如何重置WLAN信息的系统缓存? [英] How do i reset the system cache of WLAN info?
问题描述
我正在尝试使用C#中的NativeWifi编写WLAN指纹识别程序.为此，我运行了一个循环以多次获取无线局域网信息，然后稍后使用matlab对数据进行平均/分析.
I am trying to write a WLAN fingerprinting program using NativeWifi in C#. To do this i run a loop to get the wlan information many times and then later use matlab to average / analyze the data.
问题是，即使程序运行时我四处走动，我也会得到所有相同的值.从互联网上，我已经看到有一个缓存，用于存储可用网络的数据.我想知道是否有系统调用会重置此缓存.
The problem is that i get all the same values, even as i move about the house, when the program is running. From the internet i've seen that there is a cache that stores the data of available networks. I was wondering if there is a system call which resets this cache.
我也通过cmd调用看到了这一点
I have also seen this using the cmd call
netsh wlan show networks mode = bssid
netsh wlan show networks mode=bssid
这将为我提供相同的值，直到我在操作系统中打开可用的wifi网络为止，如果此后再次运行它，它将提供不同的值.
this gives me the same values until i open the available wifi networks in my OS and if i run it again after, it will give different values.
edit:该系统仅供我使用，因此，如果有已知的库可以为我处理，那么我将在Linux平台上重新开始.不过，我什至不知道要用Google来获取什么信息.与网络缓存"相关的任何事情都需要我来帮助无关主题的话题...
edit: This system will be for my use only, so i would be comfortable starting over on a linux platform if there is a known library that can handle this for me. I don't even know what to google to even get the information, though. Anything related to "network cache" takes me to help threads of unrelated topics...
我将在下面提供我代码的相关部分:
I will provide the relevant part of my code below:
public void get_info_instance(StreamWriter file)
{
try
{
foreach (WlanClient.WlanInterface wlanIface in client.Interfaces)
{
Wlan.WlanBssEntry[] wlanBssEntries = wlanIface.GetNetworkBssList();
foreach (Wlan.WlanBssEntry network in wlanBssEntries)
{
int rss = network.rssi;
byte[] macAddr = network.dot11Bssid;
string tMac = "";
for (int i = 0; i < macAddr.Length; i++)
{
tMac += macAddr[i].ToString("x2").PadLeft(2, '0').ToUpper();
}
file.WriteLine("Found network: " + System.Text.ASCIIEncoding.ASCII.GetString(network.dot11Ssid.SSID).ToString());
file.WriteLine("Signal: " + network.linkQuality + "%");
file.WriteLine("BSS Type: " + network.dot11BssType + ".");
file.WriteLine("RSSID: " + rss.ToString());
file.WriteLine("BSSID: " + tMac);
file.WriteLine(" ");
}
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
推荐答案
Internally, netsh is powered by this API. What this means, is that calling netsh wlan show networks mode=bssid just returns the cache of the networks that showed up during the last scan. This is what you've discovered.
这意味着要刷新此缓存，您需要触发扫描.如果您正在使用的C#库包含它，则可以通过调用扫描完整的通知(向源WLAN_NOTIFICATION_SOURCE_ACM注册并注意wlan_notification_acm_scan_list_refresh)，应该更新缓存.
This means that in order to refresh this cache, you need to trigger a scan. If your C# library you are using includes it, you could make this happen on demand with a call to WlanScan. I am not sure which C# wrapper you are using, but it probably includes this function. When you get a scan complete notification (register with source WLAN_NOTIFICATION_SOURCE_ACM and look out for wlan_notification_acm_scan_list_refresh), the cache should be updated.
如果您让我知道您正在使用哪个C#库，也许我可以为您提供相关功能.
If you let me know which C# library you are using, maybe I can point you to the relevant functions.
您提到打开可用网络会导致缓存刷新.这是因为打开可用网络会触发对WlanScan的呼叫.
You mentioned that opening the available networks causes the cache to refresh. This is because opening the available networks triggers a call to WlanScan.
配置文件与可用的网络列表无关-配置文件是Wlan服务用来跟踪计算机上配置的网络的配置文件-删除它们不会使WlanSvc再次扫描.删除它们恰巧与扫描同时发生，这可能是一个巧合，但比设计用途更多的是副作用.
Profiles are not relevant to the available network list -- profiles are what the Wlan service uses to keep track of which networks are configured on your machine -- deleting them does not make WlanSvc scan again. It may be a coincidence that deleting them happens to coincide with a scan, but it is more of a side effect than the designed usage.
要使用您使用的Managed Wifi API订阅通知，此代码段应该起作用:
edit: to subscribe to notifications using the Managed Wifi API you are using, this snippet should work:
wlanIface.WlanNotification += wlanIface_WlanNotification;
和回调:
static void wlanIface_WlanNotification(Wlan.WlanNotificationData notifyData)
{
if (notifyData.notificationCode == (int)Wlan.WlanNotificationCodeAcm.ScanComplete)
{
Console.WriteLine("Scan Complete!");
}
}
您可以通过运行此程序，然后在Windows上打开可用的网络来对其进行测试.每次打开后不久，您应该会看到扫描完成".如果愿意，可以使用消息框代替Console.WriteLine.
You can test this by running this, then opening the available networks on Windows. You should see "Scan Complete" shortly after you open it each time. You can use a messagebox instead of Console.WriteLine if you prefer.
要自己触发扫描:
wlanIface.Scan();
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