// // NetworkReachabilityManager.swift // // Copyright (c) 2014-2018 Alamofire Software Foundation (http://alamofire.org/) // // Permission is hereby granted, free of charge, to any person obtaining a copy // of this software and associated documentation files (the "Software"), to deal // in the Software without restriction, including without limitation the rights // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell // copies of the Software, and to permit persons to whom the Software is // furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be included in // all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN // THE SOFTWARE. // #if !os(watchOS) import Foundation import SystemConfiguration /// The `NetworkReachabilityManager` class listens for reachability changes of hosts and addresses for both WWAN and /// WiFi network interfaces. /// /// Reachability can be used to determine background information about why a network operation failed, or to retry /// network requests when a connection is established. It should not be used to prevent a user from initiating a network /// request, as it's possible that an initial request may be required to establish reachability. open class NetworkReachabilityManager { /// Defines the various states of network reachability. /// /// - unknown: It is unknown whether the network is reachable. /// - notReachable: The network is not reachable. /// - reachable: The network is reachable. public enum NetworkReachabilityStatus { case unknown case notReachable case reachable(ConnectionType) } /// Defines the various connection types detected by reachability flags. /// /// - ethernetOrWiFi: The connection type is either over Ethernet or WiFi. /// - wwan: The connection type is a WWAN connection. public enum ConnectionType { case ethernetOrWiFi case wwan } /// A closure executed when the network reachability status changes. The closure takes a single argument: the /// network reachability status. public typealias Listener = (NetworkReachabilityStatus) -> Void // MARK: - Properties /// Whether the network is currently reachable. open var isReachable: Bool { return isReachableOnWWAN || isReachableOnEthernetOrWiFi } /// Whether the network is currently reachable over the WWAN interface. open var isReachableOnWWAN: Bool { return networkReachabilityStatus == .reachable(.wwan) } /// Whether the network is currently reachable over Ethernet or WiFi interface. open var isReachableOnEthernetOrWiFi: Bool { return networkReachabilityStatus == .reachable(.ethernetOrWiFi) } /// The current network reachability status. open var networkReachabilityStatus: NetworkReachabilityStatus { guard let flags = self.flags else { return .unknown } return networkReachabilityStatusForFlags(flags) } /// The dispatch queue to execute the `listener` closure on. open var listenerQueue: DispatchQueue = DispatchQueue.main /// A closure executed when the network reachability status changes. open var listener: Listener? open var flags: SCNetworkReachabilityFlags? { var flags = SCNetworkReachabilityFlags() if SCNetworkReachabilityGetFlags(reachability, &flags) { return flags } return nil } private let reachability: SCNetworkReachability open var previousFlags: SCNetworkReachabilityFlags // MARK: - Initialization /// Creates a `NetworkReachabilityManager` instance with the specified host. /// /// - parameter host: The host used to evaluate network reachability. /// /// - returns: The new `NetworkReachabilityManager` instance. public convenience init?(host: String) { guard let reachability = SCNetworkReachabilityCreateWithName(nil, host) else { return nil } self.init(reachability: reachability) } /// Creates a `NetworkReachabilityManager` instance that monitors the address 0.0.0.0. /// /// Reachability treats the 0.0.0.0 address as a special token that causes it to monitor the general routing /// status of the device, both IPv4 and IPv6. /// /// - returns: The new `NetworkReachabilityManager` instance. public convenience init?() { var address = sockaddr_in() address.sin_len = UInt8(MemoryLayout.size) address.sin_family = sa_family_t(AF_INET) guard let reachability = withUnsafePointer(to: &address, { pointer in return pointer.withMemoryRebound(to: sockaddr.self, capacity: MemoryLayout.size) { return SCNetworkReachabilityCreateWithAddress(nil, $0) } }) else { return nil } self.init(reachability: reachability) } private init(reachability: SCNetworkReachability) { self.reachability = reachability self.previousFlags = SCNetworkReachabilityFlags() } deinit { stopListening() } // MARK: - Listening /// Starts listening for changes in network reachability status. /// /// - returns: `true` if listening was started successfully, `false` otherwise. @discardableResult open func startListening() -> Bool { var context = SCNetworkReachabilityContext(version: 0, info: nil, retain: nil, release: nil, copyDescription: nil) context.info = Unmanaged.passUnretained(self).toOpaque() let callbackEnabled = SCNetworkReachabilitySetCallback( reachability, { (_, flags, info) in let reachability = Unmanaged.fromOpaque(info!).takeUnretainedValue() reachability.notifyListener(flags) }, &context ) let queueEnabled = SCNetworkReachabilitySetDispatchQueue(reachability, listenerQueue) listenerQueue.async { self.previousFlags = SCNetworkReachabilityFlags() self.notifyListener(self.flags ?? SCNetworkReachabilityFlags()) } return callbackEnabled && queueEnabled } /// Stops listening for changes in network reachability status. open func stopListening() { SCNetworkReachabilitySetCallback(reachability, nil, nil) SCNetworkReachabilitySetDispatchQueue(reachability, nil) } // MARK: - Internal - Listener Notification func notifyListener(_ flags: SCNetworkReachabilityFlags) { guard previousFlags != flags else { return } previousFlags = flags listener?(networkReachabilityStatusForFlags(flags)) } // MARK: - Internal - Network Reachability Status func networkReachabilityStatusForFlags(_ flags: SCNetworkReachabilityFlags) -> NetworkReachabilityStatus { guard isNetworkReachable(with: flags) else { return .notReachable } var networkStatus: NetworkReachabilityStatus = .reachable(.ethernetOrWiFi) #if os(iOS) if flags.contains(.isWWAN) { networkStatus = .reachable(.wwan) } #endif return networkStatus } func isNetworkReachable(with flags: SCNetworkReachabilityFlags) -> Bool { let isReachable = flags.contains(.reachable) let needsConnection = flags.contains(.connectionRequired) let canConnectAutomatically = flags.contains(.connectionOnDemand) || flags.contains(.connectionOnTraffic) let canConnectWithoutUserInteraction = canConnectAutomatically && !flags.contains(.interventionRequired) return isReachable && (!needsConnection || canConnectWithoutUserInteraction) } } // MARK: - extension NetworkReachabilityManager.NetworkReachabilityStatus: Equatable {} /// Returns whether the two network reachability status values are equal. /// /// - parameter lhs: The left-hand side value to compare. /// - parameter rhs: The right-hand side value to compare. /// /// - returns: `true` if the two values are equal, `false` otherwise. public func ==( lhs: NetworkReachabilityManager.NetworkReachabilityStatus, rhs: NetworkReachabilityManager.NetworkReachabilityStatus) -> Bool { switch (lhs, rhs) { case (.unknown, .unknown): return true case (.notReachable, .notReachable): return true case let (.reachable(lhsConnectionType), .reachable(rhsConnectionType)): return lhsConnectionType == rhsConnectionType default: return false } } #endif