openethereum/ethcore/light/src/on_demand/request.rs
Robert Habermeier 386cdb830d Back-references for the on-demand service (#5573)
* header back-references for on demand

* initial back-reference implementation for on demand requests

* answer requests from cache

* answer requests from cache, add tests

* strongly typed responses for vectors of homogeneous requests

* fix fallout in RPC without optimizing
2017-05-23 12:39:25 +02:00

1013 lines
30 KiB
Rust

// Copyright 2015-2017 Parity Technologies (UK) Ltd.
// This file is part of Parity.
// Parity 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.
// Parity 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 Parity. If not, see <http://www.gnu.org/licenses/>.
//! Request types, verification, and verification errors.
use std::sync::Arc;
use ethcore::basic_account::BasicAccount;
use ethcore::encoded;
use ethcore::engines::Engine;
use ethcore::env_info::EnvInfo;
use ethcore::receipt::Receipt;
use ethcore::state::{self, ProvedExecution};
use ethcore::transaction::SignedTransaction;
use request::{self as net_request, IncompleteRequest, CompleteRequest, Output, OutputKind, Field};
use rlp::{RlpStream, UntrustedRlp};
use util::{Address, Bytes, DBValue, HashDB, Mutex, H256, U256};
use util::memorydb::MemoryDB;
use util::sha3::{Hashable, SHA3_NULL_RLP, SHA3_EMPTY, SHA3_EMPTY_LIST_RLP};
use util::trie::{Trie, TrieDB, TrieError};
const SUPPLIED_MATCHES: &'static str = "supplied responses always match produced requests; enforced by `check_response`; qed";
/// Core unit of the API: submit batches of these to be answered with `Response`s.
#[derive(Clone)]
pub enum Request {
/// A request for a header proof.
HeaderProof(HeaderProof),
/// A request for a header by hash.
HeaderByHash(HeaderByHash),
/// A request for block receipts.
Receipts(BlockReceipts),
/// A request for a block body.
Body(Body),
/// A request for an account.
Account(Account),
/// A request for a contract's code.
Code(Code),
/// A request for proof of execution.
Execution(TransactionProof),
}
/// A request argument.
pub trait RequestArg {
/// the response type.
type Out;
/// Create the request type.
/// `extract` must not fail when presented with the corresponding
/// `Response`.
fn make(self) -> Request;
/// May not panic if the response corresponds with the request
/// from `make`.
/// Is free to panic otherwise.
fn extract(r: Response) -> Self::Out;
}
/// An adapter can be thought of as a grouping of request argument types.
/// This is implemented for various tuples and convenient types.
pub trait RequestAdapter {
/// The output type.
type Out;
/// Infallibly produce requests. When `extract_from` is presented
/// with the corresponding response vector, it may not fail.
fn make_requests(self) -> Vec<Request>;
/// Extract the output type from the given responses.
/// If they are the corresponding responses to the requests
/// made by `make_requests`, do not panic.
fn extract_from(Vec<Response>) -> Self::Out;
}
impl<T: RequestArg> RequestAdapter for Vec<T> {
type Out = Vec<T::Out>;
fn make_requests(self) -> Vec<Request> {
self.into_iter().map(RequestArg::make).collect()
}
fn extract_from(r: Vec<Response>) -> Self::Out {
r.into_iter().map(T::extract).collect()
}
}
// helper to implement `RequestArg` and `From` for a single request kind.
macro_rules! impl_single {
($variant: ident, $me: ty, $out: ty) => {
impl RequestArg for $me {
type Out = $out;
fn make(self) -> Request {
Request::$variant(self)
}
fn extract(r: Response) -> $out {
match r {
Response::$variant(x) => x,
_ => panic!(SUPPLIED_MATCHES),
}
}
}
impl From<$me> for Request {
fn from(me: $me) -> Request {
Request::$variant(me)
}
}
}
}
// implement traits for each kind of request.
impl_single!(HeaderProof, HeaderProof, (H256, U256));
impl_single!(HeaderByHash, HeaderByHash, encoded::Header);
impl_single!(Receipts, BlockReceipts, Vec<Receipt>);
impl_single!(Body, Body, encoded::Block);
impl_single!(Account, Account, Option<BasicAccount>);
impl_single!(Code, Code, Bytes);
impl_single!(Execution, TransactionProof, super::ExecutionResult);
macro_rules! impl_args {
() => {
impl<T: RequestArg> RequestAdapter for T {
type Out = T::Out;
fn make_requests(self) -> Vec<Request> {
vec![self.make()]
}
fn extract_from(mut responses: Vec<Response>) -> Self::Out {
T::extract(responses.pop().expect(SUPPLIED_MATCHES))
}
}
};
($first: ident, $($next: ident,)*) => {
impl<
$first: RequestArg,
$($next: RequestArg,)*
>
RequestAdapter for ($first, $($next,)*) {
type Out = ($first::Out, $($next::Out,)*);
fn make_requests(self) -> Vec<Request> {
let ($first, $($next,)*) = self;
vec![
$first.make(),
$($next.make(),)*
]
}
fn extract_from(responses: Vec<Response>) -> Self::Out {
let mut iter = responses.into_iter();
(
$first::extract(iter.next().expect(SUPPLIED_MATCHES)),
$($next::extract(iter.next().expect(SUPPLIED_MATCHES)),)*
)
}
}
impl_args!($($next,)*);
}
}
mod impls {
#![allow(non_snake_case)]
use super::{RequestAdapter, RequestArg, Request, Response, SUPPLIED_MATCHES};
impl_args!(A, B, C, D, E, F, G, H, I, J, K, L,);
}
/// A block header to be used for verification.
/// May be stored or an unresolved output of a prior request.
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum HeaderRef {
/// A stored header.
Stored(encoded::Header),
/// An unresolved header. The first item here is the index of the request which
/// will return the header. The second is a back-reference pointing to a block hash
/// which can be used to make requests until that header is resolved.
Unresolved(usize, Field<H256>),
}
impl HeaderRef {
/// Attempt to inspect the header.
pub fn as_ref(&self) -> Result<&encoded::Header, Error> {
match *self {
HeaderRef::Stored(ref hdr) => Ok(hdr),
HeaderRef::Unresolved(idx, _) => Err(Error::UnresolvedHeader(idx)),
}
}
// get the blockhash field to be used in requests.
fn field(&self) -> Field<H256> {
match *self {
HeaderRef::Stored(ref hdr) => Field::Scalar(hdr.hash()),
HeaderRef::Unresolved(_, ref field) => field.clone(),
}
}
// yield the index of the request which will produce the header.
fn needs_header(&self) -> Option<(usize, Field<H256>)> {
match *self {
HeaderRef::Stored(_) => None,
HeaderRef::Unresolved(idx, ref field) => Some((idx, field.clone())),
}
}
}
impl From<encoded::Header> for HeaderRef {
fn from(header: encoded::Header) -> Self {
HeaderRef::Stored(header)
}
}
/// Requests coupled with their required data for verification.
/// This is used internally but not part of the public API.
#[derive(Clone)]
#[allow(missing_docs)]
pub enum CheckedRequest {
HeaderProof(HeaderProof, net_request::IncompleteHeaderProofRequest),
HeaderByHash(HeaderByHash, net_request::IncompleteHeadersRequest),
Receipts(BlockReceipts, net_request::IncompleteReceiptsRequest),
Body(Body, net_request::IncompleteBodyRequest),
Account(Account, net_request::IncompleteAccountRequest),
Code(Code, net_request::IncompleteCodeRequest),
Execution(TransactionProof, net_request::IncompleteExecutionRequest),
}
impl From<Request> for CheckedRequest {
fn from(req: Request) -> Self {
match req {
Request::HeaderByHash(req) => {
let net_req = net_request::IncompleteHeadersRequest {
start: req.0.map(Into::into),
skip: 0,
max: 1,
reverse: false,
};
CheckedRequest::HeaderByHash(req, net_req)
}
Request::HeaderProof(req) => {
let net_req = net_request::IncompleteHeaderProofRequest {
num: req.num().into(),
};
CheckedRequest::HeaderProof(req, net_req)
}
Request::Body(req) => {
let net_req = net_request::IncompleteBodyRequest {
hash: req.0.field(),
};
CheckedRequest::Body(req, net_req)
}
Request::Receipts(req) => {
let net_req = net_request::IncompleteReceiptsRequest {
hash: req.0.field(),
};
CheckedRequest::Receipts(req, net_req)
}
Request::Account(req) => {
let net_req = net_request::IncompleteAccountRequest {
block_hash: req.header.field(),
address_hash: ::util::Hashable::sha3(&req.address).into(),
};
CheckedRequest::Account(req, net_req)
}
Request::Code(req) => {
let net_req = net_request::IncompleteCodeRequest {
block_hash: req.header.field(),
code_hash: req.code_hash.into(),
};
CheckedRequest::Code(req, net_req)
}
Request::Execution(req) => {
let net_req = net_request::IncompleteExecutionRequest {
block_hash: req.header.field(),
from: req.tx.sender(),
gas: req.tx.gas,
gas_price: req.tx.gas_price,
action: req.tx.action.clone(),
value: req.tx.value,
data: req.tx.data.clone(),
};
CheckedRequest::Execution(req, net_req)
}
}
}
}
impl CheckedRequest {
/// Convert this into a network request.
pub fn into_net_request(self) -> net_request::Request {
use ::request::Request as NetRequest;
match self {
CheckedRequest::HeaderProof(_, req) => NetRequest::HeaderProof(req),
CheckedRequest::HeaderByHash(_, req) => NetRequest::Headers(req),
CheckedRequest::Receipts(_, req) => NetRequest::Receipts(req),
CheckedRequest::Body(_, req) => NetRequest::Body(req),
CheckedRequest::Account(_, req) => NetRequest::Account(req),
CheckedRequest::Code(_, req) => NetRequest::Code(req),
CheckedRequest::Execution(_, req) => NetRequest::Execution(req),
}
}
/// Whether this needs a header from a prior request.
/// Returns `Some` with the index of the request returning the header
/// and the field giving the hash
/// if so, `None` otherwise.
pub fn needs_header(&self) -> Option<(usize, Field<H256>)> {
match *self {
CheckedRequest::Receipts(ref x, _) => x.0.needs_header(),
CheckedRequest::Body(ref x, _) => x.0.needs_header(),
CheckedRequest::Account(ref x, _) => x.header.needs_header(),
CheckedRequest::Code(ref x, _) => x.header.needs_header(),
CheckedRequest::Execution(ref x, _) => x.header.needs_header(),
_ => None,
}
}
/// Provide a header where one was needed. Should only be called if `needs_header`
/// returns `Some`, and for correctness, only use the header yielded by the correct
/// request.
pub fn provide_header(&mut self, header: encoded::Header) {
match *self {
CheckedRequest::Receipts(ref mut x, _) => x.0 = HeaderRef::Stored(header),
CheckedRequest::Body(ref mut x, _) => x.0 = HeaderRef::Stored(header),
CheckedRequest::Account(ref mut x, _) => x.header = HeaderRef::Stored(header),
CheckedRequest::Code(ref mut x, _) => x.header = HeaderRef::Stored(header),
CheckedRequest::Execution(ref mut x, _) => x.header = HeaderRef::Stored(header),
_ => {},
}
}
/// Attempt to complete the request based on data in the cache.
pub fn respond_local(&self, cache: &Mutex<::cache::Cache>) -> Option<Response> {
match *self {
CheckedRequest::HeaderProof(ref check, _) => {
let mut cache = cache.lock();
cache.block_hash(&check.num)
.and_then(|h| cache.chain_score(&h).map(|s| (h, s)))
.map(|(h, s)| Response::HeaderProof((h, s)))
}
CheckedRequest::HeaderByHash(_, ref req) => {
if let Some(&net_request::HashOrNumber::Hash(ref h)) = req.start.as_ref() {
return cache.lock().block_header(h).map(Response::HeaderByHash);
}
None
}
CheckedRequest::Receipts(ref check, ref req) => {
// empty transactions -> no receipts
if check.0.as_ref().ok().map_or(false, |hdr| hdr.receipts_root() == SHA3_NULL_RLP) {
return Some(Response::Receipts(Vec::new()));
}
req.hash.as_ref()
.and_then(|hash| cache.lock().block_receipts(hash))
.map(Response::Receipts)
}
CheckedRequest::Body(ref check, ref req) => {
// check for empty body.
if let Some(hdr) = check.0.as_ref().ok() {
if hdr.transactions_root() == SHA3_NULL_RLP && hdr.uncles_hash() == SHA3_EMPTY_LIST_RLP {
let mut stream = RlpStream::new_list(3);
stream.append_raw(hdr.rlp().as_raw(), 1);
stream.begin_list(0);
stream.begin_list(0);
return Some(Response::Body(encoded::Block::new(stream.out())));
}
}
// otherwise, check for cached body and header.
let block_hash = req.hash.as_ref()
.cloned()
.or_else(|| check.0.as_ref().ok().map(|hdr| hdr.hash()));
let block_hash = match block_hash {
Some(hash) => hash,
None => return None,
};
let mut cache = cache.lock();
let cached_header;
// can't use as_ref here although it seems like you would be able to:
// it complains about uninitialized `cached_header`.
let block_header = match check.0.as_ref().ok() {
Some(hdr) => Some(hdr),
None => {
cached_header = cache.block_header(&block_hash);
cached_header.as_ref()
}
};
block_header
.and_then(|hdr| cache.block_body(&block_hash).map(|b| (hdr, b)))
.map(|(hdr, body)| {
let mut stream = RlpStream::new_list(3);
let body = body.rlp();
stream.append_raw(&hdr.rlp().as_raw(), 1);
stream.append_raw(&body.at(0).as_raw(), 1);
stream.append_raw(&body.at(1).as_raw(), 1);
Response::Body(encoded::Block::new(stream.out()))
})
}
CheckedRequest::Code(_, ref req) => {
if req.code_hash.as_ref().map_or(false, |&h| h == SHA3_EMPTY) {
Some(Response::Code(Vec::new()))
} else {
None
}
}
_ => None,
}
}
}
macro_rules! match_me {
($me: expr, ($check: pat, $req: pat) => $e: expr) => {
match $me {
CheckedRequest::HeaderProof($check, $req) => $e,
CheckedRequest::HeaderByHash($check, $req) => $e,
CheckedRequest::Receipts($check, $req) => $e,
CheckedRequest::Body($check, $req) => $e,
CheckedRequest::Account($check, $req) => $e,
CheckedRequest::Code($check, $req) => $e,
CheckedRequest::Execution($check, $req) => $e,
}
}
}
impl IncompleteRequest for CheckedRequest {
type Complete = CompleteRequest;
type Response = net_request::Response;
fn check_outputs<F>(&self, mut f: F) -> Result<(), net_request::NoSuchOutput>
where F: FnMut(usize, usize, OutputKind) -> Result<(), net_request::NoSuchOutput>
{
match *self {
CheckedRequest::HeaderProof(_, ref req) => req.check_outputs(f),
CheckedRequest::HeaderByHash(ref check, ref req) => {
req.check_outputs(&mut f)?;
// make sure the output given is definitively a hash.
match check.0 {
Field::BackReference(r, idx) => f(r, idx, OutputKind::Hash),
_ => Ok(()),
}
}
CheckedRequest::Receipts(_, ref req) => req.check_outputs(f),
CheckedRequest::Body(_, ref req) => req.check_outputs(f),
CheckedRequest::Account(_, ref req) => req.check_outputs(f),
CheckedRequest::Code(_, ref req) => req.check_outputs(f),
CheckedRequest::Execution(_, ref req) => req.check_outputs(f),
}
}
fn note_outputs<F>(&self, f: F) where F: FnMut(usize, OutputKind) {
match_me!(*self, (_, ref req) => req.note_outputs(f))
}
fn fill<F>(&mut self, f: F) where F: Fn(usize, usize) -> Result<Output, net_request::NoSuchOutput> {
match_me!(*self, (_, ref mut req) => req.fill(f))
}
fn complete(self) -> Result<Self::Complete, net_request::NoSuchOutput> {
match self {
CheckedRequest::HeaderProof(_, req) => req.complete().map(CompleteRequest::HeaderProof),
CheckedRequest::HeaderByHash(_, req) => req.complete().map(CompleteRequest::Headers),
CheckedRequest::Receipts(_, req) => req.complete().map(CompleteRequest::Receipts),
CheckedRequest::Body(_, req) => req.complete().map(CompleteRequest::Body),
CheckedRequest::Account(_, req) => req.complete().map(CompleteRequest::Account),
CheckedRequest::Code(_, req) => req.complete().map(CompleteRequest::Code),
CheckedRequest::Execution(_, req) => req.complete().map(CompleteRequest::Execution),
}
}
fn adjust_refs<F>(&mut self, mapping: F) where F: FnMut(usize) -> usize {
match_me!(*self, (_, ref mut req) => req.adjust_refs(mapping))
}
}
impl net_request::CheckedRequest for CheckedRequest {
type Extract = Response;
type Error = Error;
type Environment = Mutex<::cache::Cache>;
/// Check whether the response matches (beyond the type).
fn check_response(&self, complete: &Self::Complete, cache: &Mutex<::cache::Cache>, response: &Self::Response) -> Result<Response, Error> {
use ::request::Response as NetResponse;
// helper for expecting a specific response for a given request.
macro_rules! expect {
($res: pat => $e: expr) => {{
match (response, complete) {
$res => $e,
_ => Err(Error::WrongKind),
}
}}
}
// check response against contained prover.
match *self {
CheckedRequest::HeaderProof(ref prover, _) =>
expect!((&NetResponse::HeaderProof(ref res), _) =>
prover.check_response(cache, &res.proof).map(Response::HeaderProof)),
CheckedRequest::HeaderByHash(ref prover, _) =>
expect!((&NetResponse::Headers(ref res), &CompleteRequest::Headers(ref req)) =>
prover.check_response(cache, &req.start, &res.headers).map(Response::HeaderByHash)),
CheckedRequest::Receipts(ref prover, _) =>
expect!((&NetResponse::Receipts(ref res), _) =>
prover.check_response(cache, &res.receipts).map(Response::Receipts)),
CheckedRequest::Body(ref prover, _) =>
expect!((&NetResponse::Body(ref res), _) =>
prover.check_response(cache, &res.body).map(Response::Body)),
CheckedRequest::Account(ref prover, _) =>
expect!((&NetResponse::Account(ref res), _) =>
prover.check_response(cache, &res.proof).map(Response::Account)),
CheckedRequest::Code(ref prover, _) =>
expect!((&NetResponse::Code(ref res), &CompleteRequest::Code(ref req)) =>
prover.check_response(cache, &req.code_hash, &res.code).map(Response::Code)),
CheckedRequest::Execution(ref prover, _) =>
expect!((&NetResponse::Execution(ref res), _) =>
prover.check_response(cache, &res.items).map(Response::Execution)),
}
}
}
/// Responses to on-demand requests.
/// All of these are checked.
pub enum Response {
/// Response to a header proof request.
/// Returns the hash and chain score.
HeaderProof((H256, U256)),
/// Response to a header-by-hash request.
HeaderByHash(encoded::Header),
/// Response to a receipts request.
Receipts(Vec<Receipt>),
/// Response to a block body request.
Body(encoded::Block),
/// Response to an Account request.
// TODO: `unwrap_or(engine_defaults)`
Account(Option<BasicAccount>),
/// Response to a request for code.
Code(Vec<u8>),
/// Response to a request for proved execution.
Execution(super::ExecutionResult),
}
impl net_request::ResponseLike for Response {
fn fill_outputs<F>(&self, mut f: F) where F: FnMut(usize, Output) {
match *self {
Response::HeaderProof((ref hash, _)) => f(0, Output::Hash(*hash)),
Response::Account(None) => {
f(0, Output::Hash(SHA3_EMPTY)); // code hash
f(1, Output::Hash(SHA3_NULL_RLP)); // storage root.
}
Response::Account(Some(ref acc)) => {
f(0, Output::Hash(acc.code_hash));
f(1, Output::Hash(acc.storage_root));
}
_ => {}
}
}
}
/// Errors in verification.
#[derive(Debug, PartialEq)]
pub enum Error {
/// RLP decoder error.
Decoder(::rlp::DecoderError),
/// Empty response.
Empty,
/// Trie lookup error (result of bad proof)
Trie(TrieError),
/// Bad inclusion proof
BadProof,
/// Header by number instead of hash.
HeaderByNumber,
/// Unresolved header reference.
UnresolvedHeader(usize),
/// Wrong header number.
WrongNumber(u64, u64),
/// Wrong hash.
WrongHash(H256, H256),
/// Wrong trie root.
WrongTrieRoot(H256, H256),
/// Wrong response kind.
WrongKind,
}
impl From<::rlp::DecoderError> for Error {
fn from(err: ::rlp::DecoderError) -> Self {
Error::Decoder(err)
}
}
impl From<Box<TrieError>> for Error {
fn from(err: Box<TrieError>) -> Self {
Error::Trie(*err)
}
}
/// Request for header proof by number
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct HeaderProof {
/// The header's number.
num: u64,
/// The cht number for the given block number.
cht_num: u64,
/// The root of the CHT containing this header.
cht_root: H256,
}
impl HeaderProof {
/// Construct a new header-by-number request. Fails if the given number is 0.
/// Provide the expected CHT root to compare against.
pub fn new(num: u64, cht_root: H256) -> Option<Self> {
::cht::block_to_cht_number(num).map(|cht_num| HeaderProof {
num: num,
cht_num: cht_num,
cht_root: cht_root,
})
}
/// Access the requested block number.
pub fn num(&self) -> u64 { self.num }
/// Access the CHT number.
pub fn cht_num(&self) -> u64 { self.cht_num }
/// Access the expected CHT root.
pub fn cht_root(&self) -> H256 { self.cht_root }
/// Check a response with a CHT proof, get a hash and total difficulty back.
pub fn check_response(&self, cache: &Mutex<::cache::Cache>, proof: &[Bytes]) -> Result<(H256, U256), Error> {
match ::cht::check_proof(proof, self.num, self.cht_root) {
Some((expected_hash, td)) => {
let mut cache = cache.lock();
cache.insert_block_hash(self.num, expected_hash);
cache.insert_chain_score(expected_hash, td);
Ok((expected_hash, td))
}
None => Err(Error::BadProof),
}
}
}
/// Request for a header by hash.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct HeaderByHash(pub Field<H256>);
impl HeaderByHash {
/// Check a response for the header.
pub fn check_response(
&self,
cache: &Mutex<::cache::Cache>,
start: &net_request::HashOrNumber,
headers: &[encoded::Header]
) -> Result<encoded::Header, Error> {
let expected_hash = match (self.0, start) {
(Field::Scalar(ref h), &net_request::HashOrNumber::Hash(ref h2)) => {
if h != h2 { return Err(Error::WrongHash(*h, *h2)) }
*h
}
(_, &net_request::HashOrNumber::Hash(h2)) => h2,
_ => return Err(Error::HeaderByNumber),
};
let header = headers.get(0).ok_or(Error::Empty)?;
let hash = header.sha3();
match hash == expected_hash {
true => {
cache.lock().insert_block_header(hash, header.clone());
Ok(header.clone())
}
false => Err(Error::WrongHash(expected_hash, hash)),
}
}
}
/// Request for a block, with header for verification.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Body(pub HeaderRef);
impl Body {
/// Check a response for this block body.
pub fn check_response(&self, cache: &Mutex<::cache::Cache>, body: &encoded::Body) -> Result<encoded::Block, Error> {
// check the integrity of the the body against the header
let header = self.0.as_ref()?;
let tx_root = ::util::triehash::ordered_trie_root(body.rlp().at(0).iter().map(|r| r.as_raw().to_vec()));
if tx_root != header.transactions_root() {
return Err(Error::WrongTrieRoot(header.transactions_root(), tx_root));
}
let uncles_hash = body.rlp().at(1).as_raw().sha3();
if uncles_hash != header.uncles_hash() {
return Err(Error::WrongHash(header.uncles_hash(), uncles_hash));
}
// concatenate the header and the body.
let mut stream = RlpStream::new_list(3);
stream.append_raw(header.rlp().as_raw(), 1);
stream.append_raw(body.rlp().at(0).as_raw(), 1);
stream.append_raw(body.rlp().at(1).as_raw(), 1);
cache.lock().insert_block_body(header.hash(), body.clone());
Ok(encoded::Block::new(stream.out()))
}
}
/// Request for a block's receipts with header for verification.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct BlockReceipts(pub HeaderRef);
impl BlockReceipts {
/// Check a response with receipts against the stored header.
pub fn check_response(&self, cache: &Mutex<::cache::Cache>, receipts: &[Receipt]) -> Result<Vec<Receipt>, Error> {
let receipts_root = self.0.as_ref()?.receipts_root();
let found_root = ::util::triehash::ordered_trie_root(receipts.iter().map(|r| ::rlp::encode(r).to_vec()));
match receipts_root == found_root {
true => {
cache.lock().insert_block_receipts(receipts_root, receipts.to_vec());
Ok(receipts.to_vec())
}
false => Err(Error::WrongTrieRoot(receipts_root, found_root)),
}
}
}
/// Request for an account structure.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Account {
/// Header for verification.
pub header: HeaderRef,
/// Address requested.
pub address: Address,
}
impl Account {
/// Check a response with an account against the stored header.
pub fn check_response(&self, _: &Mutex<::cache::Cache>, proof: &[Bytes]) -> Result<Option<BasicAccount>, Error> {
let header = self.header.as_ref()?;
let state_root = header.state_root();
let mut db = MemoryDB::new();
for node in proof { db.insert(&node[..]); }
match TrieDB::new(&db, &state_root).and_then(|t| t.get(&self.address.sha3()))? {
Some(val) => {
let rlp = UntrustedRlp::new(&val);
Ok(Some(BasicAccount {
nonce: rlp.val_at(0)?,
balance: rlp.val_at(1)?,
storage_root: rlp.val_at(2)?,
code_hash: rlp.val_at(3)?,
}))
},
None => Ok(None),
}
}
}
/// Request for account code.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Code {
/// Header reference.
pub header: HeaderRef,
/// Account's code hash.
pub code_hash: Field<H256>,
}
impl Code {
/// Check a response with code against the code hash.
pub fn check_response(
&self,
_: &Mutex<::cache::Cache>,
code_hash: &H256,
code: &[u8]
) -> Result<Vec<u8>, Error> {
let found_hash = code.sha3();
if &found_hash == code_hash {
Ok(code.to_vec())
} else {
Err(Error::WrongHash(*code_hash, found_hash))
}
}
}
/// Request for transaction execution, along with the parts necessary to verify the proof.
#[derive(Clone)]
pub struct TransactionProof {
/// The transaction to request proof of.
pub tx: SignedTransaction,
/// Block header.
pub header: HeaderRef,
/// Transaction environment info.
// TODO: it's not really possible to provide this if the header is unknown.
pub env_info: EnvInfo,
/// Consensus engine.
pub engine: Arc<Engine>,
}
impl TransactionProof {
/// Check the proof, returning the proved execution or indicate that the proof was bad.
pub fn check_response(&self, _: &Mutex<::cache::Cache>, state_items: &[DBValue]) -> Result<super::ExecutionResult, Error> {
let root = self.header.as_ref()?.state_root();
let mut env_info = self.env_info.clone();
env_info.gas_limit = self.tx.gas.clone();
let proved_execution = state::check_proof(
state_items,
root,
&self.tx,
&*self.engine,
&self.env_info,
);
match proved_execution {
ProvedExecution::BadProof => Err(Error::BadProof),
ProvedExecution::Failed(e) => Ok(Err(e)),
ProvedExecution::Complete(e) => Ok(Ok(e)),
}
}
}
#[cfg(test)]
mod tests {
use super::*;
use util::{MemoryDB, Address, Mutex, H256};
use util::trie::{Trie, TrieMut, SecTrieDB, SecTrieDBMut};
use util::trie::recorder::Recorder;
use ethcore::client::{BlockChainClient, TestBlockChainClient, EachBlockWith};
use ethcore::header::Header;
use ethcore::encoded;
use ethcore::receipt::Receipt;
fn make_cache() -> ::cache::Cache {
::cache::Cache::new(Default::default(), ::time::Duration::seconds(1))
}
#[test]
fn no_invalid_header_by_number() {
assert!(HeaderProof::new(0, Default::default()).is_none())
}
#[test]
fn check_header_proof() {
use ::cht;
let test_client = TestBlockChainClient::new();
test_client.add_blocks(10500, EachBlockWith::Nothing);
let cht = {
let fetcher = |id| {
let hdr = test_client.block_header(id).unwrap();
let td = test_client.block_total_difficulty(id).unwrap();
Some(cht::BlockInfo {
hash: hdr.hash(),
parent_hash: hdr.parent_hash(),
total_difficulty: td,
})
};
cht::build(cht::block_to_cht_number(10_000).unwrap(), fetcher).unwrap()
};
let proof = cht.prove(10_000, 0).unwrap().unwrap();
let req = HeaderProof::new(10_000, cht.root()).unwrap();
let cache = Mutex::new(make_cache());
assert!(req.check_response(&cache, &proof[..]).is_ok());
}
#[test]
fn check_header_by_hash() {
let mut header = Header::new();
header.set_number(10_000);
header.set_extra_data(b"test_header".to_vec());
let hash = header.hash();
let raw_header = encoded::Header::new(::rlp::encode(&header).to_vec());
let cache = Mutex::new(make_cache());
assert!(HeaderByHash(hash.into()).check_response(&cache, &hash.into(), &[raw_header]).is_ok())
}
#[test]
fn check_body() {
use rlp::RlpStream;
let header = Header::new();
let mut body_stream = RlpStream::new_list(2);
body_stream.begin_list(0).begin_list(0);
let req = Body(encoded::Header::new(::rlp::encode(&header).to_vec()).into());
let cache = Mutex::new(make_cache());
let response = encoded::Body::new(body_stream.drain().to_vec());
assert!(req.check_response(&cache, &response).is_ok())
}
#[test]
fn check_receipts() {
let receipts = (0..5).map(|_| Receipt {
state_root: Some(H256::random()),
gas_used: 21_000u64.into(),
log_bloom: Default::default(),
logs: Vec::new(),
}).collect::<Vec<_>>();
let mut header = Header::new();
let receipts_root = ::util::triehash::ordered_trie_root(
receipts.iter().map(|x| ::rlp::encode(x).to_vec())
);
header.set_receipts_root(receipts_root);
let req = BlockReceipts(encoded::Header::new(::rlp::encode(&header).to_vec()).into());
let cache = Mutex::new(make_cache());
assert!(req.check_response(&cache, &receipts).is_ok())
}
#[test]
fn check_state_proof() {
use rlp::RlpStream;
let mut root = H256::default();
let mut db = MemoryDB::new();
let mut header = Header::new();
header.set_number(123_456);
header.set_extra_data(b"test_header".to_vec());
let addr = Address::random();
let rand_acc = || {
let mut stream = RlpStream::new_list(4);
stream.append(&2u64)
.append(&100_000_000u64)
.append(&H256::random())
.append(&H256::random());
stream.out()
};
{
let mut trie = SecTrieDBMut::new(&mut db, &mut root);
for _ in 0..100 {
let address = Address::random();
trie.insert(&*address, &rand_acc()).unwrap();
}
trie.insert(&*addr, &rand_acc()).unwrap();
}
let proof = {
let trie = SecTrieDB::new(&db, &root).unwrap();
let mut recorder = Recorder::new();
trie.get_with(&*addr, &mut recorder).unwrap().unwrap();
recorder.drain().into_iter().map(|r| r.data).collect::<Vec<_>>()
};
header.set_state_root(root.clone());
let req = Account {
header: encoded::Header::new(::rlp::encode(&header).to_vec()).into(),
address: addr,
};
let cache = Mutex::new(make_cache());
assert!(req.check_response(&cache, &proof[..]).is_ok());
}
#[test]
fn check_code() {
let code = vec![1u8; 256];
let code_hash = ::util::Hashable::sha3(&code);
let header = Header::new();
let req = Code {
header: encoded::Header::new(::rlp::encode(&header).to_vec()).into(),
code_hash: code_hash.into(),
};
let cache = Mutex::new(make_cache());
assert!(req.check_response(&cache, &code_hash, &code).is_ok());
assert!(req.check_response(&cache, &code_hash, &[]).is_err());
}
}