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/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
/* $Id: lwpacket.c,v 1.18 2007/06/19 23:47:22 tbox Exp $ */
/*! \file */
/**
* These functions rely on a struct lwres_lwpacket which is defined in
* \link lwpacket.h lwres/lwpacket.h.\endlink
*
* The following opcodes are currently defined:
*
* \li #LWRES_OPCODE_NOOP
* Success is always returned and the packet contents are
* echoed. The \link lwres_noop.c lwres_noop_*()\endlink functions should be used for this
* type.
*
* \li #LWRES_OPCODE_GETADDRSBYNAME
* returns all known addresses for a given name. The
* \link lwres_gabn.c lwres_gabn_*()\endlink functions should be used for this type.
*
* \li #LWRES_OPCODE_GETNAMEBYADDR
* return the hostname for the given address. The
* \link lwres_gnba.c lwres_gnba_*() \endlink functions should be used for this type.
*
* lwres_lwpacket_renderheader() transfers the contents of lightweight
* resolver packet structure #lwres_lwpacket_t *pkt in network byte
* order to the lightweight resolver buffer, *b.
*
* lwres_lwpacket_parseheader() performs the converse operation. It
* 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.
*
* \section lwpacket_return Return Values
*
* Successful calls to lwres_lwpacket_renderheader() and
* lwres_lwpacket_parseheader() return #LWRES_R_SUCCESS. If there is
* insufficient space to copy data between the buffer *b and
* lightweight resolver packet *pkt both functions return
* #LWRES_R_UNEXPECTEDEND.
*/
#include <config.h>
#include <assert.h>
#include <inttypes.h>
#include <stdlib.h>
#include <string.h>
#include <lwres/lwbuffer.h>
#include <lwres/lwpacket.h>
#include <lwres/result.h>
#include "assert_p.h"
/*% Length of Packet */
#define LWPACKET_LENGTH \
(sizeof(uint16_t) * 4 + sizeof(uint32_t) * 5)
/*% transfers the contents of lightweight resolver packet structure lwres_lwpacket_t *pkt in network byte order to the lightweight resolver buffer, *b. */
lwres_result_t
lwres_lwpacket_renderheader(lwres_buffer_t *b, lwres_lwpacket_t *pkt) {
REQUIRE(b != NULL);
REQUIRE(pkt != NULL);
if (!SPACE_OK(b, LWPACKET_LENGTH))
return (LWRES_R_UNEXPECTEDEND);
lwres_buffer_putuint32(b, pkt->length);
lwres_buffer_putuint16(b, pkt->version);
lwres_buffer_putuint16(b, pkt->pktflags);
lwres_buffer_putuint32(b, pkt->serial);
lwres_buffer_putuint32(b, pkt->opcode);
lwres_buffer_putuint32(b, pkt->result);
lwres_buffer_putuint32(b, pkt->recvlength);
lwres_buffer_putuint16(b, pkt->authtype);
lwres_buffer_putuint16(b, pkt->authlength);
return (LWRES_R_SUCCESS);
}
/*% 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. */
lwres_result_t
lwres_lwpacket_parseheader(lwres_buffer_t *b, lwres_lwpacket_t *pkt) {
uint32_t space;
REQUIRE(b != NULL);
REQUIRE(pkt != NULL);
space = LWRES_BUFFER_REMAINING(b);
if (space < LWPACKET_LENGTH)
return (LWRES_R_UNEXPECTEDEND);
pkt->length = lwres_buffer_getuint32(b);
/*
* XXXBEW/MLG Checking that the buffer is long enough probably
* shouldn't be done here, since this function is supposed to just
* parse the header.
*/
if (pkt->length > space)
return (LWRES_R_UNEXPECTEDEND);
pkt->version = lwres_buffer_getuint16(b);
pkt->pktflags = lwres_buffer_getuint16(b);
pkt->serial = lwres_buffer_getuint32(b);
pkt->opcode = lwres_buffer_getuint32(b);
pkt->result = lwres_buffer_getuint32(b);
pkt->recvlength = lwres_buffer_getuint32(b);
pkt->authtype = lwres_buffer_getuint16(b);
pkt->authlength = lwres_buffer_getuint16(b);
return (LWRES_R_SUCCESS);
}
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