ipv4: Remove flowi from struct rtable.

The only necessary parts are the src/dst addresses, the
interface indexes, the TOS, and the mark.

The rest is unnecessary bloat, which amounts to nearly
50 bytes on 64-bit.

Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/route.h

@@ -53,16 +53,20 @@ struct fib_info;
 struct rtable {
 	struct dst_entry	dst;
 
-	/* Cache lookup keys */
-	struct flowi		fl;
+	/* Lookup key. */
+	__be32			rt_key_dst;
+	__be32			rt_key_src;
 
 	int			rt_genid;
 	unsigned		rt_flags;
 	__u16			rt_type;
+	__u8			rt_tos;
 
 	__be32			rt_dst;	/* Path destination	*/
 	__be32			rt_src;	/* Path source		*/
 	int			rt_iif;
+	int			rt_oif;
+	__u32			rt_mark;
 
 	/* Info on neighbour */
 	__be32			rt_gateway;
@@ -76,12 +80,12 @@ struct rtable {
 
 static inline bool rt_is_input_route(struct rtable *rt)
 {
-	return rt->fl.iif != 0;
+	return rt->rt_iif != 0;
 }
 
 static inline bool rt_is_output_route(struct rtable *rt)
 {
-	return rt->fl.iif == 0;
+	return rt->rt_iif == 0;
 }
 
 struct ip_rt_acct {
@@ -212,11 +216,11 @@ static inline struct rtable *ip_route_newports(struct rtable *rt,
 					       __be16 dport, struct sock *sk)
 {
 	if (sport != orig_sport || dport != orig_dport) {
-		struct flowi fl = { .oif = rt->fl.oif,
-				    .mark = rt->fl.mark,
-				    .fl4_dst = rt->fl.fl4_dst,
-				    .fl4_src = rt->fl.fl4_src,
-				    .fl4_tos = rt->fl.fl4_tos,
+		struct flowi fl = { .oif = rt->rt_oif,
+				    .mark = rt->rt_mark,
+				    .fl4_dst = rt->rt_key_dst,
+				    .fl4_src = rt->rt_key_src,
+				    .fl4_tos = rt->rt_tos,
 				    .proto = protocol,
 				    .fl_ip_sport = sport,
 				    .fl_ip_dport = dport };

net/ipv4/icmp.c

@@ -563,7 +563,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
 		rcu_read_lock();
 		if (rt_is_input_route(rt) &&
 		    net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr)
-			dev = dev_get_by_index_rcu(net, rt->fl.iif);
+			dev = dev_get_by_index_rcu(net, rt->rt_iif);
 
 		if (dev)
 			saddr = inet_select_addr(dev, 0, RT_SCOPE_LINK);

net/ipv4/ipmr.c

@@ -1813,12 +1813,22 @@ int ip_mr_input(struct sk_buff *skb)
 	if (IPCB(skb)->flags & IPSKB_FORWARDED)
 		goto dont_forward;
 
-	err = ipmr_fib_lookup(net, &skb_rtable(skb)->fl, &mrt);
-	if (err < 0) {
-		kfree_skb(skb);
-		return err;
+	{
+		struct rtable *rt = skb_rtable(skb);
+		struct flowi fl = {
+			.fl4_dst = rt->rt_key_dst,
+			.fl4_src = rt->rt_key_src,
+			.fl4_tos = rt->rt_tos,
+			.oif = rt->rt_oif,
+			.iif = rt->rt_iif,
+			.mark = rt->rt_mark,
+		};
+		err = ipmr_fib_lookup(net, &fl, &mrt);
+		if (err < 0) {
+			kfree_skb(skb);
+			return err;
+		}
 	}
-
 	if (!local) {
 		if (IPCB(skb)->opt.router_alert) {
 			if (ip_call_ra_chain(skb))
@@ -1946,9 +1956,19 @@ int pim_rcv_v1(struct sk_buff *skb)
 
 	pim = igmp_hdr(skb);
 
-	if (ipmr_fib_lookup(net, &skb_rtable(skb)->fl, &mrt) < 0)
-		goto drop;
-
+	{
+		struct rtable *rt = skb_rtable(skb);
+		struct flowi fl = {
+			.fl4_dst = rt->rt_key_dst,
+			.fl4_src = rt->rt_key_src,
+			.fl4_tos = rt->rt_tos,
+			.oif = rt->rt_oif,
+			.iif = rt->rt_iif,
+			.mark = rt->rt_mark,
+		};
+		if (ipmr_fib_lookup(net, &fl, &mrt) < 0)
+			goto drop;
+	}
 	if (!mrt->mroute_do_pim ||
 	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
 		goto drop;
@@ -1978,9 +1998,19 @@ static int pim_rcv(struct sk_buff *skb)
 	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
 		goto drop;
 
-	if (ipmr_fib_lookup(net, &skb_rtable(skb)->fl, &mrt) < 0)
-		goto drop;
-
+	{
+		struct rtable *rt = skb_rtable(skb);
+		struct flowi fl = {
+			.fl4_dst = rt->rt_key_dst,
+			.fl4_src = rt->rt_key_src,
+			.fl4_tos = rt->rt_tos,
+			.oif = rt->rt_oif,
+			.iif = rt->rt_iif,
+			.mark = rt->rt_mark,
+		};
+		if (ipmr_fib_lookup(net, &fl, &mrt) < 0)
+			goto drop;
+	}
 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
 drop:
 		kfree_skb(skb);