| #!/usr/bin/env python3 |
| # |
| # Copyright 2022 The Fuchsia Authors |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License"); |
| # you may not use this file except in compliance with the License. |
| # You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| |
| import re |
| from ipaddress import IPv4Address |
| |
| from mobly import asserts, signals, test_runner |
| |
| from antlion.controllers.ap_lib import dhcp_config |
| from antlion.controllers.utils_lib.commands import ip |
| from antlion.test_utils.dhcp import base_test |
| |
| |
| class Dhcpv4DuplicateAddressTest(base_test.Dhcpv4InteropFixture): |
| def setup_test(self) -> None: |
| super().setup_test() |
| self.extra_addresses: list[IPv4Address] = [] |
| self.ap_params = self.setup_ap() |
| self.ap_ip_cmd = ip.LinuxIpCommand(self.access_point.ssh) |
| |
| def teardown_test(self) -> None: |
| super().teardown_test() |
| for ip in self.extra_addresses: |
| self.ap_ip_cmd.remove_ipv4_address(self.ap_params.id, ip) |
| |
| def test_duplicate_address_assignment(self) -> None: |
| """It's possible for a DHCP server to assign an address that already exists on the network. |
| DHCP clients are expected to perform a "gratuitous ARP" of the to-be-assigned address, and |
| refuse to assign that address. Clients should also recover by asking for a different |
| address. |
| """ |
| # Modify subnet to hold fewer addresses. |
| # A '/29' has 8 addresses (6 usable excluding router / broadcast) |
| subnet = next(self.ap_params.network.subnets(new_prefix=29)) |
| subnet_conf = dhcp_config.Subnet( |
| subnet=subnet, |
| router=self.ap_params.ip, |
| # When the DHCP server is considering dynamically allocating an IP address to a client, |
| # it first sends an ICMP Echo request (a ping) to the address being assigned. It waits |
| # for a second, and if no ICMP Echo response has been heard, it assigns the address. |
| # If a response is heard, the lease is abandoned, and the server does not respond to |
| # the client. |
| # The ping-check configuration parameter can be used to control checking - if its value |
| # is false, no ping check is done. |
| additional_parameters={"ping-check": "false"}, |
| ) |
| dhcp_conf = dhcp_config.DhcpConfig(subnets=[subnet_conf]) |
| self.access_point.start_dhcp(dhcp_conf=dhcp_conf) |
| |
| # Add each of the usable IPs as an alias for the router's interface, such that the router |
| # will respond to any pings on it. |
| for ip in subnet.hosts(): |
| self.ap_ip_cmd.add_ipv4_address(self.ap_params.id, ip) |
| # Ensure we remove the address in self.teardown_test() even if the test fails |
| self.extra_addresses.append(ip) |
| |
| self.connect(ap_params=self.ap_params) |
| with asserts.assert_raises(ConnectionError): |
| self.get_device_ipv4_addr() |
| |
| # Per spec, the flow should be: |
| # Discover -> Offer -> Request -> Ack -> client optionally performs DAD |
| dhcp_logs = self.access_point.get_dhcp_logs() |
| if dhcp_logs is None: |
| raise signals.TestError("DHCP logs not found; was the DHCP server started?") |
| |
| for expected_message in [ |
| r"DHCPDISCOVER from \S+", |
| r"DHCPOFFER on [0-9.]+ to \S+", |
| r"DHCPREQUEST for [0-9.]+", |
| r"DHCPACK on [0-9.]+", |
| r"DHCPDECLINE of [0-9.]+ from \S+ via .*: abandoned", |
| r"Abandoning IP address [0-9.]+: declined", |
| ]: |
| asserts.assert_true( |
| re.search(expected_message, dhcp_logs), |
| f"Did not find expected message ({expected_message}) in dhcp logs: {dhcp_logs}" |
| + "\n", |
| ) |
| |
| # Remove each of the IP aliases. |
| # Note: this also removes the router's address (e.g. 192.168.1.1), so pinging the |
| # router after this will not work. |
| while self.extra_addresses: |
| self.ap_ip_cmd.remove_ipv4_address( |
| self.ap_params.id, self.extra_addresses.pop() |
| ) |
| |
| # Now, we should get an address successfully |
| ip = self.get_device_ipv4_addr() |
| dhcp_logs = self.access_point.get_dhcp_logs() |
| if dhcp_logs is None: |
| raise signals.TestError("DHCP logs not found; was the DHCP server started?") |
| |
| expected_string = f"DHCPREQUEST for {ip}" |
| asserts.assert_true( |
| dhcp_logs.count(expected_string) >= 1, |
| f'Incorrect count of DHCP Requests ("{expected_string}") in logs: ' |
| + dhcp_logs |
| + "\n", |
| ) |
| |
| expected_string = f"DHCPACK on {ip}" |
| asserts.assert_true( |
| dhcp_logs.count(expected_string) >= 1, |
| f'Incorrect count of DHCP Acks ("{expected_string}") in logs: ' |
| + dhcp_logs |
| + "\n", |
| ) |
| |
| |
| if __name__ == "__main__": |
| test_runner.main() |