Revert "ipv4: tcp: dont cache unconfirmed intput dst"

This reverts commit c074da2810c118b3812f32d6754bd9ead2f169e7.

This change has several unwanted side effects:

1) Sockets will cache the DST_NOCACHE route in sk->sk_rx_dst and we'll
   thus never create a real cached route.

2) All TCP traffic will use DST_NOCACHE and never use the routing
   cache at all.

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

6 files changed, 9 insertions, 14 deletions

diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 6a979594436..2e560f0c757 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -828,7 +828,7 @@ static int arp_process(struct sk_buff *skb)
 	}
 
 	if (arp->ar_op == htons(ARPOP_REQUEST) &&
-	    ip_route_input_noref(skb, tip, sip, 0, dev, false) == 0) {
+	    ip_route_input_noref(skb, tip, sip, 0, dev) == 0) {
 
 		rt = skb_rtable(skb);
 		addr_type = rt->rt_type;
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 978d55f256e..8d07c973409 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -259,7 +259,7 @@ static void ip_expire(unsigned long arg)
 		skb_dst_drop(head);
 		iph = ip_hdr(head);
 		err = ip_route_input_noref(head, iph->daddr, iph->saddr,
-					   iph->tos, head->dev, false);
+					   iph->tos, head->dev);
 		if (err)
 			goto out_rcu_unlock;
 
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 7be54c8dcbe..2a39204de5b 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -326,7 +326,6 @@ static int ip_rcv_finish(struct sk_buff *skb)
 	 */
 	if (skb_dst(skb) == NULL) {
 		int err = -ENOENT;
-		bool nocache = false;
 
 		if (sysctl_ip_early_demux) {
 			const struct net_protocol *ipprot;
@@ -335,13 +334,13 @@ static int ip_rcv_finish(struct sk_buff *skb)
 			rcu_read_lock();
 			ipprot = rcu_dereference(inet_protos[protocol]);
 			if (ipprot && ipprot->early_demux)
-				err = ipprot->early_demux(skb, &nocache);
+				err = ipprot->early_demux(skb);
 			rcu_read_unlock();
 		}
 
 		if (err) {
 			err = ip_route_input_noref(skb, iph->daddr, iph->saddr,
-						   iph->tos, skb->dev, nocache);
+						   iph->tos, skb->dev);
 			if (unlikely(err)) {
 				if (err == -EXDEV)
 					NET_INC_STATS_BH(dev_net(skb->dev),
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index fdc7900f9d7..81533e3a23d 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2214,7 +2214,7 @@ static int ip_mkroute_input(struct sk_buff *skb,
  */
 
 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
-			       u8 tos, struct net_device *dev, bool nocache)
+			       u8 tos, struct net_device *dev)
 {
 	struct fib_result res;
 	struct in_device *in_dev = __in_dev_get_rcu(dev);
@@ -2353,8 +2353,6 @@ local_input:
 		rth->dst.error= -err;
 		rth->rt_flags 	&= ~RTCF_LOCAL;
 	}
-	if (nocache)
-		rth->dst.flags |= DST_NOCACHE;
 	hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net));
 	rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif);
 	err = 0;
@@ -2397,7 +2395,7 @@ martian_source_keep_err:
 }
 
 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
-			   u8 tos, struct net_device *dev, bool noref, bool nocache)
+			   u8 tos, struct net_device *dev, bool noref)
 {
 	struct rtable	*rth;
 	unsigned int	hash;
@@ -2473,7 +2471,7 @@ skip_cache:
 		rcu_read_unlock();
 		return -EINVAL;
 	}
-	res = ip_route_input_slow(skb, daddr, saddr, tos, dev, nocache);
+	res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
 	rcu_read_unlock();
 	return res;
 }
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 33aabd4fc20..1781dc650b9 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1673,7 +1673,7 @@ csum_err:
 }
 EXPORT_SYMBOL(tcp_v4_do_rcv);
 
-int tcp_v4_early_demux(struct sk_buff *skb, bool *no_dst_cache)
+int tcp_v4_early_demux(struct sk_buff *skb)
 {
 	struct net *net = dev_net(skb->dev);
 	const struct iphdr *iph;
@@ -1719,8 +1719,6 @@ int tcp_v4_early_demux(struct sk_buff *skb, bool *no_dst_cache)
 				}
 			}
 		}
-	} else {
-		*no_dst_cache = true;
 	}
 
 out_err:
diff --git a/net/ipv4/xfrm4_input.c b/net/ipv4/xfrm4_input.c
index eee636b191b..06814b6216d 100644
--- a/net/ipv4/xfrm4_input.c
+++ b/net/ipv4/xfrm4_input.c
@@ -28,7 +28,7 @@ static inline int xfrm4_rcv_encap_finish(struct sk_buff *skb)
 		const struct iphdr *iph = ip_hdr(skb);
 
 		if (ip_route_input_noref(skb, iph->daddr, iph->saddr,
-					 iph->tos, skb->dev, false))
+					 iph->tos, skb->dev))
 			goto drop;
 	}
 	return dst_input(skb);