ath11k: support GTK rekey offload

Host sets GTK related info to firmware before WoW is enabled, and
gets rekey replay_count and then disables GTK rekey when WoW quits.

Tested-on: QCA6390 hw2.0 PCI WLAN.HST.1.0.1-01740-QCAHSTSWPLZ_V2_TO_X86-1
Signed-off-by: Carl Huang <quic_cjhuang@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/1644308006-22784-7-git-send-email-quic_cjhuang@quicinc.com

drivers/net/wireless/ath/ath11k/core.h

@@ -230,6 +230,13 @@ struct ath11k_arp_ns_offload {
 	u8  mac_addr[ETH_ALEN];
 };
 
+struct ath11k_rekey_data {
+	u8 kck[NL80211_KCK_LEN];
+	u8 kek[NL80211_KCK_LEN];
+	u64 replay_ctr;
+	bool enable_offload;
+};
+
 struct ath11k_vif {
 	u32 vdev_id;
 	enum wmi_vdev_type vdev_type;
@@ -282,6 +289,7 @@ struct ath11k_vif {
 	bool do_not_send_tmpl;
 	struct ieee80211_chanctx_conf chanctx;
 	struct ath11k_arp_ns_offload arp_ns_offload;
+	struct ath11k_rekey_data rekey_data;
 
 #ifdef CONFIG_ATH11K_DEBUGFS
 	struct dentry *debugfs_twt;

drivers/net/wireless/ath/ath11k/mac.c

@@ -2757,6 +2757,7 @@ static void ath11k_bss_assoc(struct ieee80211_hw *hw,
 	}
 
 	arvif->is_up = true;
+	arvif->rekey_data.enable_offload = false;
 
 	ath11k_dbg(ar->ab, ATH11K_DBG_MAC,
 		   "mac vdev %d up (associated) bssid %pM aid %d\n",
@@ -2814,6 +2815,8 @@ static void ath11k_bss_disassoc(struct ieee80211_hw *hw,
 
 	arvif->is_up = false;
 
+	memset(&arvif->rekey_data, 0, sizeof(arvif->rekey_data));
+
 	cancel_delayed_work_sync(&arvif->connection_loss_work);
 }
 
@@ -8200,6 +8203,39 @@ static void ath11k_mac_op_ipv6_changed(struct ieee80211_hw *hw,
 	ath11k_generate_ns_mc_addr(ar, offload);
 }
 
+static void ath11k_mac_op_set_rekey_data(struct ieee80211_hw *hw,
+					 struct ieee80211_vif *vif,
+					 struct cfg80211_gtk_rekey_data *data)
+{
+	struct ath11k *ar = hw->priv;
+	struct ath11k_vif *arvif = ath11k_vif_to_arvif(vif);
+	struct ath11k_rekey_data *rekey_data = &arvif->rekey_data;
+
+	ath11k_dbg(ar->ab, ATH11K_DBG_MAC, "mac set rekey data vdev %d\n",
+		   arvif->vdev_id);
+
+	mutex_lock(&ar->conf_mutex);
+
+	memcpy(rekey_data->kck, data->kck, NL80211_KCK_LEN);
+	memcpy(rekey_data->kek, data->kek, NL80211_KEK_LEN);
+
+	/* The supplicant works on big-endian, the firmware expects it on
+	 * little endian.
+	 */
+	rekey_data->replay_ctr = get_unaligned_be64(data->replay_ctr);
+
+	arvif->rekey_data.enable_offload = true;
+
+	ath11k_dbg_dump(ar->ab, ATH11K_DBG_MAC, "kck", NULL,
+			rekey_data->kck, NL80211_KCK_LEN);
+	ath11k_dbg_dump(ar->ab, ATH11K_DBG_MAC, "kek", NULL,
+			rekey_data->kck, NL80211_KEK_LEN);
+	ath11k_dbg_dump(ar->ab, ATH11K_DBG_MAC, "replay ctr", NULL,
+			&rekey_data->replay_ctr, sizeof(rekey_data->replay_ctr));
+
+	mutex_unlock(&ar->conf_mutex);
+}
+
 static const struct ieee80211_ops ath11k_ops = {
 	.tx				= ath11k_mac_op_tx,
 	.start                          = ath11k_mac_op_start,
@@ -8214,6 +8250,7 @@ static const struct ieee80211_ops ath11k_ops = {
 	.hw_scan                        = ath11k_mac_op_hw_scan,
 	.cancel_hw_scan                 = ath11k_mac_op_cancel_hw_scan,
 	.set_key                        = ath11k_mac_op_set_key,
+	.set_rekey_data	                = ath11k_mac_op_set_rekey_data,
 	.sta_state                      = ath11k_mac_op_sta_state,
 	.sta_set_4addr                  = ath11k_mac_op_sta_set_4addr,
 	.sta_set_txpwr			= ath11k_mac_op_sta_set_txpwr,

drivers/net/wireless/ath/ath11k/wmi.c

@@ -7765,6 +7765,56 @@ static void ath11k_wmi_twt_add_dialog_event(struct ath11k_base *ab,
 	kfree(tb);
 }
 
+static void ath11k_wmi_gtk_offload_status_event(struct ath11k_base *ab,
+						struct sk_buff *skb)
+{
+	const void **tb;
+	const struct wmi_gtk_offload_status_event *ev;
+	struct ath11k_vif *arvif;
+	__be64 replay_ctr_be;
+	u64    replay_ctr;
+	int ret;
+
+	tb = ath11k_wmi_tlv_parse_alloc(ab, skb->data, skb->len, GFP_ATOMIC);
+	if (IS_ERR(tb)) {
+		ret = PTR_ERR(tb);
+		ath11k_warn(ab, "failed to parse tlv: %d\n", ret);
+		return;
+	}
+
+	ev = tb[WMI_TAG_GTK_OFFLOAD_STATUS_EVENT];
+	if (!ev) {
+		ath11k_warn(ab, "failed to fetch gtk offload status ev");
+		kfree(tb);
+		return;
+	}
+
+	arvif = ath11k_mac_get_arvif_by_vdev_id(ab, ev->vdev_id);
+	if (!arvif) {
+		ath11k_warn(ab, "failed to get arvif for vdev_id:%d\n",
+			    ev->vdev_id);
+		kfree(tb);
+		return;
+	}
+
+	ath11k_dbg(ab, ATH11K_DBG_WMI, "wmi gtk offload event refresh_cnt %d\n",
+		   ev->refresh_cnt);
+	ath11k_dbg_dump(ab, ATH11K_DBG_WMI, "replay_cnt",
+			NULL, ev->replay_ctr.counter, GTK_REPLAY_COUNTER_BYTES);
+
+	replay_ctr =  ev->replay_ctr.word1;
+	replay_ctr = (replay_ctr << 32) | ev->replay_ctr.word0;
+	arvif->rekey_data.replay_ctr = replay_ctr;
+
+	/* supplicant expects big-endian replay counter */
+	replay_ctr_be = cpu_to_be64(replay_ctr);
+
+	ieee80211_gtk_rekey_notify(arvif->vif, arvif->bssid,
+				   (void *)&replay_ctr_be, GFP_KERNEL);
+
+	kfree(tb);
+}
+
 static void ath11k_wmi_tlv_op_rx(struct ath11k_base *ab, struct sk_buff *skb)
 {
 	struct wmi_cmd_hdr *cmd_hdr;
@@ -7896,6 +7946,9 @@ static void ath11k_wmi_tlv_op_rx(struct ath11k_base *ab, struct sk_buff *skb)
 	case WMI_DIAG_EVENTID:
 		ath11k_wmi_diag_event(ab, skb);
 		break;
+	case WMI_GTK_OFFLOAD_STATUS_EVENTID:
+		ath11k_wmi_gtk_offload_status_event(ab, skb);
+		break;
 	/* TODO: Add remaining events */
 	default:
 		ath11k_dbg(ab, ATH11K_DBG_WMI, "Unknown eventid: 0x%x\n", id);
@@ -8735,3 +8788,69 @@ int ath11k_wmi_arp_ns_offload(struct ath11k *ar,
 
 	return ath11k_wmi_cmd_send(ar->wmi, skb, WMI_SET_ARP_NS_OFFLOAD_CMDID);
 }
+
+int ath11k_wmi_gtk_rekey_offload(struct ath11k *ar,
+				 struct ath11k_vif *arvif, bool enable)
+{
+	struct wmi_gtk_rekey_offload_cmd *cmd;
+	struct ath11k_rekey_data *rekey_data = &arvif->rekey_data;
+	int len;
+	struct sk_buff *skb;
+	__le64 replay_ctr;
+
+	len = sizeof(*cmd);
+	skb =  ath11k_wmi_alloc_skb(ar->wmi->wmi_ab, len);
+	if (!skb)
+		return -ENOMEM;
+
+	cmd = (struct wmi_gtk_rekey_offload_cmd *)skb->data;
+	cmd->tlv_header = FIELD_PREP(WMI_TLV_TAG, WMI_TAG_GTK_OFFLOAD_CMD) |
+			  FIELD_PREP(WMI_TLV_LEN, sizeof(*cmd) - TLV_HDR_SIZE);
+
+	cmd->vdev_id = arvif->vdev_id;
+
+	if (enable) {
+		cmd->flags = GTK_OFFLOAD_ENABLE_OPCODE;
+
+		/* the length in rekey_data and cmd is equal */
+		memcpy(cmd->kck, rekey_data->kck, sizeof(cmd->kck));
+		ath11k_ce_byte_swap(cmd->kck, GTK_OFFLOAD_KEK_BYTES);
+		memcpy(cmd->kek, rekey_data->kek, sizeof(cmd->kek));
+		ath11k_ce_byte_swap(cmd->kek, GTK_OFFLOAD_KEK_BYTES);
+
+		replay_ctr = cpu_to_le64(rekey_data->replay_ctr);
+		memcpy(cmd->replay_ctr, &replay_ctr,
+		       sizeof(replay_ctr));
+		ath11k_ce_byte_swap(cmd->replay_ctr, GTK_REPLAY_COUNTER_BYTES);
+	} else {
+		cmd->flags = GTK_OFFLOAD_DISABLE_OPCODE;
+	}
+
+	ath11k_dbg(ar->ab, ATH11K_DBG_WMI, "offload gtk rekey vdev: %d %d\n",
+		   arvif->vdev_id, enable);
+	return ath11k_wmi_cmd_send(ar->wmi, skb, WMI_GTK_OFFLOAD_CMDID);
+}
+
+int ath11k_wmi_gtk_rekey_getinfo(struct ath11k *ar,
+				 struct ath11k_vif *arvif)
+{
+	struct wmi_gtk_rekey_offload_cmd *cmd;
+	int len;
+	struct sk_buff *skb;
+
+	len = sizeof(*cmd);
+	skb =  ath11k_wmi_alloc_skb(ar->wmi->wmi_ab, len);
+	if (!skb)
+		return -ENOMEM;
+
+	cmd = (struct wmi_gtk_rekey_offload_cmd *)skb->data;
+	cmd->tlv_header = FIELD_PREP(WMI_TLV_TAG, WMI_TAG_GTK_OFFLOAD_CMD) |
+			  FIELD_PREP(WMI_TLV_LEN, sizeof(*cmd) - TLV_HDR_SIZE);
+
+	cmd->vdev_id = arvif->vdev_id;
+	cmd->flags = GTK_OFFLOAD_REQUEST_STATUS_OPCODE;
+
+	ath11k_dbg(ar->ab, ATH11K_DBG_WMI, "get gtk rekey vdev_id: %d\n",
+		   arvif->vdev_id);
+	return ath11k_wmi_cmd_send(ar->wmi, skb, WMI_GTK_OFFLOAD_CMDID);
+}

drivers/net/wireless/ath/ath11k/wmi.h

@@ -5840,6 +5840,51 @@ struct wmi_set_arp_ns_offload_cmd {
 	 */
 } __packed;
 
+#define GTK_OFFLOAD_OPCODE_MASK             0xFF000000
+#define GTK_OFFLOAD_ENABLE_OPCODE           0x01000000
+#define GTK_OFFLOAD_DISABLE_OPCODE          0x02000000
+#define GTK_OFFLOAD_REQUEST_STATUS_OPCODE   0x04000000
+
+#define GTK_OFFLOAD_KEK_BYTES       16
+#define GTK_OFFLOAD_KCK_BYTES       16
+#define GTK_REPLAY_COUNTER_BYTES    8
+#define WMI_MAX_KEY_LEN             32
+#define IGTK_PN_SIZE                6
+
+struct wmi_replayc_cnt {
+	union {
+		u8 counter[GTK_REPLAY_COUNTER_BYTES];
+		struct {
+			u32 word0;
+			u32 word1;
+		} __packed;
+	} __packed;
+} __packed;
+
+struct wmi_gtk_offload_status_event {
+	u32 vdev_id;
+	u32 flags;
+	u32 refresh_cnt;
+	struct wmi_replayc_cnt replay_ctr;
+	u8 igtk_key_index;
+	u8 igtk_key_length;
+	u8 igtk_key_rsc[IGTK_PN_SIZE];
+	u8 igtk_key[WMI_MAX_KEY_LEN];
+	u8 gtk_key_index;
+	u8 gtk_key_length;
+	u8 gtk_key_rsc[GTK_REPLAY_COUNTER_BYTES];
+	u8 gtk_key[WMI_MAX_KEY_LEN];
+} __packed;
+
+struct wmi_gtk_rekey_offload_cmd {
+	u32 tlv_header;
+	u32 vdev_id;
+	u32 flags;
+	u8 kek[GTK_OFFLOAD_KEK_BYTES];
+	u8 kck[GTK_OFFLOAD_KCK_BYTES];
+	u8 replay_ctr[GTK_REPLAY_COUNTER_BYTES];
+} __packed;
+
 int ath11k_wmi_cmd_send(struct ath11k_pdev_wmi *wmi, struct sk_buff *skb,
 			u32 cmd_id);
 struct sk_buff *ath11k_wmi_alloc_skb(struct ath11k_wmi_base *wmi_sc, u32 len);
@@ -6014,5 +6059,9 @@ int ath11k_wmi_hw_data_filter_cmd(struct ath11k *ar, u32 vdev_id,
 				  u32 filter_bitmap, bool enable);
 int ath11k_wmi_arp_ns_offload(struct ath11k *ar,
 			      struct ath11k_vif *arvif, bool enable);
+int ath11k_wmi_gtk_rekey_offload(struct ath11k *ar,
+				 struct ath11k_vif *arvif, bool enable);
+int ath11k_wmi_gtk_rekey_getinfo(struct ath11k *ar,
+				 struct ath11k_vif *arvif);
 
 #endif

drivers/net/wireless/ath/ath11k/wow.c

@@ -17,7 +17,9 @@
 
 static const struct wiphy_wowlan_support ath11k_wowlan_support = {
 	.flags = WIPHY_WOWLAN_DISCONNECT |
-		 WIPHY_WOWLAN_MAGIC_PKT,
+		 WIPHY_WOWLAN_MAGIC_PKT |
+		 WIPHY_WOWLAN_SUPPORTS_GTK_REKEY |
+		 WIPHY_WOWLAN_GTK_REKEY_FAILURE,
 	.pattern_min_len = WOW_MIN_PATTERN_SIZE,
 	.pattern_max_len = WOW_MAX_PATTERN_SIZE,
 	.max_pkt_offset = WOW_MAX_PKT_OFFSET,
@@ -582,6 +584,41 @@ static int ath11k_wow_arp_ns_offload(struct ath11k *ar, bool enable)
 	return 0;
 }
 
+static int ath11k_gtk_rekey_offload(struct ath11k *ar, bool enable)
+{
+	struct ath11k_vif *arvif;
+	int ret;
+
+	lockdep_assert_held(&ar->conf_mutex);
+
+	list_for_each_entry(arvif, &ar->arvifs, list) {
+		if (arvif->vdev_type != WMI_VDEV_TYPE_STA ||
+		    !arvif->is_up ||
+		    !arvif->rekey_data.enable_offload)
+			continue;
+
+		/* get rekey info before disable rekey offload */
+		if (!enable) {
+			ret = ath11k_wmi_gtk_rekey_getinfo(ar, arvif);
+			if (ret) {
+				ath11k_warn(ar->ab, "failed to request rekey info vdev %i, ret %d\n",
+					    arvif->vdev_id, ret);
+				return ret;
+			}
+		}
+
+		ret = ath11k_wmi_gtk_rekey_offload(ar, arvif, enable);
+
+		if (ret) {
+			ath11k_warn(ar->ab, "failed to offload gtk reky vdev %i: enable %d, ret %d\n",
+				    arvif->vdev_id, enable, ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
 static int ath11k_wow_protocol_offload(struct ath11k *ar, bool enable)
 {
 	int ret;
@@ -593,6 +630,13 @@ static int ath11k_wow_protocol_offload(struct ath11k *ar, bool enable)
 		return ret;
 	}
 
+	ret = ath11k_gtk_rekey_offload(ar, enable);
+	if (ret) {
+		ath11k_warn(ar->ab, "failed to offload gtk rekey %d %d\n",
+			    enable, ret);
+		return ret;
+	}
+
 	return 0;
 }