git.oblomov.eu Git - linux-2.6/blob - drivers/net/wireless/bcm43xx/bcm43xx_xmit.c

   1 /*
   2
   3   Broadcom BCM43xx wireless driver
   4
   5   Transmission (TX/RX) related functions.
   6
   7   Copyright (c) 2005 Martin Langer <martin-langer@gmx.de>,
   8                      Stefano Brivio <st3@riseup.net>
   9                      Michael Buesch <mbuesch@freenet.de>
  10                      Danny van Dyk <kugelfang@gentoo.org>
  11                      Andreas Jaggi <andreas.jaggi@waterwave.ch>
  12
  13   This program is free software; you can redistribute it and/or modify
  14   it under the terms of the GNU General Public License as published by
  15   the Free Software Foundation; either version 2 of the License, or
  16   (at your option) any later version.
  17
  18   This program is distributed in the hope that it will be useful,
  19   but WITHOUT ANY WARRANTY; without even the implied warranty of
  20   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21   GNU General Public License for more details.
  22
  23   You should have received a copy of the GNU General Public License
  24   along with this program; see the file COPYING.  If not, write to
  25   the Free Software Foundation, Inc., 51 Franklin Steet, Fifth Floor,
  26   Boston, MA 02110-1301, USA.
  27
  28 */
  29
  30 #include "bcm43xx_xmit.h"
  31
  32 #include <linux/etherdevice.h>
  33
  34
  35 /* Extract the bitrate out of a CCK PLCP header. */
  36 static u8 bcm43xx_plcp_get_bitrate_cck(struct bcm43xx_plcp_hdr4 *plcp)
  37 {
  38         switch (plcp->raw[0]) {
  39         case 0x0A:
  40                 return IEEE80211_CCK_RATE_1MB;
  41         case 0x14:
  42                 return IEEE80211_CCK_RATE_2MB;
  43         case 0x37:
  44                 return IEEE80211_CCK_RATE_5MB;
  45         case 0x6E:
  46                 return IEEE80211_CCK_RATE_11MB;
  47         }
  48         assert(0);
  49         return 0;
  50 }
  51
  52 /* Extract the bitrate out of an OFDM PLCP header. */
  53 static u8 bcm43xx_plcp_get_bitrate_ofdm(struct bcm43xx_plcp_hdr4 *plcp)
  54 {
  55         switch (plcp->raw[0] & 0xF) {
  56         case 0xB:
  57                 return IEEE80211_OFDM_RATE_6MB;
  58         case 0xF:
  59                 return IEEE80211_OFDM_RATE_9MB;
  60         case 0xA:
  61                 return IEEE80211_OFDM_RATE_12MB;
  62         case 0xE:
  63                 return IEEE80211_OFDM_RATE_18MB;
  64         case 0x9:
  65                 return IEEE80211_OFDM_RATE_24MB;
  66         case 0xD:
  67                 return IEEE80211_OFDM_RATE_36MB;
  68         case 0x8:
  69                 return IEEE80211_OFDM_RATE_48MB;
  70         case 0xC:
  71                 return IEEE80211_OFDM_RATE_54MB;
  72         }
  73         assert(0);
  74         return 0;
  75 }
  76
  77 u8 bcm43xx_plcp_get_ratecode_cck(const u8 bitrate)
  78 {
  79         switch (bitrate) {
  80         case IEEE80211_CCK_RATE_1MB:
  81                 return 0x0A;
  82         case IEEE80211_CCK_RATE_2MB:
  83                 return 0x14;
  84         case IEEE80211_CCK_RATE_5MB:
  85                 return 0x37;
  86         case IEEE80211_CCK_RATE_11MB:
  87                 return 0x6E;
  88         }
  89         assert(0);
  90         return 0;
  91 }
  92
  93 u8 bcm43xx_plcp_get_ratecode_ofdm(const u8 bitrate)
  94 {
  95         switch (bitrate) {
  96         case IEEE80211_OFDM_RATE_6MB:
  97                 return 0xB;
  98         case IEEE80211_OFDM_RATE_9MB:
  99                 return 0xF;
 100         case IEEE80211_OFDM_RATE_12MB:
 101                 return 0xA;
 102         case IEEE80211_OFDM_RATE_18MB:
 103                 return 0xE;
 104         case IEEE80211_OFDM_RATE_24MB:
 105                 return 0x9;
 106         case IEEE80211_OFDM_RATE_36MB:
 107                 return 0xD;
 108         case IEEE80211_OFDM_RATE_48MB:
 109                 return 0x8;
 110         case IEEE80211_OFDM_RATE_54MB:
 111                 return 0xC;
 112         }
 113         assert(0);
 114         return 0;
 115 }
 116
 117 static void bcm43xx_generate_plcp_hdr(struct bcm43xx_plcp_hdr4 *plcp,
 118                                       const u16 octets, const u8 bitrate,
 119                                       const int ofdm_modulation)
 120 {
 121         __le32 *data = &(plcp->data);
 122         __u8 *raw = plcp->raw;
 123
 124         if (ofdm_modulation) {
 125                 *data = bcm43xx_plcp_get_ratecode_ofdm(bitrate);
 126                 assert(!(octets & 0xF000));
 127                 *data |= (octets << 5);
 128                 *data = cpu_to_le32(*data);
 129         } else {
 130                 u32 plen;
 131
 132                 plen = octets * 16 / bitrate;
 133                 if ((octets * 16 % bitrate) > 0) {
 134                         plen++;
 135                         if ((bitrate == IEEE80211_CCK_RATE_11MB)
 136                             && ((octets * 8 % 11) < 4)) {
 137                                 raw[1] = 0x84;
 138                         } else
 139                                 raw[1] = 0x04;
 140                 } else
 141                         raw[1] = 0x04;
 142                 *data |= cpu_to_le32(plen << 16);
 143                 raw[0] = bcm43xx_plcp_get_ratecode_cck(bitrate);
 144         }
 145 }
 146
 147 static u8 bcm43xx_calc_fallback_rate(u8 bitrate)
 148 {
 149         switch (bitrate) {
 150         case IEEE80211_CCK_RATE_1MB:
 151                 return IEEE80211_CCK_RATE_1MB;
 152         case IEEE80211_CCK_RATE_2MB:
 153                 return IEEE80211_CCK_RATE_1MB;
 154         case IEEE80211_CCK_RATE_5MB:
 155                 return IEEE80211_CCK_RATE_2MB;
 156         case IEEE80211_CCK_RATE_11MB:
 157                 return IEEE80211_CCK_RATE_5MB;
 158         case IEEE80211_OFDM_RATE_6MB:
 159                 return IEEE80211_CCK_RATE_5MB;
 160         case IEEE80211_OFDM_RATE_9MB:
 161                 return IEEE80211_OFDM_RATE_6MB;
 162         case IEEE80211_OFDM_RATE_12MB:
 163                 return IEEE80211_OFDM_RATE_9MB;
 164         case IEEE80211_OFDM_RATE_18MB:
 165                 return IEEE80211_OFDM_RATE_12MB;
 166         case IEEE80211_OFDM_RATE_24MB:
 167                 return IEEE80211_OFDM_RATE_18MB;
 168         case IEEE80211_OFDM_RATE_36MB:
 169                 return IEEE80211_OFDM_RATE_24MB;
 170         case IEEE80211_OFDM_RATE_48MB:
 171                 return IEEE80211_OFDM_RATE_36MB;
 172         case IEEE80211_OFDM_RATE_54MB:
 173                 return IEEE80211_OFDM_RATE_48MB;
 174         }
 175         assert(0);
 176         return 0;
 177 }
 178
 179 static
 180 __le16 bcm43xx_calc_duration_id(const struct ieee80211_hdr *wireless_header,
 181                                 u8 bitrate)
 182 {
 183         const u16 frame_ctl = le16_to_cpu(wireless_header->frame_ctl);
 184         __le16 duration_id = wireless_header->duration_id;
 185
 186         switch (WLAN_FC_GET_TYPE(frame_ctl)) {
 187         case IEEE80211_FTYPE_DATA:
 188         case IEEE80211_FTYPE_MGMT:
 189                 //TODO: Steal the code from ieee80211, once it is completed there.
 190                 break;
 191         case IEEE80211_FTYPE_CTL:
 192                 /* Use the original duration/id. */
 193                 break;
 194         default:
 195                 assert(0);
 196         }
 197
 198         return duration_id;
 199 }
 200
 201 static inline
 202 u16 ceiling_div(u16 dividend, u16 divisor)
 203 {
 204         return ((dividend + divisor - 1) / divisor);
 205 }
 206
 207 static void bcm43xx_generate_rts(const struct bcm43xx_phyinfo *phy,
 208                                  struct bcm43xx_txhdr *txhdr,
 209                                  u16 *flags,
 210                                  u8 bitrate,
 211                                  const struct ieee80211_hdr_4addr *wlhdr)
 212 {
 213         u16 fctl;
 214         u16 dur;
 215         u8 fallback_bitrate;
 216         int ofdm_modulation;
 217         int fallback_ofdm_modulation;
 218 //      u8 *sa, *da;
 219         u16 flen;
 220
 221 //FIXME sa = ieee80211_get_SA((struct ieee80211_hdr *)wlhdr);
 222 //FIXME da = ieee80211_get_DA((struct ieee80211_hdr *)wlhdr);
 223         fallback_bitrate = bcm43xx_calc_fallback_rate(bitrate);
 224         ofdm_modulation = !(ieee80211_is_cck_rate(bitrate));
 225         fallback_ofdm_modulation = !(ieee80211_is_cck_rate(fallback_bitrate));
 226
 227         flen = sizeof(u16) + sizeof(u16) + ETH_ALEN + ETH_ALEN + IEEE80211_FCS_LEN,
 228         bcm43xx_generate_plcp_hdr((struct bcm43xx_plcp_hdr4 *)(&txhdr->rts_cts_plcp),
 229                                   flen, bitrate,
 230                                   !ieee80211_is_cck_rate(bitrate));
 231         bcm43xx_generate_plcp_hdr((struct bcm43xx_plcp_hdr4 *)(&txhdr->rts_cts_fallback_plcp),
 232                                   flen, fallback_bitrate,
 233                                   !ieee80211_is_cck_rate(fallback_bitrate));
 234         fctl = IEEE80211_FTYPE_CTL;
 235         fctl |= IEEE80211_STYPE_RTS;
 236         dur = le16_to_cpu(wlhdr->duration_id);
 237 /*FIXME: should we test for dur==0 here and let it unmodified in this case?
 238  *       The following assert checks for this case...
 239  */
 240 assert(dur);
 241 /*FIXME: The duration calculation is not really correct.
 242  *       I am not 100% sure which bitrate to use. We use the RTS rate here,
 243  *       but this is likely to be wrong.
 244  */
 245         if (phy->type == BCM43xx_PHYTYPE_A) {
 246                 /* Three times SIFS */
 247                 dur += 16 * 3;
 248                 /* Add ACK duration. */
 249                 dur += ceiling_div((16 + 8 * (14 /*bytes*/) + 6) * 10,
 250                                    bitrate * 4);
 251                 /* Add CTS duration. */
 252                 dur += ceiling_div((16 + 8 * (14 /*bytes*/) + 6) * 10,
 253                                    bitrate * 4);
 254         } else {
 255                 /* Three times SIFS */
 256                 dur += 10 * 3;
 257                 /* Add ACK duration. */
 258                 dur += ceiling_div(8 * (14 /*bytes*/) * 10,
 259                                    bitrate);
 260                 /* Add CTS duration. */
 261                 dur += ceiling_div(8 * (14 /*bytes*/) * 10,
 262                                    bitrate);
 263         }
 264
 265         txhdr->rts_cts_frame_control = cpu_to_le16(fctl);
 266         txhdr->rts_cts_dur = cpu_to_le16(dur);
 267 //printk(BCM43xx_MACFMT "  " BCM43xx_MACFMT "  " BCM43xx_MACFMT "\n", BCM43xx_MACARG(wlhdr->addr1), BCM43xx_MACARG(wlhdr->addr2), BCM43xx_MACARG(wlhdr->addr3));
 268 //printk(BCM43xx_MACFMT "  " BCM43xx_MACFMT "\n", BCM43xx_MACARG(sa), BCM43xx_MACARG(da));
 269         memcpy(txhdr->rts_cts_mac1, wlhdr->addr1, ETH_ALEN);//FIXME!
 270 //      memcpy(txhdr->rts_cts_mac2, sa, ETH_ALEN);
 271
 272         *flags |= BCM43xx_TXHDRFLAG_RTSCTS;
 273         *flags |= BCM43xx_TXHDRFLAG_RTS;
 274         if (ofdm_modulation)
 275                 *flags |= BCM43xx_TXHDRFLAG_RTSCTS_OFDM;
 276         if (fallback_ofdm_modulation)
 277                 *flags |= BCM43xx_TXHDRFLAG_RTSCTSFALLBACK_OFDM;
 278 }
 279
 280 void bcm43xx_generate_txhdr(struct bcm43xx_private *bcm,
 281                             struct bcm43xx_txhdr *txhdr,
 282                             const unsigned char *fragment_data,
 283                             const unsigned int fragment_len,
 284                             const int is_first_fragment,
 285                             const u16 cookie)
 286 {
 287         const struct bcm43xx_phyinfo *phy = bcm43xx_current_phy(bcm);
 288         const struct ieee80211_hdr_4addr *wireless_header = (const struct ieee80211_hdr_4addr *)fragment_data;
 289         const struct ieee80211_security *secinfo = &bcm->ieee->sec;
 290         u8 bitrate;
 291         u8 fallback_bitrate;
 292         int ofdm_modulation;
 293         int fallback_ofdm_modulation;
 294         u16 plcp_fragment_len = fragment_len;
 295         u16 flags = 0;
 296         u16 control = 0;
 297         u16 wsec_rate = 0;
 298         u16 encrypt_frame;
 299
 300         /* Now construct the TX header. */
 301         memset(txhdr, 0, sizeof(*txhdr));
 302
 303         bitrate = bcm->softmac->txrates.default_rate;
 304         ofdm_modulation = !(ieee80211_is_cck_rate(bitrate));
 305         fallback_bitrate = bcm43xx_calc_fallback_rate(bitrate);
 306         fallback_ofdm_modulation = !(ieee80211_is_cck_rate(fallback_bitrate));
 307
 308         /* Set Frame Control from 80211 header. */
 309         txhdr->frame_control = wireless_header->frame_ctl;
 310         /* Copy address1 from 80211 header. */
 311         memcpy(txhdr->mac1, wireless_header->addr1, 6);
 312         /* Set the fallback duration ID. */
 313         txhdr->fallback_dur_id = bcm43xx_calc_duration_id((const struct ieee80211_hdr *)wireless_header,
 314                                                           fallback_bitrate);
 315         /* Set the cookie (used as driver internal ID for the frame) */
 316         txhdr->cookie = cpu_to_le16(cookie);
 317
 318         /* Hardware appends FCS. */
 319         plcp_fragment_len += IEEE80211_FCS_LEN;
 320
 321         /* Hardware encryption. */
 322         encrypt_frame = le16_to_cpup(&wireless_header->frame_ctl) & IEEE80211_FCTL_PROTECTED;
 323         if (encrypt_frame && !bcm->ieee->host_encrypt) {
 324                 const struct ieee80211_hdr_3addr *hdr = (struct ieee80211_hdr_3addr *)wireless_header;
 325                 memcpy(txhdr->wep_iv, hdr->payload, 4);
 326                 /* Hardware appends ICV. */
 327                 plcp_fragment_len += 4;
 328
 329                 wsec_rate |= (bcm->key[secinfo->active_key].algorithm << BCM43xx_TXHDR_WSEC_ALGO_SHIFT)
 330                              & BCM43xx_TXHDR_WSEC_ALGO_MASK;
 331                 wsec_rate |= (secinfo->active_key << BCM43xx_TXHDR_WSEC_KEYINDEX_SHIFT)
 332                              & BCM43xx_TXHDR_WSEC_KEYINDEX_MASK;
 333         }
 334
 335         /* Generate the PLCP header and the fallback PLCP header. */
 336         bcm43xx_generate_plcp_hdr((struct bcm43xx_plcp_hdr4 *)(&txhdr->plcp),
 337                                   plcp_fragment_len,
 338                                   bitrate, ofdm_modulation);
 339         bcm43xx_generate_plcp_hdr(&txhdr->fallback_plcp, plcp_fragment_len,
 340                                   fallback_bitrate, fallback_ofdm_modulation);
 341
 342         /* Set the CONTROL field */
 343         if (ofdm_modulation)
 344                 control |= BCM43xx_TXHDRCTL_OFDM;
 345         if (bcm->short_preamble) //FIXME: could be the other way around, please test
 346                 control |= BCM43xx_TXHDRCTL_SHORT_PREAMBLE;
 347         control |= (phy->antenna_diversity << BCM43xx_TXHDRCTL_ANTENNADIV_SHIFT)
 348                    & BCM43xx_TXHDRCTL_ANTENNADIV_MASK;
 349
 350         /* Set the FLAGS field */
 351         if (!is_multicast_ether_addr(wireless_header->addr1) &&
 352             !is_broadcast_ether_addr(wireless_header->addr1))
 353                 flags |= BCM43xx_TXHDRFLAG_EXPECTACK;
 354         if (1 /* FIXME: PS poll?? */)
 355                 flags |= 0x10; // FIXME: unknown meaning.
 356         if (fallback_ofdm_modulation)
 357                 flags |= BCM43xx_TXHDRFLAG_FALLBACKOFDM;
 358         if (is_first_fragment)
 359                 flags |= BCM43xx_TXHDRFLAG_FIRSTFRAGMENT;
 360
 361         /* Set WSEC/RATE field */
 362         wsec_rate |= (txhdr->plcp.raw[0] << BCM43xx_TXHDR_RATE_SHIFT)
 363                      & BCM43xx_TXHDR_RATE_MASK;
 364
 365         /* Generate the RTS/CTS packet, if required. */
 366         /* FIXME: We should first try with CTS-to-self,
 367          *        if we are on 80211g. If we get too many
 368          *        failures (hidden nodes), we should switch back to RTS/CTS.
 369          */
 370         if (0/*FIXME txctl->use_rts_cts*/) {
 371                 bcm43xx_generate_rts(phy, txhdr, &flags,
 372                                      0/*FIXME txctl->rts_cts_rate*/,
 373                                      wireless_header);
 374         }
 375
 376         txhdr->flags = cpu_to_le16(flags);
 377         txhdr->control = cpu_to_le16(control);
 378         txhdr->wsec_rate = cpu_to_le16(wsec_rate);
 379 }
 380
 381 static s8 bcm43xx_rssi_postprocess(struct bcm43xx_private *bcm,
 382                                    u8 in_rssi, int ofdm,
 383                                    int adjust_2053, int adjust_2050)
 384 {
 385         struct bcm43xx_radioinfo *radio = bcm43xx_current_radio(bcm);
 386         struct bcm43xx_phyinfo *phy = bcm43xx_current_phy(bcm);
 387         s32 tmp;
 388
 389         switch (radio->version) {
 390         case 0x2050:
 391                 if (ofdm) {
 392                         tmp = in_rssi;
 393                         if (tmp > 127)
 394                                 tmp -= 256;
 395                         tmp *= 73;
 396                         tmp /= 64;
 397                         if (adjust_2050)
 398                                 tmp += 25;
 399                         else
 400                                 tmp -= 3;
 401                 } else {
 402                         if (bcm->sprom.boardflags & BCM43xx_BFL_RSSI) {
 403                                 if (in_rssi > 63)
 404                                         in_rssi = 63;
 405                                 tmp = radio->nrssi_lt[in_rssi];
 406                                 tmp = 31 - tmp;
 407                                 tmp *= -131;
 408                                 tmp /= 128;
 409                                 tmp -= 57;
 410                         } else {
 411                                 tmp = in_rssi;
 412                                 tmp = 31 - tmp;
 413                                 tmp *= -149;
 414                                 tmp /= 128;
 415                                 tmp -= 68;
 416                         }
 417                         if (phy->type == BCM43xx_PHYTYPE_G &&
 418                             adjust_2050)
 419                                 tmp += 25;
 420                 }
 421                 break;
 422         case 0x2060:
 423                 if (in_rssi > 127)
 424                         tmp = in_rssi - 256;
 425                 else
 426                         tmp = in_rssi;
 427                 break;
 428         default:
 429                 tmp = in_rssi;
 430                 tmp -= 11;
 431                 tmp *= 103;
 432                 tmp /= 64;
 433                 if (adjust_2053)
 434                         tmp -= 109;
 435                 else
 436                         tmp -= 83;
 437         }
 438
 439         return (s8)tmp;
 440 }
 441
 442 //TODO
 443 #if 0
 444 static s8 bcm43xx_rssinoise_postprocess(struct bcm43xx_private *bcm,
 445                                         u8 in_rssi)
 446 {
 447         struct bcm43xx_phyinfo *phy = bcm43xx_current_phy(bcm);
 448         s8 ret;
 449
 450         if (phy->type == BCM43xx_PHYTYPE_A) {
 451                 //TODO: Incomplete specs.
 452                 ret = 0;
 453         } else
 454                 ret = bcm43xx_rssi_postprocess(bcm, in_rssi, 0, 1, 1);
 455
 456         return ret;
 457 }
 458 #endif
 459
 460 int bcm43xx_rx(struct bcm43xx_private *bcm,
 461                struct sk_buff *skb,
 462                struct bcm43xx_rxhdr *rxhdr)
 463 {
 464         struct bcm43xx_radioinfo *radio = bcm43xx_current_radio(bcm);
 465         struct bcm43xx_phyinfo *phy = bcm43xx_current_phy(bcm);
 466         struct bcm43xx_plcp_hdr4 *plcp;
 467         struct ieee80211_rx_stats stats;
 468         struct ieee80211_hdr_4addr *wlhdr;
 469         u16 frame_ctl;
 470         int is_packet_for_us = 0;
 471         int err = -EINVAL;
 472         const u16 rxflags1 = le16_to_cpu(rxhdr->flags1);
 473         const u16 rxflags2 = le16_to_cpu(rxhdr->flags2);
 474         const u16 rxflags3 = le16_to_cpu(rxhdr->flags3);
 475         const int is_ofdm = !!(rxflags1 & BCM43xx_RXHDR_FLAGS1_OFDM);
 476
 477         if (rxflags2 & BCM43xx_RXHDR_FLAGS2_TYPE2FRAME) {
 478                 plcp = (struct bcm43xx_plcp_hdr4 *)(skb->data + 2);
 479                 /* Skip two unknown bytes and the PLCP header. */
 480                 skb_pull(skb, 2 + sizeof(struct bcm43xx_plcp_hdr6));
 481         } else {
 482                 plcp = (struct bcm43xx_plcp_hdr4 *)(skb->data);
 483                 /* Skip the PLCP header. */
 484                 skb_pull(skb, sizeof(struct bcm43xx_plcp_hdr6));
 485         }
 486         /* The SKB contains the PAYLOAD (wireless header + data)
 487          * at this point. The FCS at the end is stripped.
 488          */
 489
 490         memset(&stats, 0, sizeof(stats));
 491         stats.mac_time = le16_to_cpu(rxhdr->mactime);
 492         stats.rssi = bcm43xx_rssi_postprocess(bcm, rxhdr->rssi, is_ofdm,
 493                                               !!(rxflags1 & BCM43xx_RXHDR_FLAGS1_2053RSSIADJ),
 494                                               !!(rxflags3 & BCM43xx_RXHDR_FLAGS3_2050RSSIADJ));
 495         stats.signal = rxhdr->signal_quality;   //FIXME
 496 //TODO  stats.noise =
 497         if (is_ofdm)
 498                 stats.rate = bcm43xx_plcp_get_bitrate_ofdm(plcp);
 499         else
 500                 stats.rate = bcm43xx_plcp_get_bitrate_cck(plcp);
 501 //printk("RX ofdm %d, rate == %u\n", is_ofdm, stats.rate);
 502         stats.received_channel = radio->channel;
 503 //TODO  stats.control =
 504         stats.mask = IEEE80211_STATMASK_SIGNAL |
 505 //TODO               IEEE80211_STATMASK_NOISE |
 506                      IEEE80211_STATMASK_RATE |
 507                      IEEE80211_STATMASK_RSSI;
 508         if (phy->type == BCM43xx_PHYTYPE_A)
 509                 stats.freq = IEEE80211_52GHZ_BAND;
 510         else
 511                 stats.freq = IEEE80211_24GHZ_BAND;
 512         stats.len = skb->len;
 513
 514         bcm->stats.last_rx = jiffies;
 515         if (bcm->ieee->iw_mode == IW_MODE_MONITOR) {
 516                 err = ieee80211_rx(bcm->ieee, skb, &stats);
 517                 return (err == 0) ? -EINVAL : 0;
 518         }
 519
 520         wlhdr = (struct ieee80211_hdr_4addr *)(skb->data);
 521
 522         switch (bcm->ieee->iw_mode) {
 523         case IW_MODE_ADHOC:
 524                 if (memcmp(wlhdr->addr1, bcm->net_dev->dev_addr, ETH_ALEN) == 0 ||
 525                     memcmp(wlhdr->addr3, bcm->ieee->bssid, ETH_ALEN) == 0 ||
 526                     is_broadcast_ether_addr(wlhdr->addr1) ||
 527                     is_multicast_ether_addr(wlhdr->addr1) ||
 528                     bcm->net_dev->flags & IFF_PROMISC)
 529                         is_packet_for_us = 1;
 530                 break;
 531         case IW_MODE_INFRA:
 532         default:
 533                 /* When receiving multicast or broadcast packets, filter out
 534                    the packets we send ourself; we shouldn't see those */
 535                 if (memcmp(wlhdr->addr3, bcm->ieee->bssid, ETH_ALEN) == 0 ||
 536                     memcmp(wlhdr->addr1, bcm->net_dev->dev_addr, ETH_ALEN) == 0 ||
 537                     (memcmp(wlhdr->addr3, bcm->net_dev->dev_addr, ETH_ALEN) &&
 538                      (is_broadcast_ether_addr(wlhdr->addr1) ||
 539                       is_multicast_ether_addr(wlhdr->addr1) ||
 540                       bcm->net_dev->flags & IFF_PROMISC)))
 541                         is_packet_for_us = 1;
 542                 break;
 543         }
 544
 545         frame_ctl = le16_to_cpu(wlhdr->frame_ctl);
 546         if ((frame_ctl & IEEE80211_FCTL_PROTECTED) && !bcm->ieee->host_decrypt) {
 547                 frame_ctl &= ~IEEE80211_FCTL_PROTECTED;
 548                 wlhdr->frame_ctl = cpu_to_le16(frame_ctl);
 549                 /* trim IV and ICV */
 550                 /* FIXME: this must be done only for WEP encrypted packets */
 551                 if (skb->len < 32) {
 552                         dprintkl(KERN_ERR PFX "RX packet dropped (PROTECTED flag "
 553                                               "set and length < 32)\n");
 554                         return -EINVAL;
 555                 } else {
 556                         memmove(skb->data + 4, skb->data, 24);
 557                         skb_pull(skb, 4);
 558                         skb_trim(skb, skb->len - 4);
 559                         stats.len -= 8;
 560                 }
 561                 wlhdr = (struct ieee80211_hdr_4addr *)(skb->data);
 562         }
 563
 564         switch (WLAN_FC_GET_TYPE(frame_ctl)) {
 565         case IEEE80211_FTYPE_MGMT:
 566                 ieee80211_rx_mgt(bcm->ieee, wlhdr, &stats);
 567                 break;
 568         case IEEE80211_FTYPE_DATA:
 569                 if (is_packet_for_us) {
 570                         err = ieee80211_rx(bcm->ieee, skb, &stats);
 571                         err = (err == 0) ? -EINVAL : 0;
 572                 }
 573                 break;
 574         case IEEE80211_FTYPE_CTL:
 575                 break;
 576         default:
 577                 assert(0);
 578                 return -EINVAL;
 579         }
 580
 581         return err;
 582 }