xref: /linux/net/mac80211/tdls.c (revision 2ba9268dd603d23e17643437b2246acb6844953b)
1 /*
2  * mac80211 TDLS handling code
3  *
4  * Copyright 2006-2010	Johannes Berg <johannes@sipsolutions.net>
5  * Copyright 2014, Intel Corporation
6  * Copyright 2014  Intel Mobile Communications GmbH
7  *
8  * This file is GPLv2 as found in COPYING.
9  */
10 
11 #include <linux/ieee80211.h>
12 #include <linux/log2.h>
13 #include <net/cfg80211.h>
14 #include "ieee80211_i.h"
15 #include "driver-ops.h"
16 
17 /* give usermode some time for retries in setting up the TDLS session */
18 #define TDLS_PEER_SETUP_TIMEOUT	(15 * HZ)
19 
20 void ieee80211_tdls_peer_del_work(struct work_struct *wk)
21 {
22 	struct ieee80211_sub_if_data *sdata;
23 	struct ieee80211_local *local;
24 
25 	sdata = container_of(wk, struct ieee80211_sub_if_data,
26 			     u.mgd.tdls_peer_del_work.work);
27 	local = sdata->local;
28 
29 	mutex_lock(&local->mtx);
30 	if (!is_zero_ether_addr(sdata->u.mgd.tdls_peer)) {
31 		tdls_dbg(sdata, "TDLS del peer %pM\n", sdata->u.mgd.tdls_peer);
32 		sta_info_destroy_addr(sdata, sdata->u.mgd.tdls_peer);
33 		eth_zero_addr(sdata->u.mgd.tdls_peer);
34 	}
35 	mutex_unlock(&local->mtx);
36 }
37 
38 static void ieee80211_tdls_add_ext_capab(struct ieee80211_local *local,
39 					 struct sk_buff *skb)
40 {
41 	u8 *pos = (void *)skb_put(skb, 7);
42 	bool chan_switch = local->hw.wiphy->features &
43 			   NL80211_FEATURE_TDLS_CHANNEL_SWITCH;
44 
45 	*pos++ = WLAN_EID_EXT_CAPABILITY;
46 	*pos++ = 5; /* len */
47 	*pos++ = 0x0;
48 	*pos++ = 0x0;
49 	*pos++ = 0x0;
50 	*pos++ = chan_switch ? WLAN_EXT_CAPA4_TDLS_CHAN_SWITCH : 0;
51 	*pos++ = WLAN_EXT_CAPA5_TDLS_ENABLED;
52 }
53 
54 static u8
55 ieee80211_tdls_add_subband(struct ieee80211_sub_if_data *sdata,
56 			   struct sk_buff *skb, u16 start, u16 end,
57 			   u16 spacing)
58 {
59 	u8 subband_cnt = 0, ch_cnt = 0;
60 	struct ieee80211_channel *ch;
61 	struct cfg80211_chan_def chandef;
62 	int i, subband_start;
63 
64 	for (i = start; i <= end; i += spacing) {
65 		if (!ch_cnt)
66 			subband_start = i;
67 
68 		ch = ieee80211_get_channel(sdata->local->hw.wiphy, i);
69 		if (ch) {
70 			/* we will be active on the channel */
71 			cfg80211_chandef_create(&chandef, ch,
72 						NL80211_CHAN_NO_HT);
73 			if (cfg80211_reg_can_beacon(sdata->local->hw.wiphy,
74 						    &chandef,
75 						    sdata->wdev.iftype)) {
76 				ch_cnt++;
77 				/*
78 				 * check if the next channel is also part of
79 				 * this allowed range
80 				 */
81 				continue;
82 			}
83 		}
84 
85 		/*
86 		 * we've reached the end of a range, with allowed channels
87 		 * found
88 		 */
89 		if (ch_cnt) {
90 			u8 *pos = skb_put(skb, 2);
91 			*pos++ = ieee80211_frequency_to_channel(subband_start);
92 			*pos++ = ch_cnt;
93 
94 			subband_cnt++;
95 			ch_cnt = 0;
96 		}
97 	}
98 
99 	/* all channels in the requested range are allowed - add them here */
100 	if (ch_cnt) {
101 		u8 *pos = skb_put(skb, 2);
102 		*pos++ = ieee80211_frequency_to_channel(subband_start);
103 		*pos++ = ch_cnt;
104 
105 		subband_cnt++;
106 	}
107 
108 	return subband_cnt;
109 }
110 
111 static void
112 ieee80211_tdls_add_supp_channels(struct ieee80211_sub_if_data *sdata,
113 				 struct sk_buff *skb)
114 {
115 	/*
116 	 * Add possible channels for TDLS. These are channels that are allowed
117 	 * to be active.
118 	 */
119 	u8 subband_cnt;
120 	u8 *pos = skb_put(skb, 2);
121 
122 	*pos++ = WLAN_EID_SUPPORTED_CHANNELS;
123 
124 	/*
125 	 * 5GHz and 2GHz channels numbers can overlap. Ignore this for now, as
126 	 * this doesn't happen in real world scenarios.
127 	 */
128 
129 	/* 2GHz, with 5MHz spacing */
130 	subband_cnt = ieee80211_tdls_add_subband(sdata, skb, 2412, 2472, 5);
131 
132 	/* 5GHz, with 20MHz spacing */
133 	subband_cnt += ieee80211_tdls_add_subband(sdata, skb, 5000, 5825, 20);
134 
135 	/* length */
136 	*pos = 2 * subband_cnt;
137 }
138 
139 static void ieee80211_tdls_add_bss_coex_ie(struct sk_buff *skb)
140 {
141 	u8 *pos = (void *)skb_put(skb, 3);
142 
143 	*pos++ = WLAN_EID_BSS_COEX_2040;
144 	*pos++ = 1; /* len */
145 
146 	*pos++ = WLAN_BSS_COEX_INFORMATION_REQUEST;
147 }
148 
149 static u16 ieee80211_get_tdls_sta_capab(struct ieee80211_sub_if_data *sdata,
150 					u16 status_code)
151 {
152 	struct ieee80211_local *local = sdata->local;
153 	u16 capab;
154 
155 	/* The capability will be 0 when sending a failure code */
156 	if (status_code != 0)
157 		return 0;
158 
159 	capab = 0;
160 	if (ieee80211_get_sdata_band(sdata) != IEEE80211_BAND_2GHZ)
161 		return capab;
162 
163 	if (!(local->hw.flags & IEEE80211_HW_2GHZ_SHORT_SLOT_INCAPABLE))
164 		capab |= WLAN_CAPABILITY_SHORT_SLOT_TIME;
165 	if (!(local->hw.flags & IEEE80211_HW_2GHZ_SHORT_PREAMBLE_INCAPABLE))
166 		capab |= WLAN_CAPABILITY_SHORT_PREAMBLE;
167 
168 	return capab;
169 }
170 
171 static void ieee80211_tdls_add_link_ie(struct ieee80211_sub_if_data *sdata,
172 				       struct sk_buff *skb, const u8 *peer,
173 				       bool initiator)
174 {
175 	struct ieee80211_tdls_lnkie *lnkid;
176 	const u8 *init_addr, *rsp_addr;
177 
178 	if (initiator) {
179 		init_addr = sdata->vif.addr;
180 		rsp_addr = peer;
181 	} else {
182 		init_addr = peer;
183 		rsp_addr = sdata->vif.addr;
184 	}
185 
186 	lnkid = (void *)skb_put(skb, sizeof(struct ieee80211_tdls_lnkie));
187 
188 	lnkid->ie_type = WLAN_EID_LINK_ID;
189 	lnkid->ie_len = sizeof(struct ieee80211_tdls_lnkie) - 2;
190 
191 	memcpy(lnkid->bssid, sdata->u.mgd.bssid, ETH_ALEN);
192 	memcpy(lnkid->init_sta, init_addr, ETH_ALEN);
193 	memcpy(lnkid->resp_sta, rsp_addr, ETH_ALEN);
194 }
195 
196 /* translate numbering in the WMM parameter IE to the mac80211 notation */
197 static enum ieee80211_ac_numbers ieee80211_ac_from_wmm(int ac)
198 {
199 	switch (ac) {
200 	default:
201 		WARN_ON_ONCE(1);
202 	case 0:
203 		return IEEE80211_AC_BE;
204 	case 1:
205 		return IEEE80211_AC_BK;
206 	case 2:
207 		return IEEE80211_AC_VI;
208 	case 3:
209 		return IEEE80211_AC_VO;
210 	}
211 }
212 
213 static u8 ieee80211_wmm_aci_aifsn(int aifsn, bool acm, int aci)
214 {
215 	u8 ret;
216 
217 	ret = aifsn & 0x0f;
218 	if (acm)
219 		ret |= 0x10;
220 	ret |= (aci << 5) & 0x60;
221 	return ret;
222 }
223 
224 static u8 ieee80211_wmm_ecw(u16 cw_min, u16 cw_max)
225 {
226 	return ((ilog2(cw_min + 1) << 0x0) & 0x0f) |
227 	       ((ilog2(cw_max + 1) << 0x4) & 0xf0);
228 }
229 
230 static void ieee80211_tdls_add_wmm_param_ie(struct ieee80211_sub_if_data *sdata,
231 					    struct sk_buff *skb)
232 {
233 	struct ieee80211_wmm_param_ie *wmm;
234 	struct ieee80211_tx_queue_params *txq;
235 	int i;
236 
237 	wmm = (void *)skb_put(skb, sizeof(*wmm));
238 	memset(wmm, 0, sizeof(*wmm));
239 
240 	wmm->element_id = WLAN_EID_VENDOR_SPECIFIC;
241 	wmm->len = sizeof(*wmm) - 2;
242 
243 	wmm->oui[0] = 0x00; /* Microsoft OUI 00:50:F2 */
244 	wmm->oui[1] = 0x50;
245 	wmm->oui[2] = 0xf2;
246 	wmm->oui_type = 2; /* WME */
247 	wmm->oui_subtype = 1; /* WME param */
248 	wmm->version = 1; /* WME ver */
249 	wmm->qos_info = 0; /* U-APSD not in use */
250 
251 	/*
252 	 * Use the EDCA parameters defined for the BSS, or default if the AP
253 	 * doesn't support it, as mandated by 802.11-2012 section 10.22.4
254 	 */
255 	for (i = 0; i < IEEE80211_NUM_ACS; i++) {
256 		txq = &sdata->tx_conf[ieee80211_ac_from_wmm(i)];
257 		wmm->ac[i].aci_aifsn = ieee80211_wmm_aci_aifsn(txq->aifs,
258 							       txq->acm, i);
259 		wmm->ac[i].cw = ieee80211_wmm_ecw(txq->cw_min, txq->cw_max);
260 		wmm->ac[i].txop_limit = cpu_to_le16(txq->txop);
261 	}
262 }
263 
264 static void
265 ieee80211_tdls_add_setup_start_ies(struct ieee80211_sub_if_data *sdata,
266 				   struct sk_buff *skb, const u8 *peer,
267 				   u8 action_code, bool initiator,
268 				   const u8 *extra_ies, size_t extra_ies_len)
269 {
270 	enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
271 	struct ieee80211_local *local = sdata->local;
272 	struct ieee80211_supported_band *sband;
273 	struct ieee80211_sta_ht_cap ht_cap;
274 	struct sta_info *sta = NULL;
275 	size_t offset = 0, noffset;
276 	u8 *pos;
277 
278 	rcu_read_lock();
279 
280 	/* we should have the peer STA if we're already responding */
281 	if (action_code == WLAN_TDLS_SETUP_RESPONSE) {
282 		sta = sta_info_get(sdata, peer);
283 		if (WARN_ON_ONCE(!sta)) {
284 			rcu_read_unlock();
285 			return;
286 		}
287 	}
288 
289 	ieee80211_add_srates_ie(sdata, skb, false, band);
290 	ieee80211_add_ext_srates_ie(sdata, skb, false, band);
291 	ieee80211_tdls_add_supp_channels(sdata, skb);
292 
293 	/* add any custom IEs that go before Extended Capabilities */
294 	if (extra_ies_len) {
295 		static const u8 before_ext_cap[] = {
296 			WLAN_EID_SUPP_RATES,
297 			WLAN_EID_COUNTRY,
298 			WLAN_EID_EXT_SUPP_RATES,
299 			WLAN_EID_SUPPORTED_CHANNELS,
300 			WLAN_EID_RSN,
301 		};
302 		noffset = ieee80211_ie_split(extra_ies, extra_ies_len,
303 					     before_ext_cap,
304 					     ARRAY_SIZE(before_ext_cap),
305 					     offset);
306 		pos = skb_put(skb, noffset - offset);
307 		memcpy(pos, extra_ies + offset, noffset - offset);
308 		offset = noffset;
309 	}
310 
311 	ieee80211_tdls_add_ext_capab(local, skb);
312 
313 	/* add the QoS element if we support it */
314 	if (local->hw.queues >= IEEE80211_NUM_ACS &&
315 	    action_code != WLAN_PUB_ACTION_TDLS_DISCOVER_RES)
316 		ieee80211_add_wmm_info_ie(skb_put(skb, 9), 0); /* no U-APSD */
317 
318 	/* add any custom IEs that go before HT capabilities */
319 	if (extra_ies_len) {
320 		static const u8 before_ht_cap[] = {
321 			WLAN_EID_SUPP_RATES,
322 			WLAN_EID_COUNTRY,
323 			WLAN_EID_EXT_SUPP_RATES,
324 			WLAN_EID_SUPPORTED_CHANNELS,
325 			WLAN_EID_RSN,
326 			WLAN_EID_EXT_CAPABILITY,
327 			WLAN_EID_QOS_CAPA,
328 			WLAN_EID_FAST_BSS_TRANSITION,
329 			WLAN_EID_TIMEOUT_INTERVAL,
330 			WLAN_EID_SUPPORTED_REGULATORY_CLASSES,
331 		};
332 		noffset = ieee80211_ie_split(extra_ies, extra_ies_len,
333 					     before_ht_cap,
334 					     ARRAY_SIZE(before_ht_cap),
335 					     offset);
336 		pos = skb_put(skb, noffset - offset);
337 		memcpy(pos, extra_ies + offset, noffset - offset);
338 		offset = noffset;
339 	}
340 
341 	/*
342 	 * with TDLS we can switch channels, and HT-caps are not necessarily
343 	 * the same on all bands. The specification limits the setup to a
344 	 * single HT-cap, so use the current band for now.
345 	 */
346 	sband = local->hw.wiphy->bands[band];
347 	memcpy(&ht_cap, &sband->ht_cap, sizeof(ht_cap));
348 
349 	if (action_code == WLAN_TDLS_SETUP_REQUEST && ht_cap.ht_supported) {
350 		ieee80211_apply_htcap_overrides(sdata, &ht_cap);
351 
352 		/* disable SMPS in TDLS initiator */
353 		ht_cap.cap |= WLAN_HT_CAP_SM_PS_DISABLED
354 				<< IEEE80211_HT_CAP_SM_PS_SHIFT;
355 
356 		pos = skb_put(skb, sizeof(struct ieee80211_ht_cap) + 2);
357 		ieee80211_ie_build_ht_cap(pos, &ht_cap, ht_cap.cap);
358 	} else if (action_code == WLAN_TDLS_SETUP_RESPONSE &&
359 		   ht_cap.ht_supported && sta->sta.ht_cap.ht_supported) {
360 		/* disable SMPS in TDLS responder */
361 		sta->sta.ht_cap.cap |= WLAN_HT_CAP_SM_PS_DISABLED
362 					<< IEEE80211_HT_CAP_SM_PS_SHIFT;
363 
364 		/* the peer caps are already intersected with our own */
365 		memcpy(&ht_cap, &sta->sta.ht_cap, sizeof(ht_cap));
366 
367 		pos = skb_put(skb, sizeof(struct ieee80211_ht_cap) + 2);
368 		ieee80211_ie_build_ht_cap(pos, &ht_cap, ht_cap.cap);
369 	}
370 
371 	rcu_read_unlock();
372 
373 	if (ht_cap.ht_supported &&
374 	    (ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40))
375 		ieee80211_tdls_add_bss_coex_ie(skb);
376 
377 	/* add any remaining IEs */
378 	if (extra_ies_len) {
379 		noffset = extra_ies_len;
380 		pos = skb_put(skb, noffset - offset);
381 		memcpy(pos, extra_ies + offset, noffset - offset);
382 	}
383 
384 	ieee80211_tdls_add_link_ie(sdata, skb, peer, initiator);
385 }
386 
387 static void
388 ieee80211_tdls_add_setup_cfm_ies(struct ieee80211_sub_if_data *sdata,
389 				 struct sk_buff *skb, const u8 *peer,
390 				 bool initiator, const u8 *extra_ies,
391 				 size_t extra_ies_len)
392 {
393 	struct ieee80211_local *local = sdata->local;
394 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
395 	size_t offset = 0, noffset;
396 	struct sta_info *sta, *ap_sta;
397 	u8 *pos;
398 
399 	rcu_read_lock();
400 
401 	sta = sta_info_get(sdata, peer);
402 	ap_sta = sta_info_get(sdata, ifmgd->bssid);
403 	if (WARN_ON_ONCE(!sta || !ap_sta)) {
404 		rcu_read_unlock();
405 		return;
406 	}
407 
408 	/* add any custom IEs that go before the QoS IE */
409 	if (extra_ies_len) {
410 		static const u8 before_qos[] = {
411 			WLAN_EID_RSN,
412 		};
413 		noffset = ieee80211_ie_split(extra_ies, extra_ies_len,
414 					     before_qos,
415 					     ARRAY_SIZE(before_qos),
416 					     offset);
417 		pos = skb_put(skb, noffset - offset);
418 		memcpy(pos, extra_ies + offset, noffset - offset);
419 		offset = noffset;
420 	}
421 
422 	/* add the QoS param IE if both the peer and we support it */
423 	if (local->hw.queues >= IEEE80211_NUM_ACS && sta->sta.wme)
424 		ieee80211_tdls_add_wmm_param_ie(sdata, skb);
425 
426 	/* add any custom IEs that go before HT operation */
427 	if (extra_ies_len) {
428 		static const u8 before_ht_op[] = {
429 			WLAN_EID_RSN,
430 			WLAN_EID_QOS_CAPA,
431 			WLAN_EID_FAST_BSS_TRANSITION,
432 			WLAN_EID_TIMEOUT_INTERVAL,
433 		};
434 		noffset = ieee80211_ie_split(extra_ies, extra_ies_len,
435 					     before_ht_op,
436 					     ARRAY_SIZE(before_ht_op),
437 					     offset);
438 		pos = skb_put(skb, noffset - offset);
439 		memcpy(pos, extra_ies + offset, noffset - offset);
440 		offset = noffset;
441 	}
442 
443 	/* if HT support is only added in TDLS, we need an HT-operation IE */
444 	if (!ap_sta->sta.ht_cap.ht_supported && sta->sta.ht_cap.ht_supported) {
445 		struct ieee80211_chanctx_conf *chanctx_conf =
446 				rcu_dereference(sdata->vif.chanctx_conf);
447 		if (!WARN_ON(!chanctx_conf)) {
448 			pos = skb_put(skb, 2 +
449 				      sizeof(struct ieee80211_ht_operation));
450 			/* send an empty HT operation IE */
451 			ieee80211_ie_build_ht_oper(pos, &sta->sta.ht_cap,
452 						   &chanctx_conf->def, 0);
453 		}
454 	}
455 
456 	rcu_read_unlock();
457 
458 	/* add any remaining IEs */
459 	if (extra_ies_len) {
460 		noffset = extra_ies_len;
461 		pos = skb_put(skb, noffset - offset);
462 		memcpy(pos, extra_ies + offset, noffset - offset);
463 	}
464 
465 	ieee80211_tdls_add_link_ie(sdata, skb, peer, initiator);
466 }
467 
468 static void
469 ieee80211_tdls_add_chan_switch_req_ies(struct ieee80211_sub_if_data *sdata,
470 				       struct sk_buff *skb, const u8 *peer,
471 				       bool initiator, const u8 *extra_ies,
472 				       size_t extra_ies_len, u8 oper_class,
473 				       struct cfg80211_chan_def *chandef)
474 {
475 	struct ieee80211_tdls_data *tf;
476 	size_t offset = 0, noffset;
477 	u8 *pos;
478 
479 	if (WARN_ON_ONCE(!chandef))
480 		return;
481 
482 	tf = (void *)skb->data;
483 	tf->u.chan_switch_req.target_channel =
484 		ieee80211_frequency_to_channel(chandef->chan->center_freq);
485 	tf->u.chan_switch_req.oper_class = oper_class;
486 
487 	if (extra_ies_len) {
488 		static const u8 before_lnkie[] = {
489 			WLAN_EID_SECONDARY_CHANNEL_OFFSET,
490 		};
491 		noffset = ieee80211_ie_split(extra_ies, extra_ies_len,
492 					     before_lnkie,
493 					     ARRAY_SIZE(before_lnkie),
494 					     offset);
495 		pos = skb_put(skb, noffset - offset);
496 		memcpy(pos, extra_ies + offset, noffset - offset);
497 		offset = noffset;
498 	}
499 
500 	ieee80211_tdls_add_link_ie(sdata, skb, peer, initiator);
501 
502 	/* add any remaining IEs */
503 	if (extra_ies_len) {
504 		noffset = extra_ies_len;
505 		pos = skb_put(skb, noffset - offset);
506 		memcpy(pos, extra_ies + offset, noffset - offset);
507 	}
508 }
509 
510 static void
511 ieee80211_tdls_add_chan_switch_resp_ies(struct ieee80211_sub_if_data *sdata,
512 					struct sk_buff *skb, const u8 *peer,
513 					u16 status_code, bool initiator,
514 					const u8 *extra_ies,
515 					size_t extra_ies_len)
516 {
517 	if (status_code == 0)
518 		ieee80211_tdls_add_link_ie(sdata, skb, peer, initiator);
519 
520 	if (extra_ies_len)
521 		memcpy(skb_put(skb, extra_ies_len), extra_ies, extra_ies_len);
522 }
523 
524 static void ieee80211_tdls_add_ies(struct ieee80211_sub_if_data *sdata,
525 				   struct sk_buff *skb, const u8 *peer,
526 				   u8 action_code, u16 status_code,
527 				   bool initiator, const u8 *extra_ies,
528 				   size_t extra_ies_len, u8 oper_class,
529 				   struct cfg80211_chan_def *chandef)
530 {
531 	switch (action_code) {
532 	case WLAN_TDLS_SETUP_REQUEST:
533 	case WLAN_TDLS_SETUP_RESPONSE:
534 	case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:
535 		if (status_code == 0)
536 			ieee80211_tdls_add_setup_start_ies(sdata, skb, peer,
537 							   action_code,
538 							   initiator,
539 							   extra_ies,
540 							   extra_ies_len);
541 		break;
542 	case WLAN_TDLS_SETUP_CONFIRM:
543 		if (status_code == 0)
544 			ieee80211_tdls_add_setup_cfm_ies(sdata, skb, peer,
545 							 initiator, extra_ies,
546 							 extra_ies_len);
547 		break;
548 	case WLAN_TDLS_TEARDOWN:
549 	case WLAN_TDLS_DISCOVERY_REQUEST:
550 		if (extra_ies_len)
551 			memcpy(skb_put(skb, extra_ies_len), extra_ies,
552 			       extra_ies_len);
553 		if (status_code == 0 || action_code == WLAN_TDLS_TEARDOWN)
554 			ieee80211_tdls_add_link_ie(sdata, skb, peer, initiator);
555 		break;
556 	case WLAN_TDLS_CHANNEL_SWITCH_REQUEST:
557 		ieee80211_tdls_add_chan_switch_req_ies(sdata, skb, peer,
558 						       initiator, extra_ies,
559 						       extra_ies_len,
560 						       oper_class, chandef);
561 		break;
562 	case WLAN_TDLS_CHANNEL_SWITCH_RESPONSE:
563 		ieee80211_tdls_add_chan_switch_resp_ies(sdata, skb, peer,
564 							status_code,
565 							initiator, extra_ies,
566 							extra_ies_len);
567 		break;
568 	}
569 
570 }
571 
572 static int
573 ieee80211_prep_tdls_encap_data(struct wiphy *wiphy, struct net_device *dev,
574 			       const u8 *peer, u8 action_code, u8 dialog_token,
575 			       u16 status_code, struct sk_buff *skb)
576 {
577 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
578 	struct ieee80211_tdls_data *tf;
579 
580 	tf = (void *)skb_put(skb, offsetof(struct ieee80211_tdls_data, u));
581 
582 	memcpy(tf->da, peer, ETH_ALEN);
583 	memcpy(tf->sa, sdata->vif.addr, ETH_ALEN);
584 	tf->ether_type = cpu_to_be16(ETH_P_TDLS);
585 	tf->payload_type = WLAN_TDLS_SNAP_RFTYPE;
586 
587 	/* network header is after the ethernet header */
588 	skb_set_network_header(skb, ETH_HLEN);
589 
590 	switch (action_code) {
591 	case WLAN_TDLS_SETUP_REQUEST:
592 		tf->category = WLAN_CATEGORY_TDLS;
593 		tf->action_code = WLAN_TDLS_SETUP_REQUEST;
594 
595 		skb_put(skb, sizeof(tf->u.setup_req));
596 		tf->u.setup_req.dialog_token = dialog_token;
597 		tf->u.setup_req.capability =
598 			cpu_to_le16(ieee80211_get_tdls_sta_capab(sdata,
599 								 status_code));
600 		break;
601 	case WLAN_TDLS_SETUP_RESPONSE:
602 		tf->category = WLAN_CATEGORY_TDLS;
603 		tf->action_code = WLAN_TDLS_SETUP_RESPONSE;
604 
605 		skb_put(skb, sizeof(tf->u.setup_resp));
606 		tf->u.setup_resp.status_code = cpu_to_le16(status_code);
607 		tf->u.setup_resp.dialog_token = dialog_token;
608 		tf->u.setup_resp.capability =
609 			cpu_to_le16(ieee80211_get_tdls_sta_capab(sdata,
610 								 status_code));
611 		break;
612 	case WLAN_TDLS_SETUP_CONFIRM:
613 		tf->category = WLAN_CATEGORY_TDLS;
614 		tf->action_code = WLAN_TDLS_SETUP_CONFIRM;
615 
616 		skb_put(skb, sizeof(tf->u.setup_cfm));
617 		tf->u.setup_cfm.status_code = cpu_to_le16(status_code);
618 		tf->u.setup_cfm.dialog_token = dialog_token;
619 		break;
620 	case WLAN_TDLS_TEARDOWN:
621 		tf->category = WLAN_CATEGORY_TDLS;
622 		tf->action_code = WLAN_TDLS_TEARDOWN;
623 
624 		skb_put(skb, sizeof(tf->u.teardown));
625 		tf->u.teardown.reason_code = cpu_to_le16(status_code);
626 		break;
627 	case WLAN_TDLS_DISCOVERY_REQUEST:
628 		tf->category = WLAN_CATEGORY_TDLS;
629 		tf->action_code = WLAN_TDLS_DISCOVERY_REQUEST;
630 
631 		skb_put(skb, sizeof(tf->u.discover_req));
632 		tf->u.discover_req.dialog_token = dialog_token;
633 		break;
634 	case WLAN_TDLS_CHANNEL_SWITCH_REQUEST:
635 		tf->category = WLAN_CATEGORY_TDLS;
636 		tf->action_code = WLAN_TDLS_CHANNEL_SWITCH_REQUEST;
637 
638 		skb_put(skb, sizeof(tf->u.chan_switch_req));
639 		break;
640 	case WLAN_TDLS_CHANNEL_SWITCH_RESPONSE:
641 		tf->category = WLAN_CATEGORY_TDLS;
642 		tf->action_code = WLAN_TDLS_CHANNEL_SWITCH_RESPONSE;
643 
644 		skb_put(skb, sizeof(tf->u.chan_switch_resp));
645 		tf->u.chan_switch_resp.status_code = cpu_to_le16(status_code);
646 		break;
647 	default:
648 		return -EINVAL;
649 	}
650 
651 	return 0;
652 }
653 
654 static int
655 ieee80211_prep_tdls_direct(struct wiphy *wiphy, struct net_device *dev,
656 			   const u8 *peer, u8 action_code, u8 dialog_token,
657 			   u16 status_code, struct sk_buff *skb)
658 {
659 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
660 	struct ieee80211_mgmt *mgmt;
661 
662 	mgmt = (void *)skb_put(skb, 24);
663 	memset(mgmt, 0, 24);
664 	memcpy(mgmt->da, peer, ETH_ALEN);
665 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
666 	memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
667 
668 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
669 					  IEEE80211_STYPE_ACTION);
670 
671 	switch (action_code) {
672 	case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:
673 		skb_put(skb, 1 + sizeof(mgmt->u.action.u.tdls_discover_resp));
674 		mgmt->u.action.category = WLAN_CATEGORY_PUBLIC;
675 		mgmt->u.action.u.tdls_discover_resp.action_code =
676 			WLAN_PUB_ACTION_TDLS_DISCOVER_RES;
677 		mgmt->u.action.u.tdls_discover_resp.dialog_token =
678 			dialog_token;
679 		mgmt->u.action.u.tdls_discover_resp.capability =
680 			cpu_to_le16(ieee80211_get_tdls_sta_capab(sdata,
681 								 status_code));
682 		break;
683 	default:
684 		return -EINVAL;
685 	}
686 
687 	return 0;
688 }
689 
690 static struct sk_buff *
691 ieee80211_tdls_build_mgmt_packet_data(struct ieee80211_sub_if_data *sdata,
692 				      const u8 *peer, u8 action_code,
693 				      u8 dialog_token, u16 status_code,
694 				      bool initiator, const u8 *extra_ies,
695 				      size_t extra_ies_len, u8 oper_class,
696 				      struct cfg80211_chan_def *chandef)
697 {
698 	struct ieee80211_local *local = sdata->local;
699 	struct sk_buff *skb;
700 	int ret;
701 
702 	skb = netdev_alloc_skb(sdata->dev,
703 			       local->hw.extra_tx_headroom +
704 			       max(sizeof(struct ieee80211_mgmt),
705 				   sizeof(struct ieee80211_tdls_data)) +
706 			       50 + /* supported rates */
707 			       7 + /* ext capab */
708 			       26 + /* max(WMM-info, WMM-param) */
709 			       2 + max(sizeof(struct ieee80211_ht_cap),
710 				       sizeof(struct ieee80211_ht_operation)) +
711 			       50 + /* supported channels */
712 			       3 + /* 40/20 BSS coex */
713 			       extra_ies_len +
714 			       sizeof(struct ieee80211_tdls_lnkie));
715 	if (!skb)
716 		return NULL;
717 
718 	skb_reserve(skb, local->hw.extra_tx_headroom);
719 
720 	switch (action_code) {
721 	case WLAN_TDLS_SETUP_REQUEST:
722 	case WLAN_TDLS_SETUP_RESPONSE:
723 	case WLAN_TDLS_SETUP_CONFIRM:
724 	case WLAN_TDLS_TEARDOWN:
725 	case WLAN_TDLS_DISCOVERY_REQUEST:
726 	case WLAN_TDLS_CHANNEL_SWITCH_REQUEST:
727 	case WLAN_TDLS_CHANNEL_SWITCH_RESPONSE:
728 		ret = ieee80211_prep_tdls_encap_data(local->hw.wiphy,
729 						     sdata->dev, peer,
730 						     action_code, dialog_token,
731 						     status_code, skb);
732 		break;
733 	case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:
734 		ret = ieee80211_prep_tdls_direct(local->hw.wiphy, sdata->dev,
735 						 peer, action_code,
736 						 dialog_token, status_code,
737 						 skb);
738 		break;
739 	default:
740 		ret = -ENOTSUPP;
741 		break;
742 	}
743 
744 	if (ret < 0)
745 		goto fail;
746 
747 	ieee80211_tdls_add_ies(sdata, skb, peer, action_code, status_code,
748 			       initiator, extra_ies, extra_ies_len, oper_class,
749 			       chandef);
750 	return skb;
751 
752 fail:
753 	dev_kfree_skb(skb);
754 	return NULL;
755 }
756 
757 static int
758 ieee80211_tdls_prep_mgmt_packet(struct wiphy *wiphy, struct net_device *dev,
759 				const u8 *peer, u8 action_code, u8 dialog_token,
760 				u16 status_code, u32 peer_capability,
761 				bool initiator, const u8 *extra_ies,
762 				size_t extra_ies_len, u8 oper_class,
763 				struct cfg80211_chan_def *chandef)
764 {
765 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
766 	struct sk_buff *skb = NULL;
767 	struct sta_info *sta;
768 	u32 flags = 0;
769 	int ret = 0;
770 
771 	rcu_read_lock();
772 	sta = sta_info_get(sdata, peer);
773 
774 	/* infer the initiator if we can, to support old userspace */
775 	switch (action_code) {
776 	case WLAN_TDLS_SETUP_REQUEST:
777 		if (sta) {
778 			set_sta_flag(sta, WLAN_STA_TDLS_INITIATOR);
779 			sta->sta.tdls_initiator = false;
780 		}
781 		/* fall-through */
782 	case WLAN_TDLS_SETUP_CONFIRM:
783 	case WLAN_TDLS_DISCOVERY_REQUEST:
784 		initiator = true;
785 		break;
786 	case WLAN_TDLS_SETUP_RESPONSE:
787 		/*
788 		 * In some testing scenarios, we send a request and response.
789 		 * Make the last packet sent take effect for the initiator
790 		 * value.
791 		 */
792 		if (sta) {
793 			clear_sta_flag(sta, WLAN_STA_TDLS_INITIATOR);
794 			sta->sta.tdls_initiator = true;
795 		}
796 		/* fall-through */
797 	case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:
798 		initiator = false;
799 		break;
800 	case WLAN_TDLS_TEARDOWN:
801 	case WLAN_TDLS_CHANNEL_SWITCH_REQUEST:
802 	case WLAN_TDLS_CHANNEL_SWITCH_RESPONSE:
803 		/* any value is ok */
804 		break;
805 	default:
806 		ret = -ENOTSUPP;
807 		break;
808 	}
809 
810 	if (sta && test_sta_flag(sta, WLAN_STA_TDLS_INITIATOR))
811 		initiator = true;
812 
813 	rcu_read_unlock();
814 	if (ret < 0)
815 		goto fail;
816 
817 	skb = ieee80211_tdls_build_mgmt_packet_data(sdata, peer, action_code,
818 						    dialog_token, status_code,
819 						    initiator, extra_ies,
820 						    extra_ies_len, oper_class,
821 						    chandef);
822 	if (!skb) {
823 		ret = -EINVAL;
824 		goto fail;
825 	}
826 
827 	if (action_code == WLAN_PUB_ACTION_TDLS_DISCOVER_RES) {
828 		ieee80211_tx_skb(sdata, skb);
829 		return 0;
830 	}
831 
832 	/*
833 	 * According to 802.11z: Setup req/resp are sent in AC_BK, otherwise
834 	 * we should default to AC_VI.
835 	 */
836 	switch (action_code) {
837 	case WLAN_TDLS_SETUP_REQUEST:
838 	case WLAN_TDLS_SETUP_RESPONSE:
839 		skb_set_queue_mapping(skb, IEEE80211_AC_BK);
840 		skb->priority = 2;
841 		break;
842 	default:
843 		skb_set_queue_mapping(skb, IEEE80211_AC_VI);
844 		skb->priority = 5;
845 		break;
846 	}
847 
848 	/*
849 	 * Set the WLAN_TDLS_TEARDOWN flag to indicate a teardown in progress.
850 	 * Later, if no ACK is returned from peer, we will re-send the teardown
851 	 * packet through the AP.
852 	 */
853 	if ((action_code == WLAN_TDLS_TEARDOWN) &&
854 	    (sdata->local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS)) {
855 		bool try_resend; /* Should we keep skb for possible resend */
856 
857 		/* If not sending directly to peer - no point in keeping skb */
858 		rcu_read_lock();
859 		sta = sta_info_get(sdata, peer);
860 		try_resend = sta && test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH);
861 		rcu_read_unlock();
862 
863 		spin_lock_bh(&sdata->u.mgd.teardown_lock);
864 		if (try_resend && !sdata->u.mgd.teardown_skb) {
865 			/* Mark it as requiring TX status callback  */
866 			flags |= IEEE80211_TX_CTL_REQ_TX_STATUS |
867 				 IEEE80211_TX_INTFL_MLME_CONN_TX;
868 
869 			/*
870 			 * skb is copied since mac80211 will later set
871 			 * properties that might not be the same as the AP,
872 			 * such as encryption, QoS, addresses, etc.
873 			 *
874 			 * No problem if skb_copy() fails, so no need to check.
875 			 */
876 			sdata->u.mgd.teardown_skb = skb_copy(skb, GFP_ATOMIC);
877 			sdata->u.mgd.orig_teardown_skb = skb;
878 		}
879 		spin_unlock_bh(&sdata->u.mgd.teardown_lock);
880 	}
881 
882 	/* disable bottom halves when entering the Tx path */
883 	local_bh_disable();
884 	__ieee80211_subif_start_xmit(skb, dev, flags);
885 	local_bh_enable();
886 
887 	return ret;
888 
889 fail:
890 	dev_kfree_skb(skb);
891 	return ret;
892 }
893 
894 static int
895 ieee80211_tdls_mgmt_setup(struct wiphy *wiphy, struct net_device *dev,
896 			  const u8 *peer, u8 action_code, u8 dialog_token,
897 			  u16 status_code, u32 peer_capability, bool initiator,
898 			  const u8 *extra_ies, size_t extra_ies_len)
899 {
900 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
901 	struct ieee80211_local *local = sdata->local;
902 	int ret;
903 
904 	mutex_lock(&local->mtx);
905 
906 	/* we don't support concurrent TDLS peer setups */
907 	if (!is_zero_ether_addr(sdata->u.mgd.tdls_peer) &&
908 	    !ether_addr_equal(sdata->u.mgd.tdls_peer, peer)) {
909 		ret = -EBUSY;
910 		goto exit;
911 	}
912 
913 	/*
914 	 * make sure we have a STA representing the peer so we drop or buffer
915 	 * non-TDLS-setup frames to the peer. We can't send other packets
916 	 * during setup through the AP path.
917 	 * Allow error packets to be sent - sometimes we don't even add a STA
918 	 * before failing the setup.
919 	 */
920 	if (status_code == 0) {
921 		rcu_read_lock();
922 		if (!sta_info_get(sdata, peer)) {
923 			rcu_read_unlock();
924 			ret = -ENOLINK;
925 			goto exit;
926 		}
927 		rcu_read_unlock();
928 	}
929 
930 	ieee80211_flush_queues(local, sdata, false);
931 
932 	ret = ieee80211_tdls_prep_mgmt_packet(wiphy, dev, peer, action_code,
933 					      dialog_token, status_code,
934 					      peer_capability, initiator,
935 					      extra_ies, extra_ies_len, 0,
936 					      NULL);
937 	if (ret < 0)
938 		goto exit;
939 
940 	memcpy(sdata->u.mgd.tdls_peer, peer, ETH_ALEN);
941 	ieee80211_queue_delayed_work(&sdata->local->hw,
942 				     &sdata->u.mgd.tdls_peer_del_work,
943 				     TDLS_PEER_SETUP_TIMEOUT);
944 
945 exit:
946 	mutex_unlock(&local->mtx);
947 	return ret;
948 }
949 
950 static int
951 ieee80211_tdls_mgmt_teardown(struct wiphy *wiphy, struct net_device *dev,
952 			     const u8 *peer, u8 action_code, u8 dialog_token,
953 			     u16 status_code, u32 peer_capability,
954 			     bool initiator, const u8 *extra_ies,
955 			     size_t extra_ies_len)
956 {
957 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
958 	struct ieee80211_local *local = sdata->local;
959 	struct sta_info *sta;
960 	int ret;
961 
962 	/*
963 	 * No packets can be transmitted to the peer via the AP during setup -
964 	 * the STA is set as a TDLS peer, but is not authorized.
965 	 * During teardown, we prevent direct transmissions by stopping the
966 	 * queues and flushing all direct packets.
967 	 */
968 	ieee80211_stop_vif_queues(local, sdata,
969 				  IEEE80211_QUEUE_STOP_REASON_TDLS_TEARDOWN);
970 	ieee80211_flush_queues(local, sdata, false);
971 
972 	ret = ieee80211_tdls_prep_mgmt_packet(wiphy, dev, peer, action_code,
973 					      dialog_token, status_code,
974 					      peer_capability, initiator,
975 					      extra_ies, extra_ies_len, 0,
976 					      NULL);
977 	if (ret < 0)
978 		sdata_err(sdata, "Failed sending TDLS teardown packet %d\n",
979 			  ret);
980 
981 	/*
982 	 * Remove the STA AUTH flag to force further traffic through the AP. If
983 	 * the STA was unreachable, it was already removed.
984 	 */
985 	rcu_read_lock();
986 	sta = sta_info_get(sdata, peer);
987 	if (sta)
988 		clear_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH);
989 	rcu_read_unlock();
990 
991 	ieee80211_wake_vif_queues(local, sdata,
992 				  IEEE80211_QUEUE_STOP_REASON_TDLS_TEARDOWN);
993 
994 	return 0;
995 }
996 
997 int ieee80211_tdls_mgmt(struct wiphy *wiphy, struct net_device *dev,
998 			const u8 *peer, u8 action_code, u8 dialog_token,
999 			u16 status_code, u32 peer_capability,
1000 			bool initiator, const u8 *extra_ies,
1001 			size_t extra_ies_len)
1002 {
1003 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1004 	int ret;
1005 
1006 	if (!(wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS))
1007 		return -ENOTSUPP;
1008 
1009 	/* make sure we are in managed mode, and associated */
1010 	if (sdata->vif.type != NL80211_IFTYPE_STATION ||
1011 	    !sdata->u.mgd.associated)
1012 		return -EINVAL;
1013 
1014 	switch (action_code) {
1015 	case WLAN_TDLS_SETUP_REQUEST:
1016 	case WLAN_TDLS_SETUP_RESPONSE:
1017 		ret = ieee80211_tdls_mgmt_setup(wiphy, dev, peer, action_code,
1018 						dialog_token, status_code,
1019 						peer_capability, initiator,
1020 						extra_ies, extra_ies_len);
1021 		break;
1022 	case WLAN_TDLS_TEARDOWN:
1023 		ret = ieee80211_tdls_mgmt_teardown(wiphy, dev, peer,
1024 						   action_code, dialog_token,
1025 						   status_code,
1026 						   peer_capability, initiator,
1027 						   extra_ies, extra_ies_len);
1028 		break;
1029 	case WLAN_TDLS_DISCOVERY_REQUEST:
1030 		/*
1031 		 * Protect the discovery so we can hear the TDLS discovery
1032 		 * response frame. It is transmitted directly and not buffered
1033 		 * by the AP.
1034 		 */
1035 		drv_mgd_protect_tdls_discover(sdata->local, sdata);
1036 		/* fall-through */
1037 	case WLAN_TDLS_SETUP_CONFIRM:
1038 	case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:
1039 		/* no special handling */
1040 		ret = ieee80211_tdls_prep_mgmt_packet(wiphy, dev, peer,
1041 						      action_code,
1042 						      dialog_token,
1043 						      status_code,
1044 						      peer_capability,
1045 						      initiator, extra_ies,
1046 						      extra_ies_len, 0, NULL);
1047 		break;
1048 	default:
1049 		ret = -EOPNOTSUPP;
1050 		break;
1051 	}
1052 
1053 	tdls_dbg(sdata, "TDLS mgmt action %d peer %pM status %d\n",
1054 		 action_code, peer, ret);
1055 	return ret;
1056 }
1057 
1058 int ieee80211_tdls_oper(struct wiphy *wiphy, struct net_device *dev,
1059 			const u8 *peer, enum nl80211_tdls_operation oper)
1060 {
1061 	struct sta_info *sta;
1062 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1063 	struct ieee80211_local *local = sdata->local;
1064 	int ret;
1065 
1066 	if (!(wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS))
1067 		return -ENOTSUPP;
1068 
1069 	if (sdata->vif.type != NL80211_IFTYPE_STATION)
1070 		return -EINVAL;
1071 
1072 	switch (oper) {
1073 	case NL80211_TDLS_ENABLE_LINK:
1074 	case NL80211_TDLS_DISABLE_LINK:
1075 		break;
1076 	case NL80211_TDLS_TEARDOWN:
1077 	case NL80211_TDLS_SETUP:
1078 	case NL80211_TDLS_DISCOVERY_REQ:
1079 		/* We don't support in-driver setup/teardown/discovery */
1080 		return -ENOTSUPP;
1081 	}
1082 
1083 	mutex_lock(&local->mtx);
1084 	tdls_dbg(sdata, "TDLS oper %d peer %pM\n", oper, peer);
1085 
1086 	switch (oper) {
1087 	case NL80211_TDLS_ENABLE_LINK:
1088 		rcu_read_lock();
1089 		sta = sta_info_get(sdata, peer);
1090 		if (!sta) {
1091 			rcu_read_unlock();
1092 			ret = -ENOLINK;
1093 			break;
1094 		}
1095 
1096 		set_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH);
1097 		rcu_read_unlock();
1098 
1099 		WARN_ON_ONCE(is_zero_ether_addr(sdata->u.mgd.tdls_peer) ||
1100 			     !ether_addr_equal(sdata->u.mgd.tdls_peer, peer));
1101 		ret = 0;
1102 		break;
1103 	case NL80211_TDLS_DISABLE_LINK:
1104 		/*
1105 		 * The teardown message in ieee80211_tdls_mgmt_teardown() was
1106 		 * created while the queues were stopped, so it might still be
1107 		 * pending. Before flushing the queues we need to be sure the
1108 		 * message is handled by the tasklet handling pending messages,
1109 		 * otherwise we might start destroying the station before
1110 		 * sending the teardown packet.
1111 		 * Note that this only forces the tasklet to flush pendings -
1112 		 * not to stop the tasklet from rescheduling itself.
1113 		 */
1114 		tasklet_kill(&local->tx_pending_tasklet);
1115 		/* flush a potentially queued teardown packet */
1116 		ieee80211_flush_queues(local, sdata, false);
1117 
1118 		ret = sta_info_destroy_addr(sdata, peer);
1119 		break;
1120 	default:
1121 		ret = -ENOTSUPP;
1122 		break;
1123 	}
1124 
1125 	if (ret == 0 && ether_addr_equal(sdata->u.mgd.tdls_peer, peer)) {
1126 		cancel_delayed_work(&sdata->u.mgd.tdls_peer_del_work);
1127 		eth_zero_addr(sdata->u.mgd.tdls_peer);
1128 	}
1129 
1130 	mutex_unlock(&local->mtx);
1131 	return ret;
1132 }
1133 
1134 void ieee80211_tdls_oper_request(struct ieee80211_vif *vif, const u8 *peer,
1135 				 enum nl80211_tdls_operation oper,
1136 				 u16 reason_code, gfp_t gfp)
1137 {
1138 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
1139 
1140 	if (vif->type != NL80211_IFTYPE_STATION || !vif->bss_conf.assoc) {
1141 		sdata_err(sdata, "Discarding TDLS oper %d - not STA or disconnected\n",
1142 			  oper);
1143 		return;
1144 	}
1145 
1146 	cfg80211_tdls_oper_request(sdata->dev, peer, oper, reason_code, gfp);
1147 }
1148 EXPORT_SYMBOL(ieee80211_tdls_oper_request);
1149 
1150 static void
1151 iee80211_tdls_add_ch_switch_timing(u8 *buf, u16 switch_time, u16 switch_timeout)
1152 {
1153 	struct ieee80211_ch_switch_timing *ch_sw;
1154 
1155 	*buf++ = WLAN_EID_CHAN_SWITCH_TIMING;
1156 	*buf++ = sizeof(struct ieee80211_ch_switch_timing);
1157 
1158 	ch_sw = (void *)buf;
1159 	ch_sw->switch_time = cpu_to_le16(switch_time);
1160 	ch_sw->switch_timeout = cpu_to_le16(switch_timeout);
1161 }
1162 
1163 /* find switch timing IE in SKB ready for Tx */
1164 static const u8 *ieee80211_tdls_find_sw_timing_ie(struct sk_buff *skb)
1165 {
1166 	struct ieee80211_tdls_data *tf;
1167 	const u8 *ie_start;
1168 
1169 	/*
1170 	 * Get the offset for the new location of the switch timing IE.
1171 	 * The SKB network header will now point to the "payload_type"
1172 	 * element of the TDLS data frame struct.
1173 	 */
1174 	tf = container_of(skb->data + skb_network_offset(skb),
1175 			  struct ieee80211_tdls_data, payload_type);
1176 	ie_start = tf->u.chan_switch_req.variable;
1177 	return cfg80211_find_ie(WLAN_EID_CHAN_SWITCH_TIMING, ie_start,
1178 				skb->len - (ie_start - skb->data));
1179 }
1180 
1181 static struct sk_buff *
1182 ieee80211_tdls_ch_sw_tmpl_get(struct sta_info *sta, u8 oper_class,
1183 			      struct cfg80211_chan_def *chandef,
1184 			      u32 *ch_sw_tm_ie_offset)
1185 {
1186 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1187 	u8 extra_ies[2 + sizeof(struct ieee80211_sec_chan_offs_ie) +
1188 		     2 + sizeof(struct ieee80211_ch_switch_timing)];
1189 	int extra_ies_len = 2 + sizeof(struct ieee80211_ch_switch_timing);
1190 	u8 *pos = extra_ies;
1191 	struct sk_buff *skb;
1192 
1193 	/*
1194 	 * if chandef points to a wide channel add a Secondary-Channel
1195 	 * Offset information element
1196 	 */
1197 	if (chandef->width == NL80211_CHAN_WIDTH_40) {
1198 		struct ieee80211_sec_chan_offs_ie *sec_chan_ie;
1199 		bool ht40plus;
1200 
1201 		*pos++ = WLAN_EID_SECONDARY_CHANNEL_OFFSET;
1202 		*pos++ = sizeof(*sec_chan_ie);
1203 		sec_chan_ie = (void *)pos;
1204 
1205 		ht40plus = cfg80211_get_chandef_type(chandef) ==
1206 							NL80211_CHAN_HT40PLUS;
1207 		sec_chan_ie->sec_chan_offs = ht40plus ?
1208 					     IEEE80211_HT_PARAM_CHA_SEC_ABOVE :
1209 					     IEEE80211_HT_PARAM_CHA_SEC_BELOW;
1210 		pos += sizeof(*sec_chan_ie);
1211 
1212 		extra_ies_len += 2 + sizeof(struct ieee80211_sec_chan_offs_ie);
1213 	}
1214 
1215 	/* just set the values to 0, this is a template */
1216 	iee80211_tdls_add_ch_switch_timing(pos, 0, 0);
1217 
1218 	skb = ieee80211_tdls_build_mgmt_packet_data(sdata, sta->sta.addr,
1219 					      WLAN_TDLS_CHANNEL_SWITCH_REQUEST,
1220 					      0, 0, !sta->sta.tdls_initiator,
1221 					      extra_ies, extra_ies_len,
1222 					      oper_class, chandef);
1223 	if (!skb)
1224 		return NULL;
1225 
1226 	skb = ieee80211_build_data_template(sdata, skb, 0);
1227 	if (IS_ERR(skb)) {
1228 		tdls_dbg(sdata, "Failed building TDLS channel switch frame\n");
1229 		return NULL;
1230 	}
1231 
1232 	if (ch_sw_tm_ie_offset) {
1233 		const u8 *tm_ie = ieee80211_tdls_find_sw_timing_ie(skb);
1234 
1235 		if (!tm_ie) {
1236 			tdls_dbg(sdata, "No switch timing IE in TDLS switch\n");
1237 			dev_kfree_skb_any(skb);
1238 			return NULL;
1239 		}
1240 
1241 		*ch_sw_tm_ie_offset = tm_ie - skb->data;
1242 	}
1243 
1244 	tdls_dbg(sdata,
1245 		 "TDLS channel switch request template for %pM ch %d width %d\n",
1246 		 sta->sta.addr, chandef->chan->center_freq, chandef->width);
1247 	return skb;
1248 }
1249 
1250 int
1251 ieee80211_tdls_channel_switch(struct wiphy *wiphy, struct net_device *dev,
1252 			      const u8 *addr, u8 oper_class,
1253 			      struct cfg80211_chan_def *chandef)
1254 {
1255 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1256 	struct ieee80211_local *local = sdata->local;
1257 	struct sta_info *sta;
1258 	struct sk_buff *skb = NULL;
1259 	u32 ch_sw_tm_ie;
1260 	int ret;
1261 
1262 	mutex_lock(&local->sta_mtx);
1263 	sta = sta_info_get(sdata, addr);
1264 	if (!sta) {
1265 		tdls_dbg(sdata,
1266 			 "Invalid TDLS peer %pM for channel switch request\n",
1267 			 addr);
1268 		ret = -ENOENT;
1269 		goto out;
1270 	}
1271 
1272 	if (!test_sta_flag(sta, WLAN_STA_TDLS_CHAN_SWITCH)) {
1273 		tdls_dbg(sdata, "TDLS channel switch unsupported by %pM\n",
1274 			 addr);
1275 		ret = -ENOTSUPP;
1276 		goto out;
1277 	}
1278 
1279 	skb = ieee80211_tdls_ch_sw_tmpl_get(sta, oper_class, chandef,
1280 					    &ch_sw_tm_ie);
1281 	if (!skb) {
1282 		ret = -ENOENT;
1283 		goto out;
1284 	}
1285 
1286 	ret = drv_tdls_channel_switch(local, sdata, &sta->sta, oper_class,
1287 				      chandef, skb, ch_sw_tm_ie);
1288 	if (!ret)
1289 		set_sta_flag(sta, WLAN_STA_TDLS_OFF_CHANNEL);
1290 
1291 out:
1292 	mutex_unlock(&local->sta_mtx);
1293 	dev_kfree_skb_any(skb);
1294 	return ret;
1295 }
1296 
1297 void
1298 ieee80211_tdls_cancel_channel_switch(struct wiphy *wiphy,
1299 				     struct net_device *dev,
1300 				     const u8 *addr)
1301 {
1302 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1303 	struct ieee80211_local *local = sdata->local;
1304 	struct sta_info *sta;
1305 
1306 	mutex_lock(&local->sta_mtx);
1307 	sta = sta_info_get(sdata, addr);
1308 	if (!sta) {
1309 		tdls_dbg(sdata,
1310 			 "Invalid TDLS peer %pM for channel switch cancel\n",
1311 			 addr);
1312 		goto out;
1313 	}
1314 
1315 	if (!test_sta_flag(sta, WLAN_STA_TDLS_OFF_CHANNEL)) {
1316 		tdls_dbg(sdata, "TDLS channel switch not initiated by %pM\n",
1317 			 addr);
1318 		goto out;
1319 	}
1320 
1321 	drv_tdls_cancel_channel_switch(local, sdata, &sta->sta);
1322 	clear_sta_flag(sta, WLAN_STA_TDLS_OFF_CHANNEL);
1323 
1324 out:
1325 	mutex_unlock(&local->sta_mtx);
1326 }
1327 
1328 static struct sk_buff *
1329 ieee80211_tdls_ch_sw_resp_tmpl_get(struct sta_info *sta,
1330 				   u32 *ch_sw_tm_ie_offset)
1331 {
1332 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1333 	struct sk_buff *skb;
1334 	u8 extra_ies[2 + sizeof(struct ieee80211_ch_switch_timing)];
1335 
1336 	/* initial timing are always zero in the template */
1337 	iee80211_tdls_add_ch_switch_timing(extra_ies, 0, 0);
1338 
1339 	skb = ieee80211_tdls_build_mgmt_packet_data(sdata, sta->sta.addr,
1340 					WLAN_TDLS_CHANNEL_SWITCH_RESPONSE,
1341 					0, 0, !sta->sta.tdls_initiator,
1342 					extra_ies, sizeof(extra_ies), 0, NULL);
1343 	if (!skb)
1344 		return NULL;
1345 
1346 	skb = ieee80211_build_data_template(sdata, skb, 0);
1347 	if (IS_ERR(skb)) {
1348 		tdls_dbg(sdata,
1349 			 "Failed building TDLS channel switch resp frame\n");
1350 		return NULL;
1351 	}
1352 
1353 	if (ch_sw_tm_ie_offset) {
1354 		const u8 *tm_ie = ieee80211_tdls_find_sw_timing_ie(skb);
1355 
1356 		if (!tm_ie) {
1357 			tdls_dbg(sdata,
1358 				 "No switch timing IE in TDLS switch resp\n");
1359 			dev_kfree_skb_any(skb);
1360 			return NULL;
1361 		}
1362 
1363 		*ch_sw_tm_ie_offset = tm_ie - skb->data;
1364 	}
1365 
1366 	tdls_dbg(sdata, "TDLS get channel switch response template for %pM\n",
1367 		 sta->sta.addr);
1368 	return skb;
1369 }
1370 
1371 static int
1372 ieee80211_process_tdls_channel_switch_resp(struct ieee80211_sub_if_data *sdata,
1373 					   struct sk_buff *skb)
1374 {
1375 	struct ieee80211_local *local = sdata->local;
1376 	struct ieee802_11_elems elems;
1377 	struct sta_info *sta;
1378 	struct ieee80211_tdls_data *tf = (void *)skb->data;
1379 	bool local_initiator;
1380 	struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
1381 	int baselen = offsetof(typeof(*tf), u.chan_switch_resp.variable);
1382 	struct ieee80211_tdls_ch_sw_params params = {};
1383 	int ret;
1384 
1385 	params.action_code = WLAN_TDLS_CHANNEL_SWITCH_RESPONSE;
1386 	params.timestamp = rx_status->device_timestamp;
1387 
1388 	if (skb->len < baselen) {
1389 		tdls_dbg(sdata, "TDLS channel switch resp too short: %d\n",
1390 			 skb->len);
1391 		return -EINVAL;
1392 	}
1393 
1394 	mutex_lock(&local->sta_mtx);
1395 	sta = sta_info_get(sdata, tf->sa);
1396 	if (!sta || !test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH)) {
1397 		tdls_dbg(sdata, "TDLS chan switch from non-peer sta %pM\n",
1398 			 tf->sa);
1399 		ret = -EINVAL;
1400 		goto out;
1401 	}
1402 
1403 	params.sta = &sta->sta;
1404 	params.status = le16_to_cpu(tf->u.chan_switch_resp.status_code);
1405 	if (params.status != 0) {
1406 		ret = 0;
1407 		goto call_drv;
1408 	}
1409 
1410 	ieee802_11_parse_elems(tf->u.chan_switch_resp.variable,
1411 			       skb->len - baselen, false, &elems);
1412 	if (elems.parse_error) {
1413 		tdls_dbg(sdata, "Invalid IEs in TDLS channel switch resp\n");
1414 		ret = -EINVAL;
1415 		goto out;
1416 	}
1417 
1418 	if (!elems.ch_sw_timing || !elems.lnk_id) {
1419 		tdls_dbg(sdata, "TDLS channel switch resp - missing IEs\n");
1420 		ret = -EINVAL;
1421 		goto out;
1422 	}
1423 
1424 	/* validate the initiator is set correctly */
1425 	local_initiator =
1426 		!memcmp(elems.lnk_id->init_sta, sdata->vif.addr, ETH_ALEN);
1427 	if (local_initiator == sta->sta.tdls_initiator) {
1428 		tdls_dbg(sdata, "TDLS chan switch invalid lnk-id initiator\n");
1429 		ret = -EINVAL;
1430 		goto out;
1431 	}
1432 
1433 	params.switch_time = le16_to_cpu(elems.ch_sw_timing->switch_time);
1434 	params.switch_timeout = le16_to_cpu(elems.ch_sw_timing->switch_timeout);
1435 
1436 	params.tmpl_skb =
1437 		ieee80211_tdls_ch_sw_resp_tmpl_get(sta, &params.ch_sw_tm_ie);
1438 	if (!params.tmpl_skb) {
1439 		ret = -ENOENT;
1440 		goto out;
1441 	}
1442 
1443 call_drv:
1444 	drv_tdls_recv_channel_switch(sdata->local, sdata, &params);
1445 
1446 	tdls_dbg(sdata,
1447 		 "TDLS channel switch response received from %pM status %d\n",
1448 		 tf->sa, params.status);
1449 
1450 out:
1451 	mutex_unlock(&local->sta_mtx);
1452 	dev_kfree_skb_any(params.tmpl_skb);
1453 	return ret;
1454 }
1455 
1456 static int
1457 ieee80211_process_tdls_channel_switch_req(struct ieee80211_sub_if_data *sdata,
1458 					  struct sk_buff *skb)
1459 {
1460 	struct ieee80211_local *local = sdata->local;
1461 	struct ieee802_11_elems elems;
1462 	struct cfg80211_chan_def chandef;
1463 	struct ieee80211_channel *chan;
1464 	enum nl80211_channel_type chan_type;
1465 	int freq;
1466 	u8 target_channel, oper_class;
1467 	bool local_initiator;
1468 	struct sta_info *sta;
1469 	enum ieee80211_band band;
1470 	struct ieee80211_tdls_data *tf = (void *)skb->data;
1471 	struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
1472 	int baselen = offsetof(typeof(*tf), u.chan_switch_req.variable);
1473 	struct ieee80211_tdls_ch_sw_params params = {};
1474 	int ret = 0;
1475 
1476 	params.action_code = WLAN_TDLS_CHANNEL_SWITCH_REQUEST;
1477 	params.timestamp = rx_status->device_timestamp;
1478 
1479 	if (skb->len < baselen) {
1480 		tdls_dbg(sdata, "TDLS channel switch req too short: %d\n",
1481 			 skb->len);
1482 		return -EINVAL;
1483 	}
1484 
1485 	target_channel = tf->u.chan_switch_req.target_channel;
1486 	oper_class = tf->u.chan_switch_req.oper_class;
1487 
1488 	/*
1489 	 * We can't easily infer the channel band. The operating class is
1490 	 * ambiguous - there are multiple tables (US/Europe/JP/Global). The
1491 	 * solution here is to treat channels with number >14 as 5GHz ones,
1492 	 * and specifically check for the (oper_class, channel) combinations
1493 	 * where this doesn't hold. These are thankfully unique according to
1494 	 * IEEE802.11-2012.
1495 	 * We consider only the 2GHz and 5GHz bands and 20MHz+ channels as
1496 	 * valid here.
1497 	 */
1498 	if ((oper_class == 112 || oper_class == 2 || oper_class == 3 ||
1499 	     oper_class == 4 || oper_class == 5 || oper_class == 6) &&
1500 	     target_channel < 14)
1501 		band = IEEE80211_BAND_5GHZ;
1502 	else
1503 		band = target_channel < 14 ? IEEE80211_BAND_2GHZ :
1504 					     IEEE80211_BAND_5GHZ;
1505 
1506 	freq = ieee80211_channel_to_frequency(target_channel, band);
1507 	if (freq == 0) {
1508 		tdls_dbg(sdata, "Invalid channel in TDLS chan switch: %d\n",
1509 			 target_channel);
1510 		return -EINVAL;
1511 	}
1512 
1513 	chan = ieee80211_get_channel(sdata->local->hw.wiphy, freq);
1514 	if (!chan) {
1515 		tdls_dbg(sdata,
1516 			 "Unsupported channel for TDLS chan switch: %d\n",
1517 			 target_channel);
1518 		return -EINVAL;
1519 	}
1520 
1521 	ieee802_11_parse_elems(tf->u.chan_switch_req.variable,
1522 			       skb->len - baselen, false, &elems);
1523 	if (elems.parse_error) {
1524 		tdls_dbg(sdata, "Invalid IEs in TDLS channel switch req\n");
1525 		return -EINVAL;
1526 	}
1527 
1528 	if (!elems.ch_sw_timing || !elems.lnk_id) {
1529 		tdls_dbg(sdata, "TDLS channel switch req - missing IEs\n");
1530 		return -EINVAL;
1531 	}
1532 
1533 	mutex_lock(&local->sta_mtx);
1534 	sta = sta_info_get(sdata, tf->sa);
1535 	if (!sta || !test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH)) {
1536 		tdls_dbg(sdata, "TDLS chan switch from non-peer sta %pM\n",
1537 			 tf->sa);
1538 		ret = -EINVAL;
1539 		goto out;
1540 	}
1541 
1542 	params.sta = &sta->sta;
1543 
1544 	/* validate the initiator is set correctly */
1545 	local_initiator =
1546 		!memcmp(elems.lnk_id->init_sta, sdata->vif.addr, ETH_ALEN);
1547 	if (local_initiator == sta->sta.tdls_initiator) {
1548 		tdls_dbg(sdata, "TDLS chan switch invalid lnk-id initiator\n");
1549 		ret = -EINVAL;
1550 		goto out;
1551 	}
1552 
1553 	if (!sta->sta.ht_cap.ht_supported) {
1554 		chan_type = NL80211_CHAN_NO_HT;
1555 	} else if (!elems.sec_chan_offs) {
1556 		chan_type = NL80211_CHAN_HT20;
1557 	} else {
1558 		switch (elems.sec_chan_offs->sec_chan_offs) {
1559 		case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
1560 			chan_type = NL80211_CHAN_HT40PLUS;
1561 			break;
1562 		case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
1563 			chan_type = NL80211_CHAN_HT40MINUS;
1564 			break;
1565 		default:
1566 			chan_type = NL80211_CHAN_HT20;
1567 			break;
1568 		}
1569 	}
1570 
1571 	cfg80211_chandef_create(&chandef, chan, chan_type);
1572 	params.chandef = &chandef;
1573 
1574 	params.switch_time = le16_to_cpu(elems.ch_sw_timing->switch_time);
1575 	params.switch_timeout = le16_to_cpu(elems.ch_sw_timing->switch_timeout);
1576 
1577 	params.tmpl_skb =
1578 		ieee80211_tdls_ch_sw_resp_tmpl_get(sta,
1579 						   &params.ch_sw_tm_ie);
1580 	if (!params.tmpl_skb) {
1581 		ret = -ENOENT;
1582 		goto out;
1583 	}
1584 
1585 	drv_tdls_recv_channel_switch(sdata->local, sdata, &params);
1586 
1587 	tdls_dbg(sdata,
1588 		 "TDLS ch switch request received from %pM ch %d width %d\n",
1589 		 tf->sa, params.chandef->chan->center_freq,
1590 		 params.chandef->width);
1591 out:
1592 	mutex_unlock(&local->sta_mtx);
1593 	dev_kfree_skb_any(params.tmpl_skb);
1594 	return ret;
1595 }
1596 
1597 void ieee80211_process_tdls_channel_switch(struct ieee80211_sub_if_data *sdata,
1598 					   struct sk_buff *skb)
1599 {
1600 	struct ieee80211_tdls_data *tf = (void *)skb->data;
1601 	struct wiphy *wiphy = sdata->local->hw.wiphy;
1602 
1603 	/* make sure the driver supports it */
1604 	if (!(wiphy->features & NL80211_FEATURE_TDLS_CHANNEL_SWITCH))
1605 		return;
1606 
1607 	/* we want to access the entire packet */
1608 	if (skb_linearize(skb))
1609 		return;
1610 	/*
1611 	 * The packet/size was already validated by mac80211 Rx path, only look
1612 	 * at the action type.
1613 	 */
1614 	switch (tf->action_code) {
1615 	case WLAN_TDLS_CHANNEL_SWITCH_REQUEST:
1616 		ieee80211_process_tdls_channel_switch_req(sdata, skb);
1617 		break;
1618 	case WLAN_TDLS_CHANNEL_SWITCH_RESPONSE:
1619 		ieee80211_process_tdls_channel_switch_resp(sdata, skb);
1620 		break;
1621 	default:
1622 		WARN_ON_ONCE(1);
1623 		return;
1624 	}
1625 }
1626