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
diff --git a/service/src/com/android/server/BpfNetMaps.java b/service/src/com/android/server/BpfNetMaps.java
index ddee275..f2ca18b 100644
--- a/service/src/com/android/server/BpfNetMaps.java
+++ b/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 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 @@
         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 @@
     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);
 }
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index 6024a2a..d46ec61 100644
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -313,6 +313,7 @@
     public static final String SHORT_ARG = "--short";
     private static final String NETWORK_ARG = "networks";
     private static final String REQUEST_ARG = "requests";
+    private static final String TRAFFICCONTROLLER_ARG = "trafficcontroller";
 
     private static final boolean DBG = true;
     private static final boolean DDBG = Log.isLoggable(TAG, Log.DEBUG);
@@ -3212,6 +3213,10 @@
         } else if (CollectionUtils.contains(args, REQUEST_ARG)) {
             dumpNetworkRequests(pw);
             return;
+        } else if (CollectionUtils.contains(args, TRAFFICCONTROLLER_ARG)) {
+            boolean verbose = !CollectionUtils.contains(args, SHORT_ARG);
+            dumpTrafficController(pw, fd, verbose);
+            return;
         }
 
         pw.print("NetworkProviders for:");
@@ -3429,6 +3434,17 @@
         }
     }
 
+    private void dumpTrafficController(IndentingPrintWriter pw, final FileDescriptor fd,
+            boolean verbose) {
+        try {
+            mBpfNetMaps.dump(fd, verbose);
+        } catch (ServiceSpecificException e) {
+            pw.println(e.getMessage());
+        } catch (IOException e) {
+            loge("Dump BPF maps failed, " + e);
+        }
+    }
+
     private void dumpAllRequestInfoLogsToLogcat() {
         try (PrintWriter logPw = new PrintWriter(new Writer() {
             @Override