1 /*-
2 * Copyright (c) 2001 Atsushi Onoe
3 * Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29
30 /*
31 * IEEE 802.11 generic crypto support.
32 */
33 #include "opt_wlan.h"
34
35 #include <sys/param.h>
36 #include <sys/kernel.h>
37 #include <sys/malloc.h>
38 #include <sys/mbuf.h>
39
40 #include <sys/socket.h>
41
42 #include <net/if.h>
43 #include <net/if_var.h>
44 #include <net/if_media.h>
45 #include <net/ethernet.h> /* XXX ETHER_HDR_LEN */
46
47 #include <netproto/802_11/ieee80211_var.h>
48
49 MALLOC_DEFINE(M_80211_CRYPTO, "80211crypto", "802.11 crypto state");
50
51 static int _ieee80211_crypto_delkey(struct ieee80211vap *,
52 struct ieee80211_key *);
53
54 /*
55 * Table of registered cipher modules.
56 */
57 static const struct ieee80211_cipher *ciphers[IEEE80211_CIPHER_MAX];
58
59 /*
60 * Default "null" key management routines.
61 */
62 static int
null_key_alloc(struct ieee80211vap * vap,struct ieee80211_key * k,ieee80211_keyix * keyix,ieee80211_keyix * rxkeyix)63 null_key_alloc(struct ieee80211vap *vap, struct ieee80211_key *k,
64 ieee80211_keyix *keyix, ieee80211_keyix *rxkeyix)
65 {
66 if (!(&vap->iv_nw_keys[0] <= k &&
67 k < &vap->iv_nw_keys[IEEE80211_WEP_NKID])) {
68 /*
69 * Not in the global key table, the driver should handle this
70 * by allocating a slot in the h/w key table/cache. In
71 * lieu of that return key slot 0 for any unicast key
72 * request. We disallow the request if this is a group key.
73 * This default policy does the right thing for legacy hardware
74 * with a 4 key table. It also handles devices that pass
75 * packets through untouched when marked with the WEP bit
76 * and key index 0.
77 */
78 if (k->wk_flags & IEEE80211_KEY_GROUP)
79 return 0;
80 *keyix = 0; /* NB: use key index 0 for ucast key */
81 } else {
82 *keyix = k - vap->iv_nw_keys;
83 }
84 *rxkeyix = IEEE80211_KEYIX_NONE; /* XXX maybe *keyix? */
85 return 1;
86 }
87 static int
null_key_delete(struct ieee80211vap * vap,const struct ieee80211_key * k)88 null_key_delete(struct ieee80211vap *vap, const struct ieee80211_key *k)
89 {
90 return 1;
91 }
92 static int
null_key_set(struct ieee80211vap * vap,const struct ieee80211_key * k)93 null_key_set(struct ieee80211vap *vap, const struct ieee80211_key *k)
94 {
95 return 1;
96 }
null_key_update(struct ieee80211vap * vap)97 static void null_key_update(struct ieee80211vap *vap) {}
98
99 /*
100 * Write-arounds for common operations.
101 */
102 static __inline void
cipher_detach(struct ieee80211_key * key)103 cipher_detach(struct ieee80211_key *key)
104 {
105 key->wk_cipher->ic_detach(key);
106 }
107
108 static __inline void *
cipher_attach(struct ieee80211vap * vap,struct ieee80211_key * key)109 cipher_attach(struct ieee80211vap *vap, struct ieee80211_key *key)
110 {
111 return key->wk_cipher->ic_attach(vap, key);
112 }
113
114 /*
115 * Wrappers for driver key management methods.
116 */
117 static __inline int
dev_key_alloc(struct ieee80211vap * vap,struct ieee80211_key * key,ieee80211_keyix * keyix,ieee80211_keyix * rxkeyix)118 dev_key_alloc(struct ieee80211vap *vap,
119 struct ieee80211_key *key,
120 ieee80211_keyix *keyix, ieee80211_keyix *rxkeyix)
121 {
122 return vap->iv_key_alloc(vap, key, keyix, rxkeyix);
123 }
124
125 static __inline int
dev_key_delete(struct ieee80211vap * vap,const struct ieee80211_key * key)126 dev_key_delete(struct ieee80211vap *vap,
127 const struct ieee80211_key *key)
128 {
129 return vap->iv_key_delete(vap, key);
130 }
131
132 static __inline int
dev_key_set(struct ieee80211vap * vap,const struct ieee80211_key * key)133 dev_key_set(struct ieee80211vap *vap, const struct ieee80211_key *key)
134 {
135 return vap->iv_key_set(vap, key);
136 }
137
138 /*
139 * Setup crypto support for a device/shared instance.
140 */
141 void
ieee80211_crypto_attach(struct ieee80211com * ic)142 ieee80211_crypto_attach(struct ieee80211com *ic)
143 {
144 /* NB: we assume everything is pre-zero'd */
145 ciphers[IEEE80211_CIPHER_NONE] = &ieee80211_cipher_none;
146 }
147
148 /*
149 * Teardown crypto support.
150 */
151 void
ieee80211_crypto_detach(struct ieee80211com * ic)152 ieee80211_crypto_detach(struct ieee80211com *ic)
153 {
154 }
155
156 /*
157 * Setup crypto support for a vap.
158 */
159 void
ieee80211_crypto_vattach(struct ieee80211vap * vap)160 ieee80211_crypto_vattach(struct ieee80211vap *vap)
161 {
162 int i;
163
164 /* NB: we assume everything is pre-zero'd */
165 vap->iv_max_keyix = IEEE80211_WEP_NKID;
166 vap->iv_def_txkey = IEEE80211_KEYIX_NONE;
167 for (i = 0; i < IEEE80211_WEP_NKID; i++)
168 ieee80211_crypto_resetkey(vap, &vap->iv_nw_keys[i],
169 IEEE80211_KEYIX_NONE);
170 /*
171 * Initialize the driver key support routines to noop entries.
172 * This is useful especially for the cipher test modules.
173 */
174 vap->iv_key_alloc = null_key_alloc;
175 vap->iv_key_set = null_key_set;
176 vap->iv_key_delete = null_key_delete;
177 vap->iv_key_update_begin = null_key_update;
178 vap->iv_key_update_end = null_key_update;
179 }
180
181 /*
182 * Teardown crypto support for a vap.
183 */
184 void
ieee80211_crypto_vdetach(struct ieee80211vap * vap)185 ieee80211_crypto_vdetach(struct ieee80211vap *vap)
186 {
187 ieee80211_crypto_delglobalkeys(vap);
188 }
189
190 /*
191 * Register a crypto cipher module.
192 */
193 void
ieee80211_crypto_register(const struct ieee80211_cipher * cip)194 ieee80211_crypto_register(const struct ieee80211_cipher *cip)
195 {
196 if (cip->ic_cipher >= IEEE80211_CIPHER_MAX) {
197 kprintf("%s: cipher %s has an invalid cipher index %u\n",
198 __func__, cip->ic_name, cip->ic_cipher);
199 return;
200 }
201 if (ciphers[cip->ic_cipher] != NULL && ciphers[cip->ic_cipher] != cip) {
202 kprintf("%s: cipher %s registered with a different template\n",
203 __func__, cip->ic_name);
204 return;
205 }
206 ciphers[cip->ic_cipher] = cip;
207 }
208
209 /*
210 * Unregister a crypto cipher module.
211 */
212 void
ieee80211_crypto_unregister(const struct ieee80211_cipher * cip)213 ieee80211_crypto_unregister(const struct ieee80211_cipher *cip)
214 {
215 if (cip->ic_cipher >= IEEE80211_CIPHER_MAX) {
216 kprintf("%s: cipher %s has an invalid cipher index %u\n",
217 __func__, cip->ic_name, cip->ic_cipher);
218 return;
219 }
220 if (ciphers[cip->ic_cipher] != NULL && ciphers[cip->ic_cipher] != cip) {
221 kprintf("%s: cipher %s registered with a different template\n",
222 __func__, cip->ic_name);
223 return;
224 }
225 /* NB: don't complain about not being registered */
226 /* XXX disallow if references */
227 ciphers[cip->ic_cipher] = NULL;
228 }
229
230 int
ieee80211_crypto_available(u_int cipher)231 ieee80211_crypto_available(u_int cipher)
232 {
233 return cipher < IEEE80211_CIPHER_MAX && ciphers[cipher] != NULL;
234 }
235
236 /* XXX well-known names! */
237 static const char *cipher_modnames[IEEE80211_CIPHER_MAX] = {
238 [IEEE80211_CIPHER_WEP] = "wlan_wep",
239 [IEEE80211_CIPHER_TKIP] = "wlan_tkip",
240 [IEEE80211_CIPHER_AES_OCB] = "wlan_aes_ocb",
241 [IEEE80211_CIPHER_AES_CCM] = "wlan_ccmp",
242 [IEEE80211_CIPHER_TKIPMIC] = "#4", /* NB: reserved */
243 [IEEE80211_CIPHER_CKIP] = "wlan_ckip",
244 [IEEE80211_CIPHER_NONE] = "wlan_none",
245 };
246
247 /* NB: there must be no overlap between user-supplied and device-owned flags */
248 CTASSERT((IEEE80211_KEY_COMMON & IEEE80211_KEY_DEVICE) == 0);
249
250 /*
251 * Establish a relationship between the specified key and cipher
252 * and, if necessary, allocate a hardware index from the driver.
253 * Note that when a fixed key index is required it must be specified.
254 *
255 * This must be the first call applied to a key; all the other key
256 * routines assume wk_cipher is setup.
257 *
258 * Locking must be handled by the caller using:
259 * ieee80211_key_update_begin(vap);
260 * ieee80211_key_update_end(vap);
261 */
262 int
ieee80211_crypto_newkey(struct ieee80211vap * vap,int cipher,int flags,struct ieee80211_key * key)263 ieee80211_crypto_newkey(struct ieee80211vap *vap,
264 int cipher, int flags, struct ieee80211_key *key)
265 {
266 struct ieee80211com *ic = vap->iv_ic;
267 const struct ieee80211_cipher *cip;
268 ieee80211_keyix keyix, rxkeyix;
269 void *keyctx;
270 int oflags;
271
272 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
273 "%s: cipher %u flags 0x%x keyix %u\n",
274 __func__, cipher, flags, key->wk_keyix);
275
276 /*
277 * Validate cipher and set reference to cipher routines.
278 */
279 if (cipher >= IEEE80211_CIPHER_MAX) {
280 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
281 "%s: invalid cipher %u\n", __func__, cipher);
282 vap->iv_stats.is_crypto_badcipher++;
283 return 0;
284 }
285 cip = ciphers[cipher];
286 if (cip == NULL) {
287 /*
288 * Auto-load cipher module if we have a well-known name
289 * for it. It might be better to use string names rather
290 * than numbers and craft a module name based on the cipher
291 * name; e.g. wlan_cipher_<cipher-name>.
292 */
293 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
294 "%s: unregistered cipher %u, load module %s\n",
295 __func__, cipher, cipher_modnames[cipher]);
296 ieee80211_load_module(cipher_modnames[cipher]);
297 /*
298 * If cipher module loaded it should immediately
299 * call ieee80211_crypto_register which will fill
300 * in the entry in the ciphers array.
301 */
302 cip = ciphers[cipher];
303 if (cip == NULL) {
304 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
305 "%s: unable to load cipher %u, module %s\n",
306 __func__, cipher, cipher_modnames[cipher]);
307 vap->iv_stats.is_crypto_nocipher++;
308 return 0;
309 }
310 }
311
312 oflags = key->wk_flags;
313 flags &= IEEE80211_KEY_COMMON;
314 /* NB: preserve device attributes */
315 flags |= (oflags & IEEE80211_KEY_DEVICE);
316 /*
317 * If the hardware does not support the cipher then
318 * fallback to a host-based implementation.
319 */
320 if ((ic->ic_cryptocaps & (1<<cipher)) == 0) {
321 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
322 "%s: no h/w support for cipher %s, falling back to s/w\n",
323 __func__, cip->ic_name);
324 flags |= IEEE80211_KEY_SWCRYPT;
325 }
326 /*
327 * Hardware TKIP with software MIC is an important
328 * combination; we handle it by flagging each key,
329 * the cipher modules honor it.
330 */
331 if (cipher == IEEE80211_CIPHER_TKIP &&
332 (ic->ic_cryptocaps & IEEE80211_CRYPTO_TKIPMIC) == 0) {
333 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
334 "%s: no h/w support for TKIP MIC, falling back to s/w\n",
335 __func__);
336 flags |= IEEE80211_KEY_SWMIC;
337 }
338
339 /*
340 * Bind cipher to key instance. Note we do this
341 * after checking the device capabilities so the
342 * cipher module can optimize space usage based on
343 * whether or not it needs to do the cipher work.
344 */
345 if (key->wk_cipher != cip || key->wk_flags != flags) {
346 /*
347 * Fillin the flags so cipher modules can see s/w
348 * crypto requirements and potentially allocate
349 * different state and/or attach different method
350 * pointers.
351 */
352 key->wk_flags = flags;
353 keyctx = cip->ic_attach(vap, key);
354 if (keyctx == NULL) {
355 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
356 "%s: unable to attach cipher %s\n",
357 __func__, cip->ic_name);
358 key->wk_flags = oflags; /* restore old flags */
359 vap->iv_stats.is_crypto_attachfail++;
360 return 0;
361 }
362 cipher_detach(key);
363 key->wk_cipher = cip; /* XXX refcnt? */
364 key->wk_private = keyctx;
365 }
366
367 /*
368 * Ask the driver for a key index if we don't have one.
369 * Note that entries in the global key table always have
370 * an index; this means it's safe to call this routine
371 * for these entries just to setup the reference to the
372 * cipher template. Note also that when using software
373 * crypto we also call the driver to give us a key index.
374 */
375 if ((key->wk_flags & IEEE80211_KEY_DEVKEY) == 0) {
376 if (!dev_key_alloc(vap, key, &keyix, &rxkeyix)) {
377 /*
378 * Unable to setup driver state.
379 */
380 vap->iv_stats.is_crypto_keyfail++;
381 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
382 "%s: unable to setup cipher %s\n",
383 __func__, cip->ic_name);
384 return 0;
385 }
386 if (key->wk_flags != flags) {
387 /*
388 * Driver overrode flags we setup; typically because
389 * resources were unavailable to handle _this_ key.
390 * Re-attach the cipher context to allow cipher
391 * modules to handle differing requirements.
392 */
393 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
394 "%s: driver override for cipher %s, flags "
395 "0x%x -> 0x%x\n", __func__, cip->ic_name,
396 oflags, key->wk_flags);
397 keyctx = cip->ic_attach(vap, key);
398 if (keyctx == NULL) {
399 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
400 "%s: unable to attach cipher %s with "
401 "flags 0x%x\n", __func__, cip->ic_name,
402 key->wk_flags);
403 key->wk_flags = oflags; /* restore old flags */
404 vap->iv_stats.is_crypto_attachfail++;
405 return 0;
406 }
407 cipher_detach(key);
408 key->wk_cipher = cip; /* XXX refcnt? */
409 key->wk_private = keyctx;
410 }
411 key->wk_keyix = keyix;
412 key->wk_rxkeyix = rxkeyix;
413 key->wk_flags |= IEEE80211_KEY_DEVKEY;
414 }
415 return 1;
416 }
417
418 /*
419 * Remove the key (no locking, for internal use).
420 */
421 static int
_ieee80211_crypto_delkey(struct ieee80211vap * vap,struct ieee80211_key * key)422 _ieee80211_crypto_delkey(struct ieee80211vap *vap, struct ieee80211_key *key)
423 {
424 KASSERT(key->wk_cipher != NULL, ("No cipher!"));
425
426 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
427 "%s: %s keyix %u flags 0x%x rsc %ju tsc %ju len %u\n",
428 __func__, key->wk_cipher->ic_name,
429 key->wk_keyix, key->wk_flags,
430 key->wk_keyrsc[IEEE80211_NONQOS_TID], key->wk_keytsc,
431 key->wk_keylen);
432
433 if (key->wk_flags & IEEE80211_KEY_DEVKEY) {
434 /*
435 * Remove hardware entry.
436 */
437 /* XXX key cache */
438 if (!dev_key_delete(vap, key)) {
439 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
440 "%s: driver did not delete key index %u\n",
441 __func__, key->wk_keyix);
442 vap->iv_stats.is_crypto_delkey++;
443 /* XXX recovery? */
444 }
445 }
446 cipher_detach(key);
447 memset(key, 0, sizeof(*key));
448 ieee80211_crypto_resetkey(vap, key, IEEE80211_KEYIX_NONE);
449 return 1;
450 }
451
452 /*
453 * Remove the specified key.
454 */
455 int
ieee80211_crypto_delkey(struct ieee80211vap * vap,struct ieee80211_key * key)456 ieee80211_crypto_delkey(struct ieee80211vap *vap, struct ieee80211_key *key)
457 {
458 int status;
459
460 ieee80211_key_update_begin(vap);
461 status = _ieee80211_crypto_delkey(vap, key);
462 ieee80211_key_update_end(vap);
463 return status;
464 }
465
466 /*
467 * Clear the global key table.
468 */
469 void
ieee80211_crypto_delglobalkeys(struct ieee80211vap * vap)470 ieee80211_crypto_delglobalkeys(struct ieee80211vap *vap)
471 {
472 int i;
473
474 ieee80211_key_update_begin(vap);
475 for (i = 0; i < IEEE80211_WEP_NKID; i++)
476 (void) _ieee80211_crypto_delkey(vap, &vap->iv_nw_keys[i]);
477 ieee80211_key_update_end(vap);
478 }
479
480 /*
481 * Set the contents of the specified key.
482 *
483 * Locking must be handled by the caller using:
484 * ieee80211_key_update_begin(vap);
485 * ieee80211_key_update_end(vap);
486 */
487 int
ieee80211_crypto_setkey(struct ieee80211vap * vap,struct ieee80211_key * key)488 ieee80211_crypto_setkey(struct ieee80211vap *vap, struct ieee80211_key *key)
489 {
490 const struct ieee80211_cipher *cip = key->wk_cipher;
491
492 KASSERT(cip != NULL, ("No cipher!"));
493
494 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
495 "%s: %s keyix %u flags 0x%x mac %s rsc %ju tsc %ju len %u\n",
496 __func__, cip->ic_name, key->wk_keyix,
497 key->wk_flags, ether_sprintf(key->wk_macaddr),
498 key->wk_keyrsc[IEEE80211_NONQOS_TID], key->wk_keytsc,
499 key->wk_keylen);
500
501 if ((key->wk_flags & IEEE80211_KEY_DEVKEY) == 0) {
502 /* XXX nothing allocated, should not happen */
503 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
504 "%s: no device key setup done; should not happen!\n",
505 __func__);
506 vap->iv_stats.is_crypto_setkey_nokey++;
507 return 0;
508 }
509 /*
510 * Give cipher a chance to validate key contents.
511 * XXX should happen before modifying state.
512 */
513 if (!cip->ic_setkey(key)) {
514 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
515 "%s: cipher %s rejected key index %u len %u flags 0x%x\n",
516 __func__, cip->ic_name, key->wk_keyix,
517 key->wk_keylen, key->wk_flags);
518 vap->iv_stats.is_crypto_setkey_cipher++;
519 return 0;
520 }
521 return dev_key_set(vap, key);
522 }
523
524 uint8_t
ieee80211_crypto_get_keyid(struct ieee80211vap * vap,struct ieee80211_key * k)525 ieee80211_crypto_get_keyid(struct ieee80211vap *vap, struct ieee80211_key *k)
526 {
527 if (k >= &vap->iv_nw_keys[0] &&
528 k < &vap->iv_nw_keys[IEEE80211_WEP_NKID])
529 return (k - vap->iv_nw_keys);
530 else
531 return (0);
532 }
533
534 struct ieee80211_key *
ieee80211_crypto_get_txkey(struct ieee80211_node * ni,struct mbuf * m)535 ieee80211_crypto_get_txkey(struct ieee80211_node *ni, struct mbuf *m)
536 {
537 struct ieee80211vap *vap = ni->ni_vap;
538 struct ieee80211_frame *wh;
539
540 /*
541 * Multicast traffic always uses the multicast key.
542 * Otherwise if a unicast key is set we use that and
543 * it is always key index 0. When no unicast key is
544 * set we fall back to the default transmit key.
545 */
546 wh = mtod(m, struct ieee80211_frame *);
547 if (IEEE80211_IS_MULTICAST(wh->i_addr1) ||
548 IEEE80211_KEY_UNDEFINED(&ni->ni_ucastkey)) {
549 if (vap->iv_def_txkey == IEEE80211_KEYIX_NONE) {
550 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO,
551 wh->i_addr1,
552 "no default transmit key (%s) deftxkey %u",
553 __func__, vap->iv_def_txkey);
554 vap->iv_stats.is_tx_nodefkey++;
555 return NULL;
556 }
557 return &vap->iv_nw_keys[vap->iv_def_txkey];
558 }
559
560 return &ni->ni_ucastkey;
561 }
562
563 /*
564 * Add privacy headers appropriate for the specified key.
565 */
566 struct ieee80211_key *
ieee80211_crypto_encap(struct ieee80211_node * ni,struct mbuf * m)567 ieee80211_crypto_encap(struct ieee80211_node *ni, struct mbuf *m)
568 {
569 struct ieee80211_key *k;
570 const struct ieee80211_cipher *cip;
571
572 if ((k = ieee80211_crypto_get_txkey(ni, m)) != NULL) {
573 cip = k->wk_cipher;
574 return (cip->ic_encap(k, m) ? k : NULL);
575 }
576
577 return NULL;
578 }
579
580 /*
581 * Validate and strip privacy headers (and trailer) for a
582 * received frame that has the WEP/Privacy bit set.
583 */
584 struct ieee80211_key *
ieee80211_crypto_decap(struct ieee80211_node * ni,struct mbuf * m,int hdrlen)585 ieee80211_crypto_decap(struct ieee80211_node *ni, struct mbuf *m, int hdrlen)
586 {
587 #define IEEE80211_WEP_HDRLEN (IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN)
588 #define IEEE80211_WEP_MINLEN \
589 (sizeof(struct ieee80211_frame) + \
590 IEEE80211_WEP_HDRLEN + IEEE80211_WEP_CRCLEN)
591 struct ieee80211vap *vap = ni->ni_vap;
592 struct ieee80211_key *k;
593 struct ieee80211_frame *wh;
594 const struct ieee80211_cipher *cip;
595 uint8_t keyid;
596
597 /* NB: this minimum size data frame could be bigger */
598 if (m->m_pkthdr.len < IEEE80211_WEP_MINLEN) {
599 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ANY,
600 "%s: WEP data frame too short, len %u\n",
601 __func__, m->m_pkthdr.len);
602 vap->iv_stats.is_rx_tooshort++; /* XXX need unique stat? */
603 return NULL;
604 }
605
606 /*
607 * Locate the key. If unicast and there is no unicast
608 * key then we fall back to the key id in the header.
609 * This assumes unicast keys are only configured when
610 * the key id in the header is meaningless (typically 0).
611 */
612 wh = mtod(m, struct ieee80211_frame *);
613 m_copydata(m, hdrlen + IEEE80211_WEP_IVLEN, sizeof(keyid), &keyid);
614 if (IEEE80211_IS_MULTICAST(wh->i_addr1) ||
615 IEEE80211_KEY_UNDEFINED(&ni->ni_ucastkey))
616 k = &vap->iv_nw_keys[keyid >> 6];
617 else
618 k = &ni->ni_ucastkey;
619
620 /*
621 * Insure crypto header is contiguous for all decap work.
622 */
623 cip = k->wk_cipher;
624 if (m->m_len < hdrlen + cip->ic_header &&
625 (m = m_pullup(m, hdrlen + cip->ic_header)) == NULL) {
626 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO, wh->i_addr2,
627 "unable to pullup %s header", cip->ic_name);
628 vap->iv_stats.is_rx_wepfail++; /* XXX */
629 return NULL;
630 }
631
632 return (cip->ic_decap(k, m, hdrlen) ? k : NULL);
633 #undef IEEE80211_WEP_MINLEN
634 #undef IEEE80211_WEP_HDRLEN
635 }
636
637 static void
load_ucastkey(void * arg,struct ieee80211_node * ni)638 load_ucastkey(void *arg, struct ieee80211_node *ni)
639 {
640 struct ieee80211vap *vap = ni->ni_vap;
641 struct ieee80211_key *k;
642
643 if (vap->iv_state != IEEE80211_S_RUN)
644 return;
645 k = &ni->ni_ucastkey;
646 if (k->wk_flags & IEEE80211_KEY_DEVKEY)
647 dev_key_set(vap, k);
648 }
649
650 /*
651 * Re-load all keys known to the 802.11 layer that may
652 * have hardware state backing them. This is used by
653 * drivers on resume to push keys down into the device.
654 */
655 void
ieee80211_crypto_reload_keys(struct ieee80211com * ic)656 ieee80211_crypto_reload_keys(struct ieee80211com *ic)
657 {
658 struct ieee80211vap *vap;
659 int i;
660
661 /*
662 * Keys in the global key table of each vap.
663 */
664 /* NB: used only during resume so don't lock for now */
665 TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) {
666 if (vap->iv_state != IEEE80211_S_RUN)
667 continue;
668 for (i = 0; i < IEEE80211_WEP_NKID; i++) {
669 const struct ieee80211_key *k = &vap->iv_nw_keys[i];
670 if (k->wk_flags & IEEE80211_KEY_DEVKEY)
671 dev_key_set(vap, k);
672 }
673 }
674 /*
675 * Unicast keys.
676 */
677 ieee80211_iterate_nodes(&ic->ic_sta, load_ucastkey, NULL);
678 }
679