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- /*
- This file is part of GNUnet.
- (C) 2009 Christian Grothoff (and other contributing authors)
- GNUnet is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published
- by the Free Software Foundation; either version 3, or (at your
- option) any later version.
- GNUnet is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with GNUnet; see the file COPYING. If not, write to the
- Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA.
- */
- /**
- * @file include/gnunet_connection_lib.h
- * @brief basic, low-level TCP networking interface
- * @author Christian Grothoff
- */
- #ifndef GNUNET_CONNECTION_LIB_H
- #define GNUNET_CONNECTION_LIB_H
- #ifdef __cplusplus
- extern "C"
- {
- #if 0 /* keep Emacsens' auto-indent happy */
- }
- #endif
- #endif
- #include "gnunet_network_lib.h"
- #include "gnunet_scheduler_lib.h"
- #include "gnunet_time_lib.h"
- /**
- * Timeout we use on TCP connect before trying another
- * result from the DNS resolver. Actual value used
- * is this value divided by the number of address families.
- * Default is 5s.
- */
- #define GNUNET_CONNECTION_CONNECT_RETRY_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
- /**
- * @brief handle for a network connection
- */
- struct GNUNET_CONNECTION_Handle;
- /**
- * Credentials for UNIX domain sockets.
- */
- struct GNUNET_CONNECTION_Credentials
- {
- /**
- * UID of the other end of the connection.
- */
- uid_t uid;
- /**
- * GID of the other end of the connection.
- */
- gid_t gid;
- };
- /**
- * Function to call for access control checks.
- *
- * @param cls closure
- * @param ucred credentials, if available, otherwise NULL
- * @param addr address
- * @param addrlen length of address
- * @return GNUNET_YES to allow, GNUNET_NO to deny, GNUNET_SYSERR
- * for unknown address family (will be denied).
- */
- typedef int (*GNUNET_CONNECTION_AccessCheck) (void *cls,
- const struct
- GNUNET_CONNECTION_Credentials *
- ucred,
- const struct sockaddr * addr,
- socklen_t addrlen);
- /**
- * Callback function for data received from the network. Note that
- * both "available" and "err" would be 0 if the read simply timed out.
- *
- * @param cls closure
- * @param buf pointer to received data
- * @param available number of bytes availabe in "buf",
- * possibly 0 (on errors)
- * @param addr address of the sender
- * @param addrlen size of addr
- * @param errCode value of errno (on errors receiving)
- */
- typedef void (*GNUNET_CONNECTION_Receiver) (void *cls, const void *buf,
- size_t available,
- const struct sockaddr * addr,
- socklen_t addrlen, int errCode);
- /**
- * Set the persist option on this connection handle. Indicates
- * that the underlying socket or fd should never really be closed.
- * Used for indicating process death.
- *
- * @param connection the connection to set persistent
- */
- void
- GNUNET_CONNECTION_persist_ (struct GNUNET_CONNECTION_Handle *connection);
- /**
- * Disable the "CORK" feature for communication with the given socket,
- * forcing the OS to immediately flush the buffer on transmission
- * instead of potentially buffering multiple messages. Essentially
- * reduces the OS send buffers to zero.
- * Used to make sure that the last messages sent through the connection
- * reach the other side before the process is terminated.
- *
- * @param connection the connection to make flushing and blocking
- * @return #GNUNET_OK on success
- */
- int
- GNUNET_CONNECTION_disable_corking (struct GNUNET_CONNECTION_Handle *connection);
- /**
- * Create a connection handle by (asynchronously) connecting to a host.
- * This function returns immediately, even if the connection has not
- * yet been established. This function only creates TCP connections.
- *
- * @param s socket to connect
- * @param serv_addr server address
- * @param addrlen length of server address
- * @return the connection handle
- */
- struct GNUNET_CONNECTION_Handle *
- GNUNET_CONNECTION_connect_socket (struct GNUNET_NETWORK_Handle *s,
- const struct sockaddr *serv_addr,
- socklen_t addrlen);
- /**
- * Create a connection handle by boxing an existing OS socket. The OS
- * socket should henceforth be no longer used directly.
- * #GNUNET_CONNECTION_destroy() will close it.
- *
- * @param osSocket existing socket to box
- * @return the boxed socket handle
- */
- struct GNUNET_CONNECTION_Handle *
- GNUNET_CONNECTION_create_from_existing (struct GNUNET_NETWORK_Handle *osSocket);
- /**
- * Create a connection handle by accepting on a listen socket. This
- * function may block if the listen socket has no connection ready.
- *
- * @param access function to use to check if access is allowed
- * @param access_cls closure for access
- * @param lsock listen socket
- * @return the connection handle, NULL on error (for example, access refused)
- */
- struct GNUNET_CONNECTION_Handle *
- GNUNET_CONNECTION_create_from_accept (GNUNET_CONNECTION_AccessCheck access,
- void *access_cls,
- struct GNUNET_NETWORK_Handle *lsock);
- /**
- * Create a connection handle by (asynchronously) connecting to a host.
- * This function returns immediately, even if the connection has not
- * yet been established. This function only creates TCP connections.
- *
- * @param cfg configuration to use
- * @param hostname name of the host to connect to
- * @param port port to connect to
- * @return the connection handle
- */
- struct GNUNET_CONNECTION_Handle *
- GNUNET_CONNECTION_create_from_connect (const struct GNUNET_CONFIGURATION_Handle
- *cfg, const char *hostname,
- uint16_t port);
- /**
- * Create a connection handle by connecting to a UNIX domain service.
- * This function returns immediately, even if the connection has not
- * yet been established. This function only creates UNIX connections.
- *
- * @param cfg configuration to use
- * @param unixpath path to connect to)
- * @return the connection handle, NULL on systems without UNIX support
- */
- struct GNUNET_CONNECTION_Handle *
- GNUNET_CONNECTION_create_from_connect_to_unixpath (const struct
- GNUNET_CONFIGURATION_Handle
- *cfg, const char *unixpath);
- /**
- * Create a connection handle by (asynchronously) connecting to a host.
- * This function returns immediately, even if the connection has not
- * yet been established. This function only creates TCP connections.
- *
- * @param af_family address family to use
- * @param serv_addr server address
- * @param addrlen length of server address
- * @return the connection handle
- */
- struct GNUNET_CONNECTION_Handle *
- GNUNET_CONNECTION_create_from_sockaddr (int af_family,
- const struct sockaddr *serv_addr,
- socklen_t addrlen);
- /**
- * Check if connection is valid (no fatal errors have happened so far).
- * Note that a connection that is still trying to connect is considered
- * valid.
- *
- * @param connection handle to check
- * @return GNUNET_YES if valid, GNUNET_NO otherwise
- */
- int
- GNUNET_CONNECTION_check (struct GNUNET_CONNECTION_Handle *connection);
- /**
- * Obtain the network address of the other party.
- *
- * @param connection the client to get the address for
- * @param addr where to store the address
- * @param addrlen where to store the length of the address
- * @return GNUNET_OK on success
- */
- int
- GNUNET_CONNECTION_get_address (struct GNUNET_CONNECTION_Handle *connection,
- void **addr, size_t * addrlen);
- /**
- * Close the connection and free associated resources. There must
- * not be any pending requests for reading or writing to the
- * connection at this time.
- *
- * @param connection connection to destroy
- */
- void
- GNUNET_CONNECTION_destroy (struct GNUNET_CONNECTION_Handle *connection);
- /**
- * Receive data from the given connection. Note that this function will
- * call "receiver" asynchronously using the scheduler. It will
- * "immediately" return. Note that there MUST only be one active
- * receive call per connection at any given point in time (so do not
- * call receive again until the receiver callback has been invoked).
- *
- * @param connection connection handle
- * @param max maximum number of bytes to read
- * @param timeout maximum amount of time to wait
- * @param receiver function to call with received data
- * @param receiver_cls closure for receiver
- */
- void
- GNUNET_CONNECTION_receive (struct GNUNET_CONNECTION_Handle *connection, size_t max,
- struct GNUNET_TIME_Relative timeout,
- GNUNET_CONNECTION_Receiver receiver,
- void *receiver_cls);
- /**
- * Cancel receive job on the given connection. Note that the
- * receiver callback must not have been called yet in order
- * for the cancellation to be valid.
- *
- * @param connection connection handle
- * @return closure of the original receiver callback closure
- */
- void *
- GNUNET_CONNECTION_receive_cancel (struct GNUNET_CONNECTION_Handle *connection);
- /**
- * Function called to notify a client about the connection begin ready
- * to queue more data. @a buf will be NULL and @a size zero if the
- * connection was closed for writing in the meantime.
- *
- * @param cls closure
- * @param size number of bytes available in @a buf
- * @param buf where the callee should write the message
- * @return number of bytes written to @a buf
- */
- typedef size_t
- (*GNUNET_CONNECTION_TransmitReadyNotify) (void *cls,
- size_t size,
- void *buf);
- /**
- * Opaque handle that can be used to cancel
- * a transmit-ready notification.
- */
- struct GNUNET_CONNECTION_TransmitHandle;
- /**
- * Ask the connection to call us once the specified number of bytes
- * are free in the transmission buffer. Will never call the @a notify
- * callback in this task, but always first go into the scheduler. Note that
- * this function will abort if "size" is greater than
- * #GNUNET_SERVER_MAX_MESSAGE_SIZE.
- *
- * Note that "notify" will be called either when enough
- * buffer space is available OR when the connection is destroyed.
- * The size parameter given to notify is guaranteed to be
- * larger or equal to size if the buffer is ready, or zero
- * if the connection was destroyed (or at least closed for
- * writing). Finally, any time before 'notify' is called, a
- * client may call "notify_transmit_ready_cancel" to cancel
- * the transmission request.
- *
- * Only one transmission request can be scheduled at the same
- * time. Notify will be run with the same scheduler priority
- * as that of the caller.
- *
- * @param connection connection
- * @param size number of bytes to send
- * @param timeout after how long should we give up (and call
- * notify with buf NULL and size 0)?
- * @param notify function to call when buffer space is available
- * @param notify_cls closure for notify
- * @return non-NULL if the notify callback was queued,
- * NULL if we are already going to notify someone else (busy)
- */
- struct GNUNET_CONNECTION_TransmitHandle *
- GNUNET_CONNECTION_notify_transmit_ready (struct GNUNET_CONNECTION_Handle *connection,
- size_t size,
- struct GNUNET_TIME_Relative timeout,
- GNUNET_CONNECTION_TransmitReadyNotify
- notify, void *notify_cls);
- /**
- * Cancel the specified transmission-ready
- * notification.
- *
- * @param th handle for notification to cancel
- */
- void
- GNUNET_CONNECTION_notify_transmit_ready_cancel (struct
- GNUNET_CONNECTION_TransmitHandle
- *th);
- #if 0 /* keep Emacsens' auto-indent happy */
- {
- #endif
- #ifdef __cplusplus
- }
- #endif
- /* ifndef GNUNET_CONNECTION_LIB_H */
- #endif
- /* end of gnunet_connection_lib.h */
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