[nexus] add test for informing previous parent on reattach (#12919)

This commit adds a new Nexus test to verify that a Sleepy End Device
(SED) correctly informs its previous parent after reattaching to a new
parent. This replicates the functionality of the now-deleted
test_inform_previous_parent_on_reattach.py script.

The test scenario involves:
- Forming a network with a Leader and a Router.
- Attaching a SED to the Leader.
- Simulating a link failure between the SED and Leader while allowing
  communication between the SED and Router.
- Verifying that the SED reattaches to the Router.
- Confirming that the SED sends an empty IPv6 message (Next Header 59)
  to the Leader's RLOC to inform it of the change.
- Ensuring the SED is successfully removed from the Leader's child
  table.

Migrating this test to Nexus allows for faster execution using virtual
time and single-process simulation.
This commit is contained in:
Jonathan Hui
2026-04-18 10:52:25 -05:00
committed by GitHub
parent 88f364af1b
commit f76b876f22
5 changed files with 194 additions and 142 deletions
@@ -1,142 +0,0 @@
#!/usr/bin/env python3
#
# Copyright (c) 2021, The OpenThread Authors.
# All rights reserved.
#
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# 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
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# 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
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# 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
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# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#
import os
import unittest
import config
import thread_cert
from pktverify.packet_filter import PacketFilter
# Test description:
# The purpose of this test is to verify a MED will inform its previous parent when re-attaches to another parent.
#
# Initial Topology:
#
# LEADER ----- ROUTER
# |
# MED
#
LEADER = 1
ROUTER = 2
MED = 3
LONG_CHILD_TIMEOUT = 120
class TestReset(thread_cert.TestCase):
SUPPORT_NCP = False
USE_MESSAGE_FACTORY = False
TOPOLOGY = {
LEADER: {
'name': 'LEADER',
'mode': 'rdn',
'allowlist': [ROUTER, MED]
},
ROUTER: {
'name': 'ROUTER',
'mode': 'rdn',
'allowlist': [LEADER]
},
MED: {
'name': 'MED',
'is_mtd': True,
'mode': 'rn',
'allowlist': [LEADER],
'timeout': LONG_CHILD_TIMEOUT,
},
}
def test(self):
if 'posix' in os.getenv('OT_CLI_PATH', ''):
self.skipTest("skip for posix tests")
self.nodes[LEADER].start()
self.simulator.go(config.LEADER_STARTUP_DELAY)
self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
self.nodes[ROUTER].start()
self.simulator.go(config.ROUTER_STARTUP_DELAY)
self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
self.nodes[MED].start()
self.simulator.go(7)
self.assertEqual(self.nodes[MED].get_state(), 'child')
self.assertIsChildOf(MED, LEADER)
self.nodes[LEADER].remove_allowlist(self.nodes[MED].get_addr64())
self.nodes[MED].remove_allowlist(self.nodes[LEADER].get_addr64())
self.nodes[ROUTER].add_allowlist(self.nodes[MED].get_addr64())
self.nodes[MED].add_allowlist(self.nodes[ROUTER].get_addr64())
self.nodes[MED].set_timeout(config.DEFAULT_CHILD_TIMEOUT)
self.simulator.go(config.DEFAULT_CHILD_TIMEOUT * 2)
self.assertIsChildOf(MED, ROUTER)
# Verify MED is not in the LEADER's Child Table.
med_extaddr = self.nodes[MED].get_addr64()
self.assertFalse(any(info['extaddr'] == med_extaddr for info in self.nodes[LEADER].get_child_table().values()))
self.collect_ipaddrs()
self.collect_rlocs()
def verify(self, pv):
pkts: PacketFilter = pv.pkts
pv.summary.show()
MED = pv.vars['MED']
LEADER_RLOC = pv.vars['LEADER_RLOC']
# MED should attach to LEADER first.
pv.verify_attached('MED', 'LEADER', child_type='MTD')
# MED should re-attach to ROUTER.
pv.verify_attached('MED', 'ROUTER', child_type='MTD')
# MED should send empty IPv6 message to inform previous parent (LEADER).
pkts.filter_wpan_src64(MED).filter('lowpan.dst == {LEADER_RLOC} and lowpan.next == 0x3b',
LEADER_RLOC=LEADER_RLOC).must_next()
def assertIsChildOf(self, childid, parentid):
childRloc16 = self.nodes[childid].get_addr16()
parentRloc16 = self.nodes[parentid].get_addr16()
self.assertEqual(parentRloc16 & 0xfc00, parentRloc16)
self.assertEqual(childRloc16 & 0xfc00, parentRloc16)
child_extaddr = self.nodes[childid].get_addr64()
self.assertTrue(
any(info['extaddr'] == child_extaddr for info in self.nodes[parentid].get_child_table().values()))
if __name__ == '__main__':
unittest.main()