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Diffstat (limited to 'src/include/gnunet_connection_lib.h')
| -rw-r--r-- | src/include/gnunet_connection_lib.h | 373 |
1 files changed, 373 insertions, 0 deletions
diff --git a/src/include/gnunet_connection_lib.h b/src/include/gnunet_connection_lib.h new file mode 100644 index 0000000..3e48d32 --- /dev/null +++ b/src/include/gnunet_connection_lib.h @@ -0,0 +1,373 @@ +/* + 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 2, 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 sock the connection to set persistent + */ +void +GNUNET_CONNECTION_persist_ (struct GNUNET_CONNECTION_Handle *sock); + +/** + * 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 sock the connection to make flushing and blocking + * @return GNUNET_OK on success + */ +int +GNUNET_CONNECTION_disable_corking (struct GNUNET_CONNECTION_Handle *sock); + + +/** + * Create a socket handle by boxing an existing OS socket. The OS + * socket should henceforth be no longer used directly. + * GNUNET_socket_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 socket 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 socket 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 socket 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 socket handle + */ +struct GNUNET_CONNECTION_Handle * +GNUNET_CONNECTION_create_from_connect (const struct GNUNET_CONFIGURATION_Handle + *cfg, const char *hostname, + uint16_t port); + + +/** + * Create a socket 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 socket 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 socket 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 socket handle + */ +struct GNUNET_CONNECTION_Handle * +GNUNET_CONNECTION_create_from_sockaddr (int af_family, + const struct sockaddr *serv_addr, + socklen_t addrlen); + +/** + * Check if socket is valid (no fatal errors have happened so far). + * Note that a socket that is still trying to connect is considered + * valid. + * + * @param sock socket to check + * @return GNUNET_YES if valid, GNUNET_NO otherwise + */ +int +GNUNET_CONNECTION_check (struct GNUNET_CONNECTION_Handle *sock); + + +/** + * Obtain the network address of the other party. + * + * @param sock 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 *sock, + void **addr, size_t * addrlen); + + +/** + * Close the socket and free associated resources. Pending + * transmissions may be completed or dropped depending on the + * arguments. If a receive call is pending and should + * NOT be completed, 'GNUNET_CONNECTION_receive_cancel' + * should be called explicitly first. + * + * @param sock socket to destroy + * @param finish_pending_write should pending writes be completed or aborted? + * (this applies to transmissions where the data has already been + * read from the application; all other transmissions should be + * aborted using 'GNUNET_CONNECTION_notify_transmit_ready_cancel'). + */ +void +GNUNET_CONNECTION_destroy (struct GNUNET_CONNECTION_Handle *sock, + int finish_pending_write); + + +/** + * Receive data from the given socket. 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 socket at any given point in time (so do not + * call receive again until the receiver callback has been invoked). + * + * @param sock socket 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 *sock, size_t max, + struct GNUNET_TIME_Relative timeout, + GNUNET_CONNECTION_Receiver receiver, + void *receiver_cls); + + +/** + * Cancel receive job on the given socket. Note that the + * receiver callback must not have been called yet in order + * for the cancellation to be valid. + * + * @param sock socket handle + * @return closure of the original receiver callback closure + */ +void * +GNUNET_CONNECTION_receive_cancel (struct GNUNET_CONNECTION_Handle *sock); + + +/** + * Function called to notify a client about the socket + * begin ready to queue more data. "buf" will be + * NULL and "size" zero if the socket was closed for + * writing in the meantime. + * + * @param cls closure + * @param size number of bytes available in buf + * @param buf where the callee should write the message + * @return number of bytes written to 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 socket to call us once the specified number of bytes + * are free in the transmission buffer. May call the notify + * method immediately if enough space is available. 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 socket 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 socket 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 sock socket + * @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 *sock, + 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); + + +/** + * Configure this connection to ignore shutdown signals. + * + * @param sock socket handle + * @param do_ignore GNUNET_YES to ignore, GNUNET_NO to restore default + */ +void +GNUNET_CONNECTION_ignore_shutdown (struct GNUNET_CONNECTION_Handle *sock, + int do_ignore); + + +#if 0 /* keep Emacsens' auto-indent happy */ +{ +#endif +#ifdef __cplusplus +} +#endif + + +/* ifndef GNUNET_CONNECTION_LIB_H */ +#endif +/* end of gnunet_connection_lib.h */ |