diff options
Diffstat (limited to 'lib/lwres/man/lwres_resutil.html')
| -rw-r--r-- | lib/lwres/man/lwres_resutil.html | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/lib/lwres/man/lwres_resutil.html b/lib/lwres/man/lwres_resutil.html new file mode 100644 index 0000000..a5ed52e --- /dev/null +++ b/lib/lwres/man/lwres_resutil.html @@ -0,0 +1,260 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<!-- + - Copyright (C) 2000, 2001, 2004, 2005, 2007, 2014-2016, 2018, 2019 Internet Systems Consortium, Inc. ("ISC") + - + - This Source Code Form is subject to the terms of the Mozilla Public + - License, v. 2.0. If a copy of the MPL was not distributed with this + - file, You can obtain one at http://mozilla.org/MPL/2.0/. +--> +<html lang="en"> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> +<title>lwres_resutil</title> +<meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry"> +<a name="id-1"></a><div class="titlepage"></div> + + + + + + + + <div class="refnamediv"> +<h2>Name</h2> +<p> + lwres_string_parse, + lwres_addr_parse, + lwres_getaddrsbyname, + lwres_getnamebyaddr + — lightweight resolver utility functions + </p> +</div> + <div class="refsynopsisdiv"> +<h2>Synopsis</h2> + <div class="funcsynopsis"> +<pre class="funcsynopsisinfo">#include <lwres/lwres.h></pre> +<table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"> +<tr> +<td><code class="funcdef"> +lwres_result_t +<b class="fsfunc">lwres_string_parse</b>(</code></td> +<td>lwres_buffer_t *<var class="pdparam">b</var>, </td> +</tr> +<tr> +<td> </td> +<td>char **<var class="pdparam">c</var>, </td> +</tr> +<tr> +<td> </td> +<td>uint16_t *<var class="pdparam">len</var><code>)</code>;</td> +</tr> +</table> +<div class="funcprototype-spacer"> </div> +<table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"> +<tr> +<td><code class="funcdef"> +lwres_result_t +<b class="fsfunc">lwres_addr_parse</b>(</code></td> +<td>lwres_buffer_t *<var class="pdparam">b</var>, </td> +</tr> +<tr> +<td> </td> +<td>lwres_addr_t *<var class="pdparam">addr</var><code>)</code>;</td> +</tr> +</table> +<div class="funcprototype-spacer"> </div> +<table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"> +<tr> +<td><code class="funcdef"> +lwres_result_t +<b class="fsfunc">lwres_getaddrsbyname</b>(</code></td> +<td>lwres_context_t *<var class="pdparam">ctx</var>, </td> +</tr> +<tr> +<td> </td> +<td>const char *<var class="pdparam">name</var>, </td> +</tr> +<tr> +<td> </td> +<td>uint32_t <var class="pdparam">addrtypes</var>, </td> +</tr> +<tr> +<td> </td> +<td>lwres_gabnresponse_t **<var class="pdparam">structp</var><code>)</code>;</td> +</tr> +</table> +<div class="funcprototype-spacer"> </div> +<table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"> +<tr> +<td><code class="funcdef"> +lwres_result_t +<b class="fsfunc">lwres_getnamebyaddr</b>(</code></td> +<td>lwres_context_t *<var class="pdparam">ctx</var>, </td> +</tr> +<tr> +<td> </td> +<td>uint32_t <var class="pdparam">addrtype</var>, </td> +</tr> +<tr> +<td> </td> +<td>uint16_t <var class="pdparam">addrlen</var>, </td> +</tr> +<tr> +<td> </td> +<td>const unsigned char *<var class="pdparam">addr</var>, </td> +</tr> +<tr> +<td> </td> +<td>lwres_gnbaresponse_t **<var class="pdparam">structp</var><code>)</code>;</td> +</tr> +</table> +<div class="funcprototype-spacer"> </div> +</div> + </div> + + <div class="refsection"> +<a name="id-1.7"></a><h2>DESCRIPTION</h2> + + + <p><code class="function">lwres_string_parse()</code> + retrieves a DNS-encoded string starting the current pointer of + lightweight resolver buffer <em class="parameter"><code>b</code></em>: i.e. + <code class="constant">b->current</code>. When the function returns, + the address of the first byte of the encoded string is returned + via <em class="parameter"><code>*c</code></em> and the length of that string is + given by <em class="parameter"><code>*len</code></em>. The buffer's current + pointer is advanced to point at the character following the + string length, the encoded string, and the trailing + <span class="type">NULL</span> character. + </p> + + <p><code class="function">lwres_addr_parse()</code> + extracts an address from the buffer <em class="parameter"><code>b</code></em>. + The buffer's current pointer <code class="constant">b->current</code> + is presumed to point at an encoded address: the address preceded + by a 32-bit protocol family identifier and a 16-bit length + field. The encoded address is copied to + <code class="constant">addr->address</code> and + <code class="constant">addr->length</code> indicates the size in bytes + of the address that was copied. + <code class="constant">b->current</code> is advanced to point at the + next byte of available data in the buffer following the encoded + address. + </p> + + <p><code class="function">lwres_getaddrsbyname()</code> + and <code class="function">lwres_getnamebyaddr()</code> use the + <span class="type">lwres_gnbaresponse_t</span> structure defined below: + </p> + +<pre class="programlisting"> +typedef struct { + uint32_t flags; + uint16_t naliases; + uint16_t naddrs; + char *realname; + char **aliases; + uint16_t realnamelen; + uint16_t *aliaslen; + lwres_addrlist_t addrs; + void *base; + size_t baselen; +} lwres_gabnresponse_t; +</pre> + + <p> + The contents of this structure are not manipulated directly but + they are controlled through the + <span class="citerefentry"> + <span class="refentrytitle">lwres_gabn</span>(3) + </span> + functions. + </p> + + <p> + The lightweight resolver uses + <code class="function">lwres_getaddrsbyname()</code> to perform + forward lookups. + Hostname <em class="parameter"><code>name</code></em> is looked up using the + resolver + context <em class="parameter"><code>ctx</code></em> for memory allocation. + <em class="parameter"><code>addrtypes</code></em> is a bitmask indicating + which type of + addresses are to be looked up. Current values for this bitmask are + <span class="type">LWRES_ADDRTYPE_V4</span> for IPv4 addresses and + <span class="type">LWRES_ADDRTYPE_V6</span> for IPv6 addresses. Results of the + lookup are returned in <em class="parameter"><code>*structp</code></em>. + </p> + + <p><code class="function">lwres_getnamebyaddr()</code> + performs reverse lookups. Resolver context + <em class="parameter"><code>ctx</code></em> is used for memory allocation. The + address type is indicated by <em class="parameter"><code>addrtype</code></em>: + <span class="type">LWRES_ADDRTYPE_V4</span> or + <span class="type">LWRES_ADDRTYPE_V6</span>. The address to be looked up is + given by <em class="parameter"><code>addr</code></em> and its length is + <em class="parameter"><code>addrlen</code></em> bytes. The result of the + function call is made available through + <em class="parameter"><code>*structp</code></em>. + </p> + </div> + + <div class="refsection"> +<a name="id-1.8"></a><h2>RETURN VALUES</h2> + + <p> + Successful calls to + <code class="function">lwres_string_parse()</code> + and + <code class="function">lwres_addr_parse()</code> + return + <span class="errorcode">LWRES_R_SUCCESS.</span> + Both functions return + <span class="errorcode">LWRES_R_FAILURE</span> + if the buffer is corrupt or + <span class="errorcode">LWRES_R_UNEXPECTEDEND</span> + if the buffer has less space than expected for the components of the + encoded string or address. + </p> + + <p><code class="function">lwres_getaddrsbyname()</code> + returns <span class="errorcode">LWRES_R_SUCCESS</span> on success and it + returns <span class="errorcode">LWRES_R_NOTFOUND</span> if the hostname + <em class="parameter"><code>name</code></em> could not be found. + </p> + <p><span class="errorcode">LWRES_R_SUCCESS</span> + is returned by a successful call to + <code class="function">lwres_getnamebyaddr()</code>. + </p> + + <p> + Both + <code class="function">lwres_getaddrsbyname()</code> + and + <code class="function">lwres_getnamebyaddr()</code> + return + <span class="errorcode">LWRES_R_NOMEMORY</span> + when memory allocation requests fail and + <span class="errorcode">LWRES_R_UNEXPECTEDEND</span> + if the buffers used for sending queries and receiving replies are too + small. + </p> + + </div> + <div class="refsection"> +<a name="id-1.9"></a><h2>SEE ALSO</h2> + + <p><span class="citerefentry"> + <span class="refentrytitle">lwres_buffer</span>(3) + </span>, + + <span class="citerefentry"> + <span class="refentrytitle">lwres_gabn</span>(3) + </span>. + </p> + + </div> +</div></body> +</html> |