xref: /netbsd-src/external/bsd/tcpdump/dist/print-rt6.c (revision 26ba0b503b498a5194a71ac319838b7f5497f3fe)

/*
 * Copyright (c) 1988, 1989, 1990, 1991, 1993, 1994
 *	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.
 */

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: print-rt6.c,v 1.9 2024/09/02 16:15:32 christos Exp $");
#endif

/* \summary: IPv6 routing header printer */

#include <config.h>

#include "netdissect-stdinc.h"

#include "netdissect.h"
#include "addrtoname.h"
#include "extract.h"

#include "ip6.h"

int
rt6_print(netdissect_options *ndo, const u_char *bp, const u_char *bp2 _U_)
{
	const struct ip6_rthdr *dp;
	const struct ip6_rthdr0 *dp0;
	const struct ip6_srh *srh;
	u_int i, len, type;
	const u_char *p;

	ndo->ndo_protocol = "rt6";

	nd_print_protocol_caps(ndo);
	dp = (const struct ip6_rthdr *)bp;

	len = GET_U_1(dp->ip6r_len);
	ND_PRINT(" (len=%u", len);	/*)*/
	type = GET_U_1(dp->ip6r_type);
	ND_PRINT(", type=%u", type);
	if (type == IPV6_RTHDR_TYPE_0)
		ND_PRINT(" [Deprecated]");
	ND_PRINT(", segleft=%u", GET_U_1(dp->ip6r_segleft));

	switch (type) {
	case IPV6_RTHDR_TYPE_0:
	case IPV6_RTHDR_TYPE_2:			/* Mobile IPv6 ID-20 */
		dp0 = (const struct ip6_rthdr0 *)dp;

		if (GET_BE_U_4(dp0->ip6r0_reserved) || ndo->ndo_vflag) {
			ND_PRINT(", rsv=0x%0x",
			    GET_BE_U_4(dp0->ip6r0_reserved));
		}

		if (len % 2 == 1) {
			ND_PRINT(" [length %u]", len);
			goto invalid;
		}
		len >>= 1;
		p = (const u_char *) dp0->ip6r0_addr;
		for (i = 0; i < len; i++) {
			ND_PRINT(", [%u]%s", i, GET_IP6ADDR_STRING(p));
			p += 16;
		}
		/*(*/
		ND_PRINT(") ");
		return((GET_U_1(dp0->ip6r0_len) + 1) << 3);
		break;
	case IPV6_RTHDR_TYPE_4:
		srh = (const struct ip6_srh *)dp;
		ND_PRINT(", last-entry=%u", GET_U_1(srh->srh_last_ent));

		if (GET_U_1(srh->srh_flags) || ndo->ndo_vflag) {
			ND_PRINT(", flags=0x%0x",
				GET_U_1(srh->srh_flags));
		}

		ND_PRINT(", tag=%x", GET_BE_U_2(srh->srh_tag));

		if (len % 2 == 1) {
			ND_PRINT(" (invalid length %u)", len);
			goto invalid;
		}
		len >>= 1;
		p  = (const u_char *) srh->srh_segments;
		for (i = 0; i < len; i++) {
			ND_PRINT(", [%u]%s", i, GET_IP6ADDR_STRING(p));
			p += 16;
		}
		/*(*/
		ND_PRINT(") ");
		return((GET_U_1(srh->srh_len) + 1) << 3);
		break;
	default:
		ND_PRINT(" (unknown type)");
		goto invalid;
	}

invalid:
	nd_print_invalid(ndo);
	return -1;
}