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,
83 const struct GNUNET_CONNECTION_Credentials *ucred,
84 const struct sockaddr * addr,
89 * Callback function for data received from the network. Note that
90 * both "available" and "err" would be 0 if the read simply timed out.
93 * @param buf pointer to received data
94 * @param available number of bytes availabe in "buf",
95 * possibly 0 (on errors)
96 * @param addr address of the sender
97 * @param addrlen size of addr
98 * @param errCode value of errno (on errors receiving)
100 typedef void (*GNUNET_CONNECTION_Receiver) (void *cls,
103 const struct sockaddr * addr,
104 socklen_t addrlen, int errCode);
107 * Set the persist option on this connection handle. Indicates
108 * that the underlying socket or fd should never really be closed.
109 * Used for indicating process death.
111 * @param sock the connection to set persistent
114 GNUNET_CONNECTION_persist_(struct GNUNET_CONNECTION_Handle *sock);
117 * Create a socket handle by boxing an existing OS socket. The OS
118 * socket should henceforth be no longer used directly.
119 * GNUNET_socket_destroy will close it.
121 * @param osSocket existing socket to box
122 * @return the boxed socket handle
124 struct GNUNET_CONNECTION_Handle
125 *GNUNET_CONNECTION_create_from_existing (struct
126 GNUNET_NETWORK_Handle
131 * Create a socket handle by accepting on a listen socket. This
132 * function may block if the listen socket has no connection ready.
134 * @param access function to use to check if access is allowed
135 * @param access_cls closure for access
136 * @param lsock listen socket
137 * @return the socket handle, NULL on error (for example, access refused)
139 struct GNUNET_CONNECTION_Handle
140 *GNUNET_CONNECTION_create_from_accept (GNUNET_CONNECTION_AccessCheck
141 access, void *access_cls,
143 GNUNET_NETWORK_Handle
148 * Create a socket handle by (asynchronously) connecting to a host.
149 * This function returns immediately, even if the connection has not
150 * yet been established. This function only creates TCP connections.
152 * @param cfg configuration to use
153 * @param hostname name of the host to connect to
154 * @param port port to connect to
155 * @return the socket handle
157 struct GNUNET_CONNECTION_Handle
158 *GNUNET_CONNECTION_create_from_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
159 const char *hostname,
164 * Create a socket handle by connecting to a UNIX domain service.
165 * This function returns immediately, even if the connection has not
166 * yet been established. This function only creates UNIX connections.
168 * @param cfg configuration to use
169 * @param unixpath path to connect to)
170 * @return the socket handle, NULL on systems without UNIX support
172 struct GNUNET_CONNECTION_Handle *
173 GNUNET_CONNECTION_create_from_connect_to_unixpath (const struct
174 GNUNET_CONFIGURATION_Handle *cfg,
175 const char *unixpath);
181 * Create a socket handle by (asynchronously) connecting to a host.
182 * This function returns immediately, even if the connection has not
183 * yet been established. This function only creates TCP connections.
185 * @param af_family address family to use
186 * @param serv_addr server address
187 * @param addrlen length of server address
188 * @return the socket handle
190 struct GNUNET_CONNECTION_Handle
191 *GNUNET_CONNECTION_create_from_sockaddr (int af_family,
192 const struct sockaddr
197 * Check if socket is valid (no fatal errors have happened so far).
198 * Note that a socket that is still trying to connect is considered
201 * @param sock socket to check
202 * @return GNUNET_YES if valid, GNUNET_NO otherwise
204 int GNUNET_CONNECTION_check (struct GNUNET_CONNECTION_Handle
209 * Obtain the network address of the other party.
211 * @param sock the client to get the address for
212 * @param addr where to store the address
213 * @param addrlen where to store the length of the address
214 * @return GNUNET_OK on success
216 int GNUNET_CONNECTION_get_address (struct
217 GNUNET_CONNECTION_Handle
223 * Close the socket and free associated resources. Pending
224 * transmissions may be completed or dropped depending on the
225 * arguments. If a receive call is pending and should
226 * NOT be completed, 'GNUNET_CONNECTION_receive_cancel'
227 * should be called explicitly first.
229 * @param sock socket to destroy
230 * @param finish_pending_write should pending writes be completed or aborted?
231 * (this applies to transmissions where the data has already been
232 * read from the application; all other transmissions should be
233 * aborted using 'GNUNET_CONNECTION_notify_transmit_ready_cancel').
236 GNUNET_CONNECTION_destroy (struct GNUNET_CONNECTION_Handle *sock,
237 int finish_pending_write);
241 * Receive data from the given socket. Note that this function will
242 * call "receiver" asynchronously using the scheduler. It will
243 * "immediately" return. Note that there MUST only be one active
244 * receive call per socket at any given point in time (so do not
245 * call receive again until the receiver callback has been invoked).
247 * @param sock socket handle
248 * @param max maximum number of bytes to read
249 * @param timeout maximum amount of time to wait
250 * @param receiver function to call with received data
251 * @param receiver_cls closure for receiver
254 GNUNET_CONNECTION_receive (struct GNUNET_CONNECTION_Handle
256 struct GNUNET_TIME_Relative timeout,
257 GNUNET_CONNECTION_Receiver receiver,
262 * Cancel receive job on the given socket. Note that the
263 * receiver callback must not have been called yet in order
264 * for the cancellation to be valid.
266 * @param sock socket handle
267 * @return closure of the original receiver callback closure
269 void *GNUNET_CONNECTION_receive_cancel (struct
270 GNUNET_CONNECTION_Handle
275 * Function called to notify a client about the socket
276 * begin ready to queue more data. "buf" will be
277 * NULL and "size" zero if the socket was closed for
278 * writing in the meantime.
281 * @param size number of bytes available in buf
282 * @param buf where the callee should write the message
283 * @return number of bytes written to buf
285 typedef size_t (*GNUNET_CONNECTION_TransmitReadyNotify) (void *cls,
286 size_t size, void *buf);
290 * Opaque handle that can be used to cancel
291 * a transmit-ready notification.
293 struct GNUNET_CONNECTION_TransmitHandle;
296 * Ask the socket to call us once the specified number of bytes
297 * are free in the transmission buffer. May call the notify
298 * method immediately if enough space is available. Note that
299 * this function will abort if "size" is greater than
300 * GNUNET_SERVER_MAX_MESSAGE_SIZE.
302 * Note that "notify" will be called either when enough
303 * buffer space is available OR when the socket is destroyed.
304 * The size parameter given to notify is guaranteed to be
305 * larger or equal to size if the buffer is ready, or zero
306 * if the socket was destroyed (or at least closed for
307 * writing). Finally, any time before 'notify' is called, a
308 * client may call "notify_transmit_ready_cancel" to cancel
309 * the transmission request.
311 * Only one transmission request can be scheduled at the same
312 * time. Notify will be run with the same scheduler priority
313 * as that of the caller.
316 * @param size number of bytes to send
317 * @param timeout after how long should we give up (and call
318 * notify with buf NULL and size 0)?
319 * @param notify function to call when buffer space is available
320 * @param notify_cls closure for notify
321 * @return non-NULL if the notify callback was queued,
322 * NULL if we are already going to notify someone else (busy)
324 struct GNUNET_CONNECTION_TransmitHandle
325 *GNUNET_CONNECTION_notify_transmit_ready (struct
326 GNUNET_CONNECTION_Handle
331 GNUNET_CONNECTION_TransmitReadyNotify
332 notify, void *notify_cls);
336 * Cancel the specified transmission-ready
339 * @param h handle for notification to cancel
342 GNUNET_CONNECTION_notify_transmit_ready_cancel (struct
343 GNUNET_CONNECTION_TransmitHandle
348 * Configure this connection to ignore shutdown signals.
350 * @param sock socket handle
351 * @param do_ignore GNUNET_YES to ignore, GNUNET_NO to restore default
354 GNUNET_CONNECTION_ignore_shutdown (struct GNUNET_CONNECTION_Handle *sock,
358 #if 0 /* keep Emacsens' auto-indent happy */
366 /* ifndef GNUNET_CONNECTION_LIB_H */
368 /* end of gnunet_connection_lib.h */