In my Xamarin Forms application, I am trying to discover all devices on the local network that I am connected to. My approach is to first get the device IP address, and use to first 3 numbers to know what the gateway is (first number is always 192). And then, ping every address on that gateway. Here is my code:
public partial class MainPage : ContentPage
{
private List<Device> discoveredDevices = new List<Device>();
public MainPage()
{
InitializeComponent();
Ping_all();
}
private string GetCurrentIp()
{
IPAddress[] addresses = Dns.GetHostAddresses(Dns.GetHostName());
string ipAddress = string.Empty;
if (addresses != null && addresses[0] != null)
{
ipAddress = addresses[0].ToString();
}
else
{
ipAddress = null;
}
return ipAddress;
}
public void Ping_all()
{
string ip = GetCurrentIp();
if (ip != null)
{
//Extracting and pinging all other ip's.
string[] array = ip.Split('.');
string gateway = array[0] + "." + array[1] + "." + array[2];
for (int i = 2; i <= 255; i++)
{
string ping_var = $"{gateway}.{i}";
//time in milliseconds
Ping(ping_var, 4, 4000);
}
}
}
public void Ping(string host, int attempts, int timeout)
{
for (int i = 0; i < attempts; i++)
{
new Thread(delegate ()
{
try
{
System.Net.NetworkInformation.Ping ping = new System.Net.NetworkInformation.Ping();
ping.PingCompleted += new PingCompletedEventHandler(PingCompleted);
ping.SendAsync(host, timeout, host);
// PingCompleted never gets called
}
catch(Exception e)
{
// Do nothing and let it try again until the attempts are exausted.
// Exceptions are thrown for normal ping failurs like address lookup
// failed. For this reason we are supressing errors.
}
}).Start();
}
}
private void PingCompleted(object sender, PingCompletedEventArgs e)
{
string ip = (string)e.UserState;
if (e.Reply != null && e.Reply.Status == IPStatus.Success)
{
string hostname = GetHostName(ip);
string macaddres = GetMacAddress(ip);
var device = new Device()
{
Hostname = hostname,
IpAddress = ip,
MacAddress = macaddres
};
discoveredDevices.Add(device);
}
}
public string GetHostName(string ipAddress)
{
try
{
IPHostEntry entry = Dns.GetHostEntry(ipAddress);
if (entry != null)
{
return entry.HostName;
}
}
catch (SocketException)
{
}
return null;
}
public string GetMacAddress(string ipAddress)
{
string macAddress = string.Empty;
System.Diagnostics.Process Process = new System.Diagnostics.Process();
Process.StartInfo.FileName = "arp";
Process.StartInfo.Arguments = "-a " + ipAddress;
Process.StartInfo.UseShellExecute = false;
Process.StartInfo.RedirectStandardOutput = true;
Process.StartInfo.CreateNoWindow = true;
Process.Start();
string strOutput = Process.StandardOutput.ReadToEnd();
string[] substrings = strOutput.Split('-');
if (substrings.Length >= 8)
{
macAddress = substrings[3].Substring(Math.Max(0, substrings[3].Length - 2))
+ "-" + substrings[4] + "-" + substrings[5] + "-" + substrings[6]
+ "-" + substrings[7] + "-"
+ substrings[8].Substring(0, 2);
return macAddress;
}
else
{
return "OWN Machine";
}
}
}
I get to the part where I try to ping:
System.Net.NetworkInformation.Ping ping = new System.Net.NetworkInformation.Ping();
ping.PingCompleted += new PingCompletedEventHandler(PingCompleted);
ping.SendAsync(host, timeout, host);
But PingCompleted never gets called. No exception is thrown either. Any idea why? I'm running this on a physical Android device.
EDIT
PingCompleted started getting called for me now, not sure why it wasn't working before. But it now crashes in my GetMacAddress function on the line Process.Start(); because it can not find the resource.
I ended up using this really robust and easy to use library:
https://github.com/Yortw/RSSDP
It doesn't actually find all devices on the network, instead it uses SSDP (Simple Search Discovery Protocol) to quickly find all devices that are broadcasting a service with this protocol on the network. I filtered it to only scan devices running my app, which is what I actually needed. It takes only a second to discover my devices, which is much faster than pinging 255 addresses.
In the documentation you will see:
var deviceDefinition = new SsdpRootDevice()
{
CacheLifetime = TimeSpan.FromMinutes(30), //How long SSDP clients can cache this info.
Location = new Uri("http://mydevice/descriptiondocument.xml"), // Must point to the URL that serves your devices UPnP description document.
DeviceTypeNamespace = "my-namespace",
DeviceType = "MyCustomDevice",
FriendlyName = "Custom Device 1",
Manufacturer = "Me",
ModelName = "MyCustomDevice",
Uuid = GetPersistentUuid() // This must be a globally unique value that survives reboots etc. Get from storage or embedded hardware etc.
};
For the Location I set it as my device's IP. So that another device that discovers it can have the IP too. I don't think it's meant to be used this way, but it worked for me and I don't see why not.
I tested it on 2 physical Android devices.
I am trying to get a redirect from Google Maps using a project that is currently only at .Net Framework 4.0.
Take Microsoft's mailing address as an example:
1 Microsoft Way, Redmond, WA
Format a string that replaces Spaces , Commas , with Plus + signs:
https://www.google.com/maps?daddr=1+microsoft+way+redmond+wa
By the time Google finishes processing the page, the final URL has the Latitude and Longitude:
https://www.google.com/maps/dir//1+Microsoft+Way,+Redmond,+WA+98052/#47.6393095,-122.1327333,16z/data=!3m1!4b1!4m8!4m7!1m0!1m5!1m1!1s0x54906d73f7de150b:0x922499d19305e9a0!2m2!1d-122.1283559!2d47.6393096
I need the Latitude and Longitude from this URL.
I found this article already on SO:
Get a collection of redirected URLs from HttpWebResponse
Using the solution there, I created this very similar looking method:
private String latitude, longitude;
private void GetLatLongFromAddress(String p_street_name, String p_city, String p_state, String p_postal_code)
{
var street_name = String.Format("{0}", p_street_name.Replace(' ', '+')).Trim();
var city = String.Format("{0}", p_city).Trim();
var state = String.Format("{0}", p_state).Trim();
var postal_code = String.Format("{0}", p_postal_code).Trim();
var mapUrl = String.Format("http://maps.google.com/?daddr={0}+{1}+{2}+{3}",
street_name, city, state, postal_code);
var location = String.Copy(mapUrl);
while (!String.IsNullOrEmpty(location))
{
var req1 = (HttpWebRequest)HttpWebRequest.Create(location);
req1.AllowAutoRedirect = false;
// give page time to redirect?
// System.Threading.Thread.Sleep(5000);
using (var resp = (HttpWebResponse)req1.GetResponse())
{
location = resp.GetResponseHeader("Location");
if (!String.IsNullOrEmpty(location))
{
var postalIndex = location.IndexOf(postal_code);
var slashAtIndex = location.IndexOf("/#") + 1;
if ((postalIndex < slashAtIndex) && (slashAtIndex < location.Length))
{
var split = location.Substring(slashAtIndex).Split(',');
latitude = split[0];
longitude = split[1];
}
}
}
}
}
You can see where I format the original URL with this line:
var mapUrl = String.Format("http://maps.google.com/?daddr={0}+{1}+{2}+{3}",
street_name, city, state, postal_code);
The problem is with this line:
location = resp.GetResponseHeader("Location");
Every time I get the response, the returned location value is the same as the mapUrl value that I started with because Google does not redirect it immediately.
I tried adding a Sleep(5000) call, but that did not change anything.
How would I go about getting the final redirect?
I want the public IP address of the client who is using my website.
The code below is showing the local IP in the LAN, but I want the public IP of the client.
//get mac address
NetworkInterface[] nics = NetworkInterface.GetAllNetworkInterfaces();
String sMacAddress = string.Empty;
foreach (NetworkInterface adapter in nics)
{
if (sMacAddress == String.Empty)// only return MAC Address from first card
{
IPInterfaceProperties properties = adapter.GetIPProperties();
sMacAddress = adapter.GetPhysicalAddress().ToString();
}
}
// To Get IP Address
string IPHost = Dns.GetHostName();
string IP = Dns.GetHostByName(IPHost).AddressList[0].ToString();
Output:
Ip Address : 192.168.1.7
Please help me to get the public IP address.
This is what I use:
protected void GetUser_IP()
{
string VisitorsIPAddr = string.Empty;
if (HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"] != null)
{
VisitorsIPAddr = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"].ToString();
}
else if (HttpContext.Current.Request.UserHostAddress.Length != 0)
{
VisitorsIPAddr = HttpContext.Current.Request.UserHostAddress;
}
uip.Text = "Your IP is: " + VisitorsIPAddr;
}
"uip" is the name of the label in the aspx page that shows the user IP.
You can use "HTTP_X_FORWARDED_FOR" or "REMOTE_ADDR" header attribute.
Refer method GetVisitorIPAddress from Machine Syntax blog .
/// <summary>
/// method to get Client ip address
/// </summary>
/// <param name="GetLan"> set to true if want to get local(LAN) Connected ip address</param>
/// <returns></returns>
public static string GetVisitorIPAddress(bool GetLan = false)
{
string visitorIPAddress = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
if (String.IsNullOrEmpty(visitorIPAddress))
visitorIPAddress = HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
if (string.IsNullOrEmpty(visitorIPAddress))
visitorIPAddress = HttpContext.Current.Request.UserHostAddress;
if (string.IsNullOrEmpty(visitorIPAddress) || visitorIPAddress.Trim() == "::1")
{
GetLan = true;
visitorIPAddress = string.Empty;
}
if (GetLan && string.IsNullOrEmpty(visitorIPAddress))
{
//This is for Local(LAN) Connected ID Address
string stringHostName = Dns.GetHostName();
//Get Ip Host Entry
IPHostEntry ipHostEntries = Dns.GetHostEntry(stringHostName);
//Get Ip Address From The Ip Host Entry Address List
IPAddress[] arrIpAddress = ipHostEntries.AddressList;
try
{
visitorIPAddress = arrIpAddress[arrIpAddress.Length - 2].ToString();
}
catch
{
try
{
visitorIPAddress = arrIpAddress[0].ToString();
}
catch
{
try
{
arrIpAddress = Dns.GetHostAddresses(stringHostName);
visitorIPAddress = arrIpAddress[0].ToString();
}
catch
{
visitorIPAddress = "127.0.0.1";
}
}
}
}
return visitorIPAddress;
}
Combination of all of these suggestions, and the reasons behind them. Feel free to add more test cases too. If getting the client IP is of utmost importance, than you might wan to get all of theses are run some comparisons on which result might be more accurate.
Simple check of all suggestions in this thread plus some of my own code...
using System.IO;
using System.Net;
public string GetUserIP()
{
string strIP = String.Empty;
HttpRequest httpReq = HttpContext.Current.Request;
//test for non-standard proxy server designations of client's IP
if (httpReq.ServerVariables["HTTP_CLIENT_IP"] != null)
{
strIP = httpReq.ServerVariables["HTTP_CLIENT_IP"].ToString();
}
else if (httpReq.ServerVariables["HTTP_X_FORWARDED_FOR"] != null)
{
strIP = httpReq.ServerVariables["HTTP_X_FORWARDED_FOR"].ToString();
}
//test for host address reported by the server
else if
(
//if exists
(httpReq.UserHostAddress.Length != 0)
&&
//and if not localhost IPV6 or localhost name
((httpReq.UserHostAddress != "::1") || (httpReq.UserHostAddress != "localhost"))
)
{
strIP = httpReq.UserHostAddress;
}
//finally, if all else fails, get the IP from a web scrape of another server
else
{
WebRequest request = WebRequest.Create("http://checkip.dyndns.org/");
using (WebResponse response = request.GetResponse())
using (StreamReader sr = new StreamReader(response.GetResponseStream()))
{
strIP = sr.ReadToEnd();
}
//scrape ip from the html
int i1 = strIP.IndexOf("Address: ") + 9;
int i2 = strIP.LastIndexOf("</body>");
strIP = strIP.Substring(i1, i2 - i1);
}
return strIP;
}
That code gets you the IP address of your server not the address of the client who is accessing your website. Use the HttpContext.Current.Request.UserHostAddress property to the client's IP address.
For Web Applications ( ASP.NET MVC and WebForm )
/// <summary>
/// Get current user ip address.
/// </summary>
/// <returns>The IP Address</returns>
public static string GetUserIPAddress()
{
var context = System.Web.HttpContext.Current;
string ip = String.Empty;
if (context.Request.ServerVariables["HTTP_X_FORWARDED_FOR"] != null)
ip = context.Request.ServerVariables["HTTP_X_FORWARDED_FOR"].ToString();
else if (!String.IsNullOrWhiteSpace(context.Request.UserHostAddress))
ip = context.Request.UserHostAddress;
if (ip == "::1")
ip = "127.0.0.1";
return ip;
}
For Windows Applications ( Windows Form, Console, Windows Service , ... )
static void Main(string[] args)
{
HTTPGet req = new HTTPGet();
req.Request("http://checkip.dyndns.org");
string[] a = req.ResponseBody.Split(':');
string a2 = a[1].Substring(1);
string[] a3=a2.Split('<');
string a4 = a3[0];
Console.WriteLine(a4);
Console.ReadLine();
}
So many of these code snippets are really big and could confuse new programmers looking for help.
How about this simple and compact code to fetch the IP address of the visitor?
string ip = System.Web.HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
if (string.IsNullOrEmpty(ip))
{
ip = System.Web.HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
}
Simple, short and compact.
I have an extension method:
public static string GetIp(this HttpContextBase context)
{
if (context == null || context.Request == null)
return string.Empty;
return context.Request.ServerVariables["HTTP_X_FORWARDED_FOR"]
?? context.Request.UserHostAddress;
}
Note: "HTTP_X_FORWARDED_FOR" is for ip behind proxy. context.Request.UserHostAddress is identical to "REMOTE_ADDR".
But bear in mind it is not necessary the actual IP though.
Sources:
IIS Server Variables
Link
My version handles both ASP.NET or LAN IPs:
/**
* Get visitor's ip address.
*/
public static string GetVisitorIp() {
string ip = null;
if (HttpContext.Current != null) { // ASP.NET
ip = string.IsNullOrEmpty(HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"])
? HttpContext.Current.Request.UserHostAddress
: HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
}
if (string.IsNullOrEmpty(ip) || ip.Trim() == "::1") { // still can't decide or is LAN
var lan = Dns.GetHostEntry(Dns.GetHostName()).AddressList.FirstOrDefault(r => r.AddressFamily == AddressFamily.InterNetwork);
ip = lan == null ? string.Empty : lan.ToString();
}
return ip;
}
private string GetClientIpaddress()
{
string ipAddress = string.Empty;
ipAddress = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
if (ipAddress == "" || ipAddress == null)
{
ipAddress = HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
return ipAddress;
}
else
{
return ipAddress;
}
}
On MVC 5 you can use this:
string cIpAddress = Request.UserHostAddress; //Gets the client ip address
or
string cIpAddress = Request.ServerVariables["REMOTE_ADDR"]; //Gets the client ip address
In MVC IP can be obtained by the following Code
string ipAddress = Request.ServerVariables["REMOTE_ADDR"];
string IP = HttpContext.Current.Request.Params["HTTP_CLIENT_IP"] ?? HttpContext.Current.Request.UserHostAddress;
just use this..................
public string GetIP()
{
string externalIP = "";
externalIP = (new WebClient()).DownloadString("http://checkip.dyndns.org/");
externalIP = (new Regex(#"\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}")).Matches(externalIP)[0].ToString();
return externalIP;
}
We connect to servers that give us our external IP address and try to parse the IP from returning HTML pages. But when servers make small changes on these pages or remove them, these methods stop working properly.
Here is a method that takes the external IP address using a server which has been alive for years and returns a simple response rapidly...
https://www.codeproject.com/Tips/452024/Getting-the-External-IP-Address
Private string getExternalIp()
{
try
{
string externalIP;
externalIP = (new
WebClient()).DownloadString("http://checkip.dyndns.org/");
externalIP = (new Regex(#"\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}"))
.Matches(externalIP)[0].ToString();
return externalIP;
}
catch { return null; }
}
VB.NET
Imports System.Net
Private Function GetExternalIp() As String
Try
Dim ExternalIP As String
ExternalIP = (New WebClient()).DownloadString("http://checkip.dyndns.org/")
ExternalIP = (New Regex("\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}")) _
.Matches(ExternalIP)(0).ToString()
Return ExternalIP
Catch
Return Nothing
End Try
End Function
lblmessage.Text =Request.ServerVariables["REMOTE_HOST"].ToString();
You can download xNet at: https://drive.google.com/open?id=1fmUosINo8hnDWY6s4IV4rDnHKLizX-Hq
First, you need import xNet, code:
using xNet;
Code:
void LoadpublicIP()
{
HttpRequest httprequest = new HttpRequest();
String HTML5 = httprequest.Get("https://whoer.net/").ToString();
MatchCollection collect = Regex.Matches(HTML5, #"<strong data-clipboard-target="".your-ip(.*?)</strong>", RegexOptions.Singleline);
foreach (Match match in collect)
{
var val = Regex.Matches(match.Value, #"(?<ip>(\d|\.)+)");
foreach (Match m in val)
{
richTextBox1.Text = m.Groups[2].Value;
}
}
}
How to get the user machine account from which he access the application in the case of Form authentication .
I use the following method but it doesn't get the required data:
protected string[] TrackUser()
{
System.Web.HttpContext context = System.Web.HttpContext.Current;
string IP = context.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
string compName = (Dns.GetHostEntry(Request.ServerVariables["remote_addr"]).HostName);
string account = Request.ServerVariables["AUTH_USER"];
string[] user_network_data = new string[3];
if (!string.IsNullOrEmpty(IP))
{
string[] addresses = IP.Split(',');
if (addresses.Length != 0)
{
IP = addresses[0];
}
}
else
{
IP = context.Request.ServerVariables["REMOTE_ADDR"];
}
user_network_data[0] = IP;
user_network_data[1] = compName;
user_network_data[2] = account;
return user_network_data;
}
I think you're just grabbing the wrong initial information from the request. Try these:
string IP = context.Request.UserHostAddress;
string compName = context.Request.UserHostName;
string account = context.Request.LogonUserIdentity.Name;
I think the rest of your code should work fine once you have the right data to start off with.
Please see the below codes :
private string GetUserIPAddress()
{
string User_IPAddress = string.Empty;
string User_IPAddressRange = Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
if (string.IsNullOrEmpty(User_IPAddressRange))//without Proxy detection
{
User_IPAddress = Request.ServerVariables["REMOTE_ADDR"];
//or
//Client_IPAddress = Request.UserHostAddress;
//or
//User_IPAddress = Request.ServerVariables["REMOTE_HOST"];
}
else////with Proxy detection
{
string[] splitter = { "," };
string[] IP_Array = User_IPAddressRange.Split(splitter,
System.StringSplitOptions.None);
int LatestItem = IP_Array.Length - 1;
User_IPAddress = IP_Array[LatestItem - 1];
//User_IPAddress = IP_Array[0];
}
return User_IPAddress;
}
In the case of :
1-
User_IPAddress = Request.ServerVariables["REMOTE_ADDR"];
and
Client_IPAddress = Request.UserHostAddress;
and
User_IPAddress = Request.ServerVariables["REMOTE_HOST"];
is the lower or middle line an alternate for the other lines?
Would you please give us some explain about these lines?
What are the differences ?
2-
User_IPAddress = IP_Array[LatestItem - 1];
and
User_IPAddress = IP_Array[0];
Which line should I use?
Would you please give explain about these lines?
I Don't know the class but chances are Request.UserHostAddress is an alias for Request.ServerVariables["REMOTE_ADDR"]. Also REMOTE_HOST would be the hostname but in most cases will just be the ipaddress.
Format of X-Forwarded-For is client1, proxy1, proxy2. So you want the second one. User_IPAddress = IP_Array[0];
Just remember "Since it is easy to forge an X-Forwarded-For field the given information should be used with care."