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1 | | -diff --git a/fundamentals/src/pallet_xcm.rs b/fundamentals/src/pallet_xcm.rs |
2 | | -index 8b13789..7be7118 100644 |
3 | | ---- a/fundamentals/src/pallet_xcm.rs |
4 | | -+++ b/fundamentals/src/pallet_xcm.rs |
5 | | -@@ -1 +1,166 @@ |
6 | | -+//! # Fundamentals lesson 6: Pallet XCM |
7 | | -+//! |
8 | | -+//! Implement the core functionality of Pallet XCM |
9 | | - |
10 | | -+use crate::xcm_executor::ExecuteXcm; |
11 | | -+use frame_support::pallet_prelude::*; |
12 | | -+use frame_system::pallet_prelude::*; |
13 | | -+use xcm::{prelude::*, VersionedAssets, VersionedLocation, VersionedXcm}; |
14 | | -+ |
15 | | -+pub use pallet::*; |
16 | | -+ |
17 | | -+#[frame_support::pallet] |
18 | | -+pub mod pallet { |
19 | | -+ use super::*; |
20 | | -+ |
21 | | -+ #[pallet::pallet] |
22 | | -+ pub struct Pallet<T>(_); |
23 | | -+ |
24 | | -+ #[pallet::config] |
25 | | -+ pub trait Config: frame_system::Config { |
26 | | -+ /// Something to execute an XCM message. |
27 | | -+ type XcmExecutor: ExecuteXcm; |
28 | | -+ /// Required origin for executing XCM messages, including the teleport functionality. If |
29 | | -+ /// successful, then it resolves to `Location` which exists as an interior location |
30 | | -+ /// within this chain's XCM context. |
31 | | -+ type ExecuteXcmOrigin: EnsureOrigin< |
32 | | -+ <Self as frame_system::Config>::RuntimeOrigin, |
33 | | -+ Success = Location, |
34 | | -+ >; |
35 | | -+ /// Required origin for sending XCM messages. If successful, it resolves to `Location` |
36 | | -+ /// which exists as an interior location within this chain's XCM context. |
37 | | -+ type SendXcmOrigin: EnsureOrigin< |
38 | | -+ <Self as frame_system::Config>::RuntimeOrigin, |
39 | | -+ Success = Location, |
40 | | -+ >; |
41 | | -+ /// The type used to actually dispatch an XCM to its destination. |
42 | | -+ type XcmRouter: SendXcm; |
43 | | -+ /// This chain's Universal Location. |
44 | | -+ type UniversalLocation: Get<InteriorLocation>; |
45 | | -+ } |
46 | | -+ |
47 | | -+ #[pallet::error] |
48 | | -+ pub enum Error<T> { |
49 | | -+ /// The version of the `Versioned` value used is not able to be interpreted. |
50 | | -+ BadVersion, |
51 | | -+ /// Origin is invalid for sending. |
52 | | -+ InvalidOrigin, |
53 | | -+ /// Could not re-anchor the assets to declare the fees for the destination chain. |
54 | | -+ CannotReanchor, |
55 | | -+ /// A general error indicating something went wrong with the XCM Executor. |
56 | | -+ ExecutorError, |
57 | | -+ /// A general error indicating something went wrong with the XCM Router. |
58 | | -+ RouterError, |
59 | | -+ } |
60 | | -+ |
61 | | -+ #[pallet::call] |
62 | | -+ impl<T: Config> Pallet<T> { |
63 | | -+ /// Execute an XCM from a local, signed, origin. |
64 | | -+ #[pallet::call_index(0)] |
65 | | -+ #[pallet::weight(Weight::default())] |
66 | | -+ pub fn execute( |
67 | | -+ origin: OriginFor<T>, |
68 | | -+ message: Box<VersionedXcm<()>>, |
69 | | -+ _max_weight: Weight, |
70 | | -+ ) -> DispatchResult { |
71 | | -+ let message = (*message).try_into().map_err(|()| Error::<T>::BadVersion)?; |
72 | | -+ // Actually execute the XCM. |
73 | | -+ Self::do_execute(origin, message) |
74 | | -+ } |
75 | | -+ |
76 | | -+ /// Send an XCM to another consensus system. |
77 | | -+ #[pallet::call_index(1)] |
78 | | -+ #[pallet::weight(Weight::default())] |
79 | | -+ pub fn send( |
80 | | -+ origin: OriginFor<T>, |
81 | | -+ dest: Box<VersionedLocation>, |
82 | | -+ message: Box<VersionedXcm<()>>, |
83 | | -+ ) -> DispatchResult { |
84 | | -+ let dest = Location::try_from(*dest).map_err(|()| Error::<T>::BadVersion)?; |
85 | | -+ let message: Xcm<()> = (*message).try_into().map_err(|()| Error::<T>::BadVersion)?; |
86 | | -+ // Actually send the XCM. |
87 | | -+ Self::do_send(origin, dest, message) |
88 | | -+ } |
89 | | -+ |
90 | | -+ /// Teleport some assets from the local chain to some destination chain. |
91 | | -+ #[pallet::call_index(2)] |
92 | | -+ #[pallet::weight(Weight::default())] |
93 | | -+ pub fn teleport_assets( |
94 | | -+ origin: OriginFor<T>, |
95 | | -+ dest: Box<VersionedLocation>, |
96 | | -+ beneficiary: Box<VersionedLocation>, |
97 | | -+ assets: Box<VersionedAssets>, |
98 | | -+ fee_asset_item: u32, |
99 | | -+ ) -> DispatchResult { |
100 | | -+ let dest: Location = (*dest).try_into().map_err(|()| Error::<T>::BadVersion)?; |
101 | | -+ let beneficiary: Location = |
102 | | -+ (*beneficiary).try_into().map_err(|()| Error::<T>::BadVersion)?; |
103 | | -+ let assets: Assets = (*assets).try_into().map_err(|()| Error::<T>::BadVersion)?; |
104 | | -+ // Actually teleport the assets. |
105 | | -+ Self::do_teleport_assets(origin, dest, beneficiary, assets, fee_asset_item) |
106 | | -+ } |
107 | | -+ |
108 | | -+ /// Transfer some assets from the local chain to the destination chain through their local, |
109 | | -+ /// destination or remote reserve. |
110 | | -+ #[pallet::call_index(3)] |
111 | | -+ #[pallet::weight(Weight::default())] |
112 | | -+ pub fn reserve_transfer_assets( |
113 | | -+ origin: OriginFor<T>, |
114 | | -+ dest: Box<VersionedLocation>, |
115 | | -+ beneficiary: Box<VersionedLocation>, |
116 | | -+ assets: Box<VersionedAssets>, |
117 | | -+ fee_asset_item: u32, |
118 | | -+ ) -> DispatchResult { |
119 | | -+ let dest: Location = (*dest).try_into().map_err(|()| Error::<T>::BadVersion)?; |
120 | | -+ let beneficiary: Location = |
121 | | -+ (*beneficiary).try_into().map_err(|()| Error::<T>::BadVersion)?; |
122 | | -+ let assets: Assets = (*assets).try_into().map_err(|()| Error::<T>::BadVersion)?; |
123 | | -+ // Actually reserve transfer the assets. |
124 | | -+ Self::do_reserve_transfer_assets(origin, dest, beneficiary, assets, fee_asset_item) |
125 | | -+ } |
126 | | -+ } |
127 | | -+} |
128 | | -+ |
129 | | -+impl<T: Config> Pallet<T> { |
130 | | -+ pub fn do_execute(origin: OriginFor<T>, message: Xcm<()>) -> DispatchResult { |
131 | | -+ todo!("{:?}", message) |
132 | | -+ } |
133 | | -+ |
134 | | -+ /// Relay an XCM `message` from a given `interior` location in this context to a given `dest` |
135 | | -+ /// location. |
136 | | -+ pub fn do_send(origin: OriginFor<T>, dest: Location, mut message: Xcm<()>) -> DispatchResult { |
137 | | -+ todo!("{:?} {:?}", dest, message) |
138 | | -+ } |
139 | | -+ |
140 | | -+ pub fn do_teleport_assets( |
141 | | -+ origin: OriginFor<T>, |
142 | | -+ dest: Location, |
143 | | -+ beneficiary: Location, |
144 | | -+ assets: Assets, |
145 | | -+ // The index into `assets` of the item which should be used to pay fees. |
146 | | -+ // We don't use this in our naive implementation. |
147 | | -+ _fee_asset_item: u32, |
148 | | -+ ) -> DispatchResult { |
149 | | -+ todo!("{:?} {:?} {:?}", dest, beneficiary, assets) |
150 | | -+ } |
151 | | -+ |
152 | | -+ pub fn do_reserve_transfer_assets( |
153 | | -+ _origin: OriginFor<T>, |
154 | | -+ _dest: Location, |
155 | | -+ _beneficiary: Location, |
156 | | -+ _assets: Assets, |
157 | | -+ _fee_asset_item: u32, |
158 | | -+ ) -> DispatchResult { |
159 | | -+ // There are 3 different reserve transfer scenarios: |
160 | | -+ // - A local reserve transfer: reserve-transfer `asset` to `dest`, using local chain as |
161 | | -+ // reserve. |
162 | | -+ // - A destination reserve transfer: reserve-transfer `asset` to `dest`, using `dest` as |
163 | | -+ // reserve. |
164 | | -+ // - A remote reserve transfer: reserve-transfer `asset` to `dest`, using remote chain |
165 | | -+ // `Location` as reserve. |
166 | | -+ // |
167 | | -+ // This is a lot to do in this workshop, but a welcome challenge for the reader to |
168 | | -+ // implement. |
169 | | -+ unimplemented!() |
170 | | -+ } |
171 | | -+} |
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