not reply an ICMPv6 Error message for a packet from an obvious anycas…

…t address

CHANGELOG

@@ -1,7 +1,11 @@
 			CHANGELOG for KAME kit
-$KAME: CHANGELOG,v 1.2810 2006/01/09 01:59:03 jinmei Exp $
+$KAME: CHANGELOG,v 1.2811 2006/01/15 12:26:56 suz Exp $
 
 <200601>
+2006-01-15  SUZUKI, Shinsuke <suz@alaxala.net>
+	* kame/sys/netinet6/{icmp6.c, in6.[ch]}: not reply an ICMPv6 Error
+	message for a packet from an obvious anycast address.
+
 2006-01-09  JINMEI, Tatuya  <jinmei@isl.rdc.toshiba.co.jp>
 	* freebsd5/sys/netinet6/in6_pcb.c (in6_{set,peer}sockaddr):
 	converted embedded scope zone IDs into the sin6_scope_id field

kame/sys/netinet6/icmp6.c

@@ -1,4 +1,4 @@
-/*	$KAME: icmp6.c,v 1.410 2005/08/09 08:20:11 jinmei Exp $	*/
+/*	$KAME: icmp6.c,v 1.411 2006/01/15 12:26:57 suz Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -421,7 +421,8 @@ icmp6_error(m, type, code, param)
 	 * XXX: the case of anycast source?
 	 */
 	if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
-	    IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
+	    IN6_IS_ADDR_MULTICAST(&oip6->ip6_src) ||
+	    in6_is_addr_anycast(&oip6->ip6_src))
 		goto freeit;
 
 	/*

kame/sys/netinet6/in6.c

@@ -1,4 +1,4 @@
-/*	$KAME: in6.c,v 1.402 2006/01/02 09:06:06 jinmei Exp $	*/
+/*	$KAME: in6.c,v 1.403 2006/01/15 12:26:57 suz Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -2156,6 +2156,44 @@ in6_localaddr(in6)
 }
 #endif
 
+/*
+ * The definition of anycast address in this function is
+ *  1) an interface address with IN6_IFF_ANYCAST bit on
+ *  2) a subnet router anycast address regarding a prefix of an interface 
+ *     address
+ * Other anycast address is not checked here, since it is impossible to judge 
+ * it within a node.
+ */
+int
+in6_is_addr_anycast(in6)
+	struct in6_addr *in6;
+{
+	struct in6_ifaddr *ia;
+
+	for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
+		struct in6_addr anycast, mask;
+
+		/* case 1. an interface address with IN6_IFF_ANYCAST */
+		if (ia->ia6_flags & IN6_IFF_ANYCAST) {
+			if (IN6_ARE_ADDR_EQUAL(in6, &ia->ia_addr.sin6_addr))
+				return (1);
+			continue;
+		}
+
+		/* case 2. a subnet router anycast address */
+		anycast = ia->ia_addr.sin6_addr;
+		mask = ia->ia_prefixmask.sin6_addr;
+		anycast.s6_addr32[0] &= mask.s6_addr32[0];
+		anycast.s6_addr32[1] &= mask.s6_addr32[1];
+		anycast.s6_addr32[2] &= mask.s6_addr32[2];
+		anycast.s6_addr32[3] &= mask.s6_addr32[3];
+		if (IN6_ARE_ADDR_EQUAL(in6, &anycast))
+			return (1);
+	}
+
+	return (0);
+}
+
 /*
  * return length of part which dst and src are equal
  * hard coding...

kame/sys/netinet6/in6.h

@@ -1,4 +1,4 @@
-/*	$KAME: in6.h,v 1.162 2005/10/21 01:20:16 keiichi Exp $	*/
+/*	$KAME: in6.h,v 1.163 2006/01/15 12:26:57 suz Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -875,6 +875,7 @@ int	in6_cksum __P((struct mbuf *, u_int8_t, u_int32_t, u_int32_t));
 #if defined(__FreeBSD__) || defined(__NetBSD__)
 int	in6_localaddr __P((struct in6_addr *));
 #endif
+int	in6_is_addr_anycast __P((struct in6_addr *));
 int	in6_addrscope __P((struct in6_addr *));
 struct	in6_ifaddr *in6_ifawithifp __P((struct ifnet *, struct in6_addr *));
 extern void in6_if_up __P((struct ifnet *));