1 /* $NetBSD: ieee80211_crypto.c,v 1.17 2015/08/24 22:21:26 pooka Exp $ */ 2 /*- 3 * Copyright (c) 2001 Atsushi Onoe 4 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * Alternatively, this software may be distributed under the terms of the 19 * GNU General Public License ("GPL") version 2 as published by the Free 20 * Software Foundation. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #include <sys/cdefs.h> 35 #ifdef __FreeBSD__ 36 __FBSDID("$FreeBSD: src/sys/net80211/ieee80211_crypto.c,v 1.12 2005/08/08 18:46:35 sam Exp $"); 37 #endif 38 #ifdef __NetBSD__ 39 __KERNEL_RCSID(0, "$NetBSD: ieee80211_crypto.c,v 1.17 2015/08/24 22:21:26 pooka Exp $"); 40 #endif 41 42 #ifdef _KERNEL_OPT 43 #include "opt_inet.h" 44 #endif 45 46 /* 47 * IEEE 802.11 generic crypto support. 48 */ 49 #include <sys/param.h> 50 #include <sys/mbuf.h> 51 52 #include <sys/socket.h> 53 #include <sys/sockio.h> 54 #include <sys/endian.h> 55 #include <sys/errno.h> 56 #include <sys/proc.h> 57 #include <sys/sysctl.h> 58 59 #include <net/if.h> 60 #include <net/if_media.h> 61 #include <net/if_arp.h> 62 #include <net/if_ether.h> 63 #include <net/if_llc.h> 64 65 #include <net80211/ieee80211_netbsd.h> 66 #include <net80211/ieee80211_var.h> 67 68 /* 69 * Table of registered cipher modules. 70 */ 71 static const struct ieee80211_cipher *ciphers[IEEE80211_CIPHER_MAX]; 72 73 #ifdef INET 74 #include <netinet/in.h> 75 #include <net/if_ether.h> 76 #endif 77 78 static int _ieee80211_crypto_delkey(struct ieee80211com *, 79 struct ieee80211_key *); 80 81 /* 82 * Default "null" key management routines. 83 */ 84 static int 85 null_key_alloc(struct ieee80211com *ic, const struct ieee80211_key *k, 86 ieee80211_keyix *keyix, ieee80211_keyix *rxkeyix) 87 { 88 if (!(&ic->ic_nw_keys[0] <= k && 89 k < &ic->ic_nw_keys[IEEE80211_WEP_NKID])) { 90 /* 91 * Not in the global key table, the driver should handle this 92 * by allocating a slot in the h/w key table/cache. In 93 * lieu of that return key slot 0 for any unicast key 94 * request. We disallow the request if this is a group key. 95 * This default policy does the right thing for legacy hardware 96 * with a 4 key table. It also handles devices that pass 97 * packets through untouched when marked with the WEP bit 98 * and key index 0. 99 */ 100 if (k->wk_flags & IEEE80211_KEY_GROUP) 101 return 0; 102 *keyix = 0; /* NB: use key index 0 for ucast key */ 103 } else { 104 *keyix = k - ic->ic_nw_keys; 105 } 106 *rxkeyix = IEEE80211_KEYIX_NONE; /* XXX maybe *keyix? */ 107 return 1; 108 } 109 static int 110 null_key_delete(struct ieee80211com *ic, 111 const struct ieee80211_key *k) 112 { 113 return 1; 114 } 115 static int 116 null_key_set(struct ieee80211com *ic, 117 const struct ieee80211_key *k, 118 const u_int8_t mac[IEEE80211_ADDR_LEN]) 119 { 120 return 1; 121 } 122 static void null_key_update(struct ieee80211com *ic) {} 123 124 /* 125 * Write-arounds for common operations. 126 */ 127 static __inline void 128 cipher_detach(struct ieee80211_key *key) 129 { 130 key->wk_cipher->ic_detach(key); 131 } 132 133 /* 134 * Wrappers for driver key management methods. 135 */ 136 static __inline int 137 dev_key_alloc(struct ieee80211com *ic, 138 const struct ieee80211_key *key, 139 ieee80211_keyix *keyix, ieee80211_keyix *rxkeyix) 140 { 141 return ic->ic_crypto.cs_key_alloc(ic, key, keyix, rxkeyix); 142 } 143 144 static __inline int 145 dev_key_delete(struct ieee80211com *ic, 146 const struct ieee80211_key *key) 147 { 148 return ic->ic_crypto.cs_key_delete(ic, key); 149 } 150 151 static __inline int 152 dev_key_set(struct ieee80211com *ic, const struct ieee80211_key *key, 153 const u_int8_t mac[IEEE80211_ADDR_LEN]) 154 { 155 return ic->ic_crypto.cs_key_set(ic, key, mac); 156 } 157 158 /* 159 * Setup crypto support. 160 */ 161 void 162 ieee80211_crypto_attach(struct ieee80211com *ic) 163 { 164 struct ieee80211_crypto_state *cs = &ic->ic_crypto; 165 int i; 166 167 /* NB: we assume everything is pre-zero'd */ 168 cs->cs_def_txkey = IEEE80211_KEYIX_NONE; 169 cs->cs_max_keyix = IEEE80211_WEP_NKID; 170 ciphers[IEEE80211_CIPHER_NONE] = &ieee80211_cipher_none; 171 for (i = 0; i < IEEE80211_WEP_NKID; i++) 172 ieee80211_crypto_resetkey(ic, &cs->cs_nw_keys[i], 173 IEEE80211_KEYIX_NONE); 174 /* 175 * Initialize the driver key support routines to noop entries. 176 * This is useful especially for the cipher test modules. 177 */ 178 cs->cs_key_alloc = null_key_alloc; 179 cs->cs_key_set = null_key_set; 180 cs->cs_key_delete = null_key_delete; 181 cs->cs_key_update_begin = null_key_update; 182 cs->cs_key_update_end = null_key_update; 183 } 184 185 /* 186 * Teardown crypto support. 187 */ 188 void 189 ieee80211_crypto_detach(struct ieee80211com *ic) 190 { 191 ieee80211_crypto_delglobalkeys(ic); 192 } 193 194 /* 195 * Register a crypto cipher module. 196 */ 197 void 198 ieee80211_crypto_register(const struct ieee80211_cipher *cip) 199 { 200 if (cip->ic_cipher >= IEEE80211_CIPHER_MAX) { 201 printf("%s: cipher %s has an invalid cipher index %u\n", 202 __func__, cip->ic_name, cip->ic_cipher); 203 return; 204 } 205 if (ciphers[cip->ic_cipher] != NULL && ciphers[cip->ic_cipher] != cip) { 206 printf("%s: cipher %s registered with a different template\n", 207 __func__, cip->ic_name); 208 return; 209 } 210 ciphers[cip->ic_cipher] = cip; 211 } 212 213 /* 214 * Unregister a crypto cipher module. 215 */ 216 void 217 ieee80211_crypto_unregister(const struct ieee80211_cipher *cip) 218 { 219 if (cip->ic_cipher >= IEEE80211_CIPHER_MAX) { 220 printf("%s: cipher %s has an invalid cipher index %u\n", 221 __func__, cip->ic_name, cip->ic_cipher); 222 return; 223 } 224 if (ciphers[cip->ic_cipher] != NULL && ciphers[cip->ic_cipher] != cip) { 225 printf("%s: cipher %s registered with a different template\n", 226 __func__, cip->ic_name); 227 return; 228 } 229 /* NB: don't complain about not being registered */ 230 /* XXX disallow if references */ 231 ciphers[cip->ic_cipher] = NULL; 232 } 233 234 int 235 ieee80211_crypto_available(u_int cipher) 236 { 237 return cipher < IEEE80211_CIPHER_MAX && ciphers[cipher] != NULL; 238 } 239 240 /* XXX well-known names! */ 241 static const char *cipher_modnames[] = { 242 "wlan_wep", /* IEEE80211_CIPHER_WEP */ 243 "wlan_tkip", /* IEEE80211_CIPHER_TKIP */ 244 "wlan_aes_ocb", /* IEEE80211_CIPHER_AES_OCB */ 245 "wlan_ccmp", /* IEEE80211_CIPHER_AES_CCM */ 246 "wlan_ckip", /* IEEE80211_CIPHER_CKIP */ 247 }; 248 249 /* 250 * Establish a relationship between the specified key and cipher 251 * and, if necessary, allocate a hardware index from the driver. 252 * Note that when a fixed key index is required it must be specified 253 * and we blindly assign it w/o consulting the driver (XXX). 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(ic); 260 * ieee80211_key_update_end(ic); 261 */ 262 int 263 ieee80211_crypto_newkey(struct ieee80211com *ic, 264 int cipher, int flags, struct ieee80211_key *key) 265 { 266 #define N(a) (sizeof(a) / sizeof(a[0])) 267 const struct ieee80211_cipher *cip; 268 ieee80211_keyix keyix, rxkeyix; 269 void *keyctx; 270 int oflags; 271 272 /* 273 * Validate cipher and set reference to cipher routines. 274 */ 275 if (cipher >= IEEE80211_CIPHER_MAX) { 276 IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO, 277 "%s: invalid cipher %u\n", __func__, cipher); 278 ic->ic_stats.is_crypto_badcipher++; 279 return 0; 280 } 281 cip = ciphers[cipher]; 282 if (cip == NULL) { 283 /* 284 * Auto-load cipher module if we have a well-known name 285 * for it. It might be better to use string names rather 286 * than numbers and craft a module name based on the cipher 287 * name; e.g. wlan_cipher_<cipher-name>. 288 */ 289 if (cipher < N(cipher_modnames)) { 290 IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO, 291 "%s: unregistered cipher %u, load module %s\n", 292 __func__, cipher, cipher_modnames[cipher]); 293 ieee80211_load_module(cipher_modnames[cipher]); 294 /* 295 * If cipher module loaded it should immediately 296 * call ieee80211_crypto_register which will fill 297 * in the entry in the ciphers array. 298 */ 299 cip = ciphers[cipher]; 300 } 301 if (cip == NULL) { 302 IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO, 303 "%s: unable to load cipher %u, module %s\n", 304 __func__, cipher, 305 cipher < N(cipher_modnames) ? 306 cipher_modnames[cipher] : "<unknown>"); 307 ic->ic_stats.is_crypto_nocipher++; 308 return 0; 309 } 310 } 311 312 oflags = key->wk_flags; 313 flags &= IEEE80211_KEY_COMMON; 314 /* 315 * If the hardware does not support the cipher then 316 * fallback to a host-based implementation. 317 */ 318 if ((ic->ic_caps & (1<<cipher)) == 0) { 319 IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO, 320 "%s: no h/w support for cipher %s, falling back to s/w\n", 321 __func__, cip->ic_name); 322 flags |= IEEE80211_KEY_SWCRYPT; 323 } 324 /* 325 * Hardware TKIP with software MIC is an important 326 * combination; we handle it by flagging each key, 327 * the cipher modules honor it. 328 */ 329 if (cipher == IEEE80211_CIPHER_TKIP && 330 (ic->ic_caps & IEEE80211_C_TKIPMIC) == 0) { 331 IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO, 332 "%s: no h/w support for TKIP MIC, falling back to s/w\n", 333 __func__); 334 flags |= IEEE80211_KEY_SWMIC; 335 } 336 337 /* 338 * Bind cipher to key instance. Note we do this 339 * after checking the device capabilities so the 340 * cipher module can optimize space usage based on 341 * whether or not it needs to do the cipher work. 342 */ 343 if (key->wk_cipher != cip || key->wk_flags != flags) { 344 again: 345 /* 346 * Fillin the flags so cipher modules can see s/w 347 * crypto requirements and potentially allocate 348 * different state and/or attach different method 349 * pointers. 350 * 351 * XXX this is not right when s/w crypto fallback 352 * fails and we try to restore previous state. 353 */ 354 key->wk_flags = flags; 355 keyctx = cip->ic_attach(ic, key); 356 if (keyctx == NULL) { 357 IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO, 358 "%s: unable to attach cipher %s\n", 359 __func__, cip->ic_name); 360 key->wk_flags = oflags; /* restore old flags */ 361 ic->ic_stats.is_crypto_attachfail++; 362 return 0; 363 } 364 cipher_detach(key); 365 key->wk_cipher = cip; /* XXX refcnt? */ 366 key->wk_private = keyctx; 367 } 368 /* 369 * Commit to requested usage so driver can see the flags. 370 */ 371 key->wk_flags = flags; 372 373 /* 374 * Ask the driver for a key index if we don't have one. 375 * Note that entries in the global key table always have 376 * an index; this means it's safe to call this routine 377 * for these entries just to setup the reference to the 378 * cipher template. Note also that when using software 379 * crypto we also call the driver to give us a key index. 380 */ 381 if (key->wk_keyix == IEEE80211_KEYIX_NONE) { 382 if (!dev_key_alloc(ic, key, &keyix, &rxkeyix)) { 383 /* 384 * Driver has no room; fallback to doing crypto 385 * in the host. We change the flags and start the 386 * procedure over. If we get back here then there's 387 * no hope and we bail. Note that this can leave 388 * the key in a inconsistent state if the caller 389 * continues to use it. 390 */ 391 if ((key->wk_flags & IEEE80211_KEY_SWCRYPT) == 0) { 392 ic->ic_stats.is_crypto_swfallback++; 393 IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO, 394 "%s: no h/w resources for cipher %s, " 395 "falling back to s/w\n", __func__, 396 cip->ic_name); 397 oflags = key->wk_flags; 398 flags |= IEEE80211_KEY_SWCRYPT; 399 if (cipher == IEEE80211_CIPHER_TKIP) 400 flags |= IEEE80211_KEY_SWMIC; 401 goto again; 402 } 403 ic->ic_stats.is_crypto_keyfail++; 404 IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO, 405 "%s: unable to setup cipher %s\n", 406 __func__, cip->ic_name); 407 return 0; 408 } 409 key->wk_keyix = keyix; 410 key->wk_rxkeyix = rxkeyix; 411 } 412 return 1; 413 #undef N 414 } 415 416 /* 417 * Remove the key (no locking, for internal use). 418 */ 419 static int 420 _ieee80211_crypto_delkey(struct ieee80211com *ic, struct ieee80211_key *key) 421 { 422 ieee80211_keyix keyix; 423 424 IASSERT(key->wk_cipher != NULL, ("No cipher!")); 425 426 IEEE80211_DPRINTF(ic, 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, key->wk_keytsc, key->wk_keylen); 431 432 keyix = key->wk_keyix; 433 if (keyix != IEEE80211_KEYIX_NONE) { 434 /* 435 * Remove hardware entry. 436 */ 437 /* XXX key cache */ 438 if (!dev_key_delete(ic, key)) { 439 IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO, 440 "%s: driver did not delete key index %u\n", 441 __func__, keyix); 442 ic->ic_stats.is_crypto_delkey++; 443 /* XXX recovery? */ 444 } 445 } 446 cipher_detach(key); 447 memset(key, 0, sizeof(*key)); 448 ieee80211_crypto_resetkey(ic, key, IEEE80211_KEYIX_NONE); 449 return 1; 450 } 451 452 /* 453 * Remove the specified key. 454 */ 455 int 456 ieee80211_crypto_delkey(struct ieee80211com *ic, struct ieee80211_key *key) 457 { 458 int status; 459 460 ieee80211_key_update_begin(ic); 461 status = _ieee80211_crypto_delkey(ic, key); 462 ieee80211_key_update_end(ic); 463 return status; 464 } 465 466 /* 467 * Clear the global key table. 468 */ 469 void 470 ieee80211_crypto_delglobalkeys(struct ieee80211com *ic) 471 { 472 int i; 473 474 ieee80211_key_update_begin(ic); 475 for (i = 0; i < IEEE80211_WEP_NKID; i++) 476 (void) _ieee80211_crypto_delkey(ic, &ic->ic_nw_keys[i]); 477 ieee80211_key_update_end(ic); 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(ic); 485 * ieee80211_key_update_end(ic); 486 */ 487 int 488 ieee80211_crypto_setkey(struct ieee80211com *ic, struct ieee80211_key *key, 489 const u_int8_t macaddr[IEEE80211_ADDR_LEN]) 490 { 491 const struct ieee80211_cipher *cip = key->wk_cipher; 492 493 IASSERT(cip != NULL, ("No cipher!")); 494 495 IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO, 496 "%s: %s keyix %u flags 0x%x mac %s rsc %ju tsc %ju len %u\n", 497 __func__, cip->ic_name, key->wk_keyix, 498 key->wk_flags, ether_sprintf(macaddr), 499 key->wk_keyrsc, key->wk_keytsc, key->wk_keylen); 500 501 /* 502 * Give cipher a chance to validate key contents. 503 * XXX should happen before modifying state. 504 */ 505 if (!cip->ic_setkey(key)) { 506 IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO, 507 "%s: cipher %s rejected key index %u len %u flags 0x%x\n", 508 __func__, cip->ic_name, key->wk_keyix, 509 key->wk_keylen, key->wk_flags); 510 ic->ic_stats.is_crypto_setkey_cipher++; 511 return 0; 512 } 513 if (key->wk_keyix == IEEE80211_KEYIX_NONE) { 514 /* XXX nothing allocated, should not happen */ 515 IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO, 516 "%s: no key index; should not happen!\n", __func__); 517 ic->ic_stats.is_crypto_setkey_nokey++; 518 return 0; 519 } 520 return dev_key_set(ic, key, macaddr); 521 } 522 523 /* 524 * Add privacy headers appropriate for the specified key. 525 */ 526 struct ieee80211_key * 527 ieee80211_crypto_encap(struct ieee80211com *ic, 528 struct ieee80211_node *ni, struct mbuf *m) 529 { 530 struct ieee80211_key *k; 531 struct ieee80211_frame *wh; 532 const struct ieee80211_cipher *cip; 533 u_int8_t keyid; 534 535 /* 536 * Multicast traffic always uses the multicast key. 537 * Otherwise if a unicast key is set we use that and 538 * it is always key index 0. When no unicast key is 539 * set we fall back to the default transmit key. 540 */ 541 wh = mtod(m, struct ieee80211_frame *); 542 if (IEEE80211_IS_MULTICAST(wh->i_addr1) || 543 ni->ni_ucastkey.wk_cipher == &ieee80211_cipher_none) { 544 if (ic->ic_def_txkey == IEEE80211_KEYIX_NONE) { 545 IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO, 546 "[%s] no default transmit key (%s) deftxkey %u\n", 547 ether_sprintf(wh->i_addr1), __func__, 548 ic->ic_def_txkey); 549 ic->ic_stats.is_tx_nodefkey++; 550 return NULL; 551 } 552 keyid = ic->ic_def_txkey; 553 k = &ic->ic_nw_keys[ic->ic_def_txkey]; 554 } else { 555 keyid = 0; 556 k = &ni->ni_ucastkey; 557 } 558 cip = k->wk_cipher; 559 return (cip->ic_encap(k, m, keyid<<6) ? k : NULL); 560 } 561 562 /* 563 * Validate and strip privacy headers (and trailer) for a 564 * received frame that has the WEP/Privacy bit set. 565 */ 566 struct ieee80211_key * 567 ieee80211_crypto_decap(struct ieee80211com *ic, 568 struct ieee80211_node *ni, struct mbuf *m, int hdrlen) 569 { 570 #define IEEE80211_WEP_HDRLEN (IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN) 571 #define IEEE80211_WEP_MINLEN \ 572 (sizeof(struct ieee80211_frame) + \ 573 IEEE80211_WEP_HDRLEN + IEEE80211_WEP_CRCLEN) 574 struct ieee80211_key *k; 575 struct ieee80211_frame *wh; 576 const struct ieee80211_cipher *cip; 577 u_int8_t keyid; 578 579 /* NB: this minimum size data frame could be bigger */ 580 if (m->m_pkthdr.len < IEEE80211_WEP_MINLEN) { 581 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ANY, 582 "%s: WEP data frame too short, len %u\n", 583 __func__, m->m_pkthdr.len); 584 ic->ic_stats.is_rx_tooshort++; /* XXX need unique stat? */ 585 return NULL; 586 } 587 588 /* 589 * Locate the key. If unicast and there is no unicast 590 * key then we fall back to the key id in the header. 591 * This assumes unicast keys are only configured when 592 * the key id in the header is meaningless (typically 0). 593 */ 594 wh = mtod(m, struct ieee80211_frame *); 595 m_copydata(m, hdrlen + IEEE80211_WEP_IVLEN, sizeof(keyid), &keyid); 596 if (IEEE80211_IS_MULTICAST(wh->i_addr1) || 597 ni->ni_ucastkey.wk_cipher == &ieee80211_cipher_none) 598 k = &ic->ic_nw_keys[keyid >> 6]; 599 else 600 k = &ni->ni_ucastkey; 601 602 /* 603 * Insure crypto header is contiguous for all decap work. 604 */ 605 cip = k->wk_cipher; 606 if (m->m_len < hdrlen + cip->ic_header && 607 (m = m_pullup(m, hdrlen + cip->ic_header)) == NULL) { 608 IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO, 609 "[%s] unable to pullup %s header\n", 610 ether_sprintf(wh->i_addr2), cip->ic_name); 611 ic->ic_stats.is_rx_wepfail++; /* XXX */ 612 return NULL; 613 } 614 615 return (cip->ic_decap(k, m, hdrlen) ? k : NULL); 616 #undef IEEE80211_WEP_MINLEN 617 #undef IEEE80211_WEP_HDRLEN 618 } 619