tart run: introduce "--net-softnet-extra"

To pass extra command-line arguments to Softnet.

Sources/tart/Commands/Run.swift

@@ -234,6 +234,9 @@ struct Run: AsyncParsableCommand {
   """, valueName: "file descriptor"))
   var netSoftnetControlFd: Int32?
 
+  @Option(help: .hidden)
+  var netSoftnetExtra: [String] = []
+
   @Option(help: ArgumentHelp("Comma-separated list of TCP ports to expose (e.g. --net-softnet-expose 2222:22,8080:80)", discussion: """
   Options are comma-separated and are as follows:
 
@@ -323,7 +326,7 @@ struct Run: AsyncParsableCommand {
     }
 
     // Automatically enable --net-softnet when any of its related options are specified
-    if netSoftnetAllow != nil || netSoftnetBlock != nil || netSoftnetExpose != nil || netSoftnetControlFd != nil {
+    if netSoftnetAllow != nil || netSoftnetBlock != nil || netSoftnetExpose != nil || netSoftnetControlFd != nil || !netSoftnetExtra.isEmpty {
       netSoftnet = true
     }
 
@@ -696,6 +699,8 @@ struct Run: AsyncParsableCommand {
       softnetExtraArguments += ["--expose", netSoftnetExpose]
     }
 
+    softnetExtraArguments += netSoftnetExtra
+
     if netSoftnet {
       let config = try VMConfig.init(fromURL: vmDir.configURL)
 

Tests/TartTests/SoftnetControlFDTests.swift

@@ -161,6 +161,25 @@ final class SoftnetControlFDTests: XCTestCase {
     )
   }
 
+  func testSoftnetExtraArguments() throws {
+    // Prepare a temporary VM for command validation
+    let temporaryHome = try createTemporaryTartHome()
+    let previousHome = ProcessInfo.processInfo.environment["TART_HOME"]
+    setenv("TART_HOME", temporaryHome.path, 1)
+    defer {
+      restoreEnvironment("TART_HOME", value: previousHome)
+      try? FileManager.default.removeItem(at: temporaryHome)
+    }
+
+    // Parse repeated options with a value containing spaces
+    let extra = ["--vm-ip=172.20.0.2", "--vmnet-network=opaque value with spaces"]
+    let command = try Run.parse(["vm"] + extra.map { "--net-softnet-extra=\($0)" })
+
+    // Verify Softnet is enabled and the arguments are preserved
+    XCTAssertTrue(command.netSoftnet)
+    XCTAssertEqual(command.netSoftnetExtra, extra)
+  }
+
   private func createTemporaryTartHome() throws -> URL {
     let temporaryHome = URL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent(UUID().uuidString)
     let vm = temporaryHome.appendingPathComponent("vms/vm")