Add source code

TetheringHider/Services/SystemCommandService.swift

@@ -0,0 +1,56 @@
+import Foundation
+
+enum SystemCommandError: LocalizedError {
+    case executionFailed(String)
+    case userCancelledAuth
+    case scriptError(String)
+    
+    var errorDescription: String? {
+        switch self {
+        case .executionFailed(let reason):
+            return "Command failed: \(reason)"
+        case .userCancelledAuth:
+            return "Administrator authentication was cancelled."
+        case .scriptError(let detail):
+            return "Script error: \(detail)"
+        }
+    }
+}
+
+struct SystemCommandService: Sendable {
+    
+    /// Sets IPv4 TTL, IPv6 Hop Limit, and flushes system DNS cache with administrator privileges.
+    func setTTL(_ value: Int) async throws {
+        let command = "sysctl -w net.inet.ip.ttl=\(value) && sysctl -w net.inet6.ip6.hlim=\(value) && dscacheutil -flushcache && killall -HUP mDNSResponder"
+        try await executeWithAdminPrivileges(command)
+    }
+    
+    /// Resets IPv4 TTL and IPv6 Hop Limit to default (64) and flushes DNS cache.
+    func resetTTL() async throws {
+        try await setTTL(64)
+    }
+    
+    /// Executes a shell command with administrator privileges via NSAppleScript
+    @MainActor
+    private func executeWithAdminPrivileges(_ command: String) async throws {
+        let scriptSource = "do shell script \"\(command)\" with administrator privileges"
+        
+        guard let script = NSAppleScript(source: scriptSource) else {
+            throw SystemCommandError.scriptError("Failed to create AppleScript.")
+        }
+        
+        var errorDict: NSDictionary?
+        script.executeAndReturnError(&errorDict)
+        
+        if let error = errorDict {
+            let errorNumber = error[NSAppleScript.errorNumber] as? Int ?? -1
+            let errorMessage = error[NSAppleScript.errorMessage] as? String ?? "Unknown error"
+            
+            if errorNumber == -128 {
+                throw SystemCommandError.userCancelledAuth
+            }
+            
+            throw SystemCommandError.executionFailed(errorMessage)
+        }
+    }
+}