Merge pull request #127 from TheBlueMatt/2018-08-fuzz-fixes-5

Fix several panics introduced by #125 (#114) and #124

Author: TheBlueMatt

src/ln/channel.rs

@@ -1131,17 +1131,24 @@ impl Channel {
 				if htlc_id != 0 {
 					panic!("Duplicate HTLC payment_hash, you probably re-used payment preimages, NEVER DO THIS!");
 				}
-				htlc_id = htlc.htlc_id;
-				htlc_amount_msat += htlc.amount_msat;
 				if htlc.state == HTLCState::Committed {
 					htlc.state = HTLCState::LocalRemoved;
 				} else if htlc.state == HTLCState::RemoteAnnounced {
-					panic!("Somehow forwarded HTLC prior to remote revocation!");
+					if let Some(PendingHTLCStatus::Forward(_)) = htlc.pending_forward_state {
+						panic!("Somehow forwarded HTLC prior to remote revocation!");
+					} else {
+						// We have to pretend this isn't here - we're probably a duplicate with the
+						// same payment_hash as some other HTLC, and the other is getting failed,
+						// we'll fail this one as soon as remote commits to it.
+						continue;
+					}
 				} else if htlc.state == HTLCState::LocalRemoved || htlc.state == HTLCState::LocalRemovedAwaitingCommitment {
 					return Err(HandleError{err: "Unable to find a pending HTLC which matched the given payment preimage", action: None});
 				} else {
 					panic!("Have an inbound HTLC when not awaiting remote revoke that had a garbage state");
 				}
+				htlc_id = htlc.htlc_id;
+				htlc_amount_msat += htlc.amount_msat;
 			}
 		}
 		if htlc_amount_msat == 0 {

src/ln/channelmanager.rs

@@ -829,8 +829,8 @@ impl ChannelManager {
 					if !chan.is_live() {
 						Some(("Forwarding channel is not in a ready state.", 0x1000 | 7, self.get_channel_update(chan).unwrap()))
 					} else {
-						let fee = chan.get_our_fee_base_msat(&*self.fee_estimator) + (*amt_to_forward * self.fee_proportional_millionths as u64 / 1000000) as u32;
-						if msg.amount_msat < fee as u64 || (msg.amount_msat - fee as u64) < *amt_to_forward {
+						let fee = amt_to_forward.checked_mul(self.fee_proportional_millionths as u64).and_then(|prop_fee| { (prop_fee / 1000000).checked_add(chan.get_our_fee_base_msat(&*self.fee_estimator) as u64) });
+						if fee.is_none() || msg.amount_msat < fee.unwrap() || (msg.amount_msat - fee.unwrap()) < *amt_to_forward {
 							Some(("Prior hop has deviated from specified fees parameters or origin node has obsolete ones", 0x1000 | 12, self.get_channel_update(chan).unwrap()))
 						} else {
 							if (msg.cltv_expiry as u64) < (*outgoing_cltv_value) as u64 + CLTV_EXPIRY_DELTA as u64 {