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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsWifiAccessPoint.h"
#include "win_wifiScanner.h"
// Moz headers (alphabetical)
#include "win_wlanLibrary.h"
#define DOT11_BSS_TYPE_UNUSED static_cast<DOT11_BSS_TYPE>(0)
class InterfaceScanCallbackData {
public:
explicit InterfaceScanCallbackData(uint32_t numInterfaces)
: mCurrentlyScanningInterfaces(numInterfaces) {
mAllInterfacesDoneScanningEvent =
::CreateEvent(nullptr, // null security
TRUE, // manual reset event
FALSE, // initially nonsignaled
nullptr); // not named
MOZ_ASSERT(NULL != mAllInterfacesDoneScanningEvent);
}
~InterfaceScanCallbackData() {
::CloseHandle(mAllInterfacesDoneScanningEvent);
}
void OnInterfaceScanComplete() {
uint32_t val = ::InterlockedDecrement(&mCurrentlyScanningInterfaces);
if (!val) {
::SetEvent(mAllInterfacesDoneScanningEvent);
}
}
void WaitForAllInterfacesToFinishScanning(uint32_t msToWait) {
::WaitForSingleObject(mAllInterfacesDoneScanningEvent, msToWait);
}
private:
volatile uint32_t mCurrentlyScanningInterfaces;
HANDLE mAllInterfacesDoneScanningEvent;
};
static void WINAPI OnScanComplete(PWLAN_NOTIFICATION_DATA data, PVOID context) {
if (WLAN_NOTIFICATION_SOURCE_ACM != data->NotificationSource) {
return;
}
if (wlan_notification_acm_scan_complete != data->NotificationCode &&
wlan_notification_acm_scan_fail != data->NotificationCode) {
return;
}
InterfaceScanCallbackData* cbData =
reinterpret_cast<InterfaceScanCallbackData*>(context);
cbData->OnInterfaceScanComplete();
}
WinWifiScanner::WinWifiScanner() {
// NOTE: We assume that, if we were unable to load the WLAN library when
// we initially tried, we will not be able to load it in the future.
// Technically, on Windows XP SP2, a user could install the redistributable
// and make our assumption incorrect. We opt to avoid making a bunch of
// spurious LoadLibrary calls in the common case rather than load the
// WLAN API in the edge case.
mWlanLibrary.reset(WinWLANLibrary::Load());
if (!mWlanLibrary) {
NS_WARNING("Could not initialize Windows Wi-Fi scanner");
}
}
WinWifiScanner::~WinWifiScanner() {}
nsresult WinWifiScanner::GetAccessPointsFromWLAN(
nsCOMArray<nsWifiAccessPoint>& accessPoints) {
accessPoints.Clear();
// NOTE: We do not try to load the WLAN library if we previously failed
// to load it. See the note in WinWifiScanner constructor
if (!mWlanLibrary) {
return NS_ERROR_NOT_AVAILABLE;
}
// Get the list of interfaces. WlanEnumInterfaces allocates interface_list.
WLAN_INTERFACE_INFO_LIST* interface_list = nullptr;
if (ERROR_SUCCESS !=
(*mWlanLibrary->GetWlanEnumInterfacesPtr())(mWlanLibrary->GetWLANHandle(),
nullptr, &interface_list)) {
return NS_ERROR_FAILURE;
}
// This ensures we call WlanFreeMemory on interface_list
ScopedWLANObject scopedInterfaceList(*mWlanLibrary, interface_list);
if (!interface_list->dwNumberOfItems) {
return NS_OK;
}
InterfaceScanCallbackData cbData(interface_list->dwNumberOfItems);
DWORD wlanNotifySource;
if (ERROR_SUCCESS != (*mWlanLibrary->GetWlanRegisterNotificationPtr())(
mWlanLibrary->GetWLANHandle(),
WLAN_NOTIFICATION_SOURCE_ACM, TRUE,
(WLAN_NOTIFICATION_CALLBACK)OnScanComplete, &cbData,
NULL, &wlanNotifySource)) {
return NS_ERROR_FAILURE;
}
// Go through the list of interfaces and call `WlanScan` on each
for (unsigned int i = 0; i < interface_list->dwNumberOfItems; ++i) {
if (ERROR_SUCCESS != (*mWlanLibrary->GetWlanScanPtr())(
mWlanLibrary->GetWLANHandle(),
&interface_list->InterfaceInfo[i].InterfaceGuid,
NULL, NULL, NULL)) {
cbData.OnInterfaceScanComplete();
}
}
// From the MSDN documentation:
// "Wireless network drivers that meet Windows logo requirements are
// required to complete a WlanScan function request in 4 seconds"
cbData.WaitForAllInterfacesToFinishScanning(5000);
// Unregister for the notifications. The documentation mentions that,
// if a callback is currently running, this will wait for the callback
// to complete.
(*mWlanLibrary->GetWlanRegisterNotificationPtr())(
mWlanLibrary->GetWLANHandle(), WLAN_NOTIFICATION_SOURCE_NONE, TRUE, NULL,
NULL, NULL, &wlanNotifySource);
// Go through the list of interfaces and get the data for each.
for (uint32_t i = 0; i < interface_list->dwNumberOfItems; ++i) {
WLAN_BSS_LIST* bss_list;
if (ERROR_SUCCESS != (*mWlanLibrary->GetWlanGetNetworkBssListPtr())(
mWlanLibrary->GetWLANHandle(),
&interface_list->InterfaceInfo[i].InterfaceGuid,
nullptr, // Use all SSIDs.
DOT11_BSS_TYPE_UNUSED,
false, // bSecurityEnabled - unused
nullptr, // reserved
&bss_list)) {
continue;
}
// This ensures we call WlanFreeMemory on bss_list
ScopedWLANObject scopedBssList(*mWlanLibrary, bss_list);
// Store each discovered access point in our outparam
for (int j = 0; j < static_cast<int>(bss_list->dwNumberOfItems); ++j) {
nsWifiAccessPoint* ap = new nsWifiAccessPoint();
if (!ap) {
continue;
}
const WLAN_BSS_ENTRY bss_entry = bss_list->wlanBssEntries[j];
ap->setMac(bss_entry.dot11Bssid);
ap->setSignal(bss_entry.lRssi);
ap->setSSID(reinterpret_cast<char const*>(bss_entry.dot11Ssid.ucSSID),
bss_entry.dot11Ssid.uSSIDLength);
accessPoints.AppendObject(ap);
}
}
return NS_OK;
}