/*
This file is part of GNUnet.
- (C) 2009-2013 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2009-2013, 2016, 2017 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 free software: you can redistribute it and/or modify it
+ under the terms of the GNU Affero General Public License as published
+ by the Free Software Foundation, either version 3 of the License,
+ 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.
+ Affero General Public License for more details.
+
+ You should have received a copy of the GNU Affero General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
- * @file include/gnunet_service_lib.h
- * @brief functions related to starting services
* @author Christian Grothoff
- * @defgroup service generic functions for implementing service processes
+ *
+ * @file
+ * Functions related to starting services
+ *
+ * @defgroup service Service library
+ * Start service processes.
+ *
+ * @see [Documentation](https://gnunet.org/developer-handbook-util-services)
+ *
* @{
*/
#endif
#include "gnunet_configuration_lib.h"
-#include "gnunet_server_lib.h"
-
-
-/**
- * Get the list of addresses that a server for the given service
- * should bind to.
- *
- * @param service_name name of the service
- * @param cfg configuration (which specifies the addresses)
- * @param addrs set (call by reference) to an array of pointers to the
- * addresses the server should bind to and listen on; the
- * array will be NULL-terminated (on success)
- * @param addr_lens set (call by reference) to an array of the lengths
- * of the respective 'struct sockaddr' struct in the @a addrs
- * array (on success)
- * @return number of addresses found on success,
- * #GNUNET_SYSERR if the configuration
- * did not specify reasonable finding information or
- * if it specified a hostname that could not be resolved;
- * #GNUNET_NO if the number of addresses configured is
- * zero (in this case, '* @a addrs' and '* @a addr_lens' will be
- * set to NULL).
- */
-int
-GNUNET_SERVICE_get_server_addresses (const char *service_name,
- const struct GNUNET_CONFIGURATION_Handle
- *cfg, struct sockaddr ***addrs,
- socklen_t **addr_lens);
-
-
-/**
- * Function called by the service's run
- * method to run service-specific setup code.
- *
- * @param cls closure
- * @param server the initialized server
- * @param cfg configuration to use
- */
-typedef void (*GNUNET_SERVICE_Main) (void *cls,
- struct GNUNET_SERVER_Handle *server,
- const struct GNUNET_CONFIGURATION_Handle *cfg);
+#include "gnunet_mq_lib.h"
/**
enum GNUNET_SERVICE_Options
{
/**
- * Use defaults.
+ * Use defaults. Terminates all client connections and the listen
+ * sockets immediately upon receiving the shutdown signal.
*/
GNUNET_SERVICE_OPTION_NONE = 0,
/**
- * Do not trigger server shutdown on signals, allow for the user
- * to terminate the server explicitly when needed.
+ * Do not trigger server shutdown on signal at all; instead, allow
+ * for the user to terminate the server explicitly when needed
+ * by calling #GNUNET_SERVICE_shutdown().
*/
GNUNET_SERVICE_OPTION_MANUAL_SHUTDOWN = 1,
};
+
+/* **************** NEW SERVICE API ********************** */
+
+/**
+ * Handle to a service.
+ */
+struct GNUNET_SERVICE_Handle;
+
+
/**
- * Run a standard GNUnet service startup sequence (initialize loggers
- * and configuration, parse options).
+ * Handle to a client that is connected to a service.
+ */
+struct GNUNET_SERVICE_Client;
+
+
+/**
+ * Callback to initialize a service, called exactly once when the service is run.
*
- * @param argc number of command line arguments in @a argv
- * @param argv command line arguments
- * @param service_name our service name
- * @param options service options
- * @param task main task of the service
- * @param task_cls closure for @a task
- * @return #GNUNET_SYSERR on error, #GNUNET_OK
- * if we shutdown nicely
+ * @param cls closure passed to #GNUNET_SERVICE_MAIN
+ * @param cfg configuration to use for this service
+ * @param sh handle to the newly create service
*/
-int
-GNUNET_SERVICE_run (int argc, char *const *argv,
- const char *service_name,
- enum GNUNET_SERVICE_Options options,
- GNUNET_SERVICE_Main task,
- void *task_cls);
+typedef void
+(*GNUNET_SERVICE_InitCallback)(void *cls,
+ const struct GNUNET_CONFIGURATION_Handle *cfg,
+ struct GNUNET_SERVICE_Handle *sh);
/**
- * Opaque handle for a service.
+ * Callback to be called when a client connects to the service.
+ *
+ * @param cls closure for the service
+ * @param c the new client that connected to the service
+ * @param mq the message queue used to send messages to the client
+ * @return the client-specific (`internal') closure
*/
-struct GNUNET_SERVICE_Context;
+typedef void *
+(*GNUNET_SERVICE_ConnectHandler)(void *cls,
+ struct GNUNET_SERVICE_Client *c,
+ struct GNUNET_MQ_Handle *mq);
/**
- * Run a service startup sequence within an existing
- * initialized system.
+ * Callback to be called when a client disconnected from the service
+ *
+ * @param cls closure for the service
+ * @param c the client that disconnected
+ * @param internal_cls the client-specific (`internal') closure
+ */
+typedef void
+(*GNUNET_SERVICE_DisconnectHandler)(void *cls,
+ struct GNUNET_SERVICE_Client *c,
+ void *internal_cls);
+
+
+/**
+ * Low-level function to start a service if the scheduler
+ * is already running. Should only be used directly in
+ * special cases.
+ *
+ * The function will launch the service with the name @a service_name
+ * using the @a service_options to configure its shutdown
+ * behavior. When clients connect or disconnect, the respective
+ * @a connect_cb or @a disconnect_cb functions will be called. For
+ * messages received from the clients, the respective @a handlers will
+ * be invoked; for the closure of the handlers we use the return value
+ * from the @a connect_cb invocation of the respective client.
*
- * @param service_name our service name
+ * Each handler MUST call #GNUNET_SERVICE_client_continue() after each
+ * message to receive further messages from this client. If
+ * #GNUNET_SERVICE_client_continue() is not called within a short
+ * time, a warning will be logged. If delays are expected, services
+ * should call #GNUNET_SERVICE_client_disable_continue_warning() to
+ * disable the warning.
+ *
+ * Clients sending invalid messages (based on @a handlers) will be
+ * dropped. Additionally, clients can be dropped at any time using
+ * #GNUNET_SERVICE_client_drop().
+ *
+ * The service must be stopped using #GNUNET_SERVICE_stop().
+ *
+ * @param service_name name of the service to run
* @param cfg configuration to use
- * @param options service options
- * @return NULL on error, service handle
+ * @param connect_cb function to call whenever a client connects
+ * @param disconnect_cb function to call whenever a client disconnects
+ * @param cls closure argument for @a connect_cb and @a disconnect_cb
+ * @param handlers NULL-terminated array of message handlers for the service,
+ * the closure will be set to the value returned by
+ * the @a connect_cb for the respective connection
+ * @return NULL on error
*/
-struct GNUNET_SERVICE_Context *
+struct GNUNET_SERVICE_Handle *
GNUNET_SERVICE_start (const char *service_name,
const struct GNUNET_CONFIGURATION_Handle *cfg,
- enum GNUNET_SERVICE_Options options);
+ GNUNET_SERVICE_ConnectHandler connect_cb,
+ GNUNET_SERVICE_DisconnectHandler disconnect_cb,
+ void *cls,
+ const struct GNUNET_MQ_MessageHandler *handlers);
+
+
+/**
+ * Stops a service that was started with #GNUNET_SERVICE_start().
+ *
+ * @param srv service to stop
+ */
+void
+GNUNET_SERVICE_stop (struct GNUNET_SERVICE_Handle *srv);
+
+
+/**
+ * Creates the "main" function for a GNUnet service. You
+ * should almost always use the #GNUNET_SERVICE_MAIN macro
+ * instead of calling this function directly (except
+ * for ARM, which should call this function directly).
+ *
+ * The function will launch the service with the name @a service_name
+ * using the @a service_options to configure its shutdown
+ * behavior. Once the service is ready, the @a init_cb will be called
+ * for service-specific initialization. @a init_cb will be given the
+ * service handler which can be used to control the service's
+ * availability. When clients connect or disconnect, the respective
+ * @a connect_cb or @a disconnect_cb functions will be called. For
+ * messages received from the clients, the respective @a handlers will
+ * be invoked; for the closure of the handlers we use the return value
+ * from the @a connect_cb invocation of the respective client.
+ *
+ * Each handler MUST call #GNUNET_SERVICE_client_continue() after each
+ * message to receive further messages from this client. If
+ * #GNUNET_SERVICE_client_continue() is not called within a short
+ * time, a warning will be logged. If delays are expected, services
+ * should call #GNUNET_SERVICE_client_disable_continue_warning() to
+ * disable the warning.
+ *
+ * Clients sending invalid messages (based on @a handlers) will be
+ * dropped. Additionally, clients can be dropped at any time using
+ * #GNUNET_SERVICE_client_drop().
+ *
+ * @param argc number of command-line arguments in @a argv
+ * @param argv array of command-line arguments
+ * @param service_name name of the service to run
+ * @param options options controlling shutdown of the service
+ * @param service_init_cb function to call once the service is ready
+ * @param connect_cb function to call whenever a client connects
+ * @param disconnect_cb function to call whenever a client disconnects
+ * @param cls closure argument for @a service_init_cb, @a connect_cb and @a disconnect_cb
+ * @param handlers NULL-terminated array of message handlers for the service,
+ * the closure will be set to the value returned by
+ * the @a connect_cb for the respective connection
+ * @return 0 on success, non-zero on error
+ */
+int
+GNUNET_SERVICE_run_ (int argc,
+ char *const *argv,
+ const char *service_name,
+ enum GNUNET_SERVICE_Options options,
+ GNUNET_SERVICE_InitCallback service_init_cb,
+ GNUNET_SERVICE_ConnectHandler connect_cb,
+ GNUNET_SERVICE_DisconnectHandler disconnect_cb,
+ void *cls,
+ const struct GNUNET_MQ_MessageHandler *handlers);
+
+
+/**
+ * Creates the "main" function for a GNUnet service. You
+ * MUST use this macro to define GNUnet services (except
+ * for ARM, which MUST NOT use the macro). The reason is
+ * the GNUnet-as-a-library project, where we will not define
+ * a main function anywhere but in ARM.
+ *
+ * The macro will launch the service with the name @a service_name
+ * using the @a service_options to configure its shutdown
+ * behavior. Once the service is ready, the @a init_cb will be called
+ * for service-specific initialization. @a init_cb will be given the
+ * service handler which can be used to control the service's
+ * availability. When clients connect or disconnect, the respective
+ * @a connect_cb or @a disconnect_cb functions will be called. For
+ * messages received from the clients, the respective @a handlers will
+ * be invoked; for the closure of the handlers we use the return value
+ * from the @a connect_cb invocation of the respective client.
+ *
+ * Each handler MUST call #GNUNET_SERVICE_client_continue() after each
+ * message to receive further messages from this client. If
+ * #GNUNET_SERVICE_client_continue() is not called within a short
+ * time, a warning will be logged. If delays are expected, services
+ * should call #GNUNET_SERVICE_client_disable_continue_warning() to
+ * disable the warning.
+ *
+ * Clients sending invalid messages (based on @a handlers) will be
+ * dropped. Additionally, clients can be dropped at any time using
+ * #GNUNET_SERVICE_client_drop().
+ *
+ * @param service_name name of the service to run
+ * @param options options controlling shutdown of the service
+ * @param service_init_cb function to call once the service is ready
+ * @param connect_cb function to call whenever a client connects
+ * @param disconnect_cb function to call whenever a client disconnects
+ * @param cls closure argument for @a service_init_cb, @a connect_cb and @a disconnect_cb
+ * @param ... array of message handlers for the service, terminated
+ * by #GNUNET_MQ_handler_end();
+ * the closure will be set to the value returned by
+ * the @a connect_cb for the respective connection
+ * @return 0 on success, non-zero on error
+ *
+ * Sample invocation:
+ * <code>
+ * GNUNET_SERVICE_MAIN
+ * ("resolver",
+ * GNUNET_SERVICE_OPTION_NONE,
+ * &init_cb,
+ * &connect_cb,
+ * &disconnect_cb,
+ * closure_for_cb,
+ * GNUNET_MQ_hd_var_size (get,
+ * GNUNET_MESSAGE_TYPE_RESOLVER_REQUEST,
+ * struct GNUNET_RESOLVER_GetMessage,
+ * NULL),
+ * GNUNET_MQ_handler_end ());
+ * </code>
+ */
+#define GNUNET_SERVICE_MAIN(service_name,service_options,init_cb,connect_cb,disconnect_cb,cls,...) \
+ int \
+ main (int argc,\
+ char *const *argv)\
+ { \
+ struct GNUNET_MQ_MessageHandler mh[] = { \
+ __VA_ARGS__ \
+ }; \
+ return GNUNET_SERVICE_run_ (argc, \
+ argv, \
+ service_name, \
+ service_options, \
+ init_cb, \
+ connect_cb, \
+ disconnect_cb, \
+ cls, \
+ mh); \
+ }
+
+
+/**
+ * Suspend accepting connections from the listen socket temporarily.
+ * Resume activity using #GNUNET_SERVICE_resume.
+ *
+ * @param sh service to stop accepting connections.
+ */
+void
+GNUNET_SERVICE_suspend (struct GNUNET_SERVICE_Handle *sh);
+
+
+/**
+ * Resume accepting connections from the listen socket.
+ *
+ * @param sh service to resume accepting connections.
+ */
+void
+GNUNET_SERVICE_resume (struct GNUNET_SERVICE_Handle *sh);
+
+
+/**
+ * Continue receiving further messages from the given client.
+ * Must be called after each message received.
+ *
+ * @param c the client to continue receiving from
+ */
+void
+GNUNET_SERVICE_client_continue (struct GNUNET_SERVICE_Client *c);
/**
- * Obtain the server used by a service. Note that the server must NOT
- * be destroyed by the caller.
+ * Obtain the message queue of @a c. Convenience function.
*
- * @param ctx the service context returned from the start function
- * @return handle to the server for this service, NULL if there is none
+ * @param c the client to continue receiving from
+ * @return the message queue of @a c
*/
-struct GNUNET_SERVER_Handle *
-GNUNET_SERVICE_get_server (struct GNUNET_SERVICE_Context *ctx);
+struct GNUNET_MQ_Handle *
+GNUNET_SERVICE_client_get_mq (struct GNUNET_SERVICE_Client *c);
/**
- * Stop a service that was started with #GNUNET_SERVICE_start.
+ * Disable the warning the server issues if a message is not
+ * acknowledged in a timely fashion. Use this call if a client is
+ * intentionally delayed for a while. Only applies to the current
+ * message.
*
- * @param sctx the service context returned from the start function
+ * @param c client for which to disable the warning
*/
void
-GNUNET_SERVICE_stop (struct GNUNET_SERVICE_Context *sctx);
+GNUNET_SERVICE_client_disable_continue_warning (struct GNUNET_SERVICE_Client *c);
+
+
+/**
+ * Ask the server to disconnect from the given client. This is the
+ * same as returning #GNUNET_SYSERR within the check procedure when
+ * handling a message, except that it allows dropping of a client even
+ * when not handling a message from that client. The `disconnect_cb`
+ * will be called on @a c even if the application closes the connection
+ * using this function.
+ *
+ * This function should be called (outside of util's internal logic)
+ * if (and usually only if) the client has violated the
+ * protocol. Otherwise, we should leave it to the client to disconnect
+ * from the service.
+ *
+ * @param c client to disconnect now
+ */
+void
+GNUNET_SERVICE_client_drop (struct GNUNET_SERVICE_Client *c);
+
+
+/**
+ * Explicitly stops the service.
+ *
+ * @param sh server to shutdown
+ */
+void
+GNUNET_SERVICE_shutdown (struct GNUNET_SERVICE_Handle *sh);
+
+
+/**
+ * Set the 'monitor' flag on this client. Clients which have been
+ * marked as 'monitors' won't prevent the server from shutting down
+ * once #GNUNET_SERVICE_stop_listening() has been invoked. The idea is
+ * that for "normal" clients we likely want to allow them to process
+ * their requests; however, monitor-clients are likely to 'never'
+ * disconnect during shutdown and thus will not be considered when
+ * determining if the server should continue to exist after
+ * shutdown has been triggered.
+ *
+ * @param c client to mark as a monitor
+ */
+void
+GNUNET_SERVICE_client_mark_monitor (struct GNUNET_SERVICE_Client *c);
+
+
+/**
+ * Set the persist option on this client. Indicates that the
+ * underlying socket or fd should never really be closed. Used for
+ * indicating process death.
+ *
+ * @param c client to persist the socket (never to be closed)
+ */
+void
+GNUNET_SERVICE_client_persist (struct GNUNET_SERVICE_Client *c);
#if 0 /* keep Emacsens' auto-indent happy */
}
#endif
-
-/** @} */ /* end of group service */
-
-
/* ifndef GNUNET_SERVICE_LIB_H */
#endif
+
+/** @} */ /* end of group service */
+
/* end of gnunet_service_lib.h */
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