nl80211: add error messages to nl80211_parse_chandef()

Add some error messages to nl80211_parse_chandef() to make
failures here - especially with disabled channels - easier
to diagnose.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 60ce2eb57fbb53e2017daf0f9a93a00e97e85449..35ee15c26027387ebd2177df587cb42706d72675 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -2305,12 +2305,14 @@ static int nl80211_parse_chandef(struct cfg80211_registered_device *rdev,
                                 struct genl_info *info,
                                 struct cfg80211_chan_def *chandef)
 {
+       struct netlink_ext_ack *extack = info->extack;
+       struct nlattr **attrs = info->attrs;
        u32 control_freq;
 
-       if (!info->attrs[NL80211_ATTR_WIPHY_FREQ])
+       if (!attrs[NL80211_ATTR_WIPHY_FREQ])
                return -EINVAL;
 
-       control_freq = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]);
+       control_freq = nla_get_u32(attrs[NL80211_ATTR_WIPHY_FREQ]);
 
        chandef->chan = ieee80211_get_channel(&rdev->wiphy, control_freq);
        chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
@@ -2318,14 +2320,16 @@ static int nl80211_parse_chandef(struct cfg80211_registered_device *rdev,
        chandef->center_freq2 = 0;
 
        /* Primary channel not allowed */
-       if (!chandef->chan || chandef->chan->flags & IEEE80211_CHAN_DISABLED)
+       if (!chandef->chan || chandef->chan->flags & IEEE80211_CHAN_DISABLED) {
+               NL_SET_ERR_MSG_ATTR(extack, attrs[NL80211_ATTR_WIPHY_FREQ],
+                                   "Channel is disabled");
                return -EINVAL;
+       }
 
-       if (info->attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE]) {
+       if (attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE]) {
                enum nl80211_channel_type chantype;
 
-               chantype = nla_get_u32(
-                               info->attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE]);
+               chantype = nla_get_u32(attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE]);
 
                switch (chantype) {
                case NL80211_CHAN_NO_HT:
@@ -2335,42 +2339,56 @@ static int nl80211_parse_chandef(struct cfg80211_registered_device *rdev,
                        cfg80211_chandef_create(chandef, chandef->chan,
                                                chantype);
                        /* user input for center_freq is incorrect */
-                       if (info->attrs[NL80211_ATTR_CENTER_FREQ1] &&
-                           chandef->center_freq1 != nla_get_u32(
-                                       info->attrs[NL80211_ATTR_CENTER_FREQ1]))
+                       if (attrs[NL80211_ATTR_CENTER_FREQ1] &&
+                           chandef->center_freq1 != nla_get_u32(attrs[NL80211_ATTR_CENTER_FREQ1])) {
+                               NL_SET_ERR_MSG_ATTR(extack,
+                                                   attrs[NL80211_ATTR_CENTER_FREQ1],
+                                                   "bad center frequency 1");
                                return -EINVAL;
+                       }
                        /* center_freq2 must be zero */
-                       if (info->attrs[NL80211_ATTR_CENTER_FREQ2] &&
-                           nla_get_u32(info->attrs[NL80211_ATTR_CENTER_FREQ2]))
+                       if (attrs[NL80211_ATTR_CENTER_FREQ2] &&
+                           nla_get_u32(attrs[NL80211_ATTR_CENTER_FREQ2])) {
+                               NL_SET_ERR_MSG_ATTR(extack,
+                                                   attrs[NL80211_ATTR_CENTER_FREQ2],
+                                                   "center frequency 2 can't be used");
                                return -EINVAL;
+                       }
                        break;
                default:
+                       NL_SET_ERR_MSG_ATTR(extack,
+                                           attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE],
+                                           "invalid channel type");
                        return -EINVAL;
                }
-       } else if (info->attrs[NL80211_ATTR_CHANNEL_WIDTH]) {
+       } else if (attrs[NL80211_ATTR_CHANNEL_WIDTH]) {
                chandef->width =
-                       nla_get_u32(info->attrs[NL80211_ATTR_CHANNEL_WIDTH]);
-               if (info->attrs[NL80211_ATTR_CENTER_FREQ1])
+                       nla_get_u32(attrs[NL80211_ATTR_CHANNEL_WIDTH]);
+               if (attrs[NL80211_ATTR_CENTER_FREQ1])
                        chandef->center_freq1 =
-                               nla_get_u32(
-                                       info->attrs[NL80211_ATTR_CENTER_FREQ1]);
-               if (info->attrs[NL80211_ATTR_CENTER_FREQ2])
+                               nla_get_u32(attrs[NL80211_ATTR_CENTER_FREQ1]);
+               if (attrs[NL80211_ATTR_CENTER_FREQ2])
                        chandef->center_freq2 =
-                               nla_get_u32(
-                                       info->attrs[NL80211_ATTR_CENTER_FREQ2]);
+                               nla_get_u32(attrs[NL80211_ATTR_CENTER_FREQ2]);
        }
 
-       if (!cfg80211_chandef_valid(chandef))
+       if (!cfg80211_chandef_valid(chandef)) {
+               NL_SET_ERR_MSG(extack, "invalid channel definition");
                return -EINVAL;
+       }
 
        if (!cfg80211_chandef_usable(&rdev->wiphy, chandef,
-                                    IEEE80211_CHAN_DISABLED))
+                                    IEEE80211_CHAN_DISABLED)) {
+               NL_SET_ERR_MSG(extack, "(extension) channel is disabled");
                return -EINVAL;
+       }
 
        if ((chandef->width == NL80211_CHAN_WIDTH_5 ||
             chandef->width == NL80211_CHAN_WIDTH_10) &&
-           !(rdev->wiphy.flags & WIPHY_FLAG_SUPPORTS_5_10_MHZ))
+           !(rdev->wiphy.flags & WIPHY_FLAG_SUPPORTS_5_10_MHZ)) {
+               NL_SET_ERR_MSG(extack, "5/10 MHz not supported");
                return -EINVAL;
+       }
 
        return 0;
 }