1<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" 2 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" 3 [<!ENTITY mdash "—">]> 4<!-- 5 - Copyright (C) 2004, 2005, 2007, 2014 Internet Systems Consortium, Inc. ("ISC") 6 - Copyright (C) 2000, 2001 Internet Software Consortium. 7 - 8 - Permission to use, copy, modify, and/or distribute this software for any 9 - purpose with or without fee is hereby granted, provided that the above 10 - copyright notice and this permission notice appear in all copies. 11 - 12 - THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 13 - REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 14 - AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 15 - INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 16 - LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 17 - OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 18 - PERFORMANCE OF THIS SOFTWARE. 19--> 20 21<refentry> 22 23 <refentryinfo> 24 <date>June 18, 2007</date> 25 </refentryinfo> 26 27 <refmeta> 28 <refentrytitle>lwres_packet</refentrytitle> 29 <manvolnum>3</manvolnum> 30 <refmiscinfo>BIND9</refmiscinfo> 31 </refmeta> 32 33 <docinfo> 34 <copyright> 35 <year>2004</year> 36 <year>2005</year> 37 <year>2007</year> 38 <year>2014</year> 39 <holder>Internet Systems Consortium, Inc. ("ISC")</holder> 40 </copyright> 41 <copyright> 42 <year>2000</year> 43 <year>2001</year> 44 <holder>Internet Software Consortium.</holder> 45 </copyright> 46 </docinfo> 47 48 <refnamediv> 49 <refname>lwres_lwpacket_renderheader</refname> 50 <refname>lwres_lwpacket_parseheader</refname> 51 <refpurpose>lightweight resolver packet handling functions</refpurpose> 52 </refnamediv> 53 <refsynopsisdiv> 54 <funcsynopsis> 55<funcsynopsisinfo>#include <lwres/lwpacket.h></funcsynopsisinfo> 56<funcprototype> 57 <funcdef> 58lwres_result_t 59<function>lwres_lwpacket_renderheader</function></funcdef> 60 <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef> 61 <paramdef>lwres_lwpacket_t *<parameter>pkt</parameter></paramdef> 62 </funcprototype> 63<funcprototype> 64 <funcdef> 65lwres_result_t 66<function>lwres_lwpacket_parseheader</function></funcdef> 67 <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef> 68 <paramdef>lwres_lwpacket_t *<parameter>pkt</parameter></paramdef> 69 </funcprototype> 70</funcsynopsis> 71 </refsynopsisdiv> 72 <refsect1> 73 <title>DESCRIPTION</title> 74 <para> 75 These functions rely on a 76 <type>struct lwres_lwpacket</type> 77 which is defined in 78 <filename>lwres/lwpacket.h</filename>. 79 </para> 80 81 <para><programlisting> 82typedef struct lwres_lwpacket lwres_lwpacket_t; 83 </programlisting> 84 </para> 85 <para><programlisting> 86struct lwres_lwpacket { 87 lwres_uint32_t length; 88 lwres_uint16_t version; 89 lwres_uint16_t pktflags; 90 lwres_uint32_t serial; 91 lwres_uint32_t opcode; 92 lwres_uint32_t result; 93 lwres_uint32_t recvlength; 94 lwres_uint16_t authtype; 95 lwres_uint16_t authlength; 96}; 97</programlisting> 98 </para> 99 100 <para> 101 The elements of this structure are: 102 <variablelist> 103 <varlistentry> 104 <term><constant>length</constant></term> 105 <listitem> 106 <para> 107 the overall packet length, including the entire packet header. 108 This field is filled in by the lwres_gabn_*() and lwres_gnba_*() 109 calls. 110 </para> 111 </listitem> 112 </varlistentry> 113 <varlistentry> 114 <term><constant>version</constant></term> 115 <listitem> 116 <para> 117 the header format. There is currently only one format, 118 <type>LWRES_LWPACKETVERSION_0</type>. 119 120 This field is filled in by the lwres_gabn_*() and lwres_gnba_*() 121 calls. 122 </para> 123 </listitem> 124 </varlistentry> 125 <varlistentry> 126 <term><constant>pktflags</constant></term> 127 <listitem> 128 <para> 129 library-defined flags for this packet: for instance whether the 130 packet 131 is a request or a reply. Flag values can be set, but not defined 132 by 133 the caller. 134 This field is filled in by the application wit the exception of 135 the 136 LWRES_LWPACKETFLAG_RESPONSE bit, which is set by the library in 137 the 138 lwres_gabn_*() and lwres_gnba_*() calls. 139 </para> 140 </listitem> 141 </varlistentry> 142 <varlistentry> 143 <term><constant>serial</constant></term> 144 <listitem> 145 <para> 146 is set by the requestor and is returned in all replies. If two 147 or more 148 packets from the same source have the same serial number and are 149 from 150 the same source, they are assumed to be duplicates and the 151 latter ones 152 may be dropped. 153 This field must be set by the application. 154 </para> 155 </listitem> 156 </varlistentry> 157 <varlistentry> 158 <term><constant>opcode</constant></term> 159 <listitem> 160 <para> 161 indicates the operation. 162 Opcodes between 0x00000000 and 0x03ffffff are 163 reserved for use by the lightweight resolver library. Opcodes 164 between 165 0x04000000 and 0xffffffff are application defined. 166 This field is filled in by the lwres_gabn_*() and lwres_gnba_*() 167 calls. 168 </para> 169 </listitem> 170 </varlistentry> 171 <varlistentry> 172 <term><constant>result</constant></term> 173 <listitem> 174 <para> 175 is only valid for replies. 176 Results between 0x04000000 and 0xffffffff are application 177 defined. 178 Results between 0x00000000 and 0x03ffffff are reserved for 179 library use. 180 This field is filled in by the lwres_gabn_*() and lwres_gnba_*() 181 calls. 182 </para> 183 </listitem> 184 </varlistentry> 185 <varlistentry> 186 <term><constant>recvlength</constant></term> 187 <listitem> 188 <para> 189 is the maximum buffer size that the receiver can handle on 190 requests 191 and the size of the buffer needed to satisfy a request when the 192 buffer 193 is too large for replies. 194 This field is supplied by the application. 195 </para> 196 </listitem> 197 </varlistentry> 198 <varlistentry> 199 <term><constant>authtype</constant></term> 200 <listitem> 201 <para> 202 defines the packet level authentication that is used. 203 Authorisation types between 0x1000 and 0xffff are application 204 defined 205 and types between 0x0000 and 0x0fff are reserved for library 206 use. 207 Currently these are not used and must be zero. 208 </para> 209 </listitem> 210 </varlistentry> 211 <varlistentry> 212 <term><constant>authlen</constant></term> 213 <listitem> 214 <para> 215 gives the length of the authentication data. 216 Since packet authentication is currently not used, this must be 217 zero. 218 </para> 219 </listitem> 220 </varlistentry> 221 </variablelist> 222 </para> 223 <para> 224 The following opcodes are currently defined: 225 <variablelist> 226 <varlistentry> 227 <term><constant>NOOP</constant></term> 228 <listitem> 229 <para> 230 Success is always returned and the packet contents are echoed. 231 The lwres_noop_*() functions should be used for this type. 232 </para> 233 </listitem> 234 </varlistentry> 235 <varlistentry> 236 <term><constant>GETADDRSBYNAME</constant></term> 237 <listitem> 238 <para> 239 returns all known addresses for a given name. 240 The lwres_gabn_*() functions should be used for this type. 241 </para> 242 </listitem> 243 </varlistentry> 244 <varlistentry> 245 <term><constant>GETNAMEBYADDR</constant></term> 246 <listitem> 247 <para> 248 return the hostname for the given address. 249 The lwres_gnba_*() functions should be used for this type. 250 </para> 251 </listitem> 252 </varlistentry> 253 </variablelist> 254 </para> 255 256 <para><function>lwres_lwpacket_renderheader()</function> 257 transfers the contents of lightweight resolver packet structure 258 <type>lwres_lwpacket_t</type> <parameter>*pkt</parameter> in 259 network byte order to the lightweight resolver buffer, 260 <parameter>*b</parameter>. 261 </para> 262 263 <para><function>lwres_lwpacket_parseheader()</function> 264 performs the converse operation. It transfers data in network 265 byte order from buffer <parameter>*b</parameter> to resolver 266 packet <parameter>*pkt</parameter>. The contents of the buffer 267 <parameter>b</parameter> should correspond to a 268 <type>lwres_lwpacket_t</type>. 269 </para> 270 271 </refsect1> 272 273 <refsect1> 274 <title>RETURN VALUES</title> 275 <para> 276 Successful calls to 277 <function>lwres_lwpacket_renderheader()</function> and 278 <function>lwres_lwpacket_parseheader()</function> return 279 <errorcode>LWRES_R_SUCCESS</errorcode>. If there is insufficient 280 space to copy data between the buffer <parameter>*b</parameter> and 281 lightweight resolver packet <parameter>*pkt</parameter> both 282 functions 283 return <errorcode>LWRES_R_UNEXPECTEDEND</errorcode>. 284 </para> 285 286 </refsect1> 287</refentry><!-- 288 - Local variables: 289 - mode: sgml 290 - End: 291--> 292