mac80211: limit bandwidth in HE capabilities

[ Upstream commit 1f2c104448477512fcf7296df54bfbc3a6f9a765 ]

If we're limiting bandwidth for some reason such as regulatory
restrictions, then advertise that limitation just like we do
for VHT today, so the AP is aware we cannot use the higher BW
it might be using.

Fixes: 41cbb0f5a295 ("mac80211: add support for HE")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20220202104617.70c8e3e7ee76.If317630de69ff1146bec7d47f5b83038695eb71d@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

4 files changed, 32 insertions, 10 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 6a88195e5abe..d30bd21697a3 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -2379,7 +2379,7 @@ u8 *ieee80211_ie_build_vht_cap(u8 *pos, struct ieee80211_sta_vht_cap *vht_cap,
 u8 *ieee80211_ie_build_vht_oper(u8 *pos, struct ieee80211_sta_vht_cap *vht_cap,
 				const struct cfg80211_chan_def *chandef);
 u8 ieee80211_ie_len_he_cap(struct ieee80211_sub_if_data *sdata, u8 iftype);
-u8 *ieee80211_ie_build_he_cap(u8 *pos,
+u8 *ieee80211_ie_build_he_cap(u32 disable_flags, u8 *pos,
 			      const struct ieee80211_sta_he_cap *he_cap,
 			      u8 *end);
 void ieee80211_ie_build_he_6ghz_cap(struct ieee80211_sub_if_data *sdata,
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index 5dcfd53a4ab6..42bd81a30310 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -580,7 +580,7 @@ int mesh_add_he_cap_ie(struct ieee80211_sub_if_data *sdata,
 		return -ENOMEM;
 
 	pos = skb_put(skb, ie_len);
-	ieee80211_ie_build_he_cap(pos, he_cap, pos + ie_len);
+	ieee80211_ie_build_he_cap(0, pos, he_cap, pos + ie_len);
 
 	return 0;
 }
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 8d9fe2765836..c8332452c118 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -630,7 +630,7 @@ static void ieee80211_add_he_ie(struct ieee80211_sub_if_data *sdata,
 				struct sk_buff *skb,
 				struct ieee80211_supported_band *sband)
 {
-	u8 *pos;
+	u8 *pos, *pre_he_pos;
 	const struct ieee80211_sta_he_cap *he_cap = NULL;
 	struct ieee80211_chanctx_conf *chanctx_conf;
 	u8 he_cap_size;
@@ -647,16 +647,21 @@ static void ieee80211_add_he_ie(struct ieee80211_sub_if_data *sdata,
 
 	he_cap = ieee80211_get_he_iftype_cap(sband,
 					     ieee80211_vif_type_p2p(&sdata->vif));
-	if (!he_cap || !reg_cap)
+	if (!he_cap || !chanctx_conf || !reg_cap)
 		return;
 
+	/* get a max size estimate */
 	he_cap_size =
 		2 + 1 + sizeof(he_cap->he_cap_elem) +
 		ieee80211_he_mcs_nss_size(&he_cap->he_cap_elem) +
 		ieee80211_he_ppe_size(he_cap->ppe_thres[0],
 				      he_cap->he_cap_elem.phy_cap_info);
 	pos = skb_put(skb, he_cap_size);
-	ieee80211_ie_build_he_cap(pos, he_cap, pos + he_cap_size);
+	pre_he_pos = pos;
+	pos = ieee80211_ie_build_he_cap(sdata->u.mgd.flags,
+					pos, he_cap, pos + he_cap_size);
+	/* trim excess if any */
+	skb_trim(skb, skb->len - (pre_he_pos + he_cap_size - pos));
 
 	ieee80211_ie_build_he_6ghz_cap(sdata, skb);
 }
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 2fe71ed9137b..be1911d8089f 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1959,7 +1959,7 @@ static int ieee80211_build_preq_ies_band(struct ieee80211_sub_if_data *sdata,
 	if (he_cap &&
 	    cfg80211_any_usable_channels(local->hw.wiphy, BIT(sband->band),
 					 IEEE80211_CHAN_NO_HE)) {
-		pos = ieee80211_ie_build_he_cap(pos, he_cap, end);
+		pos = ieee80211_ie_build_he_cap(0, pos, he_cap, end);
 		if (!pos)
 			goto out_err;
 	}
@@ -2903,10 +2903,11 @@ u8 ieee80211_ie_len_he_cap(struct ieee80211_sub_if_data *sdata, u8 iftype)
 				     he_cap->he_cap_elem.phy_cap_info);
 }
 
-u8 *ieee80211_ie_build_he_cap(u8 *pos,
+u8 *ieee80211_ie_build_he_cap(u32 disable_flags, u8 *pos,
 			      const struct ieee80211_sta_he_cap *he_cap,
 			      u8 *end)
 {
+	struct ieee80211_he_cap_elem elem;
 	u8 n;
 	u8 ie_len;
 	u8 *orig_pos = pos;
@@ -2919,7 +2920,23 @@ u8 *ieee80211_ie_build_he_cap(u8 *pos,
 	if (!he_cap)
 		return orig_pos;
 
-	n = ieee80211_he_mcs_nss_size(&he_cap->he_cap_elem);
+	/* modify on stack first to calculate 'n' and 'ie_len' correctly */
+	elem = he_cap->he_cap_elem;
+
+	if (disable_flags & IEEE80211_STA_DISABLE_40MHZ)
+		elem.phy_cap_info[0] &=
+			~(IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_40MHZ_80MHZ_IN_5G |
+			  IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_40MHZ_IN_2G);
+
+	if (disable_flags & IEEE80211_STA_DISABLE_160MHZ)
+		elem.phy_cap_info[0] &=
+			~IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_160MHZ_IN_5G;
+
+	if (disable_flags & IEEE80211_STA_DISABLE_80P80MHZ)
+		elem.phy_cap_info[0] &=
+			~IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_80PLUS80_MHZ_IN_5G;
+
+	n = ieee80211_he_mcs_nss_size(&elem);
 	ie_len = 2 + 1 +
 		 sizeof(he_cap->he_cap_elem) + n +
 		 ieee80211_he_ppe_size(he_cap->ppe_thres[0],
@@ -2933,8 +2950,8 @@ u8 *ieee80211_ie_build_he_cap(u8 *pos,
 	*pos++ = WLAN_EID_EXT_HE_CAPABILITY;
 
 	/* Fixed data */
-	memcpy(pos, &he_cap->he_cap_elem, sizeof(he_cap->he_cap_elem));
-	pos += sizeof(he_cap->he_cap_elem);
+	memcpy(pos, &elem, sizeof(elem));
+	pos += sizeof(elem);
 
 	memcpy(pos, &he_cap->he_mcs_nss_supp, n);
 	pos += n;