contrib/bind9/lib/lwres/man/lwres_getnameinfo.docbook

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  21 <!-- $Id: lwres_getnameinfo.docbook,v 1.10 2007/06/18 23:47:51 tbox Exp $ -->
  22 <refentry>
  23
  24   <refentryinfo>
  25     <date>Jun 30, 2000</date>
  26   </refentryinfo>
  27
  28   <refmeta>
  29     <refentrytitle>lwres_getnameinfo</refentrytitle>
  30     <manvolnum>3</manvolnum>
  31     <refmiscinfo>BIND9</refmiscinfo>
  32   </refmeta>
  33
  34   <docinfo>
  35     <copyright>
  36       <year>2004</year>
  37       <year>2005</year>
  38       <year>2007</year>
  39       <holder>Internet Systems Consortium, Inc. ("ISC")</holder>
  40     </copyright>
  41     <copyright>
  42       <year>2000</year>
  43       <year>2001</year>
  44       <holder>Internet Software Consortium.</holder>
  45     </copyright>
  46   </docinfo>
  47
  48   <refnamediv>
  49     <refname>lwres_getnameinfo</refname>
  50     <refpurpose>lightweight resolver socket address structure to hostname and
  51       service name
  52     </refpurpose>
  53   </refnamediv>
  54   <refsynopsisdiv>
  55     <funcsynopsis>
  56 <funcsynopsisinfo>#include &lt;lwres/netdb.h&gt;</funcsynopsisinfo>
  57 <funcprototype>
  58         <funcdef>
  59 int
  60 <function>lwres_getnameinfo</function></funcdef>
  61         <paramdef>const struct sockaddr *<parameter>sa</parameter></paramdef>
  62         <paramdef>size_t <parameter>salen</parameter></paramdef>
  63         <paramdef>char *<parameter>host</parameter></paramdef>
  64         <paramdef>size_t <parameter>hostlen</parameter></paramdef>
  65         <paramdef>char *<parameter>serv</parameter></paramdef>
  66         <paramdef>size_t <parameter>servlen</parameter></paramdef>
  67         <paramdef>int <parameter>flags</parameter></paramdef>
  68       </funcprototype>
  69 </funcsynopsis>
  70   </refsynopsisdiv>
  71
  72   <refsect1>
  73     <title>DESCRIPTION</title>
  74
  75     <para>
  76        This function is equivalent to the
  77       <citerefentry>
  78         <refentrytitle>getnameinfo</refentrytitle><manvolnum>3</manvolnum>
  79       </citerefentry> function defined in RFC2133.
  80       <function>lwres_getnameinfo()</function> returns the
  81       hostname for the
  82       <type>struct sockaddr</type> <parameter>sa</parameter> which
  83       is
  84       <parameter>salen</parameter> bytes long.  The hostname is of
  85       length
  86       <parameter>hostlen</parameter> and is returned via
  87       <parameter>*host.</parameter> The maximum length of the
  88       hostname is
  89       1025 bytes: <constant>NI_MAXHOST</constant>.
  90     </para>
  91
  92     <para> The name of the service associated with the port number in
  93       <parameter>sa</parameter> is returned in <parameter>*serv.</parameter>
  94       It is <parameter>servlen</parameter> bytes long.  The
  95       maximum length
  96       of the service name is <constant>NI_MAXSERV</constant> - 32
  97       bytes.
  98     </para>
  99
 100     <para>
 101        The <parameter>flags</parameter> argument sets the
 102       following
 103       bits:
 104       <variablelist>
 105         <varlistentry>
 106           <term><constant>NI_NOFQDN</constant></term>
 107           <listitem>
 108             <para>
 109               A fully qualified domain name is not required for local hosts.
 110               The local part of the fully qualified domain name is returned
 111               instead.
 112             </para>
 113           </listitem>
 114         </varlistentry>
 115         <varlistentry>
 116           <term><constant>NI_NUMERICHOST</constant></term>
 117           <listitem>
 118             <para>
 119               Return the address in numeric form, as if calling inet_ntop(),
 120               instead of a host name.
 121             </para>
 122           </listitem>
 123         </varlistentry>
 124         <varlistentry>
 125           <term><constant>NI_NAMEREQD</constant></term>
 126           <listitem>
 127             <para>
 128               A name is required. If the hostname cannot be found in the DNS
 129               and
 130               this flag is set, a non-zero error code is returned.
 131               If the hostname is not found and the flag is not set, the
 132               address is returned in numeric form.
 133             </para>
 134           </listitem>
 135         </varlistentry>
 136         <varlistentry>
 137           <term><constant>NI_NUMERICSERV</constant></term>
 138           <listitem>
 139             <para>
 140               The service name is returned as a digit string representing the
 141               port number.
 142             </para>
 143           </listitem>
 144         </varlistentry>
 145         <varlistentry>
 146           <term><constant>NI_DGRAM</constant></term>
 147           <listitem>
 148             <para>
 149               Specifies that the service being looked up is a datagram
 150               service,  and causes getservbyport() to be called with a second
 151               argument of "udp" instead of its default of "tcp".  This is
 152               required
 153               for the few ports (512-514) that have different services for UDP
 154               and
 155               TCP.
 156             </para>
 157           </listitem>
 158         </varlistentry>
 159       </variablelist>
 160     </para>
 161   </refsect1>
 162
 163   <refsect1>
 164     <title>RETURN VALUES</title>
 165     <para><function>lwres_getnameinfo()</function>
 166       returns 0 on success or a non-zero error code if an error occurs.
 167     </para>
 168   </refsect1>
 169   <refsect1>
 170     <title>SEE ALSO</title>
 171     <para><citerefentry>
 172         <refentrytitle>RFC2133</refentrytitle>
 173       </citerefentry>,
 174       <citerefentry>
 175         <refentrytitle>getservbyport</refentrytitle><manvolnum>3</manvolnum>
 176       </citerefentry>,
 177       <citerefentry>
 178         <refentrytitle>lwres</refentrytitle><manvolnum>3</manvolnum>
 179       </citerefentry>,
 180       <citerefentry>
 181         <refentrytitle>lwres_getnameinfo</refentrytitle><manvolnum>3</manvolnum>
 182       </citerefentry>,
 183       <citerefentry>
 184         <refentrytitle>lwres_getnamebyaddr</refentrytitle><manvolnum>3</manvolnum>
 185       </citerefentry>.
 186       <citerefentry>
 187         <refentrytitle>lwres_net_ntop</refentrytitle><manvolnum>3</manvolnum>
 188       </citerefentry>.
 189     </para>
 190   </refsect1>
 191   <refsect1>
 192     <title>BUGS</title>
 193     <para>
 194       RFC2133 fails to define what the nonzero return values of
 195       <citerefentry>
 196         <refentrytitle>getnameinfo</refentrytitle><manvolnum>3</manvolnum>
 197       </citerefentry>
 198       are.
 199     </para>
 200   </refsect1>
 201 </refentry><!--
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