This patch fixes the handling of IPv6 mapped IPv4 addresses.
This got broken by the TAHI patches, which change the addr_type() 
function to return IPV6_ADDR_MAPPED ORed with the scope, instead
of just IPV6_ADDR_MAPPED.

Patch courtesy David L Stevens of IBM

Index: linux-2.6.7/net/ipv6/addrconf.c
===================================================================
--- linux-2.6.7.orig/net/ipv6/addrconf.c	2004-08-04 15:28:05.640746399 +0200
+++ linux-2.6.7/net/ipv6/addrconf.c	2004-08-04 15:40:47.998823599 +0200
@@ -1145,18 +1145,18 @@
 		return 1;
 
 	if (addr_type2 == IPV6_ADDR_ANY &&
-	    !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
+	    !(sk2_ipv6only && (addr_type & IPV6_ADDR_MAPPED)))
 		return 1;
 
 	if (addr_type == IPV6_ADDR_ANY &&
-	    !(sk_ipv6only && addr_type2 == IPV6_ADDR_MAPPED))
+	    !(sk_ipv6only && (addr_type2 & IPV6_ADDR_MAPPED)))
 		return 1;
 
 	if (sk2_rcv_saddr6 &&
 	    !ipv6_addr_cmp(sk_rcv_saddr6, sk2_rcv_saddr6))
 		return 1;
 
-	if (addr_type == IPV6_ADDR_MAPPED &&
+	if ((addr_type & IPV6_ADDR_MAPPED) &&
 	    !sk2_ipv6only &&
 	    (!sk2_rcv_saddr || !sk_rcv_saddr || sk_rcv_saddr == sk2_rcv_saddr))
 		return 1;
Index: linux-2.6.7/net/ipv6/af_inet6.c
===================================================================
--- linux-2.6.7.orig/net/ipv6/af_inet6.c	2004-08-04 15:28:00.693226152 +0200
+++ linux-2.6.7/net/ipv6/af_inet6.c	2004-08-04 15:40:47.999823502 +0200
@@ -308,7 +308,7 @@
 	}
 
 	/* Check if the address belongs to the host. */
-	if (addr_type == IPV6_ADDR_MAPPED) {
+	if (addr_type & IPV6_ADDR_MAPPED) {
 		v4addr = addr->sin6_addr.s6_addr32[3];
 		if (inet_addr_type(v4addr) != RTN_LOCAL) {
 			err = -EADDRNOTAVAIL;
Index: linux-2.6.7/net/ipv6/raw.c
===================================================================
--- linux-2.6.7.orig/net/ipv6/raw.c	2004-08-04 15:28:00.884207633 +0200
+++ linux-2.6.7/net/ipv6/raw.c	2004-08-04 15:40:48.000823405 +0200
@@ -190,7 +190,7 @@
 	addr_type = ipv6_addr_type(&addr->sin6_addr);
 
 	/* Raw sockets are IPv6 only */
-	if (addr_type == IPV6_ADDR_MAPPED)
+	if (addr_type & IPV6_ADDR_MAPPED)
 		return(-EADDRNOTAVAIL);
 
 	lock_sock(sk);
Index: linux-2.6.7/net/ipv6/tcp_ipv6.c
===================================================================
--- linux-2.6.7.orig/net/ipv6/tcp_ipv6.c	2004-08-04 15:28:00.892206857 +0200
+++ linux-2.6.7/net/ipv6/tcp_ipv6.c	2004-08-04 15:40:48.002823211 +0200
@@ -620,7 +620,7 @@
 	 *	TCP over IPv4
 	 */
 
-	if (addr_type == IPV6_ADDR_MAPPED) {
+	if (addr_type & IPV6_ADDR_MAPPED) {
 		u32 exthdrlen = tp->ext_header_len;
 		struct sockaddr_in sin;
 
Index: linux-2.6.7/net/ipv6/udp.c
===================================================================
--- linux-2.6.7.orig/net/ipv6/udp.c	2004-08-04 15:28:05.639746000 +0200
+++ linux-2.6.7/net/ipv6/udp.c	2004-08-04 15:40:48.004823017 +0200
@@ -667,7 +667,7 @@
 		daddr = NULL;
 
 	if (daddr) {
-		if (ipv6_addr_type(daddr) == IPV6_ADDR_MAPPED) {
+		if (ipv6_addr_type(daddr) & IPV6_ADDR_MAPPED) {
 			struct sockaddr_in sin;
 			sin.sin_family = AF_INET;
 			sin.sin_port = sin6 ? sin6->sin6_port : inet->dport;
Index: linux-2.6.7/net/sctp/ipv6.c
===================================================================
--- linux-2.6.7.orig/net/sctp/ipv6.c	2004-08-04 15:28:01.229174182 +0200
+++ linux-2.6.7/net/sctp/ipv6.c	2004-08-04 15:40:48.006822823 +0200
@@ -445,7 +445,7 @@
 	if (addr1->sa.sa_family != addr2->sa.sa_family) {
 		if (addr1->sa.sa_family == AF_INET &&
 		    addr2->sa.sa_family == AF_INET6 &&
-		    IPV6_ADDR_MAPPED == ipv6_addr_type(&addr2->v6.sin6_addr)) {
+		    IPV6_ADDR_MAPPED & ipv6_addr_type(&addr2->v6.sin6_addr)) {
 			if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 			    addr2->v6.sin6_addr.s6_addr32[3] ==
 			    addr1->v4.sin_addr.s_addr)
@@ -453,7 +453,7 @@
 		}
 		if (addr2->sa.sa_family == AF_INET &&
 		    addr1->sa.sa_family == AF_INET6 &&
-		    IPV6_ADDR_MAPPED == ipv6_addr_type(&addr1->v6.sin6_addr)) {
+		    IPV6_ADDR_MAPPED & ipv6_addr_type(&addr1->v6.sin6_addr)) {
 			if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 			    addr1->v6.sin6_addr.s6_addr32[3] ==
 			    addr2->v4.sin_addr.s_addr)
@@ -499,7 +499,7 @@
 	type = ipv6_addr_type(in6);
 	if (IPV6_ADDR_ANY == type)
 		return 1;
-	if (type == IPV6_ADDR_MAPPED) {
+	if (type & IPV6_ADDR_MAPPED) {
 		if (sp && !sp->v4mapped)
 			return 0;
 		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
@@ -525,7 +525,7 @@
 	int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 
 	/* Support v4-mapped-v6 address. */
-	if (ret == IPV6_ADDR_MAPPED) {
+	if (ret & IPV6_ADDR_MAPPED) {
 		/* Note: This routine is used in input, so v4-mapped-v6
 		 * are disallowed here when there is no sctp_opt.
 		 */