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_
28 #define _EVENT2_LISTENER_H_
29
30 #ifdef __cplusplus
31 extern "C" {
32 #endif
33
34 #include <event2/event.h>
35
36 struct sockaddr;
37 struct evconnlistener;
38
39 /**
40 A callback that we invoke when a listener has a new connection.
41
42 @param listener The evconnlistener
43 @param fd The new file descriptor
44 @param addr The source address of the connection
45 @param socklen The length of addr
46 @param user_arg the pointer passed to evconnlistener_new()
47 */
48 typedef void (*evconnlistener_cb)(struct evconnlistener *, evutil_socket_t, struct sockaddr *, int socklen, void *);
49
50 /**
51 A callback that we invoke when a listener encounters a non-retriable error.
52
53 @param listener The evconnlistener
54 @param user_arg the pointer passed to evconnlistener_new()
55 */
56 typedef void (*evconnlistener_errorcb)(struct evconnlistener *, void *);
57
58 /** Flag: Indicates that we should not make incoming sockets nonblocking
59 * before passing them to the callback. */
60 #define LEV_OPT_LEAVE_SOCKETS_BLOCKING (1u<<0)
61 /** Flag: Indicates that freeing the listener should close the underlying
62 * socket. */
63 #define LEV_OPT_CLOSE_ON_FREE (1u<<1)
64 /** Flag: Indicates that we should set the close-on-exec flag, if possible */
65 #define LEV_OPT_CLOSE_ON_EXEC (1u<<2)
66 /** Flag: Indicates that we should disable the timeout (if any) between when
67 * this socket is closed and when we can listen again on the same port. */
68 #define LEV_OPT_REUSEABLE (1u<<3)
69 /** Flag: Indicates that the listener should be locked so it's safe to use
70 * from multiple threadcs at once. */
71 #define LEV_OPT_THREADSAFE (1u<<4)
72
73 /**
74 Allocate a new evconnlistener object to listen for incoming TCP connections
75 on a given file descriptor.
76
77 @param base The event base to associate the listener with.
78 @param cb A callback to be invoked when a new connection arrives. If the
79 callback is NULL, the listener will be treated as disabled until the
80 callback is set.
81 @param ptr A user-supplied pointer to give to the callback.
82 @param flags Any number of LEV_OPT_* flags
83 @param backlog Passed to the listen() call to determine the length of the
84 acceptable connection backlog. Set to -1 for a reasonable default.
85 Set to 0 if the socket is already listening.
86 @param fd The file descriptor to listen on. It must be a nonblocking
87 file descriptor, and it should already be bound to an appropriate
88 port and address.
89 */
90 struct evconnlistener *evconnlistener_new(struct event_base *base,
91 evconnlistener_cb cb, void *ptr, unsigned flags, int backlog,
92 evutil_socket_t fd);
93 /**
94 Allocate a new evconnlistener object to listen for incoming TCP connections
95 on a given address.
96
97 @param base The event base to associate the listener with.
98 @param cb A callback to be invoked when a new connection arrives. If the
99 callback is NULL, the listener will be treated as disabled until the
100 callback is set.
101 @param ptr A user-supplied pointer to give to the callback.
102 @param flags Any number of LEV_OPT_* flags
103 @param backlog Passed to the listen() call to determine the length of the
104 acceptable connection backlog. Set to -1 for a reasonable default.
105 @param addr The address to listen for connections on.
106 @param socklen The length of the address.
107 */
108 struct evconnlistener *evconnlistener_new_bind(struct event_base *base,
109 evconnlistener_cb cb, void *ptr, unsigned flags, int backlog,
110 const struct sockaddr *sa, int socklen);
111 /**
112 Disable and deallocate an evconnlistener.
113 */
114 void evconnlistener_free(struct evconnlistener *lev);
115 /**
116 Re-enable an evconnlistener that has been disabled.
117 */
118 int evconnlistener_enable(struct evconnlistener *lev);
119 /**
120 Stop listening for connections on an evconnlistener.
121 */
122 int evconnlistener_disable(struct evconnlistener *lev);
123
124 /** Return an evconnlistener's associated event_base. */
125 struct event_base *evconnlistener_get_base(struct evconnlistener *lev);
126
127 /** Return the socket that an evconnlistner is listening on. */
128 evutil_socket_t evconnlistener_get_fd(struct evconnlistener *lev);
129
130 /** Change the callback on the listener to cb and its user_data to arg.
131 */
132 void evconnlistener_set_cb(struct evconnlistener *lev,
133 evconnlistener_cb cb, void *arg);
134
135 /** Set an evconnlistener's error callback. */
136 void evconnlistener_set_error_cb(struct evconnlistener *lev,
137 evconnlistener_errorcb errorcb);
138
139 #ifdef __cplusplus
140 }
141 #endif
142
143 #endif