moonbeam_runtime_common/
bridge.rs

1// Copyright 2025 Moonbeam foundation
2// This file is part of Moonbeam.
3
4// Moonbeam is free software: you can redistribute it and/or modify
5// it under the terms of the GNU General Public License as published by
6// the Free Software Foundation, either version 3 of the License, or
7// (at your option) any later version.
8
9// Moonbeam is distributed in the hope that it will be useful,
10// but WITHOUT ANY WARRANTY; without even the implied warranty of
11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12// GNU General Public License for more details.
13
14// You should have received a copy of the GNU General Public License
15// along with Moonbeam.  If not, see <http://www.gnu.org/licenses/>.
16
17use core::marker::PhantomData;
18use cumulus_primitives_core::AggregateMessageOrigin;
19use frame_support::pallet_prelude::Get;
20use frame_support::traits::{EnqueueMessage, ProcessMessage, QueueFootprintQuery};
21use frame_support::{ensure, BoundedVec};
22use pallet_xcm_bridge::BridgeId;
23use parity_scale_codec::{Decode, Encode};
24use sp_std::vec::Vec;
25use xcm::latest::{InteriorLocation, Location, SendError, SendResult, SendXcm, Xcm, XcmHash};
26use xcm::{VersionedLocation, VersionedXcm};
27use xcm_builder::{BridgeMessage, DispatchBlob, DispatchBlobError, InspectMessageQueues};
28
29/// Threshold for determining if the message queue is congested.
30/// Based on XcmpQueue pallet's QueueConfigData default (64KiB * 32 = 2MiB).
31/// It should be a good heuristic to determine if the queue is congested.
32const MESSAGE_QUEUE_CONGESTION_THRESHOLD: u32 = 32;
33
34/// The target that will be used when publishing logs related to this component.
35pub const LOG_TARGET: &str = "moonbeam-bridge";
36
37pub struct BridgeXcmRouter<MessageExporter>(PhantomData<MessageExporter>);
38
39// This struct acts as the `SendXcm` to the local instance of pallet_bridge_messages instead of
40// regular XCMP/DMP transport.
41impl<MessageExporter: SendXcm> SendXcm for BridgeXcmRouter<MessageExporter> {
42	type Ticket = MessageExporter::Ticket;
43
44	fn validate(
45		dest: &mut Option<Location>,
46		xcm: &mut Option<Xcm<()>>,
47	) -> SendResult<Self::Ticket> {
48		log::trace!(target: LOG_TARGET, "validate - msg: {xcm:?}, destination: {dest:?}");
49
50		MessageExporter::validate(dest, xcm)
51	}
52
53	fn deliver(ticket: Self::Ticket) -> Result<XcmHash, SendError> {
54		MessageExporter::deliver(ticket)
55	}
56}
57
58/// This router needs to implement `InspectMessageQueues` but doesn't have to
59/// return any messages, since it just reuses the `XcmpQueue` router.
60impl<MessageExporter> InspectMessageQueues for BridgeXcmRouter<MessageExporter> {
61	fn clear_messages() {}
62
63	fn get_messages() -> Vec<(VersionedLocation, Vec<VersionedXcm<()>>)> {
64		Vec::new()
65	}
66}
67
68pub struct LocalBlobDispatcher<MQ, OurPlace, OurPlaceBridgeInstance>(
69	PhantomData<(MQ, OurPlace, OurPlaceBridgeInstance)>,
70);
71impl<
72		MQ: EnqueueMessage<AggregateMessageOrigin>,
73		OurPlace: Get<InteriorLocation>,
74		OurPlaceBridgeInstance: Get<Option<InteriorLocation>>,
75	> DispatchBlob for LocalBlobDispatcher<MQ, OurPlace, OurPlaceBridgeInstance>
76{
77	fn dispatch_blob(blob: Vec<u8>) -> Result<(), DispatchBlobError> {
78		let our_universal = OurPlace::get();
79		let our_global = our_universal
80			.global_consensus()
81			.map_err(|()| DispatchBlobError::Unbridgable)?;
82		let BridgeMessage {
83			universal_dest,
84			message,
85		} = Decode::decode(&mut &blob[..]).map_err(|_| DispatchBlobError::InvalidEncoding)?;
86		let universal_dest: InteriorLocation = universal_dest
87			.try_into()
88			.map_err(|_| DispatchBlobError::UnsupportedLocationVersion)?;
89		// `universal_dest` is the desired destination within the universe: first we need to check
90		// we're in the right global consensus.
91		let intended_global = universal_dest
92			.global_consensus()
93			.map_err(|()| DispatchBlobError::NonUniversalDestination)?;
94		ensure!(
95			intended_global == our_global,
96			DispatchBlobError::WrongGlobal
97		);
98		let xcm: Xcm<()> = message
99			.try_into()
100			.map_err(|_| DispatchBlobError::UnsupportedXcmVersion)?;
101
102		let msg: BoundedVec<u8, MQ::MaxMessageLen> = xcm::opaque::VersionedXcm::V5(xcm)
103			.encode()
104			.try_into()
105			.map_err(|_| DispatchBlobError::InvalidEncoding)?;
106
107		MQ::enqueue_message(
108			msg.as_bounded_slice(),
109			AggregateMessageOrigin::Here, // The message came from the para-chain itself.
110		);
111
112		Ok(())
113	}
114}
115
116/// Implementation of `bp_xcm_bridge_hub::LocalXcmChannelManager` for congestion management.
117pub struct CongestionManager<Runtime>(PhantomData<Runtime>);
118impl<Runtime: pallet_message_queue::Config> pallet_xcm_bridge::LocalXcmChannelManager
119	for CongestionManager<Runtime>
120where
121	<Runtime as pallet_message_queue::Config>::MessageProcessor:
122		ProcessMessage<Origin = AggregateMessageOrigin>,
123{
124	type Error = SendError;
125
126	fn is_congested(_with: &Location) -> bool {
127		let book_state = <pallet_message_queue::Pallet<Runtime> as QueueFootprintQuery<
128			AggregateMessageOrigin,
129		>>::footprint(AggregateMessageOrigin::Here);
130
131		book_state.ready_pages >= MESSAGE_QUEUE_CONGESTION_THRESHOLD
132	}
133
134	fn suspend_bridge(_local_origin: &Location, _bridge: BridgeId) -> Result<(), Self::Error> {
135		// Currently, we send a suspend message, but we reject inbound
136		// messages when the queue is congested.
137		Ok(())
138	}
139
140	fn resume_bridge(_local_origin: &Location, _bridge: BridgeId) -> Result<(), Self::Error> {
141		Ok(())
142	}
143}
moonbeam_runtime_common/bridge.rs

moonbeam_runtime_common/
bridge.rs
