Introduce TC-CNET-4.4 automation (#32176)

- Automate TC-CNET-4.4 per test plan.

Testing done:

- Ran against ESP32 and succeeded.

Co-authored-by: cecille <cecille@google.com>

Author: 2 people

src/python_testing/TC_CNET_4_4.py

@@ -0,0 +1,132 @@
+#
+#    Copyright (c) 2024 Project CHIP Authors
+#    All rights reserved.
+#
+#    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 logging
+import random
+import string
+from typing import Optional
+
+import chip.clusters as Clusters
+from chip.clusters.Types import NullValue
+from matter_testing_support import MatterBaseTest, TestStep, async_test_body, default_matter_test_main, type_matches
+from mobly import asserts
+
+
+class TC_CNET_4_4(MatterBaseTest):
+    def steps_TC_CNET_4_4(self):
+        return [TestStep("precondition", "TH is commissioned", is_commissioning=True),
+                TestStep(1, 'TH reads from the DUT the Network Commissioning Cluster FeatureMap. If the FeatureMap does not include the WI flag (bit 0), skip the remaining steps in this test case'),
+                TestStep(2, 'TH reads from the DUT the SupportedWifiBands attribute and saves as supported_wifi_bands'),
+                TestStep(3, 'TH reads from the DUT the Networks attribute.'),
+                TestStep(4, 'TH sends ScanNetworks command to the DUT with the SSID field set to null and Breadcrumb field set to 1'),
+                TestStep(5, 'TH reads from the DUT the Breadcrumb attribute from the General Commissioning Cluster'),
+                TestStep(6, 'TH sends ScanNetworks Command to the DUT with SSID field set to known_ssid and Breadcrumb field set to 2'),
+                TestStep(7, 'TH reads Breadcrumb attribute from the General Commissioning Cluster'),
+                TestStep(8, 'TH sends ScanNetworks Command to the DUT with SSID field set to a string of 31 random alphabetical characters and Breadcrumb field set to 2')]
+
+    def def_TC_CNET_4_4(self):
+        return '[TC-CNET-4.4] [Wi-Fi] Verification for ScanNetworks command [DUT-Server]'
+
+    def pics_TC_CNET_4_4(self):
+        return ['CNET.S']
+
+    @async_test_body
+    async def test_TC_CNET_4_4(self):
+        # Commissioning is already done
+        self.step("precondition")
+
+        cnet = Clusters.NetworkCommissioning
+        attr = cnet.Attributes
+
+        self.step(1)
+        feature_map = await self.read_single_attribute_check_success(cluster=cnet, attribute=attr.FeatureMap)
+        if not (feature_map & cnet.Bitmaps.Feature.kWiFiNetworkInterface):
+            logging.info('Device does not support WiFi on endpoint, skipping remaining steps')
+            self.skip_all_remaining_steps(2)
+            return
+
+        self.step(2)
+        supported_wifi_bands = await self.read_single_attribute_check_success(cluster=cnet, attribute=attr.SupportedWiFiBands)
+
+        self.step(3)
+        networks = await self.read_single_attribute_check_success(cluster=cnet, attribute=attr.Networks)
+        connected = [network for network in networks if network.connected is True]
+        asserts.assert_greater_equal(len(connected), 1, "Did not find any connected networks on a commissioned device")
+        known_ssid = connected[0].networkID
+
+        async def scan_and_check(ssid_to_scan: Optional[bytes], breadcrumb: int, expect_results: bool = True):
+            all_security = 0
+            for security_bitmask in cnet.Bitmaps.WiFiSecurityBitmap:
+                all_security |= security_bitmask
+
+            ssid = ssid_to_scan if ssid_to_scan is not None else NullValue
+            cmd = cnet.Commands.ScanNetworks(ssid=ssid, breadcrumb=breadcrumb)
+            scan_results = await self.send_single_cmd(cmd=cmd)
+            asserts.assert_true(type_matches(scan_results, cnet.Commands.ScanNetworksResponse),
+                                "Unexpected value returned from scan network")
+            logging.info(f"Scan results: {scan_results}")
+
+            if scan_results.debugText:
+                debug_text_len = len(scan_results.debug_text)
+                asserts.assert_less_equal(debug_text_len, 512, f"DebugText length {debug_text_len} was out of range")
+
+            if expect_results:
+                asserts.assert_equal(scan_results.networkingStatus, cnet.Enums.NetworkCommissioningStatusEnum.kSuccess,
+                                     f"ScanNetworks was expected to have succeeded, got {scan_results.networkingStatus} instead")
+                asserts.assert_greater_equal(len(scan_results.wiFiScanResults), 1, "No responses returned from ScanNetwork command")
+            else:
+                asserts.assert_equal(scan_results.networkingStatus, cnet.Enums.NetworkCommissioningStatusEnum.kNetworkNotFound,
+                                     f"ScanNetworks was expected to received NetworkNotFound(5), got {scan_results.networkingStatus} instead")
+                return
+
+            for network in scan_results.wiFiScanResults:
+                asserts.assert_true((network.security & ~all_security) == 0, "Unexpected bitmap in the security field")
+                asserts.assert_less_equal(len(network.ssid), 32, f"Returned SSID {network.ssid} is too long")
+                if ssid_to_scan is not None:
+                    asserts.assert_equal(network.ssid, ssid_to_scan, "Unexpected SSID returned in directed scan")
+                asserts.assert_true(type_matches(network.bssid, bytes), "Incorrect type for BSSID")
+                asserts.assert_equal(len(network.bssid), 6, "Unexpected length of BSSID")
+                # TODO: this is inherited from the old test plan, but we should match the channel to the supported band. This range is unreasonably large.
+                asserts.assert_less_equal(network.channel, 65535, "Unexpected channel value")
+                if network.wiFiBand:
+                    asserts.assert_true(network.wiFiBand in supported_wifi_bands,
+                                        "Listed wiFiBand is not in supported_wifi_bands")
+                if network.rssi:
+                    asserts.assert_greater_equal(network.rssi, -120, "RSSI out of range")
+                    asserts.assert_less_equal(network.rssi, 0, "RSSI out of range")
+
+        self.step(4)
+        await scan_and_check(ssid_to_scan=None, breadcrumb=1, expect_results=True)
+
+        self.step(5)
+        breadcrumb = await self.read_single_attribute_check_success(cluster=Clusters.GeneralCommissioning, attribute=Clusters.GeneralCommissioning.Attributes.Breadcrumb, endpoint=0)
+        asserts.assert_equal(breadcrumb, 1, "Incorrect breadcrumb value")
+
+        self.step(6)
+        await scan_and_check(ssid_to_scan=known_ssid, breadcrumb=2, expect_results=True)
+
+        self.step(7)
+        breadcrumb = await self.read_single_attribute_check_success(cluster=Clusters.GeneralCommissioning, attribute=Clusters.GeneralCommissioning.Attributes.Breadcrumb, endpoint=0)
+        asserts.assert_equal(breadcrumb, 2, "Incorrect breadcrumb value")
+
+        self.step(8)
+        random_ssid = ''.join(random.choice(string.ascii_letters) for _ in range(31)).encode("utf-8")
+        await scan_and_check(ssid_to_scan=random_ssid, breadcrumb=2, expect_results=False)
+
+
+if __name__ == "__main__":
+    default_matter_test_main()