batman-adv: add dynamic, bridged-in TT VID detection support

Message ID 20240612213620.4135-1-linus.luessing@c0d3.blue (mailing list archive)
State New
Delegated to: Simon Wunderlich
Headers
Series batman-adv: add dynamic, bridged-in TT VID detection support |

Commit Message

Linus Lüssing June 12, 2024, 9:36 p.m. UTC
  So far, if we wanted bridge VLAN tagged frames into the mesh one would
need to manually create an according VLAN interface on top of bat0
first, to trigger batman-adv to create the according structures
for a VID.

With this change the VLAN from bridged-in clients is now automatically
detected and added to the translation table on the fly.

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
---
 net/batman-adv/hard-interface.c    |   2 +-
 net/batman-adv/multicast.c         |   8 +-
 net/batman-adv/soft-interface.c    | 121 ++++++++++++++++-------------
 net/batman-adv/soft-interface.h    |   6 +-
 net/batman-adv/translation-table.c |  19 ++---
 net/batman-adv/translation-table.h |   4 +-
 6 files changed, 88 insertions(+), 72 deletions(-)
  

Patch

diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index 96a412beab2d..f5826dd8752c 100644
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -946,7 +946,7 @@  static int batadv_hard_if_event_softif(unsigned long event,
 	switch (event) {
 	case NETDEV_REGISTER:
 		bat_priv = netdev_priv(net_dev);
-		batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
+		batadv_softif_create_vlan_own(bat_priv, BATADV_NO_FLAGS);
 		break;
 	}
 
diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c
index 38fab5e46ae2..61e765352e29 100644
--- a/net/batman-adv/multicast.c
+++ b/net/batman-adv/multicast.c
@@ -724,6 +724,7 @@  static void batadv_mcast_mla_tt_add(struct batadv_priv *bat_priv,
 {
 	struct batadv_hw_addr *mcast_entry;
 	struct hlist_node *tmp;
+	int ret;
 
 	if (!mcast_list)
 		return;
@@ -733,9 +734,10 @@  static void batadv_mcast_mla_tt_add(struct batadv_priv *bat_priv,
 						  &bat_priv->mcast.mla_list))
 			continue;
 
-		if (!batadv_tt_local_add(bat_priv->soft_iface,
-					 mcast_entry->addr, BATADV_NO_FLAGS,
-					 BATADV_NULL_IFINDEX, BATADV_NO_MARK))
+		ret = batadv_tt_local_add(bat_priv->soft_iface,
+					  mcast_entry->addr, BATADV_NO_FLAGS,
+					  BATADV_NULL_IFINDEX, BATADV_NO_MARK);
+		if (ret <= 0)
 			continue;
 
 		hlist_del(&mcast_entry->list);
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 30ecbc2ef1fd..fb647798e5c8 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -141,6 +141,10 @@  static int batadv_interface_set_mac_addr(struct net_device *dev, void *p)
 
 	rcu_read_lock();
 	hlist_for_each_entry_rcu(vlan, &bat_priv->softif_vlan_list, list) {
+		/* we don't use this VID ourself, avoid adding us to it */
+		if (!batadv_is_my_client(bat_priv, old_addr, vlan->vid))
+			continue;
+
 		batadv_tt_local_remove(bat_priv, old_addr, vlan->vid,
 				       "mac address changed", false);
 		batadv_tt_local_add(dev, addr->sa_data, vlan->vid,
@@ -549,13 +553,15 @@  struct batadv_softif_vlan *batadv_softif_vlan_get(struct batadv_priv *bat_priv,
 }
 
 /**
- * batadv_softif_create_vlan() - allocate the needed resources for a new vlan
+ * batadv_softif_create_vlan() - create a softif vlan struct
  * @bat_priv: the bat priv with all the soft interface information
  * @vid: the VLAN identifier
  *
- * Return: 0 on success, a negative error otherwise.
+ * Return: a pointer to the newly allocated softif vlan struct on success, NULL
+ * otherwise.
  */
-int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid)
+static struct batadv_softif_vlan *
+batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid)
 {
 	struct batadv_softif_vlan *vlan;
 
@@ -563,15 +569,14 @@  int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid)
 
 	vlan = batadv_softif_vlan_get(bat_priv, vid);
 	if (vlan) {
-		batadv_softif_vlan_put(vlan);
 		spin_unlock_bh(&bat_priv->softif_vlan_list_lock);
-		return -EEXIST;
+		return vlan;
 	}
 
 	vlan = kzalloc(sizeof(*vlan), GFP_ATOMIC);
 	if (!vlan) {
 		spin_unlock_bh(&bat_priv->softif_vlan_list_lock);
-		return -ENOMEM;
+		return NULL;
 	}
 
 	vlan->bat_priv = bat_priv;
@@ -584,34 +589,71 @@  int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid)
 	hlist_add_head_rcu(&vlan->list, &bat_priv->softif_vlan_list);
 	spin_unlock_bh(&bat_priv->softif_vlan_list_lock);
 
+	return vlan;
+}
+
+/**
+ * batadv_softif_vlan_get_or_create() - retrieve or create a softif vlan struct
+ * @bat_priv: the bat priv with all the soft interface information
+ * @vid: the VLAN identifier
+ *
+ * Return: the softif vlan struct if found or created or NULL otherwise.
+ */
+struct batadv_softif_vlan *
+batadv_softif_vlan_get_or_create(struct batadv_priv *bat_priv,
+				 unsigned short vid)
+{
+	struct batadv_softif_vlan *vlan = batadv_softif_vlan_get(bat_priv, vid);
+
+	if (vlan)
+		return vlan;
+
+	return batadv_softif_create_vlan(bat_priv, vid);
+}
+
+/**
+ * batadv_softif_create_vlan_own() - add our own softif to the local TT
+ * @bat_priv: the bat priv with all the soft interface information
+ * @vid: the VLAN identifier
+ *
+ * Adds the MAC address of our own soft interface with the given VLAN ID as
+ * a permanent local TT entry.
+ *
+ * Return: 0 on success, a negative error otherwise.
+ */
+int batadv_softif_create_vlan_own(struct batadv_priv *bat_priv,
+				  unsigned short vid)
+{
+	int ret;
+
 	/* add a new TT local entry. This one will be marked with the NOPURGE
 	 * flag
 	 */
-	batadv_tt_local_add(bat_priv->soft_iface,
-			    bat_priv->soft_iface->dev_addr, vid,
-			    BATADV_NULL_IFINDEX, BATADV_NO_MARK);
-
-	/* don't return reference to new softif_vlan */
-	batadv_softif_vlan_put(vlan);
+	ret = batadv_tt_local_add(bat_priv->soft_iface,
+				  bat_priv->soft_iface->dev_addr, vid,
+				  BATADV_NULL_IFINDEX, BATADV_NO_MARK);
+	if (ret < 0)
+		return ret;
 
 	return 0;
 }
 
 /**
- * batadv_softif_destroy_vlan() - remove and destroy a softif_vlan object
+ * batadv_softif_destroy_vlan_own() - remove our own softif from the local TT
  * @bat_priv: the bat priv with all the soft interface information
- * @vlan: the object to remove
+ * @vid: the VLAN identifier
+ *
+ * Removes the MAC address of our own soft interface with the given VLAN ID from
+ * the local TT.
  */
-static void batadv_softif_destroy_vlan(struct batadv_priv *bat_priv,
-				       struct batadv_softif_vlan *vlan)
+static void batadv_softif_destroy_vlan_own(struct batadv_priv *bat_priv,
+					   unsigned short vid)
 {
 	/* explicitly remove the associated TT local entry because it is marked
 	 * with the NOPURGE flag
 	 */
-	batadv_tt_local_remove(bat_priv, bat_priv->soft_iface->dev_addr,
-			       vlan->vid, "vlan interface destroyed", false);
-
-	batadv_softif_vlan_put(vlan);
+	batadv_tt_local_remove(bat_priv, bat_priv->soft_iface->dev_addr, vid,
+			       "vlan interface destroyed", false);
 }
 
 /**
@@ -629,7 +671,6 @@  static int batadv_interface_add_vid(struct net_device *dev, __be16 proto,
 				    unsigned short vid)
 {
 	struct batadv_priv *bat_priv = netdev_priv(dev);
-	struct batadv_softif_vlan *vlan;
 
 	/* only 802.1Q vlans are supported.
 	 * batman-adv does not know how to handle other types
@@ -639,25 +680,7 @@  static int batadv_interface_add_vid(struct net_device *dev, __be16 proto,
 
 	vid |= BATADV_VLAN_HAS_TAG;
 
-	/* if a new vlan is getting created and it already exists, it means that
-	 * it was not deleted yet. batadv_softif_vlan_get() increases the
-	 * refcount in order to revive the object.
-	 *
-	 * if it does not exist then create it.
-	 */
-	vlan = batadv_softif_vlan_get(bat_priv, vid);
-	if (!vlan)
-		return batadv_softif_create_vlan(bat_priv, vid);
-
-	/* add a new TT local entry. This one will be marked with the NOPURGE
-	 * flag. This must be added again, even if the vlan object already
-	 * exists, because the entry was deleted by kill_vid()
-	 */
-	batadv_tt_local_add(bat_priv->soft_iface,
-			    bat_priv->soft_iface->dev_addr, vid,
-			    BATADV_NULL_IFINDEX, BATADV_NO_MARK);
-
-	return 0;
+	return batadv_softif_create_vlan_own(bat_priv, vid);
 }
 
 /**
@@ -676,7 +699,6 @@  static int batadv_interface_kill_vid(struct net_device *dev, __be16 proto,
 				     unsigned short vid)
 {
 	struct batadv_priv *bat_priv = netdev_priv(dev);
-	struct batadv_softif_vlan *vlan;
 
 	/* only 802.1Q vlans are supported. batman-adv does not know how to
 	 * handle other types
@@ -684,15 +706,7 @@  static int batadv_interface_kill_vid(struct net_device *dev, __be16 proto,
 	if (proto != htons(ETH_P_8021Q))
 		return -EINVAL;
 
-	vlan = batadv_softif_vlan_get(bat_priv, vid | BATADV_VLAN_HAS_TAG);
-	if (!vlan)
-		return -ENOENT;
-
-	batadv_softif_destroy_vlan(bat_priv, vlan);
-
-	/* finally free the vlan object */
-	batadv_softif_vlan_put(vlan);
-
+	batadv_softif_destroy_vlan_own(bat_priv, vid | BATADV_VLAN_HAS_TAG);
 	return 0;
 }
 
@@ -1099,7 +1113,6 @@  static void batadv_softif_destroy_netlink(struct net_device *soft_iface,
 {
 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 	struct batadv_hard_iface *hard_iface;
-	struct batadv_softif_vlan *vlan;
 
 	list_for_each_entry(hard_iface, &batadv_hardif_list, list) {
 		if (hard_iface->soft_iface == soft_iface)
@@ -1107,11 +1120,7 @@  static void batadv_softif_destroy_netlink(struct net_device *soft_iface,
 	}
 
 	/* destroy the "untagged" VLAN */
-	vlan = batadv_softif_vlan_get(bat_priv, BATADV_NO_FLAGS);
-	if (vlan) {
-		batadv_softif_destroy_vlan(bat_priv, vlan);
-		batadv_softif_vlan_put(vlan);
-	}
+	batadv_softif_destroy_vlan_own(bat_priv, BATADV_NO_FLAGS);
 
 	unregister_netdevice_queue(soft_iface, head);
 }
diff --git a/net/batman-adv/soft-interface.h b/net/batman-adv/soft-interface.h
index 9f2003f1a497..7050ccd304df 100644
--- a/net/batman-adv/soft-interface.h
+++ b/net/batman-adv/soft-interface.h
@@ -21,10 +21,14 @@  void batadv_interface_rx(struct net_device *soft_iface,
 			 struct batadv_orig_node *orig_node);
 bool batadv_softif_is_valid(const struct net_device *net_dev);
 extern struct rtnl_link_ops batadv_link_ops;
-int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid);
+int batadv_softif_create_vlan_own(struct batadv_priv *bat_priv,
+				  unsigned short vid);
 void batadv_softif_vlan_release(struct kref *ref);
 struct batadv_softif_vlan *batadv_softif_vlan_get(struct batadv_priv *bat_priv,
 						  unsigned short vid);
+struct batadv_softif_vlan *
+batadv_softif_vlan_get_or_create(struct batadv_priv *bat_priv,
+				 unsigned short vid);
 
 /**
  * batadv_softif_vlan_put() - decrease the vlan object refcounter and
diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index b21ff3c36b07..ca74a46c1d93 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -591,8 +591,8 @@  static void batadv_tt_global_free(struct batadv_priv *bat_priv,
  *
  * Return: true if the client was successfully added, false otherwise.
  */
-bool batadv_tt_local_add(struct net_device *soft_iface, const u8 *addr,
-			 unsigned short vid, int ifindex, u32 mark)
+int batadv_tt_local_add(struct net_device *soft_iface, const u8 *addr,
+			unsigned short vid, int ifindex, u32 mark)
 {
 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 	struct batadv_tt_local_entry *tt_local;
@@ -604,10 +604,10 @@  bool batadv_tt_local_add(struct net_device *soft_iface, const u8 *addr,
 	struct hlist_head *head;
 	struct batadv_tt_orig_list_entry *orig_entry;
 	int hash_added, table_size, packet_size_max;
-	bool ret = false;
 	bool roamed_back = false;
 	u8 remote_flags;
 	u32 match_mark;
+	int ret = 0;
 
 	if (ifindex != BATADV_NULL_IFINDEX)
 		in_dev = dev_get_by_index(net, ifindex);
@@ -658,21 +658,22 @@  bool batadv_tt_local_add(struct net_device *soft_iface, const u8 *addr,
 		net_ratelimited_function(batadv_info, soft_iface,
 					 "Local translation table size (%i) exceeds maximum packet size (%i); Ignoring new local tt entry: %pM\n",
 					 table_size, packet_size_max, addr);
+		ret = -E2BIG;
 		goto out;
 	}
 
 	tt_local = kmem_cache_alloc(batadv_tl_cache, GFP_ATOMIC);
-	if (!tt_local)
+	if (!tt_local) {
+		ret = -ENOMEM;
 		goto out;
+	}
 
 	/* increase the refcounter of the related vlan */
-	vlan = batadv_softif_vlan_get(bat_priv, vid);
+	vlan = batadv_softif_vlan_get_or_create(bat_priv, vid);
 	if (!vlan) {
-		net_ratelimited_function(batadv_info, soft_iface,
-					 "adding TT local entry %pM to non-existent VLAN %d\n",
-					 addr, batadv_print_vid(vid));
 		kmem_cache_free(batadv_tl_cache, tt_local);
 		tt_local = NULL;
+		ret = -ENOMEM;
 		goto out;
 	}
 
@@ -769,7 +770,7 @@  bool batadv_tt_local_add(struct net_device *soft_iface, const u8 *addr,
 	if (remote_flags ^ (tt_local->common.flags & BATADV_TT_REMOTE_MASK))
 		batadv_tt_local_event(bat_priv, tt_local, BATADV_NO_FLAGS);
 
-	ret = true;
+	ret = 1;
 out:
 	batadv_hardif_put(in_hardif);
 	dev_put(in_dev);
diff --git a/net/batman-adv/translation-table.h b/net/batman-adv/translation-table.h
index d18740d9a22b..bbdda8488c14 100644
--- a/net/batman-adv/translation-table.h
+++ b/net/batman-adv/translation-table.h
@@ -16,8 +16,8 @@ 
 #include <linux/types.h>
 
 int batadv_tt_init(struct batadv_priv *bat_priv);
-bool batadv_tt_local_add(struct net_device *soft_iface, const u8 *addr,
-			 unsigned short vid, int ifindex, u32 mark);
+int batadv_tt_local_add(struct net_device *soft_iface, const u8 *addr,
+			unsigned short vid, int ifindex, u32 mark);
 u16 batadv_tt_local_remove(struct batadv_priv *bat_priv,
 			   const u8 *addr, unsigned short vid,
 			   const char *message, bool roaming);