Make setup argument optional

README.md

@@ -71,6 +71,7 @@ Options:
   -t, --tun <name>      Name of the tun interface [default: tun0]
   -p, --proxy <URL>     Proxy URL in the form proto://[username[:password]@]host:port
   -d, --dns <method>    DNS handling [default: virtual] [possible values: virtual, none]
+  -s, --setup <method>  Routing and system setup [possible values: auto]
   -h, --help            Print help
   -V, --version         Print version
 ```

src/main.rs

@@ -28,9 +28,9 @@ struct Args {
     )]
     dns: ArgDns,
 
-    /// Setup
+    /// Routing and system setup
     #[arg(short, long, value_name = "method", value_enum)]
-    setup: ArgSetup,
+    setup: Option<ArgSetup>,
 }
 
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, clap::ValueEnum)]
@@ -59,7 +59,7 @@ fn main() -> ExitCode {
     }
 
     let mut setup: Setup;
-    if args.setup == ArgSetup::Auto {
+    if args.setup == Some(ArgSetup::Auto) {
         setup = Setup::new(&args.tun, &args.proxy.addr.ip(), get_default_cidrs());
         if let Err(e) = setup.setup() {
             log::error!("{e}");