1#!/usr/bin/env python3
2#
3#  Copyright (c) 2018, The OpenThread Authors.
4#  All rights reserved.
5#
6#  Redistribution and use in source and binary forms, with or without
7#  modification, are permitted provided that the following conditions are met:
8#  1. Redistributions of source code must retain the above copyright
9#     notice, this list of conditions and the following disclaimer.
10#  2. Redistributions in binary form must reproduce the above copyright
11#     notice, this list of conditions and the following disclaimer in the
12#     documentation and/or other materials provided with the distribution.
13#  3. Neither the name of the copyright holder nor the
14#     names of its contributors may be used to endorse or promote products
15#     derived from this software without specific prior written permission.
16#
17#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
18#  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19#  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20#  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
21#  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22#  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23#  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24#  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25#  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26#  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27#  POSSIBILITY OF SUCH DAMAGE.
28
29import wpan
30from wpan import verify
31
32# -----------------------------------------------------------------------------------------------------------------------
33# Test description: Test behavior of "Inform Previous Parent" feature
34#
35# With this feature enabled, when a child attaches to a new parent, it will send
36# an IP message (with empty payload and mesh-local IP address as the source
37# address) to its previous parent. Upon receiving this message the previous
38# parent would immediately remove the child from its child table. Without this
39# feature, the child entry on previous parent would stay (and parent would
40# continue to queue messages for the sleepy child) until the child is timed out
41# and removed from child table.
42#
43#
44# Test topology:
45#
46# `child` is first attached to `parent2`. It is then forced to switch to `parent1`
47#
48#     parent1--- parent2
49#          .      /
50#           \    /
51#            .  /
52#            child
53#
54# This test verifies the behavior of the child and parents under this feature.
55#
56# Note that `OPENTHREAD_CONFIG_MLE_INFORM_PREVIOUS_PARENT_ON_REATTACH` is enabled in
57# `openthread-core-toranj.config.h` header file.
58#
59
60test_name = __file__[:-3] if __file__.endswith('.py') else __file__
61print('-' * 120)
62print('Starting \'{}\''.format(test_name))
63
64# -----------------------------------------------------------------------------------------------------------------------
65# Creating `wpan.Nodes` instances
66
67speedup = 4
68wpan.Node.set_time_speedup_factor(speedup)
69
70parent1 = wpan.Node()
71parent2 = wpan.Node()
72child = wpan.Node()
73
74# -----------------------------------------------------------------------------------------------------------------------
75# Init all nodes
76
77wpan.Node.init_all_nodes()
78
79# -----------------------------------------------------------------------------------------------------------------------
80# Build network topology
81#
82# `child` is first attached to `parent2`. It is then forced to switch to `parent1`.
83#
84#     parent1--- parent2
85#          .      /
86#           \    /
87#            .  /
88#            child
89#
90
91parent1.allowlist_node(parent2)
92parent2.allowlist_node(parent1)
93parent2.allowlist_node(child)
94
95parent1.form("inform-parent")
96parent2.join_node(parent1, wpan.JOIN_TYPE_ROUTER)
97child.join_node(parent2, wpan.JOIN_TYPE_SLEEPY_END_DEVICE)
98child.set(wpan.WPAN_POLL_INTERVAL, '300')
99
100# -----------------------------------------------------------------------------------------------------------------------
101# Test implementation
102#
103
104CHILD_SUPERVISION_CHECK_TIMEOUT = 2
105PARENT_SUPERVISION_INTERVAL = 1
106
107# Verify the `child` is attached to `parent2`.
108child_table = wpan.parse_list(parent2.get(wpan.WPAN_THREAD_CHILD_TABLE))
109verify(len(child_table) == 1)
110
111# Remove the `child` from allowlist of `parent2` and add it to allowlist
112# of `parent1` instead.
113parent1.allowlist_node(child)
114parent2.un_allowlist_node(child)
115
116# Enable supervision check on the `child` and also on `parent1`.
117
118child.set(
119    wpan.WPAN_CHILD_SUPERVISION_CHECK_TIMEOUT,
120    str(CHILD_SUPERVISION_CHECK_TIMEOUT),
121)
122parent1.set(wpan.WPAN_CHILD_SUPERVISION_INTERVAL, str(PARENT_SUPERVISION_INTERVAL))
123
124# Since child supervision is not enabled on `parent2` and the `child` is
125# removed from allowlist on `parent2`, after the supervision check timeout
126# the `child` should realize that it can no longer talk to its current
127# parent (`parent2`) and try to reattach. All re-attach attempts to `parent2`
128# should fail (due to allowlist) and cause the `child` to get detached and
129# search for a new parent and then attach to `parent1`.
130#
131# To verify that the `child` does get detached and attach to a new parent, we
132# monitor the number of state changes using wpantund property "stat:ncp".
133
134child_num_state_changes = len(wpan.parse_list(child.get("stat:ncp")))
135
136
137def check_child_is_reattached():
138    verify(len(wpan.parse_list(child.get("stat:ncp"))) > child_num_state_changes)
139    verify(child.is_associated())
140
141
142wpan.verify_within(check_child_is_reattached, CHILD_SUPERVISION_CHECK_TIMEOUT / speedup + 5)
143
144# Verify that the `child` is now attached to `parent1`
145child_table = wpan.parse_list(parent1.get(wpan.WPAN_THREAD_CHILD_TABLE))
146verify(len(child_table) == 1)
147
148# Finally verify that the `child` is removed from previous parent's child
149# table (which indicates that the `child` did indeed inform its previous
150# parent).
151
152
153def check_child_is_removed_from_parent2_table():
154    child_table = wpan.parse_list(parent2.get(wpan.WPAN_THREAD_CHILD_TABLE))
155    verify(len(child_table) == 0)
156
157
158wpan.verify_within(check_child_is_removed_from_parent2_table, 1)
159
160# -----------------------------------------------------------------------------------------------------------------------
161# Test finished
162
163wpan.Node.finalize_all_nodes()
164
165print('\'{}\' passed.'.format(test_name))
166