Disable port reuse by default (#223)

Pass `allowPortReuse: false` by default to `Socket.listen()`

Sources/KituraNet/FastCGI/FastCGIServer.swift

@@ -50,6 +50,9 @@ public class FastCGIServer: Server {
 
  /// TCP socket used for listening for new connections
  private var listenSocket: Socket?
+
+ /// Whether or not this server allows port reuse (default: disallowed)
+ public var allowPortReuse: Bool = false
 
  fileprivate let lifecycleListener = ServerLifecycleListener()
 
@@ -74,8 +77,9 @@ public class FastCGIServer: Server {
  let socket = try Socket.create()
  self.listenSocket = socket
 
- try socket.listen(on: port, maxBacklogSize: maxPendingConnections)
+ try socket.listen(on: port, maxBacklogSize: maxPendingConnections, allowPortReuse: self.allowPortReuse)
  Log.info("Listening on port \(port)")
+ Log.verbose("Options for port \(port): maxPendingConnections: \(maxPendingConnections), allowPortReuse: \(self.allowPortReuse)")
 
  // set synchronously to avoid contention in back to back server start/stop calls
  self.state = .started

Sources/KituraNet/HTTP/HTTPServer.swift

@@ -43,6 +43,9 @@ public class HTTPServer: Server {
  /// TCP socket used for listening for new connections
  private var listenSocket: Socket?
 
+ /// Whether or not this server allows port reuse (default: disallowed)
+ public var allowPortReuse: Bool = false
+
  /// Maximum number of pending connections
  private let maxPendingConnections = 100
 
@@ -92,7 +95,7 @@ public class HTTPServer: Server {
  socket.delegate = try SSLService(usingConfiguration: sslConfig);
  }
 
- try socket.listen(on: port, maxBacklogSize: maxPendingConnections)
+ try socket.listen(on: port, maxBacklogSize: maxPendingConnections, allowPortReuse: self.allowPortReuse)
 
  let socketManager = IncomingSocketManager()
  self.socketManager = socketManager
@@ -116,8 +119,10 @@ public class HTTPServer: Server {
  #endif
 
  Log.info("Listening on port \(self.port!) (delegate: \(delegate))")
+ Log.verbose("Options for port \(self.port!): delegate: \(delegate), maxPendingConnections: \(maxPendingConnections), allowPortReuse: \(self.allowPortReuse)")
  } else {
  Log.info("Listening on port \(self.port!)")
+ Log.verbose("Options for port \(self.port!): maxPendingConnections: \(maxPendingConnections), allowPortReuse: \(self.allowPortReuse)")
  }
 
  // set synchronously to avoid contention in back to back server start/stop calls

Tests/KituraNetTests/KituraNetTest.swift

@@ -26,6 +26,7 @@ class KituraNetTest: XCTestCase {
 
  static let useSSLDefault = true
  static let portDefault = 8080
+ static let portReuseDefault = false
 
  var useSSL = useSSLDefault
  var port = portDefault
@@ -56,28 +57,26 @@ class KituraNetTest: XCTestCase {
  func doTearDown() {
  }
 
- func startServer(_ delegate: ServerDelegate?, port: Int = portDefault, useSSL: Bool = useSSLDefault) throws -> HTTPServer {
+ func startServer(_ delegate: ServerDelegate?, port: Int = portDefault, useSSL: Bool = useSSLDefault, allowPortReuse: Bool = portReuseDefault) throws -> HTTPServer {
 
- let server: HTTPServer
+ let server = HTTP.createServer()
+ server.delegate = delegate
+ server.allowPortReuse = allowPortReuse
  if useSSL {
- server = HTTP.createServer()
- server.delegate = delegate
  server.sslConfig = KituraNetTest.sslConfig
- try server.listen(on: port)
- } else {
- server = try HTTPServer.listen(on: port, delegate: delegate)
  }
+ try server.listen(on: port)
  return server
  }
 
- func performServerTest(_ delegate: ServerDelegate?, port: Int = portDefault, useSSL: Bool = useSSLDefault,
+ func performServerTest(_ delegate: ServerDelegate?, port: Int = portDefault, useSSL: Bool = useSSLDefault, allowPortReuse: Bool = portReuseDefault,
  line: Int = #line, asyncTasks: (XCTestExpectation) -> Void...) {
 
  do {
  self.useSSL = useSSL
  self.port = port
 
- let server: HTTPServer = try startServer(delegate, port: port, useSSL: useSSL)
+ let server: HTTPServer = try startServer(delegate, port: port, useSSL: useSSL, allowPortReuse: allowPortReuse)
  defer {
  server.stop()
  }
@@ -99,13 +98,14 @@ class KituraNetTest: XCTestCase {
  }
  }
 
- func performFastCGIServerTest(_ delegate: ServerDelegate?, port: Int = portDefault,
+ func performFastCGIServerTest(_ delegate: ServerDelegate?, port: Int = portDefault, allowPortReuse: Bool = portReuseDefault,
  line: Int = #line, asyncTasks: (XCTestExpectation) -> Void...) {
 
  do {
  self.port = port
 
  let server = try FastCGIServer.listen(on: port, delegate: delegate)
+ server.allowPortReuse = allowPortReuse
  defer {
  server.stop()
  }

Tests/KituraNetTests/RegressionTests.swift

@@ -148,4 +148,63 @@ class RegressionTests: KituraNetTest {
  }
 
  }
+
+ /// Tests that attempting to start a second HTTPServer on the same port fails.
+ func testServersCollidingOnPort() {
+ do {
+ let server: HTTPServer = try startServer(nil, port: 0, useSSL: false)
+ defer {
+ server.stop()
+ }
+
+ guard let serverPort = server.port else {
+ XCTFail("Server port was not initialized")
+ return
+ }
+ XCTAssertTrue(serverPort != 0, "Ephemeral server port not set")
+
+ do {
+ let collidingServer: HTTPServer = try startServer(nil, port: serverPort, useSSL: false)
+ defer {
+ collidingServer.stop()
+ }
+ XCTFail("Server unexpectedly succeeded in listening on a port already in use")
+ } catch {
+ XCTAssert(error is Socket.Error, "Expected a Socket.Error, received: \(error)")
+ }
+
+ } catch {
+ XCTFail("Error: \(error)")
+ }
+ }
+
+ /// Tests that attempting to start a second HTTPServer on the same port with
+ /// SO_REUSEPORT enabled is successful.
+ func testServersSharingPort() {
+ do {
+ let server: HTTPServer = try startServer(nil, port: 0, useSSL: false, allowPortReuse: true)
+ defer {
+ server.stop()
+ }
+
+ guard let serverPort = server.port else {
+ XCTFail("Server port was not initialized")
+ return
+ }
+ XCTAssertTrue(serverPort != 0, "Ephemeral server port not set")
+
+ do {
+ let sharingServer: HTTPServer = try startServer(nil, port: serverPort, useSSL: false, allowPortReuse: true)
+ defer {
+ sharingServer.stop()
+ }
+ } catch {
+ XCTFail("Second server could not share listener port, received: \(error)")
+ }
+
+ } catch {
+ XCTFail("Error: \(error)")
+ }
+ }
+
 }