148 lines
5.0 KiB
C
148 lines
5.0 KiB
C
#ifndef lint
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static char *rcsid = "$Id: msgheader.c,v 1.7 2000/09/20 02:47:31 ishisone Exp $";
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#endif
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/*
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* Copyright (c) 2000 Japan Network Information Center. All rights reserved.
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*
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* By using this file, you agree to the terms and conditions set forth bellow.
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*
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* LICENSE TERMS AND CONDITIONS
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*
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* The following License Terms and Conditions apply, unless a different
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* license is obtained from Japan Network Information Center ("JPNIC"),
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* a Japanese association, Fuundo Bldg., 1-2 Kanda Ogawamachi, Chiyoda-ku,
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* Tokyo, Japan.
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*
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* 1. Use, Modification and Redistribution (including distribution of any
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* modified or derived work) in source and/or binary forms is permitted
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* under this License Terms and Conditions.
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*
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* 2. Redistribution of source code must retain the copyright notices as they
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* appear in each source code file, this License Terms and Conditions.
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*
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* 3. Redistribution in binary form must reproduce the Copyright Notice,
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* this License Terms and Conditions, in the documentation and/or other
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* materials provided with the distribution. For the purposes of binary
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* distribution the "Copyright Notice" refers to the following language:
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* "Copyright (c) Japan Network Information Center. All rights reserved."
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*
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* 4. Neither the name of JPNIC may be used to endorse or promote products
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* derived from this Software without specific prior written approval of
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* JPNIC.
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*
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* 5. Disclaimer/Limitation of Liability: THIS SOFTWARE IS PROVIDED BY JPNIC
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
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* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JPNIC BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
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* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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* ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
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*
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* 6. Indemnification by Licensee
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* Any person or entities using and/or redistributing this Software under
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* this License Terms and Conditions shall defend indemnify and hold
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* harmless JPNIC from and against any and all judgements damages,
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* expenses, settlement liabilities, cost and other liabilities of any
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* kind as a result of use and redistribution of this Software or any
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* claim, suite, action, litigation or proceeding by any third party
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* arising out of or relates to this License Terms and Conditions.
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*
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* 7. Governing Law, Jurisdiction and Venue
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* This License Terms and Conditions shall be governed by and and
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* construed in accordance with the law of Japan. Any person or entities
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* using and/or redistributing this Software under this License Terms and
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* Conditions hereby agrees and consent to the personal and exclusive
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* jurisdiction and venue of Tokyo District Court of Japan.
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*/
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#include <config.h>
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#include <stddef.h>
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#include <stdarg.h>
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#include <mdn/result.h>
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#include <mdn/assert.h>
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#include <mdn/logmacro.h>
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#include <mdn/debug.h>
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#include <mdn/msgheader.h>
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#define DNS_HEADER_SIZE 12
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mdn_result_t
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mdn_msgheader_parse(const char *msg, size_t msglen, mdn_msgheader_t *parsed) {
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const unsigned char *p = (const unsigned char *)msg;
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unsigned int v;
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assert(msg != NULL && parsed != NULL);
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TRACE(("mdn_msgheader_parse(msg=<%s>, msglen=%d)\n",
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mdn_debug_hexdata(msg, msglen, 12), msglen));
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if (msglen < DNS_HEADER_SIZE)
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return (mdn_invalid_message);
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#define GET16(off) ((p[off]<<8)+p[(off)+1])
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parsed->id = GET16(0);
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v = GET16(2);
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parsed->qr = (v & 0x8000) != 0;
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parsed->opcode = (v >> 11) & 0xf;
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parsed->flags = (v >> 4) & 0x7f;
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parsed->rcode = v & 0xf;
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parsed->qdcount = GET16(4);
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parsed->ancount = GET16(6);
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parsed->nscount = GET16(8);
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parsed->arcount = GET16(10);
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#undef GET16
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return (mdn_success);
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}
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mdn_result_t
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mdn_msgheader_unparse(mdn_msgheader_t *parsed, char *msg, size_t msglen) {
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unsigned char *p = (unsigned char *)msg;
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unsigned int v;
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assert(parsed != NULL && msg != NULL);
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TRACE(("mdn_msgheader_unparse()\n"));
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if (msglen < DNS_HEADER_SIZE)
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return (mdn_buffer_overflow);
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v = ((parsed->qr & 1) << 15) +
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((parsed->opcode & 0xf) << 11) +
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((parsed->flags & 0x7f) << 4) +
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(parsed->rcode & 0xf);
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#define PUT16(off, v) p[off] = ((v)>>8) & 0xff; p[(off)+1] = (v) & 0xff
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PUT16(0, parsed->id);
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PUT16(2, v);
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PUT16(4, parsed->qdcount);
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PUT16(6, parsed->ancount);
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PUT16(8, parsed->nscount);
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PUT16(10, parsed->arcount);
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#undef PUT16
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return (mdn_success);
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}
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unsigned int
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mdn_msgheader_getid(const char *msg) {
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const unsigned char *p = (const unsigned char *)msg;
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return ((p[0] << 8) + p[1]);
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}
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void
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mdn_msgheader_setid(char *msg, unsigned int id) {
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unsigned char *p = (unsigned char *)msg;
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p[0] = (id >> 8) & 0xff;
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p[1] = id & 0xff;
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}
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