create project

print-carp.c

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+/*	$OpenBSD: print-carp.c,v 1.6 2009/10/27 23:59:55 deraadt Exp $	*/
+
+/*
+ * Copyright (c) 2000 William C. Fenner.
+ *                All rights reserved.
+ *
+ * Kevin Steves <ks@hp.se> July 2000
+ * Modified to:
+ * - print version, type string and packet length
+ * - print IP address count if > 1 (-v)
+ * - verify checksum (-v)
+ * - print authentication string (-v)
+ *
+ * Copyright (c) 2011 Advanced Computing Technologies
+ * George V. Neille-Neil
+ *
+ * Modified to:
+ * - work correctly with CARP
+ * - compile into the latest tcpdump
+ * - print out the counter
+ *
+ * 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, and (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.
+ * The name of William C. Fenner may not 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
+
+#include <netdissect-stdinc.h>
+
+#include "netdissect.h" /* for checksum structure and functions */
+#include "extract.h"
+
+void
+carp_print(netdissect_options *ndo, register const u_char *bp, register u_int len, int ttl)
+{
+	int version, type;
+	const char *type_s;
+
+	ND_TCHECK(bp[0]);
+	version = (bp[0] & 0xf0) >> 4;
+	type = bp[0] & 0x0f;
+	if (type == 1)
+		type_s = "advertise";
+	else
+		type_s = "unknown";
+	ND_PRINT((ndo, "CARPv%d-%s %d: ", version, type_s, len));
+	if (ttl != 255)
+		ND_PRINT((ndo, "[ttl=%d!] ", ttl));
+	if (version != 2 || type != 1)
+		return;
+	ND_TCHECK(bp[2]);
+	ND_TCHECK(bp[5]);
+	ND_PRINT((ndo, "vhid=%d advbase=%d advskew=%d authlen=%d ",
+	    bp[1], bp[5], bp[2], bp[3]));
+	if (ndo->ndo_vflag) {
+		struct cksum_vec vec[1];
+		vec[0].ptr = (const uint8_t *)bp;
+		vec[0].len = len;
+		if (ND_TTEST2(bp[0], len) && in_cksum(vec, 1))
+			ND_PRINT((ndo, " (bad carp cksum %x!)",
+				EXTRACT_16BITS(&bp[6])));
+	}
+	ND_PRINT((ndo, "counter=%" PRIu64, EXTRACT_64BITS(&bp[8])));
+
+	return;
+trunc:
+	ND_PRINT((ndo, "[|carp]"));
+}