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//! Experimental support for vanguards.
//!
//! For more information, see the [vanguards spec].
//!
//! [vanguards spec]: https://spec.torproject.org/vanguards-spec/index.html.
pub mod config;
mod set;
use std::sync::{Arc, RwLock, Weak};
use std::time::{Duration, SystemTime};
use futures::stream::BoxStream;
use futures::task::{SpawnError, SpawnExt as _};
use futures::{future, FutureExt as _};
use futures::{select_biased, StreamExt as _};
use rand::RngCore;
use tor_config::ReconfigureError;
use tor_error::{error_report, internal, into_internal, ErrorKind, HasKind};
use tor_netdir::{DirEvent, NetDir, NetDirProvider, Timeliness};
use tor_persist::{DynStorageHandle, StateMgr};
use tor_relay_selection::RelayExclusion;
use tor_rtcompat::Runtime;
use tracing::{debug, info};
use crate::{RetireCircuits, VanguardMode};
use set::VanguardSets;
pub use config::{VanguardConfig, VanguardConfigBuilder, VanguardParams};
pub use set::Vanguard;
/// The key used for storing the vanguard sets to persistent storage using `StateMgr`.
const STORAGE_KEY: &str = "vanguards";
/// The vanguard manager.
#[allow(unused)] // TODO HS-VANGUARDS
pub struct VanguardMgr<R: Runtime> {
/// The mutable state.
inner: RwLock<Inner>,
/// The runtime.
runtime: R,
/// The persistent storage handle, used for writing the vanguard sets to disk
/// if full vanguards are enabled.
storage: DynStorageHandle<VanguardSets>,
}
/// The mutable inner state of [`VanguardMgr`].
#[allow(unused)] // TODO HS-VANGUARDS
struct Inner {
/// The current vanguard parameters.
params: VanguardParams,
/// The L2 and L3 vanguards.
///
/// The L3 vanguards are only used if we are running in
/// [`Full`](VanguardMode::Full) vanguard mode.
/// Otherwise, the L3 set is not populated, or read from.
///
/// If [`Full`](VanguardMode::Full) vanguard mode is enabled,
/// the vanguard sets will be persisted to disk whenever
/// vanuards are rotated, added, or removed.
///
/// The vanguard sets are updated and persisted to storage by
/// [`update_vanguard_sets`](Inner::update_vanguard_sets).
///
/// If the `VanguardSets` change while we are in "lite" mode,
/// the changes will not *not* be written to storage.
/// If we later switch to "full" vanguards, those previous changes still
/// won't be persisted to storage: we only flush to storage if the
/// [`VanguardSets`] change *while* we are in "full" mode
/// (changing the [`VanguardMode`] does not consistute a change in the `VanguardSets`).
//
// TODO HS-VANGUARDS: the correct behaviour here might be to never switch back to lite mode
// after enabling full vanguards. If we do that, persisting the vanguard sets will be simpler,
// as we can just unconditionally flush to storage if the vanguard mode is switched to full.
// Right now we can't do that, because we don't remember the "mode":
// we derive it on the fly from `has_onion_svc` and the current `VanguardParams`.
//
///
/// This is initialized with the vanguard sets read from the vanguard state file,
/// if the file exists, or with a [`Default`] `VanguardSets`, if it doesn't.
///
/// Note: The `VanguardSets` are read from the vanguard state file
/// even if full vanguards are not enabled. They are *not*, however, written
/// to the state file unless full vanguards are in use.
vanguard_sets: VanguardSets,
/// Whether we're running an onion service.
///
/// Used for deciding whether to use the `vanguards_hs_service` or the
/// `vanguards_enabled` [`NetParameter`](tor_netdir::params::NetParameters).
has_onion_svc: bool,
}
/// Whether the [`VanguardMgr::maintain_vanguard_sets`] task
/// should continue running or shut down.
///
/// Returned from [`VanguardMgr::run_once`].
#[derive(Copy, Clone, Debug)]
enum ShutdownStatus {
/// Continue calling `run_once`.
Continue,
/// The `VanguardMgr` was dropped, terminate the task.
Terminate,
}
/// An error coming from the vanguards subsystem.
#[derive(Clone, Debug, thiserror::Error)]
#[non_exhaustive]
pub enum VanguardMgrError {
/// Could not find a suitable relay to use for the specifier layer.
#[error("No suitable relays")]
NoSuitableRelay(Layer),
/// Could not get timely network directory.
#[error("Unable to get timely network directory")]
NetDir(#[from] tor_netdir::Error),
/// Failed to access persistent storage.
#[error("Failed to access persistent vanguard state")]
State(#[from] tor_persist::Error),
/// Could not spawn a task.
#[error("Unable to spawn a task")]
Spawn(#[source] Arc<SpawnError>),
/// An internal error occurred.
#[error("Internal error")]
Bug(#[from] tor_error::Bug),
}
impl HasKind for VanguardMgrError {
fn kind(&self) -> ErrorKind {
match self {
// TODO HS-VANGUARDS: this is not right
VanguardMgrError::NoSuitableRelay(_) => ErrorKind::Other,
VanguardMgrError::NetDir(e) => e.kind(),
VanguardMgrError::State(e) => e.kind(),
VanguardMgrError::Spawn(e) => e.kind(),
VanguardMgrError::Bug(e) => e.kind(),
}
}
}
impl<R: Runtime> VanguardMgr<R> {
/// Create a new `VanguardMgr`.
///
/// The `state_mgr` handle is used for persisting the "vanguards-full" guard pools to disk.
#[allow(clippy::needless_pass_by_value)] // TODO HS-VANGUARDS
pub fn new<S>(
_config: &VanguardConfig,
runtime: R,
state_mgr: S,
has_onion_svc: bool,
) -> Result<Self, VanguardMgrError>
where
S: StateMgr + Send + Sync + 'static,
{
// Note: we start out with default vanguard params, but we adjust them
// as soon as we obtain a NetDir (see Self::run_once()).
let params = VanguardParams::default();
let storage: DynStorageHandle<VanguardSets> = state_mgr.create_handle(STORAGE_KEY);
let vanguard_sets = match storage.load()? {
Some(mut sets) => {
info!("Loading vanguards from vanguard state file");
// Discard the now-expired the vanguards
let now = runtime.wallclock();
let _ = sets.remove_expired(now);
sets
}
None => {
debug!("Vanguard state file not found, selecting new vanguards");
// Initially, all sets have a target size of 0.
// This is OK because the target is only used for repopulating the vanguard sets,
// and we can't repopulate the sets without a netdir.
// The target gets adjusted once we obtain a netdir.
Default::default()
}
};
let inner = Inner {
params,
vanguard_sets,
has_onion_svc,
};
Ok(Self {
inner: RwLock::new(inner),
runtime,
storage,
})
}
/// Launch the vanguard pool management tasks.
///
/// These run until the `VanguardMgr` is dropped.
//
// This spawns [`VanguardMgr::maintain_vanguard_sets`].
pub fn launch_background_tasks(
self: &Arc<Self>,
netdir_provider: &Arc<dyn NetDirProvider>,
) -> Result<(), VanguardMgrError>
where
R: Runtime,
{
let netdir_provider = Arc::clone(netdir_provider);
self.runtime
.spawn(Self::maintain_vanguard_sets(
Arc::downgrade(self),
Arc::downgrade(&netdir_provider),
))
.map_err(|e| VanguardMgrError::Spawn(Arc::new(e)))?;
Ok(())
}
/// Replace the configuration in this `VanguardMgr` with the specified `config`.
pub fn reconfigure(
&self,
_config: &VanguardConfig,
) -> Result<RetireCircuits, ReconfigureError> {
// TODO: there is no VanguardConfig.
// TODO: update has_onion_svc if the new config enables onion svc usage
//
// Perhaps we should always escalate to Full if we start running an onion service,
// but not decessarily downgrade to lite if we stop.
// See <https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/2083#note_3018173>
Ok(RetireCircuits::None)
}
/// Return a [`Vanguard`] relay for use in the specified layer.
///
/// The `neighbor_exclusion` must contain the relays that would neighbor this vanguard
/// in the path.
///
/// Specifically, it should contain
/// * the last relay in the path (the one immediately preceding the vanguard): the same relay
/// cannot be used in consecutive positions in the path (a relay won't let you extend the
/// circuit to itself).
/// * the penultimate relay of the path, if there is one: relays don't allow extending the
/// circuit to their previous hop
///
/// If [`Full`](VanguardMode::Full) vanguards are in use, this function can be used
/// for selecting both [`Layer2`](Layer::Layer2) and [`Layer3`](Layer::Layer3) vanguards.
///
/// If [`Lite`](VanguardMode::Lite) vanguards are in use, this function can only be used
/// for selecting [`Layer2`](Layer::Layer2) vanguards.
/// It will return an error if a [`Layer3`](Layer::Layer3) is requested.
///
/// Returns an error is vanguards are disabled.
///
/// ### Example
///
/// If the partially built path is of the form `G - L2` and we are selecting the L3 vanguard,
/// the `RelayExclusion` should contain `G` and `L2` (to prevent building a path of the form
/// `G - L2 - G`, or `G - L2 - L2`).
///
/// If the path only contains the L1 guard (`G`), then the `RelayExclusion` should only
/// exclude `G`.
pub fn select_vanguard<'a, Rng: RngCore>(
&self,
rng: &mut Rng,
netdir: &'a NetDir,
layer: Layer,
neighbor_exclusion: &RelayExclusion<'a>,
) -> Result<Vanguard<'a>, VanguardMgrError> {
use VanguardMode::*;
let inner = self.inner.read().expect("poisoned lock");
// TODO HS-VANGUARDS: code smell.
//
// If select_vanguards() is called before maintain_vanguard_sets() has obtained a netdir
// and populated the vanguard sets, this will return a NoSuitableRelay error (because all
// our vanguard sets are empty).
//
// However, in practice, I don't think this can ever happen, because we don't attempt to
// build paths until we're done bootstrapping.
//
// If it turns out this can actually happen in practice, we can work around it by calling
// inner.replenish_vanguards(&self.runtime, netdir)? here (using the netdir arg rather than
// the one we obtained ourselves), but at that point we might as well abolish the
// maintain_vanguard_sets task and do everything synchronously in this function...
// TODO HS-VANGUARDS: come up with something with better UX
let relay =
match (layer, inner.mode()) {
(Layer::Layer2, Full) | (Layer::Layer2, Lite) => inner
.vanguard_sets
.l2()
.pick_relay(rng, netdir, neighbor_exclusion),
(Layer::Layer3, Full) => {
inner
.vanguard_sets
.l3()
.pick_relay(rng, netdir, neighbor_exclusion)
}
// TODO HS-VANGUARDS: perhaps we need a dedicated error variant for this
_ => {
return Err(internal!(
"vanguards for layer {layer} are not supported in mode {})",
inner.mode()
)
.into())
}
};
relay.ok_or(VanguardMgrError::NoSuitableRelay(layer))
}
/// The vanguard set management task.
///
/// This is a background task that:
/// * removes vanguards from the L2 and L3 vanguard sets when they expire
/// * ensures the vanguard sets are repopulated with new vanguards
/// when the number of vanguards drops below a certain threshold
/// * handles `NetDir` changes, updating the vanguard set sizes as needed
async fn maintain_vanguard_sets(mgr: Weak<Self>, netdir_provider: Weak<dyn NetDirProvider>) {
let mut netdir_events = match netdir_provider.upgrade() {
Some(provider) => provider.events(),
None => {
return;
}
};
loop {
match Self::run_once(
Weak::clone(&mgr),
Weak::clone(&netdir_provider),
&mut netdir_events,
)
.await
{
Ok(ShutdownStatus::Continue) => continue,
Ok(ShutdownStatus::Terminate) => {
debug!("Vanguard manager is shutting down");
break;
}
Err(e) => {
error_report!(e, "Vanguard manager crashed");
break;
}
}
}
}
/// Wait until a vanguard expires or until there is a new [`NetDir`].
///
/// This populates the L2 and L3 vanguard sets,
/// and rotates the vanguards when their lifetime expires.
///
/// Note: the L3 set is only populated with vanguards if
/// [`Full`](VanguardMode::Full) vanguards are enabled.
async fn run_once(
mgr: Weak<Self>,
netdir_provider: Weak<dyn NetDirProvider>,
netdir_events: &mut BoxStream<'static, DirEvent>,
) -> Result<ShutdownStatus, VanguardMgrError> {
let (mgr, netdir_provider) = match (mgr.upgrade(), netdir_provider.upgrade()) {
(Some(mgr), Some(netdir_provider)) => (mgr, netdir_provider),
_ => return Ok(ShutdownStatus::Terminate),
};
let now = mgr.runtime.wallclock();
let next_to_expire = mgr.rotate_expired(&netdir_provider, now)?;
// A future that sleeps until the next vanguard expires
let sleep_fut = async {
if let Some(dur) = next_to_expire {
let () = mgr.runtime.sleep(dur).await;
} else {
future::pending::<()>().await;
}
};
select_biased! {
event = netdir_events.next().fuse() => {
if let Some(DirEvent::NewConsensus) = event {
let netdir = netdir_provider.netdir(Timeliness::Timely)?;
mgr.inner.write().expect("poisoned lock")
.update_vanguard_sets(&mgr.runtime, &mgr.storage, &netdir)?;
}
Ok(ShutdownStatus::Continue)
},
() = sleep_fut.fuse() => {
// A vanguard expired, time to run the cleanup
Ok(ShutdownStatus::Continue)
},
}
}
/// Return a timely `NetDir`, if one is available.
///
/// Returns `None` if no directory information is available.
fn timely_netdir(
netdir_provider: &Arc<dyn NetDirProvider>,
) -> Result<Option<Arc<NetDir>>, VanguardMgrError> {
use tor_netdir::Error as NetDirError;
match netdir_provider.netdir(Timeliness::Timely) {
Ok(netdir) => Ok(Some(netdir)),
Err(NetDirError::NoInfo) | Err(NetDirError::NotEnoughInfo) => Ok(None),
Err(e) => Err(e.into()),
}
}
/// Rotate the vanguards that have expired,
/// returning how long until the next vanguard will expire,
/// or `None` if there are no vanguards in any of our sets.
fn rotate_expired(
&self,
netdir_provider: &Arc<dyn NetDirProvider>,
now: SystemTime,
) -> Result<Option<Duration>, VanguardMgrError> {
info!("Rotating vanguards");
let mut inner = self.inner.write().expect("poisoned lock");
let inner = &mut *inner;
let vanguard_sets = &mut inner.vanguard_sets;
vanguard_sets.remove_expired(now);
if let Some(netdir) = Self::timely_netdir(netdir_provider)? {
// If we have a NetDir, replenish the vanguard sets that don't have enough vanguards.
inner.update_vanguard_sets(&self.runtime, &self.storage, &netdir)?;
}
let Some(expiry) = inner.vanguard_sets.next_expiry() else {
// Both vanguard sets are empty
return Ok(None);
};
expiry
.duration_since(now)
.map_err(|_| internal!("when > now, but now is later than when?!").into())
.map(Some)
}
/// Get the current [`VanguardMode`].
pub fn mode(&self) -> VanguardMode {
self.inner.read().expect("poisoned lock").mode()
}
}
impl Inner {
/// Update the vanguard sets, handling any potential vanguard parameter changes.
///
/// This updates the [`VanguardSets`]s based on the [`VanguardParams`]
/// derived from the new `NetDir`, replenishing the sets if necessary.
///
/// NOTE: if the new `VanguardParams` specify different lifetime ranges
/// than the previous `VanguardParams`, the new lifetime requirements only
/// apply to newly selected vanguards. They are **not** retroactively applied
/// to our existing vanguards.
//
// TODO(#1352): we might want to revisit this decision.
// We could, for example, adjust the lifetime of our existing vanguards
// to comply with the new lifetime requirements.
fn update_vanguard_sets<R: Runtime>(
&mut self,
runtime: &R,
storage: &DynStorageHandle<VanguardSets>,
netdir: &Arc<NetDir>,
) -> Result<(), VanguardMgrError> {
let params = VanguardParams::try_from(netdir.params())
.map_err(into_internal!("invalid NetParameters"))?;
// Update our params with the new values.
self.update_params(params.clone());
let mode = self.mode();
self.vanguard_sets.remove_unlisted(netdir);
// If we loaded some vanguards from persistent storage but we still need more,
// we select them here.
//
// If full vanguards are not enabled and we started with an empty (default)
// vanguard set, we populate the sets here.
//
// If we have already populated the vanguard sets in a previous iteration,
// this will ensure they have enough vanguards.
self.vanguard_sets
.replenish_vanguards(runtime, netdir, ¶ms, mode)?;
// Flush the vanguard sets to disk.
self.flush_to_storage(storage)?;
Ok(())
}
/// Update our vanguard params.
fn update_params(&mut self, new_params: VanguardParams) {
self.params = new_params;
}
/// Get the current [`VanguardMode`].
///
/// If we are not running an onion service, we use the `vanguards_enabled` mode.
///
/// If we *are* running an onion service, we use whichever of `vanguards_hs_service`
/// and `vanguards_enabled` is higher for all our onion service circuits.
fn mode(&self) -> VanguardMode {
if self.has_onion_svc {
std::cmp::max(
self.params.vanguards_enabled(),
self.params.vanguards_hs_service(),
)
} else {
self.params.vanguards_enabled()
}
}
/// Flush the vanguard sets to storage, if the mode is "vanguards-full".
#[allow(unused)] // TODO HS-VANGUARDS
fn flush_to_storage(
&self,
storage: &DynStorageHandle<VanguardSets>,
) -> Result<(), VanguardMgrError> {
match self.mode() {
VanguardMode::Lite | VanguardMode::Disabled => Ok(()),
VanguardMode::Full => {
debug!("The vanguards have changed; flushing vanguards to vanguard state file");
Ok(storage.store(&self.vanguard_sets)?)
}
}
}
}
/// The vanguard layer.
#[allow(unused)] // TODO HS-VANGUARDS
#[derive(Debug, Clone, Copy, PartialEq)] //
#[derive(derive_more::Display)] //
#[non_exhaustive]
pub enum Layer {
/// L2 vanguard.
#[display(fmt = "layer 2")]
Layer2,
/// L3 vanguard.
#[display(fmt = "layer 3")]
Layer3,
}
#[cfg(test)]
mod test {
// @@ begin test lint list maintained by maint/add_warning @@
#![allow(clippy::bool_assert_comparison)]
#![allow(clippy::clone_on_copy)]
#![allow(clippy::dbg_macro)]
#![allow(clippy::mixed_attributes_style)]
#![allow(clippy::print_stderr)]
#![allow(clippy::print_stdout)]
#![allow(clippy::single_char_pattern)]
#![allow(clippy::unwrap_used)]
#![allow(clippy::unchecked_duration_subtraction)]
#![allow(clippy::useless_vec)]
#![allow(clippy::needless_pass_by_value)]
//! <!-- @@ end test lint list maintained by maint/add_warning @@ -->
use std::fmt;
use set::TimeBoundVanguard;
use super::*;
use tor_basic_utils::test_rng::testing_rng;
use tor_linkspec::{HasRelayIds, RelayIds};
use tor_netdir::{
testnet::{self, construct_custom_netdir_with_params},
testprovider::TestNetDirProvider,
};
use tor_persist::TestingStateMgr;
use tor_rtmock::MockRuntime;
use Layer::*;
use itertools::Itertools;
/// Enable lite vanguards for onion services.
const ENABLE_LITE_VANGUARDS: [(&str, i32); 1] = [("vanguards-hs-service", 1)];
/// Enable full vanguards for hidden services.
const ENABLE_FULL_VANGUARDS: [(&str, i32); 1] = [("vanguards-hs-service", 2)];
impl fmt::Debug for Vanguard<'_> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_struct("Vanguard").finish()
}
}
impl Inner {
/// Return the L2 vanguard set.
pub(super) fn l2_vanguards(&self) -> &Vec<TimeBoundVanguard> {
self.vanguard_sets.l2_vanguards()
}
/// Return the L3 vanguard set.
pub(super) fn l3_vanguards(&self) -> &Vec<TimeBoundVanguard> {
self.vanguard_sets.l3_vanguards()
}
}
/// Create a new VanguardMgr for testing.
fn new_vanguard_mgr<R: Runtime>(rt: &R, has_onion_svc: bool) -> Arc<VanguardMgr<R>> {
let config = Default::default();
let statemgr = TestingStateMgr::new();
let lock = statemgr.try_lock().unwrap();
assert!(lock.held());
Arc::new(VanguardMgr::new(&config, rt.clone(), statemgr, has_onion_svc).unwrap())
}
/// Look up the vanguard in the specified VanguardSet.
fn find_in_set<R: Runtime>(
relay_ids: &RelayIds,
mgr: &VanguardMgr<R>,
layer: Layer,
) -> Option<TimeBoundVanguard> {
let inner = mgr.inner.read().unwrap();
let vanguards = match layer {
Layer2 => inner.l2_vanguards(),
Layer3 => inner.l3_vanguards(),
};
// Look up the TimeBoundVanguard that corresponds to this Vanguard,
// and figure out its expiry.
vanguards.iter().find(|v| v.id == *relay_ids).cloned()
}
/// Get the total number of vanguard entries (L2 + L3).
fn vanguard_count<R: Runtime>(mgr: &VanguardMgr<R>) -> usize {
let inner = mgr.inner.read().unwrap();
inner.l2_vanguards().len() + inner.l3_vanguards().len()
}
/// Return a `Duration` representing how long until this vanguard expires.
fn duration_until_expiry<R: Runtime>(
relay_ids: &RelayIds,
mgr: &VanguardMgr<R>,
runtime: &R,
layer: Layer,
) -> Duration {
// Look up the TimeBoundVanguard that corresponds to this Vanguard,
// and figure out its expiry.
let vanguard = find_in_set(relay_ids, mgr, layer).unwrap();
vanguard
.when
.duration_since(runtime.wallclock())
.unwrap_or_default()
}
/// Assert the lifetime of the specified `vanguard` is within the bounds of its `layer`.
fn assert_expiry_in_bounds<R: Runtime>(
vanguard: &Vanguard<'_>,
mgr: &VanguardMgr<R>,
runtime: &R,
params: &VanguardParams,
layer: Layer,
) {
let (min, max) = match layer {
Layer2 => (params.l2_lifetime_min(), params.l2_lifetime_max()),
Layer3 => (params.l3_lifetime_min(), params.l3_lifetime_max()),
};
let vanguard = RelayIds::from_relay_ids(vanguard.relay());
// This is not exactly the lifetime of the vanguard,
// but rather the time left until it expires (but it's close enough for our purposes).
let lifetime = duration_until_expiry(&vanguard, mgr, runtime, layer);
assert!(
lifetime >= min && lifetime <= max,
"lifetime {lifetime:?} not between {min:?} and {max:?}",
);
}
/// Assert that the vanguard manager's pools are empty.
fn assert_sets_empty<R: Runtime>(vanguardmgr: &VanguardMgr<R>) {
let inner = vanguardmgr.inner.read().unwrap();
// The sets are initially empty, and the targets are set to 0
assert_eq!(inner.vanguard_sets.l2_vanguards_deficit(), 0);
assert_eq!(inner.vanguard_sets.l3_vanguards_deficit(), 0);
assert_eq!(vanguard_count(vanguardmgr), 0);
}
/// Assert that the vanguard manager's pools have been filled.
fn assert_sets_filled<R: Runtime>(vanguardmgr: &VanguardMgr<R>, params: &VanguardParams) {
let inner = vanguardmgr.inner.read().unwrap();
let l2_pool_size = params.l2_pool_size();
// The sets are initially empty
assert_eq!(inner.vanguard_sets.l2_vanguards_deficit(), 0);
if inner.mode() == VanguardMode::Full {
assert_eq!(inner.vanguard_sets.l3_vanguards_deficit(), 0);
let l3_pool_size = params.l3_pool_size();
assert_eq!(vanguard_count(vanguardmgr), l2_pool_size + l3_pool_size);
}
}
/// Assert the target size of the specified vanguard set matches the target from `params`.
fn assert_set_vanguards_targets_match_params<R: Runtime>(
mgr: &VanguardMgr<R>,
params: &VanguardParams,
) {
let inner = mgr.inner.read().unwrap();
assert_eq!(
inner.vanguard_sets.l2_vanguards_target(),
params.l2_pool_size()
);
if inner.mode() == VanguardMode::Full {
assert_eq!(
inner.vanguard_sets.l3_vanguards_target(),
params.l3_pool_size()
);
}
}
/// Wait until the vanguardmgr has populated its vanguard sets.
async fn init_vanguard_sets(
runtime: MockRuntime,
netdir: NetDir,
vanguardmgr: Arc<VanguardMgr<MockRuntime>>,
) -> Arc<TestNetDirProvider> {
let netdir_provider = Arc::new(TestNetDirProvider::new());
vanguardmgr
.launch_background_tasks(&(netdir_provider.clone() as Arc<dyn NetDirProvider>))
.unwrap();
runtime.progress_until_stalled().await;
// Call set_netdir_and_notify to trigger an event
netdir_provider
.set_netdir_and_notify(Arc::new(netdir.clone()))
.await;
// Wait until the vanguard mgr has finished handling the netdir event.
runtime.progress_until_stalled().await;
netdir_provider
}
#[test]
fn full_vanguards_disabled() {
MockRuntime::test_with_various(|rt| async move {
let vanguardmgr = new_vanguard_mgr(&rt, false);
let netdir = testnet::construct_netdir().unwrap_if_sufficient().unwrap();
let mut rng = testing_rng();
let exclusion = RelayExclusion::no_relays_excluded();
// Cannot select an L3 vanguard when running in "Lite" mode.
let err = vanguardmgr
.select_vanguard(&mut rng, &netdir, Layer3, &exclusion)
.unwrap_err();
assert!(matches!(err, VanguardMgrError::Bug(_)), "{err:?}");
});
}
#[test]
fn background_task_not_spawned() {
MockRuntime::test_with_various(|rt| async move {
let vanguardmgr = new_vanguard_mgr(&rt, false);
let netdir = testnet::construct_netdir().unwrap_if_sufficient().unwrap();
let mut rng = testing_rng();
let exclusion = RelayExclusion::no_relays_excluded();
// The sets are initially empty
assert_sets_empty(&vanguardmgr);
// VanguardMgr::launch_background tasks was not called, so select_vanguard will return
// an error (because the vanguard sets are empty)
let err = vanguardmgr
.select_vanguard(&mut rng, &netdir, Layer2, &exclusion)
.unwrap_err();
assert!(
matches!(err, VanguardMgrError::NoSuitableRelay(Layer2)),
"{err:?}"
);
});
}
#[test]
fn select_vanguards() {
MockRuntime::test_with_various(|rt| async move {
let vanguardmgr = new_vanguard_mgr(&rt, true);
let netdir = testnet::construct_netdir().unwrap_if_sufficient().unwrap();
let params = VanguardParams::try_from(netdir.params()).unwrap();
let mut rng = testing_rng();
let exclusion = RelayExclusion::no_relays_excluded();
// The sets are initially empty
assert_sets_empty(&vanguardmgr);
// Wait until the vanguard manager has bootstrapped
let _netdir_provider =
init_vanguard_sets(rt.clone(), netdir.clone(), Arc::clone(&vanguardmgr)).await;
assert_sets_filled(&vanguardmgr, ¶ms);
let vanguard1 = vanguardmgr
.select_vanguard(&mut rng, &netdir, Layer2, &exclusion)
.unwrap();
assert_expiry_in_bounds(&vanguard1, &vanguardmgr, &rt, ¶ms, Layer2);
let exclusion = RelayExclusion::exclude_identities(
vanguard1
.relay()
.identities()
.map(|id| id.to_owned())
.collect(),
);
let vanguard2 = vanguardmgr
.select_vanguard(&mut rng, &netdir, Layer3, &exclusion)
.unwrap();
assert_expiry_in_bounds(&vanguard2, &vanguardmgr, &rt, ¶ms, Layer3);
// Ensure we didn't select the same vanguard twice
assert_ne!(
vanguard1.relay().identities().collect_vec(),
vanguard2.relay().identities().collect_vec()
);
});
}
/// Override the vanguard params from the netdir, returning the new VanguardParams.
///
/// This also waits until the vanguard manager has had a chance to process the changes.
async fn install_new_params(
rt: &MockRuntime,
netdir_provider: &TestNetDirProvider,
params: impl IntoIterator<Item = (&str, i32)>,
) -> VanguardParams {
let new_netdir = testnet::construct_custom_netdir_with_params(|_, _| {}, params, None)
.unwrap()
.unwrap_if_sufficient()
.unwrap();
let new_params = VanguardParams::try_from(new_netdir.params()).unwrap();
netdir_provider.set_netdir_and_notify(new_netdir).await;
// Wait until the vanguard mgr has finished handling the new netdir.
rt.progress_until_stalled().await;
new_params
}
/// Switch the vanguard "mode" of the VanguardMgr to `mode`,
/// by setting the vanguards-hs-service parameter.
async fn switch_hs_mode(
rt: &MockRuntime,
vanguardmgr: &VanguardMgr<MockRuntime>,
netdir_provider: &TestNetDirProvider,
mode: VanguardMode,
) {
use VanguardMode::*;
let _params = match mode {
Lite => install_new_params(rt, netdir_provider, ENABLE_LITE_VANGUARDS).await,
Full => install_new_params(rt, netdir_provider, ENABLE_FULL_VANGUARDS).await,
Disabled => panic!("cannot disable vanguards in the vanguard tests!"),
};
assert_eq!(vanguardmgr.mode(), mode);
}
/// Use a new NetDir that excludes one of our L2 vanguards
async fn install_netdir_excluding_vanguard<'a>(
runtime: &MockRuntime,
vanguard: &Vanguard<'_>,
params: impl IntoIterator<Item = (&'a str, i32)>,
netdir_provider: &TestNetDirProvider,
) -> NetDir {
let new_netdir = construct_custom_netdir_with_params(
|_idx, bld| {
let md_so_far = bld.md.testing_md().unwrap();
if md_so_far.ed25519_id() == vanguard.relay().id() {
bld.omit_rs = true;
}
},
params,
None,
)
.unwrap()
.unwrap_if_sufficient()
.unwrap();
netdir_provider
.set_netdir_and_notify(new_netdir.clone())
.await;
// Wait until the vanguard mgr has finished handling the new netdir.
runtime.progress_until_stalled().await;
new_netdir
}
#[test]
fn override_vanguard_set_size() {
MockRuntime::test_with_various(|rt| async move {
let vanguardmgr = new_vanguard_mgr(&rt, false);
let netdir = testnet::construct_netdir().unwrap_if_sufficient().unwrap();
// Wait until the vanguard manager has bootstrapped
let netdir_provider =
init_vanguard_sets(rt.clone(), netdir.clone(), Arc::clone(&vanguardmgr)).await;
let params = VanguardParams::try_from(netdir.params()).unwrap();
let old_size = params.l2_pool_size();
assert_set_vanguards_targets_match_params(&vanguardmgr, ¶ms);
const PARAMS: [[(&str, i32); 2]; 2] = [
[("guard-hs-l2-number", 1), ("guard-hs-l3-number", 10)],
[("guard-hs-l2-number", 10), ("guard-hs-l3-number", 10)],
];
for params in PARAMS {
let new_params = install_new_params(&rt, &netdir_provider, params).await;
// Ensure the target size was updated.
assert_set_vanguards_targets_match_params(&vanguardmgr, &new_params);
{
let inner = vanguardmgr.inner.read().unwrap();
let l2_vanguards = inner.l2_vanguards();
let l3_vanguards = inner.l3_vanguards();
let new_l2_size = params[0].1 as usize;
if new_l2_size < old_size {
// The actual size of the set hasn't changed: it's OK to have more vanguards than
// needed in the set (they extraneous ones will eventually expire).
assert_eq!(l2_vanguards.len(), old_size);
} else {
// The new size is greater, so we have more L2 vanguards now.
assert_eq!(l2_vanguards.len(), new_l2_size);
}
// There are no L3 vanguards because full vanguards are not in use.
assert_eq!(l3_vanguards.len(), 0);
}
}
});
}
#[test]
fn expire_vanguards() {
MockRuntime::test_with_various(|rt| async move {
let vanguardmgr = new_vanguard_mgr(&rt, false);
let netdir = testnet::construct_netdir().unwrap_if_sufficient().unwrap();
let params = VanguardParams::try_from(netdir.params()).unwrap();
let initial_l2_number = params.l2_pool_size();
// Wait until the vanguard manager has bootstrapped
let netdir_provider =
init_vanguard_sets(rt.clone(), netdir.clone(), Arc::clone(&vanguardmgr)).await;
assert_eq!(vanguard_count(&vanguardmgr), params.l2_pool_size());
// Find the RelayIds of the vanguard that is due to expire next
let vanguard_id = {
let inner = vanguardmgr.inner.read().unwrap();
let next_expiry = inner.vanguard_sets.next_expiry().unwrap();
inner
.l2_vanguards()
.iter()
.find(|v| v.when == next_expiry)
.cloned()
.unwrap()
.id
};
const FEWER_VANGUARDS_PARAM: [(&str, i32); 1] = [("guard-hs-l2-number", 1)];
// Set the number of L2 vanguards to a lower value to ensure the vanguard that is about
// to expire is not replaced. This allows us to test that it has indeed expired
// (we can't simply check that the relay is no longer is the set,
// because it's possible for the set to get replenished with the same relay).
let new_params = install_new_params(&rt, &netdir_provider, FEWER_VANGUARDS_PARAM).await;
// The vanguard has not expired yet.
let timebound_vanguard = find_in_set(&vanguard_id, &vanguardmgr, Layer2);
assert!(timebound_vanguard.is_some());
assert_eq!(vanguard_count(&vanguardmgr), initial_l2_number);
let lifetime = duration_until_expiry(&vanguard_id, &vanguardmgr, &rt, Layer2);
// Wait until this vanguard expires
rt.advance_by(lifetime).await.unwrap();
rt.progress_until_stalled().await;
let timebound_vanguard = find_in_set(&vanguard_id, &vanguardmgr, Layer2);
// The vanguard expired, but was not replaced.
assert!(timebound_vanguard.is_none());
assert_eq!(vanguard_count(&vanguardmgr), initial_l2_number - 1);
// Wait until more vanguards expire. This will reduce the set size to 1
// (the new target size we set by overriding the params).
for _ in 0..initial_l2_number - 1 {
let vanguard_id = {
let inner = vanguardmgr.inner.read().unwrap();
let next_expiry = inner.vanguard_sets.next_expiry().unwrap();
inner
.l2_vanguards()
.iter()
.find(|v| v.when == next_expiry)
.cloned()
.unwrap()
.id
};
let lifetime = duration_until_expiry(&vanguard_id, &vanguardmgr, &rt, Layer2);
rt.advance_by(lifetime).await.unwrap();
rt.progress_until_stalled().await;
}
assert_eq!(vanguard_count(&vanguardmgr), new_params.l2_pool_size());
// Update the L2 set size again, to force the vanguard manager to replenish the L2 set.
const MORE_VANGUARDS_PARAM: [(&str, i32); 1] = [("guard-hs-l2-number", 5)];
// Set the number of L2 vanguards to a lower value to ensure the vanguard that is about
// to expire is not replaced. This allows us to test that it has indeed expired
// (we can't simply check that the relay is no longer is the set,
// because it's possible for the set to get replenished with the same relay).
let new_params = install_new_params(&rt, &netdir_provider, MORE_VANGUARDS_PARAM).await;
// Check that we replaced the expired vanguard with a new one:
assert_eq!(vanguard_count(&vanguardmgr), new_params.l2_pool_size());
{
let inner = vanguardmgr.inner.read().unwrap();
let l2_count = inner.l2_vanguards().len();
assert_eq!(l2_count, new_params.l2_pool_size());
}
});
}
#[test]
fn full_vanguards_persistence() {
MockRuntime::test_with_various(|rt| async move {
let vanguardmgr = new_vanguard_mgr(&rt, true);
let netdir =
construct_custom_netdir_with_params(|_, _| {}, ENABLE_LITE_VANGUARDS, None)
.unwrap()
.unwrap_if_sufficient()
.unwrap();
let netdir_provider =
init_vanguard_sets(rt.clone(), netdir.clone(), Arc::clone(&vanguardmgr)).await;
// Full vanguards are not enabled, so we don't expect anything to be written
// to persistent storage.
assert_eq!(vanguardmgr.mode(), VanguardMode::Lite);
assert!(vanguardmgr.storage.load().unwrap().is_none());
let mut rng = testing_rng();
let exclusion = RelayExclusion::no_relays_excluded();
assert!(vanguardmgr
.select_vanguard(&mut rng, &netdir, Layer3, &exclusion)
.is_err());
// Enable full vanguards again.
//
// We expect VanguardMgr to populate the L3 set, and write the VanguardSets to storage.
switch_hs_mode(&rt, &vanguardmgr, &netdir_provider, VanguardMode::Full).await;
let vanguard_sets_orig = vanguardmgr.storage.load().unwrap();
assert!(vanguardmgr
.select_vanguard(&mut rng, &netdir, Layer3, &exclusion)
.is_ok());
// Switch to lite vanguards.
switch_hs_mode(&rt, &vanguardmgr, &netdir_provider, VanguardMode::Lite).await;
// The vanguard sets should not change when switching between lite and full vanguards.
assert_eq!(vanguard_sets_orig, vanguardmgr.storage.load().unwrap());
switch_hs_mode(&rt, &vanguardmgr, &netdir_provider, VanguardMode::Full).await;
assert_eq!(vanguard_sets_orig, vanguardmgr.storage.load().unwrap());
// TODO HS-VANGUARDS: we may want to disable the ability to switch back to lite
// vanguards.
// Switch to lite vanguards and remove a relay from the consensus.
// The relay should *not* be persisted to storage until we switch back to full
// vanguards.
switch_hs_mode(&rt, &vanguardmgr, &netdir_provider, VanguardMode::Lite).await;
let mut rng = testing_rng();
let exclusion = RelayExclusion::no_relays_excluded();
let excluded_vanguard = vanguardmgr
.select_vanguard(&mut rng, &netdir, Layer2, &exclusion)
.unwrap();
let _ = install_netdir_excluding_vanguard(
&rt,
&excluded_vanguard,
ENABLE_LITE_VANGUARDS,
&netdir_provider,
)
.await;
// The vanguard sets from storage haven't changed, because we are in "lite" mode.
assert_eq!(vanguard_sets_orig, vanguardmgr.storage.load().unwrap());
let _ = install_netdir_excluding_vanguard(
&rt,
&excluded_vanguard,
ENABLE_FULL_VANGUARDS,
&netdir_provider,
)
.await;
});
}
}