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-rw-r--r--net/wireless/scan.c58
1 files changed, 49 insertions, 9 deletions
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index d36c3eb7b931..d0e7472dd9fd 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -1058,13 +1058,23 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev,
return NULL;
}
+/*
+ * Update RX channel information based on the available frame payload
+ * information. This is mainly for the 2.4 GHz band where frames can be received
+ * from neighboring channels and the Beacon frames use the DSSS Parameter Set
+ * element to indicate the current (transmitting) channel, but this might also
+ * be needed on other bands if RX frequency does not match with the actual
+ * operating channel of a BSS.
+ */
static struct ieee80211_channel *
cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
- struct ieee80211_channel *channel)
+ struct ieee80211_channel *channel,
+ enum nl80211_bss_scan_width scan_width)
{
const u8 *tmp;
u32 freq;
int channel_number = -1;
+ struct ieee80211_channel *alt_channel;
tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
if (tmp && tmp[1] == 1) {
@@ -1078,16 +1088,45 @@ cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
}
}
- if (channel_number < 0)
+ if (channel_number < 0) {
+ /* No channel information in frame payload */
return channel;
+ }
freq = ieee80211_channel_to_frequency(channel_number, channel->band);
- channel = ieee80211_get_channel(wiphy, freq);
- if (!channel)
- return NULL;
- if (channel->flags & IEEE80211_CHAN_DISABLED)
+ alt_channel = ieee80211_get_channel(wiphy, freq);
+ if (!alt_channel) {
+ if (channel->band == NL80211_BAND_2GHZ) {
+ /*
+ * Better not allow unexpected channels when that could
+ * be going beyond the 1-11 range (e.g., discovering
+ * BSS on channel 12 when radio is configured for
+ * channel 11.
+ */
+ return NULL;
+ }
+
+ /* No match for the payload channel number - ignore it */
+ return channel;
+ }
+
+ if (scan_width == NL80211_BSS_CHAN_WIDTH_10 ||
+ scan_width == NL80211_BSS_CHAN_WIDTH_5) {
+ /*
+ * Ignore channel number in 5 and 10 MHz channels where there
+ * may not be an n:1 or 1:n mapping between frequencies and
+ * channel numbers.
+ */
+ return channel;
+ }
+
+ /*
+ * Use the channel determined through the payload channel number
+ * instead of the RX channel reported by the driver.
+ */
+ if (alt_channel->flags & IEEE80211_CHAN_DISABLED)
return NULL;
- return channel;
+ return alt_channel;
}
/* Returned bss is reference counted and must be cleaned up appropriately. */
@@ -1112,7 +1151,8 @@ cfg80211_inform_bss_data(struct wiphy *wiphy,
(data->signal < 0 || data->signal > 100)))
return NULL;
- channel = cfg80211_get_bss_channel(wiphy, ie, ielen, data->chan);
+ channel = cfg80211_get_bss_channel(wiphy, ie, ielen, data->chan,
+ data->scan_width);
if (!channel)
return NULL;
@@ -1210,7 +1250,7 @@ cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
return NULL;
channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
- ielen, data->chan);
+ ielen, data->chan, data->scan_width);
if (!channel)
return NULL;