[PATCH v2 2/3] bridge: Selectively prevent bridge port flooding for proxy ARP

[Jouni Malinen <jouni@codeaurora.org>]

From: Kyeyoon Park <kyeyoonp@codeaurora.org>

Rather than completely blocking the bridge port flooding when
BR_PROXYARP is enabled, selectively prevent bridge port flooding for the
proxy ARP relevant frames. This is done by marking the "skb" with this
info when proxy ARP code executes.

Signed-off-by: Kyeyoon Park <kyeyoonp@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
---
v2: Address Stephen's comment on mixing && and & without parens

 net/bridge/br_forward.c | 3 ++-
 net/bridge/br_input.c   | 6 +++++-
 net/bridge/br_private.h | 1 +
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index f96933a..0b156aa 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -186,7 +186,8 @@ static void br_flood(struct net_bridge *br, struct sk_buff *skb,
 			continue;
 
 		/* Do not flood to ports that enable proxy ARP */
-		if (p->flags & BR_PROXYARP)
+		if ((p->flags & BR_PROXYARP) &&
+		    BR_INPUT_SKB_CB(skb)->proxyarp_replied)
 			continue;
 
 		prev = maybe_deliver(prev, p, skb, __packet_hook);
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index b2afa17..c3640d8 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -68,6 +68,8 @@ static void br_do_proxy_arp(struct sk_buff *skb, struct net_bridge *br,
 	u8 *arpptr, *sha;
 	__be32 sip, tip;
 
+	BR_INPUT_SKB_CB(skb)->proxyarp_replied = false;
+
 	if (dev->flags & IFF_NOARP)
 		return;
 
@@ -105,9 +107,11 @@ static void br_do_proxy_arp(struct sk_buff *skb, struct net_bridge *br,
 		}
 
 		f = __br_fdb_get(br, n->ha, vid);
-		if (f && f->dst && (f->dst->flags & BR_PROXYARP))
+		if (f && f->dst && (f->dst->flags & BR_PROXYARP)) {
 			arp_send(ARPOP_REPLY, ETH_P_ARP, sip, skb->dev, tip,
 				 sha, n->ha, sha);
+			BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
+		}
 
 		neigh_release(n);
 	}
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index de09199..c32e279 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -305,6 +305,7 @@ struct br_input_skb_cb {
 #endif
 
 	u16 frag_max_size;
+	bool proxyarp_replied;
 
 #ifdef CONFIG_BRIDGE_VLAN_FILTERING
 	bool vlan_filtered;
-- 
1.9.1