2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek<!DOCTYPE book [

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek<!ENTITY mdash "&#8212;">]>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek<refentry xmlns="http://docbook.org/ns/docbook" version="5.0">

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <info>

3ffd4af22052963e7a29431721ee204e634bea75Lennart Poettering <date>2007-06-18</date>

4f5dd3943bef8a04be7e3b838b822bb9a7ad6cb3Lennart Poettering </info>

3ffd4af22052963e7a29431721ee204e634bea75Lennart Poettering <refentryinfo>

4f5dd3943bef8a04be7e3b838b822bb9a7ad6cb3Lennart Poettering <corpname>ISC</corpname>

4f5dd3943bef8a04be7e3b838b822bb9a7ad6cb3Lennart Poettering <corpauthor>Internet Systems Consortium, Inc.</corpauthor>

07630cea1f3a845c09309f197ac7c4f11edd3b62Lennart Poettering </refentryinfo>

4f5dd3943bef8a04be7e3b838b822bb9a7ad6cb3Lennart Poettering

4f5dd3943bef8a04be7e3b838b822bb9a7ad6cb3Lennart Poettering <refmeta>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <refentrytitle>lwres_gethostent</refentrytitle>

8eea868708923a092ee85d6146ba4c04b7baea06Zbigniew Jędrzejewski-Szmek <manvolnum>3</manvolnum>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <refmiscinfo>BIND9</refmiscinfo>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek </refmeta>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <docinfo>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <copyright>

8eea868708923a092ee85d6146ba4c04b7baea06Zbigniew Jędrzejewski-Szmek <year>2004</year>

8eea868708923a092ee85d6146ba4c04b7baea06Zbigniew Jędrzejewski-Szmek <year>2005</year>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <year>2007</year>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <year>2014</year>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <year>2015</year>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <holder>Internet Systems Consortium, Inc. ("ISC")</holder>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek </copyright>

8eea868708923a092ee85d6146ba4c04b7baea06Zbigniew Jędrzejewski-Szmek <copyright>

8eea868708923a092ee85d6146ba4c04b7baea06Zbigniew Jędrzejewski-Szmek <year>2001</year>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <holder>Internet Software Consortium.</holder>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek </copyright>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek </docinfo>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek

ae6c3cc009a21df4b51851fb8fe3fde0b7d6d8f0Lennart Poettering <refnamediv>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <refname>lwres_gethostbyname</refname>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <refname>lwres_gethostbyname2</refname>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <refname>lwres_gethostbyaddr</refname>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <refname>lwres_gethostent</refname>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <refname>lwres_sethostent</refname>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <refname>lwres_endhostent</refname>

8eea868708923a092ee85d6146ba4c04b7baea06Zbigniew Jędrzejewski-Szmek <refname>lwres_gethostbyname_r</refname>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <refname>lwres_gethostbyaddr_r</refname>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <refname>lwres_gethostent_r</refname>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <refname>lwres_sethostent_r</refname>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <refname>lwres_endhostent_r</refname>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <refpurpose>lightweight resolver get network host entry</refpurpose>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek </refnamediv>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <refsynopsisdiv>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <funcsynopsis>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek<funcsynopsisinfo>#include &lt;lwres/netdb.h&gt;</funcsynopsisinfo>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek<funcprototype>

8eea868708923a092ee85d6146ba4c04b7baea06Zbigniew Jędrzejewski-Szmek <funcdef>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmekstruct hostent *

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek<function>lwres_gethostbyname</function></funcdef>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <paramdef>const char *<parameter>name</parameter></paramdef>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek </funcprototype>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek<funcprototype>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <funcdef>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmekstruct hostent *

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek<function>lwres_gethostbyname2</function></funcdef>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <paramdef>const char *<parameter>name</parameter></paramdef>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <paramdef>int <parameter>af</parameter></paramdef>

8eea868708923a092ee85d6146ba4c04b7baea06Zbigniew Jędrzejewski-Szmek </funcprototype>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek<funcprototype>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <funcdef>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmekstruct hostent *

45519fd6304aae453d95c6cf11bfc8539c38494cLennart Poettering<function>lwres_gethostbyaddr</function></funcdef>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <paramdef>const char *<parameter>addr</parameter></paramdef>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <paramdef>int <parameter>len</parameter></paramdef>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <paramdef>int <parameter>type</parameter></paramdef>

8eea868708923a092ee85d6146ba4c04b7baea06Zbigniew Jędrzejewski-Szmek </funcprototype>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek<funcprototype>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <funcdef>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmekstruct hostent *

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek<function>lwres_gethostent</function></funcdef>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <paramdef>void</paramdef>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek </funcprototype>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek<funcprototype>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <funcdef>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmekvoid

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek<function>lwres_sethostent</function></funcdef>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <paramdef>int <parameter>stayopen</parameter></paramdef>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek </funcprototype>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek<funcprototype>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <funcdef>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmekvoid

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek<function>lwres_endhostent</function></funcdef>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek <paramdef>void</paramdef>

8eea868708923a092ee85d6146ba4c04b7baea06Zbigniew Jędrzejewski-Szmek </funcprototype>

2968644080fd103062f070e83edd620e0a58c44dZbigniew Jędrzejewski-Szmek<funcprototype>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <funcdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmekstruct hostent *

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek<function>lwres_gethostbyname_r</function></funcdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <paramdef>const char *<parameter>name</parameter></paramdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <paramdef>struct hostent *<parameter>resbuf</parameter></paramdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <paramdef>char *<parameter>buf</parameter></paramdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <paramdef>int <parameter>buflen</parameter></paramdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <paramdef>int *<parameter>error</parameter></paramdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </funcprototype>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek<funcprototype>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <funcdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmekstruct hostent *

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek<function>lwres_gethostbyaddr_r</function></funcdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <paramdef>const char *<parameter>addr</parameter></paramdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <paramdef>int <parameter>len</parameter></paramdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <paramdef>int <parameter>type</parameter></paramdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <paramdef>struct hostent *<parameter>resbuf</parameter></paramdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <paramdef>char *<parameter>buf</parameter></paramdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <paramdef>int <parameter>buflen</parameter></paramdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <paramdef>int *<parameter>error</parameter></paramdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </funcprototype>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek<funcprototype>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <funcdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmekstruct hostent *

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek<function>lwres_gethostent_r</function></funcdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <paramdef>struct hostent *<parameter>resbuf</parameter></paramdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <paramdef>char *<parameter>buf</parameter></paramdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <paramdef>int <parameter>buflen</parameter></paramdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <paramdef>int *<parameter>error</parameter></paramdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </funcprototype>

45519fd6304aae453d95c6cf11bfc8539c38494cLennart Poettering<funcprototype>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <funcdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmekvoid

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek<function>lwres_sethostent_r</function></funcdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <paramdef>int <parameter>stayopen</parameter></paramdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </funcprototype>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek<funcprototype>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <funcdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmekvoid

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek<function>lwres_endhostent_r</function></funcdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <paramdef>void</paramdef>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </funcprototype>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek</funcsynopsis>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </refsynopsisdiv>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek

a34bf9db5da0fdd6bdb14459e203dbe41ee99614Lennart Poettering <refsection><info><title>DESCRIPTION</title></info>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <para>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek These functions provide hostname-to-address and

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek address-to-hostname lookups by means of the lightweight resolver.

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek They are similar to the standard

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <citerefentry>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <refentrytitle>gethostent</refentrytitle><manvolnum>3</manvolnum>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </citerefentry>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek functions provided by most operating systems.

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek They use a

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <type>struct hostent</type>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek which is usually defined in

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <filename>&lt;namedb.h&gt;</filename>.

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </para>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <para><programlisting>

7410616cd9dbbec97cf98d75324da5cda2b2f7a2Lennart Poetteringstruct hostent {

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek char *h_name; /* official name of host */

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek char **h_aliases; /* alias list */

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek int h_addrtype; /* host address type */

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek int h_length; /* length of address */

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek char **h_addr_list; /* list of addresses from name server */

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek};

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek#define h_addr h_addr_list[0] /* address, for backward compatibility */

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek</programlisting>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </para>

7410616cd9dbbec97cf98d75324da5cda2b2f7a2Lennart Poettering <para>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek The members of this structure are:

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <variablelist>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <varlistentry>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <term><constant>h_name</constant></term>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <listitem>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <para>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek The official (canonical) name of the host.

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </para>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </listitem>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </varlistentry>

7410616cd9dbbec97cf98d75324da5cda2b2f7a2Lennart Poettering <varlistentry>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <term><constant>h_aliases</constant></term>

7410616cd9dbbec97cf98d75324da5cda2b2f7a2Lennart Poettering <listitem>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <para>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek A NULL-terminated array of alternate names (nicknames) for the

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek host.

7410616cd9dbbec97cf98d75324da5cda2b2f7a2Lennart Poettering </para>

7410616cd9dbbec97cf98d75324da5cda2b2f7a2Lennart Poettering </listitem>

7410616cd9dbbec97cf98d75324da5cda2b2f7a2Lennart Poettering </varlistentry>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <varlistentry>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <term><constant>h_addrtype</constant></term>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <listitem>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <para>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek The type of address being returned &mdash;

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <type>PF_INET</type>

7410616cd9dbbec97cf98d75324da5cda2b2f7a2Lennart Poettering or

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <type>PF_INET6</type>.

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </para>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </listitem>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </varlistentry>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <varlistentry>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <term><constant>h_length</constant></term>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <listitem>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <para>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek The length of the address in bytes.

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </para>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </listitem>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </varlistentry>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <varlistentry>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <term><constant>h_addr_list</constant></term>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <listitem>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <para>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek A <type>NULL</type>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek terminated array of network addresses for the host.

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek Host addresses are returned in network byte order.

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </para>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </listitem>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </varlistentry>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </variablelist>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </para>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <para>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek For backward compatibility with very old software,

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <constant>h_addr</constant>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek is the first address in

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <constant>h_addr_list.</constant>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek </para>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <para><function>lwres_gethostent()</function>,

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <function>lwres_sethostent()</function>,

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <function>lwres_endhostent()</function>,

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <function>lwres_gethostent_r()</function>,

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek <function>lwres_sethostent_r()</function>

1a7f1b385cd9de8a0da934fadc379860f914ef33Zbigniew Jędrzejewski-Szmek and

<function>lwres_endhostent_r()</function>

provide iteration over the known host entries on systems that

provide such functionality through facilities like

<filename>/etc/hosts</filename>

or NIS. The lightweight resolver does not currently implement

these functions; it only provides them as stub functions that always

return failure.

</para>

<para><function>lwres_gethostbyname()</function>

and <function>lwres_gethostbyname2()</function> look up the

hostname <parameter>name</parameter>.

<function>lwres_gethostbyname()</function> always looks for an

IPv4 address while <function>lwres_gethostbyname2()</function>

looks for an address of protocol family

<parameter>af</parameter>: either <type>PF_INET</type> or

<type>PF_INET6</type> &mdash; IPv4 or IPV6 addresses

respectively. Successful calls of the functions return a

<type>struct hostent</type>for the name that was looked up.

<type>NULL</type> is returned if the lookups by

<function>lwres_gethostbyname()</function> or

<function>lwres_gethostbyname2()</function> fail.

</para>

<para>

Reverse lookups of addresses are performed by

<function>lwres_gethostbyaddr()</function>.

<parameter>addr</parameter> is an address of length

<parameter>len</parameter> bytes and protocol family

<parameter>type</parameter> &mdash; <type>PF_INET</type> or

<type>PF_INET6</type>.

<function>lwres_gethostbyname_r()</function> is a

thread-safe function

for forward lookups. If an error occurs, an error code is returned in

<parameter>*error</parameter>.

<parameter>resbuf</parameter> is a pointer to a

<type>struct hostent</type> which is initialised by a successful call to

<function>lwres_gethostbyname_r()</function>.

<parameter>buf</parameter> is a buffer of length

<parameter>len</parameter> bytes which is used to store the

<constant>h_name</constant>, <constant>h_aliases</constant>, and

<constant>h_addr_list</constant> elements of the

<type>struct hostent</type> returned in <parameter>resbuf</parameter>.

Successful calls to <function>lwres_gethostbyname_r()</function>

return <parameter>resbuf</parameter>,

which is a pointer to the <type>struct hostent</type> it created.

</para>

<para><function>lwres_gethostbyaddr_r()</function>

is a thread-safe function

that performs a reverse lookup of address <parameter>addr</parameter>

which is <parameter>len</parameter> bytes long and is of

protocol

family <parameter>type</parameter> &mdash; <type>PF_INET</type> or

<type>PF_INET6</type>. If an error occurs, the error code is returned

in <parameter>*error</parameter>. The other function

parameters are

identical to those in <function>lwres_gethostbyname_r()</function>.

<parameter>resbuf</parameter> is a pointer to a

<type>struct hostent</type> which is initialised by a successful call to

<function>lwres_gethostbyaddr_r()</function>.

<parameter>buf</parameter> is a buffer of length

<parameter>len</parameter> bytes which is used to store the

<constant>h_name</constant>, <constant>h_aliases</constant>, and

<constant>h_addr_list</constant> elements of the

<type>struct hostent</type> returned in <parameter>resbuf</parameter>.

Successful calls to <function>lwres_gethostbyaddr_r()</function> return

<parameter>resbuf</parameter>, which is a pointer to the

<function>struct hostent()</function> it created.

</para>

</refsection>

<refsection><info><title>RETURN VALUES</title></info>

<para>

The functions

<function>lwres_gethostbyname()</function>,

<function>lwres_gethostbyname2()</function>,

<function>lwres_gethostbyaddr()</function>,

and

<function>lwres_gethostent()</function>

return NULL to indicate an error. In this case the global variable

<type>lwres_h_errno</type>

will contain one of the following error codes defined in

<filename>&lt;lwres/netdb.h&gt;</filename>:

<variablelist>

<varlistentry>

<term><constant>HOST_NOT_FOUND</constant></term>

<listitem>

<para>

The host or address was not found.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>TRY_AGAIN</constant></term>

<listitem>

<para>

A recoverable error occurred, e.g., a timeout.

Retrying the lookup may succeed.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>NO_RECOVERY</constant></term>

<listitem>

<para>

A non-recoverable error occurred.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><constant>NO_DATA</constant></term>

<listitem>

<para>

The name exists, but has no address information

associated with it (or vice versa in the case

of a reverse lookup). The code NO_ADDRESS

is accepted as a synonym for NO_DATA for backwards

compatibility.

</para>

</listitem>

</varlistentry>

</variablelist>

</para>

<para><citerefentry>

<refentrytitle>lwres_hstrerror</refentrytitle><manvolnum>3</manvolnum>

</citerefentry>

translates these error codes to suitable error messages.

</para>

<para><function>lwres_gethostent()</function>

and <function>lwres_gethostent_r()</function>

always return <type>NULL</type>.

</para>

<para>

Successful calls to <function>lwres_gethostbyname_r()</function> and

<function>lwres_gethostbyaddr_r()</function> return

<parameter>resbuf</parameter>, a pointer to the

<type>struct hostent</type> that was initialised by these functions. They return

<type>NULL</type> if the lookups fail or if <parameter>buf</parameter>

was too small to hold the list of addresses and names referenced by

the <constant>h_name</constant>, <constant>h_aliases</constant>, and

<constant>h_addr_list</constant> elements of the

<type>struct hostent</type>.

If <parameter>buf</parameter> was too small, both

<function>lwres_gethostbyname_r()</function> and

<function>lwres_gethostbyaddr_r()</function> set the global

variable

<type>errno</type> to <errorcode>ERANGE</errorcode>.

</para>

</refsection>

<refsection><info><title>SEE ALSO</title></info>

<para><citerefentry>

<refentrytitle>gethostent</refentrytitle><manvolnum>3</manvolnum>

</citerefentry>,

<citerefentry>

<refentrytitle>lwres_getipnode</refentrytitle><manvolnum>3</manvolnum>

</citerefentry>,

<citerefentry>

<refentrytitle>lwres_hstrerror</refentrytitle><manvolnum>3</manvolnum>

</citerefentry>

</para>

</refsection>

<refsection><info><title>BUGS</title></info>

<para><function>lwres_gethostbyname()</function>,

<function>lwres_gethostbyname2()</function>,

<function>lwres_gethostbyaddr()</function>

and

<function>lwres_endhostent()</function>

are not thread safe; they return pointers to static data and

provide error codes through a global variable.

Thread-safe versions for name and address lookup are provided by

<function>lwres_gethostbyname_r()</function>,

and

<function>lwres_gethostbyaddr_r()</function>

respectively.

</para>

<para>

The resolver daemon does not currently support any non-DNS

name services such as

<filename>/etc/hosts</filename>

or

<type>NIS</type>,

consequently the above functions don't, either.

</para>

</refsection>

</refentry>