1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
|
#ifndef fooasyncnshfoo
#define fooasyncnshfoo
/* $Id$ */
/***
This file is part of libasyncns.
libasyncns is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
libasyncns is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with libasyncns; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
USA.
***/
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
/** \mainpage
*
* \section moo Method of operation
*
* To use libasyncns allocate an asyncns_t object with
* asyncns_new(). This will spawn a number of worker processes which
* are subsequently used to process the queries the controlling
* program issues via asyncns_getaddrinfo() and
* asyncns_getnameinfo(). Use asyncns_free() to shut down the worker
* processes.
*
* Since libasyncns forks off new processes you have to make sure that
* your program is not irritated by spurious SIGCHLD signals.
*/
/** \example asyncns-test.c
* An example program */
/** An opaque libasyncns session structure */
typedef struct asyncns asyncns_t;
/** An opaque libasyncns query structure */
typedef struct asyncns_query asyncns_query_t;
/** Allocate a new libasyncns session with n_proc worker processes */
asyncns_t* asyncns_new(int n_proc);
/** Free a libasyncns session. This destroys all attached
* asyncns_query_t objects automatically */
void asyncns_free(asyncns_t *asyncns);
/** Return the UNIX file descriptor to select() for readability
* on. Use this function to integrate libasyncns with your custom main
* loop. */
int asyncns_fd(asyncns_t *asyncns);
/** Process pending responses. If block is non-zero wait until at
* least one response has been processed. If block is zero, process
* all pending responses and return. */
int asyncns_wait(asyncns_t *asyncns, int block);
/** Issue a name to address query on the specified session. The
* arguments are compatible with the ones of libc's
* getaddrinfo(3). The function returns a new query object. When the
* query is completed you may retrieve the results using
* asyncns_getaddrinfo_done().*/
asyncns_query_t* asyncns_getaddrinfo(asyncns_t *asyncns, const char *node, const char *service, const struct addrinfo *hints);
/** Retrieve the results of a preceding asyncns_getaddrinfo()
* call. Returns a addrinfo structure and a return value compatible
* with libc's getaddrinfo(3). The query object q is destroyed by this
* call and may not be used any further. Make sure to free the
* returned addrinfo structure with asyncns_freeaddrinfo() and not
* libc's freeaddrinfo(3)! If the query is not completed yet EAI_AGAIN
* is returned.*/
int asyncns_getaddrinfo_done(asyncns_t *asyncns, asyncns_query_t* q, struct addrinfo **ret_res);
/** Issue an address to name query on the specified session. The
arguments are compatible with the ones of libc's getnameinfo(3). The
function returns a new query object. When the query is completed you
may retrieve the results using asyncns_getnameinfo_done(). Set gethost
(resp. getserv) to non-zero if you want to query the hostname
(resp. the service name). */
asyncns_query_t* asyncns_getnameinfo(asyncns_t *asyncns, const struct sockaddr *sa, socklen_t salen, int flags, int gethost, int getserv);
/** Retrieve the results of a preceding asyncns_getnameinfo)(
* call. Returns the hostname and the service name in ret_host and
* ret_serv. The query object q is destroyed by this call and may not
* be used any further. If the query is not completed yet EAI_AGAIN is
* returned. */
int asyncns_getnameinfo_done(asyncns_t *asyncns, asyncns_query_t* q, char *ret_host, size_t hostlen, char *ret_serv, size_t servlen);
/** Return the next completed query object. If no query has been completed yet, return NULL */
asyncns_query_t* asyncns_getnext(asyncns_t *asyncns);
/** Return the number of query objects (completed or not) attached to this session */
int asyncns_getnqueries(asyncns_t *asyncns);
/** Cancel a currently running query. q is is destroyed by this call
* and may not be used any futher. */
void asyncns_cancel(asyncns_t *asyncns, asyncns_query_t* q);
/** Free the addrinfo structure as returned by
asyncns_getaddrinfo_done(). Make sure to use this functions instead of
the libc's freeaddrinfo()! */
void asyncns_freeaddrinfo(struct addrinfo *ai);
/** Returns non-zero when the query operation specified by q has been completed */
int asyncns_isdone(asyncns_t *asyncns, asyncns_query_t*q);
/** Assign some opaque userdata with a query object */
void asyncns_setuserdata(asyncns_t *asyncns, asyncns_query_t *q, void *userdata);
/** Return userdata assigned to a query object. Use
* asyncns_setuserdata() to set this data. If no data has been set
* prior to this call it returns NULL. */
void* asyncns_getuserdata(asyncns_t *asyncns, asyncns_query_t *q);
#endif
|
