container/Sources/Helpers/RuntimeLinux/IsolatedInterfaceStrategy.swift

//===----------------------------------------------------------------------===//
// Copyright © 2025-2026 Apple Inc. and the container project authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//   https://www.apache.org/licenses/LICENSE-2.0
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//===----------------------------------------------------------------------===//

import ContainerResource
import ContainerSandboxService
import ContainerXPC
import Containerization

/// Isolated container network interface strategy. This strategy prohibits
/// container to container networking, but it is the only approach that
/// works for macOS Sequoia.
struct IsolatedInterfaceStrategy: InterfaceStrategy {
    public func toInterface(attachment: Attachment, interfaceIndex: Int, additionalData: XPCMessage?) -> Interface {
        let ipv4Gateway = interfaceIndex == 0 ? attachment.ipv4Gateway : nil
        return NATInterface(ipv4Address: attachment.ipv4Address, ipv4Gateway: ipv4Gateway, macAddress: attachment.macAddress)
    }
}