nl/cfg80211: force scan using an AP vif if requested

If the user wants to scan using a vif configured as AP,
cfg80211 must give him a chance to do it, even if this
will disrupt the stations performance due to off-channel
scanning. To do so, this patch adds a 'force' flag to the
SCAN_TRIGGER command which tells cfg80211 to perform the
scanning operation even if the vif is an AP and the
beaconing has already started.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Antonio Quartulli 2012-10-16 08:39:22 +02:00 committed by Johannes Berg
parent 4ee3e063f1
commit 5c95b940bd
3 changed files with 21 additions and 2 deletions

View File

@ -3050,6 +3050,7 @@ enum nl80211_ap_sme_features {
* mode
* @NL80211_FEATURE_LOW_PRIORITY_SCAN: This driver supports low priority scan
* @NL80211_FEATURE_SCAN_FLUSH: Scan flush is supported
* @NL80211_FEATURE_AP_SCAN: Support scanning using an AP vif
*/
enum nl80211_feature_flags {
NL80211_FEATURE_SK_TX_STATUS = 1 << 0,
@ -3060,6 +3061,7 @@ enum nl80211_feature_flags {
NL80211_FEATURE_SAE = 1 << 5,
NL80211_FEATURE_LOW_PRIORITY_SCAN = 1 << 6,
NL80211_FEATURE_SCAN_FLUSH = 1 << 7,
NL80211_FEATURE_AP_SCAN = 1 << 8,
};
/**
@ -3103,10 +3105,16 @@ enum nl80211_connect_failed_reason {
*
* @NL80211_SCAN_FLAG_LOW_PRIORITY: scan request has low priority
* @NL80211_SCAN_FLAG_FLUSH: flush cache before scanning
* @NL80211_SCAN_FLAG_AP: force a scan even if the interface is configured
* as AP and the beaconing has already been configured. This attribute is
* dangerous because will destroy stations performance as a lot of frames
* will be lost while scanning off-channel, therefore it must be used only
* when really needed
*/
enum nl80211_scan_flags {
NL80211_SCAN_FLAG_LOW_PRIORITY = 1<<0,
NL80211_SCAN_FLAG_FLUSH = 1<<1,
NL80211_SCAN_FLAG_AP = 1<<2,
};
#endif /* __LINUX_NL80211_H */

View File

@ -1855,7 +1855,16 @@ static int ieee80211_scan(struct wiphy *wiphy,
* beaconing hasn't been configured yet
*/
case NL80211_IFTYPE_AP:
if (sdata->u.ap.beacon)
/*
* If the scan has been forced (and the driver supports
* forcing), don't care about being beaconing already.
* This will create problems to the attached stations (e.g. all
* the frames sent while scanning on other channel will be
* lost)
*/
if (sdata->u.ap.beacon &&
(!(wiphy->features & NL80211_FEATURE_AP_SCAN) ||
!(req->flags & NL80211_SCAN_FLAG_AP)))
return -EOPNOTSUPP;
break;
default:

View File

@ -603,7 +603,9 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
NL80211_FEATURE_HT_IBSS;
if (!ops->hw_scan)
wiphy->features |= NL80211_FEATURE_LOW_PRIORITY_SCAN;
wiphy->features |= NL80211_FEATURE_LOW_PRIORITY_SCAN |
NL80211_FEATURE_AP_SCAN;
if (!ops->set_key)
wiphy->flags |= WIPHY_FLAG_IBSS_RSN;