1 files changed, 93 insertions, 28 deletions

diff --git a/Emby.Dlna/Api/DlnaServerService.cs b/Emby.Dlna/Api/DlnaServerService.cs
index 8bf3797f85..a451bbcf91 100644
--- a/Emby.Dlna/Api/DlnaServerService.cs
+++ b/Emby.Dlna/Api/DlnaServerService.cs
@@ -1,11 +1,10 @@
 using System;
-using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using Emby.Dlna.Main;
 using MediaBrowser.Common.Extensions;
+using MediaBrowser.Controller.Configuration;
 using MediaBrowser.Controller.Dlna;
 using MediaBrowser.Controller.Net;
 using MediaBrowser.Model.Services;
@@ -108,12 +107,13 @@ namespace Emby.Dlna.Api
 
     public class DlnaServerService : IService, IRequiresRequest
     {
-        private readonly IDlnaManager _dlnaManager;
-
         private const string XMLContentType = "text/xml; charset=UTF-8";
 
+        private readonly IDlnaManager _dlnaManager;
+        private readonly IHttpResultFactory _resultFactory;
+        private readonly IServerConfigurationManager _configurationManager;
+
         public IRequest Request { get; set; }
-        private IHttpResultFactory _resultFactory;
 
         private IContentDirectory ContentDirectory => DlnaEntryPoint.Current.ContentDirectory;
 
@@ -121,10 +121,14 @@ namespace Emby.Dlna.Api
 
         private IMediaReceiverRegistrar MediaReceiverRegistrar => DlnaEntryPoint.Current.MediaReceiverRegistrar;
 
-        public DlnaServerService(IDlnaManager dlnaManager, IHttpResultFactory httpResultFactory)
+        public DlnaServerService(
+            IDlnaManager dlnaManager,
+            IHttpResultFactory httpResultFactory,
+            IServerConfigurationManager configurationManager)
         {
             _dlnaManager = dlnaManager;
             _resultFactory = httpResultFactory;
+            _configurationManager = configurationManager;
         }
 
         private string GetHeader(string name)
@@ -189,7 +193,7 @@ namespace Emby.Dlna.Api
 
         private ControlResponse PostAsync(Stream requestStream, IUpnpService service)
         {
-            var id = GetPathValue(2);
+            var id = GetPathValue(2).ToString();
 
             return service.ProcessControlRequest(new ControlRequest
             {
@@ -200,38 +204,99 @@ namespace Emby.Dlna.Api
             });
         }
 
-        protected string GetPathValue(int index)
+        // Copied from MediaBrowser.Api/BaseApiService.cs
+        // TODO: Remove code duplication
+        /// <summary>
+        /// Gets the path segment at the specified index.
+        /// </summary>
+        /// <param name="index">The index of the path segment.</param>
+        /// <returns>The path segment at the specified index.</returns>
+        /// <exception cref="IndexOutOfRangeException" >Path doesn't contain enough segments.</exception>
+        /// <exception cref="InvalidDataException" >Path doesn't start with the base url.</exception>
+        protected internal ReadOnlySpan<char> GetPathValue(int index)
         {
-            var pathInfo = Parse(Request.PathInfo);
-            var first = pathInfo[0];
-
-            // backwards compatibility
-            // TODO: Work out what this is doing.
-            if (string.Equals(first, "mediabrowser", StringComparison.OrdinalIgnoreCase) ||
-                string.Equals(first, "emby", StringComparison.OrdinalIgnoreCase) ||
-                string.Equals(first, "jellyfin", StringComparison.OrdinalIgnoreCase))
+            static void ThrowIndexOutOfRangeException()
+                => throw new IndexOutOfRangeException("Path doesn't contain enough segments.");
+
+            static void ThrowInvalidDataException()
+                => throw new InvalidDataException("Path doesn't start with the base url.");
+
+            ReadOnlySpan<char> path = Request.PathInfo;
+
+            // Remove the protocol part from the url
+            int pos = path.LastIndexOf("://");
+            if (pos != -1)
             {
-                index++;
+                path = path.Slice(pos + 3);
             }
 
-            return pathInfo[index];
-        }
+            // Remove the query string
+            pos = path.LastIndexOf('?');
+            if (pos != -1)
+            {
+                path = path.Slice(0, pos);
+            }
 
-        private List<string> Parse(string pathUri)
-        {
-            var actionParts = pathUri.Split(new[] { "://" }, StringSplitOptions.None);
+            // Remove the domain
+            pos = path.IndexOf('/');
+            if (pos != -1)
+            {
+                path = path.Slice(pos);
+            }
 
-            var pathInfo = actionParts[actionParts.Length - 1];
+            // Remove base url
+            string baseUrl = _configurationManager.Configuration.BaseUrl;
+            int baseUrlLen = baseUrl.Length;
+            if (baseUrlLen != 0)
+            {
+                if (path.StartsWith(baseUrl, StringComparison.OrdinalIgnoreCase))
+                {
+                    path = path.Slice(baseUrlLen);
+                }
+                else
+                {
+                    // The path doesn't start with the base url,
+                    // how did we get here?
+                    ThrowInvalidDataException();
+                }
+            }
+
+            // Remove leading /
+            path = path.Slice(1);
 
-            var optionsPos = pathInfo.LastIndexOf('?');
-            if (optionsPos != -1)
+            // Backwards compatibility
+            const string Emby = "emby/";
+            if (path.StartsWith(Emby, StringComparison.OrdinalIgnoreCase))
             {
-                pathInfo = pathInfo.Substring(0, optionsPos);
+                path = path.Slice(Emby.Length);
             }
 
-            var args = pathInfo.Split('/');
+            const string MediaBrowser = "mediabrowser/";
+            if (path.StartsWith(MediaBrowser, StringComparison.OrdinalIgnoreCase))
+            {
+                path = path.Slice(MediaBrowser.Length);
+            }
+
+            // Skip segments until we are at the right index
+            for (int i = 0; i < index; i++)
+            {
+                pos = path.IndexOf('/');
+                if (pos == -1)
+                {
+                    ThrowIndexOutOfRangeException();
+                }
+
+                path = path.Slice(pos + 1);
+            }
+
+            // Remove the rest
+            pos = path.IndexOf('/');
+            if (pos != -1)
+            {
+                path = path.Slice(0, pos);
+            }
 
-            return args.Skip(1).ToList();
+            return path;
         }
 
         public object Get(GetIcon request)