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

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  21 <!-- $Id$ -->
  22 <refentry>
  23
  24   <refentryinfo>
  25     <date>Jun 30, 2000</date>
  26   </refentryinfo>
  27
  28   <refmeta>
  29     <refentrytitle>lwres_gabn</refentrytitle>
  30     <manvolnum>3</manvolnum>
  31     <refmiscinfo>BIND9</refmiscinfo>
  32   </refmeta>
  33
  34   <docinfo>
  35     <copyright>
  36       <year>2004</year>
  37       <year>2005</year>
  38       <year>2007</year>
  39       <year>2012</year>
  40       <holder>Internet Systems Consortium, Inc. ("ISC")</holder>
  41     </copyright>
  42     <copyright>
  43       <year>2000</year>
  44       <year>2001</year>
  45       <holder>Internet Software Consortium.</holder>
  46     </copyright>
  47   </docinfo>
  48
  49   <refnamediv>
  50     <refname>lwres_gabnrequest_render</refname>
  51     <refname>lwres_gabnresponse_render</refname>
  52     <refname>lwres_gabnrequest_parse</refname>
  53     <refname>lwres_gabnresponse_parse</refname>
  54     <refname>lwres_gabnresponse_free</refname>
  55     <refname>lwres_gabnrequest_free</refname>
  56     <refpurpose>lightweight resolver getaddrbyname message handling</refpurpose>
  57   </refnamediv>
  58   <refsynopsisdiv>
  59     <funcsynopsis>
  60 <funcsynopsisinfo>#include &lt;lwres/lwres.h&gt;</funcsynopsisinfo>
  61 <funcprototype>
  62         <funcdef>
  63 lwres_result_t
  64 <function>lwres_gabnrequest_render</function></funcdef>
  65         <paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef>
  66         <paramdef>lwres_gabnrequest_t *<parameter>req</parameter></paramdef>
  67         <paramdef>lwres_lwpacket_t *<parameter>pkt</parameter></paramdef>
  68         <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>
  69         </funcprototype>
  70 <funcprototype>
  71         <funcdef>
  72 lwres_result_t
  73 <function>lwres_gabnresponse_render</function></funcdef>
  74         <paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef>
  75         <paramdef>lwres_gabnresponse_t *<parameter>req</parameter></paramdef>
  76         <paramdef>lwres_lwpacket_t *<parameter>pkt</parameter></paramdef>
  77         <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>
  78         </funcprototype>
  79 <funcprototype>
  80         <funcdef>
  81 lwres_result_t
  82 <function>lwres_gabnrequest_parse</function></funcdef>
  83         <paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef>
  84         <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>
  85         <paramdef>lwres_lwpacket_t *<parameter>pkt</parameter></paramdef>
  86         <paramdef>lwres_gabnrequest_t **<parameter>structp</parameter></paramdef>
  87         </funcprototype>
  88 <funcprototype>
  89         <funcdef>
  90 lwres_result_t
  91 <function>lwres_gabnresponse_parse</function></funcdef>
  92         <paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef>
  93         <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>
  94         <paramdef>lwres_lwpacket_t *<parameter>pkt</parameter></paramdef>
  95         <paramdef>lwres_gabnresponse_t **<parameter>structp</parameter></paramdef>
  96         </funcprototype>
  97 <funcprototype>
  98         <funcdef>
  99 void
 100 <function>lwres_gabnresponse_free</function></funcdef>
 101         <paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef>
 102         <paramdef>lwres_gabnresponse_t **<parameter>structp</parameter></paramdef>
 103         </funcprototype>
 104 <funcprototype>
 105         <funcdef>
 106 void
 107 <function>lwres_gabnrequest_free</function></funcdef>
 108         <paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef>
 109         <paramdef>lwres_gabnrequest_t **<parameter>structp</parameter></paramdef>
 110       </funcprototype>
 111 </funcsynopsis>
 112   </refsynopsisdiv>
 113   <refsect1>
 114     <title>DESCRIPTION</title>
 115     <para>
 116       These are low-level routines for creating and parsing
 117       lightweight resolver name-to-address lookup request and
 118       response messages.
 119     </para>
 120     <para>
 121       There are four main functions for the getaddrbyname opcode.
 122       One render function converts a getaddrbyname request structure &mdash;
 123       <type>lwres_gabnrequest_t</type> &mdash;
 124       to the lighweight resolver's canonical format.
 125       It is complemented by a parse function that converts a packet in this
 126       canonical format to a getaddrbyname request structure.
 127       Another render function converts the getaddrbyname response structure
 128       &mdash; <type>lwres_gabnresponse_t</type> &mdash;
 129       to the canonical format.
 130       This is complemented by a parse function which converts a packet in
 131       canonical format to a getaddrbyname response structure.
 132     </para>
 133     <para>
 134       These structures are defined in
 135       <filename>&lt;lwres/lwres.h&gt;</filename>.
 136       They are shown below.
 137     </para>
 138     <para><programlisting>
 139 #define LWRES_OPCODE_GETADDRSBYNAME     0x00010001U
 140 </programlisting>
 141     </para>
 142     <para><programlisting>
 143 typedef struct lwres_addr lwres_addr_t;
 144 typedef LWRES_LIST(lwres_addr_t) lwres_addrlist_t;
 145 </programlisting>
 146     </para>
 147     <para><programlisting>
 148 typedef struct {
 149         lwres_uint32_t  flags;
 150         lwres_uint32_t  addrtypes;
 151         lwres_uint16_t  namelen;
 152         char           *name;
 153 } lwres_gabnrequest_t;
 154 </programlisting>
 155     </para>
 156     <para><programlisting>
 157 typedef struct {
 158         lwres_uint32_t          flags;
 159         lwres_uint16_t          naliases;
 160         lwres_uint16_t          naddrs;
 161         char                   *realname;
 162         char                  **aliases;
 163         lwres_uint16_t          realnamelen;
 164         lwres_uint16_t         *aliaslen;
 165         lwres_addrlist_t        addrs;
 166         void                   *base;
 167         size_t                  baselen;
 168 } lwres_gabnresponse_t;
 169 </programlisting>
 170     </para>
 171
 172     <para><function>lwres_gabnrequest_render()</function>
 173       uses resolver context <parameter>ctx</parameter> to convert
 174       getaddrbyname request structure <parameter>req</parameter> to
 175       canonical format.  The packet header structure
 176       <parameter>pkt</parameter> is initialised and transferred to
 177       buffer <parameter>b</parameter>.
 178
 179       The contents of <parameter>*req</parameter> are then appended to
 180       the buffer in canonical format.
 181       <function>lwres_gabnresponse_render()</function> performs the
 182       same task, except it converts a getaddrbyname response structure
 183       <type>lwres_gabnresponse_t</type> to the lightweight resolver's
 184       canonical format.
 185     </para>
 186
 187     <para><function>lwres_gabnrequest_parse()</function>
 188       uses context <parameter>ctx</parameter> to convert the contents
 189       of packet <parameter>pkt</parameter> to a
 190       <type>lwres_gabnrequest_t</type> structure.  Buffer
 191       <parameter>b</parameter> provides space to be used for storing
 192       this structure.  When the function succeeds, the resulting
 193       <type>lwres_gabnrequest_t</type> is made available through
 194       <parameter>*structp</parameter>.
 195
 196       <function>lwres_gabnresponse_parse()</function> offers the same
 197       semantics as <function>lwres_gabnrequest_parse()</function>
 198       except it yields a <type>lwres_gabnresponse_t</type> structure.
 199     </para>
 200
 201     <para><function>lwres_gabnresponse_free()</function>
 202       and <function>lwres_gabnrequest_free()</function> release the
 203       memory in resolver context <parameter>ctx</parameter> that was
 204       allocated to the <type>lwres_gabnresponse_t</type> or
 205       <type>lwres_gabnrequest_t</type> structures referenced via
 206       <parameter>structp</parameter>.
 207
 208       Any memory associated with ancillary buffers and strings for
 209       those structures is also discarded.
 210     </para>
 211   </refsect1>
 212   <refsect1>
 213     <title>RETURN VALUES</title>
 214     <para>
 215       The getaddrbyname opcode functions
 216       <function>lwres_gabnrequest_render()</function>,
 217       <function>lwres_gabnresponse_render()</function>
 218       <function>lwres_gabnrequest_parse()</function>
 219       and
 220       <function>lwres_gabnresponse_parse()</function>
 221       all return
 222       <errorcode>LWRES_R_SUCCESS</errorcode>
 223       on success.
 224       They return
 225       <errorcode>LWRES_R_NOMEMORY</errorcode>
 226       if memory allocation fails.
 227       <errorcode>LWRES_R_UNEXPECTEDEND</errorcode>
 228       is returned if the available space in the buffer
 229       <parameter>b</parameter>
 230       is too small to accommodate the packet header or the
 231       <type>lwres_gabnrequest_t</type>
 232       and
 233       <type>lwres_gabnresponse_t</type>
 234       structures.
 235       <function>lwres_gabnrequest_parse()</function>
 236       and
 237       <function>lwres_gabnresponse_parse()</function>
 238       will return
 239       <errorcode>LWRES_R_UNEXPECTEDEND</errorcode>
 240       if the buffer is not empty after decoding the received packet.
 241       These functions will return
 242       <errorcode>LWRES_R_FAILURE</errorcode>
 243       if
 244       <structfield>pktflags</structfield>
 245       in the packet header structure
 246       <type>lwres_lwpacket_t</type>
 247       indicate that the packet is not a response to an earlier query.
 248     </para>
 249   </refsect1>
 250   <refsect1>
 251     <title>SEE ALSO</title>
 252     <para><citerefentry>
 253         <refentrytitle>lwres_packet</refentrytitle><manvolnum>3</manvolnum>
 254       </citerefentry>
 255     </para>
 256   </refsect1>
 257 </refentry><!--
 258  - Local variables:
 259  - mode: sgml
 260  - End:
 261 -->