mirror of https://github.com/c-ares/c-ares.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
86 lines
2.9 KiB
86 lines
2.9 KiB
.\" |
|
.\" Copyright 1998 by the Massachusetts Institute of Technology. |
|
.\" |
|
.\" Permission to use, copy, modify, and distribute this |
|
.\" software and its documentation for any purpose and without |
|
.\" fee is hereby granted, provided that the above copyright |
|
.\" notice appear in all copies and that both that copyright |
|
.\" notice and this permission notice appear in supporting |
|
.\" documentation, and that the name of M.I.T. not be used in |
|
.\" advertising or publicity pertaining to distribution of the |
|
.\" software without specific, written prior permission. |
|
.\" M.I.T. makes no representations about the suitability of |
|
.\" this software for any purpose. It is provided "as is" |
|
.\" without express or implied warranty. |
|
.\" |
|
.\" SPDX-License-Identifier: MIT |
|
.\" |
|
.TH ARES_CREATE_QUERY 3 "17 Aug 2012" |
|
.SH NAME |
|
ares_create_query \- Compose a single-question DNS query buffer |
|
.SH SYNOPSIS |
|
.nf |
|
#include <ares.h> |
|
|
|
int ares_create_query(const char *\fIname\fP, |
|
int \fIdnsclass\fP, |
|
int \fItype\fP, |
|
unsigned short \fIid\fP, |
|
int \fIrd\fP, |
|
unsigned char **\fIbuf\fP, |
|
int *\fIbuflen\fP, |
|
int \fImax_udp_size\fP) |
|
.fi |
|
.SH DESCRIPTION |
|
The \fIares_create_query(3)\fP function composes a DNS query with a single |
|
question. The parameter \fIname\fP gives the query name as a NUL-terminated C |
|
string of period-separated labels optionally ending with a period; periods and |
|
backslashes within a label must be escaped with a backlash. |
|
|
|
The parameters \fIdnsclass\fP and \fItype\fP give the class and type of the |
|
query using the values defined in \fB<arpa/nameser.h>\fP. |
|
|
|
The parameter \fIid\fP gives a 16-bit identifier for the query. |
|
|
|
The parameter \fIrd\fP should be nonzero if recursion is desired, zero if not. |
|
|
|
The query will be placed in an allocated buffer, a pointer to which will be |
|
stored in the variable pointed to by \fIbuf\fP, and the length of which will |
|
be stored in the variable pointed to by \fIbuflen\fP. |
|
|
|
It is the caller's responsibility to free this buffer using |
|
\fIares_free_string(3)\fP when it is no longer needed. The parameter |
|
\fImax_udp_size\fP should be nonzero to activate EDNS. Usage of |
|
\fIares_create_query(3)\fP\ with \fImax_udp_size\fP set to zero is equivalent |
|
to using \fIares_mkquery(3)\fP. |
|
.SH RETURN VALUES |
|
.B ares_create_query |
|
can return any of the following values: |
|
.TP 15 |
|
.B ARES_SUCCESS |
|
Construction of the DNS query succeeded. |
|
.TP 15 |
|
.B ARES_ENOTFOUND |
|
The query name |
|
.I name |
|
refers to a |
|
.I .onion |
|
domain name. See RFC 7686. |
|
.TP 15 |
|
.B ARES_EBADNAME |
|
The query name |
|
.I name |
|
could not be encoded as a domain name, either because it contained a |
|
zero-length label or because it contained a label of more than 63 |
|
characters. |
|
.TP 15 |
|
.B ARES_ENOMEM |
|
Memory was exhausted. |
|
.SH AVAILABILITY |
|
Added in c-ares 1.10.0 |
|
.SH SEE ALSO |
|
.BR ares_dns_record (3), |
|
.BR ares_expand_name (3), |
|
.BR ares_free_string (3), |
|
.BR ares_mkquery (3) |
|
.SH AUTHOR
|
|
|