Add cfg option for initial channel scan feature

Signed-off-by: Filip Matusiak <filip.matusiak@iopsys.eu>

README.md

@@ -33,6 +33,7 @@ config controller 'controller'
 	option enable_bsta_steer '0'
 	option use_bcn_metrics '0'
 	option use_usta_metrics '0'
+	option initial_channel_scan '0'
 	option primary_vid '1'
 	option primary_pcp '0'
 	option allow_bgdfs '0'
@@ -400,8 +401,18 @@ config:
 config controller 'controller'
         option enable_sta_steer '1'
         option use_bcn_metrics '1'
+		option initial_channel_scan '1'
 ```
 
+BTM steering may also work fine w/o the initial_channel_scan set - it
+depends on the bottom layer implementation.
+
+Setting the initial_channel_scan option itself will cause a radio scan request
+to be issued towards given node and it's reported radios, providing there was
+no prior scan results reported on given radio. This radio channel scan will
+be issued once controller obtains first scan capability information tlv from
+given node. Radios, opclasses and channels to scan depend on these scan caps.
+
 The steering decision is based upon drop of the STA RCPI below certain
 threshold, which can be modified per radio via UCI config:
 

src/cntlr_map.c

@@ -1009,13 +1009,16 @@ static int cntlr_parse_radio_scan_caps(struct controller *c, struct node *n,
 
 
 		/* put addr into an array of radio MACs to be scanned */
+		if (c->cfg.initial_channel_scan)
 			memcpy(&radio_id[num_radio],
 					nr->radio_el->macaddr,
 					6);
+
 		num_radio++;
 	}
 
 	/* issue a channel scan on reported radios */
+	if (c->cfg.initial_channel_scan)
 		cntlr_initial_channel_scan_from_caps(c, n, radio_id, num_radio);
 
 	return 0;

src/config.c

@@ -563,6 +563,7 @@ static int cntlr_config_get_base(struct controller_config *c,
 		CNTLR_ENABLE_BSTA_STEER,
 		CNTLR_USE_BCN_METRICS,
 		CNTLR_USE_USTA_METRICS,
+		CNTLR_INITIAL_CHANNEL_SCAN,
 		CNTLR_STEER_MODULE,
 		CNTLR_CHANNEL_PLAN_TIMEOUT,
 		CNTLR_BGDFS_TIMEOUT,
@@ -580,6 +581,7 @@ static int cntlr_config_get_base(struct controller_config *c,
 		{ .name = "enable_bsta_steer", .type = UCI_TYPE_STRING },
 		{ .name = "use_bcn_metrics", .type = UCI_TYPE_STRING },
 		{ .name = "use_usta_metrics", .type = UCI_TYPE_STRING },
+		{ .name = "initial_channel_scan", .type = UCI_TYPE_STRING },
 		{ .name = "steer_module", .type = UCI_TYPE_LIST },
 		{ .name = "channel_plan", .type = UCI_TYPE_STRING },
 		{ .name = "allow_bgdfs", .type = UCI_TYPE_STRING },
@@ -643,6 +645,12 @@ static int cntlr_config_get_base(struct controller_config *c,
 		c->use_usta_metrics = atoi(val) == 1 ? true : false;
 	}
 
+	if (tb[CNTLR_INITIAL_CHANNEL_SCAN]) {
+		const char *val = tb[CNTLR_INITIAL_CHANNEL_SCAN]->v.string;
+
+		c->initial_channel_scan = atoi(val) == 1 ? true : false;
+	}
+
 	if (tb[CNTLR_STEER_MODULE]) {
 		struct uci_element *e;
 		struct steer_control_config *sc;

src/config.h

@@ -127,6 +127,7 @@ struct controller_config {
 	bool enable_bsta_steer;
 	bool use_bcn_metrics;
 	bool use_usta_metrics;
+	bool initial_channel_scan;
 	int num_bss;
 	int num_apolicy;
 	int acs_timeout;