From eb8d7baae21584a7b27e79c2deca3eee72376ff0 Mon Sep 17 00:00:00 2001
From: Wilson Kok <wkok@cumulusnetworks.com>
Date: Mon, 25 May 2015 06:39:31 -0700
Subject: [PATCH] bridge: skip fdb add if the port shouldn't learn
Check in fdb_add_entry() if the source port should learn, similar
check is used in br_fdb_update.
Note that new fdb entries which are added manually or
as local ones are still permitted.
This patch has been tested by running traffic via a bridge port and
switching the port's state, also by manually adding/removing entries
from the bridge's fdb.
Signed-off-by: Wilson Kok <wkok@cumulusnetworks.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/bridge/br_fdb.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index e0670d7054f97..7896cf143045b 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -736,6 +736,12 @@ static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
struct net_bridge_fdb_entry *fdb;
bool modified = false;
+ /* If the port cannot learn allow only local and static entries */
+ if (!(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
+ !(source->state == BR_STATE_LEARNING ||
+ source->state == BR_STATE_FORWARDING))
+ return -EPERM;
+
fdb = fdb_find(head, addr, vid);
if (fdb == NULL) {
if (!(flags & NLM_F_CREATE))
--
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