When creating sockets for ioctl() use AF_INET6 or AF_INET

net/base/network_interfaces_linux.cc

 // Copyright (c) 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/base/network_interfaces_linux.h"
 
 #include <memory>
 
 #if !defined(OS_ANDROID)
 #include <linux/ethtool.h>
@@ skipping 58 matching lines @@
 }
 
 }  // namespace
 
 namespace internal {
 
 // Gets the connection type for interface |ifname| by checking for wireless
 // or ethtool extensions.
 NetworkChangeNotifier::ConnectionType GetInterfaceConnectionType(
     const std::string& ifname) {
-  base::ScopedFD s(socket(AF_INET, SOCK_STREAM, 0));
+  base::ScopedFD s = GetSocketForIoctl();
   if (!s.is_valid())
     return NetworkChangeNotifier::CONNECTION_UNKNOWN;
 
   // Test wireless extensions for CONNECTION_WIFI
   struct iwreq pwrq = {};
   strncpy(pwrq.ifr_name, ifname.c_str(), IFNAMSIZ - 1);
   if (ioctl(s.get(), SIOCGIWNAME, &pwrq) != -1)
     return NetworkChangeNotifier::CONNECTION_WIFI;
 
 #if !defined(OS_ANDROID)
   // Test ethtool for CONNECTION_ETHERNET
   struct ethtool_cmd ecmd = {};
   ecmd.cmd = ETHTOOL_GSET;
   struct ifreq ifr = {};
   ifr.ifr_data = &ecmd;
   strncpy(ifr.ifr_name, ifname.c_str(), IFNAMSIZ - 1);
   if (ioctl(s.get(), SIOCETHTOOL, &ifr) != -1)
     return NetworkChangeNotifier::CONNECTION_ETHERNET;
 #endif  // !defined(OS_ANDROID)
 
   return NetworkChangeNotifier::CONNECTION_UNKNOWN;
 }
 
 std::string GetInterfaceSSID(const std::string& ifname) {
-  base::ScopedFD ioctl_socket(socket(AF_INET, SOCK_DGRAM, 0));
+  base::ScopedFD ioctl_socket = GetSocketForIoctl();
   if (!ioctl_socket.is_valid())
     return "";
   struct iwreq wreq = {};
   strncpy(wreq.ifr_name, ifname.c_str(), IFNAMSIZ - 1);
 
   char ssid[IW_ESSID_MAX_SIZE + 1] = {0};
   wreq.u.essid.pointer = ssid;
   wreq.u.essid.length = IW_ESSID_MAX_SIZE;
   if (ioctl(ioctl_socket.get(), SIOCGIWESSID, &wreq) != -1)
     return ssid;
@@ skipping 79 matching lines @@
     std::string ssid = get_interface_ssid(interfaces[i].name);
     if (i == 0) {
       connected_ssid = ssid;
     } else if (ssid != connected_ssid) {
       return "";
     }
   }
   return connected_ssid;
 }
 
+base::ScopedFD GetSocketForIoctl() {
+  base::ScopedFD ioctl_socket(socket(AF_INET6, SOCK_DGRAM, 0));
+  if (ioctl_socket.is_valid())
+    return ioctl_socket;
+  return base::ScopedFD(socket(AF_INET, SOCK_DGRAM, 0));
+}
+
 }  // namespace internal
 
 bool GetNetworkList(NetworkInterfaceList* networks, int policy) {
   if (networks == NULL)
     return false;
 
   internal::AddressTrackerLinux tracker;
   tracker.Init();
 
   return internal::GetNetworkListImpl(
       networks, policy, tracker.GetOnlineLinks(), tracker.GetAddressMap(),
       &internal::AddressTrackerLinux::GetInterfaceName);
 }
 
 std::string GetWifiSSID() {
 // On Android, obtain the SSID using the Android-specific APIs.
 #if defined(OS_ANDROID)
   return android::GetWifiSSID();
 #endif
   NetworkInterfaceList networks;
   if (GetNetworkList(&networks, INCLUDE_HOST_SCOPE_VIRTUAL_INTERFACES)) {
     return internal::GetWifiSSIDFromInterfaceListInternal(
         networks, internal::GetInterfaceSSID);
   }
   return "";
 }
 
 }  // namespace net