[PATCH 5.19 047/158] bonding: 802.3ad: fix no transmission of LACPDUs

Greg Kroah-Hartman
2022-08-29T11:27:41Z

From: Jonathan Toppins <jtoppins@redhat.com>

[ Upstream commit d745b5062ad2b5da90a5e728d7ca884fc07315fd ]

This is caused by the global variable ad_ticks_per_sec being zero as
demonstrated by the reproducer script discussed below. This causes
all timer values in __ad_timer_to_ticks to be zero, resulting
in the periodic timer to never fire.

To reproduce:
Run the script in
`tools/testing/selftests/drivers/net/bonding/bond-break-lacpdu-tx.sh` which
puts bonding into a state where it never transmits LACPDUs.

line 44: ip link add fbond type bond mode 4 miimon 200 \
xmit_hash_policy 1 ad_actor_sys_prio 65535 lacp_rate fast
setting bond param: ad_actor_sys_prio
given:
params.ad_actor_system = 0
call stack:
bond_option_ad_actor_sys_prio()
-> bond_3ad_update_ad_actor_settings()
-> set ad.system.sys_priority = bond->params.ad_actor_sys_prio
-> ad.system.sys_mac_addr = bond->dev->dev_addr; because
params.ad_actor_system == 0
results:
ad.system.sys_mac_addr = bond->dev->dev_addr

line 48: ip link set fbond address 52:54:00:3B:7C:A6
setting bond MAC addr
call stack:
bond->dev->dev_addr = new_mac

line 52: ip link set fbond type bond ad_actor_sys_prio 65535
setting bond param: ad_actor_sys_prio
given:
params.ad_actor_system = 0
call stack:
bond_option_ad_actor_sys_prio()
-> bond_3ad_update_ad_actor_settings()
-> set ad.system.sys_priority = bond->params.ad_actor_sys_prio
-> ad.system.sys_mac_addr = bond->dev->dev_addr; because
params.ad_actor_system == 0
results:
ad.system.sys_mac_addr = bond->dev->dev_addr

line 60: ip link set veth1-bond down master fbond
given:
params.ad_actor_system = 0
params.mode = BOND_MODE_8023AD
ad.system.sys_mac_addr == bond->dev->dev_addr
call stack:
bond_enslave
-> bond_3ad_initialize(); because first slave
-> if ad.system.sys_mac_addr != bond->dev->dev_addr
return
results:
Nothing is run in bond_3ad_initialize() because dev_addr equals
sys_mac_addr leaving the global ad_ticks_per_sec zero as it is
never initialized anywhere else.

The if check around the contents of bond_3ad_initialize() is no longer
needed due to commit 5ee14e6d336f ("bonding: 3ad: apply ad_actor settings
changes immediately") which sets ad.system.sys_mac_addr if any one of
the bonding parameters whos set function calls
bond_3ad_update_ad_actor_settings(). This is because if
ad.system.sys_mac_addr is zero it will be set to the current bond mac
address, this causes the if check to never be true.

Fixes: 5ee14e6d336f ("bonding: 3ad: apply ad_actor settings changes immediately")
Signed-off-by: Jonathan Toppins <jtoppins@redhat.com>
Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/bonding/bond_3ad.c | 38 ++++++++++++++--------------------
1 file changed, 16 insertions(+), 22 deletions(-)

diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c
index d7fb33c078e81..1f0120cbe9e80 100644
--- a/drivers/net/bonding/bond_3ad.c
+++ b/drivers/net/bonding/bond_3ad.c
@@ -2007,30 +2007,24 @@ void bond_3ad_initiate_agg_selection(struct bonding *bond, int timeout)
*/
void bond_3ad_initialize(struct bonding *bond, u16 tick_resolution)
{
- /* check that the bond is not initialized yet */
- if (!MAC_ADDRESS_EQUAL(&(BOND_AD_INFO(bond).system.sys_mac_addr),
- bond->dev->dev_addr)) {
-
- BOND_AD_INFO(bond).aggregator_identifier = 0;
-
- BOND_AD_INFO(bond).system.sys_priority =
- bond->params.ad_actor_sys_prio;
- if (is_zero_ether_addr(bond->params.ad_actor_system))
- BOND_AD_INFO(bond).system.sys_mac_addr =
- *((struct mac_addr *)bond->dev->dev_addr);
- else
- BOND_AD_INFO(bond).system.sys_mac_addr =
- *((struct mac_addr *)bond->params.ad_actor_system);
+ BOND_AD_INFO(bond).aggregator_identifier = 0;
+ BOND_AD_INFO(bond).system.sys_priority =
+ bond->params.ad_actor_sys_prio;
+ if (is_zero_ether_addr(bond->params.ad_actor_system))
+ BOND_AD_INFO(bond).system.sys_mac_addr =
+ *((struct mac_addr *)bond->dev->dev_addr);
+ else
+ BOND_AD_INFO(bond).system.sys_mac_addr =
+ *((struct mac_addr *)bond->params.ad_actor_system);

- /* initialize how many times this module is called in one
- * second (should be about every 100ms)
- */
- ad_ticks_per_sec = tick_resolution;
+ /* initialize how many times this module is called in one
+ * second (should be about every 100ms)
+ */
+ ad_ticks_per_sec = tick_resolution;

- bond_3ad_initiate_agg_selection(bond,
- AD_AGGREGATOR_SELECTION_TIMER *
- ad_ticks_per_sec);
- }
+ bond_3ad_initiate_agg_selection(bond,
+ AD_AGGREGATOR_SELECTION_TIMER *
+ ad_ticks_per_sec);
}

/**
--
2.35.1