xref: /openbmc/linux/net/mac80211/key.c (revision 8684014d)
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 		/* If we get here, it's during resume and the key is
99 		 * tainted so shouldn't be used/programmed any more.
100 		 * However, its flags may still indicate that it was
101 		 * programmed into the device (since we're in resume)
102 		 * so clear that flag now to avoid trying to remove
103 		 * it again later.
104 		 */
105 		key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
106 		return -EINVAL;
107 	}
108 
109 	if (!key->local->ops->set_key)
110 		goto out_unsupported;
111 
112 	assert_key_lock(key->local);
113 
114 	sta = key->sta;
115 
116 	/*
117 	 * If this is a per-STA GTK, check if it
118 	 * is supported; if not, return.
119 	 */
120 	if (sta && !(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE) &&
121 	    !(key->local->hw.flags & IEEE80211_HW_SUPPORTS_PER_STA_GTK))
122 		goto out_unsupported;
123 
124 	if (sta && !sta->uploaded)
125 		goto out_unsupported;
126 
127 	sdata = key->sdata;
128 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
129 		/*
130 		 * The driver doesn't know anything about VLAN interfaces.
131 		 * Hence, don't send GTKs for VLAN interfaces to the driver.
132 		 */
133 		if (!(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE))
134 			goto out_unsupported;
135 	}
136 
137 	ret = drv_set_key(key->local, SET_KEY, sdata,
138 			  sta ? &sta->sta : NULL, &key->conf);
139 
140 	if (!ret) {
141 		key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
142 
143 		if (!(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC))
144 			sdata->crypto_tx_tailroom_needed_cnt--;
145 
146 		WARN_ON((key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
147 			(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV));
148 
149 		return 0;
150 	}
151 
152 	if (ret != -ENOSPC && ret != -EOPNOTSUPP)
153 		sdata_err(sdata,
154 			  "failed to set key (%d, %pM) to hardware (%d)\n",
155 			  key->conf.keyidx,
156 			  sta ? sta->sta.addr : bcast_addr, ret);
157 
158  out_unsupported:
159 	switch (key->conf.cipher) {
160 	case WLAN_CIPHER_SUITE_WEP40:
161 	case WLAN_CIPHER_SUITE_WEP104:
162 	case WLAN_CIPHER_SUITE_TKIP:
163 	case WLAN_CIPHER_SUITE_CCMP:
164 	case WLAN_CIPHER_SUITE_AES_CMAC:
165 		/* all of these we can do in software */
166 		return 0;
167 	default:
168 		return -EINVAL;
169 	}
170 }
171 
172 static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
173 {
174 	struct ieee80211_sub_if_data *sdata;
175 	struct sta_info *sta;
176 	int ret;
177 
178 	might_sleep();
179 
180 	if (!key || !key->local->ops->set_key)
181 		return;
182 
183 	assert_key_lock(key->local);
184 
185 	if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
186 		return;
187 
188 	sta = key->sta;
189 	sdata = key->sdata;
190 
191 	if (!(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC))
192 		increment_tailroom_need_count(sdata);
193 
194 	ret = drv_set_key(key->local, DISABLE_KEY, sdata,
195 			  sta ? &sta->sta : NULL, &key->conf);
196 
197 	if (ret)
198 		sdata_err(sdata,
199 			  "failed to remove key (%d, %pM) from hardware (%d)\n",
200 			  key->conf.keyidx,
201 			  sta ? sta->sta.addr : bcast_addr, ret);
202 
203 	key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
204 }
205 
206 static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
207 					int idx, bool uni, bool multi)
208 {
209 	struct ieee80211_key *key = NULL;
210 
211 	assert_key_lock(sdata->local);
212 
213 	if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
214 		key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
215 
216 	if (uni) {
217 		rcu_assign_pointer(sdata->default_unicast_key, key);
218 		drv_set_default_unicast_key(sdata->local, sdata, idx);
219 	}
220 
221 	if (multi)
222 		rcu_assign_pointer(sdata->default_multicast_key, key);
223 
224 	ieee80211_debugfs_key_update_default(sdata);
225 }
226 
227 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
228 			       bool uni, bool multi)
229 {
230 	mutex_lock(&sdata->local->key_mtx);
231 	__ieee80211_set_default_key(sdata, idx, uni, multi);
232 	mutex_unlock(&sdata->local->key_mtx);
233 }
234 
235 static void
236 __ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
237 {
238 	struct ieee80211_key *key = NULL;
239 
240 	assert_key_lock(sdata->local);
241 
242 	if (idx >= NUM_DEFAULT_KEYS &&
243 	    idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
244 		key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
245 
246 	rcu_assign_pointer(sdata->default_mgmt_key, key);
247 
248 	ieee80211_debugfs_key_update_default(sdata);
249 }
250 
251 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
252 				    int idx)
253 {
254 	mutex_lock(&sdata->local->key_mtx);
255 	__ieee80211_set_default_mgmt_key(sdata, idx);
256 	mutex_unlock(&sdata->local->key_mtx);
257 }
258 
259 
260 static void ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
261 				  struct sta_info *sta,
262 				  bool pairwise,
263 				  struct ieee80211_key *old,
264 				  struct ieee80211_key *new)
265 {
266 	int idx;
267 	bool defunikey, defmultikey, defmgmtkey;
268 
269 	/* caller must provide at least one old/new */
270 	if (WARN_ON(!new && !old))
271 		return;
272 
273 	if (new)
274 		list_add_tail(&new->list, &sdata->key_list);
275 
276 	WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
277 
278 	if (old)
279 		idx = old->conf.keyidx;
280 	else
281 		idx = new->conf.keyidx;
282 
283 	if (sta) {
284 		if (pairwise) {
285 			rcu_assign_pointer(sta->ptk[idx], new);
286 			sta->ptk_idx = idx;
287 		} else {
288 			rcu_assign_pointer(sta->gtk[idx], new);
289 			sta->gtk_idx = idx;
290 		}
291 	} else {
292 		defunikey = old &&
293 			old == key_mtx_dereference(sdata->local,
294 						sdata->default_unicast_key);
295 		defmultikey = old &&
296 			old == key_mtx_dereference(sdata->local,
297 						sdata->default_multicast_key);
298 		defmgmtkey = old &&
299 			old == key_mtx_dereference(sdata->local,
300 						sdata->default_mgmt_key);
301 
302 		if (defunikey && !new)
303 			__ieee80211_set_default_key(sdata, -1, true, false);
304 		if (defmultikey && !new)
305 			__ieee80211_set_default_key(sdata, -1, false, true);
306 		if (defmgmtkey && !new)
307 			__ieee80211_set_default_mgmt_key(sdata, -1);
308 
309 		rcu_assign_pointer(sdata->keys[idx], new);
310 		if (defunikey && new)
311 			__ieee80211_set_default_key(sdata, new->conf.keyidx,
312 						    true, false);
313 		if (defmultikey && new)
314 			__ieee80211_set_default_key(sdata, new->conf.keyidx,
315 						    false, true);
316 		if (defmgmtkey && new)
317 			__ieee80211_set_default_mgmt_key(sdata,
318 							 new->conf.keyidx);
319 	}
320 
321 	if (old)
322 		list_del(&old->list);
323 }
324 
325 struct ieee80211_key *
326 ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
327 		    const u8 *key_data,
328 		    size_t seq_len, const u8 *seq,
329 		    const struct ieee80211_cipher_scheme *cs)
330 {
331 	struct ieee80211_key *key;
332 	int i, j, err;
333 
334 	if (WARN_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS))
335 		return ERR_PTR(-EINVAL);
336 
337 	key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
338 	if (!key)
339 		return ERR_PTR(-ENOMEM);
340 
341 	/*
342 	 * Default to software encryption; we'll later upload the
343 	 * key to the hardware if possible.
344 	 */
345 	key->conf.flags = 0;
346 	key->flags = 0;
347 
348 	key->conf.cipher = cipher;
349 	key->conf.keyidx = idx;
350 	key->conf.keylen = key_len;
351 	switch (cipher) {
352 	case WLAN_CIPHER_SUITE_WEP40:
353 	case WLAN_CIPHER_SUITE_WEP104:
354 		key->conf.iv_len = IEEE80211_WEP_IV_LEN;
355 		key->conf.icv_len = IEEE80211_WEP_ICV_LEN;
356 		break;
357 	case WLAN_CIPHER_SUITE_TKIP:
358 		key->conf.iv_len = IEEE80211_TKIP_IV_LEN;
359 		key->conf.icv_len = IEEE80211_TKIP_ICV_LEN;
360 		if (seq) {
361 			for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
362 				key->u.tkip.rx[i].iv32 =
363 					get_unaligned_le32(&seq[2]);
364 				key->u.tkip.rx[i].iv16 =
365 					get_unaligned_le16(seq);
366 			}
367 		}
368 		spin_lock_init(&key->u.tkip.txlock);
369 		break;
370 	case WLAN_CIPHER_SUITE_CCMP:
371 		key->conf.iv_len = IEEE80211_CCMP_HDR_LEN;
372 		key->conf.icv_len = IEEE80211_CCMP_MIC_LEN;
373 		if (seq) {
374 			for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
375 				for (j = 0; j < IEEE80211_CCMP_PN_LEN; j++)
376 					key->u.ccmp.rx_pn[i][j] =
377 						seq[IEEE80211_CCMP_PN_LEN - j - 1];
378 		}
379 		/*
380 		 * Initialize AES key state here as an optimization so that
381 		 * it does not need to be initialized for every packet.
382 		 */
383 		key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data);
384 		if (IS_ERR(key->u.ccmp.tfm)) {
385 			err = PTR_ERR(key->u.ccmp.tfm);
386 			kfree(key);
387 			return ERR_PTR(err);
388 		}
389 		break;
390 	case WLAN_CIPHER_SUITE_AES_CMAC:
391 		key->conf.iv_len = 0;
392 		key->conf.icv_len = sizeof(struct ieee80211_mmie);
393 		if (seq)
394 			for (j = 0; j < IEEE80211_CMAC_PN_LEN; j++)
395 				key->u.aes_cmac.rx_pn[j] =
396 					seq[IEEE80211_CMAC_PN_LEN - j - 1];
397 		/*
398 		 * Initialize AES key state here as an optimization so that
399 		 * it does not need to be initialized for every packet.
400 		 */
401 		key->u.aes_cmac.tfm =
402 			ieee80211_aes_cmac_key_setup(key_data);
403 		if (IS_ERR(key->u.aes_cmac.tfm)) {
404 			err = PTR_ERR(key->u.aes_cmac.tfm);
405 			kfree(key);
406 			return ERR_PTR(err);
407 		}
408 		break;
409 	default:
410 		if (cs) {
411 			size_t len = (seq_len > MAX_PN_LEN) ?
412 						MAX_PN_LEN : seq_len;
413 
414 			key->conf.iv_len = cs->hdr_len;
415 			key->conf.icv_len = cs->mic_len;
416 			for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
417 				for (j = 0; j < len; j++)
418 					key->u.gen.rx_pn[i][j] =
419 							seq[len - j - 1];
420 		}
421 	}
422 	memcpy(key->conf.key, key_data, key_len);
423 	INIT_LIST_HEAD(&key->list);
424 
425 	return key;
426 }
427 
428 static void ieee80211_key_free_common(struct ieee80211_key *key)
429 {
430 	if (key->conf.cipher == WLAN_CIPHER_SUITE_CCMP)
431 		ieee80211_aes_key_free(key->u.ccmp.tfm);
432 	if (key->conf.cipher == WLAN_CIPHER_SUITE_AES_CMAC)
433 		ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
434 	kzfree(key);
435 }
436 
437 static void __ieee80211_key_destroy(struct ieee80211_key *key,
438 				    bool delay_tailroom)
439 {
440 	if (key->local)
441 		ieee80211_key_disable_hw_accel(key);
442 
443 	if (key->local) {
444 		struct ieee80211_sub_if_data *sdata = key->sdata;
445 
446 		ieee80211_debugfs_key_remove(key);
447 
448 		if (delay_tailroom) {
449 			/* see ieee80211_delayed_tailroom_dec */
450 			sdata->crypto_tx_tailroom_pending_dec++;
451 			schedule_delayed_work(&sdata->dec_tailroom_needed_wk,
452 					      HZ/2);
453 		} else {
454 			sdata->crypto_tx_tailroom_needed_cnt--;
455 		}
456 	}
457 
458 	ieee80211_key_free_common(key);
459 }
460 
461 static void ieee80211_key_destroy(struct ieee80211_key *key,
462 				  bool delay_tailroom)
463 {
464 	if (!key)
465 		return;
466 
467 	/*
468 	 * Synchronize so the TX path can no longer be using
469 	 * this key before we free/remove it.
470 	 */
471 	synchronize_net();
472 
473 	__ieee80211_key_destroy(key, delay_tailroom);
474 }
475 
476 void ieee80211_key_free_unused(struct ieee80211_key *key)
477 {
478 	WARN_ON(key->sdata || key->local);
479 	ieee80211_key_free_common(key);
480 }
481 
482 int ieee80211_key_link(struct ieee80211_key *key,
483 		       struct ieee80211_sub_if_data *sdata,
484 		       struct sta_info *sta)
485 {
486 	struct ieee80211_local *local = sdata->local;
487 	struct ieee80211_key *old_key;
488 	int idx, ret;
489 	bool pairwise;
490 
491 	pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
492 	idx = key->conf.keyidx;
493 	key->local = sdata->local;
494 	key->sdata = sdata;
495 	key->sta = sta;
496 
497 	mutex_lock(&sdata->local->key_mtx);
498 
499 	if (sta && pairwise)
500 		old_key = key_mtx_dereference(sdata->local, sta->ptk[idx]);
501 	else if (sta)
502 		old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
503 	else
504 		old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
505 
506 	increment_tailroom_need_count(sdata);
507 
508 	ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
509 	ieee80211_key_destroy(old_key, true);
510 
511 	ieee80211_debugfs_key_add(key);
512 
513 	if (!local->wowlan) {
514 		ret = ieee80211_key_enable_hw_accel(key);
515 		if (ret)
516 			ieee80211_key_free(key, true);
517 	} else {
518 		ret = 0;
519 	}
520 
521 	mutex_unlock(&sdata->local->key_mtx);
522 
523 	return ret;
524 }
525 
526 void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom)
527 {
528 	if (!key)
529 		return;
530 
531 	/*
532 	 * Replace key with nothingness if it was ever used.
533 	 */
534 	if (key->sdata)
535 		ieee80211_key_replace(key->sdata, key->sta,
536 				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
537 				key, NULL);
538 	ieee80211_key_destroy(key, delay_tailroom);
539 }
540 
541 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
542 {
543 	struct ieee80211_key *key;
544 
545 	ASSERT_RTNL();
546 
547 	if (WARN_ON(!ieee80211_sdata_running(sdata)))
548 		return;
549 
550 	mutex_lock(&sdata->local->key_mtx);
551 
552 	sdata->crypto_tx_tailroom_needed_cnt = 0;
553 
554 	list_for_each_entry(key, &sdata->key_list, list) {
555 		increment_tailroom_need_count(sdata);
556 		ieee80211_key_enable_hw_accel(key);
557 	}
558 
559 	mutex_unlock(&sdata->local->key_mtx);
560 }
561 
562 void ieee80211_iter_keys(struct ieee80211_hw *hw,
563 			 struct ieee80211_vif *vif,
564 			 void (*iter)(struct ieee80211_hw *hw,
565 				      struct ieee80211_vif *vif,
566 				      struct ieee80211_sta *sta,
567 				      struct ieee80211_key_conf *key,
568 				      void *data),
569 			 void *iter_data)
570 {
571 	struct ieee80211_local *local = hw_to_local(hw);
572 	struct ieee80211_key *key, *tmp;
573 	struct ieee80211_sub_if_data *sdata;
574 
575 	ASSERT_RTNL();
576 
577 	mutex_lock(&local->key_mtx);
578 	if (vif) {
579 		sdata = vif_to_sdata(vif);
580 		list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
581 			iter(hw, &sdata->vif,
582 			     key->sta ? &key->sta->sta : NULL,
583 			     &key->conf, iter_data);
584 	} else {
585 		list_for_each_entry(sdata, &local->interfaces, list)
586 			list_for_each_entry_safe(key, tmp,
587 						 &sdata->key_list, list)
588 				iter(hw, &sdata->vif,
589 				     key->sta ? &key->sta->sta : NULL,
590 				     &key->conf, iter_data);
591 	}
592 	mutex_unlock(&local->key_mtx);
593 }
594 EXPORT_SYMBOL(ieee80211_iter_keys);
595 
596 static void ieee80211_free_keys_iface(struct ieee80211_sub_if_data *sdata,
597 				      struct list_head *keys)
598 {
599 	struct ieee80211_key *key, *tmp;
600 
601 	sdata->crypto_tx_tailroom_needed_cnt -=
602 		sdata->crypto_tx_tailroom_pending_dec;
603 	sdata->crypto_tx_tailroom_pending_dec = 0;
604 
605 	ieee80211_debugfs_key_remove_mgmt_default(sdata);
606 
607 	list_for_each_entry_safe(key, tmp, &sdata->key_list, list) {
608 		ieee80211_key_replace(key->sdata, key->sta,
609 				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
610 				key, NULL);
611 		list_add_tail(&key->list, keys);
612 	}
613 
614 	ieee80211_debugfs_key_update_default(sdata);
615 }
616 
617 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata,
618 			 bool force_synchronize)
619 {
620 	struct ieee80211_local *local = sdata->local;
621 	struct ieee80211_sub_if_data *vlan;
622 	struct ieee80211_key *key, *tmp;
623 	LIST_HEAD(keys);
624 
625 	cancel_delayed_work_sync(&sdata->dec_tailroom_needed_wk);
626 
627 	mutex_lock(&local->key_mtx);
628 
629 	ieee80211_free_keys_iface(sdata, &keys);
630 
631 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
632 		list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
633 			ieee80211_free_keys_iface(vlan, &keys);
634 	}
635 
636 	if (!list_empty(&keys) || force_synchronize)
637 		synchronize_net();
638 	list_for_each_entry_safe(key, tmp, &keys, list)
639 		__ieee80211_key_destroy(key, false);
640 
641 	WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
642 		     sdata->crypto_tx_tailroom_pending_dec);
643 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
644 		list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
645 			WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
646 				     vlan->crypto_tx_tailroom_pending_dec);
647 	}
648 
649 	mutex_unlock(&local->key_mtx);
650 }
651 
652 void ieee80211_free_sta_keys(struct ieee80211_local *local,
653 			     struct sta_info *sta)
654 {
655 	struct ieee80211_key *key;
656 	int i;
657 
658 	mutex_lock(&local->key_mtx);
659 	for (i = 0; i < ARRAY_SIZE(sta->gtk); i++) {
660 		key = key_mtx_dereference(local, sta->gtk[i]);
661 		if (!key)
662 			continue;
663 		ieee80211_key_replace(key->sdata, key->sta,
664 				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
665 				key, NULL);
666 		__ieee80211_key_destroy(key, true);
667 	}
668 
669 	for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
670 		key = key_mtx_dereference(local, sta->ptk[i]);
671 		if (!key)
672 			continue;
673 		ieee80211_key_replace(key->sdata, key->sta,
674 				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
675 				key, NULL);
676 		__ieee80211_key_destroy(key, true);
677 	}
678 
679 	mutex_unlock(&local->key_mtx);
680 }
681 
682 void ieee80211_delayed_tailroom_dec(struct work_struct *wk)
683 {
684 	struct ieee80211_sub_if_data *sdata;
685 
686 	sdata = container_of(wk, struct ieee80211_sub_if_data,
687 			     dec_tailroom_needed_wk.work);
688 
689 	/*
690 	 * The reason for the delayed tailroom needed decrementing is to
691 	 * make roaming faster: during roaming, all keys are first deleted
692 	 * and then new keys are installed. The first new key causes the
693 	 * crypto_tx_tailroom_needed_cnt to go from 0 to 1, which invokes
694 	 * the cost of synchronize_net() (which can be slow). Avoid this
695 	 * by deferring the crypto_tx_tailroom_needed_cnt decrementing on
696 	 * key removal for a while, so if we roam the value is larger than
697 	 * zero and no 0->1 transition happens.
698 	 *
699 	 * The cost is that if the AP switching was from an AP with keys
700 	 * to one without, we still allocate tailroom while it would no
701 	 * longer be needed. However, in the typical (fast) roaming case
702 	 * within an ESS this usually won't happen.
703 	 */
704 
705 	mutex_lock(&sdata->local->key_mtx);
706 	sdata->crypto_tx_tailroom_needed_cnt -=
707 		sdata->crypto_tx_tailroom_pending_dec;
708 	sdata->crypto_tx_tailroom_pending_dec = 0;
709 	mutex_unlock(&sdata->local->key_mtx);
710 }
711 
712 void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid,
713 				const u8 *replay_ctr, gfp_t gfp)
714 {
715 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
716 
717 	trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr);
718 
719 	cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
720 }
721 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);
722 
723 void ieee80211_get_key_tx_seq(struct ieee80211_key_conf *keyconf,
724 			      struct ieee80211_key_seq *seq)
725 {
726 	struct ieee80211_key *key;
727 	u64 pn64;
728 
729 	if (WARN_ON(!(keyconf->flags & IEEE80211_KEY_FLAG_GENERATE_IV)))
730 		return;
731 
732 	key = container_of(keyconf, struct ieee80211_key, conf);
733 
734 	switch (key->conf.cipher) {
735 	case WLAN_CIPHER_SUITE_TKIP:
736 		seq->tkip.iv32 = key->u.tkip.tx.iv32;
737 		seq->tkip.iv16 = key->u.tkip.tx.iv16;
738 		break;
739 	case WLAN_CIPHER_SUITE_CCMP:
740 		pn64 = atomic64_read(&key->u.ccmp.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 	case WLAN_CIPHER_SUITE_AES_CMAC:
749 		pn64 = atomic64_read(&key->u.aes_cmac.tx_pn);
750 		seq->ccmp.pn[5] = pn64;
751 		seq->ccmp.pn[4] = pn64 >> 8;
752 		seq->ccmp.pn[3] = pn64 >> 16;
753 		seq->ccmp.pn[2] = pn64 >> 24;
754 		seq->ccmp.pn[1] = pn64 >> 32;
755 		seq->ccmp.pn[0] = pn64 >> 40;
756 		break;
757 	default:
758 		WARN_ON(1);
759 	}
760 }
761 EXPORT_SYMBOL(ieee80211_get_key_tx_seq);
762 
763 void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
764 			      int tid, struct ieee80211_key_seq *seq)
765 {
766 	struct ieee80211_key *key;
767 	const u8 *pn;
768 
769 	key = container_of(keyconf, struct ieee80211_key, conf);
770 
771 	switch (key->conf.cipher) {
772 	case WLAN_CIPHER_SUITE_TKIP:
773 		if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
774 			return;
775 		seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
776 		seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
777 		break;
778 	case WLAN_CIPHER_SUITE_CCMP:
779 		if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
780 			return;
781 		if (tid < 0)
782 			pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
783 		else
784 			pn = key->u.ccmp.rx_pn[tid];
785 		memcpy(seq->ccmp.pn, pn, IEEE80211_CCMP_PN_LEN);
786 		break;
787 	case WLAN_CIPHER_SUITE_AES_CMAC:
788 		if (WARN_ON(tid != 0))
789 			return;
790 		pn = key->u.aes_cmac.rx_pn;
791 		memcpy(seq->aes_cmac.pn, pn, IEEE80211_CMAC_PN_LEN);
792 		break;
793 	}
794 }
795 EXPORT_SYMBOL(ieee80211_get_key_rx_seq);
796 
797 void ieee80211_set_key_tx_seq(struct ieee80211_key_conf *keyconf,
798 			      struct ieee80211_key_seq *seq)
799 {
800 	struct ieee80211_key *key;
801 	u64 pn64;
802 
803 	key = container_of(keyconf, struct ieee80211_key, conf);
804 
805 	switch (key->conf.cipher) {
806 	case WLAN_CIPHER_SUITE_TKIP:
807 		key->u.tkip.tx.iv32 = seq->tkip.iv32;
808 		key->u.tkip.tx.iv16 = seq->tkip.iv16;
809 		break;
810 	case WLAN_CIPHER_SUITE_CCMP:
811 		pn64 = (u64)seq->ccmp.pn[5] |
812 		       ((u64)seq->ccmp.pn[4] << 8) |
813 		       ((u64)seq->ccmp.pn[3] << 16) |
814 		       ((u64)seq->ccmp.pn[2] << 24) |
815 		       ((u64)seq->ccmp.pn[1] << 32) |
816 		       ((u64)seq->ccmp.pn[0] << 40);
817 		atomic64_set(&key->u.ccmp.tx_pn, pn64);
818 		break;
819 	case WLAN_CIPHER_SUITE_AES_CMAC:
820 		pn64 = (u64)seq->aes_cmac.pn[5] |
821 		       ((u64)seq->aes_cmac.pn[4] << 8) |
822 		       ((u64)seq->aes_cmac.pn[3] << 16) |
823 		       ((u64)seq->aes_cmac.pn[2] << 24) |
824 		       ((u64)seq->aes_cmac.pn[1] << 32) |
825 		       ((u64)seq->aes_cmac.pn[0] << 40);
826 		atomic64_set(&key->u.aes_cmac.tx_pn, pn64);
827 		break;
828 	default:
829 		WARN_ON(1);
830 		break;
831 	}
832 }
833 EXPORT_SYMBOL_GPL(ieee80211_set_key_tx_seq);
834 
835 void ieee80211_set_key_rx_seq(struct ieee80211_key_conf *keyconf,
836 			      int tid, struct ieee80211_key_seq *seq)
837 {
838 	struct ieee80211_key *key;
839 	u8 *pn;
840 
841 	key = container_of(keyconf, struct ieee80211_key, conf);
842 
843 	switch (key->conf.cipher) {
844 	case WLAN_CIPHER_SUITE_TKIP:
845 		if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
846 			return;
847 		key->u.tkip.rx[tid].iv32 = seq->tkip.iv32;
848 		key->u.tkip.rx[tid].iv16 = seq->tkip.iv16;
849 		break;
850 	case WLAN_CIPHER_SUITE_CCMP:
851 		if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
852 			return;
853 		if (tid < 0)
854 			pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
855 		else
856 			pn = key->u.ccmp.rx_pn[tid];
857 		memcpy(pn, seq->ccmp.pn, IEEE80211_CCMP_PN_LEN);
858 		break;
859 	case WLAN_CIPHER_SUITE_AES_CMAC:
860 		if (WARN_ON(tid != 0))
861 			return;
862 		pn = key->u.aes_cmac.rx_pn;
863 		memcpy(pn, seq->aes_cmac.pn, IEEE80211_CMAC_PN_LEN);
864 		break;
865 	default:
866 		WARN_ON(1);
867 		break;
868 	}
869 }
870 EXPORT_SYMBOL_GPL(ieee80211_set_key_rx_seq);
871 
872 void ieee80211_remove_key(struct ieee80211_key_conf *keyconf)
873 {
874 	struct ieee80211_key *key;
875 
876 	key = container_of(keyconf, struct ieee80211_key, conf);
877 
878 	assert_key_lock(key->local);
879 
880 	/*
881 	 * if key was uploaded, we assume the driver will/has remove(d)
882 	 * it, so adjust bookkeeping accordingly
883 	 */
884 	if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
885 		key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
886 
887 		if (!(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC))
888 			increment_tailroom_need_count(key->sdata);
889 	}
890 
891 	ieee80211_key_free(key, false);
892 }
893 EXPORT_SYMBOL_GPL(ieee80211_remove_key);
894 
895 struct ieee80211_key_conf *
896 ieee80211_gtk_rekey_add(struct ieee80211_vif *vif,
897 			struct ieee80211_key_conf *keyconf)
898 {
899 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
900 	struct ieee80211_local *local = sdata->local;
901 	struct ieee80211_key *key;
902 	int err;
903 
904 	if (WARN_ON(!local->wowlan))
905 		return ERR_PTR(-EINVAL);
906 
907 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
908 		return ERR_PTR(-EINVAL);
909 
910 	key = ieee80211_key_alloc(keyconf->cipher, keyconf->keyidx,
911 				  keyconf->keylen, keyconf->key,
912 				  0, NULL, NULL);
913 	if (IS_ERR(key))
914 		return ERR_CAST(key);
915 
916 	if (sdata->u.mgd.mfp != IEEE80211_MFP_DISABLED)
917 		key->conf.flags |= IEEE80211_KEY_FLAG_RX_MGMT;
918 
919 	err = ieee80211_key_link(key, sdata, NULL);
920 	if (err)
921 		return ERR_PTR(err);
922 
923 	return &key->conf;
924 }
925 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_add);
926