Store override counterparty handshake limits until we enforce them
[rust-lightning] / lightning / src / ln / channel.rs
index f385bf256bf0bb9248df26e9c697983caabbc47b..26d9dfed0d162d5d7fb9853e68ae476d6083348b 100644 (file)
@@ -39,7 +39,7 @@ use util::events::ClosureReason;
 use util::ser::{Readable, ReadableArgs, Writeable, Writer, VecWriter};
 use util::logger::Logger;
 use util::errors::APIError;
-use util::config::{UserConfig,ChannelConfig};
+use util::config::{UserConfig, ChannelConfig, ChannelHandshakeLimits};
 use util::scid_utils::scid_from_parts;
 
 use io;
@@ -484,6 +484,8 @@ pub(super) struct Channel<Signer: Sign> {
        #[cfg(not(any(test, feature = "_test_utils")))]
        config: ChannelConfig,
 
+       inbound_handshake_limits_override: Option<ChannelHandshakeLimits>,
+
        user_id: u64,
 
        channel_id: [u8; 32],
@@ -835,6 +837,7 @@ impl<Signer: Sign> Channel<Signer> {
                Ok(Channel {
                        user_id,
                        config: config.channel_options.clone(),
+                       inbound_handshake_limits_override: Some(config.peer_channel_config_limits.clone()),
 
                        channel_id: keys_provider.get_secure_random_bytes(),
                        channel_state: ChannelState::OurInitSent as u32,
@@ -942,14 +945,6 @@ impl<Signer: Sign> Channel<Signer> {
        fn check_remote_fee<F: Deref>(fee_estimator: &F, feerate_per_kw: u32) -> Result<(), ChannelError>
                where F::Target: FeeEstimator
        {
-               let lower_limit = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
-               // Some fee estimators round up to the next full sat/vbyte (ie 250 sats per kw), causing
-               // occasional issues with feerate disagreements between an initiator that wants a feerate
-               // of 1.1 sat/vbyte and a receiver that wants 1.1 rounded up to 2. Thus, we always add 250
-               // sat/kw before the comparison here.
-               if feerate_per_kw + 250 < lower_limit {
-                       return Err(ChannelError::Close(format!("Peer's feerate much too low. Actual: {}. Our expected lower limit: {} (- 250)", feerate_per_kw, lower_limit)));
-               }
                // We only bound the fee updates on the upper side to prevent completely absurd feerates,
                // always accepting up to 25 sat/vByte or 10x our fee estimator's "High Priority" fee.
                // We generally don't care too much if they set the feerate to something very high, but it
@@ -959,6 +954,14 @@ impl<Signer: Sign> Channel<Signer> {
                if feerate_per_kw as u64 > upper_limit {
                        return Err(ChannelError::Close(format!("Peer's feerate much too high. Actual: {}. Our expected upper limit: {}", feerate_per_kw, upper_limit)));
                }
+               let lower_limit = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
+               // Some fee estimators round up to the next full sat/vbyte (ie 250 sats per kw), causing
+               // occasional issues with feerate disagreements between an initiator that wants a feerate
+               // of 1.1 sat/vbyte and a receiver that wants 1.1 rounded up to 2. Thus, we always add 250
+               // sat/kw before the comparison here.
+               if feerate_per_kw + 250 < lower_limit {
+                       return Err(ChannelError::Close(format!("Peer's feerate much too low. Actual: {}. Our expected lower limit: {} (- 250)", feerate_per_kw, lower_limit)));
+               }
                Ok(())
        }
 
@@ -1134,6 +1137,7 @@ impl<Signer: Sign> Channel<Signer> {
                let chan = Channel {
                        user_id,
                        config: local_config,
+                       inbound_handshake_limits_override: None,
 
                        channel_id: msg.temporary_channel_id,
                        channel_state: (ChannelState::OurInitSent as u32) | (ChannelState::TheirInitSent as u32),
@@ -1811,7 +1815,9 @@ impl<Signer: Sign> Channel<Signer> {
 
        // Message handlers:
 
-       pub fn accept_channel(&mut self, msg: &msgs::AcceptChannel, config: &UserConfig, their_features: &InitFeatures) -> Result<(), ChannelError> {
+       pub fn accept_channel(&mut self, msg: &msgs::AcceptChannel, default_limits: &ChannelHandshakeLimits, their_features: &InitFeatures) -> Result<(), ChannelError> {
+               let peer_limits = if let Some(ref limits) = self.inbound_handshake_limits_override { limits } else { default_limits };
+
                // Check sanity of message fields:
                if !self.is_outbound() {
                        return Err(ChannelError::Close("Got an accept_channel message from an inbound peer".to_owned()));
@@ -1832,7 +1838,7 @@ impl<Signer: Sign> Channel<Signer> {
                if msg.htlc_minimum_msat >= full_channel_value_msat {
                        return Err(ChannelError::Close(format!("Minimum htlc value ({}) is full channel value ({})", msg.htlc_minimum_msat, full_channel_value_msat)));
                }
-               let max_delay_acceptable = u16::min(config.peer_channel_config_limits.their_to_self_delay, MAX_LOCAL_BREAKDOWN_TIMEOUT);
+               let max_delay_acceptable = u16::min(peer_limits.their_to_self_delay, MAX_LOCAL_BREAKDOWN_TIMEOUT);
                if msg.to_self_delay > max_delay_acceptable {
                        return Err(ChannelError::Close(format!("They wanted our payments to be delayed by a needlessly long period. Upper limit: {}. Actual: {}", max_delay_acceptable, msg.to_self_delay)));
                }
@@ -1844,17 +1850,17 @@ impl<Signer: Sign> Channel<Signer> {
                }
 
                // Now check against optional parameters as set by config...
-               if msg.htlc_minimum_msat > config.peer_channel_config_limits.max_htlc_minimum_msat {
-                       return Err(ChannelError::Close(format!("htlc_minimum_msat ({}) is higher than the user specified limit ({})", msg.htlc_minimum_msat, config.peer_channel_config_limits.max_htlc_minimum_msat)));
+               if msg.htlc_minimum_msat > peer_limits.max_htlc_minimum_msat {
+                       return Err(ChannelError::Close(format!("htlc_minimum_msat ({}) is higher than the user specified limit ({})", msg.htlc_minimum_msat, peer_limits.max_htlc_minimum_msat)));
                }
-               if msg.max_htlc_value_in_flight_msat < config.peer_channel_config_limits.min_max_htlc_value_in_flight_msat {
-                       return Err(ChannelError::Close(format!("max_htlc_value_in_flight_msat ({}) is less than the user specified limit ({})", msg.max_htlc_value_in_flight_msat, config.peer_channel_config_limits.min_max_htlc_value_in_flight_msat)));
+               if msg.max_htlc_value_in_flight_msat < peer_limits.min_max_htlc_value_in_flight_msat {
+                       return Err(ChannelError::Close(format!("max_htlc_value_in_flight_msat ({}) is less than the user specified limit ({})", msg.max_htlc_value_in_flight_msat, peer_limits.min_max_htlc_value_in_flight_msat)));
                }
-               if msg.channel_reserve_satoshis > config.peer_channel_config_limits.max_channel_reserve_satoshis {
-                       return Err(ChannelError::Close(format!("channel_reserve_satoshis ({}) is higher than the user specified limit ({})", msg.channel_reserve_satoshis, config.peer_channel_config_limits.max_channel_reserve_satoshis)));
+               if msg.channel_reserve_satoshis > peer_limits.max_channel_reserve_satoshis {
+                       return Err(ChannelError::Close(format!("channel_reserve_satoshis ({}) is higher than the user specified limit ({})", msg.channel_reserve_satoshis, peer_limits.max_channel_reserve_satoshis)));
                }
-               if msg.max_accepted_htlcs < config.peer_channel_config_limits.min_max_accepted_htlcs {
-                       return Err(ChannelError::Close(format!("max_accepted_htlcs ({}) is less than the user specified limit ({})", msg.max_accepted_htlcs, config.peer_channel_config_limits.min_max_accepted_htlcs)));
+               if msg.max_accepted_htlcs < peer_limits.min_max_accepted_htlcs {
+                       return Err(ChannelError::Close(format!("max_accepted_htlcs ({}) is less than the user specified limit ({})", msg.max_accepted_htlcs, peer_limits.min_max_accepted_htlcs)));
                }
                if msg.dust_limit_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
                        return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is less than the implementation limit ({})", msg.dust_limit_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS)));
@@ -1862,8 +1868,8 @@ impl<Signer: Sign> Channel<Signer> {
                if msg.dust_limit_satoshis > MAX_CHAN_DUST_LIMIT_SATOSHIS {
                        return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is greater than the implementation limit ({})", msg.dust_limit_satoshis, MAX_CHAN_DUST_LIMIT_SATOSHIS)));
                }
-               if msg.minimum_depth > config.peer_channel_config_limits.max_minimum_depth {
-                       return Err(ChannelError::Close(format!("We consider the minimum depth to be unreasonably large. Expected minimum: ({}). Actual: ({})", config.peer_channel_config_limits.max_minimum_depth, msg.minimum_depth)));
+               if msg.minimum_depth > peer_limits.max_minimum_depth {
+                       return Err(ChannelError::Close(format!("We consider the minimum depth to be unreasonably large. Expected minimum: ({}). Actual: ({})", peer_limits.max_minimum_depth, msg.minimum_depth)));
                }
                if msg.minimum_depth == 0 {
                        // Note that if this changes we should update the serialization minimum version to
@@ -1916,6 +1922,7 @@ impl<Signer: Sign> Channel<Signer> {
                self.counterparty_shutdown_scriptpubkey = counterparty_shutdown_scriptpubkey;
 
                self.channel_state = ChannelState::OurInitSent as u32 | ChannelState::TheirInitSent as u32;
+               self.inbound_handshake_limits_override = None; // We're done enforcing limits on our peer's handshake now.
 
                Ok(())
        }
@@ -2142,7 +2149,7 @@ impl<Signer: Sign> Channel<Signer> {
 
                log_info!(logger, "Received funding_locked from peer for channel {}", log_bytes!(self.channel_id()));
 
-               Ok(self.get_announcement_sigs(node_pk, genesis_block_hash, best_block.height()).ok())
+               Ok(self.get_announcement_sigs(node_pk, genesis_block_hash, best_block.height(), logger))
        }
 
        /// Returns transaction if there is pending funding transaction that is yet to broadcast
@@ -3416,7 +3423,7 @@ impl<Signer: Sign> Channel<Signer> {
                        })
                } else { None };
 
-               let announcement_sigs = self.get_announcement_sigs(node_pk, genesis_block_hash, best_block_height).ok();
+               let announcement_sigs = self.get_announcement_sigs(node_pk, genesis_block_hash, best_block_height, logger);
 
                let mut accepted_htlcs = Vec::new();
                mem::swap(&mut accepted_htlcs, &mut self.monitor_pending_forwards);
@@ -3609,7 +3616,7 @@ impl<Signer: Sign> Channel<Signer> {
                        })
                } else { None };
 
-               let announcement_sigs = self.get_announcement_sigs(node_pk, genesis_block_hash, best_block.height()).ok();
+               let announcement_sigs = self.get_announcement_sigs(node_pk, genesis_block_hash, best_block.height(), logger);
 
                if self.channel_state & (ChannelState::FundingSent as u32) == ChannelState::FundingSent as u32 {
                        // If we're waiting on a monitor update, we shouldn't re-send any funding_locked's.
@@ -4464,7 +4471,7 @@ impl<Signer: Sign> Channel<Signer> {
                                        // may have already happened for this block).
                                        if let Some(funding_locked) = self.check_get_funding_locked(height) {
                                                log_info!(logger, "Sending a funding_locked to our peer for channel {}", log_bytes!(self.channel_id));
-                                               let announcement_sigs = self.get_announcement_sigs(node_pk, genesis_block_hash, height).ok();
+                                               let announcement_sigs = self.get_announcement_sigs(node_pk, genesis_block_hash, height, logger);
                                                return Ok((Some(funding_locked), announcement_sigs));
                                        }
                                }
@@ -4518,7 +4525,7 @@ impl<Signer: Sign> Channel<Signer> {
 
                if let Some(funding_locked) = self.check_get_funding_locked(height) {
                        let announcement_sigs = if let Some((genesis_block_hash, node_pk)) = genesis_node_pk {
-                               self.get_announcement_sigs(node_pk, genesis_block_hash, height).ok()
+                               self.get_announcement_sigs(node_pk, genesis_block_hash, height, logger)
                        } else { None };
                        log_info!(logger, "Sending a funding_locked to our peer for channel {}", log_bytes!(self.channel_id));
                        return Ok((Some(funding_locked), timed_out_htlcs, announcement_sigs));
@@ -4554,7 +4561,7 @@ impl<Signer: Sign> Channel<Signer> {
                }
 
                let announcement_sigs = if let Some((genesis_block_hash, node_pk)) = genesis_node_pk {
-                       self.get_announcement_sigs(node_pk, genesis_block_hash, height).ok()
+                       self.get_announcement_sigs(node_pk, genesis_block_hash, height, logger)
                } else { None };
                Ok((None, timed_out_htlcs, announcement_sigs))
        }
@@ -4725,8 +4732,8 @@ impl<Signer: Sign> Channel<Signer> {
 
        /// Gets an UnsignedChannelAnnouncement for this channel. The channel must be publicly
        /// announceable and available for use (have exchanged FundingLocked messages in both
-       /// directions). Should be used for both loose and in response to an AnnouncementSignatures
-       /// message from the remote peer.
+       /// directions). Should be used for both broadcasted announcements and in response to an
+       /// AnnouncementSignatures message from the remote peer.
        ///
        /// Will only fail if we're not in a state where channel_announcement may be sent (including
        /// closing).
@@ -4759,29 +4766,43 @@ impl<Signer: Sign> Channel<Signer> {
                Ok(msg)
        }
 
-       fn get_announcement_sigs(&mut self, node_pk: PublicKey, genesis_block_hash: BlockHash, best_block_height: u32) -> Result<msgs::AnnouncementSignatures, ChannelError> {
+       fn get_announcement_sigs<L: Deref>(&mut self, node_pk: PublicKey, genesis_block_hash: BlockHash, best_block_height: u32, logger: &L)
+       -> Option<msgs::AnnouncementSignatures> where L::Target: Logger {
                if self.funding_tx_confirmation_height == 0 || self.funding_tx_confirmation_height + 5 > best_block_height {
-                       return Err(ChannelError::Ignore("Funding not yet fully confirmed".to_owned()));
+                       return None;
                }
 
                if !self.is_usable() {
-                       return Err(ChannelError::Ignore("Channel not yet available for use".to_owned()));
+                       return None;
                }
 
                if self.channel_state & ChannelState::PeerDisconnected as u32 != 0 {
-                       return Err(ChannelError::Ignore("Peer currently disconnected".to_owned()));
+                       log_trace!(logger, "Cannot create an announcement_signatures as our peer is disconnected");
+                       return None;
                }
 
                if self.announcement_sigs_state != AnnouncementSigsState::NotSent {
-                       return Err(ChannelError::Ignore("Announcement signatures already sent".to_owned()));
+                       return None;
                }
 
-               let announcement = self.get_channel_announcement(node_pk, genesis_block_hash)?;
-               let (our_node_sig, our_bitcoin_sig) = self.holder_signer.sign_channel_announcement(&announcement, &self.secp_ctx)
-                       .map_err(|_| ChannelError::Ignore("Signer rejected channel_announcement".to_owned()))?;
+               log_trace!(logger, "Creating an announcement_signatures message for channel {}", log_bytes!(self.channel_id()));
+               let announcement = match self.get_channel_announcement(node_pk, genesis_block_hash) {
+                       Ok(a) => a,
+                       Err(_) => {
+                               log_trace!(logger, "Cannot create an announcement_signatures as channel is not public.");
+                               return None;
+                       }
+               };
+               let (our_node_sig, our_bitcoin_sig) = match self.holder_signer.sign_channel_announcement(&announcement, &self.secp_ctx) {
+                       Err(_) => {
+                               log_error!(logger, "Signer rejected channel_announcement signing. Channel will not be announced!");
+                               return None;
+                       },
+                       Ok(v) => v
+               };
                self.announcement_sigs_state = AnnouncementSigsState::MessageSent;
 
-               Ok(msgs::AnnouncementSignatures {
+               Some(msgs::AnnouncementSignatures {
                        channel_id: self.channel_id(),
                        short_channel_id: self.get_short_channel_id().unwrap(),
                        node_signature: our_node_sig,
@@ -5988,6 +6009,11 @@ impl<'a, Signer: Sign, K: Deref> ReadableArgs<(&'a K, u32)> for Channel<Signer>
                        user_id,
 
                        config: config.unwrap(),
+
+                       // Note that we don't care about serializing handshake limits as we only ever serialize
+                       // channel data after the handshake has completed.
+                       inbound_handshake_limits_override: None,
+
                        channel_id,
                        channel_state,
                        announcement_sigs_state: announcement_sigs_state.unwrap(),
@@ -6140,6 +6166,13 @@ mod tests {
                        "MAX_FUNDING_SATOSHIS is greater than all satoshis in existence");
        }
 
+       #[test]
+       fn test_no_fee_check_overflow() {
+               // Previously, calling `check_remote_fee` with a fee of 0xffffffff would overflow in
+               // arithmetic, causing a panic with debug assertions enabled.
+               assert!(Channel::<InMemorySigner>::check_remote_fee(&&TestFeeEstimator { fee_est: 42 }, u32::max_value()).is_err());
+       }
+
        struct Keys {
                signer: InMemorySigner,
        }
@@ -6249,7 +6282,7 @@ mod tests {
                // Node B --> Node A: accept channel, explicitly setting B's dust limit.
                let mut accept_channel_msg = node_b_chan.get_accept_channel();
                accept_channel_msg.dust_limit_satoshis = 546;
-               node_a_chan.accept_channel(&accept_channel_msg, &config, &InitFeatures::known()).unwrap();
+               node_a_chan.accept_channel(&accept_channel_msg, &config.peer_channel_config_limits, &InitFeatures::known()).unwrap();
                node_a_chan.holder_dust_limit_satoshis = 1560;
 
                // Put some inbound and outbound HTLCs in A's channel.
@@ -6366,7 +6399,7 @@ mod tests {
 
                // Node B --> Node A: accept channel
                let accept_channel_msg = node_b_chan.get_accept_channel();
-               node_a_chan.accept_channel(&accept_channel_msg, &config, &InitFeatures::known()).unwrap();
+               node_a_chan.accept_channel(&accept_channel_msg, &config.peer_channel_config_limits, &InitFeatures::known()).unwrap();
 
                // Node A --> Node B: funding created
                let output_script = node_a_chan.get_funding_redeemscript();