establish_channel_with_system

polkadot/runtime/parachains/src/hrmp.rs

@@ -270,6 +270,10 @@ pub mod pallet {
 		/// implementation should be the same as `Balance` as used in the `Configuration`.
 		type Currency: ReservableCurrency<Self::AccountId>;
 
+		/// The default channel size and capacity to use when opening a channel to a system
+		/// parachain.
+		type DefaultChannelSizeAndCapacityToSystem: Get<(u32, u32)>;
+
 		/// Something that provides the weight of this pallet.
 		type WeightInfo: WeightInfo;
 	}
@@ -564,13 +568,13 @@ pub mod pallet {
 			T::ChannelManager::ensure_origin(origin)?;
 
 			ensure!(
-				HrmpIngressChannelsIndex::<T>::decode_len(para).unwrap_or_default() <=
-					num_inbound as usize,
+				HrmpIngressChannelsIndex::<T>::decode_len(para).unwrap_or_default()
+					<= num_inbound as usize,
 				Error::<T>::WrongWitness
 			);
 			ensure!(
-				HrmpEgressChannelsIndex::<T>::decode_len(para).unwrap_or_default() <=
-					num_outbound as usize,
+				HrmpEgressChannelsIndex::<T>::decode_len(para).unwrap_or_default()
+					<= num_outbound as usize,
 				Error::<T>::WrongWitness
 			);
 
@@ -592,8 +596,8 @@ pub mod pallet {
 			T::ChannelManager::ensure_origin(origin)?;
 
 			ensure!(
-				HrmpOpenChannelRequestsList::<T>::decode_len().unwrap_or_default() as u32 <=
-					channels,
+				HrmpOpenChannelRequestsList::<T>::decode_len().unwrap_or_default() as u32
+					<= channels,
 				Error::<T>::WrongWitness
 			);
 
@@ -616,8 +620,8 @@ pub mod pallet {
 			T::ChannelManager::ensure_origin(origin)?;
 
 			ensure!(
-				HrmpCloseChannelRequestsList::<T>::decode_len().unwrap_or_default() as u32 <=
-					channels,
+				HrmpCloseChannelRequestsList::<T>::decode_len().unwrap_or_default() as u32
+					<= channels,
 				Error::<T>::WrongWitness
 			);
 
@@ -642,8 +646,8 @@ pub mod pallet {
 		) -> DispatchResult {
 			let origin = ensure_parachain(<T as Config>::RuntimeOrigin::from(origin))?;
 			ensure!(
-				HrmpOpenChannelRequestsList::<T>::decode_len().unwrap_or_default() as u32 <=
-					open_requests,
+				HrmpOpenChannelRequestsList::<T>::decode_len().unwrap_or_default() as u32
+					<= open_requests,
 				Error::<T>::WrongWitness
 			);
 			Self::cancel_open_request(origin, channel_id.clone())?;
@@ -776,10 +780,10 @@ pub mod pallet {
 					let current_recipient_deposit = channel.recipient_deposit;
 
 					// nothing to update
-					if current_sender_deposit == new_sender_deposit &&
-						current_recipient_deposit == new_recipient_deposit
+					if current_sender_deposit == new_sender_deposit
+						&& current_recipient_deposit == new_recipient_deposit
 					{
-						return Ok(())
+						return Ok(());
 					}
 
 					// sender
@@ -827,7 +831,7 @@ pub mod pallet {
 					channel.sender_deposit = new_sender_deposit;
 					channel.recipient_deposit = new_recipient_deposit;
 				} else {
-					return Err(Error::<T>::OpenHrmpChannelDoesntExist.into())
+					return Err(Error::<T>::OpenHrmpChannelDoesntExist.into());
 				}
 				Ok(())
 			})?;
@@ -836,6 +840,36 @@ pub mod pallet {
 
 			Ok(())
 		}
+
+		/// TODO write docs
+		#[pallet::call_index(10)]
+		#[pallet::weight(<T as Config>::WeightInfo::establish_system_channel())] // TODO benchmarks
+		pub fn establish_channel_with_system(
+			origin: OriginFor<T>,
+			recipient: ParaId,
+		) -> DispatchResultWithPostInfo {
+			let sender = ensure_parachain(<T as Config>::RuntimeOrigin::from(origin))?;
+
+			ensure!(recipient.is_system(), Error::<T>::ChannelCreationNotAuthorized);
+
+			let (max_message_size, max_capacity) = T::DefaultChannelSizeAndCapacityToSystem::get();
+
+			// create bidirectional channell
+			Self::init_open_channel(sender, recipient, max_capacity, max_message_size)?;
+			Self::accept_open_channel(recipient, sender)?;
+
+			Self::init_open_channel(recipient, sender, max_capacity, max_message_size)?;
+			Self::accept_open_channel(sender, recipient)?;
+
+			Self::deposit_event(Event::HrmpSystemChannelOpened {
+				sender,
+				recipient,
+				proposed_max_capacity: max_capacity,
+				proposed_max_message_size: max_message_size,
+			});
+
+			Ok(Pays::No.into())
+		}
 	}
 }
 
@@ -937,7 +971,7 @@ impl<T: Config> Pallet<T> {
 				Some(req_data) => req_data,
 				None => {
 					// Can't normally happen but no need to panic.
-					continue
+					continue;
 				},
 			};
 
@@ -995,7 +1029,7 @@ impl<T: Config> Pallet<T> {
 	fn process_hrmp_open_channel_requests(config: &HostConfiguration<BlockNumberFor<T>>) {
 		let mut open_req_channels = HrmpOpenChannelRequestsList::<T>::get();
 		if open_req_channels.is_empty() {
-			return
+			return;
 		}
 
 		// iterate the vector starting from the end making our way to the beginning. This way we
@@ -1004,7 +1038,7 @@ impl<T: Config> Pallet<T> {
 		loop {
 			// bail if we've iterated over all items.
 			if idx == 0 {
-				break
+				break;
 			}
 
 			idx -= 1;
@@ -1018,8 +1052,8 @@ impl<T: Config> Pallet<T> {
 			let recipient_deposit = if system_channel { 0 } else { config.hrmp_recipient_deposit };
 
 			if request.confirmed {
-				if <paras::Pallet<T>>::is_valid_para(channel_id.sender) &&
-					<paras::Pallet<T>>::is_valid_para(channel_id.recipient)
+				if <paras::Pallet<T>>::is_valid_para(channel_id.sender)
+					&& <paras::Pallet<T>>::is_valid_para(channel_id.recipient)
 				{
 					HrmpChannels::<T>::insert(
 						&channel_id,
@@ -1116,22 +1150,22 @@ impl<T: Config> Pallet<T> {
 		// (b) However, a parachain cannot read into "the future", therefore the watermark should
 		//     not be greater than the relay-chain context block which the parablock refers to.
 		if new_hrmp_watermark == relay_chain_parent_number {
-			return Ok(())
+			return Ok(());
 		}
 
 		if new_hrmp_watermark > relay_chain_parent_number {
 			return Err(HrmpWatermarkAcceptanceErr::AheadRelayParent {
 				new_watermark: new_hrmp_watermark,
 				relay_chain_parent_number,
-			})
+			});
 		}
 
 		if let Some(last_watermark) = HrmpWatermarks::<T>::get(&recipient) {
 			if new_hrmp_watermark <= last_watermark {
 				return Err(HrmpWatermarkAcceptanceErr::AdvancementRule {
 					new_watermark: new_hrmp_watermark,
 					last_watermark,
-				})
+				});
 			}
 		}
 
@@ -1146,7 +1180,7 @@ impl<T: Config> Pallet<T> {
 		{
 			return Err(HrmpWatermarkAcceptanceErr::LandsOnBlockWithNoMessages {
 				new_watermark: new_hrmp_watermark,
-			})
+			});
 		}
 		Ok(())
 	}
@@ -1168,7 +1202,7 @@ impl<T: Config> Pallet<T> {
 			return Err(OutboundHrmpAcceptanceErr::MoreMessagesThanPermitted {
 				sent: out_hrmp_msgs.len() as u32,
 				permitted: config.hrmp_max_message_num_per_candidate,
-			})
+			});
 		}
 
 		let mut last_recipient = None::<ParaId>;
@@ -1180,8 +1214,9 @@ impl<T: Config> Pallet<T> {
 				// the messages must be sorted in ascending order and there must be no two messages
 				// sent to the same recipient. Thus we can check that every recipient is strictly
 				// greater than the previous one.
-				Some(last_recipient) if out_msg.recipient <= last_recipient =>
-					return Err(OutboundHrmpAcceptanceErr::NotSorted { idx }),
+				Some(last_recipient) if out_msg.recipient <= last_recipient => {
+					return Err(OutboundHrmpAcceptanceErr::NotSorted { idx })
+				},
 				_ => last_recipient = Some(out_msg.recipient),
 			}
 
@@ -1198,7 +1233,7 @@ impl<T: Config> Pallet<T> {
 					idx,
 					msg_size,
 					max_size: channel.max_message_size,
-				})
+				});
 			}
 
 			let new_total_size = channel.total_size + out_msg.data.len() as u32;
@@ -1207,7 +1242,7 @@ impl<T: Config> Pallet<T> {
 					idx,
 					total_size: new_total_size,
 					limit: channel.max_total_size,
-				})
+				});
 			}
 
 			let new_msg_count = channel.msg_count + 1;
@@ -1216,7 +1251,7 @@ impl<T: Config> Pallet<T> {
 					idx,
 					count: new_msg_count,
 					limit: channel.max_capacity,
-				})
+				});
 			}
 		}
 
@@ -1230,7 +1265,7 @@ impl<T: Config> Pallet<T> {
 
 		for recipient in recipients {
 			let Some(channel) = HrmpChannels::<T>::get(&HrmpChannelId { sender, recipient }) else {
-				continue
+				continue;
 			};
 			remaining.push((
 				recipient,
@@ -1320,7 +1355,7 @@ impl<T: Config> Pallet<T> {
 				None => {
 					// apparently, that since acceptance of this candidate the recipient was
 					// offboarded and the channel no longer exists.
-					continue
+					continue;
 				},
 			};
 

polkadot/runtime/parachains/src/mock.rs

@@ -248,13 +248,15 @@ impl crate::dmp::Config for Test {}
 
 parameter_types! {
 	pub const FirstMessageFactorPercent: u64 = 100;
+	pub const DefaultChannelSizeAndCapacityToSystem: (u32, u32) = (51200, 500);
 }
 
 impl crate::hrmp::Config for Test {
 	type RuntimeOrigin = RuntimeOrigin;
 	type RuntimeEvent = RuntimeEvent;
 	type ChannelManager = frame_system::EnsureRoot<u64>;
 	type Currency = pallet_balances::Pallet<Test>;
+	type DefaultChannelSizeAndCapacityToSystem = DefaultChannelSizeAndCapacityToSystem;
 	type WeightInfo = crate::hrmp::TestWeightInfo;
 }
 

polkadot/runtime/rococo/src/lib.rs

@@ -995,11 +995,16 @@ impl pallet_message_queue::Config for Runtime {
 
 impl parachains_dmp::Config for Runtime {}
 
+parameter_types! {
+	pub const DefaultChannelSizeAndCapacityToSystem: (u32, u32) = (51200, 500);
+}
+
 impl parachains_hrmp::Config for Runtime {
 	type RuntimeOrigin = RuntimeOrigin;
 	type RuntimeEvent = RuntimeEvent;
 	type ChannelManager = EnsureRoot<AccountId>;
 	type Currency = Balances;
+	type DefaultChannelSizeAndCapacityToSystem = DefaultChannelSizeAndCapacityToSystem;
 	type WeightInfo = weights::runtime_parachains_hrmp::WeightInfo<Runtime>;
 }
 

polkadot/runtime/test-runtime/src/lib.rs

@@ -554,13 +554,15 @@ impl parachains_dmp::Config for Runtime {}
 
 parameter_types! {
 	pub const FirstMessageFactorPercent: u64 = 100;
+	pub const DefaultChannelSizeAndCapacityToSystem: (u32, u32) = (51200, 500);
 }
 
 impl parachains_hrmp::Config for Runtime {
 	type RuntimeOrigin = RuntimeOrigin;
 	type RuntimeEvent = RuntimeEvent;
 	type ChannelManager = frame_system::EnsureRoot<AccountId>;
 	type Currency = Balances;
+	type DefaultChannelSizeAndCapacityToSystem = DefaultChannelSizeAndCapacityToSystem;
 	type WeightInfo = parachains_hrmp::TestWeightInfo;
 }
 

polkadot/runtime/westend/src/lib.rs

@@ -1200,11 +1200,16 @@ impl pallet_message_queue::Config for Runtime {
 
 impl parachains_dmp::Config for Runtime {}
 
+parameter_types! {
+	pub const DefaultChannelSizeAndCapacityToSystem: (u32, u32) = (51200, 500);
+}
+
 impl parachains_hrmp::Config for Runtime {
 	type RuntimeOrigin = RuntimeOrigin;
 	type RuntimeEvent = RuntimeEvent;
 	type ChannelManager = EnsureRoot<AccountId>;
 	type Currency = Balances;
+	type DefaultChannelSizeAndCapacityToSystem = DefaultChannelSizeAndCapacityToSystem;
 	type WeightInfo = weights::runtime_parachains_hrmp::WeightInfo<Self>;
 }