wcn36xx: Add GTK offload to WoWLAN path

Using previously set GTK KCK and KEK material this commit adds GTK rekeying
to the WoWLAN suspend/resume path. A small error in the packing of the
up to now unused command structure is fixed as we go.

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Tested-by: Benjamin Li <benl@squareup.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210605011140.2004643-9-bryan.odonoghue@linaro.org

drivers/net/wireless/ath/wcn36xx/hal.h

@@ -4905,7 +4905,7 @@ struct wcn36xx_hal_gtk_offload_req_msg {
 	u64 key_replay_counter;
 
 	u8 bss_index;
-};
+} __packed;
 
 struct wcn36xx_hal_gtk_offload_rsp_msg {
 	struct wcn36xx_hal_msg_header header;

drivers/net/wireless/ath/wcn36xx/main.c

@@ -1119,6 +1119,9 @@ static int wcn36xx_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wow)
 		if (ret)
 			goto out;
 		ret = wcn36xx_smd_ipv6_ns_offload(wcn, vif, true);
+		if (ret)
+			goto out;
+		ret = wcn36xx_smd_gtk_offload(wcn, vif, true);
 		if (ret)
 			goto out;
 		ret = wcn36xx_smd_set_power_params(wcn, true);
@@ -1139,6 +1142,7 @@ static int wcn36xx_resume(struct ieee80211_hw *hw)
 	vif = wcn36xx_get_first_assoc_vif(wcn);
 	if (vif) {
 		wcn36xx_smd_set_power_params(wcn, false);
+		wcn36xx_smd_gtk_offload(wcn, vif, false);
 		wcn36xx_smd_ipv6_ns_offload(wcn, vif, false);
 		wcn36xx_smd_arp_offload(wcn, vif, false);
 	}

drivers/net/wireless/ath/wcn36xx/smd.c

@@ -2856,6 +2856,44 @@ int wcn36xx_smd_ipv6_ns_offload(struct wcn36xx *wcn, struct ieee80211_vif *vif,
 }
 #endif
 
+int wcn36xx_smd_gtk_offload(struct wcn36xx *wcn, struct ieee80211_vif *vif,
+			    bool enable)
+{
+	struct wcn36xx_vif *vif_priv = wcn36xx_vif_to_priv(vif);
+	struct wcn36xx_hal_gtk_offload_req_msg msg_body;
+	int ret;
+
+	mutex_lock(&wcn->hal_mutex);
+
+	INIT_HAL_MSG(msg_body, WCN36XX_HAL_GTK_OFFLOAD_REQ);
+
+	if (enable) {
+		memcpy(&msg_body.kek, vif_priv->rekey_data.kek, NL80211_KEK_LEN);
+		memcpy(&msg_body.kck, vif_priv->rekey_data.kck, NL80211_KCK_LEN);
+		msg_body.key_replay_counter =
+			le64_to_cpu(vif_priv->rekey_data.replay_ctr);
+		msg_body.bss_index = vif_priv->bss_index;
+	} else {
+		msg_body.flags = WCN36XX_HAL_GTK_OFFLOAD_FLAGS_DISABLE;
+	}
+
+	PREPARE_HAL_BUF(wcn->hal_buf, msg_body);
+
+	ret = wcn36xx_smd_send_and_wait(wcn, msg_body.header.len);
+	if (ret) {
+		wcn36xx_err("Sending host_offload_arp failed\n");
+		goto out;
+	}
+	ret = wcn36xx_smd_rsp_status_check(wcn->hal_buf, wcn->hal_rsp_len);
+	if (ret) {
+		wcn36xx_err("host_offload_arp failed err=%d\n", ret);
+		goto out;
+	}
+out:
+	mutex_unlock(&wcn->hal_mutex);
+	return ret;
+}
+
 int wcn36xx_smd_rsp_process(struct rpmsg_device *rpdev,
 			    void *buf, int len, void *priv, u32 addr)
 {
@@ -2905,6 +2943,7 @@ int wcn36xx_smd_rsp_process(struct rpmsg_device *rpdev,
 	case WCN36XX_HAL_START_SCAN_OFFLOAD_RSP:
 	case WCN36XX_HAL_STOP_SCAN_OFFLOAD_RSP:
 	case WCN36XX_HAL_HOST_OFFLOAD_RSP:
+	case WCN36XX_HAL_GTK_OFFLOAD_RSP:
 		memcpy(wcn->hal_buf, buf, len);
 		wcn->hal_rsp_len = len;
 		complete(&wcn->hal_rsp_compl);

drivers/net/wireless/ath/wcn36xx/smd.h

@@ -153,4 +153,7 @@ int wcn36xx_smd_arp_offload(struct wcn36xx *wcn, struct ieee80211_vif *vif,
 int wcn36xx_smd_ipv6_ns_offload(struct wcn36xx *wcn, struct ieee80211_vif *vif,
 				bool enable);
 
+int wcn36xx_smd_gtk_offload(struct wcn36xx *wcn, struct ieee80211_vif *vif,
+			    bool enable);
+
 #endif	/* _SMD_H_ */