Merge "Allow RNDIS and NCM to be enabled at the same time." am: 2836d8b703 am: 9db81cadec

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1559090

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ia7e6e4698f80bc70112e9338c5c5ff27cbd248ce

2 files changed, 42 insertions, 4 deletions

diff --git a/core/java/android/hardware/usb/UsbManager.java b/core/java/android/hardware/usb/UsbManager.java
index 0ef55f4a60f9..3730790b92e0 100644
--- a/core/java/android/hardware/usb/UsbManager.java
+++ b/core/java/android/hardware/usb/UsbManager.java
@@ -954,7 +954,10 @@ public class UsbManager {
 
     /**
      * Returns whether the given functions are valid inputs to UsbManager.
-     * Currently the empty functions or any of MTP, PTP, RNDIS, MIDI are accepted.
+     * Currently the empty functions or any of MTP, PTP, RNDIS, MIDI, NCM are accepted.
+     *
+     * Only one function may be set at a time, except for RNDIS and NCM, which can be set together
+     * because from a user perspective they are the same function (tethering).
      *
      * @return Whether the mask is settable.
      *
@@ -962,7 +965,9 @@ public class UsbManager {
      */
     public static boolean areSettableFunctions(long functions) {
         return functions == FUNCTION_NONE
-                || ((~SETTABLE_FUNCTIONS & functions) == 0 && Long.bitCount(functions) == 1);
+                || ((~SETTABLE_FUNCTIONS & functions) == 0
+                        && ((Long.bitCount(functions) == 1)
+                                || (functions == (FUNCTION_RNDIS | FUNCTION_NCM))));
     }
 
     /**
diff --git a/tests/UsbTests/src/com/android/server/usb/UsbManagerNoPermTest.java b/tests/UsbTests/src/com/android/server/usb/UsbManagerNoPermTest.java
index a0fd9d40506b..b8bd98ea3f21 100644
--- a/tests/UsbTests/src/com/android/server/usb/UsbManagerNoPermTest.java
+++ b/tests/UsbTests/src/com/android/server/usb/UsbManagerNoPermTest.java
@@ -16,6 +16,8 @@
 
 package com.android.server.usb;
 
+import static org.junit.Assert.assertEquals;
+
 import android.content.Context;
 import android.hardware.usb.UsbManager;
 
@@ -23,12 +25,12 @@ import androidx.test.InstrumentationRegistry;
 import androidx.test.filters.SmallTest;
 import androidx.test.runner.AndroidJUnit4;
 
+import com.android.server.usblib.UsbManagerTestLib;
+
 import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
-import com.android.server.usblib.UsbManagerTestLib;
-
 /**
  * Unit tests for {@link android.hardware.usb.UsbManager}.
  * Note: NOT claimed MANAGE_USB permission in Manifest
@@ -78,4 +80,35 @@ public class UsbManagerNoPermTest {
     public void testUsbApi_SetCurrentFunctions_OnSecurityException() throws Exception {
         mUsbManagerTestLib.testSetCurrentFunctionsEx(UsbManager.FUNCTION_NONE);
     }
+
+    public void assertSettableFunctions(boolean settable, long functions) {
+        assertEquals(
+                "areSettableFunctions(" + UsbManager.usbFunctionsToString(functions) + "):",
+                settable, UsbManager.areSettableFunctions(functions));
+    }
+
+    /**
+     * Tests the behaviour of the static areSettableFunctions method. This method performs no IPCs
+     * and requires no permissions.
+     */
+    @Test
+    public void testUsbManager_AreSettableFunctions() {
+        // NONE is settable.
+        assertSettableFunctions(true, UsbManager.FUNCTION_NONE);
+
+        // MTP, PTP, RNDIS, MIDI, NCM are all settable by themselves.
+        assertSettableFunctions(true, UsbManager.FUNCTION_MTP);
+        assertSettableFunctions(true, UsbManager.FUNCTION_PTP);
+        assertSettableFunctions(true, UsbManager.FUNCTION_RNDIS);
+        assertSettableFunctions(true, UsbManager.FUNCTION_MIDI);
+        assertSettableFunctions(true, UsbManager.FUNCTION_NCM);
+
+        // Setting two functions at the same time is not allowed...
+        assertSettableFunctions(false, UsbManager.FUNCTION_MTP | UsbManager.FUNCTION_PTP);
+        assertSettableFunctions(false, UsbManager.FUNCTION_PTP | UsbManager.FUNCTION_RNDIS);
+        assertSettableFunctions(false, UsbManager.FUNCTION_MIDI | UsbManager.FUNCTION_NCM);
+
+        // ... except in the special case of RNDIS and NCM.
+        assertSettableFunctions(true, UsbManager.FUNCTION_RNDIS | UsbManager.FUNCTION_NCM);
+    }
 }