[PATCH wireless-next v3 5/5] wifi: mac80211: reject SET_BSS if any changed AP BSS param is not supported

[Gokul Sivakumar <gokulkumar.sivakumar@xxxxxxxxxxxx>]

The userspace can change more than one AP BSS Parameter in the SET_BSS
operation. Incase if any BSS param other than the list of parameters
currently supported for explicit configuration are passed by userspace,
reject the entire SET_BSS operation.

Also add an individual check for the CFG80211_BSS_PARAM_CHANGED_* flag
before handling the corresponding AP BSS param value from the userspace.
This addresses the case where driver unnecessarily checks the value of all
the supported AP BSS params, even if the userspace did not pass some of
those params in the SET_BSS request.

Signed-off-by: Gokul Sivakumar <gokulkumar.sivakumar@xxxxxxxxxxxx>
---
 net/mac80211/cfg.c | 54 +++++++++++++++++++++++++++++++++-------------
 1 file changed, 39 insertions(+), 15 deletions(-)

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index d9d88f2f2831..8bbf9730dd0e 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -2751,6 +2751,20 @@ static int ieee80211_change_bss(struct wiphy *wiphy,
 	struct ieee80211_supported_band *sband;
 	u64 changed = 0;
 
+	/* Reject the operation if any of the AP BSS params that got changed are not
+	 * supported by the driver for explicit configuration.
+	 */
+	if (params->changed &
+	    ~(CFG80211_BSS_PARAM_CHANGED_CTS_PROT |
+	      CFG80211_BSS_PARAM_CHANGED_SHORT_PREAMBLE |
+	      CFG80211_BSS_PARAM_CHANGED_SHORT_SLOT_TIME |
+	      CFG80211_BSS_PARAM_CHANGED_BASIC_RATES |
+	      CFG80211_BSS_PARAM_CHANGED_AP_ISOLATE |
+	      CFG80211_BSS_PARAM_CHANGED_HT_OPMODE |
+	      CFG80211_BSS_PARAM_CHANGED_P2P_CTWINDOW |
+	      CFG80211_BSS_PARAM_CHANGED_P2P_OPPPS))
+		return -EOPNOTSUPP;
+
 	link = ieee80211_link_or_deflink(sdata, params->link_id, true);
 	if (IS_ERR(link))
 		return PTR_ERR(link);
@@ -2762,7 +2776,8 @@ static int ieee80211_change_bss(struct wiphy *wiphy,
 	if (!sband)
 		return -EINVAL;
 
-	if (params->basic_rates) {
+	if (params->changed &
+	    CFG80211_BSS_PARAM_CHANGED_BASIC_RATES) {
 		if (!ieee80211_parse_bitrates(link->conf->chanreq.oper.width,
 					      wiphy->bands[sband->band],
 					      params->basic_rates,
@@ -2773,11 +2788,13 @@ static int ieee80211_change_bss(struct wiphy *wiphy,
 		ieee80211_check_rate_mask(link);
 	}
 
-	if (params->use_cts_prot >= 0) {
+	if (params->changed &
+	    CFG80211_BSS_PARAM_CHANGED_CTS_PROT) {
 		link->conf->use_cts_prot = params->use_cts_prot;
 		changed |= BSS_CHANGED_ERP_CTS_PROT;
 	}
-	if (params->use_short_preamble >= 0) {
+	if (params->changed &
+	    CFG80211_BSS_PARAM_CHANGED_SHORT_PREAMBLE) {
 		link->conf->use_short_preamble = params->use_short_preamble;
 		changed |= BSS_CHANGED_ERP_PREAMBLE;
 	}
@@ -2789,12 +2806,14 @@ static int ieee80211_change_bss(struct wiphy *wiphy,
 		changed |= BSS_CHANGED_ERP_SLOT;
 	}
 
-	if (params->use_short_slot_time >= 0) {
+	if (params->changed &
+	    CFG80211_BSS_PARAM_CHANGED_SHORT_SLOT_TIME) {
 		link->conf->use_short_slot = params->use_short_slot_time;
 		changed |= BSS_CHANGED_ERP_SLOT;
 	}
 
-	if (params->ap_isolate >= 0) {
+	if (params->changed &
+	    CFG80211_BSS_PARAM_CHANGED_AP_ISOLATE) {
 		if (params->ap_isolate)
 			sdata->flags |= IEEE80211_SDATA_DONT_BRIDGE_PACKETS;
 		else
@@ -2802,12 +2821,14 @@ static int ieee80211_change_bss(struct wiphy *wiphy,
 		ieee80211_check_fast_rx_iface(sdata);
 	}
 
-	if (params->ht_opmode >= 0) {
+	if (params->changed &
+	    CFG80211_BSS_PARAM_CHANGED_HT_OPMODE) {
 		link->conf->ht_operation_mode = (u16)params->ht_opmode;
 		changed |= BSS_CHANGED_HT;
 	}
 
-	if (params->p2p_ctwindow >= 0) {
+	if (params->changed &
+	    CFG80211_BSS_PARAM_CHANGED_P2P_CTWINDOW) {
 		link->conf->p2p_noa_attr.oppps_ctwindow &=
 					~IEEE80211_P2P_OPPPS_CTWINDOW_MASK;
 		link->conf->p2p_noa_attr.oppps_ctwindow |=
@@ -2815,14 +2836,17 @@ static int ieee80211_change_bss(struct wiphy *wiphy,
 		changed |= BSS_CHANGED_P2P_PS;
 	}
 
-	if (params->p2p_opp_ps > 0) {
-		link->conf->p2p_noa_attr.oppps_ctwindow |=
-					IEEE80211_P2P_OPPPS_ENABLE_BIT;
-		changed |= BSS_CHANGED_P2P_PS;
-	} else if (params->p2p_opp_ps == 0) {
-		link->conf->p2p_noa_attr.oppps_ctwindow &=
-					~IEEE80211_P2P_OPPPS_ENABLE_BIT;
-		changed |= BSS_CHANGED_P2P_PS;
+	if (params->changed &
+	    CFG80211_BSS_PARAM_CHANGED_P2P_OPPPS) {
+		if (params->p2p_opp_ps > 0) {
+			link->conf->p2p_noa_attr.oppps_ctwindow |=
+						IEEE80211_P2P_OPPPS_ENABLE_BIT;
+			changed |= BSS_CHANGED_P2P_PS;
+		} else if (params->p2p_opp_ps == 0) {
+			link->conf->p2p_noa_attr.oppps_ctwindow &=
+						~IEEE80211_P2P_OPPPS_ENABLE_BIT;
+			changed |= BSS_CHANGED_P2P_PS;
+		}
 	}
 
 	ieee80211_link_info_change_notify(sdata, link, changed);
-- 
2.47.0