diff --git a/bridges/modules/parachains/src/extension.rs b/bridges/modules/parachains/src/extension.rs
index 3ed6dd9cbeda54cc1b8fd9a0684a1800fc740d93..18e718da0e46f7346fb665d94cd65ac739223715 100644
--- a/bridges/modules/parachains/src/extension.rs
+++ b/bridges/modules/parachains/src/extension.rs
@@ -17,7 +17,7 @@
use crate::{Config, Pallet, RelayBlockHash, RelayBlockHasher, RelayBlockNumber};
use bp_runtime::FilterCall;
use frame_support::{dispatch::CallableCallFor, traits::IsSubType};
-use sp_runtime::transaction_validity::{InvalidTransaction, TransactionValidity, ValidTransaction};
+use sp_runtime::transaction_validity::{TransactionValidity, ValidTransaction};
/// Validate parachain heads in order to avoid "mining" transactions that provide
/// outdated bridged parachain heads. Without this validation, even honest relayers
@@ -43,45 +43,27 @@ where
>,
{
fn validate(call: &Call) -> TransactionValidity {
- let (bundled_relay_block_number, parachains) = match call.is_sub_type() {
+ let (updated_at_relay_block_number, parachains) = match call.is_sub_type() {
Some(crate::Call::<T, I>::submit_parachain_heads {
ref at_relay_block,
ref parachains,
..
- }) if parachains.len() == 1 => (at_relay_block.0, parachains),
+ }) => (at_relay_block.0, parachains),
+ _ => return Ok(ValidTransaction::default()),
+ };
+ let (parachain, parachain_head_hash) = match parachains.as_slice() {
+ &[(parachain, parachain_head_hash)] => (parachain, parachain_head_hash),
_ => return Ok(ValidTransaction::default()),
};
- let (parachain, parachain_head_hash) =
- parachains.get(0).expect("verified by match condition; qed");
- let best_parachain_head = crate::BestParaHeads::<T, I>::get(parachain);
-
- match best_parachain_head {
- Some(best_parachain_head)
- if best_parachain_head.at_relay_block_number >= bundled_relay_block_number =>
- {
- log::trace!(
- target: crate::LOG_TARGET,
- "Rejecting obsolete parachain-head {:?} transaction: \
- bundled relay block number: {:?} \
- best relay block number: {:?}",
- parachain,
- bundled_relay_block_number,
- best_parachain_head.at_relay_block_number,
- );
- InvalidTransaction::Stale.into()
- },
- Some(best_parachain_head) if best_parachain_head.head_hash == *parachain_head_hash => {
- log::trace!(
- target: crate::LOG_TARGET,
- "Rejecting obsolete parachain-head {:?} transaction: head hash {:?}",
- parachain,
- best_parachain_head.head_hash,
- );
- InvalidTransaction::Stale.into()
- },
- _ => Ok(ValidTransaction::default()),
- }
+ let maybe_stored_best_head = crate::BestParaHeads::<T, I>::get(parachain);
+ Self::validate_updated_parachain_head(
+ parachain,
+ &maybe_stored_best_head,
+ updated_at_relay_block_number,
+ parachain_head_hash,
+ "Rejecting obsolete parachain-head transaction",
+ )
}
}
diff --git a/bridges/modules/parachains/src/lib.rs b/bridges/modules/parachains/src/lib.rs
index 05e14575eacf3f012a4977d25ff5bb41a7315bd2..7d12ee34e08cf809765fa7b70d45cb7fee05c603 100644
--- a/bridges/modules/parachains/src/lib.rs
+++ b/bridges/modules/parachains/src/lib.rs
@@ -373,6 +373,48 @@ pub mod pallet {
storage.read_and_decode_value(parachain_head_key.0.as_ref())
}
+ /// Check if para head has been already updated at better relay chain block.
+ /// Without this check, we may import heads in random order.
+ pub fn validate_updated_parachain_head(
+ parachain: ParaId,
+ maybe_stored_best_head: &Option<BestParaHead>,
+ updated_at_relay_block_number: RelayBlockNumber,
+ updated_head_hash: ParaHash,
+ err_log_prefix: &str,
+ ) -> TransactionValidity {
+ let stored_best_head = match maybe_stored_best_head {
+ Some(stored_best_head) => stored_best_head,
+ None => return Ok(ValidTransaction::default()),
+ };
+
+ if stored_best_head.at_relay_block_number >= updated_at_relay_block_number {
+ log::trace!(
+ target: LOG_TARGET,
+ "{}. The parachain head for {:?} was already updated at better relay chain block {} >= {}.",
+ err_log_prefix,
+ parachain,
+ stored_best_head.at_relay_block_number,
+ updated_at_relay_block_number
+ );
+ return InvalidTransaction::Stale.into()
+ }
+
+ if stored_best_head.head_hash == updated_head_hash {
+ log::trace!(
+ target: LOG_TARGET,
+ "{}. The parachain head hash for {:?} was already updated to {} at block {} < {}.",
+ err_log_prefix,
+ parachain,
+ updated_head_hash,
+ stored_best_head.at_relay_block_number,
+ updated_at_relay_block_number
+ );
+ return InvalidTransaction::Stale.into()
+ }
+
+ Ok(ValidTransaction::default())
+ }
+
/// Try to update parachain head.
pub(super) fn update_parachain_head(
parachain: ParaId,
@@ -383,41 +425,16 @@ pub mod pallet {
) -> Result<UpdateParachainHeadArtifacts, ()> {
// check if head has been already updated at better relay chain block. Without this
// check, we may import heads in random order
- let next_imported_hash_position = match stored_best_head {
- Some(stored_best_head)
- if stored_best_head.at_relay_block_number <= updated_at_relay_block_number =>
- {
- // check if this head has already been imported before
- if updated_head_hash == stored_best_head.head_hash {
- log::trace!(
- target: LOG_TARGET,
- "The head of parachain {:?} can't be updated to {}, because it has been already updated \
- to the same value at previous relay chain block: {} < {}",
- parachain,
- updated_head_hash,
- stored_best_head.at_relay_block_number,
- updated_at_relay_block_number,
- );
- return Err(())
- }
-
- stored_best_head.next_imported_hash_position
- },
- None => 0,
- Some(stored_best_head) => {
- log::trace!(
- target: LOG_TARGET,
- "The head of parachain {:?} can't be updated to {}, because it has been already updated \
- to {} at better relay chain block: {} > {}",
- parachain,
- updated_head_hash,
- stored_best_head.head_hash,
- stored_best_head.at_relay_block_number,
- updated_at_relay_block_number,
- );
- return Err(())
- },
- };
+ Self::validate_updated_parachain_head(
+ parachain,
+ &stored_best_head,
+ updated_at_relay_block_number,
+ updated_head_hash,
+ "The parachain head can't be updated",
+ )
+ .map_err(|_| ())?;
+ let next_imported_hash_position = stored_best_head
+ .map_or(0, |stored_best_head| stored_best_head.next_imported_hash_position);
// insert updated best parachain head
let head_hash_to_prune =
diff --git a/bridges/relays/lib-substrate-relay/src/parachains/source.rs b/bridges/relays/lib-substrate-relay/src/parachains/source.rs
index ecc940467035ee236a29dcddfb108fbf695cbb1d..ea647c740d10fab4115b9914ba41ff909939fe95 100644
--- a/bridges/relays/lib-substrate-relay/src/parachains/source.rs
+++ b/bridges/relays/lib-substrate-relay/src/parachains/source.rs
@@ -161,11 +161,11 @@ where
at_block: HeaderIdOf<P::SourceRelayChain>,
parachains: &[ParaId],
) -> Result<(ParaHeadsProof, Vec<ParaHash>), Self::Error> {
- if parachains.len() != 1 || parachains[0].0 != P::SOURCE_PARACHAIN_PARA_ID {
+ let parachain = ParaId(P::SOURCE_PARACHAIN_PARA_ID);
+ if parachains != [parachain] {
return Err(SubstrateError::Custom(format!(
"Trying to prove unexpected parachains {:?}. Expected {:?}",
- parachains,
- P::SOURCE_PARACHAIN_PARA_ID,
+ parachains, parachain,
)))
}