ath11k: enable PN offload

Enabling PN checking in the hardware; hardware checks
the PN of the received packets and reports the errors
to the host for further handling; default action is to
drop such packets. TSC (TKIP sequence counter)
validation is also offloaded.

Hardware validates PN/TSC only for unicast packets;
for group addressed packets, PN validation is done
in mac80211.

PN errors are reported to the driver via WBM RX release
ring and can be dumped by using the following command.

"cat /sys/kernel/debug/ath11k/soc_rx_stats | grep -i pn"

Sample Output:
PN check fail: 210

Signed-off-by: Manikanta Pubbisetty <mpubbise@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

1 files changed, 106 insertions, 9 deletions

diff --git a/drivers/net/wireless/ath/ath11k/dp_rx.c b/drivers/net/wireless/ath/ath11k/dp_rx.c
index 9871f2d18ad3..320fec2aede3 100644
--- a/drivers/net/wireless/ath/ath11k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath11k/dp_rx.c
@@ -843,7 +843,8 @@ unlock_exit:
 }
 
 int ath11k_peer_rx_tid_setup(struct ath11k *ar, const u8 *peer_mac, int vdev_id,
-			     u8 tid, u32 ba_win_sz, u16 ssn)
+			     u8 tid, u32 ba_win_sz, u16 ssn,
+			     enum hal_pn_type pn_type)
 {
 	struct ath11k_base *ab = ar->ab;
 	struct ath11k_peer *peer;
@@ -904,7 +905,8 @@ int ath11k_peer_rx_tid_setup(struct ath11k *ar, const u8 *peer_mac, int vdev_id,
 
 	addr_aligned = PTR_ALIGN(vaddr, HAL_LINK_DESC_ALIGN);
 
-	ath11k_hal_reo_qdesc_setup(addr_aligned, tid, ba_win_sz, ssn);
+	ath11k_hal_reo_qdesc_setup(addr_aligned, tid, ba_win_sz,
+				   ssn, pn_type);
 
 	paddr = dma_map_single(ab->dev, addr_aligned, hw_desc_sz,
 			       DMA_BIDIRECTIONAL);
@@ -948,7 +950,7 @@ int ath11k_dp_rx_ampdu_start(struct ath11k *ar,
 
 	ret = ath11k_peer_rx_tid_setup(ar, params->sta->addr, vdev_id,
 				       params->tid, params->buf_size,
-				       params->ssn);
+				       params->ssn, arsta->pn_type);
 	if (ret)
 		ath11k_warn(ab, "failed to setup rx tid %d\n", ret);
 
@@ -1001,8 +1003,80 @@ int ath11k_dp_rx_ampdu_stop(struct ath11k *ar,
 	return ret;
 }
 
-static int ath11k_get_ppdu_user_index(struct htt_ppdu_stats *ppdu_stats,
-				      u16 peer_id)
+int ath11k_dp_peer_rx_pn_replay_config(struct ath11k_vif *arvif,
+				       const u8 *peer_addr,
+				       enum set_key_cmd key_cmd,
+				       struct ieee80211_key_conf *key)
+{
+	struct ath11k *ar = arvif->ar;
+	struct ath11k_base *ab = ar->ab;
+	struct ath11k_hal_reo_cmd cmd = {0};
+	struct ath11k_peer *peer;
+	struct dp_rx_tid *rx_tid;
+	u8 tid;
+	int ret = 0;
+
+	/* NOTE: Enable PN/TSC replay check offload only for unicast frames.
+	 * We use mac80211 PN/TSC replay check functionality for bcast/mcast
+	 * for now.
+	 */
+	if (!(key->flags & IEEE80211_KEY_FLAG_PAIRWISE))
+		return 0;
+
+	cmd.flag |= HAL_REO_CMD_FLG_NEED_STATUS;
+	cmd.upd0 |= HAL_REO_CMD_UPD0_PN |
+		    HAL_REO_CMD_UPD0_PN_SIZE |
+		    HAL_REO_CMD_UPD0_PN_VALID |
+		    HAL_REO_CMD_UPD0_PN_CHECK |
+		    HAL_REO_CMD_UPD0_SVLD;
+
+	switch (key->cipher) {
+	case WLAN_CIPHER_SUITE_TKIP:
+	case WLAN_CIPHER_SUITE_CCMP:
+	case WLAN_CIPHER_SUITE_CCMP_256:
+	case WLAN_CIPHER_SUITE_GCMP:
+	case WLAN_CIPHER_SUITE_GCMP_256:
+		if (key_cmd == SET_KEY) {
+			cmd.upd1 |= HAL_REO_CMD_UPD1_PN_CHECK;
+			cmd.pn_size = 48;
+		}
+		break;
+	default:
+		break;
+	}
+
+	spin_lock_bh(&ab->base_lock);
+
+	peer = ath11k_peer_find(ab, arvif->vdev_id, peer_addr);
+	if (!peer) {
+		ath11k_warn(ab, "failed to find the peer to configure pn replay detection\n");
+		spin_unlock_bh(&ab->base_lock);
+		return -ENOENT;
+	}
+
+	for (tid = 0; tid <= IEEE80211_NUM_TIDS; tid++) {
+		rx_tid = &peer->rx_tid[tid];
+		if (!rx_tid->active)
+			continue;
+		cmd.addr_lo = lower_32_bits(rx_tid->paddr);
+		cmd.addr_hi = upper_32_bits(rx_tid->paddr);
+		ret = ath11k_dp_tx_send_reo_cmd(ab, rx_tid,
+						HAL_REO_CMD_UPDATE_RX_QUEUE,
+						&cmd, NULL);
+		if (ret) {
+			ath11k_warn(ab, "failed to configure rx tid %d queue for pn replay detection %d\n",
+				    tid, ret);
+			break;
+		}
+	}
+
+	spin_unlock_bh(&ar->ab->base_lock);
+
+	return ret;
+}
+
+static inline int ath11k_get_ppdu_user_index(struct htt_ppdu_stats *ppdu_stats,
+					     u16 peer_id)
 {
 	int i;
 
@@ -1974,7 +2048,7 @@ static void ath11k_dp_rx_h_mpdu(struct ath11k *ar,
 	struct sk_buff *last_msdu;
 	struct sk_buff *msdu;
 	struct ath11k_skb_rxcb *last_rxcb;
-	bool is_decrypted;
+	bool is_decrypted = false, fill_crypto_hdr;
 	u32 err_bitmap;
 	u8 *qos;
 
@@ -1991,6 +2065,9 @@ static void ath11k_dp_rx_h_mpdu(struct ath11k *ar,
 		qos[0] &= ~IEEE80211_QOS_CTL_A_MSDU_PRESENT;
 	}
 
+	/* PN for multicast packets will be checked in mac80211 */
+	fill_crypto_hdr = is_multicast_ether_addr(hdr->addr1);
+
 	is_decrypted = ath11k_dp_rx_h_attn_is_decrypted(rx_desc);
 	enctype = ath11k_dp_rx_h_mpdu_start_enctype(rx_desc);
 
@@ -2013,14 +2090,27 @@ static void ath11k_dp_rx_h_mpdu(struct ath11k *ar,
 	if (err_bitmap & DP_RX_MPDU_ERR_TKIP_MIC)
 		rx_status->flag |= RX_FLAG_MMIC_ERROR;
 
-	if (is_decrypted)
-		rx_status->flag |= RX_FLAG_DECRYPTED | RX_FLAG_MMIC_STRIPPED |
-				   RX_FLAG_MIC_STRIPPED | RX_FLAG_ICV_STRIPPED;
+	if (is_decrypted) {
+		rx_status->flag |= RX_FLAG_DECRYPTED | RX_FLAG_MMIC_STRIPPED;
+
+		if (fill_crypto_hdr)
+			rx_status->flag |= RX_FLAG_MIC_STRIPPED |
+					RX_FLAG_ICV_STRIPPED;
+		else
+			rx_status->flag |= RX_FLAG_IV_STRIPPED |
+					   RX_FLAG_PN_VALIDATED;
+	}
 
 	skb_queue_walk(amsdu_list, msdu) {
 		ath11k_dp_rx_h_csum_offload(msdu);
 		ath11k_dp_rx_h_undecap(ar, msdu, rx_desc,
 				       enctype, rx_status, is_decrypted);
+
+		if (!is_decrypted || fill_crypto_hdr)
+			continue;
+
+		hdr = (void *)msdu->data;
+		hdr->frame_control &= ~__cpu_to_le16(IEEE80211_FCTL_PROTECTED);
 	}
 }
 
@@ -3603,6 +3693,13 @@ static bool ath11k_dp_rx_h_reo_err(struct ath11k *ar, struct sk_buff *msdu,
 		if (ath11k_dp_rx_h_null_q_desc(ar, msdu, status, msdu_list))
 			drop = true;
 		break;
+	case HAL_REO_DEST_RING_ERROR_CODE_PN_CHECK_FAILED:
+		/* TODO: Do not drop PN failed packets in the driver;
+		 * instead, it is good to drop such packets in mac80211
+		 * after incrementing the replay counters.
+		 */
+
+		/* fall through */
 	default:
 		/* TODO: Review other errors and process them to mac80211
 		 * as appropriate.