forked from paritytech/substrate
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
pallet-treasury: Ensure we respect max_amount for spend across ba…
…tch calls (paritytech#13468) * `pallet-treasury`: Ensure we respect `max_amount` for spend across batch calls When calling `spend` the origin defines the `max_amount` of tokens it is allowed to spend. The problem is that someone can send a `batch(spend, spend)` to circumvent this restriction as we don't check across different calls that the `max_amount` is respected. This pull request fixes this behavior by introducing a so-called dispatch context. This dispatch context is created once per outer most `dispatch` call. For more information see the docs in this pr. The treasury then uses this dispatch context to attach information about already spent funds per `max_amount` (we assume that each origin has a different `max_amount` configured). So, a `batch(spend, spend)` is now checked to stay inside the allowed spending bounds. Fixes: paritytech#13167 * Import `Box` for wasm * FMT
- Loading branch information
1 parent
6508e13
commit e7cc6b7
Showing
9 changed files
with
353 additions
and
24 deletions.
There are no files selected for viewing
Some generated files are not rendered by default. Learn more about how customized files appear on GitHub.
Oops, something went wrong.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,232 @@ | ||
| // This file is part of Substrate. | ||
|
|
||
| // Copyright (C) Parity Technologies (UK) Ltd. | ||
| // SPDX-License-Identifier: Apache-2.0 | ||
|
|
||
| // Licensed under the Apache License, Version 2.0 (the "License"); | ||
| // you may not use this file except in compliance with the License. | ||
| // You may obtain a copy of the License at | ||
| // | ||
| // http://www.apache.org/licenses/LICENSE-2.0 | ||
| // | ||
| // Unless required by applicable law or agreed to in writing, software | ||
| // distributed under the License is distributed on an "AS IS" BASIS, | ||
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | ||
| // See the License for the specific language governing permissions and | ||
| // limitations under the License. | ||
|
|
||
| //! Provides functions to interact with the dispatch context. | ||
| //! | ||
| //! A Dispatch context is created by calling [`run_in_context`] and then the given closure will be | ||
| //! executed in this dispatch context. Everyting run in this `closure` will have access to the same | ||
| //! dispatch context. This also applies to nested calls of [`run_in_context`]. The dispatch context | ||
| //! can be used to store and retrieve information locally in this context. The dispatch context can | ||
| //! be accessed by using [`with_context`]. This function will execute the given closure and give it | ||
| //! access to the value stored in the dispatch context. | ||
| //! | ||
| //! # FRAME integration | ||
| //! | ||
| //! The FRAME macros implement [`UnfilteredDispatchable`](crate::traits::UnfilteredDispatchable) for | ||
| //! each pallet `Call` enum. Part of this implementation is the call to [`run_in_context`], so that | ||
| //! each call to | ||
| //! [`UnfilteredDispatchable::dispatch_bypass_filter`](crate::traits::UnfilteredDispatchable::dispatch_bypass_filter) | ||
| //! or [`Dispatchable::dispatch`](crate::dispatch::Dispatchable::dispatch) will run in a dispatch | ||
| //! context. | ||
| //! | ||
| //! # Example | ||
| //! | ||
| //! ``` | ||
| //! use frame_support::dispatch_context::{with_context, run_in_context}; | ||
| //! | ||
| //! // Not executed in a dispatch context, so it should return `None`. | ||
| //! assert!(with_context::<(), _>(|_| println!("Hello")).is_none()); | ||
| //! | ||
| //! // Run it in a dispatch context and `with_context` returns `Some(_)`. | ||
| //! run_in_context(|| { | ||
| //! assert!(with_context::<(), _>(|_| println!("Hello")).is_some()); | ||
| //! }); | ||
| //! | ||
| //! #[derive(Default)] | ||
| //! struct CustomContext(i32); | ||
| //! | ||
| //! run_in_context(|| { | ||
| //! with_context::<CustomContext, _>(|v| { | ||
| //! // Intitialize the value to the default value. | ||
| //! assert_eq!(0, v.or_default().0); | ||
| //! v.or_default().0 = 10; | ||
| //! }); | ||
| //! | ||
| //! with_context::<CustomContext, _>(|v| { | ||
| //! // We are still in the same context and can still access the set value. | ||
| //! assert_eq!(10, v.or_default().0); | ||
| //! }); | ||
| //! | ||
| //! run_in_context(|| { | ||
| //! with_context::<CustomContext, _>(|v| { | ||
| //! // A nested call of `run_in_context` stays in the same dispatch context | ||
| //! assert_eq!(10, v.or_default().0); | ||
| //! }) | ||
| //! }) | ||
| //! }); | ||
| //! | ||
| //! run_in_context(|| { | ||
| //! with_context::<CustomContext, _>(|v| { | ||
| //! // We left the other context and created a new one, so we should be back | ||
| //! // to our default value. | ||
| //! assert_eq!(0, v.or_default().0); | ||
| //! }); | ||
| //! }); | ||
| //! ``` | ||
| //! | ||
| //! In your pallet you will only have to use [`with_context`], because as described above | ||
| //! [`run_in_context`] will be handled by FRAME for you. | ||
| use sp_std::{ | ||
| any::{Any, TypeId}, | ||
| boxed::Box, | ||
| collections::btree_map::{BTreeMap, Entry}, | ||
| }; | ||
|
|
||
| environmental::environmental!(DISPATCH_CONTEXT: BTreeMap<TypeId, Box<dyn Any>>); | ||
|
|
||
| /// Abstraction over some optional value `T` that is stored in the dispatch context. | ||
| pub struct Value<'a, T> { | ||
| value: Option<&'a mut T>, | ||
| new_value: Option<T>, | ||
| } | ||
|
|
||
| impl<T> Value<'_, T> { | ||
| /// Get the value as reference. | ||
| pub fn get(&self) -> Option<&T> { | ||
| self.new_value.as_ref().or_else(|| self.value.as_ref().map(|v| *v as &T)) | ||
| } | ||
|
|
||
| /// Get the value as mutable reference. | ||
| pub fn get_mut(&mut self) -> Option<&mut T> { | ||
| self.new_value.as_mut().or_else(|| self.value.as_mut().map(|v| *v as &mut T)) | ||
| } | ||
|
|
||
| /// Set to the given value. | ||
| /// | ||
| /// [`Self::get`] and [`Self::get_mut`] will return `new_value` afterwards. | ||
| pub fn set(&mut self, new_value: T) { | ||
| self.value = None; | ||
| self.new_value = Some(new_value); | ||
| } | ||
|
|
||
| /// Returns a mutable reference to the value. | ||
| /// | ||
| /// If the internal value isn't initialized, this will set it to [`Default::default()`] before | ||
| /// returning the mutable reference. | ||
| pub fn or_default(&mut self) -> &mut T | ||
| where | ||
| T: Default, | ||
| { | ||
| if let Some(v) = &mut self.value { | ||
| return v | ||
| } | ||
|
|
||
| self.new_value.get_or_insert_with(|| Default::default()) | ||
| } | ||
|
|
||
| /// Clear the internal value. | ||
| /// | ||
| /// [`Self::get`] and [`Self::get_mut`] will return `None` afterwards. | ||
| pub fn clear(&mut self) { | ||
| self.new_value = None; | ||
| self.value = None; | ||
| } | ||
| } | ||
|
|
||
| /// Runs the given `callback` in the dispatch context and gives access to some user defined value. | ||
| /// | ||
| /// Passes the a mutable reference of [`Value`] to the callback. The value will be of type `T` and | ||
| /// is identified using the [`TypeId`] of `T`. This means that `T` should be some unique type to | ||
| /// make the value unique. If no value is set yet [`Value::get()`] and [`Value::get_mut()`] will | ||
| /// return `None`. It is totally valid to have some `T` that is shared between different callers to | ||
| /// have access to the same value. | ||
| /// | ||
| /// Returns `None` if the current context is not a dispatch context. To create a context it is | ||
| /// required to call [`run_in_context`] with the closure to execute in this context. So, for example | ||
| /// in tests it could be that there isn't any dispatch context or when calling a dispatchable like a | ||
| /// normal Rust function from some FRAME hook. | ||
| pub fn with_context<T: 'static, R>(callback: impl FnOnce(&mut Value<T>) -> R) -> Option<R> { | ||
| DISPATCH_CONTEXT::with(|c| match c.entry(TypeId::of::<T>()) { | ||
| Entry::Occupied(mut o) => { | ||
| let value = o.get_mut().downcast_mut::<T>(); | ||
|
|
||
| if value.is_none() { | ||
| log::error!( | ||
| "Failed to downcast value for type {} in dispatch context!", | ||
| sp_std::any::type_name::<T>(), | ||
| ); | ||
| } | ||
|
|
||
| let mut value = Value { value, new_value: None }; | ||
| let res = callback(&mut value); | ||
|
|
||
| if value.value.is_none() && value.new_value.is_none() { | ||
| o.remove(); | ||
| } else if let Some(new_value) = value.new_value { | ||
| o.insert(Box::new(new_value) as Box<_>); | ||
| } | ||
|
|
||
| res | ||
| }, | ||
| Entry::Vacant(v) => { | ||
| let mut value = Value { value: None, new_value: None }; | ||
|
|
||
| let res = callback(&mut value); | ||
|
|
||
| if let Some(new_value) = value.new_value { | ||
| v.insert(Box::new(new_value) as Box<_>); | ||
| } | ||
|
|
||
| res | ||
| }, | ||
| }) | ||
| } | ||
|
|
||
| /// Run the given closure `run` in a dispatch context. | ||
| /// | ||
| /// Nested calls to this function will execute `run` in the same dispatch context as the initial | ||
| /// call to this function. In other words, all nested calls of this function will be done in the | ||
| /// same dispatch context. | ||
| pub fn run_in_context<R>(run: impl FnOnce() -> R) -> R { | ||
| DISPATCH_CONTEXT::using_once(&mut Default::default(), run) | ||
| } | ||
|
|
||
| #[cfg(test)] | ||
| mod tests { | ||
| use super::*; | ||
|
|
||
| #[test] | ||
| fn dispatch_context_works() { | ||
| // No context, so we don't execute | ||
| assert!(with_context::<(), _>(|_| ()).is_none()); | ||
|
|
||
| let ret = run_in_context(|| with_context::<(), _>(|_| 1).unwrap()); | ||
| assert_eq!(1, ret); | ||
|
|
||
| #[derive(Default)] | ||
| struct Context(i32); | ||
|
|
||
| let res = run_in_context(|| { | ||
| with_context::<Context, _>(|v| { | ||
| assert_eq!(0, v.or_default().0); | ||
|
|
||
| v.or_default().0 = 100; | ||
| }); | ||
|
|
||
| run_in_context(|| { | ||
| run_in_context(|| { | ||
| run_in_context(|| with_context::<Context, _>(|v| v.or_default().0).unwrap()) | ||
| }) | ||
| }) | ||
| }); | ||
|
|
||
| // Ensure that the initial value set in the context is also accessible after nesting the | ||
| // `run_in_context` calls. | ||
| assert_eq!(100, res); | ||
| } | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.