Fixes NetworkInterface.list crash on Android

Previously, Socket::ListInterfaces failed to set the os_error out
parameter causing a crash in the caller. This change sets an error here.

I've also added NetworkInterface.listSupported, which returns false on
Android, and true everywhere else. ifaddrs.h continues not to exist in
the NDK, so in order to support NetworkInterface.list, we'd have to
reimplement it, or find a suitable reimplementation somewhere.

related #26329

R=johnmccutchan@google.com

Review URL: https://codereview.chromium.org/1916223003 .

CHANGELOG.md

@@ -5,6 +5,11 @@
   * `Uri.replace` supports iterables as values for the query parameters.
   * `Uri.parseIPv6Address` returns a `Uint8List`.
 
+* `dart:io`
+  * Added `NetworkInterface.listSupported`, which is `true` when
+    `NetworkInterface.list` is supported, and `false` otherwise. Currently,
+    `NetworkInterface.list` is not supported on Android.
+
 ## 1.16.0
 
 ### Core library changes

runtime/bin/io_natives.cc

@@ -78,6 +78,7 @@ namespace bin {
   V(Filter_Processed, 3)                                                       \
   V(InternetAddress_Parse, 1)                                                  \
   V(IOService_NewServicePort, 0)                                               \
+  V(NetworkInterface_ListSupported, 0)                                         \
   V(Platform_NumberOfProcessors, 0)                                            \
   V(Platform_OperatingSystem, 0)                                               \
   V(Platform_PathSeparator, 0)                                                 \

runtime/bin/socket.cc

@@ -194,6 +194,11 @@ void FUNCTION_NAME(InternetAddress_Parse)(Dart_NativeArguments args) {
 }
 
 
+void FUNCTION_NAME(NetworkInterface_ListSupported)(Dart_NativeArguments args) {
+  Dart_SetReturnValue(args, Dart_NewBoolean(Socket::ListInterfacesSupported()));
+}
+
+
 void FUNCTION_NAME(Socket_CreateConnect)(Dart_NativeArguments args) {
   RawAddr addr;
   SocketAddress::GetSockAddr(Dart_GetNativeArgument(args, 1), &addr);

runtime/bin/socket.h

@@ -315,6 +315,9 @@ class Socket {
   static bool ParseAddress(int type, const char* address, RawAddr* addr);
   static bool FormatNumericAddress(const RawAddr& addr, char* address, int len);
 
+  // Whether ListInterfaces is supported.
+  static bool ListInterfacesSupported();
+
   // List interfaces. Returns a AddressList of InterfaceSocketAddress's.
   static AddressList<InterfaceSocketAddress>* ListInterfaces(
       int type,

runtime/bin/socket_android.cc

@@ -331,11 +331,21 @@ intptr_t Socket::CreateBindDatagram(const RawAddr& addr, bool reuseAddress) {
 }
 
 
+bool Socket::ListInterfacesSupported() {
+  return false;
+}
+
+
 AddressList<InterfaceSocketAddress>* Socket::ListInterfaces(
     int type,
     OSError** os_error) {
   // The ifaddrs.h header is not provided on Android.  An Android
   // implementation would have to use IOCTL or netlink.
+  ASSERT(*os_error == NULL);
+  *os_error = new OSError(-1,
+                          "Listing interfaces is not supported "
+                          "on this platform",
+                          OSError::kSystem);
   return NULL;
 }
 

runtime/bin/socket_linux.cc

@@ -338,6 +338,11 @@ static bool ShouldIncludeIfaAddrs(struct ifaddrs* ifa, int lookup_family) {
 }
 
 
+bool Socket::ListInterfacesSupported() {
+  return true;
+}
+
+
 AddressList<InterfaceSocketAddress>* Socket::ListInterfaces(
     int type,
     OSError** os_error) {

runtime/bin/socket_macos.cc

@@ -336,6 +336,11 @@ static bool ShouldIncludeIfaAddrs(struct ifaddrs* ifa, int lookup_family) {
 }
 
 
+bool Socket::ListInterfacesSupported() {
+  return true;
+}
+
+
 AddressList<InterfaceSocketAddress>* Socket::ListInterfaces(
     int type,
     OSError** os_error) {

runtime/bin/socket_patch.dart

@@ -49,6 +49,10 @@ patch class InternetAddress {
 }
 
 patch class NetworkInterface {
+  /* patch */ static bool get listSupported {
+    return _listSupported();
+  }
+
   /* patch */ static Future<List<NetworkInterface>> list({
       bool includeLoopback: false,
       bool includeLinkLocal: false,
@@ -57,6 +61,8 @@ patch class NetworkInterface {
                                         includeLinkLocal: includeLinkLocal,
                                         type: type);
   }
+
+  static bool _listSupported() native "NetworkInterface_ListSupported";
 }
 
 class _InternetAddress implements InternetAddress {

runtime/bin/socket_unsupported.cc

@@ -17,6 +17,12 @@ void FUNCTION_NAME(InternetAddress_Parse)(Dart_NativeArguments args) {
 }
 
 
+void FUNCTION_NAME(NetworkInterface_ListSupported)(Dart_NativeArguments args) {
+  Dart_ThrowException(DartUtils::NewDartArgumentError(
+      "Sockets unsupported on this platform"));
+}
+
+
 void FUNCTION_NAME(Socket_CreateConnect)(Dart_NativeArguments args) {
   Dart_ThrowException(DartUtils::NewDartArgumentError(
       "Sockets unsupported on this platform"));

runtime/bin/socket_win.cc

@@ -411,6 +411,11 @@ intptr_t Socket::CreateBindDatagram(const RawAddr& addr, bool reuseAddress) {
 }
 
 
+bool Socket::ListInterfacesSupported() {
+  return true;
+}
+
+
 AddressList<InterfaceSocketAddress>* Socket::ListInterfaces(
     int type,
     OSError** os_error) {

sdk/lib/_internal/js_runtime/lib/io_patch.dart

@@ -312,6 +312,10 @@ class InternetAddress {
 
 @patch
 class NetworkInterface {
+  @patch
+  static bool get listSupported {
+    throw new UnsupportedError("NetworkInterface.listSupported");
+  }
   @patch
   static Future<List<NetworkInterface>> list({
       bool includeLoopback: false,

sdk/lib/io/socket.dart

@@ -145,8 +145,8 @@ abstract class InternetAddress {
 
 
 /**
- * A [NetworkInterface] represent an active network interface on the current
- * system. It contains a list of [InternetAddress]s, that's bound to the
+ * A [NetworkInterface] represents an active network interface on the current
+ * system. It contains a list of [InternetAddress]es that are bound to the
  * interface.
  */
 abstract class NetworkInterface {
@@ -161,11 +161,18 @@ abstract class NetworkInterface {
   String get index;
 
   /**
-   * Get a list of [InternetAddress]s currently bound to this
+   * Get a list of [InternetAddress]es currently bound to this
    * [NetworkInterface].
    */
   List<InternetAddress> get addresses;
 
+  /**
+   * Whether [list] is supported.
+   *
+   * [list] is currently unsupported on Android.
+   */
+  external static bool get listSupported;
+
   /**
    * Query the system for [NetworkInterface]s.
    *

tests/standalone/io/network_interface_test.dart

@@ -47,6 +47,9 @@ void testListIndex() {
 
 
 void main() {
+  if (!NetworkInterface.listSupported) {
+    return;
+  }
   testListLoopback();
   testListLinkLocal();
   testListIndex();