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3 Copyright (C) 2013 Christian Grothoff (and other contributing authors)
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22 * @file include/gnunet_social_service.h
23 * @brief Social service; implements social interactions using the PSYC service.
24 * @author Gabor X Toth
25 * @author Christian Grothoff
27 #ifndef GNUNET_SOCIAL_SERVICE_H
28 #define GNUNET_SOCIAL_SERVICE_H
33 #if 0 /* keep Emacsens' auto-indent happy */
38 #include "gnunet_util_lib.h"
39 #include "gnunet_env_lib.h"
40 #include "gnunet_identity_service.h"
41 #include "gnunet_psyc_service.h"
45 * Version number of GNUnet Social API.
47 #define GNUNET_SOCIAL_VERSION 0x00000000
51 * Handle for a pseudonym of another user in the network.
53 struct GNUNET_SOCIAL_Nym;
56 * Handle for a place where social interactions happen.
58 struct GNUNET_SOCIAL_Place;
61 * Host handle for a place that we entered.
63 struct GNUNET_SOCIAL_Host;
66 * Guest handle for place that we entered.
68 struct GNUNET_SOCIAL_Guest;
71 * Handle to an implementation of try-and-slice.
73 struct GNUNET_SOCIAL_Slicer;
77 * Function called upon receiving a message indicating a call to a @e method.
79 * This function is called one or more times for each message until all data
80 * fragments arrive from the network.
85 * Message part, as it arrived from the network.
87 * Message counter, monotonically increasing from 1.
89 * The sender of the message.
90 * Can be NULL if the message is not connected to a pseudonym.
92 * OR'ed GNUNET_PSYC_MessageFlags
94 * Original method name from PSYC.
95 * May be more specific than the registered method name due to
96 * try-and-slice matching.
99 (*GNUNET_SOCIAL_MethodCallback) (void *cls,
100 const struct GNUNET_PSYC_MessageMethod *msg,
103 const struct GNUNET_SOCIAL_Nym *nym,
104 const char *method_name);
108 * Function called upon receiving a modifier of a message.
113 * Message ID this data fragment belongs to.
115 * Message part, as it arrived from the network.
117 * Operation to perform.
118 * 0 in case of a modifier continuation.
120 * Name of the modifier.
121 * NULL in case of a modifier continuation.
123 * Value of the modifier.
128 (*GNUNET_SOCIAL_ModifierCallback) (void *cls,
129 const struct GNUNET_MessageHeader *msg,
131 enum GNUNET_ENV_Operator oper,
135 uint16_t full_value_size);
139 * Function called upon receiving a data fragment of a message.
144 * Message ID this data fragment belongs to.
146 * Message part, as it arrived from the network.
148 * Byte offset of @a data in the overall data of the method.
150 * Number of bytes in @a data.
152 * Data stream given to the method.
155 * #GNUNET_NO if there are further fragments,
156 * #GNUNET_YES if this is the last fragment,
157 * #GNUNET_SYSERR indicates the message was cancelled by the sender.
160 (*GNUNET_SOCIAL_DataCallback) (void *cls,
161 const struct GNUNET_MessageHeader *msg,
163 uint64_t data_offset,
174 * Message part, as it arrived from the network.
176 * Message ID this data fragment belongs to.
178 * #GNUNET_YES if the message was cancelled,
179 * #GNUNET_NO if the message is complete.
182 (*GNUNET_SOCIAL_EndOfMessageCallback) (void *cls,
183 const struct GNUNET_MessageHeader *msg,
189 * Create a try-and-slice instance.
191 * A slicer processes incoming messages and notifies callbacks about matching
192 * methods or modifiers encountered.
194 * @return A new try-and-slice construct.
196 struct GNUNET_SOCIAL_Slicer *
197 GNUNET_SOCIAL_slicer_create (void);
201 * Add a method to the try-and-slice instance.
203 * The callbacks are called for messages with a matching @a method_name prefix.
206 * The try-and-slice instance to extend.
208 * Name of the given method, use empty string to match all.
210 * Method handler invoked upon a matching message.
212 * Modifier handler, invoked after @a method_cb
213 * for each modifier in the message.
215 * Data handler, invoked after @a modifier_cb for each data fragment.
217 * Invoked upon reaching the end of a matching message.
219 * Closure for the callbacks.
222 GNUNET_SOCIAL_slicer_method_add (struct GNUNET_SOCIAL_Slicer *slicer,
223 const char *method_name,
224 GNUNET_SOCIAL_MethodCallback method_cb,
225 GNUNET_SOCIAL_ModifierCallback modifier_cb,
226 GNUNET_SOCIAL_DataCallback data_cb,
227 GNUNET_SOCIAL_EndOfMessageCallback eom_cb,
231 * Remove a registered method from the try-and-slice instance.
233 * Removes one matching handler registered with the given
234 * @a method_name and callbacks.
237 * The try-and-slice instance.
239 * Name of the method to remove.
247 * End of message handler.
249 * @return #GNUNET_OK if a method handler was removed,
250 * #GNUNET_NO if no handler matched the given method name and callbacks.
253 GNUNET_SOCIAL_slicer_method_remove (struct GNUNET_SOCIAL_Slicer *slicer,
254 const char *method_name,
255 GNUNET_SOCIAL_MethodCallback method_cb,
256 GNUNET_SOCIAL_ModifierCallback modifier_cb,
257 GNUNET_SOCIAL_DataCallback data_cb,
258 GNUNET_SOCIAL_EndOfMessageCallback eom_cb);
262 * Watch a place for changed objects.
265 * The try-and-slice instance.
266 * @param object_filter
267 * Object prefix to match.
269 * Function to call when encountering a state modifier.
271 * Closure for callback.
274 GNUNET_SOCIAL_slicer_modifier_add (struct GNUNET_SOCIAL_Slicer *slicer,
275 const char *object_filter,
276 GNUNET_SOCIAL_ModifierCallback modifier_cb,
281 * Remove a registered modifier from the try-and-slice instance.
283 * Removes one matching handler registered with the given
284 * @a object_filter and callback.
287 * The try-and-slice instance.
288 * @param object_filter
289 * Object prefix to match.
291 * Function to call when encountering a state modifier changes.
294 GNUNET_SOCIAL_slicer_modifier_remove (struct GNUNET_SOCIAL_Slicer *slicer,
295 const char *object_filter,
296 GNUNET_SOCIAL_ModifierCallback modifier_cb);
300 * Destroy a given try-and-slice instance.
306 GNUNET_SOCIAL_slicer_destroy (struct GNUNET_SOCIAL_Slicer *slicer);
310 * Function called asking for nym to be admitted to the place.
312 * Should call either GNUNET_SOCIAL_host_admit() or
313 * GNUNET_SOCIAL_host_reject_entry() (possibly asynchronously). If this host
314 * cannot decide, it is fine to call neither function, in which case hopefully
315 * some other host of the place exists that will make the decision. The @a nym
316 * reference remains valid until the #GNUNET_SOCIAL_FarewellCallback is invoked
319 * @param cls Closure.
320 * @param nym Handle for the user who wants to enter.
321 * @param method_name Method name in the entry request.
322 * @param variable_count Number of elements in the @a variables array.
323 * @param variables Variables present in the message.
324 * @param data_size Number of bytes in @a data.
325 * @param data Payload given on enter (e.g. a password).
328 (*GNUNET_SOCIAL_AnswerDoorCallback) (void *cls,
329 struct GNUNET_SOCIAL_Nym *nym,
330 const char *method_name,
331 struct GNUNET_ENV_Environment *env,
337 * Function called when a @a nym leaves the place.
339 * This is also called if the @a nym was never given permission to enter
340 * (i.e. the @a nym stopped asking to get in).
342 * @param cls Closure.
343 * @param nym Handle for the user who left.
344 * @param variable_count Number of elements in the @a variables array.
345 * @param variables Variables present in the message.
348 (*GNUNET_SOCIAL_FarewellCallback) (void *cls,
349 struct GNUNET_SOCIAL_Nym *nym,
350 struct GNUNET_ENV_Environment *env,
351 size_t variable_count,
352 struct GNUNET_ENV_Modifier *variables);
356 * Function called after the host entered the place.
361 * #GNUNET_OK on success, or
362 * #GNUNET_SYSERR on error.
363 * @param max_message_id
364 * Last message ID sent to the channel.
365 * Or 0 if no messages have been sent to the place yet.
368 (*GNUNET_SOCIAL_HostEnterCallback) (void *cls, int result,
369 uint64_t max_message_id);
373 * Enter a place as host.
375 * A place is created upon first entering, and it is active until permanently
376 * left using GNUNET_SOCIAL_host_leave().
379 * Configuration to contact the social service.
381 * Identity of the host.
383 * Private-public key pair of the place.
384 * NULL for ephemeral places.
386 * Policy specifying entry and history restrictions for the place.
388 * Slicer to handle incoming messages.
389 * @param answer_door_cb
390 * Function to handle new nyms that want to enter.
392 * Function to handle departing nyms.
394 * Closure for the callbacks.
396 * @return Handle for the host.
398 struct GNUNET_SOCIAL_Host *
399 GNUNET_SOCIAL_host_enter (const struct GNUNET_CONFIGURATION_Handle *cfg,
400 const struct GNUNET_IDENTITY_Ego *ego,
401 const struct GNUNET_CRYPTO_EddsaPrivateKey *place_key,
402 enum GNUNET_PSYC_Policy policy,
403 struct GNUNET_SOCIAL_Slicer *slicer,
404 GNUNET_SOCIAL_HostEnterCallback enter_cb,
405 GNUNET_SOCIAL_AnswerDoorCallback answer_door_cb,
406 GNUNET_SOCIAL_FarewellCallback farewell_cb,
411 * Decision whether to admit @a nym into the place or refuse entry.
416 * Handle for the entity that wanted to enter.
418 * #GNUNET_YES if @a nym is admitted,
419 * #GNUNET_NO if @a nym is refused entry,
420 * #GNUNET_SYSERR if we cannot answer the request.
422 * Method name for the rejection message.
424 * Environment containing variables for the message, or NULL.
426 * Data for the rejection message to send back.
428 * Number of bytes in @a data for method.
429 * @return #GNUNET_OK on success,
430 * #GNUNET_SYSERR if the message is too large.
433 GNUNET_SOCIAL_host_entry_decision (struct GNUNET_SOCIAL_Host *hst,
434 struct GNUNET_SOCIAL_Nym *nym,
436 const struct GNUNET_PSYC_Message *entry_resp);
440 * Throw @a nym out of the place.
442 * The @a nym reference will remain valid until the
443 * #GNUNET_SOCIAL_FarewellCallback is invoked,
444 * which should be very soon after this call.
446 * @param host Host of the place.
447 * @param nym Handle for the entity to be ejected.
450 GNUNET_SOCIAL_host_eject (struct GNUNET_SOCIAL_Host *host,
451 struct GNUNET_SOCIAL_Nym *nym);
455 * Get the public key of a @a nym.
457 * Suitable, for example, to be used with GNUNET_NAMESTORE_zone_to_name().
460 * Pseudonym to map to a cryptographic identifier.
462 * @return Public key of nym;
464 struct GNUNET_CRYPTO_EcdsaPublicKey *
465 GNUNET_SOCIAL_nym_get_key (struct GNUNET_SOCIAL_Nym *nym);
469 * Obtain the private-public key pair of the host.
471 * @param host Host to get the key of.
472 * @param[out] host_key Set to the private-public key pair of the host. The
473 * public part is suitable for storing in GNS within a "PLACE"
474 * record, along with peer IDs to join at.
477 GNUNET_SOCIAL_host_get_key (struct GNUNET_SOCIAL_Host *host,
478 struct GNUNET_CRYPTO_EddsaPrivateKey *host_key);
482 * Advertise the place in the GNS zone of the @e ego of the @a host.
484 * @param host Host of the place.
485 * @param name The name for the PLACE record to put in the zone.
486 * @param peer_count Number of elements in the @a peers array.
487 * @param peers List of peers in the PLACE record that can be used to send join
489 * @param expiration_time Expiration time of the record, use 0 to remove the record.
490 * @param password Password used to encrypt the record.
493 GNUNET_SOCIAL_host_advertise (struct GNUNET_SOCIAL_Host *host,
496 const struct GNUNET_PeerIdentity *peers,
497 struct GNUNET_TIME_Relative expiration_time,
498 const char *password);
502 * Flags for announcements by a host.
504 enum GNUNET_SOCIAL_AnnounceFlags
506 GNUNET_SOCIAL_ANNOUNCE_NONE = 0,
509 * Whether this announcement removes all objects from the place.
511 * New objects can be still added to the now empty place using the @e env
512 * parameter of the same announcement.
514 GNUNET_SOCIAL_ANNOUNCE_CLEAR_OBJECTS = 1 << 0
519 * Handle for an announcement request.
521 struct GNUNET_SOCIAL_Announcement;
525 * Send a message to all nyms that are present in the place.
527 * This function is restricted to the host. Nyms can only send requests
528 * to the host who can decide to relay it to everyone in the place.
533 * Method to use for the announcement.
535 * Environment containing variables for the message and operations
536 * on objects of the place.
537 * Has to remain available until the first call to @a notify_data.
540 * Function to call to get the payload of the announcement.
541 * @param notify_data_cls
542 * Closure for @a notify.
544 * Flags for this announcement.
546 * @return NULL on error (another announcement already in progress?).
548 struct GNUNET_SOCIAL_Announcement *
549 GNUNET_SOCIAL_host_announce (struct GNUNET_SOCIAL_Host *host,
550 const char *method_name,
551 const struct GNUNET_ENV_Environment *env,
552 GNUNET_PSYC_TransmitNotifyData notify_data,
553 void *notify_data_cls,
554 enum GNUNET_SOCIAL_AnnounceFlags flags);
558 * Resume transmitting announcement.
561 * The announcement to resume.
564 GNUNET_SOCIAL_host_announce_resume (struct GNUNET_SOCIAL_Announcement *a);
568 * Cancel announcement.
571 * The announcement to cancel.
574 GNUNET_SOCIAL_host_announce_cancel (struct GNUNET_SOCIAL_Announcement *a);
578 * Obtain handle for a hosted place.
580 * The returned handle can be used to access the place API.
583 * Handle for the host.
585 * @return Handle for the hosted place, valid as long as @a host is valid.
587 struct GNUNET_SOCIAL_Place *
588 GNUNET_SOCIAL_host_get_place (struct GNUNET_SOCIAL_Host *host);
592 * Stop hosting a place.
594 * Invalidates host handle.
597 * Host leaving the place.
599 * Keep the place active after last host disconnected.
601 * Function called after the host left the place
602 * and disconnected from the social service.
604 * Closure for @a leave_cb.
607 GNUNET_SOCIAL_host_leave (struct GNUNET_SOCIAL_Host *host,
609 GNUNET_ContinuationCallback leave_cb,
614 * Function called after the guest entered the local copy of the place.
616 * History and object query functions can be used after this call,
617 * but new messages can't be sent or received.
622 * #GNUNET_OK on success, or
623 * #GNUNET_SYSERR on error, e.g. could not connect to the service, or
624 * could not resolve GNS name.
625 * @param max_message_id
626 * Last message ID sent to the place.
627 * Or 0 if no messages have been sent to the place yet.
630 (*GNUNET_SOCIAL_GuestEnterCallback) (void *cls, int result,
631 uint64_t max_message_id);
635 * Function called upon a guest receives a decision about entry to the place.
638 * Is the guest admitted to the place?
639 * #GNUNET_YES if admitted,
640 * #GNUNET_NO if refused entry
641 * #GNUNET_SYSERR if the request could not be answered.
643 * Method for the message sent along with the decision.
644 * NULL if no message was sent.
646 * Environment with variables for the message.
647 * NULL if there are no variables.
648 * It has to be freed using GNUNET_ENV_environment_destroy()
649 * when it is not needed anymore.
653 * Payload of the message.
656 (*GNUNET_SOCIAL_EntryDecisionCallback) (void *cls,
658 const struct GNUNET_PSYC_Message *entry_resp);
662 * Request entry to a place as a guest.
664 * @param cfg Configuration to contact the social service.
665 * @param ego Identity of the guest.
666 * @param crypto_address Public key of the place to enter.
667 * @param origin Peer identity of the origin of the underlying multicast group.
668 * @param relay_count Number of elements in the @a relays array.
669 * @param relays Relays for the underlying multicast group.
670 * @param method_name Method name for the message.
671 * @param env Environment containing variables for the message, or NULL.
672 * @param data Payload for the message to give to the enter callback.
673 * @param data_size Number of bytes in @a data.
674 * @param slicer Slicer to use for processing incoming requests from guests.
676 * @return NULL on errors, otherwise handle for the guest.
678 struct GNUNET_SOCIAL_Guest *
679 GNUNET_SOCIAL_guest_enter (const struct GNUNET_CONFIGURATION_Handle *cfg,
680 const struct GNUNET_IDENTITY_Ego *ego,
681 const struct GNUNET_CRYPTO_EddsaPublicKey *place_key,
682 const struct GNUNET_PeerIdentity *origin,
683 uint32_t relay_count,
684 const struct GNUNET_PeerIdentity *relays,
685 const struct GNUNET_PSYC_Message *entry_msg,
686 struct GNUNET_SOCIAL_Slicer *slicer,
687 GNUNET_SOCIAL_GuestEnterCallback local_enter_cb,
688 GNUNET_SOCIAL_EntryDecisionCallback entry_decision_cb,
693 * Request entry to a place as a guest using a GNS name.
695 * @param cfg Configuration to contact the social service.
696 * @param ego Identity of the guest.
697 * @param address GNS name of the place to enter. Either in the form of
698 * 'room.friend.gnu', or 'NYMPUBKEY.zkey'. This latter case refers to
699 * the 'PLACE' record of the empty label ("+") in the GNS zone with the
700 * nym's public key 'NYMPUBKEY', and can be used to request entry to a
701 * pseudonym's place directly.
702 * @param method_name Method name for the message.
703 * @param env Environment containing variables for the message, or NULL.
704 * @param data Payload for the message to give to the enter callback.
705 * @param data_size Number of bytes in @a data.
706 * @param slicer Slicer to use for processing incoming requests from guests.
708 * @return NULL on errors, otherwise handle for the guest.
710 struct GNUNET_SOCIAL_Guest *
711 GNUNET_SOCIAL_guest_enter_by_name (const struct GNUNET_CONFIGURATION_Handle *cfg,
712 struct GNUNET_IDENTITY_Ego *ego,
714 const struct GNUNET_PSYC_Message *join_msg,
715 struct GNUNET_SOCIAL_Slicer *slicer,
716 GNUNET_SOCIAL_GuestEnterCallback local_enter_cb,
717 GNUNET_SOCIAL_EntryDecisionCallback entry_decision_cb,
722 * Flags for talking to the host of a place.
724 enum GNUNET_SOCIAL_TalkFlags
726 GNUNET_SOCIAL_TALK_NONE = 0
733 struct GNUNET_SOCIAL_TalkRequest;
737 * Talk to the host of the place.
740 * Place where we want to talk to the host.
742 * Method to invoke on the host.
744 * Environment containing variables for the message, or NULL.
746 * Function to use to get the payload for the method.
747 * @param notify_data_cls
748 * Closure for @a notify_data.
750 * Flags for the message being sent.
752 * @return NULL if we are already trying to talk to the host,
753 * otherwise handle to cancel the request.
755 struct GNUNET_SOCIAL_TalkRequest *
756 GNUNET_SOCIAL_guest_talk (struct GNUNET_SOCIAL_Guest *guest,
757 const char *method_name,
758 const struct GNUNET_ENV_Environment *env,
759 GNUNET_PSYC_TransmitNotifyData notify_data,
760 void *notify_data_cls,
761 enum GNUNET_SOCIAL_TalkFlags flags);
765 * Resume talking to the host of the place.
768 * Talk request to resume.
771 GNUNET_SOCIAL_guest_talk_resume (struct GNUNET_SOCIAL_TalkRequest *tr);
775 * Cancel talking to the host of the place.
778 * Talk request to cancel.
781 GNUNET_SOCIAL_guest_talk_cancel (struct GNUNET_SOCIAL_TalkRequest *tr);
785 * Leave a place permanently.
787 * Notifies the owner of the place about leaving, and destroys the place handle.
790 * Place to leave permanently.
792 * Keep place active after last application disconnected.
794 * Function called after the guest left the place
795 * and disconnected from the social service.
797 * Closure for @a leave_cb.
800 GNUNET_SOCIAL_guest_leave (struct GNUNET_SOCIAL_Guest *guest,
802 GNUNET_ContinuationCallback leave_cb,
807 * Obtain handle for a place entered as guest.
809 * The returned handle can be used to access the place API.
811 * @param guest Handle for the guest.
813 * @return Handle for the place, valid as long as @a guest is valid.
815 struct GNUNET_SOCIAL_Place *
816 GNUNET_SOCIAL_guest_get_place (struct GNUNET_SOCIAL_Guest *guest);
822 struct GNUNET_SOCIAL_HistoryRequest;
826 * Learn about the history of a place.
828 * Messages are returned through the @a slicer function
829 * and have the #GNUNET_PSYC_MESSAGE_HISTORIC flag set.
832 * Place we want to learn more about.
833 * @param start_message_id
834 * First historic message we are interested in.
835 * @param end_message_id
836 * Last historic message we are interested in (inclusive).
837 * @param method_prefix
838 * Only retrieve messages with this method prefix.
840 * OR'ed GNUNET_PSYC_HistoryReplayFlags
842 * Slicer to use for retrieved messages.
843 * Can be the same as the slicer of the place.
845 * Function called after all messages retrieved.
846 * NULL if not needed.
847 * @param cls Closure for @a result_cb.
849 struct GNUNET_SOCIAL_HistoryRequest *
850 GNUNET_SOCIAL_place_history_replay (struct GNUNET_SOCIAL_Place *plc,
851 uint64_t start_message_id,
852 uint64_t end_message_id,
853 const char *method_prefix,
855 struct GNUNET_SOCIAL_Slicer *slicer,
856 GNUNET_ResultCallback result_cb,
861 * Learn about the history of a place.
863 * Sends messages through the slicer function of the place where
864 * start_message_id <= message_id <= end_message_id.
865 * The messages will have the #GNUNET_PSYC_MESSAGE_HISTORIC flag set.
867 * To get the latest message, use 0 for both the start and end message ID.
870 * Place we want to learn more about.
871 * @param message_limit
872 * Maximum number of historic messages we are interested in.
874 * Function called after all messages retrieved.
875 * NULL if not needed.
876 * @param cls Closure for @a result_cb.
878 struct GNUNET_SOCIAL_HistoryRequest *
879 GNUNET_SOCIAL_place_history_replay_latest (struct GNUNET_SOCIAL_Place *plc,
880 uint64_t message_limit,
881 const char *method_prefix,
883 struct GNUNET_SOCIAL_Slicer *slicer,
884 GNUNET_ResultCallback result_cb,
888 * Cancel learning about the history of a place.
891 * History lesson to cancel.
894 GNUNET_SOCIAL_place_history_replay_cancel (struct GNUNET_SOCIAL_HistoryRequest *hist);
897 struct GNUNET_SOCIAL_LookHandle;
901 * Look at a particular object in the place.
903 * The best matching object is returned (its name might be less specific than
904 * what was requested).
907 * The place to look the object at.
909 * Full name of the object.
911 * Set to the size of the returned value.
913 * @return NULL if there is no such object at this place.
915 struct GNUNET_SOCIAL_LookHandle *
916 GNUNET_SOCIAL_place_look_at (struct GNUNET_SOCIAL_Place *plc,
917 const char *full_name,
918 GNUNET_PSYC_StateVarCallback var_cb,
919 GNUNET_ResultCallback result_cb,
923 * Look for objects in the place with a matching name prefix.
926 * The place to look its objects at.
928 * Look at objects with names beginning with this value.
930 * Function to call for each object found.
932 * Closure for callback function.
934 * @return Handle that can be used to stop looking at objects.
936 struct GNUNET_SOCIAL_LookHandle *
937 GNUNET_SOCIAL_place_look_for (struct GNUNET_SOCIAL_Place *plc,
938 const char *name_prefix,
939 GNUNET_PSYC_StateVarCallback var_cb,
940 GNUNET_ResultCallback result_cb,
945 * Stop looking at objects.
947 * @param lh Look handle to stop.
950 GNUNET_SOCIAL_place_look_cancel (struct GNUNET_SOCIAL_LookHandle *lh);
953 #if 0 /* keep Emacsens' auto-indent happy */
960 /* ifndef GNUNET_SOCIAL_SERVICE_H */
962 /* end of gnunet_social_service.h */