Check system_server PID in NetworkStack calls

Add a check that callers with UID 1000 always have the same PID. This is
a proxy for checking that no system is designed to bind to the network
stack unless it is the system_server, as otherwise either the
system_server would start crashing, or that system would not have access
to binder calls.

Also remove access from PHONE_UID as it is not being used.

Test: Flashed, WiFi working, Bluetooth reverse tethering shows no
      permission issue.
Bug: 133209255
(patched automatically from Ib848aaaedfd599c1d4437378846c7dda74352019)
(command: git -C [qt repo] show -p 4895c5 | patch -p3)

Merged-In: I1205ae4b1062fe78f1e2283d6c308caa58651e86
Change-Id: I42215bd8b14d66d0150e7dac04fbb28feef991a6

1 files changed, 3 insertions, 0 deletions

diff --git a/src/com/android/server/NetworkStackService.java b/src/com/android/server/NetworkStackService.java
index c394d4c..91cc8c3 100644
--- a/src/com/android/server/NetworkStackService.java
+++ b/src/com/android/server/NetworkStackService.java
@@ -189,6 +189,7 @@ public class NetworkStackService extends Service {
         @Override
         public void makeNetworkMonitor(Network network, String name, INetworkMonitorCallbacks cb)
                 throws RemoteException {
+            checkNetworkStackCallingPermission();
             updateSystemAidlVersion(cb.getInterfaceVersion());
             final SharedLog log = addValidationLogs(network, name);
             final NetworkMonitor nm = new NetworkMonitor(mContext, cb, network, log);
@@ -197,6 +198,7 @@ public class NetworkStackService extends Service {
 
         @Override
         public void makeIpClient(String ifName, IIpClientCallbacks cb) throws RemoteException {
+            checkNetworkStackCallingPermission();
             updateSystemAidlVersion(cb.getInterfaceVersion());
             final IpClient ipClient = new IpClient(mContext, ifName, cb, mObserverRegistry, this);
 
@@ -222,6 +224,7 @@ public class NetworkStackService extends Service {
         @Override
         public void fetchIpMemoryStore(@NonNull final IIpMemoryStoreCallbacks cb)
                 throws RemoteException {
+            checkNetworkStackCallingPermission();
             updateSystemAidlVersion(cb.getInterfaceVersion());
             cb.onIpMemoryStoreFetched(mIpMemoryStoreService);
         }