Better compartmentalization of cryptokey router

This commit is contained in:
Mathias Hall-Andersen
2019-11-18 13:13:55 +01:00
parent b1fbd7fbba
commit 3ba0247634
6 changed files with 394 additions and 184 deletions

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@@ -0,0 +1,228 @@
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;
use std::thread;
use std::time::Instant;
use log::debug;
use spin::{Mutex, RwLock};
use treebitmap::IpLookupTable;
use zerocopy::LayoutVerified;
use super::anti_replay::AntiReplay;
use super::constants::*;
use super::messages::{TransportHeader, TYPE_TRANSPORT};
use super::peer::{new_peer, Peer, PeerInner};
use super::types::{Callbacks, RouterError};
use super::workers::{worker_parallel, JobParallel};
use super::SIZE_MESSAGE_PREFIX;
use super::route::get_route;
use super::super::{bind, tun, Endpoint, KeyPair};
pub struct DeviceInner<E: Endpoint, C: Callbacks, T: tun::Writer, B: bind::Writer<E>> {
// inbound writer (TUN)
pub inbound: T,
// outbound writer (Bind)
pub outbound: RwLock<(bool, Option<B>)>,
// routing
pub recv: RwLock<HashMap<u32, Arc<DecryptionState<E, C, T, B>>>>, // receiver id -> decryption state
pub ipv4: RwLock<IpLookupTable<Ipv4Addr, Arc<PeerInner<E, C, T, B>>>>, // ipv4 cryptkey routing
pub ipv6: RwLock<IpLookupTable<Ipv6Addr, Arc<PeerInner<E, C, T, B>>>>, // ipv6 cryptkey routing
// work queues
pub queue_next: AtomicUsize, // next round-robin index
pub queues: Mutex<Vec<SyncSender<JobParallel>>>, // work queues (1 per thread)
}
pub struct EncryptionState {
pub keypair: Arc<KeyPair>, // keypair
pub nonce: u64, // next available nonce
pub death: Instant, // (birth + reject-after-time - keepalive-timeout - rekey-timeout)
}
pub struct DecryptionState<E: Endpoint, C: Callbacks, T: tun::Writer, B: bind::Writer<E>> {
pub keypair: Arc<KeyPair>,
pub confirmed: AtomicBool,
pub protector: Mutex<AntiReplay>,
pub peer: Arc<PeerInner<E, C, T, B>>,
pub death: Instant, // time when the key can no longer be used for decryption
}
pub struct Device<E: Endpoint, C: Callbacks, T: tun::Writer, B: bind::Writer<E>> {
state: Arc<DeviceInner<E, C, T, B>>, // reference to device state
handles: Vec<thread::JoinHandle<()>>, // join handles for workers
}
impl<E: Endpoint, C: Callbacks, T: tun::Writer, B: bind::Writer<E>> Drop for Device<E, C, T, B> {
fn drop(&mut self) {
debug!("router: dropping device");
// drop all queues
{
let mut queues = self.state.queues.lock();
while queues.pop().is_some() {}
}
// join all worker threads
while match self.handles.pop() {
Some(handle) => {
handle.thread().unpark();
handle.join().unwrap();
true
}
_ => false,
} {}
debug!("router: device dropped");
}
}
impl<E: Endpoint, C: Callbacks, T: tun::Writer, B: bind::Writer<E>> Device<E, C, T, B> {
pub fn new(num_workers: usize, tun: T) -> Device<E, C, T, B> {
// allocate shared device state
let inner = DeviceInner {
inbound: tun,
outbound: RwLock::new((true, None)),
queues: Mutex::new(Vec::with_capacity(num_workers)),
queue_next: AtomicUsize::new(0),
recv: RwLock::new(HashMap::new()),
ipv4: RwLock::new(IpLookupTable::new()),
ipv6: RwLock::new(IpLookupTable::new()),
};
// start worker threads
let mut threads = Vec::with_capacity(num_workers);
for _ in 0..num_workers {
let (tx, rx) = sync_channel(WORKER_QUEUE_SIZE);
inner.queues.lock().push(tx);
threads.push(thread::spawn(move || worker_parallel(rx)));
}
// return exported device handle
Device {
state: Arc::new(inner),
handles: threads,
}
}
/// Brings the router down.
/// When the router is brought down it:
/// - Prevents transmission of outbound messages.
pub fn down(&self) {
self.state.outbound.write().0 = false;
}
/// Brints the router up
/// When the router is brought up it enables the transmission of outbound messages.
pub fn up(&self) {
self.state.outbound.write().0 = true;
}
/// A new secret key has been set for the device.
/// According to WireGuard semantics, this should cause all "sending" keys to be discarded.
pub fn new_sk(&self) {}
/// 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<E, C, T, B> {
new_peer(self.state.clone(), opaque)
}
/// Cryptkey routes and sends a plaintext message (IP packet)
///
/// # Arguments
///
/// - msg: IP packet to crypt-key route
///
pub fn send(&self, msg: Vec<u8>) -> Result<(), RouterError> {
debug_assert!(msg.len() > SIZE_MESSAGE_PREFIX);
log::trace!(
"Router, outbound packet = {}",
hex::encode(&msg[SIZE_MESSAGE_PREFIX..])
);
// 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 = get_route(&self.state, packet).ok_or(RouterError::NoCryptoKeyRoute)?;
// schedule for encryption and transmission to peer
if let Some(job) = peer.send_job(msg, true) {
// add job to worker queue
let idx = self.state.queue_next.fetch_add(1, Ordering::SeqCst);
let queues = self.state.queues.lock();
queues[idx % queues.len()].send(job).unwrap();
}
Ok(())
}
/// Receive an encrypted transport message
///
/// # Arguments
///
/// - src: Source address of the packet
/// - msg: Encrypted transport message
///
/// # Returns
///
///
pub fn recv(&self, src: E, msg: Vec<u8>) -> Result<(), RouterError> {
// parse / cast
let (header, _) = match LayoutVerified::new_from_prefix(&msg[..]) {
Some(v) => v,
None => {
return Err(RouterError::MalformedTransportMessage);
}
};
let header: LayoutVerified<&[u8], TransportHeader> = header;
debug_assert!(
header.f_type.get() == TYPE_TRANSPORT as u32,
"this should be checked by the message type multiplexer"
);
log::trace!(
"Router, handle transport message: (receiver = {}, counter = {})",
header.f_receiver,
header.f_counter
);
// lookup peer based on receiver id
let dec = self.state.recv.read();
let dec = dec
.get(&header.f_receiver.get())
.ok_or(RouterError::UnknownReceiverId)?;
// schedule for decryption and TUN write
if let Some(job) = dec.peer.recv_job(src, dec.clone(), msg) {
// add job to worker queue
let idx = self.state.queue_next.fetch_add(1, Ordering::SeqCst);
let queues = self.state.queues.lock();
queues[idx % queues.len()].send(job).unwrap();
}
Ok(())
}
/// Set outbound writer
///
///
pub fn set_outbound_writer(&self, new: B) {
self.state.outbound.write().1 = Some(new);
}
}

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@@ -22,7 +22,7 @@ use super::types::{Callbacks, RouterError};
use super::workers::{worker_parallel, JobParallel};
use super::SIZE_MESSAGE_PREFIX;
use super::route::get_route;
use super::route::RoutingTable;
use super::super::{bind, tun, Endpoint, KeyPair};
@@ -35,8 +35,7 @@ pub struct DeviceInner<E: Endpoint, C: Callbacks, T: tun::Writer, B: bind::Write
// routing
pub recv: RwLock<HashMap<u32, Arc<DecryptionState<E, C, T, B>>>>, // receiver id -> decryption state
pub ipv4: RwLock<IpLookupTable<Ipv4Addr, Arc<PeerInner<E, C, T, B>>>>, // ipv4 cryptkey routing
pub ipv6: RwLock<IpLookupTable<Ipv6Addr, Arc<PeerInner<E, C, T, B>>>>, // ipv6 cryptkey routing
pub table: RoutingTable<PeerInner<E, C, T, B>>,
// work queues
pub queue_next: AtomicUsize, // next round-robin index
@@ -95,8 +94,7 @@ impl<E: Endpoint, C: Callbacks, T: tun::Writer, B: bind::Writer<E>> Device<E, C,
queues: Mutex::new(Vec::with_capacity(num_workers)),
queue_next: AtomicUsize::new(0),
recv: RwLock::new(HashMap::new()),
ipv4: RwLock::new(IpLookupTable::new()),
ipv6: RwLock::new(IpLookupTable::new()),
table: RoutingTable::new(),
};
// start worker threads
@@ -157,7 +155,11 @@ impl<E: Endpoint, C: Callbacks, T: tun::Writer, B: bind::Writer<E>> Device<E, C,
let packet = &msg[SIZE_MESSAGE_PREFIX..];
// lookup peer based on IP packet destination address
let peer = get_route(&self.state, packet).ok_or(RouterError::NoCryptoKeyRoute)?;
let peer = self
.state
.table
.get_route(packet)
.ok_or(RouterError::NoCryptoKeyRoute)?;
// schedule for encryption and transmission to peer
if let Some(job) = peer.send_job(msg, true) {

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@@ -10,8 +10,6 @@ use std::thread;
use arraydeque::{ArrayDeque, Wrapping};
use log::debug;
use spin::Mutex;
use treebitmap::address::Address;
use treebitmap::IpLookupTable;
use super::super::constants::*;
use super::super::{bind, tun, Endpoint, KeyPair};
@@ -63,46 +61,6 @@ impl<E: Endpoint, C: Callbacks, T: tun::Writer, B: bind::Writer<E>> Deref for Pe
}
}
fn treebit_list<A, R, E: Endpoint, C: Callbacks, T: tun::Writer, B: bind::Writer<E>>(
peer: &Arc<PeerInner<E, C, T, B>>,
table: &spin::RwLock<IpLookupTable<A, Arc<PeerInner<E, C, T, B>>>>,
callback: Box<dyn Fn(A, u32) -> R>,
) -> Vec<R>
where
A: Address,
{
let mut res = Vec::new();
for subnet in table.read().iter() {
let (ip, masklen, p) = subnet;
if Arc::ptr_eq(&p, &peer) {
res.push(callback(ip, masklen))
}
}
res
}
fn treebit_remove<E: Endpoint, A: Address, C: Callbacks, T: tun::Writer, B: bind::Writer<E>>(
peer: &Peer<E, C, T, B>,
table: &spin::RwLock<IpLookupTable<A, Arc<PeerInner<E, C, T, B>>>>,
) {
let mut m = table.write();
// collect keys for value
let mut subnets = vec![];
for subnet in m.iter() {
let (ip, masklen, p) = subnet;
if Arc::ptr_eq(&p, &peer.state) {
subnets.push((ip, masklen))
}
}
// remove all key mappings
for (ip, masklen) in subnets {
let r = m.remove(ip, masklen);
debug_assert!(r.is_some());
}
}
impl EncryptionState {
fn new(keypair: &Arc<KeyPair>) -> EncryptionState {
EncryptionState {
@@ -134,8 +92,7 @@ impl<E: Endpoint, C: Callbacks, T: tun::Writer, B: bind::Writer<E>> Drop for Pee
// remove from cryptkey router
treebit_remove(self, &peer.device.ipv4);
treebit_remove(self, &peer.device.ipv6);
self.state.device.table.remove(peer);
// drop channels
@@ -560,23 +517,10 @@ impl<E: Endpoint, C: Callbacks, T: tun::Writer, B: bind::Writer<E>> Peer<E, C, T
/// If an identical value already exists as part of a prior peer,
/// the allowed IP entry will be removed from that peer and added to this peer.
pub fn add_allowed_ip(&self, ip: IpAddr, masklen: u32) {
debug!("peer.add_allowed_ips");
match ip {
IpAddr::V4(v4) => {
self.state
.device
.ipv4
.write()
.insert(v4.mask(masklen), masklen, self.state.clone())
}
IpAddr::V6(v6) => {
self.state
.device
.ipv6
.write()
.insert(v6.mask(masklen), masklen, self.state.clone())
}
};
self.state
.device
.table
.insert(ip, masklen, self.state.clone())
}
/// List subnets mapped to the peer
@@ -585,28 +529,14 @@ impl<E: Endpoint, C: Callbacks, T: tun::Writer, B: bind::Writer<E>> Peer<E, C, T
///
/// A vector of subnets, represented by as mask/size
pub fn list_allowed_ips(&self) -> Vec<(IpAddr, u32)> {
debug!("peer.list_allowed_ips");
let mut res = Vec::new();
res.append(&mut treebit_list(
&self.state,
&self.state.device.ipv4,
Box::new(|ip, masklen| (IpAddr::V4(ip), masklen)),
));
res.append(&mut treebit_list(
&self.state,
&self.state.device.ipv6,
Box::new(|ip, masklen| (IpAddr::V6(ip), masklen)),
));
res
self.state.device.table.list(&self.state)
}
/// Clear subnets mapped to the peer.
/// After the call, no subnets will be cryptkey routed to the peer.
/// Used for the UAPI command "replace_allowed_ips=true"
pub fn remove_allowed_ips(&self) {
debug!("peer.remove_allowed_ips");
treebit_remove(self, &self.state.device.ipv4);
treebit_remove(self, &self.state.device.ipv6);
self.state.device.table.remove(&self.state)
}
pub fn clear_src(&self) {

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@@ -1,113 +1,163 @@
use super::super::{bind, tun, Endpoint};
use super::device::DeviceInner;
use super::ip::*;
use super::peer::PeerInner;
use super::types::Callbacks;
use log::trace;
use zerocopy::LayoutVerified;
use std::mem;
use std::net::{Ipv4Addr, Ipv6Addr};
use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
use std::sync::Arc;
#[inline(always)]
pub fn get_route<E: Endpoint, C: Callbacks, T: tun::Writer, B: bind::Writer<E>>(
device: &Arc<DeviceInner<E, C, T, B>>,
packet: &[u8],
) -> Option<Arc<PeerInner<E, C, T, B>>> {
match packet.get(0)? >> 4 {
VERSION_IP4 => {
// check length and cast to IPv4 header
let (header, _): (LayoutVerified<&[u8], IPv4Header>, _) =
LayoutVerified::new_from_prefix(packet)?;
use spin::RwLock;
use treebitmap::address::Address;
use treebitmap::IpLookupTable;
log::trace!(
"Router, get route for IPv4 destination: {:?}",
Ipv4Addr::from(header.f_destination)
);
/* Functions for obtaining and validating "cryptokey" routes */
// check IPv4 source address
device
.ipv4
.read()
.longest_match(Ipv4Addr::from(header.f_destination))
.and_then(|(_, _, p)| Some(p.clone()))
}
VERSION_IP6 => {
// check length and cast to IPv6 header
let (header, _): (LayoutVerified<&[u8], IPv6Header>, _) =
LayoutVerified::new_from_prefix(packet)?;
log::trace!(
"Router, get route for IPv6 destination: {:?}",
Ipv6Addr::from(header.f_destination)
);
// check IPv6 source address
device
.ipv6
.read()
.longest_match(Ipv6Addr::from(header.f_destination))
.and_then(|(_, _, p)| Some(p.clone()))
}
_ => None,
}
pub struct RoutingTable<T> {
ipv4: RwLock<IpLookupTable<Ipv4Addr, Arc<T>>>,
ipv6: RwLock<IpLookupTable<Ipv6Addr, Arc<T>>>,
}
#[inline(always)]
pub fn check_route<E: Endpoint, C: Callbacks, T: tun::Writer, B: bind::Writer<E>>(
device: &Arc<DeviceInner<E, C, T, B>>,
peer: &Arc<PeerInner<E, C, T, B>>,
packet: &[u8],
) -> Option<usize> {
match packet.get(0)? >> 4 {
VERSION_IP4 => {
// check length and cast to IPv4 header
let (header, _): (LayoutVerified<&[u8], IPv4Header>, _) =
LayoutVerified::new_from_prefix(packet)?;
log::trace!(
"Router, check route for IPv4 source: {:?}",
Ipv4Addr::from(header.f_source)
);
// check IPv4 source address
device
.ipv4
.read()
.longest_match(Ipv4Addr::from(header.f_source))
.and_then(|(_, _, p)| {
if Arc::ptr_eq(p, peer) {
Some(header.f_total_len.get() as usize)
} else {
None
}
})
impl<T> RoutingTable<T> {
pub fn new() -> Self {
RoutingTable {
ipv4: RwLock::new(IpLookupTable::new()),
ipv6: RwLock::new(IpLookupTable::new()),
}
VERSION_IP6 => {
// check length and cast to IPv6 header
let (header, _): (LayoutVerified<&[u8], IPv6Header>, _) =
LayoutVerified::new_from_prefix(packet)?;
}
log::trace!(
"Router, check route for IPv6 source: {:?}",
Ipv6Addr::from(header.f_source)
);
// check IPv6 source address
device
.ipv6
.read()
.longest_match(Ipv6Addr::from(header.f_source))
.and_then(|(_, _, p)| {
if Arc::ptr_eq(p, peer) {
Some(header.f_len.get() as usize + mem::size_of::<IPv6Header>())
} else {
None
}
})
fn collect<A>(table: &IpLookupTable<A, Arc<T>>, value: &Arc<T>) -> Vec<(A, u32)>
where
A: Address,
{
let mut res = Vec::new();
for (ip, cidr, v) in table.iter() {
if Arc::ptr_eq(v, value) {
res.push((ip, cidr))
}
}
_ => None,
res
}
pub fn list(&self, value: &Arc<T>) -> Vec<(IpAddr, u32)> {
let mut res = vec![];
res.extend(
Self::collect(&*self.ipv4.read(), value)
.into_iter()
.map(|(ip, cidr)| (IpAddr::V4(ip), cidr)),
);
res.extend(
Self::collect(&*self.ipv6.read(), value)
.into_iter()
.map(|(ip, cidr)| (IpAddr::V6(ip), cidr)),
);
res
}
pub fn remove(&self, value: &Arc<T>) {
let mut v4 = self.ipv4.write();
let mut v6 = self.ipv6.write();
for (ip, cidr) in Self::collect(&*v4, value) {
v4.remove(ip, cidr);
}
for (ip, cidr) in Self::collect(&*v6, value) {
v6.remove(ip, cidr);
}
}
#[inline(always)]
pub fn get_route(&self, packet: &[u8]) -> Option<Arc<T>> {
match packet.get(0)? >> 4 {
VERSION_IP4 => {
// check length and cast to IPv4 header
let (header, _): (LayoutVerified<&[u8], IPv4Header>, _) =
LayoutVerified::new_from_prefix(packet)?;
log::trace!(
"Router, get route for IPv4 destination: {:?}",
Ipv4Addr::from(header.f_destination)
);
// check IPv4 source address
self.ipv4
.read()
.longest_match(Ipv4Addr::from(header.f_destination))
.and_then(|(_, _, p)| Some(p.clone()))
}
VERSION_IP6 => {
// check length and cast to IPv6 header
let (header, _): (LayoutVerified<&[u8], IPv6Header>, _) =
LayoutVerified::new_from_prefix(packet)?;
log::trace!(
"Router, get route for IPv6 destination: {:?}",
Ipv6Addr::from(header.f_destination)
);
// check IPv6 source address
self.ipv6
.read()
.longest_match(Ipv6Addr::from(header.f_destination))
.and_then(|(_, _, p)| Some(p.clone()))
}
_ => None,
}
}
#[inline(always)]
pub fn check_route(&self, peer: &Arc<T>, packet: &[u8]) -> Option<usize> {
match packet.get(0)? >> 4 {
VERSION_IP4 => {
// check length and cast to IPv4 header
let (header, _): (LayoutVerified<&[u8], IPv4Header>, _) =
LayoutVerified::new_from_prefix(packet)?;
log::trace!(
"Router, check route for IPv4 source: {:?}",
Ipv4Addr::from(header.f_source)
);
// check IPv4 source address
self.ipv4
.read()
.longest_match(Ipv4Addr::from(header.f_source))
.and_then(|(_, _, p)| {
if Arc::ptr_eq(p, peer) {
Some(header.f_total_len.get() as usize)
} else {
None
}
})
}
VERSION_IP6 => {
// check length and cast to IPv6 header
let (header, _): (LayoutVerified<&[u8], IPv6Header>, _) =
LayoutVerified::new_from_prefix(packet)?;
log::trace!(
"Router, check route for IPv6 source: {:?}",
Ipv6Addr::from(header.f_source)
);
// check IPv6 source address
self.ipv6
.read()
.longest_match(Ipv6Addr::from(header.f_source))
.and_then(|(_, _, p)| {
if Arc::ptr_eq(p, peer) {
Some(header.f_len.get() as usize + mem::size_of::<IPv6Header>())
} else {
None
}
})
}
_ => None,
}
}
pub fn insert(&self, ip: IpAddr, cidr: u32, value: Arc<T>) {
match ip {
IpAddr::V4(v4) => self.ipv4.write().insert(v4.mask(cidr), cidr, value),
IpAddr::V6(v6) => self.ipv6.write().insert(v6.mask(cidr), cidr, value),
};
}
}

View File

@@ -86,11 +86,11 @@ mod tests {
impl Callbacks for TestCallbacks {
type Opaque = Opaque;
fn send(t: &Self::Opaque, size: usize, sent: bool, keypair: &Arc<KeyPair>, counter: u64) {
fn send(t: &Self::Opaque, size: usize, sent: bool, _keypair: &Arc<KeyPair>, _counter: u64) {
t.0.send.lock().unwrap().push((size, sent))
}
fn recv(t: &Self::Opaque, size: usize, sent: bool, keypair: &Arc<KeyPair>) {
fn recv(t: &Self::Opaque, size: usize, sent: bool, _keypair: &Arc<KeyPair>) {
t.0.recv.lock().unwrap().push((size, sent))
}

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@@ -14,7 +14,6 @@ use zerocopy::{AsBytes, LayoutVerified};
use super::device::{DecryptionState, DeviceInner};
use super::messages::{TransportHeader, TYPE_TRANSPORT};
use super::peer::PeerInner;
use super::route::check_route;
use super::types::Callbacks;
use super::REJECT_AFTER_MESSAGES;
@@ -108,7 +107,8 @@ pub fn worker_inbound<E: Endpoint, C: Callbacks, T: tun::Writer, B: bind::Writer
// check if should be written to TUN
let mut sent = false;
if length > 0 {
if let Some(inner_len) = check_route(&device, &peer, &packet[..length]) {
if let Some(inner_len) = device.table.check_route(&peer, &packet[..length])
{
// TODO: Consider moving the cryptkey route check to parallel decryption worker
debug_assert!(inner_len <= length, "should be validated earlier");
if inner_len <= length {