From: Vladimir Oltean vladimir.oltean@nxp.com
[ Upstream commit f964f8399df29d3e3ced77177cf35131cd2491bf ]
Alternative short title: don't instruct the hardware to match on EtherType with "protocol 802.1Q" flower filters. It doesn't work for the reasons detailed below.
With a command such as the following:
tc filter add dev $swp1 ingress chain $(IS1 2) pref 3 \ protocol 802.1Q flower skip_sw vlan_id 200 src_mac $h1_mac \ action vlan modify id 300 \ action goto chain $(IS2 0 0)
the created filter is set by ocelot_flower_parse_key() to be of type OCELOT_VCAP_KEY_ETYPE, and etype is set to {value=0x8100, mask=0xffff}. This gets propagated all the way to is1_entry_set() which commits it to hardware (the VCAP_IS1_HK_ETYPE field of the key). Compare this to the case where src_mac isn't specified - the key type is OCELOT_VCAP_KEY_ANY, and is1_entry_set() doesn't populate VCAP_IS1_HK_ETYPE.
The problem is that for VLAN-tagged frames, the hardware interprets the ETYPE field as holding the encapsulated VLAN protocol. So the above filter will only match those packets which have an encapsulated protocol of 0x8100, rather than all packets with VLAN ID 200 and the given src_mac.
The reason why this is allowed to occur is because, although we have a block of code in ocelot_flower_parse_key() which sets "match_protocol" to false when VLAN keys are present, that code executes too late. There is another block of code, which executes for Ethernet addresses, and has a "goto finished_key_parsing" and skips the VLAN header parsing. By skipping it, "match_protocol" remains with the value it was initialized with, i.e. "true", and "proto" is set to f->common.protocol, or 0x8100.
The concept of ignoring some keys rather than erroring out when they are present but can't be offloaded is dubious in itself, but is present since the initial commit fe3490e6107e ("net: mscc: ocelot: Hardware ofload for tc flower filter"), and it's outside of the scope of this patch to change that.
The problem was introduced when the driver started to interpret the flower filter's protocol, and populate the VCAP filter's ETYPE field based on it.
To fix this, it is sufficient to move the code that parses the VLAN keys earlier than the "goto finished_key_parsing" instruction. This will ensure that if we have a flower filter with both VLAN and Ethernet address keys, it won't match on ETYPE 0x8100, because the VLAN key parsing sets "match_protocol = false".
Fixes: 86b956de119c ("net: mscc: ocelot: support matching on EtherType") Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Reviewed-by: Simon Horman simon.horman@corigine.com Link: https://lore.kernel.org/r/20230205192409.1796428-1-vladimir.oltean@nxp.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/mscc/ocelot_flower.c | 24 +++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/drivers/net/ethernet/mscc/ocelot_flower.c b/drivers/net/ethernet/mscc/ocelot_flower.c index b221b83ec5a6f..e56e540ce05c3 100644 --- a/drivers/net/ethernet/mscc/ocelot_flower.c +++ b/drivers/net/ethernet/mscc/ocelot_flower.c @@ -468,6 +468,18 @@ ocelot_flower_parse_key(struct ocelot *ocelot, int port, bool ingress, flow_rule_match_control(rule, &match); }
+ if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_VLAN)) { + struct flow_match_vlan match; + + flow_rule_match_vlan(rule, &match); + filter->key_type = OCELOT_VCAP_KEY_ANY; + filter->vlan.vid.value = match.key->vlan_id; + filter->vlan.vid.mask = match.mask->vlan_id; + filter->vlan.pcp.value[0] = match.key->vlan_priority; + filter->vlan.pcp.mask[0] = match.mask->vlan_priority; + match_protocol = false; + } + if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_ETH_ADDRS)) { struct flow_match_eth_addrs match;
@@ -600,18 +612,6 @@ ocelot_flower_parse_key(struct ocelot *ocelot, int port, bool ingress, match_protocol = false; }
- if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_VLAN)) { - struct flow_match_vlan match; - - flow_rule_match_vlan(rule, &match); - filter->key_type = OCELOT_VCAP_KEY_ANY; - filter->vlan.vid.value = match.key->vlan_id; - filter->vlan.vid.mask = match.mask->vlan_id; - filter->vlan.pcp.value[0] = match.key->vlan_priority; - filter->vlan.pcp.mask[0] = match.mask->vlan_priority; - match_protocol = false; - } - finished_key_parsing: if (match_protocol && proto != ETH_P_ALL) { if (filter->block_id == VCAP_ES0) {