[PATCH v2] ath10k: rebuild crypto header in Rx data frames

Sebastian Gottschall s.gottschall at dd-wrt.com
Tue Oct 24 12:27:47 PDT 2017


will test it and report success (or not)

Am 24.10.2017 um 19:54 schrieb Kalle Valo:
> From: Vasanthakumar Thiagarajan <vthiagar at qti.qualcomm.com>
>
> Rx data frames notified through HTT_T2H_MSG_TYPE_RX_IND and
> HTT_T2H_MSG_TYPE_RX_FRAG_IND expect PN/TSC check to be done
> on host (mac80211) rather than firmware. Rebuild cipher header
> in every received data frames (that are notified through those
> HTT interfaces) from the rx_hdr_status tlv available in the
> rx descriptor of the first msdu. Skip setting RX_FLAG_IV_STRIPPED
> flag for the packets which requires mac80211 PN/TSC check support
> and set appropriate RX_FLAG for stripped crypto tail. Hw QCA988X,
> QCA9887, QCA99X0, QCA9984, QCA9888 and QCA4019 currently need the
> rebuilding of cipher header to perform PN/TSC check for replay
> attack.
>
> Tested-by: Manikanta Pubbisetty <mpubbise at qti.qualcomm.com>
> Signed-off-by: Vasanthakumar Thiagarajan <vthiagar at qti.qualcomm.com>
> Signed-off-by: Kalle Valo <kvalo at qca.qualcomm.com>
> ---
>
> v2:
>
> * Construct cipher header from rx_hdr_status tlv rather than from
>    the msdu_start and mpdu_start tlvs. This fixes connection
>    issues, also reduces the amount of code change.
>
> * Make sure the frame is qos data before clearing AMSDU_PRESENT
>    bit of qos control field.
>
> * Fix traffic issue with QCA988X and QCA9887 hw by taking care of
>    padding bytes added for 4-byte alignment before the cipher
>    header.
>
> TODO:
>
> * CCMP-256 and GCMP/GCMP-256 are not yet supported
>
>   drivers/net/wireless/ath/ath10k/htt_rx.c | 91 ++++++++++++++++++++++++++------
>   1 file changed, 74 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
> index a3f5dc78353f..aae4f0ea9360 100644
> --- a/drivers/net/wireless/ath/ath10k/htt_rx.c
> +++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
> @@ -1050,8 +1050,14 @@ static void ath10k_htt_rx_h_undecap_raw(struct ath10k *ar,
>   
>   	hdr = (void *)msdu->data;
>   
> -	/* Tail */
> -	if (status->flag & RX_FLAG_IV_STRIPPED)
> +	/* MIC */
> +	if ((status->flag & RX_FLAG_MIC_STRIPPED) &&
> +	    enctype == HTT_RX_MPDU_ENCRYPT_AES_CCM_WPA2)
> +		skb_trim(msdu, msdu->len - 8);
> +
> +	/* ICV */
> +	if (status->flag & RX_FLAG_ICV_STRIPPED &&
> +	    enctype != HTT_RX_MPDU_ENCRYPT_AES_CCM_WPA2)
>   		skb_trim(msdu, msdu->len -
>   			 ath10k_htt_rx_crypto_tail_len(ar, enctype));
>   
> @@ -1075,7 +1081,8 @@ static void ath10k_htt_rx_h_undecap_raw(struct ath10k *ar,
>   static void ath10k_htt_rx_h_undecap_nwifi(struct ath10k *ar,
>   					  struct sk_buff *msdu,
>   					  struct ieee80211_rx_status *status,
> -					  const u8 first_hdr[64])
> +					  const u8 first_hdr[64],
> +					  enum htt_rx_mpdu_encrypt_type enctype)
>   {
>   	struct ieee80211_hdr *hdr;
>   	struct htt_rx_desc *rxd;
> @@ -1083,6 +1090,7 @@ static void ath10k_htt_rx_h_undecap_nwifi(struct ath10k *ar,
>   	u8 da[ETH_ALEN];
>   	u8 sa[ETH_ALEN];
>   	int l3_pad_bytes;
> +	int bytes_aligned = ar->hw_params.decap_align_bytes;
>   
>   	/* Delivered decapped frame:
>   	 * [nwifi 802.11 header] <-- replaced with 802.11 hdr
> @@ -1111,6 +1119,14 @@ static void ath10k_htt_rx_h_undecap_nwifi(struct ath10k *ar,
>   	/* push original 802.11 header */
>   	hdr = (struct ieee80211_hdr *)first_hdr;
>   	hdr_len = ieee80211_hdrlen(hdr->frame_control);
> +
> +	if (!(status->flag & RX_FLAG_IV_STRIPPED)) {
> +		memcpy(skb_push(msdu,
> +				ath10k_htt_rx_crypto_param_len(ar, enctype)),
> +		       (void *)hdr + round_up(hdr_len, bytes_aligned),
> +			ath10k_htt_rx_crypto_param_len(ar, enctype));
> +	}
> +
>   	memcpy(skb_push(msdu, hdr_len), hdr, hdr_len);
>   
>   	/* original 802.11 header has a different DA and in
> @@ -1171,6 +1187,7 @@ static void ath10k_htt_rx_h_undecap_eth(struct ath10k *ar,
>   	u8 sa[ETH_ALEN];
>   	int l3_pad_bytes;
>   	struct htt_rx_desc *rxd;
> +	int bytes_aligned = ar->hw_params.decap_align_bytes;
>   
>   	/* Delivered decapped frame:
>   	 * [eth header] <-- replaced with 802.11 hdr & rfc1042/llc
> @@ -1199,6 +1216,14 @@ static void ath10k_htt_rx_h_undecap_eth(struct ath10k *ar,
>   	/* push original 802.11 header */
>   	hdr = (struct ieee80211_hdr *)first_hdr;
>   	hdr_len = ieee80211_hdrlen(hdr->frame_control);
> +
> +	if (!(status->flag & RX_FLAG_IV_STRIPPED)) {
> +		memcpy(skb_push(msdu,
> +				ath10k_htt_rx_crypto_param_len(ar, enctype)),
> +		       (void *)hdr + round_up(hdr_len, bytes_aligned),
> +			ath10k_htt_rx_crypto_param_len(ar, enctype));
> +	}
> +
>   	memcpy(skb_push(msdu, hdr_len), hdr, hdr_len);
>   
>   	/* original 802.11 header has a different DA and in
> @@ -1212,12 +1237,14 @@ static void ath10k_htt_rx_h_undecap_eth(struct ath10k *ar,
>   static void ath10k_htt_rx_h_undecap_snap(struct ath10k *ar,
>   					 struct sk_buff *msdu,
>   					 struct ieee80211_rx_status *status,
> -					 const u8 first_hdr[64])
> +					 const u8 first_hdr[64],
> +					 enum htt_rx_mpdu_encrypt_type enctype)
>   {
>   	struct ieee80211_hdr *hdr;
>   	size_t hdr_len;
>   	int l3_pad_bytes;
>   	struct htt_rx_desc *rxd;
> +	int bytes_aligned = ar->hw_params.decap_align_bytes;
>   
>   	/* Delivered decapped frame:
>   	 * [amsdu header] <-- replaced with 802.11 hdr
> @@ -1233,6 +1260,14 @@ static void ath10k_htt_rx_h_undecap_snap(struct ath10k *ar,
>   
>   	hdr = (struct ieee80211_hdr *)first_hdr;
>   	hdr_len = ieee80211_hdrlen(hdr->frame_control);
> +
> +	if (!(status->flag & RX_FLAG_IV_STRIPPED)) {
> +		memcpy(skb_push(msdu,
> +				ath10k_htt_rx_crypto_param_len(ar, enctype)),
> +		       (void *)hdr + round_up(hdr_len, bytes_aligned),
> +			ath10k_htt_rx_crypto_param_len(ar, enctype));
> +	}
> +
>   	memcpy(skb_push(msdu, hdr_len), hdr, hdr_len);
>   }
>   
> @@ -1267,13 +1302,15 @@ static void ath10k_htt_rx_h_undecap(struct ath10k *ar,
>   					    is_decrypted);
>   		break;
>   	case RX_MSDU_DECAP_NATIVE_WIFI:
> -		ath10k_htt_rx_h_undecap_nwifi(ar, msdu, status, first_hdr);
> +		ath10k_htt_rx_h_undecap_nwifi(ar, msdu, status, first_hdr,
> +					      enctype);
>   		break;
>   	case RX_MSDU_DECAP_ETHERNET2_DIX:
>   		ath10k_htt_rx_h_undecap_eth(ar, msdu, status, first_hdr, enctype);
>   		break;
>   	case RX_MSDU_DECAP_8023_SNAP_LLC:
> -		ath10k_htt_rx_h_undecap_snap(ar, msdu, status, first_hdr);
> +		ath10k_htt_rx_h_undecap_snap(ar, msdu, status, first_hdr,
> +					     enctype);
>   		break;
>   	}
>   }
> @@ -1316,7 +1353,8 @@ static void ath10k_htt_rx_h_csum_offload(struct sk_buff *msdu)
>   
>   static void ath10k_htt_rx_h_mpdu(struct ath10k *ar,
>   				 struct sk_buff_head *amsdu,
> -				 struct ieee80211_rx_status *status)
> +				 struct ieee80211_rx_status *status,
> +				 bool fill_crypt_header)
>   {
>   	struct sk_buff *first;
>   	struct sk_buff *last;
> @@ -1326,7 +1364,6 @@ static void ath10k_htt_rx_h_mpdu(struct ath10k *ar,
>   	enum htt_rx_mpdu_encrypt_type enctype;
>   	u8 first_hdr[64];
>   	u8 *qos;
> -	size_t hdr_len;
>   	bool has_fcs_err;
>   	bool has_crypto_err;
>   	bool has_tkip_err;
> @@ -1351,15 +1388,17 @@ static void ath10k_htt_rx_h_mpdu(struct ath10k *ar,
>   	 * decapped header. It'll be used for undecapping of each MSDU.
>   	 */
>   	hdr = (void *)rxd->rx_hdr_status;
> -	hdr_len = ieee80211_hdrlen(hdr->frame_control);
> -	memcpy(first_hdr, hdr, hdr_len);
> +	memcpy(first_hdr, hdr, RX_HTT_HDR_STATUS_LEN);
>   
>   	/* Each A-MSDU subframe will use the original header as the base and be
>   	 * reported as a separate MSDU so strip the A-MSDU bit from QoS Ctl.
>   	 */
>   	hdr = (void *)first_hdr;
> -	qos = ieee80211_get_qos_ctl(hdr);
> -	qos[0] &= ~IEEE80211_QOS_CTL_A_MSDU_PRESENT;
> +
> +	if (ieee80211_is_data_qos(hdr->frame_control)) {
> +		qos = ieee80211_get_qos_ctl(hdr);
> +		qos[0] &= ~IEEE80211_QOS_CTL_A_MSDU_PRESENT;
> +	}
>   
>   	/* Some attention flags are valid only in the last MSDU. */
>   	last = skb_peek_tail(amsdu);
> @@ -1406,9 +1445,14 @@ static void ath10k_htt_rx_h_mpdu(struct ath10k *ar,
>   		status->flag |= RX_FLAG_DECRYPTED;
>   
>   		if (likely(!is_mgmt))
> -			status->flag |= RX_FLAG_IV_STRIPPED |
> -					RX_FLAG_MMIC_STRIPPED;
> -}
> +			status->flag |= RX_FLAG_MMIC_STRIPPED;
> +
> +		if (fill_crypt_header)
> +			status->flag |= RX_FLAG_MIC_STRIPPED |
> +					RX_FLAG_ICV_STRIPPED;
> +		else
> +			status->flag |= RX_FLAG_IV_STRIPPED;
> +	}
>   
>   	skb_queue_walk(amsdu, msdu) {
>   		ath10k_htt_rx_h_csum_offload(msdu);
> @@ -1424,6 +1468,9 @@ static void ath10k_htt_rx_h_mpdu(struct ath10k *ar,
>   		if (is_mgmt)
>   			continue;
>   
> +		if (fill_crypt_header)
> +			continue;
> +
>   		hdr = (void *)msdu->data;
>   		hdr->frame_control &= ~__cpu_to_le16(IEEE80211_FCTL_PROTECTED);
>   	}
> @@ -1434,6 +1481,9 @@ static void ath10k_htt_rx_h_deliver(struct ath10k *ar,
>   				    struct ieee80211_rx_status *status)
>   {
>   	struct sk_buff *msdu;
> +	struct sk_buff *first_subframe;
> +
> +	first_subframe = skb_peek(amsdu);
>   
>   	while ((msdu = __skb_dequeue(amsdu))) {
>   		/* Setup per-MSDU flags */
> @@ -1442,6 +1492,13 @@ static void ath10k_htt_rx_h_deliver(struct ath10k *ar,
>   		else
>   			status->flag |= RX_FLAG_AMSDU_MORE;
>   
> +		if (msdu == first_subframe) {
> +			first_subframe = NULL;
> +			status->flag &= ~RX_FLAG_ALLOW_SAME_PN;
> +		} else {
> +			status->flag |= RX_FLAG_ALLOW_SAME_PN;
> +		}
> +
>   		ath10k_process_rx(ar, status, msdu);
>   	}
>   }
> @@ -1584,7 +1641,7 @@ static int ath10k_htt_rx_handle_amsdu(struct ath10k_htt *htt)
>   		ath10k_htt_rx_h_unchain(ar, &amsdu);
>   
>   	ath10k_htt_rx_h_filter(ar, &amsdu, rx_status);
> -	ath10k_htt_rx_h_mpdu(ar, &amsdu, rx_status);
> +	ath10k_htt_rx_h_mpdu(ar, &amsdu, rx_status, true);
>   	ath10k_htt_rx_h_deliver(ar, &amsdu, rx_status);
>   
>   	return num_msdus;
> @@ -1923,7 +1980,7 @@ static int ath10k_htt_rx_in_ord_ind(struct ath10k *ar, struct sk_buff *skb,
>   			budget_left -= skb_queue_len(&amsdu);
>   			ath10k_htt_rx_h_ppdu(ar, &amsdu, status, vdev_id);
>   			ath10k_htt_rx_h_filter(ar, &amsdu, status);
> -			ath10k_htt_rx_h_mpdu(ar, &amsdu, status);
> +			ath10k_htt_rx_h_mpdu(ar, &amsdu, status, false);
>   			ath10k_htt_rx_h_deliver(ar, &amsdu, status);
>   			break;
>   		case -EAGAIN:


-- 
Mit freundlichen Grüssen / Regards

Sebastian Gottschall / CTO

NewMedia-NET GmbH - DD-WRT
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email: s.gottschall at dd-wrt.com
Tel.: +496251-582650 / Fax: +496251-5826565




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