net/mac80211/rx.c

   1 /*
   2  * Copyright 2002-2005, Instant802 Networks, Inc.
   3  * Copyright 2005-2006, Devicescape Software, Inc.
   4  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   5  * Copyright 2007       Johannes Berg <johannes@sipsolutions.net>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/netdevice.h>
  15 #include <linux/etherdevice.h>
  16 #include <linux/rcupdate.h>
  17 #include <net/mac80211.h>
  18 #include <net/ieee80211_radiotap.h>
  19
  20 #include "ieee80211_i.h"
  21 #include "ieee80211_led.h"
  22 #include "wep.h"
  23 #include "wpa.h"
  24 #include "tkip.h"
  25 #include "wme.h"
  26
  27 /*
  28  * monitor mode reception
  29  *
  30  * This function cleans up the SKB, i.e. it removes all the stuff
  31  * only useful for monitoring.
  32  */
  33 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
  34                                            struct sk_buff *skb,
  35                                            int rtap_len)
  36 {
  37         skb_pull(skb, rtap_len);
  38
  39         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
  40                 if (likely(skb->len > FCS_LEN))
  41                         skb_trim(skb, skb->len - FCS_LEN);
  42                 else {
  43                         /* driver bug */
  44                         WARN_ON(1);
  45                         dev_kfree_skb(skb);
  46                         skb = NULL;
  47                 }
  48         }
  49
  50         return skb;
  51 }
  52
  53 static inline int should_drop_frame(struct ieee80211_rx_status *status,
  54                                     struct sk_buff *skb,
  55                                     int present_fcs_len,
  56                                     int radiotap_len)
  57 {
  58         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
  59
  60         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
  61                 return 1;
  62         if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
  63                 return 1;
  64         if ((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_FTYPE)) ==
  65                         cpu_to_le16(IEEE80211_FTYPE_CTL))
  66                 return 1;
  67         return 0;
  68 }
  69
  70 /*
  71  * This function copies a received frame to all monitor interfaces and
  72  * returns a cleaned-up SKB that no longer includes the FCS nor the
  73  * radiotap header the driver might have added.
  74  */
  75 static struct sk_buff *
  76 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
  77                      struct ieee80211_rx_status *status)
  78 {
  79         struct ieee80211_sub_if_data *sdata;
  80         struct ieee80211_rate *rate;
  81         int needed_headroom = 0;
  82         struct ieee80211_rtap_hdr {
  83                 struct ieee80211_radiotap_header hdr;
  84                 u8 flags;
  85                 u8 rate;
  86                 __le16 chan_freq;
  87                 __le16 chan_flags;
  88                 u8 antsignal;
  89                 u8 padding_for_rxflags;
  90                 __le16 rx_flags;
  91         } __attribute__ ((packed)) *rthdr;
  92         struct sk_buff *skb, *skb2;
  93         struct net_device *prev_dev = NULL;
  94         int present_fcs_len = 0;
  95         int rtap_len = 0;
  96
  97         /*
  98          * First, we may need to make a copy of the skb because
  99          *  (1) we need to modify it for radiotap (if not present), and
 100          *  (2) the other RX handlers will modify the skb we got.
 101          *
 102          * We don't need to, of course, if we aren't going to return
 103          * the SKB because it has a bad FCS/PLCP checksum.
 104          */
 105         if (status->flag & RX_FLAG_RADIOTAP)
 106                 rtap_len = ieee80211_get_radiotap_len(origskb->data);
 107         else
 108                 needed_headroom = sizeof(*rthdr);
 109
 110         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 111                 present_fcs_len = FCS_LEN;
 112
 113         if (!local->monitors) {
 114                 if (should_drop_frame(status, origskb, present_fcs_len,
 115                                       rtap_len)) {
 116                         dev_kfree_skb(origskb);
 117                         return NULL;
 118                 }
 119
 120                 return remove_monitor_info(local, origskb, rtap_len);
 121         }
 122
 123         if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
 124                 /* only need to expand headroom if necessary */
 125                 skb = origskb;
 126                 origskb = NULL;
 127
 128                 /*
 129                  * This shouldn't trigger often because most devices have an
 130                  * RX header they pull before we get here, and that should
 131                  * be big enough for our radiotap information. We should
 132                  * probably export the length to drivers so that we can have
 133                  * them allocate enough headroom to start with.
 134                  */
 135                 if (skb_headroom(skb) < needed_headroom &&
 136                     pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC)) {
 137                         dev_kfree_skb(skb);
 138                         return NULL;
 139                 }
 140         } else {
 141                 /*
 142                  * Need to make a copy and possibly remove radiotap header
 143                  * and FCS from the original.
 144                  */
 145                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 146
 147                 origskb = remove_monitor_info(local, origskb, rtap_len);
 148
 149                 if (!skb)
 150                         return origskb;
 151         }
 152
 153         /* if necessary, prepend radiotap information */
 154         if (!(status->flag & RX_FLAG_RADIOTAP)) {
 155                 rthdr = (void *) skb_push(skb, sizeof(*rthdr));
 156                 memset(rthdr, 0, sizeof(*rthdr));
 157                 rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
 158                 rthdr->hdr.it_present =
 159                         cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 160                                     (1 << IEEE80211_RADIOTAP_RATE) |
 161                                     (1 << IEEE80211_RADIOTAP_CHANNEL) |
 162                                     (1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL) |
 163                                     (1 << IEEE80211_RADIOTAP_RX_FLAGS));
 164                 rthdr->flags = local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS ?
 165                                IEEE80211_RADIOTAP_F_FCS : 0;
 166
 167                 /* FIXME: when radiotap gets a 'bad PLCP' flag use it here */
 168                 rthdr->rx_flags = 0;
 169                 if (status->flag &
 170                     (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 171                         rthdr->rx_flags |=
 172                                 cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS);
 173
 174                 rate = ieee80211_get_rate(local, status->phymode,
 175                                           status->rate);
 176                 if (rate)
 177                         rthdr->rate = rate->rate / 5;
 178
 179                 rthdr->chan_freq = cpu_to_le16(status->freq);
 180
 181                 if (status->phymode == MODE_IEEE80211A)
 182                         rthdr->chan_flags =
 183                                 cpu_to_le16(IEEE80211_CHAN_OFDM |
 184                                             IEEE80211_CHAN_5GHZ);
 185                 else
 186                         rthdr->chan_flags =
 187                                 cpu_to_le16(IEEE80211_CHAN_DYN |
 188                                             IEEE80211_CHAN_2GHZ);
 189
 190                 rthdr->antsignal = status->ssi;
 191         }
 192
 193         skb_set_mac_header(skb, 0);
 194         skb->ip_summed = CHECKSUM_UNNECESSARY;
 195         skb->pkt_type = PACKET_OTHERHOST;
 196         skb->protocol = htons(ETH_P_802_2);
 197
 198         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 199                 if (!netif_running(sdata->dev))
 200                         continue;
 201
 202                 if (sdata->type != IEEE80211_IF_TYPE_MNTR)
 203                         continue;
 204
 205                 if (prev_dev) {
 206                         skb2 = skb_clone(skb, GFP_ATOMIC);
 207                         if (skb2) {
 208                                 skb2->dev = prev_dev;
 209                                 netif_rx(skb2);
 210                         }
 211                 }
 212
 213                 prev_dev = sdata->dev;
 214                 sdata->dev->stats.rx_packets++;
 215                 sdata->dev->stats.rx_bytes += skb->len;
 216         }
 217
 218         if (prev_dev) {
 219                 skb->dev = prev_dev;
 220                 netif_rx(skb);
 221         } else
 222                 dev_kfree_skb(skb);
 223
 224         return origskb;
 225 }
 226
 227
 228 /* pre-rx handlers
 229  *
 230  * these don't have dev/sdata fields in the rx data
 231  * The sta value should also not be used because it may
 232  * be NULL even though a STA (in IBSS mode) will be added.
 233  */
 234
 235 static ieee80211_txrx_result
 236 ieee80211_rx_h_parse_qos(struct ieee80211_txrx_data *rx)
 237 {
 238         u8 *data = rx->skb->data;
 239         int tid;
 240
 241         /* does the frame have a qos control field? */
 242         if (WLAN_FC_IS_QOS_DATA(rx->fc)) {
 243                 u8 *qc = data + ieee80211_get_hdrlen(rx->fc) - QOS_CONTROL_LEN;
 244                 /* frame has qos control */
 245                 tid = qc[0] & QOS_CONTROL_TID_MASK;
 246         } else {
 247                 if (unlikely((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT)) {
 248                         /* Separate TID for management frames */
 249                         tid = NUM_RX_DATA_QUEUES - 1;
 250                 } else {
 251                         /* no qos control present */
 252                         tid = 0; /* 802.1d - Best Effort */
 253                 }
 254         }
 255
 256         I802_DEBUG_INC(rx->local->wme_rx_queue[tid]);
 257         /* only a debug counter, sta might not be assigned properly yet */
 258         if (rx->sta)
 259                 I802_DEBUG_INC(rx->sta->wme_rx_queue[tid]);
 260
 261         rx->u.rx.queue = tid;
 262         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 263          * For now, set skb->priority to 0 for other cases. */
 264         rx->skb->priority = (tid > 7) ? 0 : tid;
 265
 266         return TXRX_CONTINUE;
 267 }
 268
 269 static ieee80211_txrx_result
 270 ieee80211_rx_h_load_stats(struct ieee80211_txrx_data *rx)
 271 {
 272         struct ieee80211_local *local = rx->local;
 273         struct sk_buff *skb = rx->skb;
 274         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 275         u32 load = 0, hdrtime;
 276         struct ieee80211_rate *rate;
 277         struct ieee80211_hw_mode *mode = local->hw.conf.mode;
 278         int i;
 279
 280         /* Estimate total channel use caused by this frame */
 281
 282         if (unlikely(mode->num_rates < 0))
 283                 return TXRX_CONTINUE;
 284
 285         rate = &mode->rates[0];
 286         for (i = 0; i < mode->num_rates; i++) {
 287                 if (mode->rates[i].val == rx->u.rx.status->rate) {
 288                         rate = &mode->rates[i];
 289                         break;
 290                 }
 291         }
 292
 293         /* 1 bit at 1 Mbit/s takes 1 usec; in channel_use values,
 294          * 1 usec = 1/8 * (1080 / 10) = 13.5 */
 295
 296         if (mode->mode == MODE_IEEE80211A ||
 297             (mode->mode == MODE_IEEE80211G &&
 298              rate->flags & IEEE80211_RATE_ERP))
 299                 hdrtime = CHAN_UTIL_HDR_SHORT;
 300         else
 301                 hdrtime = CHAN_UTIL_HDR_LONG;
 302
 303         load = hdrtime;
 304         if (!is_multicast_ether_addr(hdr->addr1))
 305                 load += hdrtime;
 306
 307         load += skb->len * rate->rate_inv;
 308
 309         /* Divide channel_use by 8 to avoid wrapping around the counter */
 310         load >>= CHAN_UTIL_SHIFT;
 311         local->channel_use_raw += load;
 312         rx->u.rx.load = load;
 313
 314         return TXRX_CONTINUE;
 315 }
 316
 317 ieee80211_rx_handler ieee80211_rx_pre_handlers[] =
 318 {
 319         ieee80211_rx_h_parse_qos,
 320         ieee80211_rx_h_load_stats,
 321         NULL
 322 };
 323
 324 /* rx handlers */
 325
 326 static ieee80211_txrx_result
 327 ieee80211_rx_h_if_stats(struct ieee80211_txrx_data *rx)
 328 {
 329         if (rx->sta)
 330                 rx->sta->channel_use_raw += rx->u.rx.load;
 331         rx->sdata->channel_use_raw += rx->u.rx.load;
 332         return TXRX_CONTINUE;
 333 }
 334
 335 static ieee80211_txrx_result
 336 ieee80211_rx_h_passive_scan(struct ieee80211_txrx_data *rx)
 337 {
 338         struct ieee80211_local *local = rx->local;
 339         struct sk_buff *skb = rx->skb;
 340
 341         if (unlikely(local->sta_scanning != 0)) {
 342                 ieee80211_sta_rx_scan(rx->dev, skb, rx->u.rx.status);
 343                 return TXRX_QUEUED;
 344         }
 345
 346         if (unlikely(rx->flags & IEEE80211_TXRXD_RXIN_SCAN)) {
 347                 /* scanning finished during invoking of handlers */
 348                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 349                 return TXRX_DROP;
 350         }
 351
 352         return TXRX_CONTINUE;
 353 }
 354
 355 static ieee80211_txrx_result
 356 ieee80211_rx_h_check(struct ieee80211_txrx_data *rx)
 357 {
 358         struct ieee80211_hdr *hdr;
 359         hdr = (struct ieee80211_hdr *) rx->skb->data;
 360
 361         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 362         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 363                 if (unlikely(rx->fc & IEEE80211_FCTL_RETRY &&
 364                              rx->sta->last_seq_ctrl[rx->u.rx.queue] ==
 365                              hdr->seq_ctrl)) {
 366                         if (rx->flags & IEEE80211_TXRXD_RXRA_MATCH) {
 367                                 rx->local->dot11FrameDuplicateCount++;
 368                                 rx->sta->num_duplicates++;
 369                         }
 370                         return TXRX_DROP;
 371                 } else
 372                         rx->sta->last_seq_ctrl[rx->u.rx.queue] = hdr->seq_ctrl;
 373         }
 374
 375         if (unlikely(rx->skb->len < 16)) {
 376                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 377                 return TXRX_DROP;
 378         }
 379
 380         if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
 381                 rx->skb->pkt_type = PACKET_OTHERHOST;
 382         else if (compare_ether_addr(rx->dev->dev_addr, hdr->addr1) == 0)
 383                 rx->skb->pkt_type = PACKET_HOST;
 384         else if (is_multicast_ether_addr(hdr->addr1)) {
 385                 if (is_broadcast_ether_addr(hdr->addr1))
 386                         rx->skb->pkt_type = PACKET_BROADCAST;
 387                 else
 388                         rx->skb->pkt_type = PACKET_MULTICAST;
 389         } else
 390                 rx->skb->pkt_type = PACKET_OTHERHOST;
 391
 392         /* Drop disallowed frame classes based on STA auth/assoc state;
 393          * IEEE 802.11, Chap 5.5.
 394          *
 395          * 80211.o does filtering only based on association state, i.e., it
 396          * drops Class 3 frames from not associated stations. hostapd sends
 397          * deauth/disassoc frames when needed. In addition, hostapd is
 398          * responsible for filtering on both auth and assoc states.
 399          */
 400         if (unlikely(((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA ||
 401                       ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL &&
 402                        (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)) &&
 403                      rx->sdata->type != IEEE80211_IF_TYPE_IBSS &&
 404                      (!rx->sta || !(rx->sta->flags & WLAN_STA_ASSOC)))) {
 405                 if ((!(rx->fc & IEEE80211_FCTL_FROMDS) &&
 406                      !(rx->fc & IEEE80211_FCTL_TODS) &&
 407                      (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA)
 408                     || !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) {
 409                         /* Drop IBSS frames and frames for other hosts
 410                          * silently. */
 411                         return TXRX_DROP;
 412                 }
 413
 414                 return TXRX_DROP;
 415         }
 416
 417         return TXRX_CONTINUE;
 418 }
 419
 420
 421 static ieee80211_txrx_result
 422 ieee80211_rx_h_decrypt(struct ieee80211_txrx_data *rx)
 423 {
 424         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
 425         int keyidx;
 426         int hdrlen;
 427         ieee80211_txrx_result result = TXRX_DROP;
 428         struct ieee80211_key *stakey = NULL;
 429
 430         /*
 431          * Key selection 101
 432          *
 433          * There are three types of keys:
 434          *  - GTK (group keys)
 435          *  - PTK (pairwise keys)
 436          *  - STK (station-to-station pairwise keys)
 437          *
 438          * When selecting a key, we have to distinguish between multicast
 439          * (including broadcast) and unicast frames, the latter can only
 440          * use PTKs and STKs while the former always use GTKs. Unless, of
 441          * course, actual WEP keys ("pre-RSNA") are used, then unicast
 442          * frames can also use key indizes like GTKs. Hence, if we don't
 443          * have a PTK/STK we check the key index for a WEP key.
 444          *
 445          * Note that in a regular BSS, multicast frames are sent by the
 446          * AP only, associated stations unicast the frame to the AP first
 447          * which then multicasts it on their behalf.
 448          *
 449          * There is also a slight problem in IBSS mode: GTKs are negotiated
 450          * with each station, that is something we don't currently handle.
 451          * The spec seems to expect that one negotiates the same key with
 452          * every station but there's no such requirement; VLANs could be
 453          * possible.
 454          */
 455
 456         if (!(rx->fc & IEEE80211_FCTL_PROTECTED))
 457                 return TXRX_CONTINUE;
 458
 459         /*
 460          * No point in finding a key and decrypting if the frame is neither
 461          * addressed to us nor a multicast frame.
 462          */
 463         if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
 464                 return TXRX_CONTINUE;
 465
 466         if (rx->sta)
 467                 stakey = rcu_dereference(rx->sta->key);
 468
 469         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
 470                 rx->key = stakey;
 471         } else {
 472                 /*
 473                  * The device doesn't give us the IV so we won't be
 474                  * able to look up the key. That's ok though, we
 475                  * don't need to decrypt the frame, we just won't
 476                  * be able to keep statistics accurate.
 477                  * Except for key threshold notifications, should
 478                  * we somehow allow the driver to tell us which key
 479                  * the hardware used if this flag is set?
 480                  */
 481                 if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
 482                     (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED))
 483                         return TXRX_CONTINUE;
 484
 485                 hdrlen = ieee80211_get_hdrlen(rx->fc);
 486
 487                 if (rx->skb->len < 8 + hdrlen)
 488                         return TXRX_DROP; /* TODO: count this? */
 489
 490                 /*
 491                  * no need to call ieee80211_wep_get_keyidx,
 492                  * it verifies a bunch of things we've done already
 493                  */
 494                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
 495
 496                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
 497
 498                 /*
 499                  * RSNA-protected unicast frames should always be sent with
 500                  * pairwise or station-to-station keys, but for WEP we allow
 501                  * using a key index as well.
 502                  */
 503                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
 504                     !is_multicast_ether_addr(hdr->addr1))
 505                         rx->key = NULL;
 506         }
 507
 508         if (rx->key) {
 509                 rx->key->tx_rx_count++;
 510                 /* TODO: add threshold stuff again */
 511         } else {
 512                 if (net_ratelimit())
 513                         printk(KERN_DEBUG "%s: RX protected frame,"
 514                                " but have no key\n", rx->dev->name);
 515                 return TXRX_DROP;
 516         }
 517
 518         /* Check for weak IVs if possible */
 519         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
 520             ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA) &&
 521             (!(rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED) ||
 522              !(rx->u.rx.status->flag & RX_FLAG_DECRYPTED)) &&
 523             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
 524                 rx->sta->wep_weak_iv_count++;
 525
 526         switch (rx->key->conf.alg) {
 527         case ALG_WEP:
 528                 result = ieee80211_crypto_wep_decrypt(rx);
 529                 break;
 530         case ALG_TKIP:
 531                 result = ieee80211_crypto_tkip_decrypt(rx);
 532                 break;
 533         case ALG_CCMP:
 534                 result = ieee80211_crypto_ccmp_decrypt(rx);
 535                 break;
 536         }
 537
 538         /* either the frame has been decrypted or will be dropped */
 539         rx->u.rx.status->flag |= RX_FLAG_DECRYPTED;
 540
 541         return result;
 542 }
 543
 544 static void ap_sta_ps_start(struct net_device *dev, struct sta_info *sta)
 545 {
 546         struct ieee80211_sub_if_data *sdata;
 547         DECLARE_MAC_BUF(mac);
 548
 549         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 550
 551         if (sdata->bss)
 552                 atomic_inc(&sdata->bss->num_sta_ps);
 553         sta->flags |= WLAN_STA_PS;
 554         sta->pspoll = 0;
 555 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 556         printk(KERN_DEBUG "%s: STA %s aid %d enters power save mode\n",
 557                dev->name, print_mac(mac, sta->addr), sta->aid);
 558 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 559 }
 560
 561 static int ap_sta_ps_end(struct net_device *dev, struct sta_info *sta)
 562 {
 563         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 564         struct sk_buff *skb;
 565         int sent = 0;
 566         struct ieee80211_sub_if_data *sdata;
 567         struct ieee80211_tx_packet_data *pkt_data;
 568         DECLARE_MAC_BUF(mac);
 569
 570         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 571         if (sdata->bss)
 572                 atomic_dec(&sdata->bss->num_sta_ps);
 573         sta->flags &= ~(WLAN_STA_PS | WLAN_STA_TIM);
 574         sta->pspoll = 0;
 575         if (!skb_queue_empty(&sta->ps_tx_buf)) {
 576                 if (local->ops->set_tim)
 577                         local->ops->set_tim(local_to_hw(local), sta->aid, 0);
 578                 if (sdata->bss)
 579                         bss_tim_clear(local, sdata->bss, sta->aid);
 580         }
 581 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 582         printk(KERN_DEBUG "%s: STA %s aid %d exits power save mode\n",
 583                dev->name, print_mac(mac, sta->addr), sta->aid);
 584 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 585         /* Send all buffered frames to the station */
 586         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 587                 pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
 588                 sent++;
 589                 pkt_data->flags |= IEEE80211_TXPD_REQUEUE;
 590                 dev_queue_xmit(skb);
 591         }
 592         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 593                 pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
 594                 local->total_ps_buffered--;
 595                 sent++;
 596 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 597                 printk(KERN_DEBUG "%s: STA %s aid %d send PS frame "
 598                        "since STA not sleeping anymore\n", dev->name,
 599                        print_mac(mac, sta->addr), sta->aid);
 600 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 601                 pkt_data->flags |= IEEE80211_TXPD_REQUEUE;
 602                 dev_queue_xmit(skb);
 603         }
 604
 605         return sent;
 606 }
 607
 608 static ieee80211_txrx_result
 609 ieee80211_rx_h_sta_process(struct ieee80211_txrx_data *rx)
 610 {
 611         struct sta_info *sta = rx->sta;
 612         struct net_device *dev = rx->dev;
 613         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
 614
 615         if (!sta)
 616                 return TXRX_CONTINUE;
 617
 618         /* Update last_rx only for IBSS packets which are for the current
 619          * BSSID to avoid keeping the current IBSS network alive in cases where
 620          * other STAs are using different BSSID. */
 621         if (rx->sdata->type == IEEE80211_IF_TYPE_IBSS) {
 622                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len);
 623                 if (compare_ether_addr(bssid, rx->sdata->u.sta.bssid) == 0)
 624                         sta->last_rx = jiffies;
 625         } else
 626         if (!is_multicast_ether_addr(hdr->addr1) ||
 627             rx->sdata->type == IEEE80211_IF_TYPE_STA) {
 628                 /* Update last_rx only for unicast frames in order to prevent
 629                  * the Probe Request frames (the only broadcast frames from a
 630                  * STA in infrastructure mode) from keeping a connection alive.
 631                  */
 632                 sta->last_rx = jiffies;
 633         }
 634
 635         if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
 636                 return TXRX_CONTINUE;
 637
 638         sta->rx_fragments++;
 639         sta->rx_bytes += rx->skb->len;
 640         sta->last_rssi = rx->u.rx.status->ssi;
 641         sta->last_signal = rx->u.rx.status->signal;
 642         sta->last_noise = rx->u.rx.status->noise;
 643
 644         if (!(rx->fc & IEEE80211_FCTL_MOREFRAGS)) {
 645                 /* Change STA power saving mode only in the end of a frame
 646                  * exchange sequence */
 647                 if ((sta->flags & WLAN_STA_PS) && !(rx->fc & IEEE80211_FCTL_PM))
 648                         rx->u.rx.sent_ps_buffered += ap_sta_ps_end(dev, sta);
 649                 else if (!(sta->flags & WLAN_STA_PS) &&
 650                          (rx->fc & IEEE80211_FCTL_PM))
 651                         ap_sta_ps_start(dev, sta);
 652         }
 653
 654         /* Drop data::nullfunc frames silently, since they are used only to
 655          * control station power saving mode. */
 656         if ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
 657             (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_NULLFUNC) {
 658                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
 659                 /* Update counter and free packet here to avoid counting this
 660                  * as a dropped packed. */
 661                 sta->rx_packets++;
 662                 dev_kfree_skb(rx->skb);
 663                 return TXRX_QUEUED;
 664         }
 665
 666         return TXRX_CONTINUE;
 667 } /* ieee80211_rx_h_sta_process */
 668
 669 static inline struct ieee80211_fragment_entry *
 670 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
 671                          unsigned int frag, unsigned int seq, int rx_queue,
 672                          struct sk_buff **skb)
 673 {
 674         struct ieee80211_fragment_entry *entry;
 675         int idx;
 676
 677         idx = sdata->fragment_next;
 678         entry = &sdata->fragments[sdata->fragment_next++];
 679         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
 680                 sdata->fragment_next = 0;
 681
 682         if (!skb_queue_empty(&entry->skb_list)) {
 683 #ifdef CONFIG_MAC80211_DEBUG
 684                 struct ieee80211_hdr *hdr =
 685                         (struct ieee80211_hdr *) entry->skb_list.next->data;
 686                 DECLARE_MAC_BUF(mac);
 687                 DECLARE_MAC_BUF(mac2);
 688                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
 689                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
 690                        "addr1=%s addr2=%s\n",
 691                        sdata->dev->name, idx,
 692                        jiffies - entry->first_frag_time, entry->seq,
 693                        entry->last_frag, print_mac(mac, hdr->addr1),
 694                        print_mac(mac2, hdr->addr2));
 695 #endif /* CONFIG_MAC80211_DEBUG */
 696                 __skb_queue_purge(&entry->skb_list);
 697         }
 698
 699         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
 700         *skb = NULL;
 701         entry->first_frag_time = jiffies;
 702         entry->seq = seq;
 703         entry->rx_queue = rx_queue;
 704         entry->last_frag = frag;
 705         entry->ccmp = 0;
 706         entry->extra_len = 0;
 707
 708         return entry;
 709 }
 710
 711 static inline struct ieee80211_fragment_entry *
 712 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
 713                           u16 fc, unsigned int frag, unsigned int seq,
 714                           int rx_queue, struct ieee80211_hdr *hdr)
 715 {
 716         struct ieee80211_fragment_entry *entry;
 717         int i, idx;
 718
 719         idx = sdata->fragment_next;
 720         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
 721                 struct ieee80211_hdr *f_hdr;
 722                 u16 f_fc;
 723
 724                 idx--;
 725                 if (idx < 0)
 726                         idx = IEEE80211_FRAGMENT_MAX - 1;
 727
 728                 entry = &sdata->fragments[idx];
 729                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
 730                     entry->rx_queue != rx_queue ||
 731                     entry->last_frag + 1 != frag)
 732                         continue;
 733
 734                 f_hdr = (struct ieee80211_hdr *) entry->skb_list.next->data;
 735                 f_fc = le16_to_cpu(f_hdr->frame_control);
 736
 737                 if ((fc & IEEE80211_FCTL_FTYPE) != (f_fc & IEEE80211_FCTL_FTYPE) ||
 738                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
 739                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
 740                         continue;
 741
 742                 if (entry->first_frag_time + 2 * HZ < jiffies) {
 743                         __skb_queue_purge(&entry->skb_list);
 744                         continue;
 745                 }
 746                 return entry;
 747         }
 748
 749         return NULL;
 750 }
 751
 752 static ieee80211_txrx_result
 753 ieee80211_rx_h_defragment(struct ieee80211_txrx_data *rx)
 754 {
 755         struct ieee80211_hdr *hdr;
 756         u16 sc;
 757         unsigned int frag, seq;
 758         struct ieee80211_fragment_entry *entry;
 759         struct sk_buff *skb;
 760         DECLARE_MAC_BUF(mac);
 761
 762         hdr = (struct ieee80211_hdr *) rx->skb->data;
 763         sc = le16_to_cpu(hdr->seq_ctrl);
 764         frag = sc & IEEE80211_SCTL_FRAG;
 765
 766         if (likely((!(rx->fc & IEEE80211_FCTL_MOREFRAGS) && frag == 0) ||
 767                    (rx->skb)->len < 24 ||
 768                    is_multicast_ether_addr(hdr->addr1))) {
 769                 /* not fragmented */
 770                 goto out;
 771         }
 772         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
 773
 774         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
 775
 776         if (frag == 0) {
 777                 /* This is the first fragment of a new frame. */
 778                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
 779                                                  rx->u.rx.queue, &(rx->skb));
 780                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
 781                     (rx->fc & IEEE80211_FCTL_PROTECTED)) {
 782                         /* Store CCMP PN so that we can verify that the next
 783                          * fragment has a sequential PN value. */
 784                         entry->ccmp = 1;
 785                         memcpy(entry->last_pn,
 786                                rx->key->u.ccmp.rx_pn[rx->u.rx.queue],
 787                                CCMP_PN_LEN);
 788                 }
 789                 return TXRX_QUEUED;
 790         }
 791
 792         /* This is a fragment for a frame that should already be pending in
 793          * fragment cache. Add this fragment to the end of the pending entry.
 794          */
 795         entry = ieee80211_reassemble_find(rx->sdata, rx->fc, frag, seq,
 796                                           rx->u.rx.queue, hdr);
 797         if (!entry) {
 798                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
 799                 return TXRX_DROP;
 800         }
 801
 802         /* Verify that MPDUs within one MSDU have sequential PN values.
 803          * (IEEE 802.11i, 8.3.3.4.5) */
 804         if (entry->ccmp) {
 805                 int i;
 806                 u8 pn[CCMP_PN_LEN], *rpn;
 807                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
 808                         return TXRX_DROP;
 809                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
 810                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
 811                         pn[i]++;
 812                         if (pn[i])
 813                                 break;
 814                 }
 815                 rpn = rx->key->u.ccmp.rx_pn[rx->u.rx.queue];
 816                 if (memcmp(pn, rpn, CCMP_PN_LEN) != 0) {
 817                         if (net_ratelimit())
 818                                 printk(KERN_DEBUG "%s: defrag: CCMP PN not "
 819                                        "sequential A2=%s"
 820                                        " PN=%02x%02x%02x%02x%02x%02x "
 821                                        "(expected %02x%02x%02x%02x%02x%02x)\n",
 822                                        rx->dev->name, print_mac(mac, hdr->addr2),
 823                                        rpn[0], rpn[1], rpn[2], rpn[3], rpn[4],
 824                                        rpn[5], pn[0], pn[1], pn[2], pn[3],
 825                                        pn[4], pn[5]);
 826                         return TXRX_DROP;
 827                 }
 828                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
 829         }
 830
 831         skb_pull(rx->skb, ieee80211_get_hdrlen(rx->fc));
 832         __skb_queue_tail(&entry->skb_list, rx->skb);
 833         entry->last_frag = frag;
 834         entry->extra_len += rx->skb->len;
 835         if (rx->fc & IEEE80211_FCTL_MOREFRAGS) {
 836                 rx->skb = NULL;
 837                 return TXRX_QUEUED;
 838         }
 839
 840         rx->skb = __skb_dequeue(&entry->skb_list);
 841         if (skb_tailroom(rx->skb) < entry->extra_len) {
 842                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
 843                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
 844                                               GFP_ATOMIC))) {
 845                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
 846                         __skb_queue_purge(&entry->skb_list);
 847                         return TXRX_DROP;
 848                 }
 849         }
 850         while ((skb = __skb_dequeue(&entry->skb_list))) {
 851                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
 852                 dev_kfree_skb(skb);
 853         }
 854
 855         /* Complete frame has been reassembled - process it now */
 856         rx->flags |= IEEE80211_TXRXD_FRAGMENTED;
 857
 858  out:
 859         if (rx->sta)
 860                 rx->sta->rx_packets++;
 861         if (is_multicast_ether_addr(hdr->addr1))
 862                 rx->local->dot11MulticastReceivedFrameCount++;
 863         else
 864                 ieee80211_led_rx(rx->local);
 865         return TXRX_CONTINUE;
 866 }
 867
 868 static ieee80211_txrx_result
 869 ieee80211_rx_h_ps_poll(struct ieee80211_txrx_data *rx)
 870 {
 871         struct sk_buff *skb;
 872         int no_pending_pkts;
 873         DECLARE_MAC_BUF(mac);
 874
 875         if (likely(!rx->sta ||
 876                    (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL ||
 877                    (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PSPOLL ||
 878                    !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)))
 879                 return TXRX_CONTINUE;
 880
 881         skb = skb_dequeue(&rx->sta->tx_filtered);
 882         if (!skb) {
 883                 skb = skb_dequeue(&rx->sta->ps_tx_buf);
 884                 if (skb)
 885                         rx->local->total_ps_buffered--;
 886         }
 887         no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
 888                 skb_queue_empty(&rx->sta->ps_tx_buf);
 889
 890         if (skb) {
 891                 struct ieee80211_hdr *hdr =
 892                         (struct ieee80211_hdr *) skb->data;
 893
 894                 /* tell TX path to send one frame even though the STA may
 895                  * still remain is PS mode after this frame exchange */
 896                 rx->sta->pspoll = 1;
 897
 898 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 899                 printk(KERN_DEBUG "STA %s aid %d: PS Poll (entries after %d)\n",
 900                        print_mac(mac, rx->sta->addr), rx->sta->aid,
 901                        skb_queue_len(&rx->sta->ps_tx_buf));
 902 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 903
 904                 /* Use MoreData flag to indicate whether there are more
 905                  * buffered frames for this STA */
 906                 if (no_pending_pkts) {
 907                         hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
 908                         rx->sta->flags &= ~WLAN_STA_TIM;
 909                 } else
 910                         hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
 911
 912                 dev_queue_xmit(skb);
 913
 914                 if (no_pending_pkts) {
 915                         if (rx->local->ops->set_tim)
 916                                 rx->local->ops->set_tim(local_to_hw(rx->local),
 917                                                        rx->sta->aid, 0);
 918                         if (rx->sdata->bss)
 919                                 bss_tim_clear(rx->local, rx->sdata->bss, rx->sta->aid);
 920                 }
 921 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 922         } else if (!rx->u.rx.sent_ps_buffered) {
 923                 printk(KERN_DEBUG "%s: STA %s sent PS Poll even "
 924                        "though there is no buffered frames for it\n",
 925                        rx->dev->name, print_mac(mac, rx->sta->addr));
 926 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 927
 928         }
 929
 930         /* Free PS Poll skb here instead of returning TXRX_DROP that would
 931          * count as an dropped frame. */
 932         dev_kfree_skb(rx->skb);
 933
 934         return TXRX_QUEUED;
 935 }
 936
 937 static ieee80211_txrx_result
 938 ieee80211_rx_h_remove_qos_control(struct ieee80211_txrx_data *rx)
 939 {
 940         u16 fc = rx->fc;
 941         u8 *data = rx->skb->data;
 942         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) data;
 943
 944         if (!WLAN_FC_IS_QOS_DATA(fc))
 945                 return TXRX_CONTINUE;
 946
 947         /* remove the qos control field, update frame type and meta-data */
 948         memmove(data + 2, data, ieee80211_get_hdrlen(fc) - 2);
 949         hdr = (struct ieee80211_hdr *) skb_pull(rx->skb, 2);
 950         /* change frame type to non QOS */
 951         rx->fc = fc &= ~IEEE80211_STYPE_QOS_DATA;
 952         hdr->frame_control = cpu_to_le16(fc);
 953
 954         return TXRX_CONTINUE;
 955 }
 956
 957 static ieee80211_txrx_result
 958 ieee80211_rx_h_802_1x_pae(struct ieee80211_txrx_data *rx)
 959 {
 960         if (rx->sdata->eapol && ieee80211_is_eapol(rx->skb) &&
 961             rx->sdata->type != IEEE80211_IF_TYPE_STA &&
 962             (rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
 963                 return TXRX_CONTINUE;
 964
 965         if (unlikely(rx->sdata->ieee802_1x &&
 966                      (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
 967                      (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC &&
 968                      (!rx->sta || !(rx->sta->flags & WLAN_STA_AUTHORIZED)) &&
 969                      !ieee80211_is_eapol(rx->skb))) {
 970 #ifdef CONFIG_MAC80211_DEBUG
 971                 struct ieee80211_hdr *hdr =
 972                         (struct ieee80211_hdr *) rx->skb->data;
 973                 DECLARE_MAC_BUF(mac);
 974                 printk(KERN_DEBUG "%s: dropped frame from %s"
 975                        " (unauthorized port)\n", rx->dev->name,
 976                        print_mac(mac, hdr->addr2));
 977 #endif /* CONFIG_MAC80211_DEBUG */
 978                 return TXRX_DROP;
 979         }
 980
 981         return TXRX_CONTINUE;
 982 }
 983
 984 static ieee80211_txrx_result
 985 ieee80211_rx_h_drop_unencrypted(struct ieee80211_txrx_data *rx)
 986 {
 987         /*
 988          * Pass through unencrypted frames if the hardware has
 989          * decrypted them already.
 990          */
 991         if (rx->u.rx.status->flag & RX_FLAG_DECRYPTED)
 992                 return TXRX_CONTINUE;
 993
 994         /* Drop unencrypted frames if key is set. */
 995         if (unlikely(!(rx->fc & IEEE80211_FCTL_PROTECTED) &&
 996                      (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
 997                      (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC &&
 998                      rx->sdata->drop_unencrypted &&
 999                      (rx->sdata->eapol == 0 || !ieee80211_is_eapol(rx->skb)))) {
1000                 if (net_ratelimit())
1001                         printk(KERN_DEBUG "%s: RX non-WEP frame, but expected "
1002                                "encryption\n", rx->dev->name);
1003                 return TXRX_DROP;
1004         }
1005         return TXRX_CONTINUE;
1006 }
1007
1008 static ieee80211_txrx_result
1009 ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
1010 {
1011         struct net_device *dev = rx->dev;
1012         struct ieee80211_local *local = rx->local;
1013         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
1014         u16 fc, hdrlen, ethertype;
1015         u8 *payload;
1016         u8 dst[ETH_ALEN];
1017         u8 src[ETH_ALEN];
1018         struct sk_buff *skb = rx->skb, *skb2;
1019         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1020         DECLARE_MAC_BUF(mac);
1021         DECLARE_MAC_BUF(mac2);
1022         DECLARE_MAC_BUF(mac3);
1023         DECLARE_MAC_BUF(mac4);
1024
1025         fc = rx->fc;
1026         if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
1027                 return TXRX_CONTINUE;
1028
1029         if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1030                 return TXRX_DROP;
1031
1032         hdrlen = ieee80211_get_hdrlen(fc);
1033
1034         /* convert IEEE 802.11 header + possible LLC headers into Ethernet
1035          * header
1036          * IEEE 802.11 address fields:
1037          * ToDS FromDS Addr1 Addr2 Addr3 Addr4
1038          *   0     0   DA    SA    BSSID n/a
1039          *   0     1   DA    BSSID SA    n/a
1040          *   1     0   BSSID SA    DA    n/a
1041          *   1     1   RA    TA    DA    SA
1042          */
1043
1044         switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
1045         case IEEE80211_FCTL_TODS:
1046                 /* BSSID SA DA */
1047                 memcpy(dst, hdr->addr3, ETH_ALEN);
1048                 memcpy(src, hdr->addr2, ETH_ALEN);
1049
1050                 if (unlikely(sdata->type != IEEE80211_IF_TYPE_AP &&
1051                              sdata->type != IEEE80211_IF_TYPE_VLAN)) {
1052                         if (net_ratelimit())
1053                                 printk(KERN_DEBUG "%s: dropped ToDS frame "
1054                                        "(BSSID=%s SA=%s DA=%s)\n",
1055                                        dev->name,
1056                                        print_mac(mac, hdr->addr1),
1057                                        print_mac(mac2, hdr->addr2),
1058                                        print_mac(mac3, hdr->addr3));
1059                         return TXRX_DROP;
1060                 }
1061                 break;
1062         case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
1063                 /* RA TA DA SA */
1064                 memcpy(dst, hdr->addr3, ETH_ALEN);
1065                 memcpy(src, hdr->addr4, ETH_ALEN);
1066
1067                 if (unlikely(sdata->type != IEEE80211_IF_TYPE_WDS)) {
1068                         if (net_ratelimit())
1069                                 printk(KERN_DEBUG "%s: dropped FromDS&ToDS "
1070                                        "frame (RA=%s TA=%s DA=%s SA=%s)\n",
1071                                        rx->dev->name,
1072                                        print_mac(mac, hdr->addr1),
1073                                        print_mac(mac2, hdr->addr2),
1074                                        print_mac(mac3, hdr->addr3),
1075                                        print_mac(mac4, hdr->addr4));
1076                         return TXRX_DROP;
1077                 }
1078                 break;
1079         case IEEE80211_FCTL_FROMDS:
1080                 /* DA BSSID SA */
1081                 memcpy(dst, hdr->addr1, ETH_ALEN);
1082                 memcpy(src, hdr->addr3, ETH_ALEN);
1083
1084                 if (sdata->type != IEEE80211_IF_TYPE_STA ||
1085                     (is_multicast_ether_addr(dst) &&
1086                      !compare_ether_addr(src, dev->dev_addr)))
1087                         return TXRX_DROP;
1088                 break;
1089         case 0:
1090                 /* DA SA BSSID */
1091                 memcpy(dst, hdr->addr1, ETH_ALEN);
1092                 memcpy(src, hdr->addr2, ETH_ALEN);
1093
1094                 if (sdata->type != IEEE80211_IF_TYPE_IBSS) {
1095                         if (net_ratelimit()) {
1096                                 printk(KERN_DEBUG "%s: dropped IBSS frame "
1097                                        "(DA=%s SA=%s BSSID=%s)\n",
1098                                        dev->name,
1099                                        print_mac(mac, hdr->addr1),
1100                                        print_mac(mac2, hdr->addr2),
1101                                        print_mac(mac3, hdr->addr3));
1102                         }
1103                         return TXRX_DROP;
1104                 }
1105                 break;
1106         }
1107
1108         payload = skb->data + hdrlen;
1109
1110         if (unlikely(skb->len - hdrlen < 8)) {
1111                 if (net_ratelimit()) {
1112                         printk(KERN_DEBUG "%s: RX too short data frame "
1113                                "payload\n", dev->name);
1114                 }
1115                 return TXRX_DROP;
1116         }
1117
1118         ethertype = (payload[6] << 8) | payload[7];
1119
1120         if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1121                     ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1122                    compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
1123                 /* remove RFC1042 or Bridge-Tunnel encapsulation and
1124                  * replace EtherType */
1125                 skb_pull(skb, hdrlen + 6);
1126                 memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1127                 memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1128         } else {
1129                 struct ethhdr *ehdr;
1130                 __be16 len;
1131                 skb_pull(skb, hdrlen);
1132                 len = htons(skb->len);
1133                 ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
1134                 memcpy(ehdr->h_dest, dst, ETH_ALEN);
1135                 memcpy(ehdr->h_source, src, ETH_ALEN);
1136                 ehdr->h_proto = len;
1137         }
1138         skb->dev = dev;
1139
1140         skb2 = NULL;
1141
1142         dev->stats.rx_packets++;
1143         dev->stats.rx_bytes += skb->len;
1144
1145         if (local->bridge_packets && (sdata->type == IEEE80211_IF_TYPE_AP
1146             || sdata->type == IEEE80211_IF_TYPE_VLAN) &&
1147             (rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) {
1148                 if (is_multicast_ether_addr(skb->data)) {
1149                         /* send multicast frames both to higher layers in
1150                          * local net stack and back to the wireless media */
1151                         skb2 = skb_copy(skb, GFP_ATOMIC);
1152                         if (!skb2 && net_ratelimit())
1153                                 printk(KERN_DEBUG "%s: failed to clone "
1154                                        "multicast frame\n", dev->name);
1155                 } else {
1156                         struct sta_info *dsta;
1157                         dsta = sta_info_get(local, skb->data);
1158                         if (dsta && !dsta->dev) {
1159                                 if (net_ratelimit())
1160                                         printk(KERN_DEBUG "Station with null "
1161                                                "dev structure!\n");
1162                         } else if (dsta && dsta->dev == dev) {
1163                                 /* Destination station is associated to this
1164                                  * AP, so send the frame directly to it and
1165                                  * do not pass the frame to local net stack.
1166                                  */
1167                                 skb2 = skb;
1168                                 skb = NULL;
1169                         }
1170                         if (dsta)
1171                                 sta_info_put(dsta);
1172                 }
1173         }
1174
1175         if (skb) {
1176                 /* deliver to local stack */
1177                 skb->protocol = eth_type_trans(skb, dev);
1178                 memset(skb->cb, 0, sizeof(skb->cb));
1179                 netif_rx(skb);
1180         }
1181
1182         if (skb2) {
1183                 /* send to wireless media */
1184                 skb2->protocol = __constant_htons(ETH_P_802_3);
1185                 skb_set_network_header(skb2, 0);
1186                 skb_set_mac_header(skb2, 0);
1187                 dev_queue_xmit(skb2);
1188         }
1189
1190         return TXRX_QUEUED;
1191 }
1192
1193 static ieee80211_txrx_result
1194 ieee80211_rx_h_mgmt(struct ieee80211_txrx_data *rx)
1195 {
1196         struct ieee80211_sub_if_data *sdata;
1197
1198         if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
1199                 return TXRX_DROP;
1200
1201         sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1202         if ((sdata->type == IEEE80211_IF_TYPE_STA ||
1203              sdata->type == IEEE80211_IF_TYPE_IBSS) &&
1204             !(sdata->flags & IEEE80211_SDATA_USERSPACE_MLME))
1205                 ieee80211_sta_rx_mgmt(rx->dev, rx->skb, rx->u.rx.status);
1206         else
1207                 return TXRX_DROP;
1208
1209         return TXRX_QUEUED;
1210 }
1211
1212 static inline ieee80211_txrx_result __ieee80211_invoke_rx_handlers(
1213                                 struct ieee80211_local *local,
1214                                 ieee80211_rx_handler *handlers,
1215                                 struct ieee80211_txrx_data *rx,
1216                                 struct sta_info *sta)
1217 {
1218         ieee80211_rx_handler *handler;
1219         ieee80211_txrx_result res = TXRX_DROP;
1220
1221         for (handler = handlers; *handler != NULL; handler++) {
1222                 res = (*handler)(rx);
1223
1224                 switch (res) {
1225                 case TXRX_CONTINUE:
1226                         continue;
1227                 case TXRX_DROP:
1228                         I802_DEBUG_INC(local->rx_handlers_drop);
1229                         if (sta)
1230                                 sta->rx_dropped++;
1231                         break;
1232                 case TXRX_QUEUED:
1233                         I802_DEBUG_INC(local->rx_handlers_queued);
1234                         break;
1235                 }
1236                 break;
1237         }
1238
1239         if (res == TXRX_DROP)
1240                 dev_kfree_skb(rx->skb);
1241         return res;
1242 }
1243
1244 static inline void ieee80211_invoke_rx_handlers(struct ieee80211_local *local,
1245                                                 ieee80211_rx_handler *handlers,
1246                                                 struct ieee80211_txrx_data *rx,
1247                                                 struct sta_info *sta)
1248 {
1249         if (__ieee80211_invoke_rx_handlers(local, handlers, rx, sta) ==
1250             TXRX_CONTINUE)
1251                 dev_kfree_skb(rx->skb);
1252 }
1253
1254 static void ieee80211_rx_michael_mic_report(struct net_device *dev,
1255                                             struct ieee80211_hdr *hdr,
1256                                             struct sta_info *sta,
1257                                             struct ieee80211_txrx_data *rx)
1258 {
1259         int keyidx, hdrlen;
1260         DECLARE_MAC_BUF(mac);
1261         DECLARE_MAC_BUF(mac2);
1262
1263         hdrlen = ieee80211_get_hdrlen_from_skb(rx->skb);
1264         if (rx->skb->len >= hdrlen + 4)
1265                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
1266         else
1267                 keyidx = -1;
1268
1269         if (net_ratelimit())
1270                 printk(KERN_DEBUG "%s: TKIP hwaccel reported Michael MIC "
1271                        "failure from %s to %s keyidx=%d\n",
1272                        dev->name, print_mac(mac, hdr->addr2),
1273                        print_mac(mac2, hdr->addr1), keyidx);
1274
1275         if (!sta) {
1276                 /*
1277                  * Some hardware seem to generate incorrect Michael MIC
1278                  * reports; ignore them to avoid triggering countermeasures.
1279                  */
1280                 if (net_ratelimit())
1281                         printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1282                                "error for unknown address %s\n",
1283                                dev->name, print_mac(mac, hdr->addr2));
1284                 goto ignore;
1285         }
1286
1287         if (!(rx->fc & IEEE80211_FCTL_PROTECTED)) {
1288                 if (net_ratelimit())
1289                         printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1290                                "error for a frame with no PROTECTED flag (src "
1291                                "%s)\n", dev->name, print_mac(mac, hdr->addr2));
1292                 goto ignore;
1293         }
1294
1295         if (rx->sdata->type == IEEE80211_IF_TYPE_AP && keyidx) {
1296                 /*
1297                  * APs with pairwise keys should never receive Michael MIC
1298                  * errors for non-zero keyidx because these are reserved for
1299                  * group keys and only the AP is sending real multicast
1300                  * frames in the BSS.
1301                  */
1302                 if (net_ratelimit())
1303                         printk(KERN_DEBUG "%s: ignored Michael MIC error for "
1304                                "a frame with non-zero keyidx (%d)"
1305                                " (src %s)\n", dev->name, keyidx,
1306                                print_mac(mac, hdr->addr2));
1307                 goto ignore;
1308         }
1309
1310         if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA &&
1311             ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
1312              (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH)) {
1313                 if (net_ratelimit())
1314                         printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1315                                "error for a frame that cannot be encrypted "
1316                                "(fc=0x%04x) (src %s)\n",
1317                                dev->name, rx->fc, print_mac(mac, hdr->addr2));
1318                 goto ignore;
1319         }
1320
1321         mac80211_ev_michael_mic_failure(rx->dev, keyidx, hdr);
1322  ignore:
1323         dev_kfree_skb(rx->skb);
1324         rx->skb = NULL;
1325 }
1326
1327 ieee80211_rx_handler ieee80211_rx_handlers[] =
1328 {
1329         ieee80211_rx_h_if_stats,
1330         ieee80211_rx_h_passive_scan,
1331         ieee80211_rx_h_check,
1332         ieee80211_rx_h_decrypt,
1333         ieee80211_rx_h_sta_process,
1334         ieee80211_rx_h_defragment,
1335         ieee80211_rx_h_ps_poll,
1336         ieee80211_rx_h_michael_mic_verify,
1337         /* this must be after decryption - so header is counted in MPDU mic
1338          * must be before pae and data, so QOS_DATA format frames
1339          * are not passed to user space by these functions
1340          */
1341         ieee80211_rx_h_remove_qos_control,
1342         ieee80211_rx_h_802_1x_pae,
1343         ieee80211_rx_h_drop_unencrypted,
1344         ieee80211_rx_h_data,
1345         ieee80211_rx_h_mgmt,
1346         NULL
1347 };
1348
1349 /* main receive path */
1350
1351 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
1352                                 u8 *bssid, struct ieee80211_txrx_data *rx,
1353                                 struct ieee80211_hdr *hdr)
1354 {
1355         int multicast = is_multicast_ether_addr(hdr->addr1);
1356
1357         switch (sdata->type) {
1358         case IEEE80211_IF_TYPE_STA:
1359                 if (!bssid)
1360                         return 0;
1361                 if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1362                         if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1363                                 return 0;
1364                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1365                 } else if (!multicast &&
1366                            compare_ether_addr(sdata->dev->dev_addr,
1367                                               hdr->addr1) != 0) {
1368                         if (!(sdata->dev->flags & IFF_PROMISC))
1369                                 return 0;
1370                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1371                 }
1372                 break;
1373         case IEEE80211_IF_TYPE_IBSS:
1374                 if (!bssid)
1375                         return 0;
1376                 if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1377                         if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1378                                 return 0;
1379                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1380                 } else if (!multicast &&
1381                            compare_ether_addr(sdata->dev->dev_addr,
1382                                               hdr->addr1) != 0) {
1383                         if (!(sdata->dev->flags & IFF_PROMISC))
1384                                 return 0;
1385                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1386                 } else if (!rx->sta)
1387                         rx->sta = ieee80211_ibss_add_sta(sdata->dev, rx->skb,
1388                                                          bssid, hdr->addr2);
1389                 break;
1390         case IEEE80211_IF_TYPE_VLAN:
1391         case IEEE80211_IF_TYPE_AP:
1392                 if (!bssid) {
1393                         if (compare_ether_addr(sdata->dev->dev_addr,
1394                                                hdr->addr1))
1395                                 return 0;
1396                 } else if (!ieee80211_bssid_match(bssid,
1397                                         sdata->dev->dev_addr)) {
1398                         if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1399                                 return 0;
1400                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1401                 }
1402                 if (sdata->dev == sdata->local->mdev &&
1403                     !(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1404                         /* do not receive anything via
1405                          * master device when not scanning */
1406                         return 0;
1407                 break;
1408         case IEEE80211_IF_TYPE_WDS:
1409                 if (bssid ||
1410                     (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
1411                         return 0;
1412                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
1413                         return 0;
1414                 break;
1415         case IEEE80211_IF_TYPE_MNTR:
1416                 /* take everything */
1417                 break;
1418         case IEEE80211_IF_TYPE_INVALID:
1419                 /* should never get here */
1420                 WARN_ON(1);
1421                 break;
1422         }
1423
1424         return 1;
1425 }
1426
1427 /*
1428  * This is the receive path handler. It is called by a low level driver when an
1429  * 802.11 MPDU is received from the hardware.
1430  */
1431 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
1432                     struct ieee80211_rx_status *status)
1433 {
1434         struct ieee80211_local *local = hw_to_local(hw);
1435         struct ieee80211_sub_if_data *sdata;
1436         struct sta_info *sta;
1437         struct ieee80211_hdr *hdr;
1438         struct ieee80211_txrx_data rx;
1439         u16 type;
1440         int prepres;
1441         struct ieee80211_sub_if_data *prev = NULL;
1442         struct sk_buff *skb_new;
1443         u8 *bssid;
1444
1445         /*
1446          * key references and virtual interfaces are protected using RCU
1447          * and this requires that we are in a read-side RCU section during
1448          * receive processing
1449          */
1450         rcu_read_lock();
1451
1452         /*
1453          * Frames with failed FCS/PLCP checksum are not returned,
1454          * all other frames are returned without radiotap header
1455          * if it was previously present.
1456          * Also, frames with less than 16 bytes are dropped.
1457          */
1458         skb = ieee80211_rx_monitor(local, skb, status);
1459         if (!skb) {
1460                 rcu_read_unlock();
1461                 return;
1462         }
1463
1464         hdr = (struct ieee80211_hdr *) skb->data;
1465         memset(&rx, 0, sizeof(rx));
1466         rx.skb = skb;
1467         rx.local = local;
1468
1469         rx.u.rx.status = status;
1470         rx.fc = le16_to_cpu(hdr->frame_control);
1471         type = rx.fc & IEEE80211_FCTL_FTYPE;
1472
1473         if (type == IEEE80211_FTYPE_DATA || type == IEEE80211_FTYPE_MGMT)
1474                 local->dot11ReceivedFragmentCount++;
1475
1476         sta = rx.sta = sta_info_get(local, hdr->addr2);
1477         if (sta) {
1478                 rx.dev = rx.sta->dev;
1479                 rx.sdata = IEEE80211_DEV_TO_SUB_IF(rx.dev);
1480         }
1481
1482         if ((status->flag & RX_FLAG_MMIC_ERROR)) {
1483                 ieee80211_rx_michael_mic_report(local->mdev, hdr, sta, &rx);
1484                 goto end;
1485         }
1486
1487         if (unlikely(local->sta_scanning))
1488                 rx.flags |= IEEE80211_TXRXD_RXIN_SCAN;
1489
1490         if (__ieee80211_invoke_rx_handlers(local, local->rx_pre_handlers, &rx,
1491                                            sta) != TXRX_CONTINUE)
1492                 goto end;
1493         skb = rx.skb;
1494
1495         if (sta && !(sta->flags & (WLAN_STA_WDS | WLAN_STA_ASSOC_AP)) &&
1496             !atomic_read(&local->iff_promiscs) &&
1497             !is_multicast_ether_addr(hdr->addr1)) {
1498                 rx.flags |= IEEE80211_TXRXD_RXRA_MATCH;
1499                 ieee80211_invoke_rx_handlers(local, local->rx_handlers, &rx,
1500                                              rx.sta);
1501                 sta_info_put(sta);
1502                 rcu_read_unlock();
1503                 return;
1504         }
1505
1506         bssid = ieee80211_get_bssid(hdr, skb->len);
1507
1508         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1509                 if (!netif_running(sdata->dev))
1510                         continue;
1511
1512                 if (sdata->type == IEEE80211_IF_TYPE_MNTR)
1513                         continue;
1514
1515                 rx.flags |= IEEE80211_TXRXD_RXRA_MATCH;
1516                 prepres = prepare_for_handlers(sdata, bssid, &rx, hdr);
1517                 /* prepare_for_handlers can change sta */
1518                 sta = rx.sta;
1519
1520                 if (!prepres)
1521                         continue;
1522
1523                 /*
1524                  * frame is destined for this interface, but if it's not
1525                  * also for the previous one we handle that after the
1526                  * loop to avoid copying the SKB once too much
1527                  */
1528
1529                 if (!prev) {
1530                         prev = sdata;
1531                         continue;
1532                 }
1533
1534                 /*
1535                  * frame was destined for the previous interface
1536                  * so invoke RX handlers for it
1537                  */
1538
1539                 skb_new = skb_copy(skb, GFP_ATOMIC);
1540                 if (!skb_new) {
1541                         if (net_ratelimit())
1542                                 printk(KERN_DEBUG "%s: failed to copy "
1543                                        "multicast frame for %s",
1544                                        wiphy_name(local->hw.wiphy),
1545                                        prev->dev->name);
1546                         continue;
1547                 }
1548                 rx.skb = skb_new;
1549                 rx.dev = prev->dev;
1550                 rx.sdata = prev;
1551                 ieee80211_invoke_rx_handlers(local, local->rx_handlers,
1552                                              &rx, sta);
1553                 prev = sdata;
1554         }
1555         if (prev) {
1556                 rx.skb = skb;
1557                 rx.dev = prev->dev;
1558                 rx.sdata = prev;
1559                 ieee80211_invoke_rx_handlers(local, local->rx_handlers,
1560                                              &rx, sta);
1561         } else
1562                 dev_kfree_skb(skb);
1563
1564  end:
1565         rcu_read_unlock();
1566
1567         if (sta)
1568                 sta_info_put(sta);
1569 }
1570 EXPORT_SYMBOL(__ieee80211_rx);
1571
1572 /* This is a version of the rx handler that can be called from hard irq
1573  * context. Post the skb on the queue and schedule the tasklet */
1574 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb,
1575                           struct ieee80211_rx_status *status)
1576 {
1577         struct ieee80211_local *local = hw_to_local(hw);
1578
1579         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
1580
1581         skb->dev = local->mdev;
1582         /* copy status into skb->cb for use by tasklet */
1583         memcpy(skb->cb, status, sizeof(*status));
1584         skb->pkt_type = IEEE80211_RX_MSG;
1585         skb_queue_tail(&local->skb_queue, skb);
1586         tasklet_schedule(&local->tasklet);
1587 }
1588 EXPORT_SYMBOL(ieee80211_rx_irqsafe);