1 /*
2  * hostapd / IEEE 802.11n HT
3  * Copyright (c) 2002-2009, Jouni Malinen <j@w1.fi>
4  * Copyright (c) 2007-2008, Intel Corporation
5  *
6  * This software may be distributed under the terms of the BSD license.
7  * See README for more details.
8  */
9 
10 #include "utils/includes.h"
11 
12 #include "utils/common.h"
13 #include "common/ieee802_11_defs.h"
14 #include "hostapd.h"
15 #include "ap_config.h"
16 #include "sta_info.h"
17 #include "beacon.h"
18 #include "ieee802_11.h"
19 
20 
21 u8 * hostapd_eid_ht_capabilities(struct hostapd_data *hapd, u8 *eid)
22 {
23 	struct ieee80211_ht_capabilities *cap;
24 	u8 *pos = eid;
25 
26 	if (!hapd->iconf->ieee80211n || !hapd->iface->current_mode ||
27 	    hapd->conf->disable_11n)
28 		return eid;
29 
30 	*pos++ = WLAN_EID_HT_CAP;
31 	*pos++ = sizeof(*cap);
32 
33 	cap = (struct ieee80211_ht_capabilities *) pos;
34 	os_memset(cap, 0, sizeof(*cap));
35 	cap->ht_capabilities_info = host_to_le16(hapd->iconf->ht_capab);
36 	cap->a_mpdu_params = hapd->iface->current_mode->a_mpdu_params;
37 	os_memcpy(cap->supported_mcs_set, hapd->iface->current_mode->mcs_set,
38 		  16);
39 
40 	/* TODO: ht_extended_capabilities (now fully disabled) */
41 	/* TODO: tx_bf_capability_info (now fully disabled) */
42 	/* TODO: asel_capabilities (now fully disabled) */
43 
44  	pos += sizeof(*cap);
45 
46 	if (hapd->iconf->obss_interval) {
47 		struct ieee80211_obss_scan_parameters *scan_params;
48 
49 		*pos++ = WLAN_EID_OVERLAPPING_BSS_SCAN_PARAMS;
50 		*pos++ = sizeof(*scan_params);
51 
52 		scan_params = (struct ieee80211_obss_scan_parameters *) pos;
53 		os_memset(scan_params, 0, sizeof(*scan_params));
54 		scan_params->width_trigger_scan_interval =
55 			host_to_le16(hapd->iconf->obss_interval);
56 
57 		/* TODO: Fill in more parameters (supplicant ignores them) */
58 
59 		pos += sizeof(*scan_params);
60 	}
61 
62 	return pos;
63 }
64 
65 
66 u8 * hostapd_eid_ht_operation(struct hostapd_data *hapd, u8 *eid)
67 {
68 	struct ieee80211_ht_operation *oper;
69 	u8 *pos = eid;
70 
71 	if (!hapd->iconf->ieee80211n || hapd->conf->disable_11n)
72 		return eid;
73 
74 	*pos++ = WLAN_EID_HT_OPERATION;
75 	*pos++ = sizeof(*oper);
76 
77 	oper = (struct ieee80211_ht_operation *) pos;
78 	os_memset(oper, 0, sizeof(*oper));
79 
80 	oper->control_chan = hapd->iconf->channel;
81 	oper->operation_mode = host_to_le16(hapd->iface->ht_op_mode);
82 	if (hapd->iconf->secondary_channel == 1)
83 		oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE |
84 			HT_INFO_HT_PARAM_REC_TRANS_CHNL_WIDTH;
85 	if (hapd->iconf->secondary_channel == -1)
86 		oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW |
87 			HT_INFO_HT_PARAM_REC_TRANS_CHNL_WIDTH;
88 
89 	pos += sizeof(*oper);
90 
91 	return pos;
92 }
93 
94 
95 /*
96 op_mode
97 Set to 0 (HT pure) under the followign conditions
98 	- all STAs in the BSS are 20/40 MHz HT in 20/40 MHz BSS or
99 	- all STAs in the BSS are 20 MHz HT in 20 MHz BSS
100 Set to 1 (HT non-member protection) if there may be non-HT STAs
101 	in both the primary and the secondary channel
102 Set to 2 if only HT STAs are associated in BSS,
103 	however and at least one 20 MHz HT STA is associated
104 Set to 3 (HT mixed mode) when one or more non-HT STAs are associated
105 */
106 int hostapd_ht_operation_update(struct hostapd_iface *iface)
107 {
108 	u16 cur_op_mode, new_op_mode;
109 	int op_mode_changes = 0;
110 
111 	if (!iface->conf->ieee80211n || iface->conf->ht_op_mode_fixed)
112 		return 0;
113 
114 	wpa_printf(MSG_DEBUG, "%s current operation mode=0x%X",
115 		   __func__, iface->ht_op_mode);
116 
117 	if (!(iface->ht_op_mode & HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT)
118 	    && iface->num_sta_ht_no_gf) {
119 		iface->ht_op_mode |=
120 			HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT;
121 		op_mode_changes++;
122 	} else if ((iface->ht_op_mode &
123 		    HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT) &&
124 		   iface->num_sta_ht_no_gf == 0) {
125 		iface->ht_op_mode &=
126 			~HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT;
127 		op_mode_changes++;
128 	}
129 
130 	if (!(iface->ht_op_mode & HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT) &&
131 	    (iface->num_sta_no_ht || iface->olbc_ht)) {
132 		iface->ht_op_mode |= HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT;
133 		op_mode_changes++;
134 	} else if ((iface->ht_op_mode &
135 		    HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT) &&
136 		   (iface->num_sta_no_ht == 0 && !iface->olbc_ht)) {
137 		iface->ht_op_mode &=
138 			~HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT;
139 		op_mode_changes++;
140 	}
141 
142 	new_op_mode = 0;
143 	if (iface->num_sta_no_ht)
144 		new_op_mode = OP_MODE_MIXED;
145 	else if (iface->conf->secondary_channel && iface->num_sta_ht_20mhz)
146 		new_op_mode = OP_MODE_20MHZ_HT_STA_ASSOCED;
147 	else if (iface->olbc_ht)
148 		new_op_mode = OP_MODE_MAY_BE_LEGACY_STAS;
149 	else
150 		new_op_mode = OP_MODE_PURE;
151 
152 	cur_op_mode = iface->ht_op_mode & HT_INFO_OPERATION_MODE_OP_MODE_MASK;
153 	if (cur_op_mode != new_op_mode) {
154 		iface->ht_op_mode &= ~HT_INFO_OPERATION_MODE_OP_MODE_MASK;
155 		iface->ht_op_mode |= new_op_mode;
156 		op_mode_changes++;
157 	}
158 
159 	wpa_printf(MSG_DEBUG, "%s new operation mode=0x%X changes=%d",
160 		   __func__, iface->ht_op_mode, op_mode_changes);
161 
162 	return op_mode_changes;
163 }
164 
165 
166 u16 copy_sta_ht_capab(struct hostapd_data *hapd, struct sta_info *sta,
167 		      const u8 *ht_capab, size_t ht_capab_len)
168 {
169 	/* Disable HT caps for STAs associated to no-HT BSSes. */
170 	if (!ht_capab ||
171 	    ht_capab_len < sizeof(struct ieee80211_ht_capabilities) ||
172 	    hapd->conf->disable_11n) {
173 		sta->flags &= ~WLAN_STA_HT;
174 		os_free(sta->ht_capabilities);
175 		sta->ht_capabilities = NULL;
176 		return WLAN_STATUS_SUCCESS;
177 	}
178 
179 	if (sta->ht_capabilities == NULL) {
180 		sta->ht_capabilities =
181 			os_zalloc(sizeof(struct ieee80211_ht_capabilities));
182 		if (sta->ht_capabilities == NULL)
183 			return WLAN_STATUS_UNSPECIFIED_FAILURE;
184 	}
185 
186 	sta->flags |= WLAN_STA_HT;
187 	os_memcpy(sta->ht_capabilities, ht_capab,
188 		  sizeof(struct ieee80211_ht_capabilities));
189 
190 	return WLAN_STATUS_SUCCESS;
191 }
192 
193 
194 static void update_sta_ht(struct hostapd_data *hapd, struct sta_info *sta)
195 {
196 	u16 ht_capab;
197 
198 	ht_capab = le_to_host16(sta->ht_capabilities->ht_capabilities_info);
199 	wpa_printf(MSG_DEBUG, "HT: STA " MACSTR " HT Capabilities Info: "
200 		   "0x%04x", MAC2STR(sta->addr), ht_capab);
201 	if ((ht_capab & HT_CAP_INFO_GREEN_FIELD) == 0) {
202 		if (!sta->no_ht_gf_set) {
203 			sta->no_ht_gf_set = 1;
204 			hapd->iface->num_sta_ht_no_gf++;
205 		}
206 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no greenfield, num "
207 			   "of non-gf stations %d",
208 			   __func__, MAC2STR(sta->addr),
209 			   hapd->iface->num_sta_ht_no_gf);
210 	}
211 	if ((ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) == 0) {
212 		if (!sta->ht_20mhz_set) {
213 			sta->ht_20mhz_set = 1;
214 			hapd->iface->num_sta_ht_20mhz++;
215 		}
216 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - 20 MHz HT, num of "
217 			   "20MHz HT STAs %d",
218 			   __func__, MAC2STR(sta->addr),
219 			   hapd->iface->num_sta_ht_20mhz);
220 	}
221 }
222 
223 
224 static void update_sta_no_ht(struct hostapd_data *hapd, struct sta_info *sta)
225 {
226 	if (!sta->no_ht_set) {
227 		sta->no_ht_set = 1;
228 		hapd->iface->num_sta_no_ht++;
229 	}
230 	if (hapd->iconf->ieee80211n) {
231 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no HT, num of "
232 			   "non-HT stations %d",
233 			   __func__, MAC2STR(sta->addr),
234 			   hapd->iface->num_sta_no_ht);
235 	}
236 }
237 
238 
239 void update_ht_state(struct hostapd_data *hapd, struct sta_info *sta)
240 {
241 	if ((sta->flags & WLAN_STA_HT) && sta->ht_capabilities)
242 		update_sta_ht(hapd, sta);
243 	else
244 		update_sta_no_ht(hapd, sta);
245 
246 	if (hostapd_ht_operation_update(hapd->iface) > 0)
247 		ieee802_11_set_beacons(hapd->iface);
248 }
249 
250 
251 void hostapd_get_ht_capab(struct hostapd_data *hapd,
252 			  struct ieee80211_ht_capabilities *ht_cap,
253 			  struct ieee80211_ht_capabilities *neg_ht_cap)
254 {
255 	u16 cap;
256 
257 	if (ht_cap == NULL)
258 		return;
259 	os_memcpy(neg_ht_cap, ht_cap, sizeof(*neg_ht_cap));
260 	cap = le_to_host16(neg_ht_cap->ht_capabilities_info);
261 
262 	/*
263 	 * Mask out HT features we don't support, but don't overwrite
264 	 * non-symmetric features like STBC and SMPS. Just because
265 	 * we're not in dynamic SMPS mode the STA might still be.
266 	 */
267 	cap &= (hapd->iconf->ht_capab | HT_CAP_INFO_RX_STBC_MASK |
268 		HT_CAP_INFO_TX_STBC | HT_CAP_INFO_SMPS_MASK);
269 
270 	/*
271 	 * STBC needs to be handled specially
272 	 * if we don't support RX STBC, mask out TX STBC in the STA's HT caps
273 	 * if we don't support TX STBC, mask out RX STBC in the STA's HT caps
274 	 */
275 	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_RX_STBC_MASK))
276 		cap &= ~HT_CAP_INFO_TX_STBC;
277 	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_TX_STBC))
278 		cap &= ~HT_CAP_INFO_RX_STBC_MASK;
279 
280 	neg_ht_cap->ht_capabilities_info = host_to_le16(cap);
281 }
282