From: Vladimir Oltean vladimir.oltean@nxp.com
commit ed040abca4c1db72dfd3b8483b6ed6bfb7c2571e upstream.
One thing became visible when writing the blamed commit, and that was that STP and PTP frames injected by net/dsa/tag_sja1105.c using the deferred xmit mechanism are always classified to the pvid of the CPU port, regardless of whatever VLAN there might be in these packets.
So a decision needed to be taken regarding the mechanism through which we should ensure that delivery of STP and PTP traffic is possible when we are in a VLAN awareness mode that involves tag_8021q. This is because tag_8021q is not concerned with managing the pvid of the CPU port, since as far as tag_8021q is concerned, no traffic should be sent as untagged from the CPU port. So we end up not actually having a pvid on the CPU port if we only listen to tag_8021q, and unless we do something about it.
The decision taken at the time was to keep VLAN 1 in the list of priv->dsa_8021q_vlans, and make it a pvid of the CPU port. This ensures that STP and PTP frames can always be sent to the outside world.
However there is a problem. If we do the following while we are in the best_effort_vlan_filtering=true mode:
ip link add br0 type bridge vlan_filtering 1 ip link set swp2 master br0 bridge vlan del dev swp2 vid 1
Then untagged and pvid-tagged frames should be dropped. But we observe that they aren't, and this is because of the precaution we took that VID 1 is always installed on all ports.
So clearly VLAN 1 is not good for this purpose. What about VLAN 0? Well, VLAN 0 is managed by the 8021q module, and that module wants to ensure that 802.1p tagged frames are always received by a port, and are always transmitted as VLAN-tagged (with VLAN ID 0). Whereas we want our STP and PTP frames to be untagged if the stack sent them as untagged - we don't want the driver to just decide out of the blue that it adds VID 0 to some packets.
So what to do?
Well, there is one other VLAN that is reserved, and that is 4095: $ ip link add link swp2 name swp2.4095 type vlan id 4095 Error: 8021q: Invalid VLAN id. $ bridge vlan add dev swp2 vid 4095 Error: bridge: Vlan id is invalid.
After we made this change, VLAN 1 is indeed forwarded and/or dropped according to the bridge VLAN table, there are no further alterations done by the sja1105 driver.
Fixes: ec5ae61076d0 ("net: dsa: sja1105: save/restore VLANs using a delta commit method") Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/dsa/sja1105/sja1105_main.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-)
--- a/drivers/net/dsa/sja1105/sja1105_main.c +++ b/drivers/net/dsa/sja1105/sja1105_main.c @@ -26,6 +26,7 @@ #include "sja1105_tas.h"
#define SJA1105_UNKNOWN_MULTICAST 0x010000000000ull +#define SJA1105_DEFAULT_VLAN (VLAN_N_VID - 1)
static const struct dsa_switch_ops sja1105_switch_ops;
@@ -321,6 +322,13 @@ static int sja1105_init_l2_lookup_params return 0; }
+/* Set up a default VLAN for untagged traffic injected from the CPU + * using management routes (e.g. STP, PTP) as opposed to tag_8021q. + * All DT-defined ports are members of this VLAN, and there are no + * restrictions on forwarding (since the CPU selects the destination). + * Frames from this VLAN will always be transmitted as untagged, and + * neither the bridge nor the 8021q module cannot create this VLAN ID. + */ static int sja1105_init_static_vlan(struct sja1105_private *priv) { struct sja1105_table *table; @@ -330,17 +338,13 @@ static int sja1105_init_static_vlan(stru .vmemb_port = 0, .vlan_bc = 0, .tag_port = 0, - .vlanid = 1, + .vlanid = SJA1105_DEFAULT_VLAN, }; struct dsa_switch *ds = priv->ds; int port;
table = &priv->static_config.tables[BLK_IDX_VLAN_LOOKUP];
- /* The static VLAN table will only contain the initial pvid of 1. - * All other VLANs are to be configured through dynamic entries, - * and kept in the static configuration table as backing memory. - */ if (table->entry_count) { kfree(table->entries); table->entry_count = 0; @@ -353,9 +357,6 @@ static int sja1105_init_static_vlan(stru
table->entry_count = 1;
- /* VLAN 1: all DT-defined ports are members; no restrictions on - * forwarding; always transmit as untagged. - */ for (port = 0; port < ds->num_ports; port++) { struct sja1105_bridge_vlan *v;
@@ -366,15 +367,12 @@ static int sja1105_init_static_vlan(stru pvid.vlan_bc |= BIT(port); pvid.tag_port &= ~BIT(port);
- /* Let traffic that don't need dsa_8021q (e.g. STP, PTP) be - * transmitted as untagged. - */ v = kzalloc(sizeof(*v), GFP_KERNEL); if (!v) return -ENOMEM;
v->port = port; - v->vid = 1; + v->vid = SJA1105_DEFAULT_VLAN; v->untagged = true; if (dsa_is_cpu_port(ds, port)) v->pvid = true;