Reject rumors of channels that are from one node back to itself
[rust-lightning] / src / ln / router.rs
index 1f713f69de8287fd298776179c51c3f4389e69be..6bc319d59b8145de6162f47c7c78d746fd318a12 100644 (file)
@@ -3,7 +3,10 @@ use secp256k1::{Secp256k1,Message};
 use secp256k1;
 
 use bitcoin::util::hash::Sha256dHash;
+use bitcoin::blockdata::script::Builder;
+use bitcoin::blockdata::opcodes;
 
+use chain::chaininterface::{ChainError, ChainWatchInterface};
 use ln::channelmanager;
 use ln::msgs::{ErrorAction,HandleError,RoutingMessageHandler,MsgEncodable,NetAddress,GlobalFeatures};
 use ln::msgs;
@@ -155,6 +158,7 @@ pub struct RouteHint {
 pub struct Router {
        secp_ctx: Secp256k1<secp256k1::VerifyOnly>,
        network_map: RwLock<NetworkMap>,
+       chain_monitor: Arc<ChainWatchInterface>,
        logger: Arc<Logger>,
 }
 
@@ -168,10 +172,14 @@ macro_rules! secp_verify_sig {
 }
 
 impl RoutingMessageHandler for Router {
-       fn handle_node_announcement(&self, msg: &msgs::NodeAnnouncement) -> Result<(), HandleError> {
+       fn handle_node_announcement(&self, msg: &msgs::NodeAnnouncement) -> Result<bool, HandleError> {
                let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
                secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &msg.contents.node_id);
 
+               if msg.contents.features.requires_unknown_bits() {
+                       panic!("Unknown-required-features NodeAnnouncements should never deserialize!");
+               }
+
                let mut network = self.network_map.write().unwrap();
                match network.nodes.get_mut(&msg.contents.node_id) {
                        None => Err(HandleError{err: "No existing channels for node_announcement", action: Some(ErrorAction::IgnoreError)}),
@@ -185,23 +193,47 @@ impl RoutingMessageHandler for Router {
                                node.rgb = msg.contents.rgb;
                                node.alias = msg.contents.alias;
                                node.addresses = msg.contents.addresses.clone();
-                               Ok(())
+                               Ok(msg.contents.excess_data.is_empty() && msg.contents.excess_address_data.is_empty() && !msg.contents.features.supports_unknown_bits())
                        }
                }
        }
 
        fn handle_channel_announcement(&self, msg: &msgs::ChannelAnnouncement) -> Result<bool, HandleError> {
+               if msg.contents.node_id_1 == msg.contents.node_id_2 || msg.contents.bitcoin_key_1 == msg.contents.bitcoin_key_2 {
+                       return Err(HandleError{err: "Channel announcement node had a channel with itself", action: Some(ErrorAction::IgnoreError)});
+               }
+
                let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
                secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.node_signature_1, &msg.contents.node_id_1);
                secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.node_signature_2, &msg.contents.node_id_2);
                secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.bitcoin_signature_1, &msg.contents.bitcoin_key_1);
                secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.bitcoin_signature_2, &msg.contents.bitcoin_key_2);
 
-               //TODO: Call blockchain thing to ask if the short_channel_id is valid
-               //TODO: Only allow bitcoin chain_hash
-
                if msg.contents.features.requires_unknown_bits() {
-                       return Err(HandleError{err: "Channel announcement required unknown feature flags", action: None});
+                       panic!("Unknown-required-features ChannelAnnouncements should never deserialize!");
+               }
+
+               match self.chain_monitor.get_chain_utxo(msg.contents.chain_hash, msg.contents.short_channel_id) {
+                       Ok((script_pubkey, _value)) => {
+                               let expected_script = Builder::new().push_opcode(opcodes::All::OP_PUSHNUM_2)
+                                                                   .push_slice(&msg.contents.bitcoin_key_1.serialize())
+                                                                   .push_slice(&msg.contents.bitcoin_key_2.serialize())
+                                                                   .push_opcode(opcodes::All::OP_PUSHNUM_2).push_opcode(opcodes::All::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
+                               if script_pubkey != expected_script {
+                                       return Err(HandleError{err: "Channel announcement keys didn't match on-chain script", action: Some(ErrorAction::IgnoreError)});
+                               }
+                               //TODO: Check if value is worth storing, use it to inform routing, and compare it
+                               //to the new HTLC max field in channel_update
+                       },
+                       Err(ChainError::NotSupported) => {
+                               // Tentatively accept, potentially exposing us to DoS attacks
+                       },
+                       Err(ChainError::NotWatched) => {
+                               return Err(HandleError{err: "Channel announced on an unknown chain", action: Some(ErrorAction::IgnoreError)});
+                       },
+                       Err(ChainError::UnknownTx) => {
+                               return Err(HandleError{err: "Channel announced without corresponding UTXO entry", action: Some(ErrorAction::IgnoreError)});
+                       },
                }
 
                let mut network = self.network_map.write().unwrap();
@@ -285,7 +317,7 @@ impl RoutingMessageHandler for Router {
                }
        }
 
-       fn handle_channel_update(&self, msg: &msgs::ChannelUpdate) -> Result<(), HandleError> {
+       fn handle_channel_update(&self, msg: &msgs::ChannelUpdate) -> Result<bool, HandleError> {
                let mut network = self.network_map.write().unwrap();
                let dest_node_id;
                let chan_enabled = msg.contents.flags & (1 << 1) != (1 << 1);
@@ -351,7 +383,7 @@ impl RoutingMessageHandler for Router {
                        mut_node.lowest_inbound_channel_fee_proportional_millionths = lowest_inbound_channel_fee_proportional_millionths;
                }
 
-               Ok(())
+               Ok(msg.contents.excess_data.is_empty())
        }
 }
 
@@ -384,7 +416,7 @@ struct DummyDirectionalChannelInfo {
 }
 
 impl Router {
-       pub fn new(our_pubkey: PublicKey, logger: Arc<Logger>) -> Router {
+       pub fn new(our_pubkey: PublicKey, chain_monitor: Arc<ChainWatchInterface>, logger: Arc<Logger>) -> Router {
                let mut nodes = HashMap::new();
                nodes.insert(our_pubkey.clone(), NodeInfo {
                        channels: Vec::new(),
@@ -403,6 +435,7 @@ impl Router {
                                our_node_id: our_pubkey,
                                nodes: nodes,
                        }),
+                       chain_monitor,
                        logger,
                }
        }
@@ -628,6 +661,7 @@ impl Router {
 
 #[cfg(test)]
 mod tests {
+       use chain::chaininterface;
        use ln::channelmanager;
        use ln::router::{Router,NodeInfo,NetworkMap,ChannelInfo,DirectionalChannelInfo,RouteHint};
        use ln::msgs::GlobalFeatures;
@@ -635,6 +669,7 @@ mod tests {
        use util::logger::Logger;
 
        use bitcoin::util::hash::Sha256dHash;
+       use bitcoin::network::constants::Network;
 
        use hex;
 
@@ -648,7 +683,8 @@ mod tests {
                let secp_ctx = Secp256k1::new();
                let our_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap());
                let logger: Arc<Logger> = Arc::new(test_utils::TestLogger::new());
-               let router = Router::new(our_id, Arc::clone(&logger));
+               let chain_monitor = Arc::new(chaininterface::ChainWatchInterfaceUtil::new(Network::Testnet, Arc::clone(&logger)));
+               let router = Router::new(our_id, chain_monitor, Arc::clone(&logger));
 
                // Build network from our_id to node8:
                //