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diff --git a/lib/lwres/man/lwres_context.html b/lib/lwres/man/lwres_context.html new file mode 100644 index 0000000..84fcf28 --- /dev/null +++ b/lib/lwres/man/lwres_context.html @@ -0,0 +1,294 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<!-- + - Copyright (C) 2000, 2001, 2003-2005, 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_context</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_context_create, + lwres_context_destroy, + lwres_context_nextserial, + lwres_context_initserial, + lwres_context_freemem, + lwres_context_allocmem, + lwres_context_sendrecv + — lightweight resolver context management + </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_context_create</b>(</code></td> +<td>lwres_context_t **<var class="pdparam">contextp</var>, </td> +</tr> +<tr> +<td> </td> +<td>void *<var class="pdparam">arg</var>, </td> +</tr> +<tr> +<td> </td> +<td>lwres_malloc_t <var class="pdparam">malloc_function</var>, </td> +</tr> +<tr> +<td> </td> +<td>lwres_free_t <var class="pdparam">free_function</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_context_destroy</b>(</code></td> +<td>lwres_context_t **<var class="pdparam">contextp</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"> +void +<b class="fsfunc">lwres_context_initserial</b>(</code></td> +<td>lwres_context_t *<var class="pdparam">ctx</var>, </td> +</tr> +<tr> +<td> </td> +<td>uint32_t <var class="pdparam">serial</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"> +uint32_t +<b class="fsfunc">lwres_context_nextserial</b>(</code></td> +<td>lwres_context_t *<var class="pdparam">ctx</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"> +void +<b class="fsfunc">lwres_context_freemem</b>(</code></td> +<td>lwres_context_t *<var class="pdparam">ctx</var>, </td> +</tr> +<tr> +<td> </td> +<td>void *<var class="pdparam">mem</var>, </td> +</tr> +<tr> +<td> </td> +<td>size_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"> +void +<b class="fsfunc">lwres_context_allocmem</b>(</code></td> +<td>lwres_context_t *<var class="pdparam">ctx</var>, </td> +</tr> +<tr> +<td> </td> +<td>size_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"> +void * +<b class="fsfunc">lwres_context_sendrecv</b>(</code></td> +<td>lwres_context_t *<var class="pdparam">ctx</var>, </td> +</tr> +<tr> +<td> </td> +<td>void *<var class="pdparam">sendbase</var>, </td> +</tr> +<tr> +<td> </td> +<td>int <var class="pdparam">sendlen</var>, </td> +</tr> +<tr> +<td> </td> +<td>void *<var class="pdparam">recvbase</var>, </td> +</tr> +<tr> +<td> </td> +<td>int <var class="pdparam">recvlen</var>, </td> +</tr> +<tr> +<td> </td> +<td>int *<var class="pdparam">recvd_len</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_context_create()</code> + creates a <span class="type">lwres_context_t</span> structure for use in + lightweight resolver operations. It holds a socket and other + data needed for communicating with a resolver daemon. The new + <span class="type">lwres_context_t</span> is returned through + <em class="parameter"><code>contextp</code></em>, a pointer to a + <span class="type">lwres_context_t</span> pointer. This + <span class="type">lwres_context_t</span> pointer must initially be NULL, and + is modified to point to the newly created + <span class="type">lwres_context_t</span>. + </p> + <p> + When the lightweight resolver needs to perform dynamic memory + allocation, it will call + <em class="parameter"><code>malloc_function</code></em> + to allocate memory and + <em class="parameter"><code>free_function</code></em> + to free it. If + <em class="parameter"><code>malloc_function</code></em> + and + <em class="parameter"><code>free_function</code></em> + are NULL, memory is allocated using + <span class="citerefentry"> + <span class="refentrytitle">malloc</span>(3) + </span>. + and + <span class="citerefentry"> + <span class="refentrytitle">free</span>(3) + </span>. + + It is not permitted to have a NULL + <em class="parameter"><code>malloc_function</code></em> and a non-NULL + <em class="parameter"><code>free_function</code></em> or vice versa. + <em class="parameter"><code>arg</code></em> is passed as the first parameter to + the memory allocation functions. If + <em class="parameter"><code>malloc_function</code></em> and + <em class="parameter"><code>free_function</code></em> are NULL, + <em class="parameter"><code>arg</code></em> is unused and should be passed as + NULL. + </p> + + <p> + Once memory for the structure has been allocated, + it is initialized using + <span class="citerefentry"> + <span class="refentrytitle">lwres_conf_init</span>(3) + </span> + and returned via <em class="parameter"><code>*contextp</code></em>. + </p> + + <p><code class="function">lwres_context_destroy()</code> + destroys a <span class="type">lwres_context_t</span>, closing its socket. + <em class="parameter"><code>contextp</code></em> is a pointer to a pointer to the + context that is to be destroyed. The pointer will be set to + NULL when the context has been destroyed. + </p> + + <p> + The context holds a serial number that is used to identify + resolver request packets and associate responses with the + corresponding requests. This serial number is controlled using + <code class="function">lwres_context_initserial()</code> and + <code class="function">lwres_context_nextserial()</code>. + <code class="function">lwres_context_initserial()</code> sets the serial + number for context <em class="parameter"><code>*ctx</code></em> to + <em class="parameter"><code>serial</code></em>. + <code class="function">lwres_context_nextserial()</code> increments the + serial number and returns the previous value. + </p> + + <p> + Memory for a lightweight resolver context is allocated and freed + using <code class="function">lwres_context_allocmem()</code> and + <code class="function">lwres_context_freemem()</code>. These use + whatever allocations were defined when the context was created + with <code class="function">lwres_context_create()</code>. + <code class="function">lwres_context_allocmem()</code> allocates + <em class="parameter"><code>len</code></em> bytes of memory and if successful + returns a pointer to the allocated storage. + <code class="function">lwres_context_freemem()</code> frees + <em class="parameter"><code>len</code></em> bytes of space starting at location + <em class="parameter"><code>mem</code></em>. + </p> + + <p><code class="function">lwres_context_sendrecv()</code> + performs I/O for the context <em class="parameter"><code>ctx</code></em>. Data + are read and written from the context's socket. It writes data + from <em class="parameter"><code>sendbase</code></em> — typically a + lightweight resolver query packet — and waits for a reply + which is copied to the receive buffer at + <em class="parameter"><code>recvbase</code></em>. The number of bytes that were + written to this receive buffer is returned in + <em class="parameter"><code>*recvd_len</code></em>. + </p> + </div> + + <div class="refsection"> +<a name="id-1.8"></a><h2>RETURN VALUES</h2> + + + <p><code class="function">lwres_context_create()</code> + returns <span class="errorcode">LWRES_R_NOMEMORY</span> if memory for + the <span class="type">struct lwres_context</span> could not be allocated, + <span class="errorcode">LWRES_R_SUCCESS</span> otherwise. + </p> + <p> + Successful calls to the memory allocator + <code class="function">lwres_context_allocmem()</code> + return a pointer to the start of the allocated space. + It returns NULL if memory could not be allocated. + </p> + <p><span class="errorcode">LWRES_R_SUCCESS</span> + is returned when + <code class="function">lwres_context_sendrecv()</code> + completes successfully. + <span class="errorcode">LWRES_R_IOERROR</span> + is returned if an I/O error occurs and + <span class="errorcode">LWRES_R_TIMEOUT</span> + is returned if + <code class="function">lwres_context_sendrecv()</code> + times out waiting for a response. + </p> + </div> + <div class="refsection"> +<a name="id-1.9"></a><h2>SEE ALSO</h2> + + <p><span class="citerefentry"> + <span class="refentrytitle">lwres_conf_init</span>(3) + </span>, + + <span class="citerefentry"> + <span class="refentrytitle">malloc</span>(3) + </span>, + + <span class="citerefentry"> + <span class="refentrytitle">free</span>(3) + </span>. + </p> + </div> +</div></body> +</html> |