openvswitch: Refactor ovs_nla_fill_match().

Refactor the ovs_nla_fill_match() function into separate netlink
serialization functions ovs_nla_put_{unmasked_key,mask}(). Modify
ovs_nla_put_flow() to handle attribute nesting and expose the 'is_mask'
parameter - all callers need to nest the flow, and callers have better
knowledge about whether it is serializing a mask or not.

Signed-off-by: Joe Stringer <joestringer@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index d210d1b..33751f8 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -1216,12 +1216,12 @@
 	return metadata_from_nlattrs(&match, &attrs, a, false, log);
 }
 
-int ovs_nla_put_flow(const struct sw_flow_key *swkey,
-		     const struct sw_flow_key *output, struct sk_buff *skb)
+static int __ovs_nla_put_key(const struct sw_flow_key *swkey,
+			     const struct sw_flow_key *output, bool is_mask,
+			     struct sk_buff *skb)
 {
 	struct ovs_key_ethernet *eth_key;
 	struct nlattr *nla, *encap;
-	bool is_mask = (swkey != output);
 
 	if (nla_put_u32(skb, OVS_KEY_ATTR_RECIRC_ID, output->recirc_id))
 		goto nla_put_failure;
@@ -1431,6 +1431,38 @@
 	return -EMSGSIZE;
 }
 
+int ovs_nla_put_key(const struct sw_flow_key *swkey,
+		    const struct sw_flow_key *output, int attr, bool is_mask,
+		    struct sk_buff *skb)
+{
+	int err;
+	struct nlattr *nla;
+
+	nla = nla_nest_start(skb, attr);
+	if (!nla)
+		return -EMSGSIZE;
+	err = __ovs_nla_put_key(swkey, output, is_mask, skb);
+	if (err)
+		return err;
+	nla_nest_end(skb, nla);
+
+	return 0;
+}
+
+/* Called with ovs_mutex or RCU read lock. */
+int ovs_nla_put_unmasked_key(const struct sw_flow *flow, struct sk_buff *skb)
+{
+	return ovs_nla_put_key(&flow->unmasked_key, &flow->unmasked_key,
+				OVS_FLOW_ATTR_KEY, false, skb);
+}
+
+/* Called with ovs_mutex or RCU read lock. */
+int ovs_nla_put_mask(const struct sw_flow *flow, struct sk_buff *skb)
+{
+	return ovs_nla_put_key(&flow->key, &flow->mask->key,
+				OVS_FLOW_ATTR_MASK, true, skb);
+}
+
 #define MAX_ACTIONS_BUFSIZE	(32 * 1024)
 
 static struct sw_flow_actions *nla_alloc_flow_actions(int size, bool log)