xref: /freebsd/contrib/wpa/src/ap/ieee802_11_ht.c (revision 884a2a699669ec61e2366e3e358342dbc94be24a)
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 program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  * Alternatively, this software may be distributed under the terms of BSD
11  * license.
12  *
13  * See README and COPYING for more details.
14  */
15 
16 #include "utils/includes.h"
17 
18 #include "utils/common.h"
19 #include "common/ieee802_11_defs.h"
20 #include "drivers/driver.h"
21 #include "hostapd.h"
22 #include "ap_config.h"
23 #include "sta_info.h"
24 #include "beacon.h"
25 #include "ieee802_11.h"
26 
27 
28 u8 * hostapd_eid_ht_capabilities(struct hostapd_data *hapd, u8 *eid)
29 {
30 	struct ieee80211_ht_capabilities *cap;
31 	u8 *pos = eid;
32 
33 	if (!hapd->iconf->ieee80211n || !hapd->iface->current_mode)
34 		return eid;
35 
36 	*pos++ = WLAN_EID_HT_CAP;
37 	*pos++ = sizeof(*cap);
38 
39 	cap = (struct ieee80211_ht_capabilities *) pos;
40 	os_memset(cap, 0, sizeof(*cap));
41 	cap->ht_capabilities_info = host_to_le16(hapd->iconf->ht_capab);
42 	cap->a_mpdu_params = hapd->iface->current_mode->a_mpdu_params;
43 	os_memcpy(cap->supported_mcs_set, hapd->iface->current_mode->mcs_set,
44 		  16);
45 
46 	/* TODO: ht_extended_capabilities (now fully disabled) */
47 	/* TODO: tx_bf_capability_info (now fully disabled) */
48 	/* TODO: asel_capabilities (now fully disabled) */
49 
50  	pos += sizeof(*cap);
51 
52 	return pos;
53 }
54 
55 
56 u8 * hostapd_eid_ht_operation(struct hostapd_data *hapd, u8 *eid)
57 {
58 	struct ieee80211_ht_operation *oper;
59 	u8 *pos = eid;
60 
61 	if (!hapd->iconf->ieee80211n)
62 		return eid;
63 
64 	*pos++ = WLAN_EID_HT_OPERATION;
65 	*pos++ = sizeof(*oper);
66 
67 	oper = (struct ieee80211_ht_operation *) pos;
68 	os_memset(oper, 0, sizeof(*oper));
69 
70 	oper->control_chan = hapd->iconf->channel;
71 	oper->operation_mode = host_to_le16(hapd->iface->ht_op_mode);
72 	if (hapd->iconf->secondary_channel == 1)
73 		oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE |
74 			HT_INFO_HT_PARAM_REC_TRANS_CHNL_WIDTH;
75 	if (hapd->iconf->secondary_channel == -1)
76 		oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW |
77 			HT_INFO_HT_PARAM_REC_TRANS_CHNL_WIDTH;
78 
79 	pos += sizeof(*oper);
80 
81 	return pos;
82 }
83 
84 
85 /*
86 op_mode
87 Set to 0 (HT pure) under the followign conditions
88 	- all STAs in the BSS are 20/40 MHz HT in 20/40 MHz BSS or
89 	- all STAs in the BSS are 20 MHz HT in 20 MHz BSS
90 Set to 1 (HT non-member protection) if there may be non-HT STAs
91 	in both the primary and the secondary channel
92 Set to 2 if only HT STAs are associated in BSS,
93 	however and at least one 20 MHz HT STA is associated
94 Set to 3 (HT mixed mode) when one or more non-HT STAs are associated
95 	(currently non-GF HT station is considered as non-HT STA also)
96 */
97 int hostapd_ht_operation_update(struct hostapd_iface *iface)
98 {
99 	u16 cur_op_mode, new_op_mode;
100 	int op_mode_changes = 0;
101 
102 	if (!iface->conf->ieee80211n || iface->conf->ht_op_mode_fixed)
103 		return 0;
104 
105 	wpa_printf(MSG_DEBUG, "%s current operation mode=0x%X",
106 		   __func__, iface->ht_op_mode);
107 
108 	if (!(iface->ht_op_mode & HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT)
109 	    && iface->num_sta_ht_no_gf) {
110 		iface->ht_op_mode |=
111 			HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT;
112 		op_mode_changes++;
113 	} else if ((iface->ht_op_mode &
114 		    HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT) &&
115 		   iface->num_sta_ht_no_gf == 0) {
116 		iface->ht_op_mode &=
117 			~HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT;
118 		op_mode_changes++;
119 	}
120 
121 	if (!(iface->ht_op_mode & HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT) &&
122 	    (iface->num_sta_no_ht || iface->olbc_ht)) {
123 		iface->ht_op_mode |= HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT;
124 		op_mode_changes++;
125 	} else if ((iface->ht_op_mode &
126 		    HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT) &&
127 		   (iface->num_sta_no_ht == 0 && !iface->olbc_ht)) {
128 		iface->ht_op_mode &=
129 			~HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT;
130 		op_mode_changes++;
131 	}
132 
133 	/* Note: currently we switch to the MIXED op mode if HT non-greenfield
134 	 * station is associated. Probably it's a theoretical case, since
135 	 * it looks like all known HT STAs support greenfield.
136 	 */
137 	new_op_mode = 0;
138 	if (iface->num_sta_no_ht ||
139 	    (iface->ht_op_mode & HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT))
140 		new_op_mode = OP_MODE_MIXED;
141 	else if ((iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET)
142 		 && iface->num_sta_ht_20mhz)
143 		new_op_mode = OP_MODE_20MHZ_HT_STA_ASSOCED;
144 	else if (iface->olbc_ht)
145 		new_op_mode = OP_MODE_MAY_BE_LEGACY_STAS;
146 	else
147 		new_op_mode = OP_MODE_PURE;
148 
149 	cur_op_mode = iface->ht_op_mode & HT_INFO_OPERATION_MODE_OP_MODE_MASK;
150 	if (cur_op_mode != new_op_mode) {
151 		iface->ht_op_mode &= ~HT_INFO_OPERATION_MODE_OP_MODE_MASK;
152 		iface->ht_op_mode |= new_op_mode;
153 		op_mode_changes++;
154 	}
155 
156 	wpa_printf(MSG_DEBUG, "%s new operation mode=0x%X changes=%d",
157 		   __func__, iface->ht_op_mode, op_mode_changes);
158 
159 	return op_mode_changes;
160 }
161 
162 
163 u16 copy_sta_ht_capab(struct sta_info *sta, const u8 *ht_capab,
164 		      size_t ht_capab_len)
165 {
166 	if (!ht_capab ||
167 	    ht_capab_len < sizeof(struct ieee80211_ht_capabilities)) {
168 		sta->flags &= ~WLAN_STA_HT;
169 		os_free(sta->ht_capabilities);
170 		sta->ht_capabilities = NULL;
171 		return WLAN_STATUS_SUCCESS;
172 	}
173 
174 	if (sta->ht_capabilities == NULL) {
175 		sta->ht_capabilities =
176 			os_zalloc(sizeof(struct ieee80211_ht_capabilities));
177 		if (sta->ht_capabilities == NULL)
178 			return WLAN_STATUS_UNSPECIFIED_FAILURE;
179 	}
180 
181 	sta->flags |= WLAN_STA_HT;
182 	os_memcpy(sta->ht_capabilities, ht_capab,
183 		  sizeof(struct ieee80211_ht_capabilities));
184 
185 	return WLAN_STATUS_SUCCESS;
186 }
187 
188 
189 static void update_sta_ht(struct hostapd_data *hapd, struct sta_info *sta)
190 {
191 	u16 ht_capab;
192 
193 	ht_capab = le_to_host16(sta->ht_capabilities->ht_capabilities_info);
194 	wpa_printf(MSG_DEBUG, "HT: STA " MACSTR " HT Capabilities Info: "
195 		   "0x%04x", MAC2STR(sta->addr), ht_capab);
196 	if ((ht_capab & HT_CAP_INFO_GREEN_FIELD) == 0) {
197 		if (!sta->no_ht_gf_set) {
198 			sta->no_ht_gf_set = 1;
199 			hapd->iface->num_sta_ht_no_gf++;
200 		}
201 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no greenfield, num "
202 			   "of non-gf stations %d",
203 			   __func__, MAC2STR(sta->addr),
204 			   hapd->iface->num_sta_ht_no_gf);
205 	}
206 	if ((ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) == 0) {
207 		if (!sta->ht_20mhz_set) {
208 			sta->ht_20mhz_set = 1;
209 			hapd->iface->num_sta_ht_20mhz++;
210 		}
211 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - 20 MHz HT, num of "
212 			   "20MHz HT STAs %d",
213 			   __func__, MAC2STR(sta->addr),
214 			   hapd->iface->num_sta_ht_20mhz);
215 	}
216 }
217 
218 
219 static void update_sta_no_ht(struct hostapd_data *hapd, struct sta_info *sta)
220 {
221 	if (!sta->no_ht_set) {
222 		sta->no_ht_set = 1;
223 		hapd->iface->num_sta_no_ht++;
224 	}
225 	if (hapd->iconf->ieee80211n) {
226 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no HT, num of "
227 			   "non-HT stations %d",
228 			   __func__, MAC2STR(sta->addr),
229 			   hapd->iface->num_sta_no_ht);
230 	}
231 }
232 
233 
234 void update_ht_state(struct hostapd_data *hapd, struct sta_info *sta)
235 {
236 	if ((sta->flags & WLAN_STA_HT) && sta->ht_capabilities)
237 		update_sta_ht(hapd, sta);
238 	else
239 		update_sta_no_ht(hapd, sta);
240 
241 	if (hostapd_ht_operation_update(hapd->iface) > 0)
242 		ieee802_11_set_beacons(hapd->iface);
243 }
244 
245 
246 void hostapd_get_ht_capab(struct hostapd_data *hapd,
247 			  struct ieee80211_ht_capabilities *ht_cap,
248 			  struct ieee80211_ht_capabilities *neg_ht_cap)
249 {
250 	u16 cap;
251 
252 	if (ht_cap == NULL)
253 		return;
254 	os_memcpy(neg_ht_cap, ht_cap, sizeof(*neg_ht_cap));
255 	cap = le_to_host16(neg_ht_cap->ht_capabilities_info);
256 	cap &= hapd->iconf->ht_capab;
257 	cap |= (hapd->iconf->ht_capab & HT_CAP_INFO_SMPS_DISABLED);
258 
259 	/*
260 	 * STBC needs to be handled specially
261 	 * if we don't support RX STBC, mask out TX STBC in the STA's HT caps
262 	 * if we don't support TX STBC, mask out RX STBC in the STA's HT caps
263 	 */
264 	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_RX_STBC_MASK))
265 		cap &= ~HT_CAP_INFO_TX_STBC;
266 	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_TX_STBC))
267 		cap &= ~HT_CAP_INFO_RX_STBC_MASK;
268 
269 	neg_ht_cap->ht_capabilities_info = host_to_le16(cap);
270 }
271