[PATCH net-next v3] ipv6: move IPV6_TCLASS_SHIFT into ipv6.h and define a helper

[roy.qing.li@gmail.com]

From: Li RongQing <roy.qing.li@gmail.com>

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>
---
 include/net/ipv6.h       |    5 +++++
 net/ipv6/fib6_rules.c    |    2 +-
 net/ipv6/ip6_gre.c       |    2 --
 net/ipv6/ip6_tunnel.c    |    2 --
 net/ipv6/ipv6_sockglue.c |    3 ++-
 5 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 12079c6..2a4b2d7 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -239,6 +239,7 @@ struct ip6_flowlabel {
 #define IPV6_FLOWINFO_MASK	cpu_to_be32(0x0FFFFFFF)
 #define IPV6_FLOWLABEL_MASK	cpu_to_be32(0x000FFFFF)
 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
+#define IPV6_TCLASS_SHIFT	20
 
 struct ipv6_fl_socklist {
 	struct ipv6_fl_socklist	__rcu	*next;
@@ -681,6 +682,10 @@ static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr)
 	return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK;
 }
 
+static inline u8 ip6_tclass(__be32 flowinfo)
+{
+	return ntohl(flowinfo & IPV6_TCLASS_MASK) >> IPV6_TCLASS_SHIFT;
+}
 /*
  *	Prototypes exported by ipv6
  */
diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
index 3fd0a57..b4d5e1d 100644
--- a/net/ipv6/fib6_rules.c
+++ b/net/ipv6/fib6_rules.c
@@ -169,7 +169,7 @@ static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
 			return 0;
 	}
 
-	if (r->tclass && r->tclass != ((ntohl(fl6->flowlabel) >> 20) & 0xff))
+	if (r->tclass && r->tclass != ip6_tclass(fl6->flowlabel))
 		return 0;
 
 	return 1;
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index e7a440d..f3ffb43 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -61,8 +61,6 @@ static bool log_ecn_error = true;
 module_param(log_ecn_error, bool, 0644);
 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
 
-#define IPV6_TCLASS_SHIFT 20
-
 #define HASH_SIZE_SHIFT  5
 #define HASH_SIZE (1 << HASH_SIZE_SHIFT)
 
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 1e5e240..5db8d31 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -69,8 +69,6 @@ MODULE_ALIAS_NETDEV("ip6tnl0");
 #define IP6_TNL_TRACE(x...) do {;} while(0)
 #endif
 
-#define IPV6_TCLASS_SHIFT 20
-
 #define HASH_SIZE_SHIFT  5
 #define HASH_SIZE (1 << HASH_SIZE_SHIFT)
 
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index af0ecb9..2855b00 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) {
-- 
1.7.10.4