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22 * @file util/service_new.c
23 * @brief functions related to starting services (redesign)
24 * @author Christian Grothoff
27 #include "gnunet_util_lib.h"
28 #include "gnunet_protocols.h"
29 #include "gnunet_constants.h"
30 #include "gnunet_resolver_service.h"
34 * Information the service tracks per listen operation.
36 struct ServiceListenContext
42 struct ServiceListenContext *next;
47 struct ServiceListenContext *prev;
50 * Service this listen context belongs to.
52 struct GNUNET_SERVICE_Handle *sh;
55 * Socket we are listening on.
57 struct GNUNET_NETWORK_Handle *listen_socket;
60 * Task scheduled to do the listening.
62 struct GNUNET_SCHEDULER_Task *listen_task;
68 * Handle to a service.
70 struct GNUNET_SERVICE_Handle
75 const struct GNUNET_CONFIGURATION_Handle *cfg;
78 * Name of our service.
80 const char *service_name;
83 * Main service-specific task to run.
85 GNUNET_SERVICE_InitCallback service_init_cb;
88 * Function to call when clients connect.
90 GNUNET_SERVICE_ConnectHandler connect_cb;
93 * Function to call when clients disconnect / are disconnected.
95 GNUNET_SERVICE_DisconnectHandler disconnect_cb;
98 * Closure for @e service_init_cb, @e connect_cb, @e disconnect_cb.
103 * DLL of listen sockets used to accept new connections.
105 struct ServiceListenContext *slc_head;
108 * DLL of listen sockets used to accept new connections.
110 struct ServiceListenContext *slc_tail;
113 * Our clients, kept in a DLL.
115 struct GNUNET_SERVICE_Client *clients_head;
118 * Our clients, kept in a DLL.
120 struct GNUNET_SERVICE_Client *clients_tail;
123 * Message handlers to use for all clients.
125 const struct GNUNET_MQ_MessageHandler *handlers;
128 * Closure for @e task.
133 * IPv4 addresses that are not allowed to connect.
135 struct GNUNET_STRINGS_IPv4NetworkPolicy *v4_denied;
138 * IPv6 addresses that are not allowed to connect.
140 struct GNUNET_STRINGS_IPv6NetworkPolicy *v6_denied;
143 * IPv4 addresses that are allowed to connect (if not
144 * set, all are allowed).
146 struct GNUNET_STRINGS_IPv4NetworkPolicy *v4_allowed;
149 * IPv6 addresses that are allowed to connect (if not
150 * set, all are allowed).
152 struct GNUNET_STRINGS_IPv6NetworkPolicy *v6_allowed;
155 * Do we require a matching UID for UNIX domain socket connections?
156 * #GNUNET_NO means that the UID does not have to match (however,
157 * @e match_gid may still impose other access control checks).
162 * Do we require a matching GID for UNIX domain socket connections?
163 * Ignored if @e match_uid is #GNUNET_YES. Note that this is about
164 * checking that the client's UID is in our group OR that the
165 * client's GID is our GID. If both "match_gid" and @e match_uid are
166 * #GNUNET_NO, all users on the local system have access.
171 * Set to #GNUNET_YES if we got a shutdown signal and terminate
172 * the service if #have_non_monitor_clients() returns #GNUNET_YES.
179 enum GNUNET_SERVICE_Options options;
185 * Handle to a client that is connected to a service.
187 struct GNUNET_SERVICE_Client
193 struct GNUNET_SERVICE_Client *next;
198 struct GNUNET_SERVICE_Client *prev;
201 * Server that this client belongs to.
203 struct GNUNET_SERVER_Handle *server;
206 * Task that warns about missing calls to
207 * #GNUNET_SERVICE_client_continue().
209 struct GNUNET_SCHEDULER_Task *warn_task;
212 * User context value, value returned from
213 * the connect callback.
218 * Persist the file handle for this client no matter what happens,
219 * force the OS to close once the process actually dies. Should only
220 * be used in special cases!
225 * Is this client a 'monitor' client that should not be counted
226 * when deciding on destroying the server during soft shutdown?
227 * (see also #GNUNET_SERVICE_start)
232 * Type of last message processed (for warn_no_receive_done).
239 * Check if any of the clients we have left are unrelated to
242 * @param sh service to check clients for
243 * @return #GNUNET_YES if we have non-monitoring clients left
246 have_non_monitor_clients (struct GNUNET_SERVICE_Handle *sh)
248 struct GNUNET_SERVICE_Client *client;
250 for (client = sh->clients_head;NULL != client; client = client->next)
252 if (client->is_monitor)
261 * Shutdown task triggered when a service should be terminated.
262 * This considers active clients and the service options to see
263 * how this specific service is to be terminated, and depending
264 * on this proceeds with the shutdown logic.
266 * @param cls our `struct GNUNET_SERVICE_Handle`
269 service_main (void *cls)
271 struct GNUNET_SERVICE_Handle *sh = cls;
272 struct GNUNET_SERVICE_Client *client;
277 case GNUNET_SERVICE_OPTION_NONE:
278 GNUNET_SERVICE_shutdown (sh);
280 case GNUNET_SERVICE_OPTION_MANUAL_SHUTDOWN:
281 /* This task should never be run if we are using
282 the manual shutdown. */
285 case GNUNET_SERVICE_OPTION_SOFT_SHUTDOWN:
286 sh->got_shutdown = GNUNET_YES;
287 GNUNET_SERVICE_suspend (sh);
288 if (GNUNET_NO == have_non_monitor_clients (sh))
289 GNUNET_SERVICE_shutdown (sh);
296 * First task run by any service. Initializes our shutdown task,
297 * starts the listening operation on our listen sockets and launches
298 * the custom logic of the application service.
300 * @param cls our `struct GNUNET_SERVICE_Handle`
303 service_main (void *cls)
305 struct GNUNET_SERVICE_Handle *sh = cls;
307 if (GNUNET_SERVICE_OPTION_MANUAL_SHUTDOWN != sh->options)
308 GNUNET_SCHEDULER_add_shutdown (&service_shutdown,
310 GNUNET_SERVICE_resume (sh);
311 sh->service_init_cb (sh->cb_cls,
318 * Creates the "main" function for a GNUnet service. You
319 * should almost always use the #GNUNET_SERVICE_MAIN macro
320 * instead of calling this function directly (except
321 * for ARM, which should call this function directly).
323 * The function will launch the service with the name @a service_name
324 * using the @a service_options to configure its shutdown
325 * behavior. Once the service is ready, the @a init_cb will be called
326 * for service-specific initialization. @a init_cb will be given the
327 * service handler which can be used to control the service's
328 * availability. When clients connect or disconnect, the respective
329 * @a connect_cb or @a disconnect_cb functions will be called. For
330 * messages received from the clients, the respective @a handlers will
331 * be invoked; for the closure of the handlers we use the return value
332 * from the @a connect_cb invocation of the respective client.
334 * Each handler MUST call #GNUNET_SERVICE_client_continue() after each
335 * message to receive further messages from this client. If
336 * #GNUNET_SERVICE_client_continue() is not called within a short
337 * time, a warning will be logged. If delays are expected, services
338 * should call #GNUNET_SERVICE_client_disable_continue_warning() to
339 * disable the warning.
341 * Clients sending invalid messages (based on @a handlers) will be
342 * dropped. Additionally, clients can be dropped at any time using
343 * #GNUNET_SERVICE_client_drop().
345 * @param argc number of command-line arguments in @a argv
346 * @param argv array of command-line arguments
347 * @param service_name name of the service to run
348 * @param options options controlling shutdown of the service
349 * @param service_init_cb function to call once the service is ready
350 * @param connect_cb function to call whenever a client connects
351 * @param disconnect_cb function to call whenever a client disconnects
352 * @param cls closure argument for @a service_init_cb, @a connect_cb and @a disconnect_cb
353 * @param handlers NULL-terminated array of message handlers for the service,
354 * the closure will be set to the value returned by
355 * the @a connect_cb for the respective connection
356 * @return 0 on success, non-zero on error
359 GNUNET_SERVICE_ruN_ (int argc,
361 const char *service_name,
362 enum GNUNET_SERVICE_Options options,
363 GNUNET_SERVICE_InitCallback service_init_cb,
364 GNUNET_SERVICE_ConnectHandler connect_cb,
365 GNUNET_SERVICE_DisconnectHandler disconnect_cb,
367 const struct GNUNET_MQ_MessageHandler *handlers)
369 struct GNUNET_SERVICE_Handle sh;
371 // FIXME: setup (parse command line, configuration, init sh)
372 GNUNET_SCHEDULER_run (&service_main,
380 * Suspend accepting connections from the listen socket temporarily.
381 * Resume activity using #GNUNET_SERVICE_resume.
383 * @param sh service to stop accepting connections.
386 GNUNET_SERVICE_suspend (struct GNUNET_SERVICE_Handle *sh)
388 struct ServiceListenContext *slc;
390 for (slc = slc_head; NULL != slc; slc = slc->next)
392 if (NULL != slc->listen_task)
394 GNUNET_SCHEDULER_cancel (slc->listen_task);
395 slc->listen_task = NULL;
402 * We have a client. Accept the incoming socket(s) (and reschedule
406 accept_client (void *cls)
408 struct ServiceListenContext *slc = cls;
410 slc->listen_task = NULL;
412 slc->listen_task = GNUNET_SCHEDULER_add_read (slc->listen_socket,
419 * Resume accepting connections from the listen socket.
421 * @param sh service to resume accepting connections.
424 GNUNET_SERVICE_resume (struct GNUNET_SERVICE_Handle *sh)
426 struct ServiceListenContext *slc;
428 for (slc = slc_head; NULL != slc; slc = slc->next)
430 GNUNET_assert (NULL == slc->listen_task);
431 slc->listen_task = GNUNET_SCHEDULER_add_read (slc->listen_socket,
439 * Continue receiving further messages from the given client.
440 * Must be called after each message received.
442 * @param c the client to continue receiving from
445 GNUNET_SERVICE_client_continue (struct GNUNET_SERVICE_Client *c)
447 GNUNET_break (0); // not implemented
452 * Disable the warning the server issues if a message is not
453 * acknowledged in a timely fashion. Use this call if a client is
454 * intentionally delayed for a while. Only applies to the current
457 * @param c client for which to disable the warning
460 GNUNET_SERVICE_client_disable_continue_warning (struct GNUNET_SERVICE_Client *c)
462 GNUNET_break (NULL != c->warn_task);
463 if (NULL != c->warn_task)
465 GNUNET_SCHEDULER_cancel (c->warn_task);
472 * Ask the server to disconnect from the given client. This is the
473 * same as returning #GNUNET_SYSERR within the check procedure when
474 * handling a message, wexcept that it allows dropping of a client even
475 * when not handling a message from that client. The `disconnect_cb`
476 * will be called on @a c even if the application closes the connection
477 * using this function.
479 * @param c client to disconnect now
482 GNUNET_SERVICE_client_drop (struct GNUNET_SERVICE_Client *c)
484 struct GNUNET_SERVICE_Handle *sh = c->sh;
486 GNUNET_CONTAINER_DLL_remove (sh->clients_head,
489 sh->disconnect_cb (sh->cb_cls,
492 if (NULL != c->warn_task)
494 GNUNET_SCHEDULER_cancel (c->warn_task);
497 if (GNUNET_NO == c->persist)
499 GNUNET_break (0); // FIXME: close socket, etc.
502 if ( (GNUNET_YES == sh->got_shutdown) &&
503 (GNUNET_NO == have_non_monitor_clients (sh)) )
504 GNUNET_SERVICE_shutdown (sh);
509 * Explicitly stops the service.
511 * @param sh server to shutdown
514 GNUNET_SERVICE_shutdown (struct GNUNET_SERVICE_Handle *sh)
516 struct GNUNET_SERVICE_Client *client;
518 GNUNET_SERVICE_suspend (sh);
519 sh->got_shutdown = GNUNET_NO;
520 while (NULL != (client = sh->clients_head))
521 GNUNET_SERVICE_client_drop (client);
526 * Set the 'monitor' flag on this client. Clients which have been
527 * marked as 'monitors' won't prevent the server from shutting down
528 * once #GNUNET_SERVICE_stop_listening() has been invoked. The idea is
529 * that for "normal" clients we likely want to allow them to process
530 * their requests; however, monitor-clients are likely to 'never'
531 * disconnect during shutdown and thus will not be considered when
532 * determining if the server should continue to exist after
533 * shutdown has been triggered.
535 * @param c client to mark as a monitor
538 GNUNET_SERVICE_client_mark_monitor (struct GNUNET_SERVICE_Client *c)
540 c->is_monitor = GNUNET_YES;
541 if ( (GNUNET_YES == sh->got_shutdown) &&
542 (GNUNET_NO == have_non_monitor_clients (sh)) )
543 GNUNET_SERVICE_shutdown (sh);
548 * Set the persist option on this client. Indicates that the
549 * underlying socket or fd should never really be closed. Used for
550 * indicating process death.
552 * @param c client to persist the socket (never to be closed)
555 GNUNET_SERVICE_client_persist (struct GNUNET_SERVICE_Client *c)
557 c->persist = GNUNET_YES;
561 /* end of service_new.c */