Patchwork [v9,net-next,01/12] bridge: Add vlan filtering infrastructure

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Submitter Vlad Yasevich
Date Feb. 1, 2013, 8:01 p.m.
Message ID <1359748930-31475-2-git-send-email-vyasevic@redhat.com>
Download mbox | patch
Permalink /patch/217591/
State Changes Requested
Delegated to: David Miller
Headers show

Comments

Vlad Yasevich - Feb. 1, 2013, 8:01 p.m.
Adds an optional infrustructure component to bridge that would allow
native vlan filtering in the bridge.  Each bridge port (as well
as the bridge device) now get a VLAN bitmap.  Each bit in the bitmap
is associated with a vlan id.  This way if the bit corresponding to
the vid is set in the bitmap that the packet with vid is allowed to
enter and exit the port.

Write access the bitmap is protected by RTNL and read access
protected by RCU.

Vlan functionality is disabled by default.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
---
 net/bridge/Kconfig       |   14 +++
 net/bridge/Makefile      |    2 +
 net/bridge/br_if.c       |    1 +
 net/bridge/br_private.h  |   55 +++++++++++
 net/bridge/br_sysfs_br.c |   21 +++++
 net/bridge/br_vlan.c     |  223 ++++++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 316 insertions(+), 0 deletions(-)
 create mode 100644 net/bridge/br_vlan.c
=?ISO-8859-2?Q?Micha=B3_Miros=B3aw?= - Feb. 2, 2013, 1:04 a.m.
2013/2/1 Vlad Yasevich <vyasevic@redhat.com>:
> Adds an optional infrustructure component to bridge that would allow
> native vlan filtering in the bridge.  Each bridge port (as well
> as the bridge device) now get a VLAN bitmap.  Each bit in the bitmap
> is associated with a vlan id.  This way if the bit corresponding to
> the vid is set in the bitmap that the packet with vid is allowed to
> enter and exit the port.
[...]
+struct net_port_vlans {
+       u16                             port_idx;
+       void                            *parent;
+       struct rcu_head                 rcu;
+       unsigned long                   vlan_bitmap[BR_VLAN_BITMAP_LEN];
+};
[later, in br_vlan.c]
+#define vlans_to_parent(type, pv) ((type *)(pv)->parent)

A really don't like this pointer casting. It's easy to get it wrong
(and you did in __vlan_del).

1. union { struct net_bridge *br; struct net_bridge_port *port; } parent;

2. inline net_port_vlans __rcu **br_vlan_info_parent_ptr(struct
net_port_vlans *v)
{
	return v->port_idx ? &v->parent.port->vlan_info : &v->parent.br->vlan_info;
}

(I'm not insisting on #2. Just think about it. ;)

> @@ -156,6 +166,7 @@ struct net_bridge_port
>  #ifdef CONFIG_NET_POLL_CONTROLLER
>         struct netpoll                  *np;
>  #endif
> +       struct net_port_vlans __rcu     *vlan_info;
>  };

Missing #ifdef CONFIG_BRIDGE_VLAN_FILTERING?

> +static int __vlan_del(struct net_port_vlans *v, u16 vid)
> +{
> +       unsigned long first_bit;
> +       unsigned long last_bit;
> +
> +       if (!test_bit(vid, v->vlan_bitmap))
> +               return -EINVAL;
> +
> +       /* Check to see if any other vlans are in this table.  If this
> +        * is the last vlan, delete the whole structure.  If this is not the
> +        * last vlan, just clear the bit.
> +        */
> +       first_bit = find_first_bit(v->vlan_bitmap, BR_VLAN_BITMAP_LEN);
> +       last_bit = find_last_bit(v->vlan_bitmap, BR_VLAN_BITMAP_LEN);
> +
> +       if (v->port_idx && vid) {
> +               struct net_device *dev =
> +                       vlans_to_parent(struct net_bridge, v)->dev;

struct net_bridge_port (or union and v->parent.port)

> +
> +               if (dev->features & NETIF_F_HW_VLAN_FILTER)
> +                       dev->netdev_ops->ndo_vlan_rx_kill_vid(dev, vid);
> +       }
> +
> +       clear_bit(vid, v->vlan_bitmap);
> +       if (first_bit == last_bit) {

bitmap_empty() is faster than two times find_xxx_bit().

> +               if (v->port_idx) {
> +                       struct net_bridge_port *p =
> +                               vlans_to_parent(struct net_bridge_port, v);
> +                       rcu_assign_pointer(p->vlan_info, NULL);
> +               } else {
> +                       struct net_bridge *br =
> +                               vlans_to_parent(struct net_bridge, v);
> +                       rcu_assign_pointer(br->vlan_info, NULL);
> +               }

With inline function above:

rcu_assign_pointer(*br_vlan_info_parent_ptr(v), NULL);

> +               kfree_rcu(v, rcu);
> +       }
> +       return 0;
> +}
> +
> +static void __vlan_flush(struct net_port_vlans *v)
> +{
> +       bitmap_zero(v->vlan_bitmap, BR_VLAN_BITMAP_LEN);
> +       if (v->port_idx) {
> +               struct net_bridge_port *p =
> +                               vlans_to_parent(struct net_bridge_port, v);
> +               rcu_assign_pointer(p->vlan_info, NULL);
> +       } else {
> +               struct net_bridge *br =
> +                               vlans_to_parent(struct net_bridge, v);
> +               rcu_assign_pointer(br->vlan_info, NULL);
> +       }

Same here.

> +       kfree_rcu(v, rcu);
> +}

Best Regards,
Michał Mirosław
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Vlad Yasevich - Feb. 2, 2013, 2:11 a.m.
On 02/01/2013 08:04 PM, Michał Mirosław wrote:
> 2013/2/1 Vlad Yasevich <vyasevic@redhat.com>:
>> Adds an optional infrustructure component to bridge that would allow
>> native vlan filtering in the bridge.  Each bridge port (as well
>> as the bridge device) now get a VLAN bitmap.  Each bit in the bitmap
>> is associated with a vlan id.  This way if the bit corresponding to
>> the vid is set in the bitmap that the packet with vid is allowed to
>> enter and exit the port.
> [...]
> +struct net_port_vlans {
> +       u16                             port_idx;
> +       void                            *parent;
> +       struct rcu_head                 rcu;
> +       unsigned long                   vlan_bitmap[BR_VLAN_BITMAP_LEN];
> +};
> [later, in br_vlan.c]
> +#define vlans_to_parent(type, pv) ((type *)(pv)->parent)
>
> A really don't like this pointer casting. It's easy to get it wrong
> (and you did in __vlan_del).
>
> 1. union { struct net_bridge *br; struct net_bridge_port *port; } parent;
>
> 2. inline net_port_vlans __rcu **br_vlan_info_parent_ptr(struct
> net_port_vlans *v)
> {
> 	return v->port_idx ? &v->parent.port->vlan_info : &v->parent.br->vlan_info;
> }
>
> (I'm not insisting on #2. Just think about it. ;)

I need the parent, not the vlan_info.  Sometimes I need to get to the 
device and I really don't want to then use container_of().

I suppose I could do the union, but that's really not much different 
then the type casts.  Just as easy to goof.

>
>> @@ -156,6 +166,7 @@ struct net_bridge_port
>>   #ifdef CONFIG_NET_POLL_CONTROLLER
>>          struct netpoll                  *np;
>>   #endif
>> +       struct net_port_vlans __rcu     *vlan_info;
>>   };
>
> Missing #ifdef CONFIG_BRIDGE_VLAN_FILTERING?

Yep.  Its in net_bridge, but not here.  Will fix.

>
>> +static int __vlan_del(struct net_port_vlans *v, u16 vid)
>> +{
>> +       unsigned long first_bit;
>> +       unsigned long last_bit;
>> +
>> +       if (!test_bit(vid, v->vlan_bitmap))
>> +               return -EINVAL;
>> +
>> +       /* Check to see if any other vlans are in this table.  If this
>> +        * is the last vlan, delete the whole structure.  If this is not the
>> +        * last vlan, just clear the bit.
>> +        */
>> +       first_bit = find_first_bit(v->vlan_bitmap, BR_VLAN_BITMAP_LEN);
>> +       last_bit = find_last_bit(v->vlan_bitmap, BR_VLAN_BITMAP_LEN);
>> +
>> +       if (v->port_idx && vid) {
>> +               struct net_device *dev =
>> +                       vlans_to_parent(struct net_bridge, v)->dev;
>
> struct net_bridge_port (or union and v->parent.port)

Yep.  Typo when doing conversions.

>
>> +
>> +               if (dev->features & NETIF_F_HW_VLAN_FILTER)
>> +                       dev->netdev_ops->ndo_vlan_rx_kill_vid(dev, vid);
>> +       }
>> +
>> +       clear_bit(vid, v->vlan_bitmap);
>> +       if (first_bit == last_bit) {
>
> bitmap_empty() is faster than two times find_xxx_bit().
>

WTH?  I did this change and now its gone...  Time to see what else I 
somehow lost...

>> +               if (v->port_idx) {
>> +                       struct net_bridge_port *p =
>> +                               vlans_to_parent(struct net_bridge_port, v);
>> +                       rcu_assign_pointer(p->vlan_info, NULL);
>> +               } else {
>> +                       struct net_bridge *br =
>> +                               vlans_to_parent(struct net_bridge, v);
>> +                       rcu_assign_pointer(br->vlan_info, NULL);
>> +               }
>
> With inline function above:
>
> rcu_assign_pointer(*br_vlan_info_parent_ptr(v), NULL);
>
>> +               kfree_rcu(v, rcu);
>> +       }
>> +       return 0;
>> +}
>> +
>> +static void __vlan_flush(struct net_port_vlans *v)
>> +{
>> +       bitmap_zero(v->vlan_bitmap, BR_VLAN_BITMAP_LEN);
>> +       if (v->port_idx) {
>> +               struct net_bridge_port *p =
>> +                               vlans_to_parent(struct net_bridge_port, v);
>> +               rcu_assign_pointer(p->vlan_info, NULL);
>> +       } else {
>> +               struct net_bridge *br =
>> +                               vlans_to_parent(struct net_bridge, v);
>> +               rcu_assign_pointer(br->vlan_info, NULL);
>> +       }
>
> Same here.

Thanks.  I'll probably go with the union for direct reference.

-vlad
>
>> +       kfree_rcu(v, rcu);
>> +}
>
> Best Regards,
> Michał Mirosław
>

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Patch

diff --git a/net/bridge/Kconfig b/net/bridge/Kconfig
index 6dee7bf..aa0d3b2 100644
--- a/net/bridge/Kconfig
+++ b/net/bridge/Kconfig
@@ -46,3 +46,17 @@  config BRIDGE_IGMP_SNOOPING
 	  Say N to exclude this support and reduce the binary size.
 
 	  If unsure, say Y.
+
+config BRIDGE_VLAN_FILTERING
+	bool "VLAN filtering"
+	depends on BRIDGE
+	depends on VLAN_8021Q
+	default n
+	---help---
+	  If you say Y here, then the Ethernet bridge will be able selectively
+	  receive and forward traffic based on VLAN information in the packet
+	  any VLAN information configured on the bridge port or bridge device.
+
+	  Say N to exclude this support and reduce the binary size.
+
+	  If unsure, say Y.
diff --git a/net/bridge/Makefile b/net/bridge/Makefile
index e859098..e85498b2f 100644
--- a/net/bridge/Makefile
+++ b/net/bridge/Makefile
@@ -14,4 +14,6 @@  bridge-$(CONFIG_BRIDGE_NETFILTER) += br_netfilter.o
 
 bridge-$(CONFIG_BRIDGE_IGMP_SNOOPING) += br_multicast.o br_mdb.o
 
+bridge-$(CONFIG_BRIDGE_VLAN_FILTERING) += br_vlan.o
+
 obj-$(CONFIG_BRIDGE_NF_EBTABLES) += netfilter/
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 2148d47..af9d65a 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -139,6 +139,7 @@  static void del_nbp(struct net_bridge_port *p)
 
 	br_ifinfo_notify(RTM_DELLINK, p);
 
+	nbp_vlan_flush(p);
 	br_fdb_delete_by_port(br, p, 1);
 
 	list_del_rcu(&p->list);
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 711094a..1c1b2f1 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -18,6 +18,7 @@ 
 #include <linux/netpoll.h>
 #include <linux/u64_stats_sync.h>
 #include <net/route.h>
+#include <linux/if_vlan.h>
 
 #define BR_HASH_BITS 8
 #define BR_HASH_SIZE (1 << BR_HASH_BITS)
@@ -26,6 +27,8 @@ 
 
 #define BR_PORT_BITS	10
 #define BR_MAX_PORTS	(1<<BR_PORT_BITS)
+#define BR_VLAN_BITMAP_LEN	BITS_TO_LONGS(VLAN_N_VID)
+#define BR_INVALID_VID	(1<<15)
 
 #define BR_VERSION	"2.3"
 
@@ -63,6 +66,13 @@  struct br_ip
 	__be16		proto;
 };
 
+struct net_port_vlans {
+	u16				port_idx;
+	void				*parent;
+	struct rcu_head			rcu;
+	unsigned long			vlan_bitmap[BR_VLAN_BITMAP_LEN];
+};
+
 struct net_bridge_fdb_entry
 {
 	struct hlist_node		hlist;
@@ -156,6 +166,7 @@  struct net_bridge_port
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	struct netpoll			*np;
 #endif
+	struct net_port_vlans __rcu	*vlan_info;
 };
 
 #define br_port_exists(dev) (dev->priv_flags & IFF_BRIDGE_PORT)
@@ -260,6 +271,10 @@  struct net_bridge
 	struct timer_list		topology_change_timer;
 	struct timer_list		gc_timer;
 	struct kobject			*ifobj;
+#ifdef CONFIG_BRIDGE_VLAN_FILTERING
+	u8				vlan_enabled;
+	struct net_port_vlans __rcu	*vlan_info;
+#endif
 };
 
 struct br_input_skb_cb {
@@ -534,6 +549,46 @@  static inline void br_mdb_uninit(void)
 }
 #endif
 
+/* br_vlan.c */
+#ifdef CONFIG_BRIDGE_VLAN_FILTERING
+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);
+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);
+#else
+static inline int br_vlan_add(struct net_bridge *br, u16 vid)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int br_vlan_delete(struct net_bridge *br, u16 vid)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void br_vlan_flush(struct net_bridge *br)
+{
+}
+
+static inline int nbp_vlan_add(struct net_bridge_port *port, u16 vid)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int nbp_vlan_delete(struct net_bridge_port *port, u16 vid)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void nbp_vlan_flush(struct net_bridge_port *port)
+{
+}
+
+#endif
+
 /* br_netfilter.c */
 #ifdef CONFIG_BRIDGE_NETFILTER
 extern int br_netfilter_init(void);
diff --git a/net/bridge/br_sysfs_br.c b/net/bridge/br_sysfs_br.c
index 5913a3a..8baa9c0 100644
--- a/net/bridge/br_sysfs_br.c
+++ b/net/bridge/br_sysfs_br.c
@@ -691,6 +691,24 @@  static ssize_t store_nf_call_arptables(
 static DEVICE_ATTR(nf_call_arptables, S_IRUGO | S_IWUSR,
 		   show_nf_call_arptables, store_nf_call_arptables);
 #endif
+#ifdef CONFIG_BRIDGE_VLAN_FILTERING
+static ssize_t show_vlan_filtering(struct device *d,
+				   struct device_attribute *attr,
+				   char *buf)
+{
+	struct net_bridge *br = to_bridge(d);
+	return sprintf(buf, "%d\n", br->vlan_enabled);
+}
+
+static ssize_t store_vlan_filtering(struct device *d,
+				    struct device_attribute *attr,
+				    const char *buf, size_t len)
+{
+	return store_bridge_parm(d, buf, len, br_vlan_filter_toggle);
+}
+static DEVICE_ATTR(vlan_filtering, S_IRUGO | S_IWUSR,
+		   show_vlan_filtering, store_vlan_filtering);
+#endif
 
 static struct attribute *bridge_attrs[] = {
 	&dev_attr_forward_delay.attr,
@@ -732,6 +750,9 @@  static struct attribute *bridge_attrs[] = {
 	&dev_attr_nf_call_ip6tables.attr,
 	&dev_attr_nf_call_arptables.attr,
 #endif
+#ifdef CONFIG_BRIDGE_VLAN_FILTERING
+	&dev_attr_vlan_filtering.attr,
+#endif
 	NULL
 };
 
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
new file mode 100644
index 0000000..8d9ded5
--- /dev/null
+++ b/net/bridge/br_vlan.c
@@ -0,0 +1,223 @@ 
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/rtnetlink.h>
+#include <linux/slab.h>
+
+#include "br_private.h"
+
+#define vlans_to_parent(type, pv) ((type *)(pv)->parent)
+
+static int __vlan_add(struct net_port_vlans *v, u16 vid)
+{
+	int err;
+
+	if (test_bit(vid, v->vlan_bitmap))
+		return -EEXIST;
+
+	if (v->port_idx && vid) {
+		struct net_device *dev =
+			vlans_to_parent(struct net_bridge_port, v)->dev;
+
+		/* Add VLAN to the device filter if it is supported.
+		 * Stricly speaking, this is not necessary now, since devices
+		 * are made promiscuous by the bridge, but if that ever changes
+		 * this code will allow tagged traffic to enter the bridge.
+		 */
+		if (dev->features & NETIF_F_HW_VLAN_FILTER) {
+			err = dev->netdev_ops->ndo_vlan_rx_add_vid(dev, vid);
+			if (err)
+				return err;
+		}
+	}
+
+	set_bit(vid, v->vlan_bitmap);
+	return 0;
+}
+
+static int __vlan_del(struct net_port_vlans *v, u16 vid)
+{
+	unsigned long first_bit;
+	unsigned long last_bit;
+
+	if (!test_bit(vid, v->vlan_bitmap))
+		return -EINVAL;
+
+	/* Check to see if any other vlans are in this table.  If this
+	 * is the last vlan, delete the whole structure.  If this is not the
+	 * last vlan, just clear the bit.
+	 */
+	first_bit = find_first_bit(v->vlan_bitmap, BR_VLAN_BITMAP_LEN);
+	last_bit = find_last_bit(v->vlan_bitmap, BR_VLAN_BITMAP_LEN);
+
+	if (v->port_idx && vid) {
+		struct net_device *dev =
+			vlans_to_parent(struct net_bridge, v)->dev;
+
+		if (dev->features & NETIF_F_HW_VLAN_FILTER)
+			dev->netdev_ops->ndo_vlan_rx_kill_vid(dev, vid);
+	}
+
+	clear_bit(vid, v->vlan_bitmap);
+	if (first_bit == last_bit) {
+		if (v->port_idx) {
+			struct net_bridge_port *p =
+				vlans_to_parent(struct net_bridge_port, v);
+			rcu_assign_pointer(p->vlan_info, NULL);
+		} else {
+			struct net_bridge *br =
+				vlans_to_parent(struct net_bridge, v);
+			rcu_assign_pointer(br->vlan_info, NULL);
+		}
+		kfree_rcu(v, rcu);
+	}
+	return 0;
+}
+
+static void __vlan_flush(struct net_port_vlans *v)
+{
+	bitmap_zero(v->vlan_bitmap, BR_VLAN_BITMAP_LEN);
+	if (v->port_idx) {
+		struct net_bridge_port *p =
+				vlans_to_parent(struct net_bridge_port, v);
+		rcu_assign_pointer(p->vlan_info, NULL);
+	} else {
+		struct net_bridge *br =
+				vlans_to_parent(struct net_bridge, v);
+		rcu_assign_pointer(br->vlan_info, NULL);
+	}
+	kfree_rcu(v, rcu);
+}
+
+/* Must be protected by RTNL */
+int br_vlan_add(struct net_bridge *br, u16 vid)
+{
+	struct net_port_vlans *pv = NULL;
+	int err;
+
+	ASSERT_RTNL();
+
+	pv = rtnl_dereference(br->vlan_info);
+	if (pv)
+		return __vlan_add(pv, vid);
+
+	/* Create port vlan infomration
+	 */
+	pv = kzalloc(sizeof(*pv), GFP_KERNEL);
+	if (!pv)
+		return -ENOMEM;
+
+	pv->parent = br;
+	err = __vlan_add(pv, vid);
+	if (err)
+		goto out;
+
+	rcu_assign_pointer(br->vlan_info, pv);
+	return 0;
+out:
+	kfree(pv);
+	return err;
+}
+
+/* Must be protected by RTNL */
+int br_vlan_delete(struct net_bridge *br, u16 vid)
+{
+	struct net_port_vlans *pv;
+
+	ASSERT_RTNL();
+
+	pv = rtnl_dereference(br->vlan_info);
+	if (!pv)
+		return -EINVAL;
+
+	__vlan_del(pv, vid);
+	return 0;
+}
+
+void br_vlan_flush(struct net_bridge *br)
+{
+	struct net_port_vlans *pv;
+
+	ASSERT_RTNL();
+
+	pv = rtnl_dereference(br->vlan_info);
+	if (!pv)
+		return;
+
+	__vlan_flush(pv);
+}
+
+int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val)
+{
+	if (!rtnl_trylock())
+		return restart_syscall();
+
+	if (br->vlan_enabled == val)
+		goto unlock;
+
+	br->vlan_enabled = val;
+
+unlock:
+	rtnl_unlock();
+	return 0;
+}
+
+/* Must be protected by RTNL */
+int nbp_vlan_add(struct net_bridge_port *port, u16 vid)
+{
+	struct net_port_vlans *pv = NULL;
+	int err;
+
+	ASSERT_RTNL();
+
+	pv = rtnl_dereference(port->vlan_info);
+	if (pv)
+		return __vlan_add(pv, vid);
+
+	/* Create port vlan infomration
+	 */
+	pv = kzalloc(sizeof(*pv), GFP_KERNEL);
+	if (!pv) {
+		err = -ENOMEM;
+		goto clean_up;
+	}
+
+	pv->port_idx = port->port_no;
+	pv->parent = port;
+	err = __vlan_add(pv, vid);
+	if (err)
+		goto clean_up;
+
+	rcu_assign_pointer(port->vlan_info, pv);
+	return 0;
+
+clean_up:
+	kfree(pv);
+	return err;
+}
+
+/* Must be protected by RTNL */
+int nbp_vlan_delete(struct net_bridge_port *port, u16 vid)
+{
+	struct net_port_vlans *pv;
+
+	ASSERT_RTNL();
+
+	pv = rtnl_dereference(port->vlan_info);
+	if (!pv)
+		return -EINVAL;
+
+	return __vlan_del(pv, vid);
+}
+
+void nbp_vlan_flush(struct net_bridge_port *port)
+{
+	struct net_port_vlans *pv;
+
+	ASSERT_RTNL();
+
+	pv = rtnl_dereference(port->vlan_info);
+	if (!pv)
+		return;
+
+	__vlan_flush(pv);
+}