From: Matt Corallo <git@bluematt.me>
Date: Fri, 23 Mar 2018 20:57:22 +0000 (-0400)
Subject: Hold channel_state lock into fail_htlc_backwards_internal
X-Git-Tag: v0.0.12~416^2~7
X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=729f02d2dd542c72989ac1665d669a3602bb81c8;p=rust-lightning

Hold channel_state lock into fail_htlc_backwards_internal
---

diff --git a/src/ln/channelmanager.rs b/src/ln/channelmanager.rs
index 519a6c20d..4e243935f 100644
--- a/src/ln/channelmanager.rs
+++ b/src/ln/channelmanager.rs
@@ -26,11 +26,10 @@ use crypto::digest::Digest;
 use crypto::symmetriccipher::SynchronousStreamCipher;
 use crypto::chacha20::ChaCha20;
 
-use std::sync::{Mutex,Arc};
+use std::sync::{Mutex,MutexGuard,Arc};
 use std::collections::HashMap;
 use std::collections::hash_map;
-use std::ptr;
-use std::mem;
+use std::{ptr, mem};
 use std::time::{Instant,Duration};
 
 /// Stores the info we will need to send when we want to forward an HTLC onwards
@@ -651,11 +650,10 @@ impl ChannelManager {
 
 	/// Indicates that the preimage for payment_hash is unknown after a PaymentReceived event.
 	pub fn fail_htlc_backwards(&self, payment_hash: &[u8; 32]) -> bool {
-		self.fail_htlc_backwards_internal(payment_hash, HTLCFailReason::Reason { failure_code: 0x4000 | 15 })
+		self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), payment_hash, HTLCFailReason::Reason { failure_code: 0x4000 | 15 })
 	}
 
-	fn fail_htlc_backwards_internal(&self, payment_hash: &[u8; 32], onion_error: HTLCFailReason) -> bool {
-		let mut channel_state = self.channel_state.lock().unwrap();
+	fn fail_htlc_backwards_internal(&self, mut channel_state: MutexGuard<ChannelHolder>, payment_hash: &[u8; 32], onion_error: HTLCFailReason) -> bool {
 		let mut pending_htlc = {
 			match channel_state.claimable_htlcs.remove(payment_hash) {
 				Some(pending_htlc) => pending_htlc,
@@ -674,6 +672,7 @@ impl ChannelManager {
 			PendingOutboundHTLC::CycledRoute { .. } => { panic!("WAT"); },
 			PendingOutboundHTLC::OutboundRoute { .. } => {
 				//TODO: DECRYPT route from OutboundRoute
+				mem::drop(channel_state);
 				let mut pending_events = self.pending_events.lock().unwrap();
 				pending_events.push(events::Event::PaymentFailed {
 					payment_hash: payment_hash.clone()
@@ -707,6 +706,7 @@ impl ChannelManager {
 					}
 				};
 
+				mem::drop(channel_state);
 				let mut pending_events = self.pending_events.lock().unwrap();
 				pending_events.push(events::Event::SendFailHTLC {
 					node_id,
@@ -1217,36 +1217,34 @@ impl ChannelMessageHandler for ChannelManager {
 	}
 
 	fn handle_update_fail_htlc(&self, their_node_id: &PublicKey, msg: &msgs::UpdateFailHTLC) -> Result<Option<(Vec<msgs::UpdateAddHTLC>, msgs::CommitmentSigned)>, HandleError> {
-		let res = {
-			let mut channel_state = self.channel_state.lock().unwrap();
-			match channel_state.by_id.get_mut(&msg.channel_id) {
-				Some(chan) => {
-					if chan.get_their_node_id() != *their_node_id {
-						return Err(HandleError{err: "Got a message for a channel from the wrong node!", msg: None})
-					}
-					chan.update_fail_htlc(&msg)?
-				},
-				None => return Err(HandleError{err: "Failed to find corresponding channel", msg: None})
-			}
-		};
-		self.fail_htlc_backwards_internal(&res.0, HTLCFailReason::ErrorPacket { err: &msg.reason });
+		let mut channel_state = self.channel_state.lock().unwrap();
+		let res;
+		match channel_state.by_id.get_mut(&msg.channel_id) {
+			Some(chan) => {
+				if chan.get_their_node_id() != *their_node_id {
+					return Err(HandleError{err: "Got a message for a channel from the wrong node!", msg: None})
+				}
+				res = chan.update_fail_htlc(&msg)?;
+			},
+			None => return Err(HandleError{err: "Failed to find corresponding channel", msg: None})
+		}
+		self.fail_htlc_backwards_internal(channel_state, &res.0, HTLCFailReason::ErrorPacket { err: &msg.reason });
 		Ok(res.1)
 	}
 
 	fn handle_update_fail_malformed_htlc(&self, their_node_id: &PublicKey, msg: &msgs::UpdateFailMalformedHTLC) -> Result<Option<(Vec<msgs::UpdateAddHTLC>, msgs::CommitmentSigned)>, HandleError> {
-		let res = {
-			let mut channel_state = self.channel_state.lock().unwrap();
-			match channel_state.by_id.get_mut(&msg.channel_id) {
-				Some(chan) => {
-					if chan.get_their_node_id() != *their_node_id {
-						return Err(HandleError{err: "Got a message for a channel from the wrong node!", msg: None})
-					}
-					chan.update_fail_malformed_htlc(&msg)?
-				},
-				None => return Err(HandleError{err: "Failed to find corresponding channel", msg: None})
-			}
-		};
-		self.fail_htlc_backwards_internal(&res.0, HTLCFailReason::Reason { failure_code: msg.failure_code });
+		let mut channel_state = self.channel_state.lock().unwrap();
+		let res;
+		match channel_state.by_id.get_mut(&msg.channel_id) {
+			Some(chan) => {
+				if chan.get_their_node_id() != *their_node_id {
+					return Err(HandleError{err: "Got a message for a channel from the wrong node!", msg: None})
+				}
+				res = chan.update_fail_malformed_htlc(&msg)?;
+			},
+			None => return Err(HandleError{err: "Failed to find corresponding channel", msg: None})
+		}
+		self.fail_htlc_backwards_internal(channel_state, &res.0, HTLCFailReason::Reason { failure_code: msg.failure_code });
 		Ok(res.1)
 	}