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 "utils/eloop.h"
14#include "common/ieee802_11_defs.h"
15#include "hostapd.h"
16#include "ap_config.h"
17#include "sta_info.h"
18#include "beacon.h"
19#include "ieee802_11.h"
20#include "hw_features.h"
21#include "ap_drv_ops.h"
22
23
24u8 * hostapd_eid_ht_capabilities(struct hostapd_data *hapd, u8 *eid)
25{
26	struct ieee80211_ht_capabilities *cap;
27	u8 *pos = eid;
28
29	if (!hapd->iconf->ieee80211n || !hapd->iface->current_mode ||
30	    hapd->conf->disable_11n)
31		return eid;
32
33	*pos++ = WLAN_EID_HT_CAP;
34	*pos++ = sizeof(*cap);
35
36	cap = (struct ieee80211_ht_capabilities *) pos;
37	os_memset(cap, 0, sizeof(*cap));
38	cap->ht_capabilities_info = host_to_le16(hapd->iconf->ht_capab);
39	cap->a_mpdu_params = hapd->iface->current_mode->a_mpdu_params;
40	os_memcpy(cap->supported_mcs_set, hapd->iface->current_mode->mcs_set,
41		  16);
42
43	/* TODO: ht_extended_capabilities (now fully disabled) */
44	/* TODO: tx_bf_capability_info (now fully disabled) */
45	/* TODO: asel_capabilities (now fully disabled) */
46
47 	pos += sizeof(*cap);
48
49	if (hapd->iconf->obss_interval) {
50		struct ieee80211_obss_scan_parameters *scan_params;
51
52		*pos++ = WLAN_EID_OVERLAPPING_BSS_SCAN_PARAMS;
53		*pos++ = sizeof(*scan_params);
54
55		scan_params = (struct ieee80211_obss_scan_parameters *) pos;
56		os_memset(scan_params, 0, sizeof(*scan_params));
57		scan_params->width_trigger_scan_interval =
58			host_to_le16(hapd->iconf->obss_interval);
59
60		/* Fill in default values for remaining parameters
61		 * (IEEE Std 802.11-2012, 8.4.2.61 and MIB defval) */
62		scan_params->scan_passive_dwell =
63			host_to_le16(20);
64		scan_params->scan_active_dwell =
65			host_to_le16(10);
66		scan_params->scan_passive_total_per_channel =
67			host_to_le16(200);
68		scan_params->scan_active_total_per_channel =
69			host_to_le16(20);
70		scan_params->channel_transition_delay_factor =
71			host_to_le16(5);
72		scan_params->scan_activity_threshold =
73			host_to_le16(25);
74
75		pos += sizeof(*scan_params);
76	}
77
78	return pos;
79}
80
81
82u8 * hostapd_eid_ht_operation(struct hostapd_data *hapd, u8 *eid)
83{
84	struct ieee80211_ht_operation *oper;
85	u8 *pos = eid;
86
87	if (!hapd->iconf->ieee80211n || hapd->conf->disable_11n)
88		return eid;
89
90	*pos++ = WLAN_EID_HT_OPERATION;
91	*pos++ = sizeof(*oper);
92
93	oper = (struct ieee80211_ht_operation *) pos;
94	os_memset(oper, 0, sizeof(*oper));
95
96	oper->primary_chan = hapd->iconf->channel;
97	oper->operation_mode = host_to_le16(hapd->iface->ht_op_mode);
98	if (hapd->iconf->secondary_channel == 1)
99		oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE |
100			HT_INFO_HT_PARAM_STA_CHNL_WIDTH;
101	if (hapd->iconf->secondary_channel == -1)
102		oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW |
103			HT_INFO_HT_PARAM_STA_CHNL_WIDTH;
104
105	pos += sizeof(*oper);
106
107	return pos;
108}
109
110
111/*
112op_mode
113Set to 0 (HT pure) under the followign conditions
114	- all STAs in the BSS are 20/40 MHz HT in 20/40 MHz BSS or
115	- all STAs in the BSS are 20 MHz HT in 20 MHz BSS
116Set to 1 (HT non-member protection) if there may be non-HT STAs
117	in both the primary and the secondary channel
118Set to 2 if only HT STAs are associated in BSS,
119	however and at least one 20 MHz HT STA is associated
120Set to 3 (HT mixed mode) when one or more non-HT STAs are associated
121*/
122int hostapd_ht_operation_update(struct hostapd_iface *iface)
123{
124	u16 cur_op_mode, new_op_mode;
125	int op_mode_changes = 0;
126
127	if (!iface->conf->ieee80211n || iface->conf->ht_op_mode_fixed)
128		return 0;
129
130	wpa_printf(MSG_DEBUG, "%s current operation mode=0x%X",
131		   __func__, iface->ht_op_mode);
132
133	if (!(iface->ht_op_mode & HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT)
134	    && iface->num_sta_ht_no_gf) {
135		iface->ht_op_mode |= HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
136		op_mode_changes++;
137	} else if ((iface->ht_op_mode &
138		    HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT) &&
139		   iface->num_sta_ht_no_gf == 0) {
140		iface->ht_op_mode &= ~HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
141		op_mode_changes++;
142	}
143
144	if (!(iface->ht_op_mode & HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
145	    (iface->num_sta_no_ht || iface->olbc_ht)) {
146		iface->ht_op_mode |= HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
147		op_mode_changes++;
148	} else if ((iface->ht_op_mode &
149		    HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
150		   (iface->num_sta_no_ht == 0 && !iface->olbc_ht)) {
151		iface->ht_op_mode &= ~HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
152		op_mode_changes++;
153	}
154
155	if (iface->num_sta_no_ht)
156		new_op_mode = HT_PROT_NON_HT_MIXED;
157	else if (iface->conf->secondary_channel && iface->num_sta_ht_20mhz)
158		new_op_mode = HT_PROT_20MHZ_PROTECTION;
159	else if (iface->olbc_ht)
160		new_op_mode = HT_PROT_NONMEMBER_PROTECTION;
161	else
162		new_op_mode = HT_PROT_NO_PROTECTION;
163
164	cur_op_mode = iface->ht_op_mode & HT_OPER_OP_MODE_HT_PROT_MASK;
165	if (cur_op_mode != new_op_mode) {
166		iface->ht_op_mode &= ~HT_OPER_OP_MODE_HT_PROT_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
178static int is_40_allowed(struct hostapd_iface *iface, int channel)
179{
180	int pri_freq, sec_freq;
181	int affected_start, affected_end;
182	int pri = 2407 + 5 * channel;
183
184	if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
185		return 1;
186
187	pri_freq = hostapd_hw_get_freq(iface->bss[0], iface->conf->channel);
188
189	if (iface->conf->secondary_channel > 0)
190		sec_freq = pri_freq + 20;
191	else
192		sec_freq = pri_freq - 20;
193
194	affected_start = (pri_freq + sec_freq) / 2 - 25;
195	affected_end = (pri_freq + sec_freq) / 2 + 25;
196	if ((pri < affected_start || pri > affected_end))
197		return 1; /* not within affected channel range */
198
199	wpa_printf(MSG_ERROR, "40 MHz affected channel range: [%d,%d] MHz",
200		   affected_start, affected_end);
201	wpa_printf(MSG_ERROR, "Neighboring BSS: freq=%d", pri);
202	return 0;
203}
204
205
206void hostapd_2040_coex_action(struct hostapd_data *hapd,
207			      const struct ieee80211_mgmt *mgmt, size_t len)
208{
209	struct hostapd_iface *iface = hapd->iface;
210	struct ieee80211_2040_bss_coex_ie *bc_ie;
211	struct ieee80211_2040_intol_chan_report *ic_report;
212	int is_ht_allowed = 1;
213	int i;
214	const u8 *data = ((const u8 *) mgmt) + 1;
215
216	hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
217		       HOSTAPD_LEVEL_DEBUG, "hostapd_public_action - action=%d",
218		       mgmt->u.action.u.public_action.action);
219
220	if (!(iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET))
221		return;
222
223	if (len < IEEE80211_HDRLEN + 1)
224		return;
225	data++;
226
227	bc_ie = (struct ieee80211_2040_bss_coex_ie *) &data[0];
228	ic_report = (struct ieee80211_2040_intol_chan_report *)
229		(&data[0] + sizeof(*bc_ie));
230
231	if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_20MHZ_WIDTH_REQ) {
232		hostapd_logger(hapd, mgmt->sa,
233			       HOSTAPD_MODULE_IEEE80211,
234			       HOSTAPD_LEVEL_DEBUG,
235			       "20 MHz BSS width request bit is set in BSS coexistence information field");
236		is_ht_allowed = 0;
237	}
238
239	if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_40MHZ_INTOL) {
240		hostapd_logger(hapd, mgmt->sa,
241			       HOSTAPD_MODULE_IEEE80211,
242			       HOSTAPD_LEVEL_DEBUG,
243			       "40 MHz intolerant bit is set in BSS coexistence information field");
244		is_ht_allowed = 0;
245	}
246
247	if (ic_report &&
248	    (ic_report->element_id == WLAN_EID_20_40_BSS_INTOLERANT)) {
249		/* Go through the channel report to find any BSS there in the
250		 * affected channel range */
251		for (i = 0; i < ic_report->length - 1; i++) {
252			if (is_40_allowed(iface, ic_report->variable[i]))
253				continue;
254			hostapd_logger(hapd, mgmt->sa,
255				       HOSTAPD_MODULE_IEEE80211,
256				       HOSTAPD_LEVEL_DEBUG,
257				       "20_40_INTOLERANT channel %d reported",
258				       ic_report->variable[i]);
259			is_ht_allowed = 0;
260			break;
261		}
262	}
263
264	if (!is_ht_allowed &&
265	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
266		if (iface->conf->secondary_channel) {
267			hostapd_logger(hapd, mgmt->sa,
268				       HOSTAPD_MODULE_IEEE80211,
269				       HOSTAPD_LEVEL_INFO,
270				       "Switching to 20 MHz operation");
271			iface->conf->secondary_channel = 0;
272			ieee802_11_set_beacons(iface);
273		}
274		if (!iface->num_sta_ht40_intolerant) {
275			unsigned int delay_time;
276			delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
277				iface->conf->obss_interval;
278			eloop_cancel_timeout(ap_ht2040_timeout, hapd->iface,
279					     NULL);
280			eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
281					       hapd->iface, NULL);
282		}
283	}
284}
285
286
287u16 copy_sta_ht_capab(struct hostapd_data *hapd, struct sta_info *sta,
288		      const u8 *ht_capab, size_t ht_capab_len)
289{
290	/* Disable HT caps for STAs associated to no-HT BSSes. */
291	if (!ht_capab ||
292	    ht_capab_len < sizeof(struct ieee80211_ht_capabilities) ||
293	    hapd->conf->disable_11n) {
294		sta->flags &= ~WLAN_STA_HT;
295		os_free(sta->ht_capabilities);
296		sta->ht_capabilities = NULL;
297		return WLAN_STATUS_SUCCESS;
298	}
299
300	if (sta->ht_capabilities == NULL) {
301		sta->ht_capabilities =
302			os_zalloc(sizeof(struct ieee80211_ht_capabilities));
303		if (sta->ht_capabilities == NULL)
304			return WLAN_STATUS_UNSPECIFIED_FAILURE;
305	}
306
307	sta->flags |= WLAN_STA_HT;
308	os_memcpy(sta->ht_capabilities, ht_capab,
309		  sizeof(struct ieee80211_ht_capabilities));
310
311	return WLAN_STATUS_SUCCESS;
312}
313
314
315void ht40_intolerant_add(struct hostapd_iface *iface, struct sta_info *sta)
316{
317	if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
318		return;
319
320	wpa_printf(MSG_INFO, "HT: Forty MHz Intolerant is set by STA " MACSTR
321		   " in Association Request", MAC2STR(sta->addr));
322
323	if (sta->ht40_intolerant_set)
324		return;
325
326	sta->ht40_intolerant_set = 1;
327	iface->num_sta_ht40_intolerant++;
328	eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
329
330	if (iface->conf->secondary_channel &&
331	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
332		iface->conf->secondary_channel = 0;
333		ieee802_11_set_beacons(iface);
334	}
335}
336
337
338void ht40_intolerant_remove(struct hostapd_iface *iface, struct sta_info *sta)
339{
340	if (!sta->ht40_intolerant_set)
341		return;
342
343	sta->ht40_intolerant_set = 0;
344	iface->num_sta_ht40_intolerant--;
345
346	if (iface->num_sta_ht40_intolerant == 0 &&
347	    (iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) &&
348	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
349		unsigned int delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
350			iface->conf->obss_interval;
351		wpa_printf(MSG_DEBUG,
352			   "HT: Start 20->40 MHz transition timer (%d seconds)",
353			   delay_time);
354		eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
355		eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
356				       iface, NULL);
357	}
358}
359
360
361static void update_sta_ht(struct hostapd_data *hapd, struct sta_info *sta)
362{
363	u16 ht_capab;
364
365	ht_capab = le_to_host16(sta->ht_capabilities->ht_capabilities_info);
366	wpa_printf(MSG_DEBUG, "HT: STA " MACSTR " HT Capabilities Info: "
367		   "0x%04x", MAC2STR(sta->addr), ht_capab);
368	if ((ht_capab & HT_CAP_INFO_GREEN_FIELD) == 0) {
369		if (!sta->no_ht_gf_set) {
370			sta->no_ht_gf_set = 1;
371			hapd->iface->num_sta_ht_no_gf++;
372		}
373		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no greenfield, num "
374			   "of non-gf stations %d",
375			   __func__, MAC2STR(sta->addr),
376			   hapd->iface->num_sta_ht_no_gf);
377	}
378	if ((ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) == 0) {
379		if (!sta->ht_20mhz_set) {
380			sta->ht_20mhz_set = 1;
381			hapd->iface->num_sta_ht_20mhz++;
382		}
383		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - 20 MHz HT, num of "
384			   "20MHz HT STAs %d",
385			   __func__, MAC2STR(sta->addr),
386			   hapd->iface->num_sta_ht_20mhz);
387	}
388
389	if (ht_capab & HT_CAP_INFO_40MHZ_INTOLERANT)
390		ht40_intolerant_add(hapd->iface, sta);
391}
392
393
394static void update_sta_no_ht(struct hostapd_data *hapd, struct sta_info *sta)
395{
396	if (!sta->no_ht_set) {
397		sta->no_ht_set = 1;
398		hapd->iface->num_sta_no_ht++;
399	}
400	if (hapd->iconf->ieee80211n) {
401		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no HT, num of "
402			   "non-HT stations %d",
403			   __func__, MAC2STR(sta->addr),
404			   hapd->iface->num_sta_no_ht);
405	}
406}
407
408
409void update_ht_state(struct hostapd_data *hapd, struct sta_info *sta)
410{
411	if ((sta->flags & WLAN_STA_HT) && sta->ht_capabilities)
412		update_sta_ht(hapd, sta);
413	else
414		update_sta_no_ht(hapd, sta);
415
416	if (hostapd_ht_operation_update(hapd->iface) > 0)
417		ieee802_11_set_beacons(hapd->iface);
418}
419
420
421void hostapd_get_ht_capab(struct hostapd_data *hapd,
422			  struct ieee80211_ht_capabilities *ht_cap,
423			  struct ieee80211_ht_capabilities *neg_ht_cap)
424{
425	u16 cap;
426
427	if (ht_cap == NULL)
428		return;
429	os_memcpy(neg_ht_cap, ht_cap, sizeof(*neg_ht_cap));
430	cap = le_to_host16(neg_ht_cap->ht_capabilities_info);
431
432	/*
433	 * Mask out HT features we don't support, but don't overwrite
434	 * non-symmetric features like STBC and SMPS. Just because
435	 * we're not in dynamic SMPS mode the STA might still be.
436	 */
437	cap &= (hapd->iconf->ht_capab | HT_CAP_INFO_RX_STBC_MASK |
438		HT_CAP_INFO_TX_STBC | HT_CAP_INFO_SMPS_MASK);
439
440	/*
441	 * STBC needs to be handled specially
442	 * if we don't support RX STBC, mask out TX STBC in the STA's HT caps
443	 * if we don't support TX STBC, mask out RX STBC in the STA's HT caps
444	 */
445	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_RX_STBC_MASK))
446		cap &= ~HT_CAP_INFO_TX_STBC;
447	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_TX_STBC))
448		cap &= ~HT_CAP_INFO_RX_STBC_MASK;
449
450	neg_ht_cap->ht_capabilities_info = host_to_le16(cap);
451}
452
453
454void ap_ht2040_timeout(void *eloop_data, void *user_data)
455{
456	struct hostapd_iface *iface = eloop_data;
457
458	wpa_printf(MSG_INFO, "Switching to 40 MHz operation");
459
460	iface->conf->secondary_channel = iface->secondary_ch;
461	ieee802_11_set_beacons(iface);
462}
463