2 This file is part of GNUnet.
3 (C) 2009 Christian Grothoff (and other contributing authors)
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13 General Public License for more details.
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22 * @file include/gnunet_connection_lib.h
23 * @brief basic, low-level TCP networking interface
24 * @author Christian Grothoff
26 #ifndef GNUNET_CONNECTION_LIB_H
27 #define GNUNET_CONNECTION_LIB_H
32 #if 0 /* keep Emacsens' auto-indent happy */
37 #include "gnunet_network_lib.h"
38 #include "gnunet_scheduler_lib.h"
39 #include "gnunet_time_lib.h"
42 * Timeout we use on TCP connect before trying another
43 * result from the DNS resolver. Actual value used
44 * is this value divided by the number of address families.
47 #define GNUNET_CONNECTION_CONNECT_RETRY_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
50 * @brief handle for a network connection
52 struct GNUNET_CONNECTION_Handle;
56 * Credentials for UNIX domain sockets.
58 struct GNUNET_CONNECTION_Credentials
61 * UID of the other end of the connection.
66 * GID of the other end of the connection.
73 * Function to call for access control checks.
76 * @param ucred credentials, if available, otherwise NULL
78 * @param addrlen length of address
79 * @return GNUNET_YES to allow, GNUNET_NO to deny, GNUNET_SYSERR
80 * for unknown address family (will be denied).
82 typedef int (*GNUNET_CONNECTION_AccessCheck) (void *cls,
84 GNUNET_CONNECTION_Credentials *
86 const struct sockaddr * addr,
91 * Callback function for data received from the network. Note that
92 * both "available" and "err" would be 0 if the read simply timed out.
95 * @param buf pointer to received data
96 * @param available number of bytes availabe in "buf",
97 * possibly 0 (on errors)
98 * @param addr address of the sender
99 * @param addrlen size of addr
100 * @param errCode value of errno (on errors receiving)
102 typedef void (*GNUNET_CONNECTION_Receiver) (void *cls, const void *buf,
104 const struct sockaddr * addr,
105 socklen_t addrlen, int errCode);
108 * Set the persist option on this connection handle. Indicates
109 * that the underlying socket or fd should never really be closed.
110 * Used for indicating process death.
112 * @param connection the connection to set persistent
115 GNUNET_CONNECTION_persist_ (struct GNUNET_CONNECTION_Handle *connection);
118 * Disable the "CORK" feature for communication with the given socket,
119 * forcing the OS to immediately flush the buffer on transmission
120 * instead of potentially buffering multiple messages. Essentially
121 * reduces the OS send buffers to zero.
122 * Used to make sure that the last messages sent through the connection
123 * reach the other side before the process is terminated.
125 * @param connection the connection to make flushing and blocking
126 * @return #GNUNET_OK on success
129 GNUNET_CONNECTION_disable_corking (struct GNUNET_CONNECTION_Handle *connection);
133 * Create a connection handle by (asynchronously) connecting to a host.
134 * This function returns immediately, even if the connection has not
135 * yet been established. This function only creates TCP connections.
137 * @param s socket to connect
138 * @param serv_addr server address
139 * @param addrlen length of server address
140 * @return the connection handle
142 struct GNUNET_CONNECTION_Handle *
143 GNUNET_CONNECTION_connect_socket (struct GNUNET_NETWORK_Handle *s,
144 const struct sockaddr *serv_addr,
149 * Create a connection handle by boxing an existing OS socket. The OS
150 * socket should henceforth be no longer used directly.
151 * #GNUNET_CONNECTION_destroy() will close it.
153 * @param osSocket existing socket to box
154 * @return the boxed socket handle
156 struct GNUNET_CONNECTION_Handle *
157 GNUNET_CONNECTION_create_from_existing (struct GNUNET_NETWORK_Handle *osSocket);
161 * Create a connection handle by accepting on a listen socket. This
162 * function may block if the listen socket has no connection ready.
164 * @param access function to use to check if access is allowed
165 * @param access_cls closure for access
166 * @param lsock listen socket
167 * @return the connection handle, NULL on error (for example, access refused)
169 struct GNUNET_CONNECTION_Handle *
170 GNUNET_CONNECTION_create_from_accept (GNUNET_CONNECTION_AccessCheck access,
172 struct GNUNET_NETWORK_Handle *lsock);
176 * Create a connection handle by (asynchronously) connecting to a host.
177 * This function returns immediately, even if the connection has not
178 * yet been established. This function only creates TCP connections.
180 * @param cfg configuration to use
181 * @param hostname name of the host to connect to
182 * @param port port to connect to
183 * @return the connection handle
185 struct GNUNET_CONNECTION_Handle *
186 GNUNET_CONNECTION_create_from_connect (const struct GNUNET_CONFIGURATION_Handle
187 *cfg, const char *hostname,
192 * Create a connection handle by connecting to a UNIX domain service.
193 * This function returns immediately, even if the connection has not
194 * yet been established. This function only creates UNIX connections.
196 * @param cfg configuration to use
197 * @param unixpath path to connect to)
198 * @return the connection handle, NULL on systems without UNIX support
200 struct GNUNET_CONNECTION_Handle *
201 GNUNET_CONNECTION_create_from_connect_to_unixpath (const struct
202 GNUNET_CONFIGURATION_Handle
203 *cfg, const char *unixpath);
209 * Create a connection handle by (asynchronously) connecting to a host.
210 * This function returns immediately, even if the connection has not
211 * yet been established. This function only creates TCP connections.
213 * @param af_family address family to use
214 * @param serv_addr server address
215 * @param addrlen length of server address
216 * @return the connection handle
218 struct GNUNET_CONNECTION_Handle *
219 GNUNET_CONNECTION_create_from_sockaddr (int af_family,
220 const struct sockaddr *serv_addr,
224 * Check if connection is valid (no fatal errors have happened so far).
225 * Note that a connection that is still trying to connect is considered
228 * @param connection handle to check
229 * @return GNUNET_YES if valid, GNUNET_NO otherwise
232 GNUNET_CONNECTION_check (struct GNUNET_CONNECTION_Handle *connection);
236 * Obtain the network address of the other party.
238 * @param connection the client to get the address for
239 * @param addr where to store the address
240 * @param addrlen where to store the length of the address
241 * @return GNUNET_OK on success
244 GNUNET_CONNECTION_get_address (struct GNUNET_CONNECTION_Handle *connection,
245 void **addr, size_t * addrlen);
249 * Close the connection and free associated resources. There must
250 * not be any pending requests for reading or writing to the
251 * connection at this time.
253 * @param connection connection to destroy
256 GNUNET_CONNECTION_destroy (struct GNUNET_CONNECTION_Handle *connection);
260 * Receive data from the given connection. Note that this function will
261 * call "receiver" asynchronously using the scheduler. It will
262 * "immediately" return. Note that there MUST only be one active
263 * receive call per connection at any given point in time (so do not
264 * call receive again until the receiver callback has been invoked).
266 * @param connection connection handle
267 * @param max maximum number of bytes to read
268 * @param timeout maximum amount of time to wait
269 * @param receiver function to call with received data
270 * @param receiver_cls closure for receiver
273 GNUNET_CONNECTION_receive (struct GNUNET_CONNECTION_Handle *connection, size_t max,
274 struct GNUNET_TIME_Relative timeout,
275 GNUNET_CONNECTION_Receiver receiver,
280 * Cancel receive job on the given connection. Note that the
281 * receiver callback must not have been called yet in order
282 * for the cancellation to be valid.
284 * @param connection connection handle
285 * @return closure of the original receiver callback closure
288 GNUNET_CONNECTION_receive_cancel (struct GNUNET_CONNECTION_Handle *connection);
292 * Function called to notify a client about the connection begin ready
293 * to queue more data. @a buf will be NULL and @a size zero if the
294 * connection was closed for writing in the meantime.
297 * @param size number of bytes available in @a buf
298 * @param buf where the callee should write the message
299 * @return number of bytes written to @a buf
302 (*GNUNET_CONNECTION_TransmitReadyNotify) (void *cls,
308 * Opaque handle that can be used to cancel
309 * a transmit-ready notification.
311 struct GNUNET_CONNECTION_TransmitHandle;
314 * Ask the connection to call us once the specified number of bytes
315 * are free in the transmission buffer. Will never call the @a notify
316 * callback in this task, but always first go into the scheduler. Note that
317 * this function will abort if "size" is greater than
318 * #GNUNET_SERVER_MAX_MESSAGE_SIZE.
320 * Note that "notify" will be called either when enough
321 * buffer space is available OR when the connection is destroyed.
322 * The size parameter given to notify is guaranteed to be
323 * larger or equal to size if the buffer is ready, or zero
324 * if the connection was destroyed (or at least closed for
325 * writing). Finally, any time before 'notify' is called, a
326 * client may call "notify_transmit_ready_cancel" to cancel
327 * the transmission request.
329 * Only one transmission request can be scheduled at the same
330 * time. Notify will be run with the same scheduler priority
331 * as that of the caller.
333 * @param connection connection
334 * @param size number of bytes to send
335 * @param timeout after how long should we give up (and call
336 * notify with buf NULL and size 0)?
337 * @param notify function to call when buffer space is available
338 * @param notify_cls closure for notify
339 * @return non-NULL if the notify callback was queued,
340 * NULL if we are already going to notify someone else (busy)
342 struct GNUNET_CONNECTION_TransmitHandle *
343 GNUNET_CONNECTION_notify_transmit_ready (struct GNUNET_CONNECTION_Handle *connection,
345 struct GNUNET_TIME_Relative timeout,
346 GNUNET_CONNECTION_TransmitReadyNotify
347 notify, void *notify_cls);
351 * Cancel the specified transmission-ready
354 * @param th handle for notification to cancel
357 GNUNET_CONNECTION_notify_transmit_ready_cancel (struct
358 GNUNET_CONNECTION_TransmitHandle
363 #if 0 /* keep Emacsens' auto-indent happy */
371 /* ifndef GNUNET_CONNECTION_LIB_H */
373 /* end of gnunet_connection_lib.h */