diff -ur linux-2.5.40/net/ipv6/ipv6_sockglue.c linux-2.5.40a/net/ipv6/ipv6_sockglue.c
--- linux-2.5.40/net/ipv6/ipv6_sockglue.c	Tue Oct  1 03:06:16 2002
+++ linux-2.5.40a/net/ipv6/ipv6_sockglue.c	Thu Oct  3 07:23:59 2002
@@ -143,66 +143,6 @@
 
 	switch (optname) {
 
-	case IPV6_ADDRFORM:
-		if (val == PF_INET) {
-			struct ipv6_txoptions *opt;
-			struct sk_buff *pktopt;
-
-			if (sk->protocol != IPPROTO_UDP &&
-			    sk->protocol != IPPROTO_TCP)
-				break;
-
-			if (sk->state != TCP_ESTABLISHED) {
-				retv = -ENOTCONN;
-				break;
-			}
-
-			if (!(ipv6_addr_type(&np->daddr) & IPV6_ADDR_MAPPED)) {
-				retv = -EADDRNOTAVAIL;
-				break;
-			}
-
-			fl6_free_socklist(sk);
-			ipv6_sock_mc_close(sk);
-
-			if (sk->protocol == IPPROTO_TCP) {
-				struct tcp_opt *tp = tcp_sk(sk);
-
-				local_bh_disable();
-				sock_prot_dec_use(sk->prot);
-				sock_prot_inc_use(&tcp_prot);
-				local_bh_enable();
-				sk->prot = &tcp_prot;
-				tp->af_specific = &ipv4_specific;
-				sk->socket->ops = &inet_stream_ops;
-				sk->family = PF_INET;
-				tcp_sync_mss(sk, tp->pmtu_cookie);
-			} else {
-				local_bh_disable();
-				sock_prot_dec_use(sk->prot);
-				sock_prot_inc_use(&udp_prot);
-				local_bh_enable();
-				sk->prot = &udp_prot;
-				sk->socket->ops = &inet_dgram_ops;
-				sk->family = PF_INET;
-			}
-			opt = xchg(&np->opt, NULL);
-			if (opt)
-				sock_kfree_s(sk, opt, opt->tot_len);
-			pktopt = xchg(&np->pktoptions, NULL);
-			if (pktopt)
-				kfree_skb(pktopt);
-
-			sk->destruct = inet_sock_destruct;
-#ifdef INET_REFCNT_DEBUG
-			atomic_dec(&inet6_sock_nr);
-#endif
-			MOD_DEC_USE_COUNT;
-			retv = 0;
-			break;
-		}
-		goto e_inval;
-
 	case IPV6_PKTINFO:
 		np->rxopt.bits.rxinfo = valbool;
 		retv = 0;