contrib/bind9/lib/lwres/man/lwres_packet.html

   1 <!--
   2  - Copyright (C) 2004, 2005, 2007, 2014, 2015 Internet Systems Consortium, Inc. ("ISC")
   3  - Copyright (C) 2000, 2001 Internet Software Consortium.
   4  -
   5  - Permission to use, copy, modify, and/or distribute this software for any
   6  - purpose with or without fee is hereby granted, provided that the above
   7  - copyright notice and this permission notice appear in all copies.
   8  -
   9  - THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  10  - REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  11  - AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  12  - INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  13  - LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  14  - OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  15  - PERFORMANCE OF THIS SOFTWARE.
  16 -->
  17 <html>
  18 <head>
  19 <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
  20 <title>lwres_packet</title>
  21 <meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
  22 </head>
  23 <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry">
  24 <a name="id-1"></a><div class="titlepage"></div>
  25 <div class="refnamediv">
  26 <h2>Name</h2>
  27 <p>lwres_lwpacket_renderheader, lwres_lwpacket_parseheader &#8212; lightweight resolver packet handling functions</p>
  28 </div>
  29 <div class="refsynopsisdiv">
  30 <h2>Synopsis</h2>
  31 <div class="funcsynopsis">
  32 <pre class="funcsynopsisinfo">#include &lt;lwres/lwpacket.h&gt;</pre>
  33 <table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;">
  34 <tr>
  35 <td><code class="funcdef">
  36 lwres_result_t
  37 <b class="fsfunc">lwres_lwpacket_renderheader</b>(</code></td>
  38 <td>lwres_buffer_t *<var class="pdparam">b</var>, </td>
  39 </tr>
  40 <tr>
  41 <td> </td>
  42 <td>lwres_lwpacket_t *<var class="pdparam">pkt</var><code>)</code>;</td>
  43 </tr>
  44 </table>
  45 <div class="funcprototype-spacer"> </div>
  46 <table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;">
  47 <tr>
  48 <td><code class="funcdef">
  49 lwres_result_t
  50 <b class="fsfunc">lwres_lwpacket_parseheader</b>(</code></td>
  51 <td>lwres_buffer_t *<var class="pdparam">b</var>, </td>
  52 </tr>
  53 <tr>
  54 <td> </td>
  55 <td>lwres_lwpacket_t *<var class="pdparam">pkt</var><code>)</code>;</td>
  56 </tr>
  57 </table>
  58 <div class="funcprototype-spacer"> </div>
  59 </div>
  60 </div>
  61 <div class="refsection">
  62 <a name="id-1.7"></a><h2>DESCRIPTION</h2>
  63 <p>
  64       These functions rely on a
  65       <span class="type">struct lwres_lwpacket</span>
  66       which is defined in
  67       <code class="filename">lwres/lwpacket.h</code>.
  68     </p>
  69 <pre class="programlisting">
  70 typedef struct lwres_lwpacket lwres_lwpacket_t;
  71       </pre>
  72 <p>
  73     </p>
  74 <pre class="programlisting">
  75 struct lwres_lwpacket {
  76         lwres_uint32_t          length;
  77         lwres_uint16_t          version;
  78         lwres_uint16_t          pktflags;
  79         lwres_uint32_t          serial;
  80         lwres_uint32_t          opcode;
  81         lwres_uint32_t          result;
  82         lwres_uint32_t          recvlength;
  83         lwres_uint16_t          authtype;
  84         lwres_uint16_t          authlength;
  85 };
  86 </pre>
  87 <p>
  88     </p>
  89 <p>
  90       The elements of this structure are:
  91       </p>
  92 <div class="variablelist"><dl class="variablelist">
  93 <dt><span class="term"><code class="constant">length</code></span></dt>
  94 <dd><p>
  95               the overall packet length, including the entire packet header.
  96               This field is filled in by the lwres_gabn_*() and lwres_gnba_*()
  97               calls.
  98             </p></dd>
  99 <dt><span class="term"><code class="constant">version</code></span></dt>
 100 <dd><p>
 101               the header format. There is currently only one format,
 102               <span class="type">LWRES_LWPACKETVERSION_0</span>.
 103
 104               This field is filled in by the lwres_gabn_*() and lwres_gnba_*()
 105               calls.
 106             </p></dd>
 107 <dt><span class="term"><code class="constant">pktflags</code></span></dt>
 108 <dd><p>
 109               library-defined flags for this packet: for instance whether the
 110               packet
 111               is a request or a reply. Flag values can be set, but not defined
 112               by
 113               the caller.
 114               This field is filled in by the application wit the exception of
 115               the
 116               LWRES_LWPACKETFLAG_RESPONSE bit, which is set by the library in
 117               the
 118               lwres_gabn_*() and lwres_gnba_*() calls.
 119             </p></dd>
 120 <dt><span class="term"><code class="constant">serial</code></span></dt>
 121 <dd><p>
 122               is set by the requestor and is returned in all replies. If two
 123               or more
 124               packets from the same source have the same serial number and are
 125               from
 126               the same source, they are assumed to be duplicates and the
 127               latter ones
 128               may be dropped.
 129               This field must be set by the application.
 130             </p></dd>
 131 <dt><span class="term"><code class="constant">opcode</code></span></dt>
 132 <dd><p>
 133               indicates the operation.
 134               Opcodes between 0x00000000 and 0x03ffffff are
 135               reserved for use by the lightweight resolver library. Opcodes
 136               between
 137               0x04000000 and 0xffffffff are application defined.
 138               This field is filled in by the lwres_gabn_*() and lwres_gnba_*()
 139               calls.
 140             </p></dd>
 141 <dt><span class="term"><code class="constant">result</code></span></dt>
 142 <dd><p>
 143               is only valid for replies.
 144               Results between 0x04000000 and 0xffffffff are application
 145               defined.
 146               Results between 0x00000000 and 0x03ffffff are reserved for
 147               library use.
 148               This field is filled in by the lwres_gabn_*() and lwres_gnba_*()
 149               calls.
 150             </p></dd>
 151 <dt><span class="term"><code class="constant">recvlength</code></span></dt>
 152 <dd><p>
 153               is the maximum buffer size that the receiver can handle on
 154               requests
 155               and the size of the buffer needed to satisfy a request when the
 156               buffer
 157               is too large for replies.
 158               This field is supplied by the application.
 159             </p></dd>
 160 <dt><span class="term"><code class="constant">authtype</code></span></dt>
 161 <dd><p>
 162               defines the packet level authentication that is used.
 163               Authorisation types between 0x1000 and 0xffff are application
 164               defined
 165               and types between 0x0000 and 0x0fff are reserved for library
 166               use.
 167               Currently these are not used and must be zero.
 168             </p></dd>
 169 <dt><span class="term"><code class="constant">authlen</code></span></dt>
 170 <dd><p>
 171               gives the length of the authentication data.
 172               Since packet authentication is currently not used, this must be
 173               zero.
 174             </p></dd>
 175 </dl></div>
 176 <p>
 177     </p>
 178 <p>
 179       The following opcodes are currently defined:
 180       </p>
 181 <div class="variablelist"><dl class="variablelist">
 182 <dt><span class="term"><code class="constant">NOOP</code></span></dt>
 183 <dd><p>
 184               Success is always returned and the packet contents are echoed.
 185               The lwres_noop_*() functions should be used for this type.
 186             </p></dd>
 187 <dt><span class="term"><code class="constant">GETADDRSBYNAME</code></span></dt>
 188 <dd><p>
 189               returns all known addresses for a given name.
 190               The lwres_gabn_*() functions should be used for this type.
 191             </p></dd>
 192 <dt><span class="term"><code class="constant">GETNAMEBYADDR</code></span></dt>
 193 <dd><p>
 194               return the hostname for the given address.
 195               The lwres_gnba_*() functions should be used for this type.
 196             </p></dd>
 197 </dl></div>
 198 <p>
 199     </p>
 200 <p><code class="function">lwres_lwpacket_renderheader()</code>
 201       transfers the contents of lightweight resolver packet structure
 202       <span class="type">lwres_lwpacket_t</span> <em class="parameter"><code>*pkt</code></em> in
 203       network byte order to the lightweight resolver buffer,
 204       <em class="parameter"><code>*b</code></em>.
 205     </p>
 206 <p><code class="function">lwres_lwpacket_parseheader()</code>
 207       performs the converse operation.  It transfers data in network
 208       byte order from buffer <em class="parameter"><code>*b</code></em> to resolver
 209       packet <em class="parameter"><code>*pkt</code></em>.  The contents of the buffer
 210       <em class="parameter"><code>b</code></em> should correspond to a
 211       <span class="type">lwres_lwpacket_t</span>.
 212     </p>
 213 </div>
 214 <div class="refsection">
 215 <a name="id-1.8"></a><h2>RETURN VALUES</h2>
 216 <p>
 217       Successful calls to
 218       <code class="function">lwres_lwpacket_renderheader()</code> and
 219       <code class="function">lwres_lwpacket_parseheader()</code> return
 220       <span class="errorcode">LWRES_R_SUCCESS</span>.  If there is insufficient
 221       space to copy data between the buffer <em class="parameter"><code>*b</code></em> and
 222       lightweight resolver packet <em class="parameter"><code>*pkt</code></em> both
 223       functions
 224       return <span class="errorcode">LWRES_R_UNEXPECTEDEND</span>.
 225     </p>
 226 </div>
 227 </div></body>
 228 </html>