P2P: ACS offload for the autonomous GO

This commit introduces the ACS functionality for the autonomous GO. The
optional parameter <freq> in p2p_group_add is enhanced to carry a value
"acs" with the intention to select the channels among any supported
band. freq = 2 / 5 carry the need to select the channels only in the
respective bands 2.4 / 5 GHz. This functionality is on top of the host
driver's capability to offload ACS, which is advertized through
WPA_DRIVER_FLAGS_ACS_OFFLOAD.

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

wpa_supplicant/ap.c

@@ -631,8 +631,10 @@ static void wpas_ap_configured_cb(void *ctx)
 	struct wpa_supplicant *wpa_s = ctx;
 
 #ifdef CONFIG_ACS
-	if (wpa_s->current_ssid && wpa_s->current_ssid->acs)
+	if (wpa_s->current_ssid && wpa_s->current_ssid->acs) {
 		wpa_s->assoc_freq = wpa_s->ap_iface->freq;
+		wpa_s->current_ssid->frequency = wpa_s->ap_iface->freq;
+	}
 #endif /* CONFIG_ACS */
 
 	wpa_supplicant_set_state(wpa_s, WPA_COMPLETED);
@@ -815,6 +817,14 @@ int wpa_supplicant_create_ap(struct wpa_supplicant *wpa_s,
 	os_memcpy(wpa_s->bssid, wpa_s->own_addr, ETH_ALEN);
 	wpa_s->assoc_freq = ssid->frequency;
 
+#if defined(CONFIG_P2P) && defined(CONFIG_ACS)
+	if (wpa_s->p2p_go_do_acs) {
+		wpa_s->ap_iface->conf->channel = 0;
+		wpa_s->ap_iface->conf->hw_mode = wpa_s->p2p_go_acs_band;
+		ssid->acs = 1;
+	}
+#endif /* CONFIG_P2P && CONFIG_ACS */
+
 	if (hostapd_setup_interface(wpa_s->ap_iface)) {
 		wpa_printf(MSG_ERROR, "Failed to initialize AP interface");
 		wpa_supplicant_ap_deinit(wpa_s);

wpa_supplicant/ctrl_iface.c

@@ -6241,13 +6241,21 @@ static int p2p_ctrl_group_add(struct wpa_supplicant *wpa_s, char *cmd)
 	int ht40 = wpa_s->conf->p2p_go_ht40 || vht;
 	int max_oper_chwidth, chwidth = 0, freq2 = 0;
 	char *token, *context = NULL;
+#ifdef CONFIG_ACS
+	int acs = 0;
+#endif /* CONFIG_ACS */
 
 	while ((token = str_token(cmd, " ", &context))) {
-		if (sscanf(token, "freq=%d", &freq) == 1 ||
-		    sscanf(token, "freq2=%d", &freq2) == 1 ||
+		if (sscanf(token, "freq2=%d", &freq2) == 1 ||
 		    sscanf(token, "persistent=%d", &group_id) == 1 ||
 		    sscanf(token, "max_oper_chwidth=%d", &chwidth) == 1) {
 			continue;
+#ifdef CONFIG_ACS
+		} else if (os_strcmp(token, "freq=acs") == 0) {
+			acs = 1;
+#endif /* CONFIG_ACS */
+		} else if (sscanf(token, "freq=%d", &freq) == 1) {
+			continue;
 		} else if (os_strcmp(token, "ht40") == 0) {
 			ht40 = 1;
 		} else if (os_strcmp(token, "vht") == 0) {
@@ -6263,6 +6271,24 @@ static int p2p_ctrl_group_add(struct wpa_supplicant *wpa_s, char *cmd)
 		}
 	}
 
+#ifdef CONFIG_ACS
+	if ((wpa_s->drv_flags & WPA_DRIVER_FLAGS_ACS_OFFLOAD) &&
+	    (acs || freq == 2 || freq == 5)) {
+		if (freq == 2 && wpa_s->best_24_freq <= 0) {
+			wpa_s->p2p_go_acs_band = HOSTAPD_MODE_IEEE80211G;
+			wpa_s->p2p_go_do_acs = 1;
+			freq = 0;
+		} else if (freq == 5 && wpa_s->best_5_freq <= 0) {
+			wpa_s->p2p_go_acs_band = HOSTAPD_MODE_IEEE80211A;
+			wpa_s->p2p_go_do_acs = 1;
+			freq = 0;
+		} else {
+			wpa_s->p2p_go_acs_band = HOSTAPD_MODE_IEEE80211ANY;
+			wpa_s->p2p_go_do_acs = 1;
+		}
+	}
+#endif /* CONFIG_ACS */
+
 	max_oper_chwidth = parse_freq(chwidth, freq2);
 	if (max_oper_chwidth < 0)
 		return -1;

wpa_supplicant/p2p_supplicant.c

@@ -6065,6 +6065,12 @@ wpas_p2p_get_group_iface(struct wpa_supplicant *wpa_s, int addr_allocated,
 		return NULL;
 	}
 
+	if (go && wpa_s->p2p_go_do_acs) {
+		group_wpa_s->p2p_go_do_acs = wpa_s->p2p_go_do_acs;
+		group_wpa_s->p2p_go_acs_band = wpa_s->p2p_go_acs_band;
+		wpa_s->p2p_go_do_acs = 0;
+	}
+
 	wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Use separate group interface %s",
 		group_wpa_s->ifname);
 	group_wpa_s->p2p_first_connection_timeout = 0;
@@ -6102,9 +6108,11 @@ int wpas_p2p_group_add(struct wpa_supplicant *wpa_s, int persistent_group,
 	wpa_printf(MSG_DEBUG, "P2P: Stop any on-going P2P FIND");
 	wpas_p2p_stop_find_oper(wpa_s);
 
-	freq = wpas_p2p_select_go_freq(wpa_s, freq);
-	if (freq < 0)
-		return -1;
+	if (!wpa_s->p2p_go_do_acs) {
+		freq = wpas_p2p_select_go_freq(wpa_s, freq);
+		if (freq < 0)
+			return -1;
+	}
 
 	if (wpas_p2p_init_go_params(wpa_s, &params, freq, vht_center_freq2,
 				    ht40, vht, max_oper_chwidth, NULL))

wpa_supplicant/wpa_supplicant_i.h

@@ -897,6 +897,7 @@ struct wpa_supplicant {
 
 	unsigned int p2p_auto_join:1;
 	unsigned int p2p_auto_pd:1;
+	unsigned int p2p_go_do_acs:1;
 	unsigned int p2p_persistent_group:1;
 	unsigned int p2p_fallback_to_go_neg:1;
 	unsigned int p2p_pd_before_go_neg:1;
@@ -912,6 +913,7 @@ struct wpa_supplicant {
 	unsigned int p2p_disable_ip_addr_req:1;
 	unsigned int p2ps_method_config_any:1;
 	unsigned int p2p_cli_probe:1;
+	enum hostapd_hw_mode p2p_go_acs_band;
 	int p2p_persistent_go_freq;
 	int p2p_persistent_id;
 	int p2p_go_intent;