Rust Programming By Example

Implementing the PASV command

To be able to make this command work, we need to add a few new fields in our Client struct:

struct Client {
    cwd: PathBuf,
    stream: TcpStream,
    name: Option<String>,
    data_writer: Option<TcpStream>,
}

We now need to update the Client::new method as well:

fn new(stream: TcpStream) -> Client {
    Client {
        cwd: PathBuf::from("/"),
        stream: stream,
        name: None,
        data_writer: None,
    }
}

The PASV command doesn't take arguments, so I'll let you add it to the structures and everything. Let's focus on the interesting part:

// Adding some new imports:
use std::net::{IpAddr, Ipv4Addr, SocketAddr};

Command::Pasv => {
    if self.data_writer.is_some() {
        send_cmd(&mut self.stream, ResultCode::DataConnectionAlreadyOpen, "Already  listening...") ...