如何确定IP地址是否为私有地址
本文关键字：地址 是否 IP 何确定 | 更新日期: 2023-09-27 18:14:18
到目前为止，我有以下代码：
NetworkInterface[] adapters = NetworkInterface.GetAllNetworkInterfaces();
foreach (NetworkInterface adapter in adapters)
{
IPInterfaceProperties properties = adapter.GetIPProperties();
foreach (IPAddressInformation uniCast in properties.UnicastAddresses)
{
// Ignore loop-back addresses & IPv6
if (!IPAddress.IsLoopback(uniCast.Address) &&
uniCast.Address.AddressFamily!= AddressFamily.InterNetworkV6)
Addresses.Add(uniCast.Address);
}
}
我如何也过滤私人IP地址？以同样的方式，我过滤环回IP地址。
这里有更详细的响应：
private bool _IsPrivate(string ipAddress)
{
int[] ipParts = ipAddress.Split(new String[] { "." }, StringSplitOptions.RemoveEmptyEntries)
.Select(s => int.Parse(s)).ToArray();
// in private ip range
if (ipParts[0] == 10 ||
(ipParts[0] == 192 && ipParts[1] == 168) ||
(ipParts[0] == 172 && (ipParts[1] >= 16 && ipParts[1] <= 31))) {
return true;
}
// IP Address is probably public.
// This doesn't catch some VPN ranges like OpenVPN and Hamachi.
return false;
}
私有地址范围在RFC1918中定义。它们是：
- 10.0.0.0-10.255.255.255(10/8前缀(
- 172.16.0.0-172.31.255.255(172.16/12前缀(
- 192.168.0.0-192.168.255.255(192.168/16前缀(
您可能还想过滤掉RFC3927中定义的链接本地地址(169.254/16(。
最好的方法是对IP地址类进行扩展
/// <summary>
/// An extension method to determine if an IP address is internal, as specified in RFC1918
/// </summary>
/// <param name="toTest">The IP address that will be tested</param>
/// <returns>Returns true if the IP is internal, false if it is external</returns>
public static bool IsInternal(this IPAddress toTest)
{
if (IPAddress.IsLoopback(toTest)) return true;
else if (toTest.ToString() == "::1") return false;
byte[] bytes = toTest.GetAddressBytes();
switch( bytes[ 0 ] )
{
case 10:
return true;
case 172:
return bytes[ 1 ] < 32 && bytes[ 1 ] >= 16;
case 192:
return bytes[ 1 ] == 168;
default:
return false;
}
}
然后，可以在IP地址类的实例上调用该方法
bool isIpInternal = ipAddressInformation.Address.IsInternal();
添加了IPv6和localhost情况。
/* An IP should be considered as internal when:
::1 - IPv6 loopback
10.0.0.0 - 10.255.255.255 (10/8 prefix)
127.0.0.0 - 127.255.255.255 (127/8 prefix)
172.16.0.0 - 172.31.255.255 (172.16/12 prefix)
192.168.0.0 - 192.168.255.255 (192.168/16 prefix)
*/
public bool IsInternal(string testIp)
{
if(testIp == "::1") return true;
byte[] ip = IPAddress.Parse(testIp).GetAddressBytes();
switch (ip[0])
{
case 10:
case 127:
return true;
case 172:
return ip[1] >= 16 && ip[1] < 32;
case 192:
return ip[1] == 168;
default:
return false;
}
}
此实现+测试涵盖：
- 环回(IPv4、IPv6(
- 链路本地(IPv4、IPv6(
- 站点本地(IPv6(
- 唯一本地(IPv6，需要.NET6(
- IPv4映射到IPv6
在.NET Core 3.1和.NET 6。
https://gist.github.com/angularsen/f77b53ee9966fcd914025e25a2b3a085
实施
using System;
using System.Net;
using System.Net.Sockets;
namespace MyNamespace
{
/// <summary>
/// Extension methods on <see cref="System.Net.IPAddress"/>.
/// </summary>
public static class IPAddressExtensions
{
/// <summary>
/// Returns true if the IP address is in a private range.<br/>
/// IPv4: Loopback, link local ("169.254.x.x"), class A ("10.x.x.x"), class B ("172.16.x.x" to "172.31.x.x") and class C ("192.168.x.x").<br/>
/// IPv6: Loopback, link local, site local, unique local and private IPv4 mapped to IPv6.<br/>
/// </summary>
/// <param name="ip">The IP address.</param>
/// <returns>True if the IP address was in a private range.</returns>
/// <example><code>bool isPrivate = IPAddress.Parse("127.0.0.1").IsPrivate();</code></example>
public static bool IsPrivate(this IPAddress ip)
{
// Map back to IPv4 if mapped to IPv6, for example "::ffff:1.2.3.4" to "1.2.3.4".
if (ip.IsIPv4MappedToIPv6)
ip = ip.MapToIPv4();
// Checks loopback ranges for both IPv4 and IPv6.
if (IPAddress.IsLoopback(ip)) return true;
// IPv4
if (ip.AddressFamily == AddressFamily.InterNetwork)
return IsPrivateIPv4(ip.GetAddressBytes());
// IPv6
if (ip.AddressFamily == AddressFamily.InterNetworkV6)
{
return ip.IsIPv6LinkLocal ||
#if NET6_0
ip.IsIPv6UniqueLocal ||
#endif
ip.IsIPv6SiteLocal;
}
throw new NotSupportedException(
$"IP address family {ip.AddressFamily} is not supported, expected only IPv4 (InterNetwork) or IPv6 (InterNetworkV6).");
}
private static bool IsPrivateIPv4(byte[] ipv4Bytes)
{
// Link local (no IP assigned by DHCP): 169.254.0.0 to 169.254.255.255 (169.254.0.0/16)
bool IsLinkLocal() => ipv4Bytes[0] == 169 && ipv4Bytes[1] == 254;
// Class A private range: 10.0.0.0 – 10.255.255.255 (10.0.0.0/8)
bool IsClassA() => ipv4Bytes[0] == 10;
// Class B private range: 172.16.0.0 – 172.31.255.255 (172.16.0.0/12)
bool IsClassB() => ipv4Bytes[0] == 172 && ipv4Bytes[1] >= 16 && ipv4Bytes[1] <= 31;
// Class C private range: 192.168.0.0 – 192.168.255.255 (192.168.0.0/16)
bool IsClassC() => ipv4Bytes[0] == 192 && ipv4Bytes[1] == 168;
return IsLinkLocal() || IsClassA() || IsClassC() || IsClassB();
}
}
}
测试
using System.Diagnostics.CodeAnalysis;
using System.Net;
using MyNamespace;
using FluentAssertions;
using Xunit;
namespace MyNamespace.Tests
{
[SuppressMessage("ReSharper", "InvokeAsExtensionMethod")]
public class IPAddressExtensionsTests
{
[Theory]
[InlineData("1.1.1.1" )] // Cloudflare DNS
[InlineData("8.8.8.8" )] // Google DNS
[InlineData("20.112.52.29")] // microsoft.com
public void IsPrivate_ReturnsFalse_PublicIPv4(string ip)
{
var ipAddress = IPAddress.Parse(ip);
IPAddressExtensions.IsPrivate(ipAddress).Should().BeFalse();
}
[Theory]
[InlineData("::ffff:1.1.1.1" )] // Cloudflare DNS
[InlineData("::ffff:8.8.8.8" )] // Google DNS
[InlineData("::ffff:20.112.52.29")] // microsoft.com
public void IsPrivate_ReturnsFalse_PublicIPv4MappedToIPv6(string ip)
{
var ipAddress = IPAddress.Parse(ip);
IPAddressExtensions.IsPrivate(ipAddress).Should().BeFalse();
}
[Theory]
[InlineData("127.0.0.1" )] // Loopback IPv4 127.0.0.1 - 127.255.255.255 (127.0.0.0/8)
[InlineData("127.10.20.30" )]
[InlineData("127.255.255.255")]
[InlineData("10.0.0.0" )] // Class A private IP 10.0.0.0 – 10.255.255.255 (10.0.0.0/8)
[InlineData("10.20.30.40" )]
[InlineData("10.255.255.255" )]
[InlineData("172.16.0.0" )] // Class B private IP 172.16.0.0 – 172.31.255.255 (172.16.0.0/12)
[InlineData("172.20.30.40" )]
[InlineData("172.31.255.255" )]
[InlineData("192.168.0.0" )] // Class C private IP 192.168.0.0 – 192.168.255.255 (192.168.0.0/16)
[InlineData("192.168.30.40" )]
[InlineData("192.168.255.255")]
[InlineData("169.254.0.0" )] // Link local (169.254.x.x)
[InlineData("169.254.30.40" )]
[InlineData("169.254.255.255")]
public void IsPrivate_ReturnsTrue_PrivateIPv4(string ip)
{
var ipAddress = IPAddress.Parse(ip);
IPAddressExtensions.IsPrivate(ipAddress).Should().BeTrue();
}
[Theory]
[InlineData("::ffff:127.0.0.1" )] // Loopback IPv4 127.0.0.1 - 127.255.255.254 (127.0.0.0/8)
[InlineData("::ffff:127.10.20.30" )]
[InlineData("::ffff:127.255.255.254")]
[InlineData("::ffff:10.0.0.0" )] // Class A private IP 10.0.0.0 – 10.255.255.255 (10.0.0.0/8)
[InlineData("::ffff:10.20.30.40" )]
[InlineData("::ffff:10.255.255.255" )]
[InlineData("::ffff:172.16.0.0" )] // Class B private IP 172.16.0.0 – 172.31.255.255 (172.16.0.0/12)
[InlineData("::ffff:172.20.30.40" )]
[InlineData("::ffff:172.31.255.255" )]
[InlineData("::ffff:192.168.0.0" )] // Class C private IP 192.168.0.0 – 192.168.255.255 (192.168.0.0/16)
[InlineData("::ffff:192.168.30.40" )]
[InlineData("::ffff:192.168.255.255")]
[InlineData("::ffff:169.254.0.0" )] // Link local (169.254.x.x)
[InlineData("::ffff:169.254.30.40" )]
[InlineData("::ffff:169.254.255.255")]
public void IsPrivate_ReturnsTrue_PrivateIPv4MappedToIPv6(string ip)
{
var ipAddress = IPAddress.Parse(ip);
IPAddressExtensions.IsPrivate(ipAddress).Should().BeTrue();
}
[Theory]
[InlineData("::1" )] // Loopback
[InlineData("fe80::" )] // Link local
[InlineData("fe80:1234:5678::1")] // Link local
[InlineData("fc00::" )] // Unique local, globally assigned.
[InlineData("fc00:1234:5678::1")] // Unique local, globally assigned.
[InlineData("fd00::" )] // Unique local, locally assigned.
[InlineData("fd12:3456:789a::1")] // Unique local, locally assigned.
public void IsPrivate_ReturnsTrue_PrivateIPv6(string ip)
{
var ipAddress = IPAddress.Parse(ip);
IPAddressExtensions.IsPrivate(ipAddress).Should().BeTrue();
}
[Theory]
[InlineData("2606:4700:4700::64" )] // Cloudflare DNS
[InlineData("2001:4860:4860::8888" )] // Google DNS
[InlineData("2001:0db8:85a3:0000:0000:8a2e:0370:7334")] // Commonly used example.
public void IsPrivate_ReturnsFalse_PublicIPv6(string ip)
{
var ipAddress = IPAddress.Parse(ip);
IPAddressExtensions.IsPrivate(ipAddress).Should().BeFalse();
}
}
}
10.0.0.0 - 10.255.255.255 (10/8 prefix)
172.16.0.0 - 172.31.255.255 (172.16/12 prefix)
192.168.0.0 - 192.168.255.255 (192.168/16 prefix)
使用RFC中定义的范围(如Anders所建议的(；而不是使用正则表达式从列表中检测/删除私有IP地址。
下面是一个用于检测私有IP地址的RegEx示例。(我没有测试(
(^127'.0'.0'.1)|
(^10'.)|
(^172'.1[6-9]'.)|(^172'.2[0-9]'.)|(^172'.3[0-1]'.)|
(^192'.168'.)