xref: /freebsd/contrib/wpa/src/ap/ieee802_11_ht.c (revision f4b37ed0f8b307b1f3f0f630ca725d68f1dff30d)
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 /*
112 op_mode
113 Set 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
116 Set to 1 (HT non-member protection) if there may be non-HT STAs
117 	in both the primary and the secondary channel
118 Set to 2 if only HT STAs are associated in BSS,
119 	however and at least one 20 MHz HT STA is associated
120 Set to 3 (HT mixed mode) when one or more non-HT STAs are associated
121 */
122 int 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 
178 static 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 
206 void 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 *start = (const u8 *) mgmt;
215 	const u8 *data = start + IEEE80211_HDRLEN + 2;
216 
217 	hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
218 		       HOSTAPD_LEVEL_DEBUG, "hostapd_public_action - action=%d",
219 		       mgmt->u.action.u.public_action.action);
220 
221 	if (!(iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET))
222 		return;
223 
224 	if (len < IEEE80211_HDRLEN + 2 + sizeof(*bc_ie))
225 		return;
226 
227 	bc_ie = (struct ieee80211_2040_bss_coex_ie *) data;
228 	if (bc_ie->element_id != WLAN_EID_20_40_BSS_COEXISTENCE ||
229 	    bc_ie->length < 1) {
230 		wpa_printf(MSG_DEBUG, "Unexpected IE (%u,%u) in coex report",
231 			   bc_ie->element_id, bc_ie->length);
232 		return;
233 	}
234 	if (len < IEEE80211_HDRLEN + 2 + 2 + bc_ie->length)
235 		return;
236 	data += 2 + bc_ie->length;
237 
238 	wpa_printf(MSG_DEBUG, "20/40 BSS Coexistence Information field: 0x%x",
239 		   bc_ie->coex_param);
240 	if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_20MHZ_WIDTH_REQ) {
241 		hostapd_logger(hapd, mgmt->sa,
242 			       HOSTAPD_MODULE_IEEE80211,
243 			       HOSTAPD_LEVEL_DEBUG,
244 			       "20 MHz BSS width request bit is set in BSS coexistence information field");
245 		is_ht_allowed = 0;
246 	}
247 
248 	if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_40MHZ_INTOL) {
249 		hostapd_logger(hapd, mgmt->sa,
250 			       HOSTAPD_MODULE_IEEE80211,
251 			       HOSTAPD_LEVEL_DEBUG,
252 			       "40 MHz intolerant bit is set in BSS coexistence information field");
253 		is_ht_allowed = 0;
254 	}
255 
256 	if (start + len - data >= 3 &&
257 	    data[0] == WLAN_EID_20_40_BSS_INTOLERANT && data[1] >= 1) {
258 		u8 ielen = data[1];
259 
260 		if (ielen > start + len - data - 2)
261 			return;
262 		ic_report = (struct ieee80211_2040_intol_chan_report *) data;
263 		wpa_printf(MSG_DEBUG,
264 			   "20/40 BSS Intolerant Channel Report: Operating Class %u",
265 			   ic_report->op_class);
266 
267 		/* Go through the channel report to find any BSS there in the
268 		 * affected channel range */
269 		for (i = 0; i < ielen - 1; i++) {
270 			u8 chan = ic_report->variable[i];
271 
272 			if (is_40_allowed(iface, chan))
273 				continue;
274 			hostapd_logger(hapd, mgmt->sa,
275 				       HOSTAPD_MODULE_IEEE80211,
276 				       HOSTAPD_LEVEL_DEBUG,
277 				       "20_40_INTOLERANT channel %d reported",
278 				       chan);
279 			is_ht_allowed = 0;
280 		}
281 	}
282 	wpa_printf(MSG_DEBUG, "is_ht_allowed=%d num_sta_ht40_intolerant=%d",
283 		   is_ht_allowed, iface->num_sta_ht40_intolerant);
284 
285 	if (!is_ht_allowed &&
286 	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
287 		if (iface->conf->secondary_channel) {
288 			hostapd_logger(hapd, mgmt->sa,
289 				       HOSTAPD_MODULE_IEEE80211,
290 				       HOSTAPD_LEVEL_INFO,
291 				       "Switching to 20 MHz operation");
292 			iface->conf->secondary_channel = 0;
293 			ieee802_11_set_beacons(iface);
294 		}
295 		if (!iface->num_sta_ht40_intolerant &&
296 		    iface->conf->obss_interval) {
297 			unsigned int delay_time;
298 			delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
299 				iface->conf->obss_interval;
300 			eloop_cancel_timeout(ap_ht2040_timeout, hapd->iface,
301 					     NULL);
302 			eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
303 					       hapd->iface, NULL);
304 			wpa_printf(MSG_DEBUG,
305 				   "Reschedule HT 20/40 timeout to occur in %u seconds",
306 				   delay_time);
307 		}
308 	}
309 }
310 
311 
312 u16 copy_sta_ht_capab(struct hostapd_data *hapd, struct sta_info *sta,
313 		      const u8 *ht_capab, size_t ht_capab_len)
314 {
315 	/* Disable HT caps for STAs associated to no-HT BSSes. */
316 	if (!ht_capab ||
317 	    ht_capab_len < sizeof(struct ieee80211_ht_capabilities) ||
318 	    hapd->conf->disable_11n) {
319 		sta->flags &= ~WLAN_STA_HT;
320 		os_free(sta->ht_capabilities);
321 		sta->ht_capabilities = NULL;
322 		return WLAN_STATUS_SUCCESS;
323 	}
324 
325 	if (sta->ht_capabilities == NULL) {
326 		sta->ht_capabilities =
327 			os_zalloc(sizeof(struct ieee80211_ht_capabilities));
328 		if (sta->ht_capabilities == NULL)
329 			return WLAN_STATUS_UNSPECIFIED_FAILURE;
330 	}
331 
332 	sta->flags |= WLAN_STA_HT;
333 	os_memcpy(sta->ht_capabilities, ht_capab,
334 		  sizeof(struct ieee80211_ht_capabilities));
335 
336 	return WLAN_STATUS_SUCCESS;
337 }
338 
339 
340 void ht40_intolerant_add(struct hostapd_iface *iface, struct sta_info *sta)
341 {
342 	if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
343 		return;
344 
345 	wpa_printf(MSG_INFO, "HT: Forty MHz Intolerant is set by STA " MACSTR
346 		   " in Association Request", MAC2STR(sta->addr));
347 
348 	if (sta->ht40_intolerant_set)
349 		return;
350 
351 	sta->ht40_intolerant_set = 1;
352 	iface->num_sta_ht40_intolerant++;
353 	eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
354 
355 	if (iface->conf->secondary_channel &&
356 	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
357 		iface->conf->secondary_channel = 0;
358 		ieee802_11_set_beacons(iface);
359 	}
360 }
361 
362 
363 void ht40_intolerant_remove(struct hostapd_iface *iface, struct sta_info *sta)
364 {
365 	if (!sta->ht40_intolerant_set)
366 		return;
367 
368 	sta->ht40_intolerant_set = 0;
369 	iface->num_sta_ht40_intolerant--;
370 
371 	if (iface->num_sta_ht40_intolerant == 0 &&
372 	    (iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) &&
373 	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
374 		unsigned int delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
375 			iface->conf->obss_interval;
376 		wpa_printf(MSG_DEBUG,
377 			   "HT: Start 20->40 MHz transition timer (%d seconds)",
378 			   delay_time);
379 		eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
380 		eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
381 				       iface, NULL);
382 	}
383 }
384 
385 
386 static void update_sta_ht(struct hostapd_data *hapd, struct sta_info *sta)
387 {
388 	u16 ht_capab;
389 
390 	ht_capab = le_to_host16(sta->ht_capabilities->ht_capabilities_info);
391 	wpa_printf(MSG_DEBUG, "HT: STA " MACSTR " HT Capabilities Info: "
392 		   "0x%04x", MAC2STR(sta->addr), ht_capab);
393 	if ((ht_capab & HT_CAP_INFO_GREEN_FIELD) == 0) {
394 		if (!sta->no_ht_gf_set) {
395 			sta->no_ht_gf_set = 1;
396 			hapd->iface->num_sta_ht_no_gf++;
397 		}
398 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no greenfield, num "
399 			   "of non-gf stations %d",
400 			   __func__, MAC2STR(sta->addr),
401 			   hapd->iface->num_sta_ht_no_gf);
402 	}
403 	if ((ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) == 0) {
404 		if (!sta->ht_20mhz_set) {
405 			sta->ht_20mhz_set = 1;
406 			hapd->iface->num_sta_ht_20mhz++;
407 		}
408 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - 20 MHz HT, num of "
409 			   "20MHz HT STAs %d",
410 			   __func__, MAC2STR(sta->addr),
411 			   hapd->iface->num_sta_ht_20mhz);
412 	}
413 
414 	if (ht_capab & HT_CAP_INFO_40MHZ_INTOLERANT)
415 		ht40_intolerant_add(hapd->iface, sta);
416 }
417 
418 
419 static void update_sta_no_ht(struct hostapd_data *hapd, struct sta_info *sta)
420 {
421 	if (!sta->no_ht_set) {
422 		sta->no_ht_set = 1;
423 		hapd->iface->num_sta_no_ht++;
424 	}
425 	if (hapd->iconf->ieee80211n) {
426 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no HT, num of "
427 			   "non-HT stations %d",
428 			   __func__, MAC2STR(sta->addr),
429 			   hapd->iface->num_sta_no_ht);
430 	}
431 }
432 
433 
434 void update_ht_state(struct hostapd_data *hapd, struct sta_info *sta)
435 {
436 	if ((sta->flags & WLAN_STA_HT) && sta->ht_capabilities)
437 		update_sta_ht(hapd, sta);
438 	else
439 		update_sta_no_ht(hapd, sta);
440 
441 	if (hostapd_ht_operation_update(hapd->iface) > 0)
442 		ieee802_11_set_beacons(hapd->iface);
443 }
444 
445 
446 void hostapd_get_ht_capab(struct hostapd_data *hapd,
447 			  struct ieee80211_ht_capabilities *ht_cap,
448 			  struct ieee80211_ht_capabilities *neg_ht_cap)
449 {
450 	u16 cap;
451 
452 	if (ht_cap == NULL)
453 		return;
454 	os_memcpy(neg_ht_cap, ht_cap, sizeof(*neg_ht_cap));
455 	cap = le_to_host16(neg_ht_cap->ht_capabilities_info);
456 
457 	/*
458 	 * Mask out HT features we don't support, but don't overwrite
459 	 * non-symmetric features like STBC and SMPS. Just because
460 	 * we're not in dynamic SMPS mode the STA might still be.
461 	 */
462 	cap &= (hapd->iconf->ht_capab | HT_CAP_INFO_RX_STBC_MASK |
463 		HT_CAP_INFO_TX_STBC | HT_CAP_INFO_SMPS_MASK);
464 
465 	/*
466 	 * STBC needs to be handled specially
467 	 * if we don't support RX STBC, mask out TX STBC in the STA's HT caps
468 	 * if we don't support TX STBC, mask out RX STBC in the STA's HT caps
469 	 */
470 	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_RX_STBC_MASK))
471 		cap &= ~HT_CAP_INFO_TX_STBC;
472 	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_TX_STBC))
473 		cap &= ~HT_CAP_INFO_RX_STBC_MASK;
474 
475 	neg_ht_cap->ht_capabilities_info = host_to_le16(cap);
476 }
477 
478 
479 void ap_ht2040_timeout(void *eloop_data, void *user_data)
480 {
481 	struct hostapd_iface *iface = eloop_data;
482 
483 	wpa_printf(MSG_INFO, "Switching to 40 MHz operation");
484 
485 	iface->conf->secondary_channel = iface->secondary_ch;
486 	ieee802_11_set_beacons(iface);
487 }
488