move shared content to shared project

MareSynchronosServer/MareSynchronosShared/Extensions.cs

@@ -0,0 +1,30 @@
+using Microsoft.AspNetCore.Http;
+using System.Linq;
+
+namespace MareSynchronosServer
+{
+    public static class Extensions
+    {
+        public static string GetIpAddress(this IHttpContextAccessor accessor)
+        {
+            if (!string.IsNullOrEmpty(accessor.HttpContext.Request.Headers["CF-CONNECTING-IP"]))
+                return accessor.HttpContext.Request.Headers["CF-CONNECTING-IP"];
+
+            if (!string.IsNullOrEmpty(accessor.HttpContext.Request.Headers["X-Forwarded-For"]))
+            {
+                return accessor.HttpContext.Request.Headers["X-Forwarded-For"];
+            }
+
+            var ipAddress = accessor.HttpContext.GetServerVariable("HTTP_X_FORWARDED_FOR");
+
+            if (!string.IsNullOrEmpty(ipAddress))
+            {
+                var addresses = ipAddress.Split(',');
+                if (addresses.Length != 0)
+                    return addresses.Last();
+            }
+
+            return accessor.HttpContext.Connection.RemoteIpAddress.ToString();
+        }
+    }
+}