Merge "remove BpfNetMaps.cpp" into main

service/Android.bp

@@ -114,7 +114,6 @@ cc_library_shared {
     ],
     srcs: [
         ":services.connectivity-netstats-jni-sources",
-        "jni/com_android_server_BpfNetMaps.cpp",
         "jni/com_android_server_connectivity_ClatCoordinator.cpp",
         "jni/com_android_server_ServiceManagerWrapper.cpp",
         "jni/com_android_server_TestNetworkService.cpp",

service/jni/com_android_server_BpfNetMaps.cpp

@@ -1,44 +0,0 @@
-/*
- * Copyright (C) 2022 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "bpf/BpfUtils.h"
-
-#include <jni.h>
-#include <nativehelper/JNIHelp.h>
-
-namespace android {
-
-static jint native_synchronizeKernelRCU(JNIEnv* env, jobject self) {
-    return -bpf::synchronizeKernelRCU();
-}
-
-/*
- * JNI registration.
- */
-// clang-format off
-static const JNINativeMethod gMethods[] = {
-    /* name, signature, funcPtr */
-    {"native_synchronizeKernelRCU", "()I",
-    (void*)native_synchronizeKernelRCU},
-};
-// clang-format on
-
-int register_com_android_server_BpfNetMaps(JNIEnv* env) {
-    return jniRegisterNativeMethods(env, "android/net/connectivity/com/android/server/BpfNetMaps",
-                                    gMethods, NELEM(gMethods));
-}
-
-}; // namespace android

service/jni/onload.cpp

@@ -22,7 +22,6 @@
 namespace android {
 
 int register_com_android_server_TestNetworkService(JNIEnv* env);
-int register_com_android_server_BpfNetMaps(JNIEnv* env);
 int register_com_android_server_connectivity_ClatCoordinator(JNIEnv* env);
 int register_android_server_net_NetworkStatsFactory(JNIEnv* env);
 int register_android_server_net_NetworkStatsService(JNIEnv* env);
@@ -44,10 +43,6 @@ extern "C" jint JNI_OnLoad(JavaVM* vm, void*) {
     }
 
     if (android::modules::sdklevel::IsAtLeastT()) {
-        if (register_com_android_server_BpfNetMaps(env) < 0) {
-            return JNI_ERR;
-        }
-
         if (register_com_android_server_connectivity_ClatCoordinator(env) < 0) {
             return JNI_ERR;
         }

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

@@ -45,6 +45,8 @@ import static android.system.OsConstants.EINVAL;
 import static android.system.OsConstants.ENODEV;
 import static android.system.OsConstants.ENOENT;
 import static android.system.OsConstants.EOPNOTSUPP;
+import static android.system.OsConstants.SOCK_RAW;
+import static android.system.OsConstants.SOCK_CLOEXEC;
 
 import static com.android.server.ConnectivityStatsLog.NETWORK_BPF_MAP_INFO;
 
@@ -324,10 +326,26 @@ public class BpfNetMaps {
         }
 
         /**
-         * Call synchronize_rcu()
+         * Synchronously call in to kernel to synchronize_rcu()
          */
+        @RequiresApi(Build.VERSION_CODES.TIRAMISU)
         public int synchronizeKernelRCU() {
-            return native_synchronizeKernelRCU();
+            // See p/m/C's staticlibs/native/bpf_headers/include/bpf/BpfUtils.h
+            // for equivalent C implementation of this function.
+            try {
+                // When closing socket, kernel calls synchronize_rcu()
+                // from pf_key's sock_release().
+                // Constants from //bionic/libc/include/sys/socket.h: AF_KEY=15
+                // and kernel's include/uapi/linux/pfkeyv2.h: PF_KEY_V2=2
+                Os.close(Os.socket(15 /*PF_KEY*/, SOCK_RAW | SOCK_CLOEXEC, 2));
+            } catch (ErrnoException e) {
+                // socket() can only fail due to lack of privs (selinux) or OOM,
+                // close() always succeeds, but may return a pending error,
+                // however on a freshly opened socket that cannot happen.
+                // As such this failing is basically a build configuration error.
+                return -e.errno;
+            }
+            return 0;
         }
 
         /**
@@ -1061,7 +1079,4 @@ public class BpfNetMaps {
             pw.decreaseIndent();
         }
     }
-
-    @RequiresApi(Build.VERSION_CODES.TIRAMISU)
-    private static native int native_synchronizeKernelRCU();
 }