cfg80211: fix nl80211 frequency handling

Fix two small bugs with HT frequency setting:
 * HT is accepted even when the driver is incapable
 * HT40 is accepted when the driver cannot do 40 MHz
 (both on the selected band)

Also simplify the code a little.

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

1 files changed, 26 insertions, 14 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 9caee6022e3..4335f76be71 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -365,6 +365,7 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
                 enum nl80211_sec_chan_offset sec_chan_offset =
                         NL80211_SEC_CHAN_NO_HT;
                 struct ieee80211_channel *chan;
+                struct ieee80211_sta_ht_cap *ht_cap;
                 u32 freq, sec_freq;
 
                 if (!rdev->ops->set_channel) {
@@ -372,26 +373,25 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
                         goto bad_res;
                 }
 
+                result = -EINVAL;
+
                 if (info->attrs[NL80211_ATTR_WIPHY_SEC_CHAN_OFFSET]) {
-                        sec_chan_offset = nla_get_u32(
-                                info->attrs[
+                        sec_chan_offset = nla_get_u32(info->attrs[
                                         NL80211_ATTR_WIPHY_SEC_CHAN_OFFSET]);
                         if (sec_chan_offset != NL80211_SEC_CHAN_NO_HT &&
                             sec_chan_offset != NL80211_SEC_CHAN_DISABLED &&
                             sec_chan_offset != NL80211_SEC_CHAN_BELOW &&
-                            sec_chan_offset != NL80211_SEC_CHAN_ABOVE) {
-                                result = -EINVAL;
+                            sec_chan_offset != NL80211_SEC_CHAN_ABOVE)
                                 goto bad_res;
-                        }
                 }
 
                 freq = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]);
                 chan = ieee80211_get_channel(&rdev->wiphy, freq);
-                if (!chan || chan->flags & IEEE80211_CHAN_DISABLED) {
-                        /* Primary channel not allowed */
-                        result = -EINVAL;
+
+                /* Primary channel not allowed */
+                if (!chan || chan->flags & IEEE80211_CHAN_DISABLED)
                         goto bad_res;
-                }
+
                 if (sec_chan_offset == NL80211_SEC_CHAN_BELOW)
                         sec_freq = freq - 20;
                 else if (sec_chan_offset == NL80211_SEC_CHAN_ABOVE)
@@ -399,14 +399,26 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
                 else
                         sec_freq = 0;
 
+                ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap;
+
+                /* no HT capabilities */
+                if (sec_chan_offset != NL80211_SEC_CHAN_NO_HT &&
+                    !ht_cap->ht_supported)
+                        goto bad_res;
+
                 if (sec_freq) {
                         struct ieee80211_channel *schan;
+
+                        /* no 40 MHz capabilities */
+                        if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
+                            (ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT))
+                                goto bad_res;
+
                         schan = ieee80211_get_channel(&rdev->wiphy, sec_freq);
-                        if (!schan || schan->flags & IEEE80211_CHAN_DISABLED) {
-                                /* Secondary channel not allowed */
-                                result = -EINVAL;
+
+                        /* Secondary channel not allowed */
+                        if (!schan || schan->flags & IEEE80211_CHAN_DISABLED)
                                 goto bad_res;
-                        }
                 }
 
                 result = rdev->ops->set_channel(&rdev->wiphy, chan,
@@ -416,7 +428,7 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
         }
 
 
-bad_res:
+ bad_res:
         cfg80211_put_dev(rdev);
         return result;
 }