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Nikolay Aleksandrov

2022-Apr-12 13:22 UTC

[Bridge] [PATCH net-next v3 0/8] net: bridge: add flush filtering support

Hi,
This patch-set adds support to specify filtering conditions for a bulk
delete (flush) operation. This version uses a new nlmsghdr delete flag
called NLM_F_BULK in combination with a new ndo_fdb_del_bulk op which is
used to signal that the driver supports bulk deletes (that avoids
pushing common mac address checks to ndo_fdb_del implementations and
also has a different prototype and parsed attribute expectations, more
info in patch 03). The new delete flag can be used for any RTM_DEL*
type, implementations just need to be careful with older kernels which
are doing non-strict attribute parses. Here I use the fact that mac
address attribute (lladdr) is mandatory in the classic fdb del case, but
it's not allowed if bulk deleting so older kernels will error out.
Patch 01 adds the new NLM_F_BULK delete request modifier, patch 02 then
adds the new ndo_fdb_del_bulk call. Patch 03 adds NLM_F_BULK support to
rtnl_fdb_del, on such request strict parsing is used only for the
supported attributes, and if the ndo is implemented it's called, the
NTF_SELF/MASTER rules are the same as for the standard rtnl_fdb_del.
Patch 04 implements bridge-specific minimal ndo_fdb_del_bulk call which
uses the current br_fdb_flush to delete all entries. Patch 05 adds
filtering support to the new bridge flush op which supports target
ifindex (port or bridge), vlan id and flags/state mask. Patch 06 adds
ndm state and flags mask attributes which will be used for filtering.
Patch 07 converts ndm state/flags and their masks to bridge-private flags
and fills them in the filter descriptor for matching. Finally patch 08
fills in the target ifindex (after validating it) and vlan id (already
validated by rtnl_fdb_flush) for matching. Flush filtering is needed
because user-space applications need a quick way to delete only a
specific set of entries, e.g. mlag implementations need a way to flush only
dynamic entries excluding externally learned ones or only externally
learned ones without static entries etc. Also apps usually want to target
only a specific vlan or port/vlan combination. The current 2 flush
operations (per port and bridge-wide) are not extensible and cannot
provide such filtering.

I decided against embedding new attrs into the old flush attributes for
multiple reasons - proper error handling on unsupported attributes,
older kernels silently flushing all, need for a second mechanism to
signal that the attribute should be parsed (e.g. using boolopts),
special treatment for permanent entries.

Examples:
$ bridge fdb flush dev bridge vlan 100 static
< flush all static entries on vlan 100 >
$ bridge fdb flush dev bridge vlan 1 dynamic
< flush all dynamic entries on vlan 1 >
$ bridge fdb flush dev bridge port ens16 vlan 1 dynamic
< flush all dynamic entries on port ens16 and vlan 1 >
$ bridge fdb flush dev ens16 vlan 1 dynamic master
< as above: flush all dynamic entries on port ens16 and vlan 1 >
$ bridge fdb flush dev bridge nooffloaded nopermanent self
< flush all non-offloaded and non-permanent entries >
$ bridge fdb flush dev bridge static noextern_learn
< flush all static entries which are not externally learned >
$ bridge fdb flush dev bridge permanent
< flush all permanent entries >
$ bridge fdb flush dev bridge port bridge permanent
< flush all permanent entries pointing to the bridge itself >

Example of a flush call with unsupported netlink attribute (NDA_DST):
$ bridge fdb flush dev bridge vlan 100 dynamic dst
Error: Unsupported attribute.

Example of a flush call on an older kernel:
$ bridge fdb flush dev bridge dynamic
Error: invalid address.

Note that all flags have their negated version (static vs nostatic etc)
and there are some tricky cases to handle like "static" which in flag
terms means fdbs that have NUD_NOARP but *not* NUD_PERMANENT, so the
mask matches on both but we need only NUD_NOARP to be set. That's
because permanent entries have both set so we can't just match on
NUD_NOARP. Also note that this flush operation doesn't treat permanent
entries in a special way (fdb_delete vs fdb_delete_local), it will
delete them regardless if any port is using them. We can extend the api
with a flag to do that if needed in the future.

Patch-sets (in order):
 - Initial flush infra and fdb flush filtering (this set)
 - iproute2 support
 - selftests

Future work:
 - mdb flush support (RTM_FLUSHMDB type)

Thanks to Ido for the great discussion and feedback while working on this.

v3: Add NLM_F_BULK delete modifier and ndo_fdb_del_bulk callback,
    patches 01 - 03 and 06 are new. Patch 04 is changed to implement
    bulk_del instead of flush, patches 05, 07 and 08 are adjusted to
    use NDA_ attributes

Thanks,
 Nik

Nikolay Aleksandrov (8):
  net: netlink: add NLM_F_BULK delete request modifier
  net: add ndo_fdb_del_bulk
  net: rtnetlink: add NLM_F_BULK support to rtnl_fdb_del
  net: bridge: fdb: add ndo_fdb_del_bulk
  net: bridge: fdb: add support for fine-grained flushing
  net: rtnetlink: add ndm flags and state mask attributes
  net: bridge: fdb: add support for flush filtering based on ndm flags
    and state
  net: bridge: fdb: add support for flush filtering based on ifindex and
    vlan

 include/linux/netdevice.h      |   9 ++
 include/uapi/linux/neighbour.h |   2 +
 include/uapi/linux/netlink.h   |   1 +
 net/bridge/br_device.c         |   1 +
 net/bridge/br_fdb.c            | 154 +++++++++++++++++++++++++++++++--
 net/bridge/br_netlink.c        |   9 +-
 net/bridge/br_private.h        |  19 +++-
 net/bridge/br_sysfs_br.c       |   6 +-
 net/core/rtnetlink.c           |  66 ++++++++++----
 9 files changed, 238 insertions(+), 29 deletions(-)

-- 
2.35.1

Nikolay Aleksandrov

2022-Apr-12 13:22 UTC

head link

[Bridge] [PATCH net-next v3 1/8] net: netlink: add NLM_F_BULK delete request modifier

Add a new delete request modifier called NLM_F_BULK which, when
supported, would cause the request to delete multiple objects. The flag
is a convenient way to signal that a multiple delete operation is
requested which can be gradually added to different delete requests. In
order to make sure older kernels will error out if the operation is not
supported instead of doing something unintended we have to break a
required condition when implementing support for this flag, f.e. for
neighbors we will omit the mandatory mac address attribute.
Initially it will be used to add flush with filtering support for bridge
fdbs, but it also opens the door to add similar support to others.

Signed-off-by: Nikolay Aleksandrov <razor at blackwall.org>
---
 include/uapi/linux/netlink.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/uapi/linux/netlink.h b/include/uapi/linux/netlink.h
index 4c0cde075c27..855dffb4c1c3 100644
--- a/include/uapi/linux/netlink.h
+++ b/include/uapi/linux/netlink.h
@@ -72,6 +72,7 @@ struct nlmsghdr {
 
 /* Modifiers to DELETE request */
 #define NLM_F_NONREC	0x100	/* Do not delete recursively	*/
+#define NLM_F_BULK	0x200	/* Delete multiple objects	*/
 
 /* Flags for ACK message */
 #define NLM_F_CAPPED	0x100	/* request was capped */
-- 
2.35.1

Nikolay Aleksandrov

2022-Apr-12 13:22 UTC

head link

[Bridge] [PATCH net-next v3 2/8] net: add ndo_fdb_del_bulk

Add a new netdev op called ndo_fdb_del_bulk, it will be later used for
driver-specific bulk delete implementation dispatched from rtnetlink. The
first user will be the bridge, we need it to signal to rtnetlink from
the driver that we support bulk delete operation (NLM_F_BULK).

Signed-off-by: Nikolay Aleksandrov <razor at blackwall.org>
---
 include/linux/netdevice.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 28ea4f8269d4..a602f29365b0 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1260,6 +1260,10 @@ struct netdev_net_notifier {
  *		      struct net_device *dev,
  *		      const unsigned char *addr, u16 vid)
  *	Deletes the FDB entry from dev coresponding to addr.
+ * int (*ndo_fdb_del_bulk)(struct ndmsg *ndm, struct nlattr *tb[],
+ *			   struct net_device *dev,
+ *			   u16 vid,
+ *			   struct netlink_ext_ack *extack);
  * int (*ndo_fdb_dump)(struct sk_buff *skb, struct netlink_callback *cb,
  *		       struct net_device *dev, struct net_device *filter_dev,
  *		       int *idx)
@@ -1510,6 +1514,11 @@ struct net_device_ops {
 					       struct net_device *dev,
 					       const unsigned char *addr,
 					       u16 vid);
+	int			(*ndo_fdb_del_bulk)(struct ndmsg *ndm,
+						    struct nlattr *tb[],
+						    struct net_device *dev,
+						    u16 vid,
+						    struct netlink_ext_ack *extack);
 	int			(*ndo_fdb_dump)(struct sk_buff *skb,
 						struct netlink_callback *cb,
 						struct net_device *dev,
-- 
2.35.1

Nikolay Aleksandrov

2022-Apr-12 13:22 UTC

head link

[Bridge] [PATCH net-next v3 3/8] net: rtnetlink: add NLM_F_BULK support to rtnl_fdb_del

When NLM_F_BULK is specified in a fdb del message we need to handle it
differently. First since this is a new call we can strictly validate the
passed attributes, at first only ifindex and vlan are allowed as these
will be the initially supported filter attributes, any other attribute
is rejected. The mac address is no longer mandatory, but we use it
to error out in older kernels because it cannot be specified with bulk
request (the attribute is not allowed) and then we have to dispatch
the call to ndo_fdb_del_bulk if the device supports it. The del bulk
callback can do further validation of the attributes if necessary.

Signed-off-by: Nikolay Aleksandrov <razor at blackwall.org>
---
 net/core/rtnetlink.c | 64 +++++++++++++++++++++++++++++++-------------
 1 file changed, 46 insertions(+), 18 deletions(-)

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 4041b3e2e8ec..824963aa57b1 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -4167,22 +4167,34 @@ int ndo_dflt_fdb_del(struct ndmsg *ndm,
 }
 EXPORT_SYMBOL(ndo_dflt_fdb_del);
 
+static const struct nla_policy fdb_del_bulk_policy[NDA_MAX + 1] = {
+	[NDA_VLAN]	= { .type = NLA_U16 },
+	[NDA_IFINDEX]	= NLA_POLICY_MIN(NLA_S32, 1),
+};
+
 static int rtnl_fdb_del(struct sk_buff *skb, struct nlmsghdr *nlh,
 			struct netlink_ext_ack *extack)
 {
+	bool del_bulk = !!(nlh->nlmsg_flags & NLM_F_BULK);
 	struct net *net = sock_net(skb->sk);
+	const struct net_device_ops *ops;
 	struct ndmsg *ndm;
 	struct nlattr *tb[NDA_MAX+1];
 	struct net_device *dev;
-	__u8 *addr;
+	__u8 *addr = NULL;
 	int err;
 	u16 vid;
 
 	if (!netlink_capable(skb, CAP_NET_ADMIN))
 		return -EPERM;
 
-	err = nlmsg_parse_deprecated(nlh, sizeof(*ndm), tb, NDA_MAX, NULL,
-				     extack);
+	if (!del_bulk) {
+		err = nlmsg_parse_deprecated(nlh, sizeof(*ndm), tb, NDA_MAX,
+					     NULL, extack);
+	} else {
+		err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX,
+				  fdb_del_bulk_policy, extack);
+	}
 	if (err < 0)
 		return err;
 
@@ -4198,9 +4210,12 @@ static int rtnl_fdb_del(struct sk_buff *skb, struct
nlmsghdr *nlh,
 		return -ENODEV;
 	}
 
-	if (!tb[NDA_LLADDR] || nla_len(tb[NDA_LLADDR]) != ETH_ALEN) {
-		NL_SET_ERR_MSG(extack, "invalid address");
-		return -EINVAL;
+	if (!del_bulk) {
+		if (!tb[NDA_LLADDR] || nla_len(tb[NDA_LLADDR]) != ETH_ALEN) {
+			NL_SET_ERR_MSG(extack, "invalid address");
+			return -EINVAL;
+		}
+		addr = nla_data(tb[NDA_LLADDR]);
 	}
 
 	if (dev->type != ARPHRD_ETHER) {
@@ -4208,8 +4223,6 @@ static int rtnl_fdb_del(struct sk_buff *skb, struct
nlmsghdr *nlh,
 		return -EINVAL;
 	}
 
-	addr = nla_data(tb[NDA_LLADDR]);
-
 	err = fdb_vid_parse(tb[NDA_VLAN], &vid, extack);
 	if (err)
 		return err;
@@ -4220,10 +4233,16 @@ static int rtnl_fdb_del(struct sk_buff *skb, struct
nlmsghdr *nlh,
 	if ((!ndm->ndm_flags || ndm->ndm_flags & NTF_MASTER) &&
 	    netif_is_bridge_port(dev)) {
 		struct net_device *br_dev = netdev_master_upper_dev_get(dev);
-		const struct net_device_ops *ops = br_dev->netdev_ops;
 
-		if (ops->ndo_fdb_del)
-			err = ops->ndo_fdb_del(ndm, tb, dev, addr, vid);
+		ops = br_dev->netdev_ops;
+		if (!del_bulk) {
+			if (ops->ndo_fdb_del)
+				err = ops->ndo_fdb_del(ndm, tb, dev, addr, vid);
+		} else {
+			if (ops->ndo_fdb_del_bulk)
+				err = ops->ndo_fdb_del_bulk(ndm, tb, dev, vid,
+							    extack);
+		}
 
 		if (err)
 			goto out;
@@ -4233,15 +4252,24 @@ static int rtnl_fdb_del(struct sk_buff *skb, struct
nlmsghdr *nlh,
 
 	/* Embedded bridge, macvlan, and any other device support */
 	if (ndm->ndm_flags & NTF_SELF) {
-		if (dev->netdev_ops->ndo_fdb_del)
-			err = dev->netdev_ops->ndo_fdb_del(ndm, tb, dev, addr,
-							   vid);
-		else
-			err = ndo_dflt_fdb_del(ndm, tb, dev, addr, vid);
+		ops = dev->netdev_ops;
+		if (!del_bulk) {
+			if (ops->ndo_fdb_del)
+				err = ops->ndo_fdb_del(ndm, tb, dev, addr, vid);
+			else
+				err = ndo_dflt_fdb_del(ndm, tb, dev, addr, vid);
+		} else {
+			/* in case err was cleared by NTF_MASTER call */
+			err = -EOPNOTSUPP;
+			if (ops->ndo_fdb_del_bulk)
+				err = ops->ndo_fdb_del_bulk(ndm, tb, dev, vid,
+							    extack);
+		}
 
 		if (!err) {
-			rtnl_fdb_notify(dev, addr, vid, RTM_DELNEIGH,
-					ndm->ndm_state);
+			if (!del_bulk)
+				rtnl_fdb_notify(dev, addr, vid, RTM_DELNEIGH,
+						ndm->ndm_state);
 			ndm->ndm_flags &= ~NTF_SELF;
 		}
 	}
-- 
2.35.1

Nikolay Aleksandrov

2022-Apr-12 13:22 UTC

head link

[Bridge] [PATCH net-next v3 4/8] net: bridge: fdb: add ndo_fdb_del_bulk

Add a minimal ndo_fdb_del_bulk implementation which flushes all entries.
Support for more fine-grained filtering will be added in the following
patches.

Signed-off-by: Nikolay Aleksandrov <razor at blackwall.org>
---
 net/bridge/br_device.c   |  1 +
 net/bridge/br_fdb.c      | 25 ++++++++++++++++++++++++-
 net/bridge/br_netlink.c  |  2 +-
 net/bridge/br_private.h  |  6 +++++-
 net/bridge/br_sysfs_br.c |  2 +-
 5 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index 8d6bab244c4a..58a4f70e01e3 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -465,6 +465,7 @@ static const struct net_device_ops br_netdev_ops = {
 	.ndo_fix_features        = br_fix_features,
 	.ndo_fdb_add		 = br_fdb_add,
 	.ndo_fdb_del		 = br_fdb_delete,
+	.ndo_fdb_del_bulk	 = br_fdb_delete_bulk,
 	.ndo_fdb_dump		 = br_fdb_dump,
 	.ndo_fdb_get		 = br_fdb_get,
 	.ndo_bridge_getlink	 = br_getlink,
diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index 6ccda68bd473..fd7012c32cd5 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -559,7 +559,7 @@ void br_fdb_cleanup(struct work_struct *work)
 }
 
 /* Completely flush all dynamic entries in forwarding database.*/
-void br_fdb_flush(struct net_bridge *br)
+void __br_fdb_flush(struct net_bridge *br)
 {
 	struct net_bridge_fdb_entry *f;
 	struct hlist_node *tmp;
@@ -572,6 +572,29 @@ void br_fdb_flush(struct net_bridge *br)
 	spin_unlock_bh(&br->hash_lock);
 }
 
+int br_fdb_delete_bulk(struct ndmsg *ndm, struct nlattr *tb[],
+		       struct net_device *dev, u16 vid,
+		       struct netlink_ext_ack *extack)
+{
+	struct net_bridge *br;
+
+	if (netif_is_bridge_master(dev)) {
+		br = netdev_priv(dev);
+	} else {
+		struct net_bridge_port *p = br_port_get_rtnl(dev);
+
+		if (!p) {
+			NL_SET_ERR_MSG_MOD(extack, "Device is not a bridge port");
+			return -EINVAL;
+		}
+		br = p->br;
+	}
+
+	__br_fdb_flush(br);
+
+	return 0;
+}
+
 /* Flush all entries referring to a specific port.
  * if do_all is set also flush static entries
  * if vid is set delete all entries that match the vlan_id
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 200ad05b296f..c59c775730bb 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1327,7 +1327,7 @@ static int br_changelink(struct net_device *brdev, struct
nlattr *tb[],
 	}
 
 	if (data[IFLA_BR_FDB_FLUSH])
-		br_fdb_flush(br);
+		__br_fdb_flush(br);
 
 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
 	if (data[IFLA_BR_MCAST_ROUTER]) {
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 6e62af2e07e9..3ba50e41aa4f 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -759,7 +759,8 @@ int br_fdb_init(void);
 void br_fdb_fini(void);
 int br_fdb_hash_init(struct net_bridge *br);
 void br_fdb_hash_fini(struct net_bridge *br);
-void br_fdb_flush(struct net_bridge *br);
+void __br_fdb_flush(struct net_bridge *br);
+
 void br_fdb_find_delete_local(struct net_bridge *br,
 			      const struct net_bridge_port *p,
 			      const unsigned char *addr, u16 vid);
@@ -781,6 +782,9 @@ void br_fdb_update(struct net_bridge *br, struct
net_bridge_port *source,
 
 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 		  struct net_device *dev, const unsigned char *addr, u16 vid);
+int br_fdb_delete_bulk(struct ndmsg *ndm, struct nlattr *tb[],
+		       struct net_device *dev, u16 vid,
+		       struct netlink_ext_ack *extack);
 int br_fdb_add(struct ndmsg *nlh, struct nlattr *tb[], struct net_device *dev,
 	       const unsigned char *addr, u16 vid, u16 nlh_flags,
 	       struct netlink_ext_ack *extack);
diff --git a/net/bridge/br_sysfs_br.c b/net/bridge/br_sysfs_br.c
index 3f7ca88c2aa3..7a2cf3aebc84 100644
--- a/net/bridge/br_sysfs_br.c
+++ b/net/bridge/br_sysfs_br.c
@@ -344,7 +344,7 @@ static DEVICE_ATTR_RW(group_addr);
 static int set_flush(struct net_bridge *br, unsigned long val,
 		     struct netlink_ext_ack *extack)
 {
-	br_fdb_flush(br);
+	__br_fdb_flush(br);
 	return 0;
 }
 
-- 
2.35.1

Nikolay Aleksandrov

2022-Apr-12 13:22 UTC

head link

[Bridge] [PATCH net-next v3 5/8] net: bridge: fdb: add support for fine-grained flushing

Add the ability to specify exactly which fdbs to be flushed. They are
described by a new structure - net_bridge_fdb_flush_desc. Currently it
can match on port/bridge ifindex, vlan id and fdb flags. It is used to
describe the existing dynamic fdb flush operation. Note that this flush
operation doesn't treat permanent entries in a special way (fdb_delete vs
fdb_delete_local), it will delete them regardless if any port is using
them, so currently it can't directly replace deletes which need to handle
that case, although we can extend it later for that too.

Signed-off-by: Nikolay Aleksandrov <razor at blackwall.org>
---
v2: changed the flush matches func for better readability (Ido)
v3: no change

 net/bridge/br_fdb.c      | 41 ++++++++++++++++++++++++++++++++--------
 net/bridge/br_netlink.c  |  9 +++++++--
 net/bridge/br_private.h  | 10 +++++++++-
 net/bridge/br_sysfs_br.c |  6 +++++-
 4 files changed, 54 insertions(+), 12 deletions(-)

diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index fd7012c32cd5..f1deac42bc0d 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -558,24 +558,49 @@ void br_fdb_cleanup(struct work_struct *work)
 	mod_delayed_work(system_long_wq, &br->gc_work, work_delay);
 }
 
-/* Completely flush all dynamic entries in forwarding database.*/
-void __br_fdb_flush(struct net_bridge *br)
+static bool __fdb_flush_matches(const struct net_bridge *br,
+				const struct net_bridge_fdb_entry *f,
+				const struct net_bridge_fdb_flush_desc *desc)
+{
+	const struct net_bridge_port *dst = READ_ONCE(f->dst);
+	int port_ifidx = dst ? dst->dev->ifindex : br->dev->ifindex;
+
+	if (desc->vlan_id && desc->vlan_id != f->key.vlan_id)
+		return false;
+	if (desc->port_ifindex && desc->port_ifindex != port_ifidx)
+		return false;
+	if (desc->flags_mask && (f->flags & desc->flags_mask) !=
desc->flags)
+		return false;
+
+	return true;
+}
+
+/* Flush forwarding database entries matching the description */
+void __br_fdb_flush(struct net_bridge *br,
+		    const struct net_bridge_fdb_flush_desc *desc)
 {
 	struct net_bridge_fdb_entry *f;
-	struct hlist_node *tmp;
 
-	spin_lock_bh(&br->hash_lock);
-	hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) {
-		if (!test_bit(BR_FDB_STATIC, &f->flags))
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
+		if (!__fdb_flush_matches(br, f, desc))
+			continue;
+
+		spin_lock_bh(&br->hash_lock);
+		if (!hlist_unhashed(&f->fdb_node))
 			fdb_delete(br, f, true);
+		spin_unlock_bh(&br->hash_lock);
 	}
-	spin_unlock_bh(&br->hash_lock);
+	rcu_read_unlock();
 }
 
 int br_fdb_delete_bulk(struct ndmsg *ndm, struct nlattr *tb[],
 		       struct net_device *dev, u16 vid,
 		       struct netlink_ext_ack *extack)
 {
+	struct net_bridge_fdb_flush_desc desc = {
+		.flags_mask = BR_FDB_STATIC
+	};
 	struct net_bridge *br;
 
 	if (netif_is_bridge_master(dev)) {
@@ -590,7 +615,7 @@ int br_fdb_delete_bulk(struct ndmsg *ndm, struct nlattr
*tb[],
 		br = p->br;
 	}
 
-	__br_fdb_flush(br);
+	__br_fdb_flush(br, &desc);
 
 	return 0;
 }
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index c59c775730bb..accab38b0b6a 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1326,8 +1326,13 @@ static int br_changelink(struct net_device *brdev, struct
nlattr *tb[],
 		br_recalculate_fwd_mask(br);
 	}
 
-	if (data[IFLA_BR_FDB_FLUSH])
-		__br_fdb_flush(br);
+	if (data[IFLA_BR_FDB_FLUSH]) {
+		struct net_bridge_fdb_flush_desc desc = {
+			.flags_mask = BR_FDB_STATIC
+		};
+
+		__br_fdb_flush(br, &desc);
+	}
 
 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
 	if (data[IFLA_BR_MCAST_ROUTER]) {
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 3ba50e41aa4f..dd186ac29737 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -274,6 +274,13 @@ struct net_bridge_fdb_entry {
 	struct rcu_head			rcu;
 };
 
+struct net_bridge_fdb_flush_desc {
+	unsigned long			flags;
+	unsigned long			flags_mask;
+	int				port_ifindex;
+	u16				vlan_id;
+};
+
 #define MDB_PG_FLAGS_PERMANENT	BIT(0)
 #define MDB_PG_FLAGS_OFFLOAD	BIT(1)
 #define MDB_PG_FLAGS_FAST_LEAVE	BIT(2)
@@ -759,7 +766,8 @@ int br_fdb_init(void);
 void br_fdb_fini(void);
 int br_fdb_hash_init(struct net_bridge *br);
 void br_fdb_hash_fini(struct net_bridge *br);
-void __br_fdb_flush(struct net_bridge *br);
+void __br_fdb_flush(struct net_bridge *br,
+		    const struct net_bridge_fdb_flush_desc *desc);
 
 void br_fdb_find_delete_local(struct net_bridge *br,
 			      const struct net_bridge_port *p,
diff --git a/net/bridge/br_sysfs_br.c b/net/bridge/br_sysfs_br.c
index 7a2cf3aebc84..c863151f1cde 100644
--- a/net/bridge/br_sysfs_br.c
+++ b/net/bridge/br_sysfs_br.c
@@ -344,7 +344,11 @@ static DEVICE_ATTR_RW(group_addr);
 static int set_flush(struct net_bridge *br, unsigned long val,
 		     struct netlink_ext_ack *extack)
 {
-	__br_fdb_flush(br);
+	struct net_bridge_fdb_flush_desc desc = {
+		.flags_mask = BR_FDB_STATIC
+	};
+
+	__br_fdb_flush(br, &desc);
 	return 0;
 }
 
-- 
2.35.1

Nikolay Aleksandrov

2022-Apr-12 13:22 UTC

head link

[Bridge] [PATCH net-next v3 6/8] net: rtnetlink: add ndm flags and state mask attributes

Add ndm flags/state masks which will be used for bulk delete filtering.
All of these are used by the bridge and vxlan drivers. Also minimal attr
policy validation is added, it is up to ndo_fdb_del_bulk implementers to
further validate them.

Signed-off-by: Nikolay Aleksandrov <razor at blackwall.org>
---
 include/uapi/linux/neighbour.h | 2 ++
 net/core/rtnetlink.c           | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/include/uapi/linux/neighbour.h b/include/uapi/linux/neighbour.h
index db05fb55055e..39c565e460c7 100644
--- a/include/uapi/linux/neighbour.h
+++ b/include/uapi/linux/neighbour.h
@@ -32,6 +32,8 @@ enum {
 	NDA_NH_ID,
 	NDA_FDB_EXT_ATTRS,
 	NDA_FLAGS_EXT,
+	NDA_NDM_STATE_MASK,
+	NDA_NDM_FLAGS_MASK,
 	__NDA_MAX
 };
 
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 824963aa57b1..9118523b328f 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -4170,6 +4170,8 @@ EXPORT_SYMBOL(ndo_dflt_fdb_del);
 static const struct nla_policy fdb_del_bulk_policy[NDA_MAX + 1] = {
 	[NDA_VLAN]	= { .type = NLA_U16 },
 	[NDA_IFINDEX]	= NLA_POLICY_MIN(NLA_S32, 1),
+	[NDA_NDM_STATE_MASK]	= { .type = NLA_U16  },
+	[NDA_NDM_FLAGS_MASK]	= { .type = NLA_U8 },
 };
 
 static int rtnl_fdb_del(struct sk_buff *skb, struct nlmsghdr *nlh,
-- 
2.35.1

Nikolay Aleksandrov

2022-Apr-12 13:22 UTC

head link

[Bridge] [PATCH net-next v3 7/8] net: bridge: fdb: add support for flush filtering based on ndm flags and state

Add support for fdb flush filtering based on ndm flags and state. NDM
state and flags are mapped to bridge-specific flags and matched
according to the specified masks. NTF_USE is used to represent
added_by_user flag since it sets it on fdb add and we don't have a 1:1
mapping for it. Only allowed bits can be set, NTF_USE and NTF_MASTER are
ignored.

Signed-off-by: Nikolay Aleksandrov <razor at blackwall.org>
---
v2: ignore NTF_USE/NTF_MASTER and reject unknown flags
v3: NDFA -> NDA attributes

 net/bridge/br_fdb.c     | 58 ++++++++++++++++++++++++++++++++++++++---
 net/bridge/br_private.h |  5 ++++
 2 files changed, 60 insertions(+), 3 deletions(-)

diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index f1deac42bc0d..bbb00a75ef0a 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -594,13 +594,40 @@ void __br_fdb_flush(struct net_bridge *br,
 	rcu_read_unlock();
 }
 
+static unsigned long __ndm_state_to_fdb_flags(u16 ndm_state)
+{
+	unsigned long flags = 0;
+
+	if (ndm_state & NUD_PERMANENT)
+		__set_bit(BR_FDB_LOCAL, &flags);
+	if (ndm_state & NUD_NOARP)
+		__set_bit(BR_FDB_STATIC, &flags);
+
+	return flags;
+}
+
+static unsigned long __ndm_flags_to_fdb_flags(u8 ndm_flags)
+{
+	unsigned long flags = 0;
+
+	if (ndm_flags & NTF_USE)
+		__set_bit(BR_FDB_ADDED_BY_USER, &flags);
+	if (ndm_flags & NTF_EXT_LEARNED)
+		__set_bit(BR_FDB_ADDED_BY_EXT_LEARN, &flags);
+	if (ndm_flags & NTF_OFFLOADED)
+		__set_bit(BR_FDB_OFFLOADED, &flags);
+	if (ndm_flags & NTF_STICKY)
+		__set_bit(BR_FDB_STICKY, &flags);
+
+	return flags;
+}
+
 int br_fdb_delete_bulk(struct ndmsg *ndm, struct nlattr *tb[],
 		       struct net_device *dev, u16 vid,
 		       struct netlink_ext_ack *extack)
 {
-	struct net_bridge_fdb_flush_desc desc = {
-		.flags_mask = BR_FDB_STATIC
-	};
+	u8 ndm_flags = ndm->ndm_flags & ~FDB_FLUSH_IGNORED_NDM_FLAGS;
+	struct net_bridge_fdb_flush_desc desc = {};
 	struct net_bridge *br;
 
 	if (netif_is_bridge_master(dev)) {
@@ -615,6 +642,31 @@ int br_fdb_delete_bulk(struct ndmsg *ndm, struct nlattr
*tb[],
 		br = p->br;
 	}
 
+	if (ndm_flags & ~FDB_FLUSH_ALLOWED_NDM_FLAGS) {
+		NL_SET_ERR_MSG(extack, "Unsupported fdb flush ndm flag bits set");
+		return -EINVAL;
+	}
+	if (ndm->ndm_state & ~FDB_FLUSH_ALLOWED_NDM_STATES) {
+		NL_SET_ERR_MSG(extack, "Unsupported fdb flush ndm state bits set");
+		return -EINVAL;
+	}
+
+	desc.flags |= __ndm_state_to_fdb_flags(ndm->ndm_state);
+	desc.flags |= __ndm_flags_to_fdb_flags(ndm_flags);
+	if (tb[NDA_NDM_STATE_MASK]) {
+		u16 ndm_state_mask = nla_get_u16(tb[NDA_NDM_STATE_MASK]);
+
+		desc.flags_mask |= __ndm_state_to_fdb_flags(ndm_state_mask);
+	}
+	if (tb[NDA_NDM_FLAGS_MASK]) {
+		u8 ndm_flags_mask = nla_get_u8(tb[NDA_NDM_FLAGS_MASK]);
+
+		desc.flags_mask |= __ndm_flags_to_fdb_flags(ndm_flags_mask);
+	}
+
+	br_debug(br, "flushing port ifindex: %d vlan id: %u flags: 0x%lx flags
mask: 0x%lx\n",
+		 desc.port_ifindex, desc.vlan_id, desc.flags, desc.flags_mask);
+
 	__br_fdb_flush(br, &desc);
 
 	return 0;
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index dd186ac29737..72b934d1edce 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -762,6 +762,11 @@ static inline void br_netpoll_disable(struct
net_bridge_port *p)
 #endif
 
 /* br_fdb.c */
+#define FDB_FLUSH_IGNORED_NDM_FLAGS (NTF_MASTER | NTF_SELF)
+#define FDB_FLUSH_ALLOWED_NDM_STATES (NUD_PERMANENT | NUD_NOARP)
+#define FDB_FLUSH_ALLOWED_NDM_FLAGS (NTF_USE | NTF_EXT_LEARNED | \
+				     NTF_STICKY | NTF_OFFLOADED)
+
 int br_fdb_init(void);
 void br_fdb_fini(void);
 int br_fdb_hash_init(struct net_bridge *br);
-- 
2.35.1

Nikolay Aleksandrov

2022-Apr-12 13:22 UTC

head link

[Bridge] [PATCH net-next v3 8/8] net: bridge: fdb: add support for flush filtering based on ifindex and vlan

Add support for fdb flush filtering based on destination ifindex and
vlan id. The ifindex must either match a port's device ifindex or the
bridge's. The vlan support is trivial since it's already validated by
rtnl_fdb_flush, we just need to fill it in.

Signed-off-by: Nikolay Aleksandrov <razor at blackwall.org>
---
v2: validate ifindex and fill in vlan id
v3: NDFA -> NDA attributes

 net/bridge/br_fdb.c | 42 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index bbb00a75ef0a..c44ea83ac3d9 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -622,12 +622,44 @@ static unsigned long __ndm_flags_to_fdb_flags(u8
ndm_flags)
 	return flags;
 }
 
+static int __fdb_flush_validate_ifindex(const struct net_bridge *br,
+					int ifindex,
+					struct netlink_ext_ack *extack)
+{
+	const struct net_device *dev;
+
+	dev = __dev_get_by_index(dev_net(br->dev), ifindex);
+	if (!dev) {
+		NL_SET_ERR_MSG_MOD(extack, "Unknown flush device ifindex");
+		return -ENODEV;
+	}
+	if (!netif_is_bridge_master(dev) && !netif_is_bridge_port(dev)) {
+		NL_SET_ERR_MSG_MOD(extack, "Flush device is not a bridge or bridge
port");
+		return -EINVAL;
+	}
+	if (netif_is_bridge_master(dev) && dev != br->dev) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Flush bridge device does not match target bridge device");
+		return -EINVAL;
+	}
+	if (netif_is_bridge_port(dev)) {
+		struct net_bridge_port *p = br_port_get_rtnl(dev);
+
+		if (p->br != br) {
+			NL_SET_ERR_MSG_MOD(extack, "Port belongs to a different bridge
device");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
 int br_fdb_delete_bulk(struct ndmsg *ndm, struct nlattr *tb[],
 		       struct net_device *dev, u16 vid,
 		       struct netlink_ext_ack *extack)
 {
 	u8 ndm_flags = ndm->ndm_flags & ~FDB_FLUSH_IGNORED_NDM_FLAGS;
-	struct net_bridge_fdb_flush_desc desc = {};
+	struct net_bridge_fdb_flush_desc desc = { .vlan_id = vid };
 	struct net_bridge *br;
 
 	if (netif_is_bridge_master(dev)) {
@@ -663,6 +695,14 @@ int br_fdb_delete_bulk(struct ndmsg *ndm, struct nlattr
*tb[],
 
 		desc.flags_mask |= __ndm_flags_to_fdb_flags(ndm_flags_mask);
 	}
+	if (tb[NDA_IFINDEX]) {
+		int err, ifidx = nla_get_s32(tb[NDA_IFINDEX]);
+
+		err = __fdb_flush_validate_ifindex(br, ifidx, extack);
+		if (err)
+			return err;
+		desc.port_ifindex = ifidx;
+	}
 
 	br_debug(br, "flushing port ifindex: %d vlan id: %u flags: 0x%lx flags
mask: 0x%lx\n",
 		 desc.port_ifindex, desc.vlan_id, desc.flags, desc.flags_mask);
-- 
2.35.1

Nikolay Aleksandrov

2022-Apr-12 22:50 UTC

head link

[Bridge] [PATCH net-next v3 0/8] net: bridge: add flush filtering support

On 4/12/22 16:22, Nikolay Aleksandrov wrote:> Hi,
> This patch-set adds support to specify filtering conditions for a bulk
> delete (flush) operation. This version uses a new nlmsghdr delete flag
> called NLM_F_BULK in combination with a new ndo_fdb_del_bulk op which is
> used to signal that the driver supports bulk deletes (that avoids
> pushing common mac address checks to ndo_fdb_del implementations and
> also has a different prototype and parsed attribute expectations, more
> info in patch 03). The new delete flag can be used for any RTM_DEL*
> type, implementations just need to be careful with older kernels which
> are doing non-strict attribute parses. Here I use the fact that mac
> address attribute (lladdr) is mandatory in the classic fdb del case, but
> it's not allowed if bulk deleting so older kernels will error out.
> Patch 01 adds the new NLM_F_BULK delete request modifier, patch 02 then
> adds the new ndo_fdb_del_bulk call. Patch 03 adds NLM_F_BULK support to
> rtnl_fdb_del, on such request strict parsing is used only for the
> supported attributes, and if the ndo is implemented it's called, the
> NTF_SELF/MASTER rules are the same as for the standard rtnl_fdb_del.
> Patch 04 implements bridge-specific minimal ndo_fdb_del_bulk call which
> uses the current br_fdb_flush to delete all entries. Patch 05 adds
> filtering support to the new bridge flush op which supports target
> ifindex (port or bridge), vlan id and flags/state mask. Patch 06 adds
> ndm state and flags mask attributes which will be used for filtering.
> Patch 07 converts ndm state/flags and their masks to bridge-private flags
> and fills them in the filter descriptor for matching. Finally patch 08
> fills in the target ifindex (after validating it) and vlan id (already
> validated by rtnl_fdb_flush) for matching. Flush filtering is needed
> because user-space applications need a quick way to delete only a
> specific set of entries, e.g. mlag implementations need a way to flush only
> dynamic entries excluding externally learned ones or only externally
> learned ones without static entries etc. Also apps usually want to target
> only a specific vlan or port/vlan combination. The current 2 flush
> operations (per port and bridge-wide) are not extensible and cannot
> provide such filtering.
> 
> I decided against embedding new attrs into the old flush attributes for
> multiple reasons - proper error handling on unsupported attributes,
> older kernels silently flushing all, need for a second mechanism to
> signal that the attribute should be parsed (e.g. using boolopts),
> special treatment for permanent entries.
> 
> Examples:
> $ bridge fdb flush dev bridge vlan 100 static
> < flush all static entries on vlan 100 >
> $ bridge fdb flush dev bridge vlan 1 dynamic
> < flush all dynamic entries on vlan 1 >
> $ bridge fdb flush dev bridge port ens16 vlan 1 dynamic
> < flush all dynamic entries on port ens16 and vlan 1 >
> $ bridge fdb flush dev ens16 vlan 1 dynamic master
> < as above: flush all dynamic entries on port ens16 and vlan 1 >
> $ bridge fdb flush dev bridge nooffloaded nopermanent self
> < flush all non-offloaded and non-permanent entries >
> $ bridge fdb flush dev bridge static noextern_learn
> < flush all static entries which are not externally learned >
> $ bridge fdb flush dev bridge permanent
> < flush all permanent entries >
> $ bridge fdb flush dev bridge port bridge permanent
> < flush all permanent entries pointing to the bridge itself >
> 
> Example of a flush call with unsupported netlink attribute (NDA_DST):
> $ bridge fdb flush dev bridge vlan 100 dynamic dst
> Error: Unsupported attribute.
> 
> Example of a flush call on an older kernel:
> $ bridge fdb flush dev bridge dynamic
> Error: invalid address.
> 
> Note that all flags have their negated version (static vs nostatic etc)
> and there are some tricky cases to handle like "static" which in
flag
> terms means fdbs that have NUD_NOARP but *not* NUD_PERMANENT, so the
> mask matches on both but we need only NUD_NOARP to be set. That's
> because permanent entries have both set so we can't just match on
> NUD_NOARP. Also note that this flush operation doesn't treat permanent
> entries in a special way (fdb_delete vs fdb_delete_local), it will
> delete them regardless if any port is using them. We can extend the api
> with a flag to do that if needed in the future.
> 
> Patch-sets (in order):
>   - Initial flush infra and fdb flush filtering (this set)
>   - iproute2 support
>   - selftests
> 
> Future work:
>   - mdb flush support (RTM_FLUSHMDB type)
> 
> Thanks to Ido for the great discussion and feedback while working on this.
> 
> v3: Add NLM_F_BULK delete modifier and ndo_fdb_del_bulk callback,
>      patches 01 - 03 and 06 are new. Patch 04 is changed to implement
>      bulk_del instead of flush, patches 05, 07 and 08 are adjusted to
>      use NDA_ attributes
> 
> Thanks,
>   Nik
> 
> Nikolay Aleksandrov (8):
>    net: netlink: add NLM_F_BULK delete request modifier
>    net: add ndo_fdb_del_bulk
>    net: rtnetlink: add NLM_F_BULK support to rtnl_fdb_del
>    net: bridge: fdb: add ndo_fdb_del_bulk
>    net: bridge: fdb: add support for fine-grained flushing
>    net: rtnetlink: add ndm flags and state mask attributes
>    net: bridge: fdb: add support for flush filtering based on ndm flags
>      and state
>    net: bridge: fdb: add support for flush filtering based on ifindex and
>      vlan
> 
>   include/linux/netdevice.h      |   9 ++
>   include/uapi/linux/neighbour.h |   2 +
>   include/uapi/linux/netlink.h   |   1 +
>   net/bridge/br_device.c         |   1 +
>   net/bridge/br_fdb.c            | 154 +++++++++++++++++++++++++++++++--
>   net/bridge/br_netlink.c        |   9 +-
>   net/bridge/br_private.h        |  19 +++-
>   net/bridge/br_sysfs_br.c       |   6 +-
>   net/core/rtnetlink.c           |  66 ++++++++++----
>   9 files changed, 238 insertions(+), 29 deletions(-)
> 
I realized an improvement I've missed to do in patch 08 (use port's 
ifindex when doing a bridge flush through a port and NDA_IFINDEX is not 
specified), I'll leave this set for comments and will prepare v4 with it 
and anything else that comes up in the meantime.

Thanks,
  Nik

David Ahern

2022-Apr-13 02:04 UTC

head link

[Bridge] [PATCH net-next v3 0/8] net: bridge: add flush filtering support

On 4/12/22 7:22 AM, Nikolay Aleksandrov wrote:> Hi,
> This patch-set adds support to specify filtering conditions for a bulk
> delete (flush) operation. This version uses a new nlmsghdr delete flag
> called NLM_F_BULK in combination with a new ndo_fdb_del_bulk op which is
> used to signal that the driver supports bulk deletes (that avoids
> pushing common mac address checks to ndo_fdb_del implementations and
> also has a different prototype and parsed attribute expectations, more
> info in patch 03). The new delete flag can be used for any RTM_DEL*
> type, implementations just need to be careful with older kernels which
> are doing non-strict attribute parses. Here I use the fact that mac
overall it looks fine to me. The rollout of BULK delete for other
commands will be slow so we need a way to reject the BULK flag if the
handler does not support it. One thought is to add another flag to
rtnl_link_flags (e.g., RTNL_FLAG_BULK_DEL_SUPPORTED) and pass that flag
in for handlers that handle bulk delete and reject it for others in core
rtnetlink code.

Nikolay Aleksandrov

2022-Apr-13 07:27 UTC

head link

[Bridge] [PATCH net-next v3 0/8] net: bridge: add flush filtering support

On 13/04/2022 05:04, David Ahern wrote:> On 4/12/22 7:22 AM, Nikolay Aleksandrov wrote:
>> Hi,
>> This patch-set adds support to specify filtering conditions for a bulk
>> delete (flush) operation. This version uses a new nlmsghdr delete flag
>> called NLM_F_BULK in combination with a new ndo_fdb_del_bulk op which
is
>> used to signal that the driver supports bulk deletes (that avoids
>> pushing common mac address checks to ndo_fdb_del implementations and
>> also has a different prototype and parsed attribute expectations, more
>> info in patch 03). The new delete flag can be used for any RTM_DEL*
>> type, implementations just need to be careful with older kernels which
>> are doing non-strict attribute parses. Here I use the fact that mac
> 
> overall it looks fine to me. The rollout of BULK delete for other
> commands will be slow so we need a way to reject the BULK flag if the
> handler does not support it. One thought is to add another flag to
> rtnl_link_flags (e.g., RTNL_FLAG_BULK_DEL_SUPPORTED) and pass that flag
> in for handlers that handle bulk delete and reject it for others in core
> rtnetlink code.
Good point, it will be nice to error out with something meaningful if
bulk delete isn't supported. I'll look into it.

Thanks,
 Nik

Linux Ethernet Bridging - Apr 2022 - [Bridge] [PATCH net-next v3 4/8] net: bridge: fdb: add ndo_fdb_del_bulk

[Bridge] [PATCH net-next v3 0/8] net: bridge: add flush filtering support

[Bridge] [PATCH net-next v3 1/8] net: netlink: add NLM_F_BULK delete request modifier

[Bridge] [PATCH net-next v3 2/8] net: add ndo_fdb_del_bulk

[Bridge] [PATCH net-next v3 3/8] net: rtnetlink: add NLM_F_BULK support to rtnl_fdb_del

[Bridge] [PATCH net-next v3 4/8] net: bridge: fdb: add ndo_fdb_del_bulk

[Bridge] [PATCH net-next v3 5/8] net: bridge: fdb: add support for fine-grained flushing

[Bridge] [PATCH net-next v3 6/8] net: rtnetlink: add ndm flags and state mask attributes

[Bridge] [PATCH net-next v3 7/8] net: bridge: fdb: add support for flush filtering based on ndm flags and state

[Bridge] [PATCH net-next v3 8/8] net: bridge: fdb: add support for flush filtering based on ifindex and vlan

[Bridge] [PATCH net-next v3 0/8] net: bridge: add flush filtering support

[Bridge] [PATCH net-next v3 0/8] net: bridge: add flush filtering support

[Bridge] [PATCH net-next v3 0/8] net: bridge: add flush filtering support