Add source code

TetheringHider/Models/TTLManager.swift

@@ -0,0 +1,64 @@
+import Foundation
+import Observation
+
+@Observable
+@MainActor
+final class TTLManager {
+    private(set) var currentTTL: Int = 64
+    private(set) var currentIPv6HopLimit: Int = 64
+    private(set) var isProtected: Bool = false
+    private(set) var lastError: String?
+    
+    var onStatusChanged: (() -> Void)?
+    
+    let defaultTTL: Int = 64
+    let targetTTL: Int = 65
+    
+    init() {
+        refreshStatus()
+    }
+    
+    /// Reads the current system IPv4 TTL value using sysctlbyname (no root required)
+    func readCurrentTTL() -> Int {
+        var ttl: Int32 = 0
+        var size = MemoryLayout<Int32>.size
+        let result = sysctlbyname("net.inet.ip.ttl", &ttl, &size, nil, 0)
+        if result == 0 {
+            return Int(ttl)
+        }
+        return defaultTTL
+    }
+    
+    /// Reads the current system IPv6 Hop Limit value using sysctlbyname (no root required)
+    func readCurrentIPv6HopLimit() -> Int {
+        var hlim: Int32 = 0
+        var size = MemoryLayout<Int32>.size
+        let result = sysctlbyname("net.inet6.ip6.hlim", &hlim, &size, nil, 0)
+        if result == 0 {
+            return Int(hlim)
+        }
+        return defaultTTL
+    }
+    
+    /// Refreshes current IPv4 TTL, IPv6 Hop Limit, and protection status
+    func refreshStatus() {
+        currentTTL = readCurrentTTL()
+        currentIPv6HopLimit = readCurrentIPv6HopLimit()
+        isProtected = (currentTTL == targetTTL) && (currentIPv6HopLimit == targetTTL)
+        lastError = nil
+        onStatusChanged?()
+    }
+    
+    func didSetTTL(_ value: Int) {
+        currentTTL = value
+        currentIPv6HopLimit = value
+        isProtected = value == targetTTL
+        lastError = nil
+        onStatusChanged?()
+    }
+
+    func setError(_ message: String) {
+        lastError = message
+        onStatusChanged?()
+    }
+}