[PATCH v5 net-next 0/6] Extend locked port feature with FDB locked flag (MAC-Auth/MAB)

Hans Schultz
2022-08-26T12:26:30Z

This patch set extends the locked port feature for devices
that are behind a locked port, but do not have the ability to
authorize themselves as a supplicant using IEEE 802.1X.
Such devices can be printers, meters or anything related to
fixed installations. Instead of 802.1X authorization, devices
can get access based on their MAC addresses being whitelisted.

For an authorization daemon to detect that a device is trying
to get access through a locked port, the bridge will add the
MAC address of the device to the FDB with a locked flag to it.
Thus the authorization daemon can catch the FDB add event and
check if the MAC address is in the whitelist and if so replace
the FDB entry without the locked flag enabled, and thus open
the port for the device.

This feature is known as MAC-Auth or MAC Authentication Bypass
(MAB) in Cisco terminology, where the full MAB concept involves
additional Cisco infrastructure for authorization. There is no
real authentication process, as the MAC address of the device
is the only input the authorization daemon, in the general
case, has to base the decision if to unlock the port or not.

With this patch set, an implementation of the offloaded case is
supplied for the mv88e6xxx driver. When a packet ingresses on
a locked port, an ATU miss violation event will occur. When
handling such ATU miss violation interrupts, the MAC address of
the device is added to the FDB with a zero destination port
vector (DPV) and the MAC address is communicated through the
switchdev layer to the bridge, so that a FDB entry with the
locked flag enabled can be added.

Log:
v3: Added timers and lists in the driver (mv88e6xxx)
to keep track of and remove locked entries.

v4: Leave out enforcing a limit to the number of
locked entries in the bridge.
Removed the timers in the driver and use the
worker only. Add locked FDB flag to all drivers
using port_fdb_add() from the dsa api and let
all drivers ignore entries with this flag set.
Change how to get the ageing timeout of locked
entries. See global1_atu.c and switchdev.c.
Use struct mv88e6xxx_port for locked entries
variables instead of struct dsa_port.

v5: Added 'mab' flag to enable MAB/MacAuth feature,
in a similar way to the locked feature flag.

In these implementations for the mv88e6xxx, the
switchport must be configured with learning on.

To tell userspace about the behavior of the
locked entries in the driver, a 'blackhole'
FDB flag has been added, which locked FDB
entries coming from the driver gets. Also the
'sticky' flag comes with those locked entries,
as the drivers locked entries cannot roam.

Fixed issues with taking mutex locks, and added
a function to read the fid, that supports all
versions of the chipset family.

Hans Schultz (6):
net: bridge: add locked entry fdb flag to extend locked port feature
net: switchdev: add support for offloading of fdb locked flag
drivers: net: dsa: add locked fdb entry flag to drivers
net: dsa: mv88e6xxx: allow reading FID when handling ATU violations
net: dsa: mv88e6xxx: MacAuth/MAB implementation
selftests: forwarding: add test of MAC-Auth Bypass to locked port
tests

drivers/net/dsa/b53/b53_common.c | 5 +
drivers/net/dsa/b53/b53_priv.h | 1 +
drivers/net/dsa/hirschmann/hellcreek.c | 5 +
drivers/net/dsa/lan9303-core.c | 5 +
drivers/net/dsa/lantiq_gswip.c | 5 +
drivers/net/dsa/microchip/ksz_common.c | 5 +
drivers/net/dsa/mt7530.c | 5 +
drivers/net/dsa/mv88e6xxx/Makefile | 1 +
drivers/net/dsa/mv88e6xxx/chip.c | 81 ++++-
drivers/net/dsa/mv88e6xxx/chip.h | 19 ++
drivers/net/dsa/mv88e6xxx/global1.h | 1 +
drivers/net/dsa/mv88e6xxx/global1_atu.c | 76 ++++-
drivers/net/dsa/mv88e6xxx/port.c | 15 +-
drivers/net/dsa/mv88e6xxx/port.h | 6 +
drivers/net/dsa/mv88e6xxx/switchdev.c | 285 ++++++++++++++++++
drivers/net/dsa/mv88e6xxx/switchdev.h | 37 +++
drivers/net/dsa/ocelot/felix.c | 5 +
drivers/net/dsa/qca/qca8k-common.c | 5 +
drivers/net/dsa/qca/qca8k.h | 1 +
drivers/net/dsa/sja1105/sja1105_main.c | 7 +-
include/linux/if_bridge.h | 1 +
include/net/dsa.h | 1 +
include/net/switchdev.h | 3 +
include/uapi/linux/if_link.h | 1 +
include/uapi/linux/neighbour.h | 4 +-
net/bridge/br.c | 5 +-
net/bridge/br_fdb.c | 43 ++-
net/bridge/br_input.c | 16 +-
net/bridge/br_netlink.c | 9 +-
net/bridge/br_private.h | 7 +-
net/bridge/br_switchdev.c | 5 +-
net/dsa/dsa_priv.h | 4 +-
net/dsa/port.c | 7 +-
net/dsa/slave.c | 4 +-
net/dsa/switch.c | 10 +-
.../net/forwarding/bridge_locked_port.sh | 107 ++++++-
.../net/forwarding/bridge_sticky_fdb.sh | 21 +-
37 files changed, 768 insertions(+), 50 deletions(-)
create mode 100644 drivers/net/dsa/mv88e6xxx/switchdev.c
create mode 100644 drivers/net/dsa/mv88e6xxx/switchdev.h

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2.30.2