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use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4, TcpListener, TcpStream, ToSocketAddrs};
use std::time::Duration;
pub fn is_port_reachable<A: ToSocketAddrs>(address: A) -> bool {
TcpStream::connect(address).is_ok()
}
pub fn is_port_reachable_with_timeout(address: &SocketAddr, timeout: Duration) -> bool {
TcpStream::connect_timeout(address, timeout).is_ok()
}
pub fn is_local_port_free(port: u16) -> bool {
let ipv4 = SocketAddrV4::new(Ipv4Addr::LOCALHOST, port);
TcpListener::bind(ipv4).is_ok()
}
pub fn free_local_port_in_range(min: u16, max: u16) -> Option<u16> {
(min..max).find(|port| is_local_port_free(*port))
}
pub fn free_local_port() -> Option<u16> {
let socket = SocketAddrV4::new(Ipv4Addr::LOCALHOST, 0);
TcpListener::bind(socket)
.and_then(|listener| listener.local_addr())
.and_then(|addr| Ok(addr.port()))
.ok()
}
#[cfg(test)]
mod tests {
use super::*;
use std::net::{Ipv4Addr, SocketAddrV4, TcpListener};
use std::time::Instant;
use std::{thread, time::Duration};
#[test]
fn should_return_an_unused_port() {
let result = free_local_port();
assert!(result.is_some());
assert!(is_local_port_free(result.unwrap()));
}
#[test]
fn should_return_an_unused_port_in_range() {
let free_port = free_local_port().unwrap();
let min = free_port - 100;
let max = free_port;
let port_found = free_local_port_in_range(min, max).unwrap();
assert!(port_found >= min);
assert!(port_found <= max);
}
#[test]
fn a_free_port_should_not_be_reachable() {
let available_port = free_local_port().unwrap();
assert!(!is_port_reachable(&format!("127.0.0.1:{}", available_port)));
}
#[test]
fn an_open_port_should_be_reachable() {
let socket = SocketAddrV4::new(Ipv4Addr::LOCALHOST, 0);
let listener = TcpListener::bind(socket).unwrap();
let listener_port = listener.local_addr().unwrap().to_string();
thread::spawn(move || loop {
match listener.accept() {
Ok(_) => {
println!("Connection received!");
}
Err(_) => {
println!("Error in received connection!");
}
}
});
let mut port_reachable = false;
while !port_reachable {
println!("Check for available connections on {}", &listener_port);
port_reachable = is_port_reachable(&listener_port);
thread::sleep(Duration::from_millis(10));
}
assert!(port_reachable)
}
#[test]
fn is_port_reachable_should_respect_timeout() {
let timeout = 100;
let start = Instant::now();
assert!(!is_port_reachable_with_timeout(
&"198.19.255.255:1".parse().unwrap(),
Duration::from_millis(timeout)
));
let elapsed = (start.elapsed().subsec_nanos() / 1000000) as u64;
println!("Millis elapsed {}", elapsed);
assert!(elapsed >= timeout);
assert!(elapsed < 2 * timeout);
}
}