From eb137aebc998cb6869d3679bec409746658d97c6 Mon Sep 17 00:00:00 2001
From: Chalard Jean <jchalard@google.com>
Date: Tue, 26 Sep 2017 15:45:18 +0900
Subject: [PATCH] Do not throw on call to isTetheringSupported w/o permission

...just return false instead.

Test: Made an app to test this. Made sure it doesn't have
Test: the required permission. Checked it crashes with
Test: SecurityException without this change. Checked that it
Test: doesn't with it.

Merged-In: Ib5b17a7f68c1327f47fe1f54c0454c51f4226907
Change-Id: Id20d3c240ec5d70d085e0366b92ab3a514f3e7c8
(cherry picked from commit ffacaef81322fcdcaba54ec3c6b6026c23c6ff3c)
---
 core/java/android/net/ConnectivityManager.java | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/core/java/android/net/ConnectivityManager.java b/core/java/android/net/ConnectivityManager.java
index 583cf32049..0ccebc1c7a 100644
--- a/core/java/android/net/ConnectivityManager.java
+++ b/core/java/android/net/ConnectivityManager.java
@@ -2084,16 +2084,30 @@ public class ConnectivityManager {
      * {@code ro.tether.denied} system property, Settings.TETHER_SUPPORTED or
      * due to device configuration.
      *
+     * <p>If this app does not have permission to use this API, it will always
+     * return false rather than throw an exception.</p>
+     *
+     * <p>If the device has a hotspot provisioning app, the caller is required to hold the
+     * {@link android.Manifest.permission.TETHER_PRIVILEGED} permission.</p>
+     *
+     * <p>Otherwise, this method requires the caller to hold the ability to modify system
+     * settings as determined by {@link android.provider.Settings.System#canWrite}.</p>
+     *
      * @return a boolean - {@code true} indicating Tethering is supported.
      *
      * {@hide}
      */
     @SystemApi
-    @RequiresPermission(android.Manifest.permission.TETHER_PRIVILEGED)
+    @RequiresPermission(anyOf = {android.Manifest.permission.TETHER_PRIVILEGED,
+            android.Manifest.permission.WRITE_SETTINGS})
     public boolean isTetheringSupported() {
+        String pkgName = mContext.getOpPackageName();
         try {
-            String pkgName = mContext.getOpPackageName();
             return mService.isTetheringSupported(pkgName);
+        } catch (SecurityException e) {
+            // This API is not available to this caller, but for backward-compatibility
+            // this will just return false instead of throwing.
+            return false;
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }