Pass transaction source to validate_transaction (#5366)

* WiP

* Support source in the runtime API.

* Finish implementation in txpool.

* Fix warning.

* Fix tests.

* Apply suggestions from code review

Co-Authored-By: Kian Paimani <5588131+kianenigma@users.noreply.github.com>
Co-Authored-By: Nikolay Volf <nikvolf@gmail.com>

* Extra changes.

* Fix test and benches.

* fix test

* Fix test & benches again.

* Fix tests.

* Update bumpalo

* Fix doc test.

* Fix doctest.

* Fix doctest.

Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>
Co-authored-by: Nikolay Volf <nikvolf@gmail.com>

substrate/primitives/runtime/src/generic/checked_extrinsic.rs

@@ -21,7 +21,7 @@ use crate::traits::{
 	self, Member, MaybeDisplay, SignedExtension, Dispatchable,
 };
 use crate::traits::ValidateUnsigned;
-use crate::transaction_validity::TransactionValidity;
+use crate::transaction_validity::{TransactionValidity, TransactionSource};
 
 /// Definition of something that the external world might want to say; its
 /// existence implies that it has been checked and is good, particularly with
@@ -50,6 +50,9 @@ where
 
 	fn validate<U: ValidateUnsigned<Call = Self::Call>>(
 		&self,
+		// TODO [#5006;ToDr] should source be passed to `SignedExtension`s?
+		// Perhaps a change for 2.0 to avoid breaking too much APIs?
+		source: TransactionSource,
 		info: Self::DispatchInfo,
 		len: usize,
 	) -> TransactionValidity {
@@ -57,7 +60,7 @@ where
 			Extra::validate(extra, id, &self.function, info.clone(), len)
 		} else {
 			let valid = Extra::validate_unsigned(&self.function, info, len)?;
-			let unsigned_validation = U::validate_unsigned(&self.function)?;
+			let unsigned_validation = U::validate_unsigned(source, &self.function)?;
 			Ok(valid.combine_with(unsigned_validation))
 		}
 	}

substrate/primitives/runtime/src/testing.rs

@@ -27,7 +27,7 @@ use crate::traits::ValidateUnsigned;
 use crate::{generic, KeyTypeId, ApplyExtrinsicResult};
 pub use sp_core::{H256, sr25519};
 use sp_core::{crypto::{CryptoType, Dummy, key_types, Public}, U256};
-use crate::transaction_validity::{TransactionValidity, TransactionValidityError};
+use crate::transaction_validity::{TransactionValidity, TransactionValidityError, TransactionSource};
 
 /// Authority Id
 #[derive(Default, PartialEq, Eq, Clone, Encode, Decode, Debug, Hash, Serialize, Deserialize, PartialOrd, Ord)]
@@ -357,6 +357,7 @@ impl<Origin, Call, Extra, Info> Applyable for TestXt<Call, Extra> where
 	/// Checks to see if this is a valid *transaction*. It returns information on it if so.
 	fn validate<U: ValidateUnsigned<Call=Self::Call>>(
 		&self,
+		_source: TransactionSource,
 		_info: Self::DispatchInfo,
 		_len: usize,
 	) -> TransactionValidity {

substrate/primitives/runtime/src/traits.rs

@@ -28,7 +28,8 @@ use serde::{Serialize, Deserialize, de::DeserializeOwned};
 use sp_core::{self, Hasher, TypeId, RuntimeDebug};
 use crate::codec::{Codec, Encode, Decode};
 use crate::transaction_validity::{
-	ValidTransaction, TransactionValidity, TransactionValidityError, UnknownTransaction,
+	ValidTransaction, TransactionSource, TransactionValidity, TransactionValidityError,
+	UnknownTransaction,
 };
 use crate::generic::{Digest, DigestItem};
 pub use sp_arithmetic::traits::{
@@ -851,6 +852,7 @@ pub trait Applyable: Sized + Send + Sync {
 	/// Checks to see if this is a valid *transaction*. It returns information on it if so.
 	fn validate<V: ValidateUnsigned<Call=Self::Call>>(
 		&self,
+		source: TransactionSource,
 		info: Self::DispatchInfo,
 		len: usize,
 	) -> TransactionValidity;
@@ -897,7 +899,7 @@ pub trait ValidateUnsigned {
 	///
 	/// Changes made to storage WILL be persisted if the call returns `Ok`.
 	fn pre_dispatch(call: &Self::Call) -> Result<(), TransactionValidityError> {
-		Self::validate_unsigned(call)
+		Self::validate_unsigned(TransactionSource::InBlock, call)
 			.map(|_| ())
 			.map_err(Into::into)
 	}
@@ -908,7 +910,7 @@ pub trait ValidateUnsigned {
 	/// whether the transaction would panic if it were included or not.
 	///
 	/// Changes made to storage should be discarded by caller.
-	fn validate_unsigned(call: &Self::Call) -> TransactionValidity;
+	fn validate_unsigned(source: TransactionSource, call: &Self::Call) -> TransactionValidity;
 }
 
 /// Opaque data type that may be destructured into a series of raw byte slices (which represent

substrate/primitives/runtime/src/transaction_validity.rs

@@ -161,6 +161,35 @@ impl Into<TransactionValidity> for UnknownTransaction {
 	}
 }
 
+/// The source of the transaction.
+///
+/// Depending on the source we might apply different validation schemes.
+/// For instance we can disallow specific kinds of transactions if they were not produced
+/// by our local node (for instance off-chain workers).
+#[derive(Copy, Clone, PartialEq, Eq, Encode, Decode, RuntimeDebug, parity_util_mem::MallocSizeOf)]
+pub enum TransactionSource {
+	/// Transaction is already included in block.
+	///
+	/// This means that we can't really tell where the transaction is coming from,
+	/// since it's already in the received block. Note that the custom validation logic
+	/// using either `Local` or `External` should most likely just allow `InBlock`
+	/// transactions as well.
+	InBlock,
+
+	/// Transaction is coming from a local source.
+	///
+	/// This means that the transaction was produced internally by the node
+	/// (for instance an Off-Chain Worker, or an Off-Chain Call), as opposed
+	/// to being received over the network.
+	Local,
+
+	/// Transaction has been received externally.
+	///
+	/// This means the transaction has been received from (usually) "untrusted" source,
+	/// for instance received over the network or RPC.
+	External,
+}
+
 /// Information concerning a valid transaction.
 #[derive(Clone, PartialEq, Eq, Encode, Decode, RuntimeDebug)]
 pub struct ValidTransaction {