chore: import upstream snapshot with attribution

Sources/Containerization/UnixSocketConfiguration.swift

@@ -0,0 +1,70 @@
+//===----------------------------------------------------------------------===//
+// Copyright © 2025-2026 Apple Inc. and the Containerization 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
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//===----------------------------------------------------------------------===//
+
+import Foundation
+import SystemPackage
+
+/// Represents a UnixSocket that can be shared into or out of a container/guest.
+public struct UnixSocketConfiguration: Sendable {
+    // TODO: Realistically, we can just hash this struct and use it as the "id".
+    /// The unique identifier for this socket configuration.
+    public var id: String {
+        _id
+    }
+
+    private let _id = UUID().uuidString
+
+    /// The path to the socket you'd like relayed. For .into
+    /// direction this should be the path on the host to a unix socket.
+    /// For direction .outOf this should be the path in the container/guest
+    /// to a unix socket.
+    public var source: URL
+
+    /// The path you'd like the socket to be relayed to. For .into
+    /// direction this should be the path in the container/guest. For
+    /// direction .outOf this should be the path on your host.
+    public var destination: URL
+
+    /// What to set the file permissions of the unix socket being created
+    /// to. For .into direction this will be the socket in the guest. For
+    /// .outOf direction this will be the socket on the host.
+    public var permissions: FilePermissions?
+
+    /// The direction of the relay. `.into` for sharing a unix socket on your
+    /// host into the container/guest. `outOf` shares a socket in the container/guest
+    /// onto your host.
+    public var direction: Direction
+
+    /// Type that denotes the direction of the unix socket relay.
+    public enum Direction: Sendable {
+        /// Share the socket into the container/guest.
+        case into
+        /// Share a socket in the container/guest onto the host.
+        case outOf
+    }
+
+    public init(
+        source: URL,
+        destination: URL,
+        permissions: FilePermissions? = nil,
+        direction: Direction = .into
+    ) {
+        self.source = source
+        self.destination = destination
+        self.permissions = permissions
+        self.direction = direction
+    }
+}