content/browser/geolocation/wifi_data_provider_common_win.cc

   1 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/browser/geolocation/wifi_data_provider_common_win.h"
   6
   7 #include <assert.h>
   8
   9 #include "base/strings/utf_string_conversions.h"
  10 #include "content/browser/geolocation/wifi_data_provider_common.h"
  11
  12 namespace content {
  13
  14 bool ConvertToAccessPointData(const NDIS_WLAN_BSSID& data,
  15                               AccessPointData *access_point_data) {
  16   // Currently we get only MAC address, signal strength and SSID.
  17   // TODO(steveblock): Work out how to get age, channel and signal-to-noise.
  18   DCHECK(access_point_data);
  19   access_point_data->mac_address = MacAddressAsString16(data.MacAddress);
  20   access_point_data->radio_signal_strength = data.Rssi;
  21   // Note that _NDIS_802_11_SSID::Ssid::Ssid is not null-terminated.
  22   base::UTF8ToUTF16(reinterpret_cast<const char*>(data.Ssid.Ssid),
  23                     data.Ssid.SsidLength,
  24                     &access_point_data->ssid);
  25   return true;
  26 }
  27
  28 int GetDataFromBssIdList(const NDIS_802_11_BSSID_LIST& bss_id_list,
  29                          int list_size,
  30                          WifiData::AccessPointDataSet* data) {
  31   // Walk through the BSS IDs.
  32   int found = 0;
  33   const uint8 *iterator = reinterpret_cast<const uint8*>(&bss_id_list.Bssid[0]);
  34   const uint8 *end_of_buffer =
  35       reinterpret_cast<const uint8*>(&bss_id_list) + list_size;
  36   for (int i = 0; i < static_cast<int>(bss_id_list.NumberOfItems); ++i) {
  37     const NDIS_WLAN_BSSID *bss_id =
  38         reinterpret_cast<const NDIS_WLAN_BSSID*>(iterator);
  39     // Check that the length of this BSS ID is reasonable.
  40     if (bss_id->Length < sizeof(NDIS_WLAN_BSSID) ||
  41         iterator + bss_id->Length > end_of_buffer) {
  42       break;
  43     }
  44     AccessPointData access_point_data;
  45     if (ConvertToAccessPointData(*bss_id, &access_point_data)) {
  46       data->insert(access_point_data);
  47       ++found;
  48     }
  49     // Move to the next BSS ID.
  50     iterator += bss_id->Length;
  51   }
  52   return found;
  53 }
  54
  55 }  // namespace content