policy: don't track roam_scan_done

[project/usteer.git] / policy.c

diff --git a/policy.c b/policy.c
index 67c9c75be2b255302b8cb445fea09dc10d998c4e..9d03b30b9ba23ea6e32f44ccf939647ae82d3d00 100644 (file)
--- a/policy.c
+++ b/policy.c
@@ -110,7 +110,7 @@ is_better_candidate(struct sta_info *si_cur, struct sta_info *si_new)
 }
 
 static struct sta_info *
-find_better_candidate(struct sta_info *si_ref, struct uevent *ev, uint32_t required_criteria)
+find_better_candidate(struct sta_info *si_ref, struct uevent *ev, uint32_t required_criteria, uint64_t max_age)
 {
        struct sta_info *si;
        struct sta *sta = si_ref->sta;
@@ -126,6 +126,9 @@ find_better_candidate(struct sta_info *si_ref, struct uevent *ev, uint32_t requi
                if (strcmp(si->node->ssid, si_ref->node->ssid) != 0)
                        continue;
 
+               if (max_age && max_age < current_time - si->seen)
+                       continue;
+
                reasons = is_better_candidate(si_ref, si);
                if (!reasons)
                        continue;
@@ -204,7 +207,7 @@ usteer_check_request(struct sta_info *si, enum usteer_event_type type)
                goto out;
        }
 
-       if (!find_better_candidate(si, &ev, UEV_SELECT_REASON_ALL))
+       if (!find_better_candidate(si, &ev, UEV_SELECT_REASON_ALL, 0))
                goto out;
 
        ev.reason = UEV_REASON_BETTER_CANDIDATE;
@@ -283,7 +286,7 @@ usteer_roam_sm_start_scan(struct sta_info *si, struct uevent *ev)
        }
 
        /* We are currently in scan timeout / cooldown.
-        * Check if we are in ROAM_TRIGGER_IDLE state and enter this stateif not.
+        * Check if we are in ROAM_TRIGGER_IDLE state. Enter this state if not.
         */
        if (si->roam_state == ROAM_TRIGGER_IDLE)
                return;
@@ -292,27 +295,47 @@ usteer_roam_sm_start_scan(struct sta_info *si, struct uevent *ev)
        usteer_roam_set_state(si, ROAM_TRIGGER_IDLE, ev);
 }
 
+static bool
+usteer_roam_sm_found_better_node(struct sta_info *si, struct uevent *ev, enum roam_trigger_state next_state)
+{
+       uint64_t max_age = 2 * config.roam_scan_interval;
+
+       if (max_age > current_time - si->roam_scan_start)
+               max_age = current_time - si->roam_scan_start;
+
+       if (find_better_candidate(si, ev, (1 << UEV_SELECT_REASON_SIGNAL), max_age)) {
+               usteer_roam_set_state(si, next_state, ev);
+               return true;
+       }
+
+       return false;
+}
+
 static bool
 usteer_roam_trigger_sm(struct sta_info *si)
 {
        struct uevent ev = {
                .si_cur = si,
        };
-       int min_signal;
+       uint64_t min_signal;
 
        min_signal = usteer_snr_to_signal(si->node, config.roam_trigger_snr);
 
        switch (si->roam_state) {
        case ROAM_TRIGGER_SCAN:
-               if (current_time - si->roam_event < config.roam_scan_interval)
+               if (!si->roam_tries) {
+                       si->roam_scan_start = current_time;
+               }
+
+               /* Check if we've found a better node regardless of the scan-interval */
+               if (usteer_roam_sm_found_better_node(si, &ev, ROAM_TRIGGER_SCAN_DONE))
                        break;
 
-               if (find_better_candidate(si, &ev, (1 << UEV_SELECT_REASON_SIGNAL)) ||
-                   si->roam_scan_done > si->roam_event) {
-                       usteer_roam_set_state(si, ROAM_TRIGGER_SCAN_DONE, &ev);
+               /* Only scan every scan-interval */
+               if (current_time - si->roam_event < config.roam_scan_interval)
                        break;
-               }
 
+               /* Check if no node was found within roam_scan_tries tries */
                if (config.roam_scan_tries && si->roam_tries >= config.roam_scan_tries) {
                        if (!config.roam_scan_timeout) {
                                /* Prepare to kick client */
@@ -325,29 +348,21 @@ usteer_roam_trigger_sm(struct sta_info *si)
                        break;
                }
 
+               /* Send beacon-request to client */
                usteer_ubus_trigger_client_scan(si);
                usteer_roam_sm_start_scan(si, &ev);
                break;
 
        case ROAM_TRIGGER_IDLE:
-               if (find_better_candidate(si, &ev, (1 << UEV_SELECT_REASON_SIGNAL))) {
-                       usteer_roam_set_state(si, ROAM_TRIGGER_SCAN_DONE, &ev);
-                       break;
-               }
-
                usteer_roam_sm_start_scan(si, &ev);
                break;
 
        case ROAM_TRIGGER_SCAN_DONE:
-               /* Check for stale scan results, kick back to SCAN state if necessary */
-               if (current_time - si->roam_scan_done > 2 * config.roam_scan_interval) {
-                       usteer_roam_sm_start_scan(si, &ev);
+               if (usteer_roam_sm_found_better_node(si, &ev, ROAM_TRIGGER_WAIT_KICK))
                        break;
-               }
-
-               if (find_better_candidate(si, &ev, (1 << UEV_SELECT_REASON_SIGNAL)))
-                       usteer_roam_set_state(si, ROAM_TRIGGER_WAIT_KICK, &ev);
 
+               /* Kick back to SCAN state if candidate expired */
+               usteer_roam_sm_start_scan(si, &ev);
                break;
 
        case ROAM_TRIGGER_WAIT_KICK:
@@ -495,7 +510,7 @@ usteer_local_node_kick(struct usteer_local_node *ln)
                if (is_more_kickable(kick1, si))
                        kick1 = si;
 
-               tmp = find_better_candidate(si, NULL, (1 << UEV_SELECT_REASON_LOAD));
+               tmp = find_better_candidate(si, NULL, (1 << UEV_SELECT_REASON_LOAD), 0);
                if (!tmp)
                        continue;