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3 Copyright (C) 2012, 2013 Christian Grothoff (and other contributing authors)
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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.
253 * FIXME: use data_offset instead
255 uint64_t fragment_offset GNUNET_PACKED;
258 * Sending slave's public key.
259 * Not set if the message is from the master.
261 struct GNUNET_CRYPTO_EcdsaPublicKey slave_key;
263 /* Followed by concatenated PSYC message parts:
264 * messages with GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_* types
270 * The method of a message.
272 struct GNUNET_PSYC_MessageMethod
275 * Type: GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_METHOD
277 struct GNUNET_MessageHeader header;
280 * OR'ed GNUNET_PSYC_MasterTransmitFlags
282 uint32_t flags GNUNET_PACKED;
285 * Number of message IDs since the last message that contained state
286 * operations. @see enum GNUNET_PSYC_StateDeltaValues
288 uint64_t state_delta GNUNET_PACKED;
290 /* Followed by NUL-terminated method name. */
295 * A modifier of a message.
297 struct GNUNET_PSYC_MessageModifier
300 * Type: GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MODIFIER
302 struct GNUNET_MessageHeader header;
307 uint32_t value_size GNUNET_PACKED;
310 * Size of name, including NUL terminator.
312 uint16_t name_size GNUNET_PACKED;
315 * enum GNUNET_ENV_Operator
319 /* Followed by NUL-terminated name, then the value. */
323 struct GNUNET_PSYC_CountersResultMessage
326 * Type: GNUNET_MESSAGE_TYPE_PSYC_RESULT_COUNTERS
328 struct GNUNET_MessageHeader header;
331 * Status code for the operation.
333 uint32_t result_code GNUNET_PACKED;
336 * Last message ID sent to the channel.
338 uint64_t max_message_id GNUNET_PACKED;
343 * Join request sent to a PSYC master.
345 struct GNUNET_PSYC_JoinRequestMessage
348 * Type: GNUNET_MESSAGE_TYPE_PSYC_MASTER_JOIN_REQUEST
350 struct GNUNET_MessageHeader header;
352 * Public key of the joining slave.
354 struct GNUNET_CRYPTO_EcdsaPublicKey slave_key;
356 /* Followed by struct GNUNET_MessageHeader join_request */
361 * Join decision sent in reply to a join request.
363 struct GNUNET_PSYC_JoinDecisionMessage
366 * Type: GNUNET_MESSAGE_TYPE_PSYC_JOIN_DECISION
368 struct GNUNET_MessageHeader header;
371 * #GNUNET_YES if the slave was admitted.
376 * Public key of the joining slave.
377 * Only set when the master is sending the decision,
378 * not set when a slave is receiving it.
380 struct GNUNET_CRYPTO_EcdsaPublicKey slave_key;
382 /* Followed by struct GNUNET_MessageHeader join_response */
386 enum GNUNET_PSYC_HistoryReplayFlags
389 * Replay locally available messages.
391 GNUNET_PSYC_HISTORY_REPLAY_LOCAL = 0,
394 * Replay messages from remote peers if not found locally.
396 GNUNET_PSYC_HISTORY_REPLAY_REMOTE = 1,
400 struct GNUNET_PSYC_HistoryRequestMessage
403 * Type: GNUNET_MESSAGE_TYPE_PSYC_CHANNEL_HISTORY_REPLAY
405 struct GNUNET_MessageHeader header;
408 * @see enum GNUNET_PSYC_HistoryReplayFlags
410 uint32_t flags GNUNET_PACKED;
413 * ID for this operation.
415 uint64_t op_id GNUNET_PACKED;
417 uint64_t start_message_id GNUNET_PACKED;
419 uint64_t end_message_id GNUNET_PACKED;
421 uint64_t message_limit GNUNET_PACKED;
423 /* Followed by NUL-terminated method name prefix. */
427 struct GNUNET_PSYC_StateRequestMessage
431 * - GNUNET_MESSAGE_TYPE_PSYC_CHANNEL_STATE_GET
432 * - GNUNET_MESSAGE_TYPE_PSYC_CHANNEL_STATE_GET_PREFIX
434 struct GNUNET_MessageHeader header;
436 uint32_t reserved GNUNET_PACKED;
439 * ID for this operation.
441 uint64_t op_id GNUNET_PACKED;
443 /* Followed by NUL-terminated name. */
447 /**** service -> library ****/
451 * Answer from service to client about last operation.
453 struct GNUNET_PSYC_OperationResultMessage
457 * - GNUNET_MESSAGE_TYPE_PSYC_RESULT_CODE
458 * - GNUNET_MESSAGE_TYPE_PSYC_CHANNEL_STATE_RESULT
460 struct GNUNET_MessageHeader header;
462 uint32_t reserved GNUNET_PACKED;
467 uint64_t op_id GNUNET_PACKED;
470 * Status code for the operation.
472 uint64_t result_code GNUNET_PACKED;
475 * - on error: NUL-terminated error message
476 * - on success: one of the following message types
478 * For a STATE_RESULT, one of:
479 * - GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MODIFIER
480 * - GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MOD_CONT
481 * - GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_END
485 GNUNET_NETWORK_STRUCT_END
488 #define GNUNET_PSYC_MODIFIER_MAX_PAYLOAD \
489 GNUNET_MULTICAST_FRAGMENT_MAX_PAYLOAD \
490 - sizeof (struct GNUNET_PSYC_MessageModifier)
492 #define GNUNET_PSYC_MOD_CONT_MAX_PAYLOAD \
493 GNUNET_MULTICAST_FRAGMENT_MAX_PAYLOAD \
494 - sizeof (struct GNUNET_MessageHeader)
496 #define GNUNET_PSYC_DATA_MAX_PAYLOAD \
497 GNUNET_MULTICAST_FRAGMENT_MAX_PAYLOAD \
498 - sizeof (struct GNUNET_MessageHeader)
502 * PSYC message part processing states.
504 enum GNUNET_PSYC_MessageState
506 GNUNET_PSYC_MESSAGE_STATE_START = 0,
507 GNUNET_PSYC_MESSAGE_STATE_HEADER = 1,
508 GNUNET_PSYC_MESSAGE_STATE_METHOD = 2,
509 GNUNET_PSYC_MESSAGE_STATE_MODIFIER = 3,
510 GNUNET_PSYC_MESSAGE_STATE_MOD_CONT = 4,
511 GNUNET_PSYC_MESSAGE_STATE_DATA = 5,
512 GNUNET_PSYC_MESSAGE_STATE_END = 6,
513 GNUNET_PSYC_MESSAGE_STATE_CANCEL = 7,
514 GNUNET_PSYC_MESSAGE_STATE_ERROR = 8,
519 * Handle that identifies a join request.
521 * Used to match calls to #GNUNET_PSYC_JoinCallback to the
522 * corresponding calls to GNUNET_PSYC_join_decision().
524 struct GNUNET_PSYC_JoinHandle;
528 * Method called from PSYC upon receiving a message.
530 * @param cls Closure.
531 * @param message_id Sequence number of the message.
532 * @param flags OR'ed GNUNET_PSYC_MessageFlags
533 * @param msg Message part, one of the following types:
536 (*GNUNET_PSYC_MessageCallback) (void *cls,
539 const struct GNUNET_PSYC_MessageHeader *msg);
543 * Method called from PSYC upon receiving part of a message.
548 * Public key of the slave sending the message.
549 * Only set for channel master.
551 * Sequence number of the message.
553 * OR'ed GNUNET_PSYC_MessageFlags
555 * Byte offset of data, only set if @a msg has a type
556 * #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_DATA
557 * @param msg Message part, one of the following types:
558 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_HEADER
559 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_METHOD
560 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MODIFIER
561 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MOD_CONT
562 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_DATA
563 * or NULL if an error occurred while receiving a message.
566 (*GNUNET_PSYC_MessagePartCallback) (void *cls,
567 const struct GNUNET_CRYPTO_EcdsaPublicKey *slave_key,
570 uint64_t data_offset,
571 const struct GNUNET_MessageHeader *msg);
575 * Method called from PSYC upon receiving a join request.
580 * Public key of the slave requesting join.
582 * Join message sent along with the request.
584 * Join handle to use with GNUNET_PSYC_join_decision()
587 (*GNUNET_PSYC_JoinRequestCallback) (void *cls,
588 const struct GNUNET_PSYC_JoinRequestMessage *req,
589 const struct GNUNET_CRYPTO_EcdsaPublicKey *slave_key,
590 const struct GNUNET_PSYC_Message *join_msg,
591 struct GNUNET_PSYC_JoinHandle *jh);
595 * Function to call with the decision made for a join request.
597 * Must be called once and only once in response to an invocation of the
598 * #GNUNET_PSYC_JoinCallback.
600 * @param jh Join request handle.
602 * #GNUNET_YES if the join is approved,
603 * #GNUNET_NO if it is disapproved,
604 * #GNUNET_SYSERR if we cannot answer the request.
605 * @param relay_count Number of relays given.
606 * @param relays Array of suggested peers that might be useful relays to use
607 * when joining the multicast group (essentially a list of peers that
608 * are already part of the multicast group and might thus be willing
609 * to help with routing). If empty, only this local peer (which must
610 * be the multicast origin) is a good candidate for building the
611 * multicast tree. Note that it is unnecessary to specify our own
612 * peer identity in this array.
613 * @param join_resp Application-dependent join response message to send along
616 * @return #GNUNET_OK on success,
617 * #GNUNET_SYSERR if @a join_resp is too large.
620 GNUNET_PSYC_join_decision (struct GNUNET_PSYC_JoinHandle *jh,
622 uint32_t relay_count,
623 const struct GNUNET_PeerIdentity *relays,
624 const struct GNUNET_PSYC_Message *join_resp);
628 * Handle for the master of a PSYC channel.
630 struct GNUNET_PSYC_Master;
634 * Function called after connected to the PSYC service
635 * and the channel master started.
637 * Also called when reconnected to the service
638 * after the connection closed unexpectedly.
643 * #GNUNET_YES if there were already messages sent to the channel,
644 * #GNUNET_NO if the message history is empty,
645 * #GNUNET_SYSERR on error.
646 * @param max_message_id
647 * Last message ID sent to the channel.
650 (*GNUNET_PSYC_MasterStartCallback) (void *cls, int result,
651 uint64_t max_message_id);
655 * Start a PSYC master channel.
657 * Will start a multicast group identified by the given ECC key. Messages
658 * received from group members will be given to the respective handler methods.
659 * If a new member wants to join a group, the "join" method handler will be
660 * invoked; the join handler must then generate a "join" message to approve the
661 * joining of the new member. The channel can also change group membership
662 * without explicit requests. Note that PSYC doesn't itself "understand" join
663 * or part messages, the respective methods must call other PSYC functions to
664 * inform PSYC about the meaning of the respective events.
666 * @param cfg Configuration to use (to connect to PSYC service).
667 * @param channel_key ECC key that will be used to sign messages for this
668 * PSYC session. The public key is used to identify the PSYC channel.
669 * Note that end-users will usually not use the private key directly, but
670 * rather look it up in GNS for places managed by other users, or select
671 * a file with the private key(s) when setting up their own channels
672 * FIXME: we'll likely want to use NOT the p521 curve here, but a cheaper
674 * @param policy Channel policy specifying join and history restrictions.
675 * Used to automate join decisions.
676 * @param master_start_cb Function to invoke after the channel master started.
677 * @param join_request_cb Function to invoke when a slave wants to join.
678 * @param message_cb Function to invoke on message parts sent to the channel
679 * and received from slaves
680 * @param cls Closure for @a method and @a join_cb.
682 * @return Handle for the channel master, NULL on error.
684 struct GNUNET_PSYC_Master *
685 GNUNET_PSYC_master_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
686 const struct GNUNET_CRYPTO_EddsaPrivateKey *channel_key,
687 enum GNUNET_PSYC_Policy policy,
688 GNUNET_PSYC_MasterStartCallback master_start_cb,
689 GNUNET_PSYC_JoinRequestCallback join_request_cb,
690 GNUNET_PSYC_MessageCallback message_cb,
691 GNUNET_PSYC_MessagePartCallback message_part_cb,
696 * Function called to provide data for a transmission via PSYC.
698 * Note that returning #GNUNET_YES or #GNUNET_SYSERR (but not #GNUNET_NO)
699 * invalidates the respective transmission handle.
701 * @param cls Closure.
702 * @param[in,out] data_size Initially set to the number of bytes available in
703 * @a data, should be set to the number of bytes written to data.
704 * @param[out] data Where to write the body of the message to give to the
705 * method. The function must copy at most @a data_size bytes to @a data.
706 * @return #GNUNET_SYSERR on error (fatal, aborts transmission)
707 * #GNUNET_NO on success, if more data is to be transmitted later.
708 * Should be used if @a data_size was not big enough to take all the
709 * data. If 0 is returned in @a data_size the transmission is paused,
710 * and can be resumed with GNUNET_PSYC_master_transmit_resume().
711 * #GNUNET_YES if this completes the transmission (all data supplied)
714 (*GNUNET_PSYC_TransmitNotifyData) (void *cls,
719 * Function called to provide a modifier for a transmission via PSYC.
721 * Note that returning #GNUNET_YES or #GNUNET_SYSERR (but not #GNUNET_NO)
722 * invalidates the respective transmission handle.
724 * @param cls Closure.
725 * @param[in,out] data_size Initially set to the number of bytes available in
726 * @a data, should be set to the number of bytes written to data.
727 * @param[out] data Where to write the modifier's name and value.
728 * The function must copy at most @a data_size bytes to @a data.
729 * When this callback is first called for a modifier, @a data should
730 * contain: "name\0value". If the whole value does not fit, subsequent
731 * calls to this function should write continuations of the value to
733 * @param[out] oper Where to write the operator of the modifier.
734 * Only needed during the first call to this callback at the beginning
735 * of the modifier. In case of subsequent calls asking for value
736 * continuations @a oper is set to #NULL.
737 * @param[out] full_value_size Where to write the full size of the value.
738 * Only needed during the first call to this callback at the beginning
739 * of the modifier. In case of subsequent calls asking for value
740 * continuations @a value_size is set to #NULL.
741 * @return #GNUNET_SYSERR on error (fatal, aborts transmission)
742 * #GNUNET_NO on success, if more data is to be transmitted later.
743 * Should be used if @a data_size was not big enough to take all the
744 * data for the modifier's value (the name must be always returned
745 * during the first call to this callback).
746 * If 0 is returned in @a data_size the transmission is paused,
747 * and can be resumed with GNUNET_PSYC_master_transmit_resume().
748 * #GNUNET_YES if this completes the modifier (the whole value is supplied).
751 (*GNUNET_PSYC_TransmitNotifyModifier) (void *cls,
755 uint32_t *full_value_size);
758 * Flags for transmitting messages to a channel by the master.
760 enum GNUNET_PSYC_MasterTransmitFlags
762 GNUNET_PSYC_MASTER_TRANSMIT_NONE = 0,
765 * Whether this message should reset the channel state,
766 * i.e. remove all previously stored state variables.
769 GNUNET_PSYC_MASTER_TRANSMIT_STATE_RESET = 1 << 0,
772 * Whether this message contains any state modifiers.
774 GNUNET_PSYC_MASTER_TRANSMIT_STATE_MODIFY = 1 << 1,
777 * Add PSYC header variable with the hash of the current channel state.
779 GNUNET_PSYC_MASTER_TRANSMIT_STATE_HASH = 1 << 2,
782 * Whether we need to increment the group generation counter after
783 * transmitting this message.
785 GNUNET_PSYC_MASTER_TRANSMIT_INC_GROUP_GEN = 1 << 3
790 * Handle for a pending PSYC transmission operation.
792 struct GNUNET_PSYC_MasterTransmitHandle;
796 * Send a message to call a method to all members in the PSYC channel.
798 * @param master Handle to the PSYC channel.
799 * @param method_name Which method should be invoked.
800 * @param notify_mod Function to call to obtain modifiers.
801 * @param notify_data Function to call to obtain fragments of the data.
802 * @param notify_cls Closure for @a notify_mod and @a notify_data.
803 * @param flags Flags for the message being transmitted.
804 * @return Transmission handle, NULL on error (i.e. more than one request queued).
806 struct GNUNET_PSYC_MasterTransmitHandle *
807 GNUNET_PSYC_master_transmit (struct GNUNET_PSYC_Master *master,
808 const char *method_name,
809 GNUNET_PSYC_TransmitNotifyModifier notify_mod,
810 GNUNET_PSYC_TransmitNotifyData notify_data,
812 enum GNUNET_PSYC_MasterTransmitFlags flags);
816 * Resume transmission to the channel.
818 * @param th Handle of the request that is being resumed.
821 GNUNET_PSYC_master_transmit_resume (struct GNUNET_PSYC_MasterTransmitHandle *th);
825 * Abort transmission request to channel.
827 * @param th Handle of the request that is being aborted.
830 GNUNET_PSYC_master_transmit_cancel (struct GNUNET_PSYC_MasterTransmitHandle *th);
834 * Stop a PSYC master channel.
837 * PSYC channel master to stop.
839 * Keep place active after last application disconnected.
841 * Function called after the master stopped
842 * and disconnected from the psyc service.
844 * Closure for @a part_cb.
847 GNUNET_PSYC_master_stop (struct GNUNET_PSYC_Master *master,
849 GNUNET_ContinuationCallback stop_cb,
854 * Handle for a PSYC channel slave.
856 struct GNUNET_PSYC_Slave;
860 * Function called after the slave connected to the PSYC service.
862 * Also called when reconnected to the service
863 * after the connection closed unexpectedly.
868 * #GNUNET_YES if there were already messages sent to the channel,
869 * #GNUNET_NO if the message history is empty,
870 * #GNUNET_SYSERR on error.
871 * @param max_message_id
872 * Last message ID sent to the channel.
875 (*GNUNET_PSYC_SlaveConnectCallback) (void *cls, int result,
876 uint64_t max_message_id);
880 * Method called to inform about the decision in response to a join request.
882 * If @a is_admitted is not #GNUNET_YES, then sending messages to the channel is
883 * not possible, but earlier history can be still queried.
885 * @param cls Closure.
886 * @param is_admitted #GNUNET_YES or #GNUNET_NO or #GNUNET_SYSERR
887 * @param join_msg Application-dependent join message from the origin.
890 (*GNUNET_PSYC_JoinDecisionCallback) (void *cls,
891 const struct GNUNET_PSYC_JoinDecisionMessage *dcsn,
893 const struct GNUNET_PSYC_Message *join_msg);
896 * Flags for GNUNET_PSYC_slave_join()
898 enum GNUNET_PSYC_SlaveJoinFlags
900 GNUNET_PSYC_SLAVE_JOIN_NONE = 0,
903 * Local join for history access, no network connection is established.
905 GNUNET_PSYC_SLAVE_JOIN_LOCAL = 1,
910 * Join a PSYC channel.
912 * The entity joining is always the local peer. The user must immediately use
913 * the GNUNET_PSYC_slave_transmit() functions to transmit a @e join_msg to the
914 * channel; if the join request succeeds, the channel state (and @e recent
915 * method calls) will be replayed to the joining member. There is no explicit
916 * notification on failure (as the channel may simply take days to approve,
917 * and disapproval is simply being ignored).
920 * Configuration to use.
921 * @param channel_pub_key
922 * ECC public key that identifies the channel we wish to join.
924 * ECC private-public key pair that identifies the slave, and
925 * used by multicast to sign the join request and subsequent unicast
926 * requests sent to the master.
930 * Peer identity of the origin.
932 * Number of peers in the @a relays array.
934 * Peer identities of members of the multicast group, which serve
935 * as relays and used to join the group at.
937 * Function to invoke on message fragments received from the channel.
938 * @param message_part_cb
939 * Function to invoke on message parts received from the channel.
940 * @param slave_connect_cb
941 * Function invoked once we have connected to the PSYC service.
942 * @param join_decision_cb
943 * Function invoked once we have received a join decision.
945 * Closure for @a message_cb and @a slave_joined_cb.
949 * @return Handle for the slave, NULL on error.
951 struct GNUNET_PSYC_Slave *
952 GNUNET_PSYC_slave_join (const struct GNUNET_CONFIGURATION_Handle *cfg,
953 const struct GNUNET_CRYPTO_EddsaPublicKey *channel_pub_key,
954 const struct GNUNET_CRYPTO_EcdsaPrivateKey *slave_key,
955 enum GNUNET_PSYC_SlaveJoinFlags flags,
956 const struct GNUNET_PeerIdentity *origin,
957 uint32_t relay_count,
958 const struct GNUNET_PeerIdentity *relays,
959 GNUNET_PSYC_MessageCallback message_cb,
960 GNUNET_PSYC_MessagePartCallback message_part_cb,
961 GNUNET_PSYC_SlaveConnectCallback slave_connect_cb,
962 GNUNET_PSYC_JoinDecisionCallback join_decision_cb,
964 const struct GNUNET_PSYC_Message *join_msg);
968 * Part a PSYC channel.
970 * Will terminate the connection to the PSYC service. Polite clients should
971 * first explicitly send a part request (via GNUNET_PSYC_slave_transmit()).
976 * Keep place active after last application disconnected.
978 * Function called after the slave parted the channel
979 * and disconnected from the psyc service.
981 * Closure for @a part_cb.
984 GNUNET_PSYC_slave_part (struct GNUNET_PSYC_Slave *slave,
986 GNUNET_ContinuationCallback part_cb,
991 * Flags for transmitting messages to the channel master by a slave.
993 enum GNUNET_PSYC_SlaveTransmitFlags
995 GNUNET_PSYC_SLAVE_TRANSMIT_NONE = 0
1000 * Handle for a pending PSYC transmission operation.
1002 struct GNUNET_PSYC_SlaveTransmitHandle;
1006 * Request a message to be sent to the channel master.
1008 * @param slave Slave handle.
1009 * @param method_name Which (PSYC) method should be invoked (on host).
1010 * @param notify_mod Function to call to obtain modifiers.
1011 * @param notify_data Function to call to obtain fragments of the data.
1012 * @param notify_cls Closure for @a notify.
1013 * @param flags Flags for the message being transmitted.
1014 * @return Transmission handle, NULL on error (i.e. more than one request queued).
1016 struct GNUNET_PSYC_SlaveTransmitHandle *
1017 GNUNET_PSYC_slave_transmit (struct GNUNET_PSYC_Slave *slave,
1018 const char *method_name,
1019 GNUNET_PSYC_TransmitNotifyModifier notify_mod,
1020 GNUNET_PSYC_TransmitNotifyData notify_data,
1022 enum GNUNET_PSYC_SlaveTransmitFlags flags);
1026 * Resume transmission to the master.
1028 * @param th Handle of the request that is being resumed.
1031 GNUNET_PSYC_slave_transmit_resume (struct GNUNET_PSYC_SlaveTransmitHandle *th);
1035 * Abort transmission request to master.
1037 * @param th Handle of the request that is being aborted.
1040 GNUNET_PSYC_slave_transmit_cancel (struct GNUNET_PSYC_SlaveTransmitHandle *th);
1044 * Handle to access PSYC channel operations for both the master and slaves.
1046 struct GNUNET_PSYC_Channel;
1050 * Convert a channel @a master to a @e channel handle to access the @e channel
1053 * @param master Channel master handle.
1054 * @return Channel handle, valid for as long as @a master is valid.
1056 struct GNUNET_PSYC_Channel *
1057 GNUNET_PSYC_master_get_channel (struct GNUNET_PSYC_Master *master);
1061 * Convert @a slave to a @e channel handle to access the @e channel APIs.
1063 * @param slave Slave handle.
1064 * @return Channel handle, valid for as long as @a slave is valid.
1066 struct GNUNET_PSYC_Channel *
1067 GNUNET_PSYC_slave_get_channel (struct GNUNET_PSYC_Slave *slave);
1071 * Add a slave to the channel's membership list.
1073 * Note that this will NOT generate any PSYC traffic, it will merely update the
1074 * local database to modify how we react to <em>membership test</em> queries.
1075 * The channel master still needs to explicitly transmit a @e join message to
1076 * notify other channel members and they then also must still call this function
1077 * in their respective methods handling the @e join message. This way, how @e
1078 * join and @e part operations are exactly implemented is still up to the
1079 * application; for example, there might be a @e part_all method to kick out
1082 * Note that channel slaves are explicitly trusted to execute such methods
1083 * correctly; not doing so correctly will result in either denying other slaves
1084 * access or offering access to channel data to non-members.
1089 * Identity of channel slave to add.
1090 * @param announced_at
1091 * ID of the message that announced the membership change.
1092 * @param effective_since
1093 * Addition of slave is in effect since this message ID.
1095 * Function to call with the result of the operation.
1096 * The @e result_code argument is #GNUNET_OK on success, or
1097 * #GNUNET_SYSERR on error. In case of an error, the @e data argument
1098 * can contain an optional error message.
1100 * Closure for @a result_cb.
1103 GNUNET_PSYC_channel_slave_add (struct GNUNET_PSYC_Channel *channel,
1104 const struct GNUNET_CRYPTO_EcdsaPublicKey *slave_key,
1105 uint64_t announced_at,
1106 uint64_t effective_since,
1107 GNUNET_ResultCallback result_cb,
1112 * Remove a slave from the channel's membership list.
1114 * Note that this will NOT generate any PSYC traffic, it will merely update the
1115 * local database to modify how we react to <em>membership test</em> queries.
1116 * The channel master still needs to explicitly transmit a @e part message to
1117 * notify other channel members and they then also must still call this function
1118 * in their respective methods handling the @e part message. This way, how
1119 * @e join and @e part operations are exactly implemented is still up to the
1120 * application; for example, there might be a @e part_all message to kick out
1123 * Note that channel members are explicitly trusted to perform these
1124 * operations correctly; not doing so correctly will result in either
1125 * denying members access or offering access to channel data to
1131 * Identity of channel slave to remove.
1132 * @param announced_at
1133 * ID of the message that announced the membership change.
1135 * Function to call with the result of the operation.
1136 * The @e result_code argument is #GNUNET_OK on success, or
1137 * #GNUNET_SYSERR on error. In case of an error, the @e data argument
1138 * can contain an optional error message.
1140 * Closure for @a result_cb.
1143 GNUNET_PSYC_channel_slave_remove (struct GNUNET_PSYC_Channel *channel,
1144 const struct GNUNET_CRYPTO_EcdsaPublicKey
1146 uint64_t announced_at,
1147 GNUNET_ResultCallback result_cb,
1152 * History request handle.
1154 struct GNUNET_PSYC_HistoryRequest;
1158 * Request to replay a part of the message history of the channel.
1160 * Historic messages (but NOT the state at the time) will be replayed (given to
1161 * the normal method handlers) if available and if access is permitted.
1164 * Which channel should be replayed?
1165 * @param start_message_id
1166 * Earliest interesting point in history.
1167 * @param end_message_id
1168 * Last (inclusive) interesting point in history.
1169 * @param method_prefix
1170 * Retrieve only messages with a matching method prefix.
1172 * OR'ed enum GNUNET_PSYC_HistoryReplayFlags
1174 * Function to call when the requested history has been fully replayed.
1175 * Once this function has been called, the client must not call
1176 * GNUNET_PSYC_channel_history_replay_cancel() anymore.
1178 * Closure for the callbacks.
1180 * @return Handle to cancel history replay operation.
1182 struct GNUNET_PSYC_HistoryRequest *
1183 GNUNET_PSYC_channel_history_replay (struct GNUNET_PSYC_Channel *channel,
1184 uint64_t start_message_id,
1185 uint64_t end_message_id,
1186 const char *method_prefix,
1188 GNUNET_PSYC_MessageCallback message_cb,
1189 GNUNET_PSYC_MessagePartCallback message_part_cb,
1190 GNUNET_ResultCallback result_cb,
1195 * Request to replay the latest messages from the message history of the channel.
1197 * Historic messages (but NOT the state at the time) will be replayed (given to
1198 * the normal method handlers) if available and if access is permitted.
1201 * Which channel should be replayed?
1202 * @param message_limit
1203 * Maximum number of messages to replay.
1205 * OR'ed enum GNUNET_PSYC_HistoryReplayFlags
1207 * Function to call when the requested history has been fully replayed
1208 * (counting message IDs might not suffice, as some messages might be
1209 * secret and thus the listener would not know the story is finished
1210 * without being told explicitly)o once this function has been called, the
1211 * client must not call GNUNET_PSYC_channel_history_replay_cancel() anymore.
1213 * Closure for the callbacks.
1215 * @return Handle to cancel history replay operation.
1217 struct GNUNET_PSYC_HistoryRequest *
1218 GNUNET_PSYC_channel_history_replay_latest (struct GNUNET_PSYC_Channel *channel,
1219 uint64_t message_limit,
1220 const char *method_prefix,
1222 GNUNET_PSYC_MessageCallback message_cb,
1223 GNUNET_PSYC_MessagePartCallback message_part_cb,
1224 GNUNET_ResultCallback result_cb,
1229 GNUNET_PSYC_channel_history_replay_cancel (struct GNUNET_PSYC_Channel *channel,
1230 struct GNUNET_PSYC_HistoryRequest *hr);
1234 * Function called to inform a member about stored state values for a channel.
1236 * If @a full_value_size > value_size then this function is called multiple
1237 * times until the whole value arrived.
1242 * Name of the state variable.
1243 * NULL if there are no more state variables to be returned.
1245 * Value of the state variable.
1247 * Number of bytes in @a value.
1248 * @param full_value_size
1249 * Number of bytes in the full value, including continuations.
1250 * Only set for the first part of a variable,
1251 * in case of a continuation it is 0.
1254 (*GNUNET_PSYC_StateVarCallback) (void *cls,
1255 const struct GNUNET_MessageHeader *mod,
1258 uint32_t value_size,
1259 uint32_t full_value_size);
1263 * State request handle.
1265 struct GNUNET_PSYC_StateRequest;
1269 * Retrieve the best matching channel state variable.
1271 * If the requested variable name is not present in the state, the nearest
1272 * less-specific name is matched; for example, requesting "_a_b" will match "_a"
1273 * if "_a_b" does not exist.
1278 * Full name of the requested variable.
1279 * The actual variable returned might have a shorter name.
1281 * Function called once when a matching state variable is found.
1282 * Not called if there's no matching state variable.
1284 * Function called after the operation finished.
1285 * (i.e. all state variables have been returned via @a state_cb)
1287 * Closure for the callbacks.
1289 struct GNUNET_PSYC_StateRequest *
1290 GNUNET_PSYC_channel_state_get (struct GNUNET_PSYC_Channel *channel,
1291 const char *full_name,
1292 GNUNET_PSYC_StateVarCallback var_cb,
1293 GNUNET_ResultCallback result_cb,
1298 * Return all channel state variables whose name matches a given prefix.
1300 * A name matches if it starts with the given @a name_prefix, thus requesting
1301 * the empty prefix ("") will match all values; requesting "_a_b" will also
1302 * return values stored under "_a_b_c".
1304 * The @a state_cb is invoked on all matching state variables asynchronously, as
1305 * the state is stored in and retrieved from the PSYCstore,
1309 * @param name_prefix
1310 * Prefix of the state variable name to match.
1312 * Function called once when a matching state variable is found.
1313 * Not called if there's no matching state variable.
1315 * Function called after the operation finished.
1316 * (i.e. all state variables have been returned via @a state_cb)
1318 * Closure for the callbacks.
1320 struct GNUNET_PSYC_StateRequest *
1321 GNUNET_PSYC_channel_state_get_prefix (struct GNUNET_PSYC_Channel *channel,
1322 const char *name_prefix,
1323 GNUNET_PSYC_StateVarCallback var_cb,
1324 GNUNET_ResultCallback result_cb,
1328 * Cancel a state request operation.
1331 * Handle for the operation to cancel.
1334 GNUNET_PSYC_channel_state_get_cancel (struct GNUNET_PSYC_StateRequest *sr);
1338 #if 0 /* keep Emacsens' auto-indent happy */
1345 /* ifndef GNUNET_PSYC_SERVICE_H */
1348 /** @} */ /* end of group */