From 3273a5cd2d7445e90bcb0851fbb5b7f1f72192be Mon Sep 17 00:00:00 2001
From: Sven Eckelmann <sven@narfation.org>
Date: Sun, 30 Aug 2026 17:21:46 +0200
Subject: [PATCH] batman-adv: tt: look up wifi state of incoming interface in
 helper

batadv_tt_local_add() only needs to know whether the client was seen on a
wifi interface. But it kept the net_device reference of the incoming
interface alive until its own cleanup section, together with a "net" and an
"in_dev" variable which are of no interest to the rest of the function.

Move the lookup to a small helper which acquires and releases the
net_device reference itself.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
 net/batman-adv/translation-table.c | 41 +++++++++++++++++++++---------
 1 file changed, 29 insertions(+), 12 deletions(-)

diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index 44a8cf89382c..1c22db348267 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -41,6 +41,7 @@
 #include <linux/string.h>
 #include <linux/workqueue.h>
 #include <net/genetlink.h>
+#include <net/net_namespace.h>
 #include <net/netlink.h>
 #include <uapi/linux/batadv_packet.h>
 #include <uapi/linux/batman_adv.h>
@@ -693,6 +694,32 @@ static void batadv_tt_local_add_roam(struct batadv_priv *bat_priv,
 		batadv_tt_global_free(bat_priv, tt_global, "Roaming canceled");
 }
 
+/**
+ * batadv_tt_iif_is_wifi() - check whether a client is connected via wifi
+ * @net: namespace to search the incoming interface in
+ * @ifindex: index of the interface where the client is connected to
+ *
+ * Return: true if @ifindex refers to a wifi interface, false otherwise (which
+ * includes the case of an unknown or missing incoming interface).
+ */
+static bool batadv_tt_iif_is_wifi(struct net *net, int ifindex)
+{
+	struct net_device *in_dev;
+	u32 wifi_flags;
+
+	if (ifindex == BATADV_NULL_IFINDEX)
+		return false;
+
+	in_dev = dev_get_by_index(net, ifindex);
+	if (!in_dev)
+		return false;
+
+	wifi_flags = batadv_netdev_get_wifi_flags(in_dev);
+	dev_put(in_dev);
+
+	return batadv_is_wifi(wifi_flags);
+}
+
 /**
  * batadv_tt_local_add() - add a new client to the local table or update an
  *  existing client
@@ -712,12 +739,10 @@ bool batadv_tt_local_add(struct net_device *mesh_iface, const u8 *addr,
 	struct batadv_priv *bat_priv = netdev_priv(mesh_iface);
 	struct batadv_tt_global_entry *tt_global = NULL;
 	struct batadv_tt_local_entry *tt_local;
-	struct net *net = dev_net(mesh_iface);
-	struct net_device *in_dev = NULL;
 	struct batadv_meshif_vlan *vlan;
 	bool roamed_back = false;
-	bool iif_is_wifi = false;
 	int packet_size_max;
+	bool iif_is_wifi;
 	bool ret = false;
 	u8 remote_flags;
 	int hash_added;
@@ -725,14 +750,7 @@ bool batadv_tt_local_add(struct net_device *mesh_iface, const u8 *addr,
 	u32 match_mark;
 	bool modified;
 
-	if (ifindex != BATADV_NULL_IFINDEX)
-		in_dev = dev_get_by_index(net, ifindex);
-
-	if (in_dev) {
-		u32 wifi_flags = batadv_netdev_get_wifi_flags(in_dev);
-
-		iif_is_wifi = batadv_is_wifi(wifi_flags);
-	}
+	iif_is_wifi = batadv_tt_iif_is_wifi(dev_net(mesh_iface), ifindex);
 
 	tt_local = batadv_tt_local_hash_find(bat_priv, addr, vid);
 
@@ -881,7 +899,6 @@ check_roaming:
 
 	ret = true;
 out:
-	dev_put(in_dev);
 	batadv_tt_local_entry_put(tt_local);
 	batadv_tt_global_entry_put(tt_global);
 	return ret;