Verify the access to the mdnsd socket is blocked from Android U

The untrusted apps should not directly access /dev/socket/mdnsd since
Android U(SDK 34). For untrusted apps built with target SDK 33 or less,
it should still be able to access the mdnsd socket. Fix the mts test
suits from mts-networking to mts-tethering. If the test suits is marked
as mts-networking, it would run in NetworkStack MTS, which isn't really
what is tested in the tests.

Test: atest CtsNetTestCases CtsNetTestCasesMaxTargetSdk33
Bug: 267102290
Change-Id: I851c181fa7489115fb1f335a369830078f5a5c14
diff --git a/TEST_MAPPING b/TEST_MAPPING
index 34646e2..4d3ecdf 100644
--- a/TEST_MAPPING
+++ b/TEST_MAPPING
@@ -58,6 +58,17 @@
       ]
     },
     {
+      "name": "CtsNetTestCasesMaxTargetSdk33",
+      "options": [
+        {
+          "exclude-annotation": "com.android.testutils.SkipPresubmit"
+        },
+        {
+          "exclude-annotation": "androidx.test.filters.RequiresDevice"
+        }
+      ]
+    },
+    {
       "name": "bpf_existence_test"
     },
     {
@@ -143,6 +154,17 @@
         }
       ]
     },
+    {
+      "name": "CtsNetTestCasesMaxTargetSdk33[CaptivePortalLoginGoogle.apk+NetworkStackGoogle.apk+com.google.android.resolv.apex+com.google.android.tethering.apex]",
+      "options": [
+        {
+          "exclude-annotation": "com.android.testutils.SkipPresubmit"
+        },
+        {
+          "exclude-annotation": "androidx.test.filters.RequiresDevice"
+        }
+      ]
+    },
     // Test with APK modules only, in cases where APEX is not supported, or the other modules
     // were simply not updated
     {
diff --git a/tests/cts/net/Android.bp b/tests/cts/net/Android.bp
index 23cb15c..f9fe5b0 100644
--- a/tests/cts/net/Android.bp
+++ b/tests/cts/net/Android.bp
@@ -114,34 +114,39 @@
     ],
 }
 
-android_test {
-    name: "CtsNetTestCasesMaxTargetSdk31",  // Must match CtsNetTestCasesMaxTargetSdk31 annotation.
+java_defaults {
+    name: "CtsNetTestCasesMaxTargetSdkDefaults",
     defaults: [
         "CtsNetTestCasesDefaults",
         "CtsNetTestCasesApiStableDefaults",
     ],
-    target_sdk_version: "31",
-    package_name: "android.net.cts.maxtargetsdk31",  // CTS package names must be unique.
-    instrumentation_target_package: "android.net.cts.maxtargetsdk31",
     test_suites: [
         "cts",
         "general-tests",
-        "mts-networking",
+        "mts-tethering",
     ],
 }
 
 android_test {
+    name: "CtsNetTestCasesMaxTargetSdk33",  // Must match CtsNetTestCasesMaxTargetSdk33 annotation.
+    defaults: ["CtsNetTestCasesMaxTargetSdkDefaults"],
+    target_sdk_version: "33",
+    package_name: "android.net.cts.maxtargetsdk33",
+    instrumentation_target_package: "android.net.cts.maxtargetsdk33",
+}
+
+android_test {
+    name: "CtsNetTestCasesMaxTargetSdk31",  // Must match CtsNetTestCasesMaxTargetSdk31 annotation.
+    defaults: ["CtsNetTestCasesMaxTargetSdkDefaults"],
+    target_sdk_version: "31",
+    package_name: "android.net.cts.maxtargetsdk31",  // CTS package names must be unique.
+    instrumentation_target_package: "android.net.cts.maxtargetsdk31",
+}
+
+android_test {
     name: "CtsNetTestCasesMaxTargetSdk30",  // Must match CtsNetTestCasesMaxTargetSdk30 annotation.
-    defaults: [
-        "CtsNetTestCasesDefaults",
-        "CtsNetTestCasesApiStableDefaults",
-    ],
+    defaults: ["CtsNetTestCasesMaxTargetSdkDefaults"],
     target_sdk_version: "30",
     package_name: "android.net.cts.maxtargetsdk30",  // CTS package names must be unique.
     instrumentation_target_package: "android.net.cts.maxtargetsdk30",
-    test_suites: [
-        "cts",
-        "general-tests",
-        "mts-networking",
-    ],
 }
diff --git a/tests/cts/net/src/android/net/cts/NsdManagerTest.kt b/tests/cts/net/src/android/net/cts/NsdManagerTest.kt
index 093c7f8..de5e46f 100644
--- a/tests/cts/net/src/android/net/cts/NsdManagerTest.kt
+++ b/tests/cts/net/src/android/net/cts/NsdManagerTest.kt
@@ -20,6 +20,8 @@
 import android.net.ConnectivityManager
 import android.net.ConnectivityManager.NetworkCallback
 import android.net.LinkProperties
+import android.net.LocalSocket
+import android.net.LocalSocketAddress
 import android.net.Network
 import android.net.NetworkAgentConfig
 import android.net.NetworkCapabilities
@@ -63,6 +65,8 @@
 import android.util.Log
 import androidx.test.platform.app.InstrumentationRegistry
 import androidx.test.runner.AndroidJUnit4
+import com.android.compatibility.common.util.PollingCheck
+import com.android.compatibility.common.util.PropertyUtil
 import com.android.net.module.util.ArrayTrackRecord
 import com.android.net.module.util.TrackRecord
 import com.android.networkstack.apishim.NsdShimImpl
@@ -72,14 +76,17 @@
 import com.android.testutils.TestableNetworkAgent
 import com.android.testutils.TestableNetworkCallback
 import com.android.testutils.filters.CtsNetTestCasesMaxTargetSdk30
+import com.android.testutils.filters.CtsNetTestCasesMaxTargetSdk33
 import com.android.testutils.runAsShell
 import com.android.testutils.tryTest
 import com.android.testutils.waitForIdle
 import java.io.File
+import java.io.IOException
 import java.net.ServerSocket
 import java.nio.charset.StandardCharsets
 import java.util.Random
 import java.util.concurrent.Executor
+import kotlin.math.min
 import kotlin.test.assertEquals
 import kotlin.test.assertFailsWith
 import kotlin.test.assertNotNull
@@ -763,6 +770,69 @@
         }
     }
 
+    private fun checkConnectSocketToMdnsd(shouldFail: Boolean) {
+        val discoveryRecord = NsdDiscoveryRecord()
+        val localSocket = LocalSocket()
+        tryTest {
+            // Discover any service from NsdManager to enforce NsdService to start the mdnsd.
+            nsdManager.discoverServices(serviceType, NsdManager.PROTOCOL_DNS_SD, discoveryRecord)
+            discoveryRecord.expectCallback<DiscoveryStarted>()
+
+            // Checks the /dev/socket/mdnsd is created.
+            val socket = File("/dev/socket/mdnsd")
+            val doesSocketExist = PollingCheck.waitFor(
+                TIMEOUT_MS,
+                {
+                    socket.exists()
+                },
+                { doesSocketExist ->
+                    doesSocketExist
+                },
+            )
+
+            // If the socket is not created, then no need to check the access.
+            if (doesSocketExist) {
+                // Create a LocalSocket and try to connect to mdnsd.
+                assertFalse("LocalSocket is connected.", localSocket.isConnected)
+                val address = LocalSocketAddress("mdnsd", LocalSocketAddress.Namespace.RESERVED)
+                if (shouldFail) {
+                    assertFailsWith<IOException>("Expect fail but socket connected") {
+                        localSocket.connect(address)
+                    }
+                } else {
+                    localSocket.connect(address)
+                    assertTrue("LocalSocket is not connected.", localSocket.isConnected)
+                }
+            }
+        } cleanup {
+            localSocket.close()
+            nsdManager.stopServiceDiscovery(discoveryRecord)
+            discoveryRecord.expectCallback<DiscoveryStopped>()
+        }
+    }
+
+    /**
+     * Starting from Android U, the access to the /dev/socket/mdnsd is blocked by the
+     * sepolicy(b/265364111).
+     */
+    @DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.TIRAMISU)
+    @Test
+    fun testCannotConnectSocketToMdnsd() {
+        val targetSdkVersion = context.packageManager
+                .getTargetSdkVersion(context.applicationInfo.packageName)
+        assumeTrue(targetSdkVersion > Build.VERSION_CODES.TIRAMISU)
+        val firstApiLevel = min(PropertyUtil.getFirstApiLevel(), PropertyUtil.getVendorApiLevel())
+        // The sepolicy is implemented in the vendor image, so the access may not be blocked if
+        // the vendor image is not update to date.
+        assumeTrue(firstApiLevel > Build.VERSION_CODES.TIRAMISU)
+        checkConnectSocketToMdnsd(shouldFail = true)
+    }
+
+    @Test @CtsNetTestCasesMaxTargetSdk33("mdnsd socket is accessible up to target SDK 33")
+    fun testCanConnectSocketToMdnsd() {
+        checkConnectSocketToMdnsd(shouldFail = false)
+    }
+
     @Test @CtsNetTestCasesMaxTargetSdk30("Socket is started with the service up to target SDK 30")
     fun testManagerCreatesLegacySocket() {
         nsdManager // Ensure the lazy-init member is initialized, so NsdManager is created