Fremde Laufzeiten: Claude Code und Befehl in der Sandbox, Egress-Proxy, Vorschlag statt Einsatz (#712)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/ClawdDotNet.Core/Sandbox/SandboxModels.cs

@@ -34,6 +34,75 @@ public sealed record SandboxRequest
     public SandboxLimits Limits { get; init; } = new();
 
     public string? StandardInput { get; init; }
+
+    /// <summary>
+    /// #712: Further host paths at a place of their own — a runtime's home, the MCP socket.
+    /// Applied after the workspace; a target inside <c>/work</c> is refused.
+    /// </summary>
+    public IReadOnlyList<SandboxMount> Mounts { get; init; } = [];
+
+    /// <summary>
+    /// #712/#655: The hosts the run may reach, as <c>host</c> or <c>host:port</c> (443 if
+    /// none), <c>*.example.com</c> for subdomains. Empty: no network at all. Otherwise the
+    /// sandbox still has no network of its own; an HTTPS proxy in the main process opens
+    /// only these, and only to public addresses (<see cref="EgressProxy"/>).
+    /// </summary>
+    public IReadOnlyList<string> Egress { get; init; } = [];
+
+    /// <summary>
+    /// #712: Environment the program needs but that must not stand on a command line — an
+    /// API key. Handed over in a file only the sandbox's launcher reads, never through argv.
+    /// </summary>
+    public IReadOnlyDictionary<string, string> SecretEnvironment { get; init; } = new Dictionary<string, string>();
+
+    /// <summary>Whether the run needs the launcher inside the sandbox (<see cref="SandboxLauncher"/>).</summary>
+    public bool NeedsLauncher => Egress.Count > 0 || SecretEnvironment.Count > 0;
+}
+
+/// <summary>#712: A host path mounted at <paramref name="Target"/> in the sandbox.</summary>
+public sealed record SandboxMount(string HostPath, string Target, bool Writable = false);
+
+/// <summary>
+/// #712: The program that starts the work inside the sandbox when it needs more than an
+/// <c>exec</c> — the application itself, called with <see cref="SandboxLauncher.Argument"/>.
+/// It is mounted read-only with what it needs to start.
+/// </summary>
+public sealed record SandboxHelper(
+    string Executable,
+    IReadOnlyList<string> ReadOnlyPaths,
+    IReadOnlyDictionary<string, string> Environment)
+{
+    /// <summary>
+    /// This application as the helper: its directory, and the .NET it runs on when that is
+    /// not under <c>/usr</c>. <c>null</c> when there is no executable to call (a test host).
+    /// </summary>
+    public static SandboxHelper? ForThisProcess()
+    {
+        var executable = System.Environment.ProcessPath;
+        if (string.IsNullOrEmpty(executable) || !File.Exists(executable))
+            return null;
+        var name = Path.GetFileNameWithoutExtension(executable);
+        return name is "dotnet" or "testhost" ? null : For(executable);
+    }
+
+    /// <summary>The helper at <paramref name="executable"/>, running on the same .NET as this process.</summary>
+    public static SandboxHelper For(string executable)
+    {
+        var paths = new List<string> { Path.GetDirectoryName(Path.GetFullPath(executable))! };
+        var environment = new Dictionary<string, string>(StringComparer.Ordinal)
+        {
+            // .NET reserves address space by the gigabyte; under a memory limit it would not start.
+            ["DOTNET_GCHeapHardLimit"] = "0x20000000",
+            ["DOTNET_CLI_TELEMETRY_OPTOUT"] = "1"
+        };
+        // <root>/shared/Microsoft.NETCore.App/<version>/ — the root is three levels up.
+        var runtime = System.Runtime.InteropServices.RuntimeEnvironment.GetRuntimeDirectory();
+        var root = Path.GetFullPath(Path.Combine(runtime, "..", "..", ".."));
+        if (!root.StartsWith("/usr/", StringComparison.Ordinal) && Directory.Exists(root))
+            paths.Add(root);
+        environment["DOTNET_ROOT"] = root;
+        return new SandboxHelper(Path.GetFullPath(executable), paths, environment);
+    }
 }
 
 /// <summary>#654: The limits of one run.</summary>
@@ -41,7 +110,10 @@ public sealed record SandboxLimits
 {
     public TimeSpan Timeout { get; init; } = TimeSpan.FromMinutes(5);
 
-    /// <summary>Address space per process.</summary>
+    /// <summary>
+    /// Address space per process; 0 for none. A JavaScript runtime (Claude Code) reserves
+    /// tens of gigabytes it never uses and does not start under any sensible limit.
+    /// </summary>
     public long MaxMemoryBytes { get; init; } = 2L * 1024 * 1024 * 1024;
 
     /// <summary>Processes and threads the run may have at once — a fork bomb stops here.</summary>
@@ -109,6 +181,14 @@ public static class SandboxPaths
 {
     public const string Work = "/work";
 
+    /// <summary>#712: Where the launcher finds what the runner hands it.</summary>
+    public const string Run = "/run/clawd";
+    public const string EgressSocket = Run + "/egress.sock";
+    public const string SecretFile = Run + "/env.json";
+
+    /// <summary>#712: The proxy's port on the sandbox's own loopback.</summary>
+    public const int ProxyPort = 3128;
+
     /// <summary>
     /// In the workspace, read-only by default: <c>scripts/</c> holds approved scripts and their
     /// manifests (#695) — what is checked must stay what runs.