[low-power] add cli command macsend for certification (#5573)

This command allows an Rx-Off-When-Idle device to send an empty mac
data frame or mac datarequest to its parent. This command is only used
for certification.

tests/scripts/expect/v1_2-sed_mac_send.exp

@@ -0,0 +1,41 @@
+#!/usr/bin/expect -f
+#
+#  Copyright (c) 2020, The OpenThread Authors.
+#  All rights reserved.
+#
+#  Redistribution and use in source and binary forms, with or without
+#  modification, are permitted provided that the following conditions are met:
+#  1. Redistributions of source code must retain the above copyright
+#     notice, this list of conditions and the following disclaimer.
+#  2. Redistributions in binary form must reproduce the above copyright
+#     notice, this list of conditions and the following disclaimer in the
+#     documentation and/or other materials provided with the distribution.
+#  3. Neither the name of the copyright holder nor the
+#     names of its contributors may be used to endorse or promote products
+#     derived from this software without specific prior written permission.
+#
+#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+#  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+#  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+#  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+#  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+#  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+#  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+#  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+#  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+#  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+#  POSSIBILITY OF SUCH DAMAGE.
+#
+
+source "tests/scripts/expect/_common.exp"
+source "tests/scripts/expect/_multinode.exp"
+
+setup_nodes "-"
+
+set spawn_id $spawn_2
+send "mac send emptydata\n"
+expect "Done"
+send "mac send datarequest\n"
+expect "Done"
+
+dispose_nodes

tests/scripts/thread-cert/node.py

@@ -956,6 +956,14 @@ class NodeImpl:
         self.send_command('csl timeout %d' % csl_timeout)
         self._expect('Done')
 
+    def send_mac_emptydata(self):
+        self.send_command('mac send emptydata')
+        self._expect('Done')
+
+    def send_mac_datarequest(self):
+        self.send_command('mac send datarequest')
+        self._expect('Done')
+
     def set_router_upgrade_threshold(self, threshold):
         cmd = 'routerupgradethreshold %d' % threshold
         self.send_command(cmd)