[MAC80211]: implement cfg80211's change_interface hook

This implements the cfg80211 change_interface hook that changes the
type of an interface and cleans up the code a bit.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 57 insertions, 18 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 6981ba178e19..9e2bc1fd0237 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -13,31 +13,35 @@
 #include "ieee80211_i.h"
 #include "cfg.h"
 
+static enum ieee80211_if_types
+nl80211_type_to_mac80211_type(enum nl80211_iftype type)
+{
+        switch (type) {
+        case NL80211_IFTYPE_UNSPECIFIED:
+                return IEEE80211_IF_TYPE_STA;
+        case NL80211_IFTYPE_ADHOC:
+                return IEEE80211_IF_TYPE_IBSS;
+        case NL80211_IFTYPE_STATION:
+                return IEEE80211_IF_TYPE_STA;
+        case NL80211_IFTYPE_MONITOR:
+                return IEEE80211_IF_TYPE_MNTR;
+        default:
+                return IEEE80211_IF_TYPE_INVALID;
+        }
+}
+
 static int ieee80211_add_iface(struct wiphy *wiphy, char *name,
                                enum nl80211_iftype type)
 {
         struct ieee80211_local *local = wiphy_priv(wiphy);
-        int itype;
+        enum ieee80211_if_types itype;
 
         if (unlikely(local->reg_state != IEEE80211_DEV_REGISTERED))
                 return -ENODEV;
 
-        switch (type) {
-        case NL80211_IFTYPE_UNSPECIFIED:
-                itype = IEEE80211_IF_TYPE_STA;
-                break;
-        case NL80211_IFTYPE_ADHOC:
-                itype = IEEE80211_IF_TYPE_IBSS;
-                break;
-        case NL80211_IFTYPE_STATION:
-                itype = IEEE80211_IF_TYPE_STA;
-                break;
-        case NL80211_IFTYPE_MONITOR:
-                itype = IEEE80211_IF_TYPE_MNTR;
-                break;
-        default:
+        itype = nl80211_type_to_mac80211_type(type);
+        if (itype == IEEE80211_IF_TYPE_INVALID)
                 return -EINVAL;
-        }
 
         return ieee80211_if_add(local->mdev, name, NULL, itype);
 }
@@ -51,17 +55,52 @@ static int ieee80211_del_iface(struct wiphy *wiphy, int ifindex)
         if (unlikely(local->reg_state != IEEE80211_DEV_REGISTERED))
                 return -ENODEV;
 
-        dev = dev_get_by_index(&init_net, ifindex);
+        /* we're under RTNL */
+        dev = __dev_get_by_index(&init_net, ifindex);
         if (!dev)
                 return 0;
 
         name = dev->name;
-        dev_put(dev);
 
         return ieee80211_if_remove(local->mdev, name, -1);
 }
 
+static int ieee80211_change_iface(struct wiphy *wiphy, int ifindex,
+                                  enum nl80211_iftype type)
+{
+        struct ieee80211_local *local = wiphy_priv(wiphy);
+        struct net_device *dev;
+        enum ieee80211_if_types itype;
+        struct ieee80211_sub_if_data *sdata;
+
+        if (unlikely(local->reg_state != IEEE80211_DEV_REGISTERED))
+                return -ENODEV;
+
+        /* we're under RTNL */
+        dev = __dev_get_by_index(&init_net, ifindex);
+        if (!dev)
+                return -ENODEV;
+
+        if (netif_running(dev))
+                return -EBUSY;
+
+        itype = nl80211_type_to_mac80211_type(type);
+        if (itype == IEEE80211_IF_TYPE_INVALID)
+                return -EINVAL;
+
+        sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+        if (sdata->type == IEEE80211_IF_TYPE_VLAN)
+                return -EOPNOTSUPP;
+
+        ieee80211_if_reinit(dev);
+        ieee80211_if_set_type(dev, itype);
+
+        return 0;
+}
+
 struct cfg80211_ops mac80211_config_ops = {
         .add_virtual_intf = ieee80211_add_iface,
         .del_virtual_intf = ieee80211_del_iface,
+        .change_virtual_intf = ieee80211_change_iface,
 };