Commit 23405236 authored by Felix Fietkau's avatar Felix Fietkau Committed by Kalle Valo
Browse files

mt76: fix transmission of encrypted management frames 



Hardware encryption seems to break encrypted unicast mgmt tx.
Unfortunately the hardware TXWI header does not have a bit to indicate
that a frame is software encrypted, so sw-encrypted frames need to use a
different WCID. For that to work, the CCMP PN needs to be generated in
software, which makes things a bit slower, so only do it for keys that
also need to tx management frames.

Signed-off-by: default avatarFelix Fietkau <nbd@nbd.name>
Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
parent 1cbbf69c

drivers/net/wireless/mediatek/mt76/mt76.h

+1 −0
Original line number Diff line number Diff line
@@ -129,6 +129,7 @@ struct mt76_wcid { 
	bool tx_rate_set;

	u8 tx_rate_nss;

	s8 max_txpwr_adj;

	bool sw_iv;

};



struct mt76_txq {

drivers/net/wireless/mediatek/mt76/mt76x2_mac.c

+16 −0
Original line number Diff line number Diff line
@@ -171,10 +171,12 @@ void mt76x2_mac_write_txwi(struct mt76x2_dev *dev, struct mt76x2_txwi *txwi, 
{

	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);

	struct ieee80211_tx_rate *rate = &info->control.rates[0];

	struct ieee80211_key_conf *key = info->control.hw_key;

	u16 rate_ht_mask = FIELD_PREP(MT_RXWI_RATE_PHY, BIT(1) | BIT(2));

	u16 txwi_flags = 0;

	u8 nss;

	s8 txpwr_adj, max_txpwr_adj;

	u8 ccmp_pn[8];



	memset(txwi, 0, sizeof(*txwi));
@@ -185,6 +187,20 @@ void mt76x2_mac_write_txwi(struct mt76x2_dev *dev, struct mt76x2_txwi *txwi, 


	txwi->pktid = 1;



	if (wcid && wcid->sw_iv && key) {

		u64 pn = atomic64_inc_return(&key->tx_pn);

		ccmp_pn[0] = pn;

		ccmp_pn[1] = pn >> 8;

		ccmp_pn[2] = 0;

		ccmp_pn[3] = 0x20 | (key->keyidx << 6);

		ccmp_pn[4] = pn >> 16;

		ccmp_pn[5] = pn >> 24;

		ccmp_pn[6] = pn >> 32;

		ccmp_pn[7] = pn >> 40;

		txwi->iv = *((u32 *) &ccmp_pn[0]);

		txwi->eiv = *((u32 *) &ccmp_pn[1]);

	}



	spin_lock_bh(&dev->mt76.lock);

	if (wcid && (rate->idx < 0 || !rate->count)) {

		txwi->rate = wcid->tx_rate;

drivers/net/wireless/mediatek/mt76/mt76x2_main.c

+7 −1
Original line number Diff line number Diff line
@@ -355,9 +355,15 @@ mt76x2_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd, 
	if (cmd == SET_KEY) {

		key->hw_key_idx = wcid->idx;

		wcid->hw_key_idx = idx;

		if (key->flags & IEEE80211_KEY_FLAG_RX_MGMT) {

			key->flags |= IEEE80211_KEY_FLAG_SW_MGMT_TX;

			wcid->sw_iv = true;

		}

	} else {

		if (idx == wcid->hw_key_idx)

		if (idx == wcid->hw_key_idx) {

			wcid->hw_key_idx = -1;

			wcid->sw_iv = true;

		}



		key = NULL;

	}

drivers/net/wireless/mediatek/mt76/mt76x2_tx.c

+4 −2
Original line number Diff line number Diff line
@@ -36,7 +36,9 @@ void mt76x2_tx(struct ieee80211_hw *hw, struct ieee80211_tx_control *control, 


		msta = (struct mt76x2_sta *) control->sta->drv_priv;

		wcid = &msta->wcid;

	} else if (vif) {

	}



	if (vif || (!info->control.hw_key && wcid->hw_key_idx != -1)) {

		struct mt76x2_vif *mvif;



		mvif = (struct mt76x2_vif *) vif->drv_priv;
@@ -166,7 +168,7 @@ int mt76x2_tx_prepare_skb(struct mt76_dev *mdev, void *txwi, 
	*tx_info = FIELD_PREP(MT_TXD_INFO_QSEL, qsel) |

		   MT_TXD_INFO_80211;



	if (!wcid || wcid->hw_key_idx == 0xff)

	if (!wcid || wcid->hw_key_idx == 0xff || wcid->sw_iv)

		*tx_info |= MT_TXD_INFO_WIV;



	return 0;

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