Merge pull request #199 from p2pderivatives/feat/add-reject-dlc-chann…

…el-offer-handling

feat: Add reject dlc channel offer handling

bitcoin-rpc-provider/src/lib.rs

@@ -382,6 +382,14 @@ impl Wallet for BitcoinCoreProvider {
 
         Ok(())
     }
+
+    fn unreserve_utxos(&self, outpoints: &[OutPoint]) -> Result<(), ManagerError> {
+        match self.client.lock().unwrap().unlock_unspent(outpoints).map_err(rpc_err_to_manager_err)? {
+            true => Ok(()),
+            false => Err(ManagerError::StorageError(format!("Failed to unlock utxos: {outpoints:?}")))
+        }
+
+    }
 }
 
 impl Blockchain for BitcoinCoreProvider {

dlc-manager/src/channel/mod.rs

@@ -32,6 +32,8 @@ pub enum Channel {
     /// A channel that failed when validating an
     /// [`dlc_messages::channel::SignChannel`] message.
     FailedSign(FailedSign),
+    /// A [`OfferedChannel`] that got rejected by the counterparty.
+    Cancelled(OfferedChannel),
 }
 
 impl std::fmt::Debug for Channel {
@@ -42,6 +44,7 @@ impl std::fmt::Debug for Channel {
             Channel::Signed(_) => "signed",
             Channel::FailedAccept(_) => "failed accept",
             Channel::FailedSign(_) => "failed sign",
+            Channel::Cancelled(_) => "cancelled"
         };
         f.debug_struct("Contract").field("state", &state).finish()
     }
@@ -56,6 +59,7 @@ impl Channel {
             Channel::Signed(s) => s.counter_party,
             Channel::FailedAccept(f) => f.counter_party,
             Channel::FailedSign(f) => f.counter_party,
+            Channel::Cancelled(o) => o.counter_party,
         }
     }
 }
@@ -98,6 +102,7 @@ impl Channel {
             Channel::Accepted(a) => a.temporary_channel_id,
             Channel::Signed(s) => s.temporary_channel_id,
             Channel::FailedAccept(f) => f.temporary_channel_id,
+            Channel::Cancelled(o) => o.temporary_channel_id,
             _ => unimplemented!(),
         }
     }
@@ -110,6 +115,7 @@ impl Channel {
             Channel::Signed(s) => s.channel_id,
             Channel::FailedAccept(f) => f.temporary_channel_id,
             Channel::FailedSign(f) => f.channel_id,
+            Channel::Cancelled(o) => o.temporary_channel_id,
         }
     }
 }

dlc-manager/src/lib.rs

@@ -167,6 +167,8 @@ pub trait Wallet {
         psbt: &mut PartiallySignedTransaction,
         input_index: usize,
     ) -> Result<(), Error>;
+    /// Unlock reserved utxo
+    fn unreserve_utxos(&self, outpoints: &[OutPoint]) -> Result<(), Error>;
 }
 
 /// Blockchain trait provides access to the bitcoin blockchain.

dlc-manager/src/manager.rs

@@ -19,7 +19,8 @@ use crate::contract_updater::{accept_contract, verify_accepted_and_sign_contract
 use crate::error::Error;
 use crate::{ChannelId, ContractId, ContractSignerProvider};
 use bitcoin::locktime::Height;
-use bitcoin::Transaction;
+use bitcoin::{OutPoint, Transaction};
+use bitcoin::hashes::hex::{ToHex};
 use bitcoin::{locktime, Address, LockTime};
 use dlc_messages::channel::{
     AcceptChannel, CollaborativeCloseOffer, OfferChannel, Reject, RenewAccept, RenewConfirm,
@@ -39,6 +40,7 @@ use std::collections::HashMap;
 use std::ops::Deref;
 use std::string::ToString;
 use std::sync::Arc;
+use bitcoin::consensus::Decodable;
 
 /// The number of confirmations required before moving the the confirmed state.
 pub const NB_CONFIRMATIONS: u32 = 6;
@@ -639,7 +641,7 @@ where
         contract_id: &ContractId,
         attestations: Vec<(usize, OracleAttestation)>,
     ) -> Result<Contract, Error> {
-        let contract = get_contract_in_state!(self, &contract_id, Confirmed, None::<PublicKey>)?;
+        let contract = get_contract_in_state!(self, contract_id, Confirmed, None::<PublicKey>)?;
         let contract_infos = &contract.accepted_contract.offered_contract.contract_info;
         let adaptor_infos = &contract.accepted_contract.adaptor_infos;
 
@@ -924,6 +926,26 @@ where
         Ok(msg)
     }
 
+    /// Reject a channel that was offered. Returns the [`dlc_messages::channel::Reject`]
+    /// message to be sent as well as the public key of the offering node.
+    pub fn reject_channel(&self, channel_id: &ChannelId) -> Result<(Reject, PublicKey), Error> {
+        let offered_channel = get_channel_in_state!(self, channel_id, Offered, None as Option<PublicKey>)?;
+
+        if offered_channel.is_offer_party {
+            return Err(Error::InvalidState(
+                "Cannot reject channel initiated by us.".to_string(),
+            ));
+        }
+
+        let offered_contract = get_contract_in_state!(self, &offered_channel.offered_contract_id, Offered, None as Option<PublicKey>)?;
+
+        let counterparty = offered_channel.counter_party;
+        self.store.upsert_channel(Channel::Cancelled(offered_channel), Some(Contract::Rejected(offered_contract)))?;
+
+        let msg = Reject{ channel_id: *channel_id };
+        Ok((msg, counterparty))
+    }
+
     /// Accept a channel that was offered. Returns the [`dlc_messages::channel::AcceptChannel`]
     /// message to be sent, the updated [`crate::ChannelId`] and [`crate::ContractId`],
     /// as well as the public key of the offering node.
@@ -1986,14 +2008,60 @@ where
         Ok(())
     }
 
-    fn on_reject(&mut self, reject: &Reject, counter_party: &PublicKey) -> Result<(), Error> {
-        let mut signed_channel =
-            get_channel_in_state!(self, &reject.channel_id, Signed, Some(*counter_party))?;
+    fn on_reject(&self, reject: &Reject, counter_party: &PublicKey) -> Result<(), Error> {
+        let channel = self.store.get_channel(&reject.channel_id)?;
+
+        if let Some(channel) = channel {
+            if channel.get_counter_party_id() != *counter_party {
+                return Err(Error::InvalidParameters(format!(
+                    "Peer {:02x?} is not involved with {} {:02x?}.",
+                    counter_party,
+                    stringify!(Channel),
+                    channel.get_id()
+                )));
+            }
+            match channel {
+                Channel::Offered(offered_channel) => {
+                    let offered_contract = get_contract_in_state!(self, &offered_channel.offered_contract_id, Offered, None as Option<PublicKey>)?;
+                    let utxos = offered_contract.funding_inputs_info.iter().map(|funding_input_info| {
+                        let txid = Transaction::consensus_decode(&mut funding_input_info.funding_input.prev_tx.as_slice())
+                            .expect("Transaction Decode Error")
+                            .txid();
+                        let vout = funding_input_info.funding_input.prev_tx_vout;
+                        OutPoint{txid, vout}
+                    }).collect::<Vec<_>>();
+
+                    self.wallet.unreserve_utxos(&utxos)?;
+
+                    // remove rejected channel, since nothing has been confirmed on chain yet.
+                    self.store.upsert_channel(Channel::Cancelled(offered_channel), Some(Contract::Rejected(offered_contract)))?;
+                },
+                Channel::Signed(mut signed_channel) => {
 
-        crate::channel_updater::on_reject(&mut signed_channel)?;
+                    let contract = match signed_channel.state {
+                        SignedChannelState::RenewOffered { offered_contract_id, .. } => {
+                            let offered_contract = get_contract_in_state!(self, &offered_contract_id, Offered, None::<PublicKey>)?;
+                            Some(Contract::Rejected(offered_contract))
+
+                        }
+                        _ => None
+                    };
+
+                    crate::channel_updater::on_reject(&mut signed_channel)?;
+
+                    self.store
+                        .upsert_channel(Channel::Signed(signed_channel), contract)?;
+                },
+                channel => {
+                    return Err(Error::InvalidState(
+                        format!("Not in a state adequate to receive a reject message. {:?}", channel),
+                    ))
+                }
+            }
+        } else {
+            warn!("Couldn't find rejected dlc channel with id: {}", reject.channel_id.to_hex());
+        }
 
-        self.store
-            .upsert_channel(Channel::Signed(signed_channel), None)?;
         Ok(())
     }
 

dlc-manager/tests/channel_execution_tests.rs

@@ -101,6 +101,7 @@ enum TestPath {
     RenewReject,
     RenewRace,
     RenewEstablishedClose,
+    CancelOffer,
 }
 
 #[test]
@@ -256,6 +257,12 @@ fn channel_renew_race_test() {
     channel_execution_test(get_enum_test_params(1, 1, None), TestPath::RenewRace);
 }
 
+#[test]
+#[ignore]
+fn channel_offer_reject_test() {
+    channel_execution_test(get_enum_test_params(1, 1, None), TestPath::CancelOffer);
+}
+
 fn channel_execution_test(test_params: TestParams, path: TestPath) {
     env_logger::init();
     let (alice_send, bob_receive) = channel::<Option<Message>>();
@@ -466,6 +473,18 @@ fn channel_execution_test(test_params: TestParams, path: TestPath) {
 
     assert_channel_state!(alice_manager_send, temporary_channel_id, Offered);
 
+    if let TestPath::CancelOffer = path {
+        let (reject_msg, _) = alice_manager_send.lock().unwrap().reject_channel(&temporary_channel_id).expect("Error rejecting contract offer");
+        assert_channel_state!(alice_manager_send, temporary_channel_id, Cancelled);
+        alice_send
+            .send(Some(Message::Reject(reject_msg)))
+            .unwrap();
+
+        sync_receive.recv().expect("Error synchronizing");
+        assert_channel_state!(bob_manager_send, temporary_channel_id, Cancelled);
+        return;
+    }
+
     let (mut accept_msg, channel_id, contract_id, _) = alice_manager_send
         .lock()
         .unwrap()

dlc-manager/tests/test_utils.rs

@@ -168,6 +168,7 @@ macro_rules! assert_channel_state {
                 Some(Channel::Signed(_)) => "signed",
                 Some(Channel::FailedAccept(_)) => "failed accept",
                 Some(Channel::FailedSign(_)) => "failed sign",
+                Some(Channel::Cancelled(_)) => "cancelled",
                 None => "none",
             };
             panic!("Unexpected channel state {}", state);

dlc-sled-storage-provider/src/lib.rs

@@ -121,7 +121,8 @@ convertible_enum!(
         Accepted,
         Signed,
         FailedAccept,
-        FailedSign,;
+        FailedSign,
+        Cancelled,;
     },
     Channel
 );
@@ -604,6 +605,7 @@ fn serialize_channel(channel: &Channel) -> Result<Vec<u8>, ::std::io::Error> {
         Channel::Signed(s) => s.serialize(),
         Channel::FailedAccept(f) => f.serialize(),
         Channel::FailedSign(f) => f.serialize(),
+        Channel::Cancelled(o) => o.serialize(),
     };
     let mut serialized = serialized?;
     let mut res = Vec::with_capacity(serialized.len() + 1);
@@ -638,6 +640,9 @@ fn deserialize_channel(buff: &sled::IVec) -> Result<Channel, Error> {
         ChannelPrefix::FailedSign => {
             Channel::FailedSign(FailedSign::deserialize(&mut cursor).map_err(to_storage_error)?)
         }
+        ChannelPrefix::Cancelled => {
+            Channel::Cancelled(OfferedChannel::deserialize(&mut cursor).map_err(to_storage_error)?)
+        }
     };
     Ok(channel)
 }

mocks/src/mock_wallet.rs

@@ -2,7 +2,7 @@ use std::rc::Rc;
 
 use bitcoin::psbt::PartiallySignedTransaction;
 use bitcoin::secp256k1::PublicKey;
-use bitcoin::{Address, PackedLockTime, Script, Transaction, TxOut};
+use bitcoin::{Address, OutPoint, PackedLockTime, Script, Transaction, TxOut};
 use dlc_manager::{error::Error, Blockchain, ContractSignerProvider, SimpleSigner, Utxo, Wallet};
 use secp256k1_zkp::{rand::seq::SliceRandom, SecretKey};
 
@@ -115,6 +115,10 @@ impl Wallet for MockWallet {
     fn sign_psbt_input(&self, _: &mut PartiallySignedTransaction, _: usize) -> Result<(), Error> {
         Ok(())
     }
+
+    fn unreserve_utxos(&self, _outpoints: &[OutPoint]) -> Result<(), Error> {
+        Ok(())
+    }
 }
 
 fn get_address() -> Address {

simple-wallet/src/lib.rs

@@ -6,10 +6,7 @@ use bdk::{
     FeeRate, KeychainKind, LocalUtxo, Utxo as BdkUtxo, WeightedUtxo,
 };
 use bitcoin::psbt::PartiallySignedTransaction;
-use bitcoin::{
-    hashes::Hash, Address, Network, PackedLockTime, Script, Sequence, Transaction, TxIn, TxOut,
-    Txid, Witness,
-};
+use bitcoin::{hashes::Hash, Address, Network, PackedLockTime, Script, Sequence, Transaction, TxIn, TxOut, Txid, Witness, OutPoint};
 use dlc_manager::{
     error::Error, Blockchain, ContractSignerProvider, KeysId, SimpleSigner, Utxo, Wallet,
 };
@@ -297,6 +294,14 @@ where
         Ok(())
     }
 
+    fn unreserve_utxos(&self, outputs: &[OutPoint]) -> std::result::Result<(), Error> {
+        for outpoint in outputs {
+            self.storage.unreserve_utxo(&outpoint.txid, outpoint.vout)?;
+        }
+
+        Ok(())
+    }
+
     fn sign_psbt_input(
         &self,
         psbt: &mut PartiallySignedTransaction,