4 files changed, 36 insertions, 5 deletions

diff --git a/include/net/flow.h b/include/net/flow.h
index 240b7f356c71..1ae901f24436 100644
--- a/include/net/flow.h
+++ b/include/net/flow.h
@@ -48,7 +48,8 @@ struct flowi {
 
         __u8    proto;
         __u8    flags;
-#define FLOWI_FLAG_ANYSRC 0x01
+#define FLOWI_FLAG_ANYSRC               0x01
+#define FLOWI_FLAG_PRECOW_METRICS       0x02
         union {
                 struct {
                         __be16  sport;
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index 8181498fa96c..6e6dfd757682 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -219,7 +219,13 @@ static inline struct request_sock *inet_reqsk_alloc(struct request_sock_ops *ops
 
 static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
 {
-        return inet_sk(sk)->transparent ? FLOWI_FLAG_ANYSRC : 0;
+        __u8 flags = 0;
+
+        if (inet_sk(sk)->transparent)
+                flags |= FLOWI_FLAG_ANYSRC;
+        if (sk->sk_protocol == IPPROTO_TCP)
+                flags |= FLOWI_FLAG_PRECOW_METRICS;
+        return flags;
 }
 
 #endif  /* _INET_SOCK_H */
diff --git a/include/net/route.h b/include/net/route.h
index 5677cbf0c6e6..e5864658dc76 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -182,6 +182,8 @@ static inline int ip_route_connect(struct rtable **rp, __be32 dst,
 
         if (inet_sk(sk)->transparent)
                 fl.flags |= FLOWI_FLAG_ANYSRC;
+        if (protocol == IPPROTO_TCP)
+                fl.flags |= FLOWI_FLAG_PRECOW_METRICS;
 
         if (!dst || !src) {
                 err = __ip_route_output_key(net, rp, &fl);
@@ -209,6 +211,8 @@ static inline int ip_route_newports(struct rtable **rp, u8 protocol,
                 fl.proto = protocol;
                 if (inet_sk(sk)->transparent)
                         fl.flags |= FLOWI_FLAG_ANYSRC;
+                if (protocol == IPPROTO_TCP)
+                        fl.flags |= FLOWI_FLAG_PRECOW_METRICS;
                 ip_rt_put(*rp);
                 *rp = NULL;
                 security_sk_classify_flow(sk, &fl);
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 68cee358d9a3..dd57f4896736 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1857,6 +1857,28 @@ static unsigned int ipv4_default_mtu(const struct dst_entry *dst)
         return mtu;
 }
 
+static void rt_init_metrics(struct rtable *rt, struct fib_info *fi)
+{
+        if (!(rt->fl.flags & FLOWI_FLAG_PRECOW_METRICS)) {
+        no_cow:
+                rt->fi = fi;
+                atomic_inc(&fi->fib_clntref);
+                dst_init_metrics(&rt->dst, fi->fib_metrics, true);
+        } else {
+                struct inet_peer *peer;
+
+                if (!rt->peer)
+                        rt_bind_peer(rt, 1);
+                peer = rt->peer;
+                if (!peer)
+                        goto no_cow;
+                if (inet_metrics_new(peer))
+                        memcpy(peer->metrics, fi->fib_metrics,
+                               sizeof(u32) * RTAX_MAX);
+                dst_init_metrics(&rt->dst, peer->metrics, false);
+        }
+}
+
 static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
 {
         struct dst_entry *dst = &rt->dst;
@@ -1866,9 +1888,7 @@ static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
                 if (FIB_RES_GW(*res) &&
                     FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
                         rt->rt_gateway = FIB_RES_GW(*res);
-                rt->fi = fi;
-                atomic_inc(&fi->fib_clntref);
-                dst_init_metrics(dst, fi->fib_metrics, true);
+                rt_init_metrics(rt, fi);
 #ifdef CONFIG_IP_ROUTE_CLASSID
                 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
 #endif