/**
* @file include/gnunet_psyc_service.h
- * @brief psyc service; high-level access to the PSYC protocol
+ * @brief PSYC service; high-level access to the PSYC protocol
* note that clients of this API are NOT expected to
* understand the PSYC message format, only the semantics!
+ * Parsing (and serializing) the PSYC stream format is done
+ * within the implementation of the libgnunetpsyc library,
+ * and this API deliberately exposes as little as possible
+ * of the actual data stream format to the application!
* @author Christian Grothoff
+ * @author Gabor X Toth
*
- * TODO:
- * - how to deal with very large channel state (i.e. channel
- * containing a movie); this might relate to the question
- * of how (when/etc.) we replay method calls; is only the
- * channel state persistent? What about a 'bounded'
- * channel history, how would we enable that?
- * - how to deal with seeking in large channel state (i.e.
- * skip to minute 45 in movie)
- * - need to change send operations to 'notify_transmit_ready'-style;
- * deal better with 'streaming' arguments while we're at it
+ * NOTE:
+ * - this API does not know about psyc's "root" and "places";
+ * there is no 'root' in GNUnet-Psyc as we're decentralized;
+ * 'places' and 'persons' are combined within the same
+ * abstraction, that of a "channel". Channels are identified
+ * and accessed in this API using a public/private key.
+ * Higher-level applications should use NAMES within GNS
+ * to obtain public keys, and the distinction between
+ * 'places' and 'persons' can then be made with the help
+ * of the naming system (and/or conventions).
+ * Channels are (as in PSYC) organized into a hierarchy; each
+ * channel master (the one with the private key) is then
+ * the operator of the multicast group (its Origin in
+ * the terminology of the multicast API).
+ * - The API supports passing large amounts of data using
+ * 'streaming' for the argument passed to a method. State
+ * and variables must fit into memory and cannot be streamed
+ * (thus, no passing of 4 GB of data in a variable;
+ * once we implement this, we might want to create a
+ * @c \#define for the maximum size of a variable).
+ * - PSYC defines standard variables, methods, etc. This
+ * library deliberately abstracts over all of these; a
+ * higher-level API should combine the naming system (GNS)
+ * and standard methods (message, join, part, warn,
+ * fail, error) and variables (action, color, time,
+ * tag, etc.). However, this API does take over the
+ * routing variables, specifically 'context' (channel),
+ * and 'source'. We only kind-of support 'target', as
+ * the target is either everyone in the group or the
+ * origin, and never just a single member of the group;
+ * for such individual messages, an application needs to
+ * construct an 'inbox' channel where the master (only)
+ * receives messages (but never forwards; private responses
+ * would be transmitted by joining the senders 'inbox'
+ * channel -- or a inbox#bob subchannel). The
+ * goal for all of this is to keep the abstractions in this
+ * API minimal: interaction with multicast, try \& slice,
+ * state/variable/channel management. Higher-level
+ * operations belong elsewhere (so maybe this API should
+ * be called 'PSYC-low', whereas a higher-level API
+ * implementing defaults for standard methods and
+ * variables might be called 'PSYC-std' or 'PSYC-high'.
*/
#ifndef GNUNET_PSYC_SERVICE_H
#endif
#include "gnunet_util_lib.h"
+#include "gnunet_env_lib.h"
#include "gnunet_multicast_service.h"
/**
- * Bits describing special properties of arguments.
+ * Policy flags for a channel.
*/
-enum GNUNET_PSYC_ArgumentFlags
+enum GNUNET_PSYC_ChannelFlags
{
/**
- * Argument is fixed size.
+ * Admission must be confirmed by the master.
*/
- GNUNET_PSYC_AF_FIXED_SIZE = 0,
+ GNUNET_PSYC_CHANNEL_ADMISSION_CONTROL = 1 << 0,
/**
- * Argument is variable-length
+ * Past messages are only available to slaves who were admitted at the time
+ * they were sent to the channel.
*/
- GNUNET_PSYC_AF_VARIABLE_SIZE = 1,
+ GNUNET_PSYC_CHANNEL_RESTRICTED_HISTORY = 1 << 1,
+};
+/**
+ * PSYC channel policies.
+ */
+enum GNUNET_PSYC_Policy
+{
/**
- * Argument may be supplied incrementally to the callback
+ * Anyone can join the channel, without announcing his presence;
+ * all messages are always public and can be distributed freely.
+ * Joins may be announced, but this is not required.
*/
- GNUNET_PSYC_AF_STREAMABLE = 2,
+ GNUNET_PSYC_CHANNEL_ANONYMOUS = 0,
/**
- * Argument is variable-length, incrementally supplied
- * data stream.
+ * The master must approve membership to the channel, messages must only be
+ * distributed to current channel slaves. This includes the channel
+ * state as well as transient messages.
*/
- GNUNET_PSYC_AF_STREAM = 3,
+ GNUNET_PSYC_CHANNEL_PRIVATE
+ = GNUNET_PSYC_CHANNEL_ADMISSION_CONTROL
+ | GNUNET_PSYC_CHANNEL_RESTRICTED_HISTORY,
+#if IDEAS_FOR_FUTURE
/**
- * Argument is zero-terminated character array.
+ * Anyone can freely join the channel (no approval required);
+ * however, messages must only be distributed to current channel
+ * slaves, so the master must still acknowledge that the slave
+ * joined before transient messages are delivered. As approval is
+ * guaranteed, the presistent channel state can be synchronized freely
+ * immediately, prior to master confirmation.
*/
- GNUNET_PSYC_AF_ZERO_TERMINATED_CHARARRAY = 4,
+ GNUNET_PSYC_CHANNEL_OPEN
+ = GNUNET_PSYC_CHANNEL_RESTRICTED_HISTORY,
/**
- * Argument is variable-length UTF-8 encoded, zero-terminated string.
+ * The master must approve joins to the channel, but past messages can be
+ * freely distributed to slaves.
*/
- GNUNET_PSYC_AF_UTF8 = 5,
+ GNUNET_PSYC_CHANNEL_CLOSED
+ = GNUNET_PSYC_CHANNEL_ADMISSION_CONTROL,
+,
+#endif
+};
+
+
+enum GNUNET_PSYC_MessageFlags
+{
/**
- * Payload is an unsigned integer and might thus be encoded as an
- * integer when generating PSYC stream (useful if we want to
- * generate human-readable PSYC streams, instead of just always
- * using length-prefixed binary encodings). Note that it
- * is not sufficient to just test for this bit, as it is
- * also set for 'REAL' numbers!
+ * First fragment of a message.
*/
- GNUNET_PSYC_AF_UNSIGNED_INTEGER = 8,
+ GNUNET_PSYC_MESSAGE_FIRST_FRAGMENT = 1 << 0,
/**
- * Payload is an unsigned integer and might thus be encoded as an
- * integer when generating PSYC stream (useful if we want to
- * generate human-readable PSYC streams, instead of just always
- * using length-prefixed binary encodings). Note that it
- * is not sufficient to just test for this bit, as it is
- * also set for 'REAL' numbers!
+ * Last fragment of a message.
*/
- GNUNET_PSYC_AF_SIGNED_INTEGER = 16,
+ GNUNET_PSYC_MESSAGE_LAST_FRAGMENT = 1 << 1,
/**
- * Payload is a 'real' number (float or double). We save a bit here
- * as a number cannot be both SIGNED and UNSIGNED, so setting both
- * bits is fine to use for REALs.
+ * OR'ed flags if message is not fragmented.
*/
- GNUNET_PSYC_AF_REAL_NUMBER = 24
+ GNUNET_PSYC_MESSAGE_NOT_FRAGMENTED
+ = GNUNET_PSYC_MESSAGE_FIRST_FRAGMENT
+ | GNUNET_PSYC_MESSAGE_LAST_FRAGMENT,
+ /**
+ * Historic message, retrieved from PSYCstore.
+ */
+ GNUNET_PSYC_MESSAGE_HISTORIC = 1 << 30
};
/**
- * Argument descriptors are used to describe types that can be
- * embedded in a PSYC stream. For example, a "uint32_t" is
- * described as 4-byte, fixed-length data, whereas a movie
- * would be a variable-size, streaming argument.
+ * M
*/
-struct GNUNET_PSYC_ArgumentDescriptor
+struct GNUNET_PSYC_MessageMethod
+{
+ /**
+ * Type: GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_METHOD
+ */
+ struct GNUNET_MessageHeader header;
+
+ uint32_t reserved GNUNET_PACKED;
+
+ /**
+ * Number of modifiers in the message.
+ */
+ uint32_t mod_count GNUNET_PACKED;
+
+ /**
+ * OR'ed GNUNET_PSYC_MasterTransmitFlags
+ */
+ uint32_t flags GNUNET_PACKED;
+
+ /**
+ * Sending slave's public key. NULL if the message is from the master, or when
+ * transmitting a message.
+ */
+ struct GNUNET_CRYPTO_EccPublicSignKey slave_key;
+
+ /* Followed by NUL-terminated method name. */
+};
+
+
+struct GNUNET_PSYC_MessageModifier
{
+ /**
+ * Type: GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MODIFIER
+ */
+ struct GNUNET_MessageHeader header;
+
+ /**
+ * Size of value.
+ */
+ uint32_t value_size GNUNET_PACKED;
/**
- * Required length of the argument in bytes, zero for
- * variable-size arguments.
+ * Size of name, including NUL terminator.
*/
- size_t arg_len;
+ uint16_t name_size GNUNET_PACKED;
/**
- * Flags describing additional properties of the argument,
- * such as variable-size, streaming or 0-termination. This
- * argument is a bitfield.
+ * enum GNUNET_ENV_Operator
*/
- enum GNUNET_PSYC_ArgumentFlags flags;
+ uint8_t oper;
+ /* Followed by NUL-terminated name, then the value. */
+};
+
+
+enum GNUNET_PSYC_DataStatus
+{
+ /**
+ * To be continued.
+ */
+ GNUNET_PSYC_DATA_CONT = 0,
+
+ /**
+ * Reached the end of message.
+ */
+ GNUNET_PSYC_DATA_END = 1,
+
+ /**
+ * Cancelled before the end.
+ */
+ GNUNET_PSYC_DATA_CANCEL = 2
};
+struct GNUNET_PSYC_MessageData
+{
+ /**
+ * Type: GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MODIFIER
+ */
+ struct GNUNET_MessageHeader header;
+
+ /**
+ * enum GNUNET_PSYC_DataStatus
+ */
+ uint8_t status;
+};
+
/**
- * Convenience macro to define an argument descriptor for
- * some fixed-size C data type.
+ * Handle that identifies a join request.
*
- * @param pt C data type (i.e. 'uint32_t')
+ * Used to match calls to #GNUNET_PSYC_JoinCallback to the
+ * corresponding calls to GNUNET_PSYC_join_decision().
*/
-#define GNUNET_PSYC_AD_C_TYPE(pt) { sizeof (pt), GNUNET_PSYC_AF_FIXED_SIZE }
+struct GNUNET_PSYC_JoinHandle;
+
/**
- * Convenience macro to define an argument descriptor for
- * some fixed-size unsigned integer type.
+ * Method called from PSYC upon receiving a message indicating a call to a
+ * @e method.
*
- * @param it C integer data type (i.e. 'uint32_t')
+ * @param cls Closure.
+ * @param slave_key Who transmitted the message.
+ * - NULL for multicast messages from the master.
+ * - The sending slave's public key for unicast requests from one of the
+ * slaves to the master.
+ * @param message_id Unique message counter for this message.
+ * Unique only in combination with the given sender for this channel.
+ * @param method_name Method name from PSYC.
+ * @param modifier_count Number of elements in the @a modifiers array.
+ * @param modifiers State modifiers and transient variables for the message.
+ * @param data_offset Byte offset of @a data in the overall data of the method.
+ * @param data Data stream given to the method (might not be zero-terminated
+ * if data is binary).
+ * @param data_size Number of bytes in @a data.
+ * @param frag Fragmentation status for the data.
*/
-#define GNUNET_PSYC_AD_C_UINT_TYPE(it) { sizeof (it), GNUNET_PSYC_AF_FIXED_SIZE | GNUNET_PSYC_AF_UNSIGNED_INTEGER }
+typedef int
+(*GNUNET_PSYC_Method) (void *cls,
+ const struct GNUNET_CRYPTO_EccPublicSignKey *slave_key,
+ uint64_t message_id,
+ const char *method_name,
+ size_t modifier_count,
+ const struct GNUNET_ENV_Modifier *modifiers,
+ uint64_t data_offset,
+ const void *data,
+ size_t data_size,
+ enum GNUNET_PSYC_MessageFlags flags);
+
/**
- * Argument descriptor for a 'uint8_t' argument.
+ * Method called from PSYC upon receiving a join request.
+ *
+ * @param cls Closure.
+ * @param slave requesting to join.
+ * @param method_name Method name in the join request.
+ * @param variable_count Number of elements in the @a variables array.
+ * @param variables Transient variables for the join request.
+ * @param data Data stream given to the method (might not be zero-terminated
+ * if data is binary).
+ * @param data_size Number of bytes in @a data.
+ * @param jh Join handle to use with GNUNET_PSYC_join_decision()
*/
-#define GNUNET_PSYC_AD_UINT8 GNUNET_PSYC_AD_C_UINT_TYPE(uint8_t)
+typedef int
+(*GNUNET_PSYC_JoinCallback) (void *cls,
+ const struct GNUNET_CRYPTO_EccPublicSignKey
+ *slave_key,
+ const char *method_name,
+ size_t variable_count,
+ const struct GNUNET_ENV_Modifier *variables,
+ const void *data,
+ size_t data_size,
+ struct GNUNET_PSYC_JoinHandle *jh);
+
/**
- * Argument descriptor for a 'uint16_t' argument.
+ * Function to call with the decision made for a join request.
+ *
+ * Must be called once and only once in response to an invocation of the
+ * #GNUNET_PSYC_JoinCallback.
+ *
+ * @param jh Join request handle.
+ * @param is_admitted #GNUNET_YES if joining is approved,
+ * #GNUNET_NO if it is disapproved.
+ * @param relay_count Number of relays given.
+ * @param relays Array of suggested peers that might be useful relays to use
+ * when joining the multicast group (essentially a list of peers that
+ * are already part of the multicast group and might thus be willing
+ * to help with routing). If empty, only this local peer (which must
+ * be the multicast origin) is a good candidate for building the
+ * multicast tree. Note that it is unnecessary to specify our own
+ * peer identity in this array.
+ * @param method_name Method name for the message transmitted with the response.
+ * @param env Environment containing transient variables for the message,
+ * or NULL.
+ * @param data Data of the message.
+ * @param data_size Size of @a data.
*/
-#define GNUNET_PSYC_AD_UINT16 GNUNET_PSYC_AD_C_UINT_TYPE(uint16_t)
+void
+GNUNET_PSYC_join_decision (struct GNUNET_PSYC_JoinHandle *jh,
+ int is_admitted,
+ unsigned int relay_count,
+ const struct GNUNET_PeerIdentity *relays,
+ const char *method_name,
+ const struct GNUNET_ENV_Environment *env,
+ const void *data,
+ size_t data_size);
+
/**
- * Argument descriptor for a 'uint32_t' argument.
+ * Handle for the master of a PSYC channel.
*/
-#define GNUNET_PSYC_AD_UINT32 GNUNET_PSYC_AD_C_UINT_TYPE(uint32_t)
+struct GNUNET_PSYC_Master;
+
/**
- * Argument descriptor for a 'uint64_t' argument.
+ * Function called after the channel master started.
+ *
+ * @param cls Closure.
+ * @param last_message_id Last message ID sent to the channel.
*/
-#define GNUNET_PSYC_AD_UINT64 GNUNET_PSYC_AD_C_UINT_TYPE(uint64_t)
+typedef void
+(*GNUNET_PSYC_MasterStartCallback) (void *cls, uint64_t max_message_id);
+
/**
- * Convenience macro to define an argument descriptor for
- * a 0-terminated, variable-length UTF-8 string.
+ * Start a PSYC master channel.
+ *
+ * Will start a multicast group identified by the given ECC key. Messages
+ * received from group members will be given to the respective handler methods.
+ * If a new member wants to join a group, the "join" method handler will be
+ * invoked; the join handler must then generate a "join" message to approve the
+ * joining of the new member. The channel can also change group membership
+ * without explicit requests. Note that PSYC doesn't itself "understand" join
+ * or part messages, the respective methods must call other PSYC functions to
+ * inform PSYC about the meaning of the respective events.
+ *
+ * @param cfg Configuration to use (to connect to PSYC service).
+ * @param channel_key ECC key that will be used to sign messages for this
+ * PSYC session. The public key is used to identify the PSYC channel.
+ * Note that end-users will usually not use the private key directly, but
+ * rather look it up in GNS for places managed by other users, or select
+ * a file with the private key(s) when setting up their own channels
+ * FIXME: we'll likely want to use NOT the p521 curve here, but a cheaper
+ * one in the future.
+ * @param policy Channel policy specifying join and history restrictions.
+ * Used to automate join decisions.
+ * @param method Function to invoke on messages received from slaves.
+ * @param join_cb Function to invoke when a peer wants to join.
+ * @param start_cb Function to invoke after the channel master started.
+ * @param cls Closure for @a method and @a join_cb.
+ * @return Handle for the channel master, NULL on error.
*/
-#define GNUNET_PSYC_AD_UTF8 { 0, GNUNET_PSYC_AF_UTF8 }
+struct GNUNET_PSYC_Master *
+GNUNET_PSYC_master_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
+ const struct GNUNET_CRYPTO_EccPrivateKey *channel_key,
+ enum GNUNET_PSYC_Policy policy,
+ GNUNET_PSYC_Method method,
+ GNUNET_PSYC_JoinCallback join_cb,
+ GNUNET_PSYC_MasterStartCallback start_cb,
+ void *cls);
-/* TODO: add more convenience macros for argument types later as needed */
+/**
+ * Function called to provide data for a transmission via PSYC.
+ *
+ * Note that returning #GNUNET_OK or #GNUNET_SYSERR (but not #GNUNET_NO)
+ * invalidates the respective transmission handle.
+ *
+ * @param cls Closure.
+ * @param[in,out] data_size Initially set to the number of bytes available in
+ * @a data, should be set to the number of bytes written to data.
+ * @param[out] data Where to write the body of the message to give to the
+ * method. The function must copy at most @a data_size bytes to @a data.
+ * @return #GNUNET_SYSERR on error (fatal, aborts transmission)
+ * #GNUNET_NO on success, if more data is to be transmitted later.
+ * Should be used if @a data_size was not big enough to take all the
+ * data. If 0 is returned in @a data_size the transmission is paused,
+ * and can be resumed with GNUNET_PSYC_master_transmit_resume().
+ * #GNUNET_YES if this completes the transmission (all data supplied)
+ */
+typedef int
+(*GNUNET_PSYC_MasterTransmitNotify) (void *cls,
+ size_t *data_size,
+ void *data);
/**
- * Abstract argument passed to a GNUNET_PSYC_Method.
+ * Flags for transmitting messages to a channel by the master.
*/
-struct GNUNET_PSYC_Argument
+enum GNUNET_PSYC_MasterTransmitFlags
{
-
+ GNUNET_PSYC_MASTER_TRANSMIT_NONE = 0,
/**
- * Data of the argument.
+ * Whether this message should reset the channel state,
+ * i.e. remove all previously stored state variables.
*/
- const void *data;
+ GNUNET_PSYC_MASTER_TRANSMIT_RESET_STATE = 1 << 0,
/**
- * Number of bytes in 'data', guaranteed to be the argument
- * descriptor 'arg_len' MINUS 'data_off' unless
- * GNUNET_PSYC_AF_VARIABLE_SIZE was set.
+ * Whether we need to increment the group generation counter after
+ * transmitting this message.
*/
- size_t data_size;
+ GNUNET_PSYC_MASTER_TRANSMIT_INC_GROUP_GEN = 1 << 1,
/**
- * Offset of 'data' in the overall argument,
- * always zero unless GNUNET_PSYC_AF_STREAMABLE was
- * set for the argument.
+ * Add PSYC header variable with the hash of the current channel state.
*/
- uint64_t data_off;
-
- /**
- * Total number of bytes to be expected in 'data',
- * UINT64_MAX for 'unknown' (i.e. for "infinite"
- * streams).
- */
- uint64_t value_size;
+ GNUNET_PSYC_MASTER_TRANSMIT_ADD_STATE_HASH = 1 << 2
};
/**
- * Method called from PSYC upon receiving a message indicating a call
- * to a 'method'. The arguments given will match those of the
- * respective argument descriptor. If some arguments were marked
- * as 'streaming', the function can return a value other than -1
- * to request "more" of the data for that argument. Note that all
- * non-streaming arguments will be replayed in full for each additional
- * invocation of the method. Using more than one streaming argument
- * is possible, in which case PSYC will ONLY advance the stream of the
- * argument for which the index was returned; the values of other
- * streaming arguments will be replayed at the current offset.
- *
- * Returning a value other than -1 or that of a streaming argument is
- * not allowed. Returning -1 does not indicate an error; it simply
- * indicates that the client wants to proceed with the next method
- * (and not see the rest of the data from any of the streaming
- * arguments).
- *
- * TODO: note that this API currently doesn't allow for seeking
- * in streaming data (very advanced feature)
- *
- * @param cls closure
- * @param full_method_name original method name from PSYC (may be more
- * specific than the registered method name due to try&slice matching)
- * @param sender who transmitted the message (origin, except for messages
- * from one of the members to the origin)
- * @param message_id unique message counter for this message
- * @param group_generation group generation counter for this message
- * @param argc number of arguments in argv
- * @param argv array of argc arguments to the method
- * @return -1 if we're finished with this method, index
- * of a streaming argument for which more data is
- * requested otherwise
- */
-typedef int (*GNUNET_PSYC_Method)(void *cls,
- const char *full_method_name,
- const struct GNUNET_PeerIdentity *sender,
- unsigned int argc,
- const struct GNUNET_PSYC_Argument *argv);
-
-
-/**
- * Descriptor for a PSYC method and its arguments. Here is how this
- * is expected to be used. Imagine we have a method with the
- * following signature:
- * <pre>
- * static void
- * logger (void *cls, uint32_t log_level, const char *log_message);
- * </pre>
- * where 'cls' is supposed to be a 'FILE *'.
- * Then for PSYC to call this method with 'stderr' for 'cls',
- * we would provide the following method descriptor:
- * <pre>
- * .method_name = "log";
- * .method = &wrap_logger;
- * .method_cls = stderr;
- * .argc = 2;
- * .argv = { GNUNET_PSYC_AD_UINT32, GNUNET_PSYC_AD_UTF8 };
- * </pre>
- * and define <tt>wrap_logger</tt> as follows:
- * <pre>
- * static void
- * wrap_logger (void *cls, const char full_method_name,
- * const struct GNUNET_PeerIdentity *sender,
- * unsigned int argc, const struct GNUNET_PSYC_Argument *argv)
- * {
- * uint32_t *log_level = argv[0].data;
- * const char *log_message = argv[1].data;
- * logger (cls, *log_level, log_message);
- * }
- * </pre>
- * Note that the PSYC library will take care of making sure
- * that 'argv[0].data_size == 4' and that the log message
- * is 0-terminated, as those requirements were specified
- * in the method descriptor for those arguments. Finally,
- * it is conceivable to generate the wrappers and method
- * descriptors automatically, as they are trivial.
- * <p>
- * Note that due to try & slice, the given full method name
- * might be more specific; for example, the given method
- * might be called for a request to "log_warning" instead
- * of just a request to "log".
- */
-struct GNUNET_PSYC_MethodDescriptor
-{
+ * Handle for a pending PSYC transmission operation.
+ */
+struct GNUNET_PSYC_MasterTransmitHandle;
- /**
- * Name of the method to be used in try-and-slice matching.
- */
- const char *method_name;
- /**
- * Function to call. Note that if a more specific handler exists
- * as well, the more generic handler will not be invoked.
- */
- GNUNET_PSYC_Method method;
+/**
+ * Send a message to call a method to all members in the PSYC channel.
+ *
+ * @param master Handle to the PSYC channel.
+ * @param method_name Which method should be invoked.
+ * @param env Environment containing state operations and transient variables
+ * for the message, or NULL.
+ * @param notify Function to call to obtain the arguments.
+ * @param notify_cls Closure for @a notify.
+ * @param flags Flags for the message being transmitted.
+ * @return Transmission handle, NULL on error (i.e. more than one request queued).
+ */
+struct GNUNET_PSYC_MasterTransmitHandle *
+GNUNET_PSYC_master_transmit (struct GNUNET_PSYC_Master *master,
+ const char *method_name,
+ const struct GNUNET_ENV_Environment *env,
+ GNUNET_PSYC_MasterTransmitNotify notify,
+ void *notify_cls,
+ enum GNUNET_PSYC_MasterTransmitFlags flags);
- /**
- * Closure for the method (this argument and the 'sender' argument
- * are both not included in 'argc').
- */
- void *method_cls;
- /**
- * Number of arguments to pass to the method (length of the 'ads'
- * array).
- */
- unsigned int argc;
+/**
+ * Resume transmission to the channel.
+ *
+ * @param th Handle of the request that is being resumed.
+ */
+void
+GNUNET_PSYC_master_transmit_resume (struct GNUNET_PSYC_MasterTransmitHandle *th);
- /**
- * Array of 'argc' argument descriptors describing the arguments to
- * be passed to the method. Non-matching method calls will be
- * ignored (but logged). Note that the 'ads' of all methods with
- * the same method name prefix should be identical.
- */
- const struct GNUNET_PSYC_ArgumentDescriptor *ads;
-};
+/**
+ * Abort transmission request to channel.
+ *
+ * @param th Handle of the request that is being aborted.
+ */
+void
+GNUNET_PSYC_master_transmit_cancel (struct GNUNET_PSYC_MasterTransmitHandle *th);
+
+
+/**
+ * Stop a PSYC master channel.
+ *
+ * @param master PSYC channel master to stop.
+ */
+void
+GNUNET_PSYC_master_stop (struct GNUNET_PSYC_Master *master);
/**
- * Handle for the origin of a psyc group.
+ * Handle for a PSYC channel slave.
*/
-struct GNUNET_PSYC_Origin;
+struct GNUNET_PSYC_Slave;
/**
- * Start a psyc group. Will create a multicast group identified by
- * the given public key. Messages recevied from group members will be
- * given to the respective handler methods. If a new member wants to
- * join a group, the "join" method handler will be invoked; the join
- * handler must then generate a "join" message to approve the joining
- * of the new member. The origin can also change group membership
- * without explicit requests. Note that PSYC doesn't itself "understand"
- * join or leave messages, the respective methods must call other
- * PSYC functions to inform PSYC about the meaning of the respective
- * events.
+ * Function called after the slave joined.
+ *
+ * @param cls Closure.
+ * @param max_message_id Last message ID sent to the channel.
+ */
+typedef void
+(*GNUNET_PSYC_SlaveJoinCallback) (void *cls, uint64_t max_message_id);
+
+
+/**
+ * Join a PSYC channel.
+ *
+ * The entity joining is always the local peer. The user must immediately use
+ * the GNUNET_PSYC_slave_transmit() functions to transmit a @e join_msg to the
+ * channel; if the join request succeeds, the channel state (and @e recent
+ * method calls) will be replayed to the joining member. There is no explicit
+ * notification on failure (as the channel may simply take days to approve,
+ * and disapproval is simply being ignored).
*
- * @param cfg configuration to use (to connect to PSYC service)
- * @param method_count number of methods in 'methods' array
- * @param methods functions to invoke on messages received from members,
- * typcially at least contains functions for 'join' and 'leave'.
- * @param priv_key ECC key that will be used to sign messages for this
- * psyc session; public key is used to identify the
- * psyc group; FIXME: we'll likely want to use
- * NOT the p521 curve here, but a cheaper one in the future
- * @param join_policy what is the membership policy of the group?
- * @return handle for the origin, NULL on error
+ * @param cfg Configuration to use.
+ * @param channel_key ECC public key that identifies the channel we wish to join.
+ * @param slave_key ECC private-public key pair that identifies the slave, and
+ * used by multicast to sign the join request and subsequent unicast
+ * requests sent to the master.
+ * @param origin Peer identity of the origin.
+ * @param relay_count Number of peers in the @a relays array.
+ * @param relays Peer identities of members of the multicast group, which serve
+ * as relays and used to join the group at.
+ * @param method Function to invoke on messages received from the channel,
+ * typically at least contains functions for @e join and @e part.
+ * @param join_cb Function to invoke when a peer wants to join.
+ * @param cls Closure for @a method_cb and @a join_cb.
+ * @param method_name Method name for the join request.
+ * @param env Environment containing transient variables for the request, or NULL.
+ * @param data Payload for the join message.
+ * @param data_size Number of bytes in @a data.
+ * @return Handle for the slave, NULL on error.
*/
-struct GNUNET_PSYC_Origin *
-GNUNET_PSYC_origin_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
- unsigned int method_count,
- const struct GNUNET_PSYC_MethodDescriptor *methods,
- const struct GNUNET_CRYPTO_EccPrivateKey *priv_key,
- enum GNUNET_MULTICAST_JoinPolicy join_policy);
+struct GNUNET_PSYC_Slave *
+GNUNET_PSYC_slave_join (const struct GNUNET_CONFIGURATION_Handle *cfg,
+ const struct GNUNET_CRYPTO_EccPublicSignKey *channel_key,
+ const struct GNUNET_CRYPTO_EccPrivateKey *slave_key,
+ const struct GNUNET_PeerIdentity *origin,
+ size_t relay_count,
+ const struct GNUNET_PeerIdentity *relays,
+ GNUNET_PSYC_Method method,
+ GNUNET_PSYC_JoinCallback join_cb,
+ GNUNET_PSYC_SlaveJoinCallback slave_joined_cb,
+ void *cls,
+ const char *method_name,
+ const struct GNUNET_ENV_Environment *env,
+ const void *data,
+ size_t data_size);
/**
- * Update channel state. The state of a channel must fit into the
- * memory of each member (and the origin); large values that require
- * streaming must only be passed as streaming arguments to methods.
- * State updates might not be transmitted to group members until
- * the next call to 'GNUNET_PSYC_origin_broadcast_call_method'.
+ * Part a PSYC channel.
*
- * @param origin handle to the psyc group / channel
- * @param full_state_name name of the field in the channel state to change
- * @param data_size number of bytes in data
- * @param data new state value
+ * Will terminate the connection to the PSYC service. Polite clients should
+ * first explicitly send a @e part request (via GNUNET_PSYC_slave_transmit()).
+ *
+ * @param slave Slave handle.
*/
void
-GNUNET_PSYC_origin_update_state (struct GNUNET_PSYC_Origin *origin,
- const char *full_state_name,
- size_t data_size,
- const void *data);
+GNUNET_PSYC_slave_part (struct GNUNET_PSYC_Slave *slave);
/**
- * Data needed to construct a PSYC message to call a method.
+ * Function called to provide data for a transmission to the channel master
+ * (a.k.a. the @e host of the channel).
+ *
+ * Note that returning #GNUNET_OK or #GNUNET_SYSERR (but not #GNUNET_NO)
+ * invalidates the respective transmission handle.
+ *
+ * @param cls Closure.
+ * @param[in,out] data_size Initially set to the number of bytes available in
+ * @a data, should be set to the number of bytes written to data
+ * (IN/OUT).
+ * @param[out] data Where to write the body of the message to give to the method;
+ * function must copy at most @a *data_size bytes to @a data.
+ * @return #GNUNET_SYSERR on error (fatal, aborts transmission).
+ * #GNUNET_NO on success, if more data is to be transmitted later.
+ * #GNUNET_YES if this completes the transmission (all data supplied).
*/
-struct GNUNET_PSYC_CallData
+typedef int
+(*GNUNET_PSYC_SlaveTransmitNotify) (void *cls,
+ size_t *data_size,
+ char *data);
+
+
+/**
+ * Flags for transmitting messages to the channel master by a slave.
+ */
+enum GNUNET_PSYC_SlaveTransmitFlags
{
+ GNUNET_PSYC_SLAVE_TRANSMIT_NONE = 0
+};
- /**
- * Name of the function to call. This name may be more specific
- * than the registered method name due to try&slice matching.
- */
- const char *full_method_name;
- /**
- * Number of arguments to pass (other than closure and sender),
- * length of the 'argv' array.
- */
- unsigned int argc;
+/**
+ * Handle for a pending PSYC transmission operation.
+ */
+struct GNUNET_PSYC_SlaveTransmitHandle;
- /**
- * Arguments to pass to the function.
- */
- const struct GNUNET_PSYC_Argument *argv;
-};
+/**
+ * Request a message to be sent to the channel master.
+ *
+ * @param slave Slave handle.
+ * @param method_name Which (PSYC) method should be invoked (on host).
+ * @param env Environment containing transient variables for the message, or NULL.
+ * @param notify Function to call when we are allowed to transmit (to get data).
+ * @param notify_cls Closure for @a notify.
+ * @param flags Flags for the message being transmitted.
+ * @return Transmission handle, NULL on error (i.e. more than one request queued).
+ */
+struct GNUNET_PSYC_SlaveTransmitHandle *
+GNUNET_PSYC_slave_transmit (struct GNUNET_PSYC_Slave *slave,
+ const char *method_name,
+ const struct GNUNET_ENV_Environment *env,
+ GNUNET_PSYC_SlaveTransmitNotify notify,
+ void *notify_cls,
+ enum GNUNET_PSYC_SlaveTransmitFlags flags);
/**
- * Send a message to call a method to all members in the psyc group.
+ * Resume transmission to the master.
*
- * @param origin handle to the psyc group
- * @param increment_group_generation GNUNET_YES if we need to increment
- * the group generation counter after transmitting this message
- * @param call_data data needed to determine how to call which method
- * @param message_id set to the unique message ID that was generated for
- * this message
- * @param group_generation set to the group generation used for this
- * message
- * FIXME: change to notify_transmit_ready-style to wait for ACKs?
- * that'd also help with streaming arguments!
- * => need to change multicast API first as well!
+ * @param th Handle of the request that is being resumed.
*/
void
-GNUNET_PSYC_origin_broadcast_call_method (struct GNUNET_PSYC_Origin *origin,
- int increment_group_generation,
- const struct GNUNET_PSYC_CallData *call_data,
- uint64_t *message_id,
- uint64_t *group_generation);
+GNUNET_PSYC_slave_transmit_resume (struct GNUNET_PSYC_MasterTransmitHandle *th);
/**
- * End a psyc group.
+ * Abort transmission request to master.
*
- * @param origin psyc group to terminate
+ * @param th Handle of the request that is being aborted.
*/
void
-GNUNET_PSYC_origin_end (struct GNUNET_PSYC_Origin *origin);
+GNUNET_PSYC_slave_transmit_cancel (struct GNUNET_PSYC_SlaveTransmitHandle *th);
/**
- * Handle to access PSYC group operations for all members.
+ * Handle to access PSYC channel operations for both the master and slaves.
*/
-struct GNUNET_PSYC_Group;
+struct GNUNET_PSYC_Channel;
/**
- * Convert 'origin' to a 'group' handle to access the 'group' APIs.
- *
- * @param origin origin handle
- * @return group handle, valid for as long as 'origin' is valid
- */
-struct GNUNET_PSYC_Group *
-GNUNET_PSYC_origin_get_group (struct GNUNET_PSYC_Origin *origin);
+ * Convert a channel @a master to a @e channel handle to access the @e channel
+ * APIs.
+ *
+ * @param master Channel master handle.
+ * @return Channel handle, valid for as long as @a master is valid.
+ */
+struct GNUNET_PSYC_Channel *
+GNUNET_PSYC_master_get_channel (struct GNUNET_PSYC_Master *master);
/**
- * Add a member to the group. Note that this will NOT generate any
- * PSYC traffic, it will merely update the local data base to modify
- * how we react to 'membership test' queries. The origin still needs to
- * explicitly transmit a 'leave' message to notify other group members
- * and they then also must still call this function in their respective
- * methods handling the 'leave' message. This way, how 'join' and 'leave'
- * operations are exactly implemented is still up to the application;
- * for example, there might be a 'leave_all' message to kick out everyone.
+ * Convert @a slave to a @e channel handle to access the @e channel APIs.
*
- * Note that group members are explicitly trusted to perform these
- * operations correctly; not doing so correctly will result in either
- * denying members access or offering access to group data to
- * non-members.
+ * @param slave Slave handle.
+ * @return Channel handle, valid for as long as @a slave is valid.
+ */
+struct GNUNET_PSYC_Channel *
+GNUNET_PSYC_slave_get_channel (struct GNUNET_PSYC_Slave *slave);
+
+
+/**
+ * Add a slave to the channel's membership list.
*
- * @param group group handle
- * @param member which peer to add
- * @param message_id message ID for the message that changed the membership
- * @param group_generation the generation ID where the change went into effect
+ * Note that this will NOT generate any PSYC traffic, it will merely update the
+ * local database to modify how we react to <em>membership test</em> queries.
+ * The channel master still needs to explicitly transmit a @e join message to
+ * notify other channel members and they then also must still call this function
+ * in their respective methods handling the @e join message. This way, how @e
+ * join and @e part operations are exactly implemented is still up to the
+ * application; for example, there might be a @e part_all method to kick out
+ * everyone.
+ *
+ * Note that channel slaves are explicitly trusted to execute such methods
+ * correctly; not doing so correctly will result in either denying other slaves
+ * access or offering access to channel data to non-members.
+ *
+ * @param channel Channel handle.
+ * @param slave_key Identity of channel slave to add.
+ * @param announced_at ID of the message that announced the membership change.
+ * @param effective_since Addition of slave is in effect since this message ID.
*/
void
-GNUNET_PSYC_group_member_admit (struct GNUNET_PSYC_Group *group,
- const struct GNUNET_PeerIdentity *member,
- uint64_t message_id,
- uint64_t group_generation);
+GNUNET_PSYC_channel_slave_add (struct GNUNET_PSYC_Channel *channel,
+ const struct GNUNET_CRYPTO_EccPublicSignKey
+ *slave_key,
+ uint64_t announced_at,
+ uint64_t effective_since);
/**
- * Remove a member from the group. Note that this will NOT generate any
- * PSYC traffic, it will merely update the local data base to modify
- * how we react to 'membership test' queries. The origin still needs to
- * explicitly transmit a 'leave' message to notify other group members
- * and they then also must still call this function in their respective
- * methods handling the 'leave' message. This way, how 'join' and 'leave'
- * operations are exactly implemented is still up to the application;
- * for example, there might be a 'leave_all' message to kick out everyone.
+ * Remove a slave from the channel's membership list.
+ *
+ * Note that this will NOT generate any PSYC traffic, it will merely update the
+ * local database to modify how we react to <em>membership test</em> queries.
+ * The channel master still needs to explicitly transmit a @e part message to
+ * notify other channel members and they then also must still call this function
+ * in their respective methods handling the @e part message. This way, how
+ * @e join and @e part operations are exactly implemented is still up to the
+ * application; for example, there might be a @e part_all message to kick out
+ * everyone.
*
- * Note that group members are explicitly trusted to perform these
+ * Note that channel members are explicitly trusted to perform these
* operations correctly; not doing so correctly will result in either
- * denying members access or offering access to group data to
+ * denying members access or offering access to channel data to
* non-members.
*
- * @param group group handle
- * @param member which peer to remove
- * @param message_id message ID for the message that changed the membership
- * @param group_generation the generation ID where the change went into effect
+ * @param channel Channel handle.
+ * @param slave_key Identity of channel slave to remove.
+ * @param announced_at ID of the message that announced the membership change.
*/
void
-GNUNET_PSYC_group_member_kick (struct GNUNET_PSYC_Group *group,
- const struct GNUNET_PeerIdentity *member,
- uint64_t message_id,
- uint64_t group_generation);
+GNUNET_PSYC_channel_slave_remove (struct GNUNET_PSYC_Channel *channel,
+ const struct GNUNET_CRYPTO_EccPublicSignKey
+ *slave_key,
+ uint64_t announced_at);
/**
- * Function called to inform a member about state values for a channel.
+ * Function called to inform a member about stored state values for a channel.
*
- * @param cls closure
- * @param full_state_name full name of the state
- * @param data_size number of bytes in 'data'
- * @param data raw data of the state
+ * @param cls Closure.
+ * @param name Name of the state variable. A NULL value indicates that there
+ * are no more state variables to be returned.
+ * @param value Value of the state variable.
+ * @param value_size Number of bytes in @a value.
*/
-typedef void (*GNUNET_PSYC_StateCallback)(void *cls,
- const char *full_state_name,
- size_t data_size,
- const void *data);
+typedef void
+(*GNUNET_PSYC_StateCallback) (void *cls,
+ const char *name,
+ const void *value,
+ size_t value_size);
/**
- * Descriptor for an event handler handling PSYC state updates.
+ * Function called when a requested operation has finished.
+ *
+ * @param cls Closure.
*/
-struct GNUNET_PSYC_StateHandler
-{
+typedef void
+(*GNUNET_PSYC_FinishCallback) (void *cls);
- /**
- * Name of the state this handler calls about, used in try-and-slice matching.
- */
- const char *state_name;
-
- /**
- * Function to call whenever the respective state changes.
- */
- GNUNET_PSYC_StateCallback event_handler;
- /**
- * Closure for the 'event_handler' function.
- */
- void *event_handler_cls;
+/**
+ * Handle to a story telling operation.
+ */
+struct GNUNET_PSYC_Story;
- /**
- * Description of the kind of state that the handler expects to see.
- * Non-matching state updates will be ignored (but logged). Note
- * that the state_types of all states with the same state name prefix
- * should be identical.
- */
- struct GNUNET_PSYC_ArgumentDescriptor state_type;
-};
+/**
+ * Request to be told the message history of the channel.
+ *
+ * Historic messages (but NOT the state at the time) will be replayed (given to
+ * the normal method handlers) if available and if access is permitted.
+ *
+ * To get the latest message, use 0 for both the start and end message ID.
+ *
+ * @param channel Which channel should be replayed?
+ * @param start_message_id Earliest interesting point in history.
+ * @param end_message_id Last (exclusive) interesting point in history.
+ * @param method Function to invoke on messages received from the story.
+ * @param finish_cb Function to call when the requested story has been fully
+ * told (counting message IDs might not suffice, as some messages
+ * might be secret and thus the listener would not know the story is
+ * finished without being told explicitly); once this function
+ * has been called, the client must not call
+ * GNUNET_PSYC_channel_story_tell_cancel() anymore.
+ * @param cls Closure for the callbacks.
+ * @return Handle to cancel story telling operation.
+ */
+struct GNUNET_PSYC_Story *
+GNUNET_PSYC_channel_story_tell (struct GNUNET_PSYC_Channel *channel,
+ uint64_t start_message_id,
+ uint64_t end_message_id,
+ GNUNET_PSYC_Method method,
+ GNUNET_PSYC_FinishCallback *finish_cb,
+ void *cls);
/**
- * Join a psyc group. The entity joining is always the local peer.
- * This will send a 'join_msg' to the origin; if it succeeds, the
- * channel state will be replayed to the joining member and the 'join'
- * method will be invoked to show that we joined successfully. There
- * is no explicit notification on failure (as the origin may simply
- * take days to approve, and disapproval is simply being ignored).
- *
- * Note that we also specify the message to transmit to origin on
- * 'leave' here, as a sudden crash might otherwise not permit sending
- * a 'nice' leave message. TODO: we might want an API to change
- * the 'leave' message later during the session.
- *
- * @param cfg configuration to use
- * @param pub_key ECC key that identifies the group
- * @param method_count number of methods in 'methods' array
- * @param methods functions to invoke on messages received from the origin,
- * typcially at least contains functions for 'join' and 'leave'.
- * @param state_count number of state handlers
- * @param state_handlers array of state event handlers
- * @param join_data method to invoke on origin to trigger joining;
- * use NULL to send nothing (useful for anonymous groups that permit anyone);
- arguments to give to join method, must not include streaming args
- * @param leave_data method to invoke on origin on leaving;
- * use NULL to send nothing (useful for anonymous groups that permit anyone);
- arguments to give to leave method, must not include streaming args
- * @return handle for the member, NULL on error
- */
-struct GNUNET_PSYC_Member *
-GNUNET_PSYC_member_join (const struct GNUNET_CONFIGURATION_Handle *cfg,
- const struct GNUNET_CRYPTO_EccPublicKey *pub_key,
- unsigned int method_count,
- const struct GNUNET_PSYC_MethodDescriptor *methods,
- unsigned int state_count,
- struct GNUNET_PSYC_StateHandler *state_handlers,
- const struct GNUNET_PSYC_CallData *join_data,
- const struct GNUNET_PSYC_CallData *leave_data);
-
-
-/**
- * Request a message to be send to the origin.
- *
- * @param member membership handle
- * @param request_data which method should be invoked on origin (and how)
- *
- * FIXME: change to notify_transmit_ready-style to wait for ACKs
- * and to enable streaming arguments!
+ * Abort story telling.
+ *
+ * This function must not be called from within method handlers (as given to
+ * GNUNET_PSYC_slave_join()) of the slave.
+ *
+ * @param story Story telling operation to stop.
*/
void
-GNUNET_PSYC_member_send_to_origin (struct GNUNET_PSYC_Member *member,
- const struct GNUNET_PSYC_CallData *request_data);
+GNUNET_PSYC_channel_story_tell_cancel (struct GNUNET_PSYC_Story *story);
/**
- * Call the given state callback on all matching states in the channel
- * state. The callback is invoked synchronously on all matching
- * states (as the state is fully replicated in the library in this
- * process; channel states should be small, large data is to be passed
- * as streaming data to methods).
+ * Handle for a state query operation.
+ */
+struct GNUNET_PSYC_StateQuery;
+
+
+/**
+ * Retrieve the best matching channel state variable.
+ *
+ * If the requested variable name is not present in the state, the nearest
+ * less-specific name is matched; for example, requesting "_a_b" will match "_a"
+ * if "_a_b" does not exist.
*
- * @param member membership handle
- * @param state_name name of the state to query (full name
- * might be longer, this is only the prefix that must match)
- * @param cb function to call on the matching state values
- * @param cb_cls closure for 'cb'
+ * @param channel Channel handle.
+ * @param full_name Full name of the requested variable, the actual variable
+ * returned might have a shorter name..
+ * @param cb Function called once when a matching state variable is found.
+ * Not called if there's no matching state variable.
+ * @param cb_cls Closure for the callbacks.
+ * @return Handle that can be used to cancel the query operation.
*/
-int
-GNUNET_PSYC_member_state_get (struct GNUNET_PSYC_Member *member,
- const char *state_name,
- GNUNET_PSYC_StateCallback cb,
- void *cb_cls);
+struct GNUNET_PSYC_StateQuery *
+GNUNET_PSYC_channel_state_get (struct GNUNET_PSYC_Channel *channel,
+ const char *full_name,
+ GNUNET_PSYC_StateCallback cb,
+ void *cb_cls);
/**
- * Leave a mutlicast group. Will terminate the connection to the PSYC
- * service, which will send the 'leave' method that was prepared
- * earlier to the origin. This function must not be called on a
- * 'member' that was obtained from GNUNET_PSYC_origin_get_group.
+ * Return all channel state variables whose name matches a given prefix.
+ *
+ * A name matches if it starts with the given @a name_prefix, thus requesting
+ * the empty prefix ("") will match all values; requesting "_a_b" will also
+ * return values stored under "_a_b_c".
*
- * @param member membership handle
+ * The @a state_cb is invoked on all matching state variables asynchronously, as
+ * the state is stored in and retrieved from the PSYCstore,
+ *
+ * @param channel Channel handle.
+ * @param name_prefix Prefix of the state variable name to match.
+ * @param cb Function to call with the matching state variables.
+ * @param cb_cls Closure for the callbacks.
+ * @return Handle that can be used to cancel the query operation.
*/
-void
-GNUNET_PSYC_member_leave (struct GNUNET_PSYC_Member *member);
+struct GNUNET_PSYC_StateQuery *
+GNUNET_PSYC_channel_state_get_prefix (struct GNUNET_PSYC_Channel *channel,
+ const char *name_prefix,
+ GNUNET_PSYC_StateCallback cb,
+ void *cb_cls);
+/**
+ * Cancel a state query operation.
+ *
+ * @param query Handle for the operation to cancel.
+ */
+void
+GNUNET_PSYC_channel_state_get_cancel (struct GNUNET_PSYC_StateQuery *query);
+
#if 0 /* keep Emacsens' auto-indent happy */
{
projects / oweals / gnunet.git / blobdiff