print-vjc.c | searchcode

/opensource.apple.com/source/tcpdump/tcpdump-11/tcpdump/print-vjc.c

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C | 144 lines | 78 code | 8 blank | 58 comment | 0 complexity | b9d8beae925231a7e80ef4bb4fa209ed MD5 | raw file
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<h1 style="margin:8px;" id="f1">print-vjc.c&nbsp;&nbsp;&nbsp;<span style="font-weight: normal; font-size: 0.5em;">[<a href="?txt">plain text</a>]</span></h1>
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<span class="enscript-comment">/*
 * Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996, 1997
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that: (1) source code distributions
 * retain the above copyright notice and this paragraph in its entirety, (2)
 * distributions including binary code include the above copyright notice and
 * this paragraph in its entirety in the documentation or other materials
 * provided with the distribution, and (3) all advertising materials mentioning
 * features or use of this software display the following acknowledgement:
 * ``This product includes software developed by the University of California,
 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
 * the University nor the names of its contributors may be used to endorse
 * or promote products derived from this software without specific prior
 * written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */</span>

#<span class="enscript-reference">ifdef</span> <span class="enscript-variable-name">HAVE_CONFIG_H</span>
#<span class="enscript-reference">include</span> <span class="enscript-string">&quot;config.h&quot;</span>
#<span class="enscript-reference">endif</span>

#<span class="enscript-reference">ifndef</span> <span class="enscript-variable-name">lint</span>
<span class="enscript-type">static</span> <span class="enscript-type">const</span> <span class="enscript-type">char</span> rcsid[] _U_ =
    <span class="enscript-string">&quot;@(#) $Header: /cvs/root/tcpdump/tcpdump/print-vjc.c,v 1.1.1.3 2004/02/05 19:30:57 rbraun Exp $ (LBL)&quot;</span>;
#<span class="enscript-reference">endif</span>

#<span class="enscript-reference">include</span> <span class="enscript-string">&lt;tcpdump-stdinc.h&gt;</span>

#<span class="enscript-reference">include</span> <span class="enscript-string">&lt;pcap.h&gt;</span>
#<span class="enscript-reference">include</span> <span class="enscript-string">&lt;stdio.h&gt;</span>

#<span class="enscript-reference">include</span> <span class="enscript-string">&quot;interface.h&quot;</span>
#<span class="enscript-reference">include</span> <span class="enscript-string">&quot;addrtoname.h&quot;</span>

#<span class="enscript-reference">include</span> <span class="enscript-string">&quot;slcompress.h&quot;</span>
#<span class="enscript-reference">include</span> <span class="enscript-string">&quot;ppp.h&quot;</span>

<span class="enscript-comment">/*
 * XXX - for BSD/OS PPP, what packets get supplied with a PPP header type
 * of PPP_VJC and what packets get supplied with a PPP header type of
 * PPP_VJNC?  PPP_VJNC is for &quot;UNCOMPRESSED_TCP&quot; packets, and PPP_VJC
 * is for COMPRESSED_TCP packets (PPP_IP is used for TYPE_IP packets).
 *
 * RFC 1144 implies that, on the wire, the packet type is *not* needed
 * for PPP, as different PPP protocol types can be used; it only needs
 * to be put on the wire for SLIP.
 *
 * It also indicates that, for compressed SLIP:
 *
 *	If the COMPRESSED_TCP bit is set in the first byte, it's
 *	a COMPRESSED_TCP packet; that byte is the change byte, and
 *	the COMPRESSED_TCP bit, 0x80, isn't used in the change byte.
 *
 *	If the upper 4 bits of the first byte are 7, it's an
 *	UNCOMPRESSED_TCP packet; that byte is the first byte of
 *	the UNCOMPRESSED_TCP modified IP header, with a connection
 *	number in the protocol field, and with the version field
 *	being 7, not 4.
 *
 *	Otherwise, the packet is an IPv4 packet (where the upper 4 bits
 *	of the packet are 4).
 *
 * So this routine looks as if it's sort-of intended to handle
 * compressed SLIP, although it doesn't handle UNCOMPRESSED_TCP
 * correctly for that (it doesn't fix the version number and doesn't
 * do anything to the protocol field), and doesn't check for COMPRESSED_TCP
 * packets correctly for that (you only check the first bit - see
 * B.1 in RFC 1144).
 *
 * But it's called for BSD/OS PPP, not SLIP - perhaps BSD/OS does weird
 * things with the headers?
 *
 * Without a BSD/OS VJC-compressed PPP trace, or knowledge of what the
 * BSD/OS VJC code does, we can't say what's the case.
 *
 * We therefore leave &quot;proto&quot; - which is the PPP protocol type - in place,
 * *not* marked as unused, for now, so that GCC warnings about the
 * unused argument remind us that we should fix this some day.
 */</span>
<span class="enscript-type">int</span>
<span class="enscript-function-name">vjc_print</span>(<span class="enscript-type">register</span> <span class="enscript-type">const</span> <span class="enscript-type">char</span> *bp, u_short proto)
{
	<span class="enscript-type">int</span> i;

	<span class="enscript-keyword">switch</span> (bp[0] &amp; 0xf0) {
	<span class="enscript-keyword">case</span> <span class="enscript-reference">TYPE_IP</span>:
		<span class="enscript-keyword">if</span> (eflag)
			printf(<span class="enscript-string">&quot;(vjc type=IP) &quot;</span>);
		<span class="enscript-keyword">return</span> PPP_IP;
	<span class="enscript-keyword">case</span> <span class="enscript-reference">TYPE_UNCOMPRESSED_TCP</span>:
		<span class="enscript-keyword">if</span> (eflag)
			printf(<span class="enscript-string">&quot;(vjc type=raw TCP) &quot;</span>);
		<span class="enscript-keyword">return</span> PPP_IP;
	<span class="enscript-keyword">case</span> <span class="enscript-reference">TYPE_COMPRESSED_TCP</span>:
		<span class="enscript-keyword">if</span> (eflag)
			printf(<span class="enscript-string">&quot;(vjc type=compressed TCP) &quot;</span>);
		<span class="enscript-keyword">for</span> (i = 0; i &lt; 8; i++) {
			<span class="enscript-keyword">if</span> (bp[1] &amp; (0x80 &gt;&gt; i))
				printf(<span class="enscript-string">&quot;%c&quot;</span>, <span class="enscript-string">&quot;?CI?SAWU&quot;</span>[i]);
		}
		<span class="enscript-keyword">if</span> (bp[1])
			printf(<span class="enscript-string">&quot; &quot;</span>);
		printf(<span class="enscript-string">&quot;C=0x%02x &quot;</span>, bp[2]);
		printf(<span class="enscript-string">&quot;sum=0x%04x &quot;</span>, *(u_short *)&amp;bp[3]);
		<span class="enscript-keyword">return</span> -1;
	<span class="enscript-keyword">case</span> <span class="enscript-reference">TYPE_ERROR</span>:
		<span class="enscript-keyword">if</span> (eflag)
			printf(<span class="enscript-string">&quot;(vjc type=error) &quot;</span>);
		<span class="enscript-keyword">return</span> -1;
	<span class="enscript-reference">default</span>:
		<span class="enscript-keyword">if</span> (eflag)
			printf(<span class="enscript-string">&quot;(vjc type=0x%02x) &quot;</span>, bp[0] &amp; 0xf0);
		<span class="enscript-keyword">return</span> -1;
	}
}
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