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
111u8 * hostapd_eid_secondary_channel(struct hostapd_data *hapd, u8 *eid)
112{
113	u8 sec_ch;
114
115	if (!hapd->cs_freq_params.channel ||
116	    !hapd->cs_freq_params.sec_channel_offset)
117		return eid;
118
119	if (hapd->cs_freq_params.sec_channel_offset == -1)
120		sec_ch = HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW;
121	else if (hapd->cs_freq_params.sec_channel_offset == 1)
122		sec_ch = HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE;
123	else
124		return eid;
125
126	*eid++ = WLAN_EID_SECONDARY_CHANNEL_OFFSET;
127	*eid++ = 1;
128	*eid++ = sec_ch;
129
130	return eid;
131}
132
133
134/*
135op_mode
136Set to 0 (HT pure) under the followign conditions
137	- all STAs in the BSS are 20/40 MHz HT in 20/40 MHz BSS or
138	- all STAs in the BSS are 20 MHz HT in 20 MHz BSS
139Set to 1 (HT non-member protection) if there may be non-HT STAs
140	in both the primary and the secondary channel
141Set to 2 if only HT STAs are associated in BSS,
142	however and at least one 20 MHz HT STA is associated
143Set to 3 (HT mixed mode) when one or more non-HT STAs are associated
144*/
145int hostapd_ht_operation_update(struct hostapd_iface *iface)
146{
147	u16 cur_op_mode, new_op_mode;
148	int op_mode_changes = 0;
149
150	if (!iface->conf->ieee80211n || iface->conf->ht_op_mode_fixed)
151		return 0;
152
153	wpa_printf(MSG_DEBUG, "%s current operation mode=0x%X",
154		   __func__, iface->ht_op_mode);
155
156	if (!(iface->ht_op_mode & HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT)
157	    && iface->num_sta_ht_no_gf) {
158		iface->ht_op_mode |= HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
159		op_mode_changes++;
160	} else if ((iface->ht_op_mode &
161		    HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT) &&
162		   iface->num_sta_ht_no_gf == 0) {
163		iface->ht_op_mode &= ~HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
164		op_mode_changes++;
165	}
166
167	if (!(iface->ht_op_mode & HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
168	    (iface->num_sta_no_ht || iface->olbc_ht)) {
169		iface->ht_op_mode |= HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
170		op_mode_changes++;
171	} else if ((iface->ht_op_mode &
172		    HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
173		   (iface->num_sta_no_ht == 0 && !iface->olbc_ht)) {
174		iface->ht_op_mode &= ~HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
175		op_mode_changes++;
176	}
177
178	if (iface->num_sta_no_ht)
179		new_op_mode = HT_PROT_NON_HT_MIXED;
180	else if (iface->conf->secondary_channel && iface->num_sta_ht_20mhz)
181		new_op_mode = HT_PROT_20MHZ_PROTECTION;
182	else if (iface->olbc_ht)
183		new_op_mode = HT_PROT_NONMEMBER_PROTECTION;
184	else
185		new_op_mode = HT_PROT_NO_PROTECTION;
186
187	cur_op_mode = iface->ht_op_mode & HT_OPER_OP_MODE_HT_PROT_MASK;
188	if (cur_op_mode != new_op_mode) {
189		iface->ht_op_mode &= ~HT_OPER_OP_MODE_HT_PROT_MASK;
190		iface->ht_op_mode |= new_op_mode;
191		op_mode_changes++;
192	}
193
194	wpa_printf(MSG_DEBUG, "%s new operation mode=0x%X changes=%d",
195		   __func__, iface->ht_op_mode, op_mode_changes);
196
197	return op_mode_changes;
198}
199
200
201static int is_40_allowed(struct hostapd_iface *iface, int channel)
202{
203	int pri_freq, sec_freq;
204	int affected_start, affected_end;
205	int pri = 2407 + 5 * channel;
206
207	if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
208		return 1;
209
210	pri_freq = hostapd_hw_get_freq(iface->bss[0], iface->conf->channel);
211
212	if (iface->conf->secondary_channel > 0)
213		sec_freq = pri_freq + 20;
214	else
215		sec_freq = pri_freq - 20;
216
217	affected_start = (pri_freq + sec_freq) / 2 - 25;
218	affected_end = (pri_freq + sec_freq) / 2 + 25;
219	if ((pri < affected_start || pri > affected_end))
220		return 1; /* not within affected channel range */
221
222	wpa_printf(MSG_ERROR, "40 MHz affected channel range: [%d,%d] MHz",
223		   affected_start, affected_end);
224	wpa_printf(MSG_ERROR, "Neighboring BSS: freq=%d", pri);
225	return 0;
226}
227
228
229void hostapd_2040_coex_action(struct hostapd_data *hapd,
230			      const struct ieee80211_mgmt *mgmt, size_t len)
231{
232	struct hostapd_iface *iface = hapd->iface;
233	struct ieee80211_2040_bss_coex_ie *bc_ie;
234	struct ieee80211_2040_intol_chan_report *ic_report;
235	int is_ht40_allowed = 1;
236	int i;
237	const u8 *start = (const u8 *) mgmt;
238	const u8 *data = start + IEEE80211_HDRLEN + 2;
239
240	hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
241		       HOSTAPD_LEVEL_DEBUG, "hostapd_public_action - action=%d",
242		       mgmt->u.action.u.public_action.action);
243
244	if (!(iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET))
245		return;
246
247	if (len < IEEE80211_HDRLEN + 2 + sizeof(*bc_ie))
248		return;
249
250	bc_ie = (struct ieee80211_2040_bss_coex_ie *) data;
251	if (bc_ie->element_id != WLAN_EID_20_40_BSS_COEXISTENCE ||
252	    bc_ie->length < 1) {
253		wpa_printf(MSG_DEBUG, "Unexpected IE (%u,%u) in coex report",
254			   bc_ie->element_id, bc_ie->length);
255		return;
256	}
257	if (len < IEEE80211_HDRLEN + 2 + 2 + bc_ie->length)
258		return;
259	data += 2 + bc_ie->length;
260
261	wpa_printf(MSG_DEBUG, "20/40 BSS Coexistence Information field: 0x%x",
262		   bc_ie->coex_param);
263	if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_20MHZ_WIDTH_REQ) {
264		hostapd_logger(hapd, mgmt->sa,
265			       HOSTAPD_MODULE_IEEE80211,
266			       HOSTAPD_LEVEL_DEBUG,
267			       "20 MHz BSS width request bit is set in BSS coexistence information field");
268		is_ht40_allowed = 0;
269	}
270
271	if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_40MHZ_INTOL) {
272		hostapd_logger(hapd, mgmt->sa,
273			       HOSTAPD_MODULE_IEEE80211,
274			       HOSTAPD_LEVEL_DEBUG,
275			       "40 MHz intolerant bit is set in BSS coexistence information field");
276		is_ht40_allowed = 0;
277	}
278
279	if (start + len - data >= 3 &&
280	    data[0] == WLAN_EID_20_40_BSS_INTOLERANT && data[1] >= 1) {
281		u8 ielen = data[1];
282
283		if (ielen > start + len - data - 2)
284			return;
285		ic_report = (struct ieee80211_2040_intol_chan_report *) data;
286		wpa_printf(MSG_DEBUG,
287			   "20/40 BSS Intolerant Channel Report: Operating Class %u",
288			   ic_report->op_class);
289
290		/* Go through the channel report to find any BSS there in the
291		 * affected channel range */
292		for (i = 0; i < ielen - 1; i++) {
293			u8 chan = ic_report->variable[i];
294
295			if (is_40_allowed(iface, chan))
296				continue;
297			hostapd_logger(hapd, mgmt->sa,
298				       HOSTAPD_MODULE_IEEE80211,
299				       HOSTAPD_LEVEL_DEBUG,
300				       "20_40_INTOLERANT channel %d reported",
301				       chan);
302			is_ht40_allowed = 0;
303		}
304	}
305	wpa_printf(MSG_DEBUG, "is_ht40_allowed=%d num_sta_ht40_intolerant=%d",
306		   is_ht40_allowed, iface->num_sta_ht40_intolerant);
307
308	if (!is_ht40_allowed &&
309	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
310		if (iface->conf->secondary_channel) {
311			hostapd_logger(hapd, mgmt->sa,
312				       HOSTAPD_MODULE_IEEE80211,
313				       HOSTAPD_LEVEL_INFO,
314				       "Switching to 20 MHz operation");
315			iface->conf->secondary_channel = 0;
316			ieee802_11_set_beacons(iface);
317		}
318		if (!iface->num_sta_ht40_intolerant &&
319		    iface->conf->obss_interval) {
320			unsigned int delay_time;
321			delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
322				iface->conf->obss_interval;
323			eloop_cancel_timeout(ap_ht2040_timeout, hapd->iface,
324					     NULL);
325			eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
326					       hapd->iface, NULL);
327			wpa_printf(MSG_DEBUG,
328				   "Reschedule HT 20/40 timeout to occur in %u seconds",
329				   delay_time);
330		}
331	}
332}
333
334
335u16 copy_sta_ht_capab(struct hostapd_data *hapd, struct sta_info *sta,
336		      const u8 *ht_capab)
337{
338	/*
339	 * Disable HT caps for STAs associated to no-HT BSSes, or for stations
340	 * that did not specify a valid WMM IE in the (Re)Association Request
341	 * frame.
342	 */
343	if (!ht_capab ||
344	    !(sta->flags & WLAN_STA_WMM) || hapd->conf->disable_11n) {
345		sta->flags &= ~WLAN_STA_HT;
346		os_free(sta->ht_capabilities);
347		sta->ht_capabilities = NULL;
348		return WLAN_STATUS_SUCCESS;
349	}
350
351	if (sta->ht_capabilities == NULL) {
352		sta->ht_capabilities =
353			os_zalloc(sizeof(struct ieee80211_ht_capabilities));
354		if (sta->ht_capabilities == NULL)
355			return WLAN_STATUS_UNSPECIFIED_FAILURE;
356	}
357
358	sta->flags |= WLAN_STA_HT;
359	os_memcpy(sta->ht_capabilities, ht_capab,
360		  sizeof(struct ieee80211_ht_capabilities));
361
362	return WLAN_STATUS_SUCCESS;
363}
364
365
366void ht40_intolerant_add(struct hostapd_iface *iface, struct sta_info *sta)
367{
368	if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
369		return;
370
371	wpa_printf(MSG_INFO, "HT: Forty MHz Intolerant is set by STA " MACSTR
372		   " in Association Request", MAC2STR(sta->addr));
373
374	if (sta->ht40_intolerant_set)
375		return;
376
377	sta->ht40_intolerant_set = 1;
378	iface->num_sta_ht40_intolerant++;
379	eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
380
381	if (iface->conf->secondary_channel &&
382	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
383		iface->conf->secondary_channel = 0;
384		ieee802_11_set_beacons(iface);
385	}
386}
387
388
389void ht40_intolerant_remove(struct hostapd_iface *iface, struct sta_info *sta)
390{
391	if (!sta->ht40_intolerant_set)
392		return;
393
394	sta->ht40_intolerant_set = 0;
395	iface->num_sta_ht40_intolerant--;
396
397	if (iface->num_sta_ht40_intolerant == 0 &&
398	    (iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) &&
399	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
400		unsigned int delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
401			iface->conf->obss_interval;
402		wpa_printf(MSG_DEBUG,
403			   "HT: Start 20->40 MHz transition timer (%d seconds)",
404			   delay_time);
405		eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
406		eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
407				       iface, NULL);
408	}
409}
410
411
412static void update_sta_ht(struct hostapd_data *hapd, struct sta_info *sta)
413{
414	u16 ht_capab;
415
416	ht_capab = le_to_host16(sta->ht_capabilities->ht_capabilities_info);
417	wpa_printf(MSG_DEBUG, "HT: STA " MACSTR " HT Capabilities Info: "
418		   "0x%04x", MAC2STR(sta->addr), ht_capab);
419	if ((ht_capab & HT_CAP_INFO_GREEN_FIELD) == 0) {
420		if (!sta->no_ht_gf_set) {
421			sta->no_ht_gf_set = 1;
422			hapd->iface->num_sta_ht_no_gf++;
423		}
424		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no greenfield, num "
425			   "of non-gf stations %d",
426			   __func__, MAC2STR(sta->addr),
427			   hapd->iface->num_sta_ht_no_gf);
428	}
429	if ((ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) == 0) {
430		if (!sta->ht_20mhz_set) {
431			sta->ht_20mhz_set = 1;
432			hapd->iface->num_sta_ht_20mhz++;
433		}
434		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - 20 MHz HT, num of "
435			   "20MHz HT STAs %d",
436			   __func__, MAC2STR(sta->addr),
437			   hapd->iface->num_sta_ht_20mhz);
438	}
439
440	if (ht_capab & HT_CAP_INFO_40MHZ_INTOLERANT)
441		ht40_intolerant_add(hapd->iface, sta);
442}
443
444
445static void update_sta_no_ht(struct hostapd_data *hapd, struct sta_info *sta)
446{
447	if (!sta->no_ht_set) {
448		sta->no_ht_set = 1;
449		hapd->iface->num_sta_no_ht++;
450	}
451	if (hapd->iconf->ieee80211n) {
452		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no HT, num of "
453			   "non-HT stations %d",
454			   __func__, MAC2STR(sta->addr),
455			   hapd->iface->num_sta_no_ht);
456	}
457}
458
459
460void update_ht_state(struct hostapd_data *hapd, struct sta_info *sta)
461{
462	if ((sta->flags & WLAN_STA_HT) && sta->ht_capabilities)
463		update_sta_ht(hapd, sta);
464	else
465		update_sta_no_ht(hapd, sta);
466
467	if (hostapd_ht_operation_update(hapd->iface) > 0)
468		ieee802_11_set_beacons(hapd->iface);
469}
470
471
472void hostapd_get_ht_capab(struct hostapd_data *hapd,
473			  struct ieee80211_ht_capabilities *ht_cap,
474			  struct ieee80211_ht_capabilities *neg_ht_cap)
475{
476	u16 cap;
477
478	if (ht_cap == NULL)
479		return;
480	os_memcpy(neg_ht_cap, ht_cap, sizeof(*neg_ht_cap));
481	cap = le_to_host16(neg_ht_cap->ht_capabilities_info);
482
483	/*
484	 * Mask out HT features we don't support, but don't overwrite
485	 * non-symmetric features like STBC and SMPS. Just because
486	 * we're not in dynamic SMPS mode the STA might still be.
487	 */
488	cap &= (hapd->iconf->ht_capab | HT_CAP_INFO_RX_STBC_MASK |
489		HT_CAP_INFO_TX_STBC | HT_CAP_INFO_SMPS_MASK);
490
491	/*
492	 * STBC needs to be handled specially
493	 * if we don't support RX STBC, mask out TX STBC in the STA's HT caps
494	 * if we don't support TX STBC, mask out RX STBC in the STA's HT caps
495	 */
496	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_RX_STBC_MASK))
497		cap &= ~HT_CAP_INFO_TX_STBC;
498	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_TX_STBC))
499		cap &= ~HT_CAP_INFO_RX_STBC_MASK;
500
501	neg_ht_cap->ht_capabilities_info = host_to_le16(cap);
502}
503
504
505void ap_ht2040_timeout(void *eloop_data, void *user_data)
506{
507	struct hostapd_iface *iface = eloop_data;
508
509	wpa_printf(MSG_INFO, "Switching to 40 MHz operation");
510
511	iface->conf->secondary_channel = iface->secondary_ch;
512	ieee802_11_set_beacons(iface);
513}
514