1 files changed, 67 insertions, 0 deletions
diff --git a/Sources/WireGuardKitSwift/IPAddressRange.swift b/Sources/WireGuardKitSwift/IPAddressRange.swift
new file mode 100644
index 0000000..c65ff1d
--- /dev/null
+++ b/Sources/WireGuardKitSwift/IPAddressRange.swift
@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: MIT
+// Copyright © 2018-2019 WireGuard LLC. All Rights Reserved.
+
+import Foundation
+import Network
+
+public struct IPAddressRange {
+    public let address: IPAddress
+    public let networkPrefixLength: UInt8
+
+    init(address: IPAddress, networkPrefixLength: UInt8) {
+        self.address = address
+        self.networkPrefixLength = networkPrefixLength
+    }
+}
+
+extension IPAddressRange: Equatable {
+    public static func == (lhs: IPAddressRange, rhs: IPAddressRange) -> Bool {
+        return lhs.address.rawValue == rhs.address.rawValue && lhs.networkPrefixLength == rhs.networkPrefixLength
+    }
+}
+
+extension IPAddressRange: Hashable {
+    public func hash(into hasher: inout Hasher) {
+        hasher.combine(address.rawValue)
+        hasher.combine(networkPrefixLength)
+    }
+}
+
+extension IPAddressRange {
+    public var stringRepresentation: String {
+        return "\(address)/\(networkPrefixLength)"
+    }
+
+    public init?(from string: String) {
+        guard let parsed = IPAddressRange.parseAddressString(string) else { return nil }
+        address = parsed.0
+        networkPrefixLength = parsed.1
+    }
+
+    private static func parseAddressString(_ string: String) -> (IPAddress, UInt8)? {
+        let endOfIPAddress = string.lastIndex(of: "/") ?? string.endIndex
+        let addressString = String(string[string.startIndex ..< endOfIPAddress])
+        let address: IPAddress
+        if let addr = IPv4Address(addressString) {
+            address = addr
+        } else if let addr = IPv6Address(addressString) {
+            address = addr
+        } else {
+            return nil
+        }
+
+        let maxNetworkPrefixLength: UInt8 = address is IPv4Address ? 32 : 128
+        var networkPrefixLength: UInt8
+        if endOfIPAddress < string.endIndex { // "/" was located
+            let indexOfNetworkPrefixLength = string.index(after: endOfIPAddress)
+            guard indexOfNetworkPrefixLength < string.endIndex else { return nil }
+            let networkPrefixLengthSubstring = string[indexOfNetworkPrefixLength ..< string.endIndex]
+            guard let npl = UInt8(networkPrefixLengthSubstring) else { return nil }
+            networkPrefixLength = min(npl, maxNetworkPrefixLength)
+        } else {
+            networkPrefixLength = maxNetworkPrefixLength
+        }
+
+        return (address, networkPrefixLength)
+    }
+}