[PATCH v3] ath10k: rebuild crypto header in rx data frames

Kalle Valo kvalo at qca.qualcomm.com
Thu Oct 26 09:36:14 PDT 2017


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.

Please note that removing crypto tail for CCMP-256, GCMP and GCMP-256 ciphers
in raw mode needs to be fixed. Since Rx with these ciphers in raw
mode does not work in the current form even without this patch and
removing crypto tail for these chipers needs clean up, raw mode related
issues in CCMP-256, GCMP and GCMP-256 can be addressed in follow up
patches.

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>
---

v3:

* Fix cipher header construction for CCMP-256, GCMP and GCMP-256
  ciphers.

* Fix bug in raw mode when RX_FLAG_IV_STRIPPED is set.

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.

 drivers/net/wireless/ath/ath10k/htt_rx.c  | 105 +++++++++++++++++++++++++-----
 drivers/net/wireless/ath/ath10k/rx_desc.h |   3 +
 2 files changed, 92 insertions(+), 16 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index a3f5dc78353f..5beb6ee0f091 100644
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -550,6 +550,11 @@ static int ath10k_htt_rx_crypto_param_len(struct ath10k *ar,
 		return IEEE80211_TKIP_IV_LEN;
 	case HTT_RX_MPDU_ENCRYPT_AES_CCM_WPA2:
 		return IEEE80211_CCMP_HDR_LEN;
+	case HTT_RX_MPDU_ENCRYPT_AES_CCM256_WPA2:
+		return IEEE80211_CCMP_256_HDR_LEN;
+	case HTT_RX_MPDU_ENCRYPT_AES_GCMP_WPA2:
+	case HTT_RX_MPDU_ENCRYPT_AES_GCMP256_WPA2:
+		return IEEE80211_GCMP_HDR_LEN;
 	case HTT_RX_MPDU_ENCRYPT_WEP128:
 	case HTT_RX_MPDU_ENCRYPT_WAPI:
 		break;
@@ -575,6 +580,11 @@ static int ath10k_htt_rx_crypto_tail_len(struct ath10k *ar,
 		return IEEE80211_TKIP_ICV_LEN;
 	case HTT_RX_MPDU_ENCRYPT_AES_CCM_WPA2:
 		return IEEE80211_CCMP_MIC_LEN;
+	case HTT_RX_MPDU_ENCRYPT_AES_CCM256_WPA2:
+		return IEEE80211_CCMP_256_MIC_LEN;
+	case HTT_RX_MPDU_ENCRYPT_AES_GCMP_WPA2:
+	case HTT_RX_MPDU_ENCRYPT_AES_GCMP256_WPA2:
+		return IEEE80211_GCMP_MIC_LEN;
 	case HTT_RX_MPDU_ENCRYPT_WEP128:
 	case HTT_RX_MPDU_ENCRYPT_WAPI:
 		break;
@@ -1051,9 +1061,21 @@ static void ath10k_htt_rx_h_undecap_raw(struct ath10k *ar,
 	hdr = (void *)msdu->data;
 
 	/* Tail */
-	if (status->flag & RX_FLAG_IV_STRIPPED)
+	if (status->flag & RX_FLAG_IV_STRIPPED) {
 		skb_trim(msdu, msdu->len -
 			 ath10k_htt_rx_crypto_tail_len(ar, enctype));
+	} else {
+		/* 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));
+	}
 
 	/* MMIC */
 	if ((status->flag & RX_FLAG_MMIC_STRIPPED) &&
@@ -1075,7 +1097,8 @@ 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 +1106,7 @@ 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 +1135,14 @@ 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 +1203,7 @@ 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 +1232,14 @@ 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 +1253,14 @@ 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 +1276,14 @@ 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 +1318,15 @@ 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 +1369,8 @@ 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 +1380,6 @@ 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 +1404,17 @@ 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 +1461,14 @@ 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 +1484,9 @@ 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 +1497,9 @@ 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 +1508,13 @@ 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 +1657,7 @@ 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 +1996,7 @@ 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:
diff --git a/drivers/net/wireless/ath/ath10k/rx_desc.h b/drivers/net/wireless/ath/ath10k/rx_desc.h
index c1022a1cf855..28da14398951 100644
--- a/drivers/net/wireless/ath/ath10k/rx_desc.h
+++ b/drivers/net/wireless/ath/ath10k/rx_desc.h
@@ -239,6 +239,9 @@ enum htt_rx_mpdu_encrypt_type {
 	HTT_RX_MPDU_ENCRYPT_WAPI             = 5,
 	HTT_RX_MPDU_ENCRYPT_AES_CCM_WPA2     = 6,
 	HTT_RX_MPDU_ENCRYPT_NONE             = 7,
+	HTT_RX_MPDU_ENCRYPT_AES_CCM256_WPA2  = 8,
+	HTT_RX_MPDU_ENCRYPT_AES_GCMP_WPA2    = 9,
+	HTT_RX_MPDU_ENCRYPT_AES_GCMP256_WPA2 = 10,
 };
 
 #define RX_MPDU_START_INFO0_PEER_IDX_MASK     0x000007ff
-- 
2.7.4




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