pallet-scheduler: Introduce OriginPrivilegeCmp

bin/node/runtime/src/lib.rs

@@ -26,8 +26,8 @@ use codec::{Decode, Encode, MaxEncodedLen};
 use frame_support::{
 	construct_runtime, parameter_types,
 	traits::{
-		Currency, Everything, Imbalance, InstanceFilter, KeyOwnerProofSystem, LockIdentifier,
-		Nothing, OnUnbalanced, U128CurrencyToVote,
+		Currency, EqualPrivilegeOnly, Everything, Imbalance, InstanceFilter, KeyOwnerProofSystem,
+		LockIdentifier, Nothing, OnUnbalanced, U128CurrencyToVote,
 	},
 	weights::{
 		constants::{BlockExecutionWeight, ExtrinsicBaseWeight, RocksDbWeight, WEIGHT_PER_SECOND},
@@ -345,6 +345,7 @@ impl pallet_scheduler::Config for Runtime {
 	type ScheduleOrigin = EnsureRoot<AccountId>;
 	type MaxScheduledPerBlock = MaxScheduledPerBlock;
 	type WeightInfo = pallet_scheduler::weights::SubstrateWeight<Runtime>;
+	type OriginPrivilegeCmp = EqualPrivilegeOnly;
 }
 
 parameter_types! {

frame/democracy/src/tests.rs

@@ -22,7 +22,7 @@ use crate as pallet_democracy;
 use codec::Encode;
 use frame_support::{
 	assert_noop, assert_ok, ord_parameter_types, parameter_types,
-	traits::{Contains, GenesisBuild, OnInitialize, SortedMembers},
+	traits::{Contains, EqualPrivilegeOnly, GenesisBuild, OnInitialize, SortedMembers},
 	weights::Weight,
 };
 use frame_system::{EnsureRoot, EnsureSignedBy};
@@ -118,6 +118,7 @@ impl pallet_scheduler::Config for Test {
 	type ScheduleOrigin = EnsureRoot<u64>;
 	type MaxScheduledPerBlock = ();
 	type WeightInfo = ();
+	type OriginPrivilegeCmp = EqualPrivilegeOnly;
 }
 parameter_types! {
 	pub const ExistentialDeposit: u64 = 1;

frame/scheduler/src/lib.rs

@@ -58,7 +58,7 @@ use frame_support::{
 	dispatch::{DispatchError, DispatchResult, Dispatchable, Parameter},
 	traits::{
 		schedule::{self, DispatchTime},
-		EnsureOrigin, Get, IsType, OriginTrait,
+		EnsureOrigin, Get, IsType, OriginTrait, PrivilegeCmp,
 	},
 	weights::{GetDispatchInfo, Weight},
 };
@@ -69,7 +69,7 @@ use sp_runtime::{
 	traits::{BadOrigin, One, Saturating, Zero},
 	RuntimeDebug,
 };
-use sp_std::{borrow::Borrow, marker::PhantomData, prelude::*};
+use sp_std::{borrow::Borrow, cmp::Ordering, marker::PhantomData, prelude::*};
 pub use weights::WeightInfo;
 
 /// Just a simple index for naming period tasks.
@@ -160,6 +160,15 @@ pub mod pallet {
 		/// Required origin to schedule or cancel calls.
 		type ScheduleOrigin: EnsureOrigin<<Self as system::Config>::Origin>;
 
+		/// Compare the privileges of origins.
+		///
+		/// This will be used when canceling a task, to ensure that the origin that tries
+		/// to cancel has greater or equal privileges as the origin that created the scheduled task.
+		///
+		/// For simplicity the [`EqualPrivilegeOnly`](frame_support::traits::EqualPrivilegeOnly) can
+		/// be used. This will only check if two given origins are equal.
+		type OriginPrivilegeCmp: PrivilegeCmp<Self::PalletsOrigin>;
+
 		/// The maximum number of scheduled calls in the queue for a single block.
 		/// Not strictly enforced, but used for weight estimation.
 		#[pallet::constant]
@@ -614,7 +623,10 @@ impl<T: Config> Pallet<T> {
 				Ok(None),
 				|s| -> Result<Option<Scheduled<_, _, _, _>>, DispatchError> {
 					if let (Some(ref o), Some(ref s)) = (origin, s.borrow()) {
-						if *o != s.origin {
+						if matches!(
+							T::OriginPrivilegeCmp::cmp_privilege(o, &s.origin),
+							Some(Ordering::Less) | None
+						) {
 							return Err(BadOrigin.into())
 						}
 					};
@@ -709,7 +721,10 @@ impl<T: Config> Pallet<T> {
 				Agenda::<T>::try_mutate(when, |agenda| -> DispatchResult {
 					if let Some(s) = agenda.get_mut(i) {
 						if let (Some(ref o), Some(ref s)) = (origin, s.borrow()) {
-							if *o != s.origin {
+							if matches!(
+								T::OriginPrivilegeCmp::cmp_privilege(o, &s.origin),
+								Some(Ordering::Less) | None
+							) {
 								return Err(BadOrigin.into())
 							}
 						}
@@ -832,7 +847,7 @@ mod tests {
 	use crate as scheduler;
 	use frame_support::{
 		assert_err, assert_noop, assert_ok, ord_parameter_types, parameter_types,
-		traits::{Contains, OnFinalize, OnInitialize},
+		traits::{Contains, EqualPrivilegeOnly, OnFinalize, OnInitialize},
 		weights::constants::RocksDbWeight,
 		Hashable,
 	};
@@ -980,6 +995,7 @@ mod tests {
 		type ScheduleOrigin = EnsureOneOf<u64, EnsureRoot<u64>, EnsureSignedBy<One, u64>>;
 		type MaxScheduledPerBlock = MaxScheduledPerBlock;
 		type WeightInfo = ();
+		type OriginPrivilegeCmp = EqualPrivilegeOnly;
 	}
 
 	pub type LoggerCall = logger::Call<Test>;

frame/support/src/traits.rs

@@ -50,9 +50,10 @@ pub use filter::{ClearFilterGuard, FilterStack, FilterStackGuard, InstanceFilter
 
 mod misc;
 pub use misc::{
-	Backing, ConstU32, EnsureInherentsAreFirst, EstimateCallFee, ExecuteBlock, ExtrinsicCall, Get,
-	GetBacking, GetDefault, HandleLifetime, IsSubType, IsType, Len, OffchainWorker,
-	OnKilledAccount, OnNewAccount, SameOrOther, Time, TryDrop, UnixTime, WrapperOpaque,
+	Backing, ConstU32, EnsureInherentsAreFirst, EqualPrivilegeOnly, EstimateCallFee, ExecuteBlock,
+	ExtrinsicCall, Get, GetBacking, GetDefault, HandleLifetime, IsSubType, IsType, Len,
+	OffchainWorker, OnKilledAccount, OnNewAccount, PrivilegeCmp, SameOrOther, Time, TryDrop,
+	UnixTime, WrapperOpaque,
 };
 
 mod stored_map;

frame/support/src/traits/misc.rs

@@ -21,7 +21,7 @@ use crate::dispatch::Parameter;
 use codec::{Decode, Encode, EncodeLike, Input, MaxEncodedLen};
 use scale_info::{build::Fields, meta_type, Path, Type, TypeInfo, TypeParameter};
 use sp_runtime::{traits::Block as BlockT, DispatchError};
-use sp_std::prelude::*;
+use sp_std::{cmp::Ordering, prelude::*};
 
 /// Anything that can have a `::len()` method.
 pub trait Len {
@@ -289,6 +289,30 @@ pub trait ExecuteBlock<Block: BlockT> {
 	fn execute_block(block: Block);
 }
 
+/// Something that can compare privileges of two origins.
+pub trait PrivilegeCmp<Origin> {
+	/// Compare the `left` to the `right` origin.
+	///
+	/// The returned ordering should be from the pov of the `left` origin.
+	///
+	/// Should return `None` when it can not compare the given origins.
+	fn cmp_privilege(left: &Origin, right: &Origin) -> Option<Ordering>;
+}
+
+/// Implementation of [`PrivilegeCmp`] that only checks for equal origins.
+///
+/// This means it will either return [`Origin::Equal`] or `None`.
+pub struct EqualPrivilegeOnly;
+impl<Origin: PartialEq> PrivilegeCmp<Origin> for EqualPrivilegeOnly {
+	fn cmp_privilege(left: &Origin, right: &Origin) -> Option<Ordering> {
+		if left == right {
+			Some(Ordering::Equal)
+		} else {
+			None
+		}
+	}
+}
+
 /// Off-chain computation trait.
 ///
 /// Implementing this trait on a module allows you to perform long-running tasks