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

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  20. <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
    21. 

  21. <title>lwres_gabn</title>
    22. 

  22. <meta name="generator" content="DocBook XSL Stylesheets V1.71.1">
    23. 

  23. </head>
    24. 

  24. <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry" lang="en">
    25. 

  25. <a name="id2476275"></a><div class="titlepage"></div>
    26. 

  26. <div class="refnamediv">
    27. 

  27. <h2>Name</h2>
    28. 

  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. 

  29. </div>
    30. 

  30. <div class="refsynopsisdiv">
    31. 

  31. <h2>Synopsis</h2>
    32. 

  32. <div class="funcsynopsis">
    33. 

  33. <pre class="funcsynopsisinfo">#include &lt;lwres/lwres.h&gt;</pre>
    34. 

  34. <table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em">
    35. 

  35. <tr>
    36. 

  36. <td><code class="funcdef">
    37. 

  37. lwres_result_t
    38. 

  38. <b class="fsfunc">lwres_gabnrequest_render</b>(</code></td>
    39. 

  39. <td>lwres_context_t * </td>
    40. 

  40. <td>
    41. 

  41. <var class="pdparam">ctx</var>, </td>
    42. 

  42. </tr>
    43. 

  43. <tr>
    44. 

  44. <td> </td>
    45. 

  45. <td>lwres_gabnrequest_t * </td>
    46. 

  46. <td>
    47. 

  47. <var class="pdparam">req</var>, </td>
    48. 

  48. </tr>
    49. 

  49. <tr>
    50. 

  50. <td> </td>
    51. 

  51. <td>lwres_lwpacket_t * </td>
    52. 

  52. <td>
    53. 

  53. <var class="pdparam">pkt</var>, </td>
    54. 

  54. </tr>
    55. 

  55. <tr>
    56. 

  56. <td> </td>
    57. 

  57. <td>lwres_buffer_t * </td>
    58. 

  58. <td>
    59. 

  59. <var class="pdparam">b</var><code>)</code>;</td>
    60. 

  60. </tr>
    61. 

  61. </table>
    62. 

  62. <table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em">
    63. 

  63. <tr>
    64. 

  64. <td><code class="funcdef">
    65. 

  65. lwres_result_t
    66. 

  66. <b class="fsfunc">lwres_gabnresponse_render</b>(</code></td>
    67. 

  67. <td>lwres_context_t * </td>
    68. 

  68. <td>
    69. 

  69. <var class="pdparam">ctx</var>, </td>
    70. 

  70. </tr>
    71. 

  71. <tr>
    72. 

  72. <td> </td>
    73. 

  73. <td>lwres_gabnresponse_t * </td>
    74. 

  74. <td>
    75. 

  75. <var class="pdparam">req</var>, </td>
    76. 

  76. </tr>
    77. 

  77. <tr>
    78. 

  78. <td> </td>
    79. 

  79. <td>lwres_lwpacket_t * </td>
    80. 

  80. <td>
    81. 

  81. <var class="pdparam">pkt</var>, </td>
    82. 

  82. </tr>
    83. 

  83. <tr>
    84. 

  84. <td> </td>
    85. 

  85. <td>lwres_buffer_t * </td>
    86. 

  86. <td>
    87. 

  87. <var class="pdparam">b</var><code>)</code>;</td>
    88. 

  88. </tr>
    89. 

  89. </table>
    90. 

  90. <table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em">
    91. 

  91. <tr>
    92. 

  92. <td><code class="funcdef">
    93. 

  93. lwres_result_t
    94. 

  94. <b class="fsfunc">lwres_gabnrequest_parse</b>(</code></td>
    95. 

  95. <td>lwres_context_t * </td>
    96. 

  96. <td>
    97. 

  97. <var class="pdparam">ctx</var>, </td>
    98. 

  98. </tr>
    99. 

  99. <tr>
    100. 

  100. <td> </td>
    101. 

  101. <td>lwres_buffer_t * </td>
    102. 

  102. <td>
    103. 

  103. <var class="pdparam">b</var>, </td>
    104. 

  104. </tr>
    105. 

  105. <tr>
    106. 

  106. <td> </td>
    107. 

  107. <td>lwres_lwpacket_t * </td>
    108. 

  108. <td>
    109. 

  109. <var class="pdparam">pkt</var>, </td>
    110. 

  110. </tr>
    111. 

  111. <tr>
    112. 

  112. <td> </td>
    113. 

  113. <td>lwres_gabnrequest_t ** </td>
    114. 

  114. <td>
    115. 

  115. <var class="pdparam">structp</var><code>)</code>;</td>
    116. 

  116. </tr>
    117. 

  117. </table>
    118. 

  118. <table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em">
    119. 

  119. <tr>
    120. 

  120. <td><code class="funcdef">
    121. 

  121. lwres_result_t
    122. 

  122. <b class="fsfunc">lwres_gabnresponse_parse</b>(</code></td>
    123. 

  123. <td>lwres_context_t * </td>
    124. 

  124. <td>
    125. 

  125. <var class="pdparam">ctx</var>, </td>
    126. 

  126. </tr>
    127. 

  127. <tr>
    128. 

  128. <td> </td>
    129. 

  129. <td>lwres_buffer_t * </td>
    130. 

  130. <td>
    131. 

  131. <var class="pdparam">b</var>, </td>
    132. 

  132. </tr>
    133. 

  133. <tr>
    134. 

  134. <td> </td>
    135. 

  135. <td>lwres_lwpacket_t * </td>
    136. 

  136. <td>
    137. 

  137. <var class="pdparam">pkt</var>, </td>
    138. 

  138. </tr>
    139. 

  139. <tr>
    140. 

  140. <td> </td>
    141. 

  141. <td>lwres_gabnresponse_t ** </td>
    142. 

  142. <td>
    143. 

  143. <var class="pdparam">structp</var><code>)</code>;</td>
    144. 

  144. </tr>
    145. 

  145. </table>
    146. 

  146. <table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em">
    147. 

  147. <tr>
    148. 

  148. <td><code class="funcdef">
    149. 

  149. void
    150. 

  150. <b class="fsfunc">lwres_gabnresponse_free</b>(</code></td>
    151. 

  151. <td>lwres_context_t * </td>
    152. 

  152. <td>
    153. 

  153. <var class="pdparam">ctx</var>, </td>
    154. 

  154. </tr>
    155. 

  155. <tr>
    156. 

  156. <td> </td>
    157. 

  157. <td>lwres_gabnresponse_t ** </td>
    158. 

  158. <td>
    159. 

  159. <var class="pdparam">structp</var><code>)</code>;</td>
    160. 

  160. </tr>
    161. 

  161. </table>
    162. 

  162. <table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0">
    163. 

  163. <tr>
    164. 

  164. <td><code class="funcdef">
    165. 

  165. void
    166. 

  166. <b class="fsfunc">lwres_gabnrequest_free</b>(</code></td>
    167. 

  167. <td>lwres_context_t * </td>
    168. 

  168. <td>
    169. 

  169. <var class="pdparam">ctx</var>, </td>
    170. 

  170. </tr>
    171. 

  171. <tr>
    172. 

  172. <td> </td>
    173. 

  173. <td>lwres_gabnrequest_t ** </td>
    174. 

  174. <td>
    175. 

  175. <var class="pdparam">structp</var><code>)</code>;</td>
    176. 

  176. </tr>
    177. 

  177. </table>
    178. 

  178. </div>
    179. 

  179. </div>
    180. 

  180. <div class="refsect1" lang="en">
    181. 

  181. <a name="id2543526"></a><h2>DESCRIPTION</h2>
    182. 

  182. <p>
    183. 

  183.       These are low-level routines for creating and parsing
    184. 

  184.       lightweight resolver name-to-address lookup request and
    185. 

  185.       response messages.
    186. 

  186.     </p>
    187. 

  187. <p>
    188. 

  188.       There are four main functions for the getaddrbyname opcode.
    189. 

  189.       One render function converts a getaddrbyname request structure &#8212;
    190. 

  190.       <span class="type">lwres_gabnrequest_t</span> &#8212;
    191. 

  191.       to the lighweight resolver's canonical format.
    192. 

  192.       It is complemented by a parse function that converts a packet in this
    193. 

  193.       canonical format to a getaddrbyname request structure.
    194. 

  194.       Another render function converts the getaddrbyname response structure
    195. 

  195.       &#8212; <span class="type">lwres_gabnresponse_t</span> &#8212;
    196. 

  196.       to the canonical format.
    197. 

  197.       This is complemented by a parse function which converts a packet in
    198. 

  198.       canonical format to a getaddrbyname response structure.
    199. 

  199.     </p>
    200. 

  200. <p>
    201. 

  201.       These structures are defined in
    202. 

  202.       <code class="filename">&lt;lwres/lwres.h&gt;</code>.
    203. 

  203.       They are shown below.
    204. 

  204.     </p>
    205. 

  205. <pre class="programlisting">
    206. 

  206. #define LWRES_OPCODE_GETADDRSBYNAME     0x00010001U
    207. 

  207. </pre>
    208. 

  208. <p>
    209. 

  209.     </p>
    210. 

  210. <pre class="programlisting">
    211. 

  211. typedef struct lwres_addr lwres_addr_t;
    212. 

  212. typedef LWRES_LIST(lwres_addr_t) lwres_addrlist_t;
    213. 

  213. </pre>
    214. 

  214. <p>
    215. 

  215.     </p>
    216. 

  216. <pre class="programlisting">
    217. 

  217. typedef struct {
    218. 

  218.         lwres_uint32_t  flags;
    219. 

  219.         lwres_uint32_t  addrtypes;
    220. 

  220.         lwres_uint16_t  namelen;
    221. 

  221.         char           *name;
    222. 

  222. } lwres_gabnrequest_t;
    223. 

  223. </pre>
    224. 

  224. <p>
    225. 

  225.     </p>
    226. 

  226. <pre class="programlisting">
    227. 

  227. typedef struct {
    228. 

  228.         lwres_uint32_t          flags;
    229. 

  229.         lwres_uint16_t          naliases;
    230. 

  230.         lwres_uint16_t          naddrs;
    231. 

  231.         char                   *realname;
    232. 

  232.         char                  **aliases;
    233. 

  233.         lwres_uint16_t          realnamelen;
    234. 

  234.         lwres_uint16_t         *aliaslen;
    235. 

  235.         lwres_addrlist_t        addrs;
    236. 

  236.         void                   *base;
    237. 

  237.         size_t                  baselen;
    238. 

  238. } lwres_gabnresponse_t;
    239. 

  239. </pre>
    240. 

  240. <p>
    241. 

  241.     </p>
    242. 

  242. <p><code class="function">lwres_gabnrequest_render()</code>
    243. 

  243.       uses resolver context <em class="parameter"><code>ctx</code></em> to convert
    244. 

  244.       getaddrbyname request structure <em class="parameter"><code>req</code></em> to
    245. 

  245.       canonical format.  The packet header structure
    246. 

  246.       <em class="parameter"><code>pkt</code></em> is initialised and transferred to
    247. 

  247.       buffer <em class="parameter"><code>b</code></em>.
    248. 

  248. 

  249.       The contents of <em class="parameter"><code>*req</code></em> are then appended to
    250. 

  250.       the buffer in canonical format.
    251. 

  251.       <code class="function">lwres_gabnresponse_render()</code> performs the
    252. 

  252.       same task, except it converts a getaddrbyname response structure
    253. 

  253.       <span class="type">lwres_gabnresponse_t</span> to the lightweight resolver's
    254. 

  254.       canonical format.
    255. 

  255.     </p>
    256. 

  256. <p><code class="function">lwres_gabnrequest_parse()</code>
    257. 

  257.       uses context <em class="parameter"><code>ctx</code></em> to convert the contents
    258. 

  258.       of packet <em class="parameter"><code>pkt</code></em> to a
    259. 

  259.       <span class="type">lwres_gabnrequest_t</span> structure.  Buffer
    260. 

  260.       <em class="parameter"><code>b</code></em> provides space to be used for storing
    261. 

  261.       this structure.  When the function succeeds, the resulting
    262. 

  262.       <span class="type">lwres_gabnrequest_t</span> is made available through
    263. 

  263.       <em class="parameter"><code>*structp</code></em>.
    264. 

  264. 

  265.       <code class="function">lwres_gabnresponse_parse()</code> offers the same
    266. 

  266.       semantics as <code class="function">lwres_gabnrequest_parse()</code>
    267. 

  267.       except it yields a <span class="type">lwres_gabnresponse_t</span> structure.
    268. 

  268.     </p>
    269. 

  269. <p><code class="function">lwres_gabnresponse_free()</code>
    270. 

  270.       and <code class="function">lwres_gabnrequest_free()</code> release the
    271. 

  271.       memory in resolver context <em class="parameter"><code>ctx</code></em> that was
    272. 

  272.       allocated to the <span class="type">lwres_gabnresponse_t</span> or
    273. 

  273.       <span class="type">lwres_gabnrequest_t</span> structures referenced via
    274. 

  274.       <em class="parameter"><code>structp</code></em>.
    275. 

  275. 

  276.       Any memory associated with ancillary buffers and strings for
    277. 

  277.       those structures is also discarded.
    278. 

  278.     </p>
    279. 

  279. </div>
    280. 

  280. <div class="refsect1" lang="en">
    281. 

  281. <a name="id2543671"></a><h2>RETURN VALUES</h2>
    282. 

  282. <p>
    283. 

  283.       The getaddrbyname opcode functions
    284. 

  284.       <code class="function">lwres_gabnrequest_render()</code>,
    285. 

  285.       <code class="function">lwres_gabnresponse_render()</code>
    286. 

  286.       <code class="function">lwres_gabnrequest_parse()</code>
    287. 

  287.       and
    288. 

  288.       <code class="function">lwres_gabnresponse_parse()</code>
    289. 

  289.       all return
    290. 

  290.       <span class="errorcode">LWRES_R_SUCCESS</span>
    291. 

  291.       on success.
    292. 

  292.       They return
    293. 

  293.       <span class="errorcode">LWRES_R_NOMEMORY</span>
    294. 

  294.       if memory allocation fails.
    295. 

  295.       <span class="errorcode">LWRES_R_UNEXPECTEDEND</span>
    296. 

  296.       is returned if the available space in the buffer
    297. 

  297.       <em class="parameter"><code>b</code></em>
    298. 

  298.       is too small to accommodate the packet header or the
    299. 

  299.       <span class="type">lwres_gabnrequest_t</span>
    300. 

  300.       and
    301. 

  301.       <span class="type">lwres_gabnresponse_t</span>
    302. 

  302.       structures.
    303. 

  303.       <code class="function">lwres_gabnrequest_parse()</code>
    304. 

  304.       and
    305. 

  305.       <code class="function">lwres_gabnresponse_parse()</code>
    306. 

  306.       will return
    307. 

  307.       <span class="errorcode">LWRES_R_UNEXPECTEDEND</span>
    308. 

  308.       if the buffer is not empty after decoding the received packet.
    309. 

  309.       These functions will return
    310. 

  310.       <span class="errorcode">LWRES_R_FAILURE</span>
    311. 

  311.       if
    312. 

  312.       <em class="structfield"><code>pktflags</code></em>
    313. 

  313.       in the packet header structure
    314. 

  314.       <span class="type">lwres_lwpacket_t</span>
    315. 

  315.       indicate that the packet is not a response to an earlier query.
    316. 

  316.     </p>
    317. 

  317. </div>
    318. 

  318. <div class="refsect1" lang="en">
    319. 

  319. <a name="id2543737"></a><h2>SEE ALSO</h2>
    320. 

  320. <p><span class="citerefentry"><span class="refentrytitle">lwres_packet</span>(3)</span>
    321. 

  321.     </p>
    322. 

  322. </div>
    323. 

  323. </div></body>
    324. 

  324. </html>
    325.