[PATCH v2 11/13] station: adapt roam scan logic to look at the bss group

[James Prestwood <prestwoj@gmail.com>]

In station_roam_scan_notify BSS candidates were being ignored if
their rank was not better than the current AP. This check needed
to be changed to first check the BSS group, then the rank (only
if the groups were equal). This takes into account the current BSS
roam blacklisting status rather than only rank.
---
 src/station.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/src/station.c b/src/station.c
index 066ca337..092d0b4d 100644
--- a/src/station.c
+++ b/src/station.c
@@ -2801,6 +2801,7 @@ static bool station_roam_scan_notify(int err, struct l_queue *bss_list,
 	struct handshake_state *hs = netdev_get_handshake(station->netdev);
 	struct scan_bss *current_bss = station->connected_bss;
 	struct scan_bss *bss;
+	enum scan_bss_group cur_bss_group = SCAN_BSS_GROUP_BLACKLISTED;
 	double cur_bss_rank = 0.0;
 	static const double RANK_FT_FACTOR = 1.3;
 	uint16_t mdid;
@@ -2831,6 +2832,9 @@ static bool station_roam_scan_notify(int err, struct l_queue *bss_list,
 	bss = l_queue_find(bss_list, bss_match_bssid, current_bss->addr);
 	if (bss && !station->ap_directed_roaming) {
 		cur_bss_rank = bss->rank;
+		cur_bss_group = scan_bss_evaluate_group(
+						current_bss->addr,
+						current_bss->signal_strength);
 
 		if (hs->mde && bss->mde_present && l_get_le16(bss->mde) == mdid)
 			cur_bss_rank *= RANK_FT_FACTOR;
@@ -2855,6 +2859,9 @@ static bool station_roam_scan_notify(int err, struct l_queue *bss_list,
 	while ((bss = l_queue_pop_head(bss_list))) {
 		double rank;
 		struct roam_bss *rbss;
+		enum scan_bss_group group = scan_bss_evaluate_group(
+							bss->addr,
+							bss->signal_strength);
 
 		station_print_scan_bss(bss);
 
@@ -2876,8 +2883,7 @@ static bool station_roam_scan_notify(int err, struct l_queue *bss_list,
 		if (network_can_connect_bss(network, bss) < 0)
 			goto next;
 
-		if (blacklist_contains_bss(bss->addr,
-					BLACKLIST_REASON_CONNECT_FAILED))
+		if (group == SCAN_BSS_GROUP_BLACKLISTED)
 			goto next;
 
 		rank = bss->rank;
@@ -2885,7 +2891,15 @@ static bool station_roam_scan_notify(int err, struct l_queue *bss_list,
 		if (hs->mde && bss->mde_present && l_get_le16(bss->mde) == mdid)
 			rank *= RANK_FT_FACTOR;
 
-		if (rank <= cur_bss_rank)
+		/*
+		 * First check the group:
+		 *   - If worse, disregard BSS candidate
+		 *   - If better, keep BSS candidate
+		 *   - If equal, compare based on rank
+		 */
+		if (group < cur_bss_group)
+			goto next;
+		else if (group == cur_bss_group && rank <= cur_bss_rank)
 			goto next;
 
 		/*
-- 
2.34.1