mac80211: restrict peer's VHT capabilities to own

Implement restricting peer VHT capabilities to the device's own
capabilities. This is useful when a single driver supports more
than one device and the devices have different capabilities
(often they will differ in the number of spatial streams), but
in particular is also necessary for VHT capability overrides to
work correctly -- otherwise it'd be possible to e.g. advertise,
due to overrides, that TX-STBC is not supported, but then still
use it to TX to the AP because it supports RX-STBC.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 113 insertions, 1 deletions

diff --git a/net/mac80211/vht.c b/net/mac80211/vht.c
index cacc1c74556a..171344d4eb7c 100644
--- a/net/mac80211/vht.c
+++ b/net/mac80211/vht.c
@@ -118,6 +118,8 @@ ieee80211_vht_cap_ie_to_sta_vht_cap(struct ieee80211_sub_if_data *sdata,
 				    struct sta_info *sta)
 {
 	struct ieee80211_sta_vht_cap *vht_cap = &sta->sta.vht_cap;
+	struct ieee80211_sta_vht_cap own_cap;
+	u32 cap_info, i;
 
 	memset(vht_cap, 0, sizeof(*vht_cap));
 
@@ -133,12 +135,122 @@ ieee80211_vht_cap_ie_to_sta_vht_cap(struct ieee80211_sub_if_data *sdata,
 
 	vht_cap->vht_supported = true;
 
-	vht_cap->cap = le32_to_cpu(vht_cap_ie->vht_cap_info);
+	own_cap = sband->vht_cap;
+	/*
+	 * If user has specified capability overrides, take care
+	 * of that if the station we're setting up is the AP that
+	 * we advertised a restricted capability set to. Override
+	 * our own capabilities and then use those below.
+	 */
+	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
+	    !test_sta_flag(sta, WLAN_STA_TDLS_PEER))
+		ieee80211_apply_vhtcap_overrides(sdata, &own_cap);
+
+	/* take some capabilities as-is */
+	cap_info = le32_to_cpu(vht_cap_ie->vht_cap_info);
+	vht_cap->cap = cap_info;
+	vht_cap->cap &= IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_3895 |
+			IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_7991 |
+			IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_11454 |
+			IEEE80211_VHT_CAP_RXLDPC |
+			IEEE80211_VHT_CAP_VHT_TXOP_PS |
+			IEEE80211_VHT_CAP_HTC_VHT |
+			IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK |
+			IEEE80211_VHT_CAP_VHT_LINK_ADAPTATION_VHT_UNSOL_MFB |
+			IEEE80211_VHT_CAP_VHT_LINK_ADAPTATION_VHT_MRQ_MFB |
+			IEEE80211_VHT_CAP_RX_ANTENNA_PATTERN |
+			IEEE80211_VHT_CAP_TX_ANTENNA_PATTERN;
+
+	/* and some based on our own capabilities */
+	switch (own_cap.cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK) {
+	case IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ:
+		vht_cap->cap |= cap_info &
+				IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ;
+		break;
+	case IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ:
+		vht_cap->cap |= cap_info &
+				IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
+		break;
+	default:
+		/* nothing */
+		break;
+	}
+
+	/* symmetric capabilities */
+	vht_cap->cap |= cap_info & own_cap.cap &
+			(IEEE80211_VHT_CAP_SHORT_GI_80 |
+			 IEEE80211_VHT_CAP_SHORT_GI_160);
+
+	/* remaining ones */
+	if (own_cap.cap & IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE) {
+		vht_cap->cap |= cap_info &
+				(IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE |
+				 IEEE80211_VHT_CAP_BEAMFORMER_ANTENNAS_MAX |
+				 IEEE80211_VHT_CAP_SOUNDING_DIMENSIONS_MAX);
+	}
+
+	if (own_cap.cap & IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE)
+		vht_cap->cap |= cap_info &
+				IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE;
+
+	if (own_cap.cap & IEEE80211_VHT_CAP_MU_BEAMFORMER_CAPABLE)
+		vht_cap->cap |= cap_info &
+				IEEE80211_VHT_CAP_MU_BEAMFORMEE_CAPABLE;
+
+	if (own_cap.cap & IEEE80211_VHT_CAP_MU_BEAMFORMEE_CAPABLE)
+		vht_cap->cap |= cap_info &
+				IEEE80211_VHT_CAP_MU_BEAMFORMER_CAPABLE;
+
+	if (own_cap.cap & IEEE80211_VHT_CAP_TXSTBC)
+		vht_cap->cap |= cap_info & IEEE80211_VHT_CAP_RXSTBC_MASK;
+
+	if (own_cap.cap & IEEE80211_VHT_CAP_RXSTBC_MASK)
+		vht_cap->cap |= cap_info & IEEE80211_VHT_CAP_TXSTBC;
 
 	/* Copy peer MCS info, the driver might need them. */
 	memcpy(&vht_cap->vht_mcs, &vht_cap_ie->supp_mcs,
 	       sizeof(struct ieee80211_vht_mcs_info));
 
+	/* but also restrict MCSes */
+	for (i = 0; i < 8; i++) {
+		u16 own_rx, own_tx, peer_rx, peer_tx;
+
+		own_rx = le16_to_cpu(own_cap.vht_mcs.rx_mcs_map);
+		own_rx = (own_rx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
+
+		own_tx = le16_to_cpu(own_cap.vht_mcs.tx_mcs_map);
+		own_tx = (own_tx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
+
+		peer_rx = le16_to_cpu(vht_cap->vht_mcs.rx_mcs_map);
+		peer_rx = (peer_rx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
+
+		peer_tx = le16_to_cpu(vht_cap->vht_mcs.tx_mcs_map);
+		peer_tx = (peer_tx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
+
+		if (peer_tx != IEEE80211_VHT_MCS_NOT_SUPPORTED) {
+			if (own_rx == IEEE80211_VHT_MCS_NOT_SUPPORTED)
+				peer_tx = IEEE80211_VHT_MCS_NOT_SUPPORTED;
+			else if (own_rx < peer_tx)
+				peer_tx = own_rx;
+		}
+
+		if (peer_rx != IEEE80211_VHT_MCS_NOT_SUPPORTED) {
+			if (own_tx == IEEE80211_VHT_MCS_NOT_SUPPORTED)
+				peer_rx = IEEE80211_VHT_MCS_NOT_SUPPORTED;
+			else if (own_tx < peer_rx)
+				peer_rx = own_tx;
+		}
+
+		vht_cap->vht_mcs.rx_mcs_map &=
+			~cpu_to_le16(IEEE80211_VHT_MCS_NOT_SUPPORTED << i * 2);
+		vht_cap->vht_mcs.rx_mcs_map |= cpu_to_le16(peer_rx << i * 2);
+
+		vht_cap->vht_mcs.tx_mcs_map &=
+			~cpu_to_le16(IEEE80211_VHT_MCS_NOT_SUPPORTED << i * 2);
+		vht_cap->vht_mcs.tx_mcs_map |= cpu_to_le16(peer_tx << i * 2);
+	}
+
+	/* finally set up the bandwidth */
 	switch (vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK) {
 	case IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ:
 	case IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ: