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// Copyright 2017-2020 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/>.
//! V1 Primitives.
use sp_std::prelude::*;
use parity_scale_codec::{Encode, Decode};
use bitvec::vec::BitVec;
use primitives::RuntimeDebug;
use runtime_primitives::traits::AppVerify;
use inherents::InherentIdentifier;
use runtime_primitives::traits::{BlakeTwo256, Hash as HashT};
// Export some core primitives.
pub use polkadot_core_primitives::v1::{
BlockNumber, Moment, Signature, AccountPublic, AccountId, AccountIndex,
ChainId, Hash, Nonce, Balance, Header, Block, BlockId, UncheckedExtrinsic,
Remark, DownwardMessage,
};
// Export some polkadot-parachain primitives
pub use polkadot_parachain::primitives::{
Id, ParachainDispatchOrigin, LOWEST_USER_ID, UpwardMessage, HeadData, BlockData,
ValidationCode,
};
// Export some basic parachain primitives from v0.
pub use crate::v0::{
CollatorId, CollatorSignature, PARACHAIN_KEY_TYPE_ID, ValidatorId, ValidatorIndex,
ValidatorSignature, SigningContext, Signed, ValidityAttestation,
CompactStatement, SignedStatement, ErasureChunk, EncodeAs,
};
// More exports from v0 for std.
#[cfg(feature = "std")]
pub use crate::v0::{ValidatorPair, CollatorPair};
/// Unique identifier for the Inclusion Inherent
pub const INCLUSION_INHERENT_IDENTIFIER: InherentIdentifier = *b"inclusn0";
/// Get a collator signature payload on a relay-parent, block-data combo.
pub fn collator_signature_payload<H: AsRef<[u8]>>(
relay_parent: &H,
para_id: &Id,
pov_hash: &Hash,
) -> [u8; 68] {
// 32-byte hash length is protected in a test below.
let mut payload = [0u8; 68];
payload[0..32].copy_from_slice(relay_parent.as_ref());
u32::from(*para_id).using_encoded(|s| payload[32..32 + s.len()].copy_from_slice(s));
payload[36..68].copy_from_slice(pov_hash.as_ref());
payload
}
fn check_collator_signature<H: AsRef<[u8]>>(
relay_parent: &H,
para_id: &Id,
pov_hash: &Hash,
collator: &CollatorId,
signature: &CollatorSignature,
) -> Result<(),()> {
let payload = collator_signature_payload(relay_parent, para_id, pov_hash);
if signature.verify(&payload[..], collator) {
Ok(())
} else {
Err(())
}
}
/// A unique descriptor of the candidate receipt.
#[derive(PartialEq, Eq, Clone, Encode, Decode)]
#[cfg_attr(feature = "std", derive(Debug, Default))]
pub struct CandidateDescriptor<H = Hash> {
/// The ID of the para this is a candidate for.
pub para_id: Id,
/// The hash of the relay-chain block this is executed in the context of.
pub relay_parent: H,
/// The collator's sr25519 public key.
pub collator: CollatorId,
/// Signature on blake2-256 of components of this receipt:
/// The parachain index, the relay parent, and the pov_hash.
pub signature: CollatorSignature,
/// The blake2-256 hash of the pov.
pub pov_hash: Hash,
}
impl<H: AsRef<[u8]>> CandidateDescriptor<H> {
/// Check the signature of the collator within this descriptor.
pub fn check_collator_signature(&self) -> Result<(), ()> {
check_collator_signature(
&self.relay_parent,
&self.para_id,
&self.pov_hash,
&self.collator,
&self.signature,
)
}
}
/// A candidate-receipt.
#[derive(PartialEq, Eq, Clone, Encode, Decode)]
#[cfg_attr(feature = "std", derive(Debug, Default))]
pub struct CandidateReceipt<H = Hash> {
/// The descriptor of the candidate.
pub descriptor: CandidateDescriptor<H>,
/// The hash of the encoded commitments made as a result of candidate execution.
pub commitments_hash: Hash,
}
impl<H> CandidateReceipt<H> {
/// Get a reference to the candidate descriptor.
pub fn descriptor(&self) -> &CandidateDescriptor<H> {
&self.descriptor
}
/// Computes the blake2-256 hash of the receipt.
pub fn hash(&self) -> Hash where H: Encode {
BlakeTwo256::hash_of(self)
}
}
/// All data pertaining to the execution of a para candidate.
#[derive(PartialEq, Eq, Clone, Encode, Decode)]
#[cfg_attr(feature = "std", derive(Debug, Default))]
pub struct FullCandidateReceipt<H = Hash> {
/// The inner candidate receipt.
pub inner: CandidateReceipt<H>,
/// The global validation schedule.
pub global_validation: GlobalValidationSchedule,
/// The local validation data.
pub local_validation: LocalValidationData,
}
/// A candidate-receipt with commitments directly included.
#[derive(PartialEq, Eq, Clone, Encode, Decode)]
#[cfg_attr(feature = "std", derive(Debug, Default))]
pub struct CommittedCandidateReceipt<H = Hash> {
/// The descriptor of the candidate.
pub descriptor: CandidateDescriptor<H>,
/// The commitments of the candidate receipt.
pub commitments: CandidateCommitments,
}
impl<H> CommittedCandidateReceipt<H> {
/// Get a reference to the candidate descriptor.
pub fn descriptor(&self) -> &CandidateDescriptor<H> {
&self.descriptor
}
}
impl<H: Clone> CommittedCandidateReceipt<H> {
/// Transforms this into a plain CandidateReceipt.
pub fn to_plain(&self) -> CandidateReceipt<H> {
CandidateReceipt {
descriptor: self.descriptor.clone(),
commitments_hash: self.commitments.hash(),
}
}
/// Computes the hash of the committed candidate receipt.
///
/// This computes the canonical hash, not the hash of the directly encoded data.
/// Thus this is a shortcut for `candidate.to_plain().hash()`.
pub fn hash(&self) -> Hash where H: Encode {
self.to_plain().hash()
}
}
impl PartialOrd for CommittedCandidateReceipt {
fn partial_cmp(&self, other: &Self) -> Option<sp_std::cmp::Ordering> {
Some(self.cmp(other))
}
}
impl Ord for CommittedCandidateReceipt {
fn cmp(&self, other: &Self) -> sp_std::cmp::Ordering {
// TODO: compare signatures or something more sane
// https://github.com/paritytech/polkadot/issues/222
self.descriptor().para_id.cmp(&other.descriptor().para_id)
.then_with(|| self.commitments.head_data.cmp(&other.commitments.head_data))
}
}
/// Extra data that is needed along with the other fields in a `CandidateReceipt`
/// to fully validate the candidate. These fields are parachain-specific.
#[derive(PartialEq, Eq, Clone, Encode, Decode)]
#[cfg_attr(feature = "std", derive(Debug, Default))]
pub struct LocalValidationData {
/// The parent head-data.
pub parent_head: HeadData,
/// The balance of the parachain at the moment of validation.
pub balance: Balance,
/// The blake2-256 hash of the validation code used to execute the candidate.
pub validation_code_hash: Hash,
/// Whether the parachain is allowed to upgrade its validation code.
///
/// This is `Some` if so, and contains the number of the minimum relay-chain
/// height at which the upgrade will be applied, if an upgrade is signaled
/// now.
///
/// A parachain should enact its side of the upgrade at the end of the first
/// parablock executing in the context of a relay-chain block with at least this
/// height. This may be equal to the current perceived relay-chain block height, in
/// which case the code upgrade should be applied at the end of the signaling
/// block.
pub code_upgrade_allowed: Option<BlockNumber>,
}
/// Extra data that is needed along with the other fields in a `CandidateReceipt`
/// to fully validate the candidate.
///
/// These are global parameters that apply to all candidates in a block.
#[derive(PartialEq, Eq, Clone, Encode, Decode)]
#[cfg_attr(feature = "std", derive(Debug, Default))]
pub struct GlobalValidationSchedule {
/// The maximum code size permitted, in bytes.
pub max_code_size: u32,
/// The maximum head-data size permitted, in bytes.
pub max_head_data_size: u32,
/// The relay-chain block number this is in the context of.
pub block_number: BlockNumber,
}
/// Commitments made in a `CandidateReceipt`. Many of these are outputs of validation.
#[derive(PartialEq, Eq, Clone, Encode, Decode)]
#[cfg_attr(feature = "std", derive(Debug, Default))]
pub struct CandidateCommitments {
/// Fees paid from the chain to the relay chain validators.
pub fees: Balance,
/// Messages destined to be interpreted by the Relay chain itself.
pub upward_messages: Vec<UpwardMessage>,
/// The root of a block's erasure encoding Merkle tree.
pub erasure_root: Hash,
/// New validation code.
pub new_validation_code: Option<ValidationCode>,
/// The head-data produced as a result of execution.
pub head_data: HeadData,
}
impl CandidateCommitments {
/// Compute the blake2-256 hash of the commitments.
pub fn hash(&self) -> Hash {
BlakeTwo256::hash_of(self)
}
}
/// A Proof-of-Validity
#[derive(PartialEq, Eq, Clone, Encode, Decode)]
#[cfg_attr(feature = "std", derive(Debug))]
pub struct PoV {
/// The block witness data.
pub block_data: BlockData,
}
impl PoV {
/// Get the blake2-256 hash of the PoV.
#[cfg(feature = "std")]
pub fn hash(&self) -> Hash {
BlakeTwo256::hash_of(self)
}
}
/// A bitfield concerning availability of backed candidates.
#[derive(PartialEq, Eq, Clone, Encode, Decode)]
#[cfg_attr(feature = "std", derive(Debug))]
pub struct AvailabilityBitfield(pub BitVec<bitvec::order::Lsb0, u8>);
impl From<BitVec<bitvec::order::Lsb0, u8>> for AvailabilityBitfield {
fn from(inner: BitVec<bitvec::order::Lsb0, u8>) -> Self {
AvailabilityBitfield(inner)
}
}
/// A bitfield signed by a particular validator about the availability of pending candidates.
pub type SignedAvailabilityBitfield = Signed<AvailabilityBitfield>;
/// A set of signed availability bitfields. Should be sorted by validator index, ascending.
pub type SignedAvailabilityBitfields = Vec<SignedAvailabilityBitfield>;
/// A backed (or backable, depending on context) candidate.
#[derive(Encode, Decode, Clone, PartialEq, Eq, RuntimeDebug)]
pub struct BackedCandidate<H = Hash> {
/// The candidate referred to.
pub candidate: CommittedCandidateReceipt<H>,
/// The validity votes themselves, expressed as signatures.
pub validity_votes: Vec<ValidityAttestation>,
/// The indices of the validators within the group, expressed as a bitfield.
pub validator_indices: BitVec<bitvec::order::Lsb0, u8>,
}
impl<H> BackedCandidate<H> {
/// Get a reference to the descriptor of the para.
pub fn descriptor(&self) -> &CandidateDescriptor<H> {
&self.candidate.descriptor
}
}
/// Verify the backing of the given candidate.
///
/// Provide a lookup from the index of a validator within the group assigned to this para,
/// as opposed to the index of the validator within the overall validator set, as well as
/// the number of validators in the group.
///
/// Also provide the signing context.
///
/// Returns either an error, indicating that one of the signatures was invalid or that the index
/// was out-of-bounds, or the number of signatures checked.
pub fn check_candidate_backing<H: AsRef<[u8]> + Clone + Encode>(
backed: &BackedCandidate<H>,
signing_context: &SigningContext<H>,
group_len: usize,
validator_lookup: impl Fn(usize) -> Option<ValidatorId>,
) -> Result<usize, ()> {
if backed.validator_indices.len() != group_len {
return Err(())
}
if backed.validity_votes.len() > group_len {
return Err(())
}
// this is known, even in runtime, to be blake2-256.
let hash: Hash = backed.candidate.hash();
let mut signed = 0;
for ((val_in_group_idx, _), attestation) in backed.validator_indices.iter().enumerate()
.filter(|(_, signed)| **signed)
.zip(backed.validity_votes.iter())
{
let validator_id = validator_lookup(val_in_group_idx).ok_or(())?;
let payload = attestation.signed_payload(hash.clone(), signing_context);
let sig = attestation.signature();
if sig.verify(&payload[..], &validator_id) {
signed += 1;
} else {
return Err(())
}
}
if signed != backed.validity_votes.len() {
return Err(())
}
Ok(signed)
}
/// The unique (during session) index of a core.
#[derive(Encode, Decode, Default, PartialOrd, Ord, Eq, PartialEq, Clone, Copy)]
#[cfg_attr(feature = "std", derive(Debug))]
pub struct CoreIndex(pub u32);
impl From<u32> for CoreIndex {
fn from(i: u32) -> CoreIndex {
CoreIndex(i)
}
}
/// The unique (during session) index of a validator group.
#[derive(Encode, Decode, Default, Clone, Copy)]
#[cfg_attr(feature = "std", derive(Eq, Hash, PartialEq, Debug))]
pub struct GroupIndex(pub u32);
impl From<u32> for GroupIndex {
fn from(i: u32) -> GroupIndex {
GroupIndex(i)
}
}
/// A claim on authoring the next block for a given parathread.
#[derive(Clone, Encode, Decode, Default)]
#[cfg_attr(feature = "std", derive(PartialEq, Debug))]
pub struct ParathreadClaim(pub Id, pub CollatorId);
/// An entry tracking a claim to ensure it does not pass the maximum number of retries.
#[derive(Clone, Encode, Decode, Default)]
#[cfg_attr(feature = "std", derive(PartialEq, Debug))]
pub struct ParathreadEntry {
/// The claim.
pub claim: ParathreadClaim,
/// Number of retries.
pub retries: u32,
}
/// What is occupying a specific availability core.
#[derive(Clone, Encode, Decode)]
#[cfg_attr(feature = "std", derive(PartialEq, Debug))]
pub enum CoreOccupied {
/// A parathread.
Parathread(ParathreadEntry),
/// A parachain.
Parachain,
}
/// The assignment type.
#[derive(Clone, Encode, Decode)]
#[cfg_attr(feature = "std", derive(PartialEq, Debug))]
pub enum AssignmentKind {
/// A parachain.
Parachain,
/// A parathread.
Parathread(CollatorId, u32),
}
/// How a free core is scheduled to be assigned.
#[derive(Clone, Encode, Decode)]
#[cfg_attr(feature = "std", derive(PartialEq, Debug))]
pub struct CoreAssignment {
/// The core that is assigned.
pub core: CoreIndex,
/// The unique ID of the para that is assigned to the core.
pub para_id: Id,
/// The kind of the assignment.
pub kind: AssignmentKind,
/// The index of the validator group assigned to the core.
pub group_idx: GroupIndex,
}
impl CoreAssignment {
/// Get the ID of a collator who is required to collate this block.
pub fn required_collator(&self) -> Option<&CollatorId> {
match self.kind {
AssignmentKind::Parachain => None,
AssignmentKind::Parathread(ref id, _) => Some(id),
}
}
/// Get the `CoreOccupied` from this.
pub fn to_core_occupied(&self) -> CoreOccupied {
match self.kind {
AssignmentKind::Parachain => CoreOccupied::Parachain,
AssignmentKind::Parathread(ref collator, retries) => CoreOccupied::Parathread(
ParathreadEntry {
claim: ParathreadClaim(self.para_id, collator.clone()),
retries,
}
),
}
}
}
/// Validation data omitted from most candidate descriptor structs, as it can be derived from the
/// relay-parent.
#[derive(Clone, Encode, Decode)]
#[cfg_attr(feature = "std", derive(PartialEq, Debug))]
pub struct OmittedValidationData {
/// The global validation schedule.
pub global_validation: GlobalValidationSchedule,
/// The local validation data.
pub local_validation: LocalValidationData,
}
/// This is the data we keep available for each candidate included in the relay chain.
#[derive(Clone, Encode, Decode)]
#[cfg_attr(feature = "std", derive(PartialEq, Debug))]
pub struct AvailableData {
/// The Proof-of-Validation of the candidate.
pub pov: PoV,
/// The omitted validation data.
pub omitted_validation: OmittedValidationData,
}