Fixed: Improve Bind Address validation and help text

Closes #3167

(cherry picked from commit 6bdeafcf8c78e145595f52e885356be1210abe91)

src/Lidarr.Api.V1/Config/HostConfigController.cs

@@ -33,9 +33,9 @@ namespace Lidarr.Api.V1.Config
             _userService = userService;
 
             SharedValidator.RuleFor(c => c.BindAddress)
-                           .ValidIp4Address()
+                           .ValidIpAddress()
                            .NotListenAllIp4Address()
-                           .When(c => c.BindAddress != "*");
+                           .When(c => c.BindAddress != "*" && c.BindAddress != "localhost");
 
             SharedValidator.RuleFor(c => c.Port).ValidPort();
 

src/NzbDrone.Common.Test/ExtensionTests/StringExtensionTests/IsValidIPAddressFixture.cs

@@ -0,0 +1,25 @@
+using System.Globalization;
+using FluentAssertions;
+using NUnit.Framework;
+using NzbDrone.Common.Extensions;
+
+namespace NzbDrone.Common.Test.ExtensionTests.StringExtensionTests
+{
+    [TestFixture]
+    public class IsValidIPAddressFixture
+    {
+        [TestCase("192.168.0.1")]
+        [TestCase("::1")]
+        [TestCase("2001:db8:4006:812::200e")]
+        public void should_validate_ip_address(string input)
+        {
+            input.IsValidIpAddress().Should().BeTrue();
+        }
+
+        [TestCase("sonarr.tv")]
+        public void should_not_parse_non_ip_address(string input)
+        {
+            input.IsValidIpAddress().Should().BeFalse();
+        }
+    }
+}

src/NzbDrone.Common/Extensions/StringExtensions.cs

@@ -2,6 +2,8 @@ using System;
 using System.Collections.Generic;
 using System.Globalization;
 using System.Linq;
+using System.Net;
+using System.Net.Sockets;
 using System.Text;
 using System.Text.RegularExpressions;
 
@@ -231,5 +233,25 @@ namespace NzbDrone.Common.Extensions
                 .Replace("'", "%27")
                 .Replace("%7E", "~");
         }
+
+        public static bool IsValidIpAddress(this string value)
+        {
+            if (!IPAddress.TryParse(value, out var parsedAddress))
+            {
+                return false;
+            }
+
+            if (parsedAddress.Equals(IPAddress.Parse("255.255.255.255")))
+            {
+                return false;
+            }
+
+            if (parsedAddress.IsIPv6Multicast)
+            {
+                return false;
+            }
+
+            return parsedAddress.AddressFamily == AddressFamily.InterNetwork || parsedAddress.AddressFamily == AddressFamily.InterNetworkV6;
+        }
     }
 }

src/NzbDrone.Core/Localization/Core/en.json

@@ -100,7 +100,7 @@
   "Backups": "Backups",
   "BeforeUpdate": "Before Update",
   "BindAddress": "Bind Address",
-  "BindAddressHelpText": "Valid IPv4 address or '*' for all interfaces",
+  "BindAddressHelpText": "Valid IP address, localhost or '*' for all interfaces",
   "BindAddressHelpTextWarning": "Requires restart to take effect",
   "Blocklist": "Blocklist",
   "BlocklistHelpText": "Prevents Lidarr from automatically grabbing these files again",

src/NzbDrone.Core/Validation/IpValidation.cs

@@ -1,30 +1,14 @@
-using System.Net;
-using System.Net.Sockets;
 using FluentValidation;
 using FluentValidation.Validators;
+using NzbDrone.Common.Extensions;
 
 namespace NzbDrone.Core.Validation
 {
     public static class IpValidation
     {
-        public static IRuleBuilderOptions<T, string> ValidIp4Address<T>(this IRuleBuilder<T, string> ruleBuilder)
+        public static IRuleBuilderOptions<T, string> ValidIpAddress<T>(this IRuleBuilder<T, string> ruleBuilder)
         {
-            return ruleBuilder.Must(x =>
-            {
-                IPAddress parsedAddress;
-
-                if (!IPAddress.TryParse(x, out parsedAddress))
-                {
-                    return false;
-                }
-
-                if (parsedAddress.Equals(IPAddress.Parse("255.255.255.255")))
-                {
-                    return false;
-                }
-
-                return parsedAddress.AddressFamily == AddressFamily.InterNetwork;
-            }).WithMessage("Must contain wildcard (*) or a valid IPv4 Address");
+            return ruleBuilder.Must(x => x.IsValidIpAddress()).WithMessage("Must contain wildcard (*) or a valid IP Address");
         }
 
         public static IRuleBuilderOptions<T, string> NotListenAllIp4Address<T>(this IRuleBuilder<T, string> ruleBuilder)