xref: /openbmc/linux/net/mac80211/key.c (revision 609e478b)
1 /*
2  * Copyright 2002-2005, Instant802 Networks, Inc.
3  * Copyright 2005-2006, Devicescape Software, Inc.
4  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
5  * Copyright 2007-2008	Johannes Berg <johannes@sipsolutions.net>
6  * Copyright 2013-2014  Intel Mobile Communications GmbH
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 
13 #include <linux/if_ether.h>
14 #include <linux/etherdevice.h>
15 #include <linux/list.h>
16 #include <linux/rcupdate.h>
17 #include <linux/rtnetlink.h>
18 #include <linux/slab.h>
19 #include <linux/export.h>
20 #include <net/mac80211.h>
21 #include <asm/unaligned.h>
22 #include "ieee80211_i.h"
23 #include "driver-ops.h"
24 #include "debugfs_key.h"
25 #include "aes_ccm.h"
26 #include "aes_cmac.h"
27 
28 
29 /**
30  * DOC: Key handling basics
31  *
32  * Key handling in mac80211 is done based on per-interface (sub_if_data)
33  * keys and per-station keys. Since each station belongs to an interface,
34  * each station key also belongs to that interface.
35  *
36  * Hardware acceleration is done on a best-effort basis for algorithms
37  * that are implemented in software,  for each key the hardware is asked
38  * to enable that key for offloading but if it cannot do that the key is
39  * simply kept for software encryption (unless it is for an algorithm
40  * that isn't implemented in software).
41  * There is currently no way of knowing whether a key is handled in SW
42  * or HW except by looking into debugfs.
43  *
44  * All key management is internally protected by a mutex. Within all
45  * other parts of mac80211, key references are, just as STA structure
46  * references, protected by RCU. Note, however, that some things are
47  * unprotected, namely the key->sta dereferences within the hardware
48  * acceleration functions. This means that sta_info_destroy() must
49  * remove the key which waits for an RCU grace period.
50  */
51 
52 static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
53 
54 static void assert_key_lock(struct ieee80211_local *local)
55 {
56 	lockdep_assert_held(&local->key_mtx);
57 }
58 
59 static void increment_tailroom_need_count(struct ieee80211_sub_if_data *sdata)
60 {
61 	/*
62 	 * When this count is zero, SKB resizing for allocating tailroom
63 	 * for IV or MMIC is skipped. But, this check has created two race
64 	 * cases in xmit path while transiting from zero count to one:
65 	 *
66 	 * 1. SKB resize was skipped because no key was added but just before
67 	 * the xmit key is added and SW encryption kicks off.
68 	 *
69 	 * 2. SKB resize was skipped because all the keys were hw planted but
70 	 * just before xmit one of the key is deleted and SW encryption kicks
71 	 * off.
72 	 *
73 	 * In both the above case SW encryption will find not enough space for
74 	 * tailroom and exits with WARN_ON. (See WARN_ONs at wpa.c)
75 	 *
76 	 * Solution has been explained at
77 	 * http://mid.gmane.org/1308590980.4322.19.camel@jlt3.sipsolutions.net
78 	 */
79 
80 	if (!sdata->crypto_tx_tailroom_needed_cnt++) {
81 		/*
82 		 * Flush all XMIT packets currently using HW encryption or no
83 		 * encryption at all if the count transition is from 0 -> 1.
84 		 */
85 		synchronize_net();
86 	}
87 }
88 
89 static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
90 {
91 	struct ieee80211_sub_if_data *sdata;
92 	struct sta_info *sta;
93 	int ret;
94 
95 	might_sleep();
96 
97 	if (key->flags & KEY_FLAG_TAINTED)
98 		return -EINVAL;
99 
100 	if (!key->local->ops->set_key)
101 		goto out_unsupported;
102 
103 	assert_key_lock(key->local);
104 
105 	sta = key->sta;
106 
107 	/*
108 	 * If this is a per-STA GTK, check if it
109 	 * is supported; if not, return.
110 	 */
111 	if (sta && !(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE) &&
112 	    !(key->local->hw.flags & IEEE80211_HW_SUPPORTS_PER_STA_GTK))
113 		goto out_unsupported;
114 
115 	if (sta && !sta->uploaded)
116 		goto out_unsupported;
117 
118 	sdata = key->sdata;
119 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
120 		/*
121 		 * The driver doesn't know anything about VLAN interfaces.
122 		 * Hence, don't send GTKs for VLAN interfaces to the driver.
123 		 */
124 		if (!(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE))
125 			goto out_unsupported;
126 	}
127 
128 	ret = drv_set_key(key->local, SET_KEY, sdata,
129 			  sta ? &sta->sta : NULL, &key->conf);
130 
131 	if (!ret) {
132 		key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
133 
134 		if (!(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC))
135 			sdata->crypto_tx_tailroom_needed_cnt--;
136 
137 		WARN_ON((key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
138 			(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV));
139 
140 		return 0;
141 	}
142 
143 	if (ret != -ENOSPC && ret != -EOPNOTSUPP)
144 		sdata_err(sdata,
145 			  "failed to set key (%d, %pM) to hardware (%d)\n",
146 			  key->conf.keyidx,
147 			  sta ? sta->sta.addr : bcast_addr, ret);
148 
149  out_unsupported:
150 	switch (key->conf.cipher) {
151 	case WLAN_CIPHER_SUITE_WEP40:
152 	case WLAN_CIPHER_SUITE_WEP104:
153 	case WLAN_CIPHER_SUITE_TKIP:
154 	case WLAN_CIPHER_SUITE_CCMP:
155 	case WLAN_CIPHER_SUITE_AES_CMAC:
156 		/* all of these we can do in software */
157 		return 0;
158 	default:
159 		return -EINVAL;
160 	}
161 }
162 
163 static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
164 {
165 	struct ieee80211_sub_if_data *sdata;
166 	struct sta_info *sta;
167 	int ret;
168 
169 	might_sleep();
170 
171 	if (!key || !key->local->ops->set_key)
172 		return;
173 
174 	assert_key_lock(key->local);
175 
176 	if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
177 		return;
178 
179 	sta = key->sta;
180 	sdata = key->sdata;
181 
182 	if (!(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC))
183 		increment_tailroom_need_count(sdata);
184 
185 	ret = drv_set_key(key->local, DISABLE_KEY, sdata,
186 			  sta ? &sta->sta : NULL, &key->conf);
187 
188 	if (ret)
189 		sdata_err(sdata,
190 			  "failed to remove key (%d, %pM) from hardware (%d)\n",
191 			  key->conf.keyidx,
192 			  sta ? sta->sta.addr : bcast_addr, ret);
193 
194 	key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
195 }
196 
197 static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
198 					int idx, bool uni, bool multi)
199 {
200 	struct ieee80211_key *key = NULL;
201 
202 	assert_key_lock(sdata->local);
203 
204 	if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
205 		key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
206 
207 	if (uni) {
208 		rcu_assign_pointer(sdata->default_unicast_key, key);
209 		drv_set_default_unicast_key(sdata->local, sdata, idx);
210 	}
211 
212 	if (multi)
213 		rcu_assign_pointer(sdata->default_multicast_key, key);
214 
215 	ieee80211_debugfs_key_update_default(sdata);
216 }
217 
218 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
219 			       bool uni, bool multi)
220 {
221 	mutex_lock(&sdata->local->key_mtx);
222 	__ieee80211_set_default_key(sdata, idx, uni, multi);
223 	mutex_unlock(&sdata->local->key_mtx);
224 }
225 
226 static void
227 __ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
228 {
229 	struct ieee80211_key *key = NULL;
230 
231 	assert_key_lock(sdata->local);
232 
233 	if (idx >= NUM_DEFAULT_KEYS &&
234 	    idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
235 		key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
236 
237 	rcu_assign_pointer(sdata->default_mgmt_key, key);
238 
239 	ieee80211_debugfs_key_update_default(sdata);
240 }
241 
242 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
243 				    int idx)
244 {
245 	mutex_lock(&sdata->local->key_mtx);
246 	__ieee80211_set_default_mgmt_key(sdata, idx);
247 	mutex_unlock(&sdata->local->key_mtx);
248 }
249 
250 
251 static void ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
252 				  struct sta_info *sta,
253 				  bool pairwise,
254 				  struct ieee80211_key *old,
255 				  struct ieee80211_key *new)
256 {
257 	int idx;
258 	bool defunikey, defmultikey, defmgmtkey;
259 
260 	/* caller must provide at least one old/new */
261 	if (WARN_ON(!new && !old))
262 		return;
263 
264 	if (new)
265 		list_add_tail(&new->list, &sdata->key_list);
266 
267 	WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
268 
269 	if (old)
270 		idx = old->conf.keyidx;
271 	else
272 		idx = new->conf.keyidx;
273 
274 	if (sta) {
275 		if (pairwise) {
276 			rcu_assign_pointer(sta->ptk[idx], new);
277 			sta->ptk_idx = idx;
278 		} else {
279 			rcu_assign_pointer(sta->gtk[idx], new);
280 			sta->gtk_idx = idx;
281 		}
282 	} else {
283 		defunikey = old &&
284 			old == key_mtx_dereference(sdata->local,
285 						sdata->default_unicast_key);
286 		defmultikey = old &&
287 			old == key_mtx_dereference(sdata->local,
288 						sdata->default_multicast_key);
289 		defmgmtkey = old &&
290 			old == key_mtx_dereference(sdata->local,
291 						sdata->default_mgmt_key);
292 
293 		if (defunikey && !new)
294 			__ieee80211_set_default_key(sdata, -1, true, false);
295 		if (defmultikey && !new)
296 			__ieee80211_set_default_key(sdata, -1, false, true);
297 		if (defmgmtkey && !new)
298 			__ieee80211_set_default_mgmt_key(sdata, -1);
299 
300 		rcu_assign_pointer(sdata->keys[idx], new);
301 		if (defunikey && new)
302 			__ieee80211_set_default_key(sdata, new->conf.keyidx,
303 						    true, false);
304 		if (defmultikey && new)
305 			__ieee80211_set_default_key(sdata, new->conf.keyidx,
306 						    false, true);
307 		if (defmgmtkey && new)
308 			__ieee80211_set_default_mgmt_key(sdata,
309 							 new->conf.keyidx);
310 	}
311 
312 	if (old)
313 		list_del(&old->list);
314 }
315 
316 struct ieee80211_key *
317 ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
318 		    const u8 *key_data,
319 		    size_t seq_len, const u8 *seq,
320 		    const struct ieee80211_cipher_scheme *cs)
321 {
322 	struct ieee80211_key *key;
323 	int i, j, err;
324 
325 	if (WARN_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS))
326 		return ERR_PTR(-EINVAL);
327 
328 	key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
329 	if (!key)
330 		return ERR_PTR(-ENOMEM);
331 
332 	/*
333 	 * Default to software encryption; we'll later upload the
334 	 * key to the hardware if possible.
335 	 */
336 	key->conf.flags = 0;
337 	key->flags = 0;
338 
339 	key->conf.cipher = cipher;
340 	key->conf.keyidx = idx;
341 	key->conf.keylen = key_len;
342 	switch (cipher) {
343 	case WLAN_CIPHER_SUITE_WEP40:
344 	case WLAN_CIPHER_SUITE_WEP104:
345 		key->conf.iv_len = IEEE80211_WEP_IV_LEN;
346 		key->conf.icv_len = IEEE80211_WEP_ICV_LEN;
347 		break;
348 	case WLAN_CIPHER_SUITE_TKIP:
349 		key->conf.iv_len = IEEE80211_TKIP_IV_LEN;
350 		key->conf.icv_len = IEEE80211_TKIP_ICV_LEN;
351 		if (seq) {
352 			for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
353 				key->u.tkip.rx[i].iv32 =
354 					get_unaligned_le32(&seq[2]);
355 				key->u.tkip.rx[i].iv16 =
356 					get_unaligned_le16(seq);
357 			}
358 		}
359 		spin_lock_init(&key->u.tkip.txlock);
360 		break;
361 	case WLAN_CIPHER_SUITE_CCMP:
362 		key->conf.iv_len = IEEE80211_CCMP_HDR_LEN;
363 		key->conf.icv_len = IEEE80211_CCMP_MIC_LEN;
364 		if (seq) {
365 			for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
366 				for (j = 0; j < IEEE80211_CCMP_PN_LEN; j++)
367 					key->u.ccmp.rx_pn[i][j] =
368 						seq[IEEE80211_CCMP_PN_LEN - j - 1];
369 		}
370 		/*
371 		 * Initialize AES key state here as an optimization so that
372 		 * it does not need to be initialized for every packet.
373 		 */
374 		key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data);
375 		if (IS_ERR(key->u.ccmp.tfm)) {
376 			err = PTR_ERR(key->u.ccmp.tfm);
377 			kfree(key);
378 			return ERR_PTR(err);
379 		}
380 		break;
381 	case WLAN_CIPHER_SUITE_AES_CMAC:
382 		key->conf.iv_len = 0;
383 		key->conf.icv_len = sizeof(struct ieee80211_mmie);
384 		if (seq)
385 			for (j = 0; j < IEEE80211_CMAC_PN_LEN; j++)
386 				key->u.aes_cmac.rx_pn[j] =
387 					seq[IEEE80211_CMAC_PN_LEN - j - 1];
388 		/*
389 		 * Initialize AES key state here as an optimization so that
390 		 * it does not need to be initialized for every packet.
391 		 */
392 		key->u.aes_cmac.tfm =
393 			ieee80211_aes_cmac_key_setup(key_data);
394 		if (IS_ERR(key->u.aes_cmac.tfm)) {
395 			err = PTR_ERR(key->u.aes_cmac.tfm);
396 			kfree(key);
397 			return ERR_PTR(err);
398 		}
399 		break;
400 	default:
401 		if (cs) {
402 			size_t len = (seq_len > MAX_PN_LEN) ?
403 						MAX_PN_LEN : seq_len;
404 
405 			key->conf.iv_len = cs->hdr_len;
406 			key->conf.icv_len = cs->mic_len;
407 			for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
408 				for (j = 0; j < len; j++)
409 					key->u.gen.rx_pn[i][j] =
410 							seq[len - j - 1];
411 		}
412 	}
413 	memcpy(key->conf.key, key_data, key_len);
414 	INIT_LIST_HEAD(&key->list);
415 
416 	return key;
417 }
418 
419 static void ieee80211_key_free_common(struct ieee80211_key *key)
420 {
421 	if (key->conf.cipher == WLAN_CIPHER_SUITE_CCMP)
422 		ieee80211_aes_key_free(key->u.ccmp.tfm);
423 	if (key->conf.cipher == WLAN_CIPHER_SUITE_AES_CMAC)
424 		ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
425 	kzfree(key);
426 }
427 
428 static void __ieee80211_key_destroy(struct ieee80211_key *key,
429 				    bool delay_tailroom)
430 {
431 	if (key->local)
432 		ieee80211_key_disable_hw_accel(key);
433 
434 	if (key->local) {
435 		struct ieee80211_sub_if_data *sdata = key->sdata;
436 
437 		ieee80211_debugfs_key_remove(key);
438 
439 		if (delay_tailroom) {
440 			/* see ieee80211_delayed_tailroom_dec */
441 			sdata->crypto_tx_tailroom_pending_dec++;
442 			schedule_delayed_work(&sdata->dec_tailroom_needed_wk,
443 					      HZ/2);
444 		} else {
445 			sdata->crypto_tx_tailroom_needed_cnt--;
446 		}
447 	}
448 
449 	ieee80211_key_free_common(key);
450 }
451 
452 static void ieee80211_key_destroy(struct ieee80211_key *key,
453 				  bool delay_tailroom)
454 {
455 	if (!key)
456 		return;
457 
458 	/*
459 	 * Synchronize so the TX path can no longer be using
460 	 * this key before we free/remove it.
461 	 */
462 	synchronize_net();
463 
464 	__ieee80211_key_destroy(key, delay_tailroom);
465 }
466 
467 void ieee80211_key_free_unused(struct ieee80211_key *key)
468 {
469 	WARN_ON(key->sdata || key->local);
470 	ieee80211_key_free_common(key);
471 }
472 
473 int ieee80211_key_link(struct ieee80211_key *key,
474 		       struct ieee80211_sub_if_data *sdata,
475 		       struct sta_info *sta)
476 {
477 	struct ieee80211_local *local = sdata->local;
478 	struct ieee80211_key *old_key;
479 	int idx, ret;
480 	bool pairwise;
481 
482 	pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
483 	idx = key->conf.keyidx;
484 	key->local = sdata->local;
485 	key->sdata = sdata;
486 	key->sta = sta;
487 
488 	mutex_lock(&sdata->local->key_mtx);
489 
490 	if (sta && pairwise)
491 		old_key = key_mtx_dereference(sdata->local, sta->ptk[idx]);
492 	else if (sta)
493 		old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
494 	else
495 		old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
496 
497 	increment_tailroom_need_count(sdata);
498 
499 	ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
500 	ieee80211_key_destroy(old_key, true);
501 
502 	ieee80211_debugfs_key_add(key);
503 
504 	if (!local->wowlan) {
505 		ret = ieee80211_key_enable_hw_accel(key);
506 		if (ret)
507 			ieee80211_key_free(key, true);
508 	} else {
509 		ret = 0;
510 	}
511 
512 	mutex_unlock(&sdata->local->key_mtx);
513 
514 	return ret;
515 }
516 
517 void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom)
518 {
519 	if (!key)
520 		return;
521 
522 	/*
523 	 * Replace key with nothingness if it was ever used.
524 	 */
525 	if (key->sdata)
526 		ieee80211_key_replace(key->sdata, key->sta,
527 				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
528 				key, NULL);
529 	ieee80211_key_destroy(key, delay_tailroom);
530 }
531 
532 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
533 {
534 	struct ieee80211_key *key;
535 
536 	ASSERT_RTNL();
537 
538 	if (WARN_ON(!ieee80211_sdata_running(sdata)))
539 		return;
540 
541 	mutex_lock(&sdata->local->key_mtx);
542 
543 	sdata->crypto_tx_tailroom_needed_cnt = 0;
544 
545 	list_for_each_entry(key, &sdata->key_list, list) {
546 		increment_tailroom_need_count(sdata);
547 		ieee80211_key_enable_hw_accel(key);
548 	}
549 
550 	mutex_unlock(&sdata->local->key_mtx);
551 }
552 
553 void ieee80211_iter_keys(struct ieee80211_hw *hw,
554 			 struct ieee80211_vif *vif,
555 			 void (*iter)(struct ieee80211_hw *hw,
556 				      struct ieee80211_vif *vif,
557 				      struct ieee80211_sta *sta,
558 				      struct ieee80211_key_conf *key,
559 				      void *data),
560 			 void *iter_data)
561 {
562 	struct ieee80211_local *local = hw_to_local(hw);
563 	struct ieee80211_key *key, *tmp;
564 	struct ieee80211_sub_if_data *sdata;
565 
566 	ASSERT_RTNL();
567 
568 	mutex_lock(&local->key_mtx);
569 	if (vif) {
570 		sdata = vif_to_sdata(vif);
571 		list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
572 			iter(hw, &sdata->vif,
573 			     key->sta ? &key->sta->sta : NULL,
574 			     &key->conf, iter_data);
575 	} else {
576 		list_for_each_entry(sdata, &local->interfaces, list)
577 			list_for_each_entry_safe(key, tmp,
578 						 &sdata->key_list, list)
579 				iter(hw, &sdata->vif,
580 				     key->sta ? &key->sta->sta : NULL,
581 				     &key->conf, iter_data);
582 	}
583 	mutex_unlock(&local->key_mtx);
584 }
585 EXPORT_SYMBOL(ieee80211_iter_keys);
586 
587 static void ieee80211_free_keys_iface(struct ieee80211_sub_if_data *sdata,
588 				      struct list_head *keys)
589 {
590 	struct ieee80211_key *key, *tmp;
591 
592 	sdata->crypto_tx_tailroom_needed_cnt -=
593 		sdata->crypto_tx_tailroom_pending_dec;
594 	sdata->crypto_tx_tailroom_pending_dec = 0;
595 
596 	ieee80211_debugfs_key_remove_mgmt_default(sdata);
597 
598 	list_for_each_entry_safe(key, tmp, &sdata->key_list, list) {
599 		ieee80211_key_replace(key->sdata, key->sta,
600 				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
601 				key, NULL);
602 		list_add_tail(&key->list, keys);
603 	}
604 
605 	ieee80211_debugfs_key_update_default(sdata);
606 }
607 
608 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata,
609 			 bool force_synchronize)
610 {
611 	struct ieee80211_local *local = sdata->local;
612 	struct ieee80211_sub_if_data *vlan;
613 	struct ieee80211_key *key, *tmp;
614 	LIST_HEAD(keys);
615 
616 	cancel_delayed_work_sync(&sdata->dec_tailroom_needed_wk);
617 
618 	mutex_lock(&local->key_mtx);
619 
620 	ieee80211_free_keys_iface(sdata, &keys);
621 
622 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
623 		list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
624 			ieee80211_free_keys_iface(vlan, &keys);
625 	}
626 
627 	if (!list_empty(&keys) || force_synchronize)
628 		synchronize_net();
629 	list_for_each_entry_safe(key, tmp, &keys, list)
630 		__ieee80211_key_destroy(key, false);
631 
632 	WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
633 		     sdata->crypto_tx_tailroom_pending_dec);
634 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
635 		list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
636 			WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
637 				     vlan->crypto_tx_tailroom_pending_dec);
638 	}
639 
640 	mutex_unlock(&local->key_mtx);
641 }
642 
643 void ieee80211_free_sta_keys(struct ieee80211_local *local,
644 			     struct sta_info *sta)
645 {
646 	struct ieee80211_key *key;
647 	int i;
648 
649 	mutex_lock(&local->key_mtx);
650 	for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
651 		key = key_mtx_dereference(local, sta->gtk[i]);
652 		if (!key)
653 			continue;
654 		ieee80211_key_replace(key->sdata, key->sta,
655 				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
656 				key, NULL);
657 		__ieee80211_key_destroy(key, true);
658 	}
659 
660 	for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
661 		key = key_mtx_dereference(local, sta->ptk[i]);
662 		if (!key)
663 			continue;
664 		ieee80211_key_replace(key->sdata, key->sta,
665 				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
666 				key, NULL);
667 		__ieee80211_key_destroy(key, true);
668 	}
669 
670 	mutex_unlock(&local->key_mtx);
671 }
672 
673 void ieee80211_delayed_tailroom_dec(struct work_struct *wk)
674 {
675 	struct ieee80211_sub_if_data *sdata;
676 
677 	sdata = container_of(wk, struct ieee80211_sub_if_data,
678 			     dec_tailroom_needed_wk.work);
679 
680 	/*
681 	 * The reason for the delayed tailroom needed decrementing is to
682 	 * make roaming faster: during roaming, all keys are first deleted
683 	 * and then new keys are installed. The first new key causes the
684 	 * crypto_tx_tailroom_needed_cnt to go from 0 to 1, which invokes
685 	 * the cost of synchronize_net() (which can be slow). Avoid this
686 	 * by deferring the crypto_tx_tailroom_needed_cnt decrementing on
687 	 * key removal for a while, so if we roam the value is larger than
688 	 * zero and no 0->1 transition happens.
689 	 *
690 	 * The cost is that if the AP switching was from an AP with keys
691 	 * to one without, we still allocate tailroom while it would no
692 	 * longer be needed. However, in the typical (fast) roaming case
693 	 * within an ESS this usually won't happen.
694 	 */
695 
696 	mutex_lock(&sdata->local->key_mtx);
697 	sdata->crypto_tx_tailroom_needed_cnt -=
698 		sdata->crypto_tx_tailroom_pending_dec;
699 	sdata->crypto_tx_tailroom_pending_dec = 0;
700 	mutex_unlock(&sdata->local->key_mtx);
701 }
702 
703 void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid,
704 				const u8 *replay_ctr, gfp_t gfp)
705 {
706 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
707 
708 	trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr);
709 
710 	cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
711 }
712 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);
713 
714 void ieee80211_get_key_tx_seq(struct ieee80211_key_conf *keyconf,
715 			      struct ieee80211_key_seq *seq)
716 {
717 	struct ieee80211_key *key;
718 	u64 pn64;
719 
720 	if (WARN_ON(!(keyconf->flags & IEEE80211_KEY_FLAG_GENERATE_IV)))
721 		return;
722 
723 	key = container_of(keyconf, struct ieee80211_key, conf);
724 
725 	switch (key->conf.cipher) {
726 	case WLAN_CIPHER_SUITE_TKIP:
727 		seq->tkip.iv32 = key->u.tkip.tx.iv32;
728 		seq->tkip.iv16 = key->u.tkip.tx.iv16;
729 		break;
730 	case WLAN_CIPHER_SUITE_CCMP:
731 		pn64 = atomic64_read(&key->u.ccmp.tx_pn);
732 		seq->ccmp.pn[5] = pn64;
733 		seq->ccmp.pn[4] = pn64 >> 8;
734 		seq->ccmp.pn[3] = pn64 >> 16;
735 		seq->ccmp.pn[2] = pn64 >> 24;
736 		seq->ccmp.pn[1] = pn64 >> 32;
737 		seq->ccmp.pn[0] = pn64 >> 40;
738 		break;
739 	case WLAN_CIPHER_SUITE_AES_CMAC:
740 		pn64 = atomic64_read(&key->u.aes_cmac.tx_pn);
741 		seq->ccmp.pn[5] = pn64;
742 		seq->ccmp.pn[4] = pn64 >> 8;
743 		seq->ccmp.pn[3] = pn64 >> 16;
744 		seq->ccmp.pn[2] = pn64 >> 24;
745 		seq->ccmp.pn[1] = pn64 >> 32;
746 		seq->ccmp.pn[0] = pn64 >> 40;
747 		break;
748 	default:
749 		WARN_ON(1);
750 	}
751 }
752 EXPORT_SYMBOL(ieee80211_get_key_tx_seq);
753 
754 void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
755 			      int tid, struct ieee80211_key_seq *seq)
756 {
757 	struct ieee80211_key *key;
758 	const u8 *pn;
759 
760 	key = container_of(keyconf, struct ieee80211_key, conf);
761 
762 	switch (key->conf.cipher) {
763 	case WLAN_CIPHER_SUITE_TKIP:
764 		if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
765 			return;
766 		seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
767 		seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
768 		break;
769 	case WLAN_CIPHER_SUITE_CCMP:
770 		if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
771 			return;
772 		if (tid < 0)
773 			pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
774 		else
775 			pn = key->u.ccmp.rx_pn[tid];
776 		memcpy(seq->ccmp.pn, pn, IEEE80211_CCMP_PN_LEN);
777 		break;
778 	case WLAN_CIPHER_SUITE_AES_CMAC:
779 		if (WARN_ON(tid != 0))
780 			return;
781 		pn = key->u.aes_cmac.rx_pn;
782 		memcpy(seq->aes_cmac.pn, pn, IEEE80211_CMAC_PN_LEN);
783 		break;
784 	}
785 }
786 EXPORT_SYMBOL(ieee80211_get_key_rx_seq);
787 
788 void ieee80211_set_key_tx_seq(struct ieee80211_key_conf *keyconf,
789 			      struct ieee80211_key_seq *seq)
790 {
791 	struct ieee80211_key *key;
792 	u64 pn64;
793 
794 	key = container_of(keyconf, struct ieee80211_key, conf);
795 
796 	switch (key->conf.cipher) {
797 	case WLAN_CIPHER_SUITE_TKIP:
798 		key->u.tkip.tx.iv32 = seq->tkip.iv32;
799 		key->u.tkip.tx.iv16 = seq->tkip.iv16;
800 		break;
801 	case WLAN_CIPHER_SUITE_CCMP:
802 		pn64 = (u64)seq->ccmp.pn[5] |
803 		       ((u64)seq->ccmp.pn[4] << 8) |
804 		       ((u64)seq->ccmp.pn[3] << 16) |
805 		       ((u64)seq->ccmp.pn[2] << 24) |
806 		       ((u64)seq->ccmp.pn[1] << 32) |
807 		       ((u64)seq->ccmp.pn[0] << 40);
808 		atomic64_set(&key->u.ccmp.tx_pn, pn64);
809 		break;
810 	case WLAN_CIPHER_SUITE_AES_CMAC:
811 		pn64 = (u64)seq->aes_cmac.pn[5] |
812 		       ((u64)seq->aes_cmac.pn[4] << 8) |
813 		       ((u64)seq->aes_cmac.pn[3] << 16) |
814 		       ((u64)seq->aes_cmac.pn[2] << 24) |
815 		       ((u64)seq->aes_cmac.pn[1] << 32) |
816 		       ((u64)seq->aes_cmac.pn[0] << 40);
817 		atomic64_set(&key->u.aes_cmac.tx_pn, pn64);
818 		break;
819 	default:
820 		WARN_ON(1);
821 		break;
822 	}
823 }
824 EXPORT_SYMBOL_GPL(ieee80211_set_key_tx_seq);
825 
826 void ieee80211_set_key_rx_seq(struct ieee80211_key_conf *keyconf,
827 			      int tid, struct ieee80211_key_seq *seq)
828 {
829 	struct ieee80211_key *key;
830 	u8 *pn;
831 
832 	key = container_of(keyconf, struct ieee80211_key, conf);
833 
834 	switch (key->conf.cipher) {
835 	case WLAN_CIPHER_SUITE_TKIP:
836 		if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
837 			return;
838 		key->u.tkip.rx[tid].iv32 = seq->tkip.iv32;
839 		key->u.tkip.rx[tid].iv16 = seq->tkip.iv16;
840 		break;
841 	case WLAN_CIPHER_SUITE_CCMP:
842 		if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
843 			return;
844 		if (tid < 0)
845 			pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
846 		else
847 			pn = key->u.ccmp.rx_pn[tid];
848 		memcpy(pn, seq->ccmp.pn, IEEE80211_CCMP_PN_LEN);
849 		break;
850 	case WLAN_CIPHER_SUITE_AES_CMAC:
851 		if (WARN_ON(tid != 0))
852 			return;
853 		pn = key->u.aes_cmac.rx_pn;
854 		memcpy(pn, seq->aes_cmac.pn, IEEE80211_CMAC_PN_LEN);
855 		break;
856 	default:
857 		WARN_ON(1);
858 		break;
859 	}
860 }
861 EXPORT_SYMBOL_GPL(ieee80211_set_key_rx_seq);
862 
863 void ieee80211_remove_key(struct ieee80211_key_conf *keyconf)
864 {
865 	struct ieee80211_key *key;
866 
867 	key = container_of(keyconf, struct ieee80211_key, conf);
868 
869 	assert_key_lock(key->local);
870 
871 	/*
872 	 * if key was uploaded, we assume the driver will/has remove(d)
873 	 * it, so adjust bookkeeping accordingly
874 	 */
875 	if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
876 		key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
877 
878 		if (!(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC))
879 			increment_tailroom_need_count(key->sdata);
880 	}
881 
882 	ieee80211_key_free(key, false);
883 }
884 EXPORT_SYMBOL_GPL(ieee80211_remove_key);
885 
886 struct ieee80211_key_conf *
887 ieee80211_gtk_rekey_add(struct ieee80211_vif *vif,
888 			struct ieee80211_key_conf *keyconf)
889 {
890 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
891 	struct ieee80211_local *local = sdata->local;
892 	struct ieee80211_key *key;
893 	int err;
894 
895 	if (WARN_ON(!local->wowlan))
896 		return ERR_PTR(-EINVAL);
897 
898 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
899 		return ERR_PTR(-EINVAL);
900 
901 	key = ieee80211_key_alloc(keyconf->cipher, keyconf->keyidx,
902 				  keyconf->keylen, keyconf->key,
903 				  0, NULL, NULL);
904 	if (IS_ERR(key))
905 		return ERR_CAST(key);
906 
907 	if (sdata->u.mgd.mfp != IEEE80211_MFP_DISABLED)
908 		key->conf.flags |= IEEE80211_KEY_FLAG_RX_MGMT;
909 
910 	err = ieee80211_key_link(key, sdata, NULL);
911 	if (err)
912 		return ERR_PTR(err);
913 
914 	return &key->conf;
915 }
916 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_add);
917