xref: /openbmc/linux/net/mac80211/key.c (revision 6aa7de05)
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  * Copyright 2015-2017	Intel Deutschland GmbH
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13 
14 #include <linux/if_ether.h>
15 #include <linux/etherdevice.h>
16 #include <linux/list.h>
17 #include <linux/rcupdate.h>
18 #include <linux/rtnetlink.h>
19 #include <linux/slab.h>
20 #include <linux/export.h>
21 #include <net/mac80211.h>
22 #include <asm/unaligned.h>
23 #include "ieee80211_i.h"
24 #include "driver-ops.h"
25 #include "debugfs_key.h"
26 #include "aes_ccm.h"
27 #include "aes_cmac.h"
28 #include "aes_gmac.h"
29 #include "aes_gcm.h"
30 
31 
32 /**
33  * DOC: Key handling basics
34  *
35  * Key handling in mac80211 is done based on per-interface (sub_if_data)
36  * keys and per-station keys. Since each station belongs to an interface,
37  * each station key also belongs to that interface.
38  *
39  * Hardware acceleration is done on a best-effort basis for algorithms
40  * that are implemented in software,  for each key the hardware is asked
41  * to enable that key for offloading but if it cannot do that the key is
42  * simply kept for software encryption (unless it is for an algorithm
43  * that isn't implemented in software).
44  * There is currently no way of knowing whether a key is handled in SW
45  * or HW except by looking into debugfs.
46  *
47  * All key management is internally protected by a mutex. Within all
48  * other parts of mac80211, key references are, just as STA structure
49  * references, protected by RCU. Note, however, that some things are
50  * unprotected, namely the key->sta dereferences within the hardware
51  * acceleration functions. This means that sta_info_destroy() must
52  * remove the key which waits for an RCU grace period.
53  */
54 
55 static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
56 
57 static void assert_key_lock(struct ieee80211_local *local)
58 {
59 	lockdep_assert_held(&local->key_mtx);
60 }
61 
62 static void
63 update_vlan_tailroom_need_count(struct ieee80211_sub_if_data *sdata, int delta)
64 {
65 	struct ieee80211_sub_if_data *vlan;
66 
67 	if (sdata->vif.type != NL80211_IFTYPE_AP)
68 		return;
69 
70 	/* crypto_tx_tailroom_needed_cnt is protected by this */
71 	assert_key_lock(sdata->local);
72 
73 	rcu_read_lock();
74 
75 	list_for_each_entry_rcu(vlan, &sdata->u.ap.vlans, u.vlan.list)
76 		vlan->crypto_tx_tailroom_needed_cnt += delta;
77 
78 	rcu_read_unlock();
79 }
80 
81 static void increment_tailroom_need_count(struct ieee80211_sub_if_data *sdata)
82 {
83 	/*
84 	 * When this count is zero, SKB resizing for allocating tailroom
85 	 * for IV or MMIC is skipped. But, this check has created two race
86 	 * cases in xmit path while transiting from zero count to one:
87 	 *
88 	 * 1. SKB resize was skipped because no key was added but just before
89 	 * the xmit key is added and SW encryption kicks off.
90 	 *
91 	 * 2. SKB resize was skipped because all the keys were hw planted but
92 	 * just before xmit one of the key is deleted and SW encryption kicks
93 	 * off.
94 	 *
95 	 * In both the above case SW encryption will find not enough space for
96 	 * tailroom and exits with WARN_ON. (See WARN_ONs at wpa.c)
97 	 *
98 	 * Solution has been explained at
99 	 * http://mid.gmane.org/1308590980.4322.19.camel@jlt3.sipsolutions.net
100 	 */
101 
102 	assert_key_lock(sdata->local);
103 
104 	update_vlan_tailroom_need_count(sdata, 1);
105 
106 	if (!sdata->crypto_tx_tailroom_needed_cnt++) {
107 		/*
108 		 * Flush all XMIT packets currently using HW encryption or no
109 		 * encryption at all if the count transition is from 0 -> 1.
110 		 */
111 		synchronize_net();
112 	}
113 }
114 
115 static void decrease_tailroom_need_count(struct ieee80211_sub_if_data *sdata,
116 					 int delta)
117 {
118 	assert_key_lock(sdata->local);
119 
120 	WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt < delta);
121 
122 	update_vlan_tailroom_need_count(sdata, -delta);
123 	sdata->crypto_tx_tailroom_needed_cnt -= delta;
124 }
125 
126 static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
127 {
128 	struct ieee80211_sub_if_data *sdata;
129 	struct sta_info *sta;
130 	int ret = -EOPNOTSUPP;
131 
132 	might_sleep();
133 
134 	if (key->flags & KEY_FLAG_TAINTED) {
135 		/* If we get here, it's during resume and the key is
136 		 * tainted so shouldn't be used/programmed any more.
137 		 * However, its flags may still indicate that it was
138 		 * programmed into the device (since we're in resume)
139 		 * so clear that flag now to avoid trying to remove
140 		 * it again later.
141 		 */
142 		key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
143 		return -EINVAL;
144 	}
145 
146 	if (!key->local->ops->set_key)
147 		goto out_unsupported;
148 
149 	assert_key_lock(key->local);
150 
151 	sta = key->sta;
152 
153 	/*
154 	 * If this is a per-STA GTK, check if it
155 	 * is supported; if not, return.
156 	 */
157 	if (sta && !(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE) &&
158 	    !ieee80211_hw_check(&key->local->hw, SUPPORTS_PER_STA_GTK))
159 		goto out_unsupported;
160 
161 	if (sta && !sta->uploaded)
162 		goto out_unsupported;
163 
164 	sdata = key->sdata;
165 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
166 		/*
167 		 * The driver doesn't know anything about VLAN interfaces.
168 		 * Hence, don't send GTKs for VLAN interfaces to the driver.
169 		 */
170 		if (!(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE))
171 			goto out_unsupported;
172 	}
173 
174 	ret = drv_set_key(key->local, SET_KEY, sdata,
175 			  sta ? &sta->sta : NULL, &key->conf);
176 
177 	if (!ret) {
178 		key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
179 
180 		if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
181 		      (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
182 			decrease_tailroom_need_count(sdata, 1);
183 
184 		WARN_ON((key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
185 			(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV));
186 
187 		return 0;
188 	}
189 
190 	if (ret != -ENOSPC && ret != -EOPNOTSUPP && ret != 1)
191 		sdata_err(sdata,
192 			  "failed to set key (%d, %pM) to hardware (%d)\n",
193 			  key->conf.keyidx,
194 			  sta ? sta->sta.addr : bcast_addr, ret);
195 
196  out_unsupported:
197 	switch (key->conf.cipher) {
198 	case WLAN_CIPHER_SUITE_WEP40:
199 	case WLAN_CIPHER_SUITE_WEP104:
200 	case WLAN_CIPHER_SUITE_TKIP:
201 	case WLAN_CIPHER_SUITE_CCMP:
202 	case WLAN_CIPHER_SUITE_CCMP_256:
203 	case WLAN_CIPHER_SUITE_AES_CMAC:
204 	case WLAN_CIPHER_SUITE_BIP_CMAC_256:
205 	case WLAN_CIPHER_SUITE_BIP_GMAC_128:
206 	case WLAN_CIPHER_SUITE_BIP_GMAC_256:
207 	case WLAN_CIPHER_SUITE_GCMP:
208 	case WLAN_CIPHER_SUITE_GCMP_256:
209 		/* all of these we can do in software - if driver can */
210 		if (ret == 1)
211 			return 0;
212 		if (ieee80211_hw_check(&key->local->hw, SW_CRYPTO_CONTROL))
213 			return -EINVAL;
214 		return 0;
215 	default:
216 		return -EINVAL;
217 	}
218 }
219 
220 static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
221 {
222 	struct ieee80211_sub_if_data *sdata;
223 	struct sta_info *sta;
224 	int ret;
225 
226 	might_sleep();
227 
228 	if (!key || !key->local->ops->set_key)
229 		return;
230 
231 	assert_key_lock(key->local);
232 
233 	if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
234 		return;
235 
236 	sta = key->sta;
237 	sdata = key->sdata;
238 
239 	if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
240 	      (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
241 		increment_tailroom_need_count(sdata);
242 
243 	ret = drv_set_key(key->local, DISABLE_KEY, sdata,
244 			  sta ? &sta->sta : NULL, &key->conf);
245 
246 	if (ret)
247 		sdata_err(sdata,
248 			  "failed to remove key (%d, %pM) from hardware (%d)\n",
249 			  key->conf.keyidx,
250 			  sta ? sta->sta.addr : bcast_addr, ret);
251 
252 	key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
253 }
254 
255 static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
256 					int idx, bool uni, bool multi)
257 {
258 	struct ieee80211_key *key = NULL;
259 
260 	assert_key_lock(sdata->local);
261 
262 	if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
263 		key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
264 
265 	if (uni) {
266 		rcu_assign_pointer(sdata->default_unicast_key, key);
267 		ieee80211_check_fast_xmit_iface(sdata);
268 		if (sdata->vif.type != NL80211_IFTYPE_AP_VLAN)
269 			drv_set_default_unicast_key(sdata->local, sdata, idx);
270 	}
271 
272 	if (multi)
273 		rcu_assign_pointer(sdata->default_multicast_key, key);
274 
275 	ieee80211_debugfs_key_update_default(sdata);
276 }
277 
278 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
279 			       bool uni, bool multi)
280 {
281 	mutex_lock(&sdata->local->key_mtx);
282 	__ieee80211_set_default_key(sdata, idx, uni, multi);
283 	mutex_unlock(&sdata->local->key_mtx);
284 }
285 
286 static void
287 __ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
288 {
289 	struct ieee80211_key *key = NULL;
290 
291 	assert_key_lock(sdata->local);
292 
293 	if (idx >= NUM_DEFAULT_KEYS &&
294 	    idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
295 		key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
296 
297 	rcu_assign_pointer(sdata->default_mgmt_key, key);
298 
299 	ieee80211_debugfs_key_update_default(sdata);
300 }
301 
302 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
303 				    int idx)
304 {
305 	mutex_lock(&sdata->local->key_mtx);
306 	__ieee80211_set_default_mgmt_key(sdata, idx);
307 	mutex_unlock(&sdata->local->key_mtx);
308 }
309 
310 
311 static void ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
312 				  struct sta_info *sta,
313 				  bool pairwise,
314 				  struct ieee80211_key *old,
315 				  struct ieee80211_key *new)
316 {
317 	int idx;
318 	bool defunikey, defmultikey, defmgmtkey;
319 
320 	/* caller must provide at least one old/new */
321 	if (WARN_ON(!new && !old))
322 		return;
323 
324 	if (new)
325 		list_add_tail_rcu(&new->list, &sdata->key_list);
326 
327 	WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
328 
329 	if (old)
330 		idx = old->conf.keyidx;
331 	else
332 		idx = new->conf.keyidx;
333 
334 	if (sta) {
335 		if (pairwise) {
336 			rcu_assign_pointer(sta->ptk[idx], new);
337 			sta->ptk_idx = idx;
338 			ieee80211_check_fast_xmit(sta);
339 		} else {
340 			rcu_assign_pointer(sta->gtk[idx], new);
341 		}
342 		ieee80211_check_fast_rx(sta);
343 	} else {
344 		defunikey = old &&
345 			old == key_mtx_dereference(sdata->local,
346 						sdata->default_unicast_key);
347 		defmultikey = old &&
348 			old == key_mtx_dereference(sdata->local,
349 						sdata->default_multicast_key);
350 		defmgmtkey = old &&
351 			old == key_mtx_dereference(sdata->local,
352 						sdata->default_mgmt_key);
353 
354 		if (defunikey && !new)
355 			__ieee80211_set_default_key(sdata, -1, true, false);
356 		if (defmultikey && !new)
357 			__ieee80211_set_default_key(sdata, -1, false, true);
358 		if (defmgmtkey && !new)
359 			__ieee80211_set_default_mgmt_key(sdata, -1);
360 
361 		rcu_assign_pointer(sdata->keys[idx], new);
362 		if (defunikey && new)
363 			__ieee80211_set_default_key(sdata, new->conf.keyidx,
364 						    true, false);
365 		if (defmultikey && new)
366 			__ieee80211_set_default_key(sdata, new->conf.keyidx,
367 						    false, true);
368 		if (defmgmtkey && new)
369 			__ieee80211_set_default_mgmt_key(sdata,
370 							 new->conf.keyidx);
371 	}
372 
373 	if (old)
374 		list_del_rcu(&old->list);
375 }
376 
377 struct ieee80211_key *
378 ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
379 		    const u8 *key_data,
380 		    size_t seq_len, const u8 *seq,
381 		    const struct ieee80211_cipher_scheme *cs)
382 {
383 	struct ieee80211_key *key;
384 	int i, j, err;
385 
386 	if (WARN_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS))
387 		return ERR_PTR(-EINVAL);
388 
389 	key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
390 	if (!key)
391 		return ERR_PTR(-ENOMEM);
392 
393 	/*
394 	 * Default to software encryption; we'll later upload the
395 	 * key to the hardware if possible.
396 	 */
397 	key->conf.flags = 0;
398 	key->flags = 0;
399 
400 	key->conf.cipher = cipher;
401 	key->conf.keyidx = idx;
402 	key->conf.keylen = key_len;
403 	switch (cipher) {
404 	case WLAN_CIPHER_SUITE_WEP40:
405 	case WLAN_CIPHER_SUITE_WEP104:
406 		key->conf.iv_len = IEEE80211_WEP_IV_LEN;
407 		key->conf.icv_len = IEEE80211_WEP_ICV_LEN;
408 		break;
409 	case WLAN_CIPHER_SUITE_TKIP:
410 		key->conf.iv_len = IEEE80211_TKIP_IV_LEN;
411 		key->conf.icv_len = IEEE80211_TKIP_ICV_LEN;
412 		if (seq) {
413 			for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
414 				key->u.tkip.rx[i].iv32 =
415 					get_unaligned_le32(&seq[2]);
416 				key->u.tkip.rx[i].iv16 =
417 					get_unaligned_le16(seq);
418 			}
419 		}
420 		spin_lock_init(&key->u.tkip.txlock);
421 		break;
422 	case WLAN_CIPHER_SUITE_CCMP:
423 		key->conf.iv_len = IEEE80211_CCMP_HDR_LEN;
424 		key->conf.icv_len = IEEE80211_CCMP_MIC_LEN;
425 		if (seq) {
426 			for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
427 				for (j = 0; j < IEEE80211_CCMP_PN_LEN; j++)
428 					key->u.ccmp.rx_pn[i][j] =
429 						seq[IEEE80211_CCMP_PN_LEN - j - 1];
430 		}
431 		/*
432 		 * Initialize AES key state here as an optimization so that
433 		 * it does not need to be initialized for every packet.
434 		 */
435 		key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(
436 			key_data, key_len, IEEE80211_CCMP_MIC_LEN);
437 		if (IS_ERR(key->u.ccmp.tfm)) {
438 			err = PTR_ERR(key->u.ccmp.tfm);
439 			kfree(key);
440 			return ERR_PTR(err);
441 		}
442 		break;
443 	case WLAN_CIPHER_SUITE_CCMP_256:
444 		key->conf.iv_len = IEEE80211_CCMP_256_HDR_LEN;
445 		key->conf.icv_len = IEEE80211_CCMP_256_MIC_LEN;
446 		for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++)
447 			for (j = 0; j < IEEE80211_CCMP_256_PN_LEN; j++)
448 				key->u.ccmp.rx_pn[i][j] =
449 					seq[IEEE80211_CCMP_256_PN_LEN - j - 1];
450 		/* Initialize AES key state here as an optimization so that
451 		 * it does not need to be initialized for every packet.
452 		 */
453 		key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(
454 			key_data, key_len, IEEE80211_CCMP_256_MIC_LEN);
455 		if (IS_ERR(key->u.ccmp.tfm)) {
456 			err = PTR_ERR(key->u.ccmp.tfm);
457 			kfree(key);
458 			return ERR_PTR(err);
459 		}
460 		break;
461 	case WLAN_CIPHER_SUITE_AES_CMAC:
462 	case WLAN_CIPHER_SUITE_BIP_CMAC_256:
463 		key->conf.iv_len = 0;
464 		if (cipher == WLAN_CIPHER_SUITE_AES_CMAC)
465 			key->conf.icv_len = sizeof(struct ieee80211_mmie);
466 		else
467 			key->conf.icv_len = sizeof(struct ieee80211_mmie_16);
468 		if (seq)
469 			for (j = 0; j < IEEE80211_CMAC_PN_LEN; j++)
470 				key->u.aes_cmac.rx_pn[j] =
471 					seq[IEEE80211_CMAC_PN_LEN - j - 1];
472 		/*
473 		 * Initialize AES key state here as an optimization so that
474 		 * it does not need to be initialized for every packet.
475 		 */
476 		key->u.aes_cmac.tfm =
477 			ieee80211_aes_cmac_key_setup(key_data, key_len);
478 		if (IS_ERR(key->u.aes_cmac.tfm)) {
479 			err = PTR_ERR(key->u.aes_cmac.tfm);
480 			kfree(key);
481 			return ERR_PTR(err);
482 		}
483 		break;
484 	case WLAN_CIPHER_SUITE_BIP_GMAC_128:
485 	case WLAN_CIPHER_SUITE_BIP_GMAC_256:
486 		key->conf.iv_len = 0;
487 		key->conf.icv_len = sizeof(struct ieee80211_mmie_16);
488 		if (seq)
489 			for (j = 0; j < IEEE80211_GMAC_PN_LEN; j++)
490 				key->u.aes_gmac.rx_pn[j] =
491 					seq[IEEE80211_GMAC_PN_LEN - j - 1];
492 		/* Initialize AES key state here as an optimization so that
493 		 * it does not need to be initialized for every packet.
494 		 */
495 		key->u.aes_gmac.tfm =
496 			ieee80211_aes_gmac_key_setup(key_data, key_len);
497 		if (IS_ERR(key->u.aes_gmac.tfm)) {
498 			err = PTR_ERR(key->u.aes_gmac.tfm);
499 			kfree(key);
500 			return ERR_PTR(err);
501 		}
502 		break;
503 	case WLAN_CIPHER_SUITE_GCMP:
504 	case WLAN_CIPHER_SUITE_GCMP_256:
505 		key->conf.iv_len = IEEE80211_GCMP_HDR_LEN;
506 		key->conf.icv_len = IEEE80211_GCMP_MIC_LEN;
507 		for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++)
508 			for (j = 0; j < IEEE80211_GCMP_PN_LEN; j++)
509 				key->u.gcmp.rx_pn[i][j] =
510 					seq[IEEE80211_GCMP_PN_LEN - j - 1];
511 		/* Initialize AES key state here as an optimization so that
512 		 * it does not need to be initialized for every packet.
513 		 */
514 		key->u.gcmp.tfm = ieee80211_aes_gcm_key_setup_encrypt(key_data,
515 								      key_len);
516 		if (IS_ERR(key->u.gcmp.tfm)) {
517 			err = PTR_ERR(key->u.gcmp.tfm);
518 			kfree(key);
519 			return ERR_PTR(err);
520 		}
521 		break;
522 	default:
523 		if (cs) {
524 			if (seq_len && seq_len != cs->pn_len) {
525 				kfree(key);
526 				return ERR_PTR(-EINVAL);
527 			}
528 
529 			key->conf.iv_len = cs->hdr_len;
530 			key->conf.icv_len = cs->mic_len;
531 			for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
532 				for (j = 0; j < seq_len; j++)
533 					key->u.gen.rx_pn[i][j] =
534 							seq[seq_len - j - 1];
535 			key->flags |= KEY_FLAG_CIPHER_SCHEME;
536 		}
537 	}
538 	memcpy(key->conf.key, key_data, key_len);
539 	INIT_LIST_HEAD(&key->list);
540 
541 	return key;
542 }
543 
544 static void ieee80211_key_free_common(struct ieee80211_key *key)
545 {
546 	switch (key->conf.cipher) {
547 	case WLAN_CIPHER_SUITE_CCMP:
548 	case WLAN_CIPHER_SUITE_CCMP_256:
549 		ieee80211_aes_key_free(key->u.ccmp.tfm);
550 		break;
551 	case WLAN_CIPHER_SUITE_AES_CMAC:
552 	case WLAN_CIPHER_SUITE_BIP_CMAC_256:
553 		ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
554 		break;
555 	case WLAN_CIPHER_SUITE_BIP_GMAC_128:
556 	case WLAN_CIPHER_SUITE_BIP_GMAC_256:
557 		ieee80211_aes_gmac_key_free(key->u.aes_gmac.tfm);
558 		break;
559 	case WLAN_CIPHER_SUITE_GCMP:
560 	case WLAN_CIPHER_SUITE_GCMP_256:
561 		ieee80211_aes_gcm_key_free(key->u.gcmp.tfm);
562 		break;
563 	}
564 	kzfree(key);
565 }
566 
567 static void __ieee80211_key_destroy(struct ieee80211_key *key,
568 				    bool delay_tailroom)
569 {
570 	if (key->local)
571 		ieee80211_key_disable_hw_accel(key);
572 
573 	if (key->local) {
574 		struct ieee80211_sub_if_data *sdata = key->sdata;
575 
576 		ieee80211_debugfs_key_remove(key);
577 
578 		if (delay_tailroom) {
579 			/* see ieee80211_delayed_tailroom_dec */
580 			sdata->crypto_tx_tailroom_pending_dec++;
581 			schedule_delayed_work(&sdata->dec_tailroom_needed_wk,
582 					      HZ/2);
583 		} else {
584 			decrease_tailroom_need_count(sdata, 1);
585 		}
586 	}
587 
588 	ieee80211_key_free_common(key);
589 }
590 
591 static void ieee80211_key_destroy(struct ieee80211_key *key,
592 				  bool delay_tailroom)
593 {
594 	if (!key)
595 		return;
596 
597 	/*
598 	 * Synchronize so the TX path and rcu key iterators
599 	 * can no longer be using this key before we free/remove it.
600 	 */
601 	synchronize_net();
602 
603 	__ieee80211_key_destroy(key, delay_tailroom);
604 }
605 
606 void ieee80211_key_free_unused(struct ieee80211_key *key)
607 {
608 	WARN_ON(key->sdata || key->local);
609 	ieee80211_key_free_common(key);
610 }
611 
612 int ieee80211_key_link(struct ieee80211_key *key,
613 		       struct ieee80211_sub_if_data *sdata,
614 		       struct sta_info *sta)
615 {
616 	struct ieee80211_local *local = sdata->local;
617 	struct ieee80211_key *old_key;
618 	int idx, ret;
619 	bool pairwise;
620 
621 	pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
622 	idx = key->conf.keyidx;
623 
624 	mutex_lock(&sdata->local->key_mtx);
625 
626 	if (sta && pairwise)
627 		old_key = key_mtx_dereference(sdata->local, sta->ptk[idx]);
628 	else if (sta)
629 		old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
630 	else
631 		old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
632 
633 	/*
634 	 * Silently accept key re-installation without really installing the
635 	 * new version of the key to avoid nonce reuse or replay issues.
636 	 */
637 	if (old_key && key->conf.keylen == old_key->conf.keylen &&
638 	    !memcmp(key->conf.key, old_key->conf.key, key->conf.keylen)) {
639 		ieee80211_key_free_unused(key);
640 		ret = 0;
641 		goto out;
642 	}
643 
644 	key->local = sdata->local;
645 	key->sdata = sdata;
646 	key->sta = sta;
647 
648 	increment_tailroom_need_count(sdata);
649 
650 	ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
651 	ieee80211_key_destroy(old_key, true);
652 
653 	ieee80211_debugfs_key_add(key);
654 
655 	if (!local->wowlan) {
656 		ret = ieee80211_key_enable_hw_accel(key);
657 		if (ret)
658 			ieee80211_key_free(key, true);
659 	} else {
660 		ret = 0;
661 	}
662 
663  out:
664 	mutex_unlock(&sdata->local->key_mtx);
665 
666 	return ret;
667 }
668 
669 void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom)
670 {
671 	if (!key)
672 		return;
673 
674 	/*
675 	 * Replace key with nothingness if it was ever used.
676 	 */
677 	if (key->sdata)
678 		ieee80211_key_replace(key->sdata, key->sta,
679 				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
680 				key, NULL);
681 	ieee80211_key_destroy(key, delay_tailroom);
682 }
683 
684 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
685 {
686 	struct ieee80211_key *key;
687 	struct ieee80211_sub_if_data *vlan;
688 
689 	ASSERT_RTNL();
690 
691 	if (WARN_ON(!ieee80211_sdata_running(sdata)))
692 		return;
693 
694 	mutex_lock(&sdata->local->key_mtx);
695 
696 	WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
697 		     sdata->crypto_tx_tailroom_pending_dec);
698 
699 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
700 		list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
701 			WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
702 				     vlan->crypto_tx_tailroom_pending_dec);
703 	}
704 
705 	list_for_each_entry(key, &sdata->key_list, list) {
706 		increment_tailroom_need_count(sdata);
707 		ieee80211_key_enable_hw_accel(key);
708 	}
709 
710 	mutex_unlock(&sdata->local->key_mtx);
711 }
712 
713 void ieee80211_reset_crypto_tx_tailroom(struct ieee80211_sub_if_data *sdata)
714 {
715 	struct ieee80211_sub_if_data *vlan;
716 
717 	mutex_lock(&sdata->local->key_mtx);
718 
719 	sdata->crypto_tx_tailroom_needed_cnt = 0;
720 
721 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
722 		list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
723 			vlan->crypto_tx_tailroom_needed_cnt = 0;
724 	}
725 
726 	mutex_unlock(&sdata->local->key_mtx);
727 }
728 
729 void ieee80211_iter_keys(struct ieee80211_hw *hw,
730 			 struct ieee80211_vif *vif,
731 			 void (*iter)(struct ieee80211_hw *hw,
732 				      struct ieee80211_vif *vif,
733 				      struct ieee80211_sta *sta,
734 				      struct ieee80211_key_conf *key,
735 				      void *data),
736 			 void *iter_data)
737 {
738 	struct ieee80211_local *local = hw_to_local(hw);
739 	struct ieee80211_key *key, *tmp;
740 	struct ieee80211_sub_if_data *sdata;
741 
742 	ASSERT_RTNL();
743 
744 	mutex_lock(&local->key_mtx);
745 	if (vif) {
746 		sdata = vif_to_sdata(vif);
747 		list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
748 			iter(hw, &sdata->vif,
749 			     key->sta ? &key->sta->sta : NULL,
750 			     &key->conf, iter_data);
751 	} else {
752 		list_for_each_entry(sdata, &local->interfaces, list)
753 			list_for_each_entry_safe(key, tmp,
754 						 &sdata->key_list, list)
755 				iter(hw, &sdata->vif,
756 				     key->sta ? &key->sta->sta : NULL,
757 				     &key->conf, iter_data);
758 	}
759 	mutex_unlock(&local->key_mtx);
760 }
761 EXPORT_SYMBOL(ieee80211_iter_keys);
762 
763 static void
764 _ieee80211_iter_keys_rcu(struct ieee80211_hw *hw,
765 			 struct ieee80211_sub_if_data *sdata,
766 			 void (*iter)(struct ieee80211_hw *hw,
767 				      struct ieee80211_vif *vif,
768 				      struct ieee80211_sta *sta,
769 				      struct ieee80211_key_conf *key,
770 				      void *data),
771 			 void *iter_data)
772 {
773 	struct ieee80211_key *key;
774 
775 	list_for_each_entry_rcu(key, &sdata->key_list, list) {
776 		/* skip keys of station in removal process */
777 		if (key->sta && key->sta->removed)
778 			continue;
779 		if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
780 			continue;
781 
782 		iter(hw, &sdata->vif,
783 		     key->sta ? &key->sta->sta : NULL,
784 		     &key->conf, iter_data);
785 	}
786 }
787 
788 void ieee80211_iter_keys_rcu(struct ieee80211_hw *hw,
789 			     struct ieee80211_vif *vif,
790 			     void (*iter)(struct ieee80211_hw *hw,
791 					  struct ieee80211_vif *vif,
792 					  struct ieee80211_sta *sta,
793 					  struct ieee80211_key_conf *key,
794 					  void *data),
795 			     void *iter_data)
796 {
797 	struct ieee80211_local *local = hw_to_local(hw);
798 	struct ieee80211_sub_if_data *sdata;
799 
800 	if (vif) {
801 		sdata = vif_to_sdata(vif);
802 		_ieee80211_iter_keys_rcu(hw, sdata, iter, iter_data);
803 	} else {
804 		list_for_each_entry_rcu(sdata, &local->interfaces, list)
805 			_ieee80211_iter_keys_rcu(hw, sdata, iter, iter_data);
806 	}
807 }
808 EXPORT_SYMBOL(ieee80211_iter_keys_rcu);
809 
810 static void ieee80211_free_keys_iface(struct ieee80211_sub_if_data *sdata,
811 				      struct list_head *keys)
812 {
813 	struct ieee80211_key *key, *tmp;
814 
815 	decrease_tailroom_need_count(sdata,
816 				     sdata->crypto_tx_tailroom_pending_dec);
817 	sdata->crypto_tx_tailroom_pending_dec = 0;
818 
819 	ieee80211_debugfs_key_remove_mgmt_default(sdata);
820 
821 	list_for_each_entry_safe(key, tmp, &sdata->key_list, list) {
822 		ieee80211_key_replace(key->sdata, key->sta,
823 				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
824 				key, NULL);
825 		list_add_tail(&key->list, keys);
826 	}
827 
828 	ieee80211_debugfs_key_update_default(sdata);
829 }
830 
831 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata,
832 			 bool force_synchronize)
833 {
834 	struct ieee80211_local *local = sdata->local;
835 	struct ieee80211_sub_if_data *vlan;
836 	struct ieee80211_sub_if_data *master;
837 	struct ieee80211_key *key, *tmp;
838 	LIST_HEAD(keys);
839 
840 	cancel_delayed_work_sync(&sdata->dec_tailroom_needed_wk);
841 
842 	mutex_lock(&local->key_mtx);
843 
844 	ieee80211_free_keys_iface(sdata, &keys);
845 
846 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
847 		list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
848 			ieee80211_free_keys_iface(vlan, &keys);
849 	}
850 
851 	if (!list_empty(&keys) || force_synchronize)
852 		synchronize_net();
853 	list_for_each_entry_safe(key, tmp, &keys, list)
854 		__ieee80211_key_destroy(key, false);
855 
856 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
857 		if (sdata->bss) {
858 			master = container_of(sdata->bss,
859 					      struct ieee80211_sub_if_data,
860 					      u.ap);
861 
862 			WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt !=
863 				     master->crypto_tx_tailroom_needed_cnt);
864 		}
865 	} else {
866 		WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
867 			     sdata->crypto_tx_tailroom_pending_dec);
868 	}
869 
870 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
871 		list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
872 			WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
873 				     vlan->crypto_tx_tailroom_pending_dec);
874 	}
875 
876 	mutex_unlock(&local->key_mtx);
877 }
878 
879 void ieee80211_free_sta_keys(struct ieee80211_local *local,
880 			     struct sta_info *sta)
881 {
882 	struct ieee80211_key *key;
883 	int i;
884 
885 	mutex_lock(&local->key_mtx);
886 	for (i = 0; i < ARRAY_SIZE(sta->gtk); i++) {
887 		key = key_mtx_dereference(local, sta->gtk[i]);
888 		if (!key)
889 			continue;
890 		ieee80211_key_replace(key->sdata, key->sta,
891 				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
892 				key, NULL);
893 		__ieee80211_key_destroy(key, true);
894 	}
895 
896 	for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
897 		key = key_mtx_dereference(local, sta->ptk[i]);
898 		if (!key)
899 			continue;
900 		ieee80211_key_replace(key->sdata, key->sta,
901 				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
902 				key, NULL);
903 		__ieee80211_key_destroy(key, true);
904 	}
905 
906 	mutex_unlock(&local->key_mtx);
907 }
908 
909 void ieee80211_delayed_tailroom_dec(struct work_struct *wk)
910 {
911 	struct ieee80211_sub_if_data *sdata;
912 
913 	sdata = container_of(wk, struct ieee80211_sub_if_data,
914 			     dec_tailroom_needed_wk.work);
915 
916 	/*
917 	 * The reason for the delayed tailroom needed decrementing is to
918 	 * make roaming faster: during roaming, all keys are first deleted
919 	 * and then new keys are installed. The first new key causes the
920 	 * crypto_tx_tailroom_needed_cnt to go from 0 to 1, which invokes
921 	 * the cost of synchronize_net() (which can be slow). Avoid this
922 	 * by deferring the crypto_tx_tailroom_needed_cnt decrementing on
923 	 * key removal for a while, so if we roam the value is larger than
924 	 * zero and no 0->1 transition happens.
925 	 *
926 	 * The cost is that if the AP switching was from an AP with keys
927 	 * to one without, we still allocate tailroom while it would no
928 	 * longer be needed. However, in the typical (fast) roaming case
929 	 * within an ESS this usually won't happen.
930 	 */
931 
932 	mutex_lock(&sdata->local->key_mtx);
933 	decrease_tailroom_need_count(sdata,
934 				     sdata->crypto_tx_tailroom_pending_dec);
935 	sdata->crypto_tx_tailroom_pending_dec = 0;
936 	mutex_unlock(&sdata->local->key_mtx);
937 }
938 
939 void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid,
940 				const u8 *replay_ctr, gfp_t gfp)
941 {
942 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
943 
944 	trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr);
945 
946 	cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
947 }
948 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);
949 
950 void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
951 			      int tid, struct ieee80211_key_seq *seq)
952 {
953 	struct ieee80211_key *key;
954 	const u8 *pn;
955 
956 	key = container_of(keyconf, struct ieee80211_key, conf);
957 
958 	switch (key->conf.cipher) {
959 	case WLAN_CIPHER_SUITE_TKIP:
960 		if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
961 			return;
962 		seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
963 		seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
964 		break;
965 	case WLAN_CIPHER_SUITE_CCMP:
966 	case WLAN_CIPHER_SUITE_CCMP_256:
967 		if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
968 			return;
969 		if (tid < 0)
970 			pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
971 		else
972 			pn = key->u.ccmp.rx_pn[tid];
973 		memcpy(seq->ccmp.pn, pn, IEEE80211_CCMP_PN_LEN);
974 		break;
975 	case WLAN_CIPHER_SUITE_AES_CMAC:
976 	case WLAN_CIPHER_SUITE_BIP_CMAC_256:
977 		if (WARN_ON(tid != 0))
978 			return;
979 		pn = key->u.aes_cmac.rx_pn;
980 		memcpy(seq->aes_cmac.pn, pn, IEEE80211_CMAC_PN_LEN);
981 		break;
982 	case WLAN_CIPHER_SUITE_BIP_GMAC_128:
983 	case WLAN_CIPHER_SUITE_BIP_GMAC_256:
984 		if (WARN_ON(tid != 0))
985 			return;
986 		pn = key->u.aes_gmac.rx_pn;
987 		memcpy(seq->aes_gmac.pn, pn, IEEE80211_GMAC_PN_LEN);
988 		break;
989 	case WLAN_CIPHER_SUITE_GCMP:
990 	case WLAN_CIPHER_SUITE_GCMP_256:
991 		if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
992 			return;
993 		if (tid < 0)
994 			pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
995 		else
996 			pn = key->u.gcmp.rx_pn[tid];
997 		memcpy(seq->gcmp.pn, pn, IEEE80211_GCMP_PN_LEN);
998 		break;
999 	}
1000 }
1001 EXPORT_SYMBOL(ieee80211_get_key_rx_seq);
1002 
1003 void ieee80211_set_key_rx_seq(struct ieee80211_key_conf *keyconf,
1004 			      int tid, struct ieee80211_key_seq *seq)
1005 {
1006 	struct ieee80211_key *key;
1007 	u8 *pn;
1008 
1009 	key = container_of(keyconf, struct ieee80211_key, conf);
1010 
1011 	switch (key->conf.cipher) {
1012 	case WLAN_CIPHER_SUITE_TKIP:
1013 		if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
1014 			return;
1015 		key->u.tkip.rx[tid].iv32 = seq->tkip.iv32;
1016 		key->u.tkip.rx[tid].iv16 = seq->tkip.iv16;
1017 		break;
1018 	case WLAN_CIPHER_SUITE_CCMP:
1019 	case WLAN_CIPHER_SUITE_CCMP_256:
1020 		if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1021 			return;
1022 		if (tid < 0)
1023 			pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
1024 		else
1025 			pn = key->u.ccmp.rx_pn[tid];
1026 		memcpy(pn, seq->ccmp.pn, IEEE80211_CCMP_PN_LEN);
1027 		break;
1028 	case WLAN_CIPHER_SUITE_AES_CMAC:
1029 	case WLAN_CIPHER_SUITE_BIP_CMAC_256:
1030 		if (WARN_ON(tid != 0))
1031 			return;
1032 		pn = key->u.aes_cmac.rx_pn;
1033 		memcpy(pn, seq->aes_cmac.pn, IEEE80211_CMAC_PN_LEN);
1034 		break;
1035 	case WLAN_CIPHER_SUITE_BIP_GMAC_128:
1036 	case WLAN_CIPHER_SUITE_BIP_GMAC_256:
1037 		if (WARN_ON(tid != 0))
1038 			return;
1039 		pn = key->u.aes_gmac.rx_pn;
1040 		memcpy(pn, seq->aes_gmac.pn, IEEE80211_GMAC_PN_LEN);
1041 		break;
1042 	case WLAN_CIPHER_SUITE_GCMP:
1043 	case WLAN_CIPHER_SUITE_GCMP_256:
1044 		if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1045 			return;
1046 		if (tid < 0)
1047 			pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
1048 		else
1049 			pn = key->u.gcmp.rx_pn[tid];
1050 		memcpy(pn, seq->gcmp.pn, IEEE80211_GCMP_PN_LEN);
1051 		break;
1052 	default:
1053 		WARN_ON(1);
1054 		break;
1055 	}
1056 }
1057 EXPORT_SYMBOL_GPL(ieee80211_set_key_rx_seq);
1058 
1059 void ieee80211_remove_key(struct ieee80211_key_conf *keyconf)
1060 {
1061 	struct ieee80211_key *key;
1062 
1063 	key = container_of(keyconf, struct ieee80211_key, conf);
1064 
1065 	assert_key_lock(key->local);
1066 
1067 	/*
1068 	 * if key was uploaded, we assume the driver will/has remove(d)
1069 	 * it, so adjust bookkeeping accordingly
1070 	 */
1071 	if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
1072 		key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
1073 
1074 		if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
1075 		      (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
1076 			increment_tailroom_need_count(key->sdata);
1077 	}
1078 
1079 	ieee80211_key_free(key, false);
1080 }
1081 EXPORT_SYMBOL_GPL(ieee80211_remove_key);
1082 
1083 struct ieee80211_key_conf *
1084 ieee80211_gtk_rekey_add(struct ieee80211_vif *vif,
1085 			struct ieee80211_key_conf *keyconf)
1086 {
1087 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
1088 	struct ieee80211_local *local = sdata->local;
1089 	struct ieee80211_key *key;
1090 	int err;
1091 
1092 	if (WARN_ON(!local->wowlan))
1093 		return ERR_PTR(-EINVAL);
1094 
1095 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
1096 		return ERR_PTR(-EINVAL);
1097 
1098 	key = ieee80211_key_alloc(keyconf->cipher, keyconf->keyidx,
1099 				  keyconf->keylen, keyconf->key,
1100 				  0, NULL, NULL);
1101 	if (IS_ERR(key))
1102 		return ERR_CAST(key);
1103 
1104 	if (sdata->u.mgd.mfp != IEEE80211_MFP_DISABLED)
1105 		key->conf.flags |= IEEE80211_KEY_FLAG_RX_MGMT;
1106 
1107 	err = ieee80211_key_link(key, sdata, NULL);
1108 	if (err)
1109 		return ERR_PTR(err);
1110 
1111 	return &key->conf;
1112 }
1113 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_add);
1114