AP: Add initial support for 6 GHz band

Add support for new hardware mode for 6 GHz band. 6 GHz operation is
defined in IEEE P802.11ax/D4.3. 6 GHz band adds global operating classes
131-135 that define channels in frequency range from 5940 MHz to 7105
MHz.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>

- Remove HOSTAPD_MODE_IEEE80211AX mode
- Replace check for HOSTAPD_MODE_IEEE80211AX with is_6ghz_freq()
- Move center_idx_to_bw_6ghz() to ieee802_11_common.c file

Signed-off-by: Vamsi Krishna <vamsin@codeaurora.org>

hostapd/hostapd.conf

@@ -146,7 +146,8 @@ ssid=test
 # Operation mode (a = IEEE 802.11a (5 GHz), b = IEEE 802.11b (2.4 GHz),
 # g = IEEE 802.11g (2.4 GHz), ad = IEEE 802.11ad (60 GHz); a/g options are used
 # with IEEE 802.11n (HT), too, to specify band). For IEEE 802.11ac (VHT), this
-# needs to be set to hw_mode=a. When using ACS (see channel parameter), a
+# needs to be set to hw_mode=a. For IEEE 802.11ax (HE) on 6 GHz this needs
+# to be set to hw_mode=a. When using ACS (see channel parameter), a
 # special value "any" can be used to indicate that any support band can be used.
 # This special case is currently supported only with drivers with which
 # offloaded ACS is used.
@@ -805,6 +806,11 @@ wmm_ac_vo_acm=0
 #he_rts_threshold=0
 
 # HE operating channel information; see matching vht_* parameters for details.
+# On the 6 GHz band the center freq calculation starts from 5.940 GHz offset.
+# For example idx=3 would result in 5955 MHz center frequency. In addition,
+# he_oper_chwidth is ignored, and the channel width is derived from the
+# configured operating class or center frequency indexes (see
+# IEEE P802.11ax/D4.3 Annex E, Table E-4).
 #he_oper_chwidth
 #he_oper_centr_freq_seg0_idx
 #he_oper_centr_freq_seg1_idx

src/common/hw_features_common.c

@@ -385,6 +385,71 @@ int hostapd_set_freq_params(struct hostapd_freq_params *data,
 	hostapd_encode_edmg_chan(enable_edmg, edmg_channel, channel,
 				 &data->edmg);
 
+	if (is_6ghz_freq(freq)) {
+		if (!data->he_enabled) {
+			wpa_printf(MSG_ERROR,
+				   "Can't set 6 GHz mode - HE isn't enabled");
+			return -1;
+		}
+
+		if (center_idx_to_bw_6ghz(channel) != 0) {
+			wpa_printf(MSG_ERROR,
+				   "Invalid control channel for 6 GHz band");
+			return -1;
+		}
+
+		if (!center_segment0) {
+			if (center_segment1) {
+				wpa_printf(MSG_ERROR,
+					   "Segment 0 center frequency isn't set");
+				return -1;
+			}
+
+			data->center_freq1 = data->freq;
+			data->bandwidth = 20;
+		} else {
+			int freq1, freq2 = 0;
+			int bw = center_idx_to_bw_6ghz(center_segment0);
+
+			if (bw < 0) {
+				wpa_printf(MSG_ERROR,
+					   "Invalid center frequency index for 6 GHz");
+				return -1;
+			}
+
+			freq1 = ieee80211_chan_to_freq(NULL, 131,
+						       center_segment0);
+			if (freq1 < 0) {
+				wpa_printf(MSG_ERROR,
+					   "Invalid segment 0 center frequency for 6 GHz");
+				return -1;
+			}
+
+			if (center_segment1) {
+				if (center_idx_to_bw_6ghz(center_segment1) != 2 ||
+				    bw != 2) {
+					wpa_printf(MSG_ERROR,
+						   "6 GHz 80+80 MHz configuration doesn't use valid 80 MHz channels");
+					return -1;
+				}
+
+				freq2 = ieee80211_chan_to_freq(NULL, 131,
+							       center_segment1);
+				if (freq2 < 0) {
+					wpa_printf(MSG_ERROR,
+						   "Invalid segment 1 center frequency for UHB");
+					return -1;
+				}
+			}
+
+			data->bandwidth = (1 << (u8) bw) * 20;
+			data->center_freq1 = freq1;
+			data->center_freq2 = freq2;
+		}
+
+		return 0;
+	}
+
 	if (data->vht_enabled) switch (oper_chwidth) {
 	case CHANWIDTH_USE_HT:
 		if (center_segment1 ||

src/common/ieee802_11_common.c

@@ -882,6 +882,19 @@ enum hostapd_hw_mode ieee80211_freq_to_channel_ext(unsigned int freq,
 		return HOSTAPD_MODE_IEEE80211AD;
 	}
 
+	if (freq > 5940 && freq <= 7105) {
+		int bw;
+		u8 idx = (freq - 5940) / 5;
+
+		bw = center_idx_to_bw_6ghz(idx);
+		if (bw < 0)
+			return NUM_HOSTAPD_MODES;
+
+		*channel = idx;
+		*op_class = 131 + bw;
+		return HOSTAPD_MODE_IEEE80211A;
+	}
+
 	return NUM_HOSTAPD_MODES;
 }
 
@@ -1161,6 +1174,14 @@ static int ieee80211_chan_to_freq_global(u8 op_class, u8 chan)
 		if (chan < 36 || chan > 128)
 			return -1;
 		return 5000 + 5 * chan;
+	case 131: /* UHB channels, 20 MHz: 1, 5, 9.. */
+	case 132: /* UHB channels, 40 MHz: 3, 11, 19.. */
+	case 133: /* UHB channels, 80 MHz: 7, 23, 39.. */
+	case 134: /* UHB channels, 160 MHz: 15, 47, 79.. */
+	case 135: /* UHB channels, 80+80 MHz: 7, 23, 39.. */
+		if (chan < 1 || chan > 233)
+			return -1;
+		return 5940 + chan * 5;
 	case 180: /* 60 GHz band, channels 1..6 */
 		if (chan < 1 || chan > 6)
 			return -1;
@@ -1591,6 +1612,7 @@ const struct oper_class_map global_op_class[] = {
 	{ HOSTAPD_MODE_IEEE80211A, 128, 36, 161, 4, BW80, P2P_SUPP },
 	{ HOSTAPD_MODE_IEEE80211A, 129, 50, 114, 16, BW160, P2P_SUPP },
 	{ HOSTAPD_MODE_IEEE80211A, 130, 36, 161, 4, BW80P80, P2P_SUPP },
+	{ HOSTAPD_MODE_IEEE80211A, 131, 1, 233, 4, BW20, P2P_SUPP },
 	{ HOSTAPD_MODE_IEEE80211AD, 180, 1, 4, 1, BW2160, P2P_SUPP },
 	{ -1, 0, 0, 0, 0, BW20, NO_P2P_SUPP }
 };
@@ -1905,6 +1927,37 @@ int oper_class_bw_to_int(const struct oper_class_map *map)
 }
 
 
+int center_idx_to_bw_6ghz(u8 idx)
+{
+	/* channels: 1, 5, 9, 13... */
+	if ((idx & 0x3) == 0x1)
+		return 0; /* 20 MHz */
+	/* channels 3, 11, 19... */
+	if ((idx & 0x7) == 0x3)
+		return 1; /* 40 MHz */
+	/* channels 7, 23, 39.. */
+	if ((idx & 0xf) == 0x7)
+		return 2; /* 80 MHz */
+	/* channels 15, 47, 79...*/
+	if ((idx & 0x1f) == 0xf)
+		return 3; /* 160 MHz */
+
+	return -1;
+}
+
+
+int is_6ghz_freq(int freq)
+{
+	if (freq < 5940 || freq > 7105)
+		return 0;
+
+	if (center_idx_to_bw_6ghz((freq - 5940) / 5) < 0)
+		return 0;
+
+	return 1;
+}
+
+
 int ieee802_11_parse_candidate_list(const char *pos, u8 *nei_rep,
 				    size_t nei_rep_len)
 {

src/common/ieee802_11_common.h

@@ -220,6 +220,8 @@ u8 country_to_global_op_class(const char *country, u8 op_class);
 
 const struct oper_class_map * get_oper_class(const char *country, u8 op_class);
 int oper_class_bw_to_int(const struct oper_class_map *map);
+int center_idx_to_bw_6ghz(u8 idx);
+int is_6ghz_freq(int freq);
 
 int ieee802_11_parse_candidate_list(const char *pos, u8 *nei_rep,
 				    size_t nei_rep_len);