durnitisp/src/stun.rs

149 lines
5.0 KiB
Rust

// Copyright 2020 Jeremy Wall
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
use gflags;
use log::{debug, error, info};
use prometheus::{CounterVec, IntGaugeVec};
use std::convert::From;
use std::io;
use std::net::{SocketAddr, UdpSocket};
use std::sync::Arc;
use std::sync::RwLock;
use std::time::SystemTime;
gflags::define! {
/// Read timeout for the stun server udp receive
--stunRecvTimeoutSecs: u64 = 5
}
gflags::define! {
/// Delay between lookup attempts in seconds.
--delaySecs: u64 = 60
}
const STUN_PAYLOAD: [u8; 20] = [
0, 1, // Binding request
0, 0, // Message length
0x21, 0x12, 0xa4, 0x42, // magic
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
];
enum ConnectError {
Timeout(SystemTime),
Err(io::Error),
Incomplete,
}
impl From<io::Error> for ConnectError {
fn from(e: io::Error) -> ConnectError {
if let io::ErrorKind::TimedOut = e.kind() {
return ConnectError::Timeout(SystemTime::now());
} else {
return ConnectError::Err(e);
}
}
}
fn attempt_stun_connect(addr: SocketAddr) -> Result<SystemTime, ConnectError> {
// We let the OS choose the port by specifying 0
let local_socket = UdpSocket::bind("0.0.0.0:0")?;
local_socket.connect(addr)?;
local_socket.set_read_timeout(Some(std::time::Duration::from_secs(
STUNRECVTIMEOUTSECS.flag,
)))?;
let _sent = local_socket.send(&STUN_PAYLOAD)?;
// TODO what if we didn't send the whole packet?
let mut buf = [0 as u8; 1024];
let rcvd = local_socket.recv(&mut buf)?;
if rcvd == 0 {
return Err(ConnectError::Incomplete);
}
Ok(SystemTime::now())
}
pub fn start_listen_thread(
domain_name: &str,
stop_signal: Arc<RwLock<bool>>,
s: SocketAddr,
stun_counter_vec_copy: CounterVec,
stun_latency_vec_copy: IntGaugeVec,
stun_success_vec_copy: IntGaugeVec,
) {
debug!("started thread for {}", domain_name);
loop {
{
// Limit the scope of this lock
if *stop_signal.read().unwrap() {
info!("Stopping stun thread for {}", domain_name);
return;
}
}
let now = SystemTime::now();
info!("Attempting to connect to {}", domain_name);
match attempt_stun_connect(s) {
Ok(finish_time) => {
info!("Success! connecting to {}", domain_name);
stun_counter_vec_copy
.with(&prometheus::labels! {"result" => "ok", "domain" => domain_name})
.inc();
stun_latency_vec_copy
.with(&prometheus::labels! {"domain" => domain_name})
// Technically this could be lossy but we'll chance it anyway.
.set(finish_time.duration_since(now).unwrap().as_millis() as i64);
stun_success_vec_copy
.with(&prometheus::labels! {"domain" => domain_name})
.set(1);
}
Err(ConnectError::Timeout(finish_time)) => {
info!(
"Stun connection to {} timedout after {} millis",
domain_name,
finish_time.duration_since(now).unwrap().as_millis()
);
stun_counter_vec_copy
.with(&prometheus::labels! {"result" => "timeout", "domain" => domain_name})
.inc();
stun_success_vec_copy
.with(&prometheus::labels! {"domain" => domain_name})
.set(0);
}
Err(ConnectError::Err(e)) => {
error!("Error connecting to {}: {}", domain_name, e);
stun_counter_vec_copy
.with(&prometheus::labels! {"result" => "err", "domain" => domain_name})
.inc();
stun_success_vec_copy
.with(&prometheus::labels! {"domain" => domain_name})
.set(0);
}
Err(ConnectError::Incomplete) => {
error!("Connection to {} was incomplete", domain_name);
stun_counter_vec_copy
.with(&prometheus::labels! {"result" => "incomplete", "domain" => domain_name})
.inc();
stun_success_vec_copy
.with(&prometheus::labels! {"domain" => domain_name})
.set(0);
}
}
// Then we wait for some period of time.
std::thread::sleep(std::time::Duration::from_secs(DELAYSECS.flag))
}
}
pub fn delay_secs() -> u64 {
DELAYSECS.flag
}