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openthread/tests/scripts/thread-cert/test_srp_server_anycast_mode.py
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Abtin Keshavarzian d87be657c6 [srp-client] enhance selection of TX jitter based on trigger reason (#10357)
This commit improves the `Srp::Client` mechanism for applying random
jitter delays before sending update messages to the server. It now
supports different jitter ranges based on specific triggers. Since
trigger events are often network-wide, potentially causing
simultaneous SRP re-registration from many nodes, longer jitter
intervals are used to distribute the resulting SRP update
transmissions and avoid congestion.

The following triggers are covered:

- Server switch: Client switching to a new server while already
  connected to a discovered server. This occurs when a new server
  entry appears in Network Data which is preferred over the current
  selection.

- Server restart: Client was previously connected to a server that
  disappeared from Network Data. Later, the same or a new server is
  discovered in Network Data.

- SLAAC address add or remove: This is generally triggered by updates
  to SLAAC prefixes in Network Data (e.g., OMR prefix changes).

- First registration after attach:

  - If the device is attaching to an established Thread mesh
    (e.g., after a reboot or initial pairing), the Network Data it
    receives should already include a server entry, leading to a
    quick server selection after attach. If server selection occurs
    within a short window, a shorter TX jitter is used, allowing the
    device to register quickly and become discoverable.

  - If server discovery takes longer, a longer TX jitter is used. This
    situation can indicate a server/BR starting up or a network-wide
    restart of many nodes (e.g., due to a power outage).

This commit introduces `TxJitter` class to manage the requested TX
jitter based on a trigger reason. It tracks the time of the event
that triggered a longer jitter request. If the update message is sent
immediately after the trigger event, the requested maximum jitter is
applied. However, if the update message is sent later, the maximum
jitter is adjusted proportionally to the time elapsed since the
trigger event. If the elapsed time exceeds the requested maximum
jitter interval, the default short jitter is applied to avoid
unnecessary registration delay.
2024-07-02 08:52:28 -07:00

202 lines
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Python
Executable File

#!/usr/bin/env python3
#
# Copyright (c) 2021, 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.
#
import unittest
import config
import thread_cert
# Test description:
#
# This test covers the SRP server's behavior using different address
# modes (unicast or anycast). The address mode indicates how the SRP
# server determines its address and port and how this info is
# published in the Thread Network Data. When using anycast address
# mode, the SRP server and DNS server/resolver will both listen on port
# 53 and they re-use the same socket. This test verifies the behavior of
# both modules in such a situation.
#
#
# Topology:
#
# One leader and two router nodes, all connected. The leader acts as SRP
# server and DNS resolver. One router acts as SRP client, and the
# other acts as DNS client browsing for registered service names.
#
SERVER = 1
CLIENT = 2
BROWSER = 3
DOMAIN = 'default.service.arpa.'
HOST = 'host'
INSTANCE = 'ins1'
SERVICE = '_srv._udp'
SERVICE_PORT = 1313
SRP_SERVER_ANYCAST_PORT = 53
SRP_SERVER_ANYCAST_SEQ_NUM = 17
DNS_RESOLVER_PORT = 53
THREAD_ENTERPRISE_NUMBER = 44970
ANYCAST_SERVICE_NUM = 0x5c
UNICAST_SERVICE_NUM = 0x5d
class TestSrpServerAnycastMode(thread_cert.TestCase):
SUPPORT_NCP = False
USE_MESSAGE_FACTORY = False
TOPOLOGY = {
SERVER: {
'mode': 'rdn',
},
CLIENT: {
'mode': 'rdn',
},
BROWSER: {
'mode': 'rdn',
},
}
def test(self):
server = self.nodes[SERVER]
client = self.nodes[CLIENT]
browser = self.nodes[BROWSER]
#-------------------------------------------------------------------
# Form the network.
server.start()
self.simulator.go(config.LEADER_STARTUP_DELAY)
self.assertEqual(server.get_state(), 'leader')
client.start()
browser.start()
self.simulator.go(config.ROUTER_STARTUP_DELAY)
self.assertEqual(client.get_state(), 'router')
self.assertEqual(browser.get_state(), 'router')
#-------------------------------------------------------------------
# Go through the entire test twice, first time using anycast address
# mode and second time using unicast address mode.
for addr_mode in ['anycast', 'unicast']:
#---------------------------------------------------------------
# Set the SRP server address mode and start the SRP server.
server.srp_server_set_addr_mode(addr_mode)
if addr_mode == 'anycast':
server.srp_server_set_anycast_seq_num(SRP_SERVER_ANYCAST_SEQ_NUM)
self.assertEqual(server.srp_server_get_anycast_seq_num(), SRP_SERVER_ANYCAST_SEQ_NUM)
self.assertEqual(server.srp_server_get_addr_mode(), addr_mode)
server.srp_server_set_enabled(True)
self.simulator.go(5)
#---------------------------------------------------------------
# Verify the published SRP server info in the Network Data.
netdata_services = client.get_services()
self.assertEqual(len(netdata_services), 1)
netdata_service = netdata_services[0]
self.assertEqual(int(netdata_service[0]), THREAD_ENTERPRISE_NUMBER)
data = bytes.fromhex(netdata_service[1])
self.assertEqual(netdata_service[3], 's')
if addr_mode == 'anycast':
self.assertTrue(len(data) >= 2)
self.assertEqual(data[0], ANYCAST_SERVICE_NUM)
self.assertEqual(data[1], SRP_SERVER_ANYCAST_SEQ_NUM)
else:
self.assertTrue(len(data) >= 1)
self.assertEqual(data[0], UNICAST_SERVICE_NUM)
self.assertEqual(netdata_service[3], 's')
#---------------------------------------------------------------
# Enable auto-start on SRP client. Verify that it does find the
# server and uses the proper address and port number.
client.srp_client_enable_auto_start_mode()
self.simulator.go(15)
if addr_mode == 'anycast':
server_alocs = server.get_ip6_address(config.ADDRESS_TYPE.ALOC)
self.assertEqual(client.srp_client_get_state(), 'Enabled')
self.assertIn(client.srp_client_get_server_address(), server_alocs)
self.assertEqual(client.srp_client_get_server_port(), SRP_SERVER_ANYCAST_PORT)
else:
self.assertIn(client.srp_client_get_server_address(), server.get_mleid())
self.assertEqual(client.srp_client_get_server_port(), server.get_srp_server_port())
#---------------------------------------------------------------
# Add a service on the SRP client and verify its successful
# registration with SRP server.
client.srp_client_set_host_name(HOST)
client.srp_client_set_host_address(client.get_mleid())
client.srp_client_add_service(INSTANCE, SERVICE, SERVICE_PORT)
self.simulator.go(5)
client_services = client.srp_client_get_services()
self.assertEqual(len(client_services), 1)
client_service = client_services[0]
self.assertEqual(client_service['instance'], INSTANCE)
self.assertEqual(client_service['name'], SERVICE)
self.assertEqual(int(client_service['port']), SERVICE_PORT)
self.assertEqual(client_service['state'], 'Registered')
#---------------------------------------------------------------
# Browse for a matching service name and verify that the registered
# service is successfully found. Since there is only one match the
# server should include the service info in additional section.
service_instances = browser.dns_browse(f'{SERVICE}.{DOMAIN}', server.get_mleid(), DNS_RESOLVER_PORT)
self.assertEqual({INSTANCE}, set(service_instances.keys()))
service_instance = service_instances[INSTANCE]
self.assertEqual(service_instance['host'], f'{HOST}.{DOMAIN}')
self.assertEqual(int(service_instance['port']), SERVICE_PORT)
self.assertEqual(service_instance['address'], client.get_mleid())
#---------------------------------------------------------------
# Stop SRP client and server and clear host (and service) on the
# client.
client.srp_client_clear_host()
client.srp_client_stop()
server.srp_server_set_enabled(False)
if __name__ == '__main__':
unittest.main()