contrib/bind-9.2.4rc7/lib/lwres/include/lwres/lwpacket.h

   1 /*
   2  * Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 1999-2001  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
  18 /* $Id: lwpacket.h,v 1.17.2.1 2004/03/09 06:12:37 marka Exp $ */
  19
  20 #ifndef LWRES_LWPACKET_H
  21 #define LWRES_LWPACKET_H 1
  22
  23 #include <lwres/lang.h>
  24 #include <lwres/lwbuffer.h>
  25 #include <lwres/result.h>
  26
  27 typedef struct lwres_lwpacket lwres_lwpacket_t;
  28
  29 struct lwres_lwpacket {
  30         lwres_uint32_t          length;
  31         lwres_uint16_t          version;
  32         lwres_uint16_t          pktflags;
  33         lwres_uint32_t          serial;
  34         lwres_uint32_t          opcode;
  35         lwres_uint32_t          result;
  36         lwres_uint32_t          recvlength;
  37         lwres_uint16_t          authtype;
  38         lwres_uint16_t          authlength;
  39 };
  40
  41 #define LWRES_LWPACKET_LENGTH           (4 * 5 + 2 * 4)
  42
  43 #define LWRES_LWPACKETFLAG_RESPONSE     0x0001U /* if set, pkt is a response */
  44
  45
  46 #define LWRES_LWPACKETVERSION_0         0
  47
  48 /*
  49  * "length" is the overall packet length, including the entire packet header.
  50  *
  51  * "version" specifies the header format.  Currently, there is only one
  52  * format, LWRES_LWPACKETVERSION_0.
  53  *
  54  * "flags" specifies library-defined flags for this packet.  None of these
  55  * are definable by the caller, but library-defined values can be set by
  56  * the caller.  For example, one bit in this field indicates if the packet
  57  * is a request or a response.
  58  *
  59  * "serial" is set by the requestor and is returned in all replies.  If two
  60  * packets from the same source have the same serial number and are from
  61  * the same source, they are assumed to be duplicates and the latter ones
  62  * may be dropped.  (The library does not do this by default on replies, but
  63  * does so on requests.)
  64  *
  65  * "opcode" is application defined.  Opcodes between 0x04000000 and 0xffffffff
  66  * are application defined.  Opcodes between 0x00000000 and 0x03ffffff are
  67  * reserved for library use.
  68  *
  69  * "result" is application defined, and valid only on replies.
  70  * Results between 0x04000000 and 0xffffffff are application defined.
  71  * Results between 0x00000000 and 0x03ffffff are reserved for library use.
  72  * (This is the same reserved range defined in <isc/resultclass.h>, so it
  73  * would be trivial to map ISC_R_* result codes into packet result codes
  74  * when appropriate.)
  75  *
  76  * "recvlength" is set to the maximum buffer size that the receiver can
  77  * handle on requests, and the size of the buffer needed to satisfy a request
  78  * when the buffer is too large for replies.
  79  *
  80  * "authtype" is the packet level auth type used.
  81  * Authtypes between 0x1000 and 0xffff are application defined.  Authtypes
  82  * between 0x0000 and 0x0fff are reserved for library use.  This is currently
  83  * unused and MUST be set to zero.
  84  *
  85  * "authlen" is the length of the authentication data.  See the specific
  86  * authtypes for more information on what is contained in this field.  This
  87  * is currently unused, and MUST be set to zero.
  88  *
  89  * The remainder of the packet consists of two regions, one described by
  90  * "authlen" and one of "length - authlen - sizeof(lwres_lwpacket_t)".
  91  *
  92  * That is:
  93  *
  94  *      pkt header
  95  *      authlen bytes of auth information
  96  *      data bytes
  97  */
  98
  99 /*
 100  * Currently defined opcodes:
 101  *
 102  *      NOOP.  Success is always returned, with the packet contents echoed.
 103  *
 104  *      GETADDRSBYNAME.  Return all known addresses for a given name.
 105  *              This may return NIS or /etc/hosts info as well as DNS
 106  *              information.  Flags will be provided to indicate ip4/ip6
 107  *              addresses are desired.
 108  *
 109  *      GETNAMEBYADDR.  Return the hostname for the given address.  Once
 110  *              again, it will return data from multiple sources.
 111  */
 112
 113 LWRES_LANG_BEGINDECLS
 114
 115 /* XXXMLG document */
 116 lwres_result_t
 117 lwres_lwpacket_renderheader(lwres_buffer_t *b, lwres_lwpacket_t *pkt);
 118
 119 lwres_result_t
 120 lwres_lwpacket_parseheader(lwres_buffer_t *b, lwres_lwpacket_t *pkt);
 121
 122 LWRES_LANG_ENDDECLS
 123
 124 #endif /* LWRES_LWPACKET_H */