[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>

2 files changed, 3 insertions, 0 deletions

diff --git a/include/net/dst.h b/include/net/dst.h
index 36d54fc248b0..a8d825f90305 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -54,6 +54,7 @@ struct dst_entry
         unsigned long           expires;
 
         unsigned short          header_len;     /* more space at head required */
+        unsigned short          nfheader_len;   /* more non-fragment space at head required */
         unsigned short          trailer_len;    /* space to reserve at tail */
 
         u32                     metrics[RTAX_MAX];
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index aa3ac994477b..aa93cc1f6299 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -260,6 +260,8 @@ struct xfrm_type
         char                    *description;
         struct module           *owner;
         __u8                    proto;
+        __u8                    flags;
+#define XFRM_TYPE_NON_FRAGMENT  1
 
         int                     (*init_state)(struct xfrm_state *x);
         void                    (*destructor)(struct xfrm_state *);