d5b7ba26785d7494166d48876362ba30ff30b98awrowe<!DOCTYPE book [

c30ef289fe64ac7fedc44cfcc6b439f0f8458b4cgregames<!ENTITY mdash "&#8212;">]>

b7cbb2495d82008f9fa72226b9213d639362feabjorton

07342c358cd73b304b1991e359a3faf720c966ecnd<refentry xmlns="http://docbook.org/ns/docbook" version="5.0">

07342c358cd73b304b1991e359a3faf720c966ecnd <info>

9556fb65eecaa55b866b413d5e262cd54be88f21nd <date>2007-06-18</date>

9556fb65eecaa55b866b413d5e262cd54be88f21nd </info>

9556fb65eecaa55b866b413d5e262cd54be88f21nd <refentryinfo>

9556fb65eecaa55b866b413d5e262cd54be88f21nd <corpname>ISC</corpname>

7d851311462dce44df8469009f98ba66d7f7f18end <corpauthor>Internet Systems Consortium, Inc.</corpauthor>

7d851311462dce44df8469009f98ba66d7f7f18end </refentryinfo>

7d851311462dce44df8469009f98ba66d7f7f18end

7d851311462dce44df8469009f98ba66d7f7f18end <refmeta>

7d851311462dce44df8469009f98ba66d7f7f18end <refentrytitle>lwres_gethostent</refentrytitle>

987c2c2ff2f19f306357f79d3280b347d96c470fnd <manvolnum>3</manvolnum>

987c2c2ff2f19f306357f79d3280b347d96c470fnd <refmiscinfo>BIND9</refmiscinfo>

987c2c2ff2f19f306357f79d3280b347d96c470fnd </refmeta>

987c2c2ff2f19f306357f79d3280b347d96c470fnd

99c475e760470ab8ca3d17da82a2f6158466f918rederpj <docinfo>

99c475e760470ab8ca3d17da82a2f6158466f918rederpj <copyright>

99c475e760470ab8ca3d17da82a2f6158466f918rederpj <year>2004</year>

99c475e760470ab8ca3d17da82a2f6158466f918rederpj <year>2005</year>

0b0966806a96fd817692a5420908594a0c7f9f89trawick <year>2007</year>

0b0966806a96fd817692a5420908594a0c7f9f89trawick <year>2014</year>

0b0966806a96fd817692a5420908594a0c7f9f89trawick <year>2015</year>

8eeb24cab1b849bd17726d0a030cd299209f108cnd <year>2016</year>

8eeb24cab1b849bd17726d0a030cd299209f108cnd <holder>Internet Systems Consortium, Inc. ("ISC")</holder>

8eeb24cab1b849bd17726d0a030cd299209f108cnd </copyright>

8eeb24cab1b849bd17726d0a030cd299209f108cnd <copyright>

8eeb24cab1b849bd17726d0a030cd299209f108cnd <year>2001</year>

c2d16e88f6a997b9174b5596db5e03cee5f46a8brederpj <holder>Internet Software Consortium.</holder>

c2d16e88f6a997b9174b5596db5e03cee5f46a8brederpj </copyright>

7edcfe02796a70f2a5eac12b6766d11067c629a3rederpj </docinfo>

c2d16e88f6a997b9174b5596db5e03cee5f46a8brederpj

c2d16e88f6a997b9174b5596db5e03cee5f46a8brederpj <refnamediv>

c2d16e88f6a997b9174b5596db5e03cee5f46a8brederpj <refname>lwres_gethostbyname</refname>

a4dd3688dd6645faf0c1c1bfb22017c8f03d5b24nd <refname>lwres_gethostbyname2</refname>

a4dd3688dd6645faf0c1c1bfb22017c8f03d5b24nd <refname>lwres_gethostbyaddr</refname>

a4dd3688dd6645faf0c1c1bfb22017c8f03d5b24nd <refname>lwres_gethostent</refname>

a16ca336064074171bffc3a6da3444243a06b62btrawick <refname>lwres_sethostent</refname>

a16ca336064074171bffc3a6da3444243a06b62btrawick <refname>lwres_endhostent</refname>

a16ca336064074171bffc3a6da3444243a06b62btrawick <refname>lwres_gethostbyname_r</refname>

f2fe083bb9fabd2af7eb39d4f154f27a451bb5a4nd <refname>lwres_gethostbyaddr_r</refname>

f2fe083bb9fabd2af7eb39d4f154f27a451bb5a4nd <refname>lwres_gethostent_r</refname>

f2fe083bb9fabd2af7eb39d4f154f27a451bb5a4nd <refname>lwres_sethostent_r</refname>

f2fe083bb9fabd2af7eb39d4f154f27a451bb5a4nd <refname>lwres_endhostent_r</refname>

7de6cb79f71a9007ba2b1e786cbad8b84f05d101nd <refpurpose>lightweight resolver get network host entry</refpurpose>

7de6cb79f71a9007ba2b1e786cbad8b84f05d101nd </refnamediv>

7de6cb79f71a9007ba2b1e786cbad8b84f05d101nd <refsynopsisdiv>

7de6cb79f71a9007ba2b1e786cbad8b84f05d101nd <funcsynopsis>

aa9b03a5f32732c0caaef03a7ed78ffb290e29e4trawick<funcsynopsisinfo>#include &lt;lwres/netdb.h&gt;</funcsynopsisinfo>

aa9b03a5f32732c0caaef03a7ed78ffb290e29e4trawick<funcprototype>

aa9b03a5f32732c0caaef03a7ed78ffb290e29e4trawick <funcdef>

a81c9e8561ebd18177a87fecf1226ac654b873f1rederpjstruct hostent *

a81c9e8561ebd18177a87fecf1226ac654b873f1rederpj<function>lwres_gethostbyname</function></funcdef>

a81c9e8561ebd18177a87fecf1226ac654b873f1rederpj <paramdef>const char *<parameter>name</parameter></paramdef>

a81c9e8561ebd18177a87fecf1226ac654b873f1rederpj </funcprototype>

d1c46782edbd6bd5ae4592c0174969950c5ca8aetrawick<funcprototype>

d1c46782edbd6bd5ae4592c0174969950c5ca8aetrawick <funcdef>

d1c46782edbd6bd5ae4592c0174969950c5ca8aetrawickstruct hostent *

a3954060338ccebc73071e89ac936d4ec15ab352trawick<function>lwres_gethostbyname2</function></funcdef>

a3954060338ccebc73071e89ac936d4ec15ab352trawick <paramdef>const char *<parameter>name</parameter></paramdef>

a3954060338ccebc73071e89ac936d4ec15ab352trawick <paramdef>int <parameter>af</parameter></paramdef>

a3954060338ccebc73071e89ac936d4ec15ab352trawick </funcprototype>

ab56518227d474ee08f039e4c5540011c1b8a913trawick<funcprototype>

ab56518227d474ee08f039e4c5540011c1b8a913trawick <funcdef>

ab56518227d474ee08f039e4c5540011c1b8a913trawickstruct hostent *

4e330708371c3e9b04d1043f0a1ac9368bfbd768coar<function>lwres_gethostbyaddr</function></funcdef>

4e330708371c3e9b04d1043f0a1ac9368bfbd768coar <paramdef>const char *<parameter>addr</parameter></paramdef>

4e330708371c3e9b04d1043f0a1ac9368bfbd768coar <paramdef>int <parameter>len</parameter></paramdef>

532a5de31e1a9732da4923f88e4931d0724ebe72nd <paramdef>int <parameter>type</parameter></paramdef>

532a5de31e1a9732da4923f88e4931d0724ebe72nd </funcprototype>

532a5de31e1a9732da4923f88e4931d0724ebe72nd<funcprototype>

219e31b849ef108cd8f58ba0eedae03414e5edb1thommay <funcdef>

a98959721afc481c7f3a941f85c462f0b90defdathommaystruct hostent *

a98959721afc481c7f3a941f85c462f0b90defdathommay<function>lwres_gethostent</function></funcdef>

a98959721afc481c7f3a941f85c462f0b90defdathommay <paramdef>void</paramdef>

219e31b849ef108cd8f58ba0eedae03414e5edb1thommay </funcprototype>

dbb916b882c33a4e340b0dba7d75506cfdd85640trawick<funcprototype>

dbb916b882c33a4e340b0dba7d75506cfdd85640trawick <funcdef>

dbb916b882c33a4e340b0dba7d75506cfdd85640trawickvoid

dbb916b882c33a4e340b0dba7d75506cfdd85640trawick<function>lwres_sethostent</function></funcdef>

dbb916b882c33a4e340b0dba7d75506cfdd85640trawick <paramdef>int <parameter>stayopen</parameter></paramdef>

a18a308d7a942230edcde1bf00d7ae9b4b143c90trawick </funcprototype>

a18a308d7a942230edcde1bf00d7ae9b4b143c90trawick<funcprototype>

a18a308d7a942230edcde1bf00d7ae9b4b143c90trawick <funcdef>

9efe68be3c81ee85225972195fb725dbfc2e8b24trawickvoid

9098f795fab5db41a52b6b82fa475e8f9b3850f0trawick<function>lwres_endhostent</function></funcdef>

9098f795fab5db41a52b6b82fa475e8f9b3850f0trawick <paramdef>void</paramdef>

9098f795fab5db41a52b6b82fa475e8f9b3850f0trawick </funcprototype>

9efe68be3c81ee85225972195fb725dbfc2e8b24trawick<funcprototype>

3b872593fd5f61981d9dd69a4b0b5d5f5f668929trawick <funcdef>

3b872593fd5f61981d9dd69a4b0b5d5f5f668929trawickstruct hostent *

3b872593fd5f61981d9dd69a4b0b5d5f5f668929trawick<function>lwres_gethostbyname_r</function></funcdef>

fc25339741311efd7d460f18b6287ef38d76bbe6madhum <paramdef>const char *<parameter>name</parameter></paramdef>

fc25339741311efd7d460f18b6287ef38d76bbe6madhum <paramdef>struct hostent *<parameter>resbuf</parameter></paramdef>

fc25339741311efd7d460f18b6287ef38d76bbe6madhum <paramdef>char *<parameter>buf</parameter></paramdef>

fc25339741311efd7d460f18b6287ef38d76bbe6madhum <paramdef>int <parameter>buflen</parameter></paramdef>

fcdca175a52fe517f2317ba0e2b6e6d14522b869madhum <paramdef>int *<parameter>error</parameter></paramdef>

19fdbc5566bf67dde644be9e8d38d62db4dd0ba5jerenkrantz </funcprototype>

92a2439559cf1161742650ed9c50c6483bd029cemadhum<funcprototype>

92a2439559cf1161742650ed9c50c6483bd029cemadhum <funcdef>

92a2439559cf1161742650ed9c50c6483bd029cemadhumstruct hostent *

92a2439559cf1161742650ed9c50c6483bd029cemadhum<function>lwres_gethostbyaddr_r</function></funcdef>

ebecc16986604cce1369d5075eff65032e3dd0deianh <paramdef>const char *<parameter>addr</parameter></paramdef>

0d60370bedd05f9632f54e85c417ce472d463674madhum <paramdef>int <parameter>len</parameter></paramdef>

ebecc16986604cce1369d5075eff65032e3dd0deianh <paramdef>int <parameter>type</parameter></paramdef>

764315969cef40e50cdc6a5e9638454e10c1c06end <paramdef>struct hostent *<parameter>resbuf</parameter></paramdef>

764315969cef40e50cdc6a5e9638454e10c1c06end <paramdef>char *<parameter>buf</parameter></paramdef>

764315969cef40e50cdc6a5e9638454e10c1c06end <paramdef>int <parameter>buflen</parameter></paramdef>

764315969cef40e50cdc6a5e9638454e10c1c06end <paramdef>int *<parameter>error</parameter></paramdef>

bfb54bd96690887dcdf184fd9083c2e167898ce2nd </funcprototype>

a2c036f0ca71e35c085b4cd9451a6d3718bc65daake<funcprototype>

a2c036f0ca71e35c085b4cd9451a6d3718bc65daake <funcdef>

a2c036f0ca71e35c085b4cd9451a6d3718bc65daakestruct hostent *

a2c036f0ca71e35c085b4cd9451a6d3718bc65daake<function>lwres_gethostent_r</function></funcdef>

b92cba59a0890be43b14aaf1ce30606140be9593nd <paramdef>struct hostent *<parameter>resbuf</parameter></paramdef>

b92cba59a0890be43b14aaf1ce30606140be9593nd <paramdef>char *<parameter>buf</parameter></paramdef>

b92cba59a0890be43b14aaf1ce30606140be9593nd <paramdef>int <parameter>buflen</parameter></paramdef>

b92cba59a0890be43b14aaf1ce30606140be9593nd <paramdef>int *<parameter>error</parameter></paramdef>

402d23baca89e8c4fcb4e52ad8b2d66a6904baaetrawick </funcprototype>

402d23baca89e8c4fcb4e52ad8b2d66a6904baaetrawick<funcprototype>

402d23baca89e8c4fcb4e52ad8b2d66a6904baaetrawick <funcdef>

4caa28863a3418d26cc20a998dc368c3de3b7e19jerenkrantzvoid

4caa28863a3418d26cc20a998dc368c3de3b7e19jerenkrantz<function>lwres_sethostent_r</function></funcdef>

4caa28863a3418d26cc20a998dc368c3de3b7e19jerenkrantz <paramdef>int <parameter>stayopen</parameter></paramdef>

a3f2646ef3d8a3a5234a5601de0f95f10308c2a6jerenkrantz </funcprototype>

a3f2646ef3d8a3a5234a5601de0f95f10308c2a6jerenkrantz<funcprototype>

a3f2646ef3d8a3a5234a5601de0f95f10308c2a6jerenkrantz <funcdef>

9e398d701dd430f073ff5418fb720642e064046ajerenkrantzvoid

9e398d701dd430f073ff5418fb720642e064046ajerenkrantz<function>lwres_endhostent_r</function></funcdef>

9e398d701dd430f073ff5418fb720642e064046ajerenkrantz <paramdef>void</paramdef>

1a5b9e0071f0c662036250b482d566ad87ff0b4bjerenkrantz </funcprototype>

1a5b9e0071f0c662036250b482d566ad87ff0b4bjerenkrantz</funcsynopsis>

1a5b9e0071f0c662036250b482d566ad87ff0b4bjerenkrantz </refsynopsisdiv>

a7ac9b52c3d9f7ce937f078a0d585023db626c55jerenkrantz

a7ac9b52c3d9f7ce937f078a0d585023db626c55jerenkrantz <refsection><info><title>DESCRIPTION</title></info>

a7ac9b52c3d9f7ce937f078a0d585023db626c55jerenkrantz

ba6c07204bd224fa5d4cd0e6b8bf256d6daffb74nd <para>

ba6c07204bd224fa5d4cd0e6b8bf256d6daffb74nd These functions provide hostname-to-address and

ba6c07204bd224fa5d4cd0e6b8bf256d6daffb74nd address-to-hostname lookups by means of the lightweight resolver.

db5837bbc9bef214303e755fa52122140366cb6fianh They are similar to the standard

db5837bbc9bef214303e755fa52122140366cb6fianh <citerefentry>

db5837bbc9bef214303e755fa52122140366cb6fianh <refentrytitle>gethostent</refentrytitle><manvolnum>3</manvolnum>

aac2b82fe4f1ac117e2a0702438d6615542642dand </citerefentry>

aac2b82fe4f1ac117e2a0702438d6615542642dand functions provided by most operating systems.

aac2b82fe4f1ac117e2a0702438d6615542642dand They use a

a793d402c74e50326a2401cfbdc562c5781948fdnd <type>struct hostent</type>

a793d402c74e50326a2401cfbdc562c5781948fdnd which is usually defined in

0a209fcb17b8c9a42a6149a1758e61cf6527d367nd <filename>&lt;namedb.h&gt;</filename>.

a793d402c74e50326a2401cfbdc562c5781948fdnd </para>

99d360dcbb5ac2be27694be74cc6124dbadf3315jerenkrantz <para><programlisting>

99d360dcbb5ac2be27694be74cc6124dbadf3315jerenkrantzstruct hostent {

99d360dcbb5ac2be27694be74cc6124dbadf3315jerenkrantz char *h_name; /* official name of host */

3ded62d7f2c9b12616d718b8c97d3044baa9ecdbjerenkrantz char **h_aliases; /* alias list */

3ded62d7f2c9b12616d718b8c97d3044baa9ecdbjerenkrantz int h_addrtype; /* host address type */

3ded62d7f2c9b12616d718b8c97d3044baa9ecdbjerenkrantz int h_length; /* length of address */

ab8c0315521735c73ce16c8072f91e17c406ca5bnd char **h_addr_list; /* list of addresses from name server */

ab8c0315521735c73ce16c8072f91e17c406ca5bnd};

ab8c0315521735c73ce16c8072f91e17c406ca5bnd#define h_addr h_addr_list[0] /* address, for backward compatibility */

b9e99e0d3154bbebe3e1b8d11d6c15bde79510a5nd</programlisting>

b9e99e0d3154bbebe3e1b8d11d6c15bde79510a5nd </para>

b9e99e0d3154bbebe3e1b8d11d6c15bde79510a5nd <para>

b9e99e0d3154bbebe3e1b8d11d6c15bde79510a5nd The members of this structure are:

ea5f8cfbb7ef1d19318f6994c26dd73c38ffd8ddjerenkrantz <variablelist>

ea5f8cfbb7ef1d19318f6994c26dd73c38ffd8ddjerenkrantz <varlistentry>

ea5f8cfbb7ef1d19318f6994c26dd73c38ffd8ddjerenkrantz <term><constant>h_name</constant></term>

4567cfc6a65328bd3e8dd2b758ca926b389c7058brianp <listitem>

4567cfc6a65328bd3e8dd2b758ca926b389c7058brianp <para>

4567cfc6a65328bd3e8dd2b758ca926b389c7058brianp The official (canonical) name of the host.

4cdc5446050c19b9d519a273a129188586e8d445jerenkrantz </para>

4cdc5446050c19b9d519a273a129188586e8d445jerenkrantz </listitem>

4cdc5446050c19b9d519a273a129188586e8d445jerenkrantz </varlistentry>

2f408250e9111c4b85b2b4b9b8836e83987efdefstoddard <varlistentry>

2f408250e9111c4b85b2b4b9b8836e83987efdefstoddard <term><constant>h_aliases</constant></term>

2f408250e9111c4b85b2b4b9b8836e83987efdefstoddard <listitem>

2f408250e9111c4b85b2b4b9b8836e83987efdefstoddard <para>

d5b7ba26785d7494166d48876362ba30ff30b98awrowe A NULL-terminated array of alternate names (nicknames) for the

47fe07199bddec6124ab7251c6be5c6c9ac00485jerenkrantz host.

47fe07199bddec6124ab7251c6be5c6c9ac00485jerenkrantz </para>

6646a289c2d4778c8cd43d62b5a1cc966a356f85jerenkrantz </listitem>

6646a289c2d4778c8cd43d62b5a1cc966a356f85jerenkrantz </varlistentry>

6646a289c2d4778c8cd43d62b5a1cc966a356f85jerenkrantz <varlistentry>

6646a289c2d4778c8cd43d62b5a1cc966a356f85jerenkrantz <term><constant>h_addrtype</constant></term>

aec70520ebe1e33e0d5e83c3626649d2a41dbe68wrowe <listitem>

aec70520ebe1e33e0d5e83c3626649d2a41dbe68wrowe <para>

aec70520ebe1e33e0d5e83c3626649d2a41dbe68wrowe The type of address being returned &mdash;

ad451e2e428a069086d1c18c9e3372f8846ec617wrowe <type>PF_INET</type>

ad451e2e428a069086d1c18c9e3372f8846ec617wrowe or

ad451e2e428a069086d1c18c9e3372f8846ec617wrowe <type>PF_INET6</type>.

ad451e2e428a069086d1c18c9e3372f8846ec617wrowe </para>

59b910556d04c82e951d6c6f7a413ab8fed21467trawick </listitem>

59b910556d04c82e951d6c6f7a413ab8fed21467trawick </varlistentry>

85bf271a2a8d88736575e93504528639f5971f97nd <varlistentry>

85bf271a2a8d88736575e93504528639f5971f97nd <term><constant>h_length</constant></term>

85bf271a2a8d88736575e93504528639f5971f97nd <listitem>

85bf271a2a8d88736575e93504528639f5971f97nd <para>

5c457d20a708ef42b0824290d0feda1852a37493rederpj The length of the address in bytes.

5c457d20a708ef42b0824290d0feda1852a37493rederpj </para>

13590409a89cdf7e5dc52516919ccee94edad59brederpj </listitem>

5c457d20a708ef42b0824290d0feda1852a37493rederpj </varlistentry>

a22d4a5da8c5167776b9e62737379cc9b857ef4drederpj <varlistentry>

13590409a89cdf7e5dc52516919ccee94edad59brederpj <term><constant>h_addr_list</constant></term>

a22d4a5da8c5167776b9e62737379cc9b857ef4drederpj <listitem>

cde00ab9085ea6e93db4a27bf6fe9a9b6eda4addnd <para>

cde00ab9085ea6e93db4a27bf6fe9a9b6eda4addnd A <type>NULL</type>

cde00ab9085ea6e93db4a27bf6fe9a9b6eda4addnd terminated array of network addresses for the host.

cde00ab9085ea6e93db4a27bf6fe9a9b6eda4addnd Host addresses are returned in network byte order.

cde00ab9085ea6e93db4a27bf6fe9a9b6eda4addnd </para>

cde00ab9085ea6e93db4a27bf6fe9a9b6eda4addnd </listitem>

159d95df05b3100bbef7a60cb5f5d7d8d5a3328etrawick </varlistentry>

159d95df05b3100bbef7a60cb5f5d7d8d5a3328etrawick </variablelist>

159d95df05b3100bbef7a60cb5f5d7d8d5a3328etrawick </para>

159d95df05b3100bbef7a60cb5f5d7d8d5a3328etrawick <para>

59b910556d04c82e951d6c6f7a413ab8fed21467trawick For backward compatibility with very old software,

59b910556d04c82e951d6c6f7a413ab8fed21467trawick <constant>h_addr</constant>

59b910556d04c82e951d6c6f7a413ab8fed21467trawick is the first address in

59b910556d04c82e951d6c6f7a413ab8fed21467trawick <constant>h_addr_list.</constant>

59b910556d04c82e951d6c6f7a413ab8fed21467trawick </para>

9768955299008e29705461b314b763a79104e576nd <para><function>lwres_gethostent()</function>,

761fb8d21084bd7b7eb590fbd54a925dfdf806bbnd <function>lwres_sethostent()</function>,

03e310ef946842b4dfa718776c870d012fc9ec67striker <function>lwres_endhostent()</function>,

03e310ef946842b4dfa718776c870d012fc9ec67striker <function>lwres_gethostent_r()</function>,

03e310ef946842b4dfa718776c870d012fc9ec67striker <function>lwres_sethostent_r()</function>

03e310ef946842b4dfa718776c870d012fc9ec67striker and

03e310ef946842b4dfa718776c870d012fc9ec67striker <function>lwres_endhostent_r()</function>

03e310ef946842b4dfa718776c870d012fc9ec67striker provide iteration over the known host entries on systems that

611d2f4e86b4eceb640a5301bd88a23cb459e5a8striker provide such functionality through facilities like

611d2f4e86b4eceb640a5301bd88a23cb459e5a8striker <filename>/etc/hosts</filename>

611d2f4e86b4eceb640a5301bd88a23cb459e5a8striker or NIS. The lightweight resolver does not currently implement

611d2f4e86b4eceb640a5301bd88a23cb459e5a8striker these functions; it only provides them as stub functions that always

611d2f4e86b4eceb640a5301bd88a23cb459e5a8striker return failure.

f59888906d0566361498848fa95b4c416fad976cstriker </para>

f59888906d0566361498848fa95b4c416fad976cstriker

f59888906d0566361498848fa95b4c416fad976cstriker <para><function>lwres_gethostbyname()</function>

f59888906d0566361498848fa95b4c416fad976cstriker and <function>lwres_gethostbyname2()</function> look up the

f59888906d0566361498848fa95b4c416fad976cstriker hostname <parameter>name</parameter>.

6a3078c438bee65f22004ac65cd2eb4fa521bbfastriker <function>lwres_gethostbyname()</function> always looks for an

6a3078c438bee65f22004ac65cd2eb4fa521bbfastriker IPv4 address while <function>lwres_gethostbyname2()</function>

6a3078c438bee65f22004ac65cd2eb4fa521bbfastriker looks for an address of protocol family

6a3078c438bee65f22004ac65cd2eb4fa521bbfastriker <parameter>af</parameter>: either <type>PF_INET</type> or

26acc990e97a62631a3654405d676b928a78ebbcstriker <type>PF_INET6</type> &mdash; IPv4 or IPV6 addresses

26acc990e97a62631a3654405d676b928a78ebbcstriker respectively. Successful calls of the functions return a

29ecc0949b383793b24cdd0741cb86c02138ab36striker <type>struct hostent</type>for the name that was looked up.

29ecc0949b383793b24cdd0741cb86c02138ab36striker <type>NULL</type> is returned if the lookups by

29ecc0949b383793b24cdd0741cb86c02138ab36striker <function>lwres_gethostbyname()</function> or

29ecc0949b383793b24cdd0741cb86c02138ab36striker <function>lwres_gethostbyname2()</function> fail.

29ecc0949b383793b24cdd0741cb86c02138ab36striker </para>

29ecc0949b383793b24cdd0741cb86c02138ab36striker

c97f8ff3a7479c838545de0c59770938b50ab6d3gstein <para>

c97f8ff3a7479c838545de0c59770938b50ab6d3gstein Reverse lookups of addresses are performed by

c97f8ff3a7479c838545de0c59770938b50ab6d3gstein <function>lwres_gethostbyaddr()</function>.

6fb9d10c529c2be3bb1833b0eefdd27ba4df1610trawick <parameter>addr</parameter> is an address of length

6fb9d10c529c2be3bb1833b0eefdd27ba4df1610trawick <parameter>len</parameter> bytes and protocol family

6fb9d10c529c2be3bb1833b0eefdd27ba4df1610trawick <parameter>type</parameter> &mdash; <type>PF_INET</type> or

6fb9d10c529c2be3bb1833b0eefdd27ba4df1610trawick <type>PF_INET6</type>.

6fb9d10c529c2be3bb1833b0eefdd27ba4df1610trawick <function>lwres_gethostbyname_r()</function> is a

6fb9d10c529c2be3bb1833b0eefdd27ba4df1610trawick thread-safe function

368a950bc36b428b737d079f77e8962c831f88aand for forward lookups. If an error occurs, an error code is returned in

368a950bc36b428b737d079f77e8962c831f88aand <parameter>*error</parameter>.

368a950bc36b428b737d079f77e8962c831f88aand <parameter>resbuf</parameter> is a pointer to a

368a950bc36b428b737d079f77e8962c831f88aand <type>struct hostent</type> which is initialised by a successful call to

9768955299008e29705461b314b763a79104e576nd <function>lwres_gethostbyname_r()</function>.

1ead2314e821e9ac264ea35425e7d0816030e404stoddard <parameter>buf</parameter> is a buffer of length

9768955299008e29705461b314b763a79104e576nd <parameter>len</parameter> bytes which is used to store the

9768955299008e29705461b314b763a79104e576nd <constant>h_name</constant>, <constant>h_aliases</constant>, and

9768955299008e29705461b314b763a79104e576nd <constant>h_addr_list</constant> elements of the

1005ad40d72c4a1df2c0f1b95b770a4c43c49a47mjc <type>struct hostent</type> returned in <parameter>resbuf</parameter>.

1005ad40d72c4a1df2c0f1b95b770a4c43c49a47mjc Successful calls to <function>lwres_gethostbyname_r()</function>

1005ad40d72c4a1df2c0f1b95b770a4c43c49a47mjc return <parameter>resbuf</parameter>,

1005ad40d72c4a1df2c0f1b95b770a4c43c49a47mjc which is a pointer to the <type>struct hostent</type> it created.

1005ad40d72c4a1df2c0f1b95b770a4c43c49a47mjc </para>

1005ad40d72c4a1df2c0f1b95b770a4c43c49a47mjc

1005ad40d72c4a1df2c0f1b95b770a4c43c49a47mjc <para><function>lwres_gethostbyaddr_r()</function>

1005ad40d72c4a1df2c0f1b95b770a4c43c49a47mjc is a thread-safe function

1005ad40d72c4a1df2c0f1b95b770a4c43c49a47mjc that performs a reverse lookup of address <parameter>addr</parameter>

1005ad40d72c4a1df2c0f1b95b770a4c43c49a47mjc which is <parameter>len</parameter> bytes long and is of

1005ad40d72c4a1df2c0f1b95b770a4c43c49a47mjc protocol

da5a84048552168ea64c3012573acd4de1434dcdjerenkrantz family <parameter>type</parameter> &mdash; <type>PF_INET</type> or

da5a84048552168ea64c3012573acd4de1434dcdjerenkrantz <type>PF_INET6</type>. If an error occurs, the error code is returned

da5a84048552168ea64c3012573acd4de1434dcdjerenkrantz in <parameter>*error</parameter>. The other function

da5a84048552168ea64c3012573acd4de1434dcdjerenkrantz parameters are

da5a84048552168ea64c3012573acd4de1434dcdjerenkrantz identical to those in <function>lwres_gethostbyname_r()</function>.

da5a84048552168ea64c3012573acd4de1434dcdjerenkrantz <parameter>resbuf</parameter> is a pointer to a

da5a84048552168ea64c3012573acd4de1434dcdjerenkrantz <type>struct hostent</type> which is initialised by a successful call to

da5a84048552168ea64c3012573acd4de1434dcdjerenkrantz <function>lwres_gethostbyaddr_r()</function>.

da5a84048552168ea64c3012573acd4de1434dcdjerenkrantz <parameter>buf</parameter> is a buffer of length

da5a84048552168ea64c3012573acd4de1434dcdjerenkrantz <parameter>len</parameter> bytes which is used to store the

19fdbc5566bf67dde644be9e8d38d62db4dd0ba5jerenkrantz <constant>h_name</constant>, <constant>h_aliases</constant>, and

19fdbc5566bf67dde644be9e8d38d62db4dd0ba5jerenkrantz <constant>h_addr_list</constant> elements of the

19fdbc5566bf67dde644be9e8d38d62db4dd0ba5jerenkrantz <type>struct hostent</type> returned in <parameter>resbuf</parameter>.

19fdbc5566bf67dde644be9e8d38d62db4dd0ba5jerenkrantz Successful calls to <function>lwres_gethostbyaddr_r()</function> return

19fdbc5566bf67dde644be9e8d38d62db4dd0ba5jerenkrantz <parameter>resbuf</parameter>, which is a pointer to the

19fdbc5566bf67dde644be9e8d38d62db4dd0ba5jerenkrantz <function>struct hostent()</function> it created.

19fdbc5566bf67dde644be9e8d38d62db4dd0ba5jerenkrantz </para>

19fdbc5566bf67dde644be9e8d38d62db4dd0ba5jerenkrantz

19fdbc5566bf67dde644be9e8d38d62db4dd0ba5jerenkrantz </refsection>

e874834efe9943668668c7fa498af3b3c7caffbdnd

e874834efe9943668668c7fa498af3b3c7caffbdnd <refsection><info><title>RETURN VALUES</title></info>

e874834efe9943668668c7fa498af3b3c7caffbdnd

e874834efe9943668668c7fa498af3b3c7caffbdnd <para>

e874834efe9943668668c7fa498af3b3c7caffbdnd The functions

e874834efe9943668668c7fa498af3b3c7caffbdnd <function>lwres_gethostbyname()</function>,

e874834efe9943668668c7fa498af3b3c7caffbdnd <function>lwres_gethostbyname2()</function>,

b617020883fa3b18bc9b5be5e896ceed79a7ff7fnd <function>lwres_gethostbyaddr()</function>,

b617020883fa3b18bc9b5be5e896ceed79a7ff7fnd and

b617020883fa3b18bc9b5be5e896ceed79a7ff7fnd <function>lwres_gethostent()</function>

38873f61704cbe5eadaa3fb9dca84a4bee1ae5d5wrowe return NULL to indicate an error. In this case the global variable

38873f61704cbe5eadaa3fb9dca84a4bee1ae5d5wrowe <type>lwres_h_errno</type>

38873f61704cbe5eadaa3fb9dca84a4bee1ae5d5wrowe will contain one of the following error codes defined in

38873f61704cbe5eadaa3fb9dca84a4bee1ae5d5wrowe <filename>&lt;lwres/netdb.h&gt;</filename>:

38873f61704cbe5eadaa3fb9dca84a4bee1ae5d5wrowe

68a80326bd8b6f717ae0c44d4bb7273023aad1edwrowe <variablelist>

68a80326bd8b6f717ae0c44d4bb7273023aad1edwrowe <varlistentry>

68a80326bd8b6f717ae0c44d4bb7273023aad1edwrowe <term><constant>HOST_NOT_FOUND</constant></term>

68a80326bd8b6f717ae0c44d4bb7273023aad1edwrowe <listitem>

68a80326bd8b6f717ae0c44d4bb7273023aad1edwrowe <para>

68a80326bd8b6f717ae0c44d4bb7273023aad1edwrowe The host or address was not found.

6838d0e05a193cb77265db36e3549201b3df57e6wrowe </para>

6838d0e05a193cb77265db36e3549201b3df57e6wrowe </listitem>

6838d0e05a193cb77265db36e3549201b3df57e6wrowe </varlistentry>

6838d0e05a193cb77265db36e3549201b3df57e6wrowe <varlistentry>

903c124068c87c957f1327de486017a19cccd348stoddard <term><constant>TRY_AGAIN</constant></term>

903c124068c87c957f1327de486017a19cccd348stoddard <listitem>

903c124068c87c957f1327de486017a19cccd348stoddard <para>

903c124068c87c957f1327de486017a19cccd348stoddard A recoverable error occurred, e.g., a timeout.

732269e2780cb818c1b48aeffa0b432b0ce4ee5eaaron Retrying the lookup may succeed.

732269e2780cb818c1b48aeffa0b432b0ce4ee5eaaron </para>

20aa030accab9a4df293294283fbe6a4ae961588trawick </listitem>

20aa030accab9a4df293294283fbe6a4ae961588trawick </varlistentry>

20aa030accab9a4df293294283fbe6a4ae961588trawick <varlistentry>

b617020883fa3b18bc9b5be5e896ceed79a7ff7fnd <term><constant>NO_RECOVERY</constant></term>

e08b3783b570fdea39520da5e6c174394e956d17nd <listitem>

e08b3783b570fdea39520da5e6c174394e956d17nd <para>

e08b3783b570fdea39520da5e6c174394e956d17nd A non-recoverable error occurred.

e08b3783b570fdea39520da5e6c174394e956d17nd </para>

e08b3783b570fdea39520da5e6c174394e956d17nd </listitem>

e08b3783b570fdea39520da5e6c174394e956d17nd </varlistentry>

e08b3783b570fdea39520da5e6c174394e956d17nd <varlistentry>

e08b3783b570fdea39520da5e6c174394e956d17nd <term><constant>NO_DATA</constant></term>

e08b3783b570fdea39520da5e6c174394e956d17nd <listitem>

e08b3783b570fdea39520da5e6c174394e956d17nd <para>

16de8ff78c533f06c64d5ab2b685953992ff8659thommay The name exists, but has no address information

16de8ff78c533f06c64d5ab2b685953992ff8659thommay associated with it (or vice versa in the case

16de8ff78c533f06c64d5ab2b685953992ff8659thommay of a reverse lookup). The code NO_ADDRESS

16de8ff78c533f06c64d5ab2b685953992ff8659thommay is accepted as a synonym for NO_DATA for backwards

5aef954598e763eea457d204897a6a12d281755dtrawick compatibility.

5aef954598e763eea457d204897a6a12d281755dtrawick </para>

5aef954598e763eea457d204897a6a12d281755dtrawick </listitem>

5aef954598e763eea457d204897a6a12d281755dtrawick </varlistentry>

340e970018246649e86dd3ebbd34f4719e3ceaf7trawick </variablelist>

340e970018246649e86dd3ebbd34f4719e3ceaf7trawick </para>

340e970018246649e86dd3ebbd34f4719e3ceaf7trawick

340e970018246649e86dd3ebbd34f4719e3ceaf7trawick <para><citerefentry>

1360e9b0036040edfbcd2273ae18db83a93536detrawick <refentrytitle>lwres_hstrerror</refentrytitle><manvolnum>3</manvolnum>

1360e9b0036040edfbcd2273ae18db83a93536detrawick </citerefentry>

1360e9b0036040edfbcd2273ae18db83a93536detrawick translates these error codes to suitable error messages.

1360e9b0036040edfbcd2273ae18db83a93536detrawick </para>

1360e9b0036040edfbcd2273ae18db83a93536detrawick

1360e9b0036040edfbcd2273ae18db83a93536detrawick <para><function>lwres_gethostent()</function>

c3f32ea297c5350948a0c4472c1ff8433ea4e6bastoddard and <function>lwres_gethostent_r()</function>

c3f32ea297c5350948a0c4472c1ff8433ea4e6bastoddard always return <type>NULL</type>.

c3f32ea297c5350948a0c4472c1ff8433ea4e6bastoddard </para>

c3f32ea297c5350948a0c4472c1ff8433ea4e6bastoddard

6838d0e05a193cb77265db36e3549201b3df57e6wrowe <para>

c3f32ea297c5350948a0c4472c1ff8433ea4e6bastoddard Successful calls to <function>lwres_gethostbyname_r()</function> and

946f7bd76a0dec6d67af79af56a8cff3cb6ef9c1nd <function>lwres_gethostbyaddr_r()</function> return

946f7bd76a0dec6d67af79af56a8cff3cb6ef9c1nd <parameter>resbuf</parameter>, a pointer to the

946f7bd76a0dec6d67af79af56a8cff3cb6ef9c1nd <type>struct hostent</type> that was initialised by these functions. They return

946f7bd76a0dec6d67af79af56a8cff3cb6ef9c1nd <type>NULL</type> if the lookups fail or if <parameter>buf</parameter>

8c038cdb417502a969599568ccc4020576d82a10nd was too small to hold the list of addresses and names referenced by

8c038cdb417502a969599568ccc4020576d82a10nd the <constant>h_name</constant>, <constant>h_aliases</constant>, and

8c038cdb417502a969599568ccc4020576d82a10nd <constant>h_addr_list</constant> elements of the

8c038cdb417502a969599568ccc4020576d82a10nd <type>struct hostent</type>.

8c038cdb417502a969599568ccc4020576d82a10nd If <parameter>buf</parameter> was too small, both

8c038cdb417502a969599568ccc4020576d82a10nd <function>lwres_gethostbyname_r()</function> and

8c038cdb417502a969599568ccc4020576d82a10nd <function>lwres_gethostbyaddr_r()</function> set the global

8c038cdb417502a969599568ccc4020576d82a10nd variable

6838d0e05a193cb77265db36e3549201b3df57e6wrowe <type>errno</type> to <errorcode>ERANGE</errorcode>.

6838d0e05a193cb77265db36e3549201b3df57e6wrowe </para>

83938932cb2dbe320eda488799bb7a0c04156bcdake

83938932cb2dbe320eda488799bb7a0c04156bcdake </refsection>

6838d0e05a193cb77265db36e3549201b3df57e6wrowe <refsection><info><title>SEE ALSO</title></info>

6838d0e05a193cb77265db36e3549201b3df57e6wrowe

6838d0e05a193cb77265db36e3549201b3df57e6wrowe <para><citerefentry>

6838d0e05a193cb77265db36e3549201b3df57e6wrowe <refentrytitle>gethostent</refentrytitle><manvolnum>3</manvolnum>

6838d0e05a193cb77265db36e3549201b3df57e6wrowe </citerefentry>,

6fbf645df300ffa9c9693399571f2cd821af06fdtrawick

6fbf645df300ffa9c9693399571f2cd821af06fdtrawick <citerefentry>

6fbf645df300ffa9c9693399571f2cd821af06fdtrawick <refentrytitle>lwres_getipnode</refentrytitle><manvolnum>3</manvolnum>

6fbf645df300ffa9c9693399571f2cd821af06fdtrawick </citerefentry>,

6fbf645df300ffa9c9693399571f2cd821af06fdtrawick

c8ff8621370eb28a3f697a00bf5e6b3bc1a0d9f1minfrin <citerefentry>

c8ff8621370eb28a3f697a00bf5e6b3bc1a0d9f1minfrin <refentrytitle>lwres_hstrerror</refentrytitle><manvolnum>3</manvolnum>

c8ff8621370eb28a3f697a00bf5e6b3bc1a0d9f1minfrin </citerefentry>

c8ff8621370eb28a3f697a00bf5e6b3bc1a0d9f1minfrin </para>

c8ff8621370eb28a3f697a00bf5e6b3bc1a0d9f1minfrin </refsection>

c8989f842c2ad4533950c13d99d3dfb099da0d67minfrin

c8989f842c2ad4533950c13d99d3dfb099da0d67minfrin <refsection><info><title>BUGS</title></info>

c8989f842c2ad4533950c13d99d3dfb099da0d67minfrin

c8989f842c2ad4533950c13d99d3dfb099da0d67minfrin <para><function>lwres_gethostbyname()</function>,

97610ac677a5eda4a3bb366c5bb34a27eeb4288cminfrin <function>lwres_gethostbyname2()</function>,

97610ac677a5eda4a3bb366c5bb34a27eeb4288cminfrin <function>lwres_gethostbyaddr()</function>

97610ac677a5eda4a3bb366c5bb34a27eeb4288cminfrin and

6aa783d83f4304f664233d8252cb67116769676ewrowe <function>lwres_endhostent()</function>

6aa783d83f4304f664233d8252cb67116769676ewrowe are not thread safe; they return pointers to static data and

6aa783d83f4304f664233d8252cb67116769676ewrowe provide error codes through a global variable.

6aa783d83f4304f664233d8252cb67116769676ewrowe Thread-safe versions for name and address lookup are provided by

6aa783d83f4304f664233d8252cb67116769676ewrowe <function>lwres_gethostbyname_r()</function>,

761fb8d21084bd7b7eb590fbd54a925dfdf806bbnd and

761fb8d21084bd7b7eb590fbd54a925dfdf806bbnd <function>lwres_gethostbyaddr_r()</function>

761fb8d21084bd7b7eb590fbd54a925dfdf806bbnd respectively.

761fb8d21084bd7b7eb590fbd54a925dfdf806bbnd </para>

761fb8d21084bd7b7eb590fbd54a925dfdf806bbnd <para>

761fb8d21084bd7b7eb590fbd54a925dfdf806bbnd The resolver daemon does not currently support any non-DNS

761fb8d21084bd7b7eb590fbd54a925dfdf806bbnd name services such as

761fb8d21084bd7b7eb590fbd54a925dfdf806bbnd <filename>/etc/hosts</filename>

761fb8d21084bd7b7eb590fbd54a925dfdf806bbnd or

761fb8d21084bd7b7eb590fbd54a925dfdf806bbnd <type>NIS</type>,

761fb8d21084bd7b7eb590fbd54a925dfdf806bbnd consequently the above functions don't, either.

367cefc17f8dcfe65651c9c16cb3151589c6cecetrawick </para>

5d6ffa7b5c77dd4132ed6d7f0dd63548b1c3c1c9nd </refsection>

d8f54fe5534b61afa68100dddbe2eb98285d1100wrowe</refentry>

d8f54fe5534b61afa68100dddbe2eb98285d1100wrowe