Commit fe7c3a1f authored by Janusz Dziedzic's avatar Janusz Dziedzic Committed by Johannes Berg
Browse files

cfg80211: DFS check chandef usable before CAC

Check chandef we get in CAC request is usable for CAC.
All channels have to be DFS channels. Allow DFS_USABLE
and DFS_AVAILABLE channels mix. At least one channel
has to be DFS_USABLE (require CAC).
Signed-off-by: default avatarJanusz Dziedzic <>
Reviewed-by: default avatarLuis R. Rodriguez <>
Signed-off-by: default avatarJohannes Berg <>
parent 40d1ba63
......@@ -351,6 +351,80 @@ int cfg80211_chandef_dfs_required(struct wiphy *wiphy,
static int cfg80211_get_chans_dfs_usable(struct wiphy *wiphy,
u32 center_freq,
u32 bandwidth)
struct ieee80211_channel *c;
u32 freq, start_freq, end_freq;
int count = 0;
start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
* Check entire range of channels for the bandwidth.
* Check all channels are DFS channels (DFS_USABLE or
* DFS_AVAILABLE). Return number of usable channels
* (require CAC). Allow DFS and non-DFS channel mix.
for (freq = start_freq; freq <= end_freq; freq += 20) {
c = ieee80211_get_channel(wiphy, freq);
if (!c)
return -EINVAL;
if (c->flags & IEEE80211_CHAN_DISABLED)
return -EINVAL;
if (c->flags & IEEE80211_CHAN_RADAR) {
if (c->dfs_state == NL80211_DFS_UNAVAILABLE)
return -EINVAL;
if (c->dfs_state == NL80211_DFS_USABLE)
return count;
bool cfg80211_chandef_dfs_usable(struct wiphy *wiphy,
const struct cfg80211_chan_def *chandef)
int width;
int r1, r2 = 0;
if (WARN_ON(!cfg80211_chandef_valid(chandef)))
return false;
width = cfg80211_chandef_get_width(chandef);
if (width < 0)
return false;
r1 = cfg80211_get_chans_dfs_usable(wiphy, chandef->center_freq1,
if (r1 < 0)
return false;
switch (chandef->width) {
case NL80211_CHAN_WIDTH_80P80:
r2 = cfg80211_get_chans_dfs_usable(wiphy,
if (r2 < 0)
return false;
return (r1 + r2 > 0);
static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
u32 center_freq, u32 bandwidth,
u32 prohibited_flags)
......@@ -382,6 +382,19 @@ int cfg80211_can_use_iftype_chan(struct cfg80211_registered_device *rdev,
enum cfg80211_chan_mode chanmode,
u8 radar_detect);
* cfg80211_chandef_dfs_usable - checks if chandef is DFS usable
* @wiphy: the wiphy to validate against
* @chandef: the channel definition to check
* Checks if chandef is usable and we can/need start CAC on such channel.
* Return: Return true if all channels available and at least
* one channel require CAC (NL80211_DFS_USABLE)
bool cfg80211_chandef_dfs_usable(struct wiphy *wiphy,
const struct cfg80211_chan_def *chandef);
void cfg80211_set_dfs_state(struct wiphy *wiphy,
const struct cfg80211_chan_def *chandef,
enum nl80211_dfs_state dfs_state);
......@@ -5651,7 +5651,7 @@ static int nl80211_start_radar_detection(struct sk_buff *skb,
if (err == 0)
return -EINVAL;
if (chandef.chan->dfs_state != NL80211_DFS_USABLE)
if (!cfg80211_chandef_dfs_usable(wdev->wiphy, &chandef))
return -EINVAL;
if (!rdev->ops->start_radar_detection)
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