Change tetheroffloadjni to tetheringutilsjni

Rename tetheroffloadjni to tetheringutilsjni and move setupRaSocket
jni method from NetUtils into tetheringutilsjni.

Bug: 143195885
Test: -build, flash, boot
      -atest TetheringTests
      -Off/On hotspot with ipv6 upstream

Change-Id: Ib68eb6999bbe2d3ca97e68712f22b105311ef800

Tethering/Android.bp

@@ -45,9 +45,9 @@ android_library {
 
 // Due to b/143733063, APK can't access a jni lib that is in APEX (but not in the APK).
 cc_library {
-    name: "libtetheroffloadjni",
+    name: "libtetherutilsjni",
     srcs: [
-        "jni/com_android_server_connectivity_tethering_OffloadHardwareInterface.cpp",
+        "jni/android_net_util_TetheringUtils.cpp",
     ],
     shared_libs: [
         "libcgrouprc",
@@ -87,7 +87,7 @@ java_defaults {
         "libcgrouprc",
         "libnativehelper_compat_libc++",
         "libvndksupport",
-        "libtetheroffloadjni",
+        "libtetherutilsjni",
     ],
     resource_dirs: [
         "res",

Tethering/jni/android_net_util_TetheringUtils.cpp

@@ -19,13 +19,16 @@
 #include <hidl/HidlSupport.h>
 #include <jni.h>
 #include <nativehelper/JNIHelp.h>
+#include <nativehelper/ScopedUtfChars.h>
 #include <linux/netfilter/nfnetlink.h>
 #include <linux/netlink.h>
+#include <net/if.h>
+#include <netinet/icmp6.h>
 #include <sys/socket.h>
 #include <android-base/unique_fd.h>
 #include <android/hardware/tetheroffload/config/1.0/IOffloadConfig.h>
 
-#define LOG_TAG "OffloadHardwareInterface"
+#define LOG_TAG "TetheringUtils"
 #include <utils/Log.h>
 
 namespace android {
@@ -87,7 +90,7 @@ hidl_handle handleFromFileDescriptor(base::unique_fd fd) {
 
 }  // namespace
 
-static jboolean android_server_connectivity_tethering_OffloadHardwareInterface_configOffload(
+static jboolean android_net_util_configOffload(
         JNIEnv* /* env */) {
     sp<IOffloadConfig> configInterface = IOffloadConfig::getService();
     if (configInterface.get() == nullptr) {
@@ -130,18 +133,109 @@ static jboolean android_server_connectivity_tethering_OffloadHardwareInterface_c
     return rval;
 }
 
+static void android_net_util_setupRaSocket(JNIEnv *env, jobject clazz, jobject javaFd,
+        jint ifIndex)
+{
+    static const int kLinkLocalHopLimit = 255;
+
+    int fd = jniGetFDFromFileDescriptor(env, javaFd);
+
+    // Set an ICMPv6 filter that only passes Router Solicitations.
+    struct icmp6_filter rs_only;
+    ICMP6_FILTER_SETBLOCKALL(&rs_only);
+    ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &rs_only);
+    socklen_t len = sizeof(rs_only);
+    if (setsockopt(fd, IPPROTO_ICMPV6, ICMP6_FILTER, &rs_only, len) != 0) {
+        jniThrowExceptionFmt(env, "java/net/SocketException",
+                "setsockopt(ICMP6_FILTER): %s", strerror(errno));
+        return;
+    }
+
+    // Most/all of the rest of these options can be set via Java code, but
+    // because we're here on account of setting an icmp6_filter go ahead
+    // and do it all natively for now.
+
+    // Set the multicast hoplimit to 255 (link-local only).
+    int hops = kLinkLocalHopLimit;
+    len = sizeof(hops);
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &hops, len) != 0) {
+        jniThrowExceptionFmt(env, "java/net/SocketException",
+                "setsockopt(IPV6_MULTICAST_HOPS): %s", strerror(errno));
+        return;
+    }
+
+    // Set the unicast hoplimit to 255 (link-local only).
+    hops = kLinkLocalHopLimit;
+    len = sizeof(hops);
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &hops, len) != 0) {
+        jniThrowExceptionFmt(env, "java/net/SocketException",
+                "setsockopt(IPV6_UNICAST_HOPS): %s", strerror(errno));
+        return;
+    }
+
+    // Explicitly disable multicast loopback.
+    int off = 0;
+    len = sizeof(off);
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &off, len) != 0) {
+        jniThrowExceptionFmt(env, "java/net/SocketException",
+                "setsockopt(IPV6_MULTICAST_LOOP): %s", strerror(errno));
+        return;
+    }
+
+    // Specify the IPv6 interface to use for outbound multicast.
+    len = sizeof(ifIndex);
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &ifIndex, len) != 0) {
+        jniThrowExceptionFmt(env, "java/net/SocketException",
+                "setsockopt(IPV6_MULTICAST_IF): %s", strerror(errno));
+        return;
+    }
+
+    // Additional options to be considered:
+    //     - IPV6_TCLASS
+    //     - IPV6_RECVPKTINFO
+    //     - IPV6_RECVHOPLIMIT
+
+    // Bind to [::].
+    const struct sockaddr_in6 sin6 = {
+            .sin6_family = AF_INET6,
+            .sin6_port = 0,
+            .sin6_flowinfo = 0,
+            .sin6_addr = IN6ADDR_ANY_INIT,
+            .sin6_scope_id = 0,
+    };
+    auto sa = reinterpret_cast<const struct sockaddr *>(&sin6);
+    len = sizeof(sin6);
+    if (bind(fd, sa, len) != 0) {
+        jniThrowExceptionFmt(env, "java/net/SocketException",
+                "bind(IN6ADDR_ANY): %s", strerror(errno));
+        return;
+    }
+
+    // Join the all-routers multicast group, ff02::2%index.
+    struct ipv6_mreq all_rtrs = {
+        .ipv6mr_multiaddr = {{{0xff,2,0,0,0,0,0,0,0,0,0,0,0,0,0,2}}},
+        .ipv6mr_interface = ifIndex,
+    };
+    len = sizeof(all_rtrs);
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &all_rtrs, len) != 0) {
+        jniThrowExceptionFmt(env, "java/net/SocketException",
+                "setsockopt(IPV6_JOIN_GROUP): %s", strerror(errno));
+        return;
+    }
+}
+
 /*
  * JNI registration.
  */
 static const JNINativeMethod gMethods[] = {
     /* name, signature, funcPtr */
-    { "configOffload", "()Z",
+    { "configOffload", "()Z", (void*) android_net_util_configOffload },
-      (void*) android_server_connectivity_tethering_OffloadHardwareInterface_configOffload },
+    { "setupRaSocket", "(Ljava/io/FileDescriptor;I)V", (void*) android_net_util_setupRaSocket },
 };
 
-int register_android_server_connectivity_tethering_OffloadHardwareInterface(JNIEnv* env) {
+int register_android_net_util_TetheringUtils(JNIEnv* env) {
     return jniRegisterNativeMethods(env,
-            "com/android/server/connectivity/tethering/OffloadHardwareInterface",
+            "android/net/util/TetheringUtils",
             gMethods, NELEM(gMethods));
 }
 
@@ -152,7 +246,7 @@ extern "C" jint JNI_OnLoad(JavaVM* vm, void*) {
         return JNI_ERR;
     }
 
-    if (register_android_server_connectivity_tethering_OffloadHardwareInterface(env) < 0) {
+    if (register_android_net_util_TetheringUtils(env) < 0) {
         return JNI_ERR;
     }
 

Tethering/src/android/net/ip/RouterAdvertisementDaemon.java

@@ -30,6 +30,7 @@ import android.net.LinkAddress;
 import android.net.NetworkUtils;
 import android.net.TrafficStats;
 import android.net.util.InterfaceParams;
+import android.net.util.TetheringUtils;
 import android.system.ErrnoException;
 import android.system.Os;
 import android.system.StructTimeval;
@@ -613,7 +614,7 @@ public class RouterAdvertisementDaemon {
                     mSocket, SOL_SOCKET, SO_SNDTIMEO, StructTimeval.fromMillis(send_timout_ms));
             Os.setsockoptIfreq(mSocket, SOL_SOCKET, SO_BINDTODEVICE, mInterface.name);
             NetworkUtils.protectFromVpn(mSocket);
-            NetworkUtils.setupRaSocket(mSocket, mInterface.index);
+            TetheringUtils.setupRaSocket(mSocket, mInterface.index);
         } catch (ErrnoException | IOException e) {
             Log.e(TAG, "Failed to create RA daemon socket: " + e);
             return false;

Tethering/src/android/net/util/TetheringUtils.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+package android.net.util;
+
+import java.io.FileDescriptor;
+import java.net.SocketException;
+
+/**
+ * Native methods for tethering utilization.
+ *
+ * {@hide}
+ */
+public class TetheringUtils {
+
+    /**
+     * Offload management process need to know conntrack rules to support NAT, but it may not have
+     * permission to create netlink netfilter sockets. Create two netlink netfilter sockets and
+     * share them with offload management process.
+     */
+    public static native boolean configOffload();
+
+    /**
+     * Configures a socket for receiving ICMPv6 router solicitations and sending advertisements.
+     * @param fd the socket's {@link FileDescriptor}.
+     * @param ifIndex the interface index.
+     */
+    public static native void setupRaSocket(FileDescriptor fd, int ifIndex)
+            throws SocketException;
+}

Tethering/src/com/android/server/connectivity/tethering/OffloadHardwareInterface.java

@@ -24,6 +24,7 @@ import android.hardware.tetheroffload.control.V1_0.NatTimeoutUpdate;
 import android.hardware.tetheroffload.control.V1_0.NetworkProtocol;
 import android.hardware.tetheroffload.control.V1_0.OffloadCallbackEvent;
 import android.net.util.SharedLog;
+import android.net.util.TetheringUtils;
 import android.os.Handler;
 import android.os.RemoteException;
 import android.system.OsConstants;
@@ -47,8 +48,6 @@ public class OffloadHardwareInterface {
     private static final String NO_IPV4_ADDRESS = "";
     private static final String NO_IPV4_GATEWAY = "";
 
-    private static native boolean configOffload();
-
     private final Handler mHandler;
     private final SharedLog mLog;
     private IOffloadControl mOffloadControl;
@@ -107,8 +106,6 @@ public class OffloadHardwareInterface {
     public OffloadHardwareInterface(Handler h, SharedLog log) {
         mHandler = h;
         mLog = log.forSubComponent(TAG);
-
-        System.loadLibrary("tetheroffloadjni");
     }
 
     /** Get default value indicating whether offload is supported. */
@@ -118,7 +115,7 @@ public class OffloadHardwareInterface {
 
     /** Configure offload management process. */
     public boolean initOffloadConfig() {
-        return configOffload();
+        return TetheringUtils.configOffload();
     }
 
     /** Initialize the tethering offload HAL. */

Tethering/src/com/android/server/connectivity/tethering/TetheringService.java

@@ -84,6 +84,7 @@ public class TetheringService extends Service {
      */
     @VisibleForTesting
     public Tethering makeTethering(TetheringDependencies deps) {
+        System.loadLibrary("tetherutilsjni");
         return new Tethering(deps);
     }