lwres_getnameinfo.html revision 7911e6f9de303bca5a3d8b34f4330c8f7cecffae
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c77a61a72b5ecdc507d6cf104142edd371a16c84yz<title>lwres_getnameinfo</title>
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c77a61a72b5ecdc507d6cf104142edd371a16c84yz<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry">
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<a name="id-1"></a><div class="titlepage"></div>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz
c77a61a72b5ecdc507d6cf104142edd371a16c84yz
c77a61a72b5ecdc507d6cf104142edd371a16c84yz
c77a61a72b5ecdc507d6cf104142edd371a16c84yz
c77a61a72b5ecdc507d6cf104142edd371a16c84yz
c77a61a72b5ecdc507d6cf104142edd371a16c84yz
489b7c4ab76ae8df137fbfcc2214f7baa52883a0Raymond Chen
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <div class="refnamediv">
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<h2>Name</h2>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<p>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz lwres_getnameinfo
c77a61a72b5ecdc507d6cf104142edd371a16c84yz &#8212; lightweight resolver socket address structure to hostname and
c77a61a72b5ecdc507d6cf104142edd371a16c84yz service name
c77a61a72b5ecdc507d6cf104142edd371a16c84yz
c77a61a72b5ecdc507d6cf104142edd371a16c84yz </p>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz</div>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <div class="refsynopsisdiv">
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<h2>Synopsis</h2>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <div class="funcsynopsis">
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<pre class="funcsynopsisinfo">#include &lt;lwres/netdb.h&gt;</pre>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;">
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<tr>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<td><code class="funcdef">
c77a61a72b5ecdc507d6cf104142edd371a16c84yzint
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<b class="fsfunc">lwres_getnameinfo</b>(</code></td>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<td>const struct sockaddr *<var class="pdparam">sa</var>, </td>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz</tr>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<tr>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<td>�</td>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<td>size_t <var class="pdparam">salen</var>, </td>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz</tr>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<tr>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<td>�</td>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<td>char *<var class="pdparam">host</var>, </td>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz</tr>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<tr>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<td>�</td>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<td>size_t <var class="pdparam">hostlen</var>, </td>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz</tr>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<tr>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<td>�</td>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<td>char *<var class="pdparam">serv</var>, </td>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz</tr>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<tr>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<td>�</td>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<td>size_t <var class="pdparam">servlen</var>, </td>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz</tr>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<tr>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<td>�</td>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<td>int <var class="pdparam">flags</var><code>)</code>;</td>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz</tr>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz</table>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<div class="funcprototype-spacer">�</div>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz</div>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz </div>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <div class="refsection">
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<a name="id-1.7"></a><h2>DESCRIPTION</h2>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz
c77a61a72b5ecdc507d6cf104142edd371a16c84yz
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <p>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz This function is equivalent to the
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <span class="citerefentry">
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <span class="refentrytitle">getnameinfo</span>(3)
c77a61a72b5ecdc507d6cf104142edd371a16c84yz </span> function defined in RFC2133.
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <code class="function">lwres_getnameinfo()</code> returns the
c77a61a72b5ecdc507d6cf104142edd371a16c84yz hostname for the
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <span class="type">struct sockaddr</span> <em class="parameter"><code>sa</code></em> which
c77a61a72b5ecdc507d6cf104142edd371a16c84yz is
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <em class="parameter"><code>salen</code></em> bytes long. The hostname is of
c77a61a72b5ecdc507d6cf104142edd371a16c84yz length
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <em class="parameter"><code>hostlen</code></em> and is returned via
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <em class="parameter"><code>*host.</code></em> The maximum length of the
c77a61a72b5ecdc507d6cf104142edd371a16c84yz hostname is
c77a61a72b5ecdc507d6cf104142edd371a16c84yz 1025 bytes: <code class="constant">NI_MAXHOST</code>.
c77a61a72b5ecdc507d6cf104142edd371a16c84yz </p>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <p> The name of the service associated with the port number in
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <em class="parameter"><code>sa</code></em> is returned in <em class="parameter"><code>*serv.</code></em>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz It is <em class="parameter"><code>servlen</code></em> bytes long. The
c77a61a72b5ecdc507d6cf104142edd371a16c84yz maximum length
c77a61a72b5ecdc507d6cf104142edd371a16c84yz of the service name is <code class="constant">NI_MAXSERV</code> - 32
c77a61a72b5ecdc507d6cf104142edd371a16c84yz bytes.
c77a61a72b5ecdc507d6cf104142edd371a16c84yz </p>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <p>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz The <em class="parameter"><code>flags</code></em> argument sets the
c77a61a72b5ecdc507d6cf104142edd371a16c84yz following
c77a61a72b5ecdc507d6cf104142edd371a16c84yz bits:
c77a61a72b5ecdc507d6cf104142edd371a16c84yz </p>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<div class="variablelist"><dl class="variablelist">
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<dt><span class="term"><code class="constant">NI_NOFQDN</code></span></dt>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<dd>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <p>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz A fully qualified domain name is not required for local hosts.
c77a61a72b5ecdc507d6cf104142edd371a16c84yz The local part of the fully qualified domain name is returned
c77a61a72b5ecdc507d6cf104142edd371a16c84yz instead.
c77a61a72b5ecdc507d6cf104142edd371a16c84yz </p>
489b7c4ab76ae8df137fbfcc2214f7baa52883a0Raymond Chen </dd>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<dt><span class="term"><code class="constant">NI_NUMERICHOST</code></span></dt>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<dd>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <p>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz Return the address in numeric form, as if calling inet_ntop(),
c77a61a72b5ecdc507d6cf104142edd371a16c84yz instead of a host name.
c77a61a72b5ecdc507d6cf104142edd371a16c84yz </p>
bf56214c0556fa6864189c826d39dbe156bb22a0stevel </dd>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<dt><span class="term"><code class="constant">NI_NAMEREQD</code></span></dt>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<dd>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <p>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz A name is required. If the hostname cannot be found in the DNS
c77a61a72b5ecdc507d6cf104142edd371a16c84yz and
c77a61a72b5ecdc507d6cf104142edd371a16c84yz this flag is set, a non-zero error code is returned.
c77a61a72b5ecdc507d6cf104142edd371a16c84yz If the hostname is not found and the flag is not set, the
c77a61a72b5ecdc507d6cf104142edd371a16c84yz address is returned in numeric form.
bf56214c0556fa6864189c826d39dbe156bb22a0stevel </p>
bf56214c0556fa6864189c826d39dbe156bb22a0stevel </dd>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<dt><span class="term"><code class="constant">NI_NUMERICSERV</code></span></dt>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<dd>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <p>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz The service name is returned as a digit string representing the
c77a61a72b5ecdc507d6cf104142edd371a16c84yz port number.
c77a61a72b5ecdc507d6cf104142edd371a16c84yz </p>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz </dd>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<dt><span class="term"><code class="constant">NI_DGRAM</code></span></dt>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz<dd>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz <p>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz Specifies that the service being looked up is a datagram
c77a61a72b5ecdc507d6cf104142edd371a16c84yz service, and causes getservbyport() to be called with a second
c77a61a72b5ecdc507d6cf104142edd371a16c84yz argument of "udp" instead of its default of "tcp". This is
c77a61a72b5ecdc507d6cf104142edd371a16c84yz required
c77a61a72b5ecdc507d6cf104142edd371a16c84yz for the few ports (512-514) that have different services for UDP
c77a61a72b5ecdc507d6cf104142edd371a16c84yz and
c77a61a72b5ecdc507d6cf104142edd371a16c84yz TCP.
c77a61a72b5ecdc507d6cf104142edd371a16c84yz </p>
c77a61a72b5ecdc507d6cf104142edd371a16c84yz </dd>
</dl></div>
<p>
</p>
</div>
<div class="refsection">
<a name="id-1.8"></a><h2>RETURN VALUES</h2>
<p><code class="function">lwres_getnameinfo()</code>
returns 0 on success or a non-zero error code if an error occurs.
</p>
</div>
<div class="refsection">
<a name="id-1.9"></a><h2>SEE ALSO</h2>
<p><span class="citerefentry">
<span class="refentrytitle">RFC2133</span>
</span>,
<span class="citerefentry">
<span class="refentrytitle">getservbyport</span>(3)
</span>,
<span class="citerefentry">
<span class="refentrytitle">lwres</span>(3)
</span>,
<span class="citerefentry">
<span class="refentrytitle">lwres_getnameinfo</span>(3)
</span>,
<span class="citerefentry">
<span class="refentrytitle">lwres_getnamebyaddr</span>(3)
</span>.
<span class="citerefentry">
<span class="refentrytitle">lwres_net_ntop</span>(3)
</span>.
</p>
</div>
<div class="refsection">
<a name="id-1.10"></a><h2>BUGS</h2>
<p>
RFC2133 fails to define what the nonzero return values of
<span class="citerefentry">
<span class="refentrytitle">getnameinfo</span>(3)
</span>
are.
</p>
</div>
</div></body>
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