Merge branch 'br-flush-filtering'

Nikolay Aleksandrov says:

====================
net: bridge: add flush filtering support

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. A new rtnl flag
(RTNL_FLAG_BULK_DEL_SUPPORTED) is used to show that the delete supports
NLM_F_BULK. A proper error is returned if bulk delete is not supported.
For old kernels 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 and 02 are minor rtnetlink cleanups to make the code easier to
read. They remove hardcoded values and use names instead. Patch 03 uses
BIT() for rtnl flags.
Patch 04 adds the new NLM_F_BULK delete request modifier, patch 05 adds
the new bulk delete flag and checks for it if the delete requests have
NLM_F_BULK set, it also warns if rtnl register is called with a non-delete
kind and the bulk delete flag is set.
Patch 06 adds the new ndo_fdb_del_bulk call. Patch 07 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 08 implements bridge-specific minimal ndo_fdb_del_bulk call which
uses the current br_fdb_flush to delete all entries. Patch 09 adds
filtering support to the new bridge flush op which supports target
ifindex (port or bridge), vlan id and flags/state mask. Patch 10 adds
ndm state and flags mask attributes which will be used for filtering.
Patch 11 converts ndm state/flags and their masks to bridge-private flags
and fills them in the filter descriptor for matching. Finally patch 12
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.

Example of calling PF_UNSPEC RTM_DELNEIGH which doesn't support bulk delete
with NLM_F_BULK set (ip neigh is changed to add the flag):
$ ip n del 192.168.122.5 lladdr 00:11:22:33:44:55 dev ens3
Error: Bulk delete is not supported.

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 bulk del infra and fdb flush filtering (this set)
 - iproute2 support
 - selftests

v4: Add and check for rtnl del bulk supported flag when using
    NLM_F_BULK (new patch 05), patches 01 - 03 are also new minor cleanups
    to remove use of raw values and make code easier to read, don't
    rename br_fdb_flush in patch 08, set port ifindex as flush target if
    NDA_IFINDEX is missing and flush was called with port netdev and
    NTF_MASTER (patch 12).

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
====================

Signed-off-by: David S. Miller <[email protected]>

Author: davem330

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,

include/net/rtnetlink.h

@@ -10,9 +10,23 @@ typedef int (*rtnl_doit_func)(struct sk_buff *, struct nlmsghdr *,
 typedef int (*rtnl_dumpit_func)(struct sk_buff *, struct netlink_callback *);
 
 enum rtnl_link_flags {
-	RTNL_FLAG_DOIT_UNLOCKED = 1,
+	RTNL_FLAG_DOIT_UNLOCKED		= BIT(0),
+	RTNL_FLAG_BULK_DEL_SUPPORTED	= BIT(1),
 };
 
+enum rtnl_kinds {
+	RTNL_KIND_NEW,
+	RTNL_KIND_DEL,
+	RTNL_KIND_GET,
+	RTNL_KIND_SET
+};
+#define RTNL_KIND_MASK 0x3
+
+static inline enum rtnl_kinds rtnl_msgtype_kind(int msgtype)
+{
+	return msgtype & RTNL_KIND_MASK;
+}
+
 void rtnl_register(int protocol, int msgtype,
 		   rtnl_doit_func, rtnl_dumpit_func, unsigned int flags);
 int rtnl_register_module(struct module *owner, int protocol, int msgtype,

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
 };
 

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 */

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,

net/bridge/br_fdb.c

@@ -558,18 +558,161 @@ 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();
+}
+
+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;
+}
+
+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 = { .vlan_id = vid };
+	struct net_bridge_port *p = NULL;
+	struct net_bridge *br;
+
+	if (netif_is_bridge_master(dev)) {
+		br = netdev_priv(dev);
+	} else {
+		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;
+	}
+
+	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);
+	}
+	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;
+	} else if (p) {
+		/* flush was invoked with port device and NTF_MASTER */
+		desc.port_ifindex = p->dev->ifindex;
+	}
+
+	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;
 }
 
 /* Flush all entries referring to a specific port.

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]) {

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)
@@ -755,11 +762,17 @@ 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);
 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,
 			      const unsigned char *addr, u16 vid);
@@ -781,6 +794,9 @@ 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);

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;
 }