If an interface enslaved into batman-adv is a bridge (or a virtual interface built on top of a bridge) the nf_bridge member of the skbs reaching the soft-interface is filled with the state about "netfilter bridge" operations.
Then, if one of such skbs is locally delivered, the nf_bridge member should be cleaned up to avoid that the old state could mess up with other "netfilter bridge" operations when entering a second bridge. This is needed because batman-adv is an encapsulation protocol.
However at the moment skb->nf_bridge is not released at all leading to bogus "netfilter bridge" behaviours. Fix this by releasing skb->nf_bridge before an skb gets delivered to the upper layer in interface_rx().
Signed-off-by: Antonio Quartulli antonio@meshcoding.com Signed-off-by: Marek Lindner mareklindner@neomailbox.ch --- net/batman-adv/soft-interface.c | 8 ++++++++ net/batman-adv/soft-interface.h | 16 ++++++++++++++++ 2 files changed, 24 insertions(+)
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index 36f0508..59b7397 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -392,6 +392,14 @@ void batadv_interface_rx(struct net_device *soft_iface, vid)) goto dropped;
+ /* Clean the netfilter state before delivering the skb. + * This packet may have traversed a bridge when it was encapsulated into + * the batman header. Now that the header has been removed, the + * netfilter state must be cleaned up to avoid to mess up with a + * possible second bridge + */ + batadv_nf_bridge_skb_free(skb); + netif_rx(skb); goto out;
diff --git a/net/batman-adv/soft-interface.h b/net/batman-adv/soft-interface.h index 06fc91f..21b8573 100644 --- a/net/batman-adv/soft-interface.h +++ b/net/batman-adv/soft-interface.h @@ -33,4 +33,20 @@ void batadv_softif_vlan_free_ref(struct batadv_softif_vlan *softif_vlan); struct batadv_softif_vlan *batadv_softif_vlan_get(struct batadv_priv *bat_priv, unsigned short vid);
+#ifdef CONFIG_BRIDGE_NETFILTER +/** + * batadv_nf_bridge_skb_free - clean the NF bridge data in an skb + * @skb: the skb which nf data has to be free'd + */ +static inline void batadv_nf_bridge_skb_free(struct sk_buff *skb) +{ + nf_bridge_put(skb->nf_bridge); + skb->nf_bridge = NULL; +} +#else +static inline void batadv_nf_bridge_skb_free(struct sk_buff *skb) +{ +} +#endif /* CONFIG_BRIDGE_NETFILTER */ + #endif /* _NET_BATMAN_ADV_SOFT_INTERFACE_H_ */