[dpdk-dev] [PATCH 4/6] net/enic: ignore vlan inner type when it is zero

[Hyong Youb Kim]

When a VLAN pattern is present, the flow handler always copies its
inner_type to the match buffer regardless of its value (i.e. HW
matches inner_type against packet's inner ethertype). When inner_type
spec and mask are both 0, adding it to the match buffer is usually
harmless but breaks the following pattern used in some applications
like OVS-DPDK.

flow create 0 ingress ... pattern eth ... type is 0x0800 / vlan tci spec 0x2 \
tci mask 0xefff / ipv4 / end actions count / of_pop_vlan / ...

The VLAN pattern's inner_type is 0. And the outer eth pattern's type
actually specifies the inner ethertype. The outer ethertype (0x0800)
is first copied to the match buffer. Then, the driver copies
inner_type (0) to the match buffer, which overwrites the existing
0x0800 with 0 and breaks the app usage above.

Simply ignore inner_type when it is 0, which is the correct
behavior. As a byproduct, the driver can support the usage like the
above.

Fixes: ea7768b5bba8 ("net/enic: add flow implementation based on Flow Manager API")
Cc: stable at dpdk.org

Signed-off-by: Hyong Youb Kim <hyonkim at cisco.com>
Reviewed-by: John Daley <johndale at cisco.com>
---
 drivers/net/enic/enic_fm_flow.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/net/enic/enic_fm_flow.c b/drivers/net/enic/enic_fm_flow.c
index 5f22f2a32..a350b29a3 100644
--- a/drivers/net/enic/enic_fm_flow.c
+++ b/drivers/net/enic/enic_fm_flow.c
@@ -392,8 +392,11 @@ enic_fm_copy_item_vlan(struct copy_item_args *arg)
 	eth_mask = (void *)&fm_mask->l2.eth;
 	eth_val = (void *)&fm_data->l2.eth;
 
-	/* Outer TPID cannot be matched */
-	if (eth_mask->ether_type)
+	/*
+	 * Outer TPID cannot be matched. If inner_type is 0, use what is
+	 * in the eth header.
+	 */
+	if (eth_mask->ether_type && mask->inner_type)
 		return -ENOTSUP;
 
 	/*
@@ -401,8 +404,10 @@ enic_fm_copy_item_vlan(struct copy_item_args *arg)
 	 * L2, regardless of vlan stripping settings. So, the inner type
 	 * from vlan becomes the ether type of the eth header.
 	 */
-	eth_mask->ether_type = mask->inner_type;
-	eth_val->ether_type = spec->inner_type;
+	if (mask->inner_type) {
+		eth_mask->ether_type = mask->inner_type;
+		eth_val->ether_type = spec->inner_type;
+	}
 	fm_data->fk_header_select |= FKH_ETHER | FKH_QTAG;
 	fm_mask->fk_header_select |= FKH_ETHER | FKH_QTAG;
 	fm_data->fk_vlan = rte_be_to_cpu_16(spec->tci);
-- 
2.26.2