ipv6: Introduce ip6_flowinfo() to extract flowinfo (tclass + flowlabel).

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

include/net/ipv6.h

@@ -555,6 +555,11 @@ static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
 	*(__be32 *)hdr = ntohl(0x60000000 | (tclass << 20)) | flowlabel;
 }
 
+static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
+{
+	return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
+}
+
 /*
  *	Prototypes exported by ipv6
  */

net/ipv6/datagram.c

@@ -360,7 +360,7 @@ int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)
 								  struct ipv6hdr, daddr);
 			sin->sin6_addr = ip6h->daddr;
 			if (np->sndflow)
-				sin->sin6_flowinfo = *(__be32 *)ip6h & IPV6_FLOWINFO_MASK;
+				sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 			if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 				sin->sin6_scope_id = IP6CB(skb)->iif;
 		} else {
@@ -491,9 +491,10 @@ int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
 		put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 	}
 
-	if (np->rxopt.bits.rxflow && (*(__be32 *)nh & IPV6_FLOWINFO_MASK)) {
-		__be32 flowinfo = *(__be32 *)nh & IPV6_FLOWINFO_MASK;
-		put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
+	if (np->rxopt.bits.rxflow) {
+		__be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
+		if (flowinfo)
+			put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 	}
 
 	/* HbH is allowed only once */

net/ipv6/route.c

@@ -994,7 +994,7 @@ void ip6_route_input(struct sk_buff *skb)
 		.flowi6_iif = skb->dev->ifindex,
 		.daddr = iph->daddr,
 		.saddr = iph->saddr,
-		.flowlabel = (* (__be32 *) iph) & IPV6_FLOWINFO_MASK,
+		.flowlabel = ip6_flowinfo(iph),
 		.flowi6_mark = skb->mark,
 		.flowi6_proto = iph->nexthdr,
 	};
@@ -1159,7 +1159,7 @@ void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
 	fl6.flowi6_flags = 0;
 	fl6.daddr = iph->daddr;
 	fl6.saddr = iph->saddr;
-	fl6.flowlabel = (*(__be32 *) iph) & IPV6_FLOWINFO_MASK;
+	fl6.flowlabel = ip6_flowinfo(iph);
 
 	dst = ip6_route_output(net, NULL, &fl6);
 	if (!dst->error)
@@ -1187,7 +1187,7 @@ void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark)
 	fl6.flowi6_flags = 0;
 	fl6.daddr = iph->daddr;
 	fl6.saddr = iph->saddr;
-	fl6.flowlabel = (*(__be32 *) iph) & IPV6_FLOWINFO_MASK;
+	fl6.flowlabel = ip6_flowinfo(iph);
 
 	dst = ip6_route_output(net, NULL, &fl6);
 	if (!dst->error)