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Message-Id: <1360777309-25522-3-git-send-email-vyasevic@redhat.com>
Date: Wed, 13 Feb 2013 12:41:39 -0500
From: Vlad Yasevich <vyasevic@...hat.com>
To: netdev@...r.kernel.org
Cc: bridge@...ts.linux-foundation.org, shemminger@...tta.com,
davem@...emloft.net, mirqus@...il.com
Subject: [PATCH v10 net-next 02/12] 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: Vlad Yasevich <vyasevic@...hat.com>
---
net/bridge/br_device.c | 3 ++
net/bridge/br_input.c | 4 +++
net/bridge/br_private.h | 53 +++++++++++++++++++++++++++++++++++++++++++++++
net/bridge/br_vlan.c | 25 ++++++++++++++++++++++
4 files changed, 85 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 153efb2..edac5d1 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -555,6 +555,8 @@ 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);
@@ -562,7 +564,43 @@ 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;
@@ -591,6 +629,21 @@ 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 */
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 209464e..8b4bcd8 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.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)
{
--
1.7.7.6
--
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