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diff --git a/lib/lwres/man/lwres_context.docbook b/lib/lwres/man/lwres_context.docbook new file mode 100644 index 0000000..b965374 --- /dev/null +++ b/lib/lwres/man/lwres_context.docbook @@ -0,0 +1,262 @@ +<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" + [<!ENTITY mdash "—">]> +<!-- + - Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC") + - Copyright (C) 2000, 2001, 2003 Internet Software Consortium. + - + - Permission to use, copy, modify, and/or distribute this software for any + - purpose with or without fee is hereby granted, provided that the above + - copyright notice and this permission notice appear in all copies. + - + - THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH + - REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY + - AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, + - INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM + - LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE + - OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR + - PERFORMANCE OF THIS SOFTWARE. +--> + +<!-- $Id: lwres_context.docbook,v 1.5.18.6 2007/08/28 07:20:06 tbox Exp $ --> +<refentry> + + <refentryinfo> + <date>Jun 30, 2000</date> + </refentryinfo> + + <refmeta> + <refentrytitle>lwres_context</refentrytitle> + <manvolnum>3</manvolnum> + <refmiscinfo>BIND9</refmiscinfo> + </refmeta> + + <docinfo> + <copyright> + <year>2004</year> + <year>2005</year> + <year>2007</year> + <holder>Internet Systems Consortium, Inc. ("ISC")</holder> + </copyright> + <copyright> + <year>2000</year> + <year>2001</year> + <year>2003</year> + <holder>Internet Software Consortium.</holder> + </copyright> + </docinfo> + + <refnamediv> + <refname>lwres_context_create</refname> + <refname>lwres_context_destroy</refname> + <refname>lwres_context_nextserial</refname> + <refname>lwres_context_initserial</refname> + <refname>lwres_context_freemem</refname> + <refname>lwres_context_allocmem</refname> + <refname>lwres_context_sendrecv</refname> + <refpurpose>lightweight resolver context management</refpurpose> + </refnamediv> + <refsynopsisdiv> + <funcsynopsis> +<funcsynopsisinfo>#include <lwres/lwres.h></funcsynopsisinfo> +<funcprototype> + <funcdef> +lwres_result_t +<function>lwres_context_create</function></funcdef> + <paramdef>lwres_context_t **<parameter>contextp</parameter></paramdef> + <paramdef>void *<parameter>arg</parameter></paramdef> + <paramdef>lwres_malloc_t <parameter>malloc_function</parameter></paramdef> + <paramdef>lwres_free_t <parameter>free_function</parameter></paramdef> + </funcprototype> +<funcprototype> + <funcdef> +lwres_result_t +<function>lwres_context_destroy</function></funcdef> + <paramdef>lwres_context_t **<parameter>contextp</parameter></paramdef> + </funcprototype> +<funcprototype> + <funcdef> +void +<function>lwres_context_initserial</function></funcdef> + <paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef> + <paramdef>lwres_uint32_t <parameter>serial</parameter></paramdef> + </funcprototype> +<funcprototype> + <funcdef> +lwres_uint32_t +<function>lwres_context_nextserial</function></funcdef> + <paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef> + </funcprototype> +<funcprototype> + <funcdef> +void +<function>lwres_context_freemem</function></funcdef> + <paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef> + <paramdef>void *<parameter>mem</parameter></paramdef> + <paramdef>size_t <parameter>len</parameter></paramdef> + </funcprototype> +<funcprototype> + <funcdef> +void +<function>lwres_context_allocmem</function></funcdef> + <paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef> + <paramdef>size_t <parameter>len</parameter></paramdef> + </funcprototype> +<funcprototype> + <funcdef> +void * +<function>lwres_context_sendrecv</function></funcdef> + <paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef> + <paramdef>void *<parameter>sendbase</parameter></paramdef> + <paramdef>int <parameter>sendlen</parameter></paramdef> + <paramdef>void *<parameter>recvbase</parameter></paramdef> + <paramdef>int <parameter>recvlen</parameter></paramdef> + <paramdef>int *<parameter>recvd_len</parameter></paramdef> + </funcprototype> +</funcsynopsis> + </refsynopsisdiv> + <refsect1> + <title>DESCRIPTION</title> + + <para><function>lwres_context_create()</function> + creates a <type>lwres_context_t</type> structure for use in + lightweight resolver operations. It holds a socket and other + data needed for communicating with a resolver daemon. The new + <type>lwres_context_t</type> is returned through + <parameter>contextp</parameter>, a pointer to a + <type>lwres_context_t</type> pointer. This + <type>lwres_context_t</type> pointer must initially be NULL, and + is modified to point to the newly created + <type>lwres_context_t</type>. + </para> + <para> + When the lightweight resolver needs to perform dynamic memory + allocation, it will call + <parameter>malloc_function</parameter> + to allocate memory and + <parameter>free_function</parameter> + to free it. If + <parameter>malloc_function</parameter> + and + <parameter>free_function</parameter> + are NULL, memory is allocated using + <citerefentry> + <refentrytitle>malloc</refentrytitle><manvolnum>3</manvolnum> + </citerefentry>. + and + <citerefentry> + <refentrytitle>free</refentrytitle><manvolnum>3</manvolnum> + </citerefentry>. + + It is not permitted to have a NULL + <parameter>malloc_function</parameter> and a non-NULL + <parameter>free_function</parameter> or vice versa. + <parameter>arg</parameter> is passed as the first parameter to + the memory allocation functions. If + <parameter>malloc_function</parameter> and + <parameter>free_function</parameter> are NULL, + <parameter>arg</parameter> is unused and should be passed as + NULL. + </para> + + <para> + Once memory for the structure has been allocated, + it is initialized using + <citerefentry> + <refentrytitle>lwres_conf_init</refentrytitle><manvolnum>3</manvolnum> + </citerefentry> + and returned via <parameter>*contextp</parameter>. + </para> + + <para><function>lwres_context_destroy()</function> + destroys a <type>lwres_context_t</type>, closing its socket. + <parameter>contextp</parameter> 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. + </para> + + <para> + 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 + <function>lwres_context_initserial()</function> and + <function>lwres_context_nextserial()</function>. + <function>lwres_context_initserial()</function> sets the serial + number for context <parameter>*ctx</parameter> to + <parameter>serial</parameter>. + <function>lwres_context_nextserial()</function> increments the + serial number and returns the previous value. + </para> + + <para> + Memory for a lightweight resolver context is allocated and freed + using <function>lwres_context_allocmem()</function> and + <function>lwres_context_freemem()</function>. These use + whatever allocations were defined when the context was created + with <function>lwres_context_create()</function>. + <function>lwres_context_allocmem()</function> allocates + <parameter>len</parameter> bytes of memory and if successful + returns a pointer to the allocated storage. + <function>lwres_context_freemem()</function> frees + <parameter>len</parameter> bytes of space starting at location + <parameter>mem</parameter>. + </para> + + <para><function>lwres_context_sendrecv()</function> + performs I/O for the context <parameter>ctx</parameter>. Data + are read and written from the context's socket. It writes data + from <parameter>sendbase</parameter> — typically a + lightweight resolver query packet — and waits for a reply + which is copied to the receive buffer at + <parameter>recvbase</parameter>. The number of bytes that were + written to this receive buffer is returned in + <parameter>*recvd_len</parameter>. + </para> + </refsect1> + + <refsect1> + <title>RETURN VALUES</title> + + <para><function>lwres_context_create()</function> + returns <errorcode>LWRES_R_NOMEMORY</errorcode> if memory for + the <type>struct lwres_context</type> could not be allocated, + <errorcode>LWRES_R_SUCCESS</errorcode> otherwise. + </para> + <para> + Successful calls to the memory allocator + <function>lwres_context_allocmem()</function> + return a pointer to the start of the allocated space. + It returns NULL if memory could not be allocated. + </para> + <para><errorcode>LWRES_R_SUCCESS</errorcode> + is returned when + <function>lwres_context_sendrecv()</function> + completes successfully. + <errorcode>LWRES_R_IOERROR</errorcode> + is returned if an I/O error occurs and + <errorcode>LWRES_R_TIMEOUT</errorcode> + is returned if + <function>lwres_context_sendrecv()</function> + times out waiting for a response. + </para> + </refsect1> + <refsect1> + <title>SEE ALSO</title> + <para><citerefentry> + <refentrytitle>lwres_conf_init</refentrytitle><manvolnum>3</manvolnum> + </citerefentry>, + + <citerefentry> + <refentrytitle>malloc</refentrytitle><manvolnum>3</manvolnum> + </citerefentry>, + + <citerefentry> + <refentrytitle>free</refentrytitle><manvolnum>3</manvolnum> + </citerefentry>. + </para> + </refsect1> +</refentry><!-- + - Local variables: + - mode: sgml + - End: +--> |
