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authorVladimir Oltean2021-08-24 00:22:58 +0300
committerDavid S. Miller2021-08-24 09:30:58 +0100
commit58adf9dcb15b99f047e80e10c85fb51ed3c88215 (patch)
treee190c85cd851e06cc6b74ef4a12de3ea66866043 /include/net
parent06cfb2df7eb0da54a37d37732665a1993244c25f (diff)
net: dsa: let drivers state that they need VLAN filtering while standalone
As explained in commit e358bef7c392 ("net: dsa: Give drivers the chance to veto certain upper devices"), the hellcreek driver uses some tricks to comply with the network stack expectations: it enforces port separation in standalone mode using VLANs. For untagged traffic, bridging between ports is prevented by using different PVIDs, and for VLAN-tagged traffic, it never accepts 8021q uppers with the same VID on two ports, so packets with one VLAN cannot leak from one port to another. That is almost fine*, and has worked because hellcreek relied on an implicit behavior of the DSA core that was changed by the previous patch: the standalone ports declare the 'rx-vlan-filter' feature as 'on [fixed]'. Since most of the DSA drivers are actually VLAN-unaware in standalone mode, that feature was actually incorrectly reflecting the hardware/driver state, so there was a desire to fix it. This leaves the hellcreek driver in a situation where it has to explicitly request this behavior from the DSA framework. We configure the ports as follows: - Standalone: 'rx-vlan-filter' is on. An 8021q upper on top of a standalone hellcreek port will go through dsa_slave_vlan_rx_add_vid and will add a VLAN to the hardware tables, giving the driver the opportunity to refuse it through .port_prechangeupper. - Bridged with vlan_filtering=0: 'rx-vlan-filter' is off. An 8021q upper on top of a bridged hellcreek port will not go through dsa_slave_vlan_rx_add_vid, because there will not be any attempt to offload this VLAN. The driver already disables VLAN awareness, so that upper should receive the traffic it needs. - Bridged with vlan_filtering=1: 'rx-vlan-filter' is on. An 8021q upper on top of a bridged hellcreek port will call dsa_slave_vlan_rx_add_vid, and can again be vetoed through .port_prechangeupper. *It is not actually completely fine, because if I follow through correctly, we can have the following situation: ip link add br0 type bridge vlan_filtering 0 ip link set lan0 master br0 # lan0 now becomes VLAN-unaware ip link set lan0 nomaster # lan0 fails to become VLAN-aware again, therefore breaking isolation This patch fixes that corner case by extending the DSA core logic, based on this requested attribute, to change the VLAN awareness state of the switch (port) when it leaves the bridge. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Acked-by: Kurt Kanzenbach <kurt@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net')
-rw-r--r--include/net/dsa.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/include/net/dsa.h b/include/net/dsa.h
index c7ea0f61056f..f9a17145255a 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -363,6 +363,9 @@ struct dsa_switch {
*/
bool vlan_filtering_is_global;
+ /* Keep VLAN filtering enabled on ports not offloading any upper. */
+ bool needs_standalone_vlan_filtering;
+
/* Pass .port_vlan_add and .port_vlan_del to drivers even for bridges
* that have vlan_filtering=0. All drivers should ideally set this (and
* then the option would get removed), but it is unknown whether this