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22 * @author Gabor X Toth
23 * @author Christian Grothoff
28 * @defgroup psyc PSYC service
29 * Send/receive messages in PSYC channels and access the PSYC Store.
31 * Note that clients of this API are NOT expected to understand the PSYC message
32 * format, only the semantics! Parsing (and serializing) the PSYC stream format
33 * is done within the implementation of the libgnunetpsyc library, and this API
34 * deliberately exposes as little as possible of the actual data stream format
38 * - this API does not know about PSYC's "root" and "places";
39 * there is no 'root' in GNUnet-PSYC as we're decentralized;
40 * 'places' and 'persons' are combined within the same
41 * abstraction, that of a "channel". Channels are identified
42 * and accessed in this API using a public/private key.
43 * Higher-level applications should use NAMES within GNS
44 * to obtain public keys, and the distinction between
45 * 'places' and 'persons' can then be made with the help
46 * of the naming system (and/or conventions).
47 * Channels are (as in PSYC) organized into a hierarchy; each
48 * channel master (the one with the private key) is then
49 * the operator of the multicast group (its Origin in
50 * the terminology of the multicast API).
51 * - The API supports passing large amounts of data using
52 * 'streaming' for the argument passed to a method. State
53 * and variables must fit into memory and cannot be streamed
54 * (thus, no passing of 4 GB of data in a variable;
55 * once we implement this, we might want to create a
56 * @c \#define for the maximum size of a variable).
57 * - PSYC defines standard variables, methods, etc. This
58 * library deliberately abstracts over all of these; a
59 * higher-level API should combine the naming system (GNS)
60 * and standard methods (message, join, part, warn,
61 * fail, error) and variables (action, color, time,
62 * tag, etc.). However, this API does take over the
63 * routing variables, specifically 'context' (channel),
64 * and 'source'. We only kind-of support 'target', as
65 * the target is either everyone in the group or the
66 * origin, and never just a single member of the group;
67 * for such individual messages, an application needs to
68 * construct an 'inbox' channel where the master (only)
69 * receives messages (but never forwards; private responses
70 * would be transmitted by joining the senders 'inbox'
71 * channel -- or a inbox#bob subchannel). The
72 * goal for all of this is to keep the abstractions in this
73 * API minimal: interaction with multicast, try \& slice,
74 * state/variable/channel management. Higher-level
75 * operations belong elsewhere (so maybe this API should
76 * be called 'PSYC-low', whereas a higher-level API
77 * implementing defaults for standard methods and
78 * variables might be called 'PSYC-std' or 'PSYC-high'.
83 #ifndef GNUNET_PSYC_SERVICE_H
84 #define GNUNET_PSYC_SERVICE_H
89 #if 0 /* keep Emacsens' auto-indent happy */
94 #include "gnunet_util_lib.h"
95 #include "gnunet_multicast_service.h"
99 # define UINT64_MAX 0xffffffffffffffffULL
104 * Version number of GNUnet-PSYC API.
106 #define GNUNET_PSYC_VERSION 0x00000000
110 * Policy flags for a channel.
112 enum GNUNET_PSYC_ChannelFlags
115 * Admission must be confirmed by the master.
117 GNUNET_PSYC_CHANNEL_ADMISSION_CONTROL = 1 << 0,
120 * Past messages are only available to slaves who were admitted at the time
121 * they were sent to the channel.
123 GNUNET_PSYC_CHANNEL_RESTRICTED_HISTORY = 1 << 1
128 * PSYC channel policies.
130 enum GNUNET_PSYC_Policy
133 * Anyone can join the channel, without announcing his presence;
134 * all messages are always public and can be distributed freely.
135 * Joins may be announced, but this is not required.
137 GNUNET_PSYC_CHANNEL_ANONYMOUS = 0,
140 * The master must approve membership to the channel, messages must only be
141 * distributed to current channel slaves. This includes the channel
142 * state as well as transient messages.
144 GNUNET_PSYC_CHANNEL_PRIVATE
145 = GNUNET_PSYC_CHANNEL_ADMISSION_CONTROL
146 | GNUNET_PSYC_CHANNEL_RESTRICTED_HISTORY
150 * Anyone can freely join the channel (no approval required);
151 * however, messages must only be distributed to current channel
152 * slaves, so the master must still acknowledge that the slave
153 * joined before transient messages are delivered. As approval is
154 * guaranteed, the presistent channel state can be synchronized freely
155 * immediately, prior to master confirmation.
157 GNUNET_PSYC_CHANNEL_OPEN
158 = GNUNET_PSYC_CHANNEL_RESTRICTED_HISTORY,
161 * The master must approve joins to the channel, but past messages can be
162 * freely distributed to slaves.
164 GNUNET_PSYC_CHANNEL_CLOSED
165 = GNUNET_PSYC_CHANNEL_ADMISSION_CONTROL,
170 enum GNUNET_PSYC_MessageFlags
173 * Default / no flags.
175 GNUNET_PSYC_MESSAGE_DEFAULT = 0,
178 * Historic message, retrieved from PSYCstore.
180 GNUNET_PSYC_MESSAGE_HISTORIC = 1 << 0,
183 * Request from slave to master.
185 GNUNET_PSYC_MESSAGE_REQUEST = 1 << 1,
188 * Message can be delivered out of order.
190 GNUNET_PSYC_MESSAGE_ORDER_ANY = 1 << 2
195 * Values for the @a state_delta field of GNUNET_PSYC_MessageHeader.
197 enum GNUNET_PSYC_StateDeltaValues
199 GNUNET_PSYC_STATE_RESET = 0,
201 GNUNET_PSYC_STATE_NOT_MODIFIED = UINT64_MAX
205 GNUNET_NETWORK_STRUCT_BEGIN
210 * Used for single-fragment messages e.g. in a join request or response.
212 struct GNUNET_PSYC_Message
215 * Message header with size and type information.
217 struct GNUNET_MessageHeader header;
219 /* Followed by concatenated PSYC message parts:
220 * messages with GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_* types
226 * Header of a PSYC message.
228 * The PSYC service adds this when delivering the message to local clients,
229 * not present on the multicast layer.
231 struct GNUNET_PSYC_MessageHeader
234 * Generic message header with size and type information.
236 struct GNUNET_MessageHeader header;
239 * Flags for this message fragment.
241 * @see enum GNUNET_PSYC_MessageFlags
243 uint32_t flags GNUNET_PACKED;
246 * Number of the message this message part belongs to.
247 * Monotonically increasing from 1.
249 uint64_t message_id GNUNET_PACKED;
252 * Byte offset of this @e fragment of the @e message.
254 uint64_t fragment_offset GNUNET_PACKED;
257 * Sending slave's public key.
258 * Not set if the message is from the master.
260 struct GNUNET_CRYPTO_EcdsaPublicKey slave_pub_key;
262 /* Followed by concatenated PSYC message parts:
263 * messages with GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_* types
269 * The method of a message.
271 struct GNUNET_PSYC_MessageMethod
274 * Type: GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_METHOD
276 struct GNUNET_MessageHeader header;
279 * OR'ed GNUNET_PSYC_MasterTransmitFlags
281 uint32_t flags GNUNET_PACKED;
284 * Number of message IDs since the last message that contained state
285 * operations. @see enum GNUNET_PSYC_StateDeltaValues
287 uint64_t state_delta GNUNET_PACKED;
289 /* Followed by NUL-terminated method name. */
294 * A modifier of a message.
296 struct GNUNET_PSYC_MessageModifier
299 * Type: GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MODIFIER
301 struct GNUNET_MessageHeader header;
306 uint32_t value_size GNUNET_PACKED;
309 * Size of name, including NUL terminator.
311 uint16_t name_size GNUNET_PACKED;
314 * enum GNUNET_PSYC_Operator
318 /* Followed by NUL-terminated name, then the value. */
322 struct GNUNET_PSYC_CountersResultMessage
325 * Type: GNUNET_MESSAGE_TYPE_PSYC_RESULT_COUNTERS
327 struct GNUNET_MessageHeader header;
330 * Status code for the operation.
332 uint32_t result_code GNUNET_PACKED;
335 * Last message ID sent to the channel.
337 uint64_t max_message_id GNUNET_PACKED;
342 * Join request sent to a PSYC master.
344 struct GNUNET_PSYC_JoinRequestMessage
347 * Type: GNUNET_MESSAGE_TYPE_PSYC_MASTER_JOIN_REQUEST
349 struct GNUNET_MessageHeader header;
351 * Public key of the joining slave.
353 struct GNUNET_CRYPTO_EcdsaPublicKey slave_pub_key;
355 /* Followed by struct GNUNET_MessageHeader join_request */
360 * Join decision sent in reply to a join request.
362 struct GNUNET_PSYC_JoinDecisionMessage
365 * Type: GNUNET_MESSAGE_TYPE_PSYC_JOIN_DECISION
367 struct GNUNET_MessageHeader header;
370 * #GNUNET_YES if the slave was admitted.
375 * Public key of the joining slave.
376 * Only set when the master is sending the decision,
377 * not set when a slave is receiving it.
379 struct GNUNET_CRYPTO_EcdsaPublicKey slave_pub_key;
381 /* Followed by struct GNUNET_MessageHeader join_response */
385 enum GNUNET_PSYC_HistoryReplayFlags
388 * Replay locally available messages.
390 GNUNET_PSYC_HISTORY_REPLAY_LOCAL = 0,
393 * Replay messages from remote peers if not found locally.
395 GNUNET_PSYC_HISTORY_REPLAY_REMOTE = 1,
399 struct GNUNET_PSYC_HistoryRequestMessage
402 * Type: GNUNET_MESSAGE_TYPE_PSYC_CHANNEL_HISTORY_REPLAY
404 struct GNUNET_MessageHeader header;
407 * @see enum GNUNET_PSYC_HistoryReplayFlags
409 uint32_t flags GNUNET_PACKED;
412 * ID for this operation.
414 uint64_t op_id GNUNET_PACKED;
416 uint64_t start_message_id GNUNET_PACKED;
418 uint64_t end_message_id GNUNET_PACKED;
420 uint64_t message_limit GNUNET_PACKED;
422 /* Followed by NUL-terminated method name prefix. */
426 struct GNUNET_PSYC_StateRequestMessage
430 * - GNUNET_MESSAGE_TYPE_PSYC_CHANNEL_STATE_GET
431 * - GNUNET_MESSAGE_TYPE_PSYC_CHANNEL_STATE_GET_PREFIX
433 struct GNUNET_MessageHeader header;
435 uint32_t reserved GNUNET_PACKED;
438 * ID for this operation.
440 uint64_t op_id GNUNET_PACKED;
442 /* Followed by NUL-terminated name. */
446 /**** service -> library ****/
450 * Answer from service to client about last operation.
452 struct GNUNET_PSYC_OperationResultMessage
456 * - GNUNET_MESSAGE_TYPE_PSYC_RESULT_CODE
457 * - GNUNET_MESSAGE_TYPE_PSYC_CHANNEL_STATE_RESULT
459 struct GNUNET_MessageHeader header;
461 uint32_t reserved GNUNET_PACKED;
466 uint64_t op_id GNUNET_PACKED;
469 * Status code for the operation.
471 uint64_t result_code GNUNET_PACKED;
474 * - on error: NUL-terminated error message
475 * - on success: one of the following message types
477 * For a STATE_RESULT, one of:
478 * - GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MODIFIER
479 * - GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MOD_CONT
480 * - GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_END
484 GNUNET_NETWORK_STRUCT_END
487 #define GNUNET_PSYC_MODIFIER_MAX_PAYLOAD \
488 GNUNET_MULTICAST_FRAGMENT_MAX_PAYLOAD \
489 - sizeof (struct GNUNET_PSYC_MessageModifier)
491 #define GNUNET_PSYC_MOD_CONT_MAX_PAYLOAD \
492 GNUNET_MULTICAST_FRAGMENT_MAX_PAYLOAD \
493 - sizeof (struct GNUNET_MessageHeader)
495 #define GNUNET_PSYC_DATA_MAX_PAYLOAD \
496 GNUNET_MULTICAST_FRAGMENT_MAX_PAYLOAD \
497 - sizeof (struct GNUNET_MessageHeader)
501 * PSYC message part processing states.
503 enum GNUNET_PSYC_MessageState
505 GNUNET_PSYC_MESSAGE_STATE_START = 0,
506 GNUNET_PSYC_MESSAGE_STATE_HEADER = 1,
507 GNUNET_PSYC_MESSAGE_STATE_METHOD = 2,
508 GNUNET_PSYC_MESSAGE_STATE_MODIFIER = 3,
509 GNUNET_PSYC_MESSAGE_STATE_MOD_CONT = 4,
510 GNUNET_PSYC_MESSAGE_STATE_DATA = 5,
511 GNUNET_PSYC_MESSAGE_STATE_END = 6,
512 GNUNET_PSYC_MESSAGE_STATE_CANCEL = 7,
513 GNUNET_PSYC_MESSAGE_STATE_ERROR = 8,
518 * Handle that identifies a join request.
520 * Used to match calls to #GNUNET_PSYC_JoinCallback to the
521 * corresponding calls to GNUNET_PSYC_join_decision().
523 struct GNUNET_PSYC_JoinHandle;
527 * Method called from PSYC upon receiving a message.
529 * @param cls Closure.
530 * @param message_id Sequence number of the message.
531 * @param flags OR'ed GNUNET_PSYC_MessageFlags
532 * @param msg Message part, one of the following types:
535 (*GNUNET_PSYC_MessageCallback) (void *cls,
536 const struct GNUNET_PSYC_MessageHeader *msg);
540 * Method called from PSYC upon receiving part of a message.
544 * @param slave_pub_key
545 * Public key of the slave sending the message.
546 * Only set for channel master.
548 * Sequence number of the message.
550 * OR'ed GNUNET_PSYC_MessageFlags
551 * @param fragment_offset
552 * Multicast message fragment offset.
553 * @param msg Message part, one of the following types:
554 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_HEADER
555 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_METHOD
556 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MODIFIER
557 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MOD_CONT
558 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_DATA
559 * or NULL if an error occurred while receiving a message.
562 (*GNUNET_PSYC_MessagePartCallback) (void *cls,
563 const struct GNUNET_PSYC_MessageHeader *msg,
564 const struct GNUNET_MessageHeader *pmsg);
568 * Method called from PSYC upon receiving a join request.
572 * @param slave_pub_key
573 * Public key of the slave requesting join.
575 * Join message sent along with the request.
577 * Join handle to use with GNUNET_PSYC_join_decision()
580 (*GNUNET_PSYC_JoinRequestCallback) (void *cls,
581 const struct GNUNET_PSYC_JoinRequestMessage *req,
582 const struct GNUNET_CRYPTO_EcdsaPublicKey *slave_pub_key,
583 const struct GNUNET_PSYC_Message *join_msg,
584 struct GNUNET_PSYC_JoinHandle *jh);
588 * Function to call with the decision made for a join request.
590 * Must be called once and only once in response to an invocation of the
591 * #GNUNET_PSYC_JoinCallback.
593 * @param jh Join request handle.
595 * #GNUNET_YES if the join is approved,
596 * #GNUNET_NO if it is disapproved,
597 * #GNUNET_SYSERR if we cannot answer the request.
598 * @param relay_count Number of relays given.
599 * @param relays Array of suggested peers that might be useful relays to use
600 * when joining the multicast group (essentially a list of peers that
601 * are already part of the multicast group and might thus be willing
602 * to help with routing). If empty, only this local peer (which must
603 * be the multicast origin) is a good candidate for building the
604 * multicast tree. Note that it is unnecessary to specify our own
605 * peer identity in this array.
606 * @param join_resp Application-dependent join response message to send along
609 * @return #GNUNET_OK on success,
610 * #GNUNET_SYSERR if @a join_resp is too large.
613 GNUNET_PSYC_join_decision (struct GNUNET_PSYC_JoinHandle *jh,
615 uint32_t relay_count,
616 const struct GNUNET_PeerIdentity *relays,
617 const struct GNUNET_PSYC_Message *join_resp);
621 * Handle for the master of a PSYC channel.
623 struct GNUNET_PSYC_Master;
627 * Function called after connected to the PSYC service
628 * and the channel master started.
630 * Also called when reconnected to the service
631 * after the connection closed unexpectedly.
636 * #GNUNET_YES if there were already messages sent to the channel,
637 * #GNUNET_NO if the message history is empty,
638 * #GNUNET_SYSERR on error.
639 * @param max_message_id
640 * Last message ID sent to the channel.
643 (*GNUNET_PSYC_MasterStartCallback) (void *cls, int result,
644 uint64_t max_message_id);
648 * Start a PSYC master channel.
650 * Will start a multicast group identified by the given ECC key. Messages
651 * received from group members will be given to the respective handler methods.
652 * If a new member wants to join a group, the "join" method handler will be
653 * invoked; the join handler must then generate a "join" message to approve the
654 * joining of the new member. The channel can also change group membership
655 * without explicit requests. Note that PSYC doesn't itself "understand" join
656 * or part messages, the respective methods must call other PSYC functions to
657 * inform PSYC about the meaning of the respective events.
659 * @param cfg Configuration to use (to connect to PSYC service).
660 * @param channel_key ECC key that will be used to sign messages for this
661 * PSYC session. The public key is used to identify the PSYC channel.
662 * Note that end-users will usually not use the private key directly, but
663 * rather look it up in GNS for places managed by other users, or select
664 * a file with the private key(s) when setting up their own channels
665 * FIXME: we'll likely want to use NOT the p521 curve here, but a cheaper
667 * @param policy Channel policy specifying join and history restrictions.
668 * Used to automate join decisions.
669 * @param master_start_cb Function to invoke after the channel master started.
670 * @param join_request_cb Function to invoke when a slave wants to join.
671 * @param message_cb Function to invoke on message parts sent to the channel
672 * and received from slaves
673 * @param cls Closure for @a method and @a join_cb.
675 * @return Handle for the channel master, NULL on error.
677 struct GNUNET_PSYC_Master *
678 GNUNET_PSYC_master_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
679 const struct GNUNET_CRYPTO_EddsaPrivateKey *channel_key,
680 enum GNUNET_PSYC_Policy policy,
681 GNUNET_PSYC_MasterStartCallback master_start_cb,
682 GNUNET_PSYC_JoinRequestCallback join_request_cb,
683 GNUNET_PSYC_MessageCallback message_cb,
684 GNUNET_PSYC_MessagePartCallback message_part_cb,
689 * Function called to provide data for a transmission via PSYC.
691 * Note that returning #GNUNET_YES or #GNUNET_SYSERR (but not #GNUNET_NO)
692 * invalidates the respective transmission handle.
694 * @param cls Closure.
695 * @param[in,out] data_size Initially set to the number of bytes available in
696 * @a data, should be set to the number of bytes written to data.
697 * @param[out] data Where to write the body of the message to give to the
698 * method. The function must copy at most @a data_size bytes to @a data.
699 * @return #GNUNET_SYSERR on error (fatal, aborts transmission)
700 * #GNUNET_NO on success, if more data is to be transmitted later.
701 * Should be used if @a data_size was not big enough to take all the
702 * data. If 0 is returned in @a data_size the transmission is paused,
703 * and can be resumed with GNUNET_PSYC_master_transmit_resume().
704 * #GNUNET_YES if this completes the transmission (all data supplied)
707 (*GNUNET_PSYC_TransmitNotifyData) (void *cls,
712 * Function called to provide a modifier for a transmission via PSYC.
714 * Note that returning #GNUNET_YES or #GNUNET_SYSERR (but not #GNUNET_NO)
715 * invalidates the respective transmission handle.
717 * @param cls Closure.
718 * @param[in,out] data_size Initially set to the number of bytes available in
719 * @a data, should be set to the number of bytes written to data.
720 * @param[out] data Where to write the modifier's name and value.
721 * The function must copy at most @a data_size bytes to @a data.
722 * When this callback is first called for a modifier, @a data should
723 * contain: "name\0value". If the whole value does not fit, subsequent
724 * calls to this function should write continuations of the value to
726 * @param[out] oper Where to write the operator of the modifier.
727 * Only needed during the first call to this callback at the beginning
728 * of the modifier. In case of subsequent calls asking for value
729 * continuations @a oper is set to #NULL.
730 * @param[out] full_value_size Where to write the full size of the value.
731 * Only needed during the first call to this callback at the beginning
732 * of the modifier. In case of subsequent calls asking for value
733 * continuations @a value_size is set to #NULL.
734 * @return #GNUNET_SYSERR on error (fatal, aborts transmission)
735 * #GNUNET_NO on success, if more data is to be transmitted later.
736 * Should be used if @a data_size was not big enough to take all the
737 * data for the modifier's value (the name must be always returned
738 * during the first call to this callback).
739 * If 0 is returned in @a data_size the transmission is paused,
740 * and can be resumed with GNUNET_PSYC_master_transmit_resume().
741 * #GNUNET_YES if this completes the modifier (the whole value is supplied).
744 (*GNUNET_PSYC_TransmitNotifyModifier) (void *cls,
748 uint32_t *full_value_size);
751 * Flags for transmitting messages to a channel by the master.
753 enum GNUNET_PSYC_MasterTransmitFlags
755 GNUNET_PSYC_MASTER_TRANSMIT_NONE = 0,
758 * Whether this message should reset the channel state,
759 * i.e. remove all previously stored state variables.
762 GNUNET_PSYC_MASTER_TRANSMIT_STATE_RESET = 1 << 0,
765 * Whether this message contains any state modifiers.
767 GNUNET_PSYC_MASTER_TRANSMIT_STATE_MODIFY = 1 << 1,
770 * Add PSYC header variable with the hash of the current channel state.
772 GNUNET_PSYC_MASTER_TRANSMIT_STATE_HASH = 1 << 2,
775 * Whether we need to increment the group generation counter after
776 * transmitting this message.
778 GNUNET_PSYC_MASTER_TRANSMIT_INC_GROUP_GEN = 1 << 3
783 * Handle for a pending PSYC transmission operation.
785 struct GNUNET_PSYC_MasterTransmitHandle;
789 * Send a message to call a method to all members in the PSYC channel.
791 * @param master Handle to the PSYC channel.
792 * @param method_name Which method should be invoked.
793 * @param notify_mod Function to call to obtain modifiers.
794 * @param notify_data Function to call to obtain fragments of the data.
795 * @param notify_cls Closure for @a notify_mod and @a notify_data.
796 * @param flags Flags for the message being transmitted.
797 * @return Transmission handle, NULL on error (i.e. more than one request queued).
799 struct GNUNET_PSYC_MasterTransmitHandle *
800 GNUNET_PSYC_master_transmit (struct GNUNET_PSYC_Master *master,
801 const char *method_name,
802 GNUNET_PSYC_TransmitNotifyModifier notify_mod,
803 GNUNET_PSYC_TransmitNotifyData notify_data,
805 enum GNUNET_PSYC_MasterTransmitFlags flags);
809 * Resume transmission to the channel.
811 * @param th Handle of the request that is being resumed.
814 GNUNET_PSYC_master_transmit_resume (struct GNUNET_PSYC_MasterTransmitHandle *th);
818 * Abort transmission request to channel.
820 * @param th Handle of the request that is being aborted.
823 GNUNET_PSYC_master_transmit_cancel (struct GNUNET_PSYC_MasterTransmitHandle *th);
829 * @param master Handle to the PSYC channel.
830 * @param method_name Which method should be invoked.
831 * @param notify_mod Function to call to obtain modifiers.
832 * @param notify_data Function to call to obtain fragments of the data.
833 * @param notify_cls Closure for @a notify_mod and @a notify_data.
834 * @param flags Flags for the message being transmitted.
835 * @return Transmission handle, NULL on error (i.e. more than one request queued).
837 struct GNUNET_PSYC_MasterTransmitHandle *
838 GNUNET_PSYC_master_relay (struct GNUNET_PSYC_Master *master,
839 uint64_t message_id);
843 * Stop a PSYC master channel.
846 * PSYC channel master to stop.
848 * Keep place active after last application disconnected.
850 * Function called after the master stopped
851 * and disconnected from the psyc service.
853 * Closure for @a part_cb.
856 GNUNET_PSYC_master_stop (struct GNUNET_PSYC_Master *master,
858 GNUNET_ContinuationCallback stop_cb,
863 * Handle for a PSYC channel slave.
865 struct GNUNET_PSYC_Slave;
869 * Function called after the slave connected to the PSYC service.
871 * Also called when reconnected to the service
872 * after the connection closed unexpectedly.
877 * #GNUNET_YES if there were already messages sent to the channel,
878 * #GNUNET_NO if the message history is empty,
879 * #GNUNET_SYSERR on error.
880 * @param max_message_id
881 * Last message ID sent to the channel.
884 (*GNUNET_PSYC_SlaveConnectCallback) (void *cls, int result,
885 uint64_t max_message_id);
889 * Method called to inform about the decision in response to a join request.
891 * If @a is_admitted is not #GNUNET_YES, then sending messages to the channel is
892 * not possible, but earlier history can be still queried.
894 * @param cls Closure.
895 * @param is_admitted #GNUNET_YES or #GNUNET_NO or #GNUNET_SYSERR
896 * @param join_msg Application-dependent join message from the origin.
899 (*GNUNET_PSYC_JoinDecisionCallback) (void *cls,
900 const struct GNUNET_PSYC_JoinDecisionMessage *dcsn,
902 const struct GNUNET_PSYC_Message *join_msg);
905 * Flags for GNUNET_PSYC_slave_join()
907 enum GNUNET_PSYC_SlaveJoinFlags
909 GNUNET_PSYC_SLAVE_JOIN_NONE = 0,
912 * Local join for history access, no network connection is established.
914 GNUNET_PSYC_SLAVE_JOIN_LOCAL = 1,
919 * Join a PSYC channel.
921 * The entity joining is always the local peer. The user must immediately use
922 * the GNUNET_PSYC_slave_transmit() functions to transmit a @e join_msg to the
923 * channel; if the join request succeeds, the channel state (and @e recent
924 * method calls) will be replayed to the joining member. There is no explicit
925 * notification on failure (as the channel may simply take days to approve,
926 * and disapproval is simply being ignored).
929 * Configuration to use.
930 * @param channel_pub_key
931 * ECC public key that identifies the channel we wish to join.
932 * @param slave_pub_key
933 * ECC private-public key pair that identifies the slave, and
934 * used by multicast to sign the join request and subsequent unicast
935 * requests sent to the master.
939 * Peer identity of the origin.
941 * Number of peers in the @a relays array.
943 * Peer identities of members of the multicast group, which serve
944 * as relays and used to join the group at.
946 * Function to invoke on message fragments received from the channel.
947 * @param message_part_cb
948 * Function to invoke on message parts received from the channel.
949 * @param slave_connect_cb
950 * Function invoked once we have connected to the PSYC service.
951 * @param join_decision_cb
952 * Function invoked once we have received a join decision.
954 * Closure for @a message_cb and @a slave_joined_cb.
958 * @return Handle for the slave, NULL on error.
960 struct GNUNET_PSYC_Slave *
961 GNUNET_PSYC_slave_join (const struct GNUNET_CONFIGURATION_Handle *cfg,
962 const struct GNUNET_CRYPTO_EddsaPublicKey *channel_pub_key,
963 const struct GNUNET_CRYPTO_EcdsaPrivateKey *slave_pub_key,
964 enum GNUNET_PSYC_SlaveJoinFlags flags,
965 const struct GNUNET_PeerIdentity *origin,
966 uint32_t relay_count,
967 const struct GNUNET_PeerIdentity *relays,
968 GNUNET_PSYC_MessageCallback message_cb,
969 GNUNET_PSYC_MessagePartCallback message_part_cb,
970 GNUNET_PSYC_SlaveConnectCallback slave_connect_cb,
971 GNUNET_PSYC_JoinDecisionCallback join_decision_cb,
973 const struct GNUNET_PSYC_Message *join_msg);
977 * Part a PSYC channel.
979 * Will terminate the connection to the PSYC service. Polite clients should
980 * first explicitly send a part request (via GNUNET_PSYC_slave_transmit()).
985 * Keep place active after last application disconnected.
987 * Function called after the slave parted the channel
988 * and disconnected from the psyc service.
990 * Closure for @a part_cb.
993 GNUNET_PSYC_slave_part (struct GNUNET_PSYC_Slave *slave,
995 GNUNET_ContinuationCallback part_cb,
1000 * Flags for transmitting messages to the channel master by a slave.
1002 enum GNUNET_PSYC_SlaveTransmitFlags
1004 GNUNET_PSYC_SLAVE_TRANSMIT_NONE = 0
1009 * Handle for a pending PSYC transmission operation.
1011 struct GNUNET_PSYC_SlaveTransmitHandle;
1015 * Request a message to be sent to the channel master.
1017 * @param slave Slave handle.
1018 * @param method_name Which (PSYC) method should be invoked (on host).
1019 * @param notify_mod Function to call to obtain modifiers.
1020 * @param notify_data Function to call to obtain fragments of the data.
1021 * @param notify_cls Closure for @a notify.
1022 * @param flags Flags for the message being transmitted.
1023 * @return Transmission handle, NULL on error (i.e. more than one request queued).
1025 struct GNUNET_PSYC_SlaveTransmitHandle *
1026 GNUNET_PSYC_slave_transmit (struct GNUNET_PSYC_Slave *slave,
1027 const char *method_name,
1028 GNUNET_PSYC_TransmitNotifyModifier notify_mod,
1029 GNUNET_PSYC_TransmitNotifyData notify_data,
1031 enum GNUNET_PSYC_SlaveTransmitFlags flags);
1035 * Resume transmission to the master.
1037 * @param th Handle of the request that is being resumed.
1040 GNUNET_PSYC_slave_transmit_resume (struct GNUNET_PSYC_SlaveTransmitHandle *th);
1044 * Abort transmission request to master.
1046 * @param th Handle of the request that is being aborted.
1049 GNUNET_PSYC_slave_transmit_cancel (struct GNUNET_PSYC_SlaveTransmitHandle *th);
1053 * Handle to access PSYC channel operations for both the master and slaves.
1055 struct GNUNET_PSYC_Channel;
1059 * Convert a channel @a master to a @e channel handle to access the @e channel
1062 * @param master Channel master handle.
1063 * @return Channel handle, valid for as long as @a master is valid.
1065 struct GNUNET_PSYC_Channel *
1066 GNUNET_PSYC_master_get_channel (struct GNUNET_PSYC_Master *master);
1070 * Convert @a slave to a @e channel handle to access the @e channel APIs.
1072 * @param slave Slave handle.
1073 * @return Channel handle, valid for as long as @a slave is valid.
1075 struct GNUNET_PSYC_Channel *
1076 GNUNET_PSYC_slave_get_channel (struct GNUNET_PSYC_Slave *slave);
1080 * Add a slave to the channel's membership list.
1082 * Note that this will NOT generate any PSYC traffic, it will merely update the
1083 * local database to modify how we react to <em>membership test</em> queries.
1084 * The channel master still needs to explicitly transmit a @e join message to
1085 * notify other channel members and they then also must still call this function
1086 * in their respective methods handling the @e join message. This way, how @e
1087 * join and @e part operations are exactly implemented is still up to the
1088 * application; for example, there might be a @e part_all method to kick out
1091 * Note that channel slaves are explicitly trusted to execute such methods
1092 * correctly; not doing so correctly will result in either denying other slaves
1093 * access or offering access to channel data to non-members.
1097 * @param slave_pub_key
1098 * Identity of channel slave to add.
1099 * @param announced_at
1100 * ID of the message that announced the membership change.
1101 * @param effective_since
1102 * Addition of slave is in effect since this message ID.
1104 * Function to call with the result of the operation.
1105 * The @e result_code argument is #GNUNET_OK on success, or
1106 * #GNUNET_SYSERR on error. In case of an error, the @e data argument
1107 * can contain an optional error message.
1109 * Closure for @a result_cb.
1112 GNUNET_PSYC_channel_slave_add (struct GNUNET_PSYC_Channel *channel,
1113 const struct GNUNET_CRYPTO_EcdsaPublicKey *slave_pub_key,
1114 uint64_t announced_at,
1115 uint64_t effective_since,
1116 GNUNET_ResultCallback result_cb,
1121 * Remove a slave from the channel's membership list.
1123 * Note that this will NOT generate any PSYC traffic, it will merely update the
1124 * local database to modify how we react to <em>membership test</em> queries.
1125 * The channel master still needs to explicitly transmit a @e part message to
1126 * notify other channel members and they then also must still call this function
1127 * in their respective methods handling the @e part message. This way, how
1128 * @e join and @e part operations are exactly implemented is still up to the
1129 * application; for example, there might be a @e part_all message to kick out
1132 * Note that channel members are explicitly trusted to perform these
1133 * operations correctly; not doing so correctly will result in either
1134 * denying members access or offering access to channel data to
1139 * @param slave_pub_key
1140 * Identity of channel slave to remove.
1141 * @param announced_at
1142 * ID of the message that announced the membership change.
1144 * Function to call with the result of the operation.
1145 * The @e result_code argument is #GNUNET_OK on success, or
1146 * #GNUNET_SYSERR on error. In case of an error, the @e data argument
1147 * can contain an optional error message.
1149 * Closure for @a result_cb.
1152 GNUNET_PSYC_channel_slave_remove (struct GNUNET_PSYC_Channel *channel,
1153 const struct GNUNET_CRYPTO_EcdsaPublicKey
1155 uint64_t announced_at,
1156 GNUNET_ResultCallback result_cb,
1161 * History request handle.
1163 struct GNUNET_PSYC_HistoryRequest;
1167 * Request to replay a part of the message history of the channel.
1169 * Historic messages (but NOT the state at the time) will be replayed (given to
1170 * the normal method handlers) if available and if access is permitted.
1173 * Which channel should be replayed?
1174 * @param start_message_id
1175 * Earliest interesting point in history.
1176 * @param end_message_id
1177 * Last (inclusive) interesting point in history.
1178 * @param method_prefix
1179 * Retrieve only messages with a matching method prefix.
1181 * OR'ed enum GNUNET_PSYC_HistoryReplayFlags
1183 * Function to call when the requested history has been fully replayed.
1184 * Once this function has been called, the client must not call
1185 * GNUNET_PSYC_channel_history_replay_cancel() anymore.
1187 * Closure for the callbacks.
1189 * @return Handle to cancel history replay operation.
1191 struct GNUNET_PSYC_HistoryRequest *
1192 GNUNET_PSYC_channel_history_replay (struct GNUNET_PSYC_Channel *channel,
1193 uint64_t start_message_id,
1194 uint64_t end_message_id,
1195 const char *method_prefix,
1197 GNUNET_PSYC_MessageCallback message_cb,
1198 GNUNET_PSYC_MessagePartCallback message_part_cb,
1199 GNUNET_ResultCallback result_cb,
1204 * Request to replay the latest messages from the message history of the channel.
1206 * Historic messages (but NOT the state at the time) will be replayed (given to
1207 * the normal method handlers) if available and if access is permitted.
1210 * Which channel should be replayed?
1211 * @param message_limit
1212 * Maximum number of messages to replay.
1214 * OR'ed enum GNUNET_PSYC_HistoryReplayFlags
1216 * Function to call when the requested history has been fully replayed
1217 * (counting message IDs might not suffice, as some messages might be
1218 * secret and thus the listener would not know the story is finished
1219 * without being told explicitly)o once this function has been called, the
1220 * client must not call GNUNET_PSYC_channel_history_replay_cancel() anymore.
1222 * Closure for the callbacks.
1224 * @return Handle to cancel history replay operation.
1226 struct GNUNET_PSYC_HistoryRequest *
1227 GNUNET_PSYC_channel_history_replay_latest (struct GNUNET_PSYC_Channel *channel,
1228 uint64_t message_limit,
1229 const char *method_prefix,
1231 GNUNET_PSYC_MessageCallback message_cb,
1232 GNUNET_PSYC_MessagePartCallback message_part_cb,
1233 GNUNET_ResultCallback result_cb,
1238 GNUNET_PSYC_channel_history_replay_cancel (struct GNUNET_PSYC_Channel *channel,
1239 struct GNUNET_PSYC_HistoryRequest *hr);
1243 * Function called to inform a member about stored state values for a channel.
1245 * If @a full_value_size > value_size then this function is called multiple
1246 * times until the whole value arrived.
1251 * Name of the state variable.
1252 * NULL if there are no more state variables to be returned.
1254 * Value of the state variable.
1256 * Number of bytes in @a value.
1257 * @param full_value_size
1258 * Number of bytes in the full value, including continuations.
1259 * Only set for the first part of a variable,
1260 * in case of a continuation it is 0.
1263 (*GNUNET_PSYC_StateVarCallback) (void *cls,
1264 const struct GNUNET_MessageHeader *mod,
1267 uint32_t value_size,
1268 uint32_t full_value_size);
1272 * State request handle.
1274 struct GNUNET_PSYC_StateRequest;
1278 * Retrieve the best matching channel state variable.
1280 * If the requested variable name is not present in the state, the nearest
1281 * less-specific name is matched; for example, requesting "_a_b" will match "_a"
1282 * if "_a_b" does not exist.
1287 * Full name of the requested variable.
1288 * The actual variable returned might have a shorter name.
1290 * Function called once when a matching state variable is found.
1291 * Not called if there's no matching state variable.
1293 * Function called after the operation finished.
1294 * (i.e. all state variables have been returned via @a state_cb)
1296 * Closure for the callbacks.
1298 struct GNUNET_PSYC_StateRequest *
1299 GNUNET_PSYC_channel_state_get (struct GNUNET_PSYC_Channel *channel,
1300 const char *full_name,
1301 GNUNET_PSYC_StateVarCallback var_cb,
1302 GNUNET_ResultCallback result_cb,
1307 * Return all channel state variables whose name matches a given prefix.
1309 * A name matches if it starts with the given @a name_prefix, thus requesting
1310 * the empty prefix ("") will match all values; requesting "_a_b" will also
1311 * return values stored under "_a_b_c".
1313 * The @a state_cb is invoked on all matching state variables asynchronously, as
1314 * the state is stored in and retrieved from the PSYCstore,
1318 * @param name_prefix
1319 * Prefix of the state variable name to match.
1321 * Function called once when a matching state variable is found.
1322 * Not called if there's no matching state variable.
1324 * Function called after the operation finished.
1325 * (i.e. all state variables have been returned via @a state_cb)
1327 * Closure for the callbacks.
1329 struct GNUNET_PSYC_StateRequest *
1330 GNUNET_PSYC_channel_state_get_prefix (struct GNUNET_PSYC_Channel *channel,
1331 const char *name_prefix,
1332 GNUNET_PSYC_StateVarCallback var_cb,
1333 GNUNET_ResultCallback result_cb,
1337 * Cancel a state request operation.
1340 * Handle for the operation to cancel.
1343 GNUNET_PSYC_channel_state_get_cancel (struct GNUNET_PSYC_StateRequest *sr);
1347 #if 0 /* keep Emacsens' auto-indent happy */
1354 /* ifndef GNUNET_PSYC_SERVICE_H */
1357 /** @} */ /* end of group */