cfg80211: accept no-op interface mode changes

When somebody tries to set the interface mode to the existing
mode, don't ask the driver but silently accept the setting.

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

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index a7d0b94f6b5e1e9678d1fe90d78424aca62e2116..8808431bd58126a23e5a8fe899ebb79a8d050efc 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -607,6 +607,7 @@ static int nl80211_set_interface(struct sk_buff *skb, struct genl_info *info)
        enum nl80211_iftype type;
        struct net_device *dev;
        u32 _flags, *flags = NULL;
+       bool change = false;
 
        memset(&params, 0, sizeof(params));
 
@@ -620,11 +621,17 @@ static int nl80211_set_interface(struct sk_buff *skb, struct genl_info *info)
        type = dev->ieee80211_ptr->iftype;
        dev_put(dev);
 
-       err = -EINVAL;
        if (info->attrs[NL80211_ATTR_IFTYPE]) {
-               type = nla_get_u32(info->attrs[NL80211_ATTR_IFTYPE]);
-               if (type > NL80211_IFTYPE_MAX)
+               enum nl80211_iftype ntype;
+
+               ntype = nla_get_u32(info->attrs[NL80211_ATTR_IFTYPE]);
+               if (type != ntype)
+                       change = true;
+               type = ntype;
+               if (type > NL80211_IFTYPE_MAX) {
+                       err = -EINVAL;
                        goto unlock;
+               }
        }
 
        if (!drv->ops->change_virtual_intf ||
@@ -640,6 +647,7 @@ static int nl80211_set_interface(struct sk_buff *skb, struct genl_info *info)
                }
                params.mesh_id = nla_data(info->attrs[NL80211_ATTR_MESH_ID]);
                params.mesh_id_len = nla_len(info->attrs[NL80211_ATTR_MESH_ID]);
+               change = true;
        }
 
        if (info->attrs[NL80211_ATTR_MNTR_FLAGS]) {
@@ -649,12 +657,18 @@ static int nl80211_set_interface(struct sk_buff *skb, struct genl_info *info)
                }
                err = parse_monitor_flags(info->attrs[NL80211_ATTR_MNTR_FLAGS],
                                          &_flags);
-               if (!err)
-                       flags = &_flags;
+               if (err)
+                       goto unlock;
+
+               flags = &_flags;
+               change = true;
        }
 
-       err = drv->ops->change_virtual_intf(&drv->wiphy, ifindex,
-                                           type, flags, &params);
+       if (change)
+               err = drv->ops->change_virtual_intf(&drv->wiphy, ifindex,
+                                                   type, flags, &params);
+       else
+               err = 0;
 
        dev = __dev_get_by_index(&init_net, ifindex);
        WARN_ON(!dev || (!err && dev->ieee80211_ptr->iftype != type));

diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c
index b84a9b4fe96a79409dc84caf693669c82d3315d0..0fd1db6e95bbe26ef13a9d3524a42ff5765d97c9 100644 (file)
--- a/net/wireless/wext-compat.c
+++ b/net/wireless/wext-compat.c
@@ -66,6 +66,7 @@ int cfg80211_wext_siwmode(struct net_device *dev, struct iw_request_info *info,
        struct cfg80211_registered_device *rdev;
        struct vif_params vifparams;
        enum nl80211_iftype type;
+       int ret;
 
        if (!wdev)
                return -EOPNOTSUPP;
@@ -96,10 +97,16 @@ int cfg80211_wext_siwmode(struct net_device *dev, struct iw_request_info *info,
                return -EINVAL;
        }
 
+       if (type == wdev->iftype)
+               return 0;
+
        memset(&vifparams, 0, sizeof(vifparams));
 
-       return rdev->ops->change_virtual_intf(wdev->wiphy, dev->ifindex, type,
-                                             NULL, &vifparams);
+       ret = rdev->ops->change_virtual_intf(wdev->wiphy, dev->ifindex, type,
+                                            NULL, &vifparams);
+       WARN_ON(!ret && wdev->iftype != type);
+
+       return ret;
 }
 EXPORT_SYMBOL(cfg80211_wext_siwmode);