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22 * @file include/gnunet_stream_lib.h
23 * @brief stream handling using mesh API
24 * @author Sree Harsha Totakura
27 #ifndef GNUNET_STREAM_LIB_H
28 #define GNUNET_STREAM_LIB_H
38 #include "gnunet_util_lib.h"
39 #include "gnunet_mesh_service.h"
44 enum GNUNET_STREAM_Status
47 * All previous read/write operations are successfully done
52 * A timeout occured while reading/writing the stream
54 GNUNET_STREAM_TIMEOUT = 1,
57 * Other side has shutdown the socket for this type of operation
60 GNUNET_STREAM_SHUTDOWN = 2,
63 * A serious error occured while operating on this stream
65 GNUNET_STREAM_SYSERR = 3,
68 * An error resulted in an unusable stream
74 * Opaque handler for stream
76 struct GNUNET_STREAM_Socket;
79 * Functions of this type will be called when a stream is established
81 * @param cls the closure from GNUNET_STREAM_open
82 * @param socket socket to use to communicate with the other side (read/write)
84 typedef void (*GNUNET_STREAM_OpenCallback) (void *cls,
85 struct GNUNET_STREAM_Socket *socket);
89 * Callback for signalling stream listen success; See
90 * GNUNET_STREAM_OPTION_SIGNAL_LISTEN_SUCCESS
92 typedef void (*GNUNET_STREAM_ListenSuccessCallback) (void);
96 * Options for the stream.
98 enum GNUNET_STREAM_Option
101 * End of the option list.
103 GNUNET_STREAM_OPTION_END = 0,
106 * Option to set the initial retransmission timeout (when do we retransmit
107 * a packet that did not yield an acknowledgement for the first time?).
108 * Repeated retransmissions will then use an exponential back-off.
109 * Takes a 'struct GNUNET_TIME_Relative' as the only argument. A value
110 * of '0' means to use the round-trip time (plus a tiny grace period);
111 * this is also the default.
113 GNUNET_STREAM_OPTION_INITIAL_RETRANSMIT_TIMEOUT,
116 * Option to set the write sequence number. Takes a uint32_t as parameter
117 * to set the value of the write sequence number
119 GNUNET_STREAM_OPTION_TESTING_SET_WRITE_SEQUENCE_NUMBER,
122 * Listen socket timeout in milliseconds given as uint32_t
124 GNUNET_STREAM_OPTION_LISTEN_TIMEOUT,
127 * Option to register a callback when stream listening is
128 * successfull. Takes parameter of the form
129 * GNUNET_STREAM_ListenSuccessCallback. The callback is only called if
130 * listen is successful
132 GNUNET_STREAM_OPTION_SIGNAL_LISTEN_SUCCESS
137 * Tries to open a stream to the target peer
139 * @param cfg configuration to use
140 * @param target the target peer to which the stream has to be opened
141 * @param app_port the application port number which uniquely identifies this
143 * @param open_cb this function will be called after stream has be established;
145 * @param open_cb_cls the closure for open_cb
146 * @param ... options to the stream, terminated by GNUNET_STREAM_OPTION_END
147 * @return if successful it returns the stream socket; NULL if stream cannot be
150 struct GNUNET_STREAM_Socket *
151 GNUNET_STREAM_open (const struct GNUNET_CONFIGURATION_Handle *cfg,
152 const struct GNUNET_PeerIdentity *target,
153 GNUNET_MESH_ApplicationType app_port,
154 GNUNET_STREAM_OpenCallback open_cb,
160 * Handle for shutdown
162 struct GNUNET_STREAM_ShutdownHandle;
166 * Completion callback for shutdown
168 * @param cls the closure from GNUNET_STREAM_shutdown call
169 * @param operation the operation that was shutdown (SHUT_RD, SHUT_WR,
172 typedef void (*GNUNET_STREAM_ShutdownCompletion) (void *cls,
177 * Shutdown the stream for reading or writing (similar to man 2 shutdown).
179 * @param socket the stream socket
180 * @param operation SHUT_RD, SHUT_WR or SHUT_RDWR
181 * @param completion_cb the callback that will be called upon successful
182 * shutdown of given operation
183 * @param completion_cls the closure for the completion callback
184 * @return the shutdown handle; NULL in case of any error
186 struct GNUNET_STREAM_ShutdownHandle *
187 GNUNET_STREAM_shutdown (struct GNUNET_STREAM_Socket *socket,
189 GNUNET_STREAM_ShutdownCompletion completion_cb,
190 void *completion_cls);
194 * Cancels a pending shutdown
196 * @param handle the shutdown handle returned from GNUNET_STREAM_shutdown
199 GNUNET_STREAM_shutdown_cancel (struct GNUNET_STREAM_ShutdownHandle *handle);
203 * Closes the stream and frees the associated state. The stream should be
204 * shutdown before closing.
206 * @param socket the stream socket
209 GNUNET_STREAM_close (struct GNUNET_STREAM_Socket *socket);
213 * Functions of this type are called upon new stream connection from other peers
215 * @param cls the closure from GNUNET_STREAM_listen
216 * @param socket the socket representing the stream; NULL on binding error
217 * @param initiator the identity of the peer who wants to establish a stream
218 * with us; NULL on binding error
219 * @return GNUNET_OK to keep the socket open, GNUNET_SYSERR to close the
220 * stream (the socket will be invalid after the call)
222 typedef int (*GNUNET_STREAM_ListenCallback) (void *cls,
223 struct GNUNET_STREAM_Socket *socket,
225 GNUNET_PeerIdentity *initiator);
229 * A socket for listening.
231 struct GNUNET_STREAM_ListenSocket;
234 * Listens for stream connections for a specific application ports
236 * @param cfg the configuration to use
238 * @param app_port the application port for which new streams will be
239 * accepted. If another stream is listening on the same port the
240 * listen_cb will be called to signal binding error and the returned
241 * ListenSocket will be invalidated.
243 * @param listen_cb this function will be called when a peer tries to establish
245 * @param listen_cb_cls closure for listen_cb
246 * @param ... options to the stream, terminated by GNUNET_STREAM_OPTION_END
247 * @return listen socket, NULL for any error
249 struct GNUNET_STREAM_ListenSocket *
250 GNUNET_STREAM_listen (const struct GNUNET_CONFIGURATION_Handle *cfg,
251 GNUNET_MESH_ApplicationType app_port,
252 GNUNET_STREAM_ListenCallback listen_cb,
258 * Closes the listen socket
260 * @param lsocket the listen socket
263 GNUNET_STREAM_listen_close (struct GNUNET_STREAM_ListenSocket *lsocket);
267 * Functions of this signature are called whenever writing operations
268 * on a stream are executed
270 * @param cls the closure from GNUNET_STREAM_write
271 * @param status the status of the stream at the time this function is called
272 * @param size the number of bytes written
274 typedef void (*GNUNET_STREAM_CompletionContinuation) (void *cls,
275 enum GNUNET_STREAM_Status
281 * Handle to cancel IO write operations.
283 struct GNUNET_STREAM_IOWriteHandle;
287 * Handle to cancel IO read operations.
289 struct GNUNET_STREAM_IOReadHandle;
292 * Tries to write the given data to the stream. The maximum size of data that
293 * can be written as part of a write operation is (64 * (64000 - sizeof (struct
294 * GNUNET_STREAM_DataMessage))). If size is greater than this it is not an API
295 * violation, however only the said number of maximum bytes will be written.
297 * @param socket the socket representing a stream
298 * @param data the data buffer from where the data is written into the stream
299 * @param size the number of bytes to be written from the data buffer
300 * @param timeout the timeout period
301 * @param write_cont the function to call upon writing some bytes into the
303 * @param write_cont_cls the closure
305 * @return handle to cancel the operation; if a previous write is pending or
306 * the stream has been shutdown for this operation then write_cont is
307 * immediately called and NULL is returned.
309 struct GNUNET_STREAM_IOWriteHandle *
310 GNUNET_STREAM_write (struct GNUNET_STREAM_Socket *socket,
313 struct GNUNET_TIME_Relative timeout,
314 GNUNET_STREAM_CompletionContinuation write_cont,
315 void *write_cont_cls);
319 * Functions of this signature are called whenever data is available from the
322 * @param cls the closure from GNUNET_STREAM_read
323 * @param status the status of the stream at the time this function is called
324 * @param data traffic from the other side
325 * @param size the number of bytes available in data read; will be 0 on timeout
326 * @return number of bytes of processed from 'data' (any data remaining should be
327 * given to the next time the read processor is called).
329 typedef size_t (*GNUNET_STREAM_DataProcessor) (void *cls,
330 enum GNUNET_STREAM_Status status,
336 * Tries to read data from the stream.
338 * @param socket the socket representing a stream
339 * @param timeout the timeout period
340 * @param proc function to call with data (once only)
341 * @param proc_cls the closure for proc
343 * @return handle to cancel the operation; if the stream has been shutdown for
344 * this type of opeartion then the DataProcessor is immediately
345 * called with GNUNET_STREAM_SHUTDOWN as status and NULL if returned
347 struct GNUNET_STREAM_IOReadHandle *
348 GNUNET_STREAM_read (struct GNUNET_STREAM_Socket *socket,
349 struct GNUNET_TIME_Relative timeout,
350 GNUNET_STREAM_DataProcessor proc,
355 * Cancels pending write operation. Also cancels packet retransmissions which
356 * may have resulted otherwise.
358 * CAUTION: Normally a write operation is considered successful if the data
359 * given to it is sent and acknowledged by the receiver. As data is divided
360 * into packets, it is possible that not all packets are received by the
361 * receiver. Any missing packets are then retransmitted till the receiver
362 * acknowledges all packets or until a timeout . During this scenario if the
363 * write operation is cancelled all such retransmissions are also
364 * cancelled. This may leave the receiver's receive buffer incompletely filled
365 * as some missing packets are never retransmitted. So this operation should be
366 * used before shutting down transmission from our side or before closing the
369 * @param ioh handle to operation to cancel
372 GNUNET_STREAM_io_write_cancel (struct GNUNET_STREAM_IOWriteHandle *iowh);
376 * Cancel pending read operation.
378 * @param ioh handle to operation to cancel
381 GNUNET_STREAM_io_read_cancel (struct GNUNET_STREAM_IOReadHandle *iorh);
391 #endif /* STREAM_PROTOCOL_H */