Fail RGS data processing early if there is a chain hash mismatch

[rust-lightning] / lightning-rapid-gossip-sync / src / processing.rs

diff --git a/lightning-rapid-gossip-sync/src/processing.rs b/lightning-rapid-gossip-sync/src/processing.rs
index b387d49998e9a38d6f1693e1a18d05c4da57e675..fca318a5fa5f8cfac735ff8d3880819e8b6d93a0 100644 (file)
--- a/lightning-rapid-gossip-sync/src/processing.rs
+++ b/lightning-rapid-gossip-sync/src/processing.rs
@@ -68,6 +68,16 @@ impl<NG: Deref<Target=NetworkGraph<L>>, L: Deref> RapidGossipSync<NG, L> where L
                }
 
                let chain_hash: BlockHash = Readable::read(read_cursor)?;
+               let ng_genesis_hash = self.network_graph.get_genesis_hash();
+               if chain_hash != ng_genesis_hash {
+                       return Err(
+                               LightningError {
+                                       err: "Rapid Gossip Sync data's chain hash does not match the network graph's".to_owned(),
+                                       action: ErrorAction::IgnoreError,
+                               }.into()
+                       );
+               }
+
                let latest_seen_timestamp: u32 = Readable::read(read_cursor)?;
 
                if let Some(time) = current_time_unix {
@@ -667,4 +677,22 @@ mod tests {
                        panic!("Unexpected update result: {:?}", update_result)
                }
        }
+
+       #[test]
+       fn fails_early_on_chain_hash_mismatch() {
+               let logger = TestLogger::new();
+               // Set to testnet so that the VALID_RGS_BINARY chain hash of mainnet does not match.
+               let network_graph = NetworkGraph::new(Network::Testnet, &logger);
+
+               assert_eq!(network_graph.read_only().channels().len(), 0);
+
+               let rapid_sync = RapidGossipSync::new(&network_graph, &logger);
+               let update_result = rapid_sync.update_network_graph_no_std(&VALID_RGS_BINARY, Some(0));
+               assert!(update_result.is_err());
+               if let Err(GraphSyncError::LightningError(err)) = update_result {
+                       assert_eq!(err.err, "Rapid Gossip Sync data's chain hash does not match the network graph's");
+               } else {
+                       panic!("Unexpected update result: {:?}", update_result)
+               }
+       }
 }