Put IPv4/IPv6 protocol demultiplexing into a common routine.

That means less duplication of functionality - and less chance that
XXX-over-IPv4 will be handled but XXX-over-IPv6 won't be handled, or
*vice versa*.  (CARP and VRRP were being handled over IPv4 but not over
IPv6; this fixes that.)

1 files changed, 210 insertions, 0 deletions

diff --git a/print-ip-demux.c b/print-ip-demux.c
new file mode 100644
index 00000000..265658e7
--- /dev/null
+++ b/print-ip-demux.c
@@ -0,0 +1,210 @@
+/*
+ * Copyright (c) 1988, 1989, 1990, 1991, 1992, 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.
+ */
+
+/* \summary: IPv4/IPv6 payload printer */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "netdissect-stdinc.h"
+
+#include <string.h>
+
+#include "netdissect.h"
+#include "addrtoname.h"
+#include "extract.h"
+
+#include "ip.h"
+#include "ipproto.h"
+
+void
+ip_print_demux(netdissect_options *ndo,
+	       const u_char *bp,
+	       u_int length, u_int ver, int fragmented, u_int ttl_hl, u_int nh,
+	       const u_char *iph)
+{
+	int advance;
+	const char *p_name;
+
+	advance = 0;
+
+again:
+	switch (nh) {
+
+	case IPPROTO_AH:
+		if (!ND_TTEST_1(bp)) {
+			ndo->ndo_protocol = "ah";
+			nd_print_trunc(ndo);
+			break;
+		}
+		nh = GET_U_1(bp);
+		advance = ah_print(ndo, bp);
+		if (advance <= 0)
+			break;
+		bp += advance;
+		length -= advance;
+		goto again;
+
+	case IPPROTO_ESP:
+	{
+		u_int enh, padlen;
+		advance = esp_print(ndo, bp, length,
+				          iph, &enh, &padlen);
+		if (advance <= 0)
+			break;
+		bp += advance;
+		length -= advance + padlen;
+		nh = enh & 0xff;
+		goto again;
+	}
+
+	case IPPROTO_IPCOMP:
+	{
+		ipcomp_print(ndo, bp);
+		/*
+		 * Either this has decompressed the payload and
+		 * printed it, in which case there's nothing more
+		 * to do, or it hasn't, in which case there's
+		 * nothing more to do.
+		 */
+		break;
+	}
+
+	case IPPROTO_SCTP:
+		sctp_print(ndo, bp, iph, length);
+		break;
+
+	case IPPROTO_DCCP:
+		dccp_print(ndo, bp, iph, length);
+		break;
+
+	case IPPROTO_TCP:
+		tcp_print(ndo, bp, length, iph, fragmented);
+		break;
+
+	case IPPROTO_UDP:
+		udp_print(ndo, bp, length, iph, fragmented, ttl_hl);
+		break;
+
+	case IPPROTO_ICMP:
+		icmp_print(ndo, bp, length, iph, fragmented);
+		break;
+
+	case IPPROTO_ICMPV6:
+		icmp6_print(ndo, bp, length, iph, fragmented);
+		return;
+
+	case IPPROTO_PIGP:
+		/*
+		 * XXX - the current IANA protocol number assignments
+		 * page lists 9 as "any private interior gateway
+		 * (used by Cisco for their IGRP)" and 88 as
+		 * "EIGRP" from Cisco.
+		 *
+		 * Recent BSD <netinet/in.h> headers define
+		 * IP_PROTO_PIGP as 9 and IP_PROTO_IGRP as 88.
+		 * We define IP_PROTO_PIGP as 9 and
+		 * IP_PROTO_EIGRP as 88; those names better
+		 * match was the current protocol number
+		 * assignments say.
+		 */
+		igrp_print(ndo, bp, length);
+		break;
+
+	case IPPROTO_EIGRP:
+		eigrp_print(ndo, bp, length);
+		break;
+
+	case IPPROTO_ND:
+		ND_PRINT(" nd %u", length);
+		break;
+
+	case IPPROTO_EGP:
+		egp_print(ndo, bp, length);
+		break;
+
+	case IPPROTO_OSPF:
+		if (ver == 6)
+			ospf6_print(ndo, bp, length);
+		else
+			ospf_print(ndo, bp, length, iph);
+		break;
+
+	case IPPROTO_IGMP:
+		igmp_print(ndo, bp, length);
+		break;
+
+	case IPPROTO_IPV4:
+		/* ipv4-in-ip encapsulation */
+		ip_print(ndo, bp, length);
+		if (! ndo->ndo_vflag) {
+			ND_PRINT(" (ipip-proto-4)");
+			return;
+		}
+		break;
+
+	case IPPROTO_IPV6:
+		/* ip6-in-ip encapsulation */
+		ip6_print(ndo, bp, length);
+		break;
+
+	case IPPROTO_RSVP:
+		rsvp_print(ndo, bp, length);
+		break;
+
+	case IPPROTO_GRE:
+		gre_print(ndo, bp, length);
+		break;
+
+	case IPPROTO_MOBILE:
+		mobile_print(ndo, bp, length);
+		break;
+
+	case IPPROTO_PIM:
+		pim_print(ndo, bp, length, iph);
+		break;
+
+	case IPPROTO_VRRP:
+		if (ndo->ndo_packettype == PT_CARP) {
+			carp_print(ndo, bp, length, ttl_hl);
+		} else {
+			vrrp_print(ndo, bp, length, iph, ttl_hl);
+		}
+		break;
+
+	case IPPROTO_PGM:
+		pgm_print(ndo, bp, length, iph);
+		break;
+
+	case IPPROTO_NONE:
+		ND_PRINT("no next header");
+		break;
+
+	default:
+		if (ndo->ndo_nflag==0 && (p_name = netdb_protoname(nh)) != NULL)
+			ND_PRINT(" %s", p_name);
+		else
+			ND_PRINT(" ip-proto-%u", nh);
+		ND_PRINT(" %u", length);
+		break;
+	}
+}