secretive/Sources/Packages/Sources/SecretAgentKit/SocketController.swift

84 lines
3.9 KiB
Swift

import Foundation
import OSLog
/// A controller that manages socket configuration and request dispatching.
public class SocketController {
/// The active FileHandle.
private var fileHandle: FileHandle?
/// The active SocketPort.
private var port: SocketPort?
/// A handler that will be notified when a new read/write handle is available.
/// False if no data could be read
public var handler: ((FileHandleReader, FileHandleWriter) -> Bool)?
/// Initializes a socket controller with a specified path.
/// - Parameter path: The path to use as a socket.
public init(path: String) {
Logger().debug("Socket controller setting up at \(path)")
if let _ = try? FileManager.default.removeItem(atPath: path) {
Logger().debug("Socket controller removed existing socket")
}
let exists = FileManager.default.fileExists(atPath: path)
assert(!exists)
Logger().debug("Socket controller path is clear")
port = socketPort(at: path)
configureSocket(at: path)
Logger().debug("Socket listening at \(path)")
}
/// Configures the socket and a corresponding FileHandle.
/// - Parameter path: The path to use as a socket.
func configureSocket(at path: String) {
guard let port = port else { return }
fileHandle = FileHandle(fileDescriptor: port.socket, closeOnDealloc: true)
NotificationCenter.default.addObserver(self, selector: #selector(handleConnectionAccept(notification:)), name: .NSFileHandleConnectionAccepted, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(handleConnectionDataAvailable(notification:)), name: .NSFileHandleDataAvailable, object: nil)
fileHandle?.acceptConnectionInBackgroundAndNotify(forModes: [RunLoop.current.currentMode!])
}
/// Creates a SocketPort for a path.
/// - Parameter path: The path to use as a socket.
/// - Returns: A configured SocketPort.
func socketPort(at path: String) -> SocketPort {
var addr = sockaddr_un()
addr.sun_family = sa_family_t(AF_UNIX)
let len = MemoryLayout.size(ofValue: addr.sun_path) - 1
withUnsafeMutablePointer(to: &addr.sun_path.0) { pointer in
// The buffer is pre-zeroed, so manual termination is unnecessary.
precondition(memccpy(pointer, path, 0, len) != nil)
}
addr.sun_len = UInt8(len)
let data = withUnsafeBytes(of: &addr, Data.init(_:))
return SocketPort(protocolFamily: AF_UNIX, socketType: SOCK_STREAM, protocol: 0, address: data)!
}
/// Handles a new connection being accepted, invokes the handler, and prepares to accept new connections.
/// - Parameter notification: A `Notification` that triggered the call.
@objc func handleConnectionAccept(notification: Notification) {
Logger().debug("Socket controller accepted connection")
guard let new = notification.userInfo?[NSFileHandleNotificationFileHandleItem] as? FileHandle else { return }
_ = handler?(new, new)
new.waitForDataInBackgroundAndNotify()
fileHandle?.acceptConnectionInBackgroundAndNotify(forModes: [RunLoop.current.currentMode!])
}
/// Handles a new connection providing data and invokes the handler callback.
/// - Parameter notification: A `Notification` that triggered the call.
@objc func handleConnectionDataAvailable(notification: Notification) {
Logger().debug("Socket controller has new data available")
guard let new = notification.object as? FileHandle else { return }
Logger().debug("Socket controller received new file handle")
if((handler?(new, new)) == true) {
Logger().debug("Socket controller handled data, wait for more data")
new.waitForDataInBackgroundAndNotify()
} else {
Logger().debug("Socket controller called with empty data, socked closed")
}
}
}