/*
* Copyright (c) 2000-2007 Niels Provos <provos@citi.umich.edu>
* Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#ifndef EVENT2_LISTENER_H_INCLUDED_
#define EVENT2_LISTENER_H_INCLUDED_
#include <event2/visibility.h>
#ifdef __cplusplus
extern "C" {
#endif
#include <event2/event.h>
struct sockaddr;
struct evconnlistener;
/**
A callback that we invoke when a listener has a new connection.
@param listener The evconnlistener
@param fd The new file descriptor
@param addr The source address of the connection
@param socklen The length of addr
@param user_arg the pointer passed to evconnlistener_new()
*/
typedef void (*evconnlistener_cb)(struct evconnlistener *, evutil_socket_t, struct sockaddr *, int socklen, void *);
/**
A callback that we invoke when a listener encounters a non-retriable error.
@param listener The evconnlistener
@param user_arg the pointer passed to evconnlistener_new()
*/
typedef void (*evconnlistener_errorcb)(struct evconnlistener *, void *);
/** Flag: Indicates that we should not make incoming sockets nonblocking
* before passing them to the callback. */
#define LEV_OPT_LEAVE_SOCKETS_BLOCKING (1u<<0)
/** Flag: Indicates that freeing the listener should close the underlying
* socket. */
#define LEV_OPT_CLOSE_ON_FREE (1u<<1)
/** Flag: Indicates that we should set the close-on-exec flag, if possible */
#define LEV_OPT_CLOSE_ON_EXEC (1u<<2)
/** Flag: Indicates that we should disable the timeout (if any) between when
* this socket is closed and when we can listen again on the same port. */
#define LEV_OPT_REUSEABLE (1u<<3)
/** Flag: Indicates that the listener should be locked so it's safe to use
* from multiple threadcs at once. */
#define LEV_OPT_THREADSAFE (1u<<4)
/** Flag: Indicates that the listener should be created in disabled
* state. Use evconnlistener_enable() to enable it later. */
#define LEV_OPT_DISABLED (1u<<5)
/** Flag: Indicates that the listener should defer accept() until data is
* available, if possible. Ignored on platforms that do not support this.
*
* This option can help performance for protocols where the client transmits
* immediately after connecting. Do not use this option if your protocol
* _doesn't_ start out with the client transmitting data, since in that case
* this option will sometimes cause the kernel to never tell you about the
* connection.
*
* This option is only supported by evconnlistener_new_bind(): it can't
* work with evconnlistener_new_fd(), since the listener needs to be told
* to use the option before it is actually bound.
*/
#define LEV_OPT_DEFERRED_ACCEPT (1u<<6)
/** Flag: Indicates that we ask to allow multiple servers (processes or
* threads) to bind to the same port if they each set the option.
*
* SO_REUSEPORT is what most people would expect SO_REUSEADDR to be, however
* SO_REUSEPORT does not imply SO_REUSEADDR.
*
* This is only available on Linux and kernel 3.9+
*/
#define LEV_OPT_REUSEABLE_PORT (1u<<7)
/**
Allocate a new evconnlistener object to listen for incoming TCP connections
on a given file descriptor.
@param base The event base to associate the listener with.
@param cb A callback to be invoked when a new connection arrives. If the
callback is NULL, the listener will be treated as disabled until the
callback is set.
@param ptr A user-supplied pointer to give to the callback.
@param flags Any number of LEV_OPT_* flags
@param backlog Passed to the listen() call to determine the length of the
acceptable connection backlog. Set to -1 for a reasonable default.
Set to 0 if the socket is already listening.
@param fd The file descriptor to listen on. It must be a nonblocking
file descriptor, and it should already be bound to an appropriate
port and address.
*/
EVENT2_EXPORT_SYMBOL
struct evconnlistener *evconnlistener_new(struct event_base *base,
evconnlistener_cb cb, void *ptr, unsigned flags, int backlog,
evutil_socket_t fd);
/**
Allocate a new evconnlistener object to listen for incoming TCP connections
on a given address.
@param base The event base to associate the listener with.
@param cb A callback to be invoked when a new connection arrives. If the
callback is NULL, the listener will be treated as disabled until the
callback is set.
@param ptr A user-supplied pointer to give to the callback.
@param flags Any number of LEV_OPT_* flags
@param backlog Passed to the listen() call to determine the length of the
acceptable connection backlog. Set to -1 for a reasonable default.
@param addr The address to listen for connections on.
@param socklen The length of the address.
*/
EVENT2_EXPORT_SYMBOL
struct evconnlistener *evconnlistener_new_bind(struct event_base *base,
evconnlistener_cb cb, void *ptr, unsigned flags, int backlog,
const struct sockaddr *sa, int socklen);
/**
Disable and deallocate an evconnlistener.
*/
EVENT2_EXPORT_SYMBOL
void evconnlistener_free(struct evconnlistener *lev);
/**
Re-enable an evconnlistener that has been disabled.
*/
EVENT2_EXPORT_SYMBOL
int evconnlistener_enable(struct evconnlistener *lev);
/**
Stop listening for connections on an evconnlistener.
*/
EVENT2_EXPORT_SYMBOL
int evconnlistener_disable(struct evconnlistener *lev);
/** Return an evconnlistener's associated event_base. */
EVENT2_EXPORT_SYMBOL
struct event_base *evconnlistener_get_base(struct evconnlistener *lev);
/** Return the socket that an evconnlistner is listening on. */
EVENT2_EXPORT_SYMBOL
evutil_socket_t evconnlistener_get_fd(struct evconnlistener *lev);
/** Change the callback on the listener to cb and its user_data to arg.
*/
EVENT2_EXPORT_SYMBOL
void evconnlistener_set_cb(struct evconnlistener *lev,
evconnlistener_cb cb, void *arg);
/** Set an evconnlistener's error callback. */
EVENT2_EXPORT_SYMBOL
void evconnlistener_set_error_cb(struct evconnlistener *lev,
evconnlistener_errorcb errorcb);
#ifdef __cplusplus
}
#endif
#endif
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