[PATCH net-next v2 2/4] bonding/balance-lb: don't rewrite bridged non-local MACs
From: Jarod Wilson <hidden>
Date: 2021-05-21 13:28:38
Also in:
lkml
Subsystem:
bonding driver, networking drivers, the rest · Maintainers:
Jay Vosburgh, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
With a virtual machine behind a bridge that directly incorporates a balance-alb bond as one of its ports, outgoing traffic should retain the VM's source MAC. That works fine most of the time, until doing a failover, and then the MAC gets rewritten to the bond slave's MAC, and the return traffic gets dropped. If we don't rewrite the MAC there, we don't lose the traffic. Cc: Jay Vosburgh <redacted> Cc: Veaceslav Falico <redacted> Cc: Andy Gospodarek <andy@greyhouse.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Thomas Davis <redacted> Cc: netdev@vger.kernel.org Signed-off-by: Jarod Wilson <redacted> --- drivers/net/bonding/bond_alb.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-)
diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index 3455f2cc13f2..c57f62e43328 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c@@ -1302,6 +1302,23 @@ void bond_alb_deinitialize(struct bonding *bond) rlb_deinitialize(bond); } +static bool bond_alb_bridged_mac(struct bonding *bond, struct ethhdr *eth_data) +{ + if (BOND_MODE(bond) != BOND_MODE_ALB) + return false; + + /* Don't modify source MACs that do not originate locally + * (e.g.,arrive via a bridge). + */ + if (!netif_is_bridge_port(bond->dev)) + return false; + + if (bond_slave_has_mac_rx(bond, eth_data->h_source)) + return false; + + return true; +} + static netdev_tx_t bond_do_alb_xmit(struct sk_buff *skb, struct bonding *bond, struct slave *tx_slave) {
@@ -1316,7 +1333,8 @@ static netdev_tx_t bond_do_alb_xmit(struct sk_buff *skb, struct bonding *bond, } if (tx_slave && bond_slave_can_tx(tx_slave)) { - if (tx_slave != rcu_access_pointer(bond->curr_active_slave)) { + if (tx_slave != rcu_access_pointer(bond->curr_active_slave) && + !bond_alb_bridged_mac(bond, eth_data)) { ether_addr_copy(eth_data->h_source, tx_slave->dev->dev_addr); }
--
2.30.2