/* Retrieves statistics for 'dpif' into 'stats'. */
int (*get_stats)(const struct dpif *dpif, struct dpif_dp_stats *stats);
- /* Adds 'netdev' as a new port in 'dpif'. If successful, sets '*port_no'
- * to the new port's port number. */
+ /* Adds 'netdev' as a new port in 'dpif'. If '*port_no' is not
+ * UINT16_MAX, attempts to use that as the port's port number.
+ *
+ * If port is successfully added, sets '*port_no' to the new port's
+ * port number. Returns EBUSY if caller attempted to choose a port
+ * number, and it was in use. */
int (*port_add)(struct dpif *dpif, struct netdev *netdev,
uint16_t *port_no);
* actions as the OVS_USERSPACE_ATTR_PID attribute's value, for use in
* flows whose packets arrived on port 'port_no'.
*
+ * A 'port_no' of UINT16_MAX should be treated as a special case. The
+ * implementation should return a reserved PID, not allocated to any port,
+ * that the client may use for special purposes.
+ *
* The return value only needs to be meaningful when DPIF_UC_ACTION has
* been enabled in the 'dpif''s listen mask, and it is allowed to change
* when DPIF_UC_ACTION is disabled and then re-enabled.
* taken from the flow specified in the 'execute->key_len' bytes of
* 'execute->key'. ('execute->key' is mostly redundant with
* 'execute->packet', but it contains some metadata that cannot be
- * recovered from 'execute->packet', such as tun_id and in_port.) */
+ * recovered from 'execute->packet', such as tunnel and in_port.) */
int (*execute)(struct dpif *dpif, const struct dpif_execute *execute);
/* Executes each of the 'n_ops' operations in 'ops' on 'dpif', in the order