(Second attempt at http://codereview.chromium.org/553069/show)...

chrome/browser/geolocation/wifi_data_provider_windows_common.cc

Index: chrome/browser/geolocation/wifi_data_provider_windows_common.cc
===================================================================
--- chrome/browser/geolocation/wifi_data_provider_windows_common.cc	(revision 0)
+++ chrome/browser/geolocation/wifi_data_provider_windows_common.cc	(revision 0)
@@ -0,0 +1,76 @@
+// Copyright 2008, Google Inc.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//  1. Redistributions of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//  2. Redistributions in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//  3. Neither the name of Google Inc. nor the names of its contributors may be
+//     used to endorse or promote products derived from this software without
+//     specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+// WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+// EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+// OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+// WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+// OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+// ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#if defined(WIN32) || defined(OS_WINCE)
+
+#include "gears/geolocation/wifi_data_provider_windows_common.h"
+
+#include <assert.h>
+#include "gears/base/common/string_utils.h"
+#include "gears/geolocation/device_data_provider.h"
+#include "gears/geolocation/wifi_data_provider_common.h"
+
+bool ConvertToGearsFormat(const NDIS_WLAN_BSSID &data,
+                          AccessPointData *access_point_data) {
+  // Currently we get only MAC address, signal strength and SSID.
+  // TODO(steveblock): Work out how to get age, channel and signal-to-noise.
+  assert(access_point_data);
+  access_point_data->mac_address = MacAddressAsString16(data.MacAddress);
+  access_point_data->radio_signal_strength = data.Rssi;
+  // Note that _NDIS_802_11_SSID::Ssid::Ssid is not null-terminated.
+  UTF8ToString16(reinterpret_cast<const char*>(data.Ssid.Ssid),
+                 data.Ssid.SsidLength,
+                 &access_point_data->ssid);
+  return true;
+}
+
+int GetDataFromBssIdList(const NDIS_802_11_BSSID_LIST &bss_id_list,
+                         int list_size,
+                         WifiData::AccessPointDataSet *data) {
+  // Walk through the BSS IDs.
+  int found = 0;
+  const uint8 *iterator = reinterpret_cast<const uint8*>(&bss_id_list.Bssid[0]);
+  const uint8 *end_of_buffer =
+      reinterpret_cast<const uint8*>(&bss_id_list) + list_size;
+  for (int i = 0; i < static_cast<int>(bss_id_list.NumberOfItems); ++i) {
+    const NDIS_WLAN_BSSID *bss_id =
+        reinterpret_cast<const NDIS_WLAN_BSSID*>(iterator);
+    // Check that the length of this BSS ID is reasonable.
+    if (bss_id->Length < sizeof(NDIS_WLAN_BSSID) ||
+        iterator + bss_id->Length > end_of_buffer) {
+      break;
+    }
+    AccessPointData access_point_data;
+    if (ConvertToGearsFormat(*bss_id, &access_point_data)) {
+      data->insert(access_point_data);
+      ++found;
+    }
+    // Move to the next BSS ID.
+    iterator += bss_id->Length;
+  }
+  return found;
+}
+
+#endif  // WIN32 || OS_WINCE