[PATCH net] net: mscc: ocelot: properly reject destination IP keys in VCAP IS1

From: Vladimir Oltean <vladimir.oltean@nxp.com>

An attempt is made to warn the user about the fact that VCAP IS1 cannot
offload keys matching on destination IP (at least given the current half
key format), but sadly that warning fails miserably in practice, due to
the fact that it operates on an uninitialized "match" variable. We must
first decode the keys from the flow rule.

Fixes: 75944fda1dfe ("net: mscc: ocelot: offload ingress skbedit and vlan actions to VCAP IS1")
Reported-by: Colin Ian King <redacted>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
 drivers/net/ethernet/mscc/ocelot_flower.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mscc/ocelot_flower.c b/drivers/net/ethernet/mscc/ocelot_flower.c
index c3ac026f6aea..a41b458b1b3e 100644
--- a/drivers/net/ethernet/mscc/ocelot_flower.c
+++ b/drivers/net/ethernet/mscc/ocelot_flower.c

@@ -540,13 +540,14 @@ ocelot_flower_parse_key(struct ocelot *ocelot, int port, bool ingress,
 			return -EOPNOTSUPP;
 		}
 
+		flow_rule_match_ipv4_addrs(rule, &match);
+
 		if (filter->block_id == VCAP_IS1 && *(u32 *)&match.mask->dst) {
 			NL_SET_ERR_MSG_MOD(extack,
 					   "Key type S1_NORMAL cannot match on destination IP");
 			return -EOPNOTSUPP;
 		}
 
-		flow_rule_match_ipv4_addrs(rule, &match);
 		tmp = &filter->key.ipv4.sip.value.addr[0];
 		memcpy(tmp, &match.key->src, 4);
 

-- 
2.25.1