Re: [PATCH net-next v2 2/2] net: bridge: add skb drop reasons to the most common drop points

On 12/18/24 19:19, Ido Schimmel wrote:

On Tue, Dec 17, 2024 at 06:07:11PM -0500, Radu Rendec wrote:

quoted

@@ -520,6 +522,16 @@ enum skb_drop_reason {
 	 * enabled.
 	 */
 	SKB_DROP_REASON_ARP_PVLAN_DISABLE,
+	/**
+	 * @SKB_DROP_REASON_MAC_IEEE_MAC_CONTROL: the destination MAC address
+	 * is an IEEE MAC Control address.
+	 */
+	SKB_DROP_REASON_MAC_IEEE_MAC_CONTROL,
+	/**
+	 * @SKB_DROP_REASON_BRIDGE_INGRESS_PORT_NFWD: the STP state of the

s/SKB_DROP_REASON_BRIDGE_INGRESS_PORT_NFWD/SKB_DROP_REASON_BRIDGE_INGRESS_STP_STATE/

quoted

+	 * ingress bridge port does not allow frames to be forwarded.
+	 */
+	SKB_DROP_REASON_BRIDGE_INGRESS_STP_STATE,
 	/**
 	 * @SKB_DROP_REASON_MAX: the maximum of core drop reasons, which
 	 * shouldn't be used as a real 'reason' - only for tracing code gen

diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index e19b583ff2c6d..3e9b462809b0e 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c

@@ -201,6 +201,7 @@ void br_flood(struct net_bridge *br, struct sk_buff *skb,
 	      enum br_pkt_type pkt_type, bool local_rcv, bool local_orig,
 	      u16 vid)
 {
+	enum skb_drop_reason reason = SKB_DROP_REASON_NO_TX_TARGET;
 	struct net_bridge_port *prev = NULL;
 	struct net_bridge_port *p;
 

@@ -234,8 +235,11 @@ void br_flood(struct net_bridge *br, struct sk_buff *skb,
 			continue;
 
 		prev = maybe_deliver(prev, p, skb, local_orig);
-		if (IS_ERR(prev))
+		if (IS_ERR(prev)) {
+			WARN_ON_ONCE(PTR_ERR(prev) != -ENOMEM);

I don't think we want to see a stack trace just because someone forgot
to adjust the drop reason to the error code. Maybe just set it to
'NOMEM' if error code is '-ENOMEM', otherwise to 'NOT_SPECIFIED'.

+1