Subject: [PATCH net-next v5 06/12] net: vxlan: make vxlan_snoop() return drop reasons

From: Menglong Dong <[email-masked]>
Date: Sun, 6 Oct 2024 14:56:10 +0800

Change the return type of vxlan_snoop() from bool to enum
skb_drop_reason. In this commit, two drop reasons are introduced:

  SKB_DROP_REASON_MAC_INVALID_SOURCE
  SKB_DROP_REASON_VXLAN_ENTRY_EXISTS

Signed-off-by: Menglong Dong <[email-masked]>
Reviewed-by: Simon Horman <[email-masked]>
---
v5:
- rename SKB_DROP_REASON_VXLAN_INVALID_SMAC to
  SKB_DROP_REASON_MAC_INVALID_SOURCE in the commit log
v4:
- rename SKB_DROP_REASON_VXLAN_INVALID_SMAC to
  SKB_DROP_REASON_MAC_INVALID_SOURCE
---
 drivers/net/vxlan/vxlan_core.c | 17 +++++++++--------
 include/net/dropreason-core.h  |  9 +++++++++
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 34b44755f663..1a81a3957327 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -1437,9 +1437,10 @@ static int vxlan_fdb_get(struct sk_buff *skb,
  * and Tunnel endpoint.
  * Return true if packet is bogus and should be dropped.
  */
-static bool vxlan_snoop(struct net_device *dev,
-			union vxlan_addr *src_ip, const u8 *src_mac,
-			u32 src_ifindex, __be32 vni)
+static enum skb_drop_reason vxlan_snoop(struct net_device *dev,
+					union vxlan_addr *src_ip,
+					const u8 *src_mac, u32 src_ifindex,
+					__be32 vni)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct vxlan_fdb *f;
@@ -1447,7 +1448,7 @@ static bool vxlan_snoop(struct net_device *dev,
 
 	/* Ignore packets from invalid src-address */
 	if (!is_valid_ether_addr(src_mac))
-		return true;
+		return SKB_DROP_REASON_MAC_INVALID_SOURCE;
 
 #if IS_ENABLED(CONFIG_IPV6)
 	if (src_ip->sa.sa_family == AF_INET6 &&
@@ -1461,15 +1462,15 @@ static bool vxlan_snoop(struct net_device *dev,
 
 		if (likely(vxlan_addr_equal(&rdst->remote_ip, src_ip) &&
 			   rdst->remote_ifindex == ifindex))
-			return false;
+			return SKB_NOT_DROPPED_YET;
 
 		/* Don't migrate static entries, drop packets */
 		if (f->state & (NUD_PERMANENT | NUD_NOARP))
-			return true;
+			return SKB_DROP_REASON_VXLAN_ENTRY_EXISTS;
 
 		/* Don't override an fdb with nexthop with a learnt entry */
 		if (rcu_access_pointer(f->nh))
-			return true;
+			return SKB_DROP_REASON_VXLAN_ENTRY_EXISTS;
 
 		if (net_ratelimit())
 			netdev_info(dev,
@@ -1497,7 +1498,7 @@ static bool vxlan_snoop(struct net_device *dev,
 		spin_unlock(&vxlan->hash_lock[hash_index]);
 	}
 
-	return false;
+	return SKB_NOT_DROPPED_YET;
 }
 
 static bool __vxlan_sock_release_prep(struct vxlan_sock *vs)
diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h
index 98259d2b3e92..1cb8d7c953be 100644
--- a/include/net/dropreason-core.h
+++ b/include/net/dropreason-core.h
@@ -94,6 +94,8 @@
 	FN(TC_RECLASSIFY_LOOP)		\
 	FN(VXLAN_INVALID_HDR)		\
 	FN(VXLAN_VNI_NOT_FOUND)		\
+	FN(MAC_INVALID_SOURCE)		\
+	FN(VXLAN_ENTRY_EXISTS)		\
 	FN(IP_TUNNEL_ECN)		\
 	FNe(MAX)
 
@@ -429,6 +431,13 @@ enum skb_drop_reason {
 	SKB_DROP_REASON_VXLAN_INVALID_HDR,
 	/** @SKB_DROP_REASON_VXLAN_VNI_NOT_FOUND: no VXLAN device found for VNI */
 	SKB_DROP_REASON_VXLAN_VNI_NOT_FOUND,
+	/** @SKB_DROP_REASON_MAC_INVALID_SOURCE: source mac is invalid */
+	SKB_DROP_REASON_MAC_INVALID_SOURCE,
+	/**
+	 * @SKB_DROP_REASON_VXLAN_ENTRY_EXISTS: trying to migrate a static
+	 * entry or an entry pointing to a nexthop.
+	 */
+	SKB_DROP_REASON_VXLAN_ENTRY_EXISTS,
 	/**
 	 * @SKB_DROP_REASON_IP_TUNNEL_ECN: skb is dropped according to
 	 * RFC 6040 4.2, see __INET_ECN_decapsulate() for detail.
-- 
2.39.5