1/* 2 * Copyright (c) 2000-2007 Niels Provos <provos@citi.umich.edu> 3 * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27#ifndef EVENT2_LISTENER_H_INCLUDED_ 28#define EVENT2_LISTENER_H_INCLUDED_ 29 30#include <event2/visibility.h> 31 32#ifdef __cplusplus 33extern "C" { 34#endif 35 36#include <event2/event.h> 37 38struct sockaddr; 39struct evconnlistener; 40 41/** 42 A callback that we invoke when a listener has a new connection. 43 44 @param listener The evconnlistener 45 @param fd The new file descriptor 46 @param addr The source address of the connection 47 @param socklen The length of addr 48 @param user_arg the pointer passed to evconnlistener_new() 49 */ 50typedef void (*evconnlistener_cb)(struct evconnlistener *, evutil_socket_t, struct sockaddr *, int socklen, void *); 51 52/** 53 A callback that we invoke when a listener encounters a non-retriable error. 54 55 @param listener The evconnlistener 56 @param user_arg the pointer passed to evconnlistener_new() 57 */ 58typedef void (*evconnlistener_errorcb)(struct evconnlistener *, void *); 59 60/** Flag: Indicates that we should not make incoming sockets nonblocking 61 * before passing them to the callback. */ 62#define LEV_OPT_LEAVE_SOCKETS_BLOCKING (1u<<0) 63/** Flag: Indicates that freeing the listener should close the underlying 64 * socket. */ 65#define LEV_OPT_CLOSE_ON_FREE (1u<<1) 66/** Flag: Indicates that we should set the close-on-exec flag, if possible */ 67#define LEV_OPT_CLOSE_ON_EXEC (1u<<2) 68/** Flag: Indicates that we should disable the timeout (if any) between when 69 * this socket is closed and when we can listen again on the same port. */ 70#define LEV_OPT_REUSEABLE (1u<<3) 71/** Flag: Indicates that the listener should be locked so it's safe to use 72 * from multiple threadcs at once. */ 73#define LEV_OPT_THREADSAFE (1u<<4) 74/** Flag: Indicates that the listener should be created in disabled 75 * state. Use evconnlistener_enable() to enable it later. */ 76#define LEV_OPT_DISABLED (1u<<5) 77/** Flag: Indicates that the listener should defer accept() until data is 78 * available, if possible. Ignored on platforms that do not support this. 79 * 80 * This option can help performance for protocols where the client transmits 81 * immediately after connecting. Do not use this option if your protocol 82 * _doesn't_ start out with the client transmitting data, since in that case 83 * this option will sometimes cause the kernel to never tell you about the 84 * connection. 85 * 86 * This option is only supported by evconnlistener_new_bind(): it can't 87 * work with evconnlistener_new_fd(), since the listener needs to be told 88 * to use the option before it is actually bound. 89 */ 90#define LEV_OPT_DEFERRED_ACCEPT (1u<<6) 91/** Flag: Indicates that we ask to allow multiple servers (processes or 92 * threads) to bind to the same port if they each set the option. 93 * 94 * SO_REUSEPORT is what most people would expect SO_REUSEADDR to be, however 95 * SO_REUSEPORT does not imply SO_REUSEADDR. 96 * 97 * This is only available on Linux and kernel 3.9+ 98 */ 99#define LEV_OPT_REUSEABLE_PORT (1u<<7) 100/** Flag: Indicates that the listener wants to work only in IPv6 socket. 101 * 102 * According to RFC3493 and most Linux distributions, default value is to 103 * work in IPv4-mapped mode. If there is a requirement to bind same port 104 * on same ip addresses but different handlers for both IPv4 and IPv6, 105 * it is required to set IPV6_V6ONLY socket option to be sure that the 106 * code works as expected without affected by bindv6only sysctl setting in 107 * system. 108 * 109 * This socket option also supported by Windows. 110 */ 111#define LEV_OPT_BIND_IPV6ONLY (1u<<8) 112 113/** 114 Allocate a new evconnlistener object to listen for incoming TCP connections 115 on a given file descriptor. 116 117 @param base The event base to associate the listener with. 118 @param cb A callback to be invoked when a new connection arrives. If the 119 callback is NULL, the listener will be treated as disabled until the 120 callback is set. 121 @param ptr A user-supplied pointer to give to the callback. 122 @param flags Any number of LEV_OPT_* flags 123 @param backlog Passed to the listen() call to determine the length of the 124 acceptable connection backlog. Set to -1 for a reasonable default. 125 Set to 0 if the socket is already listening. 126 @param fd The file descriptor to listen on. It must be a nonblocking 127 file descriptor, and it should already be bound to an appropriate 128 port and address. 129*/ 130EVENT2_EXPORT_SYMBOL 131struct evconnlistener *evconnlistener_new(struct event_base *base, 132 evconnlistener_cb cb, void *ptr, unsigned flags, int backlog, 133 evutil_socket_t fd); 134/** 135 Allocate a new evconnlistener object to listen for incoming TCP connections 136 on a given address. 137 138 @param base The event base to associate the listener with. 139 @param cb A callback to be invoked when a new connection arrives. If the 140 callback is NULL, the listener will be treated as disabled until the 141 callback is set. 142 @param ptr A user-supplied pointer to give to the callback. 143 @param flags Any number of LEV_OPT_* flags 144 @param backlog Passed to the listen() call to determine the length of the 145 acceptable connection backlog. Set to -1 for a reasonable default. 146 @param addr The address to listen for connections on. 147 @param socklen The length of the address. 148 */ 149EVENT2_EXPORT_SYMBOL 150struct evconnlistener *evconnlistener_new_bind(struct event_base *base, 151 evconnlistener_cb cb, void *ptr, unsigned flags, int backlog, 152 const struct sockaddr *sa, int socklen); 153/** 154 Disable and deallocate an evconnlistener. 155 */ 156EVENT2_EXPORT_SYMBOL 157void evconnlistener_free(struct evconnlistener *lev); 158/** 159 Re-enable an evconnlistener that has been disabled. 160 */ 161EVENT2_EXPORT_SYMBOL 162int evconnlistener_enable(struct evconnlistener *lev); 163/** 164 Stop listening for connections on an evconnlistener. 165 */ 166EVENT2_EXPORT_SYMBOL 167int evconnlistener_disable(struct evconnlistener *lev); 168 169/** Return an evconnlistener's associated event_base. */ 170EVENT2_EXPORT_SYMBOL 171struct event_base *evconnlistener_get_base(struct evconnlistener *lev); 172 173/** Return the socket that an evconnlistner is listening on. */ 174EVENT2_EXPORT_SYMBOL 175evutil_socket_t evconnlistener_get_fd(struct evconnlistener *lev); 176 177/** Change the callback on the listener to cb and its user_data to arg. 178 */ 179EVENT2_EXPORT_SYMBOL 180void evconnlistener_set_cb(struct evconnlistener *lev, 181 evconnlistener_cb cb, void *arg); 182 183/** Set an evconnlistener's error callback. */ 184EVENT2_EXPORT_SYMBOL 185void evconnlistener_set_error_cb(struct evconnlistener *lev, 186 evconnlistener_errorcb errorcb); 187 188#ifdef __cplusplus 189} 190#endif 191 192#endif 193