Edit File: listener.h
/* * 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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