Move SocketUtils out of the connectivity module

SocketUtils contains system APIs for modules to interact for sockets,
wrapping internal APIs. It should be part of the platform to keep access
to the internal APIs.

This involves splitting NetworkUtils.protectVpn to NetworkUtilsInternal,
since SocketUtils and VpnService are the only users of that method.

The @UnsupportedAppUsage NetworkUtils.protectVpn has low usage
count, and is already available through VpnService.protect.

Bug: 181512874
Test: boots, VPN working
Change-Id: I7028d334975f7536c06afac7a22200c33db707ac

core/api/system-current.txt

@@ -6449,6 +6449,19 @@ package android.net.sip {
 
 }
 
+package android.net.util {
+
+  public final class SocketUtils {
+    method public static void bindSocketToInterface(@NonNull java.io.FileDescriptor, @NonNull String) throws android.system.ErrnoException;
+    method public static void closeSocket(@Nullable java.io.FileDescriptor) throws java.io.IOException;
+    method @NonNull public static java.net.SocketAddress makeNetlinkSocketAddress(int, int);
+    method @NonNull public static java.net.SocketAddress makePacketSocketAddress(int, int);
+    method @Deprecated @NonNull public static java.net.SocketAddress makePacketSocketAddress(int, @NonNull byte[]);
+    method @NonNull public static java.net.SocketAddress makePacketSocketAddress(int, int, @NonNull byte[]);
+  }
+
+}
+
 package android.net.vcn {
 
   public class VcnManager {

core/java/android/net/VpnService.java

@@ -41,6 +41,7 @@ import android.os.RemoteException;
 import android.os.ServiceManager;
 import android.os.UserHandle;
 
+import com.android.internal.net.NetworkUtilsInternal;
 import com.android.internal.net.VpnConfig;
 
 import java.net.DatagramSocket;
@@ -254,7 +255,7 @@ public class VpnService extends Service {
      * @return {@code true} on success.
      */
     public boolean protect(int socket) {
-        return NetworkUtils.protectFromVpn(socket);
+        return NetworkUtilsInternal.protectFromVpn(socket);
     }
 
     /**

core/java/android/net/util/SocketUtils.java

@@ -22,12 +22,13 @@ import static android.system.OsConstants.SO_BINDTODEVICE;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.annotation.SystemApi;
-import android.net.NetworkUtils;
 import android.system.ErrnoException;
 import android.system.NetlinkSocketAddress;
 import android.system.Os;
 import android.system.PacketSocketAddress;
 
+import com.android.internal.net.NetworkUtilsInternal;
+
 import libcore.io.IoBridge;
 
 import java.io.FileDescriptor;
@@ -51,7 +52,7 @@ public final class SocketUtils {
         // of struct ifreq is a NULL-terminated interface name.
         // TODO: add a setsockoptString()
         Os.setsockoptIfreq(socket, SOL_SOCKET, SO_BINDTODEVICE, iface);
-        NetworkUtils.protectFromVpn(socket);
+        NetworkUtilsInternal.protectFromVpn(socket);
     }
 
     /**

core/java/com/android/internal/net/NetworkUtilsInternal.java

@@ -22,6 +22,8 @@ import static android.system.OsConstants.AF_INET6;
 import android.annotation.NonNull;
 import android.system.Os;
 
+import java.io.FileDescriptor;
+
 /** @hide */
 public class NetworkUtilsInternal {
 
@@ -35,6 +37,20 @@ public class NetworkUtilsInternal {
      */
     public static native void setAllowNetworkingForProcess(boolean allowNetworking);
 
+    /**
+     * Protect {@code fd} from VPN connections.  After protecting, data sent through
+     * this socket will go directly to the underlying network, so its traffic will not be
+     * forwarded through the VPN.
+     */
+    public static native boolean protectFromVpn(FileDescriptor fd);
+
+    /**
+     * Protect {@code socketfd} from VPN connections.  After protecting, data sent through
+     * this socket will go directly to the underlying network, so its traffic will not be
+     * forwarded through the VPN.
+     */
+    public static native boolean protectFromVpn(int socketfd);
+
     /**
      * Returns true if the hostname is weakly validated.
      * @param hostname Name of host to validate.

core/jni/Android.bp

@@ -149,7 +149,7 @@ cc_library_shared {
                 "android_os_VintfRuntimeInfo.cpp",
                 "android_os_incremental_IncrementalManager.cpp",
                 "android_net_LocalSocketImpl.cpp",
-                "android_net_NetUtils.cpp",
+                "android_net_NetworkUtils.cpp",
                 "android_service_DataLoaderService.cpp",
                 "android_util_AssetManager.cpp",
                 "android_util_Binder.cpp",

core/jni/android_net_NetworkUtils.cpp

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#define LOG_TAG "NetUtils"
+#define LOG_TAG "NetworkUtils"
 
 #include <vector>
 
@@ -123,15 +123,6 @@ static jint android_net_utils_bindSocketToNetwork(JNIEnv *env, jobject thiz, job
     return setNetworkForSocket(netId, AFileDescriptor_getFD(env, javaFd));
 }
 
-static jboolean android_net_utils_protectFromVpn(JNIEnv *env, jobject thiz, jint socket)
-{
-    return (jboolean) !protectFromVpn(socket);
-}
-
-static jboolean android_net_utils_protectFromVpnWithFd(JNIEnv *env, jobject thiz, jobject javaFd) {
-    return android_net_utils_protectFromVpn(env, thiz, AFileDescriptor_getFD(env, javaFd));
-}
-
 static jboolean android_net_utils_queryUserAccess(JNIEnv *env, jobject thiz, jint uid, jint netId)
 {
     return (jboolean) !queryUserAccess(uid, netId);
@@ -276,8 +267,6 @@ static const JNINativeMethod gNetworkUtilMethods[] = {
     { "getBoundNetworkForProcess", "()I", (void*) android_net_utils_getBoundNetworkForProcess },
     { "bindProcessToNetworkForHostResolution", "(I)Z", (void*) android_net_utils_bindProcessToNetworkForHostResolution },
     { "bindSocketToNetwork", "(Ljava/io/FileDescriptor;I)I", (void*) android_net_utils_bindSocketToNetwork },
-    { "protectFromVpn", "(I)Z", (void*) android_net_utils_protectFromVpn },
-    { "protectFromVpn", "(Ljava/io/FileDescriptor;)Z", (void*) android_net_utils_protectFromVpnWithFd },
     { "queryUserAccess", "(II)Z", (void*)android_net_utils_queryUserAccess },
     { "attachDropAllBPFFilter", "(Ljava/io/FileDescriptor;)V", (void*) android_net_utils_attachDropAllBPFFilter },
     { "detachBPFFilter", "(Ljava/io/FileDescriptor;)V", (void*) android_net_utils_detachBPFFilter },

core/jni/com_android_internal_net_NetworkUtilsInternal.cpp

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#include <android/file_descriptor_jni.h>
+
 #include "NetdClient.h"
 #include "core_jni_helpers.h"
 #include "jni.h"
@@ -24,9 +26,20 @@ static void android_net_utils_setAllowNetworkingForProcess(JNIEnv *env, jobject
     setAllowNetworkingForProcess(hasConnectivity == JNI_TRUE);
 }
 
+static jboolean android_net_utils_protectFromVpn(JNIEnv *env, jobject thiz, jint socket) {
+    return (jboolean)!protectFromVpn(socket);
+}
+
+static jboolean android_net_utils_protectFromVpnWithFd(JNIEnv *env, jobject thiz, jobject javaFd) {
+    return android_net_utils_protectFromVpn(env, thiz, AFileDescriptor_getFD(env, javaFd));
+}
+
 static const JNINativeMethod gNetworkUtilMethods[] = {
         {"setAllowNetworkingForProcess", "(Z)V",
          (void *)android_net_utils_setAllowNetworkingForProcess},
+        {"protectFromVpn", "(I)Z", (void *)android_net_utils_protectFromVpn},
+        {"protectFromVpn", "(Ljava/io/FileDescriptor;)Z",
+         (void *)android_net_utils_protectFromVpnWithFd},
 };
 
 int register_com_android_internal_net_NetworkUtilsInternal(JNIEnv *env) {

packages/Connectivity/framework/api/system-current.txt

@@ -392,16 +392,3 @@ package android.net.apf {
 
 }
 
-package android.net.util {
-
-  public final class SocketUtils {
-    method public static void bindSocketToInterface(@NonNull java.io.FileDescriptor, @NonNull String) throws android.system.ErrnoException;
-    method public static void closeSocket(@Nullable java.io.FileDescriptor) throws java.io.IOException;
-    method @NonNull public static java.net.SocketAddress makeNetlinkSocketAddress(int, int);
-    method @NonNull public static java.net.SocketAddress makePacketSocketAddress(int, int);
-    method @Deprecated @NonNull public static java.net.SocketAddress makePacketSocketAddress(int, @NonNull byte[]);
-    method @NonNull public static java.net.SocketAddress makePacketSocketAddress(int, int, @NonNull byte[]);
-  }
-
-}
-

packages/Connectivity/framework/src/android/net/NetworkUtils.java

@@ -86,22 +86,6 @@ public class NetworkUtils {
      */
     public static native int bindSocketToNetwork(FileDescriptor fd, int netId);
 
-    /**
-     * Protect {@code fd} from VPN connections.  After protecting, data sent through
-     * this socket will go directly to the underlying network, so its traffic will not be
-     * forwarded through the VPN.
-     */
-    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553,
-            publicAlternatives = "Use {@link android.net.VpnService#protect} instead.")
-    public static native boolean protectFromVpn(FileDescriptor fd);
-
-    /**
-     * Protect {@code socketfd} from VPN connections.  After protecting, data sent through
-     * this socket will go directly to the underlying network, so its traffic will not be
-     * forwarded through the VPN.
-     */
-    public native static boolean protectFromVpn(int socketfd);
-
     /**
      * Determine if {@code uid} can access network designated by {@code netId}.
      * @return {@code true} if {@code uid} can access network, {@code false} otherwise.