xref: /freebsd/contrib/wpa/src/ap/ieee802_11_ht.c (revision d3d381b2b194b4d24853e92eecef55f262688d1a)
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 
24 u8 * 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 
82 u8 * 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 u8 * 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 /*
135 op_mode
136 Set 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
139 Set to 1 (HT non-member protection) if there may be non-HT STAs
140 	in both the primary and the secondary channel
141 Set to 2 if only HT STAs are associated in BSS,
142 	however and at least one 20 MHz HT STA is associated
143 Set to 3 (HT mixed mode) when one or more non-HT STAs are associated
144 */
145 int 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 
201 static 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 
229 void 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 
335 u16 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 
366 void 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 
389 void 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 
412 static 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 
445 static 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 
460 void 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 
472 void 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 
505 void 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