P2P: Prefer U-NII-3 over U-NII-1 during channel selection

Some devices disable use of U-NII-1 (channels 36-48) for P2P due to it
being indoor use only in number of locations. If U-NII-3 (channels
149-161) is available, try to pick a channel from that range first
during random channel selection to reduce likelihood of interoperability
issues.

Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>

src/p2p/p2p.c

@@ -1180,8 +1180,8 @@ static int p2p_prepare_channel_pref(struct p2p_data *p2p,
 static void p2p_prepare_channel_best(struct p2p_data *p2p)
 {
 	u8 op_class, op_channel;
-	const int op_classes_5ghz[] = { 115, 124, 0 };
-	const int op_classes_ht40[] = { 116, 117, 126, 127, 0 };
+	const int op_classes_5ghz[] = { 124, 115, 0 };
+	const int op_classes_ht40[] = { 126, 127, 116, 117, 0 };
 	const int op_classes_vht[] = { 128, 0 };
 
 	p2p_dbg(p2p, "Prepare channel best");

src/p2p/p2p_go_neg.c

@@ -348,8 +348,8 @@ void p2p_reselect_channel(struct p2p_data *p2p,
 	int freq;
 	u8 op_reg_class, op_channel;
 	unsigned int i;
-	const int op_classes_5ghz[] = { 115, 124, 0 };
-	const int op_classes_ht40[] = { 116, 117, 126, 127, 0 };
+	const int op_classes_5ghz[] = { 124, 115, 0 };
+	const int op_classes_ht40[] = { 126, 127, 116, 117, 0 };
 	const int op_classes_vht[] = { 128, 0 };
 
 	if (p2p->own_freq_preference > 0 &&

src/p2p/p2p_utils.c

@@ -446,28 +446,25 @@ int p2p_channel_select(struct p2p_channels *chans, const int *classes,
 {
 	unsigned int i, j, r;
 
-	for (i = 0; i < chans->reg_classes; i++) {
-		struct p2p_reg_class *c = &chans->reg_class[i];
+	for (j = 0; classes[j]; j++) {
+		for (i = 0; i < chans->reg_classes; i++) {
+			struct p2p_reg_class *c = &chans->reg_class[i];
 
-		if (c->channels == 0)
-			continue;
+			if (c->channels == 0)
+				continue;
 
-		for (j = 0; classes[j]; j++) {
-			if (c->reg_class == classes[j])
-				break;
+			if (c->reg_class == classes[j]) {
+				/*
+				 * Pick one of the available channels in the
+				 * operating class at random.
+				 */
+				os_get_random((u8 *) &r, sizeof(r));
+				r %= c->channels;
+				*op_class = c->reg_class;
+				*op_channel = c->channel[r];
+				return 0;
+			}
 		}
-		if (!classes[j])
-			continue;
-
-		/*
-		 * Pick one of the available channels in the operating class at
-		 * random.
-		 */
-		os_get_random((u8 *) &r, sizeof(r));
-		r %= c->channels;
-		*op_class = c->reg_class;
-		*op_channel = c->channel[r];
-		return 0;
 	}
 
 	return -1;