contrib/bind-9.3/lib/lwres/man/lwres_gnba.html

   1 <!--
   2  - Copyright (C) 2004, 2005 Internet Systems Consortium, Inc. ("ISC")
   3  - Copyright (C) 2000, 2001 Internet Software Consortium.
   4  -
   5  - Permission to use, copy, modify, and 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 <!-- $Id: lwres_gnba.html,v 1.6.2.1.4.9 2005/10/13 02:33:57 marka Exp $ -->
  18 <html>
  19 <head>
  20 <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
  21 <title>lwres_gnba</title>
  22 <meta name="generator" content="DocBook XSL Stylesheets V1.69.1">
  23 </head>
  24 <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry" lang="en">
  25 <a name="id2463721"></a><div class="titlepage"></div>
  26 <div class="refnamediv">
  27 <h2>Name</h2>
  28 <p>lwres_gnbarequest_render, lwres_gnbaresponse_render, lwres_gnbarequest_parse, lwres_gnbaresponse_parse, lwres_gnbaresponse_free, lwres_gnbarequest_free &#8212; lightweight resolver getnamebyaddress message handling</p>
  29 </div>
  30 <div class="refsynopsisdiv">
  31 <h2>Synopsis</h2>
  32 <div class="funcsynopsis">
  33 <pre class="funcsynopsisinfo">
  34 #include &lt;lwres/lwres.h&gt;
  35 </pre>
  36 <table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em">
  37 <tr>
  38 <td><code class="funcdef">
  39 lwres_result_t
  40 <b class="fsfunc">lwres_gnbarequest_render</b>
  41 (</code></td>
  42 <td>lwres_context_t * </td>
  43 <td>
  44 <var class="pdparam">ctx</var>, </td>
  45 </tr>
  46 <tr>
  47 <td> </td>
  48 <td>lwres_gnbarequest_t * </td>
  49 <td>
  50 <var class="pdparam">req</var>, </td>
  51 </tr>
  52 <tr>
  53 <td> </td>
  54 <td>lwres_lwpacket_t * </td>
  55 <td>
  56 <var class="pdparam">pkt</var>, </td>
  57 </tr>
  58 <tr>
  59 <td> </td>
  60 <td>lwres_buffer_t * </td>
  61 <td>
  62 <var class="pdparam">b</var><code>)</code>;</td>
  63 </tr>
  64 </table>
  65 <table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em">
  66 <tr>
  67 <td><code class="funcdef">
  68 lwres_result_t
  69 <b class="fsfunc">lwres_gnbaresponse_render</b>
  70 (</code></td>
  71 <td> </td>
  72 <td>, </td>
  73 </tr>
  74 <tr>
  75 <td> </td>
  76 <td> </td>
  77 <td>, </td>
  78 </tr>
  79 <tr>
  80 <td> </td>
  81 <td> </td>
  82 <td>, </td>
  83 </tr>
  84 <tr>
  85 <td> </td>
  86 <td> </td>
  87 <td>
  88 <code>)</code>;</td>
  89 </tr>
  90 </table>
  91 <table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em">
  92 <tr>
  93 <td><code class="funcdef">
  94 lwres_result_t
  95 <b class="fsfunc">lwres_gnbarequest_parse</b>(</code></td>
  96 <td> </td>
  97 <td>, </td>
  98 </tr>
  99 <tr>
 100 <td> </td>
 101 <td> </td>
 102 <td>, </td>
 103 </tr>
 104 <tr>
 105 <td> </td>
 106 <td> </td>
 107 <td>, </td>
 108 </tr>
 109 <tr>
 110 <td> </td>
 111 <td> </td>
 112 <td>
 113 <code>)</code>;</td>
 114 </tr>
 115 </table>
 116 <table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em">
 117 <tr>
 118 <td><code class="funcdef">
 119 lwres_result_t
 120 <b class="fsfunc">lwres_gnbaresponse_parse</b>(</code></td>
 121 <td> </td>
 122 <td>, </td>
 123 </tr>
 124 <tr>
 125 <td> </td>
 126 <td> </td>
 127 <td>, </td>
 128 </tr>
 129 <tr>
 130 <td> </td>
 131 <td> </td>
 132 <td>, </td>
 133 </tr>
 134 <tr>
 135 <td> </td>
 136 <td> </td>
 137 <td>
 138 <code>)</code>;</td>
 139 </tr>
 140 </table>
 141 <table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em">
 142 <tr>
 143 <td><code class="funcdef">
 144 void
 145 <b class="fsfunc">lwres_gnbaresponse_free</b>
 146 (</code></td>
 147 <td> </td>
 148 <td>, </td>
 149 </tr>
 150 <tr>
 151 <td> </td>
 152 <td> </td>
 153 <td>
 154 <code>)</code>;</td>
 155 </tr>
 156 </table>
 157 <table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0">
 158 <tr>
 159 <td><code class="funcdef">
 160 void
 161 <b class="fsfunc">lwres_gnbarequest_free</b>(</code></td>
 162 <td> </td>
 163 <td>, </td>
 164 </tr>
 165 <tr>
 166 <td> </td>
 167 <td> </td>
 168 <td>
 169 <code>)</code>;</td>
 170 </tr>
 171 </table>
 172 </div>
 173 </div>
 174 <div class="refsect1" lang="en">
 175 <a name="id2525975"></a><h2>DESCRIPTION</h2>
 176 <p>
 177 These are low-level routines for creating and parsing
 178 lightweight resolver address-to-name lookup request and
 179 response messages.
 180 </p>
 181 <p>
 182 There are four main functions for the getnamebyaddr opcode.
 183 One render function converts a getnamebyaddr request structure &#8212;
 184 <span class="type">lwres_gnbarequest_t</span> &#8212;
 185 to the lightweight resolver's canonical format.
 186 It is complemented by a parse function that converts a packet in this
 187 canonical format to a getnamebyaddr request structure.
 188 Another render function converts the getnamebyaddr response structure &#8212;
 189 <span class="type">lwres_gnbaresponse_t</span>
 190 to the canonical format.
 191 This is complemented by a parse function which converts a packet in
 192 canonical format to a getnamebyaddr response structure.
 193 </p>
 194 <p>
 195 These structures are defined in
 196 <code class="filename">lwres/lwres.h</code>.
 197 They are shown below.
 198 </p>
 199 <pre class="programlisting">
 200 #define LWRES_OPCODE_GETNAMEBYADDR      0x00010002U
 201
 202 typedef struct {
 203         lwres_uint32_t  flags;
 204         lwres_addr_t    addr;
 205 } lwres_gnbarequest_t;
 206
 207 typedef struct {
 208         lwres_uint32_t  flags;
 209         lwres_uint16_t  naliases;
 210         char           *realname;
 211         char          **aliases;
 212         lwres_uint16_t  realnamelen;
 213         lwres_uint16_t *aliaslen;
 214         void           *base;
 215         size_t          baselen;
 216 } lwres_gnbaresponse_t;
 217 </pre>
 218 <p>
 219 </p>
 220 <p>
 221 <code class="function">lwres_gnbarequest_render()</code>
 222 uses resolver context
 223 <code class="varname">ctx</code>
 224 to convert getnamebyaddr request structure
 225 <code class="varname">req</code>
 226 to canonical format.
 227 The packet header structure
 228 <code class="varname">pkt</code>
 229 is initialised and transferred to
 230 buffer
 231 <code class="varname">b</code>.
 232 The contents of
 233 <code class="varname">*req</code>
 234 are then appended to the buffer in canonical format.
 235 <code class="function">lwres_gnbaresponse_render()</code>
 236 performs the same task, except it converts a getnamebyaddr response structure
 237 <span class="type">lwres_gnbaresponse_t</span>
 238 to the lightweight resolver's canonical format.
 239 </p>
 240 <p>
 241 <code class="function">lwres_gnbarequest_parse()</code>
 242 uses context
 243 <code class="varname">ctx</code>
 244 to convert the contents of packet
 245 <code class="varname">pkt</code>
 246 to a
 247 <span class="type">lwres_gnbarequest_t</span>
 248 structure.
 249 Buffer
 250 <code class="varname">b</code>
 251 provides space to be used for storing this structure.
 252 When the function succeeds, the resulting
 253 <span class="type">lwres_gnbarequest_t</span>
 254 is made available through
 255 <code class="varname">*structp</code>.
 256 <code class="function">lwres_gnbaresponse_parse()</code>
 257 offers the same semantics as
 258 <code class="function">lwres_gnbarequest_parse()</code>
 259 except it yields a
 260 <span class="type">lwres_gnbaresponse_t</span>
 261 structure.
 262 </p>
 263 <p>
 264 <code class="function">lwres_gnbaresponse_free()</code>
 265 and
 266 <code class="function">lwres_gnbarequest_free()</code>
 267 release the memory in resolver context
 268 <code class="varname">ctx</code>
 269 that was allocated to the
 270 <span class="type">lwres_gnbaresponse_t</span>
 271 or
 272 <span class="type">lwres_gnbarequest_t</span>
 273 structures referenced via
 274 <code class="varname">structp</code>.
 275 Any memory associated with ancillary buffers and strings for those
 276 structures is also discarded.
 277 </p>
 278 </div>
 279 <div class="refsect1" lang="en">
 280 <a name="id2526100"></a><h2>RETURN VALUES</h2>
 281 <p>
 282 The getnamebyaddr opcode functions
 283 <code class="function">lwres_gnbarequest_render()</code>,
 284 <code class="function">lwres_gnbaresponse_render()</code>
 285 <code class="function">lwres_gnbarequest_parse()</code>
 286 and
 287 <code class="function">lwres_gnbaresponse_parse()</code>
 288 all return
 289 <span class="errorcode">LWRES_R_SUCCESS</span>
 290 on success.
 291 They return
 292 <span class="errorcode">LWRES_R_NOMEMORY</span>
 293 if memory allocation fails.
 294 <span class="errorcode">LWRES_R_UNEXPECTEDEND</span>
 295 is returned if the available space in the buffer
 296 <code class="varname">b</code>
 297 is too small to accommodate the packet header or the
 298 <span class="type">lwres_gnbarequest_t</span>
 299 and
 300 <span class="type">lwres_gnbaresponse_t</span>
 301 structures.
 302 <code class="function">lwres_gnbarequest_parse()</code>
 303 and
 304 <code class="function">lwres_gnbaresponse_parse()</code>
 305 will return
 306 <span class="errorcode">LWRES_R_UNEXPECTEDEND</span>
 307 if the buffer is not empty after decoding the received packet.
 308 These functions will return
 309 <span class="errorcode">LWRES_R_FAILURE</span>
 310 if
 311 <em class="structfield"><code>pktflags</code></em>
 312 in the packet header structure
 313 <span class="type">lwres_lwpacket_t</span>
 314 indicate that the packet is not a response to an earlier query.
 315 </p>
 316 </div>
 317 <div class="refsect1" lang="en">
 318 <a name="id2526165"></a><h2>SEE ALSO</h2>
 319 <p>
 320 <span class="citerefentry"><span class="refentrytitle">lwres_packet</span>(3)</span>.
 321 </p>
 322 </div>
 323 </div></body>
 324 </html>