openvswitch: Add meter action support

Implements OVS kernel meter action support.
Signed-off-by: Andy Zhou <azhou@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/openvswitch.h

@@ -838,6 +838,8 @@ struct ovs_action_push_eth {
  * @OVS_ACTION_ATTR_CT_CLEAR: Clear conntrack state from the packet.
  * @OVS_ACTION_ATTR_PUSH_NSH: push NSH header to the packet.
  * @OVS_ACTION_ATTR_POP_NSH: pop the outermost NSH header off the packet.
+ * @OVS_ACTION_ATTR_METER: Run packet through a meter, which may drop the
+ * packet, or modify the packet (e.g., change the DSCP field).
  *
  * Only a single header can be set with a single %OVS_ACTION_ATTR_SET.  Not all
  * fields within a header are modifiable, e.g. the IPv4 protocol and fragment
@@ -870,6 +872,7 @@ enum ovs_action_attr {
 	OVS_ACTION_ATTR_CT_CLEAR,     /* No argument. */
 	OVS_ACTION_ATTR_PUSH_NSH,     /* Nested OVS_NSH_KEY_ATTR_*. */
 	OVS_ACTION_ATTR_POP_NSH,      /* No argument. */
+	OVS_ACTION_ATTR_METER,        /* u32 meter ID. */
 
 	__OVS_ACTION_ATTR_MAX,	      /* Nothing past this will be accepted
 				       * from userspace. */

net/openvswitch/actions.c

@@ -1330,6 +1330,12 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
 		case OVS_ACTION_ATTR_POP_NSH:
 			err = pop_nsh(skb, key);
 			break;
+
+		case OVS_ACTION_ATTR_METER:
+			if (ovs_meter_execute(dp, skb, key, nla_get_u32(a))) {
+				consume_skb(skb);
+				return 0;
+			}
 		}
 
 		if (unlikely(err)) {

net/openvswitch/datapath.h

@@ -30,6 +30,7 @@
 #include "conntrack.h"
 #include "flow.h"
 #include "flow_table.h"
+#include "meter.h"
 #include "vport-internal_dev.h"
 
 #define DP_MAX_PORTS           USHRT_MAX

net/openvswitch/flow_netlink.c

@@ -90,6 +90,7 @@ static bool actions_may_change_flow(const struct nlattr *actions)
 		case OVS_ACTION_ATTR_SAMPLE:
 		case OVS_ACTION_ATTR_SET:
 		case OVS_ACTION_ATTR_SET_MASKED:
+		case OVS_ACTION_ATTR_METER:
 		default:
 			return true;
 		}
@@ -2844,6 +2845,7 @@ static int __ovs_nla_copy_actions(struct net *net, const struct nlattr *attr,
 			[OVS_ACTION_ATTR_POP_ETH] = 0,
 			[OVS_ACTION_ATTR_PUSH_NSH] = (u32)-1,
 			[OVS_ACTION_ATTR_POP_NSH] = 0,
+			[OVS_ACTION_ATTR_METER] = sizeof(u32),
 		};
 		const struct ovs_action_push_vlan *vlan;
 		int type = nla_type(a);
@@ -3029,6 +3031,10 @@ static int __ovs_nla_copy_actions(struct net *net, const struct nlattr *attr,
 			break;
 		}
 
+		case OVS_ACTION_ATTR_METER:
+			/* Non-existent meters are simply ignored.  */
+			break;
+
 		default:
 			OVS_NLERR(log, "Unknown Action type %d", type);
 			return -EINVAL;