how to set_only_v6

[FH0]

Assume the following two scenarios

• 0.0.0.0:80 is already bound by other application.
• The ipv6 address of the network interface changes frequently.

How to listen on :::80 via tokio?

async fn main() {
  // let v6 = TcpListener::bind(":::80", set_v6_only=true).await.unwrap();

  loop {
    v6.accept().await.unwrap();
  }
}

[taiki-e]

IIRC, neither tokio::net::TcpListener nor std::net::TcpListener supports this. You probably need to use socket2 crate to create std::net::TcpListener and convert it to tokio::net::TcpListener with from_std function.

[Darksonn]

What happens if you go through TcpSocket::new_v6?

[FH0]

What happens if you go through TcpSocket::new_v6?

use tokio::net::TcpSocket;

use std::io;

#[tokio::main]
async fn main() -> io::Result<()> {
  let socket4 = TcpSocket::new_v4()?;
  socket4.bind("0.0.0.0:80".parse().unwrap())?;
  let socket6 = TcpSocket::new_v6()?;
  socket6.bind("[::]:80".parse().unwrap())?;

  socket4.listen(128)?;
  socket6.listen(128)?;

  std::thread::sleep(std::time::Duration::from_secs(1000));

  Ok(())
}

Error: Os { code: 98, kind: AddrInUse, message: "Address already in use" }