ieee802_11_ht.c revision b36ed7cd946148d829f311de8fe53ea3ffaaffe3
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
21u8 * 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		/* Fill in default values for remaining parameters
58		 * (IEEE Std 802.11-2012, 8.4.2.61 and MIB defval) */
59		scan_params->scan_passive_dwell =
60			host_to_le16(20);
61		scan_params->scan_active_dwell =
62			host_to_le16(10);
63		scan_params->scan_passive_total_per_channel =
64			host_to_le16(200);
65		scan_params->scan_active_total_per_channel =
66			host_to_le16(20);
67		scan_params->channel_transition_delay_factor =
68			host_to_le16(5);
69		scan_params->scan_activity_threshold =
70			host_to_le16(25);
71
72		pos += sizeof(*scan_params);
73	}
74
75	return pos;
76}
77
78
79u8 * hostapd_eid_ht_operation(struct hostapd_data *hapd, u8 *eid)
80{
81	struct ieee80211_ht_operation *oper;
82	u8 *pos = eid;
83
84	if (!hapd->iconf->ieee80211n || hapd->conf->disable_11n)
85		return eid;
86
87	*pos++ = WLAN_EID_HT_OPERATION;
88	*pos++ = sizeof(*oper);
89
90	oper = (struct ieee80211_ht_operation *) pos;
91	os_memset(oper, 0, sizeof(*oper));
92
93	oper->control_chan = hapd->iconf->channel;
94	oper->operation_mode = host_to_le16(hapd->iface->ht_op_mode);
95	if (hapd->iconf->secondary_channel == 1)
96		oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE |
97			HT_INFO_HT_PARAM_REC_TRANS_CHNL_WIDTH;
98	if (hapd->iconf->secondary_channel == -1)
99		oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW |
100			HT_INFO_HT_PARAM_REC_TRANS_CHNL_WIDTH;
101
102	pos += sizeof(*oper);
103
104	return pos;
105}
106
107
108/*
109op_mode
110Set to 0 (HT pure) under the followign conditions
111	- all STAs in the BSS are 20/40 MHz HT in 20/40 MHz BSS or
112	- all STAs in the BSS are 20 MHz HT in 20 MHz BSS
113Set to 1 (HT non-member protection) if there may be non-HT STAs
114	in both the primary and the secondary channel
115Set to 2 if only HT STAs are associated in BSS,
116	however and at least one 20 MHz HT STA is associated
117Set to 3 (HT mixed mode) when one or more non-HT STAs are associated
118*/
119int hostapd_ht_operation_update(struct hostapd_iface *iface)
120{
121	u16 cur_op_mode, new_op_mode;
122	int op_mode_changes = 0;
123
124	if (!iface->conf->ieee80211n || iface->conf->ht_op_mode_fixed)
125		return 0;
126
127	wpa_printf(MSG_DEBUG, "%s current operation mode=0x%X",
128		   __func__, iface->ht_op_mode);
129
130	if (!(iface->ht_op_mode & HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT)
131	    && iface->num_sta_ht_no_gf) {
132		iface->ht_op_mode |=
133			HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT;
134		op_mode_changes++;
135	} else if ((iface->ht_op_mode &
136		    HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT) &&
137		   iface->num_sta_ht_no_gf == 0) {
138		iface->ht_op_mode &=
139			~HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT;
140		op_mode_changes++;
141	}
142
143	if (!(iface->ht_op_mode & HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT) &&
144	    (iface->num_sta_no_ht || iface->olbc_ht)) {
145		iface->ht_op_mode |= HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT;
146		op_mode_changes++;
147	} else if ((iface->ht_op_mode &
148		    HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT) &&
149		   (iface->num_sta_no_ht == 0 && !iface->olbc_ht)) {
150		iface->ht_op_mode &=
151			~HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT;
152		op_mode_changes++;
153	}
154
155	if (iface->num_sta_no_ht)
156		new_op_mode = OP_MODE_MIXED;
157	else if (iface->conf->secondary_channel && iface->num_sta_ht_20mhz)
158		new_op_mode = OP_MODE_20MHZ_HT_STA_ASSOCED;
159	else if (iface->olbc_ht)
160		new_op_mode = OP_MODE_MAY_BE_LEGACY_STAS;
161	else
162		new_op_mode = OP_MODE_PURE;
163
164	cur_op_mode = iface->ht_op_mode & HT_INFO_OPERATION_MODE_OP_MODE_MASK;
165	if (cur_op_mode != new_op_mode) {
166		iface->ht_op_mode &= ~HT_INFO_OPERATION_MODE_OP_MODE_MASK;
167		iface->ht_op_mode |= new_op_mode;
168		op_mode_changes++;
169	}
170
171	wpa_printf(MSG_DEBUG, "%s new operation mode=0x%X changes=%d",
172		   __func__, iface->ht_op_mode, op_mode_changes);
173
174	return op_mode_changes;
175}
176
177
178u16 copy_sta_ht_capab(struct hostapd_data *hapd, struct sta_info *sta,
179		      const u8 *ht_capab, size_t ht_capab_len)
180{
181	/* Disable HT caps for STAs associated to no-HT BSSes. */
182	if (!ht_capab ||
183	    ht_capab_len < sizeof(struct ieee80211_ht_capabilities) ||
184	    hapd->conf->disable_11n) {
185		sta->flags &= ~WLAN_STA_HT;
186		os_free(sta->ht_capabilities);
187		sta->ht_capabilities = NULL;
188		return WLAN_STATUS_SUCCESS;
189	}
190
191	if (sta->ht_capabilities == NULL) {
192		sta->ht_capabilities =
193			os_zalloc(sizeof(struct ieee80211_ht_capabilities));
194		if (sta->ht_capabilities == NULL)
195			return WLAN_STATUS_UNSPECIFIED_FAILURE;
196	}
197
198	sta->flags |= WLAN_STA_HT;
199	os_memcpy(sta->ht_capabilities, ht_capab,
200		  sizeof(struct ieee80211_ht_capabilities));
201
202	return WLAN_STATUS_SUCCESS;
203}
204
205
206static void update_sta_ht(struct hostapd_data *hapd, struct sta_info *sta)
207{
208	u16 ht_capab;
209
210	ht_capab = le_to_host16(sta->ht_capabilities->ht_capabilities_info);
211	wpa_printf(MSG_DEBUG, "HT: STA " MACSTR " HT Capabilities Info: "
212		   "0x%04x", MAC2STR(sta->addr), ht_capab);
213	if ((ht_capab & HT_CAP_INFO_GREEN_FIELD) == 0) {
214		if (!sta->no_ht_gf_set) {
215			sta->no_ht_gf_set = 1;
216			hapd->iface->num_sta_ht_no_gf++;
217		}
218		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no greenfield, num "
219			   "of non-gf stations %d",
220			   __func__, MAC2STR(sta->addr),
221			   hapd->iface->num_sta_ht_no_gf);
222	}
223	if ((ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) == 0) {
224		if (!sta->ht_20mhz_set) {
225			sta->ht_20mhz_set = 1;
226			hapd->iface->num_sta_ht_20mhz++;
227		}
228		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - 20 MHz HT, num of "
229			   "20MHz HT STAs %d",
230			   __func__, MAC2STR(sta->addr),
231			   hapd->iface->num_sta_ht_20mhz);
232	}
233}
234
235
236static void update_sta_no_ht(struct hostapd_data *hapd, struct sta_info *sta)
237{
238	if (!sta->no_ht_set) {
239		sta->no_ht_set = 1;
240		hapd->iface->num_sta_no_ht++;
241	}
242	if (hapd->iconf->ieee80211n) {
243		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no HT, num of "
244			   "non-HT stations %d",
245			   __func__, MAC2STR(sta->addr),
246			   hapd->iface->num_sta_no_ht);
247	}
248}
249
250
251void update_ht_state(struct hostapd_data *hapd, struct sta_info *sta)
252{
253	if ((sta->flags & WLAN_STA_HT) && sta->ht_capabilities)
254		update_sta_ht(hapd, sta);
255	else
256		update_sta_no_ht(hapd, sta);
257
258	if (hostapd_ht_operation_update(hapd->iface) > 0)
259		ieee802_11_set_beacons(hapd->iface);
260}
261
262
263void hostapd_get_ht_capab(struct hostapd_data *hapd,
264			  struct ieee80211_ht_capabilities *ht_cap,
265			  struct ieee80211_ht_capabilities *neg_ht_cap)
266{
267	u16 cap;
268
269	if (ht_cap == NULL)
270		return;
271	os_memcpy(neg_ht_cap, ht_cap, sizeof(*neg_ht_cap));
272	cap = le_to_host16(neg_ht_cap->ht_capabilities_info);
273
274	/*
275	 * Mask out HT features we don't support, but don't overwrite
276	 * non-symmetric features like STBC and SMPS. Just because
277	 * we're not in dynamic SMPS mode the STA might still be.
278	 */
279	cap &= (hapd->iconf->ht_capab | HT_CAP_INFO_RX_STBC_MASK |
280		HT_CAP_INFO_TX_STBC | HT_CAP_INFO_SMPS_MASK);
281
282	/*
283	 * STBC needs to be handled specially
284	 * if we don't support RX STBC, mask out TX STBC in the STA's HT caps
285	 * if we don't support TX STBC, mask out RX STBC in the STA's HT caps
286	 */
287	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_RX_STBC_MASK))
288		cap &= ~HT_CAP_INFO_TX_STBC;
289	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_TX_STBC))
290		cap &= ~HT_CAP_INFO_RX_STBC_MASK;
291
292	neg_ht_cap->ht_capabilities_info = host_to_le16(cap);
293}
294