bridge: don't route packets while learning
While in the STP learning state, don't route packets; wait until
forwarding delay has expired. The purpose of the forwarding delay
is to detect loops in the network, and if a brouter started up
and started forwarding, it could cause a flood.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 2f5c379..8a55276 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -129,7 +129,7 @@
const unsigned char *dest = eth_hdr(skb)->h_dest;
if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
- goto err;
+ goto drop;
if (unlikely(is_link_local(dest))) {
skb->pkt_type = PACKET_HOST;
@@ -138,22 +138,25 @@
NULL, br_handle_local_finish) == 0) ? skb : NULL;
}
- if (p->state == BR_STATE_FORWARDING || p->state == BR_STATE_LEARNING) {
+ switch (p->state) {
+ case BR_STATE_FORWARDING:
+
if (br_should_route_hook) {
if (br_should_route_hook(&skb))
return skb;
dest = eth_hdr(skb)->h_dest;
}
-
+ /* fall through */
+ case BR_STATE_LEARNING:
if (!compare_ether_addr(p->br->dev->dev_addr, dest))
skb->pkt_type = PACKET_HOST;
NF_HOOK(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
br_handle_frame_finish);
- return NULL;
+ break;
+ default:
+drop:
+ kfree_skb(skb);
}
-
-err:
- kfree_skb(skb);
return NULL;
}