nl80211: Driver command for checking BTM accept/reject

Add driver interface command using the QCA vendor extensions to check
the driverr whether to accept or reject a BSS transition candidate. For
the reject case, report an MBO reject reason code.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

src/drivers/driver.h

@@ -1898,6 +1898,20 @@ struct drv_acs_params {
 	const int *freq_list;
 };
 
+struct wpa_bss_trans_info {
+	u8 mbo_transition_reason;
+	u8 n_candidates;
+	u8 *bssid;
+};
+
+struct wpa_bss_candidate_info {
+	u8 num;
+	struct candidate_list {
+		u8 bssid[ETH_ALEN];
+		u8 is_accept;
+		u32 reject_reason;
+	} *candidates;
+};
 
 /**
  * struct wpa_driver_ops - Driver interface API definition
@@ -3808,8 +3822,19 @@ struct wpa_driver_ops {
 	 * trigger control mode to the host driver.
 	 */
 	int (*set_tdls_mode)(void *priv, int tdls_external_control);
-};
 
+	/**
+	 * get_bss_transition_status - Get candidate BSS's transition status
+	 * @priv: Private driver interface data
+	 * @params: Candidate BSS list
+	 *
+	 * Get the accept or reject reason code for a list of BSS transition
+	 * candidates.
+	 */
+	struct wpa_bss_candidate_info *
+	(*get_bss_transition_status)(void *priv,
+				     struct wpa_bss_trans_info *params);
+};
 
 /**
  * enum wpa_event_type - Event type for wpa_supplicant_event() calls

src/drivers/driver_nl80211.c

@@ -9655,6 +9655,204 @@ fail:
 	return -1;
 }
 
+
+#ifdef CONFIG_MBO
+
+static enum mbo_transition_reject_reason
+nl80211_mbo_reject_reason_mapping(enum qca_wlan_btm_candidate_status status)
+{
+	switch (status) {
+	case QCA_STATUS_REJECT_EXCESSIVE_FRAME_LOSS_EXPECTED:
+		return MBO_TRANSITION_REJECT_REASON_FRAME_LOSS;
+	case QCA_STATUS_REJECT_EXCESSIVE_DELAY_EXPECTED:
+		return MBO_TRANSITION_REJECT_REASON_DELAY;
+	case QCA_STATUS_REJECT_INSUFFICIENT_QOS_CAPACITY:
+		return MBO_TRANSITION_REJECT_REASON_QOS_CAPACITY;
+	case QCA_STATUS_REJECT_LOW_RSSI:
+		return MBO_TRANSITION_REJECT_REASON_RSSI;
+	case QCA_STATUS_REJECT_HIGH_INTERFERENCE:
+		return MBO_TRANSITION_REJECT_REASON_INTERFERENCE;
+	case QCA_STATUS_REJECT_UNKNOWN:
+	default:
+		return MBO_TRANSITION_REJECT_REASON_UNSPECIFIED;
+	}
+}
+
+
+static void nl80211_parse_btm_candidate_info(struct candidate_list *candidate,
+					     struct nlattr *tb[], int num)
+{
+	enum qca_wlan_btm_candidate_status status;
+	char buf[50];
+
+	os_memcpy(candidate->bssid,
+		  nla_data(tb[QCA_WLAN_VENDOR_ATTR_BTM_CANDIDATE_INFO_BSSID]),
+		  ETH_ALEN);
+
+	status = nla_get_u32(
+		tb[QCA_WLAN_VENDOR_ATTR_BTM_CANDIDATE_INFO_STATUS]);
+	candidate->is_accept = status == QCA_STATUS_ACCEPT;
+	candidate->reject_reason = nl80211_mbo_reject_reason_mapping(status);
+
+	if (candidate->is_accept)
+		os_snprintf(buf, sizeof(buf), "Accepted");
+	else
+		os_snprintf(buf, sizeof(buf),
+			    "Rejected, Reject_reason: %d",
+			    candidate->reject_reason);
+	wpa_printf(MSG_DEBUG, "nl80211:   BSSID[%d]: " MACSTR " %s",
+		   num, MAC2STR(candidate->bssid), buf);
+}
+
+
+static int
+nl80211_get_bss_transition_status_handler(struct nl_msg *msg, void *arg)
+{
+	struct wpa_bss_candidate_info *info = arg;
+	struct candidate_list *candidate = info->candidates;
+	struct nlattr *tb_msg[NL80211_ATTR_MAX + 1];
+	struct nlattr *tb_vendor[QCA_WLAN_VENDOR_ATTR_MAX + 1];
+	struct nlattr *tb[QCA_WLAN_VENDOR_ATTR_BTM_CANDIDATE_INFO_MAX + 1];
+	static struct nla_policy policy[
+		QCA_WLAN_VENDOR_ATTR_BTM_CANDIDATE_INFO_MAX + 1] = {
+		[QCA_WLAN_VENDOR_ATTR_BTM_CANDIDATE_INFO_BSSID] = {
+			.minlen = ETH_ALEN
+		},
+		[QCA_WLAN_VENDOR_ATTR_BTM_CANDIDATE_INFO_STATUS] = {
+			.type = NLA_U32,
+		},
+	};
+	struct nlattr *attr;
+	int rem;
+	struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
+	u8 num;
+
+	num = info->num; /* number of candidates sent to driver */
+	info->num = 0;
+	nla_parse(tb_msg, NL80211_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
+		  genlmsg_attrlen(gnlh, 0), NULL);
+
+	if (!tb_msg[NL80211_ATTR_VENDOR_DATA] ||
+	    nla_parse_nested(tb_vendor, QCA_WLAN_VENDOR_ATTR_MAX,
+			     tb_msg[NL80211_ATTR_VENDOR_DATA], NULL) ||
+	    !tb_vendor[QCA_WLAN_VENDOR_ATTR_BTM_CANDIDATE_INFO])
+		return NL_SKIP;
+
+	wpa_printf(MSG_DEBUG,
+		   "nl80211: WNM Candidate list received from driver");
+	nla_for_each_nested(attr,
+			    tb_vendor[QCA_WLAN_VENDOR_ATTR_BTM_CANDIDATE_INFO],
+			    rem) {
+		if (info->num >= num ||
+		    nla_parse_nested(
+			    tb, QCA_WLAN_VENDOR_ATTR_BTM_CANDIDATE_INFO_MAX,
+			    attr, policy) ||
+		    !tb[QCA_WLAN_VENDOR_ATTR_BTM_CANDIDATE_INFO_BSSID] ||
+		    !tb[QCA_WLAN_VENDOR_ATTR_BTM_CANDIDATE_INFO_STATUS])
+			break;
+
+		nl80211_parse_btm_candidate_info(candidate, tb, info->num);
+
+		candidate++;
+		info->num++;
+	}
+
+	return NL_SKIP;
+}
+
+
+static struct wpa_bss_candidate_info *
+nl80211_get_bss_transition_status(void *priv, struct wpa_bss_trans_info *params)
+{
+	struct i802_bss *bss = priv;
+	struct wpa_driver_nl80211_data *drv = bss->drv;
+	struct nl_msg *msg;
+	struct nlattr *attr, *attr1, *attr2;
+	struct wpa_bss_candidate_info *info;
+	u8 i;
+	int ret;
+	u8 *pos;
+
+	if (!drv->fetch_bss_trans_status)
+		return NULL;
+
+	info = os_zalloc(sizeof(*info));
+	if (!info)
+		return NULL;
+	/* Allocate memory for number of candidates sent to driver */
+	info->candidates = os_calloc(params->n_candidates,
+				     sizeof(*info->candidates));
+	if (!info->candidates) {
+		os_free(info);
+		return NULL;
+	}
+
+	/* Copy the number of candidates being sent to driver. This is used in
+	 * nl80211_get_bss_transition_status_handler() to limit the number of
+	 * candidates that can be populated in info->candidates and will be
+	 * later overwritten with the actual number of candidates received from
+	 * the driver.
+	 */
+	info->num = params->n_candidates;
+
+	if (!(msg = nl80211_drv_msg(drv, 0, NL80211_CMD_VENDOR)) ||
+	    nla_put_u32(msg, NL80211_ATTR_VENDOR_ID, OUI_QCA) ||
+	    nla_put_u32(msg, NL80211_ATTR_VENDOR_SUBCMD,
+			QCA_NL80211_VENDOR_SUBCMD_FETCH_BSS_TRANSITION_STATUS))
+		goto fail;
+
+	attr = nla_nest_start(msg, NL80211_ATTR_VENDOR_DATA);
+	if (!attr)
+		goto fail;
+
+	if (nla_put_u8(msg, QCA_WLAN_VENDOR_ATTR_BTM_MBO_TRANSITION_REASON,
+		       params->mbo_transition_reason))
+		goto fail;
+
+	attr1 = nla_nest_start(msg, QCA_WLAN_VENDOR_ATTR_BTM_CANDIDATE_INFO);
+	if (!attr1)
+		goto fail;
+
+	wpa_printf(MSG_DEBUG,
+		   "nl80211: WNM Candidate list info sending to driver: mbo_transition_reason: %d n_candidates: %d",
+		   params->mbo_transition_reason, params->n_candidates);
+	pos = params->bssid;
+	for (i = 0; i < params->n_candidates; i++) {
+		wpa_printf(MSG_DEBUG, "nl80211:   BSSID[%d]: " MACSTR, i,
+			   MAC2STR(pos));
+		attr2 = nla_nest_start(msg, i);
+		if (!attr2 ||
+		    nla_put(msg, QCA_WLAN_VENDOR_ATTR_BTM_CANDIDATE_INFO_BSSID,
+			    ETH_ALEN, pos))
+			goto fail;
+		pos += ETH_ALEN;
+		nla_nest_end(msg, attr2);
+	}
+
+	nla_nest_end(msg, attr1);
+	nla_nest_end(msg, attr);
+
+	ret = send_and_recv_msgs(drv, msg,
+				 nl80211_get_bss_transition_status_handler,
+				 info);
+	msg = NULL;
+	if (ret) {
+		wpa_printf(MSG_ERROR,
+			   "nl80211: WNM Get BSS transition status failed: ret=%d (%s)",
+			   ret, strerror(-ret));
+		goto fail;
+	}
+	return info;
+
+fail:
+	nlmsg_free(msg);
+	os_free(info->candidates);
+	os_free(info);
+	return NULL;
+}
+
+#endif /* CONFIG_MBO */
+
 #endif /* CONFIG_DRIVER_NL80211_QCA */
 
 
@@ -9899,6 +10097,9 @@ const struct wpa_driver_ops wpa_driver_nl80211_ops = {
 	.p2p_lo_stop = nl80211_p2p_lo_stop,
 	.set_default_scan_ies = nl80211_set_default_scan_ies,
 	.set_tdls_mode = nl80211_set_tdls_mode,
+#ifdef CONFIG_MBO
+	.get_bss_transition_status = nl80211_get_bss_transition_status,
+#endif /* CONFIG_MBO */
 #endif /* CONFIG_DRIVER_NL80211_QCA */
 	.configure_data_frame_filters = nl80211_configure_data_frame_filters,
 	.get_ext_capab = nl80211_get_ext_capab,

src/drivers/driver_nl80211.h

@@ -162,6 +162,7 @@ struct wpa_driver_nl80211_data {
 	unsigned int connect_reassoc:1;
 	unsigned int set_wifi_conf_vendor_cmd_avail:1;
 	unsigned int he_capab_vendor_cmd_avail:1;
+	unsigned int fetch_bss_trans_status:1;
 
 	u64 vendor_scan_cookie;
 	u64 remain_on_chan_cookie;

src/drivers/driver_nl80211_capa.c

@@ -747,6 +747,9 @@ static int wiphy_info_handler(struct nl_msg *msg, void *arg)
 				case QCA_NL80211_VENDOR_SUBCMD_GET_HE_CAPABILITIES:
 					drv->he_capab_vendor_cmd_avail = 1;
 					break;
+				case QCA_NL80211_VENDOR_SUBCMD_FETCH_BSS_TRANSITION_STATUS:
+					drv->fetch_bss_trans_status = 1;
+					break;
 #endif /* CONFIG_DRIVER_NL80211_QCA */
 				}
 			}

wpa_supplicant/driver_i.h

@@ -989,4 +989,14 @@ static inline int wpa_drv_set_tdls_mode(struct wpa_supplicant *wpa_s,
 					    tdls_external_control);
 }
 
+static inline struct wpa_bss_candidate_info *
+wpa_drv_get_bss_trans_status(struct wpa_supplicant *wpa_s,
+			     struct wpa_bss_trans_info *params)
+{
+	if (!wpa_s->driver->get_bss_transition_status)
+		return NULL;
+	return wpa_s->driver->get_bss_transition_status(wpa_s->drv_priv,
+							params);
+}
+
 #endif /* DRIVER_I_H */