[PATCH] WNM: Lower rankings of current AP if disassociation imminent bit set

[Po-Hao Huang]

If the current AP advertises disassociation imminent, move it to the
back of the candidate list so we don't select it again while other
candidates are available.
---
 wpa_supplicant/wnm_sta.c | 12 ++++++++++--
 wpa_supplicant/wnm_sta.h |  1 +
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/wpa_supplicant/wnm_sta.c b/wpa_supplicant/wnm_sta.c
index ac0dd1aa0..e1c9dc42a 100644
--- a/wpa_supplicant/wnm_sta.c
+++ b/wpa_supplicant/wnm_sta.c
@@ -1207,6 +1207,12 @@ static int cand_pref_compar(const void *a, const void *b)
 	const struct neighbor_report *aa = a;
 	const struct neighbor_report *bb = b;
 
+	if (aa->disassoc_imminent && bb->disassoc_imminent)
+		return 0;
+	if (aa->disassoc_imminent)
+		return 1;
+	if (bb->disassoc_imminent)
+		return -1;
 	if (!aa->preference_present && !bb->preference_present)
 		return 0;
 	if (!aa->preference_present)
@@ -1485,8 +1491,6 @@ static void ieee802_11_rx_bss_trans_mgmt_req(struct wpa_supplicant *wpa_s,
 		wpa_msg(wpa_s, MSG_INFO, "WNM: Disassociation Imminent - "
 			"Disassociation Timer %u", wpa_s->wnm_dissoc_timer);
 		if (wpa_s->wnm_dissoc_timer && !wpa_s->scanning) {
-			/* TODO: mark current BSS less preferred for
-			 * selection */
 			wpa_printf(MSG_DEBUG, "Trying to find another BSS");
 			wpa_supplicant_req_scan(wpa_s, 0, 0);
 		}
@@ -1526,6 +1530,10 @@ static void ieee802_11_rx_bss_trans_mgmt_req(struct wpa_supplicant *wpa_s,
 				rep = &wpa_s->wnm_neighbor_report_elements[
 					wpa_s->wnm_num_neighbor_report];
 				wnm_parse_neighbor_report(wpa_s, pos, len, rep);
+				if (wpa_s->wnm_mode & WNM_BSS_TM_REQ_DISASSOC_IMMINENT
+				    && os_memcmp(rep->bssid, wpa_s->bssid, ETH_ALEN) == 0)
+					rep->disassoc_imminent = 1;
+
 				wpa_s->wnm_num_neighbor_report++;
 #ifdef CONFIG_MBO
 				if (wpa_s->wnm_mbo_trans_reason_present &&
diff --git a/wpa_supplicant/wnm_sta.h b/wpa_supplicant/wnm_sta.h
index 29625f8ca..8d89b799b 100644
--- a/wpa_supplicant/wnm_sta.h
+++ b/wpa_supplicant/wnm_sta.h
@@ -37,6 +37,7 @@ struct neighbor_report {
 	u32 distance; /* valid if bearing_present=1 */
 	u64 bss_term_tsf; /* valid if bss_term_present=1 */
 	u16 bss_term_dur; /* valid if bss_term_present=1 */
+	u8 disassoc_imminent;
 	unsigned int preference_present:1;
 	unsigned int tsf_present:1;
 	unsigned int country_present:1;
-- 
2.25.1