6 files changed, 34 insertions, 28 deletions

diff --git a/include/net/route.h b/include/net/route.h
index da22243d2760..bc40b633a5c4 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -48,7 +48,8 @@ struct rtable {
         int                     rt_genid;
         unsigned int            rt_flags;
         __u16                   rt_type;
-        __u16                   rt_is_input;
+        __u8                    rt_is_input;
+        __u8                    rt_uses_gateway;
 
         int                     rt_iif;
 
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index f0c5b9c1a957..d34ce2972c8f 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -406,7 +406,7 @@ struct dst_entry *inet_csk_route_req(struct sock *sk,
         rt = ip_route_output_flow(net, fl4, sk);
         if (IS_ERR(rt))
                 goto no_route;
-        if (opt && opt->opt.is_strictroute && rt->rt_gateway)
+        if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
                 goto route_err;
         return &rt->dst;
 
@@ -442,7 +442,7 @@ struct dst_entry *inet_csk_route_child_sock(struct sock *sk,
         rt = ip_route_output_flow(net, fl4, sk);
         if (IS_ERR(rt))
                 goto no_route;
-        if (opt && opt->opt.is_strictroute && rt->rt_gateway)
+        if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
                 goto route_err;
         rcu_read_unlock();
         return &rt->dst;
diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c
index 7f35ac26a71a..694de3b7aebf 100644
--- a/net/ipv4/ip_forward.c
+++ b/net/ipv4/ip_forward.c
@@ -85,7 +85,7 @@ int ip_forward(struct sk_buff *skb)
 
         rt = skb_rtable(skb);
 
-        if (opt->is_strictroute && rt->rt_gateway)
+        if (opt->is_strictroute && rt->rt_uses_gateway)
                 goto sr_failed;
 
         if (unlikely(skb->len > dst_mtu(&rt->dst) && !skb_is_gso(skb) &&
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 24a29a39e9a8..6537a408a4fb 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -193,7 +193,7 @@ static inline int ip_finish_output2(struct sk_buff *skb)
         }
 
         rcu_read_lock_bh();
-        nexthop = rt->rt_gateway ? rt->rt_gateway : ip_hdr(skb)->daddr;
+        nexthop = (__force u32) rt_nexthop(rt, ip_hdr(skb)->daddr);
         neigh = __ipv4_neigh_lookup_noref(dev, nexthop);
         if (unlikely(!neigh))
                 neigh = __neigh_create(&arp_tbl, &nexthop, dev, false);
@@ -371,7 +371,7 @@ int ip_queue_xmit(struct sk_buff *skb, struct flowi *fl)
         skb_dst_set_noref(skb, &rt->dst);
 
 packet_routed:
-        if (inet_opt && inet_opt->opt.is_strictroute && rt->rt_gateway)
+        if (inet_opt && inet_opt->opt.is_strictroute && rt->rt_uses_gateway)
                 goto no_route;
 
         /* OK, we know where to send it, allocate and build IP header. */
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 5b0180f11b20..3a116cb0991a 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1126,7 +1126,7 @@ static unsigned int ipv4_mtu(const struct dst_entry *dst)
         mtu = dst->dev->mtu;
 
         if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
-                if (rt->rt_gateway && mtu > 576)
+                if (rt->rt_uses_gateway && mtu > 576)
                         mtu = 576;
         }
 
@@ -1177,7 +1177,9 @@ static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
                 if (fnhe->fnhe_gw) {
                         rt->rt_flags |= RTCF_REDIRECTED;
                         rt->rt_gateway = fnhe->fnhe_gw;
-                }
+                        rt->rt_uses_gateway = 1;
+                } else if (!rt->rt_gateway)
+                        rt->rt_gateway = daddr;
 
                 orig = rcu_dereference(fnhe->fnhe_rth);
                 rcu_assign_pointer(fnhe->fnhe_rth, rt);
@@ -1186,13 +1188,6 @@ static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
 
                 fnhe->fnhe_stamp = jiffies;
                 ret = true;
-        } else {
-                /* Routes we intend to cache in nexthop exception have
-                 * the DST_NOCACHE bit clear.  However, if we are
-                 * unsuccessful at storing this route into the cache
-                 * we really need to set it.
-                 */
-                rt->dst.flags |= DST_NOCACHE;
         }
         spin_unlock_bh(&fnhe_lock);
 
@@ -1215,15 +1210,8 @@ static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
         if (prev == orig) {
                 if (orig)
                         rt_free(orig);
-        } else {
-                /* Routes we intend to cache in the FIB nexthop have
-                 * the DST_NOCACHE bit clear.  However, if we are
-                 * unsuccessful at storing this route into the cache
-                 * we really need to set it.
-                 */
-                rt->dst.flags |= DST_NOCACHE;
+        } else
                 ret = false;
-        }
 
         return ret;
 }
@@ -1284,8 +1272,10 @@ static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
         if (fi) {
                 struct fib_nh *nh = &FIB_RES_NH(*res);
 
-                if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK)
+                if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
                         rt->rt_gateway = nh->nh_gw;
+                        rt->rt_uses_gateway = 1;
+                }
                 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
 #ifdef CONFIG_IP_ROUTE_CLASSID
                 rt->dst.tclassid = nh->nh_tclassid;
@@ -1294,8 +1284,18 @@ static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
                         cached = rt_bind_exception(rt, fnhe, daddr);
                 else if (!(rt->dst.flags & DST_NOCACHE))
                         cached = rt_cache_route(nh, rt);
-        }
-        if (unlikely(!cached))
+                if (unlikely(!cached)) {
+                        /* Routes we intend to cache in nexthop exception or
+                         * FIB nexthop have the DST_NOCACHE bit clear.
+                         * However, if we are unsuccessful at storing this
+                         * route into the cache we really need to set it.
+                         */
+                        rt->dst.flags |= DST_NOCACHE;
+                        if (!rt->rt_gateway)
+                                rt->rt_gateway = daddr;
+                        rt_add_uncached_list(rt);
+                }
+        } else
                 rt_add_uncached_list(rt);
 
 #ifdef CONFIG_IP_ROUTE_CLASSID
@@ -1363,6 +1363,7 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
         rth->rt_iif     = 0;
         rth->rt_pmtu    = 0;
         rth->rt_gateway = 0;
+        rth->rt_uses_gateway = 0;
         INIT_LIST_HEAD(&rth->rt_uncached);
         if (our) {
                 rth->dst.input= ip_local_deliver;
@@ -1432,7 +1433,6 @@ static int __mkroute_input(struct sk_buff *skb,
                 return -EINVAL;
         }
 
-
         err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
                                   in_dev->dev, in_dev, &itag);
         if (err < 0) {
@@ -1488,6 +1488,7 @@ static int __mkroute_input(struct sk_buff *skb,
         rth->rt_iif     = 0;
         rth->rt_pmtu    = 0;
         rth->rt_gateway = 0;
+        rth->rt_uses_gateway = 0;
         INIT_LIST_HEAD(&rth->rt_uncached);
 
         rth->dst.input = ip_forward;
@@ -1658,6 +1659,7 @@ local_input:
         rth->rt_iif     = 0;
         rth->rt_pmtu    = 0;
         rth->rt_gateway = 0;
+        rth->rt_uses_gateway = 0;
         INIT_LIST_HEAD(&rth->rt_uncached);
         if (res.type == RTN_UNREACHABLE) {
                 rth->dst.input= ip_error;
@@ -1826,6 +1828,7 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
         rth->rt_iif     = orig_oif ? : 0;
         rth->rt_pmtu    = 0;
         rth->rt_gateway = 0;
+        rth->rt_uses_gateway = 0;
         INIT_LIST_HEAD(&rth->rt_uncached);
 
         RT_CACHE_STAT_INC(out_slow_tot);
@@ -2104,6 +2107,7 @@ struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_or
                 rt->rt_flags = ort->rt_flags;
                 rt->rt_type = ort->rt_type;
                 rt->rt_gateway = ort->rt_gateway;
+                rt->rt_uses_gateway = ort->rt_uses_gateway;
 
                 INIT_LIST_HEAD(&rt->rt_uncached);
 
@@ -2182,7 +2186,7 @@ static int rt_fill_info(struct net *net,  __be32 dst, __be32 src,
                 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
                         goto nla_put_failure;
         }
-        if (rt->rt_gateway &&
+        if (rt->rt_uses_gateway &&
             nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
                 goto nla_put_failure;
 
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 681ea2f413e2..05c5ab8d983c 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -91,6 +91,7 @@ static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
                                               RTCF_LOCAL);
         xdst->u.rt.rt_type = rt->rt_type;
         xdst->u.rt.rt_gateway = rt->rt_gateway;
+        xdst->u.rt.rt_uses_gateway = rt->rt_uses_gateway;
         xdst->u.rt.rt_pmtu = rt->rt_pmtu;
         INIT_LIST_HEAD(&xdst->u.rt.rt_uncached);