WifiNative plumbing for reading back the APF program & data buffer

Bug: 73804303
Test: frameworks/opt/net/wifi/tests/wifitests/runtests.sh
Change-Id: Ib2a0f2ec04df28aabf422fa3149850f601f55db9

4 files changed, 101 insertions, 4 deletions

diff --git a/service/java/com/android/server/wifi/WifiNative.java b/service/java/com/android/server/wifi/WifiNative.java
index c86f566a0..8a76c4d3b 100644
--- a/service/java/com/android/server/wifi/WifiNative.java
+++ b/service/java/com/android/server/wifi/WifiNative.java
@@ -2195,7 +2195,7 @@ public class WifiNative {
     /**
      * Installs an APF program on this iface, replacing any existing program.
      *
-     * @param ifaceName Name of the interface.
+     * @param ifaceName Name of the interface
      * @param filter is the android packet filter program
      * @return true for success
      */
@@ -2204,6 +2204,16 @@ public class WifiNative {
     }
 
     /**
+     * Reads the APF program and data buffer for this iface.
+     *
+     * @param ifaceName Name of the interface
+     * @return the buffer returned by the driver, or null in case of an error
+     */
+    public byte[] readPacketFilter(@NonNull String ifaceName) {
+        return mWifiVendorHal.readPacketFilter(ifaceName);
+    }
+
+    /**
      * Set country code for this AP iface.
      * @param ifaceName Name of the interface.
      * @param countryCode - two-letter country code (as ISO 3166)
diff --git a/service/java/com/android/server/wifi/WifiStateMachine.java b/service/java/com/android/server/wifi/WifiStateMachine.java
index 32427c92c..4cb7d3722 100644
--- a/service/java/com/android/server/wifi/WifiStateMachine.java
+++ b/service/java/com/android/server/wifi/WifiStateMachine.java
@@ -636,6 +636,9 @@ public class WifiStateMachine extends StateMachine {
     /* used to indicate that the foreground user was switched */
     static final int CMD_USER_STOP                                      = BASE + 207;
 
+    /* Read the APF program & data buffer */
+    static final int CMD_READ_PACKET_FILTER                             = BASE + 208;
+
     /* Indicates that diagnostics should time out a connection start event. */
     private static final int CMD_DIAGS_CONNECT_TIMEOUT                  = BASE + 252;
 
@@ -1065,6 +1068,11 @@ public class WifiStateMachine extends StateMachine {
         }
 
         @Override
+        public void startReadPacketFilter() {
+            sendMessage(CMD_READ_PACKET_FILTER);
+        }
+
+        @Override
         public void setFallbackMulticastFilter(boolean enabled) {
             sendMessage(CMD_SET_FALLBACK_PACKET_FILTERING, enabled);
         }
@@ -3578,6 +3586,10 @@ public class WifiStateMachine extends StateMachine {
                 case CMD_INSTALL_PACKET_FILTER:
                     mWifiNative.installPacketFilter(mInterfaceName, (byte[]) message.obj);
                     break;
+                case CMD_READ_PACKET_FILTER:
+                    byte[] data = mWifiNative.readPacketFilter(mInterfaceName);
+                    mIpClient.readPacketFilterComplete(data);
+                    break;
                 case CMD_SET_FALLBACK_PACKET_FILTERING:
                     if ((boolean) message.obj) {
                         mWifiNative.startFilteringMulticastV4Packets(mInterfaceName);
@@ -5636,8 +5648,8 @@ public class WifiStateMachine extends StateMachine {
     }
 
     /**
-     * State machine initiated requests can have replyTo set to null indicating
-     * there are no recepients, we ignore those reply actions.
+     * State machine initiated requests can have replyTo set to null, indicating
+     * there are no recipients, we ignore those reply actions.
      */
     private void replyToMessage(Message msg, int what) {
         if (msg.replyTo == null) return;
diff --git a/service/java/com/android/server/wifi/WifiVendorHal.java b/service/java/com/android/server/wifi/WifiVendorHal.java
index 36060fa55..16a279833 100644
--- a/service/java/com/android/server/wifi/WifiVendorHal.java
+++ b/service/java/com/android/server/wifi/WifiVendorHal.java
@@ -74,6 +74,7 @@ import android.util.MutableInt;
 
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.util.ArrayUtils;
+import com.android.internal.util.HexDump;
 import com.android.server.wifi.HalDeviceManager.InterfaceDestroyedListener;
 import com.android.server.wifi.util.BitMask;
 import com.android.server.wifi.util.NativeUtil;
@@ -185,6 +186,26 @@ public class WifiVendorHal {
     }
 
     /**
+     * Logs the argument along with the method name.
+     *
+     * Always returns its argument.
+     */
+    private byte[] byteArrayResult(byte[] result) {
+        if (mVerboseLog == sNoLog) return result;
+        // Currently only seen if verbose logging is on
+
+        Thread cur = Thread.currentThread();
+        StackTraceElement[] trace = cur.getStackTrace();
+
+        mVerboseLog.err("% returns %")
+                .c(niceMethodName(trace, 3))
+                .c(HexDump.dumpHexString(result))
+                .flush();
+
+        return result;
+    }
+
+    /**
      * Logs at method entry
      *
      * @param format string with % placeholders
@@ -1738,6 +1759,36 @@ public class WifiVendorHal {
     }
 
     /**
+     * Reads the APF program and data buffer on this iface.
+     *
+     * @param ifaceName Name of the interface
+     * @return the buffer returned by the driver, or null in case of an error
+     */
+    public byte[] readPacketFilter(@NonNull String ifaceName) {
+        class AnswerBox {
+            public byte[] data = null;
+        }
+        AnswerBox answer = new AnswerBox();
+        enter("").flush();
+        // TODO: Must also take the wakelock here to prevent going to sleep with APF disabled.
+        synchronized (sLock) {
+            try {
+                android.hardware.wifi.V1_2.IWifiStaIface ifaceV12 =
+                        getWifiStaIfaceForV1_2Mockable(ifaceName);
+                if (ifaceV12 == null) return byteArrayResult(null);
+                ifaceV12.readApfPacketFilterData((status, dataByteArray) -> {
+                    if (!ok(status)) return;
+                    answer.data = NativeUtil.byteArrayFromArrayList(dataByteArray);
+                });
+                return byteArrayResult(answer.data);
+            } catch (RemoteException e) {
+                handleRemoteException(e);
+                return byteArrayResult(null);
+            }
+        }
+    }
+
+    /**
      * Set country code for this AP iface.
      *
      * @param ifaceName Name of the interface.
diff --git a/tests/wifitests/src/com/android/server/wifi/WifiVendorHalTest.java b/tests/wifitests/src/com/android/server/wifi/WifiVendorHalTest.java
index 70c612918..9d20235ad 100644
--- a/tests/wifitests/src/com/android/server/wifi/WifiVendorHalTest.java
+++ b/tests/wifitests/src/com/android/server/wifi/WifiVendorHalTest.java
@@ -1233,6 +1233,31 @@ public class WifiVendorHalTest {
     }
 
     /**
+     * Test that an APF program and data buffer can be read back.
+     */
+    @Test
+    public void testReadApf() throws Exception {
+        // Expose the 1.2 IWifiStaIface.
+        mWifiVendorHal = new WifiVendorHalSpyV1_2(mHalDeviceManager, mLooper.getLooper());
+
+        byte[] program = new byte[] {65, 66, 67};
+        ArrayList<Byte> expected = new ArrayList<>(3);
+        for (byte b : program) expected.add(b);
+
+        doAnswer(new AnswerWithArguments() {
+            public void answer(
+                    android.hardware.wifi.V1_2.IWifiStaIface.readApfPacketFilterDataCallback cb)
+                    throws RemoteException {
+                cb.onValues(mWifiStatusSuccess, expected);
+            }
+        }).when(mIWifiStaIfaceV12).readApfPacketFilterData(any(
+                android.hardware.wifi.V1_2.IWifiStaIface.readApfPacketFilterDataCallback.class));
+
+        assertTrue(mWifiVendorHal.startVendorHalSta());
+        assertArrayEquals(program, mWifiVendorHal.readPacketFilter(TEST_IFACE_NAME));
+    }
+
+    /**
      * Test that the country code is set in AP mode (when it should be).
      */
     @Test
@@ -1348,7 +1373,6 @@ public class WifiVendorHalTest {
         assertEquals(halBufferStatus.size(), actual.length);
         assertEquals(oneExpect, actual[0].toString());
         assertEquals(two.ringId, actual[1].ringBufferId);
-
     }
 
     /**