/
main.rs
86 lines (76 loc) · 2.19 KB
/
main.rs
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#![feature(tcp)]
use std::net::{TcpListener, TcpStream};
use std::thread;
use std::io;
use std::env;
use std::mem;
use std::str::FromStr;
use std::io::Read;
use std::io::Write;
fn main() {
let port_ : Option<String> = env::args().skip(2).next();
if let None = port_ {
println!("usage: {} -p port", env::args().next().unwrap());
return;
}
let port = u16::from_str(&port_.unwrap());
if let Err(ref e) = port {
println!("invalid port number given: {}", e);
return;
}
let listener = TcpListener::bind(("127.0.0.1", port.unwrap()));
if let Err(ref e) = listener {
println!("failed to listen on port: {}", e);
return;
}
for stream in listener.unwrap().incoming() {
match stream {
Ok(stream) => {
thread::spawn(move|| {
handle_client(stream)
});
}
Err(e) => {
println!("failed to accept connection: {}", e);
}
}
}
}
fn handle_client(mut stream: TcpStream) {
let mut buf = [0u8; 4];
let mut challenge;
let mut nread;
let _ = stream.set_nodelay(true);
loop {
nread = 0;
while nread < buf.len() {
match stream.read(&mut buf[nread..]) {
Ok(n) if n == 0 => return,
Ok(n) => nread += n,
Err(ref e) if e.kind() == io::ErrorKind::Interrupted => {}
Err(e) => {
println!("{}", e);
return;
}
}
}
challenge = unsafe { mem::transmute(buf) };
challenge = u32::from_be(challenge);
if challenge == 0 {
std::process::exit(0);
}
challenge = u32::to_be(challenge + 1);
buf = unsafe { mem::transmute(challenge) };
let mut nwritten = 0;
while nwritten < buf.len() {
match stream.write(&buf[nwritten..]) {
Ok(n) => nwritten += n,
Err(ref e) if e.kind() == io::ErrorKind::Interrupted => {}
Err(e) => {
println!("{}", e);
return;
}
}
}
}
}