Adopt Sendable in NIOSOCKS (#173)

Incremental `Sendable` adoption.

Co-authored-by: Cory Benfield <lukasa@apple.com>

Sources/NIOSOCKS/Channel Handlers/SOCKSClientHandler.swift

@@ -114,6 +114,11 @@ public final class SOCKSClientHandler: ChannelDuplexHandler {
     }
 }
 
+#if swift(>=5.6)
+@available(*, unavailable)
+extension SOCKSClientHandler: Sendable {}
+#endif
+
 extension SOCKSClientHandler {
     
     private func beginHandshake(context: ChannelHandlerContext) {
@@ -207,7 +212,7 @@ extension SOCKSClientHandler: RemovableChannelHandler {
 /// A `Channel` user event that is sent when a SOCKS connection has been established
 ///
 /// After this event has been received it is save to remove the `SOCKSClientHandler` from the channel pipeline.
-public struct SOCKSProxyEstablishedEvent {
+public struct SOCKSProxyEstablishedEvent: NIOSendable {
     public init() {
     }
 }

Sources/NIOSOCKS/Channel Handlers/SOCKSServerHandshakeHandler.swift

@@ -121,3 +121,8 @@ public final class SOCKSServerHandshakeHandler: ChannelDuplexHandler, RemovableC
     }
     
 }
+
+#if swift(>=5.6)
+@available(*, unavailable)
+extension SOCKSServerHandshakeHandler: Sendable {}
+#endif

Sources/NIOSOCKS/Messages/AuthenticationMethod.swift

@@ -12,8 +12,10 @@
 //
 //===----------------------------------------------------------------------===//
 
+import NIOCore
+
 /// The SOCKS authentication method to use, defined in RFC 1928.
-public struct AuthenticationMethod: Hashable {
+public struct AuthenticationMethod: Hashable, NIOSendable {
     
     /// No authentication required
     public static let noneRequired = AuthenticationMethod(value: 0x00)

Sources/NIOSOCKS/Messages/ClientGreeting.swift

@@ -17,7 +17,7 @@ import NIOCore
 /// Clients begin the SOCKS handshake process
 /// by providing an array of suggested authentication
 /// methods.
-public struct ClientGreeting: Hashable {
+public struct ClientGreeting: Hashable, NIOSendable {
     
     /// The protocol version.
     public let version: UInt8 = 5

Sources/NIOSOCKS/Messages/Messages.swift

@@ -15,7 +15,7 @@
 import NIOCore
 
 /// Sent by the client and received by the server.
-public enum ClientMessage: Hashable {
+public enum ClientMessage: Hashable, NIOSendable {
     
     /// Contains the proposed authentication methods.
     case greeting(ClientGreeting)
@@ -28,7 +28,7 @@ public enum ClientMessage: Hashable {
 }
 
 /// Sent by the server and received by the client.
-public enum ServerMessage: Hashable {
+public enum ServerMessage: Hashable, NIOSendable {
     
     /// Used by the server to instruct the client of the authentication method to use.
     case selectedAuthenticationMethod(SelectedAuthenticationMethod)

Sources/NIOSOCKS/Messages/SOCKSRequest.swift

@@ -24,7 +24,7 @@ import NIOCore
 
 /// Instructs the SOCKS proxy server of the target host,
 /// and how to connect.
-public struct SOCKSRequest: Hashable {
+public struct SOCKSRequest: Hashable, NIOSendable {
     
     /// The SOCKS protocol version - we currently only support v5.
     public let version: UInt8 = 5
@@ -75,7 +75,7 @@ extension ByteBuffer {
 
 /// What type of connection the SOCKS server should establish with
 /// the target host.
-public struct SOCKSCommand: Hashable {
+public struct SOCKSCommand: Hashable, NIOSendable {
     
     /// Typically the primary connection type, suitable for HTTP.
     public static let connect = SOCKSCommand(value: 0x01)
@@ -99,7 +99,7 @@ public struct SOCKSCommand: Hashable {
 // MARK: - SOCKSAddress
 
 /// The address used to connect to the target host.
-public enum SOCKSAddress: Hashable {
+public enum SOCKSAddress: Hashable, NIOSendable {
     /// Socket Adress
     case address(SocketAddress)
     /// Host and port

Sources/NIOSOCKS/Messages/SOCKSResponse.swift

@@ -18,7 +18,7 @@ import NIOCore
 
 /// The SOCKS Server's response to the client's request
 /// indicating if the request succeeded or failed.
-public struct SOCKSResponse: Hashable {
+public struct SOCKSResponse: Hashable, NIOSendable {
     
     /// The SOCKS protocol version - we currently only support v5.
     public let version: UInt8 = 5
@@ -69,7 +69,7 @@ extension ByteBuffer {
 
 /// Used to indicate if the SOCKS client's connection request succeeded
 /// or failed.
-public struct SOCKSServerReply: Hashable {
+public struct SOCKSServerReply: Hashable, NIOSendable {
     
     /// The connection succeeded and data can now be transmitted.
     public static let succeeded = SOCKSServerReply(value: 0x00)

Sources/NIOSOCKS/Messages/SelectedAuthenticationMethod.swift

@@ -17,7 +17,7 @@ import NIOCore
 /// Used by the SOCKS server to inform the client which
 /// authentication method it would like to use out of those
 /// offered.
-public struct SelectedAuthenticationMethod: Hashable {
+public struct SelectedAuthenticationMethod: Hashable, NIOSendable {
     
     /// The SOCKS protocol version - we currently only support v5.
     public let version: UInt8 = 5