From bd061abd87987e8233aa8fa91d209d42637df8f8 Mon Sep 17 00:00:00 2001 From: Yu Watanabe Date: Thu, 12 Mar 2026 16:48:29 +0900 Subject: [PATCH] test-network: improve reliability of test case of DHCPRELEASE message --- test/test-network/systemd-networkd-tests.py | 81 ++++++++++++++------- 1 file changed, 54 insertions(+), 27 deletions(-) diff --git a/test/test-network/systemd-networkd-tests.py b/test/test-network/systemd-networkd-tests.py index 835f31656e8..b1754cd80d2 100755 --- a/test/test-network/systemd-networkd-tests.py +++ b/test/test-network/systemd-networkd-tests.py @@ -7992,6 +7992,44 @@ class NetworkdDHCPClientTests(unittest.TestCase, Utilities): self.teardown_nftset('addr4', 'network4', 'ifindex') + def _test_dhcp_client_send_release_one(self) -> bool: + start_dnsmasq( + namespace='ns-server', + interface='server', + ipv4_range='192.0.2.100,192.0.2.109', + ipv4_router='192.0.2.1', + ) + + start_networkd() + self.wait_online('client:routable') + + print('## ip -4 address show dev client scope global') + output = check_output('ip -4 address show dev client scope global') + print(output) + self.assertRegex(output, r'192.0.2.10[0-9]/24') + + print('## ip -4 route show dev client') + output = check_output('ip -4 route show dev client') + print(output) + self.assertRegex(output, r'default via 192.0.2.1 proto dhcp src 192.0.2.10[0-9]') + self.assertRegex(output, r'192.0.2.0/24 proto kernel scope link src 192.0.2.10[0-9]') + self.assertRegex(output, r'192.0.2.1 proto dhcp scope link src 192.0.2.10[0-9]') + + networkctl('down', 'client') + + success = False + for _ in range(20): + time.sleep(0.5) + output = read_dnsmasq_log_file() + if 'DHCPRELEASE' in output: + success = True + break + + print('## dnsmasq log') + print(output) + + return success + def test_dhcp_client_send_release(self): check_output('ip netns add ns-bridge') check_output('ip netns exec ns-bridge ip link add bridge99 type bridge') @@ -8013,40 +8051,29 @@ class NetworkdDHCPClientTests(unittest.TestCase, Utilities): check_output('ip netns exec ns-server ip link set server up') check_output('ip netns exec ns-server ip address add 192.0.2.1/24 dev server') - start_dnsmasq( - namespace='ns-server', - interface='server', - ipv4_range='192.0.2.100,192.0.2.109', - ipv4_router='192.0.2.1', - ) - copy_network_unit('25-dhcp-client-simple.network') - start_networkd() - self.wait_online('client:routable') - print('## ip -4 address show dev client scope global') - output = check_output('ip -4 address show dev client scope global') - print(output) - self.assertRegex(output, r'192.0.2.10[0-9]/24') + ''' + Sending DHCPRELEASE is best-effort. Even if send() succeeds, the packet may be dropped later in the + networking stack (e.g. due to unresolved neighbor state or interface teardown). Userspace cannot + reliably determine whether the packet was eventually transmitted or dropped. - print('## ip -4 route show dev client') - output = check_output('ip -4 route show dev client') - print(output) - self.assertRegex(output, r'default via 192.0.2.1 proto dhcp src 192.0.2.10[0-9]') - self.assertRegex(output, r'192.0.2.0/24 proto kernel scope link src 192.0.2.10[0-9]') - self.assertRegex(output, r'192.0.2.1 proto dhcp scope link src 192.0.2.10[0-9]') + Hence, the test below may be flaky. In most cases, neighbor resolution completes quickly enough and + the packet is transmitted before the interface is brought down. Running the test multiple times + should make it sufficiently reliable. + ''' - networkctl('down', 'client') + first = True + for _ in range(5): + if not first: + stop_dnsmasq() + stop_networkd(show_logs=False) - print('## dnsmasq log') - for _ in range(20): - time.sleep(0.5) - output = read_dnsmasq_log_file() - if 'DHCPRELEASE' in output: - print(output) + first = False + + if self._test_dhcp_client_send_release_one(): break else: - print(output) self.fail('Timed out waiting for DHCPRELEASE in dnsmasq log') def test_dhcp_client_ipv4_dbus_status(self):