lwres_getnameinfo.docbook revision dafcb997e390efa4423883dafd100c975c4095d6
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook V4.1//EN">
<!--
- Copyright (C) 2004 Internet Systems Consortium, Inc. ("ISC")
- Copyright (C) 2001 Internet Software Consortium.
-
- Permission to use, copy, modify, and distribute this software for any
- purpose with or without fee is hereby granted, provided that the above
- copyright notice and this permission notice appear in all copies.
-
- THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
- REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
- AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
- INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
- LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
- OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
- PERFORMANCE OF THIS SOFTWARE.
-->
<!-- $Id: lwres_getnameinfo.docbook,v 1.4 2004/03/05 05:12:56 marka Exp $ -->
<refentry>
<refentryinfo>
<date>Jun 30, 2000</date>
</refentryinfo>
<refmeta>
<refentrytitle>lwres_getnameinfo</refentrytitle>
<manvolnum>3</manvolnum>
<refmiscinfo>BIND9</refmiscinfo>
</refmeta>
<refnamediv>
<refname>lwres_getnameinfo</refname>
<refpurpose>lightweight resolver socket address structure to hostname and service name</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
<funcdef>
int
<function>lwres_getnameinfo</function></funcdef>
<paramdef>const struct sockaddr *sa</paramdef>
<paramdef>size_t salen</paramdef>
<paramdef>char *host</paramdef>
<paramdef>size_t hostlen</paramdef>
<paramdef>char *serv</paramdef>
<paramdef>size_t servlen</paramdef>
<paramdef>int flags</paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>DESCRIPTION</title>
<para> This function is equivalent to the <citerefentry>
<refentrytitle>getnameinfo</refentrytitle><manvolnum>3</manvolnum>
</citerefentry> function defined in RFC2133.
<function>lwres_getnameinfo()</function> returns the hostname for the
<type>struct sockaddr</type> <parameter>sa</parameter> which is
<parameter>salen</parameter> bytes long. The hostname is of length
<parameter>hostlen</parameter> and is returned via
<parameter>*host.</parameter> The maximum length of the hostname is
1025 bytes: <constant>NI_MAXHOST</constant>.</para>
<para> The name of the service associated with the port number in
<parameter>sa</parameter> is returned in <parameter>*serv.</parameter>
It is <parameter>servlen</parameter> bytes long. The maximum length
of the service name is <constant>NI_MAXSERV</constant> - 32 bytes.
</para>
<para> The <parameter>flags</parameter> argument sets the following
bits:
<variablelist>
<varlistentry><term><constant>NI_NOFQDN</constant></term>
<listitem>
<para>
A fully qualified domain name is not required for local hosts.
The local part of the fully qualified domain name is returned instead.
</para></listitem></varlistentry>
<varlistentry><term><constant>NI_NUMERICHOST</constant></term>
<listitem>
<para>
Return the address in numeric form, as if calling inet_ntop(),
instead of a host name.
</para></listitem></varlistentry>
<varlistentry><term><constant>NI_NAMEREQD</constant></term>
<listitem>
<para>
A name is required. If the hostname cannot be found in the DNS and
this flag is set, a non-zero error code is returned.
If the hostname is not found and the flag is not set, the
address is returned in numeric form.
</para></listitem></varlistentry>
<varlistentry><term><constant>NI_NUMERICSERV</constant></term>
<listitem>
<para>
The service name is returned as a digit string representing the port number.
</para></listitem></varlistentry>
<varlistentry><term><constant>NI_DGRAM</constant></term>
<listitem>
<para>
Specifies that the service being looked up is a datagram
service, and causes getservbyport() to be called with a second
argument of "udp" instead of its default of "tcp". This is required
for the few ports (512-514) that have different services for UDP and
TCP.
</para></listitem></varlistentry>
</variablelist>
</para>
</refsect1>
<refsect1>
<title>RETURN VALUES</title>
<para>
<function>lwres_getnameinfo()</function>
returns 0 on success or a non-zero error code if an error occurs.
</para>
</refsect1>
<refsect1>
<title>SEE ALSO</title>
<para>
<citerefentry>
<refentrytitle>RFC2133</refentrytitle>
</citerefentry>,
<citerefentry>
<refentrytitle>getservbyport</refentrytitle><manvolnum>3</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>lwres</refentrytitle><manvolnum>3</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>lwres_getnameinfo</refentrytitle><manvolnum>3</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>lwres_getnamebyaddr</refentrytitle><manvolnum>3</manvolnum>
</citerefentry>.
<citerefentry>
<refentrytitle>lwres_net_ntop</refentrytitle><manvolnum>3</manvolnum>
</citerefentry>.
</refsect1>
<refsect1>
<title>BUGS</title>
<para>
RFC2133 fails to define what the nonzero return values of
<citerefentry>
<refentrytitle>getnameinfo</refentrytitle><manvolnum>3</manvolnum>
</citerefentry>
are.
</para>
</refsect1>
</refentry>