batman-adv: multi vlan support for bridge loop detection

The bridge loop detection for batman-adv allows the bat0 interface
to be bridged into an ethernet segment which other batman-adv nodes
are connected to. In order to also allow multiple VLANs on top of
the bat0 interface to be bridged into the ethernet segment this
patch extends the aforementioned bridge loop detection.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>

1 files changed, 284 insertions, 109 deletions

diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index ea5e58c252f0..8cb13a03b0e1 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -90,135 +90,251 @@ static void softif_neigh_free_ref(struct softif_neigh *softif_neigh)
                 call_rcu(&softif_neigh->rcu, softif_neigh_free_rcu);
 }
 
-static struct softif_neigh *softif_neigh_get_selected(struct bat_priv *bat_priv)
+static void softif_neigh_vid_free_rcu(struct rcu_head *rcu)
 {
-        struct softif_neigh *neigh;
-
-        rcu_read_lock();
-        neigh = rcu_dereference(bat_priv->softif_neigh);
-
-        if (neigh && !atomic_inc_not_zero(&neigh->refcount))
-                neigh = NULL;
-
-        rcu_read_unlock();
-        return neigh;
-}
+        struct softif_neigh_vid *softif_neigh_vid;
+        struct softif_neigh *softif_neigh;
+        struct hlist_node *node, *node_tmp;
+        struct bat_priv *bat_priv;
 
-static void softif_neigh_select(struct bat_priv *bat_priv,
-                                struct softif_neigh *new_neigh)
-{
-        struct softif_neigh *curr_neigh;
+        softif_neigh_vid = container_of(rcu, struct softif_neigh_vid, rcu);
+        bat_priv = softif_neigh_vid->bat_priv;
 
         spin_lock_bh(&bat_priv->softif_neigh_lock);
-
-        if (new_neigh && !atomic_inc_not_zero(&new_neigh->refcount))
-                new_neigh = NULL;
-
-        curr_neigh = bat_priv->softif_neigh;
-        rcu_assign_pointer(bat_priv->softif_neigh, new_neigh);
-
-        if (curr_neigh)
-                softif_neigh_free_ref(curr_neigh);
-
+        hlist_for_each_entry_safe(softif_neigh, node, node_tmp,
+                                  &softif_neigh_vid->softif_neigh_list, list) {
+                hlist_del_rcu(&softif_neigh->list);
+                softif_neigh_free_ref(softif_neigh);
+        }
         spin_unlock_bh(&bat_priv->softif_neigh_lock);
+
+        kfree(softif_neigh_vid);
 }
 
-static void softif_neigh_deselect(struct bat_priv *bat_priv)
+static void softif_neigh_vid_free_ref(struct softif_neigh_vid *softif_neigh_vid)
 {
-        softif_neigh_select(bat_priv, NULL);
+        if (atomic_dec_and_test(&softif_neigh_vid->refcount))
+                call_rcu(&softif_neigh_vid->rcu, softif_neigh_vid_free_rcu);
 }
 
-void softif_neigh_purge(struct bat_priv *bat_priv)
+static struct softif_neigh_vid *softif_neigh_vid_get(struct bat_priv *bat_priv,
+                                                     short vid)
 {
-        struct softif_neigh *softif_neigh, *curr_softif_neigh;
-        struct hlist_node *node, *node_tmp;
-        char do_deselect = 0;
-
-        curr_softif_neigh = softif_neigh_get_selected(bat_priv);
-
-        spin_lock_bh(&bat_priv->softif_neigh_lock);
-
-        hlist_for_each_entry_safe(softif_neigh, node, node_tmp,
-                                  &bat_priv->softif_neigh_list, list) {
+        struct softif_neigh_vid *softif_neigh_vid;
+        struct hlist_node *node;
 
-                if ((!time_after(jiffies, softif_neigh->last_seen +
-                                msecs_to_jiffies(SOFTIF_NEIGH_TIMEOUT))) &&
-                    (atomic_read(&bat_priv->mesh_state) == MESH_ACTIVE))
+        rcu_read_lock();
+        hlist_for_each_entry_rcu(softif_neigh_vid, node,
+                                 &bat_priv->softif_neigh_vids, list) {
+                if (softif_neigh_vid->vid != vid)
                         continue;
 
-                if (curr_softif_neigh == softif_neigh) {
-                        bat_dbg(DBG_ROUTES, bat_priv,
-                                 "Current mesh exit point '%pM' vanished "
-                                 "(vid: %d).\n",
-                                 softif_neigh->addr, softif_neigh->vid);
-                        do_deselect = 1;
-                }
+                if (!atomic_inc_not_zero(&softif_neigh_vid->refcount))
+                        continue;
 
-                hlist_del_rcu(&softif_neigh->list);
-                softif_neigh_free_ref(softif_neigh);
+                goto out;
         }
 
-        spin_unlock_bh(&bat_priv->softif_neigh_lock);
+        softif_neigh_vid = kzalloc(sizeof(struct softif_neigh_vid),
+                                   GFP_ATOMIC);
+        if (!softif_neigh_vid)
+                goto out;
 
-        /* soft_neigh_deselect() needs to acquire the softif_neigh_lock */
-        if (do_deselect)
-                softif_neigh_deselect(bat_priv);
+        softif_neigh_vid->vid = vid;
+        softif_neigh_vid->bat_priv = bat_priv;
 
-        if (curr_softif_neigh)
-                softif_neigh_free_ref(curr_softif_neigh);
+        /* initialize with 2 - caller decrements counter by one */
+        atomic_set(&softif_neigh_vid->refcount, 2);
+        INIT_HLIST_HEAD(&softif_neigh_vid->softif_neigh_list);
+        INIT_HLIST_NODE(&softif_neigh_vid->list);
+        spin_lock_bh(&bat_priv->softif_neigh_vid_lock);
+        hlist_add_head_rcu(&softif_neigh_vid->list,
+                           &bat_priv->softif_neigh_vids);
+        spin_unlock_bh(&bat_priv->softif_neigh_vid_lock);
+
+out:
+        rcu_read_unlock();
+        return softif_neigh_vid;
 }
 
 static struct softif_neigh *softif_neigh_get(struct bat_priv *bat_priv,
                                              uint8_t *addr, short vid)
 {
-        struct softif_neigh *softif_neigh;
+        struct softif_neigh_vid *softif_neigh_vid;
+        struct softif_neigh *softif_neigh = NULL;
         struct hlist_node *node;
 
+        softif_neigh_vid = softif_neigh_vid_get(bat_priv, vid);
+        if (!softif_neigh_vid)
+                goto out;
+
         rcu_read_lock();
         hlist_for_each_entry_rcu(softif_neigh, node,
-                                 &bat_priv->softif_neigh_list, list) {
+                                 &softif_neigh_vid->softif_neigh_list,
+                                 list) {
                 if (!compare_eth(softif_neigh->addr, addr))
                         continue;
 
-                if (softif_neigh->vid != vid)
-                        continue;
-
                 if (!atomic_inc_not_zero(&softif_neigh->refcount))
                         continue;
 
                 softif_neigh->last_seen = jiffies;
-                goto out;
+                goto unlock;
         }
 
         softif_neigh = kzalloc(sizeof(struct softif_neigh), GFP_ATOMIC);
         if (!softif_neigh)
-                goto out;
+                goto unlock;
 
         memcpy(softif_neigh->addr, addr, ETH_ALEN);
-        softif_neigh->vid = vid;
         softif_neigh->last_seen = jiffies;
         /* initialize with 2 - caller decrements counter by one */
         atomic_set(&softif_neigh->refcount, 2);
 
         INIT_HLIST_NODE(&softif_neigh->list);
         spin_lock_bh(&bat_priv->softif_neigh_lock);
-        hlist_add_head_rcu(&softif_neigh->list, &bat_priv->softif_neigh_list);
+        hlist_add_head_rcu(&softif_neigh->list,
+                           &softif_neigh_vid->softif_neigh_list);
         spin_unlock_bh(&bat_priv->softif_neigh_lock);
 
+unlock:
+        rcu_read_unlock();
 out:
+        if (softif_neigh_vid)
+                softif_neigh_vid_free_ref(softif_neigh_vid);
+        return softif_neigh;
+}
+
+static struct softif_neigh *softif_neigh_get_selected(
+                                struct softif_neigh_vid *softif_neigh_vid)
+{
+        struct softif_neigh *softif_neigh;
+
+        rcu_read_lock();
+        softif_neigh = rcu_dereference(softif_neigh_vid->softif_neigh);
+
+        if (softif_neigh && !atomic_inc_not_zero(&softif_neigh->refcount))
+                softif_neigh = NULL;
+
         rcu_read_unlock();
         return softif_neigh;
 }
 
+static struct softif_neigh *softif_neigh_vid_get_selected(
+                                                struct bat_priv *bat_priv,
+                                                short vid)
+{
+        struct softif_neigh_vid *softif_neigh_vid;
+        struct softif_neigh *softif_neigh = NULL;
+
+        softif_neigh_vid = softif_neigh_vid_get(bat_priv, vid);
+        if (!softif_neigh_vid)
+                goto out;
+
+        softif_neigh = softif_neigh_get_selected(softif_neigh_vid);
+out:
+        if (softif_neigh_vid)
+                softif_neigh_vid_free_ref(softif_neigh_vid);
+        return softif_neigh;
+}
+
+static void softif_neigh_vid_select(struct bat_priv *bat_priv,
+                                    struct softif_neigh *new_neigh,
+                                    short vid)
+{
+        struct softif_neigh_vid *softif_neigh_vid;
+        struct softif_neigh *curr_neigh;
+
+        softif_neigh_vid = softif_neigh_vid_get(bat_priv, vid);
+        if (!softif_neigh_vid)
+                goto out;
+
+        spin_lock_bh(&bat_priv->softif_neigh_lock);
+
+        if (new_neigh && !atomic_inc_not_zero(&new_neigh->refcount))
+                new_neigh = NULL;
+
+        curr_neigh = softif_neigh_vid->softif_neigh;
+        rcu_assign_pointer(softif_neigh_vid->softif_neigh, new_neigh);
+
+        if ((curr_neigh) && (!new_neigh))
+                bat_dbg(DBG_ROUTES, bat_priv,
+                        "Removing mesh exit point on vid: %d (prev: %pM).\n",
+                        vid, curr_neigh->addr);
+        else if ((curr_neigh) && (new_neigh))
+                bat_dbg(DBG_ROUTES, bat_priv,
+                        "Changing mesh exit point on vid: %d from %pM "
+                        "to %pM.\n", vid, curr_neigh->addr, new_neigh->addr);
+        else if ((!curr_neigh) && (new_neigh))
+                bat_dbg(DBG_ROUTES, bat_priv,
+                        "Setting mesh exit point on vid: %d to %pM.\n",
+                        vid, new_neigh->addr);
+
+        if (curr_neigh)
+                softif_neigh_free_ref(curr_neigh);
+
+        spin_unlock_bh(&bat_priv->softif_neigh_lock);
+
+out:
+        if (softif_neigh_vid)
+                softif_neigh_vid_free_ref(softif_neigh_vid);
+}
+
+static void softif_neigh_vid_deselect(struct bat_priv *bat_priv,
+                                      struct softif_neigh_vid *softif_neigh_vid)
+{
+        struct softif_neigh *curr_neigh;
+        struct softif_neigh *softif_neigh = NULL, *softif_neigh_tmp;
+        struct hard_iface *primary_if = NULL;
+        struct hlist_node *node;
+
+        primary_if = primary_if_get_selected(bat_priv);
+        if (!primary_if)
+                goto out;
+
+        /* find new softif_neigh immediately to avoid temporary loops */
+        rcu_read_lock();
+        curr_neigh = rcu_dereference(softif_neigh_vid->softif_neigh);
+
+        hlist_for_each_entry_rcu(softif_neigh_tmp, node,
+                                 &softif_neigh_vid->softif_neigh_list,
+                                 list) {
+                if (softif_neigh_tmp == curr_neigh)
+                        continue;
+
+                /* we got a neighbor but its mac is 'bigger' than ours  */
+                if (memcmp(primary_if->net_dev->dev_addr,
+                           softif_neigh_tmp->addr, ETH_ALEN) < 0)
+                        continue;
+
+                if (!atomic_inc_not_zero(&softif_neigh_tmp->refcount))
+                        continue;
+
+                softif_neigh = softif_neigh_tmp;
+                goto unlock;
+        }
+
+unlock:
+        rcu_read_unlock();
+out:
+        softif_neigh_vid_select(bat_priv, softif_neigh, softif_neigh_vid->vid);
+
+        if (primary_if)
+                hardif_free_ref(primary_if);
+        if (softif_neigh)
+                softif_neigh_free_ref(softif_neigh);
+}
+
 int softif_neigh_seq_print_text(struct seq_file *seq, void *offset)
 {
         struct net_device *net_dev = (struct net_device *)seq->private;
         struct bat_priv *bat_priv = netdev_priv(net_dev);
+        struct softif_neigh_vid *softif_neigh_vid;
         struct softif_neigh *softif_neigh;
         struct hard_iface *primary_if;
-        struct hlist_node *node;
+        struct hlist_node *node, *node_tmp;
         struct softif_neigh *curr_softif_neigh;
-        int ret = 0;
+        int ret = 0, last_seen_secs, last_seen_msecs;
 
         primary_if = primary_if_get_selected(bat_priv);
         if (!primary_if) {
@@ -237,17 +353,33 @@ int softif_neigh_seq_print_text(struct seq_file *seq, void *offset)
 
         seq_printf(seq, "Softif neighbor list (%s)\n", net_dev->name);
 
-        curr_softif_neigh = softif_neigh_get_selected(bat_priv);
         rcu_read_lock();
-        hlist_for_each_entry_rcu(softif_neigh, node,
-                                 &bat_priv->softif_neigh_list, list)
-                seq_printf(seq, "%s %pM (vid: %d)\n",
-                                curr_softif_neigh == softif_neigh
-                                ? "=>" : "  ", softif_neigh->addr,
-                                softif_neigh->vid);
+        hlist_for_each_entry_rcu(softif_neigh_vid, node,
+                                 &bat_priv->softif_neigh_vids, list) {
+                seq_printf(seq, "     %-15s %s on vid: %d\n",
+                           "Originator", "last-seen", softif_neigh_vid->vid);
+
+                curr_softif_neigh = softif_neigh_get_selected(softif_neigh_vid);
+
+                hlist_for_each_entry_rcu(softif_neigh, node_tmp,
+                                         &softif_neigh_vid->softif_neigh_list,
+                                         list) {
+                        last_seen_secs = jiffies_to_msecs(jiffies -
+                                                softif_neigh->last_seen) / 1000;
+                        last_seen_msecs = jiffies_to_msecs(jiffies -
+                                                softif_neigh->last_seen) % 1000;
+                        seq_printf(seq, "%s %pM  %3i.%03is\n",
+                                   curr_softif_neigh == softif_neigh
+                                   ? "=>" : "  ", softif_neigh->addr,
+                                   last_seen_secs, last_seen_msecs);
+                }
+
+                if (curr_softif_neigh)
+                        softif_neigh_free_ref(curr_softif_neigh);
+
+                seq_printf(seq, "\n");
+        }
         rcu_read_unlock();
-        if (curr_softif_neigh)
-                softif_neigh_free_ref(curr_softif_neigh);
 
 out:
         if (primary_if)
@@ -255,6 +387,70 @@ out:
         return ret;
 }
 
+void softif_neigh_purge(struct bat_priv *bat_priv)
+{
+        struct softif_neigh *softif_neigh, *curr_softif_neigh;
+        struct softif_neigh_vid *softif_neigh_vid;
+        struct hlist_node *node, *node_tmp, *node_tmp2;
+        char do_deselect;
+
+        rcu_read_lock();
+        hlist_for_each_entry_rcu(softif_neigh_vid, node,
+                                 &bat_priv->softif_neigh_vids, list) {
+                if (!atomic_inc_not_zero(&softif_neigh_vid->refcount))
+                        continue;
+
+                curr_softif_neigh = softif_neigh_get_selected(softif_neigh_vid);
+                do_deselect = 0;
+
+                spin_lock_bh(&bat_priv->softif_neigh_lock);
+                hlist_for_each_entry_safe(softif_neigh, node_tmp, node_tmp2,
+                                          &softif_neigh_vid->softif_neigh_list,
+                                          list) {
+                        if ((!time_after(jiffies, softif_neigh->last_seen +
+                                msecs_to_jiffies(SOFTIF_NEIGH_TIMEOUT))) &&
+                            (atomic_read(&bat_priv->mesh_state) == MESH_ACTIVE))
+                                continue;
+
+                        if (curr_softif_neigh == softif_neigh) {
+                                bat_dbg(DBG_ROUTES, bat_priv,
+                                        "Current mesh exit point on vid: %d "
+                                        "'%pM' vanished.\n",
+                                        softif_neigh_vid->vid,
+                                        softif_neigh->addr);
+                                do_deselect = 1;
+                        }
+
+                        hlist_del_rcu(&softif_neigh->list);
+                        softif_neigh_free_ref(softif_neigh);
+                }
+                spin_unlock_bh(&bat_priv->softif_neigh_lock);
+
+                /* soft_neigh_vid_deselect() needs to acquire the
+                 * softif_neigh_lock */
+                if (do_deselect)
+                        softif_neigh_vid_deselect(bat_priv, softif_neigh_vid);
+
+                if (curr_softif_neigh)
+                        softif_neigh_free_ref(curr_softif_neigh);
+
+                softif_neigh_vid_free_ref(softif_neigh_vid);
+        }
+        rcu_read_unlock();
+
+        spin_lock_bh(&bat_priv->softif_neigh_vid_lock);
+        hlist_for_each_entry_safe(softif_neigh_vid, node, node_tmp,
+                                  &bat_priv->softif_neigh_vids, list) {
+                if (!hlist_empty(&softif_neigh_vid->softif_neigh_list))
+                        continue;
+
+                hlist_del_rcu(&softif_neigh_vid->list);
+                softif_neigh_vid_free_ref(softif_neigh_vid);
+        }
+        spin_unlock_bh(&bat_priv->softif_neigh_vid_lock);
+
+}
+
 static void softif_batman_recv(struct sk_buff *skb, struct net_device *dev,
                                short vid)
 {
@@ -287,10 +483,7 @@ static void softif_batman_recv(struct sk_buff *skb, struct net_device *dev,
         if (!softif_neigh)
                 goto out;
 
-        curr_softif_neigh = softif_neigh_get_selected(bat_priv);
-        if (!curr_softif_neigh)
-                goto out;
-
+        curr_softif_neigh = softif_neigh_vid_get_selected(bat_priv, vid);
         if (curr_softif_neigh == softif_neigh)
                 goto out;
 
@@ -303,33 +496,16 @@ static void softif_batman_recv(struct sk_buff *skb, struct net_device *dev,
                    softif_neigh->addr, ETH_ALEN) < 0)
                 goto out;
 
-        /* switch to new 'smallest neighbor' */
-        if ((curr_softif_neigh) &&
-            (memcmp(softif_neigh->addr, curr_softif_neigh->addr,
-                                                        ETH_ALEN) < 0)) {
-                bat_dbg(DBG_ROUTES, bat_priv,
-                        "Changing mesh exit point from %pM (vid: %d) "
-                        "to %pM (vid: %d).\n",
-                         curr_softif_neigh->addr,
-                         curr_softif_neigh->vid,
-                         softif_neigh->addr, softif_neigh->vid);
-
-                softif_neigh_select(bat_priv, softif_neigh);
-                goto out;
-        }
-
         /* close own batX device and use softif_neigh as exit node */
-        if ((!curr_softif_neigh) &&
-            (memcmp(softif_neigh->addr,
-                    primary_if->net_dev->dev_addr, ETH_ALEN) < 0)) {
-                bat_dbg(DBG_ROUTES, bat_priv,
-                        "Setting mesh exit point to %pM (vid: %d).\n",
-                        softif_neigh->addr, softif_neigh->vid);
-
-                softif_neigh_select(bat_priv, softif_neigh);
+        if (!curr_softif_neigh) {
+                softif_neigh_vid_select(bat_priv, softif_neigh, vid);
                 goto out;
         }
 
+        /* switch to new 'smallest neighbor' */
+        if (memcmp(softif_neigh->addr, curr_softif_neigh->addr, ETH_ALEN) < 0)
+                softif_neigh_vid_select(bat_priv, softif_neigh, vid);
+
 out:
         kfree_skb(skb);
         if (softif_neigh)
@@ -424,8 +600,8 @@ int interface_tx(struct sk_buff *skb, struct net_device *soft_iface)
          * if we have a another chosen mesh exit node in range
          * it will transport the packets to the mesh
          */
-        curr_softif_neigh = softif_neigh_get_selected(bat_priv);
-        if ((curr_softif_neigh) && (curr_softif_neigh->vid == vid))
+        curr_softif_neigh = softif_neigh_vid_get_selected(bat_priv, vid);
+        if (curr_softif_neigh)
                 goto dropped;
 
         /* TODO: check this for locks */
@@ -533,8 +709,8 @@ void interface_rx(struct net_device *soft_iface,
          * if we have a another chosen mesh exit node in range
          * it will transport the packets to the non-mesh network
          */
-        curr_softif_neigh = softif_neigh_get_selected(bat_priv);
-        if (curr_softif_neigh && (curr_softif_neigh->vid == vid)) {
+        curr_softif_neigh = softif_neigh_vid_get_selected(bat_priv, vid);
+        if (curr_softif_neigh) {
                 skb_push(skb, hdr_size);
                 unicast_packet = (struct unicast_packet *)skb->data;
 
@@ -671,7 +847,6 @@ struct net_device *softif_create(char *name)
 
         bat_priv->primary_if = NULL;
         bat_priv->num_ifaces = 0;
-        bat_priv->softif_neigh = NULL;
 
         ret = sysfs_add_meshif(soft_iface);
         if (ret < 0)