Add push_msat to new outbound API
[rust-lightning] / src / ln / channel.rs
index a1ca7e25e65a5ea8cff9f5d0a27710751ea5ae94..c88e1d7763125f118c015cb82bc3dbc5914a2c78 100644 (file)
@@ -24,6 +24,7 @@ use chain::transaction::OutPoint;
 use util::{transaction_utils,rng};
 use util::sha2::Sha256;
 use util::logger::{Logger, Record};
+use util::errors::APIError;
 
 use std;
 use std::default::Default;
@@ -88,18 +89,21 @@ impl ChannelKeys {
 #[derive(PartialEq)]
 enum HTLCState {
        /// Added by remote, to be included in next local commitment tx.
+       /// Implies HTLCOutput::outbound: false
        RemoteAnnounced,
        /// Included in a received commitment_signed message (implying we've revoke_and_ack'ed it), but
        /// the remote side hasn't yet revoked their previous state, which we need them to do before we
        /// accept this HTLC. Implies AwaitingRemoteRevoke.
        /// We also have not yet included this HTLC in a commitment_signed message, and are waiting on
        /// a remote revoke_and_ack on a previous state before we can do so.
+       /// Implies HTLCOutput::outbound: false
        AwaitingRemoteRevokeToAnnounce,
        /// Included in a received commitment_signed message (implying we've revoke_and_ack'ed it), but
        /// the remote side hasn't yet revoked their previous state, which we need them to do before we
        /// accept this HTLC. Implies AwaitingRemoteRevoke.
        /// We have included this HTLC in our latest commitment_signed and are now just waiting on a
        /// revoke_and_ack.
+       /// Implies HTLCOutput::outbound: true
        AwaitingAnnouncedRemoteRevoke,
        /// Added by us and included in a commitment_signed (if we were AwaitingRemoteRevoke when we
        /// created it we would have put it in the holding cell instead). When they next revoke_and_ack
@@ -111,22 +115,26 @@ enum HTLCState {
        ///    allowed to remove it, the "can only be removed once committed on both sides" requirement
        ///    doesn't matter to us and its up to them to enforce it, worst-case they jump ahead but
        ///    we'll never get out of sync).
+       /// Implies HTLCOutput::outbound: true
        LocalAnnounced,
        Committed,
        /// Remote removed this (outbound) HTLC. We're waiting on their commitment_signed to finalize
        /// the change (though they'll need to revoke before we fail the payment).
+       /// Implies HTLCOutput::outbound: true
        RemoteRemoved,
        /// Remote removed this and sent a commitment_signed (implying we've revoke_and_ack'ed it), but
        /// the remote side hasn't yet revoked their previous state, which we need them to do before we
        /// can do any backwards failing. Implies AwaitingRemoteRevoke.
        /// We also have not yet removed this HTLC in a commitment_signed message, and are waiting on a
        /// remote revoke_and_ack on a previous state before we can do so.
+       /// Implies HTLCOutput::outbound: true
        AwaitingRemoteRevokeToRemove,
        /// Remote removed this and sent a commitment_signed (implying we've revoke_and_ack'ed it), but
        /// the remote side hasn't yet revoked their previous state, which we need them to do before we
        /// can do any backwards failing. Implies AwaitingRemoteRevoke.
        /// We have removed this HTLC in our latest commitment_signed and are now just waiting on a
        /// revoke_and_ack to drop completely.
+       /// Implies HTLCOutput::outbound: true
        AwaitingRemovedRemoteRevoke,
        /// Removed by us and a new commitment_signed was sent (if we were AwaitingRemoteRevoke when we
        /// created it we would have put it in the holding cell instead). When they next revoke_and_ack
@@ -136,9 +144,11 @@ enum HTLCState {
        /// commitment transaction without it as otherwise we'll have to force-close the channel to
        /// claim it before the timeout (obviously doesn't apply to revoked HTLCs that we can't claim
        /// anyway).
+       /// Implies HTLCOutput::outbound: false
        LocalRemoved,
        /// Removed by us, sent a new commitment_signed and got a revoke_and_ack. Just waiting on an
        /// updated local commitment transaction. Implies local_removed_fulfilled.
+       /// Implies HTLCOutput::outbound: false
        LocalRemovedAwaitingCommitment,
 }
 
@@ -363,11 +373,13 @@ impl Channel {
        }
 
        // Constructors:
-
-       /// panics if channel_value_satoshis is >= `MAX_FUNDING_SATOSHIS`
-       pub fn new_outbound(fee_estimator: &FeeEstimator, chan_keys: ChannelKeys, their_node_id: PublicKey, channel_value_satoshis: u64, announce_publicly: bool, user_id: u64, logger: Arc<Logger>) -> Channel {
+       pub fn new_outbound(fee_estimator: &FeeEstimator, chan_keys: ChannelKeys, their_node_id: PublicKey, channel_value_satoshis: u64, push_msat: u64, announce_publicly: bool, user_id: u64, logger: Arc<Logger>) -> Result<Channel, APIError> {
                if channel_value_satoshis >= MAX_FUNDING_SATOSHIS {
-                       panic!("funding value > 2^24");
+                       return Err(APIError::APIMisuseError{err: "funding value > 2^24"});
+               }
+
+               if push_msat > channel_value_satoshis * 1000 {
+                       return Err(APIError::APIMisuseError{err: "push value > channel value"});
                }
 
                let feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
@@ -381,7 +393,7 @@ impl Channel {
                                                          &chan_keys.htlc_base_key,
                                                          BREAKDOWN_TIMEOUT, our_channel_monitor_claim_script);
 
-               Channel {
+               Ok(Channel {
                        user_id: user_id,
 
                        channel_id: rng::rand_u832(),
@@ -394,7 +406,7 @@ impl Channel {
                        local_keys: chan_keys,
                        cur_local_commitment_transaction_number: (1 << 48) - 1,
                        cur_remote_commitment_transaction_number: (1 << 48) - 1,
-                       value_to_self_msat: channel_value_satoshis * 1000, //TODO: give them something on open? Parameterize it?
+                       value_to_self_msat: channel_value_satoshis * 1000 - push_msat,
                        pending_htlcs: Vec::new(),
                        holding_cell_htlc_updates: Vec::new(),
                        next_local_htlc_id: 0,
@@ -435,7 +447,7 @@ impl Channel {
                        channel_monitor: channel_monitor,
 
                        logger,
-               }
+               })
        }
 
        fn check_remote_fee(fee_estimator: &FeeEstimator, feerate_per_kw: u32) -> Result<(), HandleError> {
@@ -956,7 +968,7 @@ impl Channel {
                for (idx, htlc) in self.pending_htlcs.iter().enumerate() {
                        if !htlc.outbound && htlc.payment_hash == payment_hash_calc {
                                if pending_idx != std::usize::MAX {
-                                       panic!("Duplicate HTLC payment_hash, you probably re-used payment preimages, NEVER DO THIS!");
+                                       panic!("Duplicate HTLC payment_hash, ChannelManager should have prevented this!");
                                }
                                pending_idx = idx;
                        }
@@ -998,8 +1010,14 @@ impl Channel {
                        if htlc.state == HTLCState::Committed {
                                htlc.state = HTLCState::LocalRemoved;
                                htlc.local_removed_fulfilled = true;
-                       } else if htlc.state == HTLCState::RemoteAnnounced {
-                               panic!("Somehow forwarded HTLC prior to remote revocation!");
+                       } else if htlc.state == HTLCState::RemoteAnnounced || htlc.state == HTLCState::AwaitingRemoteRevokeToAnnounce || htlc.state == HTLCState::AwaitingAnnouncedRemoteRevoke {
+                               // Theoretically we can hit this if we get the preimage on an HTLC prior to us
+                               // having forwarded it to anyone. This implies that the sender is busted as someone
+                               // else knows the preimage, but handling this case and implementing the logic to
+                               // take their money would be a lot of (never-tested) code to handle a case that
+                               // hopefully never happens. Instead, we make sure we get the preimage into the
+                               // channel_monitor and pretend we didn't just see the preimage.
+                               return Ok((None, Some(self.channel_monitor.clone())));
                        } else if htlc.state == HTLCState::LocalRemoved || htlc.state == HTLCState::LocalRemovedAwaitingCommitment {
                                return Err(HandleError{err: "Unable to find a pending HTLC which matched the given payment preimage", action: None});
                        } else {
@@ -2016,12 +2034,12 @@ impl Channel {
        // Methods to get unprompted messages to send to the remote end (or where we already returned
        // something in the handler for the message that prompted this message):
 
-       pub fn get_open_channel(&self, chain_hash: Sha256dHash, fee_estimator: &FeeEstimator) -> Result<msgs::OpenChannel, HandleError> {
+       pub fn get_open_channel(&self, chain_hash: Sha256dHash, fee_estimator: &FeeEstimator) -> Result<msgs::OpenChannel, APIError> {
                if !self.channel_outbound {
                        panic!("Tried to open a channel for an inbound channel?");
                }
                if self.channel_state != ChannelState::OurInitSent as u32 {
-                       return Err(HandleError{err: "Cannot generate an open_channel after we've moved forward", action: None});
+                       panic!("Cannot generate an open_channel after we've moved forward");
                }
 
                if self.cur_local_commitment_transaction_number != (1 << 48) - 1 {
@@ -2034,7 +2052,7 @@ impl Channel {
                        chain_hash: chain_hash,
                        temporary_channel_id: self.channel_id,
                        funding_satoshis: self.channel_value_satoshis,
-                       push_msat: 0, //TODO: Something about feerate?
+                       push_msat: self.channel_value_satoshis * 1000 - self.value_to_self_msat,
                        dust_limit_satoshis: self.our_dust_limit_satoshis,
                        max_htlc_value_in_flight_msat: Channel::get_our_max_htlc_value_in_flight_msat(self.channel_value_satoshis),
                        channel_reserve_satoshis: Channel::get_our_channel_reserve_satoshis(self.channel_value_satoshis),
@@ -2463,7 +2481,7 @@ mod tests {
                assert_eq!(PublicKey::from_secret_key(&secp_ctx, &chan_keys.funding_key).unwrap().serialize()[..],
                                hex::decode("023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb").unwrap()[..]);
 
-               let mut chan = Channel::new_outbound(&feeest, chan_keys, PublicKey::new(), 10000000, false, 42, Arc::clone(&logger)); // Nothing uses their network key in this test
+               let mut chan = Channel::new_outbound(&feeest, chan_keys, PublicKey::new(), 10000000, 100000, false, 42, Arc::clone(&logger)).unwrap(); // Nothing uses their network key in this test
                chan.their_to_self_delay = 144;
                chan.our_dust_limit_satoshis = 546;