2 This file is part of GNUnet.
3 (C) 2011, 2012 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
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
69 * Opaque handler for stream
71 struct GNUNET_STREAM_Socket;
74 * Functions of this type will be called when a stream is established
76 * @param cls the closure from GNUNET_STREAM_open
77 * @param socket socket to use to communicate with the other side (read/write)
79 typedef void (*GNUNET_STREAM_OpenCallback) (void *cls,
80 struct GNUNET_STREAM_Socket *socket);
84 * Options for the stream.
86 enum GNUNET_STREAM_Option
89 * End of the option list.
91 GNUNET_STREAM_OPTION_END = 0,
94 * Option to set the initial retransmission timeout (when do we retransmit
95 * a packet that did not yield an acknowledgement for the first time?).
96 * Repeated retransmissions will then use an exponential back-off.
97 * Takes a 'struct GNUNET_TIME_Relative' as the only argument. A value
98 * of '0' means to use the round-trip time (plus a tiny grace period);
99 * this is also the default.
101 GNUNET_STREAM_OPTION_INITIAL_RETRANSMIT_TIMEOUT
106 * Tries to open a stream to the target peer
108 * @param cfg configuration to use
109 * @param target the target peer to which the stream has to be opened
110 * @param app_port the application port number which uniquely identifies this
112 * @param open_cb this function will be called after stream has be established
113 * @param open_cb_cls the closure for open_cb
114 * @param ... options to the stream, terminated by GNUNET_STREAM_OPTION_END
115 * @return if successful it returns the stream socket; NULL if stream cannot be
118 struct GNUNET_STREAM_Socket *
119 GNUNET_STREAM_open (const struct GNUNET_CONFIGURATION_Handle *cfg,
120 const struct GNUNET_PeerIdentity *target,
121 GNUNET_MESH_ApplicationType app_port,
122 GNUNET_STREAM_OpenCallback open_cb,
128 * Handle for shutdown
130 struct GNUNET_STREAM_ShutdownHandle;
134 * Shutdown the stream for reading or writing (man 2 shutdown).
136 * @param socket the stream socket
137 * @param how SHUT_RD, SHUT_WR or SHUT_RDWR
138 * @return the shutdown handle
140 struct GNUNET_STREAM_ShutdownHandle *
141 GNUNET_STREAM_shutdown (struct GNUNET_STREAM_Socket *socket,
146 * Cancels a pending shutdown
148 * @param the shutdown handle returned from GNUNET_STREAM_shutdown
151 GNUNET_STREAM_shutdown_cancel (struct GNUNET_STREAM_ShutdownHandle *handle);
155 * Closes the stream and frees the associated state. The stream should be
156 * shutdown before closing.
158 * @param socket the stream socket
161 GNUNET_STREAM_close (struct GNUNET_STREAM_Socket *socket);
165 * Functions of this type are called upon new stream connection from other peers
167 * @param cls the closure from GNUNET_STREAM_listen
168 * @param socket the socket representing the stream
169 * @param initiator the identity of the peer who wants to establish a stream
171 * @return GNUNET_OK to keep the socket open, GNUNET_SYSERR to close the
172 * stream (the socket will be invalid after the call)
174 typedef int (*GNUNET_STREAM_ListenCallback) (void *cls,
175 struct GNUNET_STREAM_Socket *socket,
177 GNUNET_PeerIdentity *initiator);
181 * A socket for listening.
183 struct GNUNET_STREAM_ListenSocket;
186 * Listens for stream connections for a specific application ports
188 * @param cfg the configuration to use
189 * @param app_port the application port for which new streams will be accepted
190 * @param listen_cb this function will be called when a peer tries to establish
192 * @param listen_cb_cls closure for listen_cb
193 * @return listen socket, NULL for any error
195 struct GNUNET_STREAM_ListenSocket *
196 GNUNET_STREAM_listen (const struct GNUNET_CONFIGURATION_Handle *cfg,
197 GNUNET_MESH_ApplicationType app_port,
198 GNUNET_STREAM_ListenCallback listen_cb,
199 void *listen_cb_cls);
203 * Closes the listen socket
205 * @param lsocket the listen socket
208 GNUNET_STREAM_listen_close (struct GNUNET_STREAM_ListenSocket *lsocket);
212 * Functions of this signature are called whenever writing operations
213 * on a stream are executed
215 * @param cls the closure from GNUNET_STREAM_write
216 * @param status the status of the stream at the time this function is called
217 * @param size the number of bytes written
219 typedef void (*GNUNET_STREAM_CompletionContinuation) (void *cls,
220 enum GNUNET_STREAM_Status
226 * Handle to cancel IO write operations.
228 struct GNUNET_STREAM_IOWriteHandle;
232 * Handle to cancel IO read operations.
234 struct GNUNET_STREAM_IOReadHandle;
237 * Tries to write the given data to the stream. The maximum size of data that
238 * can be written as part of a write operation is (64 * (64000 - sizeof (struct
239 * GNUNET_STREAM_DataMessage))). If size is greater than this it is not an API
240 * violation, however only the said number of maximum bytes will be written.
242 * @param socket the socket representing a stream
243 * @param data the data buffer from where the data is written into the stream
244 * @param size the number of bytes to be written from the data buffer
245 * @param timeout the timeout period
246 * @param write_cont the function to call upon writing some bytes into the
248 * @param write_cont_cls the closure
249 * @return handle to cancel the operation; NULL if a previous write is pending
251 struct GNUNET_STREAM_IOWriteHandle *
252 GNUNET_STREAM_write (struct GNUNET_STREAM_Socket *socket,
255 struct GNUNET_TIME_Relative timeout,
256 GNUNET_STREAM_CompletionContinuation write_cont,
257 void *write_cont_cls);
261 * Functions of this signature are called whenever data is available from the
264 * @param cls the closure from GNUNET_STREAM_read
265 * @param status the status of the stream at the time this function is called
266 * @param data traffic from the other side
267 * @param size the number of bytes available in data read; will be 0 on timeout
268 * @return number of bytes of processed from 'data' (any data remaining should be
269 * given to the next time the read processor is called).
271 typedef size_t (*GNUNET_STREAM_DataProcessor) (void *cls,
272 enum GNUNET_STREAM_Status status,
278 * Tries to read data from the stream
280 * @param socket the socket representing a stream
281 * @param timeout the timeout period
282 * @param proc function to call with data (once only)
283 * @param proc_cls the closure for proc
284 * @return handle to cancel the operation
286 struct GNUNET_STREAM_IOReadHandle *
287 GNUNET_STREAM_read (struct GNUNET_STREAM_Socket *socket,
288 struct GNUNET_TIME_Relative timeout,
289 GNUNET_STREAM_DataProcessor proc,
294 * Cancels pending write operation. Also cancels packet retransmissions which
295 * may have resulted otherwise.
297 * CAUTION: Normally a write operation is considered successful if the data
298 * given to it is sent and acknowledged by the receiver. As data is divided
299 * into packets, it is possible that not all packets are received by the
300 * receiver. Any missing packets are then retransmitted till the receiver
301 * acknowledges all packets or until a timeout . During this scenario if the
302 * write operation is cancelled all such retransmissions are also
303 * cancelled. This may leave the receiver's receive buffer incompletely filled
304 * as some missing packets are never retransmitted. So this operation should be
305 * used before shutting down transmission from our side or before closing the
308 * @param ioh handle to operation to cancel
311 GNUNET_STREAM_io_write_cancel (struct GNUNET_STREAM_IOWriteHandle *iowh);
315 * Cancel pending read operation.
317 * @param ioh handle to operation to cancel
320 GNUNET_STREAM_io_read_cancel (struct GNUNET_STREAM_IOReadHandle *iorh);
330 #endif /* STREAM_PROTOCOL_H */