P2P: Try using one of the social channels for GO

In case there is no preference for the GO operating channel,
try using one of 1, 6, 11 (randomly), and only if the random
selection is not suitable traverse all the channels 1..11.

Signed-off-by: Ilan Peer <ilan.peer@intel.com>

wpa_supplicant/p2p_supplicant.c

@@ -5014,6 +5014,39 @@ static int wpas_p2p_select_go_freq(struct wpa_supplicant *wpa_s, int freq)
 }
 
 
+static int wpas_p2p_select_freq_no_pref(struct wpa_supplicant *wpa_s,
+					struct p2p_go_neg_results *params,
+					const struct p2p_channels *channels)
+{
+	unsigned int i, r;
+
+	/* first try some random selection of the social channels */
+	os_get_random((u8 *) &r, sizeof(r));
+
+	for (i = 0; i < 3; i++) {
+		params->freq = 2412 + ((r + i) % 3) * 25;
+		if (!wpas_p2p_disallowed_freq(wpa_s->global, params->freq) &&
+		    freq_included(channels, params->freq))
+			goto out;
+	}
+
+	/* try all channels in reg. class 81 */
+	for (i = 0; i < 11; i++) {
+		params->freq = 2412 + i * 5;
+		if (!wpas_p2p_disallowed_freq(wpa_s->global, params->freq) &&
+		    freq_included(channels, params->freq))
+			goto out;
+	}
+
+	wpa_printf(MSG_DEBUG, "P2P: No 2.4 GHz channel allowed");
+	return -1;
+out:
+	wpa_printf(MSG_DEBUG, "P2P: Set GO freq %d MHz (no preference known)",
+		   params->freq);
+	return 0;
+}
+
+
 static int wpas_p2p_init_go_params(struct wpa_supplicant *wpa_s,
 				   struct p2p_go_neg_results *params,
 				   int freq, int ht40, int vht,
@@ -5085,21 +5118,9 @@ static int wpas_p2p_init_go_params(struct wpa_supplicant *wpa_s,
 		wpa_printf(MSG_DEBUG, "P2P: Set GO freq %d MHz from preferred "
 			   "channels", params->freq);
 	} else {
-		int chan;
-		for (chan = 0; chan < 11; chan++) {
-			params->freq = 2412 + chan * 5;
-			if (!wpas_p2p_disallowed_freq(wpa_s->global,
-						      params->freq) &&
-			    freq_included(channels, params->freq))
-				break;
-		}
-		if (chan == 11) {
-			wpa_printf(MSG_DEBUG, "P2P: No 2.4 GHz channel "
-				   "allowed");
+		/* no preference, select some channel */
+		if (wpas_p2p_select_freq_no_pref(wpa_s, params, channels) < 0)
 			return -1;
-		}
-		wpa_printf(MSG_DEBUG, "P2P: Set GO freq %d MHz (no preference "
-			   "known)", params->freq);
 	}
 
 	freqs = os_calloc(wpa_s->num_multichan_concurrent,