Add BSS-TM-RESP ctrl_iface event

This event allows external monitors to track STA response to BSS
Transition Management Request.

BSS-TM-RESP <STA addr> status_code=<#> bss_termination_delay=<#>
[target_bssid=<BSSID>]

Signed-off-by: Jouni Malinen <j@w1.fi>
diff --git a/src/ap/wnm_ap.c b/src/ap/wnm_ap.c
index a24900a..7e8fb5c 100644
--- a/src/ap/wnm_ap.c
+++ b/src/ap/wnm_ap.c
@@ -11,6 +11,7 @@
 #include "utils/common.h"
 #include "utils/eloop.h"
 #include "common/ieee802_11_defs.h"
+#include "common/wpa_ctrl.h"
 #include "ap/hostapd.h"
 #include "ap/sta_info.h"
 #include "ap/ap_config.h"
@@ -358,7 +359,16 @@
 		}
 		wpa_printf(MSG_DEBUG, "WNM: Target BSSID: " MACSTR,
 			   MAC2STR(pos));
+		wpa_msg(hapd->msg_ctx, MSG_INFO, BSS_TM_RESP MACSTR
+			" status_code=%u bss_termination_delay=%u target_bssid="
+			MACSTR,
+			MAC2STR(addr), status_code, bss_termination_delay,
+			MAC2STR(pos));
 		pos += ETH_ALEN;
+	} else {
+		wpa_msg(hapd->msg_ctx, MSG_INFO, BSS_TM_RESP MACSTR
+			" status_code=%u bss_termination_delay=%u",
+			MAC2STR(addr), status_code, bss_termination_delay);
 	}
 
 	wpa_hexdump(MSG_DEBUG, "WNM: BSS Transition Candidate List Entries",
diff --git a/src/common/wpa_ctrl.h b/src/common/wpa_ctrl.h
index 4c88a0c..e48bbed 100644
--- a/src/common/wpa_ctrl.h
+++ b/src/common/wpa_ctrl.h
@@ -232,6 +232,9 @@
 
 #define AP_CSA_FINISHED "AP-CSA-FINISHED "
 
+/* BSS Transition Management Response frame received */
+#define BSS_TM_RESP "BSS-TM-RESP "
+
 /* BSS command information masks */
 
 #define WPA_BSS_MASK_ALL		0xFFFDFFFF