012a352f4b26cfd874db8d06debc495c2303e8b2Bob Halley<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook V4.1//EN">

f5cfcbf2f7906fb59c2b8b9b8fc9c7a75ac44dabMark Andrews

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<refentry>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley

460b427411b72da26b1836b9424e2e70d65d9394David Lawrence<refentryinfo>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<date>Jun 30, 2000</date>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley</refentryinfo>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley <refmeta>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley <refentrytitle>lwres_gnba</refentrytitle>

b897c52f865b2fc4e220e2110b874e59c716456bBob Halley <manvolnum>3</manvolnum>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley <refmiscinfo>BIND9</refmiscinfo>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley </refmeta>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<refnamediv>

b897c52f865b2fc4e220e2110b874e59c716456bBob Halley<refname>lwres_gnbarequest_render</refname>

460b427411b72da26b1836b9424e2e70d65d9394David Lawrence<refname>lwres_gnbaresponse_render</refname>

460b427411b72da26b1836b9424e2e70d65d9394David Lawrence<refname>lwres_gnbarequest_parse</refname>

460b427411b72da26b1836b9424e2e70d65d9394David Lawrence<refname>lwres_gnbaresponse_parse</refname>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<refname>lwres_gnbaresponse_free</refname>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<refname>lwres_gnbarequest_free</refname>

460b427411b72da26b1836b9424e2e70d65d9394David Lawrence<refpurpose>lightweight resolver getnamebyaddress message handling</refpurpose>

460b427411b72da26b1836b9424e2e70d65d9394David Lawrence</refnamediv>

460b427411b72da26b1836b9424e2e70d65d9394David Lawrence

fcb54ce0a4f7377486df5bec83b3aa4711bf4131Mark Andrews<refsynopsisdiv>

460b427411b72da26b1836b9424e2e70d65d9394David Lawrence

460b427411b72da26b1836b9424e2e70d65d9394David Lawrence<funcsynopsis>

460b427411b72da26b1836b9424e2e70d65d9394David Lawrence<funcsynopsisinfo>

460b427411b72da26b1836b9424e2e70d65d9394David Lawrence#include &lt;lwres/lwres.h&gt;

460b427411b72da26b1836b9424e2e70d65d9394David Lawrence</funcsynopsisinfo>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley

12e63bfe1d111ccb57f482b28d56c785cccc7cf7David Lawrence<funcprototype>

12e63bfe1d111ccb57f482b28d56c785cccc7cf7David Lawrence<funcdef>

12e63bfe1d111ccb57f482b28d56c785cccc7cf7David Lawrencelwres_result_t

12e63bfe1d111ccb57f482b28d56c785cccc7cf7David Lawrence<function>lwres_gnbarequest_render</function>

dabea86dac4c01f852b7aea728f73b4f55a89d44Mark Andrews</funcdef>

dabea86dac4c01f852b7aea728f73b4f55a89d44Mark Andrews<paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef>

dabea86dac4c01f852b7aea728f73b4f55a89d44Mark Andrews<paramdef>lwres_gnbarequest_t *<parameter>req</parameter></paramdef>

f5cfcbf2f7906fb59c2b8b9b8fc9c7a75ac44dabMark Andrews<paramdef>lwres_lwpacket_t *<parameter>pkt</parameter></paramdef>

f5cfcbf2f7906fb59c2b8b9b8fc9c7a75ac44dabMark Andrews<paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>

2d46d268ccff30bb50e661b47c6496d23d9156c7Mark Andrews</funcprototype>

2d46d268ccff30bb50e661b47c6496d23d9156c7Mark Andrews

dabea86dac4c01f852b7aea728f73b4f55a89d44Mark Andrews<funcprototype>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<funcdef>

12e63bfe1d111ccb57f482b28d56c785cccc7cf7David Lawrencelwres_result_t

460b427411b72da26b1836b9424e2e70d65d9394David Lawrence<function>lwres_gnbaresponse_render</function>

12e63bfe1d111ccb57f482b28d56c785cccc7cf7David Lawrence</funcdef>

460b427411b72da26b1836b9424e2e70d65d9394David Lawrence<paramdef>lwres_context_t *ctx</paramdef>

12e63bfe1d111ccb57f482b28d56c785cccc7cf7David Lawrence<paramdef>lwres_gnbaresponse_t *req</paramdef>

460b427411b72da26b1836b9424e2e70d65d9394David Lawrence<paramdef>lwres_lwpacket_t *pkt</paramdef>

596912ee9ca8eb14d30707ec286ab5d28bd39b3eMark Andrews<paramdef>lwres_buffer_t *b</paramdef>

8319af16557b81eba3277ee67215285f0823b587Mark Andrews</funcprototype>

8319af16557b81eba3277ee67215285f0823b587Mark Andrews<funcprototype>

aee5e9cbacd8f88325840b8a498876f4319b0890Mark Andrews<funcdef>

12e63bfe1d111ccb57f482b28d56c785cccc7cf7David Lawrencelwres_result_t

460b427411b72da26b1836b9424e2e70d65d9394David Lawrence<function>lwres_gnbarequest_parse</function></funcdef>

12e63bfe1d111ccb57f482b28d56c785cccc7cf7David Lawrence<paramdef>lwres_context_t *ctx</paramdef>

460b427411b72da26b1836b9424e2e70d65d9394David Lawrence<paramdef>lwres_buffer_t *b</paramdef>

12e63bfe1d111ccb57f482b28d56c785cccc7cf7David Lawrence<paramdef>lwres_lwpacket_t *pkt</paramdef>

c32b87bc54abacf95fb3b063d72b7d1855c1643bMichael Graff<paramdef>lwres_gnbarequest_t **structp</paramdef>

7f9f8c13c5e5e26e0ba2b82c0900d11ecf6269ceMark Andrews</funcprototype>

460b427411b72da26b1836b9424e2e70d65d9394David Lawrence<funcprototype>

12e63bfe1d111ccb57f482b28d56c785cccc7cf7David Lawrence<funcdef>

12e63bfe1d111ccb57f482b28d56c785cccc7cf7David Lawrencelwres_result_t

12e63bfe1d111ccb57f482b28d56c785cccc7cf7David Lawrence<function>lwres_gnbaresponse_parse</function></funcdef>

460b427411b72da26b1836b9424e2e70d65d9394David Lawrence<paramdef>lwres_context_t *ctx</paramdef>

b616f6ed69209ab4c87f610b472aeb20760652f2Mark Andrews<paramdef>lwres_buffer_t *b</paramdef>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<paramdef>lwres_lwpacket_t *pkt</paramdef>

2320f230995995595438a9d9301d84931fd266ceMark Andrews<paramdef>lwres_gnbaresponse_t **structp</paramdef>

c427260a8678f2e99a2337fb95ec98d9c9ee8c05Mark Andrews</funcprototype>

620a452ebe92fff63e85c5930a6e6dc8d9455918Mark Andrews

620a452ebe92fff63e85c5930a6e6dc8d9455918Mark Andrews<funcprototype>

6dcb47e37f9f0cdb94bdabc3fa157ff07983c590Mark Andrews<funcdef>

6dcb47e37f9f0cdb94bdabc3fa157ff07983c590Mark Andrewsvoid

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<function>lwres_gnbaresponse_free</function>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley</funcdef>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<paramdef>lwres_context_t *ctx</paramdef>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<paramdef>lwres_gnbaresponse_t **structp</paramdef>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley</funcprototype>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<funcprototype>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<funcdef>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halleyvoid

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<function>lwres_gnbarequest_free</function></funcdef>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<paramdef>lwres_context_t *ctx</paramdef>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<paramdef>lwres_gnbarequest_t **structp</paramdef>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley</funcprototype>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley</funcsynopsis>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley</refsynopsisdiv>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<refsect1>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<title>DESCRIPTION</title>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<para>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob HalleyThese are low-level routines for creating and parsing

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halleylightweight resolver address-to-name lookup request and

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halleyresponse messages.

0014d6342b0d50ae37126ac16d5bf821d02ffff7David Lawrence</para>

0014d6342b0d50ae37126ac16d5bf821d02ffff7David Lawrence<para>

0014d6342b0d50ae37126ac16d5bf821d02ffff7David LawrenceThere are four main functions for the getnamebyaddr opcode.

0014d6342b0d50ae37126ac16d5bf821d02ffff7David LawrenceOne render function converts a getnamebyaddr request structure -

0014d6342b0d50ae37126ac16d5bf821d02ffff7David Lawrence<type>lwres_gnbarequest_t</type> -

0014d6342b0d50ae37126ac16d5bf821d02ffff7David Lawrenceto the lightweight resolver's canonical format.

a9558a6c63d9c6dbb2f3800b39ccb008652fcde3Mark AndrewsIt is complemented by a parse function that converts a packet in this

a9558a6c63d9c6dbb2f3800b39ccb008652fcde3Mark Andrewscanonical format to a getnamebyaddr request structure.

a9558a6c63d9c6dbb2f3800b39ccb008652fcde3Mark AndrewsAnother render function converts the getnamebyaddr response structure -

c651f15b30f1dae5cc2f00878fb5da5b3a35a468Mark Andrews<type>lwres_gnbaresponse_t</type>

c651f15b30f1dae5cc2f00878fb5da5b3a35a468Mark Andrewsto the canonical format.

0014d6342b0d50ae37126ac16d5bf821d02ffff7David LawrenceThis is complemented by a parse function which converts a packet in

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halleycanonical format to a getnamebyaddr response structure.

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley</para>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<para>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob HalleyThese structures are defined in

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<filename>lwres/lwres.h</filename>.

0b72c791466d0807bcf22522b5ddb7da902c2720Bob HalleyThey are shown below.

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<programlisting>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley#define LWRES_OPCODE_GETNAMEBYADDR 0x00010002U

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halleytypedef struct {

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley lwres_uint32_t flags;

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley lwres_addr_t addr;

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley} lwres_gnbarequest_t;

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halleytypedef struct {

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley lwres_uint32_t flags;

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley lwres_uint16_t naliases;

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley char *realname;

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley char **aliases;

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley lwres_uint16_t realnamelen;

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley lwres_uint16_t *aliaslen;

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley void *base;

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley size_t baselen;

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley} lwres_gnbaresponse_t;

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley</programlisting>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley</para>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<para>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<function>lwres_gnbarequest_render()</function>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halleyuses resolver context

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<varname>ctx</varname>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halleyto convert getnamebyaddr request structure

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<varname>req</varname>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halleyto canonical format.

0b72c791466d0807bcf22522b5ddb7da902c2720Bob HalleyThe packet header structure

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<varname>pkt</varname>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halleyis initialised and transferred to

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halleybuffer

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<varname>b</varname>.

0b72c791466d0807bcf22522b5ddb7da902c2720Bob HalleyThe contents of

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<varname>*req</varname>

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halleyare then appended to the buffer in canonical format.

0b72c791466d0807bcf22522b5ddb7da902c2720Bob Halley<function>lwres_gnbaresponse_render()</function>

performs the same task, except it converts a getnamebyaddr response structure

<type>lwres_gnbaresponse_t</type>

to the lightweight resolver's canonical format.

</para>

<para>

<function>lwres_gnbarequest_parse()</function>

uses context

<varname>ctx</varname>

to convert the contents of packet

<varname>pkt</varname>

to a

<type>lwres_gnbarequest_t</type>

structure.

Buffer

<varname>b</varname>

provides space to be used for storing this structure.

When the function succeeds, the resulting

<type>lwres_gnbarequest_t</type>

is made available through

<varname>*structp</varname>.

<function>lwres_gnbaresponse_parse()</function>

offers the same semantics as

<function>lwres_gnbarequest_parse()</function>

except it yields a

<type>lwres_gnbaresponse_t</type>

structure.

</para>

<para>

<function>lwres_gnbaresponse_free()</function>

and

<function>lwres_gnbarequest_free()</function>

release the memory in resolver context

<varname>ctx</varname>

that was allocated to the

<type>lwres_gnbaresponse_t</type>

or

<type>lwres_gnbarequest_t</type>

structures referenced via

<varname>structp</varname>.

Any memory associated with ancillary buffers and strings for those

structures is also discarded.

</para>

</refsect1>

<refsect1>

<title>RETURN VALUES</title>

<para>

The getnamebyaddr opcode functions

<function>lwres_gnbarequest_render()</function>,

<function>lwres_gnbaresponse_render()</function>

<function>lwres_gnbarequest_parse()</function>

and

<function>lwres_gnbaresponse_parse()</function>

all return

<errorname>LWRES_R_SUCCESS</errorname>

on success.

They return

<errorname>LWRES_R_NOMEMORY</errorname>

if memory allocation fails.

<errorname>LWRES_R_UNEXPECTEDEND</errorname>

is returned if the available space in the buffer

<varname>b</varname>

is too small to accommodate the packet header or the

<type>lwres_gnbarequest_t</type>

and

<type>lwres_gnbaresponse_t</type>

structures.

<function>lwres_gnbarequest_parse()</function>

and

<function>lwres_gnbaresponse_parse()</function>

will return

<errorname>LWRES_R_UNEXPECTEDEND</errorname>

if the buffer is not empty after decoding the received packet.

These functions will return

<errorname>LWRES_R_FAILURE</errorname>

if

<structfield>pktflags</structfield>

in the packet header structure

<type>lwres_lwpacket_t</type>

indicate that the packet is not a response to an earlier query.

</para>

</refsect1>

<refsect1>

<title>SEE ALSO</title>

<para>

<citerefentry>

<refentrytitle>lwres_packet</refentrytitle>

<manvolnum>3</manvolnum>

</citerefentry>.

</refsect1>

</refentry>