Catch fee overflow panic in get_route

diff --git a/src/ln/router.rs b/src/ln/router.rs
index ad7ae675117f935561979b1ff97277dde314b48f..f30eb7912792df24f1dd6bcedae86cadb2e8f69a 100644 (file)
--- a/src/ln/router.rs
+++ b/src/ln/router.rs
@@ -428,39 +428,42 @@ impl Router {
                        ( $chan_id: expr, $dest_node_id: expr, $directional_info: expr, $starting_fee_msat: expr ) => {
                                //TODO: Explore simply adding fee to hit htlc_minimum_msat
                                if $starting_fee_msat as u64 + final_value_msat > $directional_info.htlc_minimum_msat {
-                                       let new_fee = $directional_info.fee_base_msat as u64 + ($starting_fee_msat + final_value_msat) * ($directional_info.fee_proportional_millionths as u64) / 1000000;
-                                       let mut total_fee = $starting_fee_msat as u64;
-                                       let mut hm_entry = dist.entry(&$directional_info.src_node_id);
-                                       let old_entry = hm_entry.or_insert_with(|| {
-                                               let node = network.nodes.get(&$directional_info.src_node_id).unwrap();
-                                               (u64::max_value(),
-                                                       node.lowest_inbound_channel_fee_base_msat as u64,
-                                                       node.lowest_inbound_channel_fee_proportional_millionths as u64,
-                                                       RouteHop {
-                                                               pubkey: PublicKey::new(),
-                                                               short_channel_id: 0,
-                                                               fee_msat: 0,
-                                                               cltv_expiry_delta: 0,
-                                               })
-                                       });
-                                       if $directional_info.src_node_id != network.our_node_id {
-                                               // Ignore new_fee for channel-from-us as we assume all channels-from-us
-                                               // will have the same effective-fee
-                                               total_fee += new_fee;
-                                               total_fee += old_entry.2 * (final_value_msat + total_fee) / 1000000 + old_entry.1;
-                                       }
-                                       let new_graph_node = RouteGraphNode {
-                                               pubkey: $directional_info.src_node_id,
-                                               lowest_fee_to_peer_through_node: total_fee,
-                                       };
-                                       if old_entry.0 > total_fee {
-                                               targets.push(new_graph_node);
-                                               old_entry.0 = total_fee;
-                                               old_entry.3 = RouteHop {
-                                                       pubkey: $dest_node_id.clone(),
-                                                       short_channel_id: $chan_id.clone(),
-                                                       fee_msat: new_fee, // This field is ignored on the last-hop anyway
-                                                       cltv_expiry_delta: $directional_info.cltv_expiry_delta as u32,
+                                       let proportional_fee_millions = ($starting_fee_msat + final_value_msat).checked_mul($directional_info.fee_proportional_millionths as u64);
+                                       if let Some(proportional_fee) = proportional_fee_millions {
+                                               let new_fee = $directional_info.fee_base_msat as u64 + proportional_fee / 1000000;
+                                               let mut total_fee = $starting_fee_msat as u64;
+                                               let mut hm_entry = dist.entry(&$directional_info.src_node_id);
+                                               let old_entry = hm_entry.or_insert_with(|| {
+                                                       let node = network.nodes.get(&$directional_info.src_node_id).unwrap();
+                                                       (u64::max_value(),
+                                                               node.lowest_inbound_channel_fee_base_msat as u64,
+                                                               node.lowest_inbound_channel_fee_proportional_millionths as u64,
+                                                               RouteHop {
+                                                                       pubkey: PublicKey::new(),
+                                                                       short_channel_id: 0,
+                                                                       fee_msat: 0,
+                                                                       cltv_expiry_delta: 0,
+                                                       })
+                                               });
+                                               if $directional_info.src_node_id != network.our_node_id {
+                                                       // Ignore new_fee for channel-from-us as we assume all channels-from-us
+                                                       // will have the same effective-fee
+                                                       total_fee += new_fee;
+                                                       total_fee += old_entry.2 * (final_value_msat + total_fee) / 1000000 + old_entry.1;
+                                               }
+                                               let new_graph_node = RouteGraphNode {
+                                                       pubkey: $directional_info.src_node_id,
+                                                       lowest_fee_to_peer_through_node: total_fee,
+                                               };
+                                               if old_entry.0 > total_fee {
+                                                       targets.push(new_graph_node);
+                                                       old_entry.0 = total_fee;
+                                                       old_entry.3 = RouteHop {
+                                                               pubkey: $dest_node_id.clone(),
+                                                               short_channel_id: $chan_id.clone(),
+                                                               fee_msat: new_fee, // This field is ignored on the last-hop anyway
+                                                               cltv_expiry_delta: $directional_info.cltv_expiry_delta as u32,
+                                                       }
                                                }
                                        }
                                }