[PATCH net-next v3 08/10] net: ip: make ip_route_input() return drop reasons

[Menglong Dong]

In this commit, we make ip_route_input() return skb drop reasons that come
from ip_route_input_noref().

Meanwhile, adjust all the call to it.

Signed-off-by: Menglong Dong <dongml2@xxxxxxxxxxxxxxx>
---
 include/net/route.h             |  7 ++++---
 net/bridge/br_netfilter_hooks.c | 11 ++++++-----
 net/ipv4/icmp.c                 |  1 +
 3 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/include/net/route.h b/include/net/route.h
index 11674f7c6be6..f4ab5412c9c9 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -210,8 +210,9 @@ int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 		      dscp_t dscp, struct net_device *dev,
 		      const struct sk_buff *hint);
 
-static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
-				 dscp_t dscp, struct net_device *devin)
+static inline enum skb_drop_reason
+ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src, dscp_t dscp,
+	       struct net_device *devin)
 {
 	enum skb_drop_reason reason;
 
@@ -224,7 +225,7 @@ static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
 	}
 	rcu_read_unlock();
 
-	return reason ? -EINVAL : 0;
+	return reason;
 }
 
 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, int oif,
diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c
index 17a5f5923d61..110cffc24a1d 100644
--- a/net/bridge/br_netfilter_hooks.c
+++ b/net/bridge/br_netfilter_hooks.c
@@ -373,8 +373,8 @@ static int br_nf_pre_routing_finish(struct net *net, struct sock *sk, struct sk_
 	struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
 	struct net_device *dev = skb->dev, *br_indev;
 	const struct iphdr *iph = ip_hdr(skb);
+	enum skb_drop_reason reason;
 	struct rtable *rt;
-	int err;
 
 	br_indev = nf_bridge_get_physindev(skb, net);
 	if (!br_indev) {
@@ -390,9 +390,9 @@ static int br_nf_pre_routing_finish(struct net *net, struct sock *sk, struct sk_
 	}
 	nf_bridge->in_prerouting = 0;
 	if (br_nf_ipv4_daddr_was_changed(skb, nf_bridge)) {
-		err = ip_route_input(skb, iph->daddr, iph->saddr,
-				     ip4h_dscp(iph), dev);
-		if (err) {
+		reason = ip_route_input(skb, iph->daddr, iph->saddr,
+					ip4h_dscp(iph), dev);
+		if (reason) {
 			struct in_device *in_dev = __in_dev_get_rcu(dev);
 
 			/* If err equals -EHOSTUNREACH the error is due to a
@@ -402,7 +402,8 @@ static int br_nf_pre_routing_finish(struct net *net, struct sock *sk, struct sk_
 			 * martian destinations: loopback destinations and destination
 			 * 0.0.0.0. In both cases the packet will be dropped because the
 			 * destination is the loopback device and not the bridge. */
-			if (err != -EHOSTUNREACH || !in_dev || IN_DEV_FORWARD(in_dev))
+			if (reason != SKB_DROP_REASON_IP_INADDRERRORS || !in_dev ||
+			    IN_DEV_FORWARD(in_dev))
 				goto free_skb;
 
 			rt = ip_route_output(net, iph->daddr, 0,
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 23664434922e..c3bafff093e0 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -546,6 +546,7 @@ static struct rtable *icmp_route_lookup(struct net *net, struct flowi4 *fl4,
 		skb_dst_set(skb_in, NULL);
 		err = ip_route_input(skb_in, fl4_dec.daddr, fl4_dec.saddr,
 				     dscp, rt2->dst.dev);
+		err = err ? -EINVAL : 0;
 
 		dst_release(&rt2->dst);
 		rt2 = skb_rtable(skb_in);
-- 
2.39.5