Commit 5c95b940 authored by Antonio Quartulli's avatar Antonio Quartulli Committed by Johannes Berg
Browse files

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: default avatarAntonio Quartulli <ordex@autistici.org>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 4ee3e063

include/uapi/linux/nl80211.h

+8 −0
Original line number Diff line number Diff line
@@ -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 */

net/mac80211/cfg.c

+10 −1
Original line number Diff line number Diff line
@@ -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:

net/mac80211/main.c

+3 −1
Original line number Diff line number Diff line
@@ -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;

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