Refactored NetworkPolicyManagerService mUidRules.

NetworkPolicyManagerService (NMPS) keeps an internal list of uid
rules (mUidRules) for network restrictions, and when these rules
changes it needs to notify external listeners (such as
ConnectivityService / CS).

Prior to Android N, both Data Saver mode (the feature previously known
as "Restrict Baground Data") and Battery Save mode used the same set of
firewall rules to implement their restrictions: when Battery Saver mode
NPMS would mark all networks as metered and set the proper firewall
rules externally.

Recently, these 2 modes were split in 2 distinct firewall rules and
NMPS.updateRuleForRestrictBackgroundLocked() was changed to update
the mUidRules logic based on the Data Saver firewall (since the Battery
Saver firewall changes are handled externally, on
updateRuleForRestrictPowerLocked()). As such, CS was not notified when
the power-related changes were made, which would cause apps to get a
state of CONNECTED / CONNECTED when querying its active connection.

This change refactores the mUidRules to use bitmasks, in preparation for
another change that will fix the issue.

It also fixes a minor bug that was preventing removed packages to be
removed from the whitelist.

BUG: 28521946
Change-Id: I9f0e1509a6192cad403f740c1cd76a6b7dab7d26
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 06255a2..3508701 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -30,10 +30,11 @@
 import static android.net.NetworkCapabilities.NET_CAPABILITY_VALIDATED;
 import static android.net.NetworkPolicyManager.RULE_ALLOW_ALL;
 import static android.net.NetworkPolicyManager.RULE_ALLOW_METERED;
+import static android.net.NetworkPolicyManager.RULE_NONE;
 import static android.net.NetworkPolicyManager.RULE_REJECT_ALL;
 import static android.net.NetworkPolicyManager.RULE_REJECT_METERED;
 import static android.net.NetworkPolicyManager.RULE_TEMPORARY_ALLOW_METERED;
-import static android.net.NetworkPolicyManager.RULE_UNKNOWN;
+import static android.net.NetworkPolicyManager.uidRulesToString;
 
 import android.annotation.Nullable;
 import android.app.BroadcastOptions;
@@ -915,7 +916,7 @@
         final String iface = (lp == null ? "" : lp.getInterfaceName());
         synchronized (mRulesLock) {
             networkMetered = mMeteredIfaces.contains(iface);
-            uidRules = mUidRules.get(uid, RULE_UNKNOWN);
+            uidRules = mUidRules.get(uid, RULE_NONE);
         }
 
         switch (uidRules) {
@@ -927,7 +928,7 @@
                 return networkMetered;
             case RULE_REJECT_ALL:
                 return true;
-            case RULE_UNKNOWN:
+            case RULE_NONE:
             default:
                 // When background data is restricted device-wide, the default
                 // behavior for apps should be like RULE_REJECT_METERED
@@ -1861,6 +1862,21 @@
         pw.println(mRestrictBackground);
         pw.println();
 
+        pw.println("Status for known UIDs:");
+        pw.increaseIndent();
+        final int size = mUidRules.size();
+        for (int i = 0; i < size; i++) {
+            final int uid = mUidRules.keyAt(i);
+            pw.print("UID=");
+            pw.print(uid);
+            final int uidRules = mUidRules.get(uid, RULE_NONE);
+            pw.print(" rules=");
+            pw.print(uidRulesToString(uidRules));
+            pw.println();
+        }
+        pw.println();
+        pw.decreaseIndent();
+
         pw.println("Network Requests:");
         pw.increaseIndent();
         for (NetworkRequestInfo nri : mNetworkRequests.values()) {