2 This file is part of GNUnet.
3 (C) 2009 Christian Grothoff (and other contributing authors)
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12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
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17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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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 sock the connection to set persistent
114 void GNUNET_CONNECTION_persist_ (struct GNUNET_CONNECTION_Handle *sock);
117 * Disable the "CORK" feature for communication with the given socket,
118 * forcing the OS to immediately flush the buffer on transmission
119 * instead of potentially buffering multiple messages. Essentially
120 * reduces the OS send buffers to zero.
121 * Used to make sure that the last messages sent through the connection
122 * reach the other side before the process is terminated.
124 * @param sock the connection to make flushing and blocking
125 * @return GNUNET_OK on success
127 int GNUNET_CONNECTION_disable_corking (struct GNUNET_CONNECTION_Handle *sock);
131 * Create a socket handle by boxing an existing OS socket. The OS
132 * socket should henceforth be no longer used directly.
133 * GNUNET_socket_destroy will close it.
135 * @param osSocket existing socket to box
136 * @return the boxed socket handle
138 struct GNUNET_CONNECTION_Handle *GNUNET_CONNECTION_create_from_existing (struct
139 GNUNET_NETWORK_Handle
144 * Create a socket handle by accepting on a listen socket. This
145 * function may block if the listen socket has no connection ready.
147 * @param access function to use to check if access is allowed
148 * @param access_cls closure for access
149 * @param lsock listen socket
150 * @return the socket handle, NULL on error (for example, access refused)
152 struct GNUNET_CONNECTION_Handle
153 *GNUNET_CONNECTION_create_from_accept (GNUNET_CONNECTION_AccessCheck access,
155 struct GNUNET_NETWORK_Handle *lsock);
159 * Create a socket handle by (asynchronously) connecting to a host.
160 * This function returns immediately, even if the connection has not
161 * yet been established. This function only creates TCP connections.
163 * @param cfg configuration to use
164 * @param hostname name of the host to connect to
165 * @param port port to connect to
166 * @return the socket handle
168 struct GNUNET_CONNECTION_Handle *GNUNET_CONNECTION_create_from_connect (const
170 GNUNET_CONFIGURATION_Handle
180 * Create a socket handle by connecting to a UNIX domain service.
181 * This function returns immediately, even if the connection has not
182 * yet been established. This function only creates UNIX connections.
184 * @param cfg configuration to use
185 * @param unixpath path to connect to)
186 * @return the socket handle, NULL on systems without UNIX support
188 struct GNUNET_CONNECTION_Handle
189 *GNUNET_CONNECTION_create_from_connect_to_unixpath (const struct
190 GNUNET_CONFIGURATION_Handle
192 const char *unixpath);
198 * Create a socket handle by (asynchronously) connecting to a host.
199 * This function returns immediately, even if the connection has not
200 * yet been established. This function only creates TCP connections.
202 * @param af_family address family to use
203 * @param serv_addr server address
204 * @param addrlen length of server address
205 * @return the socket handle
207 struct GNUNET_CONNECTION_Handle *GNUNET_CONNECTION_create_from_sockaddr (int
217 * Check if socket is valid (no fatal errors have happened so far).
218 * Note that a socket that is still trying to connect is considered
221 * @param sock socket to check
222 * @return GNUNET_YES if valid, GNUNET_NO otherwise
224 int GNUNET_CONNECTION_check (struct GNUNET_CONNECTION_Handle *sock);
228 * Obtain the network address of the other party.
230 * @param sock the client to get the address for
231 * @param addr where to store the address
232 * @param addrlen where to store the length of the address
233 * @return GNUNET_OK on success
235 int GNUNET_CONNECTION_get_address (struct GNUNET_CONNECTION_Handle *sock,
236 void **addr, size_t * addrlen);
240 * Close the socket and free associated resources. Pending
241 * transmissions may be completed or dropped depending on the
242 * arguments. If a receive call is pending and should
243 * NOT be completed, 'GNUNET_CONNECTION_receive_cancel'
244 * should be called explicitly first.
246 * @param sock socket to destroy
247 * @param finish_pending_write should pending writes be completed or aborted?
248 * (this applies to transmissions where the data has already been
249 * read from the application; all other transmissions should be
250 * aborted using 'GNUNET_CONNECTION_notify_transmit_ready_cancel').
252 void GNUNET_CONNECTION_destroy (struct GNUNET_CONNECTION_Handle *sock,
253 int finish_pending_write);
257 * Receive data from the given socket. Note that this function will
258 * call "receiver" asynchronously using the scheduler. It will
259 * "immediately" return. Note that there MUST only be one active
260 * receive call per socket at any given point in time (so do not
261 * call receive again until the receiver callback has been invoked).
263 * @param sock socket handle
264 * @param max maximum number of bytes to read
265 * @param timeout maximum amount of time to wait
266 * @param receiver function to call with received data
267 * @param receiver_cls closure for receiver
269 void GNUNET_CONNECTION_receive (struct GNUNET_CONNECTION_Handle *sock,
270 size_t max, struct GNUNET_TIME_Relative timeout,
271 GNUNET_CONNECTION_Receiver receiver,
276 * Cancel receive job on the given socket. Note that the
277 * receiver callback must not have been called yet in order
278 * for the cancellation to be valid.
280 * @param sock socket handle
281 * @return closure of the original receiver callback closure
283 void *GNUNET_CONNECTION_receive_cancel (struct GNUNET_CONNECTION_Handle *sock);
287 * Function called to notify a client about the socket
288 * begin ready to queue more data. "buf" will be
289 * NULL and "size" zero if the socket was closed for
290 * writing in the meantime.
293 * @param size number of bytes available in buf
294 * @param buf where the callee should write the message
295 * @return number of bytes written to buf
297 typedef size_t (*GNUNET_CONNECTION_TransmitReadyNotify) (void *cls, size_t size,
302 * Opaque handle that can be used to cancel
303 * a transmit-ready notification.
305 struct GNUNET_CONNECTION_TransmitHandle;
308 * Ask the socket to call us once the specified number of bytes
309 * are free in the transmission buffer. May call the notify
310 * method immediately if enough space is available. Note that
311 * this function will abort if "size" is greater than
312 * GNUNET_SERVER_MAX_MESSAGE_SIZE.
314 * Note that "notify" will be called either when enough
315 * buffer space is available OR when the socket is destroyed.
316 * The size parameter given to notify is guaranteed to be
317 * larger or equal to size if the buffer is ready, or zero
318 * if the socket was destroyed (or at least closed for
319 * writing). Finally, any time before 'notify' is called, a
320 * client may call "notify_transmit_ready_cancel" to cancel
321 * the transmission request.
323 * Only one transmission request can be scheduled at the same
324 * time. Notify will be run with the same scheduler priority
325 * as that of the caller.
328 * @param size number of bytes to send
329 * @param timeout after how long should we give up (and call
330 * notify with buf NULL and size 0)?
331 * @param notify function to call when buffer space is available
332 * @param notify_cls closure for notify
333 * @return non-NULL if the notify callback was queued,
334 * NULL if we are already going to notify someone else (busy)
336 struct GNUNET_CONNECTION_TransmitHandle
337 *GNUNET_CONNECTION_notify_transmit_ready (struct GNUNET_CONNECTION_Handle
339 struct GNUNET_TIME_Relative
341 GNUNET_CONNECTION_TransmitReadyNotify
342 notify, void *notify_cls);
346 * Cancel the specified transmission-ready
349 * @param h handle for notification to cancel
351 void GNUNET_CONNECTION_notify_transmit_ready_cancel (struct
352 GNUNET_CONNECTION_TransmitHandle
357 * Configure this connection to ignore shutdown signals.
359 * @param sock socket handle
360 * @param do_ignore GNUNET_YES to ignore, GNUNET_NO to restore default
362 void GNUNET_CONNECTION_ignore_shutdown (struct GNUNET_CONNECTION_Handle *sock,
366 #if 0 /* keep Emacsens' auto-indent happy */
374 /* ifndef GNUNET_CONNECTION_LIB_H */
376 /* end of gnunet_connection_lib.h */