xref: /netbsd-src/external/bsd/tcpdump/dist/print-carp.c (revision 26ba0b503b498a5194a71ac319838b7f5497f3fe)
19546e36dSchristos /*	$OpenBSD: print-carp.c,v 1.6 2009/10/27 23:59:55 deraadt Exp $	*/
29546e36dSchristos 
39546e36dSchristos /*
49546e36dSchristos  * Copyright (c) 2000 William C. Fenner.
59546e36dSchristos  *                All rights reserved.
69546e36dSchristos  *
79546e36dSchristos  * Kevin Steves <ks@hp.se> July 2000
89546e36dSchristos  * Modified to:
99546e36dSchristos  * - print version, type string and packet length
109546e36dSchristos  * - print IP address count if > 1 (-v)
119546e36dSchristos  * - verify checksum (-v)
129546e36dSchristos  * - print authentication string (-v)
139546e36dSchristos  *
149546e36dSchristos  * Copyright (c) 2011 Advanced Computing Technologies
159546e36dSchristos  * George V. Neille-Neil
169546e36dSchristos  *
179546e36dSchristos  * Modified to:
189546e36dSchristos  * - work correctly with CARP
199546e36dSchristos  * - compile into the latest tcpdump
209546e36dSchristos  * - print out the counter
219546e36dSchristos  *
229546e36dSchristos  * Redistribution and use in source and binary forms, with or without
239546e36dSchristos  * modification, are permitted provided that: (1) source code
249546e36dSchristos  * distributions retain the above copyright notice and this paragraph
259546e36dSchristos  * in its entirety, and (2) distributions including binary code include
269546e36dSchristos  * the above copyright notice and this paragraph in its entirety in
279546e36dSchristos  * the documentation or other materials provided with the distribution.
289546e36dSchristos  * The name of William C. Fenner may not be used to endorse or
299546e36dSchristos  * promote products derived from this software without specific prior
309546e36dSchristos  * written permission.  THIS SOFTWARE IS PROVIDED ``AS IS'' AND
319546e36dSchristos  * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
329546e36dSchristos  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
339546e36dSchristos  * FOR A PARTICULAR PURPOSE.
349546e36dSchristos  *
359546e36dSchristos  */
369546e36dSchristos 
37fdccd7e4Schristos #include <sys/cdefs.h>
38fdccd7e4Schristos #ifndef lint
39*26ba0b50Schristos __RCSID("$NetBSD: print-carp.c,v 1.5 2024/09/02 16:15:30 christos Exp $");
40fdccd7e4Schristos #endif
41fdccd7e4Schristos 
42dc860a36Sspz /* \summary: Common Address Redundancy Protocol (CARP) printer */
43dc860a36Sspz 
44c74ad251Schristos #include <config.h>
459546e36dSchristos 
46c74ad251Schristos #include "netdissect-stdinc.h"
479546e36dSchristos 
48784088dfSchristos #include "netdissect.h" /* for checksum structure and functions */
499546e36dSchristos #include "extract.h"
509546e36dSchristos 
519546e36dSchristos void
52c74ad251Schristos carp_print(netdissect_options *ndo, const u_char *bp, u_int len, u_int ttl)
539546e36dSchristos {
54c74ad251Schristos 	u_int version, type;
559546e36dSchristos 	const char *type_s;
569546e36dSchristos 
57c74ad251Schristos 	ndo->ndo_protocol = "carp";
58*26ba0b50Schristos 	nd_print_protocol_caps(ndo);
59c74ad251Schristos 	version = (GET_U_1(bp) & 0xf0) >> 4;
60c74ad251Schristos 	type = GET_U_1(bp) & 0x0f;
619546e36dSchristos 	if (type == 1)
629546e36dSchristos 		type_s = "advertise";
639546e36dSchristos 	else
649546e36dSchristos 		type_s = "unknown";
65*26ba0b50Schristos 	ND_PRINT("v%u-%s %u: ", version, type_s, len);
669546e36dSchristos 	if (ttl != 255)
67c74ad251Schristos 		ND_PRINT("[ttl=%u!] ", ttl);
689546e36dSchristos 	if (version != 2 || type != 1)
699546e36dSchristos 		return;
70c74ad251Schristos 	ND_PRINT("vhid=%u advbase=%u advskew=%u authlen=%u ",
71c74ad251Schristos 	    GET_U_1(bp + 1), GET_U_1(bp + 5), GET_U_1(bp + 2),
72c74ad251Schristos 	    GET_U_1(bp + 3));
73c47fd378Schristos 	if (ndo->ndo_vflag) {
749546e36dSchristos 		struct cksum_vec vec[1];
75c47fd378Schristos 		vec[0].ptr = (const uint8_t *)bp;
769546e36dSchristos 		vec[0].len = len;
77c74ad251Schristos 		if (ND_TTEST_LEN(bp, len) && in_cksum(vec, 1))
78c74ad251Schristos 			ND_PRINT(" (bad carp cksum %x!)",
79c74ad251Schristos 				GET_BE_U_2(bp + 6));
809546e36dSchristos 	}
81c74ad251Schristos 	ND_PRINT("counter=%" PRIu64, GET_BE_U_8(bp + 8));
829546e36dSchristos }
83