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SubjectRe: [PATCH net-next v3] bond: add mac filter option for balance-xor
From
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@redhat.com>
> Signed-off-by: Long Xin <lxin@redhat.com>
> Signed-off-by: Jonathan Toppins <jtoppins@redhat.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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