/contrib/bind9/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
 77lwres_result_t
 78lwres_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
100lwres_result_t
101lwres_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}