1 files changed, 76 insertions, 0 deletions
diff --git a/Jellyfin.Server/Middleware/IpBasedAccessValidationMiddleware.cs b/Jellyfin.Server/Middleware/IpBasedAccessValidationMiddleware.cs
new file mode 100644
index 000000000..59b5fb1ed
--- /dev/null
+++ b/Jellyfin.Server/Middleware/IpBasedAccessValidationMiddleware.cs
@@ -0,0 +1,76 @@
+using System.Linq;
+using System.Threading.Tasks;
+using MediaBrowser.Common.Extensions;
+using MediaBrowser.Common.Net;
+using MediaBrowser.Controller.Configuration;
+using Microsoft.AspNetCore.Http;
+
+namespace Jellyfin.Server.Middleware
+{
+    /// <summary>
+    /// Validates the IP of requests coming from local networks wrt. remote access.
+    /// </summary>
+    public class IpBasedAccessValidationMiddleware
+    {
+        private readonly RequestDelegate _next;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="IpBasedAccessValidationMiddleware"/> class.
+        /// </summary>
+        /// <param name="next">The next delegate in the pipeline.</param>
+        public IpBasedAccessValidationMiddleware(RequestDelegate next)
+        {
+            _next = next;
+        }
+
+        /// <summary>
+        /// Executes the middleware action.
+        /// </summary>
+        /// <param name="httpContext">The current HTTP context.</param>
+        /// <param name="networkManager">The network manager.</param>
+        /// <param name="serverConfigurationManager">The server configuration manager.</param>
+        /// <returns>The async task.</returns>
+        public async Task Invoke(HttpContext httpContext, INetworkManager networkManager, IServerConfigurationManager serverConfigurationManager)
+        {
+            if (httpContext.Request.IsLocal())
+            {
+                await _next(httpContext).ConfigureAwait(false);
+                return;
+            }
+
+            var remoteIp = httpContext.Request.RemoteIp();
+
+            if (serverConfigurationManager.Configuration.EnableRemoteAccess)
+            {
+                var addressFilter = serverConfigurationManager.Configuration.RemoteIPFilter.Where(i => !string.IsNullOrWhiteSpace(i)).ToArray();
+
+                if (addressFilter.Length > 0 && !networkManager.IsInLocalNetwork(remoteIp))
+                {
+                    if (serverConfigurationManager.Configuration.IsRemoteIPFilterBlacklist)
+                    {
+                        if (networkManager.IsAddressInSubnets(remoteIp, addressFilter))
+                        {
+                            return;
+                        }
+                    }
+                    else
+                    {
+                        if (!networkManager.IsAddressInSubnets(remoteIp, addressFilter))
+                        {
+                            return;
+                        }
+                    }
+                }
+            }
+            else
+            {
+                if (!networkManager.IsInLocalNetwork(remoteIp))
+                {
+                    return;
+                }
+            }
+
+            await _next(httpContext).ConfigureAwait(false);
+        }
+    }
+}