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Date:   Sun, 15 May 2022 00:41:26 +0300
From:   Nikolay Aleksandrov <razor@...ckwall.org>
To:     Jonathan Toppins <jtoppins@...hat.com>, netdev@...r.kernel.org
Cc:     toke@...hat.com, Long Xin <lxin@...hat.com>,
        "David S. Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>,
        Jonathan Corbet <corbet@....net>,
        Jay Vosburgh <j.vosburgh@...il.com>,
        Veaceslav Falico <vfalico@...il.com>,
        Andy Gospodarek <andy@...yhouse.net>,
        linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH net-next v3] bond: add mac filter option for balance-xor

On 13/05/2022 20:43, Jonathan Toppins wrote:
> Implement a MAC filter that prevents duplicate frame delivery when
> handling BUM traffic. This attempts to partially replicate OvS SLB
> Bonding[1] like functionality without requiring significant change
> in the Linux bridging code.
> 
> A typical network setup for this feature would be:
> 
>             .--------------------------------------------.
>             |         .--------------------.             |
>             |         |                    |             |
>        .-------------------.               |             |
>        |    | Bond 0  |    |               |             |
>        | .--'---. .---'--. |               |             |
>   .----|-| eth0 |-| eth1 |-|----.    .-----+----.   .----+------.
>   |    | '------' '------' |    |    | Switch 1 |   | Switch 2  |
>   |    '---,---------------'    |    |          +---+           |
>   |       /                     |    '----+-----'   '----+------'
>   |  .---'---.    .------.      |         |              |
>   |  |  br0  |----| VM 1 |      |      ~~~~~~~~~~~~~~~~~~~~~
>   |  '-------'    '------'      |     (                     )
>   |      |        .------.      |     ( Rest of Network     )
>   |      '--------| VM # |      |     (_____________________)
>   |               '------'      |
>   |  Host 1                     |
>   '-----------------------------'
> 
> Where 'VM1' and 'VM#' are hosts connected to a Linux bridge, br0, with
> bond0 and its associated links, eth0 & eth1, provide ingress/egress. One
> can assume bond0, br1, and hosts VM1 to VM# are all contained in a
> single box, as depicted. Interfaces eth0 and eth1 provide redundant
> connections to the data center with the requirement to use all bandwidth
> when the system is functioning normally. Switch 1 and Switch 2 are
> physical switches that do not implement any advanced L2 management
> features such as MLAG, Cisco's VPC, or LACP.
> 
> Combining this feature with vlan+srcmac hash policy allows a user to
> create an access network without the need to use expensive switches that
> support features like Cisco's VCP.
> 
> [1] https://docs.openvswitch.org/en/latest/topics/bonding/#slb-bonding
> 
> Co-developed-by: Long Xin <lxin@...hat.com>
> Signed-off-by: Long Xin <lxin@...hat.com>
> Signed-off-by: Jonathan Toppins <jtoppins@...hat.com>
> ---
> 
> Notes:
>     v2:
>      * dropped needless abstraction functions and put code in module init
>      * renamed variable "rc" to "ret" to stay consistent with most of the
>        code
>      * fixed parameter setting management, when arp-monitor is turned on
>        this feature will be turned off similar to how miimon and arp-monitor
>        interact
>      * renamed bond_xor_recv to bond_mac_filter_recv for a little more
>        clarity
>      * it appears the implied default return code for any bonding recv probe
>        must be `RX_HANDLER_ANOTHER`. Changed the default return code of
>        bond_mac_filter_recv to use this return value to not break skb
>        processing when the skb dev is switched to the bond dev:
>          `skb->dev = bond->dev`
>     
>     v3: Nik's comments
>      * clarified documentation
>      * fixed inline and basic reverse Christmas tree formatting
>      * zero'ed entry in mac_create
>      * removed read_lock taking in bond_mac_filter_recv
>      * made has_expired() atomic and removed critical sections
>        surrounding calls to has_expired(), this also removed the
>        use-after-free that would have occurred:
>            spin_lock_irqsave(&entry->lock, flags);
>                if (has_expired(bond, entry))
>                    mac_delete(bond, entry);
>            spin_unlock_irqrestore(&entry->lock, flags); <---
>      * moved init/destroy of mac_filter_tbl to bond_open/bond_close
>        this removed the complex option dependencies, the only behavioural
>        change the user will see is if the bond is up and mac_filter is
>        enabled if they try and set arp_interval they will receive -EBUSY
>      * in bond_changelink moved processing of mac_filter option just below
>        mode processing
> 
>  Documentation/networking/bonding.rst  |  20 +++
>  drivers/net/bonding/Makefile          |   2 +-
>  drivers/net/bonding/bond_mac_filter.c | 201 ++++++++++++++++++++++++++
>  drivers/net/bonding/bond_mac_filter.h |  37 +++++
>  drivers/net/bonding/bond_main.c       |  30 ++++
>  drivers/net/bonding/bond_netlink.c    |  13 ++
>  drivers/net/bonding/bond_options.c    |  81 +++++++++--
>  drivers/net/bonding/bonding_priv.h    |   1 +
>  include/net/bond_options.h            |   1 +
>  include/net/bonding.h                 |   3 +
>  include/uapi/linux/if_link.h          |   1 +
>  11 files changed, 373 insertions(+), 17 deletions(-)
>  create mode 100644 drivers/net/bonding/bond_mac_filter.c
>  create mode 100644 drivers/net/bonding/bond_mac_filter.h
> 

Hi,
The old version of this patch is still under discussion here:
https://lore.kernel.org/netdev/d2696dab-2490-feb5-ccb2-96906fc652f0@redhat.com/

It is still my opinion this patch should not be applied. We can achieve the same with
about <100 lines of simple eBPF for a lot more kernel versions and it will be a lot more scalable
out of the box, too[1]. Also this solution adds a new test for *all* in the fast path, even if it's
not enabled. It uses a spinlock per mac, but most xor/3ad users have the same source mac for different
flows, which means they will hit the same lock on multiple CPUs. This is not scalable at all and I don't
think anyone would opt-in for it.

The eBPF solution which is very simple (as can be seen[1]), doesn't use any locking for the common cases
(the race is well undestood and not a problem), it comes with an easy way to dump the current entries,
it works on way more kernels, it doesn't affect the fast-path for everyone even if not loaded (no new test) and you
can improve it as needed in the future without any kernel maintainting cost.

This is really a straight-forward use case which fits perfectly.

The obvious pros are:
 - scales much better
 - you can dump the map with all entries (debugging)
 - you can affect the map (control)
 - no effect on fast-path if not enabled (additional test otherwise)
 - no long-term maintining cost for something that is irrelevant even now
 - any change (hold time, whatever variable) doesn't require kernel patches and new kernel versions to get in 
 - supports older kernels (you don't need net-next to get it out of the box)

I'm sure there are items I'm missing, but this is from the top of my head.

I have a few technical comments below for this version as well.

> diff --git a/Documentation/networking/bonding.rst b/Documentation/networking/bonding.rst
> index 43be3782e5df..c2992ab2e019 100644
> --- a/Documentation/networking/bonding.rst
> +++ b/Documentation/networking/bonding.rst
> @@ -550,6 +550,26 @@ lacp_rate
>  
>  	The default is slow.
>  
> +mac_filter
> +
> +	Tells the bonding device to drop frames received who's source MAC
> +	address	matches entries in a filter table. The filter table is
> +	populated when the bond transmits frames. This is similar in
> +	concept to the MAC learning table implemented in the bridge code.
> +
> +	This filtering is only enabled for the balance-xor bonding mode.
> +
> +	off or 0
> +		Turns the feature off
> +
> +	number
> +		A number greater than zero turns the feature on and sets
> +		the maximum number of MAC addresses to store in the hash
> +		table. This value is used as the exponent in a 2^N calculation
> +		to determine the actual size of the hashtable.
> +
> +	The default is off.
> +
>  max_bonds
>  
>  	Specifies the number of bonding devices to create for this
> diff --git a/drivers/net/bonding/Makefile b/drivers/net/bonding/Makefile
> index 30e8ae3da2da..5dbc360a8522 100644
> --- a/drivers/net/bonding/Makefile
> +++ b/drivers/net/bonding/Makefile
> @@ -5,7 +5,7 @@
>  
>  obj-$(CONFIG_BONDING) += bonding.o
>  
> -bonding-objs := bond_main.o bond_3ad.o bond_alb.o bond_sysfs.o bond_sysfs_slave.o bond_debugfs.o bond_netlink.o bond_options.o
> +bonding-objs := bond_main.o bond_3ad.o bond_alb.o bond_sysfs.o bond_sysfs_slave.o bond_debugfs.o bond_netlink.o bond_options.o bond_mac_filter.o
>  
>  proc-$(CONFIG_PROC_FS) += bond_procfs.o
>  bonding-objs += $(proc-y)
> diff --git a/drivers/net/bonding/bond_mac_filter.c b/drivers/net/bonding/bond_mac_filter.c
> new file mode 100644
> index 000000000000..0ab17edfe59a
> --- /dev/null
> +++ b/drivers/net/bonding/bond_mac_filter.c
> @@ -0,0 +1,201 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Filter received frames based on MAC addresses "behind" the bond.
> + */
> +
> +#include "bonding_priv.h"
> +
> +static const struct rhashtable_params bond_rht_params = {
> +	.head_offset         = offsetof(struct bond_mac_cache_entry, rhnode),
> +	.key_offset          = offsetof(struct bond_mac_cache_entry, key),
> +	.key_len             = sizeof(struct mac_addr),
> +	.automatic_shrinking = true,
> +};
> +
> +static unsigned long hold_time(const struct bonding *bond)
> +{
> +	return msecs_to_jiffies(5000);

What if anyone decides at some point 5 seconds are not enough or too much?

> +}
> +
> +static bool has_expired(const struct bonding *bond,
> +			struct bond_mac_cache_entry *mac)
> +{
> +	unsigned long flags;
> +	bool ret;
> +
> +	spin_lock_irqsave(&mac->lock, flags);
> +	ret = time_before_eq(mac->used + hold_time(bond), jiffies);
> +	spin_unlock_irqrestore(&mac->lock, flags);
> +
> +	return ret;
> +}
> +
> +static void mac_delete_rcu(struct callback_head *head)
> +{
> +	kmem_cache_free(bond_mac_cache,
> +			container_of(head, struct bond_mac_cache_entry, rcu));
> +}
> +
> +static int mac_delete(struct bonding *bond,
> +		      struct bond_mac_cache_entry *entry)
> +{
> +	int ret;
> +
> +	set_bit(BOND_MAC_DEAD, &entry->flags);
> +	ret = rhashtable_remove_fast(bond->mac_filter_tbl,
> +				     &entry->rhnode,
> +				     bond->mac_filter_tbl->p);
> +	call_rcu(&entry->rcu, mac_delete_rcu);
> +	return ret;
> +}
> +
> +void bond_mac_hash_release_entries(struct work_struct *work)
> +{
> +	struct bonding *bond = container_of(work, struct bonding,
> +				mac_work.work);
> +	struct bond_mac_cache_entry *entry;
> +	struct rhashtable_iter iter;
> +
> +	rhashtable_walk_enter(bond->mac_filter_tbl, &iter);
> +	rhashtable_walk_start(&iter);
> +	while ((entry = rhashtable_walk_next(&iter)) != NULL) {
> +		if (IS_ERR(entry))
> +			continue;
> +
> +		if (!test_bit(BOND_MAC_DEAD, &entry->flags) &&
> +		    has_expired(bond, entry))
> +			mac_delete(bond, entry);
> +	}
> +	rhashtable_walk_stop(&iter);
> +	rhashtable_walk_exit(&iter);
> +	queue_delayed_work(bond->wq, &bond->mac_work,
> +			   msecs_to_jiffies(5 * 60 * 1000));
> +}
> +
> +int bond_mac_hash_init(struct bonding *bond)
> +{
> +	int ret;
> +
> +	bond->mac_filter_tbl = kzalloc(sizeof(*bond->mac_filter_tbl),
> +				       GFP_KERNEL);
> +	if (!bond->mac_filter_tbl)
> +		return -ENOMEM;
> +
> +	ret = rhashtable_init(bond->mac_filter_tbl, &bond_rht_params);
> +	if (ret) {
> +		kfree(bond->mac_filter_tbl);
> +		bond->mac_filter_tbl = NULL;
> +	}
> +
> +	bond->mac_filter_tbl->p.max_size = 1 << bond->params.mac_filter;
> +	netdev_dbg(bond->dev, "mac_filter hash table size: %d\n",
> +		   bond->mac_filter_tbl->p.max_size);
> +	return ret;
> +}
> +
> +static void bond_mac_free_entry(void *entry, void *ctx)
> +{
> +	kmem_cache_free((struct kmem_cache *)ctx, entry);
> +}
> +
> +void bond_mac_hash_destroy(struct bonding *bond)
> +{
> +	if (bond->mac_filter_tbl) {
> +		rhashtable_free_and_destroy(bond->mac_filter_tbl,
> +					    bond_mac_free_entry,
> +					    bond_mac_cache);
> +		kfree(bond->mac_filter_tbl);
> +		bond->mac_filter_tbl = NULL;
> +	}
> +}
> +
> +static int mac_create(struct bonding *bond, const u8 *addr)
> +{
> +	struct bond_mac_cache_entry *entry;
> +	int ret;
> +
> +	entry = kmem_cache_alloc(bond_mac_cache, GFP_ATOMIC);
> +	if (!entry)
> +		return -ENOMEM;
> +
> +	memset(entry, 0, sizeof(*entry));
> +	spin_lock_init(&entry->lock);
> +	memcpy(&entry->key, addr, sizeof(entry->key));
> +	entry->used = jiffies;
> +	ret = rhashtable_lookup_insert_fast(bond->mac_filter_tbl,
> +					    &entry->rhnode,
> +					    bond->mac_filter_tbl->p);
> +	if (ret) {
> +		kmem_cache_free(bond_mac_cache, entry);
> +		if (ret == -EEXIST)
> +			return 0;
> +		netdev_dbg(bond->dev, "Failed to insert mac entry %d\n", ret);
> +	}
> +	return ret;
> +}
> +
> +static struct bond_mac_cache_entry *mac_find(struct bonding *bond,
> +					     const u8 *addr)
> +{
> +	struct mac_addr key;
> +
> +	memcpy(&key, addr, sizeof(key));
> +	return rhashtable_lookup(bond->mac_filter_tbl, &key,
> +				 bond->mac_filter_tbl->p);
> +}
> +
> +static void mac_update(struct bond_mac_cache_entry *entry)
> +{
> +	entry->used = jiffies;
> +}
> +
> +int bond_mac_insert(struct bonding *bond, const u8 *addr)
> +{
> +	struct bond_mac_cache_entry *entry;
> +	int ret = 0;
> +
> +	if (!is_valid_ether_addr(addr))
> +		return -EINVAL;
> +
> +	rcu_read_lock();

This is always called with rcu already held, this is unnecessary.

> +	entry = mac_find(bond, addr);
> +	if (entry) {
> +		unsigned long flags;
> +
> +		spin_lock_irqsave(&entry->lock, flags);
> +		if (!test_bit(BOND_MAC_DEAD, &entry->flags)) {
> +			mac_update(entry);
> +			spin_unlock_irqrestore(&entry->lock, flags);
> +			goto out;
> +		}
> +		spin_unlock_irqrestore(&entry->lock, flags);
> +	}
> +
> +	ret = mac_create(bond, addr);
> +
> +out:
> +	rcu_read_unlock();
> +	return ret;
> +}
> +
> +int bond_mac_filter_recv(const struct sk_buff *skb, struct bonding *bond,
> +			 struct slave *slave)
> +{
> +	struct bond_mac_cache_entry *entry;
> +	const struct ethhdr *mac_hdr;
> +	int ret = RX_HANDLER_ANOTHER;
> +
> +	mac_hdr = (struct ethhdr *)skb_mac_header(skb);
> +	if (is_multicast_ether_addr(mac_hdr->h_dest) &&
> +	    slave != rcu_dereference(bond->curr_active_slave)) {
> +		ret = RX_HANDLER_CONSUMED;
> +		goto out;
> +	}
> +
> +	entry = mac_find(bond, mac_hdr->h_source);
> +	if (entry && !has_expired(bond, entry))> +		ret = RX_HANDLER_CONSUMED;
> +
> +out:
> +	return ret;
> +}
> diff --git a/drivers/net/bonding/bond_mac_filter.h b/drivers/net/bonding/bond_mac_filter.h
> new file mode 100644
> index 000000000000..1d4dfc1d6396
> --- /dev/null
> +++ b/drivers/net/bonding/bond_mac_filter.h
> @@ -0,0 +1,37 @@
> +/* SPDX-License-Identifier: GPL-2.0-only
> + *
> + * Filter received frames based on MAC addresses "behind" the bond.
> + */
> +
> +#ifndef _BOND_MAC_FILTER_H
> +#define _BOND_MAC_FILTER_H
> +#include <net/bonding.h>
> +#include <linux/spinlock.h>
> +#include <linux/rhashtable.h>
> +
> +enum {
> +	BOND_MAC_DEAD,
> +};

This bit is pointless, you still have races even though not critical.

> +
> +struct bond_mac_cache_entry {
> +	struct rhash_head	rhnode;
> +	struct mac_addr		key;
> +
> +	spinlock_t		lock; /* protects used member */
> +	unsigned long		flags;
> +	unsigned long		used;
> +	struct rcu_head		rcu;
> +};
> +
> +extern struct kmem_cache *bond_mac_cache;
> +
> +void bond_mac_hash_release_entries(struct work_struct *work);
> +int bond_mac_hash_init(struct bonding *bond);
> +void bond_mac_hash_destroy(struct bonding *bond);
> +
> +int bond_mac_insert(struct bonding *bond, const u8 *addr);
> +int bond_mac_filter_recv(const struct sk_buff *skb,
> +			 struct bonding *bond,
> +			 struct slave *slave);
> +
> +#endif
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index f245e439f44c..723d19b4f10b 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -207,6 +207,7 @@ MODULE_PARM_DESC(lp_interval, "The number of seconds between instances where "
>  atomic_t netpoll_block_tx = ATOMIC_INIT(0);
>  #endif
>  
> +struct kmem_cache *bond_mac_cache __read_mostly;
>  unsigned int bond_net_id __read_mostly;
>  
>  static const struct flow_dissector_key flow_keys_bonding_keys[] = {
> @@ -4122,6 +4123,7 @@ void bond_work_init_all(struct bonding *bond)
>  	INIT_DELAYED_WORK(&bond->arp_work, bond_arp_monitor);
>  	INIT_DELAYED_WORK(&bond->ad_work, bond_3ad_state_machine_handler);
>  	INIT_DELAYED_WORK(&bond->slave_arr_work, bond_slave_arr_handler);
> +	INIT_DELAYED_WORK(&bond->mac_work, bond_mac_hash_release_entries);
>  }
>  
>  static void bond_work_cancel_all(struct bonding *bond)
> @@ -4132,6 +4134,7 @@ static void bond_work_cancel_all(struct bonding *bond)
>  	cancel_delayed_work_sync(&bond->ad_work);
>  	cancel_delayed_work_sync(&bond->mcast_work);
>  	cancel_delayed_work_sync(&bond->slave_arr_work);
> +	cancel_delayed_work_sync(&bond->mac_work);
>  }
>  
>  static int bond_open(struct net_device *bond_dev)
> @@ -4179,6 +4182,15 @@ static int bond_open(struct net_device *bond_dev)
>  		bond_3ad_initiate_agg_selection(bond, 1);
>  	}
>  
> +	if (BOND_MODE(bond) == BOND_MODE_XOR && bond->params.mac_filter) {
> +		int ret = bond_mac_hash_init(bond);
> +
> +		if (ret)
> +			return ret;
> +		bond->recv_probe = bond_mac_filter_recv;
> +		queue_delayed_work(bond->wq, &bond->mac_work, 0);
> +	}
> +
>  	if (bond_mode_can_use_xmit_hash(bond))
>  		bond_update_slave_arr(bond, NULL);
>  
> @@ -4194,6 +4206,7 @@ static int bond_close(struct net_device *bond_dev)
>  	if (bond_is_lb(bond))
>  		bond_alb_deinitialize(bond);
>  	bond->recv_probe = NULL;
> +	bond_mac_hash_destroy(bond);
>  
>  	return 0;
>  }
> @@ -5048,6 +5061,13 @@ static struct slave *bond_xmit_3ad_xor_slave_get(struct bonding *bond,
>  	if (unlikely(!count))
>  		return NULL;
>  
> +	if (BOND_MODE(bond) == BOND_MODE_XOR && bond->params.mac_filter) {
> +		const struct ethhdr *mac_hdr;
> +
> +		mac_hdr = (struct ethhdr *)skb_mac_header(skb);
> +		if (bond_mac_insert(bond, mac_hdr->h_source))

This is not scalable at all, you get the lock even to update the expire
on *every* packet, most users go for L3 or L3+L4 and will hit this with different
flows on different CPUs.

> +			return NULL;
> +	}
>  	slave = slaves->arr[hash % count];
>  	return slave;
>  }
> @@ -6120,6 +6140,7 @@ static int bond_check_params(struct bond_params *params)
>  	params->downdelay = downdelay;
>  	params->peer_notif_delay = 0;
>  	params->use_carrier = use_carrier;
> +	params->mac_filter = 0;
>  	params->lacp_active = 1;
>  	params->lacp_fast = lacp_fast;
>  	params->primary[0] = 0;
> @@ -6322,6 +6343,14 @@ static int __init bonding_init(void)
>  			goto err;
>  	}
>  
> +	bond_mac_cache = kmem_cache_create("bond_mac_cache",
> +					   sizeof(struct bond_mac_cache_entry),
> +					   0, SLAB_HWCACHE_ALIGN, NULL);
> +	if (!bond_mac_cache) {
> +		res = -ENOMEM;
> +		goto err;
> +	}
> +
>  	skb_flow_dissector_init(&flow_keys_bonding,
>  				flow_keys_bonding_keys,
>  				ARRAY_SIZE(flow_keys_bonding_keys));
> @@ -6351,6 +6380,7 @@ static void __exit bonding_exit(void)
>  	/* Make sure we don't have an imbalance on our netpoll blocking */
>  	WARN_ON(atomic_read(&netpoll_block_tx));
>  #endif
> +	kmem_cache_destroy(bond_mac_cache);
>  }
>  
>  module_init(bonding_init);
> diff --git a/drivers/net/bonding/bond_netlink.c b/drivers/net/bonding/bond_netlink.c
> index f427fa1737c7..1593dc6aca12 100644
> --- a/drivers/net/bonding/bond_netlink.c
> +++ b/drivers/net/bonding/bond_netlink.c
> @@ -113,6 +113,7 @@ static const struct nla_policy bond_policy[IFLA_BOND_MAX + 1] = {
>  	[IFLA_BOND_PEER_NOTIF_DELAY]    = { .type = NLA_U32 },
>  	[IFLA_BOND_MISSED_MAX]		= { .type = NLA_U8 },
>  	[IFLA_BOND_NS_IP6_TARGET]	= { .type = NLA_NESTED },
> +	[IFLA_BOND_MAC_FILTER]		= { .type = NLA_U8 },
>  };
>  
>  static const struct nla_policy bond_slave_policy[IFLA_BOND_SLAVE_MAX + 1] = {
> @@ -179,6 +180,14 @@ static int bond_changelink(struct net_device *bond_dev, struct nlattr *tb[],
>  		if (err)
>  			return err;
>  	}
> +	if (data[IFLA_BOND_MAC_FILTER]) {
> +		u8 mac_filter = nla_get_u8(data[IFLA_BOND_MAC_FILTER]);
> +
> +		bond_opt_initval(&newval, mac_filter);
> +		err = __bond_opt_set(bond, BOND_OPT_MAC_FILTER, &newval);
> +		if (err)
> +			return err;
> +	}
>  	if (data[IFLA_BOND_ACTIVE_SLAVE]) {
>  		int ifindex = nla_get_u32(data[IFLA_BOND_ACTIVE_SLAVE]);
>  		struct net_device *slave_dev;
> @@ -565,6 +574,7 @@ static size_t bond_get_size(const struct net_device *bond_dev)
>  						/* IFLA_BOND_NS_IP6_TARGET */
>  		nla_total_size(sizeof(struct nlattr)) +
>  		nla_total_size(sizeof(struct in6_addr)) * BOND_MAX_NS_TARGETS +
> +		nla_total_size(sizeof(u8)) +	/* IFLA_BOND_MAC_FILTER */
>  		0;
>  }
>  
> @@ -723,6 +733,9 @@ static int bond_fill_info(struct sk_buff *skb,
>  	if (nla_put_u8(skb, IFLA_BOND_MISSED_MAX,
>  		       bond->params.missed_max))
>  		goto nla_put_failure;
> +	if (nla_put_u8(skb, IFLA_BOND_MAC_FILTER,
> +		       bond->params.mac_filter))
> +		goto nla_put_failure;
>  
>  	if (BOND_MODE(bond) == BOND_MODE_8023AD) {
>  		struct ad_info info;
> diff --git a/drivers/net/bonding/bond_options.c b/drivers/net/bonding/bond_options.c
> index 64f7db2627ce..4fcce09b1780 100644
> --- a/drivers/net/bonding/bond_options.c
> +++ b/drivers/net/bonding/bond_options.c
> @@ -15,6 +15,7 @@
>  #include <linux/sched/signal.h>
>  
>  #include <net/bonding.h>
> +#include "bonding_priv.h"
>  
>  static int bond_option_active_slave_set(struct bonding *bond,
>  					const struct bond_opt_value *newval);
> @@ -84,7 +85,8 @@ static int bond_option_ad_user_port_key_set(struct bonding *bond,
>  					    const struct bond_opt_value *newval);
>  static int bond_option_missed_max_set(struct bonding *bond,
>  				      const struct bond_opt_value *newval);
> -
> +static int bond_option_mac_filter_set(struct bonding *bond,
> +				      const struct bond_opt_value *newval);
>  
>  static const struct bond_opt_value bond_mode_tbl[] = {
>  	{ "balance-rr",    BOND_MODE_ROUNDROBIN,   BOND_VALFLAG_DEFAULT},
> @@ -226,6 +228,12 @@ static const struct bond_opt_value bond_missed_max_tbl[] = {
>  	{ NULL,		-1,	0},
>  };
>  
> +static const struct bond_opt_value bond_mac_filter_tbl[] = {
> +	{ "off",	0,	BOND_VALFLAG_MIN | BOND_VALFLAG_DEFAULT},
> +	{ "maxval",	18,	BOND_VALFLAG_MAX},
> +	{ NULL,		-1,	0}
> +};
> +
>  static const struct bond_option bond_opts[BOND_OPT_LAST] = {
>  	[BOND_OPT_MODE] = {
>  		.id = BOND_OPT_MODE,
> @@ -482,7 +490,16 @@ static const struct bond_option bond_opts[BOND_OPT_LAST] = {
>  		.desc = "Delay between each peer notification on failover event, in milliseconds",
>  		.values = bond_intmax_tbl,
>  		.set = bond_option_peer_notif_delay_set
> -	}
> +	},
> +	[BOND_OPT_MAC_FILTER] = {
> +		.id = BOND_OPT_MAC_FILTER,
> +		.name = "mac_filter",
> +		.unsuppmodes = BOND_MODE_ALL_EX(BIT(BOND_MODE_XOR)),
> +		.desc = "filter received frames based on MAC addresses that have transmitted from the bond, number of MAC addresses to track",
> +		.flags = BOND_OPTFLAG_IFDOWN,
> +		.values = bond_mac_filter_tbl,
> +		.set = bond_option_mac_filter_set
> +	},
>  };
>  
>  /* Searches for an option by name */
> @@ -829,25 +846,38 @@ static bool bond_set_tls_features(struct bonding *bond)
>  	return true;
>  }
>  
> +static void disable_arp_enable_mii(struct bonding *bond, const char *feature,
> +				   const char *suffix)
> +{
> +	if (bond->params.arp_interval) {
> +		netdev_dbg(bond->dev, "%s%s is incompatible with arp monitoring, start mii monitoring\n",
> +			   feature, suffix);
> +		/* disable arp monitoring */
> +		bond->params.arp_interval = 0;
> +	}
> +
> +	if (!bond->params.miimon) {
> +		/* set miimon to default value */
> +		bond->params.miimon = BOND_DEFAULT_MIIMON;
> +		netdev_dbg(bond->dev, "Setting MII monitoring interval to %d\n",
> +			   bond->params.miimon);
> +	}
> +}
> +
>  static int bond_option_mode_set(struct bonding *bond,
>  				const struct bond_opt_value *newval)
>  {
> -	if (!bond_mode_uses_arp(newval->value)) {
> -		if (bond->params.arp_interval) {
> -			netdev_dbg(bond->dev, "%s mode is incompatible with arp monitoring, start mii monitoring\n",
> -				   newval->string);
> -			/* disable arp monitoring */
> -			bond->params.arp_interval = 0;
> -		}
> -
> -		if (!bond->params.miimon) {
> -			/* set miimon to default value */
> -			bond->params.miimon = BOND_DEFAULT_MIIMON;
> -			netdev_dbg(bond->dev, "Setting MII monitoring interval to %d\n",
> -				   bond->params.miimon);
> -		}
> +	if (bond->params.mac_filter && newval->value != BOND_MODE_XOR) {
> +		netdev_dbg(bond->dev, "%s mode is incompatible with mac filtering, disabling\n",
> +			   newval->string);
> +		bond->params.mac_filter = 0;
>  	}
>  
> +	if (!bond_mode_uses_arp(newval->value))
> +		disable_arp_enable_mii(bond, newval->string, " mode");
> +	else if (bond->params.mac_filter && bond->params.arp_interval)
> +		disable_arp_enable_mii(bond, "MAC filtering", "");
> +
>  	if (newval->value == BOND_MODE_ALB)
>  		bond->params.tlb_dynamic_lb = 1;
>  
> @@ -1035,6 +1065,17 @@ static int bond_option_use_carrier_set(struct bonding *bond,
>  	return 0;
>  }
>  
> +static int bond_option_mac_filter_set(struct bonding *bond,
> +				      const struct bond_opt_value *newval)
> +{
> +	if (newval->value && bond->params.arp_interval)
> +		disable_arp_enable_mii(bond, "MAC filtering", "");
> +
> +	netdev_dbg(bond->dev, "Setting mac_filter to %llu\n", newval->value);
> +	bond->params.mac_filter = newval->value;
> +	return 0;
> +}
> +
>  /* There are two tricky bits here.  First, if ARP monitoring is activated, then
>   * we must disable MII monitoring.  Second, if the ARP timer isn't running,
>   * we must start it.
> @@ -1042,6 +1083,14 @@ static int bond_option_use_carrier_set(struct bonding *bond,
>  static int bond_option_arp_interval_set(struct bonding *bond,
>  					const struct bond_opt_value *newval)
>  {
> +	if (newval->value && bond->params.mac_filter) {
> +		if (bond->dev->flags & IFF_UP)
> +			return -EBUSY;
> +
> +		netdev_dbg(bond->dev, "MAC filtering cannot be used with ARP monitoring. Disabling MAC filtering\n");
> +		bond->params.mac_filter = 0;
> +	}
> +
>  	netdev_dbg(bond->dev, "Setting ARP monitoring interval to %llu\n",
>  		   newval->value);
>  	bond->params.arp_interval = newval->value;
> diff --git a/drivers/net/bonding/bonding_priv.h b/drivers/net/bonding/bonding_priv.h
> index 48cdf3a49a7d..0299f8bcb5fd 100644
> --- a/drivers/net/bonding/bonding_priv.h
> +++ b/drivers/net/bonding/bonding_priv.h
> @@ -15,6 +15,7 @@
>  #ifndef _BONDING_PRIV_H
>  #define _BONDING_PRIV_H
>  #include <generated/utsrelease.h>
> +#include "bond_mac_filter.h"
>  
>  #define DRV_NAME	"bonding"
>  #define DRV_DESCRIPTION	"Ethernet Channel Bonding Driver"
> diff --git a/include/net/bond_options.h b/include/net/bond_options.h
> index 61b49063791c..42e3e676b9c2 100644
> --- a/include/net/bond_options.h
> +++ b/include/net/bond_options.h
> @@ -67,6 +67,7 @@ enum {
>  	BOND_OPT_LACP_ACTIVE,
>  	BOND_OPT_MISSED_MAX,
>  	BOND_OPT_NS_TARGETS,
> +	BOND_OPT_MAC_FILTER,
>  	BOND_OPT_LAST
>  };
>  
> diff --git a/include/net/bonding.h b/include/net/bonding.h
> index b14f4c0b4e9e..5bc3e7b5a2af 100644
> --- a/include/net/bonding.h
> +++ b/include/net/bonding.h
> @@ -125,6 +125,7 @@ struct bond_params {
>  	int miimon;
>  	u8 num_peer_notif;
>  	u8 missed_max;
> +	u8 mac_filter;
>  	int arp_interval;
>  	int arp_validate;
>  	int arp_all_targets;
> @@ -248,6 +249,7 @@ struct bonding {
>  	struct   delayed_work alb_work;
>  	struct   delayed_work ad_work;
>  	struct   delayed_work mcast_work;
> +	struct   delayed_work mac_work;
>  	struct   delayed_work slave_arr_work;
>  #ifdef CONFIG_DEBUG_FS
>  	/* debugging support via debugfs */
> @@ -260,6 +262,7 @@ struct bonding {
>  	spinlock_t ipsec_lock;
>  #endif /* CONFIG_XFRM_OFFLOAD */
>  	struct bpf_prog *xdp_prog;
> +	struct rhashtable *mac_filter_tbl;
>  };
>  
>  #define bond_slave_get_rcu(dev) \
> diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
> index d1e600816b82..55e54d54f358 100644
> --- a/include/uapi/linux/if_link.h
> +++ b/include/uapi/linux/if_link.h
> @@ -934,6 +934,7 @@ enum {
>  	IFLA_BOND_AD_LACP_ACTIVE,
>  	IFLA_BOND_MISSED_MAX,
>  	IFLA_BOND_NS_IP6_TARGET,
> +	IFLA_BOND_MAC_FILTER,
>  	__IFLA_BOND_MAX,
>  };
>  

[1] Very simple wrote it in a few minutes, probably can be done better.

#define NSEC_PER_SEC    (1000ULL * 1000ULL * 1000UL)

#define READ_ONCE(X)         (*(volatile typeof(X) *)&X)
#define WRITE_ONCE(X, V)     (*(volatile typeof(X) *)&X) = (V)

#define TC_ACT_OK       0
#define TC_ACT_SHOT     2

union mac_key {
        __u8            mac[ETH_ALEN];
        unsigned long   key;
};

struct mac_info {
        __u64           last;
};

struct {
        __uint(type, BPF_MAP_TYPE_HASH);
        __type(key, union mac_key);
        __type(value, struct mac_info);
        __uint(pinning, LIBBPF_PIN_BY_NAME);
        __uint(max_entries, 65536);
        __uint(map_flags, BPF_F_NO_PREALLOC);
} MAC_MAP __attribute__((section(".maps"), used));

static __always_inline struct mac_info *mac_find(struct __sk_buff *ctx)
{
        union mac_key key;

        key.key = 0;
        if (bpf_skb_load_bytes(ctx, ETH_ALEN, key.mac, ETH_ALEN) < 0)
                return NULL;

        return bpf_map_lookup_elem(&MAC_MAP, &key);
}

static __always_inline void mac_update(struct __sk_buff *ctx)
{
        __u64 now = bpf_ktime_get_ns();
        struct mac_info *mac_info;

        mac_info = mac_find(ctx);
        if (!mac_info) {
                struct mac_info _info = {};
                union mac_key key;

                key.key = 0;
                if (bpf_skb_load_bytes(ctx, ETH_ALEN, key.mac, ETH_ALEN) < 0)
                        return;
                _info.last = now;
                bpf_map_update_elem(&MAC_MAP, &key, &_info, 0);
                return;
        }
        WRITE_ONCE(mac_info->last, now);
}

__attribute__((section("egress"), used))
int tc_egress(struct __sk_buff *skb)
{
        mac_update(skb);
        return TC_ACT_OK;
}

__attribute__((section("ingress"), used))
int tc_ingress(struct __sk_buff *skb)
{
        struct mac_info *mac_info;

        mac_info = mac_find(ctx);
        if (mac_info && mac_info->last + 5 * NSEC_PER_SEC >= bpf_ktime_get_ns())
                return TC_ACT_SHOT;
        return TC_ACT_OK;
}

char __license[] __attribute__((section("license"), used)) = "GPL";

----
here obviously you load egress on egress, and ingress on ingress

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