Correct error when a peer opens a channel with a huge push_msat

[rust-lightning] / lightning / src / ln / channel.rs

diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs
index 9ccdf816ad398d764d599b62e45e0e1274391572..60ff1ded1ad99220686729be383ea8967869ec68 100644 (file)
--- a/lightning/src/ln/channel.rs
+++ b/lightning/src/ln/channel.rs
@@ -1082,14 +1082,13 @@ impl<Signer: Sign> Channel<Signer> {
                if msg.channel_reserve_satoshis > msg.funding_satoshis {
                        return Err(ChannelError::Close(format!("Bogus channel_reserve_satoshis ({}). Must be not greater than funding_satoshis: {}", msg.channel_reserve_satoshis, msg.funding_satoshis)));
                }
-               let funding_value = (msg.funding_satoshis - msg.channel_reserve_satoshis) * 1000;
-               if msg.push_msat > funding_value {
-                       return Err(ChannelError::Close(format!("push_msat {} was larger than funding value {}", msg.push_msat, funding_value)));
+               let full_channel_value_msat = (msg.funding_satoshis - msg.channel_reserve_satoshis) * 1000;
+               if msg.push_msat > full_channel_value_msat {
+                       return Err(ChannelError::Close(format!("push_msat {} was larger than channel amount minus reserve ({})", msg.push_msat, full_channel_value_msat)));
                }
                if msg.dust_limit_satoshis > msg.funding_satoshis {
                        return Err(ChannelError::Close(format!("dust_limit_satoshis {} was larger than funding_satoshis {}. Peer never wants payout outputs?", msg.dust_limit_satoshis, msg.funding_satoshis)));
                }
-               let full_channel_value_msat = (msg.funding_satoshis - msg.channel_reserve_satoshis) * 1000;
                if msg.htlc_minimum_msat >= full_channel_value_msat {
                        return Err(ChannelError::Close(format!("Minimum htlc value ({}) was larger than full channel value ({})", msg.htlc_minimum_msat, full_channel_value_msat)));
                }
@@ -1143,6 +1142,9 @@ impl<Signer: Sign> Channel<Signer> {
                if holder_selected_channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
                        return Err(ChannelError::Close(format!("Suitable channel reserve not found. remote_channel_reserve was ({}). dust_limit_satoshis is ({}).", holder_selected_channel_reserve_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS)));
                }
+               if holder_selected_channel_reserve_satoshis * 1000 >= full_channel_value_msat {
+                       return Err(ChannelError::Close(format!("Suitable channel reserve not found. remote_channel_reserve was ({}). Channel value is ({} - {}).", holder_selected_channel_reserve_satoshis, full_channel_value_msat, msg.push_msat)));
+               }
                if msg.channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
                        log_debug!(logger, "channel_reserve_satoshis ({}) is smaller than our dust limit ({}). We can broadcast stale states without any risk, implying this channel is very insecure for our counterparty.",
                                msg.channel_reserve_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS);
@@ -4321,11 +4323,15 @@ impl<Signer: Sign> Channel<Signer> {
        }
 
        /// Allowed in any state (including after shutdown)
-       #[cfg(test)]
        pub fn get_holder_htlc_minimum_msat(&self) -> u64 {
                self.holder_htlc_minimum_msat
        }
 
+       /// Allowed in any state (including after shutdown), but will return none before TheirInitSent
+       pub fn get_holder_htlc_maximum_msat(&self) -> Option<u64> {
+               self.get_htlc_maximum_msat(self.holder_max_htlc_value_in_flight_msat)
+       }
+
        /// Allowed in any state (including after shutdown)
        pub fn get_announced_htlc_max_msat(&self) -> u64 {
                return cmp::min(
@@ -4343,6 +4349,21 @@ impl<Signer: Sign> Channel<Signer> {
                self.counterparty_htlc_minimum_msat
        }
 
+       /// Allowed in any state (including after shutdown), but will return none before TheirInitSent
+       pub fn get_counterparty_htlc_maximum_msat(&self) -> Option<u64> {
+               self.get_htlc_maximum_msat(self.counterparty_max_htlc_value_in_flight_msat)
+       }
+
+       fn get_htlc_maximum_msat(&self, party_max_htlc_value_in_flight_msat: u64) -> Option<u64> {
+               self.counterparty_selected_channel_reserve_satoshis.map(|counterparty_reserve| {
+                       let holder_reserve = self.holder_selected_channel_reserve_satoshis;
+                       cmp::min(
+                               (self.channel_value_satoshis - counterparty_reserve - holder_reserve) * 1000,
+                               party_max_htlc_value_in_flight_msat
+                       )
+               })
+       }
+
        pub fn get_value_satoshis(&self) -> u64 {
                self.channel_value_satoshis
        }