contrib/bind/lib/lwres/lwpacket.c

   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/or 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.c,v 1.18 2007/06/19 23:47:22 tbox Exp $ */
  19
  20 /*! \file */
  21
  22 /**
  23  *    These functions rely on a struct lwres_lwpacket which is defined in
  24  *    \link lwpacket.h lwres/lwpacket.h.\endlink
  25  *
  26  *    The following opcodes are currently defined:
  27  *
  28  * \li   #LWRES_OPCODE_NOOP
  29  *           Success is always returned and the packet contents are
  30  *           echoed. The \link lwres_noop.c lwres_noop_*()\endlink functions should be used for this
  31  *           type.
  32  *
  33  * \li   #LWRES_OPCODE_GETADDRSBYNAME
  34  *           returns all known addresses for a given name. The
  35  *           \link lwres_gabn.c lwres_gabn_*()\endlink functions should be used for this type.
  36  *
  37  * \li   #LWRES_OPCODE_GETNAMEBYADDR
  38  *           return the hostname for the given address. The
  39  *           \link lwres_gnba.c lwres_gnba_*() \endlink functions should be used for this type.
  40  *
  41  *    lwres_lwpacket_renderheader() transfers the contents of lightweight
  42  *    resolver packet structure #lwres_lwpacket_t *pkt in network byte
  43  *    order to the lightweight resolver buffer, *b.
  44  *
  45  *    lwres_lwpacket_parseheader() performs the converse operation. It
  46  *    transfers data in network byte order from buffer *b to resolver
  47  *    packet *pkt. The contents of the buffer b should correspond to a
  48  *    #lwres_lwpacket_t.
  49  *
  50  * \section lwpacket_return Return Values
  51  *
  52  *    Successful calls to lwres_lwpacket_renderheader() and
  53  *    lwres_lwpacket_parseheader() return #LWRES_R_SUCCESS. If there is
  54  *    insufficient space to copy data between the buffer *b and
  55  *    lightweight resolver packet *pkt both functions return
  56  *    #LWRES_R_UNEXPECTEDEND.
  57  */
  58
  59 #include <config.h>
  60
  61 #include <assert.h>
  62 #include <stdlib.h>
  63 #include <string.h>
  64
  65 #include <lwres/lwbuffer.h>
  66 #include <lwres/lwpacket.h>
  67 #include <lwres/result.h>
  68
  69 #include "assert_p.h"
  70
  71 /*% Length of Packet */
  72 #define LWPACKET_LENGTH \
  73         (sizeof(lwres_uint16_t) * 4 + sizeof(lwres_uint32_t) * 5)
  74
  75 /*% transfers the contents of lightweight resolver packet structure lwres_lwpacket_t *pkt in network byte order to the lightweight resolver buffer, *b. */
  76
  77 lwres_result_t
  78 lwres_lwpacket_renderheader(lwres_buffer_t *b, lwres_lwpacket_t *pkt) {
  79         REQUIRE(b != NULL);
  80         REQUIRE(pkt != NULL);
  81
  82         if (!SPACE_OK(b, LWPACKET_LENGTH))
  83                 return (LWRES_R_UNEXPECTEDEND);
  84
  85         lwres_buffer_putuint32(b, pkt->length);
  86         lwres_buffer_putuint16(b, pkt->version);
  87         lwres_buffer_putuint16(b, pkt->pktflags);
  88         lwres_buffer_putuint32(b, pkt->serial);
  89         lwres_buffer_putuint32(b, pkt->opcode);
  90         lwres_buffer_putuint32(b, pkt->result);
  91         lwres_buffer_putuint32(b, pkt->recvlength);
  92         lwres_buffer_putuint16(b, pkt->authtype);
  93         lwres_buffer_putuint16(b, pkt->authlength);
  94
  95         return (LWRES_R_SUCCESS);
  96 }
  97
  98 /*% transfers data in network byte order from buffer *b to resolver packet *pkt. The contents of the buffer b should correspond to a lwres_lwpacket_t. */
  99
 100 lwres_result_t
 101 lwres_lwpacket_parseheader(lwres_buffer_t *b, lwres_lwpacket_t *pkt) {
 102         lwres_uint32_t space;
 103
 104         REQUIRE(b != NULL);
 105         REQUIRE(pkt != NULL);
 106
 107         space = LWRES_BUFFER_REMAINING(b);
 108         if (space < LWPACKET_LENGTH)
 109                 return (LWRES_R_UNEXPECTEDEND);
 110
 111         pkt->length = lwres_buffer_getuint32(b);
 112         /*
 113          * XXXBEW/MLG Checking that the buffer is long enough probably
 114          * shouldn't be done here, since this function is supposed to just
 115          * parse the header.
 116          */
 117         if (pkt->length > space)
 118                 return (LWRES_R_UNEXPECTEDEND);
 119         pkt->version = lwres_buffer_getuint16(b);
 120         pkt->pktflags = lwres_buffer_getuint16(b);
 121         pkt->serial = lwres_buffer_getuint32(b);
 122         pkt->opcode = lwres_buffer_getuint32(b);
 123         pkt->result = lwres_buffer_getuint32(b);
 124         pkt->recvlength = lwres_buffer_getuint32(b);
 125         pkt->authtype = lwres_buffer_getuint16(b);
 126         pkt->authlength = lwres_buffer_getuint16(b);
 127
 128         return (LWRES_R_SUCCESS);
 129 }