poa-bridge/bridge/src/bridge/withdraw_relay.rs

329 lines
12 KiB
Rust

use std::sync::{Arc, RwLock};
use futures::{self, Future, Stream, stream::{Collect, FuturesUnordered, futures_unordered}, Poll};
use futures::future::{JoinAll, join_all, Join};
use tokio_timer::Timeout;
use web3::Transport;
use web3::types::{U256, Address, FilterBuilder, Log, Bytes};
use ethabi::{RawLog, self};
use app::App;
use api::{self, LogStream, ApiCall};
use contracts::foreign;
use util::web3_filter;
use database::Database;
use error::{self, Error, ErrorKind};
use message_to_mainnet::MessageToMainnet;
use signature::Signature;
use ethcore_transaction::{Transaction, Action};
use super::nonce::{NonceCheck, SendRawTransaction};
use super::BridgeChecked;
use itertools::Itertools;
/// returns a filter for `ForeignBridge.CollectedSignatures` events
fn collected_signatures_filter<I: IntoIterator<Item = Address>>(foreign: &foreign::ForeignBridge, addresses: I) -> FilterBuilder {
let filter = foreign.events().collected_signatures().create_filter();
web3_filter(filter, addresses)
}
/// payloads for calls to `ForeignBridge.signature` and `ForeignBridge.message`
/// to retrieve the signatures (v, r, s) and messages
/// which the withdraw relay process should later relay to `HomeBridge`
/// by calling `HomeBridge.withdraw(v, r, s, message)`
#[derive(Debug, PartialEq)]
struct RelayAssignment {
signature_payloads: Vec<Bytes>,
message_payload: Bytes,
}
fn signatures_payload(foreign: &foreign::ForeignBridge, my_address: Address, log: Log) -> error::Result<Option<RelayAssignment>> {
// convert web3::Log to ethabi::RawLog since ethabi events can
// only be parsed from the latter
let raw_log = RawLog {
topics: log.topics.into_iter().map(|t| t.0.into()).collect(),
data: log.data.0,
};
let collected_signatures = foreign.events().collected_signatures().parse_log(raw_log)?;
if collected_signatures.authority_responsible_for_relay != my_address.0.into() {
info!("bridge not responsible for relaying transaction to home. tx hash: {}", log.transaction_hash.unwrap());
// this authority is not responsible for relaying this transaction.
// someone else will relay this transaction to home.
return Ok(None);
}
let required_signatures: U256 = (&foreign.functions().message().input(collected_signatures.number_of_collected_signatures)[4..]).into();
let signature_payloads = (0..required_signatures.low_u32()).into_iter()
.map(|index| foreign.functions().signature().input(collected_signatures.message_hash, index))
.map(Into::into)
.collect();
let message_payload = foreign.functions().message().input(collected_signatures.message_hash).into();
Ok(Some(RelayAssignment {
signature_payloads,
message_payload,
}))
}
/// state of the withdraw relay state machine
pub enum WithdrawRelayState<T: Transport> {
Wait,
FetchMessagesSignatures {
future: Join<
JoinAll<Vec<Timeout<ApiCall<Bytes, T::Out>>>>,
JoinAll<Vec<JoinAll<Vec<Timeout<ApiCall<Bytes, T::Out>>>>>>
>,
block: u64,
},
RelayWithdraws {
future: Collect<FuturesUnordered<NonceCheck<T, SendRawTransaction<T>>>>,
block: u64,
},
Yield(Option<u64>),
}
pub fn create_withdraw_relay<T: Transport + Clone>(app: Arc<App<T>>, init: &Database, home_balance: Arc<RwLock<Option<U256>>>, home_chain_id: u64, home_gas_price: Arc<RwLock<u64>>) -> WithdrawRelay<T> {
let logs_init = api::LogStreamInit {
after: init.checked_withdraw_relay,
request_timeout: app.config.foreign.request_timeout,
poll_interval: app.config.foreign.poll_interval,
confirmations: app.config.foreign.required_confirmations,
filter: collected_signatures_filter(&app.foreign_bridge, vec![init.foreign_contract_address]),
};
WithdrawRelay {
logs: api::log_stream(app.connections.foreign.clone(), app.timer.clone(), logs_init),
home_contract: init.home_contract_address,
foreign_contract: init.foreign_contract_address,
state: WithdrawRelayState::Wait,
app,
home_balance,
home_chain_id,
home_gas_price,
}
}
pub struct WithdrawRelay<T: Transport> {
app: Arc<App<T>>,
logs: LogStream<T>,
state: WithdrawRelayState<T>,
foreign_contract: Address,
home_contract: Address,
home_balance: Arc<RwLock<Option<U256>>>,
home_chain_id: u64,
home_gas_price: Arc<RwLock<u64>>,
}
impl<T: Transport> Stream for WithdrawRelay<T> {
type Item = BridgeChecked;
type Error = Error;
fn poll(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
let app = &self.app;
let gas = self.app.config.txs.withdraw_relay.gas.into();
let gas_price = U256::from(*self.home_gas_price.read().unwrap());
let contract = self.home_contract.clone();
let home = &self.app.config.home;
let t = &self.app.connections.home;
let foreign = &self.app.connections.foreign;
let chain_id = self.home_chain_id;
let foreign_bridge = &self.app.foreign_bridge;
let foreign_account = self.app.config.foreign.account;
let timer = &self.app.timer;
let foreign_contract = self.foreign_contract;
let foreign_request_timeout = self.app.config.foreign.request_timeout;
loop {
let next_state = match self.state {
WithdrawRelayState::Wait => {
let item = try_stream!(self.logs.poll().map_err(|e| ErrorKind::ContextualizedError(Box::new(e), "polling foreign for collected signatures")));
info!("got {} new signed withdraws to relay", item.logs.len());
let assignments = item.logs
.into_iter()
.map(|log| signatures_payload(
foreign_bridge,
foreign_account,
log))
.collect::<error::Result<Vec<_>>>()?;
let (signatures, messages): (Vec<_>, Vec<_>) = assignments.into_iter()
.filter_map(|a| a)
.map(|assignment| (assignment.signature_payloads, assignment.message_payload))
.unzip();
let message_calls = messages.into_iter()
.map(|payload| {
timer.timeout(
api::call(foreign, foreign_contract.clone(), payload),
foreign_request_timeout)
})
.collect::<Vec<_>>();
let signature_calls = signatures.into_iter()
.map(|payloads| {
payloads.into_iter()
.map(|payload| {
timer.timeout(
api::call(foreign, foreign_contract.clone(), payload),
foreign_request_timeout)
})
.collect::<Vec<_>>()
})
.map(|calls| join_all(calls))
.collect::<Vec<_>>();
info!("fetching messages and signatures");
WithdrawRelayState::FetchMessagesSignatures {
future: join_all(message_calls).join(join_all(signature_calls)),
block: item.to,
}
},
WithdrawRelayState::FetchMessagesSignatures { ref mut future, block } => {
let home_balance = self.home_balance.read().unwrap();
if home_balance.is_none() {
warn!("home contract balance is unknown");
return Ok(futures::Async::NotReady);
}
let (messages_raw, signatures_raw) = try_ready!(future.poll().map_err(|e| ErrorKind::ContextualizedError(Box::new(e), "fetching messages and signatures from foreign")));
info!("fetching messages and signatures complete");
assert_eq!(messages_raw.len(), signatures_raw.len());
let balance_required = gas * gas_price * U256::from(messages_raw.len());
if balance_required > *home_balance.as_ref().unwrap() {
return Err(ErrorKind::InsufficientFunds.into())
}
let messages = messages_raw
.iter()
.map(|message| {
app.foreign_bridge.functions().message().output(message.0.as_slice()).map(Bytes)
})
.collect::<ethabi::Result<Vec<_>>>()
.map_err(error::Error::from)?;
let len = messages.len();
let signatures = signatures_raw
.iter()
.map(|signatures|
signatures.iter().map(
|signature| {
Signature::from_bytes(
app.foreign_bridge
.functions()
.signature()
.output(signature.0.as_slice())?
.as_slice())
}
)
.collect::<Result<Vec<_>, Error>>()
.map_err(error::Error::from)
)
.collect::<error::Result<Vec<_>>>()?;
let relays = messages.into_iter()
.zip(signatures.into_iter())
.map(|(message, signatures)| {
let payload: Bytes = app.home_bridge.functions().withdraw().input(
signatures.iter().map(|x| x.v),
signatures.iter().map(|x| x.r),
signatures.iter().map(|x| x.s),
message.clone().0).into();
let gas_price = MessageToMainnet::from_bytes(message.0.as_slice()).mainnet_gas_price;
let tx = Transaction {
gas,
gas_price,
value: U256::zero(),
data: payload.0,
nonce: U256::zero(),
action: Action::Call(contract),
};
api::send_transaction_with_nonce(t.clone(), app.clone(), home.clone(), tx, chain_id, SendRawTransaction(t.clone()))
}).collect_vec();
info!("relaying {} withdraws", len);
WithdrawRelayState::RelayWithdraws {
future: futures_unordered(relays).collect(),
block,
}
},
WithdrawRelayState::RelayWithdraws { ref mut future, block } => {
let _ = try_ready!(future.poll().map_err(|e| ErrorKind::ContextualizedError(Box::new(e), "sending withdrawal to home")));
info!("relaying withdraws complete");
WithdrawRelayState::Yield(Some(block))
},
WithdrawRelayState::Yield(ref mut block) => match block.take() {
None => {
info!("waiting for signed withdraws to relay");
WithdrawRelayState::Wait
},
Some(v) => return Ok(Some(BridgeChecked::WithdrawRelay(v)).into()),
}
};
self.state = next_state;
}
}
}
#[cfg(test)]
mod tests {
use rustc_hex::FromHex;
use web3::types::{Log, Bytes, Address};
use contracts::foreign;
use super::signatures_payload;
#[test]
fn test_signatures_payload() {
let foreign = foreign::ForeignBridge::default();
let my_address = "aff3454fce5edbc8cca8697c15331677e6ebcccc".into();
let data = "000000000000000000000000aff3454fce5edbc8cca8697c15331677e6ebcccc00000000000000000000000000000000000000000000000000000000000000f00000000000000000000000000000000000000000000000000000000000000002".from_hex().unwrap();
let log = Log {
data: data.into(),
topics: vec!["415557404d88a0c0b8e3b16967cafffc511213fd9c465c16832ee17ed57d7237".into()],
transaction_hash: Some("884edad9ce6fa2440d8a54cc123490eb96d2768479d49ff9c7366125a9424364".into()),
address: Address::zero(),
block_hash: None,
transaction_index: None,
log_index: None,
transaction_log_index: None,
log_type: None,
block_number: None,
removed: None,
};
let assignment = signatures_payload(&foreign, my_address, log).unwrap().unwrap();
let expected_message: Bytes = "490a32c600000000000000000000000000000000000000000000000000000000000000f0".from_hex().unwrap().into();
let expected_signatures: Vec<Bytes> = vec![
"1812d99600000000000000000000000000000000000000000000000000000000000000f00000000000000000000000000000000000000000000000000000000000000000".from_hex().unwrap().into(),
"1812d99600000000000000000000000000000000000000000000000000000000000000f00000000000000000000000000000000000000000000000000000000000000001".from_hex().unwrap().into(),
];
assert_eq!(expected_message, assignment.message_payload);
assert_eq!(expected_signatures, assignment.signature_payloads);
}
#[test]
fn test_signatures_payload_not_ours() {
let foreign = foreign::ForeignBridge::default();
let my_address = "aff3454fce5edbc8cca8697c15331677e6ebcccd".into();
let data = "000000000000000000000000aff3454fce5edbc8cca8697c15331677e6ebcccc00000000000000000000000000000000000000000000000000000000000000f00000000000000000000000000000000000000000000000000000000000000002".from_hex().unwrap();
let log = Log {
data: data.into(),
topics: vec!["415557404d88a0c0b8e3b16967cafffc511213fd9c465c16832ee17ed57d7237".into()],
transaction_hash: Some("884edad9ce6fa2440d8a54cc123490eb96d2768479d49ff9c7366125a9424364".into()),
address: Address::zero(),
block_hash: None,
transaction_index: None,
log_index: None,
transaction_log_index: None,
log_type: None,
block_number: None,
removed: None,
};
let assignment = signatures_payload(&foreign, my_address, log).unwrap();
assert_eq!(None, assignment);
}
}