[INET]: Give outer DSCP directly to ip*_copy_dscp

This patch changes the prototype of ipv4_copy_dscp and ipv6_copy_dscp so
that they directly take the outer DSCP rather than the outer IP header.
This will help us to unify the code for inter-family tunnels.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/inet_ecn.h

@@ -83,9 +83,9 @@ static inline void IP_ECN_clear(struct iphdr *iph)
 	iph->tos &= ~INET_ECN_MASK;
 }
 
-static inline void ipv4_copy_dscp(struct iphdr *outer, struct iphdr *inner)
+static inline void ipv4_copy_dscp(unsigned int dscp, struct iphdr *inner)
 {
-	u32 dscp = ipv4_get_dsfield(outer) & ~INET_ECN_MASK;
+	dscp &= ~INET_ECN_MASK;
 	ipv4_change_dsfield(inner, INET_ECN_MASK, dscp);
 }
 
@@ -104,9 +104,9 @@ static inline void IP6_ECN_clear(struct ipv6hdr *iph)
 	*(__be32*)iph &= ~htonl(INET_ECN_MASK << 20);
 }
 
-static inline void ipv6_copy_dscp(struct ipv6hdr *outer, struct ipv6hdr *inner)
+static inline void ipv6_copy_dscp(unsigned int dscp, struct ipv6hdr *inner)
 {
-	u32 dscp = ipv6_get_dsfield(outer) & ~INET_ECN_MASK;
+	dscp &= ~INET_ECN_MASK;
 	ipv6_change_dsfield(inner, INET_ECN_MASK, dscp);
 }
 

net/ipv4/xfrm4_mode_tunnel.c

@@ -113,7 +113,7 @@ static int xfrm4_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
 	iph = ip_hdr(skb);
 	if (iph->protocol == IPPROTO_IPIP) {
 		if (x->props.flags & XFRM_STATE_DECAP_DSCP)
-			ipv4_copy_dscp(iph, ipip_hdr(skb));
+			ipv4_copy_dscp(ipv4_get_dsfield(iph), ipip_hdr(skb));
 		if (!(x->props.flags & XFRM_STATE_NOECN))
 			ipip_ecn_decapsulate(skb);
 	}

net/ipv6/ip6_tunnel.c

@@ -635,7 +635,7 @@ static void ip6ip6_dscp_ecn_decapsulate(struct ip6_tnl *t,
 					struct sk_buff *skb)
 {
 	if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
-		ipv6_copy_dscp(ipv6h, ipv6_hdr(skb));
+		ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
 
 	if (INET_ECN_is_ce(ipv6_get_dsfield(ipv6h)))
 		IP6_ECN_set_ce(ipv6_hdr(skb));

net/ipv6/xfrm6_mode_tunnel.c

@@ -95,7 +95,8 @@ static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
 	nh = skb_network_header(skb);
 	if (nh[IP6CB(skb)->nhoff] == IPPROTO_IPV6) {
 		if (x->props.flags & XFRM_STATE_DECAP_DSCP)
-			ipv6_copy_dscp(ipv6_hdr(skb), ipipv6_hdr(skb));
+			ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb)),
+				       ipipv6_hdr(skb));
 		if (!(x->props.flags & XFRM_STATE_NOECN))
 			ipip6_ecn_decapsulate(skb);
 	} else {