1 files changed, 119 insertions, 0 deletions
diff --git a/contrib/tcpdump/print-vjc.c b/contrib/tcpdump/print-vjc.c
new file mode 100644
index 0000000..55b7d08
--- /dev/null
+++ b/contrib/tcpdump/print-vjc.c
@@ -0,0 +1,119 @@
+/*
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifndef lint
+static const char rcsid[] _U_ =
+    "@(#) $Header: /tcpdump/master/tcpdump/print-vjc.c,v 1.15 2004/03/25 03:31:17 mcr Exp $ (LBL)";
+#endif
+
+#include <tcpdump-stdinc.h>
+
+#include <pcap.h>
+#include <stdio.h>
+
+#include "interface.h"
+#include "addrtoname.h"
+
+#include "slcompress.h"
+#include "ppp.h"
+
+/*
+ * 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 "UNCOMPRESSED_TCP" 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 "proto" - 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.
+ */
+int
+vjc_print(register const char *bp, u_short proto _U_)
+{
+	int i;
+
+	switch (bp[0] & 0xf0) {
+	case TYPE_IP:
+		if (eflag)
+			printf("(vjc type=IP) ");
+		return PPP_IP;
+	case TYPE_UNCOMPRESSED_TCP:
+		if (eflag)
+			printf("(vjc type=raw TCP) ");
+		return PPP_IP;
+	case TYPE_COMPRESSED_TCP:
+		if (eflag)
+			printf("(vjc type=compressed TCP) ");
+		for (i = 0; i < 8; i++) {
+			if (bp[1] & (0x80 >> i))
+				printf("%c", "?CI?SAWU"[i]);
+		}
+		if (bp[1])
+			printf(" ");
+		printf("C=0x%02x ", bp[2]);
+		printf("sum=0x%04x ", *(u_short *)&bp[3]);
+		return -1;
+	case TYPE_ERROR:
+		if (eflag)
+			printf("(vjc type=error) ");
+		return -1;
+	default:
+		if (eflag)
+			printf("(vjc type=0x%02x) ", bp[0] & 0xf0);
+		return -1;
+	}
+}