wifi: mac80211: use bandwidth indication element for CSA

In CSA, parse the (EHT) bandwidth indication element and
use it (in fact prefer it if present).
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230920211508.43ef01920556.If4f24a61cd634ab1e50eba43899b9e992bf25602@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

include/linux/ieee80211.h

@@ -3139,6 +3139,28 @@ ieee80211_eht_oper_size_ok(const u8 *data, u8 len)
 	return len >= needed;
 }
 
+#define IEEE80211_BW_IND_DIS_SUBCH_PRESENT	BIT(1)
+
+struct ieee80211_bandwidth_indication {
+	u8 params;
+	struct ieee80211_eht_operation_info info;
+} __packed;
+
+static inline bool
+ieee80211_bandwidth_indication_size_ok(const u8 *data, u8 len)
+{
+	const struct ieee80211_bandwidth_indication *bwi = (const void *)data;
+
+	if (len < sizeof(*bwi))
+		return false;
+
+	if (bwi->params & IEEE80211_BW_IND_DIS_SUBCH_PRESENT &&
+	    len < sizeof(*bwi) + 2)
+		return false;
+
+	return true;
+}
+
 #define LISTEN_INT_USF	GENMASK(15, 14)
 #define LISTEN_INT_UI	GENMASK(13, 0)
 
@@ -3596,6 +3618,7 @@ enum ieee80211_eid_ext {
 	WLAN_EID_EXT_EHT_OPERATION = 106,
 	WLAN_EID_EXT_EHT_MULTI_LINK = 107,
 	WLAN_EID_EXT_EHT_CAPABILITY = 108,
+	WLAN_EID_EXT_BANDWIDTH_INDICATION = 135,
 };
 
 /* Action category code */

net/mac80211/ieee80211_i.h

@@ -1677,6 +1677,7 @@ struct ieee802_11_elems {
 	const struct ieee80211_eht_operation *eht_operation;
 	const struct ieee80211_multi_link_elem *ml_basic;
 	const struct ieee80211_multi_link_elem *ml_reconf;
+	const struct ieee80211_bandwidth_indication *bandwidth_indication;
 
 	/* length of them, respectively */
 	u8 ext_capab_len;
@@ -2463,7 +2464,7 @@ bool ieee80211_chandef_vht_oper(struct ieee80211_hw *hw, u32 vht_cap_info,
 				const struct ieee80211_vht_operation *oper,
 				const struct ieee80211_ht_operation *htop,
 				struct cfg80211_chan_def *chandef);
-void ieee80211_chandef_eht_oper(const struct ieee80211_eht_operation *eht_oper,
+void ieee80211_chandef_eht_oper(const struct ieee80211_eht_operation_info *info,
 				bool support_160, bool support_320,
 				struct cfg80211_chan_def *chandef);
 bool ieee80211_chandef_he_6ghz_oper(struct ieee80211_sub_if_data *sdata,

net/mac80211/mlme.c

@@ -109,7 +109,8 @@ ieee80211_extract_dis_subch_bmap(const struct ieee80211_eht_operation *eht_oper,
 		return 0;
 
 	/* set 160/320 supported to get the full AP definition */
-	ieee80211_chandef_eht_oper(eht_oper, true, true, &ap_chandef);
+	ieee80211_chandef_eht_oper((const void *)eht_oper->optional,
+				   true, true, &ap_chandef);
 	ap_center_freq = ap_chandef.center_freq1;
 	ap_bw = 20 * BIT(u8_get_bits(info->control,
 				     IEEE80211_EHT_OPER_CHAN_WIDTH));
@@ -387,7 +388,7 @@ ieee80211_determine_chantype(struct ieee80211_sub_if_data *sdata,
 	if (eht_oper && (eht_oper->params & IEEE80211_EHT_OPER_INFO_PRESENT)) {
 		struct cfg80211_chan_def eht_chandef = *chandef;
 
-		ieee80211_chandef_eht_oper(eht_oper,
+		ieee80211_chandef_eht_oper((const void *)eht_oper->optional,
 					   eht_chandef.width ==
 					   NL80211_CHAN_WIDTH_160,
 					   false, &eht_chandef);

net/mac80211/spectmgmt.c

@@ -9,7 +9,7 @@
  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
  * Copyright 2007-2008, Intel Corporation
  * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
- * Copyright (C) 2018, 2020, 2022 Intel Corporation
+ * Copyright (C) 2018, 2020, 2022-2023 Intel Corporation
  */
 
 #include <linux/ieee80211.h>
@@ -33,12 +33,14 @@ int ieee80211_parse_ch_switch_ie(struct ieee80211_sub_if_data *sdata,
 	struct cfg80211_chan_def new_vht_chandef = {};
 	const struct ieee80211_sec_chan_offs_ie *sec_chan_offs;
 	const struct ieee80211_wide_bw_chansw_ie *wide_bw_chansw_ie;
+	const struct ieee80211_bandwidth_indication *bwi;
 	int secondary_channel_offset = -1;
 
 	memset(csa_ie, 0, sizeof(*csa_ie));
 
 	sec_chan_offs = elems->sec_chan_offs;
 	wide_bw_chansw_ie = elems->wide_bw_chansw_ie;
+	bwi = elems->bandwidth_indication;
 
 	if (conn_flags & (IEEE80211_CONN_DISABLE_HT |
 			  IEEE80211_CONN_DISABLE_40MHZ)) {
@@ -132,7 +134,14 @@ int ieee80211_parse_ch_switch_ie(struct ieee80211_sub_if_data *sdata,
 		break;
 	}
 
-	if (wide_bw_chansw_ie) {
+	if (bwi) {
+		/* start with the CSA one */
+		new_vht_chandef = csa_ie->chandef;
+		/* and update the width accordingly */
+		/* FIXME: support 160/320 */
+		ieee80211_chandef_eht_oper(&bwi->info, true, true,
+					   &new_vht_chandef);
+	} else if (wide_bw_chansw_ie) {
 		u8 new_seg1 = wide_bw_chansw_ie->new_center_freq_seg1;
 		struct ieee80211_vht_operation vht_oper = {
 			.chan_width =

net/mac80211/util.c

@@ -990,6 +990,11 @@ ieee80211_parse_extension_element(u32 *crc,
 			}
 		}
 		break;
+	case WLAN_EID_EXT_BANDWIDTH_INDICATION:
+		if (ieee80211_bandwidth_indication_size_ok(data, len))
+			elems->bandwidth_indication = data;
+		calc_crc = true;
+		break;
 	}
 
 	if (crc && calc_crc)
@@ -1005,11 +1010,11 @@ _ieee802_11_parse_elems_full(struct ieee80211_elems_parse_params *params,
 	bool calc_crc = params->filter != 0;
 	DECLARE_BITMAP(seen_elems, 256);
 	u32 crc = params->crc;
-	const u8 *ie;
 
 	bitmap_zero(seen_elems, 256);
 
 	for_each_element(elem, params->start, params->len) {
+		const struct element *subelem;
 		bool elem_parse_failed;
 		u8 id = elem->id;
 		u8 elen = elem->datalen;
@@ -1267,15 +1272,27 @@ _ieee802_11_parse_elems_full(struct ieee80211_elems_parse_params *params,
 			}
 			/*
 			 * This is a bit tricky, but as we only care about
-			 * the wide bandwidth channel switch element, so
-			 * just parse it out manually.
+			 * a few elements, parse them out manually.
 			 */
-			ie = cfg80211_find_ie(WLAN_EID_WIDE_BW_CHANNEL_SWITCH,
-					      pos, elen);
-			if (ie) {
-				if (ie[1] >= sizeof(*elems->wide_bw_chansw_ie))
+			subelem = cfg80211_find_elem(WLAN_EID_WIDE_BW_CHANNEL_SWITCH,
+						     pos, elen);
+			if (subelem) {
+				if (subelem->datalen >= sizeof(*elems->wide_bw_chansw_ie))
 					elems->wide_bw_chansw_ie =
-						(void *)(ie + 2);
+						(void *)subelem->data;
+				else
+					elem_parse_failed = true;
+			}
+
+			subelem = cfg80211_find_ext_elem(WLAN_EID_EXT_BANDWIDTH_INDICATION,
+							 pos, elen);
+			if (subelem) {
+				const void *edata = subelem->data + 1;
+				u8 edatalen = subelem->datalen - 1;
+
+				if (ieee80211_bandwidth_indication_size_ok(edata,
+									   edatalen))
+					elems->bandwidth_indication = edata;
 				else
 					elem_parse_failed = true;
 			}
@@ -3746,12 +3763,10 @@ bool ieee80211_chandef_vht_oper(struct ieee80211_hw *hw, u32 vht_cap_info,
 	return true;
 }
 
-void ieee80211_chandef_eht_oper(const struct ieee80211_eht_operation *eht_oper,
+void ieee80211_chandef_eht_oper(const struct ieee80211_eht_operation_info *info,
 				bool support_160, bool support_320,
 				struct cfg80211_chan_def *chandef)
 {
-	struct ieee80211_eht_operation_info *info = (void *)eht_oper->optional;
-
 	chandef->center_freq1 =
 		ieee80211_channel_to_frequency(info->ccfs0,
 					       chandef->chan->band);
@@ -3920,8 +3935,9 @@ bool ieee80211_chandef_he_6ghz_oper(struct ieee80211_sub_if_data *sdata,
 		support_320 =
 			eht_phy_cap & IEEE80211_EHT_PHY_CAP0_320MHZ_IN_6GHZ;
 
-		ieee80211_chandef_eht_oper(eht_oper, support_160,
-					   support_320, &he_chandef);
+		ieee80211_chandef_eht_oper((const void *)eht_oper->optional,
+					   support_160, support_320,
+					   &he_chandef);
 	}
 
 	if (!cfg80211_chandef_valid(&he_chandef)) {