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 <vyasevic@xxxxxxxxxx>
---
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
