UdpSocket.send_to以"无效参数"失败

我在使用Rust尝试使用BitTorrent跟踪器协议时遇到了这个问题.

这个应该使用UDP套接字发送一些数据的简单程序失败了:

use std::collections::HashSet;
use std::io::net::addrinfo;
use std::io::net::ip::{Ipv4Addr, SocketAddr, IpAddr};
use std::io::net::udp::UdpSocket;

fn main() {
    let addr = SocketAddr { ip: Ipv4Addr(127, 0, 0, 1), port: 34254 };
    let mut socket = match UdpSocket::bind(addr) {
        Ok(s) => s,
        Err(e) => panic!("couldn't bind socket: {}", e),
    };

    let host_addr = "tracker.openbittorrent.com";
    let port = "80";

    let host_ips: HashSet =
        addrinfo::get_host_addresses(host_addr.as_slice()).unwrap().into_iter().collect();

    for host_ip in host_ips.into_iter() {
        let socket_addr = SocketAddr {
            ip: host_ip,
            port: from_str(port).unwrap(),
        };
        println!("Sending to {}", socket_addr);
        let data: &[u8] = [0x1, 0x2, 0x3];
        println!("{}", socket.send_to(data, socket_addr));
    }
}

输出:

Sending to 31.172.63.252:80
Err(invalid argument (Invalid argument))
Sending to 31.172.63.253:80
Err(invalid argument (Invalid argument))

关于出了什么问题的任何想法？