1 /*
2  * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. The name of the author may not be used to endorse or promote products
14  *    derived from this software without specific prior written permission.
15  *
16  * Alternatively, this software may be distributed under the terms of the
17  * GNU General Public License ("GPL") version 2 as published by the Free
18  * Software Foundation.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  *
31  * $FreeBSD: src/sys/net80211/ieee80211_crypto_wep.c,v 1.7.2.1 2005/12/22 19:02:08 sam Exp $
32  * $DragonFly: src/sys/netproto/802_11/wlan_wep/ieee80211_crypto_wep.c,v 1.4 2006/12/22 23:57:53 swildner Exp $
33  */
34 
35 /*
36  * IEEE 802.11 WEP crypto support.
37  */
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/mbuf.h>
41 #include <sys/malloc.h>
42 #include <sys/kernel.h>
43 #include <sys/module.h>
44 #include <sys/endian.h>
45 
46 #include <sys/socket.h>
47 
48 #include <net/if.h>
49 #include <net/if_arp.h>
50 #include <net/if_media.h>
51 #include <net/ethernet.h>
52 
53 #include <netproto/802_11/ieee80211_var.h>
54 
55 static	void *wep_attach(struct ieee80211com *, struct ieee80211_key *);
56 static	void wep_detach(struct ieee80211_key *);
57 static	int wep_setkey(struct ieee80211_key *);
58 static	int wep_encap(struct ieee80211_key *, struct mbuf *, uint8_t keyid);
59 static	int wep_decap(struct ieee80211_key *, struct mbuf *, int hdrlen);
60 static	int wep_enmic(struct ieee80211_key *, struct mbuf *, int);
61 static	int wep_demic(struct ieee80211_key *, struct mbuf *, int);
62 
63 static const struct ieee80211_cipher wep = {
64 	.ic_name	= "WEP",
65 	.ic_cipher	= IEEE80211_CIPHER_WEP,
66 	.ic_header	= IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN,
67 	.ic_trailer	= IEEE80211_WEP_CRCLEN,
68 	.ic_miclen	= 0,
69 	.ic_attach	= wep_attach,
70 	.ic_detach	= wep_detach,
71 	.ic_setkey	= wep_setkey,
72 	.ic_encap	= wep_encap,
73 	.ic_decap	= wep_decap,
74 	.ic_enmic	= wep_enmic,
75 	.ic_demic	= wep_demic,
76 };
77 
78 static	int wep_encrypt(struct ieee80211_key *, struct mbuf *, int hdrlen);
79 static	int wep_decrypt(struct ieee80211_key *, struct mbuf *, int hdrlen);
80 
81 struct wep_ctx {
82 	struct ieee80211com *wc_ic;	/* for diagnostics */
83 	uint32_t	wc_iv;		/* initial vector for crypto */
84 };
85 
86 /* number of references from net80211 layer */
87 static	int nrefs = 0;
88 
89 static void *
90 wep_attach(struct ieee80211com *ic, struct ieee80211_key *k)
91 {
92 	struct wep_ctx *ctx;
93 
94 	ctx = kmalloc(sizeof(struct wep_ctx), M_DEVBUF, M_NOWAIT | M_ZERO);
95 	if (ctx == NULL) {
96 		ic->ic_stats.is_crypto_nomem++;
97 		return NULL;
98 	}
99 
100 	ctx->wc_ic = ic;
101 	get_random_bytes(&ctx->wc_iv, sizeof(ctx->wc_iv));
102 	nrefs++;			/* NB: we assume caller locking */
103 	return ctx;
104 }
105 
106 static void
107 wep_detach(struct ieee80211_key *k)
108 {
109 	struct wep_ctx *ctx = k->wk_private;
110 
111 	FREE(ctx, M_DEVBUF);
112 	KASSERT(nrefs > 0, ("imbalanced attach/detach"));
113 	nrefs--;			/* NB: we assume caller locking */
114 }
115 
116 static int
117 wep_setkey(struct ieee80211_key *k)
118 {
119 	return k->wk_keylen >= 40/NBBY;
120 }
121 
122 /*
123  * Add privacy headers appropriate for the specified key.
124  */
125 static int
126 wep_encap(struct ieee80211_key *k, struct mbuf *m, uint8_t keyid)
127 {
128 	struct wep_ctx *ctx = k->wk_private;
129 	struct ieee80211com *ic = ctx->wc_ic;
130 	uint32_t iv;
131 	uint8_t *ivp;
132 	int hdrlen;
133 
134 	hdrlen = ieee80211_hdrspace(ic, mtod(m, void *));
135 
136 	/*
137 	 * Copy down 802.11 header and add the IV + KeyID.
138 	 */
139 	M_PREPEND(m, wep.ic_header, MB_DONTWAIT);
140 	if (m == NULL)
141 		return 0;
142 	ivp = mtod(m, uint8_t *);
143 	ovbcopy(ivp + wep.ic_header, ivp, hdrlen);
144 	ivp += hdrlen;
145 
146 	/*
147 	 * XXX
148 	 * IV must not duplicate during the lifetime of the key.
149 	 * But no mechanism to renew keys is defined in IEEE 802.11
150 	 * for WEP.  And the IV may be duplicated at other stations
151 	 * because the session key itself is shared.  So we use a
152 	 * pseudo random IV for now, though it is not the right way.
153 	 *
154 	 * NB: Rather than use a strictly random IV we select a
155 	 * random one to start and then increment the value for
156 	 * each frame.  This is an explicit tradeoff between
157 	 * overhead and security.  Given the basic insecurity of
158 	 * WEP this seems worthwhile.
159 	 */
160 
161 	/*
162 	 * Skip 'bad' IVs from Fluhrer/Mantin/Shamir:
163 	 * (B, 255, N) with 3 <= B < 16 and 0 <= N <= 255
164 	 */
165 	iv = ctx->wc_iv;
166 	if ((iv & 0xff00) == 0xff00) {
167 		int B = (iv & 0xff0000) >> 16;
168 		if (3 <= B && B < 16)
169 			iv += 0x0100;
170 	}
171 	ctx->wc_iv = iv + 1;
172 
173 	/*
174 	 * NB: Preserve byte order of IV for packet
175 	 *     sniffers; it doesn't matter otherwise.
176 	 */
177 #if _BYTE_ORDER == _BIG_ENDIAN
178 	ivp[0] = iv >> 0;
179 	ivp[1] = iv >> 8;
180 	ivp[2] = iv >> 16;
181 #else
182 	ivp[2] = iv >> 0;
183 	ivp[1] = iv >> 8;
184 	ivp[0] = iv >> 16;
185 #endif
186 	ivp[3] = keyid;
187 
188 	/*
189 	 * Finally, do software encrypt if neeed.
190 	 */
191 	if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) &&
192 	    !wep_encrypt(k, m, hdrlen))
193 		return 0;
194 
195 	return 1;
196 }
197 
198 /*
199  * Add MIC to the frame as needed.
200  */
201 static int
202 wep_enmic(struct ieee80211_key *k, struct mbuf *m, int force)
203 {
204 	return 1;
205 }
206 
207 /*
208  * Validate and strip privacy headers (and trailer) for a
209  * received frame.  If necessary, decrypt the frame using
210  * the specified key.
211  */
212 static int
213 wep_decap(struct ieee80211_key *k, struct mbuf *m, int hdrlen)
214 {
215 	struct wep_ctx *ctx = k->wk_private;
216 	struct ieee80211_frame *wh;
217 
218 	wh = mtod(m, struct ieee80211_frame *);
219 
220 	/*
221 	 * Check if the device handled the decrypt in hardware.
222 	 * If so we just strip the header; otherwise we need to
223 	 * handle the decrypt in software.
224 	 */
225 	if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) &&
226 	    !wep_decrypt(k, m, hdrlen)) {
227 		IEEE80211_DPRINTF(ctx->wc_ic, IEEE80211_MSG_CRYPTO,
228 		    "[%6D] WEP ICV mismatch on decrypt\n",
229 		    wh->i_addr2, ":");
230 		ctx->wc_ic->ic_stats.is_rx_wepfail++;
231 		return 0;
232 	}
233 
234 	/*
235 	 * Copy up 802.11 header and strip crypto bits.
236 	 */
237 	ovbcopy(mtod(m, void *), mtod(m, uint8_t *) + wep.ic_header, hdrlen);
238 	m_adj(m, wep.ic_header);
239 	m_adj(m, -wep.ic_trailer);
240 
241 	return 1;
242 }
243 
244 /*
245  * Verify and strip MIC from the frame.
246  */
247 static int
248 wep_demic(struct ieee80211_key *k, struct mbuf *skb, int force)
249 {
250 	return 1;
251 }
252 
253 static const uint32_t crc32_table[256] = {
254 	0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
255 	0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
256 	0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
257 	0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
258 	0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
259 	0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
260 	0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
261 	0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
262 	0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
263 	0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
264 	0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
265 	0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
266 	0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
267 	0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
268 	0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
269 	0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
270 	0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
271 	0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
272 	0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
273 	0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
274 	0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
275 	0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
276 	0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
277 	0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
278 	0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
279 	0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
280 	0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
281 	0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
282 	0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
283 	0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
284 	0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
285 	0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
286 	0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
287 	0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
288 	0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
289 	0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
290 	0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
291 	0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
292 	0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
293 	0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
294 	0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
295 	0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
296 	0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
297 	0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
298 	0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
299 	0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
300 	0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
301 	0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
302 	0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
303 	0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
304 	0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
305 	0x2d02ef8dL
306 };
307 
308 static int
309 wep_encrypt(struct ieee80211_key *key, struct mbuf *m0, int hdrlen)
310 {
311 #define S_SWAP(a,b) do { uint8_t t = S[a]; S[a] = S[b]; S[b] = t; } while(0)
312 	struct wep_ctx *ctx = key->wk_private;
313 	struct mbuf *m = m0;
314 	uint8_t rc4key[IEEE80211_WEP_IVLEN + IEEE80211_KEYBUF_SIZE];
315 	uint8_t icv[IEEE80211_WEP_CRCLEN];
316 	uint32_t i, j, k, crc;
317 	size_t buflen, data_len;
318 	uint8_t S[256];
319 	uint8_t *pos;
320 	u_int off, keylen;
321 
322 	ctx->wc_ic->ic_stats.is_crypto_wep++;
323 
324 	/* NB: this assumes the header was pulled up */
325 	memcpy(rc4key, mtod(m, uint8_t *) + hdrlen, IEEE80211_WEP_IVLEN);
326 	memcpy(rc4key + IEEE80211_WEP_IVLEN, key->wk_key, key->wk_keylen);
327 
328 	/* Setup RC4 state */
329 	for (i = 0; i < 256; i++)
330 		S[i] = i;
331 	j = 0;
332 	keylen = key->wk_keylen + IEEE80211_WEP_IVLEN;
333 	for (i = 0; i < 256; i++) {
334 		j = (j + S[i] + rc4key[i % keylen]) & 0xff;
335 		S_SWAP(i, j);
336 	}
337 
338 	off = hdrlen + wep.ic_header;
339 	data_len = m->m_pkthdr.len - off;
340 
341 	/* Compute CRC32 over unencrypted data and apply RC4 to data */
342 	crc = ~0;
343 	i = j = 0;
344 	pos = mtod(m, uint8_t *) + off;
345 	buflen = m->m_len - off;
346 	for (;;) {
347 		if (buflen > data_len)
348 			buflen = data_len;
349 		data_len -= buflen;
350 		for (k = 0; k < buflen; k++) {
351 			crc = crc32_table[(crc ^ *pos) & 0xff] ^ (crc >> 8);
352 			i = (i + 1) & 0xff;
353 			j = (j + S[i]) & 0xff;
354 			S_SWAP(i, j);
355 			*pos++ ^= S[(S[i] + S[j]) & 0xff];
356 		}
357 		if (m->m_next == NULL) {
358 			if (data_len != 0) {		/* out of data */
359 				IEEE80211_DPRINTF(ctx->wc_ic,
360 				    IEEE80211_MSG_CRYPTO,
361 				    "[%6D] out of data for WEP "
362 				    "(data_len %zu)\n",
363 				    mtod(m0, struct ieee80211_frame *)->i_addr2,
364 				    ":", data_len);
365 				return 0;
366 			}
367 			break;
368 		}
369 		m = m->m_next;
370 		pos = mtod(m, uint8_t *);
371 		buflen = m->m_len;
372 	}
373 	crc = ~crc;
374 
375 	/* Append little-endian CRC32 and encrypt it to produce ICV */
376 	icv[0] = crc;
377 	icv[1] = crc >> 8;
378 	icv[2] = crc >> 16;
379 	icv[3] = crc >> 24;
380 	for (k = 0; k < IEEE80211_WEP_CRCLEN; k++) {
381 		i = (i + 1) & 0xff;
382 		j = (j + S[i]) & 0xff;
383 		S_SWAP(i, j);
384 		icv[k] ^= S[(S[i] + S[j]) & 0xff];
385 	}
386 	return ieee80211_mbuf_append(m0, IEEE80211_WEP_CRCLEN, icv);
387 #undef S_SWAP
388 }
389 
390 static int
391 wep_decrypt(struct ieee80211_key *key, struct mbuf *m0, int hdrlen)
392 {
393 #define S_SWAP(a,b) do { uint8_t t = S[a]; S[a] = S[b]; S[b] = t; } while(0)
394 	struct wep_ctx *ctx = key->wk_private;
395 	struct mbuf *m = m0;
396 	uint8_t rc4key[IEEE80211_WEP_IVLEN + IEEE80211_KEYBUF_SIZE];
397 	uint8_t icv[IEEE80211_WEP_CRCLEN];
398 	uint32_t i, j, k, crc;
399 	size_t buflen, data_len;
400 	uint8_t S[256];
401 	uint8_t *pos;
402 	u_int off, keylen;
403 
404 	ctx->wc_ic->ic_stats.is_crypto_wep++;
405 
406 	/* NB: this assumes the header was pulled up */
407 	memcpy(rc4key, mtod(m, uint8_t *) + hdrlen, IEEE80211_WEP_IVLEN);
408 	memcpy(rc4key + IEEE80211_WEP_IVLEN, key->wk_key, key->wk_keylen);
409 
410 	/* Setup RC4 state */
411 	for (i = 0; i < 256; i++)
412 		S[i] = i;
413 	j = 0;
414 	keylen = key->wk_keylen + IEEE80211_WEP_IVLEN;
415 	for (i = 0; i < 256; i++) {
416 		j = (j + S[i] + rc4key[i % keylen]) & 0xff;
417 		S_SWAP(i, j);
418 	}
419 
420 	off = hdrlen + wep.ic_header;
421 	data_len = m->m_pkthdr.len - (off + wep.ic_trailer),
422 
423 	/* Compute CRC32 over unencrypted data and apply RC4 to data */
424 	crc = ~0;
425 	i = j = 0;
426 	pos = mtod(m, uint8_t *) + off;
427 	buflen = m->m_len - off;
428 	for (;;) {
429 		if (buflen > data_len)
430 			buflen = data_len;
431 		data_len -= buflen;
432 		for (k = 0; k < buflen; k++) {
433 			i = (i + 1) & 0xff;
434 			j = (j + S[i]) & 0xff;
435 			S_SWAP(i, j);
436 			*pos ^= S[(S[i] + S[j]) & 0xff];
437 			crc = crc32_table[(crc ^ *pos) & 0xff] ^ (crc >> 8);
438 			pos++;
439 		}
440 		m = m->m_next;
441 		if (m == NULL) {
442 			if (data_len != 0) {		/* out of data */
443 				IEEE80211_DPRINTF(ctx->wc_ic,
444 				    IEEE80211_MSG_CRYPTO,
445 				    "[%s] out of data for WEP "
446 				    "(data_len %zu)\n",
447 				    mtod(m0, struct ieee80211_frame *)->i_addr2,
448 				    ":", data_len);
449 				return 0;
450 			}
451 			break;
452 		}
453 		pos = mtod(m, uint8_t *);
454 		buflen = m->m_len;
455 	}
456 	crc = ~crc;
457 
458 	/* Encrypt little-endian CRC32 and verify that it matches with
459 	 * received ICV */
460 	icv[0] = crc;
461 	icv[1] = crc >> 8;
462 	icv[2] = crc >> 16;
463 	icv[3] = crc >> 24;
464 	for (k = 0; k < IEEE80211_WEP_CRCLEN; k++) {
465 		i = (i + 1) & 0xff;
466 		j = (j + S[i]) & 0xff;
467 		S_SWAP(i, j);
468 		/* XXX assumes ICV is contiguous in mbuf */
469 		if ((icv[k] ^ S[(S[i] + S[j]) & 0xff]) != *pos++) {
470 			/* ICV mismatch - drop frame */
471 			return 0;
472 		}
473 	}
474 	return 1;
475 #undef S_SWAP
476 }
477 
478 /*
479  * Module glue.
480  */
481 static int
482 wep_modevent(module_t mod, int type, void *unused)
483 {
484 	switch (type) {
485 	case MOD_LOAD:
486 		ieee80211_crypto_register(&wep);
487 		return 0;
488 	case MOD_UNLOAD:
489 		if (nrefs) {
490 			kprintf("wlan_wep: still in use (%u dynamic refs)\n",
491 				nrefs);
492 			return EBUSY;
493 		}
494 		ieee80211_crypto_unregister(&wep);
495 		return 0;
496 	}
497 	return EINVAL;
498 }
499 
500 static moduledata_t wep_mod = {
501 	"wlan_wep",
502 	wep_modevent,
503 	0
504 };
505 DECLARE_MODULE(wlan_wep, wep_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
506 MODULE_VERSION(wlan_wep, 1);
507 MODULE_DEPEND(wlan_wep, wlan, 1, 1, 1);
508