Make GetNetworkList on Windows filter out 'down' interfaces, as on POSIX.

net/base/net_util_win.cc

 // Copyright (c) 2011 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/net_util.h"
 
 #include <iphlpapi.h>
 
 #include <algorithm>
 
@@ skipping 87 matching lines @@
     return false;
   }
 
   for (IP_ADAPTER_ADDRESSES *adapter = adapters; adapter != NULL;
        adapter = adapter->Next) {
     // Ignore the loopback device.
     if (adapter->IfType == IF_TYPE_SOFTWARE_LOOPBACK) {
       continue;
     }
 
+    if (adapter->OperStatus != IfOperStatusUp) {
+      continue;
+    }
+
     IP_ADAPTER_UNICAST_ADDRESS* address;
     for (address = adapter->FirstUnicastAddress; address != NULL;
          address = address->Next) {

[wtc, 2012/02/17 19:36:23]

Comparing this code with the GetNetworkList function for
POSIX, I still see two differences.

1. The POSIX code says "Skip interfaces with no address
configured".  I suspect that is handled by this for loop's
termination condition (address != NULL).

2. The POSIX code says "Skip loopback addresses configured
on non-loopback interfaces."  There is no equivalent code
here.  I am not sure if a non-loopback network interface
may have a loopback address configured though.

wez added that code in http://codereview.chromium.org/7612012.
You can ask him if it's necessary or just defensive
programming.

       int family = address->Address.lpSockaddr->sa_family;
       if (family == AF_INET || family == AF_INET6) {
         IPEndPoint endpoint;
         if (endpoint.FromSockAddr(address->Address.lpSockaddr,
                                   address->Address.iSockaddrLength)) {
           std::string name = adapter->AdapterName;
           networks->push_back(NetworkInterface(name, endpoint.address()));
         }
       }
     }
   }
 
   return true;
 }
 
 }  // namespace net