-
Notifications
You must be signed in to change notification settings - Fork 741
/
universal_exports.rs
907 lines (820 loc) · 32.1 KB
/
universal_exports.rs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
// Copyright (C) Parity Technologies (UK) Ltd.
// This file is part of Polkadot.
// Polkadot is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// Polkadot is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with Polkadot. If not, see <http://www.gnu.org/licenses/>.
//! Traits and utilities to help with origin mutation and bridging.
use crate::InspectMessageQueues;
use alloc::{vec, vec::Vec};
use codec::{Decode, Encode};
use core::{convert::TryInto, marker::PhantomData};
use frame_support::{ensure, traits::Get};
use xcm::prelude::*;
use xcm_executor::traits::{validate_export, ExportXcm};
use SendError::*;
/// Returns the network ID and consensus location within that network of the remote
/// location `dest` which is itself specified as a location relative to the local
/// chain, itself situated at `universal_local` within the consensus universe. If
/// `dest` is not a location in remote consensus, then an error is returned.
pub fn ensure_is_remote(
universal_local: impl Into<InteriorLocation>,
dest: impl Into<Location>,
) -> Result<(NetworkId, InteriorLocation), Location> {
let dest = dest.into();
let universal_local = universal_local.into();
let local_net = match universal_local.global_consensus() {
Ok(x) => x,
Err(_) => return Err(dest),
};
let universal_destination: InteriorLocation = universal_local
.into_location()
.appended_with(dest.clone())
.map_err(|x| x.1)?
.try_into()?;
let (remote_dest, remote_net) = match universal_destination.split_first() {
(d, Some(GlobalConsensus(n))) if n != local_net => (d, n),
_ => return Err(dest),
};
Ok((remote_net, remote_dest))
}
/// Implementation of `SendXcm` which uses the given `ExportXcm` implementation in order to forward
/// the message over a bridge.
///
/// No effort is made to charge for any bridge fees, so this can only be used when it is known
/// that the message sending cannot be abused in any way.
///
/// This is only useful when the local chain has bridging capabilities.
pub struct UnpaidLocalExporter<Exporter, UniversalLocation>(
PhantomData<(Exporter, UniversalLocation)>,
);
impl<Exporter: ExportXcm, UniversalLocation: Get<InteriorLocation>> SendXcm
for UnpaidLocalExporter<Exporter, UniversalLocation>
{
type Ticket = Exporter::Ticket;
fn validate(
dest: &mut Option<Location>,
msg: &mut Option<Xcm<()>>,
) -> SendResult<Exporter::Ticket> {
// This `clone` ensures that `dest` is not consumed in any case.
let d = dest.clone().take().ok_or(MissingArgument)?;
let universal_source = UniversalLocation::get();
let devolved = ensure_is_remote(universal_source.clone(), d).map_err(|_| NotApplicable)?;
let (remote_network, remote_location) = devolved;
let xcm = msg.take().ok_or(MissingArgument)?;
validate_export::<Exporter>(
remote_network,
0,
universal_source,
remote_location,
xcm.clone(),
)
.inspect_err(|err| {
if let NotApplicable = err {
// We need to make sure that msg is not consumed in case of `NotApplicable`.
*msg = Some(xcm);
}
})
}
fn deliver(ticket: Exporter::Ticket) -> Result<XcmHash, SendError> {
Exporter::deliver(ticket)
}
#[cfg(feature = "runtime-benchmarks")]
fn ensure_successful_delivery(_: Option<Location>) {}
}
pub trait ExporterFor {
/// Return the locally-routable bridge (if any) capable of forwarding `message` to the
/// `remote_location` on the remote `network`, together with the payment which is required.
///
/// The payment is specified from the local context, not the bridge chain. This is the
/// total amount to withdraw in to Holding and should cover both payment for the execution on
/// the bridge chain and payment for the use of the `ExportMessage` instruction.
fn exporter_for(
network: &NetworkId,
remote_location: &InteriorLocation,
message: &Xcm<()>,
) -> Option<(Location, Option<Asset>)>;
}
#[impl_trait_for_tuples::impl_for_tuples(30)]
impl ExporterFor for Tuple {
fn exporter_for(
network: &NetworkId,
remote_location: &InteriorLocation,
message: &Xcm<()>,
) -> Option<(Location, Option<Asset>)> {
for_tuples!( #(
if let Some(r) = Tuple::exporter_for(network, remote_location, message) {
return Some(r);
}
)* );
None
}
}
/// Configuration item representing a single exporter in the `NetworkExportTable`.
pub struct NetworkExportTableItem {
/// Supported remote network.
pub remote_network: NetworkId,
/// Remote location filter.
/// If `Some`, the requested remote location must be equal to one of the items in the vector.
/// These are locations in the remote network.
/// If `None`, then the check is skipped.
pub remote_location_filter: Option<Vec<InteriorLocation>>,
/// Locally-routable bridge with bridging capabilities to the `remote_network` and
/// `remote_location`. See [`ExporterFor`] for more details.
pub bridge: Location,
/// The local payment.
/// See [`ExporterFor`] for more details.
pub payment: Option<Asset>,
}
impl NetworkExportTableItem {
pub fn new(
remote_network: NetworkId,
remote_location_filter: Option<Vec<InteriorLocation>>,
bridge: Location,
payment: Option<Asset>,
) -> Self {
Self { remote_network, remote_location_filter, bridge, payment }
}
}
/// An adapter for the implementation of `ExporterFor`, which attempts to find the
/// `(bridge_location, payment)` for the requested `network` and `remote_location` in the provided
/// `T` table containing various exporters.
pub struct NetworkExportTable<T>(core::marker::PhantomData<T>);
impl<T: Get<Vec<NetworkExportTableItem>>> ExporterFor for NetworkExportTable<T> {
fn exporter_for(
network: &NetworkId,
remote_location: &InteriorLocation,
_: &Xcm<()>,
) -> Option<(Location, Option<Asset>)> {
T::get()
.into_iter()
.find(|item| {
&item.remote_network == network &&
item.remote_location_filter
.as_ref()
.map(|filters| filters.iter().any(|filter| filter == remote_location))
.unwrap_or(true)
})
.map(|item| (item.bridge, item.payment))
}
}
pub fn forward_id_for(original_id: &XcmHash) -> XcmHash {
(b"forward_id_for", original_id).using_encoded(sp_io::hashing::blake2_256)
}
/// Implementation of `SendXcm` which wraps the message inside an `ExportMessage` instruction
/// and sends it to a destination known to be able to handle it.
///
/// No effort is made to make payment to the bridge for its services, so the bridge location
/// must have been configured with a barrier rule allowing unpaid execution for this message
/// coming from our origin.
///
/// This is only useful if we have special dispensation by the remote bridges to have the
/// `ExportMessage` instruction executed without payment.
///
/// The `XcmHash` value returned by `deliver` will always be the same as that returned by the
/// message exporter (`Bridges`). Generally this should take notice of the message should it
/// end with the `SetTopic` instruction.
///
/// In the case that the message ends with a `SetTopic(T)` (as should be the case if the top-level
/// router is `WithUniqueTopic`), then the forwarding message (i.e. the one carrying the
/// export instruction *to* the bridge in local consensus) will also end with a `SetTopic` whose
/// inner is `forward_id_for(T)`. If this is not the case then the onward message will not be given
/// the `SetTopic` afterword.
pub struct UnpaidRemoteExporter<Bridges, Router, UniversalLocation>(
PhantomData<(Bridges, Router, UniversalLocation)>,
);
impl<Bridges: ExporterFor, Router: SendXcm, UniversalLocation: Get<InteriorLocation>> SendXcm
for UnpaidRemoteExporter<Bridges, Router, UniversalLocation>
{
type Ticket = Router::Ticket;
fn validate(
dest: &mut Option<Location>,
msg: &mut Option<Xcm<()>>,
) -> SendResult<Router::Ticket> {
// This `clone` ensures that `dest` is not consumed in any case.
let d = dest.clone().take().ok_or(MissingArgument)?;
let devolved = ensure_is_remote(UniversalLocation::get(), d).map_err(|_| NotApplicable)?;
let (remote_network, remote_location) = devolved;
let xcm = msg.take().ok_or(MissingArgument)?;
// find exporter
let Some((bridge, maybe_payment)) =
Bridges::exporter_for(&remote_network, &remote_location, &xcm)
else {
// We need to make sure that msg is not consumed in case of `NotApplicable`.
*msg = Some(xcm);
return Err(NotApplicable)
};
ensure!(maybe_payment.is_none(), Unroutable);
// `xcm` should already end with `SetTopic` - if it does, then extract and derive into
// an onward topic ID.
let maybe_forward_id = match xcm.last() {
Some(SetTopic(t)) => Some(forward_id_for(t)),
_ => None,
};
// We then send a normal message to the bridge asking it to export the prepended
// message to the remote chain. This will only work if the bridge will do the message
// export for free. Common-good chains will typically be afforded this.
let mut message = Xcm(vec![
UnpaidExecution { weight_limit: Unlimited, check_origin: None },
ExportMessage {
network: remote_network,
destination: remote_location,
xcm: xcm.clone(),
},
]);
if let Some(forward_id) = maybe_forward_id {
message.0.push(SetTopic(forward_id));
}
validate_send::<Router>(bridge, message).inspect_err(|err| {
if let NotApplicable = err {
// We need to make sure that msg is not consumed in case of `NotApplicable`.
*msg = Some(xcm);
}
})
}
fn deliver(validation: Self::Ticket) -> Result<XcmHash, SendError> {
Router::deliver(validation)
}
#[cfg(feature = "runtime-benchmarks")]
fn ensure_successful_delivery(location: Option<Location>) {
Router::ensure_successful_delivery(location);
}
}
/// Implementation of `SendXcm` which wraps the message inside an `ExportMessage` instruction
/// and sends it to a destination known to be able to handle it.
///
/// The `ExportMessage` instruction on the bridge is paid for from the local chain's sovereign
/// account on the bridge. The amount paid is determined through the `ExporterFor` trait.
///
/// The `XcmHash` value returned by `deliver` will always be the same as that returned by the
/// message exporter (`Bridges`). Generally this should take notice of the message should it
/// end with the `SetTopic` instruction.
///
/// In the case that the message ends with a `SetTopic(T)` (as should be the case if the top-level
/// router is `WithUniqueTopic`), then the forwarding message (i.e. the one carrying the
/// export instruction *to* the bridge in local consensus) will also end with a `SetTopic` whose
/// inner is `forward_id_for(T)`. If this is not the case then the onward message will not be given
/// the `SetTopic` afterword.
pub struct SovereignPaidRemoteExporter<Bridges, Router, UniversalLocation>(
PhantomData<(Bridges, Router, UniversalLocation)>,
);
impl<Bridges: ExporterFor, Router: SendXcm, UniversalLocation: Get<InteriorLocation>> SendXcm
for SovereignPaidRemoteExporter<Bridges, Router, UniversalLocation>
{
type Ticket = Router::Ticket;
fn validate(
dest: &mut Option<Location>,
msg: &mut Option<Xcm<()>>,
) -> SendResult<Router::Ticket> {
// This `clone` ensures that `dest` is not consumed in any case.
let d = dest.clone().take().ok_or(MissingArgument)?;
let devolved = ensure_is_remote(UniversalLocation::get(), d).map_err(|_| NotApplicable)?;
let (remote_network, remote_location) = devolved;
let xcm = msg.take().ok_or(MissingArgument)?;
// find exporter
let Some((bridge, maybe_payment)) =
Bridges::exporter_for(&remote_network, &remote_location, &xcm)
else {
// We need to make sure that msg is not consumed in case of `NotApplicable`.
*msg = Some(xcm);
return Err(NotApplicable)
};
// `xcm` should already end with `SetTopic` - if it does, then extract and derive into
// an onward topic ID.
let maybe_forward_id = match xcm.last() {
Some(SetTopic(t)) => Some(forward_id_for(t)),
_ => None,
};
let local_from_bridge =
UniversalLocation::get().invert_target(&bridge).map_err(|_| Unroutable)?;
let export_instruction = ExportMessage {
network: remote_network,
destination: remote_location,
xcm: xcm.clone(),
};
let mut message = Xcm(if let Some(ref payment) = maybe_payment {
let fees = payment
.clone()
.reanchored(&bridge, &UniversalLocation::get())
.map_err(|_| Unroutable)?;
vec![
WithdrawAsset(fees.clone().into()),
BuyExecution { fees, weight_limit: Unlimited },
// `SetAppendix` ensures that `fees` are not trapped in any case, for example, when
// `ExportXcm::validate` encounters an error during the processing of
// `ExportMessage`.
SetAppendix(Xcm(vec![DepositAsset {
assets: AllCounted(1).into(),
beneficiary: local_from_bridge,
}])),
export_instruction,
]
} else {
vec![export_instruction]
});
if let Some(forward_id) = maybe_forward_id {
message.0.push(SetTopic(forward_id));
}
// We then send a normal message to the bridge asking it to export the prepended
// message to the remote chain.
let (v, mut cost) = validate_send::<Router>(bridge, message).inspect_err(|err| {
if let NotApplicable = err {
// We need to make sure that msg is not consumed in case of `NotApplicable`.
*msg = Some(xcm);
}
})?;
if let Some(bridge_payment) = maybe_payment {
cost.push(bridge_payment);
}
Ok((v, cost))
}
fn deliver(ticket: Router::Ticket) -> Result<XcmHash, SendError> {
Router::deliver(ticket)
}
#[cfg(feature = "runtime-benchmarks")]
fn ensure_successful_delivery(location: Option<Location>) {
Router::ensure_successful_delivery(location);
}
}
impl<Bridges, Router, UniversalLocation> InspectMessageQueues
for SovereignPaidRemoteExporter<Bridges, Router, UniversalLocation>
{
fn clear_messages() {}
/// This router needs to implement `InspectMessageQueues` but doesn't have to
/// return any messages, since it just reuses the `XcmpQueue` router.
fn get_messages() -> Vec<(VersionedLocation, Vec<VersionedXcm<()>>)> {
Vec::new()
}
}
pub trait DispatchBlob {
/// Takes an incoming blob from over some point-to-point link (usually from some sort of
/// inter-consensus bridge) and then does what needs to be done with it. Usually this means
/// forwarding it on into some other location sharing our consensus or possibly just enqueuing
/// it for execution locally if it is destined for the local chain.
///
/// NOTE: The API does not provide for any kind of weight or fee management; the size of the
/// `blob` is known to the caller and so the operation must have a linear weight relative to
/// `blob`'s length. This means that you will generally only want to **enqueue** the blob, not
/// enact it. Fees must be handled by the caller.
fn dispatch_blob(blob: Vec<u8>) -> Result<(), DispatchBlobError>;
}
pub trait HaulBlob {
/// Sends a blob over some point-to-point link. This will generally be implemented by a bridge.
fn haul_blob(blob: Vec<u8>) -> Result<(), HaulBlobError>;
}
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum HaulBlobError {
/// Represents point-to-point link failure with a human-readable explanation of the specific
/// issue is provided.
Transport(&'static str),
}
impl From<HaulBlobError> for SendError {
fn from(err: HaulBlobError) -> Self {
match err {
HaulBlobError::Transport(reason) => SendError::Transport(reason),
}
}
}
#[derive(Clone, Encode, Decode)]
pub struct BridgeMessage {
/// The message destination as a *Universal Location*. This means it begins with a
/// `GlobalConsensus` junction describing the network under which global consensus happens.
/// If this does not match our global consensus then it's a fatal error.
pub universal_dest: VersionedInteriorLocation,
pub message: VersionedXcm<()>,
}
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum DispatchBlobError {
Unbridgable,
InvalidEncoding,
UnsupportedLocationVersion,
UnsupportedXcmVersion,
RoutingError,
NonUniversalDestination,
WrongGlobal,
}
pub struct BridgeBlobDispatcher<Router, OurPlace, OurPlaceBridgeInstance>(
PhantomData<(Router, OurPlace, OurPlaceBridgeInstance)>,
);
impl<
Router: SendXcm,
OurPlace: Get<InteriorLocation>,
OurPlaceBridgeInstance: Get<Option<InteriorLocation>>,
> DispatchBlob for BridgeBlobDispatcher<Router, OurPlace, OurPlaceBridgeInstance>
{
fn dispatch_blob(blob: Vec<u8>) -> Result<(), DispatchBlobError> {
let our_universal = OurPlace::get();
let our_global =
our_universal.global_consensus().map_err(|()| DispatchBlobError::Unbridgable)?;
let BridgeMessage { universal_dest, message } =
Decode::decode(&mut &blob[..]).map_err(|_| DispatchBlobError::InvalidEncoding)?;
let universal_dest: InteriorLocation = universal_dest
.try_into()
.map_err(|_| DispatchBlobError::UnsupportedLocationVersion)?;
// `universal_dest` is the desired destination within the universe: first we need to check
// we're in the right global consensus.
let intended_global = universal_dest
.global_consensus()
.map_err(|()| DispatchBlobError::NonUniversalDestination)?;
ensure!(intended_global == our_global, DispatchBlobError::WrongGlobal);
let dest = universal_dest.relative_to(&our_universal);
let mut message: Xcm<()> =
message.try_into().map_err(|_| DispatchBlobError::UnsupportedXcmVersion)?;
// Prepend our bridge instance discriminator.
// Can be used for fine-grained control of origin on destination in case of multiple bridge
// instances, e.g. restrict `type UniversalAliases` and `UniversalOrigin` instruction to
// trust just particular bridge instance for `NetworkId`.
if let Some(bridge_instance) = OurPlaceBridgeInstance::get() {
message.0.insert(0, DescendOrigin(bridge_instance));
}
let _ = send_xcm::<Router>(dest, message).map_err(|_| DispatchBlobError::RoutingError)?;
Ok(())
}
}
pub struct HaulBlobExporter<Bridge, BridgedNetwork, DestinationVersion, Price>(
PhantomData<(Bridge, BridgedNetwork, DestinationVersion, Price)>,
);
/// `ExportXcm` implementation for `HaulBlobExporter`.
///
/// # Type Parameters
///
/// ```text
/// - Bridge: Implements `HaulBlob`.
/// - BridgedNetwork: The relative location of the bridged consensus system with the expected `GlobalConsensus` junction.
/// - DestinationVersion: Implements `GetVersion` for retrieving XCM version for the destination.
/// - Price: potential fees for exporting.
/// ```
impl<
Bridge: HaulBlob,
BridgedNetwork: Get<Location>,
DestinationVersion: GetVersion,
Price: Get<Assets>,
> ExportXcm for HaulBlobExporter<Bridge, BridgedNetwork, DestinationVersion, Price>
{
type Ticket = (Vec<u8>, XcmHash);
fn validate(
network: NetworkId,
_channel: u32,
universal_source: &mut Option<InteriorLocation>,
destination: &mut Option<InteriorLocation>,
message: &mut Option<Xcm<()>>,
) -> Result<((Vec<u8>, XcmHash), Assets), SendError> {
let (bridged_network, bridged_network_location_parents) = {
let Location { parents, interior: mut junctions } = BridgedNetwork::get();
match junctions.take_first() {
Some(GlobalConsensus(network)) => (network, parents),
_ => return Err(NotApplicable),
}
};
ensure!(&network == &bridged_network, NotApplicable);
// We don't/can't use the `channel` for this adapter.
let dest = destination.take().ok_or(SendError::MissingArgument)?;
// Let's resolve the known/supported XCM version for the destination because we don't know
// if it supports the same/latest version.
let (universal_dest, version) =
match dest.pushed_front_with(GlobalConsensus(bridged_network)) {
Ok(d) => {
let version = DestinationVersion::get_version_for(&Location::from(
AncestorThen(bridged_network_location_parents, d.clone()),
))
.ok_or(SendError::DestinationUnsupported)?;
(d, version)
},
Err((dest, _)) => {
*destination = Some(dest);
return Err(NotApplicable)
},
};
// Let's adjust XCM with `UniversalOrigin`, `DescendOrigin` and`SetTopic`.
let (local_net, local_sub) = universal_source
.take()
.ok_or(SendError::MissingArgument)?
.split_global()
.map_err(|()| SendError::Unroutable)?;
let mut message = message.take().ok_or(SendError::MissingArgument)?;
let maybe_id = match message.last() {
Some(SetTopic(t)) => Some(*t),
_ => None,
};
message.0.insert(0, UniversalOrigin(GlobalConsensus(local_net)));
if local_sub != Here {
message.0.insert(1, DescendOrigin(local_sub));
}
// We cannot use the latest `Versioned` because we don't know if the target chain already
// supports the same version. Therefore, we better control the destination version with best
// efforts.
let message = VersionedXcm::from(message)
.into_version(version)
.map_err(|()| SendError::DestinationUnsupported)?;
let universal_dest = VersionedInteriorLocation::from(universal_dest)
.into_version(version)
.map_err(|()| SendError::DestinationUnsupported)?;
let id = maybe_id.unwrap_or_else(|| message.using_encoded(sp_io::hashing::blake2_256));
let blob = BridgeMessage { universal_dest, message }.encode();
Ok(((blob, id), Price::get()))
}
fn deliver((blob, id): (Vec<u8>, XcmHash)) -> Result<XcmHash, SendError> {
Bridge::haul_blob(blob)?;
Ok(id)
}
}
#[cfg(test)]
mod tests {
use super::*;
use frame_support::{
assert_err, assert_ok,
traits::{Contains, Equals},
};
#[test]
fn ensure_is_remote_works() {
// A Kusama parachain is remote from the Polkadot Relay.
let x = ensure_is_remote(Polkadot, (Parent, Kusama, Parachain(1000)));
assert_eq!(x, Ok((Kusama, Parachain(1000).into())));
// Polkadot Relay is remote from a Kusama parachain.
let x = ensure_is_remote((Kusama, Parachain(1000)), (Parent, Parent, Polkadot));
assert_eq!(x, Ok((Polkadot, Here)));
// Our own parachain is local.
let x = ensure_is_remote(Polkadot, Parachain(1000));
assert_eq!(x, Err(Parachain(1000).into()));
// Polkadot's parachain is not remote if we are Polkadot.
let x = ensure_is_remote(Polkadot, (Parent, Polkadot, Parachain(1000)));
assert_eq!(x, Err((Parent, Polkadot, Parachain(1000)).into()));
// If we don't have a consensus ancestor, then we cannot determine remoteness.
let x = ensure_is_remote((), (Parent, Polkadot, Parachain(1000)));
assert_eq!(x, Err((Parent, Polkadot, Parachain(1000)).into()));
}
pub struct OkFor<Filter>(PhantomData<Filter>);
impl<Filter: Contains<Location>> SendXcm for OkFor<Filter> {
type Ticket = ();
fn validate(
destination: &mut Option<Location>,
_message: &mut Option<Xcm<()>>,
) -> SendResult<Self::Ticket> {
if let Some(d) = destination.as_ref() {
if Filter::contains(&d) {
return Ok(((), Assets::new()))
}
}
Err(NotApplicable)
}
fn deliver(_ticket: Self::Ticket) -> Result<XcmHash, SendError> {
Ok([0; 32])
}
#[cfg(feature = "runtime-benchmarks")]
fn ensure_successful_delivery(_: Option<Location>) {}
}
impl<Filter: Contains<(NetworkId, InteriorLocation)>> ExportXcm for OkFor<Filter> {
type Ticket = ();
fn validate(
network: NetworkId,
_: u32,
_: &mut Option<InteriorLocation>,
destination: &mut Option<InteriorLocation>,
_: &mut Option<Xcm<()>>,
) -> SendResult<Self::Ticket> {
if let Some(d) = destination.as_ref() {
if Filter::contains(&(network, d.clone())) {
return Ok(((), Assets::new()))
}
}
Err(NotApplicable)
}
fn deliver(_ticket: Self::Ticket) -> Result<XcmHash, SendError> {
Ok([1; 32])
}
}
/// Generic test case asserting that dest and msg is not consumed by `validate` implementation
/// of `SendXcm` in case of expected result.
fn ensure_validate_does_not_consume_dest_or_msg<S: SendXcm>(
dest: Location,
assert_result: impl Fn(SendResult<S::Ticket>),
) {
let mut dest_wrapper = Some(dest.clone());
let msg = Xcm::<()>::new();
let mut msg_wrapper = Some(msg.clone());
assert_result(S::validate(&mut dest_wrapper, &mut msg_wrapper));
// ensure dest and msg are untouched
assert_eq!(Some(dest), dest_wrapper);
assert_eq!(Some(msg), msg_wrapper);
}
#[test]
fn local_exporters_works() {
frame_support::parameter_types! {
pub Local: NetworkId = ByGenesis([0; 32]);
pub UniversalLocation: InteriorLocation = [GlobalConsensus(Local::get()), Parachain(1234)].into();
pub DifferentRemote: NetworkId = ByGenesis([22; 32]);
pub RemoteDestination: Junction = Parachain(9657);
pub RoutableBridgeFilter: (NetworkId, InteriorLocation) = (DifferentRemote::get(), RemoteDestination::get().into());
}
type RoutableBridgeExporter = OkFor<Equals<RoutableBridgeFilter>>;
type NotApplicableBridgeExporter = OkFor<()>;
assert_ok!(validate_export::<RoutableBridgeExporter>(
DifferentRemote::get(),
0,
UniversalLocation::get(),
RemoteDestination::get().into(),
Xcm::default()
));
assert_err!(
validate_export::<NotApplicableBridgeExporter>(
DifferentRemote::get(),
0,
UniversalLocation::get(),
RemoteDestination::get().into(),
Xcm::default()
),
NotApplicable
);
// 1. check with local destination (should be remote)
let local_dest: Location = (Parent, Parachain(5678)).into();
assert!(ensure_is_remote(UniversalLocation::get(), local_dest.clone()).is_err());
// UnpaidLocalExporter
ensure_validate_does_not_consume_dest_or_msg::<
UnpaidLocalExporter<RoutableBridgeExporter, UniversalLocation>,
>(local_dest.clone(), |result| assert_eq!(Err(NotApplicable), result));
// 2. check with not applicable from the inner router (using `NotApplicableBridgeSender`)
let remote_dest: Location =
(Parent, Parent, DifferentRemote::get(), RemoteDestination::get()).into();
assert!(ensure_is_remote(UniversalLocation::get(), remote_dest.clone()).is_ok());
// UnpaidLocalExporter
ensure_validate_does_not_consume_dest_or_msg::<
UnpaidLocalExporter<NotApplicableBridgeExporter, UniversalLocation>,
>(remote_dest.clone(), |result| assert_eq!(Err(NotApplicable), result));
// 3. Ok - deliver
// UnpaidRemoteExporter
assert_ok!(send_xcm::<UnpaidLocalExporter<RoutableBridgeExporter, UniversalLocation>>(
remote_dest,
Xcm::default()
));
}
#[test]
fn remote_exporters_works() {
frame_support::parameter_types! {
pub Local: NetworkId = ByGenesis([0; 32]);
pub UniversalLocation: InteriorLocation = [GlobalConsensus(Local::get()), Parachain(1234)].into();
pub DifferentRemote: NetworkId = ByGenesis([22; 32]);
pub RoutableBridge: Location = Location::new(1, Parachain(9657));
// not routable
pub NotApplicableBridgeTable: Vec<NetworkExportTableItem> = vec![];
// routable
pub RoutableBridgeTable: Vec<NetworkExportTableItem> = vec![
NetworkExportTableItem::new(
DifferentRemote::get(),
None,
RoutableBridge::get(),
None
)
];
}
type RoutableBridgeSender = OkFor<Equals<RoutableBridge>>;
type NotApplicableBridgeSender = OkFor<()>;
assert_ok!(validate_send::<RoutableBridgeSender>(RoutableBridge::get(), Xcm::default()));
assert_err!(
validate_send::<NotApplicableBridgeSender>(RoutableBridge::get(), Xcm::default()),
NotApplicable
);
// 1. check with local destination (should be remote)
let local_dest: Location = (Parent, Parachain(5678)).into();
assert!(ensure_is_remote(UniversalLocation::get(), local_dest.clone()).is_err());
// UnpaidRemoteExporter
ensure_validate_does_not_consume_dest_or_msg::<
UnpaidRemoteExporter<
NetworkExportTable<RoutableBridgeTable>,
RoutableBridgeSender,
UniversalLocation,
>,
>(local_dest.clone(), |result| assert_eq!(Err(NotApplicable), result));
// SovereignPaidRemoteExporter
ensure_validate_does_not_consume_dest_or_msg::<
SovereignPaidRemoteExporter<
NetworkExportTable<RoutableBridgeTable>,
RoutableBridgeSender,
UniversalLocation,
>,
>(local_dest, |result| assert_eq!(Err(NotApplicable), result));
// 2. check with not applicable destination (`NotApplicableBridgeTable`)
let remote_dest: Location = (Parent, Parent, DifferentRemote::get()).into();
assert!(ensure_is_remote(UniversalLocation::get(), remote_dest.clone()).is_ok());
// UnpaidRemoteExporter
ensure_validate_does_not_consume_dest_or_msg::<
UnpaidRemoteExporter<
NetworkExportTable<NotApplicableBridgeTable>,
RoutableBridgeSender,
UniversalLocation,
>,
>(remote_dest.clone(), |result| assert_eq!(Err(NotApplicable), result));
// SovereignPaidRemoteExporter
ensure_validate_does_not_consume_dest_or_msg::<
SovereignPaidRemoteExporter<
NetworkExportTable<NotApplicableBridgeTable>,
RoutableBridgeSender,
UniversalLocation,
>,
>(remote_dest, |result| assert_eq!(Err(NotApplicable), result));
// 3. check with not applicable from the inner router (using `NotApplicableBridgeSender`)
let remote_dest: Location = (Parent, Parent, DifferentRemote::get()).into();
assert!(ensure_is_remote(UniversalLocation::get(), remote_dest.clone()).is_ok());
// UnpaidRemoteExporter
ensure_validate_does_not_consume_dest_or_msg::<
UnpaidRemoteExporter<
NetworkExportTable<RoutableBridgeTable>,
NotApplicableBridgeSender,
UniversalLocation,
>,
>(remote_dest.clone(), |result| assert_eq!(Err(NotApplicable), result));
// SovereignPaidRemoteExporter
ensure_validate_does_not_consume_dest_or_msg::<
SovereignPaidRemoteExporter<
NetworkExportTable<RoutableBridgeTable>,
NotApplicableBridgeSender,
UniversalLocation,
>,
>(remote_dest.clone(), |result| assert_eq!(Err(NotApplicable), result));
// 4. Ok - deliver
// UnpaidRemoteExporter
assert_ok!(send_xcm::<
UnpaidRemoteExporter<
NetworkExportTable<RoutableBridgeTable>,
RoutableBridgeSender,
UniversalLocation,
>,
>(remote_dest.clone(), Xcm::default()));
// SovereignPaidRemoteExporter
assert_ok!(send_xcm::<
SovereignPaidRemoteExporter<
NetworkExportTable<RoutableBridgeTable>,
RoutableBridgeSender,
UniversalLocation,
>,
>(remote_dest, Xcm::default()));
}
#[test]
fn network_export_table_works() {
frame_support::parameter_types! {
pub NetworkA: NetworkId = ByGenesis([0; 32]);
pub Parachain1000InNetworkA: InteriorLocation = [Parachain(1000)].into();
pub Parachain2000InNetworkA: InteriorLocation = [Parachain(2000)].into();
pub NetworkB: NetworkId = ByGenesis([1; 32]);
pub BridgeToALocation: Location = Location::new(1, [Parachain(1234)]);
pub BridgeToBLocation: Location = Location::new(1, [Parachain(4321)]);
pub PaymentForNetworkAAndParachain2000: Asset = (Location::parent(), 150).into();
pub BridgeTable: alloc::vec::Vec<NetworkExportTableItem> = alloc::vec![
// NetworkA allows `Parachain(1000)` as remote location WITHOUT payment.
NetworkExportTableItem::new(
NetworkA::get(),
Some(vec![Parachain1000InNetworkA::get()]),
BridgeToALocation::get(),
None
),
// NetworkA allows `Parachain(2000)` as remote location WITH payment.
NetworkExportTableItem::new(
NetworkA::get(),
Some(vec![Parachain2000InNetworkA::get()]),
BridgeToALocation::get(),
Some(PaymentForNetworkAAndParachain2000::get())
),
// NetworkB allows all remote location.
NetworkExportTableItem::new(
NetworkB::get(),
None,
BridgeToBLocation::get(),
None
)
];
}
let test_data: Vec<(NetworkId, InteriorLocation, Option<(Location, Option<Asset>)>)> = vec![
(NetworkA::get(), [Parachain(1000)].into(), Some((BridgeToALocation::get(), None))),
(NetworkA::get(), [Parachain(1000), GeneralIndex(1)].into(), None),
(
NetworkA::get(),
[Parachain(2000)].into(),
Some((BridgeToALocation::get(), Some(PaymentForNetworkAAndParachain2000::get()))),
),
(NetworkA::get(), [Parachain(2000), GeneralIndex(1)].into(), None),
(NetworkA::get(), [Parachain(3000)].into(), None),
(NetworkB::get(), [Parachain(1000)].into(), Some((BridgeToBLocation::get(), None))),
(NetworkB::get(), [Parachain(2000)].into(), Some((BridgeToBLocation::get(), None))),
(NetworkB::get(), [Parachain(3000)].into(), Some((BridgeToBLocation::get(), None))),
];
for (network, remote_location, expected_result) in test_data {
assert_eq!(
NetworkExportTable::<BridgeTable>::exporter_for(
&network,
&remote_location,
&Xcm::default()
),
expected_result,
"expected_result: {:?} not matched for network: {:?} and remote_location: {:?}",
expected_result,
network,
remote_location,
)
}
}
}