Call GetAdaptersAddresses in the way recommended by MSDN.

net/base/network_interfaces_win.cc

 // Copyright (c) 2012 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_win.h"
 
 #include <algorithm>
 #include <memory>
 
 #include "base/files/file_path.h"
@@ skipping 179 matching lines @@
         }
       }
     }
   }
   return true;
 }
 
 }  // namespace internal
 
 bool GetNetworkList(NetworkInterfaceList* networks, int policy) {
-  ULONG len = 0;
+  // Max number of times to retry GetAdaptersAddresses due to
+  // ERROR_BUFFER_OVERFLOW. If GetAdaptersAddresses returns this indefinitely
+  // due to an unforseen reason, we don't want to be stuck in an endless loop.
+  static constexpr int MAX_GETADAPTERSADDRESSES_TRIES = 10;
+  // Use an initial buffer size of 15KB, as recommended by MSDN. See:
+  // https://msdn.microsoft.com/en-us/library/windows/desktop/aa365915(v=vs.85).aspx
+  static constexpr int INITIAL_BUFFER_SIZE = 15000;
+
+  ULONG len = INITIAL_BUFFER_SIZE;
   ULONG flags = 0;
+  // Initial buffer allocated on stack.
+  char initial_buf[INITIAL_BUFFER_SIZE];
+  // Dynamic buffer in case initial buffer isn't large enough.
+  std::unique_ptr<char[]> buf;
+
   // GetAdaptersAddresses() may require IO operations.
   base::ThreadRestrictions::AssertIOAllowed();
-  ULONG result = GetAdaptersAddresses(AF_UNSPEC, flags, NULL, NULL, &len);
-  if (result != ERROR_BUFFER_OVERFLOW) {
+
+  IP_ADAPTER_ADDRESSES* adapters =
+      reinterpret_cast<IP_ADAPTER_ADDRESSES*>(&initial_buf);
+  ULONG result =
+      GetAdaptersAddresses(AF_UNSPEC, flags, nullptr, adapters, &len);
+
+  // If we get ERROR_BUFFER_OVERFLOW, call GetAdaptersAddresses in a loop,
+  // because the required size may increase between successive calls, resulting
+  // in ERROR_BUFFER_OVERFLOW multiple times.
+  for (int tries = 1; result == ERROR_BUFFER_OVERFLOW &&
+                      tries < MAX_GETADAPTERSADDRESSES_TRIES;
+       ++tries) {
+    buf.reset(new char[len]);
+    adapters = reinterpret_cast<IP_ADAPTER_ADDRESSES*>(buf.get());
+    result = GetAdaptersAddresses(AF_UNSPEC, flags, nullptr, adapters, &len);
+  }
+
+  if (result == ERROR_NO_DATA) {
     // There are 0 networks.
     return true;
-  }
-  std::unique_ptr<char[]> buf(new char[len]);
-  IP_ADAPTER_ADDRESSES* adapters =
-      reinterpret_cast<IP_ADAPTER_ADDRESSES*>(buf.get());
-  result = GetAdaptersAddresses(AF_UNSPEC, flags, NULL, adapters, &len);
-  if (result != NO_ERROR) {
+  } else if (result != NO_ERROR) {
     LOG(ERROR) << "GetAdaptersAddresses failed: " << result;
     return false;
   }
 
   return internal::GetNetworkListImpl(networks, policy, adapters);
 }
 
 WifiPHYLayerProtocol GetWifiPHYLayerProtocol() {
   auto conn_info = GetConnectionAttributes();
 
@@ skipping 81 matching lines @@
 
   if (!conn_info.get())
     return "";
 
   const DOT11_SSID dot11_ssid = conn_info->wlanAssociationAttributes.dot11Ssid;
   return std::string(reinterpret_cast<const char*>(dot11_ssid.ucSSID),
                      dot11_ssid.uSSIDLength);
 }
 
 }  // namespace net