Multiple bridged interfaces (#578)

* Support multiple Bridged Network interfaces

Fixes #572

* Allow duplicated bridged interfaces

.cirrus.yml

@@ -1,7 +1,7 @@
 use_compute_credits: true
 
 env: 
-  XCODE_TAG: 15-beta-2
+  XCODE_TAG: 15-beta-5
 
 task:
   name: Test on Ventura

Sources/tart/Commands/Run.swift

@@ -91,7 +91,7 @@ struct Run: AsyncParsableCommand {
   """, discussion: """
   Specify "list" as an interface name (--net-bridged=list) to list the available bridged interfaces.
   """, valueName: "interface name"))
-  var netBridged: String?
+  var netBridged: [String]
 
   @Flag(help: ArgumentHelp("Use software networking instead of the default shared (NAT) networking",
                            discussion: "Learn how to configure Softnet for use with Tart here: https://github.com/cirruslabs/softnet"))
@@ -105,7 +105,7 @@ struct Run: AsyncParsableCommand {
       throw ValidationError("--vnc and --vnc-experimental are mutually exclusive")
     }
 
-    if netBridged != nil && netSoftnet {
+    if netBridged.count > 0 && netSoftnet {
       throw ValidationError("--net-bridged and --net-softnet are mutually exclusive")
     }
 
@@ -331,23 +331,19 @@ struct Run: AsyncParsableCommand {
       return try Softnet(vmMACAddress: config.macAddress.string)
     }
 
-    if let netBridged = netBridged {
-      let matchingInterfaces = VZBridgedNetworkInterface.networkInterfaces.filter { interface in
-        interface.identifier == netBridged || interface.localizedDisplayName == netBridged
+    if netBridged.count > 0 {      
+      func findBridgedInterface(_ name: String) throws -> VZBridgedNetworkInterface {
+        let interface = VZBridgedNetworkInterface.networkInterfaces.first { interface in
+          interface.identifier == name || interface.localizedDisplayName == name
+        }
+        if (interface == nil) {
+          throw ValidationError("no bridge interfaces matched \"\(netBridged)\", "
+            + "available interfaces: \(bridgeInterfaces())")
+        }
+        return interface!
       }
 
-      if matchingInterfaces.isEmpty {
-        let available = bridgeInterfaces().joined(separator: ", ")
-        throw ValidationError("no bridge interfaces matched \"\(netBridged)\", "
-          + "available interfaces: \(available)")
-      }
-
-      if matchingInterfaces.count > 1 {
-        throw ValidationError("more than one bridge interface matched \"\(netBridged)\", "
-          + "consider refining the search criteria")
-      }
-
-      return NetworkBridged(interface: matchingInterfaces.first!)
+      return NetworkBridged(interfaces: try netBridged.map { try findBridgedInterface($0) })
     }
 
     return nil

Sources/tart/Network/Network.swift

@@ -1,7 +1,7 @@
 import Virtualization
 
 protocol Network {
-  func attachment() -> VZNetworkDeviceAttachment
+  func attachments() -> [VZNetworkDeviceAttachment]
   func run(_ sema: DispatchSemaphore) throws
   func stop() async throws
 }

Sources/tart/Network/NetworkBridged.swift

@@ -2,14 +2,14 @@ import Foundation
 import Virtualization
 
 class NetworkBridged: Network {
-  let interface: VZBridgedNetworkInterface
+  let interfaces: [VZBridgedNetworkInterface]
 
-  init(interface: VZBridgedNetworkInterface) {
-    self.interface = interface
+  init(interfaces: [VZBridgedNetworkInterface]) {
+    self.interfaces = interfaces
   }
 
-  func attachment() -> VZNetworkDeviceAttachment {
-    VZBridgedNetworkDeviceAttachment(interface: interface)
+  func attachments() -> [VZNetworkDeviceAttachment] {
+    interfaces.map { VZBridgedNetworkDeviceAttachment(interface: $0) }
   }
 
   func run(_ sema: DispatchSemaphore) throws {

Sources/tart/Network/NetworkShared.swift

@@ -2,8 +2,8 @@ import Foundation
 import Virtualization
 
 class NetworkShared: Network {
-  func attachment() -> VZNetworkDeviceAttachment {
-    VZNATNetworkDeviceAttachment()
+  func attachments() -> [VZNetworkDeviceAttachment] {
+    [VZNATNetworkDeviceAttachment()]
   }
 
   func run(_ sema: DispatchSemaphore) throws {

Sources/tart/Network/Softnet.swift

@@ -92,9 +92,9 @@ class Softnet: Network {
     }
   }
 
-  func attachment() -> VZNetworkDeviceAttachment {
+  func attachments() -> [VZNetworkDeviceAttachment] {
     let fh = FileHandle.init(fileDescriptor: vmFD)
-    return VZFileHandleNetworkDeviceAttachment(fileHandle: fh)
+    return [VZFileHandleNetworkDeviceAttachment(fileHandle: fh)]
   }
 
   static func configureSUIDBitIfNeeded() throws {

Sources/tart/VM.swift

@@ -320,10 +320,12 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
     }
 
     // Networking
-    let vio = VZVirtioNetworkDeviceConfiguration()
-    vio.attachment = network.attachment()
-    vio.macAddress = vmConfig.macAddress
-    configuration.networkDevices = [vio]
+    configuration.networkDevices = network.attachments().map {
+      let vio = VZVirtioNetworkDeviceConfiguration()
+      vio.attachment = $0
+      vio.macAddress = vmConfig.macAddress
+      return vio  
+    }
 
     // Storage
     var attachments = [try VZDiskImageStorageDeviceAttachment(url: diskURL, readOnly: false)]