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20 * @author Gabor X Toth
21 * @author Christian Grothoff
26 * @defgroup psyc PSYC service
27 * Send/receive messages in PSYC channels and access the PSYC Store.
29 * Note that clients of this API are NOT expected to understand the PSYC message
30 * format, only the semantics! Parsing (and serializing) the PSYC stream format
31 * is done within the implementation of the libgnunetpsyc library, and this API
32 * deliberately exposes as little as possible of the actual data stream format
36 * - this API does not know about PSYC's "root" and "places";
37 * there is no 'root' in GNUnet-PSYC as we're decentralized;
38 * 'places' and 'persons' are combined within the same
39 * abstraction, that of a "channel". Channels are identified
40 * and accessed in this API using a public/private key.
41 * Higher-level applications should use NAMES within GNS
42 * to obtain public keys, and the distinction between
43 * 'places' and 'persons' can then be made with the help
44 * of the naming system (and/or conventions).
45 * Channels are (as in PSYC) organized into a hierarchy; each
46 * channel master (the one with the private key) is then
47 * the operator of the multicast group (its Origin in
48 * the terminology of the multicast API).
49 * - The API supports passing large amounts of data using
50 * 'streaming' for the argument passed to a method. State
51 * and variables must fit into memory and cannot be streamed
52 * (thus, no passing of 4 GB of data in a variable;
53 * once we implement this, we might want to create a
54 * @c \#define for the maximum size of a variable).
55 * - PSYC defines standard variables, methods, etc. This
56 * library deliberately abstracts over all of these; a
57 * higher-level API should combine the naming system (GNS)
58 * and standard methods (_converse, _notice, _request,
59 * _warning, _error etc) and variables (_action, _color,
60 * _time, etc). However, this API does take over the
61 * routing variables, specifically '_context' (channel),
62 * and '_source'. We only kind-of support '_target', as
63 * the target is either everyone in the group or the
64 * origin, and never just a single member of the group;
65 * for such individual messages, an application needs to
66 * construct an 'inbox' channel where the master (only)
67 * receives messages (but never forwards; private responses
68 * would be transmitted by joining the senders 'inbox'
69 * channel -- or a inbox#bob subchannel). The
70 * goal for all of this is to keep the abstractions in this
71 * API minimal: interaction with multicast, try \& slice,
72 * state/variable/channel management. Higher-level
73 * operations belong elsewhere (so maybe this API should
74 * be called 'PSYC-low', whereas a higher-level API
75 * implementing defaults for standard methods and
76 * variables might be called 'PSYC-std' or 'PSYC-high'.
78 * In PSYC terminology this is simply called the "PSYC
79 * routing layer" and the abstractions, for instance in
80 * psyced, are quite similar. The higher one is called
81 * "PSYC entity layer." In the text rendering of the
82 * protocol the two are separated by an empty line. See
83 * http://about.psyc.eu/Spec:Packet and related. --lynX
88 #ifndef GNUNET_PSYC_SERVICE_H
89 #define GNUNET_PSYC_SERVICE_H
94 #if 0 /* keep Emacsens' auto-indent happy */
99 #include "gnunet_util_lib.h"
100 #include "gnunet_multicast_service.h"
104 # define UINT64_MAX 0xffffffffffffffffULL
109 * Version number of GNUnet-PSYC API.
111 #define GNUNET_PSYC_VERSION 0x00000000
115 * Policy flags for a channel.
117 enum GNUNET_PSYC_ChannelFlags
120 * Admission must be confirmed by the master.
122 GNUNET_PSYC_CHANNEL_ADMISSION_CONTROL = 1 << 0,
125 * Past messages are only available to slaves who were admitted at the time
126 * they were sent to the channel.
128 GNUNET_PSYC_CHANNEL_RESTRICTED_HISTORY = 1 << 1
133 * PSYC channel policies.
135 enum GNUNET_PSYC_Policy
138 * Anyone can join the channel, without announcing their presence;
139 * all messages are always public and can be distributed freely.
140 * Joins may be announced, but this is not required.
142 GNUNET_PSYC_CHANNEL_ANONYMOUS = 0,
145 * The master must approve membership to the channel, messages must only be
146 * distributed to current channel slaves. This includes the channel
147 * state as well as transient messages.
149 GNUNET_PSYC_CHANNEL_PRIVATE
150 = GNUNET_PSYC_CHANNEL_ADMISSION_CONTROL
151 | GNUNET_PSYC_CHANNEL_RESTRICTED_HISTORY
155 * Anyone can freely join the channel (no approval required);
156 * however, messages must only be distributed to current channel
157 * slaves, so the master must still acknowledge that the slave
158 * joined before transient messages are delivered. As approval is
159 * guaranteed, the presistent channel state can be synchronized freely
160 * immediately, prior to master confirmation.
162 GNUNET_PSYC_CHANNEL_OPEN
163 = GNUNET_PSYC_CHANNEL_RESTRICTED_HISTORY,
166 * The master must approve joins to the channel, but past messages can be
167 * freely distributed to slaves.
169 GNUNET_PSYC_CHANNEL_CLOSED
170 = GNUNET_PSYC_CHANNEL_ADMISSION_CONTROL,
175 enum GNUNET_PSYC_MessageFlags
178 * Default / no flags.
180 GNUNET_PSYC_MESSAGE_DEFAULT = 0,
183 * Historic message, retrieved from PSYCstore.
185 GNUNET_PSYC_MESSAGE_HISTORIC = 1 << 0,
188 * Request from slave to master.
190 GNUNET_PSYC_MESSAGE_REQUEST = 1 << 1,
193 * Message can be delivered out of order.
195 GNUNET_PSYC_MESSAGE_ORDER_ANY = 1 << 2
200 * Values for the @a state_delta field of GNUNET_PSYC_MessageHeader.
202 enum GNUNET_PSYC_StateDeltaValues
204 GNUNET_PSYC_STATE_RESET = 0,
206 GNUNET_PSYC_STATE_NOT_MODIFIED = UINT64_MAX
210 GNUNET_NETWORK_STRUCT_BEGIN
215 * Used for single-fragment messages e.g. in a join request or response.
217 struct GNUNET_PSYC_Message
220 * Message header with size and type information.
222 struct GNUNET_MessageHeader header;
224 /* Followed by concatenated PSYC message parts:
225 * messages with GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_* types
231 * Header of a PSYC message.
233 * The PSYC service adds this when delivering the message to local clients,
234 * not present on the multicast layer.
236 struct GNUNET_PSYC_MessageHeader
239 * Generic message header with size and type information.
241 struct GNUNET_MessageHeader header;
244 * Flags for this message fragment.
246 * @see enum GNUNET_PSYC_MessageFlags
248 uint32_t flags GNUNET_PACKED;
251 * Number of the message this message part belongs to.
252 * Monotonically increasing from 1.
254 uint64_t message_id GNUNET_PACKED;
257 * Byte offset of this @e fragment of the @e message.
259 uint64_t fragment_offset GNUNET_PACKED;
262 * Sending slave's public key.
263 * Not set if the message is from the master.
265 struct GNUNET_CRYPTO_EcdsaPublicKey slave_pub_key;
267 /* Followed by concatenated PSYC message parts:
268 * messages with GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_* types
274 * The method of a message.
276 struct GNUNET_PSYC_MessageMethod
279 * Type: GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_METHOD
281 struct GNUNET_MessageHeader header;
284 * OR'ed GNUNET_PSYC_MasterTransmitFlags
286 uint32_t flags GNUNET_PACKED;
289 * Number of message IDs since the last message that contained state
290 * operations. @see enum GNUNET_PSYC_StateDeltaValues
292 uint64_t state_delta GNUNET_PACKED;
294 /* Followed by NUL-terminated method name. */
299 * A modifier of a message.
301 struct GNUNET_PSYC_MessageModifier
304 * Type: GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MODIFIER
306 struct GNUNET_MessageHeader header;
311 uint32_t value_size GNUNET_PACKED;
314 * Size of name, including NUL terminator.
316 uint16_t name_size GNUNET_PACKED;
319 * enum GNUNET_PSYC_Operator
323 /* Followed by NUL-terminated name, then the value. */
327 struct GNUNET_PSYC_CountersResultMessage
330 * Type: GNUNET_MESSAGE_TYPE_PSYC_RESULT_COUNTERS
332 struct GNUNET_MessageHeader header;
335 * Status code for the operation.
337 uint32_t result_code GNUNET_PACKED;
340 * Last message ID sent to the channel.
342 uint64_t max_message_id GNUNET_PACKED;
347 * Join request sent to a PSYC master.
349 struct GNUNET_PSYC_JoinRequestMessage
352 * Type: GNUNET_MESSAGE_TYPE_PSYC_MASTER_JOIN_REQUEST
354 struct GNUNET_MessageHeader header;
356 * Public key of the joining slave.
358 struct GNUNET_CRYPTO_EcdsaPublicKey slave_pub_key;
360 /* Followed by struct GNUNET_MessageHeader join_request */
365 * Join decision sent in reply to a join request.
367 struct GNUNET_PSYC_JoinDecisionMessage
370 * Type: GNUNET_MESSAGE_TYPE_PSYC_JOIN_DECISION
372 struct GNUNET_MessageHeader header;
375 * #GNUNET_YES if the slave was admitted.
380 * Public key of the joining slave.
381 * Only set when the master is sending the decision,
382 * not set when a slave is receiving it.
384 struct GNUNET_CRYPTO_EcdsaPublicKey slave_pub_key;
386 /* Followed by struct GNUNET_MessageHeader join_response */
390 enum GNUNET_PSYC_HistoryReplayFlags
393 * Replay locally available messages.
395 GNUNET_PSYC_HISTORY_REPLAY_LOCAL = 0,
398 * Replay messages from remote peers if not found locally.
400 GNUNET_PSYC_HISTORY_REPLAY_REMOTE = 1,
404 struct GNUNET_PSYC_HistoryRequestMessage
407 * Type: GNUNET_MESSAGE_TYPE_PSYC_CHANNEL_HISTORY_REPLAY
409 struct GNUNET_MessageHeader header;
412 * @see enum GNUNET_PSYC_HistoryReplayFlags
414 uint32_t flags GNUNET_PACKED;
417 * ID for this operation.
419 uint64_t op_id GNUNET_PACKED;
421 uint64_t start_message_id GNUNET_PACKED;
423 uint64_t end_message_id GNUNET_PACKED;
425 uint64_t message_limit GNUNET_PACKED;
427 /* Followed by NUL-terminated method name prefix. */
431 struct GNUNET_PSYC_StateRequestMessage
435 * - GNUNET_MESSAGE_TYPE_PSYC_CHANNEL_STATE_GET
436 * - GNUNET_MESSAGE_TYPE_PSYC_CHANNEL_STATE_GET_PREFIX
438 struct GNUNET_MessageHeader header;
440 uint32_t reserved GNUNET_PACKED;
443 * ID for this operation.
445 uint64_t op_id GNUNET_PACKED;
447 /* Followed by NUL-terminated name. */
451 /**** service -> library ****/
455 * Answer from service to client about last operation.
457 struct GNUNET_PSYC_OperationResultMessage
461 * - GNUNET_MESSAGE_TYPE_PSYC_RESULT_CODE
462 * - GNUNET_MESSAGE_TYPE_PSYC_CHANNEL_STATE_RESULT
464 struct GNUNET_MessageHeader header;
466 uint32_t reserved GNUNET_PACKED;
471 uint64_t op_id GNUNET_PACKED;
474 * Status code for the operation.
476 uint64_t result_code GNUNET_PACKED;
479 * - on error: NUL-terminated error message
480 * - on success: one of the following message types
482 * For a STATE_RESULT, one of:
483 * - GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MODIFIER
484 * - GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MOD_CONT
485 * - GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_END
489 GNUNET_NETWORK_STRUCT_END
492 #define GNUNET_PSYC_MODIFIER_MAX_PAYLOAD \
493 GNUNET_MULTICAST_FRAGMENT_MAX_PAYLOAD \
494 - sizeof (struct GNUNET_PSYC_MessageModifier)
496 #define GNUNET_PSYC_MOD_CONT_MAX_PAYLOAD \
497 GNUNET_MULTICAST_FRAGMENT_MAX_PAYLOAD \
498 - sizeof (struct GNUNET_MessageHeader)
500 #define GNUNET_PSYC_DATA_MAX_PAYLOAD \
501 GNUNET_MULTICAST_FRAGMENT_MAX_PAYLOAD \
502 - sizeof (struct GNUNET_MessageHeader)
506 * PSYC message part processing states.
508 enum GNUNET_PSYC_MessageState
510 GNUNET_PSYC_MESSAGE_STATE_START = 0,
511 GNUNET_PSYC_MESSAGE_STATE_HEADER = 1,
512 GNUNET_PSYC_MESSAGE_STATE_METHOD = 2,
513 GNUNET_PSYC_MESSAGE_STATE_MODIFIER = 3,
514 GNUNET_PSYC_MESSAGE_STATE_MOD_CONT = 4,
515 GNUNET_PSYC_MESSAGE_STATE_DATA = 5,
516 GNUNET_PSYC_MESSAGE_STATE_END = 6,
517 GNUNET_PSYC_MESSAGE_STATE_CANCEL = 7,
518 GNUNET_PSYC_MESSAGE_STATE_ERROR = 8,
523 * Handle that identifies a join request.
525 * Used to match calls to #GNUNET_PSYC_JoinCallback to the
526 * corresponding calls to GNUNET_PSYC_join_decision().
528 struct GNUNET_PSYC_JoinHandle;
532 * Method called from PSYC upon receiving a message.
534 * @param cls Closure.
535 * @param message_id Sequence number of the message.
536 * @param flags OR'ed GNUNET_PSYC_MessageFlags
537 * @param msg Message part, one of the following types:
540 (*GNUNET_PSYC_MessageCallback) (void *cls,
541 const struct GNUNET_PSYC_MessageHeader *msg);
545 * Method called from PSYC upon receiving part of a message.
549 * @param slave_pub_key
550 * Public key of the slave sending the message.
551 * Only set for channel master.
553 * Sequence number of the message.
555 * OR'ed GNUNET_PSYC_MessageFlags
556 * @param fragment_offset
557 * Multicast message fragment offset.
558 * @param msg Message part, one of the following types:
559 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_HEADER
560 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_METHOD
561 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MODIFIER
562 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MOD_CONT
563 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_DATA
564 * or NULL if an error occurred while receiving a message.
567 (*GNUNET_PSYC_MessagePartCallback) (void *cls,
568 const struct GNUNET_PSYC_MessageHeader *msg,
569 const struct GNUNET_MessageHeader *pmsg);
573 * Method called from PSYC upon receiving a join request.
577 * @param slave_pub_key
578 * Public key of the slave requesting join.
580 * Join message sent along with the request.
582 * Join handle to use with GNUNET_PSYC_join_decision()
585 (*GNUNET_PSYC_JoinRequestCallback) (void *cls,
586 const struct GNUNET_PSYC_JoinRequestMessage *req,
587 const struct GNUNET_CRYPTO_EcdsaPublicKey *slave_pub_key,
588 const struct GNUNET_PSYC_Message *join_msg,
589 struct GNUNET_PSYC_JoinHandle *jh);
593 * Function to call with the decision made for a join request.
595 * Must be called once and only once in response to an invocation of the
596 * #GNUNET_PSYC_JoinCallback.
598 * @param jh Join request handle.
600 * #GNUNET_YES if the join is approved,
601 * #GNUNET_NO if it is disapproved,
602 * #GNUNET_SYSERR if we cannot answer the request.
603 * @param relay_count Number of relays given.
604 * @param relays Array of suggested peers that might be useful relays to use
605 * when joining the multicast group (essentially a list of peers that
606 * are already part of the multicast group and might thus be willing
607 * to help with routing). If empty, only this local peer (which must
608 * be the multicast origin) is a good candidate for building the
609 * multicast tree. Note that it is unnecessary to specify our own
610 * peer identity in this array.
611 * @param join_resp Application-dependent join response message to send along
614 * @return #GNUNET_OK on success,
615 * #GNUNET_SYSERR if @a join_resp is too large.
618 GNUNET_PSYC_join_decision (struct GNUNET_PSYC_JoinHandle *jh,
620 uint32_t relay_count,
621 const struct GNUNET_PeerIdentity *relays,
622 const struct GNUNET_PSYC_Message *join_resp);
626 * Handle for the master of a PSYC channel.
628 struct GNUNET_PSYC_Master;
632 * Function called once we are connected to the PSYC service
633 * and the channel master is started.
635 * Also called when we reconnected to the service
636 * after the connection closed unexpectedly.
641 * #GNUNET_YES if there were already messages sent to the channel,
642 * #GNUNET_NO if the message history is empty,
643 * #GNUNET_SYSERR on error.
644 * @param max_message_id
645 * Last message ID sent to the channel.
648 (*GNUNET_PSYC_MasterStartCallback) (void *cls, int result,
649 uint64_t max_message_id);
653 * Start a PSYC master channel.
655 * Will start a multicast group identified by the given ECC key. Messages
656 * received from group members will be given to the respective handler methods.
657 * If a new member wants to join a group, the "join" method handler will be
658 * invoked; the join handler must then generate a "join" message to approve the
659 * joining of the new member. The channel can also change group membership
660 * without explicit requests. Note that PSYC doesn't itself "understand" join
661 * or part messages, the respective methods must call other PSYC functions to
662 * inform PSYC about the meaning of the respective events.
664 * @param cfg Configuration to use (to connect to PSYC service).
665 * @param channel_key ECC key that will be used to sign messages for this
666 * PSYC session. The public key is used to identify the PSYC channel.
667 * Note that end-users will usually not use the private key directly, but
668 * rather look it up in GNS for places managed by other users, or select
669 * a file with the private key(s) when setting up their own channels
670 * FIXME: we'll likely want to use NOT the p521 curve here, but a cheaper
672 * @param policy Channel policy specifying join and history restrictions.
673 * Used to automate join decisions.
674 * @param master_start_cb Function to invoke after the channel master started.
675 * @param join_request_cb Function to invoke when a slave wants to join.
676 * @param message_cb Function to invoke on message parts sent to the channel
677 * and received from slaves
678 * @param cls Closure for @a method and @a join_cb.
680 * @return Handle for the channel master, NULL on error.
682 struct GNUNET_PSYC_Master *
683 GNUNET_PSYC_master_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
684 const struct GNUNET_CRYPTO_EddsaPrivateKey *channel_key,
685 enum GNUNET_PSYC_Policy policy,
686 GNUNET_PSYC_MasterStartCallback master_start_cb,
687 GNUNET_PSYC_JoinRequestCallback join_request_cb,
688 GNUNET_PSYC_MessageCallback message_cb,
689 GNUNET_PSYC_MessagePartCallback message_part_cb,
694 * Function called to provide data for a transmission via PSYC.
696 * Note that returning #GNUNET_YES or #GNUNET_SYSERR (but not #GNUNET_NO)
697 * invalidates the respective transmission handle.
699 * @param cls Closure.
700 * @param[in,out] data_size Initially set to the number of bytes available in
701 * @a data, should be set to the number of bytes written to data.
702 * @param[out] data Where to write the body of the message to give to the
703 * method. The function must copy at most @a data_size bytes to @a data.
704 * @return #GNUNET_SYSERR on error (fatal, aborts transmission)
705 * #GNUNET_NO on success, if more data is to be transmitted later.
706 * Should be used if @a data_size was not big enough to take all the
707 * data. If 0 is returned in @a data_size the transmission is paused,
708 * and can be resumed with GNUNET_PSYC_master_transmit_resume().
709 * #GNUNET_YES if this completes the transmission (all data supplied)
712 (*GNUNET_PSYC_TransmitNotifyData) (void *cls,
717 * Function called to provide a modifier for a transmission via PSYC.
719 * Note that returning #GNUNET_YES or #GNUNET_SYSERR (but not #GNUNET_NO)
720 * invalidates the respective transmission handle.
722 * @param cls Closure.
723 * @param[in,out] data_size Initially set to the number of bytes available in
724 * @a data, should be set to the number of bytes written to data.
725 * @param[out] data Where to write the modifier's name and value.
726 * The function must copy at most @a data_size bytes to @a data.
727 * When this callback is first called for a modifier, @a data should
728 * contain: "name\0value". If the whole value does not fit, subsequent
729 * calls to this function should write continuations of the value to
731 * @param[out] oper Where to write the operator of the modifier.
732 * Only needed during the first call to this callback at the beginning
733 * of the modifier. In case of subsequent calls asking for value
734 * continuations @a oper is set to #NULL.
735 * @param[out] full_value_size Where to write the full size of the value.
736 * Only needed during the first call to this callback at the beginning
737 * of the modifier. In case of subsequent calls asking for value
738 * continuations @a value_size is set to #NULL.
739 * @return #GNUNET_SYSERR on error (fatal, aborts transmission)
740 * #GNUNET_NO on success, if more data is to be transmitted later.
741 * Should be used if @a data_size was not big enough to take all the
742 * data for the modifier's value (the name must be always returned
743 * during the first call to this callback).
744 * If 0 is returned in @a data_size the transmission is paused,
745 * and can be resumed with GNUNET_PSYC_master_transmit_resume().
746 * #GNUNET_YES if this completes the modifier (the whole value is supplied).
749 (*GNUNET_PSYC_TransmitNotifyModifier) (void *cls,
753 uint32_t *full_value_size);
756 * Flags for transmitting messages to a channel by the master.
758 enum GNUNET_PSYC_MasterTransmitFlags
760 GNUNET_PSYC_MASTER_TRANSMIT_NONE = 0,
763 * Whether this message should reset the channel state,
764 * i.e. remove all previously stored state variables.
767 GNUNET_PSYC_MASTER_TRANSMIT_STATE_RESET = 1 << 0,
770 * Whether this message contains any state modifiers.
772 GNUNET_PSYC_MASTER_TRANSMIT_STATE_MODIFY = 1 << 1,
775 * Add PSYC header variable with the hash of the current channel state.
777 GNUNET_PSYC_MASTER_TRANSMIT_STATE_HASH = 1 << 2,
780 * Whether we need to increment the group generation counter after
781 * transmitting this message.
783 GNUNET_PSYC_MASTER_TRANSMIT_INC_GROUP_GEN = 1 << 3
788 * Handle for a pending PSYC transmission operation.
790 struct GNUNET_PSYC_MasterTransmitHandle;
794 * Send a message to call a method to all members in the PSYC channel.
796 * @param master Handle to the PSYC channel.
797 * @param method_name Which method should be invoked.
798 * @param notify_mod Function to call to obtain modifiers.
799 * @param notify_data Function to call to obtain fragments of the data.
800 * @param notify_cls Closure for @a notify_mod and @a notify_data.
801 * @param flags Flags for the message being transmitted.
802 * @return Transmission handle, NULL on error (i.e. more than one request queued).
804 struct GNUNET_PSYC_MasterTransmitHandle *
805 GNUNET_PSYC_master_transmit (struct GNUNET_PSYC_Master *master,
806 const char *method_name,
807 GNUNET_PSYC_TransmitNotifyModifier notify_mod,
808 GNUNET_PSYC_TransmitNotifyData notify_data,
810 enum GNUNET_PSYC_MasterTransmitFlags flags);
814 * Resume transmission to the channel.
816 * @param th Handle of the request that is being resumed.
819 GNUNET_PSYC_master_transmit_resume (struct GNUNET_PSYC_MasterTransmitHandle *th);
823 * Abort transmission request to channel.
825 * @param th Handle of the request that is being aborted.
828 GNUNET_PSYC_master_transmit_cancel (struct GNUNET_PSYC_MasterTransmitHandle *th);
834 * @param master Handle to the PSYC channel.
835 * @param method_name Which method should be invoked.
836 * @param notify_mod Function to call to obtain modifiers.
837 * @param notify_data Function to call to obtain fragments of the data.
838 * @param notify_cls Closure for @a notify_mod and @a notify_data.
839 * @param flags Flags for the message being transmitted.
840 * @return Transmission handle, NULL on error (i.e. more than one request queued).
842 struct GNUNET_PSYC_MasterTransmitHandle *
843 GNUNET_PSYC_master_relay (struct GNUNET_PSYC_Master *master,
844 uint64_t message_id);
848 * Stop a PSYC master channel.
851 * PSYC channel master to stop.
853 * Keep place active after last application disconnected.
855 * Function called after the master stopped
856 * and disconnected from the psyc service.
858 * Closure for @a part_cb.
861 GNUNET_PSYC_master_stop (struct GNUNET_PSYC_Master *master,
863 GNUNET_ContinuationCallback stop_cb,
868 * Handle for a PSYC channel slave.
870 struct GNUNET_PSYC_Slave;
874 * Function called after the slave connected to the PSYC service.
876 * Also called when reconnected to the service
877 * after the connection closed unexpectedly.
882 * #GNUNET_YES if there were already messages sent to the channel,
883 * #GNUNET_NO if the message history is empty,
884 * #GNUNET_SYSERR on error.
885 * @param max_message_id
886 * Last message ID sent to the channel.
889 (*GNUNET_PSYC_SlaveConnectCallback) (void *cls, int result,
890 uint64_t max_message_id);
894 * Method called to inform about the decision in response to a join request.
896 * If @a is_admitted is not #GNUNET_YES, then sending messages to the channel is
897 * not possible, but earlier history can be still queried.
899 * @param cls Closure.
900 * @param is_admitted #GNUNET_YES or #GNUNET_NO or #GNUNET_SYSERR
901 * @param join_msg Application-dependent join message from the origin.
904 (*GNUNET_PSYC_JoinDecisionCallback) (void *cls,
905 const struct GNUNET_PSYC_JoinDecisionMessage *dcsn,
907 const struct GNUNET_PSYC_Message *join_msg);
910 * Flags for GNUNET_PSYC_slave_join()
912 enum GNUNET_PSYC_SlaveJoinFlags
914 GNUNET_PSYC_SLAVE_JOIN_NONE = 0,
917 * Local join for history access, no network connection is established.
919 GNUNET_PSYC_SLAVE_JOIN_LOCAL = 1,
924 * Join a PSYC channel.
926 * The entity joining is always the local peer. The user must immediately use
927 * the GNUNET_PSYC_slave_transmit() functions to transmit a @e join_msg to the
928 * channel; if the join request succeeds, the channel state (and @e recent
929 * method calls) will be replayed to the joining member. There is no explicit
930 * notification on failure (as the channel may simply take days to approve,
931 * and disapproval is simply being ignored).
934 * Configuration to use.
935 * @param channel_pub_key
936 * ECC public key that identifies the channel we wish to join.
937 * @param slave_pub_key
938 * ECC private-public key pair that identifies the slave, and
939 * used by multicast to sign the join request and subsequent unicast
940 * requests sent to the master.
944 * Peer identity of the origin.
946 * Number of peers in the @a relays array.
948 * Peer identities of members of the multicast group, which serve
949 * as relays and used to join the group at.
951 * Function to invoke on message fragments received from the channel.
952 * @param message_part_cb
953 * Function to invoke on message parts received from the channel.
954 * @param slave_connect_cb
955 * Function invoked once we have connected to the PSYC service.
956 * @param join_decision_cb
957 * Function invoked once we have received a join decision.
959 * Closure for @a message_cb and @a slave_joined_cb.
963 * @return Handle for the slave, NULL on error.
965 struct GNUNET_PSYC_Slave *
966 GNUNET_PSYC_slave_join (const struct GNUNET_CONFIGURATION_Handle *cfg,
967 const struct GNUNET_CRYPTO_EddsaPublicKey *channel_pub_key,
968 const struct GNUNET_CRYPTO_EcdsaPrivateKey *slave_pub_key,
969 enum GNUNET_PSYC_SlaveJoinFlags flags,
970 const struct GNUNET_PeerIdentity *origin,
971 uint32_t relay_count,
972 const struct GNUNET_PeerIdentity *relays,
973 GNUNET_PSYC_MessageCallback message_cb,
974 GNUNET_PSYC_MessagePartCallback message_part_cb,
975 GNUNET_PSYC_SlaveConnectCallback slave_connect_cb,
976 GNUNET_PSYC_JoinDecisionCallback join_decision_cb,
978 const struct GNUNET_PSYC_Message *join_msg);
982 * Part a PSYC channel.
984 * Will terminate the connection to the PSYC service. Polite clients should
985 * first explicitly send a part request (via GNUNET_PSYC_slave_transmit()).
990 * Keep place active after last application disconnected.
992 * Function called after the slave parted the channel
993 * and disconnected from the psyc service.
995 * Closure for @a part_cb.
998 GNUNET_PSYC_slave_part (struct GNUNET_PSYC_Slave *slave,
1000 GNUNET_ContinuationCallback part_cb,
1005 * Flags for transmitting messages to the channel master by a slave.
1007 enum GNUNET_PSYC_SlaveTransmitFlags
1009 GNUNET_PSYC_SLAVE_TRANSMIT_NONE = 0
1014 * Handle for a pending PSYC transmission operation.
1016 struct GNUNET_PSYC_SlaveTransmitHandle;
1020 * Request a message to be sent to the channel master.
1022 * @param slave Slave handle.
1023 * @param method_name Which (PSYC) method should be invoked (on host).
1024 * @param notify_mod Function to call to obtain modifiers.
1025 * @param notify_data Function to call to obtain fragments of the data.
1026 * @param notify_cls Closure for @a notify.
1027 * @param flags Flags for the message being transmitted.
1028 * @return Transmission handle, NULL on error (i.e. more than one request queued).
1030 struct GNUNET_PSYC_SlaveTransmitHandle *
1031 GNUNET_PSYC_slave_transmit (struct GNUNET_PSYC_Slave *slave,
1032 const char *method_name,
1033 GNUNET_PSYC_TransmitNotifyModifier notify_mod,
1034 GNUNET_PSYC_TransmitNotifyData notify_data,
1036 enum GNUNET_PSYC_SlaveTransmitFlags flags);
1040 * Resume transmission to the master.
1042 * @param th Handle of the request that is being resumed.
1045 GNUNET_PSYC_slave_transmit_resume (struct GNUNET_PSYC_SlaveTransmitHandle *th);
1049 * Abort transmission request to master.
1051 * @param th Handle of the request that is being aborted.
1054 GNUNET_PSYC_slave_transmit_cancel (struct GNUNET_PSYC_SlaveTransmitHandle *th);
1058 * Handle to access PSYC channel operations for both the master and slaves.
1060 struct GNUNET_PSYC_Channel;
1064 * Convert a channel @a master to a @e channel handle to access the @e channel
1067 * @param master Channel master handle.
1068 * @return Channel handle, valid for as long as @a master is valid.
1070 struct GNUNET_PSYC_Channel *
1071 GNUNET_PSYC_master_get_channel (struct GNUNET_PSYC_Master *master);
1075 * Convert @a slave to a @e channel handle to access the @e channel APIs.
1077 * @param slave Slave handle.
1078 * @return Channel handle, valid for as long as @a slave is valid.
1080 struct GNUNET_PSYC_Channel *
1081 GNUNET_PSYC_slave_get_channel (struct GNUNET_PSYC_Slave *slave);
1085 * Add a slave to the channel's membership list.
1087 * Note that this will NOT generate any PSYC traffic, it will merely update the
1088 * local database to modify how we react to <em>membership test</em> queries.
1089 * The channel master still needs to explicitly transmit a @e join message to
1090 * notify other channel members and they then also must still call this function
1091 * in their respective methods handling the @e join message. This way, how @e
1092 * join and @e part operations are exactly implemented is still up to the
1093 * application; for example, there might be a @e part_all method to kick out
1096 * Note that channel slaves are explicitly trusted to execute such methods
1097 * correctly; not doing so correctly will result in either denying other slaves
1098 * access or offering access to channel data to non-members.
1102 * @param slave_pub_key
1103 * Identity of channel slave to add.
1104 * @param announced_at
1105 * ID of the message that announced the membership change.
1106 * @param effective_since
1107 * Addition of slave is in effect since this message ID.
1109 * Function to call with the result of the operation.
1110 * The @e result_code argument is #GNUNET_OK on success, or
1111 * #GNUNET_SYSERR on error. In case of an error, the @e data argument
1112 * can contain an optional error message.
1114 * Closure for @a result_cb.
1117 GNUNET_PSYC_channel_slave_add (struct GNUNET_PSYC_Channel *channel,
1118 const struct GNUNET_CRYPTO_EcdsaPublicKey *slave_pub_key,
1119 uint64_t announced_at,
1120 uint64_t effective_since,
1121 GNUNET_ResultCallback result_cb,
1126 * Remove a slave from the channel's membership list.
1128 * Note that this will NOT generate any PSYC traffic, it will merely update the
1129 * local database to modify how we react to <em>membership test</em> queries.
1130 * The channel master still needs to explicitly transmit a @e part message to
1131 * notify other channel members and they then also must still call this function
1132 * in their respective methods handling the @e part message. This way, how
1133 * @e join and @e part operations are exactly implemented is still up to the
1134 * application; for example, there might be a @e part_all message to kick out
1137 * Note that channel members are explicitly trusted to perform these
1138 * operations correctly; not doing so correctly will result in either
1139 * denying members access or offering access to channel data to
1144 * @param slave_pub_key
1145 * Identity of channel slave to remove.
1146 * @param announced_at
1147 * ID of the message that announced the membership change.
1149 * Function to call with the result of the operation.
1150 * The @e result_code argument is #GNUNET_OK on success, or
1151 * #GNUNET_SYSERR on error. In case of an error, the @e data argument
1152 * can contain an optional error message.
1154 * Closure for @a result_cb.
1157 GNUNET_PSYC_channel_slave_remove (struct GNUNET_PSYC_Channel *channel,
1158 const struct GNUNET_CRYPTO_EcdsaPublicKey
1160 uint64_t announced_at,
1161 GNUNET_ResultCallback result_cb,
1166 * History request handle.
1168 struct GNUNET_PSYC_HistoryRequest;
1172 * Request to replay a part of the message history of the channel.
1174 * Historic messages (but NOT the state at the time) will be replayed (given to
1175 * the normal method handlers) if available and if access is permitted.
1178 * Which channel should be replayed?
1179 * @param start_message_id
1180 * Earliest interesting point in history.
1181 * @param end_message_id
1182 * Last (inclusive) interesting point in history.
1183 * @param method_prefix
1184 * Retrieve only messages with a matching method prefix.
1186 * OR'ed enum GNUNET_PSYC_HistoryReplayFlags
1188 * Function to call when the requested history has been fully replayed.
1189 * Once this function has been called, the client must not call
1190 * GNUNET_PSYC_channel_history_replay_cancel() anymore.
1192 * Closure for the callbacks.
1194 * @return Handle to cancel history replay operation.
1196 struct GNUNET_PSYC_HistoryRequest *
1197 GNUNET_PSYC_channel_history_replay (struct GNUNET_PSYC_Channel *channel,
1198 uint64_t start_message_id,
1199 uint64_t end_message_id,
1200 const char *method_prefix,
1202 GNUNET_PSYC_MessageCallback message_cb,
1203 GNUNET_PSYC_MessagePartCallback message_part_cb,
1204 GNUNET_ResultCallback result_cb,
1209 * Request to replay the latest messages from the message history of the channel.
1211 * Historic messages (but NOT the state at the time) will be replayed (given to
1212 * the normal method handlers) if available and if access is permitted.
1215 * Which channel should be replayed?
1216 * @param message_limit
1217 * Maximum number of messages to replay.
1219 * OR'ed enum GNUNET_PSYC_HistoryReplayFlags
1221 * Function to call when the requested history has been fully replayed
1222 * (counting message IDs might not suffice, as some messages might be
1223 * secret and thus the listener would not know the story is finished
1224 * without being told explicitly)o once this function has been called, the
1225 * client must not call GNUNET_PSYC_channel_history_replay_cancel() anymore.
1227 * Closure for the callbacks.
1229 * @return Handle to cancel history replay operation.
1231 struct GNUNET_PSYC_HistoryRequest *
1232 GNUNET_PSYC_channel_history_replay_latest (struct GNUNET_PSYC_Channel *channel,
1233 uint64_t message_limit,
1234 const char *method_prefix,
1236 GNUNET_PSYC_MessageCallback message_cb,
1237 GNUNET_PSYC_MessagePartCallback message_part_cb,
1238 GNUNET_ResultCallback result_cb,
1243 GNUNET_PSYC_channel_history_replay_cancel (struct GNUNET_PSYC_Channel *channel,
1244 struct GNUNET_PSYC_HistoryRequest *hr);
1248 * Function called to inform a member about stored state values for a channel.
1250 * If @a full_value_size > value_size then this function is called multiple
1251 * times until the whole value arrived.
1256 * Name of the state variable.
1257 * NULL if there are no more state variables to be returned.
1259 * Value of the state variable.
1261 * Number of bytes in @a value.
1262 * @param full_value_size
1263 * Number of bytes in the full value, including continuations.
1264 * Only set for the first part of a variable,
1265 * in case of a continuation it is 0.
1268 (*GNUNET_PSYC_StateVarCallback) (void *cls,
1269 const struct GNUNET_MessageHeader *mod,
1272 uint32_t value_size,
1273 uint32_t full_value_size);
1277 * State request handle.
1279 struct GNUNET_PSYC_StateRequest;
1283 * Retrieve the best matching channel state variable.
1285 * If the requested variable name is not present in the state, the nearest
1286 * less-specific name is matched; for example, requesting "_a_b" will match "_a"
1287 * if "_a_b" does not exist.
1292 * Full name of the requested variable.
1293 * The actual variable returned might have a shorter name.
1295 * Function called once when a matching state variable is found.
1296 * Not called if there's no matching state variable.
1298 * Function called after the operation finished.
1299 * (i.e. all state variables have been returned via @a state_cb)
1301 * Closure for the callbacks.
1303 struct GNUNET_PSYC_StateRequest *
1304 GNUNET_PSYC_channel_state_get (struct GNUNET_PSYC_Channel *channel,
1305 const char *full_name,
1306 GNUNET_PSYC_StateVarCallback var_cb,
1307 GNUNET_ResultCallback result_cb,
1312 * Return all channel state variables whose name matches a given prefix.
1314 * A name matches if it starts with the given @a name_prefix, thus requesting
1315 * the empty prefix ("") will match all values; requesting "_a_b" will also
1316 * return values stored under "_a_b_c".
1318 * The @a state_cb is invoked on all matching state variables asynchronously, as
1319 * the state is stored in and retrieved from the PSYCstore,
1323 * @param name_prefix
1324 * Prefix of the state variable name to match.
1326 * Function called once when a matching state variable is found.
1327 * Not called if there's no matching state variable.
1329 * Function called after the operation finished.
1330 * (i.e. all state variables have been returned via @a state_cb)
1332 * Closure for the callbacks.
1334 struct GNUNET_PSYC_StateRequest *
1335 GNUNET_PSYC_channel_state_get_prefix (struct GNUNET_PSYC_Channel *channel,
1336 const char *name_prefix,
1337 GNUNET_PSYC_StateVarCallback var_cb,
1338 GNUNET_ResultCallback result_cb,
1342 * Cancel a state request operation.
1345 * Handle for the operation to cancel.
1348 GNUNET_PSYC_channel_state_get_cancel (struct GNUNET_PSYC_StateRequest *sr);
1352 #if 0 /* keep Emacsens' auto-indent happy */
1359 /* ifndef GNUNET_PSYC_SERVICE_H */
1362 /** @} */ /* end of group */