From d46f9d547a9d22560ec624ac0ae12c8277d49266 Mon Sep 17 00:00:00 2001
From: Louis Royer <infos.louis.royer@gmail.com>
Date: Tue, 4 Feb 2025 17:02:07 +0100
Subject: [PATCH] Prevent duplicated creation of default path

---
 internal/context/sm_context.go | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/internal/context/sm_context.go b/internal/context/sm_context.go
index 4dc2783..81246b5 100644
--- a/internal/context/sm_context.go
+++ b/internal/context/sm_context.go
@@ -579,7 +579,7 @@ func (c *SMContext) AllocUeIP() error {
 // This function create ULCL data paths.
 func (c *SMContext) SelectULCLDataPaths() error {
 	if c.SelectionParam == nil || c.SelectedUPF == nil {
-		return fmt.Errorf("SelectDefaultDataPath err: SelectionParam or SelectedUPF is nil")
+		return fmt.Errorf("SelectULCLDataPath err: SelectionParam or SelectedUPF is nil")
 	}
 
 	if GetSelf().ULCLSupport && CheckUEHasPreConfig(c.Supi) {
@@ -600,17 +600,19 @@ func (c *SMContext) SelectDefaultDataPath() error {
 		return fmt.Errorf("SelectDefaultDataPath err: SelectionParam or SelectedUPF is nil")
 	}
 
-	var defaultPath *DataPath
-	if GetSelf().ULCLSupport && CheckUEHasPreConfig(c.Supi) {
+	defaultPath := c.Tunnel.DataPathPool.GetDefaultPath()
+	if defaultPath != nil {
+		// A default path already exists.
+		// Use this one.
+		c.Log.Infof("Has default path")
+		defaultPath = c.Tunnel.DataPathPool.GetDefaultPath()
+	} else if GetSelf().ULCLSupport && CheckUEHasPreConfig(c.Supi) {
+		// Fallback on pre-config default path
 		c.Log.Infof("Has pre-config default path")
 		uePreConfigPaths := GetUEPreConfigPaths(c.Supi, c.SelectedUPF.Name)
-		for _, dp := range uePreConfigPaths.DataPathPool {
-			if dp.IsDefaultPath {
-				c.Tunnel.AddDataPath(dp)
-			}
-		}
 		defaultPath = uePreConfigPaths.DataPathPool.GetDefaultPath()
-	} else if c.Tunnel.DataPathPool.GetDefaultPath() == nil {
+		c.Tunnel.AddDataPath(defaultPath)
+	} else {
 		// UE has no pre-config path and default path
 		// Use default route
 		c.Log.Infof("Has no pre-config route. Has no default path")
@@ -621,9 +623,6 @@ func (c *SMContext) SelectDefaultDataPath() error {
 			defaultPath.IsDefaultPath = true
 			c.Tunnel.AddDataPath(defaultPath)
 		}
-	} else {
-		c.Log.Infof("Has no pre-config route. Has default path")
-		defaultPath = c.Tunnel.DataPathPool.GetDefaultPath()
 	}
 
 	if defaultPath == nil {