xref: /freebsd/contrib/wpa/src/ap/ieee802_11_ht.c (revision 2e3507c25e42292b45a5482e116d278f5515d04d)
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 || is_6ghz_op_class(hapd->iconf->op_class))
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 	    is_6ghz_op_class(hapd->iconf->op_class))
89 		return eid;
90 
91 	*pos++ = WLAN_EID_HT_OPERATION;
92 	*pos++ = sizeof(*oper);
93 
94 	oper = (struct ieee80211_ht_operation *) pos;
95 	os_memset(oper, 0, sizeof(*oper));
96 
97 	oper->primary_chan = hapd->iconf->channel;
98 	oper->operation_mode = host_to_le16(hapd->iface->ht_op_mode);
99 	if (hapd->iconf->secondary_channel == 1)
100 		oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE |
101 			HT_INFO_HT_PARAM_STA_CHNL_WIDTH;
102 	if (hapd->iconf->secondary_channel == -1)
103 		oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW |
104 			HT_INFO_HT_PARAM_STA_CHNL_WIDTH;
105 
106 	pos += sizeof(*oper);
107 
108 	return pos;
109 }
110 
111 
112 /*
113 op_mode
114 Set to 0 (HT pure) under the following conditions
115 	- all STAs in the BSS are 20/40 MHz HT in 20/40 MHz BSS or
116 	- all STAs in the BSS are 20 MHz HT in 20 MHz BSS
117 Set to 1 (HT non-member protection) if there may be non-HT STAs
118 	in both the primary and the secondary channel
119 Set to 2 if only HT STAs are associated in BSS,
120 	however and at least one 20 MHz HT STA is associated
121 Set to 3 (HT mixed mode) when one or more non-HT STAs are associated
122 */
123 int hostapd_ht_operation_update(struct hostapd_iface *iface)
124 {
125 	u16 cur_op_mode, new_op_mode;
126 	int op_mode_changes = 0;
127 
128 	if (!iface->conf->ieee80211n || iface->conf->ht_op_mode_fixed)
129 		return 0;
130 
131 	wpa_printf(MSG_DEBUG, "%s current operation mode=0x%X",
132 		   __func__, iface->ht_op_mode);
133 
134 	if (!(iface->ht_op_mode & HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT)
135 	    && iface->num_sta_ht_no_gf) {
136 		iface->ht_op_mode |= HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
137 		op_mode_changes++;
138 	} else if ((iface->ht_op_mode &
139 		    HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT) &&
140 		   iface->num_sta_ht_no_gf == 0) {
141 		iface->ht_op_mode &= ~HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
142 		op_mode_changes++;
143 	}
144 
145 	if (!(iface->ht_op_mode & HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
146 	    (iface->num_sta_no_ht || iface->olbc_ht)) {
147 		iface->ht_op_mode |= HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
148 		op_mode_changes++;
149 	} else if ((iface->ht_op_mode &
150 		    HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
151 		   (iface->num_sta_no_ht == 0 && !iface->olbc_ht)) {
152 		iface->ht_op_mode &= ~HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
153 		op_mode_changes++;
154 	}
155 
156 	if (iface->num_sta_no_ht)
157 		new_op_mode = HT_PROT_NON_HT_MIXED;
158 	else if (iface->conf->secondary_channel && iface->num_sta_ht_20mhz)
159 		new_op_mode = HT_PROT_20MHZ_PROTECTION;
160 	else if (iface->olbc_ht)
161 		new_op_mode = HT_PROT_NONMEMBER_PROTECTION;
162 	else
163 		new_op_mode = HT_PROT_NO_PROTECTION;
164 
165 	cur_op_mode = iface->ht_op_mode & HT_OPER_OP_MODE_HT_PROT_MASK;
166 	if (cur_op_mode != new_op_mode) {
167 		iface->ht_op_mode &= ~HT_OPER_OP_MODE_HT_PROT_MASK;
168 		iface->ht_op_mode |= new_op_mode;
169 		op_mode_changes++;
170 	}
171 
172 	wpa_printf(MSG_DEBUG, "%s new operation mode=0x%X changes=%d",
173 		   __func__, iface->ht_op_mode, op_mode_changes);
174 
175 	return op_mode_changes;
176 }
177 
178 
179 static int is_40_allowed(struct hostapd_iface *iface, int channel)
180 {
181 	int pri_freq, sec_freq;
182 	int affected_start, affected_end;
183 	int pri = 2407 + 5 * channel;
184 
185 	if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
186 		return 1;
187 
188 	pri_freq = hostapd_hw_get_freq(iface->bss[0], iface->conf->channel);
189 
190 	if (iface->conf->secondary_channel > 0)
191 		sec_freq = pri_freq + 20;
192 	else
193 		sec_freq = pri_freq - 20;
194 
195 	affected_start = (pri_freq + sec_freq) / 2 - 25;
196 	affected_end = (pri_freq + sec_freq) / 2 + 25;
197 	if ((pri < affected_start || pri > affected_end))
198 		return 1; /* not within affected channel range */
199 
200 	wpa_printf(MSG_ERROR, "40 MHz affected channel range: [%d,%d] MHz",
201 		   affected_start, affected_end);
202 	wpa_printf(MSG_ERROR, "Neighboring BSS: freq=%d", pri);
203 	return 0;
204 }
205 
206 
207 void hostapd_2040_coex_action(struct hostapd_data *hapd,
208 			      const struct ieee80211_mgmt *mgmt, size_t len)
209 {
210 	struct hostapd_iface *iface = hapd->iface;
211 	struct ieee80211_2040_bss_coex_ie *bc_ie;
212 	struct ieee80211_2040_intol_chan_report *ic_report;
213 	int is_ht40_allowed = 1;
214 	int i;
215 	const u8 *start = (const u8 *) mgmt;
216 	const u8 *data = start + IEEE80211_HDRLEN + 2;
217 	struct sta_info *sta;
218 
219 	wpa_printf(MSG_DEBUG,
220 		   "HT: Received 20/40 BSS Coexistence Management frame from "
221 		   MACSTR, MAC2STR(mgmt->sa));
222 
223 	hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
224 		       HOSTAPD_LEVEL_DEBUG, "hostapd_public_action - action=%d",
225 		       mgmt->u.action.u.public_action.action);
226 
227 	if (!(iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET)) {
228 		wpa_printf(MSG_DEBUG,
229 			   "Ignore 20/40 BSS Coexistence Management frame since 40 MHz capability is not enabled");
230 		return;
231 	}
232 
233 	if (len < IEEE80211_HDRLEN + 2 + sizeof(*bc_ie)) {
234 		wpa_printf(MSG_DEBUG,
235 			   "Ignore too short 20/40 BSS Coexistence Management frame");
236 		return;
237 	}
238 
239 	/* 20/40 BSS Coexistence element */
240 	bc_ie = (struct ieee80211_2040_bss_coex_ie *) data;
241 	if (bc_ie->element_id != WLAN_EID_20_40_BSS_COEXISTENCE ||
242 	    bc_ie->length < 1) {
243 		wpa_printf(MSG_DEBUG, "Unexpected IE (%u,%u) in coex report",
244 			   bc_ie->element_id, bc_ie->length);
245 		return;
246 	}
247 	if (len < IEEE80211_HDRLEN + 2 + 2 + bc_ie->length) {
248 		wpa_printf(MSG_DEBUG,
249 			   "Truncated 20/40 BSS Coexistence element");
250 		return;
251 	}
252 	data += 2 + bc_ie->length;
253 
254 	wpa_printf(MSG_DEBUG,
255 		   "20/40 BSS Coexistence Information field: 0x%x (%s%s%s%s%s%s)",
256 		   bc_ie->coex_param,
257 		   (bc_ie->coex_param & BIT(0)) ? "[InfoReq]" : "",
258 		   (bc_ie->coex_param & BIT(1)) ? "[40MHzIntolerant]" : "",
259 		   (bc_ie->coex_param & BIT(2)) ? "[20MHzBSSWidthReq]" : "",
260 		   (bc_ie->coex_param & BIT(3)) ? "[OBSSScanExemptionReq]" : "",
261 		   (bc_ie->coex_param & BIT(4)) ?
262 		   "[OBSSScanExemptionGrant]" : "",
263 		   (bc_ie->coex_param & (BIT(5) | BIT(6) | BIT(7))) ?
264 		   "[Reserved]" : "");
265 
266 	if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_20MHZ_WIDTH_REQ) {
267 		/* Intra-BSS communication prohibiting 20/40 MHz BSS operation
268 		 */
269 		sta = ap_get_sta(hapd, mgmt->sa);
270 		if (!sta || !(sta->flags & WLAN_STA_ASSOC)) {
271 			wpa_printf(MSG_DEBUG,
272 				   "Ignore intra-BSS 20/40 BSS Coexistence Management frame from not-associated STA");
273 			return;
274 		}
275 
276 		hostapd_logger(hapd, mgmt->sa,
277 			       HOSTAPD_MODULE_IEEE80211,
278 			       HOSTAPD_LEVEL_DEBUG,
279 			       "20 MHz BSS width request bit is set in BSS coexistence information field");
280 		is_ht40_allowed = 0;
281 	}
282 
283 	if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_40MHZ_INTOL) {
284 		/* Inter-BSS communication prohibiting 20/40 MHz BSS operation
285 		 */
286 		hostapd_logger(hapd, mgmt->sa,
287 			       HOSTAPD_MODULE_IEEE80211,
288 			       HOSTAPD_LEVEL_DEBUG,
289 			       "40 MHz intolerant bit is set in BSS coexistence information field");
290 		is_ht40_allowed = 0;
291 	}
292 
293 	/* 20/40 BSS Intolerant Channel Report element (zero or more times) */
294 	while (start + len - data >= 3 &&
295 	       data[0] == WLAN_EID_20_40_BSS_INTOLERANT && data[1] >= 1) {
296 		u8 ielen = data[1];
297 
298 		if (ielen > start + len - data - 2) {
299 			wpa_printf(MSG_DEBUG,
300 				   "Truncated 20/40 BSS Intolerant Channel Report element");
301 			return;
302 		}
303 		ic_report = (struct ieee80211_2040_intol_chan_report *) data;
304 		wpa_printf(MSG_DEBUG,
305 			   "20/40 BSS Intolerant Channel Report: Operating Class %u",
306 			   ic_report->op_class);
307 
308 		/* Go through the channel report to find any BSS there in the
309 		 * affected channel range */
310 		for (i = 0; i < ielen - 1; i++) {
311 			u8 chan = ic_report->variable[i];
312 
313 			if (chan == iface->conf->channel)
314 				continue; /* matching own primary channel */
315 			if (is_40_allowed(iface, chan))
316 				continue; /* not within affected channels */
317 			hostapd_logger(hapd, mgmt->sa,
318 				       HOSTAPD_MODULE_IEEE80211,
319 				       HOSTAPD_LEVEL_DEBUG,
320 				       "20_40_INTOLERANT channel %d reported",
321 				       chan);
322 			is_ht40_allowed = 0;
323 		}
324 
325 		data += 2 + ielen;
326 	}
327 	wpa_printf(MSG_DEBUG, "is_ht40_allowed=%d num_sta_ht40_intolerant=%d",
328 		   is_ht40_allowed, iface->num_sta_ht40_intolerant);
329 
330 	if (!is_ht40_allowed &&
331 	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
332 		if (iface->conf->secondary_channel) {
333 			hostapd_logger(hapd, mgmt->sa,
334 				       HOSTAPD_MODULE_IEEE80211,
335 				       HOSTAPD_LEVEL_INFO,
336 				       "Switching to 20 MHz operation");
337 			iface->conf->secondary_channel = 0;
338 			ieee802_11_set_beacons(iface);
339 		}
340 		if (!iface->num_sta_ht40_intolerant &&
341 		    iface->conf->obss_interval) {
342 			unsigned int delay_time;
343 			delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
344 				iface->conf->obss_interval;
345 			eloop_cancel_timeout(ap_ht2040_timeout, hapd->iface,
346 					     NULL);
347 			eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
348 					       hapd->iface, NULL);
349 			wpa_printf(MSG_DEBUG,
350 				   "Reschedule HT 20/40 timeout to occur in %u seconds",
351 				   delay_time);
352 		}
353 	}
354 }
355 
356 
357 u16 copy_sta_ht_capab(struct hostapd_data *hapd, struct sta_info *sta,
358 		      const u8 *ht_capab)
359 {
360 	/*
361 	 * Disable HT caps for STAs associated to no-HT BSSes, or for stations
362 	 * that did not specify a valid WMM IE in the (Re)Association Request
363 	 * frame.
364 	 */
365 	if (!ht_capab || !(sta->flags & WLAN_STA_WMM) ||
366 	    !hapd->iconf->ieee80211n || hapd->conf->disable_11n) {
367 		sta->flags &= ~WLAN_STA_HT;
368 		os_free(sta->ht_capabilities);
369 		sta->ht_capabilities = NULL;
370 		return WLAN_STATUS_SUCCESS;
371 	}
372 
373 	if (sta->ht_capabilities == NULL) {
374 		sta->ht_capabilities =
375 			os_zalloc(sizeof(struct ieee80211_ht_capabilities));
376 		if (sta->ht_capabilities == NULL)
377 			return WLAN_STATUS_UNSPECIFIED_FAILURE;
378 	}
379 
380 	sta->flags |= WLAN_STA_HT;
381 	os_memcpy(sta->ht_capabilities, ht_capab,
382 		  sizeof(struct ieee80211_ht_capabilities));
383 
384 	return WLAN_STATUS_SUCCESS;
385 }
386 
387 
388 void ht40_intolerant_add(struct hostapd_iface *iface, struct sta_info *sta)
389 {
390 	if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
391 		return;
392 
393 	wpa_printf(MSG_INFO, "HT: Forty MHz Intolerant is set by STA " MACSTR
394 		   " in Association Request", MAC2STR(sta->addr));
395 
396 	if (sta->ht40_intolerant_set)
397 		return;
398 
399 	sta->ht40_intolerant_set = 1;
400 	iface->num_sta_ht40_intolerant++;
401 	eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
402 
403 	if (iface->conf->secondary_channel &&
404 	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
405 		iface->conf->secondary_channel = 0;
406 		ieee802_11_set_beacons(iface);
407 	}
408 }
409 
410 
411 void ht40_intolerant_remove(struct hostapd_iface *iface, struct sta_info *sta)
412 {
413 	if (!sta->ht40_intolerant_set)
414 		return;
415 
416 	sta->ht40_intolerant_set = 0;
417 	iface->num_sta_ht40_intolerant--;
418 
419 	if (iface->num_sta_ht40_intolerant == 0 &&
420 	    (iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) &&
421 	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
422 		unsigned int delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
423 			iface->conf->obss_interval;
424 		wpa_printf(MSG_DEBUG,
425 			   "HT: Start 20->40 MHz transition timer (%d seconds)",
426 			   delay_time);
427 		eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
428 		eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
429 				       iface, NULL);
430 	}
431 }
432 
433 
434 static void update_sta_ht(struct hostapd_data *hapd, struct sta_info *sta)
435 {
436 	u16 ht_capab;
437 
438 	ht_capab = le_to_host16(sta->ht_capabilities->ht_capabilities_info);
439 	wpa_printf(MSG_DEBUG, "HT: STA " MACSTR " HT Capabilities Info: "
440 		   "0x%04x", MAC2STR(sta->addr), ht_capab);
441 	if ((ht_capab & HT_CAP_INFO_GREEN_FIELD) == 0) {
442 		if (!sta->no_ht_gf_set) {
443 			sta->no_ht_gf_set = 1;
444 			hapd->iface->num_sta_ht_no_gf++;
445 		}
446 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no greenfield, num "
447 			   "of non-gf stations %d",
448 			   __func__, MAC2STR(sta->addr),
449 			   hapd->iface->num_sta_ht_no_gf);
450 	}
451 	if ((ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) == 0) {
452 		if (!sta->ht_20mhz_set) {
453 			sta->ht_20mhz_set = 1;
454 			hapd->iface->num_sta_ht_20mhz++;
455 		}
456 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - 20 MHz HT, num of "
457 			   "20MHz HT STAs %d",
458 			   __func__, MAC2STR(sta->addr),
459 			   hapd->iface->num_sta_ht_20mhz);
460 	}
461 
462 	if (ht_capab & HT_CAP_INFO_40MHZ_INTOLERANT)
463 		ht40_intolerant_add(hapd->iface, sta);
464 }
465 
466 
467 static void update_sta_no_ht(struct hostapd_data *hapd, struct sta_info *sta)
468 {
469 	if (!sta->no_ht_set) {
470 		sta->no_ht_set = 1;
471 		hapd->iface->num_sta_no_ht++;
472 	}
473 	if (hapd->iconf->ieee80211n) {
474 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no HT, num of "
475 			   "non-HT stations %d",
476 			   __func__, MAC2STR(sta->addr),
477 			   hapd->iface->num_sta_no_ht);
478 	}
479 }
480 
481 
482 void update_ht_state(struct hostapd_data *hapd, struct sta_info *sta)
483 {
484 	if ((sta->flags & WLAN_STA_HT) && sta->ht_capabilities)
485 		update_sta_ht(hapd, sta);
486 	else
487 		update_sta_no_ht(hapd, sta);
488 
489 	if (hostapd_ht_operation_update(hapd->iface) > 0)
490 		ieee802_11_set_beacons(hapd->iface);
491 }
492 
493 
494 void hostapd_get_ht_capab(struct hostapd_data *hapd,
495 			  struct ieee80211_ht_capabilities *ht_cap,
496 			  struct ieee80211_ht_capabilities *neg_ht_cap)
497 {
498 	u16 cap;
499 
500 	if (ht_cap == NULL)
501 		return;
502 	os_memcpy(neg_ht_cap, ht_cap, sizeof(*neg_ht_cap));
503 	cap = le_to_host16(neg_ht_cap->ht_capabilities_info);
504 
505 	/*
506 	 * Mask out HT features we don't support, but don't overwrite
507 	 * non-symmetric features like STBC and SMPS. Just because
508 	 * we're not in dynamic SMPS mode the STA might still be.
509 	 */
510 	cap &= (hapd->iconf->ht_capab | HT_CAP_INFO_RX_STBC_MASK |
511 		HT_CAP_INFO_TX_STBC | HT_CAP_INFO_SMPS_MASK);
512 
513 	/*
514 	 * STBC needs to be handled specially
515 	 * if we don't support RX STBC, mask out TX STBC in the STA's HT caps
516 	 * if we don't support TX STBC, mask out RX STBC in the STA's HT caps
517 	 */
518 	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_RX_STBC_MASK))
519 		cap &= ~HT_CAP_INFO_TX_STBC;
520 	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_TX_STBC))
521 		cap &= ~HT_CAP_INFO_RX_STBC_MASK;
522 
523 	neg_ht_cap->ht_capabilities_info = host_to_le16(cap);
524 }
525 
526 
527 void ap_ht2040_timeout(void *eloop_data, void *user_data)
528 {
529 	struct hostapd_iface *iface = eloop_data;
530 
531 	wpa_printf(MSG_INFO, "Switching to 40 MHz operation");
532 
533 	iface->conf->secondary_channel = iface->secondary_ch;
534 	ieee802_11_set_beacons(iface);
535 }
536