sys/dev/netif/awi/awi_wep.c

   1 /*      $NetBSD: awi_wep.c,v 1.4 2000/08/14 11:28:03 onoe Exp $ */
   2 /* $FreeBSD: src/sys/dev/awi/awi_wep.c,v 1.3.2.2 2003/01/23 21:06:42 sam Exp $ */
   3 /* $DragonFly: src/sys/dev/netif/awi/Attic/awi_wep.c,v 1.17 2006/10/25 20:55:56 dillon Exp $ */
   4
   5 /*
   6  * Copyright (c) 2000 The NetBSD Foundation, Inc.
   7  * All rights reserved.
   8  *
   9  * This code is derived from software contributed to The NetBSD Foundation
  10  * by Atsushi Onoe.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 3. All advertising materials mentioning features or use of this software
  21  *    must display the following acknowledgement:
  22  *      This product includes software developed by the NetBSD
  23  *      Foundation, Inc. and its contributors.
  24  * 4. Neither the name of The NetBSD Foundation nor the names of its
  25  *    contributors may be used to endorse or promote products derived
  26  *    from this software without specific prior written permission.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  29  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  30  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  31  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  32  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  33  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  34  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  35  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  36  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  37  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  38  * POSSIBILITY OF SUCH DAMAGE.
  39  */
  40
  41 /*
  42  * WEP support framework for the awi driver.
  43  *
  44  * No actual encryption capability is provided here, but any can be added
  45  * to awi_wep_algo table below.
  46  *
  47  * Note that IEEE802.11 specification states WEP uses RC4 with 40bit key,
  48  * which is a proprietary encryption algorithm available under license
  49  * from RSA Data Security Inc.  Using another algorithm, includes null
  50  * encryption provided here, the awi driver cannot be able to communicate
  51  * with other stations.
  52  */
  53
  54 #include <sys/param.h>
  55 #include <sys/systm.h>
  56 #include <sys/kernel.h>
  57 #include <sys/mbuf.h>
  58 #include <sys/malloc.h>
  59 #include <sys/proc.h>
  60 #include <sys/socket.h>
  61 #include <sys/errno.h>
  62 #include <sys/sockio.h>
  63 #include <sys/bus.h>
  64
  65 #include <net/if.h>
  66 #include <net/if_dl.h>
  67 #include <net/ethernet.h>
  68 #include <net/if_arp.h>
  69 #include <net/if_media.h>
  70 #include <netproto/802_11/ieee80211.h>
  71 #include <netproto/802_11/ieee80211_ioctl.h>
  72
  73 #include <machine/cpu.h>
  74
  75 #include <dev/netif/awi/am79c930reg.h>
  76 #include <dev/netif/awi/am79c930var.h>
  77 #include <dev/netif/awi/awireg.h>
  78 #include <dev/netif/awi/awivar.h>
  79
  80 #include <crypto/rc4/rc4.h>
  81 static __inline int
  82 arc4_ctxlen(void)
  83 {
  84         return sizeof(struct rc4_state);
  85 }
  86
  87 static __inline void
  88 arc4_setkey(void *ctx, u_int8_t *key, int keylen)
  89 {
  90         rc4_init(ctx, key, keylen);
  91 }
  92
  93 static __inline void
  94 arc4_encrypt(void *ctx, u_int8_t *dst, u_int8_t *src, int len)
  95 {
  96         rc4_crypt(ctx, src, dst, len);
  97 }
  98
  99 static void awi_crc_init (void);
 100 static u_int32_t awi_crc_update (u_int32_t crc, u_int8_t *buf, int len);
 101
 102 static int awi_null_ctxlen (void);
 103 static void awi_null_setkey (void *ctx, u_int8_t *key, int keylen);
 104 static void awi_null_copy (void *ctx, u_int8_t *dst, u_int8_t *src, int len);
 105
 106 /* XXX: the order should be known to wiconfig/user */
 107
 108 static struct awi_wep_algo awi_wep_algo[] = {
 109 /* 0: no wep */
 110         { "no" },       /* dummy for no wep */
 111
 112 /* 1: normal wep (arc4) */
 113         { "arc4", arc4_ctxlen, arc4_setkey,
 114             arc4_encrypt, arc4_encrypt },
 115
 116 /* 2: debug wep (null) */
 117         { "null", awi_null_ctxlen, awi_null_setkey,
 118             awi_null_copy, awi_null_copy },
 119                         /* dummy for wep without encryption */
 120 };
 121
 122 int
 123 awi_wep_setnwkey(struct awi_softc *sc, struct ieee80211_nwkey *nwkey)
 124 {
 125         int i, len, error;
 126         u_int8_t keybuf[AWI_MAX_KEYLEN];
 127
 128         if (nwkey->i_defkid <= 0 ||
 129             nwkey->i_defkid > IEEE80211_WEP_NKID)
 130                 return EINVAL;
 131         error = 0;
 132         for (i = 0; i < IEEE80211_WEP_NKID; i++) {
 133                 if (nwkey->i_key[i].i_keydat == NULL)
 134                         continue;
 135                 len = nwkey->i_key[i].i_keylen;
 136                 if (len > sizeof(keybuf)) {
 137                         error = EINVAL;
 138                         break;
 139                 }
 140                 error = copyin(nwkey->i_key[i].i_keydat, keybuf, len);
 141                 if (error)
 142                         break;
 143                 error = awi_wep_setkey(sc, i, keybuf, len);
 144                 if (error)
 145                         break;
 146         }
 147         if (error == 0) {
 148                 sc->sc_wep_defkid = nwkey->i_defkid - 1;
 149                 error = awi_wep_setalgo(sc, nwkey->i_wepon);
 150                 if (error == 0 && sc->sc_enabled) {
 151                         awi_stop(sc);
 152                         error = awi_init(sc);
 153                 }
 154         }
 155         return error;
 156 }
 157
 158 int
 159 awi_wep_getnwkey(struct awi_softc *sc, struct ieee80211_nwkey *nwkey)
 160 {
 161         int i, len, error, suerr;
 162         u_int8_t keybuf[AWI_MAX_KEYLEN];
 163
 164         nwkey->i_wepon = awi_wep_getalgo(sc);
 165         nwkey->i_defkid = sc->sc_wep_defkid + 1;
 166         /* do not show any keys to non-root user */
 167         suerr = suser(curthread);       /* note: EPERM if no proc */
 168         error = 0;
 169         for (i = 0; i < IEEE80211_WEP_NKID; i++) {
 170                 if (nwkey->i_key[i].i_keydat == NULL)
 171                         continue;
 172                 if (suerr) {
 173                         error = suerr;
 174                         break;
 175                 }
 176                 len = sizeof(keybuf);
 177                 error = awi_wep_getkey(sc, i, keybuf, &len);
 178                 if (error)
 179                         break;
 180                 if (nwkey->i_key[i].i_keylen < len) {
 181                         error = ENOSPC;
 182                         break;
 183                 }
 184                 nwkey->i_key[i].i_keylen = len;
 185                 error = copyout(keybuf, nwkey->i_key[i].i_keydat, len);
 186                 if (error)
 187                         break;
 188         }
 189         return error;
 190 }
 191
 192 int
 193 awi_wep_getalgo(struct awi_softc *sc)
 194 {
 195
 196         if (sc->sc_wep_algo == NULL)
 197                 return 0;
 198         return sc->sc_wep_algo - awi_wep_algo;
 199 }
 200
 201 int
 202 awi_wep_setalgo(struct awi_softc *sc, int algo)
 203 {
 204         struct awi_wep_algo *awa;
 205         int ctxlen;
 206
 207         awi_crc_init(); /* XXX: not belongs here */
 208         if (algo < 0 || algo > sizeof(awi_wep_algo)/sizeof(awi_wep_algo[0]))
 209                 return EINVAL;
 210         awa = &awi_wep_algo[algo];
 211         if (awa->awa_name == NULL)
 212                 return EINVAL;
 213         if (awa->awa_ctxlen == NULL) {
 214                 awa = NULL;
 215                 ctxlen = 0;
 216         } else
 217                 ctxlen = awa->awa_ctxlen();
 218         if (sc->sc_wep_ctx != NULL) {
 219                 kfree(sc->sc_wep_ctx, M_DEVBUF);
 220                 sc->sc_wep_ctx = NULL;
 221         }
 222         if (ctxlen) {
 223                 sc->sc_wep_ctx = kmalloc(ctxlen, M_DEVBUF, M_INTWAIT);
 224                 if (sc->sc_wep_ctx == NULL)
 225                         return ENOMEM;
 226         }
 227         sc->sc_wep_algo = awa;
 228         return 0;
 229 }
 230
 231 int
 232 awi_wep_setkey(struct awi_softc *sc, int kid, unsigned char *key, int keylen)
 233 {
 234
 235         if (kid < 0 || kid >= IEEE80211_WEP_NKID)
 236                 return EINVAL;
 237         if (keylen < 0 || keylen + IEEE80211_WEP_IVLEN > AWI_MAX_KEYLEN)
 238                 return EINVAL;
 239         sc->sc_wep_keylen[kid] = keylen;
 240         if (keylen > 0)
 241                 memcpy(sc->sc_wep_key[kid] + IEEE80211_WEP_IVLEN, key, keylen);
 242         return 0;
 243 }
 244
 245 int
 246 awi_wep_getkey(struct awi_softc *sc, int kid, unsigned char *key, int *keylen)
 247 {
 248
 249         if (kid < 0 || kid >= IEEE80211_WEP_NKID)
 250                 return EINVAL;
 251         if (*keylen < sc->sc_wep_keylen[kid])
 252                 return ENOSPC;
 253         *keylen = sc->sc_wep_keylen[kid];
 254         if (*keylen > 0)
 255                 memcpy(key, sc->sc_wep_key[kid] + IEEE80211_WEP_IVLEN, *keylen);
 256         return 0;
 257 }
 258
 259 struct mbuf *
 260 awi_wep_encrypt(struct awi_softc *sc, struct mbuf *m0, int txflag)
 261 {
 262         struct mbuf *m, *n, *n0;
 263         struct ieee80211_frame *wh;
 264         struct awi_wep_algo *awa;
 265         int left, len, plen, msize, moff, noff, keylen, kid;
 266         u_int32_t iv, crc;
 267         u_int8_t *key, *ivp;
 268         void *ctx;
 269         u_int8_t crcbuf[IEEE80211_WEP_CRCLEN];
 270
 271         n0 = NULL;
 272         awa = sc->sc_wep_algo;
 273         if (awa == NULL)
 274                 goto fail;
 275         ctx = sc->sc_wep_ctx;
 276         m = m0;
 277         left = m->m_pkthdr.len;
 278
 279         len = IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN + IEEE80211_WEP_CRCLEN;
 280         if (txflag) {
 281                 plen = m->m_pkthdr.len + len;
 282         } else {
 283                 plen = m->m_pkthdr.len - len;
 284                 left -= len;
 285         }
 286         n0 = n = m_getl(plen, MB_DONTWAIT, m->m_type, M_PKTHDR, &msize);
 287         if (n == NULL)
 288                 goto fail;
 289         n->m_len = msize;
 290         n->m_pkthdr.len = plen;
 291         M_MOVE_PKTHDR(n, m);
 292         len = sizeof(struct ieee80211_frame);
 293
 294         memcpy(mtod(n, caddr_t), mtod(m, caddr_t), len);
 295         left -= len;
 296         moff = len;
 297         noff = len;
 298         if (txflag) {
 299                 kid = sc->sc_wep_defkid;
 300                 wh = mtod(n, struct ieee80211_frame *);
 301                 wh->i_fc[1] |= IEEE80211_FC1_WEP;
 302                 iv = krandom();
 303                 /*
 304                  * store IV, byte order is not the matter since it's random.
 305                  * assuming IEEE80211_WEP_IVLEN is 3
 306                  */
 307                 ivp = mtod(n, u_int8_t *) + noff;
 308                 ivp[0] = (iv >> 16) & 0xff;
 309                 ivp[1] = (iv >> 8) & 0xff;
 310                 ivp[2] = iv & 0xff;
 311                 ivp[3] = kid & 0x03;    /* clear pad and keyid */
 312                 noff += IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN;
 313         } else {
 314                 ivp = mtod(m, u_int8_t *) + moff;
 315                 moff += IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN;
 316                 kid = ivp[IEEE80211_WEP_IVLEN] & 0x03;
 317         }
 318         key = sc->sc_wep_key[kid];
 319         keylen = sc->sc_wep_keylen[kid];
 320         /* assuming IEEE80211_WEP_IVLEN is 3 */
 321         key[0] = ivp[0];
 322         key[1] = ivp[1];
 323         key[2] = ivp[2];
 324         awa->awa_setkey(ctx, key, IEEE80211_WEP_IVLEN + keylen);
 325
 326         /* encrypt with calculating CRC */
 327         crc = ~0;
 328         while (left > 0) {
 329                 len = m->m_len - moff;
 330                 if (len == 0) {
 331                         m = m->m_next;
 332                         moff = 0;
 333                         continue;
 334                 }
 335                 if (len > n->m_len - noff) {
 336                         len = n->m_len - noff;
 337                         if (len == 0) {
 338                                 n->m_next = m_getl(left, MB_DONTWAIT,
 339                                                    n->m_type, 0, &msize);
 340                                 if (n->m_next == NULL)
 341                                         goto fail;
 342                                 n->m_next->m_len = msize;
 343                                 n = n->m_next;
 344                                 noff = 0;
 345                                 continue;
 346                         }
 347                 }
 348                 if (len > left)
 349                         len = left;
 350                 if (txflag) {
 351                         awa->awa_encrypt(ctx, mtod(n, caddr_t) + noff,
 352                             mtod(m, caddr_t) + moff, len);
 353                         crc = awi_crc_update(crc, mtod(m, caddr_t) + moff, len);
 354                 } else {
 355                         awa->awa_decrypt(ctx, mtod(n, caddr_t) + noff,
 356                             mtod(m, caddr_t) + moff, len);
 357                         crc = awi_crc_update(crc, mtod(n, caddr_t) + noff, len);
 358                 }
 359                 left -= len;
 360                 moff += len;
 361                 noff += len;
 362         }
 363         crc = ~crc;
 364         if (txflag) {
 365                 LE_WRITE_4(crcbuf, crc);
 366                 if (n->m_len >= noff + sizeof(crcbuf))
 367                         n->m_len = noff + sizeof(crcbuf);
 368                 else {
 369                         n->m_len = noff;
 370                         MGET(n->m_next, MB_DONTWAIT, n->m_type);
 371                         if (n->m_next == NULL)
 372                                 goto fail;
 373                         n = n->m_next;
 374                         n->m_len = sizeof(crcbuf);
 375                         noff = 0;
 376                 }
 377                 awa->awa_encrypt(ctx, mtod(n, caddr_t) + noff, crcbuf,
 378                     sizeof(crcbuf));
 379         } else {
 380                 n->m_len = noff;
 381                 for (noff = 0; noff < sizeof(crcbuf); noff += len) {
 382                         len = sizeof(crcbuf) - noff;
 383                         if (len > m->m_len - moff)
 384                                 len = m->m_len - moff;
 385                         if (len > 0)
 386                                 awa->awa_decrypt(ctx, crcbuf + noff,
 387                                     mtod(m, caddr_t) + moff, len);
 388                         m = m->m_next;
 389                         moff = 0;
 390                 }
 391                 if (crc != LE_READ_4(crcbuf))
 392                         goto fail;
 393         }
 394         m_freem(m0);
 395         return n0;
 396
 397   fail:
 398         m_freem(m0);
 399         m_freem(n0);
 400         return NULL;
 401 }
 402
 403 /*
 404  * CRC 32 -- routine from RFC 2083
 405  */
 406
 407 /* Table of CRCs of all 8-bit messages */
 408 static u_int32_t awi_crc_table[256];
 409 static int awi_crc_table_computed = 0;
 410
 411 /* Make the table for a fast CRC. */
 412 static void
 413 awi_crc_init(void)
 414 {
 415         u_int32_t c;
 416         int n, k;
 417
 418         if (awi_crc_table_computed)
 419                 return;
 420         for (n = 0; n < 256; n++) {
 421                 c = (u_int32_t)n;
 422                 for (k = 0; k < 8; k++) {
 423                         if (c & 1)
 424                                 c = 0xedb88320UL ^ (c >> 1);
 425                         else
 426                                 c = c >> 1;
 427                 }
 428                 awi_crc_table[n] = c;
 429         }
 430         awi_crc_table_computed = 1;
 431 }
 432
 433 /*
 434  * Update a running CRC with the bytes buf[0..len-1]--the CRC
 435  * should be initialized to all 1's, and the transmitted value
 436  * is the 1's complement of the final running CRC
 437  */
 438
 439 static u_int32_t
 440 awi_crc_update(u_int32_t crc, u_int8_t *buf, int len)
 441 {
 442         u_int8_t *endbuf;
 443
 444         for (endbuf = buf + len; buf < endbuf; buf++)
 445                 crc = awi_crc_table[(crc ^ *buf) & 0xff] ^ (crc >> 8);
 446         return crc;
 447 }
 448
 449 /*
 450  * Null -- do nothing but copy.
 451  */
 452
 453 static int
 454 awi_null_ctxlen(void)
 455 {
 456
 457         return 0;
 458 }
 459
 460 static void
 461 awi_null_setkey(void *ctx, u_char *key, int keylen)
 462 {
 463 }
 464
 465 static void
 466 awi_null_copy(void *ctx, u_char *dst, u_char *src, int len)
 467 {
 468
 469         memcpy(dst, src, len);
 470 }