[PATCHv2 net-next] bonding: report duplicate MAC address in all situations

[PATCHv2 net-next] bonding: report duplicate MAC address in all situations

[Hangbin Liu]

Normally, a bond uses the MAC address of the first added slave as the bond’s
MAC address. And the bond will set active slave’s MAC address to bond’s
address if fail_over_mac is set to none (0) or follow (2).

When the first slave is removed, the bond will still use the removed slave’s
MAC address, which can lead to a duplicate MAC address and potentially cause
issues with the switch. To avoid confusion, let's warn the user in all
situations, including when fail_over_mac is set to 2 or not in active-backup
mode.

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
---

v2: add fail_over_mac != BOND_FOM_ACTIVE to condition (Jakub Kicinski)

---
 drivers/net/bonding/bond_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 7d716e90a84c..7d98fee5a27f 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2548,7 +2548,7 @@ static int __bond_release_one(struct net_device *bond_dev,
 
 	RCU_INIT_POINTER(bond->current_arp_slave, NULL);
 
-	if (!all && (!bond->params.fail_over_mac ||
+	if (!all && (bond->params.fail_over_mac != BOND_FOM_ACTIVE ||
 		     BOND_MODE(bond) != BOND_MODE_ACTIVEBACKUP)) {
 		if (ether_addr_equal_64bits(bond_dev->dev_addr, slave->perm_hwaddr) &&
 		    bond_has_slaves(bond))
-- 
2.46.0

Re: [PATCHv2 net-next] bonding: report duplicate MAC address in all situations

[Nikolay Aleksandrov]

On 2/25/25 05:39, Hangbin Liu wrote:
> Normally, a bond uses the MAC address of the first added slave as the bond’s
> MAC address. And the bond will set active slave’s MAC address to bond’s
> address if fail_over_mac is set to none (0) or follow (2).
> 
> When the first slave is removed, the bond will still use the removed slave’s
> MAC address, which can lead to a duplicate MAC address and potentially cause
> issues with the switch. To avoid confusion, let's warn the user in all
> situations, including when fail_over_mac is set to 2 or not in active-backup
> mode.
> 
> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
> ---
> 
> v2: add fail_over_mac != BOND_FOM_ACTIVE to condition (Jakub Kicinski)
> 
> ---
>  drivers/net/bonding/bond_main.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index 7d716e90a84c..7d98fee5a27f 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -2548,7 +2548,7 @@ static int __bond_release_one(struct net_device *bond_dev,
>  
>  	RCU_INIT_POINTER(bond->current_arp_slave, NULL);
>  
> -	if (!all && (!bond->params.fail_over_mac ||
> +	if (!all && (bond->params.fail_over_mac != BOND_FOM_ACTIVE ||
>  		     BOND_MODE(bond) != BOND_MODE_ACTIVEBACKUP)) {
>  		if (ether_addr_equal_64bits(bond_dev->dev_addr, slave->perm_hwaddr) &&
>  		    bond_has_slaves(bond))

LGTM,
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>

Re: [PATCHv2 net-next] bonding: report duplicate MAC address in all situations

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Tue, 25 Feb 2025 03:39:14 +0000 you wrote:
> Normally, a bond uses the MAC address of the first added slave as the bond’s
> MAC address. And the bond will set active slave’s MAC address to bond’s
> address if fail_over_mac is set to none (0) or follow (2).
> 
> When the first slave is removed, the bond will still use the removed slave’s
> MAC address, which can lead to a duplicate MAC address and potentially cause
> issues with the switch. To avoid confusion, let's warn the user in all
> situations, including when fail_over_mac is set to 2 or not in active-backup
> mode.
> 
> [...]

Here is the summary with links:
  - [PATCHv2,net-next] bonding: report duplicate MAC address in all situations
    https://git.kernel.org/netdev/net-next/c/28d68d396a1c

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html