hostapd: ubus: add notification for BSS transition response

To allow steering daemons to be aware of the STA-decided transition
target, publish WNM transition responses to ubus. This way, steerings
daemons can learn about STA-chosen targets and send a better selection
of transition candidates.

Signed-off-by: David Bauer <mail@david-bauer.net>

package/network/services/hostapd/patches/600-ubus_support.patch

@@ -514,3 +514,33 @@
  	struct os_reltime backlogged_until;
  #endif /* CONFIG_AIRTIME_POLICY */
  
+--- a/src/ap/wnm_ap.c
++++ b/src/ap/wnm_ap.c
+@@ -463,7 +463,7 @@ static void ieee802_11_rx_bss_trans_mgmt
+ 					      size_t len)
+ {
+ 	u8 dialog_token, status_code, bss_termination_delay;
+-	const u8 *pos, *end;
++	const u8 *pos, *end, *target_bssid;
+ 	int enabled = hapd->conf->bss_transition;
+ 	struct sta_info *sta;
+ 
+@@ -510,6 +510,7 @@ static void ieee802_11_rx_bss_trans_mgmt
+ 			wpa_printf(MSG_DEBUG, "WNM: not enough room for Target BSSID field");
+ 			return;
+ 		}
++		target_bssid = pos;
+ 		sta->agreed_to_steer = 1;
+ 		eloop_cancel_timeout(ap_sta_reset_steer_flag_timer, hapd, sta);
+ 		eloop_register_timeout(2, 0, ap_sta_reset_steer_flag_timer,
+@@ -529,6 +530,10 @@ static void ieee802_11_rx_bss_trans_mgmt
+ 			MAC2STR(addr), status_code, bss_termination_delay);
+ 	}
+ 
++	hostapd_ubus_notify_bss_transition_response(hapd, sta->addr, dialog_token,
++						    status_code, bss_termination_delay,
++						    target_bssid, pos, end - pos);
++
+ 	wpa_hexdump(MSG_DEBUG, "WNM: BSS Transition Candidate List Entries",
+ 		    pos, end - pos);
+ }

package/network/services/hostapd/src/src/ap/ubus.c

@@ -1757,3 +1757,36 @@ void hostapd_ubus_notify_radar_detected(struct hostapd_iface *iface, int frequen
 		ubus_notify(ctx, &hapd->ubus.obj, "radar-detected", b.head, -1);
 	}
 }
+
+void hostapd_ubus_notify_bss_transition_response(
+	struct hostapd_data *hapd, const u8 *addr, u8 dialog_token, u8 status_code,
+	u8 bss_termination_delay, const u8 *target_bssid,
+	const u8 *candidate_list, u16 candidate_list_len)
+{
+#ifdef CONFIG_WNM_AP
+	char *cl_str;
+	u16 i;
+
+	if (!hapd->ubus.obj.has_subscribers)
+		return;
+
+	if (!addr)
+		return;
+
+	blob_buf_init(&b, 0);
+	blobmsg_add_macaddr(&b, "address", addr);
+	blobmsg_add_u8(&b, "dialog-token", dialog_token);
+	blobmsg_add_u8(&b, "status-code", status_code);
+	blobmsg_add_u8(&b, "bss-termination-delay", bss_termination_delay);
+	if (target_bssid)
+		blobmsg_add_macaddr(&b, "target-bssid", target_bssid);
+	if (candidate_list_len > 0) {
+		cl_str = blobmsg_alloc_string_buffer(&b, "candidate-list", candidate_list_len * 2 + 1);
+		for (i = 0; i < candidate_list_len; i++)
+			snprintf(&cl_str[i*2], 3, "%02X", candidate_list[i]);
+		blobmsg_add_string_buffer(&b);
+	}
+
+	ubus_notify(ctx, &hapd->ubus.obj, "bss-transition-response", b.head, -1);
+#endif
+}

package/network/services/hostapd/src/src/ap/ubus.h

@@ -55,6 +55,10 @@ void hostapd_ubus_notify_beacon_report(struct hostapd_data *hapd,
 void hostapd_ubus_notify_radar_detected(struct hostapd_iface *iface, int frequency,
 					int chan_width, int cf1, int cf2);
 
+void hostapd_ubus_notify_bss_transition_response(
+	struct hostapd_data *hapd, const u8 *addr, u8 dialog_token, u8 status_code,
+	u8 bss_termination_delay, const u8 *target_bssid,
+	const u8 *candidate_list, u16 candidate_list_len);
 void hostapd_ubus_add(struct hapd_interfaces *interfaces);
 void hostapd_ubus_free(struct hapd_interfaces *interfaces);
 
@@ -107,6 +111,13 @@ static inline void hostapd_ubus_notify_radar_detected(struct hostapd_iface *ifac
 {
 }
 
+static inline void hostapd_ubus_notify_bss_transition_response(
+	struct hostapd_data *hapd, const u8 *addr, u8 dialog_token, u8 status_code,
+	u8 bss_termination_delay, const u8 *target_bssid,
+	const u8 *candidate_list, u16 candidate_list_len)
+{
+}
+
 static inline void hostapd_ubus_add(struct hapd_interfaces *interfaces)
 {
 }