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 | 25 +++++++++++++++++++++++++ net/bridge/br_vlan.c | 20 ++++++++++++++++++++ 4 files changed, 52 insertions(+), 0 deletions(-) diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c index b64b5c8..6b8f816 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->vlan_info, 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..cc959fa 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->vlan_info, 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 615f10c..7018546 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -582,6 +582,7 @@ static inline bool br_multicast_is_router(struct net_bridge *br) /* br_vlan.c */ #ifdef CONFIG_BRIDGE_VLAN_FILTERING +extern bool br_allowed_ingress(struct net_port_vlans *v, struct sk_buff *skb); extern struct net_bridge_vlan *br_vlan_find(struct net_bridge *br, u16 vid); extern void br_vlan_flush(struct net_bridge *br); extern int nbp_vlan_add(struct net_port_vlans *v, u16 vid); @@ -589,7 +590,27 @@ extern int nbp_vlan_delete(struct net_port_vlans *v, u16 vid); extern struct net_port_vlan *nbp_vlan_find(const struct net_port_vlans *v, u16 vid); extern void nbp_vlan_flush(struct net_port_vlans *vlans); + +static inline u16 br_get_vlan(const struct sk_buff *skb) +{ + u16 tag; + + if (vlan_tx_tag_present(skb)) + return vlan_tx_tag_get(skb) & VLAN_VID_MASK; + + if (vlan_get_tag(skb, &tag)) + return 0; + + return tag & VLAN_VID_MASK; +} + #else +static inline bool br_allowed_ingress(struct net_port_vlans *v, + struct sk_buff *skb) +{ + return true; +} + static inline struct net_bridge_vlan *br_vlan_find(struct net_bridge *br, u16 vid) { @@ -621,6 +642,10 @@ static inline void nbp_vlan_flush(struct net_port_vlans *vlans) { } +static inline u16 br_get_vlan(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 816e85e..72b4892 100644 --- a/net/bridge/br_vlan.c +++ b/net/bridge/br_vlan.c @@ -5,6 +5,26 @@ #include "br_private.h" +/* Called under RCU */ +bool br_allowed_ingress(struct net_port_vlans *v, struct sk_buff *skb) +{ + struct net_port_vlan *pve; + u16 vid; + + /* If there are no vlan in the permitted list, all packets are + * permitted. + */ + if (list_empty(&v->vlan_list)) + return true; + + vid = br_get_vlan(skb); + pve = nbp_vlan_find(v, vid); + if (pve) + return true; + + return false; +} + static void br_vlan_destroy(struct net_bridge_vlan *vlan) { if (!bitmap_empty(vlan->port_bitmap, PORT_BITMAP_LEN)) { -- 1.7.7.6
