[PATCH 20/26] hostapd: Add MBO IE to BSS transition management request

[Ilan Peer]

From: Avraham Stern <avraham.stern at intel.com>

Add an option to add MBO IE to BSS transition management request.
The MBO IE includes the transition reason code, cellular data
connection preference and, if the disaasoc imminent bit is set, it
may include also re-association retry delay. Otherwise the
re-association retry delay should be set to zero.

Signed-off-by: Avraham Stern <avraham.stern at intel.com>
---
 hostapd/ctrl_iface.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 src/ap/wnm_ap.c      |  7 ++++++-
 src/ap/wnm_ap.h      |  3 ++-
 3 files changed, 65 insertions(+), 3 deletions(-)

diff --git a/hostapd/ctrl_iface.c b/hostapd/ctrl_iface.c
index cb6fb17..a45ccf2 100644
--- a/hostapd/ctrl_iface.c
+++ b/hostapd/ctrl_iface.c
@@ -884,6 +884,8 @@ static int hostapd_ctrl_iface_bss_tm_req(struct hostapd_data *hapd,
 	int ret;
 	u8 nei_rep[1000];
 	u8 *nei_pos = nei_rep;
+	u8 mbo[10];
+	size_t mbo_len;
 
 	if (hwaddr_aton(cmd, addr)) {
 		wpa_printf(MSG_DEBUG, "Invalid STA MAC address");
@@ -1049,10 +1051,64 @@ static int hostapd_ctrl_iface_bss_tm_req(struct hostapd_data *hapd,
 	if (os_strstr(cmd, " disassoc_imminent=1"))
 		req_mode |= WNM_BSS_TM_REQ_DISASSOC_IMMINENT;
 
+	mbo_len = 0;
+	pos = os_strstr(cmd, "mbo=");
+	if (pos) {
+		u8 mbo_reason, cell_pref;
+		u16 reassoc_delay;
+		int ret;
+
+		ret = sscanf(pos, "mbo=%hhu:%hu:%hhu", &mbo_reason,
+			     &reassoc_delay, &cell_pref);
+		if (ret != 3) {
+			wpa_printf(MSG_DEBUG,
+				   "MBO requires three arguments: mbo=<reason>:<reassoc_delay>:<cell_pref>");
+				   return -1;
+		}
+
+		if (mbo_reason > MBO_TRANSITION_REASON_PREMIUM_AP) {
+			wpa_printf(MSG_DEBUG,
+				   "Invalid MBO transition reason code %hhu",
+				   mbo_reason);
+			return -1;
+		}
+
+		/* Valid values for Cellular preference are: 0, 1, 255 */
+		if (cell_pref > 1 && cell_pref != 255) {
+			wpa_printf(MSG_DEBUG,
+				   "Invalid MBO cellular capability %hhu",
+				   cell_pref);
+			return -1;
+		}
+
+		if (reassoc_delay &&
+		    !(req_mode & WNM_BSS_TM_REQ_DISASSOC_IMMINENT)) {
+			wpa_printf(MSG_DEBUG,
+				   "assoc retry delay is only valid in disassoc imminent mode");
+			return -1;
+		}
+
+		mbo[0] = MBO_ATTR_ID_TRANSITION_REASON;
+		mbo[1] = 1;
+		mbo[2] = mbo_reason;
+		mbo[3] = MBO_ATTR_ID_CELL_DATA_PREF;
+		mbo[4] = 1;
+		mbo[5] = cell_pref;
+
+		if (reassoc_delay) {
+			mbo[6] = MBO_ATTR_ID_ASSOC_RETRY_DELAY;
+			mbo[7] = 2;
+			WPA_PUT_LE16(mbo + 8, reassoc_delay);
+		}
+
+		mbo_len = reassoc_delay ? 10 : 6;
+	}
+
 	ret = wnm_send_bss_tm_req(hapd, sta, req_mode, disassoc_timer,
 				  valid_int, bss_term_dur, url,
 				  nei_pos > nei_rep ? nei_rep : NULL,
-				  nei_pos - nei_rep);
+				  nei_pos - nei_rep, mbo_len ? mbo : NULL,
+				  mbo_len);
 	os_free(url);
 	return ret;
 }
diff --git a/src/ap/wnm_ap.c b/src/ap/wnm_ap.c
index 4c8bc10..9c2d713 100644
--- a/src/ap/wnm_ap.c
+++ b/src/ap/wnm_ap.c
@@ -527,7 +527,8 @@ int wnm_send_ess_disassoc_imminent(struct hostapd_data *hapd,
 int wnm_send_bss_tm_req(struct hostapd_data *hapd, struct sta_info *sta,
 			u8 req_mode, int disassoc_timer, u8 valid_int,
 			const u8 *bss_term_dur, const char *url,
-			const u8 *nei_rep, size_t nei_rep_len)
+			const u8 *nei_rep, size_t nei_rep_len, u8 *mbo_attrs,
+			size_t mbo_len)
 {
 	u8 *buf, *pos;
 	struct ieee80211_mgmt *mgmt;
@@ -579,6 +580,10 @@ int wnm_send_bss_tm_req(struct hostapd_data *hapd, struct sta_info *sta,
 		pos += nei_rep_len;
 	}
 
+	if (mbo_len > 0)
+		pos += mbo_add_ie(pos, buf + sizeof(buf) - pos, mbo_attrs,
+				  mbo_len);
+
 	if (hostapd_drv_send_mlme(hapd, buf, pos - buf, 0) < 0) {
 		wpa_printf(MSG_DEBUG,
 			   "Failed to send BSS Transition Management Request frame");
diff --git a/src/ap/wnm_ap.h b/src/ap/wnm_ap.h
index 7789307..850ae20 100644
--- a/src/ap/wnm_ap.h
+++ b/src/ap/wnm_ap.h
@@ -21,6 +21,7 @@ int wnm_send_ess_disassoc_imminent(struct hostapd_data *hapd,
 int wnm_send_bss_tm_req(struct hostapd_data *hapd, struct sta_info *sta,
 			u8 req_mode, int disassoc_timer, u8 valid_int,
 			const u8 *bss_term_dur, const char *url,
-			const u8 *nei_rep, size_t nei_rep_len);
+			const u8 *nei_rep, size_t nei_rep_len, u8 *mbo_attrs,
+			size_t mbo_len);
 
 #endif /* WNM_AP_H */
-- 
1.9.1