diff --git a/polkadot/xcm/xcm-builder/src/tests/barriers.rs b/polkadot/xcm/xcm-builder/src/tests/barriers.rs
index 99a9dd5a6609fe59e5e5ac6af073d8031c41c14c..6516263f57a0936b45171ca262f4001b4315ee95 100644
--- a/polkadot/xcm/xcm-builder/src/tests/barriers.rs
+++ b/polkadot/xcm/xcm-builder/src/tests/barriers.rs
@@ -309,3 +309,62 @@ fn suspension_should_work() {
);
assert_eq!(r, Ok(()));
}
+
+#[test]
+fn allow_subscriptions_from_should_work() {
+ // allow only parent
+ AllowSubsFrom::set(vec![Location::parent()]);
+
+ let valid_xcm_1 = Xcm::<TestCall>(vec![SubscribeVersion {
+ query_id: 42,
+ max_response_weight: Weight::from_parts(5000, 5000),
+ }]);
+ let valid_xcm_2 = Xcm::<TestCall>(vec![UnsubscribeVersion]);
+ let invalid_xcm_1 = Xcm::<TestCall>(vec![
+ SetAppendix(Xcm(vec![])),
+ SubscribeVersion { query_id: 42, max_response_weight: Weight::from_parts(5000, 5000) },
+ ]);
+ let invalid_xcm_2 = Xcm::<TestCall>(vec![
+ SubscribeVersion { query_id: 42, max_response_weight: Weight::from_parts(5000, 5000) },
+ SetTopic([0; 32]),
+ ]);
+
+ let test_data = vec![
+ (
+ valid_xcm_1.clone(),
+ Parachain(1).into_location(),
+ // not allowed origin
+ Err(ProcessMessageError::Unsupported),
+ ),
+ (valid_xcm_1, Location::parent(), Ok(())),
+ (
+ valid_xcm_2.clone(),
+ Parachain(1).into_location(),
+ // not allowed origin
+ Err(ProcessMessageError::Unsupported),
+ ),
+ (valid_xcm_2, Location::parent(), Ok(())),
+ (
+ invalid_xcm_1,
+ Location::parent(),
+ // invalid XCM
+ Err(ProcessMessageError::BadFormat),
+ ),
+ (
+ invalid_xcm_2,
+ Location::parent(),
+ // invalid XCM
+ Err(ProcessMessageError::BadFormat),
+ ),
+ ];
+
+ for (mut message, origin, expected_result) in test_data {
+ let r = AllowSubscriptionsFrom::<IsInVec<AllowSubsFrom>>::should_execute(
+ &origin,
+ message.inner_mut(),
+ Weight::from_parts(10, 10),
+ &mut props(Weight::zero()),
+ );
+ assert_eq!(r, expected_result, "Failed for origin: {origin:?} and message: {message:?}");
+ }
+}
diff --git a/polkadot/xcm/xcm-builder/src/tests/mod.rs b/polkadot/xcm/xcm-builder/src/tests/mod.rs
index e11caf6282be70314d4245a413194f41c7e1082f..63d254a1067582d3359c6a7dc1b27102bd1e45e7 100644
--- a/polkadot/xcm/xcm-builder/src/tests/mod.rs
+++ b/polkadot/xcm/xcm-builder/src/tests/mod.rs
@@ -36,6 +36,7 @@ mod locking;
mod origins;
mod pay;
mod querying;
+mod routing;
mod transacting;
mod version_subscriptions;
mod weight;
diff --git a/polkadot/xcm/xcm-builder/src/tests/routing.rs b/polkadot/xcm/xcm-builder/src/tests/routing.rs
new file mode 100644
index 0000000000000000000000000000000000000000..28117d647a086907dc490217d02d6cbd612c7b88
--- /dev/null
+++ b/polkadot/xcm/xcm-builder/src/tests/routing.rs
@@ -0,0 +1,95 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Polkadot is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Polkadot. If not, see <http://www.gnu.org/licenses/>.
+
+use super::*;
+use frame_support::{assert_ok, traits::Everything};
+use xcm_executor::traits::Properties;
+
+fn props() -> Properties {
+ Properties { weight_credit: Weight::zero(), message_id: None }
+}
+
+#[test]
+fn trailing_set_topic_as_id_with_unique_topic_should_work() {
+ type AllowSubscriptions = AllowSubscriptionsFrom<Everything>;
+
+ // check the validity of XCM for the `AllowSubscriptions` barrier
+ let valid_xcm = Xcm::<()>(vec![SubscribeVersion {
+ query_id: 42,
+ max_response_weight: Weight::from_parts(5000, 5000),
+ }]);
+ assert_eq!(
+ AllowSubscriptions::should_execute(
+ &Location::parent(),
+ valid_xcm.clone().inner_mut(),
+ Weight::from_parts(10, 10),
+ &mut props(),
+ ),
+ Ok(())
+ );
+
+ // simulate sending `valid_xcm` with the `WithUniqueTopic` router
+ let mut sent_xcm = sp_io::TestExternalities::default().execute_with(|| {
+ assert_ok!(send_xcm::<WithUniqueTopic<TestMessageSender>>(Location::parent(), valid_xcm,));
+ sent_xcm()
+ });
+ assert_eq!(1, sent_xcm.len());
+
+ // `sent_xcm` should contain `SubscribeVersion` and have `SetTopic` added
+ let mut sent_xcm = sent_xcm.remove(0).1;
+ let _ = sent_xcm
+ .0
+ .matcher()
+ .assert_remaining_insts(2)
+ .expect("two instructions")
+ .match_next_inst(|instr| match instr {
+ SubscribeVersion { .. } => Ok(()),
+ _ => Err(ProcessMessageError::BadFormat),
+ })
+ .expect("expected instruction `SubscribeVersion`")
+ .match_next_inst(|instr| match instr {
+ SetTopic(..) => Ok(()),
+ _ => Err(ProcessMessageError::BadFormat),
+ })
+ .expect("expected instruction `SetTopic`");
+
+ // `sent_xcm` contains `SetTopic` and is now invalid for `AllowSubscriptions`
+ assert_eq!(
+ AllowSubscriptions::should_execute(
+ &Location::parent(),
+ sent_xcm.clone().inner_mut(),
+ Weight::from_parts(10, 10),
+ &mut props(),
+ ),
+ Err(ProcessMessageError::BadFormat)
+ );
+
+ // let's apply `TrailingSetTopicAsId` before `AllowSubscriptions`
+ let mut props = props();
+ assert!(props.message_id.is_none());
+
+ // should pass, and the `message_id` is set
+ assert_eq!(
+ TrailingSetTopicAsId::<AllowSubscriptions>::should_execute(
+ &Location::parent(),
+ sent_xcm.clone().inner_mut(),
+ Weight::from_parts(10, 10),
+ &mut props,
+ ),
+ Ok(())
+ );
+ assert!(props.message_id.is_some());
+}
diff --git a/polkadot/xcm/xcm-builder/src/tests/version_subscriptions.rs b/polkadot/xcm/xcm-builder/src/tests/version_subscriptions.rs
index e29e3a546615b3aa725d30418e2e173fe67db920..01047fde989f9720f410c9067bf3bffd3cac9880 100644
--- a/polkadot/xcm/xcm-builder/src/tests/version_subscriptions.rs
+++ b/polkadot/xcm/xcm-builder/src/tests/version_subscriptions.rs
@@ -27,16 +27,32 @@ fn simple_version_subscriptions_should_work() {
]);
let mut hash = fake_message_hash(&message);
let weight_limit = Weight::from_parts(20, 20);
- let r = XcmExecutor::<TestConfig>::prepare_and_execute(
- origin,
- message,
- &mut hash,
- weight_limit,
- Weight::zero(),
+
+ // this case fails because the origin is not allowed
+ assert_eq!(
+ XcmExecutor::<TestConfig>::prepare_and_execute(
+ origin,
+ message.clone(),
+ &mut hash,
+ weight_limit,
+ Weight::zero(),
+ ),
+ Outcome::Error { error: XcmError::Barrier }
+ );
+
+ // this case fails because the additional `SetAppendix` instruction is not allowed in the
+ // `AllowSubscriptionsFrom`
+ assert_eq!(
+ XcmExecutor::<TestConfig>::prepare_and_execute(
+ Parent,
+ message,
+ &mut hash,
+ weight_limit,
+ Weight::zero(),
+ ),
+ Outcome::Error { error: XcmError::Barrier }
);
- assert_eq!(r, Outcome::Error { error: XcmError::Barrier });
- let origin = Parachain(1000);
let message = Xcm::<TestCall>(vec![SubscribeVersion {
query_id: 42,
max_response_weight: Weight::from_parts(5000, 5000),
diff --git a/polkadot/xcm/xcm-executor/src/traits/should_execute.rs b/polkadot/xcm/xcm-executor/src/traits/should_execute.rs
index 12e8fd6b87f1004da2da250a62cf7480bbb178af..e76d56bfe6164d16487f65ed79c1a1a58a9949fe 100644
--- a/polkadot/xcm/xcm-executor/src/traits/should_execute.rs
+++ b/polkadot/xcm/xcm-executor/src/traits/should_execute.rs
@@ -33,9 +33,9 @@ pub struct Properties {
/// Trait to determine whether the execution engine should actually execute a given XCM.
///
/// Can be amalgamated into a tuple to have multiple trials. If any of the tuple elements returns
-/// `Ok()`, the execution stops. Else, `Err(_)` is returned if all elements reject the message.
+/// `Ok(())`, the execution stops. Else, `Err(_)` is returned if all elements reject the message.
pub trait ShouldExecute {
- /// Returns `true` if the given `message` may be executed.
+ /// Returns `Ok(())` if the given `message` may be executed.
///
/// - `origin`: The origin (sender) of the message.
/// - `instructions`: The message itself.