openvswitch: Fix NDP flow mask validation

match_validate() enforce that a mask matching on NDP attributes has also an
exact match on ICMPv6 type.
The ICMPv6 type, which is 8-bit wide, is stored in the 'tp.src' field of
'struct sw_flow_key', which is 16-bit wide.
Therefore, an exact match on ICMPv6 type should only check the first 8 bits.

This commit fixes a bug that prevented flows with an exact match on NDP field
from being installed
Introduced by commit 03f0d916aa03 ("openvswitch: Mega flow implementation").

Signed-off-by: Daniele Di Proietto <ddiproietto@vmware.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>

net/openvswitch/flow_netlink.c

@@ -145,7 +145,7 @@ static bool match_validate(const struct sw_flow_match *match,
 	if (match->key->eth.type == htons(ETH_P_ARP)
 			|| match->key->eth.type == htons(ETH_P_RARP)) {
 		key_expected |= 1 << OVS_KEY_ATTR_ARP;
-		if (match->mask && (match->mask->key.eth.type == htons(0xffff)))
+		if (match->mask && (match->mask->key.tp.src == htons(0xff)))
 			mask_allowed |= 1 << OVS_KEY_ATTR_ARP;
 	}