fn main()

in vsock_proxy/src/main.rs [15:123]

• 97 lines of code
• 2 McCabe index (conditional complexity)

fn main() -> VsockProxyResult<()> {
    init();

    let matches = App::new("Vsock-TCP proxy")
        .about("Vsock-TCP proxy")
        .setting(AppSettings::DisableVersion)
        .arg(
            Arg::with_name("ipv4")
                .short("4")
                .long("ipv4")
                .help("Force the proxy to use IPv4 addresses only.")
                .required(false),
        )
        .arg(
            Arg::with_name("ipv6")
                .short("6")
                .long("ipv6")
                .help("Force the proxy to use IPv6 addresses only.")
                .required(false)
                .conflicts_with("ipv4"),
        )
        .arg(
            Arg::with_name("workers")
                .short("w")
                .long("num_workers")
                .help("Set the maximum number of simultaneous\nconnections supported.")
                .required(false)
                .takes_value(true)
                .default_value("4"),
        )
        .arg(
            Arg::with_name("local_port")
                .help("Local Vsock port to listen for incoming connections.")
                .required(true),
        )
        .arg(
            Arg::with_name("remote_addr")
                .help("Address of the server to be proxyed.")
                .required(true),
        )
        .arg(
            Arg::with_name("remote_port")
                .help("Remote TCP port of the server to be proxyed.")
                .required(true),
        )
        .arg(
            Arg::with_name("config_file")
                .long("config")
                .help("YAML file containing the services that\ncan be forwarded.\n")
                .required(false)
                .takes_value(true)
                .default_value("/etc/nitro_enclaves/vsock-proxy.yaml"),
        )
        .get_matches();

    let local_port = matches
        .value_of("local_port")
        // This argument is required, so clap ensures it's available
        .unwrap();
    let local_port = local_port
        .parse::<u32>()
        .map_err(|_| "Local port is not valid")?;

    let only_4 = matches.is_present("ipv4");
    let only_6 = matches.is_present("ipv6");
    let remote_addr = matches
        .value_of("remote_addr")
        // This argument is required, so clap ensures it's available
        .unwrap();

    let remote_port = matches
        .value_of("remote_port")
        // This argument is required, so clap ensures it's available
        .unwrap();
    let remote_port = remote_port
        .parse::<u16>()
        .map_err(|_| "Remote port is not valid")?;

    let num_workers = matches
        .value_of("workers")
        // This argument has a default value, so it is available
        .unwrap();
    let num_workers = num_workers
        .parse::<usize>()
        .map_err(|_| "Number of workers is not valid")?;

    let config_file = matches.value_of("config_file");

    let proxy = Proxy::new(
        local_port,
        remote_addr,
        remote_port,
        num_workers,
        config_file,
        only_4,
        only_6,
    )
    .map_err(|err| format!("Could not create proxy: {}", err))?;

    let listener = proxy
        .sock_listen()
        .map_err(|err| format!("Could not listen for connections: {}", err))?;
    info!("Proxy is now in listening state");
    loop {
        proxy
            .sock_accept(&listener)
            .map_err(|err| format!("Could not accept connection: {}", err))?;
    }
}