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|
use crate::handshake;
use crate::router;
use crate::types::{Bind, Endpoint, Tun};
use std::sync::atomic::{AtomicBool, AtomicU64, AtomicUsize, Ordering};
use std::sync::Arc;
use std::thread;
use std::time::{Duration, Instant};
use std::collections::HashMap;
use log::debug;
use rand::rngs::OsRng;
use spin::{Mutex, RwLock};
use byteorder::{ByteOrder, LittleEndian};
use crossbeam_channel::{bounded, Sender};
use x25519_dalek::{PublicKey, StaticSecret};
const SIZE_HANDSHAKE_QUEUE: usize = 128;
const THRESHOLD_UNDER_LOAD: usize = SIZE_HANDSHAKE_QUEUE / 4;
const DURATION_UNDER_LOAD: Duration = Duration::from_millis(10_000);
#[derive(Clone)]
pub struct Peer<T: Tun, B: Bind>(Arc<PeerInner<T, B>>);
pub struct PeerInner<T: Tun, B: Bind> {
router: router::Peer<Events, T, B>,
timers: Timers,
rx: AtomicU64,
tx: AtomicU64,
}
pub struct Timers {}
pub struct Events();
impl router::Callbacks for Events {
type Opaque = Timers;
fn send(t: &Timers, size: usize, data: bool, sent: bool) {}
fn recv(t: &Timers, size: usize, data: bool, sent: bool) {}
fn need_key(t: &Timers) {}
}
struct Handshake {
device: handshake::Device,
active: bool,
}
struct WireguardInner<T: Tun, B: Bind> {
// identify and configuration map
peers: RwLock<HashMap<[u8; 32], Peer<T, B>>>,
// cryptkey routing
router: router::Device<Events, T, B>,
// handshake related state
handshake: RwLock<Handshake>,
under_load: AtomicBool,
pending: AtomicUsize, // num of pending handshake packets in queue
queue: Mutex<Sender<(Vec<u8>, B::Endpoint)>>,
// IO
bind: B,
}
pub struct Wireguard<T: Tun, B: Bind> {
state: Arc<WireguardInner<T, B>>,
}
impl<T: Tun, B: Bind> Wireguard<T, B> {
fn set_key(&self, sk: Option<StaticSecret>) {
let mut handshake = self.state.handshake.write();
match sk {
None => {
let mut rng = OsRng::new().unwrap();
handshake.device.set_sk(StaticSecret::new(&mut rng));
handshake.active = false;
}
Some(sk) => {
handshake.device.set_sk(sk);
handshake.active = true;
}
}
}
fn new(tun: T, bind: B) -> Wireguard<T, B> {
// create device state
let mut rng = OsRng::new().unwrap();
let (tx, rx): (Sender<(Vec<u8>, B::Endpoint)>, _) = bounded(SIZE_HANDSHAKE_QUEUE);
let wg = Arc::new(WireguardInner {
peers: RwLock::new(HashMap::new()),
router: router::Device::new(num_cpus::get(), tun.clone(), bind.clone()),
pending: AtomicUsize::new(0),
handshake: RwLock::new(Handshake {
device: handshake::Device::new(StaticSecret::new(&mut rng)),
active: false,
}),
under_load: AtomicBool::new(false),
bind: bind.clone(),
queue: Mutex::new(tx),
});
// start handshake workers
for _ in 0..num_cpus::get() {
let wg = wg.clone();
let rx = rx.clone();
let bind = bind.clone();
thread::spawn(move || {
// prepare OsRng instance for this thread
let mut rng = OsRng::new().unwrap();
// process elements from the handshake queue
for (msg, src) in rx {
wg.pending.fetch_sub(1, Ordering::SeqCst);
// feed message to handshake device
let src_validate = (&src).into_address(); // TODO avoid
let state = wg.handshake.read();
if !state.active {
continue;
}
// process message
match state.device.process(
&mut rng,
&msg[..],
if wg.under_load.load(Ordering::Relaxed) {
Some(&src_validate)
} else {
None
},
) {
Ok((pk, msg, keypair)) => {
// send response
if let Some(msg) = msg {
let _ = bind.send(&msg[..], &src).map_err(|e| {
debug!(
"handshake worker, failed to send response, error = {:?}",
e
)
});
}
// update timers
if let Some(pk) = pk {
// add keypair to peer and free any unused ids
if let Some(keypair) = keypair {
if let Some(peer) = wg.peers.read().get(pk.as_bytes()) {
for id in peer.0.router.add_keypair(keypair) {
state.device.release(id);
}
}
}
}
}
Err(e) => debug!("handshake worker, error = {:?}", e),
}
}
});
}
// start UDP read IO thread
{
let wg = wg.clone();
let tun = tun.clone();
let bind = bind.clone();
thread::spawn(move || {
let mut last_under_load =
Instant::now() - DURATION_UNDER_LOAD - Duration::from_millis(1000);
loop {
// read UDP packet into vector
let size = tun.mtu() + 148; // maximum message size
let mut msg: Vec<u8> = Vec::with_capacity(size);
msg.resize(size, 0);
let (size, src) = bind.recv(&mut msg).unwrap(); // TODO handle error
msg.truncate(size);
// message type de-multiplexer
if msg.len() < std::mem::size_of::<u32>() {
continue;
}
match LittleEndian::read_u32(&msg[..]) {
handshake::TYPE_COOKIE_REPLY
| handshake::TYPE_INITIATION
| handshake::TYPE_RESPONSE => {
// update under_load flag
if wg.pending.fetch_add(1, Ordering::SeqCst) > THRESHOLD_UNDER_LOAD {
last_under_load = Instant::now();
wg.under_load.store(true, Ordering::SeqCst);
} else if last_under_load.elapsed() > DURATION_UNDER_LOAD {
wg.under_load.store(false, Ordering::SeqCst);
}
wg.queue.lock().send((msg, src)).unwrap();
}
router::TYPE_TRANSPORT => {
// transport message
// pad the message
let _ = wg.router.recv(src, msg);
}
_ => (),
}
}
});
}
// start TUN read IO thread
{
let wg = wg.clone();
thread::spawn(move || loop {
// read a new IP packet
let mtu = tun.mtu();
let size = mtu + 148;
let mut msg: Vec<u8> = Vec::with_capacity(size + router::CAPACITY_MESSAGE_POSTFIX);
let size = tun.read(&mut msg[..], router::SIZE_MESSAGE_PREFIX).unwrap();
msg.truncate(size);
// pad message to multiple of 16
while msg.len() < mtu && msg.len() % 16 != 0 {
msg.push(0);
}
// crypt-key route
let _ = wg.router.send(msg);
});
}
Wireguard { state: wg }
}
}
|
