1 files changed, 202 insertions, 128 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 723ac9181558..fccb05fb3a79 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -189,7 +189,11 @@ const __u8 ip_tos2prio[16] = {
 EXPORT_SYMBOL(ip_tos2prio);
 
 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
+#ifndef CONFIG_PREEMPT_RT
 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
+#else
+#define RT_CACHE_STAT_INC(field) this_cpu_inc(rt_cache_stat.field)
+#endif
 
 #ifdef CONFIG_PROC_FS
 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
@@ -390,7 +394,13 @@ static inline int ip_rt_proc_init(void)
 
 static inline bool rt_is_expired(const struct rtable *rth)
 {
-	return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
+	bool res;
+
+	rcu_read_lock();
+	res = rth->rt_genid != rt_genid_ipv4(dev_net_rcu(rth->dst.dev));
+	rcu_read_unlock();
+
+	return res;
 }
 
 void rt_cache_flush(struct net *net)
@@ -870,11 +880,11 @@ void ip_rt_send_redirect(struct sk_buff *skb)
 	}
 	log_martians = IN_DEV_LOG_MARTIANS(in_dev);
 	vif = l3mdev_master_ifindex_rcu(rt->dst.dev);
-	rcu_read_unlock();
 
 	net = dev_net(rt->dst.dev);
-	peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1);
+	peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif);
 	if (!peer) {
+		rcu_read_unlock();
 		icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
 			  rt_nexthop(rt, ip_hdr(skb)->daddr));
 		return;
@@ -893,7 +903,7 @@ void ip_rt_send_redirect(struct sk_buff *skb)
 	 */
 	if (peer->n_redirects >= ip_rt_redirect_number) {
 		peer->rate_last = jiffies;
-		goto out_put_peer;
+		goto out_unlock;
 	}
 
 	/* Check for load limit; set rate_last to the latest sent
@@ -914,8 +924,8 @@ void ip_rt_send_redirect(struct sk_buff *skb)
 					     &ip_hdr(skb)->saddr, inet_iif(skb),
 					     &ip_hdr(skb)->daddr, &gw);
 	}
-out_put_peer:
-	inet_putpeer(peer);
+out_unlock:
+	rcu_read_unlock();
 }
 
 static int ip_error(struct sk_buff *skb)
@@ -975,9 +985,9 @@ static int ip_error(struct sk_buff *skb)
 		break;
 	}
 
+	rcu_read_lock();
 	peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr,
-			       l3mdev_master_ifindex(skb->dev), 1);
-
+			       l3mdev_master_ifindex_rcu(skb->dev));
 	send = true;
 	if (peer) {
 		now = jiffies;
@@ -989,8 +999,9 @@ static int ip_error(struct sk_buff *skb)
 			peer->rate_tokens -= ip_rt_error_cost;
 		else
 			send = false;
-		inet_putpeer(peer);
 	}
+	rcu_read_unlock();
+
 	if (send)
 		icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
 
@@ -1001,9 +1012,9 @@ out:	kfree_skb_reason(skb, reason);
 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
 {
 	struct dst_entry *dst = &rt->dst;
-	struct net *net = dev_net(dst->dev);
 	struct fib_result res;
 	bool lock = false;
+	struct net *net;
 	u32 old_mtu;
 
 	if (ip_mtu_locked(dst))
@@ -1013,6 +1024,8 @@ static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
 	if (old_mtu < mtu)
 		return;
 
+	rcu_read_lock();
+	net = dev_net_rcu(dst->dev);
 	if (mtu < net->ipv4.ip_rt_min_pmtu) {
 		lock = true;
 		mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu);
@@ -1020,17 +1033,29 @@ static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
 
 	if (rt->rt_pmtu == mtu && !lock &&
 	    time_before(jiffies, dst->expires - net->ipv4.ip_rt_mtu_expires / 2))
-		return;
+		goto out;
 
-	rcu_read_lock();
 	if (fib_lookup(net, fl4, &res, 0) == 0) {
 		struct fib_nh_common *nhc;
 
 		fib_select_path(net, &res, fl4, NULL);
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+		if (fib_info_num_path(res.fi) > 1) {
+			int nhsel;
+
+			for (nhsel = 0; nhsel < fib_info_num_path(res.fi); nhsel++) {
+				nhc = fib_info_nhc(res.fi, nhsel);
+				update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock,
+						      jiffies + net->ipv4.ip_rt_mtu_expires);
+			}
+			goto out;
+		}
+#endif /* CONFIG_IP_ROUTE_MULTIPATH */
 		nhc = FIB_RES_NHC(res);
 		update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock,
 				      jiffies + net->ipv4.ip_rt_mtu_expires);
 	}
+out:
 	rcu_read_unlock();
 }
 
@@ -1263,7 +1288,7 @@ void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
 		struct flowi4 fl4 = {
 			.daddr = iph->daddr,
 			.saddr = iph->saddr,
-			.flowi4_tos = iph->tos & INET_DSCP_MASK,
+			.flowi4_tos = inet_dscp_to_dsfield(ip4h_dscp(iph)),
 			.flowi4_oif = rt->dst.dev->ifindex,
 			.flowi4_iif = skb->dev->ifindex,
 			.flowi4_mark = skb->mark,
@@ -1293,10 +1318,15 @@ static void set_class_tag(struct rtable *rt, u32 tag)
 
 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
 {
-	struct net *net = dev_net(dst->dev);
 	unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr);
-	unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size,
-				    net->ipv4.ip_rt_min_advmss);
+	unsigned int advmss;
+	struct net *net;
+
+	rcu_read_lock();
+	net = dev_net_rcu(dst->dev);
+	advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size,
+				   net->ipv4.ip_rt_min_advmss);
+	rcu_read_unlock();
 
 	return min(advmss, IPV4_MAX_PMTU - header_size);
 }
@@ -1665,49 +1695,54 @@ struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt)
 EXPORT_SYMBOL(rt_dst_clone);
 
 /* called in rcu_read_lock() section */
-int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
-			  u8 tos, struct net_device *dev,
-			  struct in_device *in_dev, u32 *itag)
+enum skb_drop_reason
+ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
+		      dscp_t dscp, struct net_device *dev,
+		      struct in_device *in_dev, u32 *itag)
 {
-	int err;
+	enum skb_drop_reason reason;
 
 	/* Primary sanity checks. */
 	if (!in_dev)
-		return -EINVAL;
+		return SKB_DROP_REASON_NOT_SPECIFIED;
 
-	if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
-	    skb->protocol != htons(ETH_P_IP))
-		return -EINVAL;
+	if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
+		return SKB_DROP_REASON_IP_INVALID_SOURCE;
+
+	if (skb->protocol != htons(ETH_P_IP))
+		return SKB_DROP_REASON_INVALID_PROTO;
 
 	if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
-		return -EINVAL;
+		return SKB_DROP_REASON_IP_LOCALNET;
 
 	if (ipv4_is_zeronet(saddr)) {
 		if (!ipv4_is_local_multicast(daddr) &&
 		    ip_hdr(skb)->protocol != IPPROTO_IGMP)
-			return -EINVAL;
+			return SKB_DROP_REASON_IP_INVALID_SOURCE;
 	} else {
-		err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
-					  in_dev, itag);
-		if (err < 0)
-			return err;
+		reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0,
+						    dev, in_dev, itag);
+		if (reason)
+			return reason;
 	}
-	return 0;
+	return SKB_NOT_DROPPED_YET;
 }
 
 /* called in rcu_read_lock() section */
-static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
-			     u8 tos, struct net_device *dev, int our)
+static enum skb_drop_reason
+ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
+		  dscp_t dscp, struct net_device *dev, int our)
 {
 	struct in_device *in_dev = __in_dev_get_rcu(dev);
 	unsigned int flags = RTCF_MULTICAST;
+	enum skb_drop_reason reason;
 	struct rtable *rth;
 	u32 itag = 0;
-	int err;
 
-	err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag);
-	if (err)
-		return err;
+	reason = ip_mc_validate_source(skb, daddr, saddr, dscp, dev, in_dev,
+				       &itag);
+	if (reason)
+		return reason;
 
 	if (our)
 		flags |= RTCF_LOCAL;
@@ -1718,7 +1753,7 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 	rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
 			   false);
 	if (!rth)
-		return -ENOBUFS;
+		return SKB_DROP_REASON_NOMEM;
 
 #ifdef CONFIG_IP_ROUTE_CLASSID
 	rth->dst.tclassid = itag;
@@ -1734,7 +1769,7 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 
 	skb_dst_drop(skb);
 	skb_dst_set(skb, &rth->dst);
-	return 0;
+	return SKB_NOT_DROPPED_YET;
 }
 
 
@@ -1764,11 +1799,12 @@ static void ip_handle_martian_source(struct net_device *dev,
 }
 
 /* called in rcu_read_lock() section */
-static int __mkroute_input(struct sk_buff *skb,
-			   const struct fib_result *res,
-			   struct in_device *in_dev,
-			   __be32 daddr, __be32 saddr, u32 tos)
+static enum skb_drop_reason
+__mkroute_input(struct sk_buff *skb, const struct fib_result *res,
+		struct in_device *in_dev, __be32 daddr,
+		__be32 saddr, dscp_t dscp)
 {
+	enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
 	struct fib_nh_common *nhc = FIB_RES_NHC(*res);
 	struct net_device *dev = nhc->nhc_dev;
 	struct fib_nh_exception *fnhe;
@@ -1782,12 +1818,13 @@ static int __mkroute_input(struct sk_buff *skb,
 	out_dev = __in_dev_get_rcu(dev);
 	if (!out_dev) {
 		net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
-		return -EINVAL;
+		return reason;
 	}
 
-	err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
+	err = fib_validate_source(skb, saddr, daddr, dscp, FIB_RES_OIF(*res),
 				  in_dev->dev, in_dev, &itag);
 	if (err < 0) {
+		reason = -err;
 		ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
 					 saddr);
 
@@ -1815,7 +1852,7 @@ static int __mkroute_input(struct sk_buff *skb,
 		 */
 		if (out_dev == in_dev &&
 		    IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
-			err = -EINVAL;
+			reason = SKB_DROP_REASON_ARP_PVLAN_DISABLE;
 			goto cleanup;
 		}
 	}
@@ -1838,7 +1875,7 @@ static int __mkroute_input(struct sk_buff *skb,
 	rth = rt_dst_alloc(out_dev->dev, 0, res->type,
 			   IN_DEV_ORCONF(out_dev, NOXFRM));
 	if (!rth) {
-		err = -ENOBUFS;
+		reason = SKB_DROP_REASON_NOMEM;
 		goto cleanup;
 	}
 
@@ -1852,9 +1889,9 @@ static int __mkroute_input(struct sk_buff *skb,
 	lwtunnel_set_redirect(&rth->dst);
 	skb_dst_set(skb, &rth->dst);
 out:
-	err = 0;
- cleanup:
-	return err;
+	reason = SKB_NOT_DROPPED_YET;
+cleanup:
+	return reason;
 }
 
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
@@ -2004,8 +2041,12 @@ static u32 fib_multipath_custom_hash_fl4(const struct net *net,
 		hash_keys.addrs.v4addrs.dst = fl4->daddr;
 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
 		hash_keys.basic.ip_proto = fl4->flowi4_proto;
-	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
-		hash_keys.ports.src = fl4->fl4_sport;
+	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) {
+		if (fl4->flowi4_flags & FLOWI_FLAG_ANY_SPORT)
+			hash_keys.ports.src = (__force __be16)get_random_u16();
+		else
+			hash_keys.ports.src = fl4->fl4_sport;
+	}
 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
 		hash_keys.ports.dst = fl4->fl4_dport;
 
@@ -2060,7 +2101,10 @@ int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
 			hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 			hash_keys.addrs.v4addrs.src = fl4->saddr;
 			hash_keys.addrs.v4addrs.dst = fl4->daddr;
-			hash_keys.ports.src = fl4->fl4_sport;
+			if (fl4->flowi4_flags & FLOWI_FLAG_ANY_SPORT)
+				hash_keys.ports.src = (__force __be16)get_random_u16();
+			else
+				hash_keys.ports.src = fl4->fl4_sport;
 			hash_keys.ports.dst = fl4->fl4_dport;
 			hash_keys.basic.ip_proto = fl4->flowi4_proto;
 		}
@@ -2112,66 +2156,72 @@ int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
 }
 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
 
-static int ip_mkroute_input(struct sk_buff *skb,
-			    struct fib_result *res,
-			    struct in_device *in_dev,
-			    __be32 daddr, __be32 saddr, u32 tos,
-			    struct flow_keys *hkeys)
+static enum skb_drop_reason
+ip_mkroute_input(struct sk_buff *skb, struct fib_result *res,
+		 struct in_device *in_dev, __be32 daddr,
+		 __be32 saddr, dscp_t dscp, struct flow_keys *hkeys)
 {
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 	if (res->fi && fib_info_num_path(res->fi) > 1) {
 		int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys);
 
-		fib_select_multipath(res, h);
+		fib_select_multipath(res, h, NULL);
 		IPCB(skb)->flags |= IPSKB_MULTIPATH;
 	}
 #endif
 
 	/* create a routing cache entry */
-	return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
+	return __mkroute_input(skb, res, in_dev, daddr, saddr, dscp);
 }
 
 /* Implements all the saddr-related checks as ip_route_input_slow(),
  * assuming daddr is valid and the destination is not a local broadcast one.
  * Uses the provided hint instead of performing a route lookup.
  */
-int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr,
-		      u8 tos, struct net_device *dev,
-		      const struct sk_buff *hint)
+enum skb_drop_reason
+ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr,
+		  dscp_t dscp, struct net_device *dev,
+		  const struct sk_buff *hint)
 {
+	enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
 	struct in_device *in_dev = __in_dev_get_rcu(dev);
 	struct rtable *rt = skb_rtable(hint);
 	struct net *net = dev_net(dev);
-	int err = -EINVAL;
 	u32 tag = 0;
 
 	if (!in_dev)
-		return -EINVAL;
+		return reason;
 
-	if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
+	if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) {
+		reason = SKB_DROP_REASON_IP_INVALID_SOURCE;
 		goto martian_source;
+	}
 
-	if (ipv4_is_zeronet(saddr))
+	if (ipv4_is_zeronet(saddr)) {
+		reason = SKB_DROP_REASON_IP_INVALID_SOURCE;
 		goto martian_source;
+	}
 
-	if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
+	if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) {
+		reason = SKB_DROP_REASON_IP_LOCALNET;
 		goto martian_source;
+	}
 
 	if (rt->rt_type != RTN_LOCAL)
 		goto skip_validate_source;
 
-	tos &= INET_DSCP_MASK;
-	err = fib_validate_source(skb, saddr, daddr, tos, 0, dev, in_dev, &tag);
-	if (err < 0)
+	reason = fib_validate_source_reason(skb, saddr, daddr, dscp, 0, dev,
+					    in_dev, &tag);
+	if (reason)
 		goto martian_source;
 
 skip_validate_source:
 	skb_dst_copy(skb, hint);
-	return 0;
+	return SKB_NOT_DROPPED_YET;
 
 martian_source:
 	ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
-	return err;
+	return reason;
 }
 
 /* get device for dst_alloc with local routes */
@@ -2200,10 +2250,12 @@ static struct net_device *ip_rt_get_dev(struct net *net,
  *	called with rcu_read_lock()
  */
 
-static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
-			       u8 tos, struct net_device *dev,
-			       struct fib_result *res)
+static enum skb_drop_reason
+ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
+		    dscp_t dscp, struct net_device *dev,
+		    struct fib_result *res)
 {
+	enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
 	struct in_device *in_dev = __in_dev_get_rcu(dev);
 	struct flow_keys *flkeys = NULL, _flkeys;
 	struct net    *net = dev_net(dev);
@@ -2231,8 +2283,10 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 		fl4.flowi4_tun_key.tun_id = 0;
 	skb_dst_drop(skb);
 
-	if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
+	if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) {
+		reason = SKB_DROP_REASON_IP_INVALID_SOURCE;
 		goto martian_source;
+	}
 
 	res->fi = NULL;
 	res->table = NULL;
@@ -2242,21 +2296,29 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 	/* Accept zero addresses only to limited broadcast;
 	 * I even do not know to fix it or not. Waiting for complains :-)
 	 */
-	if (ipv4_is_zeronet(saddr))
+	if (ipv4_is_zeronet(saddr)) {
+		reason = SKB_DROP_REASON_IP_INVALID_SOURCE;
 		goto martian_source;
+	}
 
-	if (ipv4_is_zeronet(daddr))
+	if (ipv4_is_zeronet(daddr)) {
+		reason = SKB_DROP_REASON_IP_INVALID_DEST;
 		goto martian_destination;
+	}
 
 	/* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
 	 * and call it once if daddr or/and saddr are loopback addresses
 	 */
 	if (ipv4_is_loopback(daddr)) {
-		if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
+		if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) {
+			reason = SKB_DROP_REASON_IP_LOCALNET;
 			goto martian_destination;
+		}
 	} else if (ipv4_is_loopback(saddr)) {
-		if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
+		if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) {
+			reason = SKB_DROP_REASON_IP_LOCALNET;
 			goto martian_source;
+		}
 	}
 
 	/*
@@ -2266,7 +2328,7 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 	fl4.flowi4_oif = 0;
 	fl4.flowi4_iif = dev->ifindex;
 	fl4.flowi4_mark = skb->mark;
-	fl4.flowi4_tos = tos;
+	fl4.flowi4_tos = inet_dscp_to_dsfield(dscp);
 	fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
 	fl4.flowi4_flags = 0;
 	fl4.daddr = daddr;
@@ -2298,10 +2360,11 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 		goto brd_input;
 	}
 
+	err = -EINVAL;
 	if (res->type == RTN_LOCAL) {
-		err = fib_validate_source(skb, saddr, daddr, tos,
-					  0, dev, in_dev, &itag);
-		if (err < 0)
+		reason = fib_validate_source_reason(skb, saddr, daddr, dscp,
+						    0, dev, in_dev, &itag);
+		if (reason)
 			goto martian_source;
 		goto local_input;
 	}
@@ -2310,21 +2373,28 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 		err = -EHOSTUNREACH;
 		goto no_route;
 	}
-	if (res->type != RTN_UNICAST)
+	if (res->type != RTN_UNICAST) {
+		reason = SKB_DROP_REASON_IP_INVALID_DEST;
 		goto martian_destination;
+	}
 
 make_route:
-	err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys);
-out:	return err;
+	reason = ip_mkroute_input(skb, res, in_dev, daddr, saddr, dscp,
+				  flkeys);
+
+out:
+	return reason;
 
 brd_input:
-	if (skb->protocol != htons(ETH_P_IP))
-		goto e_inval;
+	if (skb->protocol != htons(ETH_P_IP)) {
+		reason = SKB_DROP_REASON_INVALID_PROTO;
+		goto out;
+	}
 
 	if (!ipv4_is_zeronet(saddr)) {
-		err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
-					  in_dev, &itag);
-		if (err < 0)
+		reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0,
+						    dev, in_dev, &itag);
+		if (reason)
 			goto martian_source;
 	}
 	flags |= RTCF_BROADCAST;
@@ -2342,7 +2412,7 @@ local_input:
 		rth = rcu_dereference(nhc->nhc_rth_input);
 		if (rt_cache_valid(rth)) {
 			skb_dst_set_noref(skb, &rth->dst);
-			err = 0;
+			reason = SKB_NOT_DROPPED_YET;
 			goto out;
 		}
 	}
@@ -2379,7 +2449,7 @@ local_input:
 			rt_add_uncached_list(rth);
 	}
 	skb_dst_set(skb, &rth->dst);
-	err = 0;
+	reason = SKB_NOT_DROPPED_YET;
 	goto out;
 
 no_route:
@@ -2399,13 +2469,10 @@ martian_destination:
 		net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
 				     &daddr, &saddr, dev->name);
 #endif
-
-e_inval:
-	err = -EINVAL;
 	goto out;
 
 e_nobufs:
-	err = -ENOBUFS;
+	reason = SKB_DROP_REASON_NOMEM;
 	goto out;
 
 martian_source:
@@ -2414,8 +2481,10 @@ martian_source:
 }
 
 /* called with rcu_read_lock held */
-static int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
-			      u8 tos, struct net_device *dev, struct fib_result *res)
+static enum skb_drop_reason
+ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
+		   dscp_t dscp, struct net_device *dev,
+		   struct fib_result *res)
 {
 	/* Multicast recognition logic is moved from route cache to here.
 	 * The problem was that too many Ethernet cards have broken/missing
@@ -2429,12 +2498,13 @@ static int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 	 * route cache entry is created eventually.
 	 */
 	if (ipv4_is_multicast(daddr)) {
+		enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
 		struct in_device *in_dev = __in_dev_get_rcu(dev);
 		int our = 0;
-		int err = -EINVAL;
 
 		if (!in_dev)
-			return err;
+			return reason;
+
 		our = ip_check_mc_rcu(in_dev, daddr, saddr,
 				      ip_hdr(skb)->protocol);
 
@@ -2455,27 +2525,27 @@ static int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 		     IN_DEV_MFORWARD(in_dev))
 #endif
 		   ) {
-			err = ip_route_input_mc(skb, daddr, saddr,
-						tos, dev, our);
+			reason = ip_route_input_mc(skb, daddr, saddr, dscp,
+						   dev, our);
 		}
-		return err;
+		return reason;
 	}
 
-	return ip_route_input_slow(skb, daddr, saddr, tos, dev, res);
+	return ip_route_input_slow(skb, daddr, saddr, dscp, dev, res);
 }
 
-int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
-			 u8 tos, struct net_device *dev)
+enum skb_drop_reason ip_route_input_noref(struct sk_buff *skb, __be32 daddr,
+					  __be32 saddr, dscp_t dscp,
+					  struct net_device *dev)
 {
+	enum skb_drop_reason reason;
 	struct fib_result res;
-	int err;
 
-	tos &= INET_DSCP_MASK;
 	rcu_read_lock();
-	err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res);
+	reason = ip_route_input_rcu(skb, daddr, saddr, dscp, dev, &res);
 	rcu_read_unlock();
 
-	return err;
+	return reason;
 }
 EXPORT_SYMBOL(ip_route_input_noref);
 
@@ -2640,8 +2710,7 @@ struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4,
 
 	if (fl4->saddr) {
 		if (ipv4_is_multicast(fl4->saddr) ||
-		    ipv4_is_lbcast(fl4->saddr) ||
-		    ipv4_is_zeronet(fl4->saddr)) {
+		    ipv4_is_lbcast(fl4->saddr)) {
 			rth = ERR_PTR(-EINVAL);
 			goto out;
 		}
@@ -3147,7 +3216,8 @@ static int inet_rtm_valid_getroute_req(struct sk_buff *skb,
 	struct rtmsg *rtm;
 	int i, err;
 
-	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
+	rtm = nlmsg_payload(nlh, sizeof(*rtm));
+	if (!rtm) {
 		NL_SET_ERR_MSG(extack,
 			       "ipv4: Invalid header for route get request");
 		return -EINVAL;
@@ -3157,7 +3227,6 @@ static int inet_rtm_valid_getroute_req(struct sk_buff *skb,
 		return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
 					      rtm_ipv4_policy, extack);
 
-	rtm = nlmsg_data(nlh);
 	if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
 	    (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
 	    rtm->rtm_table || rtm->rtm_protocol ||
@@ -3223,6 +3292,7 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 	struct flowi4 fl4 = {};
 	__be32 dst = 0;
 	__be32 src = 0;
+	dscp_t dscp;
 	kuid_t uid;
 	u32 iif;
 	int err;
@@ -3233,10 +3303,11 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 		return err;
 
 	rtm = nlmsg_data(nlh);
-	src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
-	dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
-	iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
-	mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
+	src = nla_get_in_addr_default(tb[RTA_SRC], 0);
+	dst = nla_get_in_addr_default(tb[RTA_DST], 0);
+	iif = nla_get_u32_default(tb[RTA_IIF], 0);
+	mark = nla_get_u32_default(tb[RTA_MARK], 0);
+	dscp = inet_dsfield_to_dscp(rtm->rtm_tos);
 	if (tb[RTA_UID])
 		uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID]));
 	else
@@ -3261,8 +3332,8 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 
 	fl4.daddr = dst;
 	fl4.saddr = src;
-	fl4.flowi4_tos = rtm->rtm_tos & INET_DSCP_MASK;
-	fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
+	fl4.flowi4_tos = inet_dscp_to_dsfield(dscp);
+	fl4.flowi4_oif = nla_get_u32_default(tb[RTA_OIF], 0);
 	fl4.flowi4_mark = mark;
 	fl4.flowi4_uid = uid;
 	if (sport)
@@ -3285,9 +3356,8 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 		fl4.flowi4_iif = iif; /* for rt_fill_info */
 		skb->dev	= dev;
 		skb->mark	= mark;
-		err = ip_route_input_rcu(skb, dst, src,
-					 rtm->rtm_tos & INET_DSCP_MASK, dev,
-					 &res);
+		err = ip_route_input_rcu(skb, dst, src, dscp, dev,
+					 &res) ? -EINVAL : 0;
 
 		rt = skb_rtable(skb);
 		if (err == 0 && rt->dst.error)
@@ -3634,6 +3704,11 @@ static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
 #endif /* CONFIG_IP_ROUTE_CLASSID */
 
+static const struct rtnl_msg_handler ip_rt_rtnl_msg_handlers[] __initconst = {
+	{.protocol = PF_INET, .msgtype = RTM_GETROUTE,
+	 .doit = inet_rtm_getroute, .flags = RTNL_FLAG_DOIT_UNLOCKED},
+};
+
 int __init ip_rt_init(void)
 {
 	void *idents_hash;
@@ -3691,8 +3766,7 @@ int __init ip_rt_init(void)
 	xfrm_init();
 	xfrm4_init();
 #endif
-	rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL,
-		      RTNL_FLAG_DOIT_UNLOCKED);
+	rtnl_register_many(ip_rt_rtnl_msg_handlers);
 
 #ifdef CONFIG_SYSCTL
 	register_pernet_subsys(&sysctl_route_ops);