Add SMS Middleware layer.

Add fix so ordered broadcasts are delivered to system
apps first in the event of a tie. This works around
the issue where terrible apps steal SMS notifications
from the broadcast queue to simply prevent notifications
that could otherwise be removed by a toggle.

Change-Id: I4fff0c584f8fce9c5f2f4fe86a82fe6480c307c7

6 files changed, 42 insertions, 3 deletions

diff --git a/core/java/android/content/IntentFilter.java b/core/java/android/content/IntentFilter.java
index 3b0d846..642a37d 100644
--- a/core/java/android/content/IntentFilter.java
+++ b/core/java/android/content/IntentFilter.java
@@ -1385,6 +1385,15 @@ public class IntentFilter implements Parcelable {
     }
 
     /**
+     * {@hide}
+     * @param other
+     * @return
+     */
+    public int onCompareTie(IntentFilter other) {
+        return 0;
+    }
+
+    /**
      * For debugging -- perform a check on the filter, return true if it passed
      * or false if it failed.
      *
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 74dccdd..ce9b3a8 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -1942,6 +1942,14 @@
         android:description="@string/permdesc_broadcastPackageRemoved"
         android:protectionLevel="signature" />
 
+    <!-- Allows an application to intercept and rewrite outgoing SMS
+         @hide -->
+    <permission android:name="android.permission.INTERCEPT_SMS"
+        android:permissionGroup="android.permission-group.MESSAGES"
+        android:label="@string/permlab_interceptSmsSent"
+        android:description="@string/permdesc_interceptSmsSent"
+        android:protectionLevel="signature" />
+
     <!-- Allows an application to broadcast an SMS receipt notification -->
     <permission android:name="android.permission.BROADCAST_SMS"
         android:permissionGroup="android.permission-group.MESSAGES"
diff --git a/core/res/res/values/cm_strings.xml b/core/res/res/values/cm_strings.xml
index c8a37903..5dd2a24 100644
--- a/core/res/res/values/cm_strings.xml
+++ b/core/res/res/values/cm_strings.xml
@@ -169,4 +169,12 @@
 
     <!-- The item label for the no profile selection item. -->
     <string name="profile_none">None</string>
+
+    <!-- Title of an application permission, listed so the user can choose whether they want to allow the application to do this. -->
+    <string name="permlab_interceptSmsSent">intercept outgoing SMS</string>
+    <!-- Description of an application permission, listed so the user can choose whether they want to allow the application to do this. -->
+    <string name="permdesc_interceptSmsSent">Allows the app to
+        intercept an outgoing SMS.
+        Malicious apps may use this to prevent outgoing SMS messages.</string>
+
 </resources>
diff --git a/services/java/com/android/server/IntentResolver.java b/services/java/com/android/server/IntentResolver.java
index 9b19008..8f703f0 100644
--- a/services/java/com/android/server/IntentResolver.java
+++ b/services/java/com/android/server/IntentResolver.java
@@ -609,7 +609,7 @@ public abstract class IntentResolver<F extends IntentFilter, R extends Object> {
         public int compare(Object o1, Object o2) {
             final int q1 = ((IntentFilter) o1).getPriority();
             final int q2 = ((IntentFilter) o2).getPriority();
-            return (q1 > q2) ? -1 : ((q1 < q2) ? 1 : 0);
+            return (q1 > q2) ? -1 : ((q1 < q2) ? 1 : ((IntentFilter) o1).onCompareTie((IntentFilter) o2));
         }
     };
 
diff --git a/services/java/com/android/server/am/ActivityManagerService.java b/services/java/com/android/server/am/ActivityManagerService.java
index 618f02c..d7f9eb4 100644
--- a/services/java/com/android/server/am/ActivityManagerService.java
+++ b/services/java/com/android/server/am/ActivityManagerService.java
@@ -11522,7 +11522,7 @@ public final class ActivityManagerService extends ActivityManagerNative
                         + " was previously registered for user " + rl.userId);
             }
             BroadcastFilter bf = new BroadcastFilter(filter, rl, callerPackage,
-                    permission, callingUid, userId);
+                    permission, callingUid, userId, (callerApp.info.flags & ApplicationInfo.FLAG_SYSTEM) != 0);
             rl.add(bf);
             if (!bf.debugCheck()) {
                 Slog.w(TAG, "==> For Dynamic broadast");
diff --git a/services/java/com/android/server/am/BroadcastFilter.java b/services/java/com/android/server/am/BroadcastFilter.java
index c631b6e..1d983c7 100644
--- a/services/java/com/android/server/am/BroadcastFilter.java
+++ b/services/java/com/android/server/am/BroadcastFilter.java
@@ -29,15 +29,17 @@ class BroadcastFilter extends IntentFilter {
     final String requiredPermission;
     final int owningUid;
     final int owningUserId;
+    final boolean isSystem;
 
     BroadcastFilter(IntentFilter _filter, ReceiverList _receiverList,
-            String _packageName, String _requiredPermission, int _owningUid, int _userId) {
+            String _packageName, String _requiredPermission, int _owningUid, int _userId, boolean _isSystem) {
         super(_filter);
         receiverList = _receiverList;
         packageName = _packageName;
         requiredPermission = _requiredPermission;
         owningUid = _owningUid;
         owningUserId = _userId;
+        isSystem = _isSystem;
     }
     
     public void dump(PrintWriter pw, String prefix) {
@@ -71,4 +73,16 @@ class BroadcastFilter extends IntentFilter {
         sb.append('}');
         return sb.toString();
     }
+
+    @Override
+    public int onCompareTie(IntentFilter other) {
+        // in case of a tie when sorting ordered broadcasts,
+        // favor system apps.
+        BroadcastFilter bf = (BroadcastFilter)other;
+        if (isSystem)
+            return -1;
+        if (bf.isSystem)
+            return 1;
+        return 0;
+    }
 }