/*
This file is part of GNUnet.
- Copyright (C) 2009-2014 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2009-2017 GNUnet e.V.
- GNUnet is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published
- by the Free Software Foundation; either version 3, or (at your
- option) any later version.
+ GNUnet is free software: you can redistribute it and/or modify it
+ under the terms of the GNU Affero General Public License as published
+ by the Free Software Foundation, either version 3 of the License,
+ or (at your option) any later version.
GNUnet is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with GNUnet; see the file COPYING. If not, write to the
- Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA.
+ Affero General Public License for more details.
+
+ You should have received a copy of the GNU Affero General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
- * @file include/gnunet_cadet_service.h
- * @brief cadet service; establish channels to distant peers
* @author Christian Grothoff
* @author Bart Polot
+ *
+ * @file
+ * CADET service; establish channels to distant peers
+ *
+ * @defgroup cadet CADET service
+ * Confidential Ad-hoc Decentralized End-to-End Transport
+ *
+ * @see [Documentation](https://gnunet.org/cadet-subsystem)
+ * @see [Paper](https://gnunet.org/cadet)
+ *
+ * @{
*/
#ifndef GNUNET_CADET_SERVICE_H
#define GNUNET_CADET_SERVICE_H
/**
* Version number of GNUnet-cadet API.
*/
-#define GNUNET_CADET_VERSION 0x00000003
+#define GNUNET_CADET_VERSION 0x00000005
/**
struct GNUNET_CADET_Channel;
/**
- * Hash to be used in Cadet communication. Only 256 bits needed,
- * instead of the 512 from `struct GNUNET_HashCode`.
+ * Opaque handle to a port.
+ */
+struct GNUNET_CADET_Port;
+
+
+/**
+ * Hash uniquely identifying a connection below a tunnel.
*/
-struct GNUNET_CADET_Hash
+struct GNUNET_CADET_ConnectionTunnelIdentifier
{
- unsigned char bits[256 / 8];
+ struct GNUNET_ShortHashCode connection_of_tunnel;
+};
+
+
+/**
+ * Number identifying a CADET channel within a tunnel.
+ */
+struct GNUNET_CADET_ChannelTunnelNumber
+{
+ /**
+ * Which number does this channel have that uniquely identfies
+ * it within its tunnel, in network byte order.
+ *
+ * Given two peers, both may initiate channels over the same tunnel.
+ * The @e cn must be greater or equal to 0x80000000 (high-bit set)
+ * for tunnels initiated with the peer that has the larger peer
+ * identity as compared using #GNUNET_CRYPTO_cmp_peer_identity().
+ */
+ uint32_t cn GNUNET_PACKED;
};
/**
* Enable out of order delivery of messages.
- * Yes/No.
+ * Set bit for out-of-order delivery.
*/
- GNUNET_CADET_OPTION_OOORDER = 0x4,
+ GNUNET_CADET_OPTION_OUT_OF_ORDER = 0x4,
/**
* Who is the peer at the other end of the channel.
/**
- * Functions with this signature are called whenever a message is
- * received.
- *
- * Each time the function must call #GNUNET_CADET_receive_done on the channel
- * in order to receive the next message. This doesn't need to be immediate:
- * can be delayed if some processing is done on the message.
+ * Method called whenever a peer connects to a port in MQ-based CADET.
*
- * @param cls Closure (set from #GNUNET_CADET_connect).
- * @param channel Connection to the other end.
- * @param channel_ctx Place to store local state associated with the channel.
- * @param message The actual message.
- * @return #GNUNET_OK to keep the channel open,
- * #GNUNET_SYSERR to close it (signal serious error).
+ * @param cls Closure from #GNUNET_CADET_open_port.
+ * @param channel New handle to the channel.
+ * @param source Peer that started this channel.
+ * @return Closure for the incoming @a channel. It's given to:
+ * - The #GNUNET_CADET_DisconnectEventHandler (given to
+ * #GNUNET_CADET_open_port) when the channel dies.
+ * - Each the #GNUNET_MQ_MessageCallback handlers for each message
+ * received on the @a channel.
*/
-typedef int
-(*GNUNET_CADET_MessageCallback) (void *cls,
- struct GNUNET_CADET_Channel *channel,
- void **channel_ctx,
- const struct GNUNET_MessageHeader *message);
-
-
-/**
- * Message handler. Each struct specifies how to handle on particular
- * type of message received.
- */
-struct GNUNET_CADET_MessageHandler
-{
- /**
- * Function to call for messages of type @e type.
- */
- GNUNET_CADET_MessageCallback callback;
-
- /**
- * Type of the message this handler covers.
- */
- uint16_t type;
-
- /**
- * Expected size of messages of this type. Use 0 for variable-size.
- * If non-zero, messages of the given type will be discarded if they
- * do not have the right size.
- */
- uint16_t expected_size;
-};
+typedef void *
+(*GNUNET_CADET_ConnectEventHandler) (void *cls,
+ struct GNUNET_CADET_Channel *channel,
+ const struct GNUNET_PeerIdentity *source);
/**
- * Method called whenever another peer has added us to a channel
- * the other peer initiated.
- * Only called (once) upon reception of data with a message type which was
- * subscribed to in #GNUNET_CADET_connect.
- *
- * A call to #GNUNET_CADET_channel_destroy causes te channel to be ignored. In
- * this case the handler MUST return NULL.
+ * Function called whenever an MQ-channel is destroyed, even if the destruction
+ * was requested by #GNUNET_CADET_channel_destroy.
+ * It must NOT call #GNUNET_CADET_channel_destroy on the channel.
*
- * @param cls closure
- * @param channel new handle to the channel
- * @param initiator peer that started the channel
- * @param port Port this channel is for.
- * @param options CadetOption flag field, with all active option bits set to 1.
+ * It should clean up any associated state, including cancelling any pending
+ * transmission on this channel.
*
- * @return initial channel context for the channel
- * (can be NULL -- that's not an error)
+ * @param cls Channel closure.
+ * @param channel Connection to the other end (henceforth invalid).
*/
-typedef void *
-(GNUNET_CADET_InboundChannelNotificationHandler) (void *cls,
- struct GNUNET_CADET_Channel *channel,
- const struct GNUNET_PeerIdentity *initiator,
- uint32_t port,
- enum GNUNET_CADET_ChannelOption options);
+typedef void
+(*GNUNET_CADET_DisconnectEventHandler) (void *cls,
+ const struct GNUNET_CADET_Channel *channel);
/**
- * Function called whenever a channel is destroyed. Should clean up
- * any associated state, including cancelling any pending transmission on this
- * channel.
+ * Function called whenever an MQ-channel's transmission window size changes.
*
- * It must NOT call #GNUNET_CADET_channel_destroy on the channel.
+ * The first callback in an outgoing channel will be with a non-zero value
+ * and will mean the channel is connected to the destination.
*
- * @param cls closure (set from #GNUNET_CADET_connect)
- * @param channel connection to the other end (henceforth invalid)
- * @param channel_ctx place where local state associated
- * with the channel is stored
+ * For an incoming channel it will be called immediately after the
+ * #GNUNET_CADET_ConnectEventHandler, also with a non-zero value.
+ *
+ * @param cls Channel closure.
+ * @param channel Connection to the other end --- FIXME: drop?
+ * @param window_size New window size. If the is more messages than buffer size
+ * this value will be negative. -- FIXME: make unsigned, we never call negative?
*/
typedef void
-(GNUNET_CADET_ChannelEndHandler) (void *cls,
- const struct GNUNET_CADET_Channel *channel,
- void *channel_ctx);
+(*GNUNET_CADET_WindowSizeEventHandler) (void *cls,
+ const struct GNUNET_CADET_Channel *channel,
+ int window_size);
/**
- * Connect to the cadet service.
+ * Connect to the MQ-based cadet service.
*
* @param cfg Configuration to use.
- * @param cls Closure for the various callbacks that follow (including
- * handlers in the handlers array).
- * @param new_channel Function called when an *incoming* channel is created.
- * Can be NULL if no inbound channels are desired.
- * See @a ports.
- * @param cleaner Function called when a channel is destroyed.
- * It is called immediately if #GNUNET_CADET_channel_destroy
- * is called on the channel.
- * @param handlers Callbacks for messages we care about, NULL-terminated. Each
- * one must call #GNUNET_CADET_receive_done on the channel to
- * receive the next message. Messages of a type that is not
- * in the handlers array are ignored if received.
- * @param ports NULL or 0-terminated array of port numbers for incoming channels.
- * See @a new_channel.
- *
- * @return handle to the cadet service NULL on error
- * (in this case, init is never called)
+ * @return Handle to the cadet service NULL on error.
*/
struct GNUNET_CADET_Handle *
-GNUNET_CADET_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
- void *cls,
- GNUNET_CADET_InboundChannelNotificationHandler new_channel,
- GNUNET_CADET_ChannelEndHandler cleaner,
- const struct GNUNET_CADET_MessageHandler *handlers,
- const uint32_t *ports);
+GNUNET_CADET_connect (const struct GNUNET_CONFIGURATION_Handle *cfg);
/**
GNUNET_CADET_disconnect (struct GNUNET_CADET_Handle *handle);
+/**
+ * Open a port to receive incomming MQ-based channels.
+ *
+ * @param h CADET handle.
+ * @param port Hash identifying the port.
+ * @param connects Function called when an incoming channel is connected.
+ * @param connects_cls Closure for the @a connects handler.
+ * @param window_changes Function called when the transmit window size changes.
+ * Can be NULL.
+ * @param disconnects Function called when a channel is disconnected.
+ * @param handlers Callbacks for messages we care about, NULL-terminated.
+ * @return Port handle, NULL if port is in use
+ */
+struct GNUNET_CADET_Port *
+GNUNET_CADET_open_port (struct GNUNET_CADET_Handle *h,
+ const struct GNUNET_HashCode *port,
+ GNUNET_CADET_ConnectEventHandler connects,
+ void *connects_cls,
+ GNUNET_CADET_WindowSizeEventHandler window_changes,
+ GNUNET_CADET_DisconnectEventHandler disconnects,
+ const struct GNUNET_MQ_MessageHandler *handlers);
+
+
+/**
+ * Close a port opened with @a GNUNET_CADET_open_port.
+ * The @a new_channel callback will no longer be called.
+ *
+ * @param p Port handle.
+ */
+void
+GNUNET_CADET_close_port (struct GNUNET_CADET_Port *p);
+
+
/**
* Create a new channel towards a remote peer.
*
* If the destination port is not open by any peer or the destination peer
- * does not accept the channel, #GNUNET_CADET_ChannelEndHandler will be called
+ * does not accept the channel, @a disconnects will be called
* for this channel.
*
- * @param h cadet handle
- * @param channel_ctx client's channel context to associate with the channel
- * @param peer peer identity the channel should go to
- * @param port Port number.
+ * @param h CADET handle.
+ * @param channel_cls Closure for the channel. It's given to:
+ * - The management handler @a window_changes.
+ * - The disconnect handler @a disconnects
+ * - Each message type callback in @a handlers
+ * @param destination Peer identity the channel should go to.
+ * @param port Identification of the destination port.
* @param options CadetOption flag field, with all desired option bits set to 1.
- *
- * @return handle to the channel
+ * @param window_changes Function called when the transmit window size changes.
+ * Can be NULL if this data is of no interest.
+ * TODO Not yet implemented.
+ * @param disconnects Function called when the channel is disconnected.
+ * @param handlers Callbacks for messages we care about, NULL-terminated.
+ * @return Handle to the channel.
*/
struct GNUNET_CADET_Channel *
GNUNET_CADET_channel_create (struct GNUNET_CADET_Handle *h,
- void *channel_ctx,
- const struct GNUNET_PeerIdentity *peer,
- uint32_t port,
- enum GNUNET_CADET_ChannelOption options);
+ void *channel_cls,
+ const struct GNUNET_PeerIdentity *destination,
+ const struct GNUNET_HashCode *port,
+ enum GNUNET_CADET_ChannelOption options,
+ GNUNET_CADET_WindowSizeEventHandler window_changes,
+ GNUNET_CADET_DisconnectEventHandler disconnects,
+ const struct GNUNET_MQ_MessageHandler *handlers);
/**
GNUNET_CADET_channel_destroy (struct GNUNET_CADET_Channel *channel);
+/**
+ * Obtain the message queue for a connected channel.
+ *
+ * @param channel The channel handle from which to get the MQ.
+ * @return The message queue of the channel.
+ */
+struct GNUNET_MQ_Handle *
+GNUNET_CADET_get_mq (const struct GNUNET_CADET_Channel *channel);
+
+
+/**
+ * Indicate readiness to receive the next message on a channel.
+ *
+ * Should only be called once per handler called.
+ *
+ * @param channel Channel that will be allowed to call another handler.
+ */
+void
+GNUNET_CADET_receive_done (struct GNUNET_CADET_Channel *channel);
+
+
+/******************************************************************************/
+/******************** MONITORING /DEBUG API *************************/
+/******************************************************************************/
+/* The following calls are not useful for normal CADET operation, but for */
+/* debug and monitoring of the cadet state. They can be safely ignored. */
+/* The API can change at any point without notice. */
+/* Please contact the developer if you consider any of this calls useful for */
+/* normal cadet applications. */
+/******************************************************************************/
+
+
+/**
+ * Transitional function to convert an unsigned int port to a hash value.
+ * WARNING: local static value returned, NOT reentrant!
+ * WARNING: do not use this function for new code!
+ *
+ * @param port Numerical port (unsigned int format).
+ *
+ * @return A GNUNET_HashCode usable for the new CADET API.
+ */
+const struct GNUNET_HashCode *
+GC_u2h (uint32_t port);
+
+
+
/**
* Struct to retrieve info about a channel.
*/
*/
const union GNUNET_CADET_ChannelInfo *
GNUNET_CADET_channel_get_info (struct GNUNET_CADET_Channel *channel,
- enum GNUNET_CADET_ChannelOption option, ...);
-
-
-/**
- * Handle for a transmission request.
- */
-struct GNUNET_CADET_TransmitHandle;
-
-
-/**
- * Ask the cadet to call @a notify once it is ready to transmit the
- * given number of bytes to the specified channel.
- * Only one call can be active at any time, to issue another request,
- * wait for the callback or cancel the current request.
- *
- * @param channel channel to use for transmission
- * @param cork is corking allowed for this transmission?
- * @param maxdelay how long can the message wait?
- * @param notify_size how many bytes of buffer space does notify want?
- * @param notify function to call when buffer space is available;
- * will be called with NULL on timeout or if the overall queue
- * for this peer is larger than queue_size and this is currently
- * the message with the lowest priority
- * @param notify_cls closure for @a notify
- * @return non-NULL if the notify callback was queued,
- * NULL if we can not even queue the request (insufficient
- * memory); if NULL is returned, @a notify will NOT be called.
- */
-struct GNUNET_CADET_TransmitHandle *
-GNUNET_CADET_notify_transmit_ready (struct GNUNET_CADET_Channel *channel,
- int cork,
- struct GNUNET_TIME_Relative maxdelay,
- size_t notify_size,
- GNUNET_CONNECTION_TransmitReadyNotify notify,
- void *notify_cls);
-
-
-/**
- * Cancel the specified transmission-ready notification.
- *
- * @param th handle that was returned by "notify_transmit_ready".
- */
-void
-GNUNET_CADET_notify_transmit_ready_cancel (struct GNUNET_CADET_TransmitHandle *th);
-
-
-/**
- * Indicate readiness to receive the next message on a channel.
- *
- * Should only be called once per handler called.
- *
- * @param channel Channel that will be allowed to call another handler.
- */
-void
-GNUNET_CADET_receive_done (struct GNUNET_CADET_Channel *channel);
-
-
-
-/******************************************************************************/
-/******************** MONITORING /DEBUG API *************************/
-/******************************************************************************/
-/* The following calls are not useful for normal CADET operation, but for */
-/* debug and monitoring of the cadet state. They can be safely ignored. */
-/* The API can change at any point without notice. */
-/* Please contact the developer if you consider any of this calls useful for */
-/* normal cadet applications. */
-/******************************************************************************/
+ enum GNUNET_CADET_ChannelOption option,
+ ...);
/**
(*GNUNET_CADET_ChannelCB) (void *cls,
const struct GNUNET_PeerIdentity *root,
const struct GNUNET_PeerIdentity *dest,
- uint32_t port,
- uint32_t root_channel_number,
- uint32_t dest_channel_number,
- uint32_t public_channel_number);
+ uint32_t /* UGH */ port,
+ uint32_t /* ugh */ root_channel_number,
+ uint32_t /* ugh */ dest_channel_number,
+ uint32_t /* ugh */ public_channel_number);
/**
* Method called to retrieve information about all peers in CADET, called
* @param neighbor Is this a direct neighbor? #GNUNET_YES/#GNUNET_NO
* @param n_paths Number of paths known towards peer.
* @param paths Array of PEER_IDs representing all paths to reach the peer.
- * Each path starts with the local peer.
+ * Each path starts with the first hop (local peer not included).
* Each path ends with the destination peer (given in @c peer).
*/
typedef void
int tunnel,
int neighbor,
unsigned int n_paths,
- struct GNUNET_PeerIdentity *paths);
+ const struct GNUNET_PeerIdentity *paths);
/**
const struct GNUNET_PeerIdentity *peer,
unsigned int n_channels,
unsigned int n_connections,
- uint32_t *channels,
- struct GNUNET_CADET_Hash *connections,
+ const struct GNUNET_CADET_ChannelTunnelNumber *channels,
+ const struct GNUNET_CADET_ConnectionTunnelIdentifier *connections,
unsigned int estate,
unsigned int cstate);
void
GNUNET_CADET_get_channel (struct GNUNET_CADET_Handle *h,
struct GNUNET_PeerIdentity *peer,
- uint32_t channel_number,
+ uint32_t /* UGH */ channel_number,
GNUNET_CADET_ChannelCB callback,
void *callback_cls);
void *callback_cls);
-/**
- * Create a message queue for a cadet channel.
- * The message queue can only be used to transmit messages,
- * not to receive them.
- *
- * @param channel the channel to create the message qeue for
- * @return a message queue to messages over the channel
- */
-struct GNUNET_MQ_Handle *
-GNUNET_CADET_mq_create (struct GNUNET_CADET_Channel *channel);
-
#if 0 /* keep Emacsens' auto-indent happy */
{
/* ifndef GNUNET_CADET_SERVICE_H */
#endif
+
+/** @} */ /* end of group */
+
/* end of gnunet_cadet_service.h */