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Message-ID: <5b3af47c-7efb-4ca3-93bd-06c682dfc84f@linutronix.de>
Date: Mon, 15 Apr 2024 08:49:27 +0200
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MIME-Version: 1.0
Subject: Re: [PATCH] wifi: rtl8xxxu: enable MFP support
To: Bitterblue Smith <rtl8821cerfe2@gmail.com>, linux-wireless@vger.kernel.org
Cc: Jes Sorensen <Jes.Sorensen@gmail.com>, Kalle Valo <kvalo@kernel.org>,
 Ping-Ke Shih <pkshih@realtek.com>,
 Sebastian Andrzej Siewior <bigeasy@linutronix.de>
References: <20240314164850.86432-1-martin.kaistra@linutronix.de>
 <fa903f58-2362-49a1-9880-2b3fcbe1869e@gmail.com>
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From: Martin Kaistra <martin.kaistra@linutronix.de>
In-Reply-To: <fa903f58-2362-49a1-9880-2b3fcbe1869e@gmail.com>
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Am 14.04.24 um 13:32 schrieb Bitterblue Smith:
> On 14/03/2024 18:48, Martin Kaistra wrote:
>> In order to connect to networks which require 802.11w, add the
>> MFP_CAPABLE flag and let mac80211 do the actual crypto in software.
>>
>> When a robust management frames is received, rx_dec->swdec is not set,
>> even though the HW did not decrypt it. Extend the check and don't set
>> RX_FLAG_DECRYPTED for these frames in order to use SW decryption.
>>
>> Signed-off-by: Martin Kaistra <martin.kaistra@linutronix.de>
>> ---
>>   drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 9 +++++++--
>>   1 file changed, 7 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>> index 4a49f8f9d80f2..870bd952f5902 100644
>> --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>> +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>> @@ -6473,7 +6473,9 @@ int rtl8xxxu_parse_rxdesc16(struct rtl8xxxu_priv *priv, struct sk_buff *skb)
>>   			rx_status->mactime = rx_desc->tsfl;
>>   			rx_status->flag |= RX_FLAG_MACTIME_START;
>>   
>> -			if (!rx_desc->swdec)
>> +			if (!rx_desc->swdec &&
>> +			    !(_ieee80211_is_robust_mgmt_frame(hdr) &&
>> +			      ieee80211_has_protected(hdr->frame_control)))
>>   				rx_status->flag |= RX_FLAG_DECRYPTED;
>>   			if (rx_desc->crc32)
>>   				rx_status->flag |= RX_FLAG_FAILED_FCS_CRC;
>> @@ -6578,7 +6580,9 @@ int rtl8xxxu_parse_rxdesc24(struct rtl8xxxu_priv *priv, struct sk_buff *skb)
>>   			rx_status->mactime = rx_desc->tsfl;
>>   			rx_status->flag |= RX_FLAG_MACTIME_START;
>>   
>> -			if (!rx_desc->swdec)
>> +			if (!rx_desc->swdec &&
>> +			    !(_ieee80211_is_robust_mgmt_frame(hdr) &&
>> +			      ieee80211_has_protected(hdr->frame_control)))
>>   				rx_status->flag |= RX_FLAG_DECRYPTED;
>>   			if (rx_desc->crc32)
>>   				rx_status->flag |= RX_FLAG_FAILED_FCS_CRC;
>> @@ -7998,6 +8002,7 @@ static int rtl8xxxu_probe(struct usb_interface *interface,
>>   	ieee80211_hw_set(hw, HAS_RATE_CONTROL);
>>   	ieee80211_hw_set(hw, SUPPORT_FAST_XMIT);
>>   	ieee80211_hw_set(hw, AMPDU_AGGREGATION);
>> +	ieee80211_hw_set(hw, MFP_CAPABLE);
>>   
>>   	wiphy_ext_feature_set(hw->wiphy, NL80211_EXT_FEATURE_CQM_RSSI_LIST);
>>   
> 
> I ran into this problem recently with rtl8192du:
> https://lore.kernel.org/linux-wireless/ed12ec17-ae6e-45fa-a72f-23e0a34654da@gmail.com/
> 
> Does the same fix work for you in rtl8xxxu? Checking the "security"
> field of the RX descriptor is simpler than calling two functions.
> Sorry to bother you when the patch is already applied.

Thanks for the hint. I tried to do something similar to what has been done in 
other rtlwifi drivers and missed the solution in rtw88, which is probably better:

rtlwifi/rtl8188ee/trx.c
rtlwifi/rtl8192ce/trx.c
rtlwifi/rtl8192ee/trx.c
rtlwifi/rtl8192se/trx.c
rtlwifi/rtl8723ae/trx.c
rtlwifi/rtl8723be/trx.c
rtlwifi/rtl8821ae/trx.c

Shouldn't it be changed in these locations as well?

I will do a test for rtl8xxxu and if it is successful send a new patch.

> 
> Also, won't you send the patch to the stable tree?

The rtl8xxxu driver previously did not have the MFP_CAPABLE flag set. As I am 
adding new functionality (support for WPA3), I don't think this should go to stable.