6/contrib/bind9/lib/lwres/man/lwres_gabn.html

   1 <!--
   2  - Copyright (C) 2004, 2005, 2007 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_gabn.html,v 1.6.2.1.4.14 2007/01/30 00:11:48 marka Exp $ -->
  18 <html>
  19 <head>
  20 <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
  21 <title>lwres_gabn</title>
  22 <meta name="generator" content="DocBook XSL Stylesheets V1.71.1">
  23 </head>
  24 <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry" lang="en">
  25 <a name="id2476275"></a><div class="titlepage"></div>
  26 <div class="refnamediv">
  27 <h2>Name</h2>
  28 <p>lwres_gabnrequest_render, lwres_gabnresponse_render, lwres_gabnrequest_parse, lwres_gabnresponse_parse, lwres_gabnresponse_free, lwres_gabnrequest_free &#8212; lightweight resolver getaddrbyname message handling</p>
  29 </div>
  30 <div class="refsynopsisdiv">
  31 <h2>Synopsis</h2>
  32 <div class="funcsynopsis">
  33 <pre class="funcsynopsisinfo">#include &lt;lwres/lwres.h&gt;</pre>
  34 <table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em">
  35 <tr>
  36 <td><code class="funcdef">
  37 lwres_result_t
  38 <b class="fsfunc">lwres_gabnrequest_render</b>(</code></td>
  39 <td> </td>
  40 <td>, </td>
  41 </tr>
  42 <tr>
  43 <td> </td>
  44 <td> </td>
  45 <td>, </td>
  46 </tr>
  47 <tr>
  48 <td> </td>
  49 <td> </td>
  50 <td>, </td>
  51 </tr>
  52 <tr>
  53 <td> </td>
  54 <td> </td>
  55 <td>
  56 <code>)</code>;</td>
  57 </tr>
  58 </table>
  59 <table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em">
  60 <tr>
  61 <td><code class="funcdef">
  62 lwres_result_t
  63 <b class="fsfunc">lwres_gabnresponse_render</b>(</code></td>
  64 <td> </td>
  65 <td>, </td>
  66 </tr>
  67 <tr>
  68 <td> </td>
  69 <td> </td>
  70 <td>, </td>
  71 </tr>
  72 <tr>
  73 <td> </td>
  74 <td> </td>
  75 <td>, </td>
  76 </tr>
  77 <tr>
  78 <td> </td>
  79 <td> </td>
  80 <td>
  81 <code>)</code>;</td>
  82 </tr>
  83 </table>
  84 <table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em">
  85 <tr>
  86 <td><code class="funcdef">
  87 lwres_result_t
  88 <b class="fsfunc">lwres_gabnrequest_parse</b>(</code></td>
  89 <td> </td>
  90 <td>, </td>
  91 </tr>
  92 <tr>
  93 <td> </td>
  94 <td> </td>
  95 <td>, </td>
  96 </tr>
  97 <tr>
  98 <td> </td>
  99 <td> </td>
 100 <td>, </td>
 101 </tr>
 102 <tr>
 103 <td> </td>
 104 <td> </td>
 105 <td>
 106 <code>)</code>;</td>
 107 </tr>
 108 </table>
 109 <table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em">
 110 <tr>
 111 <td><code class="funcdef">
 112 lwres_result_t
 113 <b class="fsfunc">lwres_gabnresponse_parse</b>(</code></td>
 114 <td> </td>
 115 <td>, </td>
 116 </tr>
 117 <tr>
 118 <td> </td>
 119 <td> </td>
 120 <td>, </td>
 121 </tr>
 122 <tr>
 123 <td> </td>
 124 <td> </td>
 125 <td>, </td>
 126 </tr>
 127 <tr>
 128 <td> </td>
 129 <td> </td>
 130 <td>
 131 <code>)</code>;</td>
 132 </tr>
 133 </table>
 134 <table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em">
 135 <tr>
 136 <td><code class="funcdef">
 137 void
 138 <b class="fsfunc">lwres_gabnresponse_free</b>(</code></td>
 139 <td> </td>
 140 <td>, </td>
 141 </tr>
 142 <tr>
 143 <td> </td>
 144 <td> </td>
 145 <td>
 146 <code>)</code>;</td>
 147 </tr>
 148 </table>
 149 <table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0">
 150 <tr>
 151 <td><code class="funcdef">
 152 void
 153 <b class="fsfunc">lwres_gabnrequest_free</b>(</code></td>
 154 <td> </td>
 155 <td>, </td>
 156 </tr>
 157 <tr>
 158 <td> </td>
 159 <td> </td>
 160 <td>
 161 <code>)</code>;</td>
 162 </tr>
 163 </table>
 164 </div>
 165 </div>
 166 <div class="refsect1" lang="en">
 167 <a name="id2543469"></a><h2>DESCRIPTION</h2>
 168 <p>
 169 These are low-level routines for creating and parsing
 170 lightweight resolver name-to-address lookup request and
 171 response messages.
 172 </p>
 173 <p>
 174 There are four main functions for the getaddrbyname opcode.
 175 One render function converts a getaddrbyname request structure &#8212;
 176 <span class="type">lwres_gabnrequest_t</span> &#8212;
 177 to the lighweight resolver's canonical format.
 178 It is complemented by a parse function that converts a packet in this
 179 canonical format to a getaddrbyname request structure.
 180 Another render function converts the getaddrbyname response structure &#8212;
 181 <span class="type">lwres_gabnresponse_t</span> &#8212;
 182 to the canonical format.
 183 This is complemented by a parse function which converts a packet in
 184 canonical format to a getaddrbyname response structure.
 185 </p>
 186 <p>
 187 These structures are defined in
 188 <code class="filename">&lt;lwres/lwres.h&gt;</code>.
 189 They are shown below.
 190 </p>
 191 <pre class="programlisting">
 192 #define LWRES_OPCODE_GETADDRSBYNAME     0x00010001U
 193
 194 typedef struct lwres_addr lwres_addr_t;
 195 typedef LWRES_LIST(lwres_addr_t) lwres_addrlist_t;
 196
 197 typedef struct {
 198         lwres_uint32_t  flags;
 199         lwres_uint32_t  addrtypes;
 200         lwres_uint16_t  namelen;
 201         char           *name;
 202 } lwres_gabnrequest_t;
 203
 204 typedef struct {
 205         lwres_uint32_t          flags;
 206         lwres_uint16_t          naliases;
 207         lwres_uint16_t          naddrs;
 208         char                   *realname;
 209         char                  **aliases;
 210         lwres_uint16_t          realnamelen;
 211         lwres_uint16_t         *aliaslen;
 212         lwres_addrlist_t        addrs;
 213         void                   *base;
 214         size_t                  baselen;
 215 } lwres_gabnresponse_t;
 216 </pre>
 217 <p>
 218 </p>
 219 <p>
 220 <code class="function">lwres_gabnrequest_render()</code>
 221 uses resolver context
 222 <em class="parameter"><code>ctx</code></em>
 223 to convert getaddrbyname request structure
 224 <em class="parameter"><code>req</code></em>
 225 to canonical format.
 226 The packet header structure
 227 <em class="parameter"><code>pkt</code></em>
 228 is initialised and transferred to
 229 buffer
 230 <em class="parameter"><code>b</code></em>.
 231
 232 The contents of
 233 <em class="parameter"><code>*req</code></em>
 234 are then appended to the buffer in canonical format.
 235 <code class="function">lwres_gabnresponse_render()</code>
 236 performs the same task, except it converts a getaddrbyname response structure
 237 <span class="type">lwres_gabnresponse_t</span>
 238 to the lightweight resolver's canonical format.
 239 </p>
 240 <p>
 241 <code class="function">lwres_gabnrequest_parse()</code>
 242 uses context
 243 <em class="parameter"><code>ctx</code></em>
 244 to convert the contents of packet
 245 <em class="parameter"><code>pkt</code></em>
 246 to a
 247 <span class="type">lwres_gabnrequest_t</span>
 248 structure.
 249 Buffer
 250 <em class="parameter"><code>b</code></em>
 251 provides space to be used for storing this structure.
 252 When the function succeeds, the resulting
 253 <span class="type">lwres_gabnrequest_t</span>
 254 is made available through
 255 <em class="parameter"><code>*structp</code></em>.
 256
 257 <code class="function">lwres_gabnresponse_parse()</code>
 258 offers the same semantics as
 259 <code class="function">lwres_gabnrequest_parse()</code>
 260 except it yields a
 261 <span class="type">lwres_gabnresponse_t</span>
 262 structure.
 263 </p>
 264 <p>
 265 <code class="function">lwres_gabnresponse_free()</code>
 266 and
 267 <code class="function">lwres_gabnrequest_free()</code>
 268 release the memory in resolver context
 269 <em class="parameter"><code>ctx</code></em>
 270 that was allocated to the
 271 <span class="type">lwres_gabnresponse_t</span>
 272 or
 273 <span class="type">lwres_gabnrequest_t</span>
 274 structures referenced via
 275 <em class="parameter"><code>structp</code></em>.
 276
 277 Any memory associated with ancillary buffers and strings for those
 278 structures is also discarded.
 279 </p>
 280 </div>
 281 <div class="refsect1" lang="en">
 282 <a name="id2543593"></a><h2>RETURN VALUES</h2>
 283 <p>
 284 The getaddrbyname opcode functions
 285 <code class="function">lwres_gabnrequest_render()</code>,
 286 <code class="function">lwres_gabnresponse_render()</code>
 287 <code class="function">lwres_gabnrequest_parse()</code>
 288 and
 289 <code class="function">lwres_gabnresponse_parse()</code>
 290 all return
 291 <span class="errorcode">LWRES_R_SUCCESS</span>
 292 on success.
 293 They return
 294 <span class="errorcode">LWRES_R_NOMEMORY</span>
 295 if memory allocation fails.
 296 <span class="errorcode">LWRES_R_UNEXPECTEDEND</span>
 297 is returned if the available space in the buffer
 298 <em class="parameter"><code>b</code></em>
 299 is too small to accommodate the packet header or the
 300 <span class="type">lwres_gabnrequest_t</span>
 301 and
 302 <span class="type">lwres_gabnresponse_t</span>
 303 structures.
 304 <code class="function">lwres_gabnrequest_parse()</code>
 305 and
 306 <code class="function">lwres_gabnresponse_parse()</code>
 307 will return
 308 <span class="errorcode">LWRES_R_UNEXPECTEDEND</span>
 309 if the buffer is not empty after decoding the received packet.
 310 These functions will return
 311 <span class="errorcode">LWRES_R_FAILURE</span>
 312 if
 313 <em class="structfield"><code>pktflags</code></em>
 314 in the packet header structure
 315 <span class="type">lwres_lwpacket_t</span>
 316 indicate that the packet is not a response to an earlier query.
 317 </p>
 318 </div>
 319 <div class="refsect1" lang="en">
 320 <a name="id2543658"></a><h2>SEE ALSO</h2>
 321 <p>
 322 <span class="citerefentry"><span class="refentrytitle">lwres_packet</span>(3
 323 )</span>
 324 </p>
 325 </div>
 326 </div></body>
 327 </html>