/*
* util/tube.h - pipe service
*
* Copyright (c) 2008, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file
*
* This file contains pipe service functions.
*/
#ifndef UTIL_TUBE_H
#define UTIL_TUBE_H
struct comm_reply;
struct comm_point;
struct comm_base;
struct tube;
struct tube_res_list;
#ifdef USE_WINSOCK
#include "util/locks.h"
#include "util/winsock_event.h"
#endif
/**
* Callback from pipe listen function
* void mycallback(tube, msg, len, error, user_argument);
* if error is true (NETEVENT_*), msg is probably NULL.
*/
typedef void tube_callback_t(struct tube*, uint8_t*, size_t, int, void*);
/**
* A pipe
*/
struct tube {
#ifndef USE_WINSOCK
/** pipe end to read from */
int sr;
/** pipe end to write on */
int sw;
/** listen commpoint */
struct comm_point* listen_com;
/** listen callback */
tube_callback_t* listen_cb;
/** listen callback user arg */
void* listen_arg;
/** are we currently reading a command, 0 if not, else bytecount */
size_t cmd_read;
/** size of current read command, may be partially read */
uint32_t cmd_len;
/** the current read command content, malloced, can be partially read*/
uint8_t* cmd_msg;
/** background write queue, commpoint to write results back */
struct comm_point* res_com;
/** are we currently writing a result, 0 if not, else bytecount into
* the res_list first entry. */
size_t res_write;
/** list of outstanding results to be written back */
struct tube_res_list* res_list;
/** last in list */
struct tube_res_list* res_last;
#else /* USE_WINSOCK */
/** listen callback */
tube_callback_t* listen_cb;
/** listen callback user arg */
void* listen_arg;
/** the windows sockets event (signaled if items in pipe) */
WSAEVENT event;
/** winsock event storage when registered with event base */
struct event ev_listen;
/** lock on the list of outstanding items */
lock_basic_t res_lock;
/** list of outstanding results on pipe */
struct tube_res_list* res_list;
/** last in list */
struct tube_res_list* res_last;
#endif /* USE_WINSOCK */
};
/**
* List of results (arbitrary command serializations) to write back
*/
struct tube_res_list {
/** next in list */
struct tube_res_list* next;
/** serialized buffer to write */
uint8_t* buf;
/** length to write */
uint32_t len;
};
/**
* Create a pipe
* @return: new tube struct or NULL on error.
*/
struct tube* tube_create(void);
/**
* Delete and destroy a pipe
* @param tube: to delete
*/
void tube_delete(struct tube* tube);
/**
* Write length bytes followed by message.
* @param tube: the tube to write on.
* If that tube is a pipe, its write fd is used as
* the socket to write on. Is nonblocking.
* Set to blocking by the function,
* and back to non-blocking at exit of function.
* @param buf: the message.
* @param len: length of message.
* @param nonblock: if set to true, the first write is nonblocking.
* If the first write fails the function returns -1.
* If set false, the first write is blocking.
* @return: all remainder writes are nonblocking.
* return 0 on error, in that case blocking/nonblocking of socket is
* unknown.
* return 1 if all OK.
*/
int tube_write_msg(struct tube* tube, uint8_t* buf, uint32_t len,
int nonblock);
/**
* Read length bytes followed by message.
* @param tube: The tube to read on.
* If that tube is a pipe, its read fd is used as
* the socket to read on. Is nonblocking.
* Set to blocking by the function,
* and back to non-blocking at exit of function.
* @param buf: the message, malloced.
* @param len: length of message, returned.
* @param nonblock: if set to true, the first read is nonblocking.
* If the first read fails the function returns -1.
* If set false, the first read is blocking.
* @return: all remainder reads are nonblocking.
* return 0 on error, in that case blocking/nonblocking of socket is
* unknown. On EOF 0 is returned.
* return 1 if all OK.
*/
int tube_read_msg(struct tube* tube, uint8_t** buf, uint32_t* len,
int nonblock);
/**
* Close read part of the pipe.
* The tube can no longer be read from.
* @param tube: tube to operate on.
*/
void tube_close_read(struct tube* tube);
/**
* Close write part of the pipe.
* The tube can no longer be written to.
* @param tube: tube to operate on.
*/
void tube_close_write(struct tube* tube);
/**
* See if data is ready for reading on the tube without blocking.
* @param tube: tube to check for readable items
* @return true if readable items are present. False if not (or error).
* true on pipe_closed.
*/
int tube_poll(struct tube* tube);
/**
* Wait for data to be ready for reading on the tube. is blocking.
* No timeout.
* @param tube: the tube to wait on.
* @return: if there was something to read (false on error).
* true on pipe_closed.
*/
int tube_wait(struct tube* tube);
/**
* Get FD that is readable when new information arrives.
* @param tube
* @return file descriptor.
*/
int tube_read_fd(struct tube* tube);
/**
* Start listening for information over the pipe.
* Background registration of a read listener, callback when read completed.
* Do not mix with tube_read_msg style direct reads from the pipe.
* @param tube: tube to listen on
* @param base: what base to register event callback.
* @param cb: callback routine.
* @param arg: user argument for callback routine.
* @return true if successful, false on error.
*/
int tube_setup_bg_listen(struct tube* tube, struct comm_base* base,
tube_callback_t* cb, void* arg);
/**
* Remove bg listen setup from event base.
* @param tube: what tube to cleanup
*/
void tube_remove_bg_listen(struct tube* tube);
/**
* Start background write handler for the pipe.
* Do not mix with tube_write_msg style direct writes to the pipe.
* @param tube: tube to write on
* @param base: what base to register event handler on.
* @return true if successful, false on error.
*/
int tube_setup_bg_write(struct tube* tube, struct comm_base* base);
/**
* Remove bg write setup from event base.
* @param tube: what tube to cleanup
*/
void tube_remove_bg_write(struct tube* tube);
/**
* Append data item to background list of writes.
* Mallocs a list entry behind the scenes.
* Not locked behind the scenes, call from one thread or lock on outside.
* @param tube: what tube to queue on.
* @param msg: memory message to send. Is free()d after use.
* Put at the end of the to-send queue.
* @param len: length of item.
* @return 0 on failure (msg freed).
*/
int tube_queue_item(struct tube* tube, uint8_t* msg, size_t len);
/** for fptr wlist, callback function */
int tube_handle_listen(struct comm_point* c, void* arg, int error,
struct comm_reply* reply_info);
/** for fptr wlist, callback function */
int tube_handle_write(struct comm_point* c, void* arg, int error,
struct comm_reply* reply_info);
/** for fptr wlist, winsock signal event callback function */
void tube_handle_signal(int fd, short events, void* arg);
#endif /* UTIL_TUBE_H */
