Merge pull request #4978 from BaronGreenback/MultipeProxies

(cherry picked from commit 14bd4a110f91f1f5e8d2412b3e125e39e2b79e51)
Signed-off-by: Joshua M. Boniface <joshua@boniface.me>

Jellyfin.Networking/Configuration/NetworkConfiguration.cs

@@ -224,7 +224,7 @@ namespace Jellyfin.Networking.Configuration
         public string[] LocalNetworkAddresses { get; set; } = Array.Empty<string>();
 
         /// <summary>
-        /// Gets or sets the known proxies.
+        /// Gets or sets the known proxies. If the proxy is a network, it's added to the KnownNetworks.
         /// </summary>
         public string[] KnownProxies { get; set; } = Array.Empty<string>();
     }

Jellyfin.Server/Extensions/ApiServiceCollectionExtensions.cs

@@ -1,9 +1,13 @@
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.IO;
 using System.Linq;
 using System.Net;
+using System.Net.Sockets;
 using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Text;
 using Emby.Server.Implementations;
 using Jellyfin.Api.Auth;
 using Jellyfin.Api.Auth.DefaultAuthorizationPolicy;
@@ -20,6 +24,8 @@ using Jellyfin.Api.Constants;
 using Jellyfin.Api.Controllers;
 using Jellyfin.Api.ModelBinders;
 using Jellyfin.Data.Enums;
+using Jellyfin.Networking.Configuration;
+using Jellyfin.Networking.Manager;
 using Jellyfin.Server.Configuration;
 using Jellyfin.Server.Filters;
 using Jellyfin.Server.Formatters;
@@ -174,30 +180,33 @@ namespace Jellyfin.Server.Extensions
         /// </summary>
         /// <param name="serviceCollection">The service collection.</param>
         /// <param name="pluginAssemblies">An IEnumerable containing all plugin assemblies with API controllers.</param>
-        /// <param name="knownProxies">A list of all known proxies to trust for X-Forwarded-For.</param>
+        /// <param name="config">The <see cref="NetworkConfiguration"/>.</param>
         /// <returns>The MVC builder.</returns>
-        public static IMvcBuilder AddJellyfinApi(this IServiceCollection serviceCollection, IEnumerable<Assembly> pluginAssemblies, IReadOnlyList<string> knownProxies)
+        public static IMvcBuilder AddJellyfinApi(this IServiceCollection serviceCollection, IEnumerable<Assembly> pluginAssemblies, NetworkConfiguration config)
         {
             IMvcBuilder mvcBuilder = serviceCollection
                 .AddCors()
                 .AddTransient<ICorsPolicyProvider, CorsPolicyProvider>()
                 .Configure<ForwardedHeadersOptions>(options =>
                 {
+                    // https://github.com/dotnet/aspnetcore/blob/master/src/Middleware/HttpOverrides/src/ForwardedHeadersMiddleware.cs
+                    // Enable debug logging on Microsoft.AspNetCore.HttpOverrides.ForwardedHeadersMiddleware to help investigate issues.
+
                     options.ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto;
-                    if (knownProxies.Count == 0)
+                    if (config.KnownProxies.Length == 0)
                     {
                         options.KnownNetworks.Clear();
                         options.KnownProxies.Clear();
                     }
                     else
                     {
-                        for (var i = 0; i < knownProxies.Count; i++)
-                        {
-                            if (IPHost.TryParse(knownProxies[i], out var host))
-                            {
-                                options.KnownProxies.Add(host.Address);
-                            }
-                        }
+                        AddProxyAddresses(config, config.KnownProxies, options);
+                    }
+
+                    // Only set forward limit if we have some known proxies or some known networks.
+                    if (options.KnownProxies.Count != 0 || options.KnownNetworks.Count != 0)
+                    {
+                        options.ForwardLimit = null;
                     }
                 })
                 .AddMvc(opts =>
@@ -312,6 +321,55 @@ namespace Jellyfin.Server.Extensions
             });
         }
 
+        /// <summary>
+        /// Sets up the proxy configuration based on the addresses in <paramref name="allowedProxies"/>.
+        /// </summary>
+        /// <param name="config">The <see cref="NetworkConfiguration"/> containing the config settings.</param>
+        /// <param name="allowedProxies">The string array to parse.</param>
+        /// <param name="options">The <see cref="ForwardedHeadersOptions"/> instance.</param>
+        internal static void AddProxyAddresses(NetworkConfiguration config, string[] allowedProxies, ForwardedHeadersOptions options)
+        {
+            for (var i = 0; i < allowedProxies.Length; i++)
+            {
+                if (IPNetAddress.TryParse(allowedProxies[i], out var addr))
+                {
+                    AddIpAddress(config, options, addr.Address, addr.PrefixLength);
+                }
+                else if (IPHost.TryParse(allowedProxies[i], out var host))
+                {
+                    foreach (var address in host.GetAddresses())
+                    {
+                        AddIpAddress(config, options, addr.Address, addr.PrefixLength);
+                    }
+                }
+            }
+        }
+
+        private static void AddIpAddress(NetworkConfiguration config, ForwardedHeadersOptions options, IPAddress addr, int prefixLength)
+        {
+            if ((!config.EnableIPV4 && addr.AddressFamily == AddressFamily.InterNetwork) || (!config.EnableIPV6 && addr.AddressFamily == AddressFamily.InterNetworkV6))
+            {
+                return;
+            }
+
+            // In order for dual-mode sockets to be used, IP6 has to be enabled in JF and an interface has to have an IP6 address.
+            if (addr.AddressFamily == AddressFamily.InterNetwork && config.EnableIPV6)
+            {
+                // If the server is using dual-mode sockets, IPv4 addresses are supplied in an IPv6 format.
+                // https://docs.microsoft.com/en-us/aspnet/core/host-and-deploy/proxy-load-balancer?view=aspnetcore-5.0 .
+                addr = addr.MapToIPv6();
+            }
+
+            if (prefixLength == 32)
+            {
+                options.KnownProxies.Add(addr);
+            }
+            else
+            {
+                options.KnownNetworks.Add(new IPNetwork(addr, prefixLength));
+            }
+        }
+
         private static void AddSwaggerTypeMappings(this SwaggerGenOptions options)
         {
             /*

Jellyfin.Server/Properties/AssemblyInfo.cs

@@ -1,5 +1,6 @@
 using System.Reflection;
 using System.Resources;
+using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
 // General Information about an assembly is controlled through the following
@@ -19,3 +20,5 @@ using System.Runtime.InteropServices;
 // to COM components.  If you need to access a type in this assembly from
 // COM, set the ComVisible attribute to true on that type.
 [assembly: ComVisible(false)]
+
+[assembly: InternalsVisibleTo("Jellyfin.Api.Tests")]

Jellyfin.Server/Startup.cs

@@ -52,7 +52,7 @@ namespace Jellyfin.Server
             {
                 options.HttpsPort = _serverApplicationHost.HttpsPort;
             });
-            services.AddJellyfinApi(_serverApplicationHost.GetApiPluginAssemblies(), _serverConfigurationManager.GetNetworkConfiguration().KnownProxies);
+            services.AddJellyfinApi(_serverApplicationHost.GetApiPluginAssemblies(), _serverConfigurationManager.GetNetworkConfiguration());
 
             services.AddJellyfinApiSwagger();
 

tests/Jellyfin.Api.Tests/ParseNetworkTests.cs

@@ -0,0 +1,88 @@
+using System;
+using System.Globalization;
+using System.Text;
+using Jellyfin.Networking.Configuration;
+using Jellyfin.Networking.Manager;
+using Jellyfin.Server.Extensions;
+using MediaBrowser.Common.Configuration;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.Extensions.Logging.Abstractions;
+using Moq;
+using Xunit;
+
+namespace Jellyfin.Api.Tests
+{
+    public class ParseNetworkTests
+    {
+        /// <summary>
+        /// Order of the result has always got to be hosts, then networks.
+        /// </summary>
+        /// <param name="ip4">IP4 enabled.</param>
+        /// <param name="ip6">IP6 enabled.</param>
+        /// <param name="hostList">List to parse.</param>
+        /// <param name="match">What it should match.</param>
+        [Theory]
+        // [InlineData(true, true, "192.168.0.0/16,www.yahoo.co.uk", "::ffff:212.82.100.150,::ffff:192.168.0.0/16")]  <- fails on Max. www.yahoo.co.uk resolves to a different ip address.
+        // [InlineData(true, false, "192.168.0.0/16,www.yahoo.co.uk", "212.82.100.150,192.168.0.0/16")]
+        [InlineData(true, true, "192.168.t,127.0.0.1,1234.1232.12.1234", "::ffff:127.0.0.1")]
+        [InlineData(true, false, "192.168.x,127.0.0.1,1234.1232.12.1234", "127.0.0.1")]
+        [InlineData(true, true, "::1", "::1/128")]
+        public void TestNetworks(bool ip4, bool ip6, string hostList, string match)
+        {
+            using var nm = CreateNetworkManager();
+
+            var settings = new NetworkConfiguration
+            {
+                EnableIPV4 = ip4,
+                EnableIPV6 = ip6
+            };
+
+            var result = match + ',';
+            ForwardedHeadersOptions options = new ForwardedHeadersOptions();
+
+            // Need this here as ::1 and 127.0.0.1 are in them by default.
+            options.KnownProxies.Clear();
+            options.KnownNetworks.Clear();
+
+            ApiServiceCollectionExtensions.AddProxyAddresses(settings, hostList.Split(","), options);
+
+            var sb = new StringBuilder();
+            foreach (var item in options.KnownProxies)
+            {
+                sb.Append(item);
+                sb.Append(',');
+            }
+
+            foreach (var item in options.KnownNetworks)
+            {
+                sb.Append(item.Prefix);
+                sb.Append('/');
+                sb.Append(item.PrefixLength.ToString(CultureInfo.InvariantCulture));
+                sb.Append(',');
+            }
+
+            Assert.Equal(sb.ToString(), result);
+        }
+
+        private static IConfigurationManager GetMockConfig(NetworkConfiguration conf)
+        {
+            var configManager = new Mock<IConfigurationManager>
+            {
+                CallBase = true
+            };
+            configManager.Setup(x => x.GetConfiguration(It.IsAny<string>())).Returns(conf);
+            return configManager.Object;
+        }
+
+        private static NetworkManager CreateNetworkManager()
+        {
+            var conf = new NetworkConfiguration()
+            {
+                EnableIPV6 = true,
+                EnableIPV4 = true,
+            };
+
+            return new NetworkManager(GetMockConfig(conf), new NullLogger<NetworkManager>());
+        }
+    }
+}