From cbafc3e0c3566c619c6cc5b40fbcfb07594f5d4d Mon Sep 17 00:00:00 2001
From: premultiply <4681172+premultiply@users.noreply.github.com>
Date: Sat, 14 Sep 2024 14:38:02 +0200
Subject: [PATCH] Ocpp: generate globally unique transaction ids (#15951)

---
 charger/ocpp/connector.go      |  5 ++---
 charger/ocpp/connector_core.go | 27 ++-------------------------
 charger/ocpp/cs.go             | 12 +++++++++++-
 charger/ocpp/instance.go       |  1 +
 4 files changed, 16 insertions(+), 29 deletions(-)

diff --git a/charger/ocpp/connector.go b/charger/ocpp/connector.go
index 461e716d6..862b3f02c 100644
--- a/charger/ocpp/connector.go
+++ b/charger/ocpp/connector.go
@@ -29,9 +29,8 @@ type Connector struct {
 	meterUpdated time.Time
 	measurements map[types.Measurand]types.SampledValue
 
-	txnCount int // change initial value to the last known global transaction. Needs persistence
-	txnId    int
-	idTag    string
+	txnId int
+	idTag string
 
 	remoteIdTag string
 }
diff --git a/charger/ocpp/connector_core.go b/charger/ocpp/connector_core.go
index 66ddd38e6..df0d38d2d 100644
--- a/charger/ocpp/connector_core.go
+++ b/charger/ocpp/connector_core.go
@@ -64,7 +64,7 @@ func (conn *Connector) MeterValues(request *core.MeterValuesRequest) (*core.Mete
 		(conn.status.Status == core.ChargePointStatusCharging ||
 			conn.status.Status == core.ChargePointStatusSuspendedEV ||
 			conn.status.Status == core.ChargePointStatusSuspendedEVSE) {
-		conn.log.DEBUG.Printf("hijacking transaction: %d", *request.TransactionId)
+		conn.log.DEBUG.Printf("recovered transaction: %d", *request.TransactionId)
 		conn.txnId = *request.TransactionId
 	}
 
@@ -91,19 +91,7 @@ func (conn *Connector) StartTransaction(request *core.StartTransactionRequest) (
 	conn.mu.Lock()
 	defer conn.mu.Unlock()
 
-	// expired request
-	if request.Timestamp != nil && conn.clock.Since(request.Timestamp.Time) > Timeout {
-		res := &core.StartTransactionConfirmation{
-			IdTagInfo: &types.IdTagInfo{
-				Status: types.AuthorizationStatusExpired, // reject
-			},
-		}
-
-		return res, nil
-	}
-
-	conn.txnCount++
-	conn.txnId = conn.txnCount
+	conn.txnId = instance.NewTransactionID()
 	conn.idTag = request.IdTag
 
 	res := &core.StartTransactionConfirmation{
@@ -140,17 +128,6 @@ func (conn *Connector) StopTransaction(request *core.StopTransactionRequest) (*c
 	conn.mu.Lock()
 	defer conn.mu.Unlock()
 
-	// expired request
-	if request.Timestamp != nil && conn.clock.Since(request.Timestamp.Time) > Timeout {
-		res := &core.StopTransactionConfirmation{
-			IdTagInfo: &types.IdTagInfo{
-				Status: types.AuthorizationStatusExpired, // reject
-			},
-		}
-
-		return res, nil
-	}
-
 	conn.txnId = 0
 	conn.idTag = ""
 
diff --git a/charger/ocpp/cs.go b/charger/ocpp/cs.go
index 70e0d1986..72be4ac00 100644
--- a/charger/ocpp/cs.go
+++ b/charger/ocpp/cs.go
@@ -13,7 +13,8 @@ type CS struct {
 	mu  sync.Mutex
 	log *util.Logger
 	ocpp16.CentralSystem
-	cps map[string]*CP
+	cps   map[string]*CP
+	txnId int
 }
 
 // Register registers a charge point with the central system.
@@ -106,3 +107,12 @@ func (cs *CS) ChargePointDisconnected(chargePoint ocpp16.ChargePointConnection)
 		cp.connect(false)
 	}
 }
+
+// NewTransactionID returns a CS-wide unique transactionId
+func (cs *CS) NewTransactionID() int {
+	cs.mu.Lock()
+	defer cs.mu.Unlock()
+
+	cs.txnId++
+	return cs.txnId
+}
diff --git a/charger/ocpp/instance.go b/charger/ocpp/instance.go
index 4220fc50c..ec6315f13 100644
--- a/charger/ocpp/instance.go
+++ b/charger/ocpp/instance.go
@@ -42,6 +42,7 @@ func Instance() *CS {
 			log:           log,
 			cps:           make(map[string]*CP),
 			CentralSystem: cs,
+			txnId:         int(time.Now().UTC().Unix()),
 		}
 
 		ocppj.SetLogger(instance)