Adding shell commands for modifying content.

1. Added methods to the ActivityManagerService remote interface
   that allow accessing content providers outside of an application.
   These methods are guarded by an internal signature protected
   permission which is given to the shell user. This enables a
   shell program to access content providers.

2. Implemented a shell command that takes as input as standart
   fagls with values and manipulates content via the content provider
   mechanism.

Change-Id: I2943f8b59fbab33eb623458fa01ea61a077b9845
diff --git a/services/java/com/android/server/am/ActivityManagerService.java b/services/java/com/android/server/am/ActivityManagerService.java
index 9d5caae..7852123 100644
--- a/services/java/com/android/server/am/ActivityManagerService.java
+++ b/services/java/com/android/server/am/ActivityManagerService.java
@@ -5754,7 +5754,7 @@
                 ComponentName comp = new ComponentName(cpi.packageName, cpi.name);
                 ContentProviderRecord cpr = mProviderMap.getProviderByClass(comp, userId);
                 if (cpr == null) {
-                    cpr = new ContentProviderRecord(cpi, app.info, comp);
+                    cpr = new ContentProviderRecord(this, cpi, app.info, comp);
                     mProviderMap.putProviderByClass(comp, cpr);
                 }
                 if (DEBUG_MU)
@@ -5826,7 +5826,8 @@
         return msg;
     }
 
-    boolean incProviderCount(ProcessRecord r, ContentProviderRecord cpr) {
+    boolean incProviderCount(ProcessRecord r, final ContentProviderRecord cpr,
+            IBinder externalProcessToken) {
         if (r != null) {
             Integer cnt = r.conProviders.get(cpr);
             if (DEBUG_PROVIDER) Slog.v(TAG,
@@ -5842,12 +5843,13 @@
                 r.conProviders.put(cpr, new Integer(cnt.intValue()+1));
             }
         } else {
-            cpr.externals++;
+            cpr.addExternalProcessHandleLocked(externalProcessToken);
         }
         return false;
     }
 
-    boolean decProviderCount(ProcessRecord r, ContentProviderRecord cpr) {
+    boolean decProviderCount(ProcessRecord r, final ContentProviderRecord cpr,
+            IBinder externalProcessToken) {
         if (r != null) {
             Integer cnt = r.conProviders.get(cpr);
             if (DEBUG_PROVIDER) Slog.v(TAG,
@@ -5863,13 +5865,13 @@
                 r.conProviders.put(cpr, new Integer(cnt.intValue()-1));
             }
         } else {
-            cpr.externals++;
+            cpr.removeExternalProcessHandleLocked(externalProcessToken);
         }
         return false;
     }
 
     private final ContentProviderHolder getContentProviderImpl(IApplicationThread caller,
-            String name) {
+            String name, IBinder token) {
         ContentProviderRecord cpr;
         ProviderInfo cpi = null;
 
@@ -5913,7 +5915,7 @@
 
                 // In this case the provider instance already exists, so we can
                 // return it right away.
-                final boolean countChanged = incProviderCount(r, cpr);
+                final boolean countChanged = incProviderCount(r, cpr, token);
                 if (countChanged) {
                     if (cpr.proc != null && r.setAdj <= ProcessList.PERCEPTIBLE_APP_ADJ) {
                         // If this is a perceptible app accessing the provider,
@@ -5947,7 +5949,7 @@
                         Slog.i(TAG,
                                 "Existing provider " + cpr.name.flattenToShortString()
                                 + " is crashing; detaching " + r);
-                        boolean lastRef = decProviderCount(r, cpr);
+                        boolean lastRef = decProviderCount(r, cpr, token);
                         appDiedLocked(cpr.proc, cpr.proc.pid, cpr.proc.thread);
                         if (!lastRef) {
                             // This wasn't the last ref our process had on
@@ -6005,7 +6007,7 @@
                             return null;
                         }
                         ai = getAppInfoForUser(ai, Binder.getOrigCallingUser());
-                        cpr = new ContentProviderRecord(cpi, ai, comp);
+                        cpr = new ContentProviderRecord(this, cpi, ai, comp);
                     } catch (RemoteException ex) {
                         // pm is in same process, this will never happen.
                     }
@@ -6075,8 +6077,9 @@
                 if (firstClass) {
                     mProviderMap.putProviderByClass(comp, cpr);
                 }
+
                 mProviderMap.putProviderByName(name, cpr);
-                incProviderCount(r, cpr);
+                incProviderCount(r, cpr, token);
             }
         }
 
@@ -6116,12 +6119,17 @@
             throw new SecurityException(msg);
         }
 
-        ContentProviderHolder contentProvider = getContentProviderImpl(caller, name);
-        return contentProvider;
+        return getContentProviderImpl(caller, name, null);
     }
 
-    private ContentProviderHolder getContentProviderExternal(String name) {
-        return getContentProviderImpl(null, name);
+    public ContentProviderHolder getContentProviderExternal(String name, IBinder token) {
+        enforceCallingPermission(android.Manifest.permission.ACCESS_CONTENT_PROVIDERS_EXTERNALLY,
+            "Do not have permission in call getContentProviderExternal()");
+        return getContentProviderExternalUnchecked(name, token);
+    }
+
+    private ContentProviderHolder getContentProviderExternalUnchecked(String name,IBinder token) {
+        return getContentProviderImpl(null, name, token);
     }
 
     /**
@@ -6157,14 +6165,20 @@
                         + cpr.info.name + " in process " + r.processName);
                 return;
             } else {
-                if (decProviderCount(r, localCpr)) {
+                if (decProviderCount(r, localCpr, null)) {
                     updateOomAdjLocked();
                 }
             }
         }
     }
 
-    private void removeContentProviderExternal(String name) {
+    public void removeContentProviderExternal(String name, IBinder token) {
+        enforceCallingPermission(android.Manifest.permission.ACCESS_CONTENT_PROVIDERS_EXTERNALLY,
+            "Do not have permission in call removeContentProviderExternal()");
+        removeContentProviderExternalUnchecked(name, token);
+    }
+
+    private void removeContentProviderExternalUnchecked(String name, IBinder token) {
         synchronized (this) {
             ContentProviderRecord cpr = mProviderMap.getProviderByName(name,
                     Binder.getOrigCallingUser());
@@ -6178,11 +6192,18 @@
             ComponentName comp = new ComponentName(cpr.info.packageName, cpr.info.name);
             ContentProviderRecord localCpr = mProviderMap.getProviderByClass(comp,
                     Binder.getOrigCallingUser());
-            localCpr.externals--;
-            if (localCpr.externals < 0) {
-                Slog.e(TAG, "Externals < 0 for content provider " + localCpr);
+            if (localCpr.hasExternalProcessHandles()) {
+                if (localCpr.removeExternalProcessHandleLocked(token)) {
+                    updateOomAdjLocked();
+                } else {
+                    Slog.e(TAG, "Attmpt to remove content provider " + localCpr
+                            + " with no external reference for token: "
+                            + token + ".");
+                }
+            } else {
+                Slog.e(TAG, "Attmpt to remove content provider: " + localCpr
+                        + " with no external references.");
             }
-            updateOomAdjLocked();
         }
     }
     
@@ -6286,7 +6307,7 @@
         ContentProviderHolder holder = null;
 
         try {
-            holder = getContentProviderExternal(name);
+            holder = getContentProviderExternalUnchecked(name, null);
             if (holder != null) {
                 return holder.provider.getType(uri);
             }
@@ -6295,7 +6316,7 @@
             return null;
         } finally {
             if (holder != null) {
-                removeContentProviderExternal(name);
+                removeContentProviderExternalUnchecked(name, null);
             }
             Binder.restoreCallingIdentity(ident);
         }
@@ -6400,7 +6421,7 @@
     public ParcelFileDescriptor openContentUri(Uri uri) throws RemoteException {
         enforceNotIsolatedCaller("openContentUri");
         String name = uri.getAuthority();
-        ContentProviderHolder cph = getContentProviderExternal(name);
+        ContentProviderHolder cph = getContentProviderExternalUnchecked(name, null);
         ParcelFileDescriptor pfd = null;
         if (cph != null) {
             // We record the binder invoker's uid in thread-local storage before
@@ -6422,7 +6443,7 @@
             }
 
             // We've got the fd now, so we're done with the provider.
-            removeContentProviderExternal(name);
+            removeContentProviderExternalUnchecked(name, null);
         } else {
             Slog.d(TAG, "Failed to get provider for authority '" + name + "'");
         }
@@ -10253,7 +10274,7 @@
             for (int i=0; i<NL; i++) {
                 ContentProviderRecord cpr = (ContentProviderRecord)
                         mLaunchingProviders.get(i);
-                if (cpr.clients.size() <= 0 && cpr.externals <= 0) {
+                if (cpr.clients.size() <= 0 && !cpr.hasExternalProcessHandles()) {
                     synchronized (cpr) {
                         cpr.launchingApp = null;
                         cpr.notifyAll();
@@ -13455,7 +13476,7 @@
                 // If the provider has external (non-framework) process
                 // dependencies, ensure that its adjustment is at least
                 // FOREGROUND_APP_ADJ.
-                if (cpr.externals != 0) {
+                if (cpr.hasExternalProcessHandles()) {
                     if (adj > ProcessList.FOREGROUND_APP_ADJ) {
                         adj = ProcessList.FOREGROUND_APP_ADJ;
                         schedGroup = Process.THREAD_GROUP_DEFAULT;