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use std::cmp;
use std::collections::HashMap;
use std::net::{Ipv4Addr, Ipv6Addr};
use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
use std::sync::mpsc::sync_channel;
use std::sync::mpsc::SyncSender;
use std::sync::{Arc, Weak};
use std::thread;
use std::time::Instant;
use log::debug;
use spin;
use treebitmap::IpLookupTable;
use super::super::types::{Bind, KeyPair, Tun};
use super::anti_replay::AntiReplay;
use super::peer;
use super::peer::{Peer, PeerInner};
use super::SIZE_MESSAGE_PREFIX;
use super::constants::WORKER_QUEUE_SIZE;
use super::messages::TYPE_TRANSPORT;
use super::types::{Callback, Callbacks, KeyCallback, Opaque, PhantomCallbacks, RouterError};
use super::workers::{worker_parallel, JobParallel};
// minimum sizes for IP headers
const SIZE_IP4_HEADER: usize = 16;
const SIZE_IP6_HEADER: usize = 36;
const VERSION_IP4: u8 = 4;
const VERSION_IP6: u8 = 6;
const OFFSET_IP4_DST: usize = 16;
const OFFSET_IP6_DST: usize = 24;
pub struct DeviceInner<C: Callbacks, T: Tun, B: Bind> {
// IO & timer generics
pub tun: T,
pub bind: B,
pub call_recv: C::CallbackRecv,
pub call_send: C::CallbackSend,
pub call_need_key: C::CallbackKey,
// routing
pub recv: spin::RwLock<HashMap<u32, DecryptionState<C, T, B>>>, // receiver id -> decryption state
pub ipv4: spin::RwLock<IpLookupTable<Ipv4Addr, Weak<PeerInner<C, T, B>>>>, // ipv4 cryptkey routing
pub ipv6: spin::RwLock<IpLookupTable<Ipv6Addr, Weak<PeerInner<C, T, B>>>>, // ipv6 cryptkey routing
}
pub struct EncryptionState {
pub key: [u8; 32], // encryption key
pub id: u32, // receiver id
pub nonce: u64, // next available nonce
pub death: Instant, // (birth + reject-after-time - keepalive-timeout - rekey-timeout)
}
pub struct DecryptionState<C: Callbacks, T: Tun, B: Bind> {
pub key: [u8; 32],
pub keypair: Weak<KeyPair>,
pub confirmed: AtomicBool,
pub protector: spin::Mutex<AntiReplay>,
pub peer: Weak<PeerInner<C, T, B>>,
pub death: Instant, // time when the key can no longer be used for decryption
}
pub struct Device<C: Callbacks, T: Tun, B: Bind> {
pub state: Arc<DeviceInner<C, T, B>>, // reference to device state
pub handles: Vec<thread::JoinHandle<()>>, // join handles for workers
pub queue_next: AtomicUsize, // next round-robin index
pub queues: Vec<spin::Mutex<SyncSender<JobParallel>>>, // work queues (1 per thread)
}
impl<C: Callbacks, T: Tun, B: Bind> Drop for Device<C, T, B> {
fn drop(&mut self) {
// drop all queues
while self.queues.pop().is_some() {}
// join all worker threads
while match self.handles.pop() {
Some(handle) => {
handle.thread().unpark();
handle.join().unwrap();
true
}
_ => false,
} {}
debug!("device dropped");
}
}
impl<O: Opaque, R: Callback<O>, S: Callback<O>, K: KeyCallback<O>, T: Tun, B: Bind>
Device<PhantomCallbacks<O, R, S, K>, T, B>
{
pub fn new(
num_workers: usize,
tun: T,
bind: B,
call_send: S,
call_recv: R,
call_need_key: K,
) -> Device<PhantomCallbacks<O, R, S, K>, T, B> {
// allocate shared device state
let inner = Arc::new(DeviceInner {
tun,
bind,
call_recv,
call_send,
call_need_key,
recv: spin::RwLock::new(HashMap::new()),
ipv4: spin::RwLock::new(IpLookupTable::new()),
ipv6: spin::RwLock::new(IpLookupTable::new()),
});
// start worker threads
let mut queues = Vec::with_capacity(num_workers);
let mut threads = Vec::with_capacity(num_workers);
for _ in 0..num_workers {
let (tx, rx) = sync_channel(WORKER_QUEUE_SIZE);
queues.push(spin::Mutex::new(tx));
threads.push(thread::spawn(move || worker_parallel(rx)));
}
// return exported device handle
Device {
state: inner,
handles: threads,
queue_next: AtomicUsize::new(0),
queues: queues,
}
}
}
impl<C: Callbacks, T: Tun, B: Bind> Device<C, T, B> {
/// Adds a new peer to the device
///
/// # Returns
///
/// A atomic ref. counted peer (with liftime matching the device)
pub fn new_peer(&self, opaque: C::Opaque) -> Peer<C, T, B> {
peer::new_peer(self.state.clone(), opaque)
}
/// Cryptkey routes and sends a plaintext message (IP packet)
///
/// # Arguments
///
/// - pt_msg: IP packet to cryptkey route
///
pub fn send(&self, msg: Vec<u8>) -> Result<(), RouterError> {
// ensure that the type field access is within bounds
if msg.len() < cmp::min(SIZE_IP4_HEADER, SIZE_IP6_HEADER) + SIZE_MESSAGE_PREFIX {
return Err(RouterError::MalformedIPHeader);
}
// ignore header prefix (for in-place transport message construction)
let packet = &msg[SIZE_MESSAGE_PREFIX..];
// lookup peer based on IP packet destination address
let peer = match packet[0] >> 4 {
VERSION_IP4 => {
if msg.len() >= SIZE_IP4_HEADER {
// extract IPv4 destination address
let mut dst = [0u8; 4];
dst.copy_from_slice(&packet[OFFSET_IP4_DST..OFFSET_IP4_DST + 4]);
let dst = Ipv4Addr::from(dst);
// lookup peer (project unto and clone "value" field)
self.state
.ipv4
.read()
.longest_match(dst)
.and_then(|(_, _, p)| p.upgrade())
.ok_or(RouterError::NoCryptKeyRoute)
} else {
Err(RouterError::MalformedIPHeader)
}
}
VERSION_IP6 => {
if msg.len() >= SIZE_IP6_HEADER {
// extract IPv6 destination address
let mut dst = [0u8; 16];
dst.copy_from_slice(&packet[OFFSET_IP6_DST..OFFSET_IP6_DST + 16]);
let dst = Ipv6Addr::from(dst);
// lookup peer (project unto and clone "value" field)
self.state
.ipv6
.read()
.longest_match(dst)
.and_then(|(_, _, p)| p.upgrade())
.ok_or(RouterError::NoCryptKeyRoute)
} else {
Err(RouterError::MalformedIPHeader)
}
}
_ => Err(RouterError::MalformedIPHeader),
}?;
// schedule for encryption and transmission to peer
if let Some(job) = peer.send_job(msg) {
// add job to worker queue
let idx = self.queue_next.fetch_add(1, Ordering::SeqCst);
self.queues[idx % self.queues.len()]
.lock()
.send(job)
.unwrap();
}
Ok(())
}
/// Receive an encrypted transport message
///
/// # Arguments
///
/// - msg: Encrypted transport message
pub fn recv(&self, msg: Vec<u8>) -> Result<(), RouterError> {
// ensure that the type field access is within bounds
if msg.len() < SIZE_MESSAGE_PREFIX || msg[0] != TYPE_TRANSPORT {
return Err(RouterError::MalformedTransportMessage);
}
// parse / cast
// lookup peer based on receiver id
unimplemented!();
}
}
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