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//! Tests for padding
// @@ 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_time_subtraction)]
#![allow(clippy::useless_vec)]
#![allow(clippy::needless_pass_by_value)]
#![allow(clippy::string_slice)] // See arti#2571
//! <!-- @@ end test lint list maintained by maint/add_warning @@ -->
use super::*;
use std::iter;
use async_trait::async_trait;
use futures::channel::mpsc;
use itertools::{Itertools, zip_eq};
#[cfg(feature = "relay")]
use safelog::Sensitive;
use tor_cell::chancell::msg::PaddingNegotiateCmd;
use tor_config::PaddingLevel;
use tor_linkspec::{HasRelayIds, OwnedChanTarget};
use tor_memquota::ArcMemoryQuotaTrackerExt as _;
use tor_netdir::NetDir;
use tor_proto::channel::{Channel, CtrlMsg};
use tor_proto::memquota::{ChannelAccount, ToplevelAccount};
use tor_rtcompat::{Runtime, test_with_all_runtimes};
use crate::ChannelUsage;
use crate::mgr::{AbstractChanMgr, AbstractChannelFactory};
use crate::factory::BootstrapReporter;
use PaddingLevel as PL;
const DEF_MS: [u32; 2] = [1500, 9500];
const REDUCED_MS: [u32; 2] = [9000, 14000];
const ADJ_MS: [u32; 2] = [1499, 9499];
const ADJ_REDUCED_MS: [u32; 2] = [8999, 13999];
/// Returns a NetDir that has consensus parameters as specified
fn some_interesting_netdir<'v, V>(values: V) -> Arc<NetDir>
where
V: IntoIterator<Item = (&'v str, i32)>,
{
tor_netdir::testnet::construct_custom_netdir_with_params(|_, _, _| {}, values, None)
.unwrap()
.unwrap_if_sufficient()
.into()
}
/// Returns a NetDir that has consensus parameters different from the protocol default
fn interesting_netdir() -> Arc<NetDir> {
some_interesting_netdir(
[
("nf_ito_low", ADJ_MS[0]),
("nf_ito_high", ADJ_MS[1]),
("nf_ito_low_reduced", ADJ_REDUCED_MS[0]),
("nf_ito_high_reduced", ADJ_REDUCED_MS[1]),
]
.into_iter()
.map(|(k, v)| (k, v as _)),
)
#[test]
fn padding_parameters_calculation() {
fn one(pconfig: PaddingLevel, netparams: &NetParamsExtract, exp: Option<[u32; 2]>) {
eprintln!(
"### {:?} {:?}",
&pconfig,
netparams.nf_ito.map(|l| l.map(|v| v.as_millis().get())),
);
let got = padding_parameters(pconfig, netparams).unwrap();
let exp = exp.map(|exp| {
PaddingParameters::builder()
.low(exp[0].into())
.high(exp[1].into())
.build()
});
assert_eq!(got, exp);
one(
PL::default(),
&NetParamsExtract::from(interesting_netdir().params()),
Some(ADJ_MS),
PL::Reduced,
Some(ADJ_REDUCED_MS),
let make_bogus_netdir = |values: &[(&str, i32)]| {
NetParamsExtract::from(
tor_netdir::testnet::construct_custom_netdir_with_params(
|_, _, _| {},
values.iter().cloned(),
None,
.params(),
};
let bogus_netdir = make_bogus_netdir(&[
// for testing low > high
("nf_ito_low", ADJ_REDUCED_MS[1] as _),
("nf_ito_high", ADJ_REDUCED_MS[0] as _),
]);
one(PL::default(), &bogus_netdir, Some(DEF_MS));
#[derive(Clone)]
struct FakeChannelFactory {
channel: Arc<Channel>,
#[async_trait]
impl AbstractChannelFactory for FakeChannelFactory {
type Channel = Channel;
type BuildSpec = tor_linkspec::OwnedChanTarget;
type Stream = ();
async fn build_channel(
&self,
_target: &Self::BuildSpec,
_reporter: BootstrapReporter,
_memquota: ChannelAccount,
) -> Result<Arc<Self::Channel>> {
Ok(self.channel.clone())
async fn build_channel_using_incoming(
_peer: Sensitive<std::net::SocketAddr>,
_stream: Self::Stream,
unimplemented!()
struct CaseContext {
recv: mpsc::UnboundedReceiver<CtrlMsg>,
chanmgr: AbstractChanMgr<FakeChannelFactory>,
netparams: Arc<dyn AsRef<NetParameters>>,
/// Details of an expected control message
#[derive(Debug, Clone, Default)]
struct Expected {
enabled: Option<bool>,
timing: Option<[u32; 2]>,
nego: Option<(PaddingNegotiateCmd, [u32; 2])>,
async fn case(
rt: &impl Runtime,
level: PaddingLevel,
dormancy: Dormancy,
usage: ChannelUsage,
) -> CaseContext {
let mut cconfig = ChannelConfig::builder();
cconfig.padding(level);
let cconfig = cconfig.build().unwrap();
eprintln!("\n---- {:?} {:?} {:?} ----", &cconfig, &dormancy, &usage);
let (channel, recv) =
Channel::new_fake(rt.clone(), tor_proto::channel::ChannelType::ClientInitiator);
let peer_id = channel.target().ed_identity().unwrap().clone();
let relay_ids = OwnedChanTarget::builder()
.ed_identity(peer_id.clone())
.unwrap();
let factory = FakeChannelFactory {
channel: Arc::new(channel),
let netparams = Arc::new(NetParameters::default());
let chanmgr = AbstractChanMgr::new(
factory,
cconfig,
dormancy,
&netparams,
BootstrapReporter::fake(),
ToplevelAccount::new_noop(),
let (channel, _prov) = chanmgr.get_or_launch(relay_ids, usage).await.unwrap();
CaseContext {
channel,
recv,
chanmgr,
netparams,
impl CaseContext {
fn netparams(&self) -> Arc<dyn AsRef<NetParameters>> {
self.netparams.clone()
fn expect_1(&mut self, exp: Expected) {
self.expect(vec![exp]);
fn expect_0(&mut self) {
self.expect(vec![]);
fn expect(&mut self, expected: Vec<Expected>) {
#[allow(deprecated)] // TODO(#2386)
let messages = iter::from_fn(|| match self.recv.try_next() {
Ok(Some(t)) => Some(Ok(t)),
Ok(None) => Some(Err(())),
Err(_) => None,
})
.collect_vec();
eprintln!("{:#?}", &messages);
for (i, (got, exp)) in zip_eq(messages, expected).enumerate() {
eprintln!("{} {:?} {:?}", i, got, exp);
let got: ChannelPaddingInstructionsUpdates = match got {
Ok(CtrlMsg::ConfigUpdate(u)) => (*u).clone(),
_ => panic!("wrong message {:?}", got),
let Expected {
enabled,
timing,
nego,
} = exp;
let nego =
nego.map(|(cmd, [low, high])| PaddingNegotiate::from_raw(cmd, low as _, high as _));
let timing = timing.map(|[low, high]| {
.low(low.into())
.high(high.into())
assert_eq!(got.padding_enable(), enabled.as_ref());
assert_eq!(got.padding_parameters(), timing.as_ref());
assert_eq!(got.padding_negotiate(), nego.as_ref());
/// Test padding control from the top of chanmgr through to just before the channel reactor
///
/// The rules about when to send padding and what negotiation cells to send are super complex.
/// Furthermore, our implementation is spread across several layers, mostly for performance
/// reasons (in particular, to do as much of the work centrally, in
/// the channel manager, as possible).
/// So here we test what happens if we call the various channel manager methods (the methods on
/// `AbstractChanMgr`, not `ChanMgr`, because our channel factory is strange, but the methods of
/// `ChanMgr` are simple passthroughs).
/// We observe the effect by pretending that we are the channel reactor, and reading out
/// the control messages. The channel reactor logic is very simple: it just does as it's
/// told. For example each PaddingNegotiation in a control message will be sent precisely
/// once (assuming it can be sent before the channel is closed or the next one arrives).
/// The timing parameters, and enablement, are passed directly to the padding timer.
fn padding_control_through_layer() {
test_with_all_runtimes!(padding_control_through_layer_impl);
/// Helper for padding_control_through_layer: takes a runtime as an argument.
async fn padding_control_through_layer_impl(rt: impl tor_rtcompat::Runtime) {
const STOP_MSG: (PaddingNegotiateCmd, [u32; 2]) = (PaddingNegotiateCmd::STOP, [0, 0]);
const START_CMD: PaddingNegotiateCmd = PaddingNegotiateCmd::START;
// ---- simple case, active exit, defaults ----
let mut c = case(
&rt,
Dormancy::Active,
ChannelUsage::UserTraffic,
.await;
c.expect_1(Expected {
enabled: Some(true),
timing: Some(DEF_MS),
nego: None,
// ---- reduced padding ----
timing: Some(REDUCED_MS),
nego: Some(STOP_MSG),
// ---- dormant ----
Dormancy::Dormant,
enabled: None,
timing: None,
// ---- more complicated evolution ----
let cconfig_reduced = {
cconfig.padding(PL::Reduced);
cconfig.build().unwrap()
let mut c = case(&rt, PL::default(), Dormancy::Active, ChannelUsage::Dir).await;
// directory circuits don't get padding (and we don't need to tell the peer to disable)
c.expect_0();
eprintln!("### UserTraffic ###");
c.channel.engage_padding_activities();
enabled: Some(true), // we now turn on our padding sender
timing: Some(DEF_MS), // with default parameters
nego: None, // the peer will start padding when it sees us do non-dir stuff
eprintln!("### set_dormancy - Dormant ###");
c.chanmgr
.set_dormancy(Dormancy::Dormant, c.netparams())
enabled: Some(false), // we now must turn off our padding sender
nego: Some(STOP_MSG), // and tell the peer to stop
eprintln!("### change to reduced padding while dormant ###");
.reconfigure(&cconfig_reduced, c.netparams())
eprintln!("### set_dormancy - Active ###");
.set_dormancy(Dormancy::Active, c.netparams())
nego: None, // don't enable inbound padding again
eprintln!("### imagine a netdir turns up, with some different parameters ###");
c.netparams = interesting_netdir();
c.chanmgr.update_netparams(c.netparams()).unwrap();
enabled: None, // still enabled
timing: Some(ADJ_REDUCED_MS), // parameters adjusted a bit
nego: None, // no need to send an update
eprintln!("### change back to normal padding ###");
.reconfigure(&ChannelConfig::default(), c.netparams())
timing: Some(ADJ_MS), // parameters adjusted
nego: Some((START_CMD, [0, 0])), // ask peer to use consensus default
eprintln!("### consensus changes to no padding ###");
// ---- consensus is no padding ----
c.netparams = some_interesting_netdir(
"nf_ito_low",
"nf_ito_high",
"nf_ito_low_reduced",
"nf_ito_high_reduced",
.map(|k| (k, 0)),
enabled: Some(false),
// Ideally we would somehow test the sending of a START message with nonzero parameters.
//
// However, that can only occur if we want the peer to send some padding which is not the
// consensus default. And we get our own desired parameters from our idea of the consensus:
// the config can only enable/disable/reduce (and for reduced, we ask our peer not to send
// padding at all).
// The only current arrangements for providing alternative parameters are via netdir overrides,
// which (because they override our view of the netdir) alter not only our idea of what to do,
// but also our idea of what our peer will do.
// Possibly at some future point we might support specifying padding parameters
// separately in the config.