Changing GetRemoteIpAddress() to resolve clean IPv4 or IPv6 addresses from headers

AMWD.Common.AspNetCore/Extensions/HttpContextExtensions.cs

@@ -67,7 +67,7 @@ namespace Microsoft.AspNetCore.Http
 			}
 
 			if (!string.IsNullOrWhiteSpace(forwardedForAddress) && IPAddress.TryParse(forwardedForAddress, out var remoteAddress))
-				return remoteAddress;
+				return remoteAddress.IsIPv4MappedToIPv6 ? remoteAddress.MapToIPv4() : remoteAddress;
 
 			return httpContext.Connection.RemoteIpAddress;
 		}

CHANGELOG.md

@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - Using `AddHostedService<>()` with "implementation factory" for `AddSingletonHostedService<>()` to resove singleton instance
+- `GetRemoteIpAddress()` converts a mixed IPv4 address on IPv6 (e.g. `::ffff:127.0.0.1`) to a clean IPv4 address (e.g. `127.0.0.1`)
 
 ### Removed
 

UnitTests/AspNetCore/Extensions/HttpContextExtensionsTests.cs

@@ -188,6 +188,25 @@ namespace UnitTests.AspNetCore.Extensions
 			Assert.AreEqual(header, result);
 		}
 
+		[TestMethod]
+		public void ShouldReturnV4AddressOnMapped()
+		{
+			// arrange
+			remote = IPAddress.Parse("1.2.3.4");
+			var header = IPAddress.Parse("::ffff:127.0.0.1");
+			requestHeaders.Add("X-Forwarded-For", "::ffff:127.0.0.1");
+
+			var context = GetContext();
+
+			// act
+			var result = context.GetRemoteIpAddress();
+
+			// assert
+			Assert.AreNotEqual(remote, result);
+			Assert.AreNotEqual(header, result);
+			Assert.AreEqual(header.MapToIPv4(), result);
+		}
+
 		#endregion RemoteAddres
 
 		#region Local Request