When a frame arrives on a port or transmitted by the bridge, if we have VLANs configured, validate that a given VLAN is allowed to enter the bridge.
Signed-off-by: Vlad Yasevich <[email protected]> --- net/bridge/br_device.c | 3 +++ net/bridge/br_input.c | 4 ++++ net/bridge/br_private.h | 44 ++++++++++++++++++++++++++++++++++++++++++++ net/bridge/br_vlan.c | 25 +++++++++++++++++++++++++ 4 files changed, 76 insertions(+), 0 deletions(-) diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c index e1bc090..92b5b18 100644 --- a/net/bridge/br_device.c +++ b/net/bridge/br_device.c @@ -45,6 +45,9 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) brstats->tx_bytes += skb->len; u64_stats_update_end(&brstats->syncp); + if (!br_allowed_ingress(br, br_get_vlan_info(br), skb)) + goto out; + BR_INPUT_SKB_CB(skb)->brdev = dev; skb_reset_mac_header(skb); diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c index 4b34207..4ef3f6b 100644 --- a/net/bridge/br_input.c +++ b/net/bridge/br_input.c @@ -17,6 +17,7 @@ #include <linux/etherdevice.h> #include <linux/netfilter_bridge.h> #include <linux/export.h> +#include <linux/rculist.h> #include "br_private.h" /* Hook for brouter */ @@ -54,6 +55,9 @@ int br_handle_frame_finish(struct sk_buff *skb) if (!p || p->state == BR_STATE_DISABLED) goto drop; + if (!br_allowed_ingress(p->br, nbp_get_vlan_info(p), skb)) + goto drop; + /* insert into forwarding database after filtering to avoid spoofing */ br = p->br; br_fdb_update(br, p, eth_hdr(skb)->h_source); diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index 1c1b2f1..be9ba73 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -551,6 +551,8 @@ static inline void br_mdb_uninit(void) /* br_vlan.c */ #ifdef CONFIG_BRIDGE_VLAN_FILTERING +extern bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v, + struct sk_buff *skb); extern int br_vlan_add(struct net_bridge *br, u16 vid); extern int br_vlan_delete(struct net_bridge *br, u16 vid); extern void br_vlan_flush(struct net_bridge *br); @@ -558,7 +560,36 @@ extern int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val); extern int nbp_vlan_add(struct net_bridge_port *port, u16 vid); extern int nbp_vlan_delete(struct net_bridge_port *port, u16 vid); extern void nbp_vlan_flush(struct net_bridge_port *port); + +static inline struct net_port_vlans *br_get_vlan_info(struct net_bridge *br) +{ + return rcu_dereference(br->vlan_info); +} + +static inline struct net_port_vlans *nbp_get_vlan_info(struct net_bridge_port *p) +{ + return rcu_dereference(p->vlan_info); +} + +static inline u16 br_vlan_get_tag(const struct sk_buff *skb) +{ + u16 tag; + + if (vlan_tx_tag_present(skb)) + tag = vlan_tx_tag_get(skb); + else if (vlan_get_tag(skb, &tag)) + tag = 0; + + return tag & VLAN_VID_MASK; +} #else +static inline bool br_allowed_ingress(struct net_bridge *br, + struct net_port_vlans *v, + struct sk_buff *skb) +{ + return true; +} + static inline int br_vlan_add(struct net_bridge *br, u16 vid) { return -EOPNOTSUPP; @@ -587,6 +618,19 @@ static inline void nbp_vlan_flush(struct net_bridge_port *port) { } +static inline struct net_port_vlans *br_get_vlan_info(struct net_bridge *br) +{ + return NULL; +} +static inline struct net_port_vlans *nbp_get_vlan_info(struct net_bridge_port *p) +{ + return NULL; +} + +static inline u16 br_vlan_get_tag(const struct sk_buff *skb) +{ + return 0; +} #endif /* br_netfilter.c */ diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c index 1c7ae56..d8174e3 100644 --- a/net/bridge/br_vlan.c +++ b/net/bridge/br_vlan.c @@ -97,6 +97,31 @@ static void __vlan_flush(struct net_port_vlans *v) kfree_rcu(v, rcu); } +/* Called under RCU */ +bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v, + struct sk_buff *skb) +{ + u16 vid; + + /* If VLAN filtering is disabled on the bridge, all packets are + * permitted. + */ + if (!br->vlan_enabled) + return true; + + /* If there are no vlan in the permitted list, all packets are + * rejected. + */ + if (!v) + return false; + + vid = br_vlan_get_tag(skb); + if (test_bit(vid, v->vlan_bitmap)) + return true; + + return false; +} + /* Must be protected by RTNL */ int br_vlan_add(struct net_bridge *br, u16 vid) { -- 1.7.7.6
