The bridge input code may drop frames for various reasons and at various
points in the ingress handling logic. Currently kfree_skb() is used
everywhere, and therefore no drop reason is specified. Add drop reasons
to the most common drop points.
Drop reasons are not added exhaustively to the entire bridge code. The
intention is to incrementally add drop reasons to the rest of the bridge
code in follow up patches.
Signed-off-by: Radu Rendec <rrendec@xxxxxxxxxx>
---
include/net/dropreason-core.h | 12 ++++++++++++
net/bridge/br_forward.c | 16 ++++++++++++----
net/bridge/br_input.c | 24 +++++++++++++++---------
3 files changed, 39 insertions(+), 13 deletions(-)
diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h
index be58c97c64a1b..eeb7c67586431 100644
--- a/include/net/dropreason-core.h
+++ b/include/net/dropreason-core.h
@@ -111,6 +111,8 @@
FN(TUNNEL_TXINFO) \
FN(LOCAL_MAC) \
FN(ARP_PVLAN_DISABLE) \
+ FN(MAC_IEEE_MAC_CONTROL) \
+ FN(BRIDGE_INGRESS_STP_STATE) \
FNe(MAX)
/**
@@ -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
+ * 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);
+ reason = SKB_DROP_REASON_NOMEM;
goto out;
+ }
}
if (!prev)
@@ -249,7 +253,7 @@ void br_flood(struct net_bridge *br, struct sk_buff *skb,
out:
if (!local_rcv)
- kfree_skb(skb);
+ kfree_skb_reason(skb, reason);
}
#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
@@ -289,6 +293,7 @@ void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
struct net_bridge_mcast *brmctx,
bool local_rcv, bool local_orig)
{
+ enum skb_drop_reason reason = SKB_DROP_REASON_NO_TX_TARGET;
struct net_bridge_port *prev = NULL;
struct net_bridge_port_group *p;
bool allow_mode_include = true;
@@ -329,8 +334,11 @@ void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
}
prev = maybe_deliver(prev, port, skb, local_orig);
- if (IS_ERR(prev))
+ if (IS_ERR(prev)) {
+ WARN_ON_ONCE(PTR_ERR(prev) != -ENOMEM);
+ reason = SKB_DROP_REASON_NOMEM;
goto out;
+ }
delivered:
if ((unsigned long)lport >= (unsigned long)port)
p = rcu_dereference(p->next);
@@ -349,6 +357,6 @@ void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
out:
if (!local_rcv)
- kfree_skb(skb);
+ kfree_skb_reason(skb, reason);
}
#endif
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index ceaa5a89b947f..0adad3986c77d 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -96,8 +96,10 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
if (br_mst_is_enabled(br)) {
state = BR_STATE_FORWARDING;
} else {
- if (p->state == BR_STATE_DISABLED)
- goto drop;
+ if (p->state == BR_STATE_DISABLED) {
+ kfree_skb_reason(skb, SKB_DROP_REASON_BRIDGE_INGRESS_STP_STATE);
+ return 0;
+ }
state = p->state;
}
@@ -155,8 +157,10 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
}
}
- if (state == BR_STATE_LEARNING)
- goto drop;
+ if (state == BR_STATE_LEARNING) {
+ kfree_skb_reason(skb, SKB_DROP_REASON_BRIDGE_INGRESS_STP_STATE);
+ return 0;
+ }
BR_INPUT_SKB_CB(skb)->brdev = br->dev;
BR_INPUT_SKB_CB(skb)->src_port_isolated = !!(p->flags & BR_ISOLATED);
@@ -331,8 +335,10 @@ static rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
return RX_HANDLER_PASS;
- if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
- goto drop;
+ if (!is_valid_ether_addr(eth_hdr(skb)->h_source)) {
+ kfree_skb_reason(skb, SKB_DROP_REASON_MAC_INVALID_SOURCE);
+ return RX_HANDLER_CONSUMED;
+ }
skb = skb_share_check(skb, GFP_ATOMIC);
if (!skb)
@@ -374,7 +380,8 @@ static rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
return RX_HANDLER_PASS;
case 0x01: /* IEEE MAC (Pause) */
- goto drop;
+ kfree_skb_reason(skb, SKB_DROP_REASON_MAC_IEEE_MAC_CONTROL);
+ return RX_HANDLER_CONSUMED;
case 0x0E: /* 802.1AB LLDP */
fwd_mask |= p->br->group_fwd_mask;
@@ -423,8 +430,7 @@ static rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
return nf_hook_bridge_pre(skb, pskb);
default:
-drop:
- kfree_skb(skb);
+ kfree_skb_reason(skb, SKB_DROP_REASON_BRIDGE_INGRESS_STP_STATE);
}
return RX_HANDLER_CONSUMED;
}
--
2.47.1
