[IPV6]: ROUTE: Add support for Router Preference (RFC4191).

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/linux/ipv6_route.h b/include/linux/ipv6_route.h
index d7c41d1d706a..f4b085c91608 100644
--- a/include/linux/ipv6_route.h
+++ b/include/linux/ipv6_route.h
@@ -27,8 +27,16 @@
 #define RTF_FLOW        0x02000000      /* flow significant route       */
 #define RTF_POLICY      0x04000000      /* policy route                 */
 
+#define RTF_PREF(pref)  ((pref) << 27)
+#define RTF_PREF_MASK   0x18000000
+
 #define RTF_LOCAL       0x80000000
 
+#ifdef __KERNEL__
+#define IPV6_EXTRACT_PREF(flag) (((flag) & RTF_PREF_MASK) >> 27)
+#define IPV6_DECODE_PREF(pref)  ((pref) ^ 2)    /* 1:low,2:med,3:high */
+#endif
+
 struct in6_rtmsg {
         struct in6_addr         rtmsg_dst;
         struct in6_addr         rtmsg_src;