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1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * cfg80211 scan result handling
4  *
5  * Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
6  * Copyright 2013-2014  Intel Mobile Communications GmbH
7  * Copyright 2016	Intel Deutschland GmbH
8  * Copyright (C) 2018-2022 Intel Corporation
9  */
10 #include <linux/kernel.h>
11 #include <linux/slab.h>
12 #include <linux/module.h>
13 #include <linux/netdevice.h>
14 #include <linux/wireless.h>
15 #include <linux/nl80211.h>
16 #include <linux/etherdevice.h>
17 #include <linux/crc32.h>
18 #include <linux/bitfield.h>
19 #include <net/arp.h>
20 #include <net/cfg80211.h>
21 #include <net/cfg80211-wext.h>
22 #include <net/iw_handler.h>
23 #include "core.h"
24 #include "nl80211.h"
25 #include "wext-compat.h"
26 #include "rdev-ops.h"
27 
28 /**
29  * DOC: BSS tree/list structure
30  *
31  * At the top level, the BSS list is kept in both a list in each
32  * registered device (@bss_list) as well as an RB-tree for faster
33  * lookup. In the RB-tree, entries can be looked up using their
34  * channel, MESHID, MESHCONF (for MBSSes) or channel, BSSID, SSID
35  * for other BSSes.
36  *
37  * Due to the possibility of hidden SSIDs, there's a second level
38  * structure, the "hidden_list" and "hidden_beacon_bss" pointer.
39  * The hidden_list connects all BSSes belonging to a single AP
40  * that has a hidden SSID, and connects beacon and probe response
41  * entries. For a probe response entry for a hidden SSID, the
42  * hidden_beacon_bss pointer points to the BSS struct holding the
43  * beacon's information.
44  *
45  * Reference counting is done for all these references except for
46  * the hidden_list, so that a beacon BSS struct that is otherwise
47  * not referenced has one reference for being on the bss_list and
48  * one for each probe response entry that points to it using the
49  * hidden_beacon_bss pointer. When a BSS struct that has such a
50  * pointer is get/put, the refcount update is also propagated to
51  * the referenced struct, this ensure that it cannot get removed
52  * while somebody is using the probe response version.
53  *
54  * Note that the hidden_beacon_bss pointer never changes, due to
55  * the reference counting. Therefore, no locking is needed for
56  * it.
57  *
58  * Also note that the hidden_beacon_bss pointer is only relevant
59  * if the driver uses something other than the IEs, e.g. private
60  * data stored in the BSS struct, since the beacon IEs are
61  * also linked into the probe response struct.
62  */
63 
64 /*
65  * Limit the number of BSS entries stored in mac80211. Each one is
66  * a bit over 4k at most, so this limits to roughly 4-5M of memory.
67  * If somebody wants to really attack this though, they'd likely
68  * use small beacons, and only one type of frame, limiting each of
69  * the entries to a much smaller size (in order to generate more
70  * entries in total, so overhead is bigger.)
71  */
72 static int bss_entries_limit = 1000;
73 module_param(bss_entries_limit, int, 0644);
74 MODULE_PARM_DESC(bss_entries_limit,
75                  "limit to number of scan BSS entries (per wiphy, default 1000)");
76 
77 #define IEEE80211_SCAN_RESULT_EXPIRE	(30 * HZ)
78 
79 /**
80  * struct cfg80211_colocated_ap - colocated AP information
81  *
82  * @list: linked list to all colocated aPS
83  * @bssid: BSSID of the reported AP
84  * @ssid: SSID of the reported AP
85  * @ssid_len: length of the ssid
86  * @center_freq: frequency the reported AP is on
87  * @unsolicited_probe: the reported AP is part of an ESS, where all the APs
88  *	that operate in the same channel as the reported AP and that might be
89  *	detected by a STA receiving this frame, are transmitting unsolicited
90  *	Probe Response frames every 20 TUs
91  * @oct_recommended: OCT is recommended to exchange MMPDUs with the reported AP
92  * @same_ssid: the reported AP has the same SSID as the reporting AP
93  * @multi_bss: the reported AP is part of a multiple BSSID set
94  * @transmitted_bssid: the reported AP is the transmitting BSSID
95  * @colocated_ess: all the APs that share the same ESS as the reported AP are
96  *	colocated and can be discovered via legacy bands.
97  * @short_ssid_valid: short_ssid is valid and can be used
98  * @short_ssid: the short SSID for this SSID
99  */
100 struct cfg80211_colocated_ap {
101 	struct list_head list;
102 	u8 bssid[ETH_ALEN];
103 	u8 ssid[IEEE80211_MAX_SSID_LEN];
104 	size_t ssid_len;
105 	u32 short_ssid;
106 	u32 center_freq;
107 	u8 unsolicited_probe:1,
108 	   oct_recommended:1,
109 	   same_ssid:1,
110 	   multi_bss:1,
111 	   transmitted_bssid:1,
112 	   colocated_ess:1,
113 	   short_ssid_valid:1;
114 };
115 
bss_free(struct cfg80211_internal_bss * bss)116 static void bss_free(struct cfg80211_internal_bss *bss)
117 {
118 	struct cfg80211_bss_ies *ies;
119 
120 	if (WARN_ON(atomic_read(&bss->hold)))
121 		return;
122 
123 	ies = (void *)rcu_access_pointer(bss->pub.beacon_ies);
124 	if (ies && !bss->pub.hidden_beacon_bss)
125 		kfree_rcu(ies, rcu_head);
126 	ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies);
127 	if (ies)
128 		kfree_rcu(ies, rcu_head);
129 
130 	/*
131 	 * This happens when the module is removed, it doesn't
132 	 * really matter any more save for completeness
133 	 */
134 	if (!list_empty(&bss->hidden_list))
135 		list_del(&bss->hidden_list);
136 
137 	kfree(bss);
138 }
139 
bss_ref_get(struct cfg80211_registered_device * rdev,struct cfg80211_internal_bss * bss)140 static inline void bss_ref_get(struct cfg80211_registered_device *rdev,
141 			       struct cfg80211_internal_bss *bss)
142 {
143 	lockdep_assert_held(&rdev->bss_lock);
144 
145 	bss->refcount++;
146 
147 	if (bss->pub.hidden_beacon_bss)
148 		bss_from_pub(bss->pub.hidden_beacon_bss)->refcount++;
149 
150 	if (bss->pub.transmitted_bss)
151 		bss_from_pub(bss->pub.transmitted_bss)->refcount++;
152 }
153 
bss_ref_put(struct cfg80211_registered_device * rdev,struct cfg80211_internal_bss * bss)154 static inline void bss_ref_put(struct cfg80211_registered_device *rdev,
155 			       struct cfg80211_internal_bss *bss)
156 {
157 	lockdep_assert_held(&rdev->bss_lock);
158 
159 	if (bss->pub.hidden_beacon_bss) {
160 		struct cfg80211_internal_bss *hbss;
161 		hbss = container_of(bss->pub.hidden_beacon_bss,
162 				    struct cfg80211_internal_bss,
163 				    pub);
164 		hbss->refcount--;
165 		if (hbss->refcount == 0)
166 			bss_free(hbss);
167 	}
168 
169 	if (bss->pub.transmitted_bss) {
170 		struct cfg80211_internal_bss *tbss;
171 
172 		tbss = container_of(bss->pub.transmitted_bss,
173 				    struct cfg80211_internal_bss,
174 				    pub);
175 		tbss->refcount--;
176 		if (tbss->refcount == 0)
177 			bss_free(tbss);
178 	}
179 
180 	bss->refcount--;
181 	if (bss->refcount == 0)
182 		bss_free(bss);
183 }
184 
__cfg80211_unlink_bss(struct cfg80211_registered_device * rdev,struct cfg80211_internal_bss * bss)185 static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev,
186 				  struct cfg80211_internal_bss *bss)
187 {
188 	lockdep_assert_held(&rdev->bss_lock);
189 
190 	if (!list_empty(&bss->hidden_list)) {
191 		/*
192 		 * don't remove the beacon entry if it has
193 		 * probe responses associated with it
194 		 */
195 		if (!bss->pub.hidden_beacon_bss)
196 			return false;
197 		/*
198 		 * if it's a probe response entry break its
199 		 * link to the other entries in the group
200 		 */
201 		list_del_init(&bss->hidden_list);
202 	}
203 
204 	list_del_init(&bss->list);
205 	list_del_init(&bss->pub.nontrans_list);
206 	rb_erase(&bss->rbn, &rdev->bss_tree);
207 	rdev->bss_entries--;
208 	WARN_ONCE((rdev->bss_entries == 0) ^ list_empty(&rdev->bss_list),
209 		  "rdev bss entries[%d]/list[empty:%d] corruption\n",
210 		  rdev->bss_entries, list_empty(&rdev->bss_list));
211 	bss_ref_put(rdev, bss);
212 	return true;
213 }
214 
cfg80211_is_element_inherited(const struct element * elem,const struct element * non_inherit_elem)215 bool cfg80211_is_element_inherited(const struct element *elem,
216 				   const struct element *non_inherit_elem)
217 {
218 	u8 id_len, ext_id_len, i, loop_len, id;
219 	const u8 *list;
220 
221 	if (elem->id == WLAN_EID_MULTIPLE_BSSID)
222 		return false;
223 
224 	if (!non_inherit_elem || non_inherit_elem->datalen < 2)
225 		return true;
226 
227 	/*
228 	 * non inheritance element format is:
229 	 * ext ID (56) | IDs list len | list | extension IDs list len | list
230 	 * Both lists are optional. Both lengths are mandatory.
231 	 * This means valid length is:
232 	 * elem_len = 1 (extension ID) + 2 (list len fields) + list lengths
233 	 */
234 	id_len = non_inherit_elem->data[1];
235 	if (non_inherit_elem->datalen < 3 + id_len)
236 		return true;
237 
238 	ext_id_len = non_inherit_elem->data[2 + id_len];
239 	if (non_inherit_elem->datalen < 3 + id_len + ext_id_len)
240 		return true;
241 
242 	if (elem->id == WLAN_EID_EXTENSION) {
243 		if (!ext_id_len)
244 			return true;
245 		loop_len = ext_id_len;
246 		list = &non_inherit_elem->data[3 + id_len];
247 		id = elem->data[0];
248 	} else {
249 		if (!id_len)
250 			return true;
251 		loop_len = id_len;
252 		list = &non_inherit_elem->data[2];
253 		id = elem->id;
254 	}
255 
256 	for (i = 0; i < loop_len; i++) {
257 		if (list[i] == id)
258 			return false;
259 	}
260 
261 	return true;
262 }
263 EXPORT_SYMBOL(cfg80211_is_element_inherited);
264 
265 /**
266  * cfg80211_handle_rnr_ie_for_mbssid() - parse and modify RNR IE for MBSSID
267  *                                       feature
268  * @elem: The pointer to RNR IE
269  * @bssid_index: BSSID index from MBSSID index IE
270  * @pos: The buffer pointer to save the transformed RNR IE, caller is expected
271  *       to supply a buffer that is at least as big as @elem
272  *
273  * Per the description about Neighbor AP Information field about MLD
274  * parameters subfield in section 9.4.2.170.2 of Draft P802.11be_D1.4.
275  * If the reported AP is affiliated with the same MLD of the reporting AP,
276  * the TBTT information is skipped; If the reported AP is affiliated with
277  * the same MLD of the nontransmitted BSSID, the TBTT information is copied
278  * and the MLD ID is changed to 0.
279  *
280  * Return: Length of the element written to @pos
281  */
cfg80211_handle_rnr_ie_for_mbssid(const struct element * elem,u8 bssid_index,u8 * pos)282 static size_t cfg80211_handle_rnr_ie_for_mbssid(const struct element *elem,
283 						u8 bssid_index, u8 *pos)
284 {
285 	size_t rnr_len;
286 	const u8 *rnr, *data, *rnr_end;
287 	u8 *rnr_new, *tbtt_info_field;
288 	u8 tbtt_type, tbtt_len, tbtt_count;
289 	u8 mld_pos, mld_id;
290 	u32 i, copy_len;
291 	/* The count of TBTT info field whose MLD ID equals to 0 in a neighbor
292 	 * AP information field.
293 	 */
294 	u32 tbtt_info_field_count;
295 	/* The total bytes of TBTT info fields whose MLD ID equals to 0 in
296 	 * current RNR IE.
297 	 */
298 	u32 tbtt_info_field_len = 0;
299 
300 	rnr_new = pos;
301 	rnr = (u8 *)elem;
302 	rnr_len = elem->datalen;
303 	rnr_end = rnr + rnr_len + 2;
304 
305 	memcpy(pos, rnr, 2);
306 	pos += 2;
307 	data = elem->data;
308 	while (data < rnr_end) {
309 		tbtt_type = u8_get_bits(data[0], IEEE80211_TBTT_TYPE_MASK);
310 		tbtt_count = u8_get_bits(data[0], IEEE80211_TBTT_COUNT_MASK);
311 		tbtt_len = data[1];
312 
313 		copy_len = tbtt_len * (tbtt_count + 1) +
314 			   IEEE80211_NBR_AP_INFO_LEN;
315 		if (data + copy_len > rnr_end)
316 			return 0;
317 
318 		if (tbtt_len >=
319 		    IEEE80211_TBTT_INFO_BSSID_SSID_BSS_PARAM_PSD_MLD_PARAM)
320 			mld_pos =
321 			    IEEE80211_TBTT_INFO_BSSID_SSID_BSS_PARAM_PSD;
322 		else
323 			mld_pos = 0;
324 		/* If MLD params do not exist, copy this neighbor AP
325 		 * information field.
326 		 * Draft P802.11be_D1.4, tbtt_type value 1, 2 and 3
327 		 * are reserved.
328 		 */
329 		if (mld_pos == 0 || tbtt_type != 0) {
330 			memcpy(pos, data, copy_len);
331 			pos += copy_len;
332 			data += copy_len;
333 			continue;
334 		}
335 
336 		memcpy(pos, data, IEEE80211_NBR_AP_INFO_LEN);
337 		tbtt_info_field = pos;
338 		pos += IEEE80211_NBR_AP_INFO_LEN;
339 		data += IEEE80211_NBR_AP_INFO_LEN;
340 
341 		tbtt_info_field_count = 0;
342 		for (i = 0; i < tbtt_count + 1; i++) {
343 			mld_id = data[mld_pos];
344 			/* Refer to Draft P802.11be_D1.4
345 			 * 9.4.2.170.2 Neighbor AP Information field about
346 			 * MLD parameters subfield
347 			 */
348 			if (mld_id == 0) {
349 				/* Skip this TBTT information since this
350 				 * reported AP is affiliated with the same MLD
351 				 * of the reporting AP who sending the frame
352 				 * carrying this element.
353 				 */
354 				tbtt_info_field_len += tbtt_len;
355 				data += tbtt_len;
356 				tbtt_info_field_count++;
357 			} else if (mld_id == bssid_index) {
358 				/* Copy this TBTT information and change MLD
359 				 * to 0 as this reported AP is affiliated with
360 				 * the same MLD of the nontransmitted BSSID.
361 				 */
362 				memcpy(pos, data, tbtt_len);
363 				pos[mld_pos] = 0;
364 				data += tbtt_len;
365 				pos += tbtt_len;
366 			} else {
367 				memcpy(pos, data, tbtt_len);
368 				data += tbtt_len;
369 				pos += tbtt_len;
370 			}
371 		}
372 		if (tbtt_info_field_count == (tbtt_count + 1)) {
373 			/* If all the TBTT informations are skipped, then also
374 			 * revert the neighbor AP info which has been copied.
375 			 */
376 			pos -= IEEE80211_NBR_AP_INFO_LEN;
377 			tbtt_info_field_len += IEEE80211_NBR_AP_INFO_LEN;
378 		} else {
379 			u8p_replace_bits(&tbtt_info_field[0],
380 					 tbtt_count - tbtt_info_field_count,
381 					 IEEE80211_TBTT_COUNT_MASK);
382 		}
383 	}
384 
385 	rnr_new[1] = rnr_len - tbtt_info_field_len;
386 	if (rnr_new[1] == 0)
387 		pos = rnr_new;
388 
389 	return pos - rnr_new;
390 }
391 
cfg80211_gen_new_ie(const u8 * ie,size_t ielen,const u8 * subelement,size_t subie_len,u8 * new_ie,u8 bssid_index,gfp_t gfp)392 static size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen,
393 				  const u8 *subelement, size_t subie_len,
394 				  u8 *new_ie, u8 bssid_index, gfp_t gfp)
395 {
396 	u8 *pos, *tmp;
397 	const u8 *tmp_old, *tmp_new;
398 	const struct element *non_inherit_elem;
399 	u8 *sub_copy;
400 
401 	/* copy subelement as we need to change its content to
402 	 * mark an ie after it is processed.
403 	 */
404 	sub_copy = kmemdup(subelement, subie_len, gfp);
405 	if (!sub_copy)
406 		return 0;
407 
408 	pos = &new_ie[0];
409 
410 	/* set new ssid */
411 	tmp_new = cfg80211_find_ie(WLAN_EID_SSID, sub_copy, subie_len);
412 	if (tmp_new) {
413 		memcpy(pos, tmp_new, tmp_new[1] + 2);
414 		pos += (tmp_new[1] + 2);
415 	}
416 
417 	/* get non inheritance list if exists */
418 	non_inherit_elem =
419 		cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE,
420 				       sub_copy, subie_len);
421 
422 	/* go through IEs in ie (skip SSID) and subelement,
423 	 * merge them into new_ie
424 	 */
425 	tmp_old = cfg80211_find_ie(WLAN_EID_SSID, ie, ielen);
426 	tmp_old = (tmp_old) ? tmp_old + tmp_old[1] + 2 : ie;
427 
428 	while (tmp_old + 2 - ie <= ielen &&
429 	       tmp_old + tmp_old[1] + 2 - ie <= ielen) {
430 		if (tmp_old[0] == 0) {
431 			tmp_old++;
432 			continue;
433 		}
434 
435 		if (tmp_old[0] == WLAN_EID_EXTENSION)
436 			tmp = (u8 *)cfg80211_find_ext_ie(tmp_old[2], sub_copy,
437 							 subie_len);
438 		else
439 			tmp = (u8 *)cfg80211_find_ie(tmp_old[0], sub_copy,
440 						     subie_len);
441 
442 		if (!tmp) {
443 			const struct element *old_elem = (void *)tmp_old;
444 
445 			/* ie in old ie but not in subelement */
446 			if (tmp_old[0] == WLAN_EID_REDUCED_NEIGHBOR_REPORT) {
447 				pos +=
448 				  cfg80211_handle_rnr_ie_for_mbssid(old_elem,
449 								    bssid_index,
450 								    pos);
451 			} else if (cfg80211_is_element_inherited(old_elem,
452 								 non_inherit_elem)) {
453 				memcpy(pos, tmp_old, tmp_old[1] + 2);
454 				pos += tmp_old[1] + 2;
455 			}
456 		} else {
457 			/* ie in transmitting ie also in subelement,
458 			 * copy from subelement and flag the ie in subelement
459 			 * as copied (by setting eid field to WLAN_EID_SSID,
460 			 * which is skipped anyway).
461 			 * For vendor ie, compare OUI + type + subType to
462 			 * determine if they are the same ie.
463 			 */
464 			if (tmp_old[0] == WLAN_EID_VENDOR_SPECIFIC) {
465 				if (tmp_old[1] >= 5 && tmp[1] >= 5 &&
466 				    !memcmp(tmp_old + 2, tmp + 2, 5)) {
467 					/* same vendor ie, copy from
468 					 * subelement
469 					 */
470 					memcpy(pos, tmp, tmp[1] + 2);
471 					pos += tmp[1] + 2;
472 					tmp[0] = WLAN_EID_SSID;
473 				} else {
474 					memcpy(pos, tmp_old, tmp_old[1] + 2);
475 					pos += tmp_old[1] + 2;
476 				}
477 			} else {
478 				/* copy ie from subelement into new ie */
479 				memcpy(pos, tmp, tmp[1] + 2);
480 				pos += tmp[1] + 2;
481 				tmp[0] = WLAN_EID_SSID;
482 			}
483 		}
484 
485 		if (tmp_old + tmp_old[1] + 2 - ie == ielen)
486 			break;
487 
488 		tmp_old += tmp_old[1] + 2;
489 	}
490 
491 	/* go through subelement again to check if there is any ie not
492 	 * copied to new ie, skip ssid, capability, bssid-index ie
493 	 */
494 	tmp_new = sub_copy;
495 	while (tmp_new + 2 - sub_copy <= subie_len &&
496 	       tmp_new + tmp_new[1] + 2 - sub_copy <= subie_len) {
497 		if (!(tmp_new[0] == WLAN_EID_NON_TX_BSSID_CAP ||
498 		      tmp_new[0] == WLAN_EID_SSID)) {
499 			memcpy(pos, tmp_new, tmp_new[1] + 2);
500 			pos += tmp_new[1] + 2;
501 		}
502 		if (tmp_new + tmp_new[1] + 2 - sub_copy == subie_len)
503 			break;
504 		tmp_new += tmp_new[1] + 2;
505 	}
506 
507 	kfree(sub_copy);
508 	return pos - new_ie;
509 }
510 
is_bss(struct cfg80211_bss * a,const u8 * bssid,const u8 * ssid,size_t ssid_len)511 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
512 		   const u8 *ssid, size_t ssid_len)
513 {
514 	const struct cfg80211_bss_ies *ies;
515 	const u8 *ssidie;
516 
517 	if (bssid && !ether_addr_equal(a->bssid, bssid))
518 		return false;
519 
520 	if (!ssid)
521 		return true;
522 
523 	ies = rcu_access_pointer(a->ies);
524 	if (!ies)
525 		return false;
526 	ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
527 	if (!ssidie)
528 		return false;
529 	if (ssidie[1] != ssid_len)
530 		return false;
531 	return memcmp(ssidie + 2, ssid, ssid_len) == 0;
532 }
533 
534 static int
cfg80211_add_nontrans_list(struct cfg80211_bss * trans_bss,struct cfg80211_bss * nontrans_bss)535 cfg80211_add_nontrans_list(struct cfg80211_bss *trans_bss,
536 			   struct cfg80211_bss *nontrans_bss)
537 {
538 	const struct element *ssid_elem;
539 	struct cfg80211_bss *bss = NULL;
540 
541 	rcu_read_lock();
542 	ssid_elem = ieee80211_bss_get_elem(nontrans_bss, WLAN_EID_SSID);
543 	if (!ssid_elem) {
544 		rcu_read_unlock();
545 		return -EINVAL;
546 	}
547 
548 	/* check if nontrans_bss is in the list */
549 	list_for_each_entry(bss, &trans_bss->nontrans_list, nontrans_list) {
550 		if (is_bss(bss, nontrans_bss->bssid, ssid_elem->data,
551 			   ssid_elem->datalen)) {
552 			rcu_read_unlock();
553 			return 0;
554 		}
555 	}
556 
557 	rcu_read_unlock();
558 
559 	/*
560 	 * This is a bit weird - it's not on the list, but already on another
561 	 * one! The only way that could happen is if there's some BSSID/SSID
562 	 * shared by multiple APs in their multi-BSSID profiles, potentially
563 	 * with hidden SSID mixed in ... ignore it.
564 	 */
565 	if (!list_empty(&nontrans_bss->nontrans_list))
566 		return -EINVAL;
567 
568 	/* add to the list */
569 	list_add_tail(&nontrans_bss->nontrans_list, &trans_bss->nontrans_list);
570 	return 0;
571 }
572 
__cfg80211_bss_expire(struct cfg80211_registered_device * rdev,unsigned long expire_time)573 static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev,
574 				  unsigned long expire_time)
575 {
576 	struct cfg80211_internal_bss *bss, *tmp;
577 	bool expired = false;
578 
579 	lockdep_assert_held(&rdev->bss_lock);
580 
581 	list_for_each_entry_safe(bss, tmp, &rdev->bss_list, list) {
582 		if (atomic_read(&bss->hold))
583 			continue;
584 		if (!time_after(expire_time, bss->ts))
585 			continue;
586 
587 		if (__cfg80211_unlink_bss(rdev, bss))
588 			expired = true;
589 	}
590 
591 	if (expired)
592 		rdev->bss_generation++;
593 }
594 
cfg80211_bss_expire_oldest(struct cfg80211_registered_device * rdev)595 static bool cfg80211_bss_expire_oldest(struct cfg80211_registered_device *rdev)
596 {
597 	struct cfg80211_internal_bss *bss, *oldest = NULL;
598 	bool ret;
599 
600 	lockdep_assert_held(&rdev->bss_lock);
601 
602 	list_for_each_entry(bss, &rdev->bss_list, list) {
603 		if (atomic_read(&bss->hold))
604 			continue;
605 
606 		if (!list_empty(&bss->hidden_list) &&
607 		    !bss->pub.hidden_beacon_bss)
608 			continue;
609 
610 		if (oldest && time_before(oldest->ts, bss->ts))
611 			continue;
612 		oldest = bss;
613 	}
614 
615 	if (WARN_ON(!oldest))
616 		return false;
617 
618 	/*
619 	 * The callers make sure to increase rdev->bss_generation if anything
620 	 * gets removed (and a new entry added), so there's no need to also do
621 	 * it here.
622 	 */
623 
624 	ret = __cfg80211_unlink_bss(rdev, oldest);
625 	WARN_ON(!ret);
626 	return ret;
627 }
628 
cfg80211_parse_bss_param(u8 data,struct cfg80211_colocated_ap * coloc_ap)629 static u8 cfg80211_parse_bss_param(u8 data,
630 				   struct cfg80211_colocated_ap *coloc_ap)
631 {
632 	coloc_ap->oct_recommended =
633 		u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_OCT_RECOMMENDED);
634 	coloc_ap->same_ssid =
635 		u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_SAME_SSID);
636 	coloc_ap->multi_bss =
637 		u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_MULTI_BSSID);
638 	coloc_ap->transmitted_bssid =
639 		u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_TRANSMITTED_BSSID);
640 	coloc_ap->unsolicited_probe =
641 		u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_PROBE_ACTIVE);
642 	coloc_ap->colocated_ess =
643 		u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_COLOC_ESS);
644 
645 	return u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_COLOC_AP);
646 }
647 
cfg80211_calc_short_ssid(const struct cfg80211_bss_ies * ies,const struct element ** elem,u32 * s_ssid)648 static int cfg80211_calc_short_ssid(const struct cfg80211_bss_ies *ies,
649 				    const struct element **elem, u32 *s_ssid)
650 {
651 
652 	*elem = cfg80211_find_elem(WLAN_EID_SSID, ies->data, ies->len);
653 	if (!*elem || (*elem)->datalen > IEEE80211_MAX_SSID_LEN)
654 		return -EINVAL;
655 
656 	*s_ssid = ~crc32_le(~0, (*elem)->data, (*elem)->datalen);
657 	return 0;
658 }
659 
cfg80211_free_coloc_ap_list(struct list_head * coloc_ap_list)660 static void cfg80211_free_coloc_ap_list(struct list_head *coloc_ap_list)
661 {
662 	struct cfg80211_colocated_ap *ap, *tmp_ap;
663 
664 	list_for_each_entry_safe(ap, tmp_ap, coloc_ap_list, list) {
665 		list_del(&ap->list);
666 		kfree(ap);
667 	}
668 }
669 
cfg80211_parse_ap_info(struct cfg80211_colocated_ap * entry,const u8 * pos,u8 length,const struct element * ssid_elem,int s_ssid_tmp)670 static int cfg80211_parse_ap_info(struct cfg80211_colocated_ap *entry,
671 				  const u8 *pos, u8 length,
672 				  const struct element *ssid_elem,
673 				  int s_ssid_tmp)
674 {
675 	/* skip the TBTT offset */
676 	pos++;
677 
678 	memcpy(entry->bssid, pos, ETH_ALEN);
679 	pos += ETH_ALEN;
680 
681 	if (length >= IEEE80211_TBTT_INFO_OFFSET_BSSID_SSSID_BSS_PARAM) {
682 		memcpy(&entry->short_ssid, pos,
683 		       sizeof(entry->short_ssid));
684 		entry->short_ssid_valid = true;
685 		pos += 4;
686 	}
687 
688 	/* skip non colocated APs */
689 	if (!cfg80211_parse_bss_param(*pos, entry))
690 		return -EINVAL;
691 	pos++;
692 
693 	if (length == IEEE80211_TBTT_INFO_OFFSET_BSSID_BSS_PARAM) {
694 		/*
695 		 * no information about the short ssid. Consider the entry valid
696 		 * for now. It would later be dropped in case there are explicit
697 		 * SSIDs that need to be matched
698 		 */
699 		if (!entry->same_ssid)
700 			return 0;
701 	}
702 
703 	if (entry->same_ssid) {
704 		entry->short_ssid = s_ssid_tmp;
705 		entry->short_ssid_valid = true;
706 
707 		/*
708 		 * This is safe because we validate datalen in
709 		 * cfg80211_parse_colocated_ap(), before calling this
710 		 * function.
711 		 */
712 		memcpy(&entry->ssid, &ssid_elem->data,
713 		       ssid_elem->datalen);
714 		entry->ssid_len = ssid_elem->datalen;
715 	}
716 	return 0;
717 }
718 
cfg80211_parse_colocated_ap(const struct cfg80211_bss_ies * ies,struct list_head * list)719 static int cfg80211_parse_colocated_ap(const struct cfg80211_bss_ies *ies,
720 				       struct list_head *list)
721 {
722 	struct ieee80211_neighbor_ap_info *ap_info;
723 	const struct element *elem, *ssid_elem;
724 	const u8 *pos, *end;
725 	u32 s_ssid_tmp;
726 	int n_coloc = 0, ret;
727 	LIST_HEAD(ap_list);
728 
729 	elem = cfg80211_find_elem(WLAN_EID_REDUCED_NEIGHBOR_REPORT, ies->data,
730 				  ies->len);
731 	if (!elem)
732 		return 0;
733 
734 	pos = elem->data;
735 	end = pos + elem->datalen;
736 
737 	ret = cfg80211_calc_short_ssid(ies, &ssid_elem, &s_ssid_tmp);
738 	if (ret)
739 		return 0;
740 
741 	/* RNR IE may contain more than one NEIGHBOR_AP_INFO */
742 	while (pos + sizeof(*ap_info) <= end) {
743 		enum nl80211_band band;
744 		int freq;
745 		u8 length, i, count;
746 
747 		ap_info = (void *)pos;
748 		count = u8_get_bits(ap_info->tbtt_info_hdr,
749 				    IEEE80211_AP_INFO_TBTT_HDR_COUNT) + 1;
750 		length = ap_info->tbtt_info_len;
751 
752 		pos += sizeof(*ap_info);
753 
754 		if (!ieee80211_operating_class_to_band(ap_info->op_class,
755 						       &band))
756 			break;
757 
758 		freq = ieee80211_channel_to_frequency(ap_info->channel, band);
759 
760 		if (end - pos < count * length)
761 			break;
762 
763 		/*
764 		 * TBTT info must include bss param + BSSID +
765 		 * (short SSID or same_ssid bit to be set).
766 		 * ignore other options, and move to the
767 		 * next AP info
768 		 */
769 		if (band != NL80211_BAND_6GHZ ||
770 		    (length != IEEE80211_TBTT_INFO_OFFSET_BSSID_BSS_PARAM &&
771 		     length < IEEE80211_TBTT_INFO_OFFSET_BSSID_SSSID_BSS_PARAM)) {
772 			pos += count * length;
773 			continue;
774 		}
775 
776 		for (i = 0; i < count; i++) {
777 			struct cfg80211_colocated_ap *entry;
778 
779 			entry = kzalloc(sizeof(*entry) + IEEE80211_MAX_SSID_LEN,
780 					GFP_ATOMIC);
781 
782 			if (!entry)
783 				break;
784 
785 			entry->center_freq = freq;
786 
787 			if (!cfg80211_parse_ap_info(entry, pos, length,
788 						    ssid_elem, s_ssid_tmp)) {
789 				n_coloc++;
790 				list_add_tail(&entry->list, &ap_list);
791 			} else {
792 				kfree(entry);
793 			}
794 
795 			pos += length;
796 		}
797 	}
798 
799 	if (pos != end) {
800 		cfg80211_free_coloc_ap_list(&ap_list);
801 		return 0;
802 	}
803 
804 	list_splice_tail(&ap_list, list);
805 	return n_coloc;
806 }
807 
cfg80211_scan_req_add_chan(struct cfg80211_scan_request * request,struct ieee80211_channel * chan,bool add_to_6ghz)808 static  void cfg80211_scan_req_add_chan(struct cfg80211_scan_request *request,
809 					struct ieee80211_channel *chan,
810 					bool add_to_6ghz)
811 {
812 	int i;
813 	u32 n_channels = request->n_channels;
814 	struct cfg80211_scan_6ghz_params *params =
815 		&request->scan_6ghz_params[request->n_6ghz_params];
816 
817 	for (i = 0; i < n_channels; i++) {
818 		if (request->channels[i] == chan) {
819 			if (add_to_6ghz)
820 				params->channel_idx = i;
821 			return;
822 		}
823 	}
824 
825 	request->channels[n_channels] = chan;
826 	if (add_to_6ghz)
827 		request->scan_6ghz_params[request->n_6ghz_params].channel_idx =
828 			n_channels;
829 
830 	request->n_channels++;
831 }
832 
cfg80211_find_ssid_match(struct cfg80211_colocated_ap * ap,struct cfg80211_scan_request * request)833 static bool cfg80211_find_ssid_match(struct cfg80211_colocated_ap *ap,
834 				     struct cfg80211_scan_request *request)
835 {
836 	int i;
837 	u32 s_ssid;
838 
839 	for (i = 0; i < request->n_ssids; i++) {
840 		/* wildcard ssid in the scan request */
841 		if (!request->ssids[i].ssid_len) {
842 			if (ap->multi_bss && !ap->transmitted_bssid)
843 				continue;
844 
845 			return true;
846 		}
847 
848 		if (ap->ssid_len &&
849 		    ap->ssid_len == request->ssids[i].ssid_len) {
850 			if (!memcmp(request->ssids[i].ssid, ap->ssid,
851 				    ap->ssid_len))
852 				return true;
853 		} else if (ap->short_ssid_valid) {
854 			s_ssid = ~crc32_le(~0, request->ssids[i].ssid,
855 					   request->ssids[i].ssid_len);
856 
857 			if (ap->short_ssid == s_ssid)
858 				return true;
859 		}
860 	}
861 
862 	return false;
863 }
864 
cfg80211_scan_6ghz(struct cfg80211_registered_device * rdev)865 static int cfg80211_scan_6ghz(struct cfg80211_registered_device *rdev)
866 {
867 	u8 i;
868 	struct cfg80211_colocated_ap *ap;
869 	int n_channels, count = 0, err;
870 	struct cfg80211_scan_request *request, *rdev_req = rdev->scan_req;
871 	LIST_HEAD(coloc_ap_list);
872 	bool need_scan_psc = true;
873 	const struct ieee80211_sband_iftype_data *iftd;
874 
875 	rdev_req->scan_6ghz = true;
876 
877 	if (!rdev->wiphy.bands[NL80211_BAND_6GHZ])
878 		return -EOPNOTSUPP;
879 
880 	iftd = ieee80211_get_sband_iftype_data(rdev->wiphy.bands[NL80211_BAND_6GHZ],
881 					       rdev_req->wdev->iftype);
882 	if (!iftd || !iftd->he_cap.has_he)
883 		return -EOPNOTSUPP;
884 
885 	n_channels = rdev->wiphy.bands[NL80211_BAND_6GHZ]->n_channels;
886 
887 	if (rdev_req->flags & NL80211_SCAN_FLAG_COLOCATED_6GHZ) {
888 		struct cfg80211_internal_bss *intbss;
889 
890 		spin_lock_bh(&rdev->bss_lock);
891 		list_for_each_entry(intbss, &rdev->bss_list, list) {
892 			struct cfg80211_bss *res = &intbss->pub;
893 			const struct cfg80211_bss_ies *ies;
894 
895 			ies = rcu_access_pointer(res->ies);
896 			count += cfg80211_parse_colocated_ap(ies,
897 							     &coloc_ap_list);
898 		}
899 		spin_unlock_bh(&rdev->bss_lock);
900 	}
901 
902 	request = kzalloc(struct_size(request, channels, n_channels) +
903 			  sizeof(*request->scan_6ghz_params) * count +
904 			  sizeof(*request->ssids) * rdev_req->n_ssids,
905 			  GFP_KERNEL);
906 	if (!request) {
907 		cfg80211_free_coloc_ap_list(&coloc_ap_list);
908 		return -ENOMEM;
909 	}
910 
911 	*request = *rdev_req;
912 	request->n_channels = 0;
913 	request->scan_6ghz_params =
914 		(void *)&request->channels[n_channels];
915 
916 	/*
917 	 * PSC channels should not be scanned in case of direct scan with 1 SSID
918 	 * and at least one of the reported co-located APs with same SSID
919 	 * indicating that all APs in the same ESS are co-located
920 	 */
921 	if (count && request->n_ssids == 1 && request->ssids[0].ssid_len) {
922 		list_for_each_entry(ap, &coloc_ap_list, list) {
923 			if (ap->colocated_ess &&
924 			    cfg80211_find_ssid_match(ap, request)) {
925 				need_scan_psc = false;
926 				break;
927 			}
928 		}
929 	}
930 
931 	/*
932 	 * add to the scan request the channels that need to be scanned
933 	 * regardless of the collocated APs (PSC channels or all channels
934 	 * in case that NL80211_SCAN_FLAG_COLOCATED_6GHZ is not set)
935 	 */
936 	for (i = 0; i < rdev_req->n_channels; i++) {
937 		if (rdev_req->channels[i]->band == NL80211_BAND_6GHZ &&
938 		    ((need_scan_psc &&
939 		      cfg80211_channel_is_psc(rdev_req->channels[i])) ||
940 		     !(rdev_req->flags & NL80211_SCAN_FLAG_COLOCATED_6GHZ))) {
941 			cfg80211_scan_req_add_chan(request,
942 						   rdev_req->channels[i],
943 						   false);
944 		}
945 	}
946 
947 	if (!(rdev_req->flags & NL80211_SCAN_FLAG_COLOCATED_6GHZ))
948 		goto skip;
949 
950 	list_for_each_entry(ap, &coloc_ap_list, list) {
951 		bool found = false;
952 		struct cfg80211_scan_6ghz_params *scan_6ghz_params =
953 			&request->scan_6ghz_params[request->n_6ghz_params];
954 		struct ieee80211_channel *chan =
955 			ieee80211_get_channel(&rdev->wiphy, ap->center_freq);
956 
957 		if (!chan || chan->flags & IEEE80211_CHAN_DISABLED)
958 			continue;
959 
960 		for (i = 0; i < rdev_req->n_channels; i++) {
961 			if (rdev_req->channels[i] == chan)
962 				found = true;
963 		}
964 
965 		if (!found)
966 			continue;
967 
968 		if (request->n_ssids > 0 &&
969 		    !cfg80211_find_ssid_match(ap, request))
970 			continue;
971 
972 		if (!is_broadcast_ether_addr(request->bssid) &&
973 		    !ether_addr_equal(request->bssid, ap->bssid))
974 			continue;
975 
976 		if (!request->n_ssids && ap->multi_bss && !ap->transmitted_bssid)
977 			continue;
978 
979 		cfg80211_scan_req_add_chan(request, chan, true);
980 		memcpy(scan_6ghz_params->bssid, ap->bssid, ETH_ALEN);
981 		scan_6ghz_params->short_ssid = ap->short_ssid;
982 		scan_6ghz_params->short_ssid_valid = ap->short_ssid_valid;
983 		scan_6ghz_params->unsolicited_probe = ap->unsolicited_probe;
984 
985 		/*
986 		 * If a PSC channel is added to the scan and 'need_scan_psc' is
987 		 * set to false, then all the APs that the scan logic is
988 		 * interested with on the channel are collocated and thus there
989 		 * is no need to perform the initial PSC channel listen.
990 		 */
991 		if (cfg80211_channel_is_psc(chan) && !need_scan_psc)
992 			scan_6ghz_params->psc_no_listen = true;
993 
994 		request->n_6ghz_params++;
995 	}
996 
997 skip:
998 	cfg80211_free_coloc_ap_list(&coloc_ap_list);
999 
1000 	if (request->n_channels) {
1001 		struct cfg80211_scan_request *old = rdev->int_scan_req;
1002 		rdev->int_scan_req = request;
1003 
1004 		/*
1005 		 * Add the ssids from the parent scan request to the new scan
1006 		 * request, so the driver would be able to use them in its
1007 		 * probe requests to discover hidden APs on PSC channels.
1008 		 */
1009 		request->ssids = (void *)&request->channels[request->n_channels];
1010 		request->n_ssids = rdev_req->n_ssids;
1011 		memcpy(request->ssids, rdev_req->ssids, sizeof(*request->ssids) *
1012 		       request->n_ssids);
1013 
1014 		/*
1015 		 * If this scan follows a previous scan, save the scan start
1016 		 * info from the first part of the scan
1017 		 */
1018 		if (old)
1019 			rdev->int_scan_req->info = old->info;
1020 
1021 		err = rdev_scan(rdev, request);
1022 		if (err) {
1023 			rdev->int_scan_req = old;
1024 			kfree(request);
1025 		} else {
1026 			kfree(old);
1027 		}
1028 
1029 		return err;
1030 	}
1031 
1032 	kfree(request);
1033 	return -EINVAL;
1034 }
1035 
cfg80211_scan(struct cfg80211_registered_device * rdev)1036 int cfg80211_scan(struct cfg80211_registered_device *rdev)
1037 {
1038 	struct cfg80211_scan_request *request;
1039 	struct cfg80211_scan_request *rdev_req = rdev->scan_req;
1040 	u32 n_channels = 0, idx, i;
1041 
1042 	if (!(rdev->wiphy.flags & WIPHY_FLAG_SPLIT_SCAN_6GHZ))
1043 		return rdev_scan(rdev, rdev_req);
1044 
1045 	for (i = 0; i < rdev_req->n_channels; i++) {
1046 		if (rdev_req->channels[i]->band != NL80211_BAND_6GHZ)
1047 			n_channels++;
1048 	}
1049 
1050 	if (!n_channels)
1051 		return cfg80211_scan_6ghz(rdev);
1052 
1053 	request = kzalloc(struct_size(request, channels, n_channels),
1054 			  GFP_KERNEL);
1055 	if (!request)
1056 		return -ENOMEM;
1057 
1058 	*request = *rdev_req;
1059 	request->n_channels = n_channels;
1060 
1061 	for (i = idx = 0; i < rdev_req->n_channels; i++) {
1062 		if (rdev_req->channels[i]->band != NL80211_BAND_6GHZ)
1063 			request->channels[idx++] = rdev_req->channels[i];
1064 	}
1065 
1066 	rdev_req->scan_6ghz = false;
1067 	rdev->int_scan_req = request;
1068 	return rdev_scan(rdev, request);
1069 }
1070 
___cfg80211_scan_done(struct cfg80211_registered_device * rdev,bool send_message)1071 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev,
1072 			   bool send_message)
1073 {
1074 	struct cfg80211_scan_request *request, *rdev_req;
1075 	struct wireless_dev *wdev;
1076 	struct sk_buff *msg;
1077 #ifdef CONFIG_CFG80211_WEXT
1078 	union iwreq_data wrqu;
1079 #endif
1080 
1081 	lockdep_assert_held(&rdev->wiphy.mtx);
1082 
1083 	if (rdev->scan_msg) {
1084 		nl80211_send_scan_msg(rdev, rdev->scan_msg);
1085 		rdev->scan_msg = NULL;
1086 		return;
1087 	}
1088 
1089 	rdev_req = rdev->scan_req;
1090 	if (!rdev_req)
1091 		return;
1092 
1093 	wdev = rdev_req->wdev;
1094 	request = rdev->int_scan_req ? rdev->int_scan_req : rdev_req;
1095 
1096 	if (wdev_running(wdev) &&
1097 	    (rdev->wiphy.flags & WIPHY_FLAG_SPLIT_SCAN_6GHZ) &&
1098 	    !rdev_req->scan_6ghz && !request->info.aborted &&
1099 	    !cfg80211_scan_6ghz(rdev))
1100 		return;
1101 
1102 	/*
1103 	 * This must be before sending the other events!
1104 	 * Otherwise, wpa_supplicant gets completely confused with
1105 	 * wext events.
1106 	 */
1107 	if (wdev->netdev)
1108 		cfg80211_sme_scan_done(wdev->netdev);
1109 
1110 	if (!request->info.aborted &&
1111 	    request->flags & NL80211_SCAN_FLAG_FLUSH) {
1112 		/* flush entries from previous scans */
1113 		spin_lock_bh(&rdev->bss_lock);
1114 		__cfg80211_bss_expire(rdev, request->scan_start);
1115 		spin_unlock_bh(&rdev->bss_lock);
1116 	}
1117 
1118 	msg = nl80211_build_scan_msg(rdev, wdev, request->info.aborted);
1119 
1120 #ifdef CONFIG_CFG80211_WEXT
1121 	if (wdev->netdev && !request->info.aborted) {
1122 		memset(&wrqu, 0, sizeof(wrqu));
1123 
1124 		wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL);
1125 	}
1126 #endif
1127 
1128 	dev_put(wdev->netdev);
1129 
1130 	kfree(rdev->int_scan_req);
1131 	rdev->int_scan_req = NULL;
1132 
1133 	kfree(rdev->scan_req);
1134 	rdev->scan_req = NULL;
1135 
1136 	if (!send_message)
1137 		rdev->scan_msg = msg;
1138 	else
1139 		nl80211_send_scan_msg(rdev, msg);
1140 }
1141 
__cfg80211_scan_done(struct work_struct * wk)1142 void __cfg80211_scan_done(struct work_struct *wk)
1143 {
1144 	struct cfg80211_registered_device *rdev;
1145 
1146 	rdev = container_of(wk, struct cfg80211_registered_device,
1147 			    scan_done_wk);
1148 
1149 	wiphy_lock(&rdev->wiphy);
1150 	___cfg80211_scan_done(rdev, true);
1151 	wiphy_unlock(&rdev->wiphy);
1152 }
1153 
cfg80211_scan_done(struct cfg80211_scan_request * request,struct cfg80211_scan_info * info)1154 void cfg80211_scan_done(struct cfg80211_scan_request *request,
1155 			struct cfg80211_scan_info *info)
1156 {
1157 	struct cfg80211_scan_info old_info = request->info;
1158 
1159 	trace_cfg80211_scan_done(request, info);
1160 	WARN_ON(request != wiphy_to_rdev(request->wiphy)->scan_req &&
1161 		request != wiphy_to_rdev(request->wiphy)->int_scan_req);
1162 
1163 	request->info = *info;
1164 
1165 	/*
1166 	 * In case the scan is split, the scan_start_tsf and tsf_bssid should
1167 	 * be of the first part. In such a case old_info.scan_start_tsf should
1168 	 * be non zero.
1169 	 */
1170 	if (request->scan_6ghz && old_info.scan_start_tsf) {
1171 		request->info.scan_start_tsf = old_info.scan_start_tsf;
1172 		memcpy(request->info.tsf_bssid, old_info.tsf_bssid,
1173 		       sizeof(request->info.tsf_bssid));
1174 	}
1175 
1176 	request->notified = true;
1177 	queue_work(cfg80211_wq, &wiphy_to_rdev(request->wiphy)->scan_done_wk);
1178 }
1179 EXPORT_SYMBOL(cfg80211_scan_done);
1180 
cfg80211_add_sched_scan_req(struct cfg80211_registered_device * rdev,struct cfg80211_sched_scan_request * req)1181 void cfg80211_add_sched_scan_req(struct cfg80211_registered_device *rdev,
1182 				 struct cfg80211_sched_scan_request *req)
1183 {
1184 	lockdep_assert_held(&rdev->wiphy.mtx);
1185 
1186 	list_add_rcu(&req->list, &rdev->sched_scan_req_list);
1187 }
1188 
cfg80211_del_sched_scan_req(struct cfg80211_registered_device * rdev,struct cfg80211_sched_scan_request * req)1189 static void cfg80211_del_sched_scan_req(struct cfg80211_registered_device *rdev,
1190 					struct cfg80211_sched_scan_request *req)
1191 {
1192 	lockdep_assert_held(&rdev->wiphy.mtx);
1193 
1194 	list_del_rcu(&req->list);
1195 	kfree_rcu(req, rcu_head);
1196 }
1197 
1198 static struct cfg80211_sched_scan_request *
cfg80211_find_sched_scan_req(struct cfg80211_registered_device * rdev,u64 reqid)1199 cfg80211_find_sched_scan_req(struct cfg80211_registered_device *rdev, u64 reqid)
1200 {
1201 	struct cfg80211_sched_scan_request *pos;
1202 
1203 	list_for_each_entry_rcu(pos, &rdev->sched_scan_req_list, list,
1204 				lockdep_is_held(&rdev->wiphy.mtx)) {
1205 		if (pos->reqid == reqid)
1206 			return pos;
1207 	}
1208 	return NULL;
1209 }
1210 
1211 /*
1212  * Determines if a scheduled scan request can be handled. When a legacy
1213  * scheduled scan is running no other scheduled scan is allowed regardless
1214  * whether the request is for legacy or multi-support scan. When a multi-support
1215  * scheduled scan is running a request for legacy scan is not allowed. In this
1216  * case a request for multi-support scan can be handled if resources are
1217  * available, ie. struct wiphy::max_sched_scan_reqs limit is not yet reached.
1218  */
cfg80211_sched_scan_req_possible(struct cfg80211_registered_device * rdev,bool want_multi)1219 int cfg80211_sched_scan_req_possible(struct cfg80211_registered_device *rdev,
1220 				     bool want_multi)
1221 {
1222 	struct cfg80211_sched_scan_request *pos;
1223 	int i = 0;
1224 
1225 	list_for_each_entry(pos, &rdev->sched_scan_req_list, list) {
1226 		/* request id zero means legacy in progress */
1227 		if (!i && !pos->reqid)
1228 			return -EINPROGRESS;
1229 		i++;
1230 	}
1231 
1232 	if (i) {
1233 		/* no legacy allowed when multi request(s) are active */
1234 		if (!want_multi)
1235 			return -EINPROGRESS;
1236 
1237 		/* resource limit reached */
1238 		if (i == rdev->wiphy.max_sched_scan_reqs)
1239 			return -ENOSPC;
1240 	}
1241 	return 0;
1242 }
1243 
cfg80211_sched_scan_results_wk(struct work_struct * work)1244 void cfg80211_sched_scan_results_wk(struct work_struct *work)
1245 {
1246 	struct cfg80211_registered_device *rdev;
1247 	struct cfg80211_sched_scan_request *req, *tmp;
1248 
1249 	rdev = container_of(work, struct cfg80211_registered_device,
1250 			   sched_scan_res_wk);
1251 
1252 	wiphy_lock(&rdev->wiphy);
1253 	list_for_each_entry_safe(req, tmp, &rdev->sched_scan_req_list, list) {
1254 		if (req->report_results) {
1255 			req->report_results = false;
1256 			if (req->flags & NL80211_SCAN_FLAG_FLUSH) {
1257 				/* flush entries from previous scans */
1258 				spin_lock_bh(&rdev->bss_lock);
1259 				__cfg80211_bss_expire(rdev, req->scan_start);
1260 				spin_unlock_bh(&rdev->bss_lock);
1261 				req->scan_start = jiffies;
1262 			}
1263 			nl80211_send_sched_scan(req,
1264 						NL80211_CMD_SCHED_SCAN_RESULTS);
1265 		}
1266 	}
1267 	wiphy_unlock(&rdev->wiphy);
1268 }
1269 
cfg80211_sched_scan_results(struct wiphy * wiphy,u64 reqid)1270 void cfg80211_sched_scan_results(struct wiphy *wiphy, u64 reqid)
1271 {
1272 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1273 	struct cfg80211_sched_scan_request *request;
1274 
1275 	trace_cfg80211_sched_scan_results(wiphy, reqid);
1276 	/* ignore if we're not scanning */
1277 
1278 	rcu_read_lock();
1279 	request = cfg80211_find_sched_scan_req(rdev, reqid);
1280 	if (request) {
1281 		request->report_results = true;
1282 		queue_work(cfg80211_wq, &rdev->sched_scan_res_wk);
1283 	}
1284 	rcu_read_unlock();
1285 }
1286 EXPORT_SYMBOL(cfg80211_sched_scan_results);
1287 
cfg80211_sched_scan_stopped_locked(struct wiphy * wiphy,u64 reqid)1288 void cfg80211_sched_scan_stopped_locked(struct wiphy *wiphy, u64 reqid)
1289 {
1290 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1291 
1292 	lockdep_assert_held(&wiphy->mtx);
1293 
1294 	trace_cfg80211_sched_scan_stopped(wiphy, reqid);
1295 
1296 	__cfg80211_stop_sched_scan(rdev, reqid, true);
1297 }
1298 EXPORT_SYMBOL(cfg80211_sched_scan_stopped_locked);
1299 
cfg80211_sched_scan_stopped(struct wiphy * wiphy,u64 reqid)1300 void cfg80211_sched_scan_stopped(struct wiphy *wiphy, u64 reqid)
1301 {
1302 	wiphy_lock(wiphy);
1303 	cfg80211_sched_scan_stopped_locked(wiphy, reqid);
1304 	wiphy_unlock(wiphy);
1305 }
1306 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
1307 
cfg80211_stop_sched_scan_req(struct cfg80211_registered_device * rdev,struct cfg80211_sched_scan_request * req,bool driver_initiated)1308 int cfg80211_stop_sched_scan_req(struct cfg80211_registered_device *rdev,
1309 				 struct cfg80211_sched_scan_request *req,
1310 				 bool driver_initiated)
1311 {
1312 	lockdep_assert_held(&rdev->wiphy.mtx);
1313 
1314 	if (!driver_initiated) {
1315 		int err = rdev_sched_scan_stop(rdev, req->dev, req->reqid);
1316 		if (err)
1317 			return err;
1318 	}
1319 
1320 	nl80211_send_sched_scan(req, NL80211_CMD_SCHED_SCAN_STOPPED);
1321 
1322 	cfg80211_del_sched_scan_req(rdev, req);
1323 
1324 	return 0;
1325 }
1326 
__cfg80211_stop_sched_scan(struct cfg80211_registered_device * rdev,u64 reqid,bool driver_initiated)1327 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
1328 			       u64 reqid, bool driver_initiated)
1329 {
1330 	struct cfg80211_sched_scan_request *sched_scan_req;
1331 
1332 	lockdep_assert_held(&rdev->wiphy.mtx);
1333 
1334 	sched_scan_req = cfg80211_find_sched_scan_req(rdev, reqid);
1335 	if (!sched_scan_req)
1336 		return -ENOENT;
1337 
1338 	return cfg80211_stop_sched_scan_req(rdev, sched_scan_req,
1339 					    driver_initiated);
1340 }
1341 
cfg80211_bss_age(struct cfg80211_registered_device * rdev,unsigned long age_secs)1342 void cfg80211_bss_age(struct cfg80211_registered_device *rdev,
1343                       unsigned long age_secs)
1344 {
1345 	struct cfg80211_internal_bss *bss;
1346 	unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
1347 
1348 	spin_lock_bh(&rdev->bss_lock);
1349 	list_for_each_entry(bss, &rdev->bss_list, list)
1350 		bss->ts -= age_jiffies;
1351 	spin_unlock_bh(&rdev->bss_lock);
1352 }
1353 
cfg80211_bss_expire(struct cfg80211_registered_device * rdev)1354 void cfg80211_bss_expire(struct cfg80211_registered_device *rdev)
1355 {
1356 	__cfg80211_bss_expire(rdev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
1357 }
1358 
cfg80211_bss_flush(struct wiphy * wiphy)1359 void cfg80211_bss_flush(struct wiphy *wiphy)
1360 {
1361 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1362 
1363 	spin_lock_bh(&rdev->bss_lock);
1364 	__cfg80211_bss_expire(rdev, jiffies);
1365 	spin_unlock_bh(&rdev->bss_lock);
1366 }
1367 EXPORT_SYMBOL(cfg80211_bss_flush);
1368 
1369 const struct element *
cfg80211_find_elem_match(u8 eid,const u8 * ies,unsigned int len,const u8 * match,unsigned int match_len,unsigned int match_offset)1370 cfg80211_find_elem_match(u8 eid, const u8 *ies, unsigned int len,
1371 			 const u8 *match, unsigned int match_len,
1372 			 unsigned int match_offset)
1373 {
1374 	const struct element *elem;
1375 
1376 	for_each_element_id(elem, eid, ies, len) {
1377 		if (elem->datalen >= match_offset + match_len &&
1378 		    !memcmp(elem->data + match_offset, match, match_len))
1379 			return elem;
1380 	}
1381 
1382 	return NULL;
1383 }
1384 EXPORT_SYMBOL(cfg80211_find_elem_match);
1385 
cfg80211_find_vendor_elem(unsigned int oui,int oui_type,const u8 * ies,unsigned int len)1386 const struct element *cfg80211_find_vendor_elem(unsigned int oui, int oui_type,
1387 						const u8 *ies,
1388 						unsigned int len)
1389 {
1390 	const struct element *elem;
1391 	u8 match[] = { oui >> 16, oui >> 8, oui, oui_type };
1392 	int match_len = (oui_type < 0) ? 3 : sizeof(match);
1393 
1394 	if (WARN_ON(oui_type > 0xff))
1395 		return NULL;
1396 
1397 	elem = cfg80211_find_elem_match(WLAN_EID_VENDOR_SPECIFIC, ies, len,
1398 					match, match_len, 0);
1399 
1400 	if (!elem || elem->datalen < 4)
1401 		return NULL;
1402 
1403 	return elem;
1404 }
1405 EXPORT_SYMBOL(cfg80211_find_vendor_elem);
1406 
1407 /**
1408  * enum bss_compare_mode - BSS compare mode
1409  * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
1410  * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
1411  * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
1412  */
1413 enum bss_compare_mode {
1414 	BSS_CMP_REGULAR,
1415 	BSS_CMP_HIDE_ZLEN,
1416 	BSS_CMP_HIDE_NUL,
1417 };
1418 
cmp_bss(struct cfg80211_bss * a,struct cfg80211_bss * b,enum bss_compare_mode mode)1419 static int cmp_bss(struct cfg80211_bss *a,
1420 		   struct cfg80211_bss *b,
1421 		   enum bss_compare_mode mode)
1422 {
1423 	const struct cfg80211_bss_ies *a_ies, *b_ies;
1424 	const u8 *ie1 = NULL;
1425 	const u8 *ie2 = NULL;
1426 	int i, r;
1427 
1428 	if (a->channel != b->channel)
1429 		return b->channel->center_freq - a->channel->center_freq;
1430 
1431 	a_ies = rcu_access_pointer(a->ies);
1432 	if (!a_ies)
1433 		return -1;
1434 	b_ies = rcu_access_pointer(b->ies);
1435 	if (!b_ies)
1436 		return 1;
1437 
1438 	if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
1439 		ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
1440 				       a_ies->data, a_ies->len);
1441 	if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
1442 		ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
1443 				       b_ies->data, b_ies->len);
1444 	if (ie1 && ie2) {
1445 		int mesh_id_cmp;
1446 
1447 		if (ie1[1] == ie2[1])
1448 			mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
1449 		else
1450 			mesh_id_cmp = ie2[1] - ie1[1];
1451 
1452 		ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
1453 				       a_ies->data, a_ies->len);
1454 		ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
1455 				       b_ies->data, b_ies->len);
1456 		if (ie1 && ie2) {
1457 			if (mesh_id_cmp)
1458 				return mesh_id_cmp;
1459 			if (ie1[1] != ie2[1])
1460 				return ie2[1] - ie1[1];
1461 			return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
1462 		}
1463 	}
1464 
1465 	r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
1466 	if (r)
1467 		return r;
1468 
1469 	ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
1470 	ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
1471 
1472 	if (!ie1 && !ie2)
1473 		return 0;
1474 
1475 	/*
1476 	 * Note that with "hide_ssid", the function returns a match if
1477 	 * the already-present BSS ("b") is a hidden SSID beacon for
1478 	 * the new BSS ("a").
1479 	 */
1480 
1481 	/* sort missing IE before (left of) present IE */
1482 	if (!ie1)
1483 		return -1;
1484 	if (!ie2)
1485 		return 1;
1486 
1487 	switch (mode) {
1488 	case BSS_CMP_HIDE_ZLEN:
1489 		/*
1490 		 * In ZLEN mode we assume the BSS entry we're
1491 		 * looking for has a zero-length SSID. So if
1492 		 * the one we're looking at right now has that,
1493 		 * return 0. Otherwise, return the difference
1494 		 * in length, but since we're looking for the
1495 		 * 0-length it's really equivalent to returning
1496 		 * the length of the one we're looking at.
1497 		 *
1498 		 * No content comparison is needed as we assume
1499 		 * the content length is zero.
1500 		 */
1501 		return ie2[1];
1502 	case BSS_CMP_REGULAR:
1503 	default:
1504 		/* sort by length first, then by contents */
1505 		if (ie1[1] != ie2[1])
1506 			return ie2[1] - ie1[1];
1507 		return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
1508 	case BSS_CMP_HIDE_NUL:
1509 		if (ie1[1] != ie2[1])
1510 			return ie2[1] - ie1[1];
1511 		/* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
1512 		for (i = 0; i < ie2[1]; i++)
1513 			if (ie2[i + 2])
1514 				return -1;
1515 		return 0;
1516 	}
1517 }
1518 
cfg80211_bss_type_match(u16 capability,enum nl80211_band band,enum ieee80211_bss_type bss_type)1519 static bool cfg80211_bss_type_match(u16 capability,
1520 				    enum nl80211_band band,
1521 				    enum ieee80211_bss_type bss_type)
1522 {
1523 	bool ret = true;
1524 	u16 mask, val;
1525 
1526 	if (bss_type == IEEE80211_BSS_TYPE_ANY)
1527 		return ret;
1528 
1529 	if (band == NL80211_BAND_60GHZ) {
1530 		mask = WLAN_CAPABILITY_DMG_TYPE_MASK;
1531 		switch (bss_type) {
1532 		case IEEE80211_BSS_TYPE_ESS:
1533 			val = WLAN_CAPABILITY_DMG_TYPE_AP;
1534 			break;
1535 		case IEEE80211_BSS_TYPE_PBSS:
1536 			val = WLAN_CAPABILITY_DMG_TYPE_PBSS;
1537 			break;
1538 		case IEEE80211_BSS_TYPE_IBSS:
1539 			val = WLAN_CAPABILITY_DMG_TYPE_IBSS;
1540 			break;
1541 		default:
1542 			return false;
1543 		}
1544 	} else {
1545 		mask = WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS;
1546 		switch (bss_type) {
1547 		case IEEE80211_BSS_TYPE_ESS:
1548 			val = WLAN_CAPABILITY_ESS;
1549 			break;
1550 		case IEEE80211_BSS_TYPE_IBSS:
1551 			val = WLAN_CAPABILITY_IBSS;
1552 			break;
1553 		case IEEE80211_BSS_TYPE_MBSS:
1554 			val = 0;
1555 			break;
1556 		default:
1557 			return false;
1558 		}
1559 	}
1560 
1561 	ret = ((capability & mask) == val);
1562 	return ret;
1563 }
1564 
1565 /* Returned bss is reference counted and must be cleaned up appropriately. */
cfg80211_get_bss(struct wiphy * wiphy,struct ieee80211_channel * channel,const u8 * bssid,const u8 * ssid,size_t ssid_len,enum ieee80211_bss_type bss_type,enum ieee80211_privacy privacy)1566 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
1567 				      struct ieee80211_channel *channel,
1568 				      const u8 *bssid,
1569 				      const u8 *ssid, size_t ssid_len,
1570 				      enum ieee80211_bss_type bss_type,
1571 				      enum ieee80211_privacy privacy)
1572 {
1573 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1574 	struct cfg80211_internal_bss *bss, *res = NULL;
1575 	unsigned long now = jiffies;
1576 	int bss_privacy;
1577 
1578 	trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, bss_type,
1579 			       privacy);
1580 
1581 	spin_lock_bh(&rdev->bss_lock);
1582 
1583 	list_for_each_entry(bss, &rdev->bss_list, list) {
1584 		if (!cfg80211_bss_type_match(bss->pub.capability,
1585 					     bss->pub.channel->band, bss_type))
1586 			continue;
1587 
1588 		bss_privacy = (bss->pub.capability & WLAN_CAPABILITY_PRIVACY);
1589 		if ((privacy == IEEE80211_PRIVACY_ON && !bss_privacy) ||
1590 		    (privacy == IEEE80211_PRIVACY_OFF && bss_privacy))
1591 			continue;
1592 		if (channel && bss->pub.channel != channel)
1593 			continue;
1594 		if (!is_valid_ether_addr(bss->pub.bssid))
1595 			continue;
1596 		/* Don't get expired BSS structs */
1597 		if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
1598 		    !atomic_read(&bss->hold))
1599 			continue;
1600 		if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
1601 			res = bss;
1602 			bss_ref_get(rdev, res);
1603 			break;
1604 		}
1605 	}
1606 
1607 	spin_unlock_bh(&rdev->bss_lock);
1608 	if (!res)
1609 		return NULL;
1610 	trace_cfg80211_return_bss(&res->pub);
1611 	return &res->pub;
1612 }
1613 EXPORT_SYMBOL(cfg80211_get_bss);
1614 
rb_insert_bss(struct cfg80211_registered_device * rdev,struct cfg80211_internal_bss * bss)1615 static void rb_insert_bss(struct cfg80211_registered_device *rdev,
1616 			  struct cfg80211_internal_bss *bss)
1617 {
1618 	struct rb_node **p = &rdev->bss_tree.rb_node;
1619 	struct rb_node *parent = NULL;
1620 	struct cfg80211_internal_bss *tbss;
1621 	int cmp;
1622 
1623 	while (*p) {
1624 		parent = *p;
1625 		tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
1626 
1627 		cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
1628 
1629 		if (WARN_ON(!cmp)) {
1630 			/* will sort of leak this BSS */
1631 			return;
1632 		}
1633 
1634 		if (cmp < 0)
1635 			p = &(*p)->rb_left;
1636 		else
1637 			p = &(*p)->rb_right;
1638 	}
1639 
1640 	rb_link_node(&bss->rbn, parent, p);
1641 	rb_insert_color(&bss->rbn, &rdev->bss_tree);
1642 }
1643 
1644 static struct cfg80211_internal_bss *
rb_find_bss(struct cfg80211_registered_device * rdev,struct cfg80211_internal_bss * res,enum bss_compare_mode mode)1645 rb_find_bss(struct cfg80211_registered_device *rdev,
1646 	    struct cfg80211_internal_bss *res,
1647 	    enum bss_compare_mode mode)
1648 {
1649 	struct rb_node *n = rdev->bss_tree.rb_node;
1650 	struct cfg80211_internal_bss *bss;
1651 	int r;
1652 
1653 	while (n) {
1654 		bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
1655 		r = cmp_bss(&res->pub, &bss->pub, mode);
1656 
1657 		if (r == 0)
1658 			return bss;
1659 		else if (r < 0)
1660 			n = n->rb_left;
1661 		else
1662 			n = n->rb_right;
1663 	}
1664 
1665 	return NULL;
1666 }
1667 
cfg80211_combine_bsses(struct cfg80211_registered_device * rdev,struct cfg80211_internal_bss * new)1668 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
1669 				   struct cfg80211_internal_bss *new)
1670 {
1671 	const struct cfg80211_bss_ies *ies;
1672 	struct cfg80211_internal_bss *bss;
1673 	const u8 *ie;
1674 	int i, ssidlen;
1675 	u8 fold = 0;
1676 	u32 n_entries = 0;
1677 
1678 	ies = rcu_access_pointer(new->pub.beacon_ies);
1679 	if (WARN_ON(!ies))
1680 		return false;
1681 
1682 	ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
1683 	if (!ie) {
1684 		/* nothing to do */
1685 		return true;
1686 	}
1687 
1688 	ssidlen = ie[1];
1689 	for (i = 0; i < ssidlen; i++)
1690 		fold |= ie[2 + i];
1691 
1692 	if (fold) {
1693 		/* not a hidden SSID */
1694 		return true;
1695 	}
1696 
1697 	/* This is the bad part ... */
1698 
1699 	list_for_each_entry(bss, &rdev->bss_list, list) {
1700 		/*
1701 		 * we're iterating all the entries anyway, so take the
1702 		 * opportunity to validate the list length accounting
1703 		 */
1704 		n_entries++;
1705 
1706 		if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
1707 			continue;
1708 		if (bss->pub.channel != new->pub.channel)
1709 			continue;
1710 		if (bss->pub.scan_width != new->pub.scan_width)
1711 			continue;
1712 		if (rcu_access_pointer(bss->pub.beacon_ies))
1713 			continue;
1714 		ies = rcu_access_pointer(bss->pub.ies);
1715 		if (!ies)
1716 			continue;
1717 		ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
1718 		if (!ie)
1719 			continue;
1720 		if (ssidlen && ie[1] != ssidlen)
1721 			continue;
1722 		if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
1723 			continue;
1724 		if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
1725 			list_del(&bss->hidden_list);
1726 		/* combine them */
1727 		list_add(&bss->hidden_list, &new->hidden_list);
1728 		bss->pub.hidden_beacon_bss = &new->pub;
1729 		new->refcount += bss->refcount;
1730 		rcu_assign_pointer(bss->pub.beacon_ies,
1731 				   new->pub.beacon_ies);
1732 	}
1733 
1734 	WARN_ONCE(n_entries != rdev->bss_entries,
1735 		  "rdev bss entries[%d]/list[len:%d] corruption\n",
1736 		  rdev->bss_entries, n_entries);
1737 
1738 	return true;
1739 }
1740 
1741 struct cfg80211_non_tx_bss {
1742 	struct cfg80211_bss *tx_bss;
1743 	u8 max_bssid_indicator;
1744 	u8 bssid_index;
1745 };
1746 
cfg80211_update_hidden_bsses(struct cfg80211_internal_bss * known,const struct cfg80211_bss_ies * new_ies,const struct cfg80211_bss_ies * old_ies)1747 static void cfg80211_update_hidden_bsses(struct cfg80211_internal_bss *known,
1748 					 const struct cfg80211_bss_ies *new_ies,
1749 					 const struct cfg80211_bss_ies *old_ies)
1750 {
1751 	struct cfg80211_internal_bss *bss;
1752 
1753 	/* Assign beacon IEs to all sub entries */
1754 	list_for_each_entry(bss, &known->hidden_list, hidden_list) {
1755 		const struct cfg80211_bss_ies *ies;
1756 
1757 		ies = rcu_access_pointer(bss->pub.beacon_ies);
1758 		WARN_ON(ies != old_ies);
1759 
1760 		rcu_assign_pointer(bss->pub.beacon_ies, new_ies);
1761 	}
1762 }
1763 
1764 static bool
cfg80211_update_known_bss(struct cfg80211_registered_device * rdev,struct cfg80211_internal_bss * known,struct cfg80211_internal_bss * new,bool signal_valid)1765 cfg80211_update_known_bss(struct cfg80211_registered_device *rdev,
1766 			  struct cfg80211_internal_bss *known,
1767 			  struct cfg80211_internal_bss *new,
1768 			  bool signal_valid)
1769 {
1770 	lockdep_assert_held(&rdev->bss_lock);
1771 
1772 	/* Update IEs */
1773 	if (rcu_access_pointer(new->pub.proberesp_ies)) {
1774 		const struct cfg80211_bss_ies *old;
1775 
1776 		old = rcu_access_pointer(known->pub.proberesp_ies);
1777 
1778 		rcu_assign_pointer(known->pub.proberesp_ies,
1779 				   new->pub.proberesp_ies);
1780 		/* Override possible earlier Beacon frame IEs */
1781 		rcu_assign_pointer(known->pub.ies,
1782 				   new->pub.proberesp_ies);
1783 		if (old)
1784 			kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head);
1785 	} else if (rcu_access_pointer(new->pub.beacon_ies)) {
1786 		const struct cfg80211_bss_ies *old;
1787 
1788 		if (known->pub.hidden_beacon_bss &&
1789 		    !list_empty(&known->hidden_list)) {
1790 			const struct cfg80211_bss_ies *f;
1791 
1792 			/* The known BSS struct is one of the probe
1793 			 * response members of a group, but we're
1794 			 * receiving a beacon (beacon_ies in the new
1795 			 * bss is used). This can only mean that the
1796 			 * AP changed its beacon from not having an
1797 			 * SSID to showing it, which is confusing so
1798 			 * drop this information.
1799 			 */
1800 
1801 			f = rcu_access_pointer(new->pub.beacon_ies);
1802 			kfree_rcu((struct cfg80211_bss_ies *)f, rcu_head);
1803 			return false;
1804 		}
1805 
1806 		old = rcu_access_pointer(known->pub.beacon_ies);
1807 
1808 		rcu_assign_pointer(known->pub.beacon_ies, new->pub.beacon_ies);
1809 
1810 		/* Override IEs if they were from a beacon before */
1811 		if (old == rcu_access_pointer(known->pub.ies))
1812 			rcu_assign_pointer(known->pub.ies, new->pub.beacon_ies);
1813 
1814 		cfg80211_update_hidden_bsses(known,
1815 					     rcu_access_pointer(new->pub.beacon_ies),
1816 					     old);
1817 
1818 		if (old)
1819 			kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head);
1820 	}
1821 
1822 	known->pub.beacon_interval = new->pub.beacon_interval;
1823 
1824 	/* don't update the signal if beacon was heard on
1825 	 * adjacent channel.
1826 	 */
1827 	if (signal_valid)
1828 		known->pub.signal = new->pub.signal;
1829 	known->pub.capability = new->pub.capability;
1830 	known->ts = new->ts;
1831 	known->ts_boottime = new->ts_boottime;
1832 	known->parent_tsf = new->parent_tsf;
1833 	known->pub.chains = new->pub.chains;
1834 	memcpy(known->pub.chain_signal, new->pub.chain_signal,
1835 	       IEEE80211_MAX_CHAINS);
1836 	ether_addr_copy(known->parent_bssid, new->parent_bssid);
1837 	known->pub.max_bssid_indicator = new->pub.max_bssid_indicator;
1838 	known->pub.bssid_index = new->pub.bssid_index;
1839 
1840 	return true;
1841 }
1842 
1843 /* Returned bss is reference counted and must be cleaned up appropriately. */
1844 struct cfg80211_internal_bss *
cfg80211_bss_update(struct cfg80211_registered_device * rdev,struct cfg80211_internal_bss * tmp,bool signal_valid,unsigned long ts)1845 cfg80211_bss_update(struct cfg80211_registered_device *rdev,
1846 		    struct cfg80211_internal_bss *tmp,
1847 		    bool signal_valid, unsigned long ts)
1848 {
1849 	struct cfg80211_internal_bss *found = NULL;
1850 
1851 	if (WARN_ON(!tmp->pub.channel))
1852 		return NULL;
1853 
1854 	tmp->ts = ts;
1855 
1856 	spin_lock_bh(&rdev->bss_lock);
1857 
1858 	if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
1859 		spin_unlock_bh(&rdev->bss_lock);
1860 		return NULL;
1861 	}
1862 
1863 	found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR);
1864 
1865 	if (found) {
1866 		if (!cfg80211_update_known_bss(rdev, found, tmp, signal_valid))
1867 			goto drop;
1868 	} else {
1869 		struct cfg80211_internal_bss *new;
1870 		struct cfg80211_internal_bss *hidden;
1871 		struct cfg80211_bss_ies *ies;
1872 
1873 		/*
1874 		 * create a copy -- the "res" variable that is passed in
1875 		 * is allocated on the stack since it's not needed in the
1876 		 * more common case of an update
1877 		 */
1878 		new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size,
1879 			      GFP_ATOMIC);
1880 		if (!new) {
1881 			ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
1882 			if (ies)
1883 				kfree_rcu(ies, rcu_head);
1884 			ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
1885 			if (ies)
1886 				kfree_rcu(ies, rcu_head);
1887 			goto drop;
1888 		}
1889 		memcpy(new, tmp, sizeof(*new));
1890 		new->refcount = 1;
1891 		INIT_LIST_HEAD(&new->hidden_list);
1892 		INIT_LIST_HEAD(&new->pub.nontrans_list);
1893 		/* we'll set this later if it was non-NULL */
1894 		new->pub.transmitted_bss = NULL;
1895 
1896 		if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
1897 			hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN);
1898 			if (!hidden)
1899 				hidden = rb_find_bss(rdev, tmp,
1900 						     BSS_CMP_HIDE_NUL);
1901 			if (hidden) {
1902 				new->pub.hidden_beacon_bss = &hidden->pub;
1903 				list_add(&new->hidden_list,
1904 					 &hidden->hidden_list);
1905 				hidden->refcount++;
1906 
1907 				ies = (void *)rcu_access_pointer(new->pub.beacon_ies);
1908 				rcu_assign_pointer(new->pub.beacon_ies,
1909 						   hidden->pub.beacon_ies);
1910 				if (ies)
1911 					kfree_rcu(ies, rcu_head);
1912 			}
1913 		} else {
1914 			/*
1915 			 * Ok so we found a beacon, and don't have an entry. If
1916 			 * it's a beacon with hidden SSID, we might be in for an
1917 			 * expensive search for any probe responses that should
1918 			 * be grouped with this beacon for updates ...
1919 			 */
1920 			if (!cfg80211_combine_bsses(rdev, new)) {
1921 				bss_ref_put(rdev, new);
1922 				goto drop;
1923 			}
1924 		}
1925 
1926 		if (rdev->bss_entries >= bss_entries_limit &&
1927 		    !cfg80211_bss_expire_oldest(rdev)) {
1928 			bss_ref_put(rdev, new);
1929 			goto drop;
1930 		}
1931 
1932 		/* This must be before the call to bss_ref_get */
1933 		if (tmp->pub.transmitted_bss) {
1934 			struct cfg80211_internal_bss *pbss =
1935 				container_of(tmp->pub.transmitted_bss,
1936 					     struct cfg80211_internal_bss,
1937 					     pub);
1938 
1939 			new->pub.transmitted_bss = tmp->pub.transmitted_bss;
1940 			bss_ref_get(rdev, pbss);
1941 		}
1942 
1943 		list_add_tail(&new->list, &rdev->bss_list);
1944 		rdev->bss_entries++;
1945 		rb_insert_bss(rdev, new);
1946 		found = new;
1947 	}
1948 
1949 	rdev->bss_generation++;
1950 	bss_ref_get(rdev, found);
1951 	spin_unlock_bh(&rdev->bss_lock);
1952 
1953 	return found;
1954  drop:
1955 	spin_unlock_bh(&rdev->bss_lock);
1956 	return NULL;
1957 }
1958 
1959 /*
1960  * Update RX channel information based on the available frame payload
1961  * information. This is mainly for the 2.4 GHz band where frames can be received
1962  * from neighboring channels and the Beacon frames use the DSSS Parameter Set
1963  * element to indicate the current (transmitting) channel, but this might also
1964  * be needed on other bands if RX frequency does not match with the actual
1965  * operating channel of a BSS.
1966  */
1967 static struct ieee80211_channel *
cfg80211_get_bss_channel(struct wiphy * wiphy,const u8 * ie,size_t ielen,struct ieee80211_channel * channel,enum nl80211_bss_scan_width scan_width)1968 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
1969 			 struct ieee80211_channel *channel,
1970 			 enum nl80211_bss_scan_width scan_width)
1971 {
1972 	const u8 *tmp;
1973 	u32 freq;
1974 	int channel_number = -1;
1975 	struct ieee80211_channel *alt_channel;
1976 
1977 	if (channel->band == NL80211_BAND_S1GHZ) {
1978 		tmp = cfg80211_find_ie(WLAN_EID_S1G_OPERATION, ie, ielen);
1979 		if (tmp && tmp[1] >= sizeof(struct ieee80211_s1g_oper_ie)) {
1980 			struct ieee80211_s1g_oper_ie *s1gop = (void *)(tmp + 2);
1981 
1982 			channel_number = s1gop->primary_ch;
1983 		}
1984 	} else {
1985 		tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
1986 		if (tmp && tmp[1] == 1) {
1987 			channel_number = tmp[2];
1988 		} else {
1989 			tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
1990 			if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
1991 				struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
1992 
1993 				channel_number = htop->primary_chan;
1994 			}
1995 		}
1996 	}
1997 
1998 	if (channel_number < 0) {
1999 		/* No channel information in frame payload */
2000 		return channel;
2001 	}
2002 
2003 	freq = ieee80211_channel_to_freq_khz(channel_number, channel->band);
2004 	alt_channel = ieee80211_get_channel_khz(wiphy, freq);
2005 	if (!alt_channel) {
2006 		if (channel->band == NL80211_BAND_2GHZ) {
2007 			/*
2008 			 * Better not allow unexpected channels when that could
2009 			 * be going beyond the 1-11 range (e.g., discovering
2010 			 * BSS on channel 12 when radio is configured for
2011 			 * channel 11.
2012 			 */
2013 			return NULL;
2014 		}
2015 
2016 		/* No match for the payload channel number - ignore it */
2017 		return channel;
2018 	}
2019 
2020 	if (scan_width == NL80211_BSS_CHAN_WIDTH_10 ||
2021 	    scan_width == NL80211_BSS_CHAN_WIDTH_5) {
2022 		/*
2023 		 * Ignore channel number in 5 and 10 MHz channels where there
2024 		 * may not be an n:1 or 1:n mapping between frequencies and
2025 		 * channel numbers.
2026 		 */
2027 		return channel;
2028 	}
2029 
2030 	/*
2031 	 * Use the channel determined through the payload channel number
2032 	 * instead of the RX channel reported by the driver.
2033 	 */
2034 	if (alt_channel->flags & IEEE80211_CHAN_DISABLED)
2035 		return NULL;
2036 	return alt_channel;
2037 }
2038 
2039 /* Returned bss is reference counted and must be cleaned up appropriately. */
2040 static struct cfg80211_bss *
cfg80211_inform_single_bss_data(struct wiphy * wiphy,struct cfg80211_inform_bss * data,enum cfg80211_bss_frame_type ftype,const u8 * bssid,u64 tsf,u16 capability,u16 beacon_interval,const u8 * ie,size_t ielen,struct cfg80211_non_tx_bss * non_tx_data,gfp_t gfp)2041 cfg80211_inform_single_bss_data(struct wiphy *wiphy,
2042 				struct cfg80211_inform_bss *data,
2043 				enum cfg80211_bss_frame_type ftype,
2044 				const u8 *bssid, u64 tsf, u16 capability,
2045 				u16 beacon_interval, const u8 *ie, size_t ielen,
2046 				struct cfg80211_non_tx_bss *non_tx_data,
2047 				gfp_t gfp)
2048 {
2049 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
2050 	struct cfg80211_bss_ies *ies;
2051 	struct ieee80211_channel *channel;
2052 	struct cfg80211_internal_bss tmp = {}, *res;
2053 	int bss_type;
2054 	bool signal_valid;
2055 	unsigned long ts;
2056 
2057 	if (WARN_ON(!wiphy))
2058 		return NULL;
2059 
2060 	if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
2061 		    (data->signal < 0 || data->signal > 100)))
2062 		return NULL;
2063 
2064 	channel = cfg80211_get_bss_channel(wiphy, ie, ielen, data->chan,
2065 					   data->scan_width);
2066 	if (!channel)
2067 		return NULL;
2068 
2069 	memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
2070 	tmp.pub.channel = channel;
2071 	tmp.pub.scan_width = data->scan_width;
2072 	tmp.pub.signal = data->signal;
2073 	tmp.pub.beacon_interval = beacon_interval;
2074 	tmp.pub.capability = capability;
2075 	tmp.ts_boottime = data->boottime_ns;
2076 	tmp.parent_tsf = data->parent_tsf;
2077 	ether_addr_copy(tmp.parent_bssid, data->parent_bssid);
2078 
2079 	if (non_tx_data) {
2080 		tmp.pub.transmitted_bss = non_tx_data->tx_bss;
2081 		ts = bss_from_pub(non_tx_data->tx_bss)->ts;
2082 		tmp.pub.bssid_index = non_tx_data->bssid_index;
2083 		tmp.pub.max_bssid_indicator = non_tx_data->max_bssid_indicator;
2084 	} else {
2085 		ts = jiffies;
2086 	}
2087 
2088 	/*
2089 	 * If we do not know here whether the IEs are from a Beacon or Probe
2090 	 * Response frame, we need to pick one of the options and only use it
2091 	 * with the driver that does not provide the full Beacon/Probe Response
2092 	 * frame. Use Beacon frame pointer to avoid indicating that this should
2093 	 * override the IEs pointer should we have received an earlier
2094 	 * indication of Probe Response data.
2095 	 */
2096 	ies = kzalloc(sizeof(*ies) + ielen, gfp);
2097 	if (!ies)
2098 		return NULL;
2099 	ies->len = ielen;
2100 	ies->tsf = tsf;
2101 	ies->from_beacon = false;
2102 	memcpy(ies->data, ie, ielen);
2103 
2104 	switch (ftype) {
2105 	case CFG80211_BSS_FTYPE_BEACON:
2106 		ies->from_beacon = true;
2107 		fallthrough;
2108 	case CFG80211_BSS_FTYPE_UNKNOWN:
2109 		rcu_assign_pointer(tmp.pub.beacon_ies, ies);
2110 		break;
2111 	case CFG80211_BSS_FTYPE_PRESP:
2112 		rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
2113 		break;
2114 	}
2115 	rcu_assign_pointer(tmp.pub.ies, ies);
2116 
2117 	signal_valid = data->chan == channel;
2118 	res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid, ts);
2119 	if (!res)
2120 		return NULL;
2121 
2122 	if (channel->band == NL80211_BAND_60GHZ) {
2123 		bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
2124 		if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
2125 		    bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
2126 			regulatory_hint_found_beacon(wiphy, channel, gfp);
2127 	} else {
2128 		if (res->pub.capability & WLAN_CAPABILITY_ESS)
2129 			regulatory_hint_found_beacon(wiphy, channel, gfp);
2130 	}
2131 
2132 	if (non_tx_data) {
2133 		/* this is a nontransmitting bss, we need to add it to
2134 		 * transmitting bss' list if it is not there
2135 		 */
2136 		spin_lock_bh(&rdev->bss_lock);
2137 		if (cfg80211_add_nontrans_list(non_tx_data->tx_bss,
2138 					       &res->pub)) {
2139 			if (__cfg80211_unlink_bss(rdev, res)) {
2140 				rdev->bss_generation++;
2141 				res = NULL;
2142 			}
2143 		}
2144 		spin_unlock_bh(&rdev->bss_lock);
2145 
2146 		if (!res)
2147 			return NULL;
2148 	}
2149 
2150 	trace_cfg80211_return_bss(&res->pub);
2151 	/* cfg80211_bss_update gives us a referenced result */
2152 	return &res->pub;
2153 }
2154 
2155 static const struct element
cfg80211_get_profile_continuation(const u8 * ie,size_t ielen,const struct element * mbssid_elem,const struct element * sub_elem)2156 *cfg80211_get_profile_continuation(const u8 *ie, size_t ielen,
2157 				   const struct element *mbssid_elem,
2158 				   const struct element *sub_elem)
2159 {
2160 	const u8 *mbssid_end = mbssid_elem->data + mbssid_elem->datalen;
2161 	const struct element *next_mbssid;
2162 	const struct element *next_sub;
2163 
2164 	next_mbssid = cfg80211_find_elem(WLAN_EID_MULTIPLE_BSSID,
2165 					 mbssid_end,
2166 					 ielen - (mbssid_end - ie));
2167 
2168 	/*
2169 	 * If it is not the last subelement in current MBSSID IE or there isn't
2170 	 * a next MBSSID IE - profile is complete.
2171 	*/
2172 	if ((sub_elem->data + sub_elem->datalen < mbssid_end - 1) ||
2173 	    !next_mbssid)
2174 		return NULL;
2175 
2176 	/* For any length error, just return NULL */
2177 
2178 	if (next_mbssid->datalen < 4)
2179 		return NULL;
2180 
2181 	next_sub = (void *)&next_mbssid->data[1];
2182 
2183 	if (next_mbssid->data + next_mbssid->datalen <
2184 	    next_sub->data + next_sub->datalen)
2185 		return NULL;
2186 
2187 	if (next_sub->id != 0 || next_sub->datalen < 2)
2188 		return NULL;
2189 
2190 	/*
2191 	 * Check if the first element in the next sub element is a start
2192 	 * of a new profile
2193 	 */
2194 	return next_sub->data[0] == WLAN_EID_NON_TX_BSSID_CAP ?
2195 	       NULL : next_mbssid;
2196 }
2197 
cfg80211_merge_profile(const u8 * ie,size_t ielen,const struct element * mbssid_elem,const struct element * sub_elem,u8 * merged_ie,size_t max_copy_len)2198 size_t cfg80211_merge_profile(const u8 *ie, size_t ielen,
2199 			      const struct element *mbssid_elem,
2200 			      const struct element *sub_elem,
2201 			      u8 *merged_ie, size_t max_copy_len)
2202 {
2203 	size_t copied_len = sub_elem->datalen;
2204 	const struct element *next_mbssid;
2205 
2206 	if (sub_elem->datalen > max_copy_len)
2207 		return 0;
2208 
2209 	memcpy(merged_ie, sub_elem->data, sub_elem->datalen);
2210 
2211 	while ((next_mbssid = cfg80211_get_profile_continuation(ie, ielen,
2212 								mbssid_elem,
2213 								sub_elem))) {
2214 		const struct element *next_sub = (void *)&next_mbssid->data[1];
2215 
2216 		if (copied_len + next_sub->datalen > max_copy_len)
2217 			break;
2218 		memcpy(merged_ie + copied_len, next_sub->data,
2219 		       next_sub->datalen);
2220 		copied_len += next_sub->datalen;
2221 	}
2222 
2223 	return copied_len;
2224 }
2225 EXPORT_SYMBOL(cfg80211_merge_profile);
2226 
cfg80211_parse_mbssid_data(struct wiphy * wiphy,struct cfg80211_inform_bss * data,enum cfg80211_bss_frame_type ftype,const u8 * bssid,u64 tsf,u16 beacon_interval,const u8 * ie,size_t ielen,struct cfg80211_non_tx_bss * non_tx_data,gfp_t gfp)2227 static void cfg80211_parse_mbssid_data(struct wiphy *wiphy,
2228 				       struct cfg80211_inform_bss *data,
2229 				       enum cfg80211_bss_frame_type ftype,
2230 				       const u8 *bssid, u64 tsf,
2231 				       u16 beacon_interval, const u8 *ie,
2232 				       size_t ielen,
2233 				       struct cfg80211_non_tx_bss *non_tx_data,
2234 				       gfp_t gfp)
2235 {
2236 	const u8 *mbssid_index_ie;
2237 	const struct element *elem, *sub;
2238 	size_t new_ie_len;
2239 	u8 new_bssid[ETH_ALEN];
2240 	u8 *new_ie, *profile;
2241 	u64 seen_indices = 0;
2242 	u16 capability;
2243 	struct cfg80211_bss *bss;
2244 	u8 bssid_index;
2245 
2246 	if (!non_tx_data)
2247 		return;
2248 	if (!cfg80211_find_ie(WLAN_EID_MULTIPLE_BSSID, ie, ielen))
2249 		return;
2250 	if (!wiphy->support_mbssid)
2251 		return;
2252 	if (wiphy->support_only_he_mbssid &&
2253 	    !cfg80211_find_ext_ie(WLAN_EID_EXT_HE_CAPABILITY, ie, ielen))
2254 		return;
2255 
2256 	new_ie = kmalloc(IEEE80211_MAX_DATA_LEN, gfp);
2257 	if (!new_ie)
2258 		return;
2259 
2260 	profile = kmalloc(ielen, gfp);
2261 	if (!profile)
2262 		goto out;
2263 
2264 	for_each_element_id(elem, WLAN_EID_MULTIPLE_BSSID, ie, ielen) {
2265 		if (elem->datalen < 4)
2266 			continue;
2267 		if (elem->data[0] < 1 || (int)elem->data[0] > 8)
2268 			continue;
2269 		for_each_element(sub, elem->data + 1, elem->datalen - 1) {
2270 			u8 profile_len;
2271 
2272 			if (sub->id != 0 || sub->datalen < 4) {
2273 				/* not a valid BSS profile */
2274 				continue;
2275 			}
2276 
2277 			if (sub->data[0] != WLAN_EID_NON_TX_BSSID_CAP ||
2278 			    sub->data[1] != 2) {
2279 				/* The first element within the Nontransmitted
2280 				 * BSSID Profile is not the Nontransmitted
2281 				 * BSSID Capability element.
2282 				 */
2283 				continue;
2284 			}
2285 
2286 			memset(profile, 0, ielen);
2287 			profile_len = cfg80211_merge_profile(ie, ielen,
2288 							     elem,
2289 							     sub,
2290 							     profile,
2291 							     ielen);
2292 
2293 			/* found a Nontransmitted BSSID Profile */
2294 			mbssid_index_ie = cfg80211_find_ie
2295 				(WLAN_EID_MULTI_BSSID_IDX,
2296 				 profile, profile_len);
2297 			if (!mbssid_index_ie || mbssid_index_ie[1] < 1 ||
2298 			    mbssid_index_ie[2] == 0 ||
2299 			    mbssid_index_ie[2] > 46) {
2300 				/* No valid Multiple BSSID-Index element */
2301 				continue;
2302 			}
2303 
2304 			if (seen_indices & BIT_ULL(mbssid_index_ie[2]))
2305 				/* We don't support legacy split of a profile */
2306 				net_dbg_ratelimited("Partial info for BSSID index %d\n",
2307 						    mbssid_index_ie[2]);
2308 
2309 			seen_indices |= BIT_ULL(mbssid_index_ie[2]);
2310 
2311 			non_tx_data->bssid_index = mbssid_index_ie[2];
2312 			non_tx_data->max_bssid_indicator = elem->data[0];
2313 			bssid_index = non_tx_data->bssid_index;
2314 
2315 			cfg80211_gen_new_bssid(bssid,
2316 					       non_tx_data->max_bssid_indicator,
2317 					       non_tx_data->bssid_index,
2318 					       new_bssid);
2319 			memset(new_ie, 0, IEEE80211_MAX_DATA_LEN);
2320 			new_ie_len = cfg80211_gen_new_ie(ie, ielen,
2321 							 profile,
2322 							 profile_len, new_ie,
2323 							 bssid_index, gfp);
2324 			if (!new_ie_len)
2325 				continue;
2326 
2327 			capability = get_unaligned_le16(profile + 2);
2328 			bss = cfg80211_inform_single_bss_data(wiphy, data,
2329 							      ftype,
2330 							      new_bssid, tsf,
2331 							      capability,
2332 							      beacon_interval,
2333 							      new_ie,
2334 							      new_ie_len,
2335 							      non_tx_data,
2336 							      gfp);
2337 			if (!bss)
2338 				break;
2339 			cfg80211_put_bss(wiphy, bss);
2340 		}
2341 	}
2342 
2343 out:
2344 	kfree(new_ie);
2345 	kfree(profile);
2346 }
2347 
2348 struct cfg80211_bss *
cfg80211_inform_bss_data(struct wiphy * wiphy,struct cfg80211_inform_bss * data,enum cfg80211_bss_frame_type ftype,const u8 * bssid,u64 tsf,u16 capability,u16 beacon_interval,const u8 * ie,size_t ielen,gfp_t gfp)2349 cfg80211_inform_bss_data(struct wiphy *wiphy,
2350 			 struct cfg80211_inform_bss *data,
2351 			 enum cfg80211_bss_frame_type ftype,
2352 			 const u8 *bssid, u64 tsf, u16 capability,
2353 			 u16 beacon_interval, const u8 *ie, size_t ielen,
2354 			 gfp_t gfp)
2355 {
2356 	struct cfg80211_bss *res;
2357 	struct cfg80211_non_tx_bss non_tx_data;
2358 
2359 	res = cfg80211_inform_single_bss_data(wiphy, data, ftype, bssid, tsf,
2360 					      capability, beacon_interval, ie,
2361 					      ielen, NULL, gfp);
2362 	if (!res)
2363 		return NULL;
2364 	non_tx_data.tx_bss = res;
2365 	cfg80211_parse_mbssid_data(wiphy, data, ftype, bssid, tsf,
2366 				   beacon_interval, ie, ielen, &non_tx_data,
2367 				   gfp);
2368 	return res;
2369 }
2370 EXPORT_SYMBOL(cfg80211_inform_bss_data);
2371 
2372 static void
cfg80211_parse_mbssid_frame_data(struct wiphy * wiphy,struct cfg80211_inform_bss * data,struct ieee80211_mgmt * mgmt,size_t len,struct cfg80211_non_tx_bss * non_tx_data,gfp_t gfp)2373 cfg80211_parse_mbssid_frame_data(struct wiphy *wiphy,
2374 				 struct cfg80211_inform_bss *data,
2375 				 struct ieee80211_mgmt *mgmt, size_t len,
2376 				 struct cfg80211_non_tx_bss *non_tx_data,
2377 				 gfp_t gfp)
2378 {
2379 	enum cfg80211_bss_frame_type ftype;
2380 	const u8 *ie = mgmt->u.probe_resp.variable;
2381 	size_t ielen = len - offsetof(struct ieee80211_mgmt,
2382 				      u.probe_resp.variable);
2383 
2384 	ftype = ieee80211_is_beacon(mgmt->frame_control) ?
2385 		CFG80211_BSS_FTYPE_BEACON : CFG80211_BSS_FTYPE_PRESP;
2386 
2387 	cfg80211_parse_mbssid_data(wiphy, data, ftype, mgmt->bssid,
2388 				   le64_to_cpu(mgmt->u.probe_resp.timestamp),
2389 				   le16_to_cpu(mgmt->u.probe_resp.beacon_int),
2390 				   ie, ielen, non_tx_data, gfp);
2391 }
2392 
2393 static void
cfg80211_update_notlisted_nontrans(struct wiphy * wiphy,struct cfg80211_bss * nontrans_bss,struct ieee80211_mgmt * mgmt,size_t len)2394 cfg80211_update_notlisted_nontrans(struct wiphy *wiphy,
2395 				   struct cfg80211_bss *nontrans_bss,
2396 				   struct ieee80211_mgmt *mgmt, size_t len)
2397 {
2398 	u8 *ie, *new_ie, *pos;
2399 	const struct element *nontrans_ssid;
2400 	const u8 *trans_ssid, *mbssid;
2401 	size_t ielen = len - offsetof(struct ieee80211_mgmt,
2402 				      u.probe_resp.variable);
2403 	size_t new_ie_len;
2404 	struct cfg80211_bss_ies *new_ies;
2405 	const struct cfg80211_bss_ies *old;
2406 	size_t cpy_len;
2407 
2408 	lockdep_assert_held(&wiphy_to_rdev(wiphy)->bss_lock);
2409 
2410 	ie = mgmt->u.probe_resp.variable;
2411 
2412 	new_ie_len = ielen;
2413 	trans_ssid = cfg80211_find_ie(WLAN_EID_SSID, ie, ielen);
2414 	if (!trans_ssid)
2415 		return;
2416 	new_ie_len -= trans_ssid[1];
2417 	mbssid = cfg80211_find_ie(WLAN_EID_MULTIPLE_BSSID, ie, ielen);
2418 	/*
2419 	 * It's not valid to have the MBSSID element before SSID
2420 	 * ignore if that happens - the code below assumes it is
2421 	 * after (while copying things inbetween).
2422 	 */
2423 	if (!mbssid || mbssid < trans_ssid)
2424 		return;
2425 	new_ie_len -= mbssid[1];
2426 
2427 	nontrans_ssid = ieee80211_bss_get_elem(nontrans_bss, WLAN_EID_SSID);
2428 	if (!nontrans_ssid)
2429 		return;
2430 
2431 	new_ie_len += nontrans_ssid->datalen;
2432 
2433 	/* generate new ie for nontrans BSS
2434 	 * 1. replace SSID with nontrans BSS' SSID
2435 	 * 2. skip MBSSID IE
2436 	 */
2437 	new_ie = kzalloc(new_ie_len, GFP_ATOMIC);
2438 	if (!new_ie)
2439 		return;
2440 
2441 	new_ies = kzalloc(sizeof(*new_ies) + new_ie_len, GFP_ATOMIC);
2442 	if (!new_ies)
2443 		goto out_free;
2444 
2445 	pos = new_ie;
2446 
2447 	/* copy the nontransmitted SSID */
2448 	cpy_len = nontrans_ssid->datalen + 2;
2449 	memcpy(pos, nontrans_ssid, cpy_len);
2450 	pos += cpy_len;
2451 	/* copy the IEs between SSID and MBSSID */
2452 	cpy_len = trans_ssid[1] + 2;
2453 	memcpy(pos, (trans_ssid + cpy_len), (mbssid - (trans_ssid + cpy_len)));
2454 	pos += (mbssid - (trans_ssid + cpy_len));
2455 	/* copy the IEs after MBSSID */
2456 	cpy_len = mbssid[1] + 2;
2457 	memcpy(pos, mbssid + cpy_len, ((ie + ielen) - (mbssid + cpy_len)));
2458 
2459 	/* update ie */
2460 	new_ies->len = new_ie_len;
2461 	new_ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
2462 	new_ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control);
2463 	memcpy(new_ies->data, new_ie, new_ie_len);
2464 	if (ieee80211_is_probe_resp(mgmt->frame_control)) {
2465 		old = rcu_access_pointer(nontrans_bss->proberesp_ies);
2466 		rcu_assign_pointer(nontrans_bss->proberesp_ies, new_ies);
2467 		rcu_assign_pointer(nontrans_bss->ies, new_ies);
2468 		if (old)
2469 			kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head);
2470 	} else {
2471 		old = rcu_access_pointer(nontrans_bss->beacon_ies);
2472 		rcu_assign_pointer(nontrans_bss->beacon_ies, new_ies);
2473 		cfg80211_update_hidden_bsses(bss_from_pub(nontrans_bss),
2474 					     new_ies, old);
2475 		rcu_assign_pointer(nontrans_bss->ies, new_ies);
2476 		if (old)
2477 			kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head);
2478 	}
2479 
2480 out_free:
2481 	kfree(new_ie);
2482 }
2483 
2484 /* cfg80211_inform_bss_width_frame helper */
2485 static struct cfg80211_bss *
cfg80211_inform_single_bss_frame_data(struct wiphy * wiphy,struct cfg80211_inform_bss * data,struct ieee80211_mgmt * mgmt,size_t len,gfp_t gfp)2486 cfg80211_inform_single_bss_frame_data(struct wiphy *wiphy,
2487 				      struct cfg80211_inform_bss *data,
2488 				      struct ieee80211_mgmt *mgmt, size_t len,
2489 				      gfp_t gfp)
2490 {
2491 	struct cfg80211_internal_bss tmp = {}, *res;
2492 	struct cfg80211_bss_ies *ies;
2493 	struct ieee80211_channel *channel;
2494 	bool signal_valid;
2495 	struct ieee80211_ext *ext = NULL;
2496 	u8 *bssid, *variable;
2497 	u16 capability, beacon_int;
2498 	size_t ielen, min_hdr_len = offsetof(struct ieee80211_mgmt,
2499 					     u.probe_resp.variable);
2500 	int bss_type;
2501 
2502 	BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
2503 			offsetof(struct ieee80211_mgmt, u.beacon.variable));
2504 
2505 	trace_cfg80211_inform_bss_frame(wiphy, data, mgmt, len);
2506 
2507 	if (WARN_ON(!mgmt))
2508 		return NULL;
2509 
2510 	if (WARN_ON(!wiphy))
2511 		return NULL;
2512 
2513 	if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
2514 		    (data->signal < 0 || data->signal > 100)))
2515 		return NULL;
2516 
2517 	if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
2518 		ext = (void *) mgmt;
2519 		min_hdr_len = offsetof(struct ieee80211_ext, u.s1g_beacon);
2520 		if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
2521 			min_hdr_len = offsetof(struct ieee80211_ext,
2522 					       u.s1g_short_beacon.variable);
2523 	}
2524 
2525 	if (WARN_ON(len < min_hdr_len))
2526 		return NULL;
2527 
2528 	ielen = len - min_hdr_len;
2529 	variable = mgmt->u.probe_resp.variable;
2530 	if (ext) {
2531 		if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
2532 			variable = ext->u.s1g_short_beacon.variable;
2533 		else
2534 			variable = ext->u.s1g_beacon.variable;
2535 	}
2536 
2537 	channel = cfg80211_get_bss_channel(wiphy, variable,
2538 					   ielen, data->chan, data->scan_width);
2539 	if (!channel)
2540 		return NULL;
2541 
2542 	if (ext) {
2543 		const struct ieee80211_s1g_bcn_compat_ie *compat;
2544 		const struct element *elem;
2545 
2546 		elem = cfg80211_find_elem(WLAN_EID_S1G_BCN_COMPAT,
2547 					  variable, ielen);
2548 		if (!elem)
2549 			return NULL;
2550 		if (elem->datalen < sizeof(*compat))
2551 			return NULL;
2552 		compat = (void *)elem->data;
2553 		bssid = ext->u.s1g_beacon.sa;
2554 		capability = le16_to_cpu(compat->compat_info);
2555 		beacon_int = le16_to_cpu(compat->beacon_int);
2556 	} else {
2557 		bssid = mgmt->bssid;
2558 		beacon_int = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
2559 		capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
2560 	}
2561 
2562 	ies = kzalloc(sizeof(*ies) + ielen, gfp);
2563 	if (!ies)
2564 		return NULL;
2565 	ies->len = ielen;
2566 	ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
2567 	ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control) ||
2568 			   ieee80211_is_s1g_beacon(mgmt->frame_control);
2569 	memcpy(ies->data, variable, ielen);
2570 
2571 	if (ieee80211_is_probe_resp(mgmt->frame_control))
2572 		rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
2573 	else
2574 		rcu_assign_pointer(tmp.pub.beacon_ies, ies);
2575 	rcu_assign_pointer(tmp.pub.ies, ies);
2576 
2577 	memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
2578 	tmp.pub.beacon_interval = beacon_int;
2579 	tmp.pub.capability = capability;
2580 	tmp.pub.channel = channel;
2581 	tmp.pub.scan_width = data->scan_width;
2582 	tmp.pub.signal = data->signal;
2583 	tmp.ts_boottime = data->boottime_ns;
2584 	tmp.parent_tsf = data->parent_tsf;
2585 	tmp.pub.chains = data->chains;
2586 	memcpy(tmp.pub.chain_signal, data->chain_signal, IEEE80211_MAX_CHAINS);
2587 	ether_addr_copy(tmp.parent_bssid, data->parent_bssid);
2588 
2589 	signal_valid = data->chan == channel;
2590 	res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid,
2591 				  jiffies);
2592 	if (!res)
2593 		return NULL;
2594 
2595 	if (channel->band == NL80211_BAND_60GHZ) {
2596 		bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
2597 		if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
2598 		    bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
2599 			regulatory_hint_found_beacon(wiphy, channel, gfp);
2600 	} else {
2601 		if (res->pub.capability & WLAN_CAPABILITY_ESS)
2602 			regulatory_hint_found_beacon(wiphy, channel, gfp);
2603 	}
2604 
2605 	trace_cfg80211_return_bss(&res->pub);
2606 	/* cfg80211_bss_update gives us a referenced result */
2607 	return &res->pub;
2608 }
2609 
2610 struct cfg80211_bss *
cfg80211_inform_bss_frame_data(struct wiphy * wiphy,struct cfg80211_inform_bss * data,struct ieee80211_mgmt * mgmt,size_t len,gfp_t gfp)2611 cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
2612 			       struct cfg80211_inform_bss *data,
2613 			       struct ieee80211_mgmt *mgmt, size_t len,
2614 			       gfp_t gfp)
2615 {
2616 	struct cfg80211_bss *res, *tmp_bss;
2617 	const u8 *ie = mgmt->u.probe_resp.variable;
2618 	const struct cfg80211_bss_ies *ies1, *ies2;
2619 	size_t ielen = len - offsetof(struct ieee80211_mgmt,
2620 				      u.probe_resp.variable);
2621 	struct cfg80211_non_tx_bss non_tx_data = {};
2622 
2623 	res = cfg80211_inform_single_bss_frame_data(wiphy, data, mgmt,
2624 						    len, gfp);
2625 
2626 	/* don't do any further MBSSID handling for S1G */
2627 	if (ieee80211_is_s1g_beacon(mgmt->frame_control))
2628 		return res;
2629 
2630 	if (!res || !wiphy->support_mbssid ||
2631 	    !cfg80211_find_ie(WLAN_EID_MULTIPLE_BSSID, ie, ielen))
2632 		return res;
2633 	if (wiphy->support_only_he_mbssid &&
2634 	    !cfg80211_find_ext_ie(WLAN_EID_EXT_HE_CAPABILITY, ie, ielen))
2635 		return res;
2636 
2637 	non_tx_data.tx_bss = res;
2638 	/* process each non-transmitting bss */
2639 	cfg80211_parse_mbssid_frame_data(wiphy, data, mgmt, len,
2640 					 &non_tx_data, gfp);
2641 
2642 	spin_lock_bh(&wiphy_to_rdev(wiphy)->bss_lock);
2643 
2644 	/* check if the res has other nontransmitting bss which is not
2645 	 * in MBSSID IE
2646 	 */
2647 	ies1 = rcu_access_pointer(res->ies);
2648 
2649 	/* go through nontrans_list, if the timestamp of the BSS is
2650 	 * earlier than the timestamp of the transmitting BSS then
2651 	 * update it
2652 	 */
2653 	list_for_each_entry(tmp_bss, &res->nontrans_list,
2654 			    nontrans_list) {
2655 		ies2 = rcu_access_pointer(tmp_bss->ies);
2656 		if (ies2->tsf < ies1->tsf)
2657 			cfg80211_update_notlisted_nontrans(wiphy, tmp_bss,
2658 							   mgmt, len);
2659 	}
2660 	spin_unlock_bh(&wiphy_to_rdev(wiphy)->bss_lock);
2661 
2662 	return res;
2663 }
2664 EXPORT_SYMBOL(cfg80211_inform_bss_frame_data);
2665 
cfg80211_ref_bss(struct wiphy * wiphy,struct cfg80211_bss * pub)2666 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
2667 {
2668 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
2669 	struct cfg80211_internal_bss *bss;
2670 
2671 	if (!pub)
2672 		return;
2673 
2674 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
2675 
2676 	spin_lock_bh(&rdev->bss_lock);
2677 	bss_ref_get(rdev, bss);
2678 	spin_unlock_bh(&rdev->bss_lock);
2679 }
2680 EXPORT_SYMBOL(cfg80211_ref_bss);
2681 
cfg80211_put_bss(struct wiphy * wiphy,struct cfg80211_bss * pub)2682 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
2683 {
2684 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
2685 	struct cfg80211_internal_bss *bss;
2686 
2687 	if (!pub)
2688 		return;
2689 
2690 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
2691 
2692 	spin_lock_bh(&rdev->bss_lock);
2693 	bss_ref_put(rdev, bss);
2694 	spin_unlock_bh(&rdev->bss_lock);
2695 }
2696 EXPORT_SYMBOL(cfg80211_put_bss);
2697 
cfg80211_unlink_bss(struct wiphy * wiphy,struct cfg80211_bss * pub)2698 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
2699 {
2700 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
2701 	struct cfg80211_internal_bss *bss, *tmp1;
2702 	struct cfg80211_bss *nontrans_bss, *tmp;
2703 
2704 	if (WARN_ON(!pub))
2705 		return;
2706 
2707 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
2708 
2709 	spin_lock_bh(&rdev->bss_lock);
2710 	if (list_empty(&bss->list))
2711 		goto out;
2712 
2713 	list_for_each_entry_safe(nontrans_bss, tmp,
2714 				 &pub->nontrans_list,
2715 				 nontrans_list) {
2716 		tmp1 = container_of(nontrans_bss,
2717 				    struct cfg80211_internal_bss, pub);
2718 		if (__cfg80211_unlink_bss(rdev, tmp1))
2719 			rdev->bss_generation++;
2720 	}
2721 
2722 	if (__cfg80211_unlink_bss(rdev, bss))
2723 		rdev->bss_generation++;
2724 out:
2725 	spin_unlock_bh(&rdev->bss_lock);
2726 }
2727 EXPORT_SYMBOL(cfg80211_unlink_bss);
2728 
cfg80211_bss_iter(struct wiphy * wiphy,struct cfg80211_chan_def * chandef,void (* iter)(struct wiphy * wiphy,struct cfg80211_bss * bss,void * data),void * iter_data)2729 void cfg80211_bss_iter(struct wiphy *wiphy,
2730 		       struct cfg80211_chan_def *chandef,
2731 		       void (*iter)(struct wiphy *wiphy,
2732 				    struct cfg80211_bss *bss,
2733 				    void *data),
2734 		       void *iter_data)
2735 {
2736 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
2737 	struct cfg80211_internal_bss *bss;
2738 
2739 	spin_lock_bh(&rdev->bss_lock);
2740 
2741 	list_for_each_entry(bss, &rdev->bss_list, list) {
2742 		if (!chandef || cfg80211_is_sub_chan(chandef, bss->pub.channel,
2743 						     false))
2744 			iter(wiphy, &bss->pub, iter_data);
2745 	}
2746 
2747 	spin_unlock_bh(&rdev->bss_lock);
2748 }
2749 EXPORT_SYMBOL(cfg80211_bss_iter);
2750 
cfg80211_update_assoc_bss_entry(struct wireless_dev * wdev,unsigned int link_id,struct ieee80211_channel * chan)2751 void cfg80211_update_assoc_bss_entry(struct wireless_dev *wdev,
2752 				     unsigned int link_id,
2753 				     struct ieee80211_channel *chan)
2754 {
2755 	struct wiphy *wiphy = wdev->wiphy;
2756 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
2757 	struct cfg80211_internal_bss *cbss = wdev->links[link_id].client.current_bss;
2758 	struct cfg80211_internal_bss *new = NULL;
2759 	struct cfg80211_internal_bss *bss;
2760 	struct cfg80211_bss *nontrans_bss;
2761 	struct cfg80211_bss *tmp;
2762 
2763 	spin_lock_bh(&rdev->bss_lock);
2764 
2765 	/*
2766 	 * Some APs use CSA also for bandwidth changes, i.e., without actually
2767 	 * changing the control channel, so no need to update in such a case.
2768 	 */
2769 	if (cbss->pub.channel == chan)
2770 		goto done;
2771 
2772 	/* use transmitting bss */
2773 	if (cbss->pub.transmitted_bss)
2774 		cbss = container_of(cbss->pub.transmitted_bss,
2775 				    struct cfg80211_internal_bss,
2776 				    pub);
2777 
2778 	cbss->pub.channel = chan;
2779 
2780 	list_for_each_entry(bss, &rdev->bss_list, list) {
2781 		if (!cfg80211_bss_type_match(bss->pub.capability,
2782 					     bss->pub.channel->band,
2783 					     wdev->conn_bss_type))
2784 			continue;
2785 
2786 		if (bss == cbss)
2787 			continue;
2788 
2789 		if (!cmp_bss(&bss->pub, &cbss->pub, BSS_CMP_REGULAR)) {
2790 			new = bss;
2791 			break;
2792 		}
2793 	}
2794 
2795 	if (new) {
2796 		/* to save time, update IEs for transmitting bss only */
2797 		if (cfg80211_update_known_bss(rdev, cbss, new, false)) {
2798 			new->pub.proberesp_ies = NULL;
2799 			new->pub.beacon_ies = NULL;
2800 		}
2801 
2802 		list_for_each_entry_safe(nontrans_bss, tmp,
2803 					 &new->pub.nontrans_list,
2804 					 nontrans_list) {
2805 			bss = container_of(nontrans_bss,
2806 					   struct cfg80211_internal_bss, pub);
2807 			if (__cfg80211_unlink_bss(rdev, bss))
2808 				rdev->bss_generation++;
2809 		}
2810 
2811 		WARN_ON(atomic_read(&new->hold));
2812 		if (!WARN_ON(!__cfg80211_unlink_bss(rdev, new)))
2813 			rdev->bss_generation++;
2814 	}
2815 
2816 	rb_erase(&cbss->rbn, &rdev->bss_tree);
2817 	rb_insert_bss(rdev, cbss);
2818 	rdev->bss_generation++;
2819 
2820 	list_for_each_entry_safe(nontrans_bss, tmp,
2821 				 &cbss->pub.nontrans_list,
2822 				 nontrans_list) {
2823 		bss = container_of(nontrans_bss,
2824 				   struct cfg80211_internal_bss, pub);
2825 		bss->pub.channel = chan;
2826 		rb_erase(&bss->rbn, &rdev->bss_tree);
2827 		rb_insert_bss(rdev, bss);
2828 		rdev->bss_generation++;
2829 	}
2830 
2831 done:
2832 	spin_unlock_bh(&rdev->bss_lock);
2833 }
2834 
2835 #ifdef CONFIG_CFG80211_WEXT
2836 static struct cfg80211_registered_device *
cfg80211_get_dev_from_ifindex(struct net * net,int ifindex)2837 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
2838 {
2839 	struct cfg80211_registered_device *rdev;
2840 	struct net_device *dev;
2841 
2842 	ASSERT_RTNL();
2843 
2844 	dev = dev_get_by_index(net, ifindex);
2845 	if (!dev)
2846 		return ERR_PTR(-ENODEV);
2847 	if (dev->ieee80211_ptr)
2848 		rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy);
2849 	else
2850 		rdev = ERR_PTR(-ENODEV);
2851 	dev_put(dev);
2852 	return rdev;
2853 }
2854 
cfg80211_wext_siwscan(struct net_device * dev,struct iw_request_info * info,union iwreq_data * wrqu,char * extra)2855 int cfg80211_wext_siwscan(struct net_device *dev,
2856 			  struct iw_request_info *info,
2857 			  union iwreq_data *wrqu, char *extra)
2858 {
2859 	struct cfg80211_registered_device *rdev;
2860 	struct wiphy *wiphy;
2861 	struct iw_scan_req *wreq = NULL;
2862 	struct cfg80211_scan_request *creq;
2863 	int i, err, n_channels = 0;
2864 	enum nl80211_band band;
2865 
2866 	if (!netif_running(dev))
2867 		return -ENETDOWN;
2868 
2869 	if (wrqu->data.length == sizeof(struct iw_scan_req))
2870 		wreq = (struct iw_scan_req *)extra;
2871 
2872 	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
2873 
2874 	if (IS_ERR(rdev))
2875 		return PTR_ERR(rdev);
2876 
2877 	if (rdev->scan_req || rdev->scan_msg)
2878 		return -EBUSY;
2879 
2880 	wiphy = &rdev->wiphy;
2881 
2882 	/* Determine number of channels, needed to allocate creq */
2883 	if (wreq && wreq->num_channels)
2884 		n_channels = wreq->num_channels;
2885 	else
2886 		n_channels = ieee80211_get_num_supported_channels(wiphy);
2887 
2888 	creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
2889 		       n_channels * sizeof(void *),
2890 		       GFP_ATOMIC);
2891 	if (!creq)
2892 		return -ENOMEM;
2893 
2894 	creq->wiphy = wiphy;
2895 	creq->wdev = dev->ieee80211_ptr;
2896 	/* SSIDs come after channels */
2897 	creq->ssids = (void *)&creq->channels[n_channels];
2898 	creq->n_channels = n_channels;
2899 	creq->n_ssids = 1;
2900 	creq->scan_start = jiffies;
2901 
2902 	/* translate "Scan on frequencies" request */
2903 	i = 0;
2904 	for (band = 0; band < NUM_NL80211_BANDS; band++) {
2905 		int j;
2906 
2907 		if (!wiphy->bands[band])
2908 			continue;
2909 
2910 		for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
2911 			/* ignore disabled channels */
2912 			if (wiphy->bands[band]->channels[j].flags &
2913 						IEEE80211_CHAN_DISABLED)
2914 				continue;
2915 
2916 			/* If we have a wireless request structure and the
2917 			 * wireless request specifies frequencies, then search
2918 			 * for the matching hardware channel.
2919 			 */
2920 			if (wreq && wreq->num_channels) {
2921 				int k;
2922 				int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
2923 				for (k = 0; k < wreq->num_channels; k++) {
2924 					struct iw_freq *freq =
2925 						&wreq->channel_list[k];
2926 					int wext_freq =
2927 						cfg80211_wext_freq(freq);
2928 
2929 					if (wext_freq == wiphy_freq)
2930 						goto wext_freq_found;
2931 				}
2932 				goto wext_freq_not_found;
2933 			}
2934 
2935 		wext_freq_found:
2936 			creq->channels[i] = &wiphy->bands[band]->channels[j];
2937 			i++;
2938 		wext_freq_not_found: ;
2939 		}
2940 	}
2941 	/* No channels found? */
2942 	if (!i) {
2943 		err = -EINVAL;
2944 		goto out;
2945 	}
2946 
2947 	/* Set real number of channels specified in creq->channels[] */
2948 	creq->n_channels = i;
2949 
2950 	/* translate "Scan for SSID" request */
2951 	if (wreq) {
2952 		if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
2953 			if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
2954 				err = -EINVAL;
2955 				goto out;
2956 			}
2957 			memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
2958 			creq->ssids[0].ssid_len = wreq->essid_len;
2959 		}
2960 		if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
2961 			creq->n_ssids = 0;
2962 	}
2963 
2964 	for (i = 0; i < NUM_NL80211_BANDS; i++)
2965 		if (wiphy->bands[i])
2966 			creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
2967 
2968 	eth_broadcast_addr(creq->bssid);
2969 
2970 	wiphy_lock(&rdev->wiphy);
2971 
2972 	rdev->scan_req = creq;
2973 	err = rdev_scan(rdev, creq);
2974 	if (err) {
2975 		rdev->scan_req = NULL;
2976 		/* creq will be freed below */
2977 	} else {
2978 		nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
2979 		/* creq now owned by driver */
2980 		creq = NULL;
2981 		dev_hold(dev);
2982 	}
2983 	wiphy_unlock(&rdev->wiphy);
2984  out:
2985 	kfree(creq);
2986 	return err;
2987 }
2988 EXPORT_WEXT_HANDLER(cfg80211_wext_siwscan);
2989 
ieee80211_scan_add_ies(struct iw_request_info * info,const struct cfg80211_bss_ies * ies,char * current_ev,char * end_buf)2990 static char *ieee80211_scan_add_ies(struct iw_request_info *info,
2991 				    const struct cfg80211_bss_ies *ies,
2992 				    char *current_ev, char *end_buf)
2993 {
2994 	const u8 *pos, *end, *next;
2995 	struct iw_event iwe;
2996 
2997 	if (!ies)
2998 		return current_ev;
2999 
3000 	/*
3001 	 * If needed, fragment the IEs buffer (at IE boundaries) into short
3002 	 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
3003 	 */
3004 	pos = ies->data;
3005 	end = pos + ies->len;
3006 
3007 	while (end - pos > IW_GENERIC_IE_MAX) {
3008 		next = pos + 2 + pos[1];
3009 		while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
3010 			next = next + 2 + next[1];
3011 
3012 		memset(&iwe, 0, sizeof(iwe));
3013 		iwe.cmd = IWEVGENIE;
3014 		iwe.u.data.length = next - pos;
3015 		current_ev = iwe_stream_add_point_check(info, current_ev,
3016 							end_buf, &iwe,
3017 							(void *)pos);
3018 		if (IS_ERR(current_ev))
3019 			return current_ev;
3020 		pos = next;
3021 	}
3022 
3023 	if (end > pos) {
3024 		memset(&iwe, 0, sizeof(iwe));
3025 		iwe.cmd = IWEVGENIE;
3026 		iwe.u.data.length = end - pos;
3027 		current_ev = iwe_stream_add_point_check(info, current_ev,
3028 							end_buf, &iwe,
3029 							(void *)pos);
3030 		if (IS_ERR(current_ev))
3031 			return current_ev;
3032 	}
3033 
3034 	return current_ev;
3035 }
3036 
3037 static char *
ieee80211_bss(struct wiphy * wiphy,struct iw_request_info * info,struct cfg80211_internal_bss * bss,char * current_ev,char * end_buf)3038 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
3039 	      struct cfg80211_internal_bss *bss, char *current_ev,
3040 	      char *end_buf)
3041 {
3042 	const struct cfg80211_bss_ies *ies;
3043 	struct iw_event iwe;
3044 	const u8 *ie;
3045 	u8 buf[50];
3046 	u8 *cfg, *p, *tmp;
3047 	int rem, i, sig;
3048 	bool ismesh = false;
3049 
3050 	memset(&iwe, 0, sizeof(iwe));
3051 	iwe.cmd = SIOCGIWAP;
3052 	iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
3053 	memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
3054 	current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
3055 						IW_EV_ADDR_LEN);
3056 	if (IS_ERR(current_ev))
3057 		return current_ev;
3058 
3059 	memset(&iwe, 0, sizeof(iwe));
3060 	iwe.cmd = SIOCGIWFREQ;
3061 	iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
3062 	iwe.u.freq.e = 0;
3063 	current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
3064 						IW_EV_FREQ_LEN);
3065 	if (IS_ERR(current_ev))
3066 		return current_ev;
3067 
3068 	memset(&iwe, 0, sizeof(iwe));
3069 	iwe.cmd = SIOCGIWFREQ;
3070 	iwe.u.freq.m = bss->pub.channel->center_freq;
3071 	iwe.u.freq.e = 6;
3072 	current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
3073 						IW_EV_FREQ_LEN);
3074 	if (IS_ERR(current_ev))
3075 		return current_ev;
3076 
3077 	if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
3078 		memset(&iwe, 0, sizeof(iwe));
3079 		iwe.cmd = IWEVQUAL;
3080 		iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
3081 				     IW_QUAL_NOISE_INVALID |
3082 				     IW_QUAL_QUAL_UPDATED;
3083 		switch (wiphy->signal_type) {
3084 		case CFG80211_SIGNAL_TYPE_MBM:
3085 			sig = bss->pub.signal / 100;
3086 			iwe.u.qual.level = sig;
3087 			iwe.u.qual.updated |= IW_QUAL_DBM;
3088 			if (sig < -110)		/* rather bad */
3089 				sig = -110;
3090 			else if (sig > -40)	/* perfect */
3091 				sig = -40;
3092 			/* will give a range of 0 .. 70 */
3093 			iwe.u.qual.qual = sig + 110;
3094 			break;
3095 		case CFG80211_SIGNAL_TYPE_UNSPEC:
3096 			iwe.u.qual.level = bss->pub.signal;
3097 			/* will give range 0 .. 100 */
3098 			iwe.u.qual.qual = bss->pub.signal;
3099 			break;
3100 		default:
3101 			/* not reached */
3102 			break;
3103 		}
3104 		current_ev = iwe_stream_add_event_check(info, current_ev,
3105 							end_buf, &iwe,
3106 							IW_EV_QUAL_LEN);
3107 		if (IS_ERR(current_ev))
3108 			return current_ev;
3109 	}
3110 
3111 	memset(&iwe, 0, sizeof(iwe));
3112 	iwe.cmd = SIOCGIWENCODE;
3113 	if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
3114 		iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
3115 	else
3116 		iwe.u.data.flags = IW_ENCODE_DISABLED;
3117 	iwe.u.data.length = 0;
3118 	current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
3119 						&iwe, "");
3120 	if (IS_ERR(current_ev))
3121 		return current_ev;
3122 
3123 	rcu_read_lock();
3124 	ies = rcu_dereference(bss->pub.ies);
3125 	rem = ies->len;
3126 	ie = ies->data;
3127 
3128 	while (rem >= 2) {
3129 		/* invalid data */
3130 		if (ie[1] > rem - 2)
3131 			break;
3132 
3133 		switch (ie[0]) {
3134 		case WLAN_EID_SSID:
3135 			memset(&iwe, 0, sizeof(iwe));
3136 			iwe.cmd = SIOCGIWESSID;
3137 			iwe.u.data.length = ie[1];
3138 			iwe.u.data.flags = 1;
3139 			current_ev = iwe_stream_add_point_check(info,
3140 								current_ev,
3141 								end_buf, &iwe,
3142 								(u8 *)ie + 2);
3143 			if (IS_ERR(current_ev))
3144 				goto unlock;
3145 			break;
3146 		case WLAN_EID_MESH_ID:
3147 			memset(&iwe, 0, sizeof(iwe));
3148 			iwe.cmd = SIOCGIWESSID;
3149 			iwe.u.data.length = ie[1];
3150 			iwe.u.data.flags = 1;
3151 			current_ev = iwe_stream_add_point_check(info,
3152 								current_ev,
3153 								end_buf, &iwe,
3154 								(u8 *)ie + 2);
3155 			if (IS_ERR(current_ev))
3156 				goto unlock;
3157 			break;
3158 		case WLAN_EID_MESH_CONFIG:
3159 			ismesh = true;
3160 			if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
3161 				break;
3162 			cfg = (u8 *)ie + 2;
3163 			memset(&iwe, 0, sizeof(iwe));
3164 			iwe.cmd = IWEVCUSTOM;
3165 			sprintf(buf, "Mesh Network Path Selection Protocol ID: "
3166 				"0x%02X", cfg[0]);
3167 			iwe.u.data.length = strlen(buf);
3168 			current_ev = iwe_stream_add_point_check(info,
3169 								current_ev,
3170 								end_buf,
3171 								&iwe, buf);
3172 			if (IS_ERR(current_ev))
3173 				goto unlock;
3174 			sprintf(buf, "Path Selection Metric ID: 0x%02X",
3175 				cfg[1]);
3176 			iwe.u.data.length = strlen(buf);
3177 			current_ev = iwe_stream_add_point_check(info,
3178 								current_ev,
3179 								end_buf,
3180 								&iwe, buf);
3181 			if (IS_ERR(current_ev))
3182 				goto unlock;
3183 			sprintf(buf, "Congestion Control Mode ID: 0x%02X",
3184 				cfg[2]);
3185 			iwe.u.data.length = strlen(buf);
3186 			current_ev = iwe_stream_add_point_check(info,
3187 								current_ev,
3188 								end_buf,
3189 								&iwe, buf);
3190 			if (IS_ERR(current_ev))
3191 				goto unlock;
3192 			sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
3193 			iwe.u.data.length = strlen(buf);
3194 			current_ev = iwe_stream_add_point_check(info,
3195 								current_ev,
3196 								end_buf,
3197 								&iwe, buf);
3198 			if (IS_ERR(current_ev))
3199 				goto unlock;
3200 			sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
3201 			iwe.u.data.length = strlen(buf);
3202 			current_ev = iwe_stream_add_point_check(info,
3203 								current_ev,
3204 								end_buf,
3205 								&iwe, buf);
3206 			if (IS_ERR(current_ev))
3207 				goto unlock;
3208 			sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
3209 			iwe.u.data.length = strlen(buf);
3210 			current_ev = iwe_stream_add_point_check(info,
3211 								current_ev,
3212 								end_buf,
3213 								&iwe, buf);
3214 			if (IS_ERR(current_ev))
3215 				goto unlock;
3216 			sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
3217 			iwe.u.data.length = strlen(buf);
3218 			current_ev = iwe_stream_add_point_check(info,
3219 								current_ev,
3220 								end_buf,
3221 								&iwe, buf);
3222 			if (IS_ERR(current_ev))
3223 				goto unlock;
3224 			break;
3225 		case WLAN_EID_SUPP_RATES:
3226 		case WLAN_EID_EXT_SUPP_RATES:
3227 			/* display all supported rates in readable format */
3228 			p = current_ev + iwe_stream_lcp_len(info);
3229 
3230 			memset(&iwe, 0, sizeof(iwe));
3231 			iwe.cmd = SIOCGIWRATE;
3232 			/* Those two flags are ignored... */
3233 			iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
3234 
3235 			for (i = 0; i < ie[1]; i++) {
3236 				iwe.u.bitrate.value =
3237 					((ie[i + 2] & 0x7f) * 500000);
3238 				tmp = p;
3239 				p = iwe_stream_add_value(info, current_ev, p,
3240 							 end_buf, &iwe,
3241 							 IW_EV_PARAM_LEN);
3242 				if (p == tmp) {
3243 					current_ev = ERR_PTR(-E2BIG);
3244 					goto unlock;
3245 				}
3246 			}
3247 			current_ev = p;
3248 			break;
3249 		}
3250 		rem -= ie[1] + 2;
3251 		ie += ie[1] + 2;
3252 	}
3253 
3254 	if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
3255 	    ismesh) {
3256 		memset(&iwe, 0, sizeof(iwe));
3257 		iwe.cmd = SIOCGIWMODE;
3258 		if (ismesh)
3259 			iwe.u.mode = IW_MODE_MESH;
3260 		else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
3261 			iwe.u.mode = IW_MODE_MASTER;
3262 		else
3263 			iwe.u.mode = IW_MODE_ADHOC;
3264 		current_ev = iwe_stream_add_event_check(info, current_ev,
3265 							end_buf, &iwe,
3266 							IW_EV_UINT_LEN);
3267 		if (IS_ERR(current_ev))
3268 			goto unlock;
3269 	}
3270 
3271 	memset(&iwe, 0, sizeof(iwe));
3272 	iwe.cmd = IWEVCUSTOM;
3273 	sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
3274 	iwe.u.data.length = strlen(buf);
3275 	current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
3276 						&iwe, buf);
3277 	if (IS_ERR(current_ev))
3278 		goto unlock;
3279 	memset(&iwe, 0, sizeof(iwe));
3280 	iwe.cmd = IWEVCUSTOM;
3281 	sprintf(buf, " Last beacon: %ums ago",
3282 		elapsed_jiffies_msecs(bss->ts));
3283 	iwe.u.data.length = strlen(buf);
3284 	current_ev = iwe_stream_add_point_check(info, current_ev,
3285 						end_buf, &iwe, buf);
3286 	if (IS_ERR(current_ev))
3287 		goto unlock;
3288 
3289 	current_ev = ieee80211_scan_add_ies(info, ies, current_ev, end_buf);
3290 
3291  unlock:
3292 	rcu_read_unlock();
3293 	return current_ev;
3294 }
3295 
3296 
ieee80211_scan_results(struct cfg80211_registered_device * rdev,struct iw_request_info * info,char * buf,size_t len)3297 static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
3298 				  struct iw_request_info *info,
3299 				  char *buf, size_t len)
3300 {
3301 	char *current_ev = buf;
3302 	char *end_buf = buf + len;
3303 	struct cfg80211_internal_bss *bss;
3304 	int err = 0;
3305 
3306 	spin_lock_bh(&rdev->bss_lock);
3307 	cfg80211_bss_expire(rdev);
3308 
3309 	list_for_each_entry(bss, &rdev->bss_list, list) {
3310 		if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
3311 			err = -E2BIG;
3312 			break;
3313 		}
3314 		current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
3315 					   current_ev, end_buf);
3316 		if (IS_ERR(current_ev)) {
3317 			err = PTR_ERR(current_ev);
3318 			break;
3319 		}
3320 	}
3321 	spin_unlock_bh(&rdev->bss_lock);
3322 
3323 	if (err)
3324 		return err;
3325 	return current_ev - buf;
3326 }
3327 
3328 
cfg80211_wext_giwscan(struct net_device * dev,struct iw_request_info * info,struct iw_point * data,char * extra)3329 int cfg80211_wext_giwscan(struct net_device *dev,
3330 			  struct iw_request_info *info,
3331 			  struct iw_point *data, char *extra)
3332 {
3333 	struct cfg80211_registered_device *rdev;
3334 	int res;
3335 
3336 	if (!netif_running(dev))
3337 		return -ENETDOWN;
3338 
3339 	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
3340 
3341 	if (IS_ERR(rdev))
3342 		return PTR_ERR(rdev);
3343 
3344 	if (rdev->scan_req || rdev->scan_msg)
3345 		return -EAGAIN;
3346 
3347 	res = ieee80211_scan_results(rdev, info, extra, data->length);
3348 	data->length = 0;
3349 	if (res >= 0) {
3350 		data->length = res;
3351 		res = 0;
3352 	}
3353 
3354 	return res;
3355 }
3356 EXPORT_WEXT_HANDLER(cfg80211_wext_giwscan);
3357 #endif
3358