[PATCH 2/3] bridge: don't route packets while learning
From: Stephen Hemminger <hidden>
Date: 2007-03-20 21:20:13
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 <redacted> --- net/bridge/br_input.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-)
--- netem.orig/net/bridge/br_input.c
+++ netem/net/bridge/br_input.c@@ -129,7 +129,7 @@ struct sk_buff *br_handle_frame(struct n 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 @@ struct sk_buff *br_handle_frame(struct n 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; }