contracts: Allow contracts to dispatch calls into the runtime (#9276)

* contracts: Allow contracts to dispatch calls into the runtime * Fix RPC tests * Fix typo * Replace () by AllowAllFilter and DenyAllFilter * Add rust doc * Fixup for `()` removal * Fix lowest gas calculation * Rename AllowAllFilter and DenyAllFilter * Updated changelog
paritytech · Jul 12, 2021 · 2543f6f · 2543f6f
1 parent 00de218
commit 2543f6f
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diff --git a/Cargo.lock b/Cargo.lock
diff --git a/bin/node-template/pallets/template/src/mock.rs b/bin/node-template/pallets/template/src/mock.rs
@@ -27,7 +27,7 @@ parameter_types! {
 }
 
 impl system::Config for Test {
-	type BaseCallFilter = ();
+	type BaseCallFilter = frame_support::traits::AllowAll;
 	type BlockWeights = ();
 	type BlockLength = ();
 	type DbWeight = ();

diff --git a/bin/node-template/runtime/src/lib.rs b/bin/node-template/runtime/src/lib.rs
@@ -146,7 +146,7 @@ parameter_types! {
 
 impl frame_system::Config for Runtime {
 	/// The basic call filter to use in dispatchable.
-	type BaseCallFilter = ();
+	type BaseCallFilter = frame_support::traits::AllowAll;
 	/// Block & extrinsics weights: base values and limits.
 	type BlockWeights = BlockWeights;
 	/// The maximum length of a block (in bytes).

diff --git a/bin/node/runtime/src/lib.rs b/bin/node/runtime/src/lib.rs
@@ -33,7 +33,7 @@ use frame_support::{
 	},
 	traits::{
 		Currency, Imbalance, KeyOwnerProofSystem, OnUnbalanced, LockIdentifier,
-		U128CurrencyToVote,
+		U128CurrencyToVote, AllowAll, DenyAll,
 	},
 };
 use frame_system::{
@@ -193,7 +193,7 @@ parameter_types! {
 const_assert!(NORMAL_DISPATCH_RATIO.deconstruct() >= AVERAGE_ON_INITIALIZE_RATIO.deconstruct());
 
 impl frame_system::Config for Runtime {
-	type BaseCallFilter = ();
+	type BaseCallFilter = AllowAll;
 	type BlockWeights = RuntimeBlockWeights;
 	type BlockLength = RuntimeBlockLength;
 	type DbWeight = RocksDbWeight;
@@ -839,6 +839,14 @@ impl pallet_contracts::Config for Runtime {
 	type Randomness = RandomnessCollectiveFlip;
 	type Currency = Balances;
 	type Event = Event;
+	type Call = Call;
+	/// The safest default is to allow no calls at all.
+	///
+	/// Runtimes should whitelist dispatchables that are allowed to be called from contracts
+	/// and make sure they are stable. Dispatchables exposed to contracts are not allowed to
+	/// change because that would break already deployed contracts. The `Call` structure itself
+	/// is not allowed to change the indices of existing pallets, too.
+	type CallFilter = DenyAll;
 	type RentPayment = ();
 	type SignedClaimHandicap = SignedClaimHandicap;
 	type TombstoneDeposit = TombstoneDeposit;

diff --git a/docs/Upgrading-2.0-to-3.0.md b/docs/Upgrading-2.0-to-3.0.md
@@ -143,7 +143,7 @@ And update the overall definition for weights on frame and a few related types a
 +const_assert!(NORMAL_DISPATCH_RATIO.deconstruct() >= AVERAGE_ON_INITIALIZE_RATIO.deconstruct());
 +
 +impl frame_system::Config for Runtime {
- 	type BaseCallFilter = ();
+ 	type BaseCallFilter = frame_support::traits::AllowAll;
 +	type BlockWeights = RuntimeBlockWeights;
 +	type BlockLength = RuntimeBlockLength;
 +	type DbWeight = RocksDbWeight;

diff --git a/frame/assets/src/mock.rs b/frame/assets/src/mock.rs
@@ -43,7 +43,7 @@ parameter_types! {
 	pub const BlockHashCount: u64 = 250;
 }
 impl frame_system::Config for Test {
-	type BaseCallFilter = ();
+	type BaseCallFilter = frame_support::traits::AllowAll;
 	type BlockWeights = ();
 	type BlockLength = ();
 	type Origin = Origin;

diff --git a/frame/atomic-swap/src/tests.rs b/frame/atomic-swap/src/tests.rs
@@ -31,7 +31,7 @@ parameter_types! {
 		frame_system::limits::BlockWeights::simple_max(1024);
 }
 impl frame_system::Config for Test {
-	type BaseCallFilter = ();
+	type BaseCallFilter = frame_support::traits::AllowAll;
 	type BlockWeights = ();
 	type BlockLength = ();
 	type DbWeight = ();

diff --git a/frame/aura/src/mock.rs b/frame/aura/src/mock.rs
@@ -48,7 +48,7 @@ parameter_types! {
 }
 
 impl frame_system::Config for Test {
-	type BaseCallFilter = ();
+	type BaseCallFilter = frame_support::traits::AllowAll;
 	type BlockWeights = ();
 	type BlockLength = ();
 	type DbWeight = ();

diff --git a/frame/authority-discovery/src/lib.rs b/frame/authority-discovery/src/lib.rs
@@ -50,7 +50,7 @@ pub mod pallet {
 		Vec<AuthorityId>,
 		ValueQuery,
 	>;
-	
+
 	#[pallet::storage]
 	#[pallet::getter(fn next_keys)]
 	/// Keys of the next authority set.
@@ -212,7 +212,7 @@ mod tests {
 	}
 
 	impl frame_system::Config for Test {
-		type BaseCallFilter = ();
+		type BaseCallFilter = frame_support::traits::AllowAll;
 		type BlockWeights = ();
 		type BlockLength = ();
 		type DbWeight = ();

diff --git a/frame/authorship/src/lib.rs b/frame/authorship/src/lib.rs
@@ -440,7 +440,7 @@ mod tests {
 	}
 
 	impl frame_system::Config for Test {
-		type BaseCallFilter = ();
+		type BaseCallFilter = frame_support::traits::AllowAll;
 		type BlockWeights = ();
 		type BlockLength = ();
 		type DbWeight = ();

diff --git a/frame/babe/src/mock.rs b/frame/babe/src/mock.rs
@@ -70,7 +70,7 @@ parameter_types! {
 }
 
 impl frame_system::Config for Test {
-	type BaseCallFilter = ();
+	type BaseCallFilter = frame_support::traits::AllowAll;
 	type BlockWeights = ();
 	type BlockLength = ();
 	type DbWeight = ();

diff --git a/frame/balances/src/tests_composite.rs b/frame/balances/src/tests_composite.rs
@@ -54,7 +54,7 @@ parameter_types! {
 	pub static ExistentialDeposit: u64 = 0;
 }
 impl frame_system::Config for Test {
-	type BaseCallFilter = ();
+	type BaseCallFilter = frame_support::traits::AllowAll;
 	type BlockWeights = BlockWeights;
 	type BlockLength = ();
 	type DbWeight = ();

diff --git a/frame/balances/src/tests_local.rs b/frame/balances/src/tests_local.rs
@@ -56,7 +56,7 @@ parameter_types! {
 	pub static ExistentialDeposit: u64 = 0;
 }
 impl frame_system::Config for Test {
-	type BaseCallFilter = ();
+	type BaseCallFilter = frame_support::traits::AllowAll;
 	type BlockWeights = BlockWeights;
 	type BlockLength = ();
 	type DbWeight = ();

diff --git a/frame/balances/src/tests_reentrancy.rs b/frame/balances/src/tests_reentrancy.rs
@@ -64,7 +64,7 @@ parameter_types! {
 	pub static ExistentialDeposit: u64 = 0;
 }
 impl frame_system::Config for Test {
-	type BaseCallFilter = ();
+	type BaseCallFilter = frame_support::traits::AllowAll;
 	type BlockWeights = BlockWeights;
 	type BlockLength = ();
 	type DbWeight = ();

diff --git a/frame/benchmarking/src/tests.rs b/frame/benchmarking/src/tests.rs
@@ -82,7 +82,7 @@ frame_support::construct_runtime!(
 );
 
 impl frame_system::Config for Test {
-	type BaseCallFilter = ();
+	type BaseCallFilter = frame_support::traits::AllowAll;
 	type BlockWeights = ();
 	type BlockLength = ();
 	type DbWeight = ();

diff --git a/frame/bounties/src/tests.rs b/frame/bounties/src/tests.rs
@@ -59,7 +59,7 @@ parameter_types! {
 }
 
 impl frame_system::Config for Test {
-	type BaseCallFilter = ();
+	type BaseCallFilter = frame_support::traits::AllowAll;
 	type BlockWeights = ();
 	type BlockLength = ();
 	type DbWeight = ();

diff --git a/frame/collective/src/lib.rs b/frame/collective/src/lib.rs
@@ -986,7 +986,7 @@ mod tests {
 			frame_system::limits::BlockWeights::simple_max(1024);
 	}
 	impl frame_system::Config for Test {
-		type BaseCallFilter = ();
+		type BaseCallFilter = frame_support::traits::AllowAll;
 		type BlockWeights = ();
 		type BlockLength = ();
 		type DbWeight = ();

diff --git a/frame/contracts/CHANGELOG.md b/frame/contracts/CHANGELOG.md
@@ -20,6 +20,9 @@ In other words: Upgrading this pallet will not break pre-existing contracts.
 
 ### Added
 
+- Allow contracts to dispatch calls into the runtime (**unstable**)
+[#9276](https://github.com/paritytech/substrate/pull/9276)
+
 - New **unstable** version of `seal_call` that offers more features.
 [#8909](https://github.com/paritytech/substrate/pull/8909)
 

diff --git a/frame/contracts/Cargo.toml b/frame/contracts/Cargo.toml
@@ -48,6 +48,7 @@ wat = "1"
 pallet-balances = { version = "4.0.0-dev", path = "../balances" }
 pallet-timestamp = { version = "4.0.0-dev", path = "../timestamp" }
 pallet-randomness-collective-flip = { version = "4.0.0-dev", path = "../randomness-collective-flip" }
+pallet-utility = { version = "4.0.0-dev", path = "../utility" }
 
 [features]
 default = ["std"]

diff --git a/frame/contracts/common/src/lib.rs b/frame/contracts/common/src/lib.rs
@@ -37,6 +37,15 @@ use serde::{Serialize, Deserialize};
 pub struct ContractResult<T> {
 	/// How much gas was consumed during execution.
 	pub gas_consumed: u64,
+	/// How much gas is required as gas limit in order to execute this call.
+	///
+	/// This value should be used to determine the gas limit for on-chain execution.
+	///
+	/// # Note
+	///
+	/// This can only different from [`Self::gas_consumed`] when weight pre charging
+	/// is used. Currently, only `seal_call_runtime` makes use of pre charging.
+	pub gas_required: u64,
 	/// An optional debug message. This message is only filled when explicitly requested
 	/// by the code that calls into the contract. Otherwise it is empty.
 	///

diff --git a/frame/contracts/fixtures/call_runtime.wat b/frame/contracts/fixtures/call_runtime.wat
@@ -0,0 +1,33 @@
+;; This passes its input to `seal_call_runtime` and returns the return value to its caller.
+(module
+	(import "__unstable__" "seal_call_runtime" (func $seal_call_runtime (param i32 i32) (result i32)))
+	(import "seal0" "seal_input" (func $seal_input (param i32 i32)))
+	(import "seal0" "seal_return" (func $seal_return (param i32 i32 i32)))
+	(import "env" "memory" (memory 1 1))
+
+	;; 0x1000 = 4k in little endian
+	;; size of input buffer
+	(data (i32.const 0) "\00\10")
+
+	(func (export "call")
+		;; Receive the encoded call
+		(call $seal_input
+			(i32.const 4)	;; Pointer to the input buffer
+			(i32.const 0)	;; Size of the length buffer
+		)
+		;; Just use the call passed as input and store result to memory
+		(i32.store (i32.const 0)
+			(call $seal_call_runtime
+				(i32.const 4)				;; Pointer where the call is stored
+				(i32.load (i32.const 0))	;; Size of the call
+			)
+		)
+		(call $seal_return
+			(i32.const 0)	;; flags
+			(i32.const 0)	;; returned value
+			(i32.const 4)	;; length of returned value
+		)
+	)
+
+	(func (export "deploy"))
+)
diff --git a/frame/contracts/fixtures/call_with_limit.wat b/frame/contracts/fixtures/call_with_limit.wat
@@ -0,0 +1,37 @@
+;; This expects [account_id, gas_limit] as input and calls the account_id with the supplied gas_limit.
+;; It returns the result of the call as output data.
+(module
+	(import "seal0" "seal_input" (func $seal_input (param i32 i32)))
+	(import "seal0" "seal_call" (func $seal_call (param i32 i32 i64 i32 i32 i32 i32 i32 i32) (result i32)))
+	(import "seal0" "seal_return" (func $seal_return (param i32 i32 i32)))
+	(import "env" "memory" (memory 1 1))
+
+	;; 0x1000 = 4k in little endian
+	;; size of input buffer
+	(data (i32.const 0) "\00\10")
+
+	(func (export "deploy"))
+
+	(func (export "call")
+		;; Receive the encoded call + gas_limit
+		(call $seal_input
+			(i32.const 4)	;; Pointer to the input buffer
+			(i32.const 0)	;; Size of the length buffer
+		)
+		(i32.store
+			(i32.const 0)
+			(call $seal_call
+				(i32.const 4) ;; Pointer to "callee" address.
+				(i32.const 32) ;; Length of "callee" address.
+				(i64.load (i32.const 36)) ;; How much gas to devote for the execution.
+				(i32.const 0) ;; Pointer to the buffer with value to transfer
+				(i32.const 0) ;; Length of the buffer with value to transfer.
+				(i32.const 0) ;; Pointer to input data buffer address
+				(i32.const 0) ;; Length of input data buffer
+				(i32.const 0xffffffff) ;; u32 max sentinel value: do not copy output
+				(i32.const 0) ;; Ptr to output buffer len
+			)
+		)
+		(call $seal_return (i32.const 0) (i32.const 0) (i32.const 4))
+	)
+)
diff --git a/frame/contracts/rpc/src/lib.rs b/frame/contracts/rpc/src/lib.rs
@@ -385,7 +385,8 @@ mod tests {
 		}
 		test(r#"{
 			"gasConsumed": 5000,
-			"debugMessage": "0x68656c704f6b",
+			"gasRequired": 8000,
+			"debugMessage": "HelloWorld",
 			"result": {
 			  "Ok": {
 				"flags": 5,
@@ -395,7 +396,8 @@ mod tests {
 		}"#);
 		test(r#"{
 			"gasConsumed": 3400,
-			"debugMessage": "0x68656c70457272",
+			"gasRequired": 5200,
+			"debugMessage": "HelloWorld",
 			"result": {
 			  "Err": "BadOrigin"
 			}
@@ -411,7 +413,8 @@ mod tests {
 		}
 		test(r#"{
 			"gasConsumed": 5000,
-			"debugMessage": "0x68656c704f6b",
+			"gasRequired": 8000,
+			"debugMessage": "HelloWorld",
 			"result": {
 			   "Ok": {
 				  "result": {
@@ -425,7 +428,8 @@ mod tests {
 		}"#);
 		test(r#"{
 			"gasConsumed": 3400,
-			"debugMessage": "0x68656c70457272",
+			"gasRequired": 5200,
+			"debugMessage": "HelloWorld",
 			"result": {
 			  "Err": "BadOrigin"
 			}

diff --git a/frame/contracts/src/chain_extension.rs b/frame/contracts/src/chain_extension.rs
@@ -57,6 +57,7 @@
 use crate::{
 	Error,
 	wasm::{Runtime, RuntimeCosts},
+	gas::ChargedAmount,
 };
 use codec::{Decode, MaxEncodedLen};
 use frame_support::weights::Weight;
@@ -167,11 +168,22 @@ where
 	/// `weight`. It returns `Err` otherwise. In this case the chain extension should
 	/// abort the execution and pass through the error.
 	///
+	/// The returned value can be used to with [`Self::adjust_weight`]. Other than that
+	/// it has no purpose.
+	///
 	/// # Note
 	///
 	/// Weight is synonymous with gas in substrate.
-	pub fn charge_weight(&mut self, amount: Weight) -> Result<()> {
-		self.inner.runtime.charge_gas(RuntimeCosts::ChainExtension(amount)).map(|_| ())
+	pub fn charge_weight(&mut self, amount: Weight) -> Result<ChargedAmount> {
+		self.inner.runtime.charge_gas(RuntimeCosts::ChainExtension(amount))
+	}
+
+	/// Adjust a previously charged amount down to its actual amount.
+	///
+	/// This is when a maximum a priori amount was charged and then should be partially
+	/// refunded to match the actual amount.
+	pub fn adjust_weight(&mut self, charged: ChargedAmount, actual_weight: Weight) {
+		self.inner.runtime.adjust_gas(charged, RuntimeCosts::ChainExtension(actual_weight))
 	}
 
 	/// Grants access to the execution environment of the current contract call.