iOS Xray support (#864)

Xray for ios

client/platforms/ios/HevSocksTunnel.swift

@@ -0,0 +1,73 @@
+import HevSocks5Tunnel
+
+public enum Socks5Tunnel {
+
+    private static var tunnelFileDescriptor: Int32? {
+        var ctlInfo = ctl_info()
+        withUnsafeMutablePointer(to: &ctlInfo.ctl_name) {
+            $0.withMemoryRebound(to: CChar.self, capacity: MemoryLayout.size(ofValue: $0.pointee)) {
+                _ = strcpy($0, "com.apple.net.utun_control")
+            }
+        }
+        for fd: Int32 in 0...1024 {
+            var addr = sockaddr_ctl()
+            var ret: Int32 = -1
+            var len = socklen_t(MemoryLayout.size(ofValue: addr))
+            withUnsafeMutablePointer(to: &addr) {
+                $0.withMemoryRebound(to: sockaddr.self, capacity: 1) {
+                    ret = getpeername(fd, $0, &len)
+                }
+            }
+            if ret != 0 || addr.sc_family != AF_SYSTEM {
+                continue
+            }
+            if ctlInfo.ctl_id == 0 {
+                ret = ioctl(fd, CTLIOCGINFO, &ctlInfo)
+                if ret != 0 {
+                    continue
+                }
+            }
+            if addr.sc_id == ctlInfo.ctl_id {
+                return fd
+            }
+        }
+        return nil
+    }
+
+    private static var interfaceName: String? {
+        guard let tunnelFileDescriptor = self.tunnelFileDescriptor else {
+            return nil
+        }
+        var buffer = [UInt8](repeating: 0, count: Int(IFNAMSIZ))
+        return buffer.withUnsafeMutableBufferPointer { mutableBufferPointer in
+            guard let baseAddress = mutableBufferPointer.baseAddress else {
+                return nil
+            }
+            var ifnameSize = socklen_t(IFNAMSIZ)
+            let result = getsockopt(
+                tunnelFileDescriptor,
+                2 /* SYSPROTO_CONTROL */,
+                2 /* UTUN_OPT_IFNAME */,
+                baseAddress,
+                &ifnameSize
+            )
+            if result == 0 {
+                return String(cString: baseAddress)
+            } else {
+                return nil
+            }
+        }
+    }
+
+    @discardableResult
+    public static func run(withConfig filePath: String) -> Int32 {
+        guard let fileDescriptor = self.tunnelFileDescriptor else {
+            fatalError("Get tunnel file descriptor failed.")
+        }
+        return hev_socks5_tunnel_main(filePath.cString(using: .utf8), fileDescriptor)
+    }
+
+    public static func quit() {
+        hev_socks5_tunnel_quit()
+    }
+}