DFS offload: Add main DFS handler for offloaded case

Add handling logic for DFS offloaded case, and add a helper function
that takes the frequency (MHz) as a param and returns 1 if given channel
requires DFS, or 0 otherwise.

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

src/ap/dfs.c

@@ -1,7 +1,7 @@
 /*
  * DFS - Dynamic Frequency Selection
  * Copyright (c) 2002-2013, Jouni Malinen <j@w1.fi>
- * Copyright (c) 2013, Qualcomm Atheros, Inc.
+ * Copyright (c) 2013-2015, Qualcomm Atheros, Inc.
  *
  * This software may be distributed under the terms of the BSD license.
  * See README for more details.
@@ -1012,3 +1012,53 @@ int hostapd_is_dfs_required(struct hostapd_iface *iface)
 		res = dfs_check_chans_radar(iface, start_chan_idx1, n_chans1);
 	return res;
 }
+
+
+int hostapd_dfs_start_cac(struct hostapd_iface *iface, int freq,
+			  int ht_enabled, int chan_offset, int chan_width,
+			  int cf1, int cf2)
+{
+	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_CAC_START
+		"freq=%d chan=%d chan_offset=%d width=%d seg0=%d "
+		"seg1=%d cac_time=%ds",
+		freq, (freq - 5000) / 5, chan_offset, chan_width, cf1, cf2, 60);
+	iface->cac_started = 1;
+	return 0;
+}
+
+
+/*
+ * Main DFS handler for offloaded case.
+ * 2 - continue channel/AP setup for non-DFS channel
+ * 1 - continue channel/AP setup for DFS channel
+ * 0 - channel/AP setup will be continued after CAC
+ * -1 - hit critical error
+ */
+int hostapd_handle_dfs_offload(struct hostapd_iface *iface)
+{
+	wpa_printf(MSG_DEBUG, "%s: iface->cac_started: %d",
+		   __func__, iface->cac_started);
+
+	/*
+	 * If DFS has already been started, then we are being called from a
+	 * callback to continue AP/channel setup. Reset the CAC start flag and
+	 * return.
+	 */
+	if (iface->cac_started) {
+		wpa_printf(MSG_DEBUG, "%s: iface->cac_started: %d",
+			   __func__, iface->cac_started);
+		iface->cac_started = 0;
+		return 1;
+	}
+
+	if (ieee80211_is_dfs(iface->freq)) {
+		wpa_printf(MSG_DEBUG, "%s: freq %d MHz requires DFS",
+			   __func__, iface->freq);
+		return 0;
+	}
+
+	wpa_printf(MSG_DEBUG,
+		   "%s: freq %d MHz does not require DFS. Continue channel/AP setup",
+		   __func__, iface->freq);
+	return 2;
+}

src/ap/dfs.h

@@ -22,5 +22,9 @@ int hostapd_dfs_nop_finished(struct hostapd_iface *iface, int freq,
 			     int ht_enabled,
 			     int chan_offset, int chan_width, int cf1, int cf2);
 int hostapd_is_dfs_required(struct hostapd_iface *iface);
+int hostapd_dfs_start_cac(struct hostapd_iface *iface, int freq,
+			  int ht_enabled, int chan_offset, int chan_width,
+			  int cf1, int cf2);
+int hostapd_handle_dfs_offload(struct hostapd_iface *iface);
 
 #endif /* DFS_H */

src/ap/drv_callbacks.c

@@ -1032,6 +1032,16 @@ static void hostapd_event_dfs_nop_finished(struct hostapd_data *hapd,
 				 radar->cf1, radar->cf2);
 }
 
+
+static void hostapd_event_dfs_cac_started(struct hostapd_data *hapd,
+					  struct dfs_event *radar)
+{
+	wpa_printf(MSG_DEBUG, "DFS offload CAC started on %d MHz", radar->freq);
+	hostapd_dfs_start_cac(hapd->iface, radar->freq, radar->ht_enabled,
+			      radar->chan_offset, radar->chan_width,
+			      radar->cf1, radar->cf2);
+}
+
 #endif /* NEED_AP_MLME */
 
 
@@ -1207,6 +1217,11 @@ void wpa_supplicant_event(void *ctx, enum wpa_event_type event,
 		hostapd_channel_list_updated(
 			hapd->iface, data->channel_list_changed.initiator);
 		break;
+	case EVENT_DFS_CAC_STARTED:
+		if (!data)
+			break;
+		hostapd_event_dfs_cac_started(hapd, &data->dfs_event);
+		break;
 #endif /* NEED_AP_MLME */
 	case EVENT_INTERFACE_ENABLED:
 		wpa_msg(hapd->msg_ctx, MSG_INFO, INTERFACE_ENABLED);

src/ap/hostapd.c

@@ -1377,6 +1377,7 @@ int hostapd_setup_interface_complete(struct hostapd_iface *iface, int err)
 	size_t j;
 	u8 *prev_addr;
 	int delay_apply_cfg = 0;
+	int res_dfs_offload = 0;
 
 	if (err)
 		goto fail;
@@ -1403,6 +1404,23 @@ int hostapd_setup_interface_complete(struct hostapd_iface *iface, int err)
 					goto fail;
 				return res;
 			}
+		} else {
+			/* If DFS is offloaded to the driver */
+			res_dfs_offload = hostapd_handle_dfs_offload(iface);
+			if (res_dfs_offload <= 0) {
+				if (res_dfs_offload < 0)
+					goto fail;
+			} else {
+				wpa_printf(MSG_DEBUG,
+					   "Proceed with AP/channel setup");
+				/*
+				 * If this is a DFS channel, move to completing
+				 * AP setup.
+				 */
+				if (res_dfs_offload == 1)
+					goto dfs_offload;
+				/* Otherwise fall through. */
+			}
 		}
 #endif /* NEED_AP_MLME */
 
@@ -1497,6 +1515,19 @@ int hostapd_setup_interface_complete(struct hostapd_iface *iface, int err)
 			goto fail;
 	}
 
+	if ((iface->drv_flags & WPA_DRIVER_FLAGS_DFS_OFFLOAD) &&
+	    !res_dfs_offload) {
+		/*
+		 * If freq is DFS, and DFS is offloaded to the driver, then wait
+		 * for CAC to complete.
+		 */
+		wpa_printf(MSG_DEBUG, "%s: Wait for CAC to complete", __func__);
+		return res_dfs_offload;
+	}
+
+#ifdef NEED_AP_MLME
+dfs_offload:
+#endif /* NEED_AP_MLME */
 	hostapd_set_state(iface, HAPD_IFACE_ENABLED);
 	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, AP_EVENT_ENABLED);
 	if (hapd->setup_complete_cb)

src/common/ieee802_11_common.c

@@ -826,6 +826,13 @@ int ieee80211_chan_to_freq(const char *country, u8 op_class, u8 chan)
 }
 
 
+int ieee80211_is_dfs(int freq)
+{
+	/* TODO: this could be more accurate to better cover all domains */
+	return (freq >= 5260 && freq <= 5320) || (freq >= 5500 && freq <= 5700);
+}
+
+
 static int is_11b(u8 rate)
 {
 	return rate == 0x02 || rate == 0x04 || rate == 0x0b || rate == 0x16;

src/common/ieee802_11_common.h

@@ -108,6 +108,7 @@ int hostapd_config_wmm_ac(struct hostapd_wmm_ac_params wmm_ac_params[],
 			  const char *name, const char *val);
 enum hostapd_hw_mode ieee80211_freq_to_chan(int freq, u8 *channel);
 int ieee80211_chan_to_freq(const char *country, u8 op_class, u8 chan);
+int ieee80211_is_dfs(int freq);
 
 int supp_rates_11b_only(struct ieee802_11_elems *elems);