From 82de382ce8e1c7645984616728dc7aaa057821e4 Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Thu, 29 Nov 2007 23:58:58 +1100 Subject: [PATCH] [BRIDGE]: Properly dereference the br_should_route_hook This hook is protected with the RCU, so simple if (br_should_route_hook) br_should_route_hook(...) is not enough on some architectures. Use the rcu_dereference/rcu_assign_pointer in this case. Fixed Stephen's comment concerning using the typeof(). Signed-off-by: Pavel Emelyanov Signed-off-by: Herbert Xu --- net/bridge/br_input.c | 7 ++++--- net/bridge/netfilter/ebtable_broute.c | 4 ++-- 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c index 3cedd4eeeed6..0ee79a726d91 100644 --- a/net/bridge/br_input.c +++ b/net/bridge/br_input.c @@ -122,6 +122,7 @@ static inline int is_link_local(const unsigned char *dest) struct sk_buff *br_handle_frame(struct net_bridge_port *p, struct sk_buff *skb) { const unsigned char *dest = eth_hdr(skb)->h_dest; + int (*rhook)(struct sk_buff *skb); if (!is_valid_ether_addr(eth_hdr(skb)->h_source)) goto drop; @@ -147,9 +148,9 @@ struct sk_buff *br_handle_frame(struct net_bridge_port *p, struct sk_buff *skb) switch (p->state) { case BR_STATE_FORWARDING: - - if (br_should_route_hook) { - if (br_should_route_hook(skb)) + rhook = rcu_dereference(br_should_route_hook); + if (rhook != NULL) { + if (rhook(skb)) return skb; dest = eth_hdr(skb)->h_dest; } diff --git a/net/bridge/netfilter/ebtable_broute.c b/net/bridge/netfilter/ebtable_broute.c index e44519ebf1d2..be6f18681053 100644 --- a/net/bridge/netfilter/ebtable_broute.c +++ b/net/bridge/netfilter/ebtable_broute.c @@ -70,13 +70,13 @@ static int __init ebtable_broute_init(void) if (ret < 0) return ret; /* see br_input.c */ - br_should_route_hook = ebt_broute; + rcu_assign_pointer(br_should_route_hook, ebt_broute); return ret; } static void __exit ebtable_broute_fini(void) { - br_should_route_hook = NULL; + rcu_assign_pointer(br_should_route_hook, NULL); synchronize_net(); ebt_unregister_table(&broute_table); } -- GitLab