DnsApplicationAssemblyLoadContext: updated implementation to use AssemblyDependencyResolver. Moved assembly loading code here. Fixed issue with loading alpine musl native dll.

2026-01-23 09:04:58 +00:00 · 2024-05-19 14:54:29 +05:30
parent 7cefb102ea
commit ba7e05a450
1 changed files with 164 additions and 52 deletions
--- a/DnsServerCore/Dns/Applications/DnsApplicationAssemblyLoadContext.cs
+++ b/DnsServerCore/Dns/Applications/DnsApplicationAssemblyLoadContext.cs
@@ -1,6 +1,6 @@
 /*
 Technitium DNS Server
-Copyright (C) 2022  Shreyas Zare (shreyas@technitium.com)
+Copyright (C) 2024  Shreyas Zare (shreyas@technitium.com)

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
@@ -17,6 +17,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */

+using DnsServerCore.ApplicationCommon;
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -30,7 +31,12 @@ namespace DnsServerCore.Dns
    {
        #region variables

-        readonly string _applicationFolder;
+        readonly static Type _dnsApplicationInterface = typeof(IDnsApplication);
+
+        readonly IDnsServer _dnsServer;
+
+        readonly List<Assembly> _appAssemblies;
+        readonly AssemblyDependencyResolver _dependencyResolver;

        readonly Dictionary<string, IntPtr> _loadedUnmanagedDlls = new Dictionary<string, IntPtr>();
        readonly List<string> _unmanagedDllTempPaths = new List<string>();
@@ -39,10 +45,10 @@ namespace DnsServerCore.Dns

        #region constructor

-        public DnsApplicationAssemblyLoadContext(string applicationFolder)
+        public DnsApplicationAssemblyLoadContext(IDnsServer dnsServer)
            : base(true)
        {
-            _applicationFolder = applicationFolder;
+            _dnsServer = dnsServer;

            Unloading += delegate (AssemblyLoadContext obj)
            {
@@ -56,6 +62,95 @@ namespace DnsServerCore.Dns
                    { }
                }
            };
+
+            _appAssemblies = new List<Assembly>();
+
+            IEnumerable<Assembly> loadedAssemblies = Default.Assemblies;
+
+            foreach (string dllFile in Directory.GetFiles(_dnsServer.ApplicationFolder, "*.dll", SearchOption.TopDirectoryOnly))
+            {
+                string dllFileName = Path.GetFileNameWithoutExtension(dllFile);
+
+                bool isLoaded = false;
+
+                foreach (Assembly loadedAssembly in loadedAssemblies)
+                {
+                    if (!string.IsNullOrEmpty(loadedAssembly.Location))
+                    {
+                        if (Path.GetFileNameWithoutExtension(loadedAssembly.Location).Equals(dllFileName, StringComparison.OrdinalIgnoreCase))
+                        {
+                            isLoaded = true;
+                            break;
+                        }
+                    }
+                    else
+                    {
+                        AssemblyName assemblyName = loadedAssembly.GetName();
+
+                        if ((assemblyName.Name != null) && assemblyName.Name.Equals(dllFileName, StringComparison.OrdinalIgnoreCase))
+                        {
+                            isLoaded = true;
+                            break;
+                        }
+                    }
+                }
+
+                if (isLoaded)
+                    continue;
+
+                try
+                {
+                    Assembly appAssembly;
+                    string pdbFile = Path.Combine(_dnsServer.ApplicationFolder, Path.GetFileNameWithoutExtension(dllFile) + ".pdb");
+
+                    if (File.Exists(pdbFile))
+                    {
+                        using (FileStream dllStream = new FileStream(dllFile, FileMode.Open, FileAccess.Read))
+                        {
+                            using (FileStream pdbStream = new FileStream(pdbFile, FileMode.Open, FileAccess.Read))
+                            {
+                                appAssembly = LoadFromStream(dllStream, pdbStream);
+                            }
+                        }
+                    }
+                    else
+                    {
+                        using (FileStream dllStream = new FileStream(dllFile, FileMode.Open, FileAccess.Read))
+                        {
+                            appAssembly = LoadFromStream(dllStream);
+                        }
+                    }
+
+                    if (_dependencyResolver is null)
+                    {
+                        bool isMainAssembly = false;
+
+                        foreach (Type classType in appAssembly.ExportedTypes)
+                        {
+                            foreach (Type interfaceType in classType.GetInterfaces())
+                            {
+                                if (interfaceType == _dnsApplicationInterface)
+                                {
+                                    isMainAssembly = true;
+                                    break;
+                                }
+                            }
+
+                            if (isMainAssembly)
+                                break;
+                        }
+
+                        if (isMainAssembly)
+                            _dependencyResolver = new AssemblyDependencyResolver(dllFile);
+                    }
+
+                    _appAssemblies.Add(appAssembly);
+                }
+                catch (Exception ex)
+                {
+                    _dnsServer.WriteLog(ex);
+                }
+            }
        }

        #endregion
@@ -71,59 +166,69 @@ namespace DnsServerCore.Dns
        {
            string unmanagedDllPath = null;

-            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+            if (_dependencyResolver is not null)
            {
-                string runtime = "win-" + RuntimeInformation.ProcessArchitecture.ToString().ToLower();
-                string[] prefixes = new string[] { "" };
-                string[] extensions = new string[] { ".dll" };
-
-                unmanagedDllPath = FindUnmanagedDllPath(unmanagedDllName, runtime, prefixes, extensions);
-            }
-            else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
-            {
-                bool isAlpine = false;
-
-                try
-                {
-                    string osReleaseFile = "/etc/os-release";
-
-                    if (File.Exists(osReleaseFile))
-                        isAlpine = File.ReadAllText(osReleaseFile).Contains("alpine", StringComparison.OrdinalIgnoreCase);
-                }
-                catch
-                { }
-
-                string runtimeAlpine = "alpine-" + RuntimeInformation.ProcessArchitecture.ToString().ToLower();
-                string runtimeLinux = "linux-" + RuntimeInformation.ProcessArchitecture.ToString().ToLower();
-                string[] prefixes = new string[] { "", "lib" };
-                string[] extensions = new string[] { ".so", ".so.1" };
-
-                if (isAlpine)
-                {
-                    unmanagedDllPath = FindUnmanagedDllPath(unmanagedDllName, runtimeAlpine, prefixes, extensions);
-                    if (unmanagedDllPath is null)
-                        unmanagedDllPath = FindUnmanagedDllPath(unmanagedDllName, runtimeLinux, prefixes, extensions);
-                }
-                else
-                {
-                    unmanagedDllPath = FindUnmanagedDllPath(unmanagedDllName, runtimeLinux, prefixes, extensions);
-                }
-            }
-            else if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
-            {
-                string runtime = "osx-" + RuntimeInformation.ProcessArchitecture.ToString().ToLower();
-                string[] prefixes = new string[] { "", "lib" };
-                string[] extensions = new string[] { ".dylib" };
-
-                unmanagedDllPath = FindUnmanagedDllPath(unmanagedDllName, runtime, prefixes, extensions);
+                string resolvedPath = _dependencyResolver.ResolveUnmanagedDllToPath(unmanagedDllName);
+                if (!string.IsNullOrEmpty(resolvedPath) && File.Exists(resolvedPath))
+                    unmanagedDllPath = resolvedPath;
            }

            if (unmanagedDllPath is null)
-                return IntPtr.Zero;
+            {
+                if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+                {
+                    string runtime = "win-" + RuntimeInformation.ProcessArchitecture.ToString().ToLowerInvariant();
+                    string[] prefixes = new string[] { "" };
+                    string[] extensions = new string[] { ".dll" };
+
+                    unmanagedDllPath = FindUnmanagedDllPath(unmanagedDllName, runtime, prefixes, extensions);
+                }
+                else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
+                {
+                    bool isAlpine = false;
+
+                    try
+                    {
+                        string osReleaseFile = "/etc/os-release";
+
+                        if (File.Exists(osReleaseFile))
+                            isAlpine = File.ReadAllText(osReleaseFile).Contains("alpine", StringComparison.OrdinalIgnoreCase);
+                    }
+                    catch
+                    { }
+
+                    string runtimeAlpine = "linux-musl-" + RuntimeInformation.ProcessArchitecture.ToString().ToLowerInvariant();
+                    string runtimeLinux = "linux-" + RuntimeInformation.ProcessArchitecture.ToString().ToLowerInvariant();
+                    string[] prefixes = new string[] { "", "lib" };
+                    string[] extensions = new string[] { ".so", ".so.1" };
+
+                    if (isAlpine)
+                    {
+                        unmanagedDllPath = FindUnmanagedDllPath(unmanagedDllName, runtimeAlpine, prefixes, extensions);
+                        if (unmanagedDllPath is null)
+                            unmanagedDllPath = FindUnmanagedDllPath(unmanagedDllName, runtimeLinux, prefixes, extensions);
+                    }
+                    else
+                    {
+                        unmanagedDllPath = FindUnmanagedDllPath(unmanagedDllName, runtimeLinux, prefixes, extensions);
+                    }
+                }
+                else if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
+                {
+                    string runtime = "osx-" + RuntimeInformation.ProcessArchitecture.ToString().ToLowerInvariant();
+                    string[] prefixes = new string[] { "", "lib" };
+                    string[] extensions = new string[] { ".dylib" };
+
+                    unmanagedDllPath = FindUnmanagedDllPath(unmanagedDllName, runtime, prefixes, extensions);
+                }
+
+                if (unmanagedDllPath is null)
+                    return IntPtr.Zero;
+            }

            lock (_loadedUnmanagedDlls)
            {
-                if (!_loadedUnmanagedDlls.TryGetValue(unmanagedDllPath.ToLower(), out IntPtr value))
+                if (!_loadedUnmanagedDlls.TryGetValue(unmanagedDllPath.ToLowerInvariant(), out IntPtr value))
                {
                    //load the unmanaged DLL
                    //copy unmanaged dll into temp file for loading to allow uninstalling/updating app at runtime.
@@ -140,7 +245,7 @@ namespace DnsServerCore.Dns
                    _unmanagedDllTempPaths.Add(tempPath);

                    value = LoadUnmanagedDllFromPath(tempPath);
-                    _loadedUnmanagedDlls.Add(unmanagedDllPath.ToLower(), value);
+                    _loadedUnmanagedDlls.Add(unmanagedDllPath.ToLowerInvariant(), value);
                }

                return value;
@@ -157,7 +262,7 @@ namespace DnsServerCore.Dns
            {
                foreach (string extension in extensions)
                {
-                    string path = Path.Combine(_applicationFolder, "runtimes", runtime, "native", prefix + unmanagedDllName + extension);
+                    string path = Path.Combine(_dnsServer.ApplicationFolder, "runtimes", runtime, "native", prefix + unmanagedDllName + extension);
                    if (File.Exists(path))
                        return path;
                }
@@ -167,5 +272,12 @@ namespace DnsServerCore.Dns
        }

        #endregion
+
+        #region properties
+
+        public IReadOnlyList<Assembly> AppAssemblies
+        { get { return _appAssemblies; } }
+
+        #endregion
    }
 }