content/browser/geolocation/wifi_data_provider_mac.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 // For OSX 10.5 we use the system API function WirelessScanSplit. This function
   6 // is not documented or included in the SDK, so we use a reverse-engineered
   7 // header, osx_wifi_.h. This file is taken from the iStumbler project
   8 // (http://www.istumbler.net).
   9
  10 #include "content/browser/geolocation/wifi_data_provider_mac.h"
  11
  12 #include <dlfcn.h>
  13 #include <stdio.h>
  14
  15 #include "base/strings/utf_string_conversions.h"
  16 #include "content/browser/geolocation/osx_wifi.h"
  17 #include "content/browser/geolocation/wifi_data_provider_common.h"
  18 #include "content/browser/geolocation/wifi_data_provider_manager.h"
  19
  20 namespace content {
  21 namespace {
  22 // The time periods, in milliseconds, between successive polls of the wifi data.
  23 const int kDefaultPollingInterval = 120000;  // 2 mins
  24 const int kNoChangePollingInterval = 300000;  // 5 mins
  25 const int kTwoNoChangePollingInterval = 600000;  // 10 mins
  26 const int kNoWifiPollingIntervalMilliseconds = 20 * 1000; // 20s
  27
  28 // Provides the wifi API binding for use when running on OSX 10.5 machines using
  29 // the Apple80211 framework.
  30 class Apple80211Api : public WifiDataProviderCommon::WlanApiInterface {
  31  public:
  32   Apple80211Api();
  33   ~Apple80211Api() override;
  34
  35   // Must be called before any other interface method. Will return false if the
  36   // Apple80211 framework cannot be initialized (e.g. running on post-10.5 OSX),
  37   // in which case no other method may be called.
  38   bool Init();
  39
  40   // WlanApiInterface
  41   bool GetAccessPointData(WifiData::AccessPointDataSet* data) override;
  42
  43  private:
  44   // Handle, context and function pointers for Apple80211 library.
  45   void* apple_80211_library_;
  46   WirelessContext* wifi_context_;
  47   WirelessAttachFunction WirelessAttach_function_;
  48   WirelessScanSplitFunction WirelessScanSplit_function_;
  49   WirelessDetachFunction WirelessDetach_function_;
  50
  51   WifiData wifi_data_;
  52
  53   DISALLOW_COPY_AND_ASSIGN(Apple80211Api);
  54 };
  55
  56 Apple80211Api::Apple80211Api()
  57     : apple_80211_library_(NULL), wifi_context_(NULL),
  58       WirelessAttach_function_(NULL), WirelessScanSplit_function_(NULL),
  59       WirelessDetach_function_(NULL) {
  60 }
  61
  62 Apple80211Api::~Apple80211Api() {
  63   if (WirelessDetach_function_)
  64     (*WirelessDetach_function_)(wifi_context_);
  65   dlclose(apple_80211_library_);
  66 }
  67
  68 bool Apple80211Api::Init() {
  69   DVLOG(1) << "Apple80211Api::Init";
  70   apple_80211_library_ = dlopen(
  71       "/System/Library/PrivateFrameworks/Apple80211.framework/Apple80211",
  72       RTLD_LAZY);
  73   if (!apple_80211_library_) {
  74     DLOG(WARNING) << "Could not open Apple80211 library";
  75     return false;
  76   }
  77   WirelessAttach_function_ = reinterpret_cast<WirelessAttachFunction>(
  78       dlsym(apple_80211_library_, "WirelessAttach"));
  79   WirelessScanSplit_function_ = reinterpret_cast<WirelessScanSplitFunction>(
  80       dlsym(apple_80211_library_, "WirelessScanSplit"));
  81   WirelessDetach_function_ = reinterpret_cast<WirelessDetachFunction>(
  82       dlsym(apple_80211_library_, "WirelessDetach"));
  83   DCHECK(WirelessAttach_function_);
  84   DCHECK(WirelessScanSplit_function_);
  85   DCHECK(WirelessDetach_function_);
  86
  87   if (!WirelessAttach_function_ || !WirelessScanSplit_function_ ||
  88       !WirelessDetach_function_) {
  89     DLOG(WARNING) << "Symbol error. Attach: " << !!WirelessAttach_function_
  90         << " Split: " << !!WirelessScanSplit_function_
  91         << " Detach: " << !!WirelessDetach_function_;
  92     return false;
  93   }
  94
  95   WIErr err = (*WirelessAttach_function_)(&wifi_context_, 0);
  96   if (err != noErr) {
  97     DLOG(WARNING) << "Error attaching: " << err;
  98     return false;
  99   }
 100   return true;
 101 }
 102
 103 bool Apple80211Api::GetAccessPointData(WifiData::AccessPointDataSet* data) {
 104   DVLOG(1) << "Apple80211Api::GetAccessPointData";
 105   DCHECK(data);
 106   DCHECK(WirelessScanSplit_function_);
 107   CFArrayRef managed_access_points = NULL;
 108   CFArrayRef adhoc_access_points = NULL;
 109   // Arrays returned here are owned by the caller.
 110   WIErr err = (*WirelessScanSplit_function_)(wifi_context_,
 111                                              &managed_access_points,
 112                                              &adhoc_access_points,
 113                                              0);
 114   if (err != noErr) {
 115     DLOG(WARNING) << "Error spliting scan: " << err;
 116     return false;
 117   }
 118
 119   if (managed_access_points == NULL) {
 120     DLOG(WARNING) << "managed_access_points == NULL";
 121     return false;
 122   }
 123
 124   int num_access_points = CFArrayGetCount(managed_access_points);
 125   DVLOG(1) << "Found " << num_access_points << " managed access points";
 126   for (int i = 0; i < num_access_points; ++i) {
 127     const WirelessNetworkInfo* access_point_info =
 128         reinterpret_cast<const WirelessNetworkInfo*>(
 129         CFDataGetBytePtr(
 130         reinterpret_cast<const CFDataRef>(
 131         CFArrayGetValueAtIndex(managed_access_points, i))));
 132
 133     // Currently we get only MAC address, signal strength, channel
 134     // signal-to-noise and SSID
 135     AccessPointData access_point_data;
 136     access_point_data.mac_address =
 137         MacAddressAsString16(access_point_info->macAddress);
 138     // WirelessNetworkInfo::signal appears to be signal strength in dBm.
 139     access_point_data.radio_signal_strength = access_point_info->signal;
 140     access_point_data.channel = access_point_info->channel;
 141     // WirelessNetworkInfo::noise appears to be noise floor in dBm.
 142     access_point_data.signal_to_noise = access_point_info->signal -
 143                                         access_point_info->noise;
 144     if (!base::UTF8ToUTF16(reinterpret_cast<const char*>(
 145                                access_point_info->name),
 146                            access_point_info->nameLen,
 147                            &access_point_data.ssid)) {
 148       access_point_data.ssid.clear();
 149     }
 150     data->insert(access_point_data);
 151   }
 152
 153   if (managed_access_points)
 154     CFRelease(managed_access_points);
 155   if (adhoc_access_points)
 156     CFRelease(adhoc_access_points);
 157
 158   return true;
 159 }
 160 }  // namespace
 161
 162 // static
 163 WifiDataProvider* WifiDataProviderManager::DefaultFactoryFunction() {
 164   return new WifiDataProviderMac();
 165 }
 166
 167 WifiDataProviderMac::WifiDataProviderMac() {
 168 }
 169
 170 WifiDataProviderMac::~WifiDataProviderMac() {
 171 }
 172
 173 WifiDataProviderMac::WlanApiInterface* WifiDataProviderMac::NewWlanApi() {
 174   // Try and find a API binding that works: first try the officially supported
 175   // CoreWLAN API, and if this fails (e.g. on OSX 10.5) fall back to the reverse
 176   // engineered Apple80211 API.
 177   WifiDataProviderMac::WlanApiInterface* core_wlan_api = NewCoreWlanApi();
 178   if (core_wlan_api)
 179     return core_wlan_api;
 180
 181   scoped_ptr<Apple80211Api> wlan_api(new Apple80211Api);
 182   if (wlan_api->Init())
 183     return wlan_api.release();
 184
 185   DVLOG(1) << "WifiDataProviderMac : failed to initialize any wlan api";
 186   return NULL;
 187 }
 188
 189 WifiPollingPolicy* WifiDataProviderMac::NewPollingPolicy() {
 190   return new GenericWifiPollingPolicy<kDefaultPollingInterval,
 191                                       kNoChangePollingInterval,
 192                                       kTwoNoChangePollingInterval,
 193                                       kNoWifiPollingIntervalMilliseconds>;
 194 }
 195
 196 }  // namespace content