[XFRM] STATE: Support non-fragment outbound transformation headers.

For originated outbound IPv6 packets which will fragment, ip6_append_data()
should know length of extension headers before sending them and
the length is carried by dst_entry.
IPv6 IPsec headers fragment then transformation was
designed to place all headers after fragment header.
OTOH Mobile IPv6 extension headers do not fragment then
it is a good idea to make dst_entry have non-fragment length to tell it
to ip6_append_data().

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index a5bed74..e517981 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -135,6 +135,7 @@
 		dst_prev->flags	       |= DST_HOST;
 		dst_prev->lastuse	= jiffies;
 		dst_prev->header_len	= header_len;
+		dst_prev->nfheader_len	= 0;
 		dst_prev->trailer_len	= trailer_len;
 		memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics));