Handle receiver cancelling an inbound transaction that is later received

This PR addresses the following scenario spotted by @stanimal:

 - NodeA sends to nodeB(offline) 
- NodeA goes offline 
- NodeB receives tx, and cancels it (weird I know) 
- NodeA comes online and broadcasts the transaction 
- NodeB is not aware of the transaction, transaction complete for NodeA

This is handled by adding logic that if a FinalizedTransaction is received with no active Receive Protocols that the database is checked if there is a matching cancelled inbound transaction from the same pubkey. If there is the receiver might as well restart that protocol and accept the finalized transaction.

A cucumber test is provided to test this case.

applications/tari_app_grpc/proto/wallet.proto

@@ -50,6 +50,8 @@ service Wallet {
     rpc GetNetworkStatus(Empty) returns (NetworkStatusResponse);
     // List currently connected peers
     rpc ListConnectedPeers(Empty) returns (ListConnectedPeersResponse);
+    // Cancel pending transaction
+    rpc CancelTransaction (CancelTransactionRequest) returns (CancelTransactionResponse);
 }
 
 message GetVersionRequest { }
@@ -185,3 +187,11 @@ message ImportUtxosResponse {
     repeated uint64 tx_ids = 1;
 }
 
+message CancelTransactionRequest {
+    uint64 tx_id = 1;
+}
+
+message CancelTransactionResponse {
+    bool is_success = 1;
+    string failure_message = 2;
+}

applications/tari_console_wallet/src/grpc/wallet_grpc_server.rs

@@ -393,6 +393,33 @@ impl wallet_server::Wallet for WalletGrpcServer {
 
         Ok(Response::new(resp))
     }
+
+    async fn cancel_transaction(
+        &self,
+        request: Request<tari_rpc::CancelTransactionRequest>,
+    ) -> Result<Response<tari_rpc::CancelTransactionResponse>, Status> {
+        let message = request.into_inner();
+        debug!(
+            target: LOG_TARGET,
+            "Incoming gRPC request to Cancel Transaction (TxId: {})", message.tx_id,
+        );
+        let mut transaction_service = self.get_transaction_service();
+
+        match transaction_service.cancel_transaction(message.tx_id).await {
+            Ok(_) => {
+                return Ok(Response::new(tari_rpc::CancelTransactionResponse {
+                    is_success: true,
+                    failure_message: "".to_string(),
+                }))
+            },
+            Err(e) => {
+                return Ok(Response::new(tari_rpc::CancelTransactionResponse {
+                    is_success: false,
+                    failure_message: e.to_string(),
+                }))
+            },
+        }
+    }
 }
 
 fn convert_wallet_transaction_into_transaction_info(

base_layer/wallet/src/output_manager_service/handle.rs

@@ -76,6 +76,7 @@ pub enum OutputManagerRequest {
     ScanForRecoverableOutputs(Vec<TransactionOutput>),
     ScanOutputs(Vec<TransactionOutput>),
     AddKnownOneSidedPaymentScript(KnownOneSidedPaymentScript),
+    ReinstateCancelledInboundTx(TxId),
 }
 
 impl fmt::Display for OutputManagerRequest {
@@ -115,6 +116,7 @@ impl fmt::Display for OutputManagerRequest {
             ScanForRecoverableOutputs(_) => write!(f, "ScanForRecoverableOutputs"),
             ScanOutputs(_) => write!(f, "ScanRewindAndImportOutputs"),
             AddKnownOneSidedPaymentScript(_) => write!(f, "AddKnownOneSidedPaymentScript"),
+            ReinstateCancelledInboundTx(_) => write!(f, "ReinstateCancelledInboundTx"),
         }
     }
 }
@@ -149,6 +151,7 @@ pub enum OutputManagerResponse {
     RewoundOutputs(Vec<UnblindedOutput>),
     ScanOutputs(Vec<UnblindedOutput>),
     AddKnownOneSidedPaymentScript,
+    ReinstatedCancelledInboundTx,
 }
 
 pub type OutputManagerEventSender = broadcast::Sender<Arc<OutputManagerEvent>>;
@@ -545,4 +548,15 @@ impl OutputManagerHandle {
             _ => Err(OutputManagerError::UnexpectedApiResponse),
         }
     }
+
+    pub async fn reinstate_cancelled_inbound_transaction(&mut self, tx_id: TxId) -> Result<(), OutputManagerError> {
+        match self
+            .handle
+            .call(OutputManagerRequest::ReinstateCancelledInboundTx(tx_id))
+            .await??
+        {
+            OutputManagerResponse::ReinstatedCancelledInboundTx => Ok(()),
+            _ => Err(OutputManagerError::UnexpectedApiResponse),
+        }
+    }
 }

base_layer/wallet/src/output_manager_service/service.rs

@@ -40,6 +40,7 @@ use crate::{
     types::{HashDigest, ValidationRetryStrategy},
 };
 use blake2::Digest;
+use chrono::Utc;
 use diesel::result::{DatabaseErrorKind, Error as DieselError};
 use futures::{pin_mut, StreamExt};
 use log::*;
@@ -343,6 +344,10 @@ where TBackend: OutputManagerBackend + 'static
                 .add_known_script(known_script)
                 .await
                 .map(|_| OutputManagerResponse::AddKnownOneSidedPaymentScript),
+            OutputManagerRequest::ReinstateCancelledInboundTx(tx_id) => self
+                .reinstate_cancelled_inbound_transaction(tx_id)
+                .await
+                .map(|_| OutputManagerResponse::ReinstatedCancelledInboundTx),
         }
     }
 
@@ -896,6 +901,27 @@ where TBackend: OutputManagerBackend + 'static
         Ok(self.resources.db.cancel_pending_transaction_outputs(tx_id).await?)
     }
 
+    /// Restore the pending transaction encumberance and output for an inbound transaction that was previously
+    /// cancelled.
+    async fn reinstate_cancelled_inbound_transaction(&mut self, tx_id: TxId) -> Result<(), OutputManagerError> {
+        self.resources.db.reinstate_inbound_output(tx_id).await?;
+
+        self.resources
+            .db
+            .add_pending_transaction_outputs(PendingTransactionOutputs {
+                tx_id,
+                outputs_to_be_spent: Vec::new(),
+                outputs_to_be_received: Vec::new(),
+                timestamp: Utc::now().naive_utc(),
+                coinbase_block_height: None,
+            })
+            .await?;
+
+        self.confirm_encumberance(tx_id).await?;
+
+        Ok(())
+    }
+
     /// Go through the pending transaction and if any have existed longer than the specified duration, cancel them
     async fn timeout_pending_transactions(&mut self, period: Duration) -> Result<(), OutputManagerError> {
         Ok(self.resources.db.timeout_pending_transaction_outputs(period).await?)

base_layer/wallet/src/output_manager_service/storage/database.rs

@@ -23,7 +23,7 @@
 use crate::output_manager_service::{
     error::OutputManagerStorageError,
     service::Balance,
-    storage::models::{DbUnblindedOutput, KnownOneSidedPaymentScript},
+    storage::models::{DbUnblindedOutput, KnownOneSidedPaymentScript, OutputStatus},
     TxId,
 };
 use aes_gcm::Aes256Gcm;
@@ -135,6 +135,7 @@ pub enum DbKey {
     KeyManagerState,
     InvalidOutputs,
     KnownOneSidedPaymentScripts,
+    OutputsByTxIdAndStatus(TxId, OutputStatus),
 }
 
 #[derive(Debug)]
@@ -149,6 +150,7 @@ pub enum DbValue {
     KeyManagerState(KeyManagerState),
     KnownOneSidedPaymentScripts(Vec<KnownOneSidedPaymentScript>),
     AnyOutput(Box<DbUnblindedOutput>),
+    AnyOutputs(Vec<DbUnblindedOutput>),
 }
 
 pub enum DbKeyValuePair {
@@ -158,6 +160,7 @@ pub enum DbKeyValuePair {
     PendingTransactionOutputs(TxId, Box<PendingTransactionOutputs>),
     KeyManagerState(KeyManagerState),
     KnownOneSidedPaymentScripts(KnownOneSidedPaymentScript),
+    UpdateOutputStatus(Commitment, OutputStatus),
 }
 
 pub enum WriteOperation {
@@ -713,6 +716,48 @@ where T: OutputManagerBackend + 'static
         .map_err(|err| OutputManagerStorageError::BlockingTaskSpawnError(err.to_string()))??;
         Ok(())
     }
+
+    /// Check if a single cancelled inbound output exists that matches this TxID, if it does then return its status to
+    /// EncumberedToBeReceived
+    pub async fn reinstate_inbound_output(&self, tx_id: TxId) -> Result<(), OutputManagerStorageError> {
+        let db_clone = self.db.clone();
+        let outputs = tokio::task::spawn_blocking(move || {
+            match db_clone.fetch(&DbKey::OutputsByTxIdAndStatus(tx_id, OutputStatus::CancelledInbound)) {
+                Ok(None) => Err(OutputManagerStorageError::ValueNotFound),
+                Ok(Some(DbValue::AnyOutputs(o))) => Ok(o),
+                Ok(Some(other)) => unexpected_result(
+                    DbKey::OutputsByTxIdAndStatus(tx_id, OutputStatus::CancelledInbound),
+                    other,
+                ),
+                Err(e) => log_error(DbKey::OutputsByTxIdAndStatus(tx_id, OutputStatus::CancelledInbound), e),
+            }
+        })
+        .await
+        .map_err(|err| OutputManagerStorageError::BlockingTaskSpawnError(err.to_string()))
+        .and_then(|inner_result| inner_result)?;
+
+        if outputs.len() != 1 {
+            return Err(OutputManagerStorageError::UnexpectedResult(
+                "There should be only 1 output for a cancelled inbound transaction but more were found".to_string(),
+            ));
+        }
+        let db_clone2 = self.db.clone();
+
+        tokio::task::spawn_blocking(move || {
+            db_clone2.write(WriteOperation::Insert(DbKeyValuePair::UpdateOutputStatus(
+                outputs
+                    .first()
+                    .expect("Must be only one element in outputs")
+                    .commitment
+                    .clone(),
+                OutputStatus::EncumberedToBeReceived,
+            )))
+        })
+        .await
+        .map_err(|err| OutputManagerStorageError::BlockingTaskSpawnError(err.to_string()))??;
+
+        Ok(())
+    }
 }
 
 fn unexpected_result<T>(req: DbKey, res: DbValue) -> Result<T, OutputManagerStorageError> {
@@ -737,6 +782,7 @@ impl Display for DbKey {
             DbKey::TimeLockedUnspentOutputs(_t) => f.write_str(&"Timelocked Outputs"),
             DbKey::KnownOneSidedPaymentScripts => f.write_str(&"Known claiming scripts"),
             DbKey::AnyOutputByCommitment(_) => f.write_str(&"AnyOutputByCommitment"),
+            DbKey::OutputsByTxIdAndStatus(_, _) => f.write_str(&"OutputsByTxIdAndStatus"),
         }
     }
 }
@@ -754,6 +800,7 @@ impl Display for DbValue {
             DbValue::InvalidOutputs(_) => f.write_str("Invalid Outputs"),
             DbValue::KnownOneSidedPaymentScripts(_) => f.write_str(&"Known claiming scripts"),
             DbValue::AnyOutput(_) => f.write_str(&"Any Output"),
+            DbValue::AnyOutputs(_) => f.write_str(&"Any Outputs"),
         }
     }
 }

base_layer/wallet/src/output_manager_service/storage/models.rs

@@ -105,3 +105,14 @@ impl PartialEq for KnownOneSidedPaymentScript {
         self.script_hash == other.script_hash
     }
 }
+
+/// The status of a given output
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub enum OutputStatus {
+    Unspent,
+    Spent,
+    EncumberedToBeReceived,
+    EncumberedToBeSpent,
+    Invalid,
+    CancelledInbound,
+}

base_layer/wallet/src/output_manager_service/storage/sqlite_db.rs

@@ -33,7 +33,7 @@ use crate::{
                 PendingTransactionOutputs,
                 WriteOperation,
             },
-            models::{DbUnblindedOutput, KnownOneSidedPaymentScript},
+            models::{DbUnblindedOutput, KnownOneSidedPaymentScript, OutputStatus},
         },
         TxId,
     },
@@ -105,6 +105,7 @@ impl OutputManagerSqliteDatabase {
     }
 }
 impl OutputManagerBackend for OutputManagerSqliteDatabase {
+    #[allow(clippy::cognitive_complexity)]
     fn fetch(&self, key: &DbKey) -> Result<Option<DbValue>, OutputManagerStorageError> {
         let conn = self.database_connection.acquire_lock();
 
@@ -135,6 +136,7 @@ impl OutputManagerBackend for OutputManagerSqliteDatabase {
                     None
                 },
             },
+
             DbKey::AnyOutputByCommitment(commitment) => {
                 match OutputSql::find_by_commitment(&commitment.to_vec(), &(*conn)) {
                     Ok(mut o) => {
@@ -173,6 +175,18 @@ impl OutputManagerBackend for OutputManagerSqliteDatabase {
                     None
                 },
             },
+            DbKey::OutputsByTxIdAndStatus(tx_id, status) => {
+                let mut outputs = OutputSql::find_by_tx_id_and_status(*tx_id, *status, &(*conn))?;
+                for o in outputs.iter_mut() {
+                    self.decrypt_if_necessary(o)?;
+                }
+                Some(DbValue::AnyOutputs(
+                    outputs
+                        .iter()
+                        .map(|o| DbUnblindedOutput::try_from(o.clone()))
+                        .collect::<Result<Vec<_>, _>>()?,
+                ))
+            },
             DbKey::UnspentOutputs => {
                 let mut outputs = OutputSql::index_status(OutputStatus::Unspent, &(*conn))?;
                 for o in outputs.iter_mut() {
@@ -273,6 +287,7 @@ impl OutputManagerBackend for OutputManagerSqliteDatabase {
         Ok(result)
     }
 
+    #[allow(clippy::cognitive_complexity)]
     fn write(&self, op: WriteOperation) -> Result<Option<DbValue>, OutputManagerStorageError> {
         let conn = self.database_connection.acquire_lock();
 
@@ -337,6 +352,20 @@ impl OutputManagerBackend for OutputManagerSqliteDatabase {
                     self.encrypt_if_necessary(&mut script_sql)?;
                     script_sql.commit(&(*conn))?
                 },
+                DbKeyValuePair::UpdateOutputStatus(commitment, status) => {
+                    let output = OutputSql::find_by_commitment(&commitment.to_vec(), &(*conn))?;
+                    output.update(
+                        UpdateOutput {
+                            status: Some(status),
+                            tx_id: None,
+                            spending_key: None,
+                            script_private_key: None,
+                            metadata_signature_nonce: None,
+                            metadata_signature_u_key: None,
+                        },
+                        &(*conn),
+                    )?;
+                },
             },
             WriteOperation::Remove(k) => match k {
                 DbKey::SpentOutput(s) => match OutputSql::find_status(&s.to_vec(), OutputStatus::Spent, &(*conn)) {
@@ -409,6 +438,7 @@ impl OutputManagerBackend for OutputManagerSqliteDatabase {
                 DbKey::InvalidOutputs => return Err(OutputManagerStorageError::OperationNotSupported),
                 DbKey::TimeLockedUnspentOutputs(_) => return Err(OutputManagerStorageError::OperationNotSupported),
                 DbKey::KnownOneSidedPaymentScripts => return Err(OutputManagerStorageError::OperationNotSupported),
+                DbKey::OutputsByTxIdAndStatus(_, _) => return Err(OutputManagerStorageError::OperationNotSupported),
             },
         }
 
@@ -840,17 +870,6 @@ fn pending_transaction_outputs_from_sql_outputs(
     })
 }
 
-/// The status of a given output
-#[derive(PartialEq)]
-enum OutputStatus {
-    Unspent,
-    Spent,
-    EncumberedToBeReceived,
-    EncumberedToBeSpent,
-    Invalid,
-    CancelledInbound,
-}
-
 impl TryFrom<i32> for OutputStatus {
     type Error = OutputManagerStorageError;
 
@@ -1011,6 +1030,17 @@ impl OutputSql {
         Ok(request.first::<OutputSql>(conn)?)
     }
 
+    pub fn find_by_tx_id_and_status(
+        tx_id: TxId,
+        status: OutputStatus,
+        conn: &SqliteConnection,
+    ) -> Result<Vec<OutputSql>, OutputManagerStorageError> {
+        Ok(outputs::table
+            .filter(outputs::tx_id.eq(Some(tx_id as i64)))
+            .filter(outputs::status.eq(status as i32))
+            .load(conn)?)
+    }
+
     /// Find outputs via tx_id that are encumbered. Any outputs that are encumbered cannot be marked as spent.
     pub fn find_by_tx_id_and_encumbered(
         tx_id: TxId,