Commit a37b85c9 authored by Vlad Yasevich's avatar Vlad Yasevich Committed by David S. Miller
Browse files

bridge: Validate that vlan is permitted on ingress



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: default avatarVlad Yasevich <vyasevic@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 243a2e63
......@@ -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);
......
......@@ -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);
......
......@@ -552,6 +552,8 @@ 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);
......@@ -559,7 +561,43 @@ 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(
const struct net_bridge *br)
{
return rcu_dereference(br->vlan_info);
}
static inline struct net_port_vlans *nbp_get_vlan_info(
const struct net_bridge_port *p)
{
return rcu_dereference(p->vlan_info);
}
/* Since bridge now depends on 8021Q module, but the time bridge sees the
* skb, the vlan tag will always be present if the frame was tagged.
*/
static inline int br_vlan_get_tag(const struct sk_buff *skb, u16 *vid)
{
int err = 0;
if (vlan_tx_tag_present(skb))
*vid = vlan_tx_tag_get(skb) & VLAN_VID_MASK;
else {
*vid = 0;
err = -EINVAL;
}
return err;
}
#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;
......@@ -588,6 +626,21 @@ static inline void nbp_vlan_flush(struct net_bridge_port *port)
{
}
static inline struct net_port_vlans *br_get_vlan_info(
const struct net_bridge *br)
{
return NULL;
}
static inline struct net_port_vlans *nbp_get_vlan_info(
const 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 */
......
......@@ -64,6 +64,31 @@ 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;
br_vlan_get_tag(skb, &vid);
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)
{
......
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