/*
This file is part of GNUnet.
- (C) 2011, Christian Grothoff (and other contributing authors)
+ (C) 2011, 2012 Christian Grothoff (and other contributing authors)
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
* @author Sree Harsha Totakura
*/
-#ifndef GNUNET_STREAM_LIB_H_
-#define GNUNET_STREAM_LIB_H_
+#ifndef GNUNET_STREAM_LIB_H
+#define GNUNET_STREAM_LIB_H
#ifdef __cplusplus
extern "C"
GNUNET_STREAM_TIMEOUT = 1,
/**
- * A serious error occured while operating of this stream
+ * Other side has shutdown the socket for this type of operation
+ * (reading/writing)
*/
- GNUNET_STREAM_SYSERR = 2
+ GNUNET_STREAM_SHUTDOWN = 2,
+
+ /**
+ * A serious error occured while operating on this stream
+ */
+ GNUNET_STREAM_SYSERR = 3,
+
+ /**
+ * An error resulted in an unusable stream
+ */
+ GNUNET_STREAM_BROKEN
};
/**
* Opaque handler for stream
*/
-struct GNUNET_STREAM_socket;
+struct GNUNET_STREAM_Socket;
/**
* Functions of this type will be called when a stream is established
*
* @param cls the closure from GNUNET_STREAM_open
+ * @param socket socket to use to communicate with the other side (read/write)
+ */
+typedef void (*GNUNET_STREAM_OpenCallback) (void *cls,
+ struct GNUNET_STREAM_Socket *socket);
+
+
+/**
+ * Callback for signalling stream listen success; See
+ * GNUNET_STREAM_OPTION_SIGNAL_LISTEN_SUCCESS
*/
-typedef void (*GNUNET_STREAM_OpenCallback) (void *cls);
+typedef void (*GNUNET_STREAM_ListenSuccessCallback) (void);
+
+
+/**
+ * Options for the stream.
+ */
+enum GNUNET_STREAM_Option
+ {
+ /**
+ * End of the option list.
+ */
+ GNUNET_STREAM_OPTION_END = 0,
+
+ /**
+ * Option to set the initial retransmission timeout (when do we retransmit
+ * a packet that did not yield an acknowledgement for the first time?).
+ * Repeated retransmissions will then use an exponential back-off.
+ * Takes a 'struct GNUNET_TIME_Relative' as the only argument. A value
+ * of '0' means to use the round-trip time (plus a tiny grace period);
+ * this is also the default.
+ */
+ GNUNET_STREAM_OPTION_INITIAL_RETRANSMIT_TIMEOUT,
+
+ /**
+ * Option to set the write sequence number. Takes a uint32_t as parameter
+ * to set the value of the write sequence number
+ */
+ GNUNET_STREAM_OPTION_TESTING_SET_WRITE_SEQUENCE_NUMBER,
+
+ /**
+ * Listen socket timeout in milliseconds given as uint32_t
+ */
+ GNUNET_STREAM_OPTION_LISTEN_TIMEOUT,
+
+ /**
+ * Option to register a callback when stream listening is
+ * successfull. Takes parameter of the form
+ * GNUNET_STREAM_ListenSuccessCallback. The callback is only called if
+ * listen is successful
+ */
+ GNUNET_STREAM_OPTION_SIGNAL_LISTEN_SUCCESS,
+
+ /**
+ * Option to set the maximum payload size in bytes of a stream data
+ * packets. Takes an uint16_t as argument. Note that this should be less
+ * than 64000 and cannot be zero. Default is 64000 bytes.
+ */
+ GNUNET_STREAM_OPTION_MAX_PAYLOAD_SIZE
+ };
+
/**
* Tries to open a stream to the target peer
*
- * @param cls the closure
+ * @param cfg configuration to use
* @param target the target peer to which the stream has to be opened
* @param app_port the application port number which uniquely identifies this
* stream
- * @param open_cb this function will be called after stream has be established
+ * @param open_cb this function will be called after stream has be established;
+ * cannot be NULL
+ * @param open_cb_cls the closure for open_cb
+ * @param ... options to the stream, terminated by GNUNET_STREAM_OPTION_END
* @return if successful it returns the stream socket; NULL if stream cannot be
* opened
*/
-struct GNUNET_STREAM_socket *
-GNUNET_STREAM_open (void *cls,
+struct GNUNET_STREAM_Socket *
+GNUNET_STREAM_open (const struct GNUNET_CONFIGURATION_Handle *cfg,
const struct GNUNET_PeerIdentity *target,
GNUNET_MESH_ApplicationType app_port,
- GNUNET_STREAM_OpenCallback open_cb);
+ GNUNET_STREAM_OpenCallback open_cb,
+ void *open_cb_cls,
+ ...);
+
+
+/**
+ * Handle for shutdown
+ */
+struct GNUNET_STREAM_ShutdownHandle;
+
+
+/**
+ * Completion callback for shutdown
+ *
+ * @param cls the closure from GNUNET_STREAM_shutdown call
+ * @param operation the operation that was shutdown (SHUT_RD, SHUT_WR,
+ * SHUT_RDWR)
+ */
+typedef void (*GNUNET_STREAM_ShutdownCompletion) (void *cls,
+ int operation);
+
+
+/**
+ * Shutdown the stream for reading or writing (similar to man 2 shutdown).
+ *
+ * @param socket the stream socket
+ * @param operation SHUT_RD, SHUT_WR or SHUT_RDWR
+ * @param completion_cb the callback that will be called upon successful
+ * shutdown of given operation
+ * @param completion_cls the closure for the completion callback
+ * @return the shutdown handle; NULL in case of any error
+ */
+struct GNUNET_STREAM_ShutdownHandle *
+GNUNET_STREAM_shutdown (struct GNUNET_STREAM_Socket *socket,
+ int operation,
+ GNUNET_STREAM_ShutdownCompletion completion_cb,
+ void *completion_cls);
+
+
+/**
+ * Cancels a pending shutdown
+ *
+ * @param handle the shutdown handle returned from GNUNET_STREAM_shutdown
+ */
+void
+GNUNET_STREAM_shutdown_cancel (struct GNUNET_STREAM_ShutdownHandle *handle);
+
+
+/**
+ * Closes the stream and frees the associated state. The stream should be
+ * shutdown before closing.
+ *
+ * @param socket the stream socket
+ */
+void
+GNUNET_STREAM_close (struct GNUNET_STREAM_Socket *socket);
+
/**
* Functions of this type are called upon new stream connection from other peers
*
* @param cls the closure from GNUNET_STREAM_listen
- * @param socket the socket representing the stream
+ * @param socket the socket representing the stream; NULL on binding error
* @param initiator the identity of the peer who wants to establish a stream
- * with us
+ * with us; NULL on binding error
* @return GNUNET_OK to keep the socket open, GNUNET_SYSERR to close the
* stream (the socket will be invalid after the call)
*/
typedef int (*GNUNET_STREAM_ListenCallback) (void *cls,
- struct GNUNET_STREAM_socket *socket,
+ struct GNUNET_STREAM_Socket *socket,
const struct
GNUNET_PeerIdentity *initiator);
+
+/**
+ * A socket for listening.
+ */
+struct GNUNET_STREAM_ListenSocket;
+
/**
* Listens for stream connections for a specific application ports
*
- * @param app_port the application port for which new streams will be accepted
+ * @param cfg the configuration to use
+ *
+ * @param app_port the application port for which new streams will be
+ * accepted. If another stream is listening on the same port the
+ * listen_cb will be called to signal binding error and the returned
+ * ListenSocket will be invalidated.
+ *
* @param listen_cb this function will be called when a peer tries to establish
* a stream with us
- * @return GNUNET_OK if we are listening, GNUNET_SYSERR for any error
+ * @param listen_cb_cls closure for listen_cb
+ * @param ... options to the stream, terminated by GNUNET_STREAM_OPTION_END
+ * @return listen socket, NULL for any error
*/
-int
-GNUNET_STREAM_listen (GNUNET_MESH_ApplicationType app_port,
+struct GNUNET_STREAM_ListenSocket *
+GNUNET_STREAM_listen (const struct GNUNET_CONFIGURATION_Handle *cfg,
+ GNUNET_MESH_ApplicationType app_port,
GNUNET_STREAM_ListenCallback listen_cb,
- void *cls);
+ void *listen_cb_cls,
+ ...);
+
/**
- * Functions of this signature are called whenever reading/writing operations
+ * Closes the listen socket
+ *
+ * @param lsocket the listen socket
+ */
+void
+GNUNET_STREAM_listen_close (struct GNUNET_STREAM_ListenSocket *lsocket);
+
+
+/**
+ * Functions of this signature are called whenever writing operations
* on a stream are executed
*
- * @param cls the closure from GNUNET_STREAM_write/read
+ * @param cls the closure from GNUNET_STREAM_write
* @param status the status of the stream at the time this function is called
- * @param size the number of bytes read or written
+ * @param size the number of bytes written
+ */
+typedef void (*GNUNET_STREAM_CompletionContinuation) (void *cls,
+ enum GNUNET_STREAM_Status
+ status,
+ size_t size);
+
+
+/**
+ * Handle to cancel IO write operations.
*/
-typedef void (*GNUNET_STREAM_CompletionCallback) (void *cls,
- enum GNUNET_STREAM_Status
- status,
- size_t size);
+struct GNUNET_STREAM_IOWriteHandle;
+
/**
- * Tries to write the given data to the stream
+ * Handle to cancel IO read operations.
+ */
+struct GNUNET_STREAM_IOReadHandle;
+
+/**
+ * Tries to write the given data to the stream. The maximum size of data that
+ * can be written as part of a write operation is (64 * (64000 - sizeof (struct
+ * GNUNET_STREAM_DataMessage))). If size is greater than this it is not an API
+ * violation, however only the said number of maximum bytes will be written.
*
* @param socket the socket representing a stream
* @param data the data buffer from where the data is written into the stream
* @param size the number of bytes to be written from the data buffer
- * @param write_cb the function to call upon writing some bytes into the stream
* @param timeout the timeout period
- * @param cls the closure
+ * @param write_cont the function to call upon writing some bytes into the
+ * stream
+ * @param write_cont_cls the closure
+ *
+ * @return handle to cancel the operation; if a previous write is pending or
+ * the stream has been shutdown for this operation then write_cont is
+ * immediately called and NULL is returned.
*/
-void
-GNUNET_STREAM_write (const struct GNUNET_STREAM_socket *socket,
- void *data,
+struct GNUNET_STREAM_IOWriteHandle *
+GNUNET_STREAM_write (struct GNUNET_STREAM_Socket *socket,
+ const void *data,
size_t size,
- GNUNET_STREAM_CompletionCallback write_cb,
struct GNUNET_TIME_Relative timeout,
- void *cls);
+ GNUNET_STREAM_CompletionContinuation write_cont,
+ void *write_cont_cls);
+
/**
- * Tries to read data from the stream
+ * Functions of this signature are called whenever data is available from the
+ * stream.
+ *
+ * @param cls the closure from GNUNET_STREAM_read
+ * @param status the status of the stream at the time this function is called
+ * @param data traffic from the other side
+ * @param size the number of bytes available in data read; will be 0 on timeout
+ * @return number of bytes of processed from 'data' (any data remaining should be
+ * given to the next time the read processor is called).
+ */
+typedef size_t (*GNUNET_STREAM_DataProcessor) (void *cls,
+ enum GNUNET_STREAM_Status status,
+ const void *data,
+ size_t size);
+
+
+/**
+ * Tries to read data from the stream.
*
* @param socket the socket representing a stream
- * @param buffer the buffer into which the read data is stored
- * @param size the number of bytes that are to be read
- * @param read_cb the completion callback function which is called after
- * attempting to read size number of bytes from the stream
* @param timeout the timeout period
- * @param cls the closure
+ * @param proc function to call with data (once only)
+ * @param proc_cls the closure for proc
+ *
+ * @return handle to cancel the operation; if the stream has been shutdown for
+ * this type of opeartion then the DataProcessor is immediately
+ * called with GNUNET_STREAM_SHUTDOWN as status and NULL if returned
*/
-void
-GNUNET_STREAM_read (const struct GNUNET_STREAM_socket *socket,
- void *buffer,
- size_t size,
- GNUNET_STREAM_CompletionCallback read_cb,
+struct GNUNET_STREAM_IOReadHandle *
+GNUNET_STREAM_read (struct GNUNET_STREAM_Socket *socket,
struct GNUNET_TIME_Relative timeout,
- void *cls);
+ GNUNET_STREAM_DataProcessor proc,
+ void *proc_cls);
+
+
/**
- * Closes the stream
+ * Cancels pending write operation. Also cancels packet retransmissions which
+ * may have resulted otherwise.
*
- * @param socket the stream socket
+ * CAUTION: Normally a write operation is considered successful if the data
+ * given to it is sent and acknowledged by the receiver. As data is divided
+ * into packets, it is possible that not all packets are received by the
+ * receiver. Any missing packets are then retransmitted till the receiver
+ * acknowledges all packets or until a timeout . During this scenario if the
+ * write operation is cancelled all such retransmissions are also
+ * cancelled. This may leave the receiver's receive buffer incompletely filled
+ * as some missing packets are never retransmitted. So this operation should be
+ * used before shutting down transmission from our side or before closing the
+ * socket.
+ *
+ * @param ioh handle to operation to cancel
*/
void
-GNUNET_STREAM_close (struct GNUNET_STREAM_socket *socket);
+GNUNET_STREAM_io_write_cancel (struct GNUNET_STREAM_IOWriteHandle *iowh);
+
+
+/**
+ * Cancel pending read operation.
+ *
+ * @param ioh handle to operation to cancel
+ */
+void
+GNUNET_STREAM_io_read_cancel (struct GNUNET_STREAM_IOReadHandle *iorh);
+
#if 0
{
}
#endif
-#endif
+#endif /* STREAM_PROTOCOL_H */
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