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#ifndef lint
static char *rcsid = "$Id: msgheader.c,v 1.8 2001/10/31 08:51:28 m-kasahr Exp $";
#endif
/*
* Copyright (c) 2000 Japan Network Information Center. All rights reserved.
*
* By using this file, you agree to the terms and conditions set forth bellow.
*
* LICENSE TERMS AND CONDITIONS
*
* The following License Terms and Conditions apply, unless a different
* license is obtained from Japan Network Information Center ("JPNIC"),
* a Japanese association, Kokusai-Kougyou-Kanda Bldg 6F, 2-3-4 Uchi-Kanda,
* Chiyoda-ku, Tokyo 101-0047, Japan.
*
* 1. Use, Modification and Redistribution (including distribution of any
* modified or derived work) in source and/or binary forms is permitted
* under this License Terms and Conditions.
*
* 2. Redistribution of source code must retain the copyright notices as they
* appear in each source code file, this License Terms and Conditions.
*
* 3. Redistribution in binary form must reproduce the Copyright Notice,
* this License Terms and Conditions, in the documentation and/or other
* materials provided with the distribution. For the purposes of binary
* distribution the "Copyright Notice" refers to the following language:
* "Copyright (c) Japan Network Information Center. All rights reserved."
*
* 4. Neither the name of JPNIC may be used to endorse or promote products
* derived from this Software without specific prior written approval of
* JPNIC.
*
* 5. Disclaimer/Limitation of Liability: THIS SOFTWARE IS PROVIDED BY JPNIC
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JPNIC BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* 6. Indemnification by Licensee
* Any person or entities using and/or redistributing this Software under
* this License Terms and Conditions shall defend indemnify and hold
* harmless JPNIC from and against any and all judgements damages,
* expenses, settlement liabilities, cost and other liabilities of any
* kind as a result of use and redistribution of this Software or any
* claim, suite, action, litigation or proceeding by any third party
* arising out of or relates to this License Terms and Conditions.
*
* 7. Governing Law, Jurisdiction and Venue
* This License Terms and Conditions shall be governed by and and
* construed in accordance with the law of Japan. Any person or entities
* using and/or redistributing this Software under this License Terms and
* Conditions hereby agrees and consent to the personal and exclusive
* jurisdiction and venue of Tokyo District Court of Japan.
*/
#include <config.h>
#include <stddef.h>
#include <stdarg.h>
#include <mdn/result.h>
#include <mdn/assert.h>
#include <mdn/logmacro.h>
#include <mdn/debug.h>
#include <mdn/msgheader.h>
#define DNS_HEADER_SIZE 12
mdn_result_t
mdn_msgheader_parse(const char *msg, size_t msglen, mdn_msgheader_t *parsed) {
const unsigned char *p = (const unsigned char *)msg;
unsigned int v;
assert(msg != NULL && parsed != NULL);
TRACE(("mdn_msgheader_parse(msg=<%s>, msglen=%d)\n",
mdn_debug_hexdata(msg, msglen, 12), msglen));
if (msglen < DNS_HEADER_SIZE)
return (mdn_invalid_message);
#define GET16(off) ((p[off]<<8)+p[(off)+1])
parsed->id = GET16(0);
v = GET16(2);
parsed->qr = (v & 0x8000) != 0;
parsed->opcode = (v >> 11) & 0xf;
parsed->flags = (v >> 4) & 0x7f;
parsed->rcode = v & 0xf;
parsed->qdcount = GET16(4);
parsed->ancount = GET16(6);
parsed->nscount = GET16(8);
parsed->arcount = GET16(10);
#undef GET16
return (mdn_success);
}
mdn_result_t
mdn_msgheader_unparse(mdn_msgheader_t *parsed, char *msg, size_t msglen) {
unsigned char *p = (unsigned char *)msg;
unsigned int v;
assert(parsed != NULL && msg != NULL);
TRACE(("mdn_msgheader_unparse()\n"));
if (msglen < DNS_HEADER_SIZE)
return (mdn_buffer_overflow);
v = ((parsed->qr & 1) << 15) +
((parsed->opcode & 0xf) << 11) +
((parsed->flags & 0x7f) << 4) +
(parsed->rcode & 0xf);
#define PUT16(off, v) p[off] = ((v)>>8) & 0xff; p[(off)+1] = (v) & 0xff
PUT16(0, parsed->id);
PUT16(2, v);
PUT16(4, parsed->qdcount);
PUT16(6, parsed->ancount);
PUT16(8, parsed->nscount);
PUT16(10, parsed->arcount);
#undef PUT16
return (mdn_success);
}
unsigned int
mdn_msgheader_getid(const char *msg) {
const unsigned char *p = (const unsigned char *)msg;
return ((p[0] << 8) + p[1]);
}
void
mdn_msgheader_setid(char *msg, unsigned int id) {
unsigned char *p = (unsigned char *)msg;
p[0] = (id >> 8) & 0xff;
p[1] = id & 0xff;
}
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