/// <summary>
/// Retrieves the IP address of the current request -- handles proxies and private networks.
/// </summary>
/// <param name="serverVariables">The server variables collection to extract the IP from.</param>
public static string GetRemoteIP(this NameValueCollection serverVariables)
{
var ip = serverVariables["REMOTE_ADDR"]; // could be a proxy -- beware
var forwardedFor = serverVariables["HTTP_X_FORWARDED_FOR"] ?? "";
var remoteIPs = forwardedFor.Split(_commaSpace, StringSplitOptions.RemoveEmptyEntries);
// Loop from the end until we get the first IP that's *not* internal:
for (var i = remoteIPs.Length - 1; i >= 0; i--)
{
var remoteIp = remoteIPs[i];
// Nothing? Toss it.
if (remoteIp == null)
{
continue;
}
// Not valid? Toss it.
if (!IPNet.TryParse(remoteIp, out IPNet remoteIpNet))
{
continue;
}
// Usual prod behavior: Never match a private address, unless it's the last.
// Get the first IP outside current networks.
// Take the first external IP we match, or the last IP we match - e.g. from another web server
if (!remoteIpNet.IsPrivate || i == 0)
{
ip = remoteIp;
break;
}
}
return(ip.HasValue() ? ip : UnknownIP);
}
public bool Contains(IPNet network)
{
return(network != null &&
AddressFamily == network.AddressFamily &&
TinyFirstAddressInSubnet <= network.TinyFirstAddressInSubnet &&
network.TinyLastAddressInSubnet <= TinyLastAddressInSubnet);
//return (TSubnet & TIPAddress) == (TSubnet & network.TIPAddress & TIPAddress );
}
public static bool TryParse(string ipOrCidr, out IPNet net)
{
try { net = Parse(ipOrCidr); return(true); }
catch { net = null; return(false); }
}
public static bool IsPrivateNetwork(IPNet network)
{
return(ReservedPrivateRanges.Any(r => r.Contains(network)));
}