batman-adv: fix gw_node_update() and gw_election()

This is a regression from c4aac1ab9b973798163b34939b522f01e4d28ac9

- gw_node_update() doesn't add a new gw_node in case of empty curr_gw.
This means that at the beginning no gw_node is added, leading to an
empty gateway list.

- gw_election() is terminating in case of curr_gw == NULL. It has to
terminate in case of curr_gw != NULL

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Sven Eckelmann <sven@narfation.org>

diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
index 2acd7a6..af128ef 100644 (file)
--- a/net/batman-adv/gateway_client.c
+++ b/net/batman-adv/gateway_client.c
@@ -127,7 +127,7 @@ void gw_election(struct bat_priv *bat_priv)
                return;
 
        curr_gw = gw_get_selected_gw_node(bat_priv);
-       if (!curr_gw)
+       if (curr_gw)
                goto out;
 
        rcu_read_lock();
@@ -310,9 +310,13 @@ void gw_node_update(struct bat_priv *bat_priv,
        struct hlist_node *node;
        struct gw_node *gw_node, *curr_gw;
 
+       /**
+        * Note: We don't need a NULL check here, since curr_gw never gets
+        * dereferenced. If curr_gw is NULL we also should not exit as we may
+        * have this gateway in our list (duplication check!) even though we
+        * have no currently selected gateway.
+        */
        curr_gw = gw_get_selected_gw_node(bat_priv);
-       if (!curr_gw)
-               goto out;
 
        rcu_read_lock();
        hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
@@ -350,7 +354,7 @@ deselect:
        gw_deselect(bat_priv);
 unlock:
        rcu_read_unlock();
-out:
+
        if (curr_gw)
                gw_node_free_ref(curr_gw);
 }