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Diffstat (limited to 'target/linux/generic/backport-5.4/775-v5.12-net-dsa-listen-for-SWITCHDEV_-FDB-DEL-_ADD_TO_DEVICE.patch')
-rw-r--r--target/linux/generic/backport-5.4/775-v5.12-net-dsa-listen-for-SWITCHDEV_-FDB-DEL-_ADD_TO_DEVICE.patch263
1 files changed, 0 insertions, 263 deletions
diff --git a/target/linux/generic/backport-5.4/775-v5.12-net-dsa-listen-for-SWITCHDEV_-FDB-DEL-_ADD_TO_DEVICE.patch b/target/linux/generic/backport-5.4/775-v5.12-net-dsa-listen-for-SWITCHDEV_-FDB-DEL-_ADD_TO_DEVICE.patch
deleted file mode 100644
index e4ed6e808f..0000000000
--- a/target/linux/generic/backport-5.4/775-v5.12-net-dsa-listen-for-SWITCHDEV_-FDB-DEL-_ADD_TO_DEVICE.patch
+++ /dev/null
@@ -1,263 +0,0 @@
-From d5f19486cee79d04c054427577ac96ed123706db Mon Sep 17 00:00:00 2001
-From: Vladimir Oltean <vladimir.oltean@nxp.com>
-Date: Wed, 6 Jan 2021 11:51:35 +0200
-Subject: [PATCH] net: dsa: listen for SWITCHDEV_{FDB,DEL}_ADD_TO_DEVICE on
- foreign bridge neighbors
-
-Some DSA switches (and not only) cannot learn source MAC addresses from
-packets injected from the CPU. They only perform hardware address
-learning from inbound traffic.
-
-This can be problematic when we have a bridge spanning some DSA switch
-ports and some non-DSA ports (which we'll call "foreign interfaces" from
-DSA's perspective).
-
-There are 2 classes of problems created by the lack of learning on
-CPU-injected traffic:
-- excessive flooding, due to the fact that DSA treats those addresses as
- unknown
-- the risk of stale routes, which can lead to temporary packet loss
-
-To illustrate the second class, consider the following situation, which
-is common in production equipment (wireless access points, where there
-is a WLAN interface and an Ethernet switch, and these form a single
-bridging domain).
-
- AP 1:
- +------------------------------------------------------------------------+
- | br0 |
- +------------------------------------------------------------------------+
- +------------+ +------------+ +------------+ +------------+ +------------+
- | swp0 | | swp1 | | swp2 | | swp3 | | wlan0 |
- +------------+ +------------+ +------------+ +------------+ +------------+
- | ^ ^
- | | |
- | | |
- | Client A Client B
- |
- |
- |
- +------------+ +------------+ +------------+ +------------+ +------------+
- | swp0 | | swp1 | | swp2 | | swp3 | | wlan0 |
- +------------+ +------------+ +------------+ +------------+ +------------+
- +------------------------------------------------------------------------+
- | br0 |
- +------------------------------------------------------------------------+
- AP 2
-
-- br0 of AP 1 will know that Clients A and B are reachable via wlan0
-- the hardware fdb of a DSA switch driver today is not kept in sync with
- the software entries on other bridge ports, so it will not know that
- clients A and B are reachable via the CPU port UNLESS the hardware
- switch itself performs SA learning from traffic injected from the CPU.
- Nonetheless, a substantial number of switches don't.
-- the hardware fdb of the DSA switch on AP 2 may autonomously learn that
- Client A and B are reachable through swp0. Therefore, the software br0
- of AP 2 also may or may not learn this. In the example we're
- illustrating, some Ethernet traffic has been going on, and br0 from AP
- 2 has indeed learnt that it can reach Client B through swp0.
-
-One of the wireless clients, say Client B, disconnects from AP 1 and
-roams to AP 2. The topology now looks like this:
-
- AP 1:
- +------------------------------------------------------------------------+
- | br0 |
- +------------------------------------------------------------------------+
- +------------+ +------------+ +------------+ +------------+ +------------+
- | swp0 | | swp1 | | swp2 | | swp3 | | wlan0 |
- +------------+ +------------+ +------------+ +------------+ +------------+
- | ^
- | |
- | Client A
- |
- |
- | Client B
- | |
- | v
- +------------+ +------------+ +------------+ +------------+ +------------+
- | swp0 | | swp1 | | swp2 | | swp3 | | wlan0 |
- +------------+ +------------+ +------------+ +------------+ +------------+
- +------------------------------------------------------------------------+
- | br0 |
- +------------------------------------------------------------------------+
- AP 2
-
-- br0 of AP 1 still knows that Client A is reachable via wlan0 (no change)
-- br0 of AP 1 will (possibly) know that Client B has left wlan0. There
- are cases where it might never find out though. Either way, DSA today
- does not process that notification in any way.
-- the hardware FDB of the DSA switch on AP 1 may learn autonomously that
- Client B can be reached via swp0, if it receives any packet with
- Client 1's source MAC address over Ethernet.
-- the hardware FDB of the DSA switch on AP 2 still thinks that Client B
- can be reached via swp0. It does not know that it has roamed to wlan0,
- because it doesn't perform SA learning from the CPU port.
-
-Now Client A contacts Client B.
-AP 1 routes the packet fine towards swp0 and delivers it on the Ethernet
-segment.
-AP 2 sees a frame on swp0 and its fdb says that the destination is swp0.
-Hairpinning is disabled => drop.
-
-This problem comes from the fact that these switches have a 'blind spot'
-for addresses coming from software bridging. The generic solution is not
-to assume that hardware learning can be enabled somehow, but to listen
-to more bridge learning events. It turns out that the bridge driver does
-learn in software from all inbound frames, in __br_handle_local_finish.
-A proper SWITCHDEV_FDB_ADD_TO_DEVICE notification is emitted for the
-addresses serviced by the bridge on 'foreign' interfaces. The software
-bridge also does the right thing on migration, by notifying that the old
-entry is deleted, so that does not need to be special-cased in DSA. When
-it is deleted, we just need to delete our static FDB entry towards the
-CPU too, and wait.
-
-The problem is that DSA currently only cares about SWITCHDEV_FDB_ADD_TO_DEVICE
-events received on its own interfaces, such as static FDB entries.
-
-Luckily we can change that, and DSA can listen to all switchdev FDB
-add/del events in the system and figure out if those events were emitted
-by a bridge that spans at least one of DSA's own ports. In case that is
-true, DSA will also offload that address towards its own CPU port, in
-the eventuality that there might be bridge clients attached to the DSA
-switch who want to talk to the station connected to the foreign
-interface.
-
-In terms of implementation, we need to keep the fdb_info->added_by_user
-check for the case where the switchdev event was targeted directly at a
-DSA switch port. But we don't need to look at that flag for snooped
-events. So the check is currently too late, we need to move it earlier.
-This also simplifies the code a bit, since we avoid uselessly allocating
-and freeing switchdev_work.
-
-We could probably do some improvements in the future. For example,
-multi-bridge support is rudimentary at the moment. If there are two
-bridges spanning a DSA switch's ports, and both of them need to service
-the same MAC address, then what will happen is that the migration of one
-of those stations will trigger the deletion of the FDB entry from the
-CPU port while it is still used by other bridge. That could be improved
-with reference counting but is left for another time.
-
-This behavior needs to be enabled at driver level by setting
-ds->assisted_learning_on_cpu_port = true. This is because we don't want
-to inflict a potential performance penalty (accesses through
-MDIO/I2C/SPI are expensive) to hardware that really doesn't need it
-because address learning on the CPU port works there.
-
-Reported-by: DENG Qingfang <dqfext@gmail.com>
-Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
-Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
-Reviewed-by: Andrew Lunn <andrew@lunn.ch>
-Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-[Backported to linux-5.4.y]
-Signed-off-by: DENG Qingfang <dqfext@gmail.com>
----
- include/net/dsa.h | 5 ++++
- net/dsa/slave.c | 63 ++++++++++++++++++++++++++++++++++++++---------
- 2 files changed, 57 insertions(+), 11 deletions(-)
-
---- a/include/net/dsa.h
-+++ b/include/net/dsa.h
-@@ -279,6 +279,11 @@ struct dsa_switch {
- */
- bool configure_vlan_while_not_filtering;
-
-+ /* Let DSA manage the FDB entries towards the CPU, based on the
-+ * software bridge database.
-+ */
-+ bool assisted_learning_on_cpu_port;
-+
- /* In case vlan_filtering_is_global is set, the VLAN awareness state
- * should be retrieved from here and not from the per-port settings.
- */
---- a/net/dsa/slave.c
-+++ b/net/dsa/slave.c
-@@ -1630,6 +1630,25 @@ static void dsa_slave_switchdev_event_wo
- dev_put(dp->slave);
- }
-
-+static int dsa_lower_dev_walk(struct net_device *lower_dev, void *data)
-+{
-+ if (dsa_slave_dev_check(lower_dev)) {
-+ *((void **)data) = (void *)netdev_priv(lower_dev);
-+ return 1;
-+ }
-+
-+ return 0;
-+}
-+
-+static struct dsa_slave_priv *dsa_slave_dev_lower_find(struct net_device *dev)
-+{
-+ struct dsa_slave_priv *data = NULL;
-+
-+ netdev_walk_all_lower_dev_rcu(dev, dsa_lower_dev_walk, (void **) &data);
-+
-+ return data;
-+}
-+
- /* Called under rcu_read_lock() */
- static int dsa_slave_switchdev_event(struct notifier_block *unused,
- unsigned long event, void *ptr)
-@@ -1648,10 +1667,37 @@ static int dsa_slave_switchdev_event(str
- return notifier_from_errno(err);
- case SWITCHDEV_FDB_ADD_TO_DEVICE:
- case SWITCHDEV_FDB_DEL_TO_DEVICE:
-- if (!dsa_slave_dev_check(dev))
-- return NOTIFY_DONE;
-+ fdb_info = ptr;
-+
-+ if (dsa_slave_dev_check(dev)) {
-+ if (!fdb_info->added_by_user)
-+ return NOTIFY_OK;
-+
-+ dp = dsa_slave_to_port(dev);
-+ } else {
-+ /* Snoop addresses learnt on foreign interfaces
-+ * bridged with us, for switches that don't
-+ * automatically learn SA from CPU-injected traffic
-+ */
-+ struct net_device *br_dev;
-+ struct dsa_slave_priv *p;
-+
-+ br_dev = netdev_master_upper_dev_get_rcu(dev);
-+ if (!br_dev)
-+ return NOTIFY_DONE;
-+
-+ if (!netif_is_bridge_master(br_dev))
-+ return NOTIFY_DONE;
-+
-+ p = dsa_slave_dev_lower_find(br_dev);
-+ if (!p)
-+ return NOTIFY_DONE;
-
-- dp = dsa_slave_to_port(dev);
-+ dp = p->dp->cpu_dp;
-+
-+ if (!dp->ds->assisted_learning_on_cpu_port)
-+ return NOTIFY_DONE;
-+ }
-
- if (!dp->ds->ops->port_fdb_add || !dp->ds->ops->port_fdb_del)
- return NOTIFY_DONE;
-@@ -1666,18 +1712,13 @@ static int dsa_slave_switchdev_event(str
- switchdev_work->port = dp->index;
- switchdev_work->event = event;
-
-- fdb_info = ptr;
--
-- if (!fdb_info->added_by_user) {
-- kfree(switchdev_work);
-- return NOTIFY_OK;
-- }
--
- ether_addr_copy(switchdev_work->addr,
- fdb_info->addr);
- switchdev_work->vid = fdb_info->vid;
-
-- dev_hold(dev);
-+ /* Hold a reference on the slave for dsa_fdb_offload_notify */
-+ if (dsa_is_user_port(dp->ds, dp->index))
-+ dev_hold(dev);
- dsa_schedule_work(&switchdev_work->work);
- break;
- default:
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-06 22:59:06 +0000