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|
/* SPDX-License-Identifier: GPL-2.0
*
* Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
*/
#![allow(dead_code)]
use timestamp::Timestamp;
use failure::Error;
use futures::{unsync::mpsc, Async, Future, Poll, Stream, Sink};
use tokio_timer::Interval;
use tokio_core::reactor::Handle;
use std::collections::HashMap;
use std::net::IpAddr;
use std::time::{Duration, Instant};
const PACKETS_PER_SECOND : u64 = 20;
const PACKETS_BURSTABLE : u64 = 5;
const PACKET_COST : u64 = 1_000_000_000 / PACKETS_PER_SECOND;
const MAX_TOKENS : u64 = PACKET_COST * PACKETS_BURSTABLE;
lazy_static! {
pub static ref GC_INTERVAL: Duration = Duration::new(1, 0);
}
struct Entry {
pub last_time : Timestamp,
pub tokens : u64,
}
pub struct RateLimiter {
table : HashMap<IpAddr, Entry>,
rx : mpsc::Receiver<()>,
}
impl RateLimiter {
pub fn new(handle: &Handle) -> Result<Self, Error> {
let (tx, rx) = mpsc::channel(128);
let i_handle = handle.clone();
let gc = Interval::new(Instant::now(), *GC_INTERVAL)
.map_err(|e| panic!("timer failed; err={:?}", e))
.for_each(move |_| {
i_handle.spawn(tx.clone().send(()).then(|_| Ok(())));
Ok(())
});
handle.spawn(gc);
Ok(Self {
table: HashMap::new(),
rx
})
}
fn _new_for_test() -> Self {
let (_tx, rx) = mpsc::channel(1);
Self { table: HashMap::new(), rx }
}
pub fn allow(&mut self, addr: &IpAddr) -> bool {
if let Some(entry) = self.table.get_mut(addr) {
entry.tokens = MAX_TOKENS.min(entry.tokens + u64::from(entry.last_time.elapsed().subsec_nanos()));
entry.last_time = Timestamp::now();
if entry.tokens > PACKET_COST {
entry.tokens -= PACKET_COST;
return true;
} else {
return false;
}
}
self.table.insert(*addr, Entry {
last_time: Timestamp::now(),
tokens: MAX_TOKENS - PACKET_COST
});
true
}
fn handle_gc(&mut self) {
self.table.retain(|_, ref mut entry| entry.last_time.elapsed() <= *GC_INTERVAL);
}
}
impl Future for RateLimiter {
type Item = ();
type Error = ();
fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
if let Ok(Async::Ready(Some(()))) = self.rx.poll() {
self.handle_gc();
}
Ok(Async::NotReady)
}
}
#[cfg(test)]
mod tests {
use super::*;
use std;
struct Result {
allowed: bool,
text: &'static str,
wait: Duration,
}
#[test]
fn test_ratelimiter() {
let mut ratelimiter = RateLimiter::_new_for_test();
let mut expected = vec![];
let ips = vec![
"127.0.0.1".parse().unwrap(),
"192.168.1.1".parse().unwrap(),
"172.167.2.3".parse().unwrap(),
"97.231.252.215".parse().unwrap(),
"248.97.91.167".parse().unwrap(),
"188.208.233.47".parse().unwrap(),
"104.2.183.179".parse().unwrap(),
"72.129.46.120".parse().unwrap(),
"2001:0db8:0a0b:12f0:0000:0000:0000:0001".parse().unwrap(),
"f5c2:818f:c052:655a:9860:b136:6894:25f0".parse().unwrap(),
"b2d7:15ab:48a7:b07c:a541:f144:a9fe:54fc".parse().unwrap(),
"a47b:786e:1671:a22b:d6f9:4ab0:abc7:c918".parse().unwrap(),
"ea1e:d155:7f7a:98fb:2bf5:9483:80f6:5445".parse().unwrap(),
"3f0e:54a2:f5b4:cd19:a21d:58e1:3746:84c4".parse().unwrap(),];
for _ in 0..PACKETS_BURSTABLE {
expected.push(Result {
allowed : true,
wait : Duration::new(0, 0),
text : "inital burst",
});
}
expected.push(Result {
allowed : false,
wait : Duration::new(0, 0),
text : "after burst",
});
expected.push(Result {
allowed : true,
wait : Duration::new(0, PACKET_COST as u32),
text : "filling tokens for single packet",
});
expected.push(Result {
allowed : false,
wait : Duration::new(0, 0),
text : "not having refilled enough",
});
expected.push(Result {
allowed : true,
wait : Duration::new(0, 2 * PACKET_COST as u32),
text : "filling tokens for 2 * packet burst",
});
expected.push(Result {
allowed : true,
wait : Duration::new(0, 0),
text : "second packet in 2 packet burst",
});
expected.push(Result {
allowed : false,
wait : Duration::new(0, 0),
text : "packet following 2 packet burst",
});
for item in expected {
std::thread::sleep(item.wait);
for ip in ips.iter() {
if ratelimiter.allow(&ip) != item.allowed {
panic!("test failed for {} on {}. expected: {}, got: {}", ip, item.text, item.allowed, !item.allowed)
}
}
}
}
}
|
