Kusama origins as xcm multi_location (#6273)

* Kusamsa origins as xcm multilocation

* Fellows origin index

* origins to xcm plurality body

* cleanup

* fix cargo spellcheck

* Apply suggestions from code review

Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>

* include Fellows into scope

* include Fellows into scope

Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>
Co-authored-by: Gavin Wood <gavin@parity.io>

polkadot/xcm/pallet-xcm/src/lib.rs

@@ -1527,6 +1527,19 @@ impl<Prefix: Get<MultiLocation>, Body: Get<BodyId>> Contains<MultiLocation>
 	}
 }
 
+/// Filter for `MultiLocation` to find those which represent a voice of an identified plurality.
+///
+/// May reasonably be used with `EnsureXcm`.
+pub struct IsVoiceOfBody<Prefix, Body>(PhantomData<(Prefix, Body)>);
+impl<Prefix: Get<MultiLocation>, Body: Get<BodyId>> Contains<MultiLocation>
+	for IsVoiceOfBody<Prefix, Body>
+{
+	fn contains(l: &MultiLocation) -> bool {
+		let maybe_suffix = l.match_and_split(&Prefix::get());
+		matches!(maybe_suffix, Some(Plurality { id, part }) if id == &Body::get() && part == &BodyPart::Voice)
+	}
+}
+
 /// `EnsureOrigin` implementation succeeding with a `MultiLocation` value to recognize and filter the
 /// `Origin::Xcm` item.
 pub struct EnsureXcm<F>(PhantomData<F>);

polkadot/xcm/src/v0/junction.rs

@@ -52,6 +52,15 @@ pub enum BodyId {
 	/// The unambiguous judicial body (this doesn't exist on Polkadot, but if it were to get a "grand oracle", it
 	/// may be considered as that).
 	Judicial,
+	/// The unambiguous defense body (for Polkadot, an opinion on the topic given via a public referendum
+	/// on the `staking_admin` track).
+	Defense,
+	/// The unambiguous administration body (for Polkadot, an opinion on the topic given via a public referendum
+	/// on the `general_admin` track).
+	Administration,
+	/// The unambiguous treasury body (for Polkadot, an opinion on the topic given via a public referendum
+	/// on the `treasurer` track).
+	Treasury,
 }
 
 /// A part of a pluralistic body.

polkadot/xcm/xcm-builder/src/lib.rs

@@ -37,7 +37,7 @@ pub use location_conversion::{
 mod origin_conversion;
 pub use origin_conversion::{
 	BackingToPlurality, ChildParachainAsNative, ChildSystemParachainAsSuperuser, EnsureXcmOrigin,
-	ParentAsSuperuser, RelayChainAsNative, SiblingParachainAsNative,
+	OriginToPluralityVoice, ParentAsSuperuser, RelayChainAsNative, SiblingParachainAsNative,
 	SiblingSystemParachainAsSuperuser, SignedAccountId32AsNative, SignedAccountKey20AsNative,
 	SignedToAccountId32, SovereignSignedViaLocation,
 };

polkadot/xcm/xcm-builder/src/origin_conversion.rs

@@ -321,3 +321,20 @@ where
 		})
 	}
 }
+
+/// `Convert` implementation to convert from an origin which passes the check of an `EnsureOrigin`
+/// into a voice of a given pluralistic `Body`.
+pub struct OriginToPluralityVoice<RuntimeOrigin, EnsureBodyOrigin, Body>(
+	PhantomData<(RuntimeOrigin, EnsureBodyOrigin, Body)>,
+);
+impl<RuntimeOrigin: Clone, EnsureBodyOrigin: EnsureOrigin<RuntimeOrigin>, Body: Get<BodyId>>
+	Convert<RuntimeOrigin, MultiLocation>
+	for OriginToPluralityVoice<RuntimeOrigin, EnsureBodyOrigin, Body>
+{
+	fn convert(o: RuntimeOrigin) -> Result<MultiLocation, RuntimeOrigin> {
+		match EnsureBodyOrigin::try_origin(o) {
+			Ok(_) => Ok(Junction::Plurality { id: Body::get(), part: BodyPart::Voice }.into()),
+			Err(o) => Err(o),
+		}
+	}
+}