
- */
- GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
- /**
- * Time for next connect retry.
- */
- struct GNUNET_TIME_Relative reconnect_delay;
- /**
- * Are we currently polling for incoming messages?
- */
- uint8_t in_receive;
- /**
- * #GNUNET_YES if GNUNET_CLIENT_MANAGER_disconnect() was called
- * and we're transmitting the last messages from the queue.
- */
- uint8_t is_disconnecting;
- };
- /**
- * Handle received messages from the service.
- */
- static void
- recv_message (void *cls, const struct GNUNET_MessageHeader *msg)
- {
- struct GNUNET_CLIENT_MANAGER_Connection *mgr = cls;
- uint16_t type = 0, size = 0;
- if (NULL != msg)
- {
- type = ntohs (msg->type);
- size = ntohs (msg->size);
- /* FIXME: decrease reconnect_delay gradually after a successful reconnection */
- }
- size_t i = 0;
- while (NULL != mgr->handlers[i].callback)
- {
- const struct GNUNET_CLIENT_MANAGER_MessageHandler *mh = &mgr->handlers[i];
- if ((mh->type == type) || (mh->type == GNUNET_MESSAGE_TYPE_ALL))
- {
- if (0 != mh->expected_size
- && ((GNUNET_NO == mh->is_variable_size && size != mh->expected_size)
- || (GNUNET_YES == mh->is_variable_size && size < mh->expected_size)))
- {
- LOG (GNUNET_ERROR_TYPE_ERROR,
- "Expected %u bytes for message of type %u, got %u.\n",
- mh->expected_size, type, size);
- GNUNET_break_op (0);
- GNUNET_CLIENT_disconnect (mgr->client);
- mgr->client = NULL;
- recv_message (mgr, NULL);
- break;
- }
- mh->callback (mh->callback_cls, mgr, msg);
- }
- i++;
- }
- if (NULL != mgr->client)
- {
- GNUNET_CLIENT_receive (mgr->client, &recv_message, mgr,
- GNUNET_TIME_UNIT_FOREVER_REL);
- }
- }
- /**
- * Schedule transmission of the next message from our queue.
- *
- * @param mgr Client manager connection.
- */
- static void
- transmit_next (struct GNUNET_CLIENT_MANAGER_Connection *mgr);
- static void
- schedule_disconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
- {
- struct GNUNET_CLIENT_MANAGER_Connection *mgr = cls;
- GNUNET_CLIENT_MANAGER_disconnect (mgr, GNUNET_NO,
- mgr->disconnect_cb, mgr->disconnect_cls);
- }
- /**
- * Transmit next message to service.
- *
- * @param cls
- * struct GNUNET_CLIENT_MANAGER_Connection
- * @param size
- * Number of bytes available in @a buf.
- * @param buf
- * Where to copy the message.
- *
- * @return Number of bytes copied to @a buf.
- */
- static size_t
- send_next_message (void *cls, size_t buf_size, void *buf)
- {
- LOG (GNUNET_ERROR_TYPE_DEBUG, "send_next_message()\n");
- struct GNUNET_CLIENT_MANAGER_Connection *mgr = cls;
- if (NULL == buf)
- {
- /* disconnected */
- recv_message (mgr, NULL);
- return 0;
- }
- struct MessageQueueItem *mqi = mgr->tmit_head;
- if (NULL == mqi)
- return 0;
- uint16_t size = ntohs (mqi->msg->size);
- mgr->client_tmit = NULL;
- GNUNET_assert (size <= buf_size);
- memcpy (buf, mqi->msg, size);
- GNUNET_CONTAINER_DLL_remove (mgr->tmit_head, mgr->tmit_tail, mqi);
- GNUNET_free (mqi->msg);
- GNUNET_free (mqi);
- if (NULL != mgr->tmit_head)
- {
- transmit_next (mgr);
- }
- else if (GNUNET_YES == mgr->is_disconnecting)
- {
- GNUNET_SCHEDULER_add_now (&schedule_disconnect, mgr);
- return size;
- }
- if (GNUNET_NO == mgr->in_receive)
- {
- mgr->in_receive = GNUNET_YES;
- GNUNET_CLIENT_receive (mgr->client, &recv_message, mgr,
- GNUNET_TIME_UNIT_FOREVER_REL);
- }
- return size;
- }
- /**
- * Schedule transmission of the next message from our queue.
- *
- * @param mgr Client manager connection.
- */
- static void
- transmit_next (struct GNUNET_CLIENT_MANAGER_Connection *mgr)
- {
- LOG (GNUNET_ERROR_TYPE_DEBUG, "transmit_next()\n");
- if (NULL != mgr->client_tmit || NULL == mgr->client)
- return;
- if (NULL == mgr->tmit_head)
- {
- if (GNUNET_YES == mgr->is_disconnecting)
- GNUNET_CLIENT_MANAGER_disconnect (mgr, GNUNET_NO,
- mgr->disconnect_cb, mgr->disconnect_cls);
- return;
- }
- mgr->client_tmit
- = GNUNET_CLIENT_notify_transmit_ready (mgr->client,
- ntohs (mgr->tmit_head->msg->size),
- GNUNET_TIME_UNIT_FOREVER_REL,
- GNUNET_NO,
- &send_next_message,
- mgr);
- }
- /**
- * Try again to connect to the service.
- *
- * @param cls
- * Channel handle.
- * @param tc
- * Scheduler context.
- */
- static void
- schedule_reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
- {
- struct GNUNET_CLIENT_MANAGER_Connection *mgr = cls;
- mgr->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
- LOG (GNUNET_ERROR_TYPE_DEBUG,
- "Connecting to %s service.\n", mgr->service_name);
- GNUNET_assert (NULL == mgr->client);
- mgr->client = GNUNET_CLIENT_connect (mgr->service_name, mgr->cfg);
- GNUNET_assert (NULL != mgr->client);
- transmit_next (mgr);
- }
- /**
- * Connect to service.
- *
- * @param cfg
- * Configuration to use.
- * @param service_name
- * Service name to connect to.
- * @param handlers
- * Message handlers.
- *
- * @return Client manager connection handle.
- */
- struct GNUNET_CLIENT_MANAGER_Connection *
- GNUNET_CLIENT_MANAGER_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
- const char *service_name,
- const struct
- GNUNET_CLIENT_MANAGER_MessageHandler *handlers)
- {
- struct GNUNET_CLIENT_MANAGER_Connection *
- mgr = GNUNET_malloc (sizeof (*mgr));
- mgr->cfg = cfg;
- mgr->service_name = service_name;
- mgr->handlers = handlers;
- mgr->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
- mgr->reconnect_task = GNUNET_SCHEDULER_add_now (&schedule_reconnect, mgr);
- return mgr;
- }
- /**
- * Disconnect from the service.
- *
- * @param mgr
- * Client manager connection.
- * @param transmit_queue
- * Transmit pending messages in queue before disconnecting.
- * @param disconnect_cb
- * Function called after disconnected from the service.
- * @param cls
- * Closure for @a disconnect_cb.
- */
- void
- GNUNET_CLIENT_MANAGER_disconnect (struct GNUNET_CLIENT_MANAGER_Connection *mgr,
- int transmit_queue,
- GNUNET_ContinuationCallback disconnect_cb,
- void *cls)
- {
- LOG (GNUNET_ERROR_TYPE_DEBUG, "Disconnecting (%d)\n", transmit_queue);
- mgr->disconnect_cb = disconnect_cb;
- mgr->disconnect_cls = cls;
- if (NULL != mgr->tmit_head)
- {
- if (GNUNET_YES == transmit_queue)
- {
- mgr->is_disconnecting = GNUNET_YES;
- transmit_next (mgr);
- return;
- }
- else
- {
- LOG (GNUNET_ERROR_TYPE_DEBUG,
- "Disconnecting while there are still messages "
- "in the transmission queue.\n");
- GNUNET_CLIENT_MANAGER_drop_queue (mgr);
- }
- }
- if (mgr->reconnect_task != GNUNET_SCHEDULER_NO_TASK)
- {
- GNUNET_SCHEDULER_cancel (mgr->reconnect_task);
- mgr->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
- }
- if (NULL != mgr->client_tmit)
- {
- GNUNET_CLIENT_notify_transmit_ready_cancel (mgr->client_tmit);
- mgr->client_tmit = NULL;
- }
- if (NULL != mgr->client)
- {
- GNUNET_CLIENT_disconnect (mgr->client);
- mgr->client = NULL;
- }
- if (NULL != mgr->disconnect_cb)
- mgr->disconnect_cb (mgr->disconnect_cls);
- GNUNET_free (mgr);
- LOG (GNUNET_ERROR_TYPE_DEBUG, "Disconnected.\n");
- }
- /**
- * Reschedule connect to the service using exponential back-off.
- *
- * @param mgr
- * Client manager connection.
- */
- void
- GNUNET_CLIENT_MANAGER_reconnect (struct GNUNET_CLIENT_MANAGER_Connection *mgr)
- {
- if (GNUNET_SCHEDULER_NO_TASK != mgr->reconnect_task)
- return;
- if (NULL != mgr->client_tmit)
- {
- GNUNET_CLIENT_notify_transmit_ready_cancel (mgr->client_tmit);
- mgr->client_tmit = NULL;
- }
- if (NULL != mgr->client)
- {
- GNUNET_CLIENT_disconnect (mgr->client);
- mgr->client = NULL;
- }
- mgr->in_receive = GNUNET_NO;
- LOG (GNUNET_ERROR_TYPE_DEBUG,
- "Scheduling task to reconnect to service in %s.\n",
- GNUNET_STRINGS_relative_time_to_string (mgr->reconnect_delay, GNUNET_YES));
- mgr->reconnect_task =
- GNUNET_SCHEDULER_add_delayed (mgr->reconnect_delay, &schedule_reconnect, mgr);
- mgr->reconnect_delay = GNUNET_TIME_STD_BACKOFF (mgr->reconnect_delay);
- }
- /**
- * Add a message to the end of the transmission queue.
- *
- * @param mgr
- * Client manager connection.
- * @param msg
- * Message to transmit, should be allocated with GNUNET_malloc() or
- * GNUNET_new(), as it is freed with GNUNET_free() after transmission.
- */
- void
- GNUNET_CLIENT_MANAGER_transmit (struct GNUNET_CLIENT_MANAGER_Connection *mgr,
- struct GNUNET_MessageHeader *msg)
- {
- struct MessageQueueItem *mqi = GNUNET_malloc (sizeof (*mqi));
- mqi->msg = msg;
- GNUNET_CONTAINER_DLL_insert_tail (mgr->tmit_head, mgr->tmit_tail, mqi);
- transmit_next (mgr);
- }
- /**
- * Add a message to the beginning of the transmission queue.
- *
- * @param mgr
- * Client manager connection.
- * @param msg
- * Message to transmit, should be allocated with GNUNET_malloc() or
- * GNUNET_new(), as it is freed with GNUNET_free() after transmission.
- */
- void
- GNUNET_CLIENT_MANAGER_transmit_now (struct GNUNET_CLIENT_MANAGER_Connection *mgr,
- struct GNUNET_MessageHeader *msg)
- {
- struct MessageQueueItem *mqi = GNUNET_malloc (sizeof (*mqi));
- mqi->msg = msg;
- GNUNET_CONTAINER_DLL_insert (mgr->tmit_head, mgr->tmit_tail, mqi);
- transmit_next (mgr);
- }
- /**
- * Drop all queued messages.
- *
- * @param mgr
- * Client manager connection.
- */
- void
- GNUNET_CLIENT_MANAGER_drop_queue (struct GNUNET_CLIENT_MANAGER_Connection *mgr)
- {
- struct MessageQueueItem *cur, *next = mgr->tmit_head;
- while (NULL != next)
- {
- cur = next;
- next = cur->next;
- GNUNET_free (cur->msg);
- GNUNET_free (cur);
- }
- }
- /**
- * Obtain client connection handle.
- *
- * @param mgr
- * Client manager connection.
- *
- * @return Client connection handle.
- */
- struct GNUNET_CLIENT_Connection *
- GNUNET_CLIENT_MANAGER_get_client (struct GNUNET_CLIENT_MANAGER_Connection *mgr)
- {
- return mgr->client;
- }
- /**
- * Return user context associated with the given client.
- * Note: you should probably use the macro (call without the underscore).
- *
- * @param mgr
- * Client manager connection.
- * @param size
- * Number of bytes in user context struct (for verification only).
- *
- * @return User context.
- */
- void *
- GNUNET_CLIENT_MANAGER_get_user_context_ (struct GNUNET_CLIENT_MANAGER_Connection *mgr,
- size_t size)
- {
- if ((0 == mgr->user_ctx_size) &&
- (NULL == mgr->user_ctx))
- return NULL; /* never set */
- GNUNET_assert (size == mgr->user_ctx_size);
- return mgr->user_ctx;
- }
- /**
- * Set user context to be associated with the given client.
- * Note: you should probably use the macro (call without the underscore).
- *
- * @param mgr
- * Client manager connection.
- * @param ctx
- * User context.
- * @param size
- * Number of bytes in user context struct (for verification only).
- */
- void
- GNUNET_CLIENT_MANAGER_set_user_context_ (struct GNUNET_CLIENT_MANAGER_Connection *mgr,
- void *ctx,
- size_t size)
- {
- if (NULL == ctx)
- {
- mgr->user_ctx_size = 0;
- mgr->user_ctx = ctx;
- return;
- }
- mgr->user_ctx_size = size;
- mgr->user_ctx = ctx;
- }
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