Define NETID_UNSET in ConnectivityManager.

This allows some cleanup and removal of dead code.

bug:15489928
Change-Id: Iaf0507bc2e8ec6dcc253f01f61c5b221d46581f9

core/java/android/net/ConnectivityManager.java

@@ -529,11 +529,6 @@ public class ConnectivityManager {
      */
     public static final int CONNECTIVITY_CHANGE_DELAY_DEFAULT = 3000;
 
-    /**
-     * @hide
-     */
-    public final static int INVALID_NET_ID = 0;
-
     /**
      * @hide
      */
@@ -2508,13 +2503,16 @@ public class ConnectivityManager {
      * @return {@code true} on success, {@code false} if the {@link Network} is no longer valid.
      */
     public static boolean setProcessDefaultNetwork(Network network) {
-        if (network == null) {
-            return NetworkUtils.unbindProcessToNetwork();
-        } else {
-            return NetworkUtils.bindProcessToNetwork(network.netId);
-        }
+        return NetworkUtils.bindProcessToNetwork(network == null ? NETID_UNSET : network.netId);
     }
 
+    /**
+     * A NetID indicating no Network is selected.
+     * Keep in sync with bionic/libc/dns/include/resolv_netid.h
+     * @hide
+     */
+    public static final int NETID_UNSET = 0;
+
     /**
      * Returns the {@link Network} currently bound to this process via
      * {@link #setProcessDefaultNetwork}, or {@code null} if no {@link Network} is explicitly bound.
@@ -2523,7 +2521,7 @@ public class ConnectivityManager {
      */
     public static Network getProcessDefaultNetwork() {
         int netId = NetworkUtils.getNetworkBoundToProcess();
-        if (netId == 0) return null;
+        if (netId == NETID_UNSET) return null;
         return new Network(netId);
     }
 
@@ -2538,10 +2536,7 @@ public class ConnectivityManager {
      * @deprecated This is strictly for legacy usage to support {@link #startUsingNetworkFeature}.
      */
     public static boolean setProcessDefaultNetworkForHostResolution(Network network) {
-        if (network == null) {
-            return NetworkUtils.unbindProcessToNetworkForHostResolution();
-        } else {
-            return NetworkUtils.bindProcessToNetworkForHostResolution(network.netId);
-        }
+        return NetworkUtils.bindProcessToNetworkForHostResolution(
+                network == null ? NETID_UNSET : network.netId);
     }
 }

core/java/android/net/NetworkUtils.java

@@ -116,16 +116,10 @@ public class NetworkUtils {
      * {@link Network#getSocketFactory}) will be bound to this network.  Note that if this
      * {@code Network} ever disconnects all sockets created in this way will cease to work.  This
      * is by design so an application doesn't accidentally use sockets it thinks are still bound to
-     * a particular {@code Network}.
+     * a particular {@code Network}.  Passing NETID_UNSET clears the binding.
      */
     public native static boolean bindProcessToNetwork(int netId);
 
-    /**
-     * Clear any process specific {@code Network} binding.  This reverts a call to
-     * {@link #bindProcessToNetwork}.
-     */
-    public native static boolean unbindProcessToNetwork();
-
     /**
      * Return the netId last passed to {@link #bindProcessToNetwork}, or NETID_UNSET if
      * {@link #unbindProcessToNetwork} has been called since {@link #bindProcessToNetwork}.
@@ -134,20 +128,13 @@ public class NetworkUtils {
 
     /**
      * Binds host resolutions performed by this process to the network designated by {@code netId}.
-     * {@link #bindProcessToNetwork} takes precedence over this setting.
+     * {@link #bindProcessToNetwork} takes precedence over this setting.  Passing NETID_UNSET clears
+     * the binding.
      *
      * @deprecated This is strictly for legacy usage to support startUsingNetworkFeature().
      */
     public native static boolean bindProcessToNetworkForHostResolution(int netId);
 
-    /**
-     * Clears any process specific {@link Network} binding for host resolution.  This does
-     * not clear bindings enacted via {@link #bindProcessToNetwork}.
-     *
-     * @deprecated This is strictly for legacy usage to support startUsingNetworkFeature().
-     */
-    public native static boolean unbindProcessToNetworkForHostResolution();
-
     /**
      * Explicitly binds {@code socketfd} to the network designated by {@code netId}.  This
      * overrides any binding via {@link #bindProcessToNetwork}.

core/jni/android_net_NetUtils.cpp

@@ -258,11 +258,6 @@ static jboolean android_net_utils_bindProcessToNetwork(JNIEnv *env, jobject thiz
     return (jboolean) !setNetworkForProcess(netId);
 }
 
-static jboolean android_net_utils_unbindProcessToNetwork(JNIEnv *env, jobject thiz)
-{
-    return (jboolean) !setNetworkForProcess(NETID_UNSET);
-}
-
 static jint android_net_utils_getNetworkBoundToProcess(JNIEnv *env, jobject thiz)
 {
     return getNetworkForProcess();
@@ -274,11 +269,6 @@ static jboolean android_net_utils_bindProcessToNetworkForHostResolution(JNIEnv *
     return (jboolean) !setNetworkForResolv(netId);
 }
 
-static jboolean android_net_utils_unbindProcessToNetworkForHostResolution(JNIEnv *env, jobject thiz)
-{
-    return (jboolean) !setNetworkForResolv(NETID_UNSET);
-}
-
 static jboolean android_net_utils_bindSocketToNetwork(JNIEnv *env, jobject thiz, jint socket,
         jint netId)
 {
@@ -309,9 +299,7 @@ static JNINativeMethod gNetworkUtilMethods[] = {
     { "markSocket", "(II)V", (void*) android_net_utils_markSocket },
     { "bindProcessToNetwork", "(I)Z", (void*) android_net_utils_bindProcessToNetwork },
     { "getNetworkBoundToProcess", "()I", (void*) android_net_utils_getNetworkBoundToProcess },
-    { "unbindProcessToNetwork", "()Z", (void*) android_net_utils_unbindProcessToNetwork },
     { "bindProcessToNetworkForHostResolution", "(I)Z", (void*) android_net_utils_bindProcessToNetworkForHostResolution },
-    { "unbindProcessToNetworkForHostResolution", "()Z", (void*) android_net_utils_unbindProcessToNetworkForHostResolution },
     { "bindSocketToNetwork", "(II)Z", (void*) android_net_utils_bindSocketToNetwork },
     { "protectFromVpn", "(I)Z", (void*)android_net_utils_protectFromVpn },
 };