From 1dffb201997804a6df5bb805fe6b33a1d9474808 Mon Sep 17 00:00:00 2001 From: Elias Rohrer Date: Fri, 13 Oct 2023 11:30:15 +0200 Subject: [PATCH] Allow to verify channel updates without applying them We introduce a new `NetworkGraph::verify_channel_update` method that allows to check whether an update would be applied by `update_channel`. --- lightning/src/routing/gossip.rs | 32 +++++++++++++++++++++++++------- 1 file changed, 25 insertions(+), 7 deletions(-) diff --git a/lightning/src/routing/gossip.rs b/lightning/src/routing/gossip.rs index edb622604..d13fe9a2b 100644 --- a/lightning/src/routing/gossip.rs +++ b/lightning/src/routing/gossip.rs @@ -1845,14 +1845,14 @@ impl NetworkGraph where L::Target: Logger { /// For an already known (from announcement) channel, update info about one of the directions /// of the channel. /// - /// You probably don't want to call this directly, instead relying on a P2PGossipSync's - /// RoutingMessageHandler implementation to call it indirectly. This may be useful to accept + /// You probably don't want to call this directly, instead relying on a [`P2PGossipSync`]'s + /// [`RoutingMessageHandler`] implementation to call it indirectly. This may be useful to accept /// routing messages from a source using a protocol other than the lightning P2P protocol. /// /// If built with `no-std`, any updates with a timestamp more than two weeks in the past or /// materially in the future will be rejected. pub fn update_channel(&self, msg: &msgs::ChannelUpdate) -> Result<(), LightningError> { - self.update_channel_intern(&msg.contents, Some(&msg), Some(&msg.signature)) + self.update_channel_internal(&msg.contents, Some(&msg), Some(&msg.signature), false) } /// For an already known (from announcement) channel, update info about one of the directions @@ -1862,10 +1862,23 @@ impl NetworkGraph where L::Target: Logger { /// If built with `no-std`, any updates with a timestamp more than two weeks in the past or /// materially in the future will be rejected. pub fn update_channel_unsigned(&self, msg: &msgs::UnsignedChannelUpdate) -> Result<(), LightningError> { - self.update_channel_intern(msg, None, None) + self.update_channel_internal(msg, None, None, false) } - fn update_channel_intern(&self, msg: &msgs::UnsignedChannelUpdate, full_msg: Option<&msgs::ChannelUpdate>, sig: Option<&secp256k1::ecdsa::Signature>) -> Result<(), LightningError> { + /// For an already known (from announcement) channel, verify the given [`ChannelUpdate`]. + /// + /// This checks whether the update currently is applicable by [`Self::update_channel`]. + /// + /// If built with `no-std`, any updates with a timestamp more than two weeks in the past or + /// materially in the future will be rejected. + pub fn verify_channel_update(&self, msg: &msgs::ChannelUpdate) -> Result<(), LightningError> { + self.update_channel_internal(&msg.contents, Some(&msg), Some(&msg.signature), true) + } + + fn update_channel_internal(&self, msg: &msgs::UnsignedChannelUpdate, + full_msg: Option<&msgs::ChannelUpdate>, sig: Option<&secp256k1::ecdsa::Signature>, + only_verify: bool) -> Result<(), LightningError> + { let chan_enabled = msg.flags & (1 << 1) != (1 << 1); if msg.chain_hash != self.chain_hash { @@ -1961,7 +1974,9 @@ impl NetworkGraph where L::Target: Logger { action: ErrorAction::IgnoreAndLog(Level::Debug) })?, "channel_update"); } - channel.two_to_one = get_new_channel_info!(); + if !only_verify { + channel.two_to_one = get_new_channel_info!(); + } } else { check_update_latest!(channel.one_to_two); if let Some(sig) = sig { @@ -1970,7 +1985,9 @@ impl NetworkGraph where L::Target: Logger { action: ErrorAction::IgnoreAndLog(Level::Debug) })?, "channel_update"); } - channel.one_to_two = get_new_channel_info!(); + if !only_verify { + channel.one_to_two = get_new_channel_info!(); + } } } } @@ -2411,6 +2428,7 @@ pub(crate) mod tests { } let valid_channel_update = get_signed_channel_update(|_| {}, node_1_privkey, &secp_ctx); + network_graph.verify_channel_update(&valid_channel_update).unwrap(); match gossip_sync.handle_channel_update(&valid_channel_update) { Ok(res) => assert!(res), _ => panic!(), -- 2.39.5