Subject: bridge: only accept EAP locally
From: Felix Fietkau <[email-masked]>
Date: Fri, 7 Jul 2017 17:18:54 +0200

When bridging, do not forward EAP frames to other ports, only deliver
them locally, regardless of the state.

Signed-off-by: Felix Fietkau <[email-masked]>
[add disable_eap_hack sysfs attribute]
Signed-off-by: Etienne Champetier <[email-masked]>
---

--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -103,10 +103,14 @@ int br_handle_frame_finish(struct net *n
 		}
 	}
 
+	BR_INPUT_SKB_CB(skb)->brdev = br->dev;
+
+	if (skb->protocol == htons(ETH_P_PAE) && !br->disable_eap_hack)
+		return br_pass_frame_up(skb);
+
 	if (p->state == BR_STATE_LEARNING)
 		goto drop;
 
-	BR_INPUT_SKB_CB(skb)->brdev = br->dev;
 	BR_INPUT_SKB_CB(skb)->src_port_isolated = !!(p->flags & BR_ISOLATED);
 
 	if (IS_ENABLED(CONFIG_INET) &&
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -345,6 +345,8 @@ struct net_bridge {
 	u16				group_fwd_mask;
 	u16				group_fwd_mask_required;
 
+	bool				disable_eap_hack;
+
 	/* STP */
 	bridge_id			designated_root;
 	bridge_id			bridge_id;
--- a/net/bridge/br_sysfs_br.c
+++ b/net/bridge/br_sysfs_br.c
@@ -166,6 +166,30 @@ static ssize_t group_fwd_mask_store(stru
 }
 static DEVICE_ATTR_RW(group_fwd_mask);
 
+static ssize_t disable_eap_hack_show(struct device *d,
+				   struct device_attribute *attr,
+				   char *buf)
+{
+	struct net_bridge *br = to_bridge(d);
+	return sprintf(buf, "%u\n", br->disable_eap_hack);
+}
+
+static int set_disable_eap_hack(struct net_bridge *br, unsigned long val)
+{
+	br->disable_eap_hack = !!val;
+
+	return 0;
+}
+
+static ssize_t disable_eap_hack_store(struct device *d,
+				    struct device_attribute *attr,
+				    const char *buf,
+				    size_t len)
+{
+	return store_bridge_parm(d, buf, len, set_disable_eap_hack);
+}
+static DEVICE_ATTR_RW(disable_eap_hack);
+
 static ssize_t priority_show(struct device *d, struct device_attribute *attr,
 			     char *buf)
 {
@@ -851,6 +875,7 @@ static struct attribute *bridge_attrs[]
 	&dev_attr_ageing_time.attr,
 	&dev_attr_stp_state.attr,
 	&dev_attr_group_fwd_mask.attr,
+	&dev_attr_disable_eap_hack.attr,
 	&dev_attr_priority.attr,
 	&dev_attr_bridge_id.attr,
 	&dev_attr_root_id.attr,