Thread (16 messages) 16 messages, 2 authors, 2024-11-06

Re: [PATCH RESEND net-next v4 9/9] net: ip: make ip_route_use_hint() return drop reasons

From: Paolo Abeni <pabeni@redhat.com>
Date: 2024-11-05 11:28:47
Also in: bpf, bridge, lkml, netfilter-devel

On 10/30/24 02:41, Menglong Dong wrote:
quoted hunk ↗ jump to hunk
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index e248e5577d0e..7f969c865c81 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2142,28 +2142,34 @@ ip_mkroute_input(struct sk_buff *skb, struct fib_result *res,
  * 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,
-		      dscp_t dscp, 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);
-	enum skb_drop_reason reason;
-	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 = IP_LOCALNET;
 		goto martian_source;
+	}
 
 	if (rt->rt_type != RTN_LOCAL)
 		goto skip_validate_source;
Please explicitly replace also the

	return 0;

with

	return SKB_NOT_DROPPED_YET;

So that is clear the drop reason is always specified.

Thanks,

Paolo
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help