lwres/man/lwres_packet.html

	lwres_packet.html revision c651f15b30f1dae5cc2f00878fb5da5b3a35a468
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync<!--
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync - Copyright (C) 2004, 2005  Internet Systems Consortium, Inc. ("ISC")
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync - Copyright (C) 2000, 2001  Internet Software Consortium.
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync -
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync - Permission to use, copy, modify, and distribute this software for any
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync - purpose with or without fee is hereby granted, provided that the above
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync - copyright notice and this permission notice appear in all copies.
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync -
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync - THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync - REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync - AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync - INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync - LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync - OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync - PERFORMANCE OF THIS SOFTWARE.
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync-->
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync<!-- $Id: lwres_packet.html,v 1.14 2005/04/07 03:50:04 marka Exp $ -->
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync<HTML
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><HEAD
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><TITLE
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync>lwres_packet</TITLE
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><META
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncNAME="GENERATOR"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncCONTENT="Modular DocBook HTML Stylesheet Version 1.79"></HEAD
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><BODY
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncCLASS="REFENTRY"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncBGCOLOR="#FFFFFF"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncTEXT="#000000"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncLINK="#0000FF"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncVLINK="#840084"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncALINK="#0000FF"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><H1
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><A
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncNAME="AEN1"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync></A
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync>lwres_packet</H1
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><DIV
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncCLASS="REFNAMEDIV"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><A
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncNAME="AEN8"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync></A
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><H2
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync>Name</H2
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync>lwres_lwpacket_renderheader, lwres_lwpacket_parseheader&nbsp;--&nbsp;lightweight resolver packet handling functions</DIV
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><DIV
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncCLASS="REFSYNOPSISDIV"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><A
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncNAME="AEN12"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync></A
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><H2
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync>Synopsis</H2
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><DIV
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncCLASS="FUNCSYNOPSIS"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><P
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync></P
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><A
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncNAME="AEN13"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync></A
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><PRE
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncCLASS="FUNCSYNOPSISINFO"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync>#include &lt;lwres/lwpacket.h&gt;</PRE
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><P
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><CODE
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><CODE
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncCLASS="FUNCDEF"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync>lwres_result_t
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsynclwres_lwpacket_renderheader</CODE
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync>(lwres_buffer_t *b, lwres_lwpacket_t *pkt);</CODE
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync></P
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><P
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><CODE
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><CODE
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncCLASS="FUNCDEF"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync>lwres_result_t
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsynclwres_lwpacket_parseheader</CODE
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync>(lwres_buffer_t *b, lwres_lwpacket_t *pkt);</CODE
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync></P
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><P
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync></P
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync></DIV
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync></DIV
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><DIV
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncCLASS="REFSECT1"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><A
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncNAME="AEN25"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync></A
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><H2
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync>DESCRIPTION</H2
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync><P
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync>These functions rely on a
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync<SPAN
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncCLASS="TYPE"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync>struct lwres_lwpacket</SPAN
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync>
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncwhich is defined in
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync<TT
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncCLASS="FILENAME"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync>lwres/lwpacket.h</TT
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync>.
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync<PRE
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncCLASS="PROGRAMLISTING"
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync>typedef struct lwres_lwpacket lwres_lwpacket_t;
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsyncstruct lwres_lwpacket {
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync        lwres_uint32_t          length;
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync        lwres_uint16_t          version;
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync        lwres_uint16_t          pktflags;
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync        lwres_uint32_t          serial;
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync        lwres_uint32_t          opcode;
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync        lwres_uint32_t          result;
14ea49401f3c8c61422aefbda43809e275f60c6cvboxsync        lwres_uint32_t          recvlength;
        lwres_uint16_t          authtype;
        lwres_uint16_t          authlength;
};</PRE
></P
><P
>The elements of this structure are:
<P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><CODE
CLASS="CONSTANT"
>length</CODE
></DT
><DD
><P
>the overall packet length, including the entire packet header.
This field is filled in by the lwres_gabn_*() and lwres_gnba_*()
calls.</P
></DD
><DT
><CODE
CLASS="CONSTANT"
>version</CODE
></DT
><DD
><P
>the header format. There is currently only one format,
<SPAN
CLASS="TYPE"
>LWRES_LWPACKETVERSION_0</SPAN
>.

This field is filled in by the lwres_gabn_*() and lwres_gnba_*()
calls.</P
></DD
><DT
><CODE
CLASS="CONSTANT"
>pktflags</CODE
></DT
><DD
><P
>library-defined flags for this packet: for instance whether the packet
is a request or a reply. Flag values can be set, but not defined by
the caller.
This field is filled in by the application wit the exception of the
LWRES_LWPACKETFLAG_RESPONSE bit, which is set by the library in the
lwres_gabn_*() and lwres_gnba_*() calls.</P
></DD
><DT
><CODE
CLASS="CONSTANT"
>serial</CODE
></DT
><DD
><P
>is set by the requestor and is returned in all replies. If two or more
packets from the same source have the same serial number and are from
the same source, they are assumed to be duplicates and the latter ones
may be dropped.
This field must be set by the application.</P
></DD
><DT
><CODE
CLASS="CONSTANT"
>opcode</CODE
></DT
><DD
><P
>indicates the operation.
Opcodes between 0x00000000 and 0x03ffffff are
reserved for use by the lightweight resolver library. Opcodes between
0x04000000 and 0xffffffff are application defined.
This field is filled in by the lwres_gabn_*() and lwres_gnba_*()
calls.</P
></DD
><DT
><CODE
CLASS="CONSTANT"
>result</CODE
></DT
><DD
><P
>is only valid for replies.
Results between 0x04000000 and 0xffffffff are application defined.
Results between 0x00000000 and 0x03ffffff are reserved for library use.
This field is filled in by the lwres_gabn_*() and lwres_gnba_*()
calls.</P
></DD
><DT
><CODE
CLASS="CONSTANT"
>recvlength</CODE
></DT
><DD
><P
>is the maximum buffer size that the receiver can handle on requests
and the size of the buffer needed to satisfy a request when the buffer
is too large for replies.
This field is supplied by the application.</P
></DD
><DT
><CODE
CLASS="CONSTANT"
>authtype</CODE
></DT
><DD
><P
>defines the packet level authentication that is used.
Authorisation types between 0x1000 and 0xffff are application defined
and types between 0x0000 and 0x0fff are reserved for library use.
Currently these are not used and must be zero.</P
></DD
><DT
><CODE
CLASS="CONSTANT"
>authlen</CODE
></DT
><DD
><P
>gives the length of the authentication data.
Since packet authentication is currently not used, this must be zero.</P
></DD
></DL
></DIV
></P
><P
>The following opcodes are currently defined:
<P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><CODE
CLASS="CONSTANT"
>NOOP</CODE
></DT
><DD
><P
>Success is always returned and the packet contents are echoed.
The lwres_noop_*() functions should be used for this type.</P
></DD
><DT
><CODE
CLASS="CONSTANT"
>GETADDRSBYNAME</CODE
></DT
><DD
><P
>returns all known addresses for a given name.
The lwres_gabn_*() functions should be used for this type.</P
></DD
><DT
><CODE
CLASS="CONSTANT"
>GETNAMEBYADDR</CODE
></DT
><DD
><P
>return the hostname for the given address.
The lwres_gnba_*() functions should be used for this type.</P
></DD
></DL
></DIV
></P
><P
><CODE
CLASS="FUNCTION"
>lwres_lwpacket_renderheader()</CODE
> transfers the
contents of lightweight resolver packet structure
<SPAN
CLASS="TYPE"
>lwres_lwpacket_t</SPAN
> <CODE
CLASS="PARAMETER"
>*pkt</CODE
> in network
byte order to the lightweight resolver buffer,
<CODE
CLASS="PARAMETER"
>*b</CODE
>.</P
><P
><CODE
CLASS="FUNCTION"
>lwres_lwpacket_parseheader()</CODE
> performs the
converse operation.  It transfers data in network byte order from
buffer <CODE
CLASS="PARAMETER"
>*b</CODE
> to resolver packet
<CODE
CLASS="PARAMETER"
>*pkt</CODE
>.  The contents of the buffer
<CODE
CLASS="PARAMETER"
>b</CODE
> should correspond to a
<SPAN
CLASS="TYPE"
>lwres_lwpacket_t</SPAN
>.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN107"
></A
><H2
>RETURN VALUES</H2
><P
> Successful calls to
<CODE
CLASS="FUNCTION"
>lwres_lwpacket_renderheader()</CODE
> and
<CODE
CLASS="FUNCTION"
>lwres_lwpacket_parseheader()</CODE
> return
<SPAN
CLASS="ERRORCODE"
>LWRES_R_SUCCESS</SPAN
>.  If there is insufficient
space to copy data between the buffer <CODE
CLASS="PARAMETER"
>*b</CODE
> and
lightweight resolver packet <CODE
CLASS="PARAMETER"
>*pkt</CODE
> both functions
return <SPAN
CLASS="ERRORCODE"
>LWRES_R_UNEXPECTEDEND</SPAN
>.</P
></DIV
></BODY
></HTML
>