Use "struct" in data models to leverage Equatable

This way Configuration objects can be compared for changes.

Sources/TunnelKitCore/BidirectionalState.swift

@@ -26,7 +26,7 @@
 import Foundation
 
 /// A generic structure holding a pair of inbound/outbound states.
-public class BidirectionalState<T> {
+public struct BidirectionalState<T> {
     private let resetValue: T
 
     /// The inbound state.
@@ -58,7 +58,7 @@ public class BidirectionalState<T> {
     /**
      Resets state to the value provided with `init(withResetValue:)`.
      */
-    public func reset() {
+    public mutating func reset() {
         inbound = resetValue
         outbound = resetValue
     }

Sources/TunnelKitCore/IPv4Settings.swift

@@ -26,7 +26,7 @@
 import Foundation
 
 /// Encapsulates the IPv4 settings for the tunnel.
-public struct IPv4Settings: Codable, CustomStringConvertible {
+public struct IPv4Settings: Codable, Equatable, CustomStringConvertible {
     
     /// Represents an IPv4 route in the routing table.
     public struct Route: Codable, Hashable, CustomStringConvertible {

Sources/TunnelKitCore/IPv6Settings.swift

@@ -26,7 +26,7 @@
 import Foundation
 
 /// Encapsulates the IPv6 settings for the tunnel.
-public struct IPv6Settings: Codable, CustomStringConvertible {
+public struct IPv6Settings: Codable, Equatable, CustomStringConvertible {
     
     /// Represents an IPv6 route in the routing table.
     public struct Route: Codable, Hashable, CustomStringConvertible {

Sources/TunnelKitCore/Proxy.swift

@@ -26,7 +26,7 @@
 import Foundation
 
 /// Encapsulates a proxy setting.
-public struct Proxy: Codable, RawRepresentable, CustomStringConvertible {
+public struct Proxy: Codable, Equatable, RawRepresentable, CustomStringConvertible {
     
     /// The proxy address.
     public let address: String

Sources/TunnelKitOpenVPNCore/Configuration.swift

@@ -356,7 +356,7 @@ extension OpenVPN {
     }
     
     /// The immutable configuration for `OpenVPNSession`.
-    public struct Configuration: Codable {
+    public struct Configuration: Codable, Equatable {
 
         /// - Seealso: `ConfigurationBuilder.cipher`
         public let cipher: Cipher?

Sources/TunnelKitOpenVPNCore/StaticKey.swift

@@ -30,7 +30,7 @@ import CTunnelKitCore
 extension OpenVPN {
 
     /// Represents an OpenVPN static key file (as generated with --genkey)
-    public class StaticKey: Codable {
+    public struct StaticKey: Codable, Equatable {
         enum CodingKeys: CodingKey {
             case data
             
@@ -147,12 +147,12 @@ extension OpenVPN {
          - Parameter file: The text file containing the key.
          - Parameter direction: The key direction, or bidirectional if nil.
          */
-        public convenience init?(file: String, direction: Direction?) {
+        public init?(file: String, direction: Direction?) {
             let lines = file.split(separator: "\n")
             self.init(lines: lines, direction: direction)
         }
         
-        public convenience init?(lines: [Substring], direction: Direction?) {
+        public init?(lines: [Substring], direction: Direction?) {
             var isHead = true
             var hexLines: [Substring] = []
 
@@ -196,7 +196,7 @@ extension OpenVPN {
          
          - Parameter biData: The key data.
          */
-        public convenience init(biData data: Data) {
+        public init(biData data: Data) {
             self.init(data: data, direction: nil)
         }
         
@@ -216,7 +216,7 @@ extension OpenVPN {
         
         // MARK: Codable
         
-        public required init(from decoder: Decoder) throws {
+        public init(from decoder: Decoder) throws {
             let container = try decoder.container(keyedBy: CodingKeys.self)
             secureData = Z(try container.decode(Data.self, forKey: .data))
             direction = try container.decodeIfPresent(Direction.self, forKey: .dir)

Sources/TunnelKitOpenVPNCore/TLSWrap.swift

@@ -28,10 +28,10 @@ import Foundation
 extension OpenVPN {
 
     /// Holds parameters for TLS wrapping.
-    public class TLSWrap: Codable {
+    public struct TLSWrap: Codable, Equatable {
 
         /// The wrapping strategy.
-        public enum Strategy: String, Codable {
+        public enum Strategy: String, Codable, Equatable {
             
             /// Authenticates payload (--tls-auth).
             case auth

Sources/TunnelKitOpenVPNProtocol/Packet.swift

@@ -63,7 +63,7 @@ extension ControlPacket {
 }
 
 extension OpenVPN {
-    class DataPacket {
+    struct DataPacket {
         static let pingString = Data(hex: "2a187bf3641eb4cb07ed2d0a981fc748")
     }
 

Sources/TunnelKitWireGuardCore/Configuration.swift

@@ -203,7 +203,7 @@ extension WireGuard {
         }
     }
 
-    public struct Configuration: Codable, WireGuardConfigurationProviding {
+    public struct Configuration: Codable, Equatable, WireGuardConfigurationProviding {
         public let tunnelConfiguration: TunnelConfiguration
         
         public var interface: InterfaceConfiguration {