ipv6: move IPV6_TCLASS_SHIFT into ipv6.h and define a helper

Two places defined IPV6_TCLASS_SHIFT, so we should move it into ipv6.h,
and use this macro as possible. And define ip6_tclass helper to return
tclass

Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index af0ecb94b3b4..2855b00ed49d 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -1019,7 +1019,8 @@ static int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
                                 put_cmsg(&msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
                         }
                         if (np->rxopt.bits.rxtclass) {
-                                int tclass = ntohl(np->rcv_flowinfo & IPV6_TCLASS_MASK) >> 20;
+                                int tclass = (int)ip6_tclass(np->rcv_flowinfo);
+
                                 put_cmsg(&msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
                         }
                         if (np->rxopt.bits.rxoinfo) {