commit 3969c26127e314f986a0f39932e871fb44a1d518
author Chenbo Feng <fengc@google.com> Tue Mar 19 14:53:57 2019 -0700
committer Chenbo Feng <fengc@google.com> Wed Mar 20 15:33:59 2019 -0700
tree 7d40a9673adc4b6338399cf722c059618d35e73f
parent 9c2dca83373ca74afc7d5cbf12971cd28d278f0b

Fix the UPDATE_DEVICE_STATS permission for multiuser

When an additional user is using the device, netd should filter out the
userId prefix when checking the UPDATE_DEVICE_STATS permission.

Bug: 111560570
Test: run NetStatsHostTest#testASetThreadStatsUid on a non-default
      user profile.

Change-Id: I4353a383bd898340489e7dd70374a63b2ca0938b

server/TrafficController.cpp

diff --git a/server/TrafficController.cpp b/server/TrafficController.cpp
index 74a80fe..9902874 100644
--- a/server/TrafficController.cpp
+++ b/server/TrafficController.cpp
@@ -95,8 +95,11 @@
 }
 
 bool TrafficController::hasUpdateDeviceStatsPermission(uid_t uid) {
-    return ((uid == AID_ROOT) || (uid == AID_SYSTEM) ||
-            mPrivilegedUser.find(uid) != mPrivilegedUser.end());
+    // This implementation is the same logic as method ActivityManager#checkComponentPermission.
+    // It implies that the calling uid can never be the same as PER_USER_RANGE.
+    uint32_t appId = uid % PER_USER_RANGE;
+    return ((appId == AID_ROOT) || (appId == AID_SYSTEM) ||
+            mPrivilegedUser.find(appId) != mPrivilegedUser.end());
 }
 
 const std::string UidPermissionTypeToString(uint8_t permission) {