use std::convert::From;
use std::convert::TryFrom;
use std::convert::TryInto;
+use std::str::FromStr;
use bitcoin::hashes::Hash;
+impl TryInto<serde_json::Value> for JsonResponse {
+ type Error = std::io::Error;
+ fn try_into(self) -> Result<serde_json::Value, std::io::Error> { Ok(self.0) }
+}
+
/// Conversion from `std::io::Error` into `BlockSourceError`.
impl From<std::io::Error> for BlockSourceError {
fn from(e: std::io::Error) -> BlockSourceError {
}
}
+/// Parses binary data as a block hash.
+impl TryInto<BlockHash> for BinaryResponse {
+ type Error = std::io::Error;
+
+ fn try_into(self) -> std::io::Result<BlockHash> {
+ BlockHash::from_slice(&self.0).map_err(|_|
+ std::io::Error::new(std::io::ErrorKind::InvalidData, "bad block hash length")
+ )
+ }
+}
+
/// Converts a JSON value into block header data. The JSON value may be an object representing a
/// block header or an array of such objects. In the latter case, the first object is converted.
impl TryInto<BlockHeaderData> for JsonResponse {
}
}
+impl TryInto<BlockHash> for JsonResponse {
+ type Error = std::io::Error;
+
+ fn try_into(self) -> std::io::Result<BlockHash> {
+ match self.0.as_str() {
+ None => Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "expected JSON string")),
+ Some(hex_data) if hex_data.len() != 64 =>
+ Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "invalid hash length")),
+ Some(hex_data) => BlockHash::from_str(hex_data)
+ .map_err(|_| std::io::Error::new(std::io::ErrorKind::InvalidData, "invalid hex data")),
+ }
+ }
+}
+
+/// The REST `getutxos` endpoint retuns a whole pile of data we don't care about and one bit we do
+/// - whether the `hit bitmap` field had any entries. Thus we condense the result down into only
+/// that.
+pub(crate) struct GetUtxosResponse {
+ pub(crate) hit_bitmap_nonempty: bool
+}
+
+impl TryInto<GetUtxosResponse> for JsonResponse {
+ type Error = std::io::Error;
+
+ fn try_into(self) -> std::io::Result<GetUtxosResponse> {
+ let bitmap_str =
+ self.0.as_object().ok_or(std::io::Error::new(std::io::ErrorKind::InvalidData, "expected an object"))?
+ .get("bitmap").ok_or(std::io::Error::new(std::io::ErrorKind::InvalidData, "missing bitmap field"))?
+ .as_str().ok_or(std::io::Error::new(std::io::ErrorKind::InvalidData, "bitmap should be an str"))?;
+ let mut hit_bitmap_nonempty = false;
+ for c in bitmap_str.chars() {
+ if c < '0' || c > '9' {
+ return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "invalid byte"));
+ }
+ if c > '0' { hit_bitmap_nonempty = true; }
+ }
+ Ok(GetUtxosResponse { hit_bitmap_nonempty })
+ }
+}
+
#[cfg(test)]
pub(crate) mod tests {
use super::*;
--- /dev/null
+//! When fetching gossip from peers, lightning nodes need to validate that gossip against the
+//! current UTXO set. This module defines an implementation of the LDK API required to do so
+//! against a [`BlockSource`] which implements a few additional methods for accessing the UTXO set.
+
+use crate::{AsyncBlockSourceResult, BlockData, BlockSource};
+
+use bitcoin::blockdata::transaction::{TxOut, OutPoint};
+use bitcoin::hash_types::BlockHash;
+
+use lightning::sign::NodeSigner;
+
+use lightning::ln::peer_handler::{CustomMessageHandler, PeerManager, SocketDescriptor};
+use lightning::ln::msgs::{ChannelMessageHandler, OnionMessageHandler};
+
+use lightning::routing::gossip::{NetworkGraph, P2PGossipSync};
+use lightning::routing::utxo::{UtxoFuture, UtxoLookup, UtxoResult, UtxoLookupError};
+
+use lightning::util::logger::Logger;
+
+use std::sync::Arc;
+use std::future::Future;
+use std::ops::Deref;
+
+/// A trait which extends [`BlockSource`] and can be queried to fetch the block at a given height
+/// as well as whether a given output is unspent (i.e. a member of the current UTXO set).
+///
+/// Note that while this is implementable for a [`BlockSource`] which returns filtered block data
+/// (i.e. [`BlockData::HeaderOnly`] for [`BlockSource::get_block`] requests), such an
+/// implementation will reject all gossip as it is not fully able to verify the UTXOs referenced.
+///
+/// For efficiency, an implementation may consider caching some set of blocks, as many redundant
+/// calls may be made.
+pub trait UtxoSource : BlockSource + 'static {
+ /// Fetches the block hash of the block at the given height.
+ ///
+ /// This will, in turn, be passed to to [`BlockSource::get_block`] to fetch the block needed
+ /// for gossip validation.
+ fn get_block_hash_by_height<'a>(&'a self, block_height: u32) -> AsyncBlockSourceResult<'a, BlockHash>;
+
+ /// Returns true if the given output has *not* been spent, i.e. is a member of the current UTXO
+ /// set.
+ fn is_output_unspent<'a>(&'a self, outpoint: OutPoint) -> AsyncBlockSourceResult<'a, bool>;
+}
+
+/// A generic trait which is able to spawn futures in the background.
+///
+/// If the `tokio` feature is enabled, this is implemented on `TokioSpawner` struct which
+/// delegates to `tokio::spawn()`.
+pub trait FutureSpawner : Send + Sync + 'static {
+ /// Spawns the given future as a background task.
+ ///
+ /// This method MUST NOT block on the given future immediately.
+ fn spawn<T: Future<Output = ()> + Send + 'static>(&self, future: T);
+}
+
+#[cfg(feature = "tokio")]
+/// A trivial [`FutureSpawner`] which delegates to `tokio::spawn`.
+pub struct TokioSpawner;
+#[cfg(feature = "tokio")]
+impl FutureSpawner for TokioSpawner {
+ fn spawn<T: Future<Output = ()> + Send + 'static>(&self, future: T) {
+ tokio::spawn(future);
+ }
+}
+
+/// A struct which wraps a [`UtxoSource`] and a few LDK objects and implements the LDK
+/// [`UtxoLookup`] trait.
+///
+/// Note that if you're using this against a Bitcoin Core REST or RPC server, you likely wish to
+/// increase the `rpcworkqueue` setting in Bitcoin Core as LDK attempts to parallelize requests (a
+/// value of 1024 should more than suffice), and ensure you have sufficient file descriptors
+/// available on both Bitcoin Core and your LDK application for each request to hold its own
+/// connection.
+pub struct GossipVerifier<S: FutureSpawner,
+ Blocks: Deref + Send + Sync + 'static + Clone,
+ L: Deref + Send + Sync + 'static,
+ Descriptor: SocketDescriptor + Send + Sync + 'static,
+ CM: Deref + Send + Sync + 'static,
+ OM: Deref + Send + Sync + 'static,
+ CMH: Deref + Send + Sync + 'static,
+ NS: Deref + Send + Sync + 'static,
+> where
+ Blocks::Target: UtxoSource,
+ L::Target: Logger,
+ CM::Target: ChannelMessageHandler,
+ OM::Target: OnionMessageHandler,
+ CMH::Target: CustomMessageHandler,
+ NS::Target: NodeSigner,
+{
+ source: Blocks,
+ peer_manager: Arc<PeerManager<Descriptor, CM, Arc<P2PGossipSync<Arc<NetworkGraph<L>>, Self, L>>, OM, L, CMH, NS>>,
+ gossiper: Arc<P2PGossipSync<Arc<NetworkGraph<L>>, Self, L>>,
+ spawn: S,
+}
+
+impl<S: FutureSpawner,
+ Blocks: Deref + Send + Sync + Clone,
+ L: Deref + Send + Sync,
+ Descriptor: SocketDescriptor + Send + Sync,
+ CM: Deref + Send + Sync,
+ OM: Deref + Send + Sync,
+ CMH: Deref + Send + Sync,
+ NS: Deref + Send + Sync,
+> GossipVerifier<S, Blocks, L, Descriptor, CM, OM, CMH, NS> where
+ Blocks::Target: UtxoSource,
+ L::Target: Logger,
+ CM::Target: ChannelMessageHandler,
+ OM::Target: OnionMessageHandler,
+ CMH::Target: CustomMessageHandler,
+ NS::Target: NodeSigner,
+{
+ /// Constructs a new [`GossipVerifier`].
+ ///
+ /// This is expected to be given to a [`P2PGossipSync`] (initially constructed with `None` for
+ /// the UTXO lookup) via [`P2PGossipSync::add_utxo_lookup`].
+ pub fn new(source: Blocks, spawn: S, gossiper: Arc<P2PGossipSync<Arc<NetworkGraph<L>>, Self, L>>, peer_manager: Arc<PeerManager<Descriptor, CM, Arc<P2PGossipSync<Arc<NetworkGraph<L>>, Self, L>>, OM, L, CMH, NS>>) -> Self {
+ Self { source, spawn, gossiper, peer_manager }
+ }
+
+ async fn retrieve_utxo(source: Blocks, short_channel_id: u64) -> Result<TxOut, UtxoLookupError> {
+ let block_height = (short_channel_id >> 5 * 8) as u32; // block height is most significant three bytes
+ let transaction_index = ((short_channel_id >> 2 * 8) & 0xffffff) as u32;
+ let output_index = (short_channel_id & 0xffff) as u16;
+
+ let block_hash = source.get_block_hash_by_height(block_height).await
+ .map_err(|_| UtxoLookupError::UnknownTx)?;
+ let block_data = source.get_block(&block_hash).await
+ .map_err(|_| UtxoLookupError::UnknownTx)?;
+ let mut block = match block_data {
+ BlockData::HeaderOnly(_) => return Err(UtxoLookupError::UnknownTx),
+ BlockData::FullBlock(block) => block,
+ };
+ if transaction_index as usize >= block.txdata.len() {
+ return Err(UtxoLookupError::UnknownTx);
+ }
+ let mut transaction = block.txdata.swap_remove(transaction_index as usize);
+ if output_index as usize >= transaction.output.len() {
+ return Err(UtxoLookupError::UnknownTx);
+ }
+ let outpoint_unspent =
+ source.is_output_unspent(OutPoint::new(transaction.txid(), output_index.into())).await
+ .map_err(|_| UtxoLookupError::UnknownTx)?;
+ if outpoint_unspent {
+ Ok(transaction.output.swap_remove(output_index as usize))
+ } else {
+ Err(UtxoLookupError::UnknownTx)
+ }
+ }
+}
+
+impl<S: FutureSpawner,
+ Blocks: Deref + Send + Sync + Clone,
+ L: Deref + Send + Sync,
+ Descriptor: SocketDescriptor + Send + Sync,
+ CM: Deref + Send + Sync,
+ OM: Deref + Send + Sync,
+ CMH: Deref + Send + Sync,
+ NS: Deref + Send + Sync,
+> Deref for GossipVerifier<S, Blocks, L, Descriptor, CM, OM, CMH, NS> where
+ Blocks::Target: UtxoSource,
+ L::Target: Logger,
+ CM::Target: ChannelMessageHandler,
+ OM::Target: OnionMessageHandler,
+ CMH::Target: CustomMessageHandler,
+ NS::Target: NodeSigner,
+{
+ type Target = Self;
+ fn deref(&self) -> &Self { self }
+}
+
+
+impl<S: FutureSpawner,
+ Blocks: Deref + Send + Sync + Clone,
+ L: Deref + Send + Sync,
+ Descriptor: SocketDescriptor + Send + Sync,
+ CM: Deref + Send + Sync,
+ OM: Deref + Send + Sync,
+ CMH: Deref + Send + Sync,
+ NS: Deref + Send + Sync,
+> UtxoLookup for GossipVerifier<S, Blocks, L, Descriptor, CM, OM, CMH, NS> where
+ Blocks::Target: UtxoSource,
+ L::Target: Logger,
+ CM::Target: ChannelMessageHandler,
+ OM::Target: OnionMessageHandler,
+ CMH::Target: CustomMessageHandler,
+ NS::Target: NodeSigner,
+{
+ fn get_utxo(&self, _genesis_hash: &BlockHash, short_channel_id: u64) -> UtxoResult {
+ let res = UtxoFuture::new();
+ let fut = res.clone();
+ let source = self.source.clone();
+ let gossiper = Arc::clone(&self.gossiper);
+ let pm = Arc::clone(&self.peer_manager);
+ self.spawn.spawn(async move {
+ let res = Self::retrieve_utxo(source, short_channel_id).await;
+ fut.resolve(gossiper.network_graph(), &*gossiper, res);
+ pm.process_events();
+ });
+ UtxoResult::Async(res)
+ }
+}
use crate::{BlockData, BlockHeaderData, BlockSource, AsyncBlockSourceResult};
use crate::http::{BinaryResponse, HttpEndpoint, HttpClient, JsonResponse};
+use crate::gossip::UtxoSource;
+use crate::convert::GetUtxosResponse;
+use bitcoin::OutPoint;
use bitcoin::hash_types::BlockHash;
use bitcoin::hashes::hex::ToHex;
}
}
+impl UtxoSource for RestClient {
+ fn get_block_hash_by_height<'a>(&'a self, block_height: u32) -> AsyncBlockSourceResult<'a, BlockHash> {
+ Box::pin(async move {
+ let resource_path = format!("blockhashbyheight/{}.bin", block_height);
+ Ok(self.request_resource::<BinaryResponse, _>(&resource_path).await?)
+ })
+ }
+
+ fn is_output_unspent<'a>(&'a self, outpoint: OutPoint) -> AsyncBlockSourceResult<'a, bool> {
+ Box::pin(async move {
+ let resource_path = format!("getutxos/{}-{}.json", outpoint.txid.to_hex(), outpoint.vout);
+ let utxo_result =
+ self.request_resource::<JsonResponse, GetUtxosResponse>(&resource_path).await?;
+ Ok(utxo_result.hit_bitmap_nonempty)
+ })
+ }
+}
+
#[cfg(test)]
mod tests {
use super::*;
use crate::http::BinaryResponse;
use crate::http::client_tests::{HttpServer, MessageBody};
+ use bitcoin::hashes::Hash;
/// Parses binary data as a string-encoded `u32`.
impl TryInto<u32> for BinaryResponse {
Ok(n) => assert_eq!(n, 42),
}
}
+
+ #[tokio::test]
+ async fn parses_negative_getutxos() {
+ let server = HttpServer::responding_with_ok(MessageBody::Content(
+ // A real response contains a few more fields, but we actually only look at the
+ // "bitmap" field, so this should suffice for testing
+ "{\"chainHeight\": 1, \"bitmap\":\"0\",\"utxos\":[]}"
+ ));
+ let client = RestClient::new(server.endpoint()).unwrap();
+
+ let outpoint = OutPoint::new(bitcoin::Txid::from_inner([0; 32]), 0);
+ let unspent_output = client.is_output_unspent(outpoint).await.unwrap();
+ assert_eq!(unspent_output, false);
+ }
+
+ #[tokio::test]
+ async fn parses_positive_getutxos() {
+ let server = HttpServer::responding_with_ok(MessageBody::Content(
+ // A real response contains lots more data, but we actually only look at the "bitmap"
+ // field, so this should suffice for testing
+ "{\"chainHeight\": 1, \"bitmap\":\"1\",\"utxos\":[]}"
+ ));
+ let client = RestClient::new(server.endpoint()).unwrap();
+
+ let outpoint = OutPoint::new(bitcoin::Txid::from_inner([0; 32]), 0);
+ let unspent_output = client.is_output_unspent(outpoint).await.unwrap();
+ assert_eq!(unspent_output, true);
+ }
}
use crate::{BlockData, BlockHeaderData, BlockSource, AsyncBlockSourceResult};
use crate::http::{HttpClient, HttpEndpoint, HttpError, JsonResponse};
+use crate::gossip::UtxoSource;
use bitcoin::hash_types::BlockHash;
use bitcoin::hashes::hex::ToHex;
+use bitcoin::OutPoint;
use std::sync::Mutex;
}
}
+impl UtxoSource for RpcClient {
+ fn get_block_hash_by_height<'a>(&'a self, block_height: u32) -> AsyncBlockSourceResult<'a, BlockHash> {
+ Box::pin(async move {
+ let height_param = serde_json::json!(block_height);
+ Ok(self.call_method("getblockhash", &[height_param]).await?)
+ })
+ }
+
+ fn is_output_unspent<'a>(&'a self, outpoint: OutPoint) -> AsyncBlockSourceResult<'a, bool> {
+ Box::pin(async move {
+ let txid_param = serde_json::json!(outpoint.txid.to_hex());
+ let vout_param = serde_json::json!(outpoint.vout);
+ let include_mempool = serde_json::json!(false);
+ let utxo_opt: serde_json::Value = self.call_method(
+ "gettxout", &[txid_param, vout_param, include_mempool]).await?;
+ Ok(!utxo_opt.is_null())
+ })
+ }
+}
+
#[cfg(test)]
mod tests {
use super::*;
use crate::http::client_tests::{HttpServer, MessageBody};
+ use bitcoin::hashes::Hash;
+
/// Credentials encoded in base64.
const CREDENTIALS: &'static str = "dXNlcjpwYXNzd29yZA==";
Ok(count) => assert_eq!(count, 654470),
}
}
+
+ #[tokio::test]
+ async fn fails_to_fetch_spent_utxo() {
+ let response = serde_json::json!({ "result": null });
+ let server = HttpServer::responding_with_ok(MessageBody::Content(response));
+ let client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
+ let outpoint = OutPoint::new(bitcoin::Txid::from_inner([0; 32]), 0);
+ let unspent_output = client.is_output_unspent(outpoint).await.unwrap();
+ assert_eq!(unspent_output, false);
+ }
+
+ #[tokio::test]
+ async fn fetches_utxo() {
+ let response = serde_json::json!({ "result": {"bestblock": 1, "confirmations": 42}});
+ let server = HttpServer::responding_with_ok(MessageBody::Content(response));
+ let client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
+ let outpoint = OutPoint::new(bitcoin::Txid::from_inner([0; 32]), 0);
+ let unspent_output = client.is_output_unspent(outpoint).await.unwrap();
+ assert_eq!(unspent_output, true);
+ }
}
projects / rust-lightning / commitdiff