GetIpAddress

Gets the client address for the current request from the connection, normalized so an IPv4 address tunneled as IPv4-mapped IPv6 comes back in its IPv4 form. Without that normalization the same client can appear as ::ffff:203.0.113.10 or 203.0.113.10 depending on how the socket was opened, which breaks equality checks and allow lists.

Usage

using Microsoft.AspNetCore.Mvc;
using AlmightyShogun.AspNet.Core;

[ApiController]
[Route("audit")]
public sealed class AuditController(IAuditLog auditLog) : ControllerBase
{
    [HttpPost]
    public IActionResult Record()
    {
        auditLog.Write(HttpContext.GetIpAddress() ?? "unknown");

        return Ok();
    }
}

WARNING

The address comes from the connection, never from a forwarded header, because a header-supplied address is chosen by the caller and cannot be trusted. Behind a proxy or CDN the connection address is the proxy until forwarded headers have been processed, so call UseForwardedHeaders first and see AddCloudflareHeaders.

Returns

The client address, or null when the connection has none.

Type signature

public string? GetIpAddress();