Support "dumpsys connectivity trafficcontroller"

Enable ConnectivityService to dump BPF maps from libtraffic_controller.

Bug: 202086915
Test: adb shell dumpsys connectivity trafficcontroller
Test: atest CtsNetTestCases:ConnectivityManagerTest#testDumpBpfNetMaps
Test: run CTS in I021789813f116940d581e2c4a1fd357ff47bfa08
Change-Id: Ib0e935ee2b714ac61daceba6d13fa7a20f97f68f

service/src/com/android/server/BpfNetMaps.java

@@ -16,6 +16,8 @@
 
 package com.android.server;
 
+import static android.system.OsConstants.EOPNOTSUPP;
+
 import android.net.INetd;
 import android.os.RemoteException;
 import android.os.ServiceSpecificException;
@@ -24,6 +26,9 @@ import android.util.Log;
 
 import com.android.modules.utils.build.SdkLevel;
 
+import java.io.FileDescriptor;
+import java.io.IOException;
+
 /**
  * BpfNetMaps is responsible for providing traffic controller relevant functionality.
  *
@@ -273,6 +278,23 @@ public class BpfNetMaps {
         native_setPermissionForUids(permissions, uids);
     }
 
+    /**
+     * Dump BPF maps
+     *
+     * @param fd file descriptor to output
+     * @throws IOException when file descriptor is invalid.
+     * @throws ServiceSpecificException when the method is called on an unsupported device.
+     */
+    public void dump(final FileDescriptor fd, boolean verbose)
+            throws IOException, ServiceSpecificException {
+        if (USE_NETD) {
+            throw new ServiceSpecificException(
+                    EOPNOTSUPP, "dumpsys connectivity trafficcontroller dump not available on pre-T"
+                    + " devices, use dumpsys netd trafficcontroller instead.");
+        }
+        native_dump(fd, verbose);
+    }
+
     private static native void native_init();
     private native int native_addNaughtyApp(int uid);
     private native int native_removeNaughtyApp(int uid);
@@ -285,4 +307,5 @@ public class BpfNetMaps {
     private native int native_removeUidInterfaceRules(int[] uids);
     private native int native_swapActiveStatsMap();
     private native void native_setPermissionForUids(int permissions, int[] uids);
+    private native void native_dump(FileDescriptor fd, boolean verbose);
 }