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 u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
  28                                 struct tid_ampdu_rx *tid_agg_rx,
  29                                 struct sk_buff *skb, u16 mpdu_seq_num,
  30                                 int bar_req);
  31 /*
  32  * monitor mode reception
  33  *
  34  * This function cleans up the SKB, i.e. it removes all the stuff
  35  * only useful for monitoring.
  36  */
  37 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
  38                                            struct sk_buff *skb,
  39                                            int rtap_len)
  40 {
  41         skb_pull(skb, rtap_len);
  42
  43         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
  44                 if (likely(skb->len > FCS_LEN))
  45                         skb_trim(skb, skb->len - FCS_LEN);
  46                 else {
  47                         /* driver bug */
  48                         WARN_ON(1);
  49                         dev_kfree_skb(skb);
  50                         skb = NULL;
  51                 }
  52         }
  53
  54         return skb;
  55 }
  56
  57 static inline int should_drop_frame(struct ieee80211_rx_status *status,
  58                                     struct sk_buff *skb,
  59                                     int present_fcs_len,
  60                                     int radiotap_len)
  61 {
  62         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
  63
  64         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
  65                 return 1;
  66         if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
  67                 return 1;
  68         if (((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_FTYPE)) ==
  69                         cpu_to_le16(IEEE80211_FTYPE_CTL)) &&
  70             ((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE)) !=
  71                         cpu_to_le16(IEEE80211_STYPE_PSPOLL)) &&
  72             ((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE)) !=
  73                         cpu_to_le16(IEEE80211_STYPE_BACK_REQ)))
  74                 return 1;
  75         return 0;
  76 }
  77
  78 /*
  79  * This function copies a received frame to all monitor interfaces and
  80  * returns a cleaned-up SKB that no longer includes the FCS nor the
  81  * radiotap header the driver might have added.
  82  */
  83 static struct sk_buff *
  84 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
  85                      struct ieee80211_rx_status *status)
  86 {
  87         struct ieee80211_sub_if_data *sdata;
  88         struct ieee80211_rate *rate;
  89         int needed_headroom = 0;
  90         struct ieee80211_radiotap_header *rthdr;
  91         __le64 *rttsft = NULL;
  92         struct ieee80211_rtap_fixed_data {
  93                 u8 flags;
  94                 u8 rate;
  95                 __le16 chan_freq;
  96                 __le16 chan_flags;
  97                 u8 antsignal;
  98                 u8 padding_for_rxflags;
  99                 __le16 rx_flags;
 100         } __attribute__ ((packed)) *rtfixed;
 101         struct sk_buff *skb, *skb2;
 102         struct net_device *prev_dev = NULL;
 103         int present_fcs_len = 0;
 104         int rtap_len = 0;
 105
 106         /*
 107          * First, we may need to make a copy of the skb because
 108          *  (1) we need to modify it for radiotap (if not present), and
 109          *  (2) the other RX handlers will modify the skb we got.
 110          *
 111          * We don't need to, of course, if we aren't going to return
 112          * the SKB because it has a bad FCS/PLCP checksum.
 113          */
 114         if (status->flag & RX_FLAG_RADIOTAP)
 115                 rtap_len = ieee80211_get_radiotap_len(origskb->data);
 116         else
 117                 /* room for radiotap header, always present fields and TSFT */
 118                 needed_headroom = sizeof(*rthdr) + sizeof(*rtfixed) + 8;
 119
 120         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 121                 present_fcs_len = FCS_LEN;
 122
 123         if (!local->monitors) {
 124                 if (should_drop_frame(status, origskb, present_fcs_len,
 125                                       rtap_len)) {
 126                         dev_kfree_skb(origskb);
 127                         return NULL;
 128                 }
 129
 130                 return remove_monitor_info(local, origskb, rtap_len);
 131         }
 132
 133         if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
 134                 /* only need to expand headroom if necessary */
 135                 skb = origskb;
 136                 origskb = NULL;
 137
 138                 /*
 139                  * This shouldn't trigger often because most devices have an
 140                  * RX header they pull before we get here, and that should
 141                  * be big enough for our radiotap information. We should
 142                  * probably export the length to drivers so that we can have
 143                  * them allocate enough headroom to start with.
 144                  */
 145                 if (skb_headroom(skb) < needed_headroom &&
 146                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
 147                         dev_kfree_skb(skb);
 148                         return NULL;
 149                 }
 150         } else {
 151                 /*
 152                  * Need to make a copy and possibly remove radiotap header
 153                  * and FCS from the original.
 154                  */
 155                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 156
 157                 origskb = remove_monitor_info(local, origskb, rtap_len);
 158
 159                 if (!skb)
 160                         return origskb;
 161         }
 162
 163         /* if necessary, prepend radiotap information */
 164         if (!(status->flag & RX_FLAG_RADIOTAP)) {
 165                 rtfixed = (void *) skb_push(skb, sizeof(*rtfixed));
 166                 rtap_len = sizeof(*rthdr) + sizeof(*rtfixed);
 167                 if (status->flag & RX_FLAG_TSFT) {
 168                         rttsft = (void *) skb_push(skb, sizeof(*rttsft));
 169                         rtap_len += 8;
 170                 }
 171                 rthdr = (void *) skb_push(skb, sizeof(*rthdr));
 172                 memset(rthdr, 0, sizeof(*rthdr));
 173                 memset(rtfixed, 0, sizeof(*rtfixed));
 174                 rthdr->it_present =
 175                         cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 176                                     (1 << IEEE80211_RADIOTAP_RATE) |
 177                                     (1 << IEEE80211_RADIOTAP_CHANNEL) |
 178                                     (1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL) |
 179                                     (1 << IEEE80211_RADIOTAP_RX_FLAGS));
 180                 rtfixed->flags = 0;
 181                 if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 182                         rtfixed->flags |= IEEE80211_RADIOTAP_F_FCS;
 183
 184                 if (rttsft) {
 185                         *rttsft = cpu_to_le64(status->mactime);
 186                         rthdr->it_present |=
 187                                 cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
 188                 }
 189
 190                 /* FIXME: when radiotap gets a 'bad PLCP' flag use it here */
 191                 rtfixed->rx_flags = 0;
 192                 if (status->flag &
 193                     (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 194                         rtfixed->rx_flags |=
 195                                 cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS);
 196
 197                 rate = ieee80211_get_rate(local, status->phymode,
 198                                           status->rate);
 199                 if (rate)
 200                         rtfixed->rate = rate->rate / 5;
 201
 202                 rtfixed->chan_freq = cpu_to_le16(status->freq);
 203
 204                 if (status->phymode == MODE_IEEE80211A)
 205                         rtfixed->chan_flags =
 206                                 cpu_to_le16(IEEE80211_CHAN_OFDM |
 207                                             IEEE80211_CHAN_5GHZ);
 208                 else
 209                         rtfixed->chan_flags =
 210                                 cpu_to_le16(IEEE80211_CHAN_DYN |
 211                                             IEEE80211_CHAN_2GHZ);
 212
 213                 rtfixed->antsignal = status->ssi;
 214                 rthdr->it_len = cpu_to_le16(rtap_len);
 215         }
 216
 217         skb_reset_mac_header(skb);
 218         skb->ip_summed = CHECKSUM_UNNECESSARY;
 219         skb->pkt_type = PACKET_OTHERHOST;
 220         skb->protocol = htons(ETH_P_802_2);
 221
 222         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 223                 if (!netif_running(sdata->dev))
 224                         continue;
 225
 226                 if (sdata->vif.type != IEEE80211_IF_TYPE_MNTR)
 227                         continue;
 228
 229                 if (prev_dev) {
 230                         skb2 = skb_clone(skb, GFP_ATOMIC);
 231                         if (skb2) {
 232                                 skb2->dev = prev_dev;
 233                                 netif_rx(skb2);
 234                         }
 235                 }
 236
 237                 prev_dev = sdata->dev;
 238                 sdata->dev->stats.rx_packets++;
 239                 sdata->dev->stats.rx_bytes += skb->len;
 240         }
 241
 242         if (prev_dev) {
 243                 skb->dev = prev_dev;
 244                 netif_rx(skb);
 245         } else
 246                 dev_kfree_skb(skb);
 247
 248         return origskb;
 249 }
 250
 251
 252 /* pre-rx handlers
 253  *
 254  * these don't have dev/sdata fields in the rx data
 255  * The sta value should also not be used because it may
 256  * be NULL even though a STA (in IBSS mode) will be added.
 257  */
 258
 259 static ieee80211_txrx_result
 260 ieee80211_rx_h_parse_qos(struct ieee80211_txrx_data *rx)
 261 {
 262         u8 *data = rx->skb->data;
 263         int tid;
 264
 265         /* does the frame have a qos control field? */
 266         if (WLAN_FC_IS_QOS_DATA(rx->fc)) {
 267                 u8 *qc = data + ieee80211_get_hdrlen(rx->fc) - QOS_CONTROL_LEN;
 268                 /* frame has qos control */
 269                 tid = qc[0] & QOS_CONTROL_TID_MASK;
 270                 if (qc[0] & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
 271                         rx->flags |= IEEE80211_TXRXD_RX_AMSDU;
 272                 else
 273                         rx->flags &= ~IEEE80211_TXRXD_RX_AMSDU;
 274         } else {
 275                 if (unlikely((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT)) {
 276                         /* Separate TID for management frames */
 277                         tid = NUM_RX_DATA_QUEUES - 1;
 278                 } else {
 279                         /* no qos control present */
 280                         tid = 0; /* 802.1d - Best Effort */
 281                 }
 282         }
 283
 284         I802_DEBUG_INC(rx->local->wme_rx_queue[tid]);
 285         /* only a debug counter, sta might not be assigned properly yet */
 286         if (rx->sta)
 287                 I802_DEBUG_INC(rx->sta->wme_rx_queue[tid]);
 288
 289         rx->u.rx.queue = tid;
 290         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 291          * For now, set skb->priority to 0 for other cases. */
 292         rx->skb->priority = (tid > 7) ? 0 : tid;
 293
 294         return TXRX_CONTINUE;
 295 }
 296
 297
 298 static u32 ieee80211_rx_load_stats(struct ieee80211_local *local,
 299                               struct sk_buff *skb,
 300                               struct ieee80211_rx_status *status)
 301 {
 302         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 303         u32 load = 0, hdrtime;
 304         struct ieee80211_rate *rate;
 305         struct ieee80211_hw_mode *mode = local->hw.conf.mode;
 306         int i;
 307
 308         /* Estimate total channel use caused by this frame */
 309
 310         if (unlikely(mode->num_rates < 0))
 311                 return TXRX_CONTINUE;
 312
 313         rate = &mode->rates[0];
 314         for (i = 0; i < mode->num_rates; i++) {
 315                 if (mode->rates[i].val == status->rate) {
 316                         rate = &mode->rates[i];
 317                         break;
 318                 }
 319         }
 320
 321         /* 1 bit at 1 Mbit/s takes 1 usec; in channel_use values,
 322          * 1 usec = 1/8 * (1080 / 10) = 13.5 */
 323
 324         if (mode->mode == MODE_IEEE80211A ||
 325             (mode->mode == MODE_IEEE80211G &&
 326              rate->flags & IEEE80211_RATE_ERP))
 327                 hdrtime = CHAN_UTIL_HDR_SHORT;
 328         else
 329                 hdrtime = CHAN_UTIL_HDR_LONG;
 330
 331         load = hdrtime;
 332         if (!is_multicast_ether_addr(hdr->addr1))
 333                 load += hdrtime;
 334
 335         load += skb->len * rate->rate_inv;
 336
 337         /* Divide channel_use by 8 to avoid wrapping around the counter */
 338         load >>= CHAN_UTIL_SHIFT;
 339
 340         return load;
 341 }
 342
 343 #ifdef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
 344 static ieee80211_txrx_result
 345 ieee80211_rx_h_verify_ip_alignment(struct ieee80211_txrx_data *rx)
 346 {
 347         int hdrlen;
 348
 349         if (!WLAN_FC_DATA_PRESENT(rx->fc))
 350                 return TXRX_CONTINUE;
 351
 352         /*
 353          * Drivers are required to align the payload data in a way that
 354          * guarantees that the contained IP header is aligned to a four-
 355          * byte boundary. In the case of regular frames, this simply means
 356          * aligning the payload to a four-byte boundary (because either
 357          * the IP header is directly contained, or IV/RFC1042 headers that
 358          * have a length divisible by four are in front of it.
 359          *
 360          * With A-MSDU frames, however, the payload data address must
 361          * yield two modulo four because there are 14-byte 802.3 headers
 362          * within the A-MSDU frames that push the IP header further back
 363          * to a multiple of four again. Thankfully, the specs were sane
 364          * enough this time around to require padding each A-MSDU subframe
 365          * to a length that is a multiple of four.
 366          *
 367          * Padding like atheros hardware adds which is inbetween the 802.11
 368          * header and the payload is not supported, the driver is required
 369          * to move the 802.11 header further back in that case.
 370          */
 371         hdrlen = ieee80211_get_hdrlen(rx->fc);
 372         if (rx->flags & IEEE80211_TXRXD_RX_AMSDU)
 373                 hdrlen += ETH_HLEN;
 374         WARN_ON_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3);
 375
 376         return TXRX_CONTINUE;
 377 }
 378 #endif
 379
 380 ieee80211_rx_handler ieee80211_rx_pre_handlers[] =
 381 {
 382         ieee80211_rx_h_parse_qos,
 383 #ifdef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
 384         ieee80211_rx_h_verify_ip_alignment,
 385 #endif
 386         NULL
 387 };
 388
 389 /* rx handlers */
 390
 391 static ieee80211_txrx_result
 392 ieee80211_rx_h_if_stats(struct ieee80211_txrx_data *rx)
 393 {
 394         if (rx->sta)
 395                 rx->sta->channel_use_raw += rx->u.rx.load;
 396         rx->sdata->channel_use_raw += rx->u.rx.load;
 397         return TXRX_CONTINUE;
 398 }
 399
 400 static ieee80211_txrx_result
 401 ieee80211_rx_h_passive_scan(struct ieee80211_txrx_data *rx)
 402 {
 403         struct ieee80211_local *local = rx->local;
 404         struct sk_buff *skb = rx->skb;
 405
 406         if (unlikely(local->sta_hw_scanning))
 407                 return ieee80211_sta_rx_scan(rx->dev, skb, rx->u.rx.status);
 408
 409         if (unlikely(local->sta_sw_scanning)) {
 410                 /* drop all the other packets during a software scan anyway */
 411                 if (ieee80211_sta_rx_scan(rx->dev, skb, rx->u.rx.status)
 412                     != TXRX_QUEUED)
 413                         dev_kfree_skb(skb);
 414                 return TXRX_QUEUED;
 415         }
 416
 417         if (unlikely(rx->flags & IEEE80211_TXRXD_RXIN_SCAN)) {
 418                 /* scanning finished during invoking of handlers */
 419                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 420                 return TXRX_DROP;
 421         }
 422
 423         return TXRX_CONTINUE;
 424 }
 425
 426 static ieee80211_txrx_result
 427 ieee80211_rx_h_check(struct ieee80211_txrx_data *rx)
 428 {
 429         struct ieee80211_hdr *hdr;
 430         hdr = (struct ieee80211_hdr *) rx->skb->data;
 431
 432         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 433         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 434                 if (unlikely(rx->fc & IEEE80211_FCTL_RETRY &&
 435                              rx->sta->last_seq_ctrl[rx->u.rx.queue] ==
 436                              hdr->seq_ctrl)) {
 437                         if (rx->flags & IEEE80211_TXRXD_RXRA_MATCH) {
 438                                 rx->local->dot11FrameDuplicateCount++;
 439                                 rx->sta->num_duplicates++;
 440                         }
 441                         return TXRX_DROP;
 442                 } else
 443                         rx->sta->last_seq_ctrl[rx->u.rx.queue] = hdr->seq_ctrl;
 444         }
 445
 446         if (unlikely(rx->skb->len < 16)) {
 447                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 448                 return TXRX_DROP;
 449         }
 450
 451         /* Drop disallowed frame classes based on STA auth/assoc state;
 452          * IEEE 802.11, Chap 5.5.
 453          *
 454          * 80211.o does filtering only based on association state, i.e., it
 455          * drops Class 3 frames from not associated stations. hostapd sends
 456          * deauth/disassoc frames when needed. In addition, hostapd is
 457          * responsible for filtering on both auth and assoc states.
 458          */
 459         if (unlikely(((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA ||
 460                       ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL &&
 461                        (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)) &&
 462                      rx->sdata->vif.type != IEEE80211_IF_TYPE_IBSS &&
 463                      (!rx->sta || !(rx->sta->flags & WLAN_STA_ASSOC)))) {
 464                 if ((!(rx->fc & IEEE80211_FCTL_FROMDS) &&
 465                      !(rx->fc & IEEE80211_FCTL_TODS) &&
 466                      (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA)
 467                     || !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) {
 468                         /* Drop IBSS frames and frames for other hosts
 469                          * silently. */
 470                         return TXRX_DROP;
 471                 }
 472
 473                 return TXRX_DROP;
 474         }
 475
 476         return TXRX_CONTINUE;
 477 }
 478
 479
 480 static ieee80211_txrx_result
 481 ieee80211_rx_h_decrypt(struct ieee80211_txrx_data *rx)
 482 {
 483         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
 484         int keyidx;
 485         int hdrlen;
 486         ieee80211_txrx_result result = TXRX_DROP;
 487         struct ieee80211_key *stakey = NULL;
 488
 489         /*
 490          * Key selection 101
 491          *
 492          * There are three types of keys:
 493          *  - GTK (group keys)
 494          *  - PTK (pairwise keys)
 495          *  - STK (station-to-station pairwise keys)
 496          *
 497          * When selecting a key, we have to distinguish between multicast
 498          * (including broadcast) and unicast frames, the latter can only
 499          * use PTKs and STKs while the former always use GTKs. Unless, of
 500          * course, actual WEP keys ("pre-RSNA") are used, then unicast
 501          * frames can also use key indizes like GTKs. Hence, if we don't
 502          * have a PTK/STK we check the key index for a WEP key.
 503          *
 504          * Note that in a regular BSS, multicast frames are sent by the
 505          * AP only, associated stations unicast the frame to the AP first
 506          * which then multicasts it on their behalf.
 507          *
 508          * There is also a slight problem in IBSS mode: GTKs are negotiated
 509          * with each station, that is something we don't currently handle.
 510          * The spec seems to expect that one negotiates the same key with
 511          * every station but there's no such requirement; VLANs could be
 512          * possible.
 513          */
 514
 515         if (!(rx->fc & IEEE80211_FCTL_PROTECTED))
 516                 return TXRX_CONTINUE;
 517
 518         /*
 519          * No point in finding a key and decrypting if the frame is neither
 520          * addressed to us nor a multicast frame.
 521          */
 522         if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
 523                 return TXRX_CONTINUE;
 524
 525         if (rx->sta)
 526                 stakey = rcu_dereference(rx->sta->key);
 527
 528         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
 529                 rx->key = stakey;
 530         } else {
 531                 /*
 532                  * The device doesn't give us the IV so we won't be
 533                  * able to look up the key. That's ok though, we
 534                  * don't need to decrypt the frame, we just won't
 535                  * be able to keep statistics accurate.
 536                  * Except for key threshold notifications, should
 537                  * we somehow allow the driver to tell us which key
 538                  * the hardware used if this flag is set?
 539                  */
 540                 if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
 541                     (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED))
 542                         return TXRX_CONTINUE;
 543
 544                 hdrlen = ieee80211_get_hdrlen(rx->fc);
 545
 546                 if (rx->skb->len < 8 + hdrlen)
 547                         return TXRX_DROP; /* TODO: count this? */
 548
 549                 /*
 550                  * no need to call ieee80211_wep_get_keyidx,
 551                  * it verifies a bunch of things we've done already
 552                  */
 553                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
 554
 555                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
 556
 557                 /*
 558                  * RSNA-protected unicast frames should always be sent with
 559                  * pairwise or station-to-station keys, but for WEP we allow
 560                  * using a key index as well.
 561                  */
 562                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
 563                     !is_multicast_ether_addr(hdr->addr1))
 564                         rx->key = NULL;
 565         }
 566
 567         if (rx->key) {
 568                 rx->key->tx_rx_count++;
 569                 /* TODO: add threshold stuff again */
 570         } else {
 571 #ifdef CONFIG_MAC80211_DEBUG
 572                 if (net_ratelimit())
 573                         printk(KERN_DEBUG "%s: RX protected frame,"
 574                                " but have no key\n", rx->dev->name);
 575 #endif /* CONFIG_MAC80211_DEBUG */
 576                 return TXRX_DROP;
 577         }
 578
 579         /* Check for weak IVs if possible */
 580         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
 581             ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA) &&
 582             (!(rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED) ||
 583              !(rx->u.rx.status->flag & RX_FLAG_DECRYPTED)) &&
 584             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
 585                 rx->sta->wep_weak_iv_count++;
 586
 587         switch (rx->key->conf.alg) {
 588         case ALG_WEP:
 589                 result = ieee80211_crypto_wep_decrypt(rx);
 590                 break;
 591         case ALG_TKIP:
 592                 result = ieee80211_crypto_tkip_decrypt(rx);
 593                 break;
 594         case ALG_CCMP:
 595                 result = ieee80211_crypto_ccmp_decrypt(rx);
 596                 break;
 597         }
 598
 599         /* either the frame has been decrypted or will be dropped */
 600         rx->u.rx.status->flag |= RX_FLAG_DECRYPTED;
 601
 602         return result;
 603 }
 604
 605 static void ap_sta_ps_start(struct net_device *dev, struct sta_info *sta)
 606 {
 607         struct ieee80211_sub_if_data *sdata;
 608         DECLARE_MAC_BUF(mac);
 609
 610         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 611
 612         if (sdata->bss)
 613                 atomic_inc(&sdata->bss->num_sta_ps);
 614         sta->flags |= WLAN_STA_PS;
 615         sta->pspoll = 0;
 616 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 617         printk(KERN_DEBUG "%s: STA %s aid %d enters power save mode\n",
 618                dev->name, print_mac(mac, sta->addr), sta->aid);
 619 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 620 }
 621
 622 static int ap_sta_ps_end(struct net_device *dev, struct sta_info *sta)
 623 {
 624         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 625         struct sk_buff *skb;
 626         int sent = 0;
 627         struct ieee80211_sub_if_data *sdata;
 628         struct ieee80211_tx_packet_data *pkt_data;
 629         DECLARE_MAC_BUF(mac);
 630
 631         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 632         if (sdata->bss)
 633                 atomic_dec(&sdata->bss->num_sta_ps);
 634         sta->flags &= ~(WLAN_STA_PS | WLAN_STA_TIM);
 635         sta->pspoll = 0;
 636         if (!skb_queue_empty(&sta->ps_tx_buf)) {
 637                 if (local->ops->set_tim)
 638                         local->ops->set_tim(local_to_hw(local), sta->aid, 0);
 639                 if (sdata->bss)
 640                         bss_tim_clear(local, sdata->bss, sta->aid);
 641         }
 642 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 643         printk(KERN_DEBUG "%s: STA %s aid %d exits power save mode\n",
 644                dev->name, print_mac(mac, sta->addr), sta->aid);
 645 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 646         /* Send all buffered frames to the station */
 647         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 648                 pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
 649                 sent++;
 650                 pkt_data->flags |= IEEE80211_TXPD_REQUEUE;
 651                 dev_queue_xmit(skb);
 652         }
 653         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 654                 pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
 655                 local->total_ps_buffered--;
 656                 sent++;
 657 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 658                 printk(KERN_DEBUG "%s: STA %s aid %d send PS frame "
 659                        "since STA not sleeping anymore\n", dev->name,
 660                        print_mac(mac, sta->addr), sta->aid);
 661 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 662                 pkt_data->flags |= IEEE80211_TXPD_REQUEUE;
 663                 dev_queue_xmit(skb);
 664         }
 665
 666         return sent;
 667 }
 668
 669 static ieee80211_txrx_result
 670 ieee80211_rx_h_sta_process(struct ieee80211_txrx_data *rx)
 671 {
 672         struct sta_info *sta = rx->sta;
 673         struct net_device *dev = rx->dev;
 674         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
 675
 676         if (!sta)
 677                 return TXRX_CONTINUE;
 678
 679         /* Update last_rx only for IBSS packets which are for the current
 680          * BSSID to avoid keeping the current IBSS network alive in cases where
 681          * other STAs are using different BSSID. */
 682         if (rx->sdata->vif.type == IEEE80211_IF_TYPE_IBSS) {
 683                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
 684                                                 IEEE80211_IF_TYPE_IBSS);
 685                 if (compare_ether_addr(bssid, rx->sdata->u.sta.bssid) == 0)
 686                         sta->last_rx = jiffies;
 687         } else
 688         if (!is_multicast_ether_addr(hdr->addr1) ||
 689             rx->sdata->vif.type == IEEE80211_IF_TYPE_STA) {
 690                 /* Update last_rx only for unicast frames in order to prevent
 691                  * the Probe Request frames (the only broadcast frames from a
 692                  * STA in infrastructure mode) from keeping a connection alive.
 693                  */
 694                 sta->last_rx = jiffies;
 695         }
 696
 697         if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
 698                 return TXRX_CONTINUE;
 699
 700         sta->rx_fragments++;
 701         sta->rx_bytes += rx->skb->len;
 702         sta->last_rssi = rx->u.rx.status->ssi;
 703         sta->last_signal = rx->u.rx.status->signal;
 704         sta->last_noise = rx->u.rx.status->noise;
 705
 706         if (!(rx->fc & IEEE80211_FCTL_MOREFRAGS)) {
 707                 /* Change STA power saving mode only in the end of a frame
 708                  * exchange sequence */
 709                 if ((sta->flags & WLAN_STA_PS) && !(rx->fc & IEEE80211_FCTL_PM))
 710                         rx->u.rx.sent_ps_buffered += ap_sta_ps_end(dev, sta);
 711                 else if (!(sta->flags & WLAN_STA_PS) &&
 712                          (rx->fc & IEEE80211_FCTL_PM))
 713                         ap_sta_ps_start(dev, sta);
 714         }
 715
 716         /* Drop data::nullfunc frames silently, since they are used only to
 717          * control station power saving mode. */
 718         if ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
 719             (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_NULLFUNC) {
 720                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
 721                 /* Update counter and free packet here to avoid counting this
 722                  * as a dropped packed. */
 723                 sta->rx_packets++;
 724                 dev_kfree_skb(rx->skb);
 725                 return TXRX_QUEUED;
 726         }
 727
 728         return TXRX_CONTINUE;
 729 } /* ieee80211_rx_h_sta_process */
 730
 731 static inline struct ieee80211_fragment_entry *
 732 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
 733                          unsigned int frag, unsigned int seq, int rx_queue,
 734                          struct sk_buff **skb)
 735 {
 736         struct ieee80211_fragment_entry *entry;
 737         int idx;
 738
 739         idx = sdata->fragment_next;
 740         entry = &sdata->fragments[sdata->fragment_next++];
 741         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
 742                 sdata->fragment_next = 0;
 743
 744         if (!skb_queue_empty(&entry->skb_list)) {
 745 #ifdef CONFIG_MAC80211_DEBUG
 746                 struct ieee80211_hdr *hdr =
 747                         (struct ieee80211_hdr *) entry->skb_list.next->data;
 748                 DECLARE_MAC_BUF(mac);
 749                 DECLARE_MAC_BUF(mac2);
 750                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
 751                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
 752                        "addr1=%s addr2=%s\n",
 753                        sdata->dev->name, idx,
 754                        jiffies - entry->first_frag_time, entry->seq,
 755                        entry->last_frag, print_mac(mac, hdr->addr1),
 756                        print_mac(mac2, hdr->addr2));
 757 #endif /* CONFIG_MAC80211_DEBUG */
 758                 __skb_queue_purge(&entry->skb_list);
 759         }
 760
 761         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
 762         *skb = NULL;
 763         entry->first_frag_time = jiffies;
 764         entry->seq = seq;
 765         entry->rx_queue = rx_queue;
 766         entry->last_frag = frag;
 767         entry->ccmp = 0;
 768         entry->extra_len = 0;
 769
 770         return entry;
 771 }
 772
 773 static inline struct ieee80211_fragment_entry *
 774 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
 775                           u16 fc, unsigned int frag, unsigned int seq,
 776                           int rx_queue, struct ieee80211_hdr *hdr)
 777 {
 778         struct ieee80211_fragment_entry *entry;
 779         int i, idx;
 780
 781         idx = sdata->fragment_next;
 782         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
 783                 struct ieee80211_hdr *f_hdr;
 784                 u16 f_fc;
 785
 786                 idx--;
 787                 if (idx < 0)
 788                         idx = IEEE80211_FRAGMENT_MAX - 1;
 789
 790                 entry = &sdata->fragments[idx];
 791                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
 792                     entry->rx_queue != rx_queue ||
 793                     entry->last_frag + 1 != frag)
 794                         continue;
 795
 796                 f_hdr = (struct ieee80211_hdr *) entry->skb_list.next->data;
 797                 f_fc = le16_to_cpu(f_hdr->frame_control);
 798
 799                 if ((fc & IEEE80211_FCTL_FTYPE) != (f_fc & IEEE80211_FCTL_FTYPE) ||
 800                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
 801                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
 802                         continue;
 803
 804                 if (entry->first_frag_time + 2 * HZ < jiffies) {
 805                         __skb_queue_purge(&entry->skb_list);
 806                         continue;
 807                 }
 808                 return entry;
 809         }
 810
 811         return NULL;
 812 }
 813
 814 static ieee80211_txrx_result
 815 ieee80211_rx_h_defragment(struct ieee80211_txrx_data *rx)
 816 {
 817         struct ieee80211_hdr *hdr;
 818         u16 sc;
 819         unsigned int frag, seq;
 820         struct ieee80211_fragment_entry *entry;
 821         struct sk_buff *skb;
 822         DECLARE_MAC_BUF(mac);
 823
 824         hdr = (struct ieee80211_hdr *) rx->skb->data;
 825         sc = le16_to_cpu(hdr->seq_ctrl);
 826         frag = sc & IEEE80211_SCTL_FRAG;
 827
 828         if (likely((!(rx->fc & IEEE80211_FCTL_MOREFRAGS) && frag == 0) ||
 829                    (rx->skb)->len < 24 ||
 830                    is_multicast_ether_addr(hdr->addr1))) {
 831                 /* not fragmented */
 832                 goto out;
 833         }
 834         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
 835
 836         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
 837
 838         if (frag == 0) {
 839                 /* This is the first fragment of a new frame. */
 840                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
 841                                                  rx->u.rx.queue, &(rx->skb));
 842                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
 843                     (rx->fc & IEEE80211_FCTL_PROTECTED)) {
 844                         /* Store CCMP PN so that we can verify that the next
 845                          * fragment has a sequential PN value. */
 846                         entry->ccmp = 1;
 847                         memcpy(entry->last_pn,
 848                                rx->key->u.ccmp.rx_pn[rx->u.rx.queue],
 849                                CCMP_PN_LEN);
 850                 }
 851                 return TXRX_QUEUED;
 852         }
 853
 854         /* This is a fragment for a frame that should already be pending in
 855          * fragment cache. Add this fragment to the end of the pending entry.
 856          */
 857         entry = ieee80211_reassemble_find(rx->sdata, rx->fc, frag, seq,
 858                                           rx->u.rx.queue, hdr);
 859         if (!entry) {
 860                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
 861                 return TXRX_DROP;
 862         }
 863
 864         /* Verify that MPDUs within one MSDU have sequential PN values.
 865          * (IEEE 802.11i, 8.3.3.4.5) */
 866         if (entry->ccmp) {
 867                 int i;
 868                 u8 pn[CCMP_PN_LEN], *rpn;
 869                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
 870                         return TXRX_DROP;
 871                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
 872                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
 873                         pn[i]++;
 874                         if (pn[i])
 875                                 break;
 876                 }
 877                 rpn = rx->key->u.ccmp.rx_pn[rx->u.rx.queue];
 878                 if (memcmp(pn, rpn, CCMP_PN_LEN) != 0) {
 879                         if (net_ratelimit())
 880                                 printk(KERN_DEBUG "%s: defrag: CCMP PN not "
 881                                        "sequential A2=%s"
 882                                        " PN=%02x%02x%02x%02x%02x%02x "
 883                                        "(expected %02x%02x%02x%02x%02x%02x)\n",
 884                                        rx->dev->name, print_mac(mac, hdr->addr2),
 885                                        rpn[0], rpn[1], rpn[2], rpn[3], rpn[4],
 886                                        rpn[5], pn[0], pn[1], pn[2], pn[3],
 887                                        pn[4], pn[5]);
 888                         return TXRX_DROP;
 889                 }
 890                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
 891         }
 892
 893         skb_pull(rx->skb, ieee80211_get_hdrlen(rx->fc));
 894         __skb_queue_tail(&entry->skb_list, rx->skb);
 895         entry->last_frag = frag;
 896         entry->extra_len += rx->skb->len;
 897         if (rx->fc & IEEE80211_FCTL_MOREFRAGS) {
 898                 rx->skb = NULL;
 899                 return TXRX_QUEUED;
 900         }
 901
 902         rx->skb = __skb_dequeue(&entry->skb_list);
 903         if (skb_tailroom(rx->skb) < entry->extra_len) {
 904                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
 905                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
 906                                               GFP_ATOMIC))) {
 907                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
 908                         __skb_queue_purge(&entry->skb_list);
 909                         return TXRX_DROP;
 910                 }
 911         }
 912         while ((skb = __skb_dequeue(&entry->skb_list))) {
 913                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
 914                 dev_kfree_skb(skb);
 915         }
 916
 917         /* Complete frame has been reassembled - process it now */
 918         rx->flags |= IEEE80211_TXRXD_FRAGMENTED;
 919
 920  out:
 921         if (rx->sta)
 922                 rx->sta->rx_packets++;
 923         if (is_multicast_ether_addr(hdr->addr1))
 924                 rx->local->dot11MulticastReceivedFrameCount++;
 925         else
 926                 ieee80211_led_rx(rx->local);
 927         return TXRX_CONTINUE;
 928 }
 929
 930 static ieee80211_txrx_result
 931 ieee80211_rx_h_ps_poll(struct ieee80211_txrx_data *rx)
 932 {
 933         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
 934         struct sk_buff *skb;
 935         int no_pending_pkts;
 936         DECLARE_MAC_BUF(mac);
 937
 938         if (likely(!rx->sta ||
 939                    (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL ||
 940                    (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PSPOLL ||
 941                    !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)))
 942                 return TXRX_CONTINUE;
 943
 944         if ((sdata->vif.type != IEEE80211_IF_TYPE_AP) &&
 945             (sdata->vif.type != IEEE80211_IF_TYPE_VLAN))
 946                 return TXRX_DROP;
 947
 948         skb = skb_dequeue(&rx->sta->tx_filtered);
 949         if (!skb) {
 950                 skb = skb_dequeue(&rx->sta->ps_tx_buf);
 951                 if (skb)
 952                         rx->local->total_ps_buffered--;
 953         }
 954         no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
 955                 skb_queue_empty(&rx->sta->ps_tx_buf);
 956
 957         if (skb) {
 958                 struct ieee80211_hdr *hdr =
 959                         (struct ieee80211_hdr *) skb->data;
 960
 961                 /* tell TX path to send one frame even though the STA may
 962                  * still remain is PS mode after this frame exchange */
 963                 rx->sta->pspoll = 1;
 964
 965 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 966                 printk(KERN_DEBUG "STA %s aid %d: PS Poll (entries after %d)\n",
 967                        print_mac(mac, rx->sta->addr), rx->sta->aid,
 968                        skb_queue_len(&rx->sta->ps_tx_buf));
 969 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 970
 971                 /* Use MoreData flag to indicate whether there are more
 972                  * buffered frames for this STA */
 973                 if (no_pending_pkts) {
 974                         hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
 975                         rx->sta->flags &= ~WLAN_STA_TIM;
 976                 } else
 977                         hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
 978
 979                 dev_queue_xmit(skb);
 980
 981                 if (no_pending_pkts) {
 982                         if (rx->local->ops->set_tim)
 983                                 rx->local->ops->set_tim(local_to_hw(rx->local),
 984                                                        rx->sta->aid, 0);
 985                         if (rx->sdata->bss)
 986                                 bss_tim_clear(rx->local, rx->sdata->bss, rx->sta->aid);
 987                 }
 988 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 989         } else if (!rx->u.rx.sent_ps_buffered) {
 990                 printk(KERN_DEBUG "%s: STA %s sent PS Poll even "
 991                        "though there is no buffered frames for it\n",
 992                        rx->dev->name, print_mac(mac, rx->sta->addr));
 993 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 994
 995         }
 996
 997         /* Free PS Poll skb here instead of returning TXRX_DROP that would
 998          * count as an dropped frame. */
 999         dev_kfree_skb(rx->skb);
1000
1001         return TXRX_QUEUED;
1002 }
1003
1004 static ieee80211_txrx_result
1005 ieee80211_rx_h_remove_qos_control(struct ieee80211_txrx_data *rx)
1006 {
1007         u16 fc = rx->fc;
1008         u8 *data = rx->skb->data;
1009         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) data;
1010
1011         if (!WLAN_FC_IS_QOS_DATA(fc))
1012                 return TXRX_CONTINUE;
1013
1014         /* remove the qos control field, update frame type and meta-data */
1015         memmove(data + 2, data, ieee80211_get_hdrlen(fc) - 2);
1016         hdr = (struct ieee80211_hdr *) skb_pull(rx->skb, 2);
1017         /* change frame type to non QOS */
1018         rx->fc = fc &= ~IEEE80211_STYPE_QOS_DATA;
1019         hdr->frame_control = cpu_to_le16(fc);
1020
1021         return TXRX_CONTINUE;
1022 }
1023
1024 static int
1025 ieee80211_802_1x_port_control(struct ieee80211_txrx_data *rx)
1026 {
1027         if (unlikely(rx->sdata->ieee802_1x_pac &&
1028                      (!rx->sta || !(rx->sta->flags & WLAN_STA_AUTHORIZED)))) {
1029 #ifdef CONFIG_MAC80211_DEBUG
1030                 printk(KERN_DEBUG "%s: dropped frame "
1031                        "(unauthorized port)\n", rx->dev->name);
1032 #endif /* CONFIG_MAC80211_DEBUG */
1033                 return -EACCES;
1034         }
1035
1036         return 0;
1037 }
1038
1039 static int
1040 ieee80211_drop_unencrypted(struct ieee80211_txrx_data *rx)
1041 {
1042         /*
1043          * Pass through unencrypted frames if the hardware has
1044          * decrypted them already.
1045          */
1046         if (rx->u.rx.status->flag & RX_FLAG_DECRYPTED)
1047                 return 0;
1048
1049         /* Drop unencrypted frames if key is set. */
1050         if (unlikely(!(rx->fc & IEEE80211_FCTL_PROTECTED) &&
1051                      (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
1052                      (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC &&
1053                      (rx->key || rx->sdata->drop_unencrypted)))
1054                 return -EACCES;
1055
1056         return 0;
1057 }
1058
1059 static int
1060 ieee80211_data_to_8023(struct ieee80211_txrx_data *rx)
1061 {
1062         struct net_device *dev = rx->dev;
1063         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
1064         u16 fc, hdrlen, ethertype;
1065         u8 *payload;
1066         u8 dst[ETH_ALEN];
1067         u8 src[ETH_ALEN];
1068         struct sk_buff *skb = rx->skb;
1069         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1070         DECLARE_MAC_BUF(mac);
1071         DECLARE_MAC_BUF(mac2);
1072         DECLARE_MAC_BUF(mac3);
1073         DECLARE_MAC_BUF(mac4);
1074
1075         fc = rx->fc;
1076
1077         if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1078                 return -1;
1079
1080         hdrlen = ieee80211_get_hdrlen(fc);
1081
1082         /* convert IEEE 802.11 header + possible LLC headers into Ethernet
1083          * header
1084          * IEEE 802.11 address fields:
1085          * ToDS FromDS Addr1 Addr2 Addr3 Addr4
1086          *   0     0   DA    SA    BSSID n/a
1087          *   0     1   DA    BSSID SA    n/a
1088          *   1     0   BSSID SA    DA    n/a
1089          *   1     1   RA    TA    DA    SA
1090          */
1091
1092         switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
1093         case IEEE80211_FCTL_TODS:
1094                 /* BSSID SA DA */
1095                 memcpy(dst, hdr->addr3, ETH_ALEN);
1096                 memcpy(src, hdr->addr2, ETH_ALEN);
1097
1098                 if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_AP &&
1099                              sdata->vif.type != IEEE80211_IF_TYPE_VLAN)) {
1100                         if (net_ratelimit())
1101                                 printk(KERN_DEBUG "%s: dropped ToDS frame "
1102                                        "(BSSID=%s SA=%s DA=%s)\n",
1103                                        dev->name,
1104                                        print_mac(mac, hdr->addr1),
1105                                        print_mac(mac2, hdr->addr2),
1106                                        print_mac(mac3, hdr->addr3));
1107                         return -1;
1108                 }
1109                 break;
1110         case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
1111                 /* RA TA DA SA */
1112                 memcpy(dst, hdr->addr3, ETH_ALEN);
1113                 memcpy(src, hdr->addr4, ETH_ALEN);
1114
1115                 if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_WDS)) {
1116                         if (net_ratelimit())
1117                                 printk(KERN_DEBUG "%s: dropped FromDS&ToDS "
1118                                        "frame (RA=%s TA=%s DA=%s SA=%s)\n",
1119                                        rx->dev->name,
1120                                        print_mac(mac, hdr->addr1),
1121                                        print_mac(mac2, hdr->addr2),
1122                                        print_mac(mac3, hdr->addr3),
1123                                        print_mac(mac4, hdr->addr4));
1124                         return -1;
1125                 }
1126                 break;
1127         case IEEE80211_FCTL_FROMDS:
1128                 /* DA BSSID SA */
1129                 memcpy(dst, hdr->addr1, ETH_ALEN);
1130                 memcpy(src, hdr->addr3, ETH_ALEN);
1131
1132                 if (sdata->vif.type != IEEE80211_IF_TYPE_STA ||
1133                     (is_multicast_ether_addr(dst) &&
1134                      !compare_ether_addr(src, dev->dev_addr)))
1135                         return -1;
1136                 break;
1137         case 0:
1138                 /* DA SA BSSID */
1139                 memcpy(dst, hdr->addr1, ETH_ALEN);
1140                 memcpy(src, hdr->addr2, ETH_ALEN);
1141
1142                 if (sdata->vif.type != IEEE80211_IF_TYPE_IBSS) {
1143                         if (net_ratelimit()) {
1144                                 printk(KERN_DEBUG "%s: dropped IBSS frame "
1145                                        "(DA=%s SA=%s BSSID=%s)\n",
1146                                        dev->name,
1147                                        print_mac(mac, hdr->addr1),
1148                                        print_mac(mac2, hdr->addr2),
1149                                        print_mac(mac3, hdr->addr3));
1150                         }
1151                         return -1;
1152                 }
1153                 break;
1154         }
1155
1156         if (unlikely(skb->len - hdrlen < 8)) {
1157                 if (net_ratelimit()) {
1158                         printk(KERN_DEBUG "%s: RX too short data frame "
1159                                "payload\n", dev->name);
1160                 }
1161                 return -1;
1162         }
1163
1164         payload = skb->data + hdrlen;
1165         ethertype = (payload[6] << 8) | payload[7];
1166
1167         if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1168                     ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1169                    compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
1170                 /* remove RFC1042 or Bridge-Tunnel encapsulation and
1171                  * replace EtherType */
1172                 skb_pull(skb, hdrlen + 6);
1173                 memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1174                 memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1175         } else {
1176                 struct ethhdr *ehdr;
1177                 __be16 len;
1178
1179                 skb_pull(skb, hdrlen);
1180                 len = htons(skb->len);
1181                 ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
1182                 memcpy(ehdr->h_dest, dst, ETH_ALEN);
1183                 memcpy(ehdr->h_source, src, ETH_ALEN);
1184                 ehdr->h_proto = len;
1185         }
1186         return 0;
1187 }
1188
1189 /*
1190  * requires that rx->skb is a frame with ethernet header
1191  */
1192 static bool ieee80211_frame_allowed(struct ieee80211_txrx_data *rx)
1193 {
1194         static const u8 pae_group_addr[ETH_ALEN]
1195                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1196         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1197
1198         /*
1199          * Allow EAPOL frames to us/the PAE group address regardless
1200          * of whether the frame was encrypted or not.
1201          */
1202         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1203             (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1204              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1205                 return true;
1206
1207         if (ieee80211_802_1x_port_control(rx) ||
1208             ieee80211_drop_unencrypted(rx))
1209                 return false;
1210
1211         return true;
1212 }
1213
1214 /*
1215  * requires that rx->skb is a frame with ethernet header
1216  */
1217 static void
1218 ieee80211_deliver_skb(struct ieee80211_txrx_data *rx)
1219 {
1220         struct net_device *dev = rx->dev;
1221         struct ieee80211_local *local = rx->local;
1222         struct sk_buff *skb, *xmit_skb;
1223         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1224         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1225         struct sta_info *dsta;
1226
1227         skb = rx->skb;
1228         xmit_skb = NULL;
1229
1230         if (local->bridge_packets && (sdata->vif.type == IEEE80211_IF_TYPE_AP ||
1231                                       sdata->vif.type == IEEE80211_IF_TYPE_VLAN) &&
1232             (rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) {
1233                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1234                         /*
1235                          * send multicast frames both to higher layers in
1236                          * local net stack and back to the wireless medium
1237                          */
1238                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1239                         if (!xmit_skb && net_ratelimit())
1240                                 printk(KERN_DEBUG "%s: failed to clone "
1241                                        "multicast frame\n", dev->name);
1242                 } else {
1243                         dsta = sta_info_get(local, skb->data);
1244                         if (dsta && dsta->dev == dev) {
1245                                 /*
1246                                  * The destination station is associated to
1247                                  * this AP (in this VLAN), so send the frame
1248                                  * directly to it and do not pass it to local
1249                                  * net stack.
1250                                  */
1251                                 xmit_skb = skb;
1252                                 skb = NULL;
1253                         }
1254                         if (dsta)
1255                                 sta_info_put(dsta);
1256                 }
1257         }
1258
1259         if (skb) {
1260                 /* deliver to local stack */
1261                 skb->protocol = eth_type_trans(skb, dev);
1262                 memset(skb->cb, 0, sizeof(skb->cb));
1263                 netif_rx(skb);
1264         }
1265
1266         if (xmit_skb) {
1267                 /* send to wireless media */
1268                 xmit_skb->protocol = htons(ETH_P_802_3);
1269                 skb_reset_network_header(xmit_skb);
1270                 skb_reset_mac_header(xmit_skb);
1271                 dev_queue_xmit(xmit_skb);
1272         }
1273 }
1274
1275 static ieee80211_txrx_result
1276 ieee80211_rx_h_amsdu(struct ieee80211_txrx_data *rx)
1277 {
1278         struct net_device *dev = rx->dev;
1279         struct ieee80211_local *local = rx->local;
1280         u16 fc, ethertype;
1281         u8 *payload;
1282         struct sk_buff *skb = rx->skb, *frame = NULL;
1283         const struct ethhdr *eth;
1284         int remaining, err;
1285         u8 dst[ETH_ALEN];
1286         u8 src[ETH_ALEN];
1287         DECLARE_MAC_BUF(mac);
1288
1289         fc = rx->fc;
1290         if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
1291                 return TXRX_CONTINUE;
1292
1293         if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1294                 return TXRX_DROP;
1295
1296         if (!(rx->flags & IEEE80211_TXRXD_RX_AMSDU))
1297                 return TXRX_CONTINUE;
1298
1299         err = ieee80211_data_to_8023(rx);
1300         if (unlikely(err))
1301                 return TXRX_DROP;
1302
1303         skb->dev = dev;
1304
1305         dev->stats.rx_packets++;
1306         dev->stats.rx_bytes += skb->len;
1307
1308         /* skip the wrapping header */
1309         eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1310         if (!eth)
1311                 return TXRX_DROP;
1312
1313         while (skb != frame) {
1314                 u8 padding;
1315                 __be16 len = eth->h_proto;
1316                 unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1317
1318                 remaining = skb->len;
1319                 memcpy(dst, eth->h_dest, ETH_ALEN);
1320                 memcpy(src, eth->h_source, ETH_ALEN);
1321
1322                 padding = ((4 - subframe_len) & 0x3);
1323                 /* the last MSDU has no padding */
1324                 if (subframe_len > remaining) {
1325                         printk(KERN_DEBUG "%s: wrong buffer size", dev->name);
1326                         return TXRX_DROP;
1327                 }
1328
1329                 skb_pull(skb, sizeof(struct ethhdr));
1330                 /* if last subframe reuse skb */
1331                 if (remaining <= subframe_len + padding)
1332                         frame = skb;
1333                 else {
1334                         frame = dev_alloc_skb(local->hw.extra_tx_headroom +
1335                                               subframe_len);
1336
1337                         if (frame == NULL)
1338                                 return TXRX_DROP;
1339
1340                         skb_reserve(frame, local->hw.extra_tx_headroom +
1341                                     sizeof(struct ethhdr));
1342                         memcpy(skb_put(frame, ntohs(len)), skb->data,
1343                                 ntohs(len));
1344
1345                         eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1346                                                         padding);
1347                         if (!eth) {
1348                                 printk(KERN_DEBUG "%s: wrong buffer size ",
1349                                        dev->name);
1350                                 dev_kfree_skb(frame);
1351                                 return TXRX_DROP;
1352                         }
1353                 }
1354
1355                 skb_reset_network_header(frame);
1356                 frame->dev = dev;
1357                 frame->priority = skb->priority;
1358                 rx->skb = frame;
1359
1360                 payload = frame->data;
1361                 ethertype = (payload[6] << 8) | payload[7];
1362
1363                 if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1364                             ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1365                            compare_ether_addr(payload,
1366                                               bridge_tunnel_header) == 0)) {
1367                         /* remove RFC1042 or Bridge-Tunnel
1368                          * encapsulation and replace EtherType */
1369                         skb_pull(frame, 6);
1370                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1371                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1372                 } else {
1373                         memcpy(skb_push(frame, sizeof(__be16)),
1374                                &len, sizeof(__be16));
1375                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1376                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1377                 }
1378
1379                 if (!ieee80211_frame_allowed(rx)) {
1380                         if (skb == frame) /* last frame */
1381                                 return TXRX_DROP;
1382                         dev_kfree_skb(frame);
1383                         continue;
1384                 }
1385
1386                 ieee80211_deliver_skb(rx);
1387         }
1388
1389         return TXRX_QUEUED;
1390 }
1391
1392 static ieee80211_txrx_result
1393 ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
1394 {
1395         struct net_device *dev = rx->dev;
1396         u16 fc;
1397         int err;
1398
1399         fc = rx->fc;
1400         if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
1401                 return TXRX_CONTINUE;
1402
1403         if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1404                 return TXRX_DROP;
1405
1406         err = ieee80211_data_to_8023(rx);
1407         if (unlikely(err))
1408                 return TXRX_DROP;
1409
1410         if (!ieee80211_frame_allowed(rx))
1411                 return TXRX_DROP;
1412
1413         rx->skb->dev = dev;
1414
1415         dev->stats.rx_packets++;
1416         dev->stats.rx_bytes += rx->skb->len;
1417
1418         ieee80211_deliver_skb(rx);
1419
1420         return TXRX_QUEUED;
1421 }
1422
1423 static ieee80211_txrx_result
1424 ieee80211_rx_h_ctrl(struct ieee80211_txrx_data *rx)
1425 {
1426         struct ieee80211_local *local = rx->local;
1427         struct ieee80211_hw *hw = &local->hw;
1428         struct sk_buff *skb = rx->skb;
1429         struct ieee80211_bar *bar = (struct ieee80211_bar *) skb->data;
1430         struct tid_ampdu_rx *tid_agg_rx;
1431         u16 start_seq_num;
1432         u16 tid;
1433
1434         if (likely((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL))
1435                 return TXRX_CONTINUE;
1436
1437         if ((rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BACK_REQ) {
1438                 if (!rx->sta)
1439                         return TXRX_CONTINUE;
1440                 tid = le16_to_cpu(bar->control) >> 12;
1441                 tid_agg_rx = &(rx->sta->ampdu_mlme.tid_rx[tid]);
1442                 if (tid_agg_rx->state != HT_AGG_STATE_OPERATIONAL)
1443                         return TXRX_CONTINUE;
1444
1445                 start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1446
1447                 /* reset session timer */
1448                 if (tid_agg_rx->timeout) {
1449                         unsigned long expires =
1450                                 jiffies + (tid_agg_rx->timeout / 1000) * HZ;
1451                         mod_timer(&tid_agg_rx->session_timer, expires);
1452                 }
1453
1454                 /* manage reordering buffer according to requested */
1455                 /* sequence number */
1456                 rcu_read_lock();
1457                 ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL,
1458                                                  start_seq_num, 1);
1459                 rcu_read_unlock();
1460                 return TXRX_DROP;
1461         }
1462
1463         return TXRX_CONTINUE;
1464 }
1465
1466 static ieee80211_txrx_result
1467 ieee80211_rx_h_mgmt(struct ieee80211_txrx_data *rx)
1468 {
1469         struct ieee80211_sub_if_data *sdata;
1470
1471         if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
1472                 return TXRX_DROP;
1473
1474         sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1475         if ((sdata->vif.type == IEEE80211_IF_TYPE_STA ||
1476              sdata->vif.type == IEEE80211_IF_TYPE_IBSS) &&
1477             !(sdata->flags & IEEE80211_SDATA_USERSPACE_MLME))
1478                 ieee80211_sta_rx_mgmt(rx->dev, rx->skb, rx->u.rx.status);
1479         else
1480                 return TXRX_DROP;
1481
1482         return TXRX_QUEUED;
1483 }
1484
1485 static inline ieee80211_txrx_result __ieee80211_invoke_rx_handlers(
1486                                 struct ieee80211_local *local,
1487                                 ieee80211_rx_handler *handlers,
1488                                 struct ieee80211_txrx_data *rx,
1489                                 struct sta_info *sta)
1490 {
1491         ieee80211_rx_handler *handler;
1492         ieee80211_txrx_result res = TXRX_DROP;
1493
1494         for (handler = handlers; *handler != NULL; handler++) {
1495                 res = (*handler)(rx);
1496
1497                 switch (res) {
1498                 case TXRX_CONTINUE:
1499                         continue;
1500                 case TXRX_DROP:
1501                         I802_DEBUG_INC(local->rx_handlers_drop);
1502                         if (sta)
1503                                 sta->rx_dropped++;
1504                         break;
1505                 case TXRX_QUEUED:
1506                         I802_DEBUG_INC(local->rx_handlers_queued);
1507                         break;
1508                 }
1509                 break;
1510         }
1511
1512         if (res == TXRX_DROP)
1513                 dev_kfree_skb(rx->skb);
1514         return res;
1515 }
1516
1517 static inline void ieee80211_invoke_rx_handlers(struct ieee80211_local *local,
1518                                                 ieee80211_rx_handler *handlers,
1519                                                 struct ieee80211_txrx_data *rx,
1520                                                 struct sta_info *sta)
1521 {
1522         if (__ieee80211_invoke_rx_handlers(local, handlers, rx, sta) ==
1523             TXRX_CONTINUE)
1524                 dev_kfree_skb(rx->skb);
1525 }
1526
1527 static void ieee80211_rx_michael_mic_report(struct net_device *dev,
1528                                             struct ieee80211_hdr *hdr,
1529                                             struct sta_info *sta,
1530                                             struct ieee80211_txrx_data *rx)
1531 {
1532         int keyidx, hdrlen;
1533         DECLARE_MAC_BUF(mac);
1534         DECLARE_MAC_BUF(mac2);
1535
1536         hdrlen = ieee80211_get_hdrlen_from_skb(rx->skb);
1537         if (rx->skb->len >= hdrlen + 4)
1538                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
1539         else
1540                 keyidx = -1;
1541
1542         if (net_ratelimit())
1543                 printk(KERN_DEBUG "%s: TKIP hwaccel reported Michael MIC "
1544                        "failure from %s to %s keyidx=%d\n",
1545                        dev->name, print_mac(mac, hdr->addr2),
1546                        print_mac(mac2, hdr->addr1), keyidx);
1547
1548         if (!sta) {
1549                 /*
1550                  * Some hardware seem to generate incorrect Michael MIC
1551                  * reports; ignore them to avoid triggering countermeasures.
1552                  */
1553                 if (net_ratelimit())
1554                         printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1555                                "error for unknown address %s\n",
1556                                dev->name, print_mac(mac, hdr->addr2));
1557                 goto ignore;
1558         }
1559
1560         if (!(rx->fc & IEEE80211_FCTL_PROTECTED)) {
1561                 if (net_ratelimit())
1562                         printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1563                                "error for a frame with no PROTECTED flag (src "
1564                                "%s)\n", dev->name, print_mac(mac, hdr->addr2));
1565                 goto ignore;
1566         }
1567
1568         if (rx->sdata->vif.type == IEEE80211_IF_TYPE_AP && keyidx) {
1569                 /*
1570                  * APs with pairwise keys should never receive Michael MIC
1571                  * errors for non-zero keyidx because these are reserved for
1572                  * group keys and only the AP is sending real multicast
1573                  * frames in the BSS.
1574                  */
1575                 if (net_ratelimit())
1576                         printk(KERN_DEBUG "%s: ignored Michael MIC error for "
1577                                "a frame with non-zero keyidx (%d)"
1578                                " (src %s)\n", dev->name, keyidx,
1579                                print_mac(mac, hdr->addr2));
1580                 goto ignore;
1581         }
1582
1583         if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA &&
1584             ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
1585              (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH)) {
1586                 if (net_ratelimit())
1587                         printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1588                                "error for a frame that cannot be encrypted "
1589                                "(fc=0x%04x) (src %s)\n",
1590                                dev->name, rx->fc, print_mac(mac, hdr->addr2));
1591                 goto ignore;
1592         }
1593
1594         mac80211_ev_michael_mic_failure(rx->dev, keyidx, hdr);
1595  ignore:
1596         dev_kfree_skb(rx->skb);
1597         rx->skb = NULL;
1598 }
1599
1600 ieee80211_rx_handler ieee80211_rx_handlers[] =
1601 {
1602         ieee80211_rx_h_if_stats,
1603         ieee80211_rx_h_passive_scan,
1604         ieee80211_rx_h_check,
1605         ieee80211_rx_h_decrypt,
1606         ieee80211_rx_h_sta_process,
1607         ieee80211_rx_h_defragment,
1608         ieee80211_rx_h_ps_poll,
1609         ieee80211_rx_h_michael_mic_verify,
1610         /* this must be after decryption - so header is counted in MPDU mic
1611          * must be before pae and data, so QOS_DATA format frames
1612          * are not passed to user space by these functions
1613          */
1614         ieee80211_rx_h_remove_qos_control,
1615         ieee80211_rx_h_amsdu,
1616         ieee80211_rx_h_data,
1617         ieee80211_rx_h_ctrl,
1618         ieee80211_rx_h_mgmt,
1619         NULL
1620 };
1621
1622 /* main receive path */
1623
1624 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
1625                                 u8 *bssid, struct ieee80211_txrx_data *rx,
1626                                 struct ieee80211_hdr *hdr)
1627 {
1628         int multicast = is_multicast_ether_addr(hdr->addr1);
1629
1630         switch (sdata->vif.type) {
1631         case IEEE80211_IF_TYPE_STA:
1632                 if (!bssid)
1633                         return 0;
1634                 if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1635                         if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1636                                 return 0;
1637                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1638                 } else if (!multicast &&
1639                            compare_ether_addr(sdata->dev->dev_addr,
1640                                               hdr->addr1) != 0) {
1641                         if (!(sdata->dev->flags & IFF_PROMISC))
1642                                 return 0;
1643                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1644                 }
1645                 break;
1646         case IEEE80211_IF_TYPE_IBSS:
1647                 if (!bssid)
1648                         return 0;
1649                 if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1650                         if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1651                                 return 0;
1652                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1653                 } else if (!multicast &&
1654                            compare_ether_addr(sdata->dev->dev_addr,
1655                                               hdr->addr1) != 0) {
1656                         if (!(sdata->dev->flags & IFF_PROMISC))
1657                                 return 0;
1658                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1659                 } else if (!rx->sta)
1660                         rx->sta = ieee80211_ibss_add_sta(sdata->dev, rx->skb,
1661                                                          bssid, hdr->addr2);
1662                 break;
1663         case IEEE80211_IF_TYPE_VLAN:
1664         case IEEE80211_IF_TYPE_AP:
1665                 if (!bssid) {
1666                         if (compare_ether_addr(sdata->dev->dev_addr,
1667                                                hdr->addr1))
1668                                 return 0;
1669                 } else if (!ieee80211_bssid_match(bssid,
1670                                         sdata->dev->dev_addr)) {
1671                         if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1672                                 return 0;
1673                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1674                 }
1675                 if (sdata->dev == sdata->local->mdev &&
1676                     !(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1677                         /* do not receive anything via
1678                          * master device when not scanning */
1679                         return 0;
1680                 break;
1681         case IEEE80211_IF_TYPE_WDS:
1682                 if (bssid ||
1683                     (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
1684                         return 0;
1685                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
1686                         return 0;
1687                 break;
1688         case IEEE80211_IF_TYPE_MNTR:
1689                 /* take everything */
1690                 break;
1691         case IEEE80211_IF_TYPE_INVALID:
1692                 /* should never get here */
1693                 WARN_ON(1);
1694                 break;
1695         }
1696
1697         return 1;
1698 }
1699
1700 /*
1701  * This is the actual Rx frames handler. as it blongs to Rx path it must
1702  * be called with rcu_read_lock protection.
1703  */
1704 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
1705                                          struct sk_buff *skb,
1706                                          struct ieee80211_rx_status *status,
1707                                          u32 load)
1708 {
1709         struct ieee80211_local *local = hw_to_local(hw);
1710         struct ieee80211_sub_if_data *sdata;
1711         struct sta_info *sta;
1712         struct ieee80211_hdr *hdr;
1713         struct ieee80211_txrx_data rx;
1714         u16 type;
1715         int prepares;
1716         struct ieee80211_sub_if_data *prev = NULL;
1717         struct sk_buff *skb_new;
1718         u8 *bssid;
1719
1720         hdr = (struct ieee80211_hdr *) skb->data;
1721         memset(&rx, 0, sizeof(rx));
1722         rx.skb = skb;
1723         rx.local = local;
1724
1725         rx.u.rx.status = status;
1726         rx.u.rx.load = load;
1727         rx.fc = le16_to_cpu(hdr->frame_control);
1728         type = rx.fc & IEEE80211_FCTL_FTYPE;
1729
1730         if (type == IEEE80211_FTYPE_DATA || type == IEEE80211_FTYPE_MGMT)
1731                 local->dot11ReceivedFragmentCount++;
1732
1733         sta = rx.sta = sta_info_get(local, hdr->addr2);
1734         if (sta) {
1735                 rx.dev = rx.sta->dev;
1736                 rx.sdata = IEEE80211_DEV_TO_SUB_IF(rx.dev);
1737         }
1738
1739         if ((status->flag & RX_FLAG_MMIC_ERROR)) {
1740                 ieee80211_rx_michael_mic_report(local->mdev, hdr, sta, &rx);
1741                 goto end;
1742         }
1743
1744         if (unlikely(local->sta_sw_scanning || local->sta_hw_scanning))
1745                 rx.flags |= IEEE80211_TXRXD_RXIN_SCAN;
1746
1747         if (__ieee80211_invoke_rx_handlers(local, local->rx_pre_handlers, &rx,
1748                                            sta) != TXRX_CONTINUE)
1749                 goto end;
1750         skb = rx.skb;
1751
1752         if (sta && !(sta->flags & (WLAN_STA_WDS | WLAN_STA_ASSOC_AP)) &&
1753             !atomic_read(&local->iff_promiscs) &&
1754             !is_multicast_ether_addr(hdr->addr1)) {
1755                 rx.flags |= IEEE80211_TXRXD_RXRA_MATCH;
1756                 ieee80211_invoke_rx_handlers(local, local->rx_handlers, &rx,
1757                                              rx.sta);
1758                 sta_info_put(sta);
1759                 return;
1760         }
1761
1762         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1763                 if (!netif_running(sdata->dev))
1764                         continue;
1765
1766                 if (sdata->vif.type == IEEE80211_IF_TYPE_MNTR)
1767                         continue;
1768
1769                 bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
1770                 rx.flags |= IEEE80211_TXRXD_RXRA_MATCH;
1771                 prepares = prepare_for_handlers(sdata, bssid, &rx, hdr);
1772                 /* prepare_for_handlers can change sta */
1773                 sta = rx.sta;
1774
1775                 if (!prepares)
1776                         continue;
1777
1778                 /*
1779                  * frame is destined for this interface, but if it's not
1780                  * also for the previous one we handle that after the
1781                  * loop to avoid copying the SKB once too much
1782                  */
1783
1784                 if (!prev) {
1785                         prev = sdata;
1786                         continue;
1787                 }
1788
1789                 /*
1790                  * frame was destined for the previous interface
1791                  * so invoke RX handlers for it
1792                  */
1793
1794                 skb_new = skb_copy(skb, GFP_ATOMIC);
1795                 if (!skb_new) {
1796                         if (net_ratelimit())
1797                                 printk(KERN_DEBUG "%s: failed to copy "
1798                                        "multicast frame for %s",
1799                                        wiphy_name(local->hw.wiphy),
1800                                        prev->dev->name);
1801                         continue;
1802                 }
1803                 rx.fc = le16_to_cpu(hdr->frame_control);
1804                 rx.skb = skb_new;
1805                 rx.dev = prev->dev;
1806                 rx.sdata = prev;
1807                 ieee80211_invoke_rx_handlers(local, local->rx_handlers,
1808                                              &rx, sta);
1809                 prev = sdata;
1810         }
1811         if (prev) {
1812                 rx.fc = le16_to_cpu(hdr->frame_control);
1813                 rx.skb = skb;
1814                 rx.dev = prev->dev;
1815                 rx.sdata = prev;
1816                 ieee80211_invoke_rx_handlers(local, local->rx_handlers,
1817                                              &rx, sta);
1818         } else
1819                 dev_kfree_skb(skb);
1820
1821  end:
1822         if (sta)
1823                 sta_info_put(sta);
1824 }
1825
1826 #define SEQ_MODULO 0x1000
1827 #define SEQ_MASK   0xfff
1828
1829 static inline int seq_less(u16 sq1, u16 sq2)
1830 {
1831         return (((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1));
1832 }
1833
1834 static inline u16 seq_inc(u16 sq)
1835 {
1836         return ((sq + 1) & SEQ_MASK);
1837 }
1838
1839 static inline u16 seq_sub(u16 sq1, u16 sq2)
1840 {
1841         return ((sq1 - sq2) & SEQ_MASK);
1842 }
1843
1844
1845 /*
1846  * As it function blongs to Rx path it must be called with
1847  * the proper rcu_read_lock protection for its flow.
1848  */
1849 u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
1850                                 struct tid_ampdu_rx *tid_agg_rx,
1851                                 struct sk_buff *skb, u16 mpdu_seq_num,
1852                                 int bar_req)
1853 {
1854         struct ieee80211_local *local = hw_to_local(hw);
1855         struct ieee80211_rx_status status;
1856         u16 head_seq_num, buf_size;
1857         int index;
1858         u32 pkt_load;
1859
1860         buf_size = tid_agg_rx->buf_size;
1861         head_seq_num = tid_agg_rx->head_seq_num;
1862
1863         /* frame with out of date sequence number */
1864         if (seq_less(mpdu_seq_num, head_seq_num)) {
1865                 dev_kfree_skb(skb);
1866                 return 1;
1867         }
1868
1869         /* if frame sequence number exceeds our buffering window size or
1870          * block Ack Request arrived - release stored frames */
1871         if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
1872                 /* new head to the ordering buffer */
1873                 if (bar_req)
1874                         head_seq_num = mpdu_seq_num;
1875                 else
1876                         head_seq_num =
1877                                 seq_inc(seq_sub(mpdu_seq_num, buf_size));
1878                 /* release stored frames up to new head to stack */
1879                 while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
1880                         index = seq_sub(tid_agg_rx->head_seq_num,
1881                                 tid_agg_rx->ssn)
1882                                 % tid_agg_rx->buf_size;
1883
1884                         if (tid_agg_rx->reorder_buf[index]) {
1885                                 /* release the reordered frames to stack */
1886                                 memcpy(&status,
1887                                         tid_agg_rx->reorder_buf[index]->cb,
1888                                         sizeof(status));
1889                                 pkt_load = ieee80211_rx_load_stats(local,
1890                                                 tid_agg_rx->reorder_buf[index],
1891                                                 &status);
1892                                 __ieee80211_rx_handle_packet(hw,
1893                                         tid_agg_rx->reorder_buf[index],
1894                                         &status, pkt_load);
1895                                 tid_agg_rx->stored_mpdu_num--;
1896                                 tid_agg_rx->reorder_buf[index] = NULL;
1897                         }
1898                         tid_agg_rx->head_seq_num =
1899                                 seq_inc(tid_agg_rx->head_seq_num);
1900                 }
1901                 if (bar_req)
1902                         return 1;
1903         }
1904
1905         /* now the new frame is always in the range of the reordering */
1906         /* buffer window */
1907         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
1908                                 % tid_agg_rx->buf_size;
1909         /* check if we already stored this frame */
1910         if (tid_agg_rx->reorder_buf[index]) {
1911                 dev_kfree_skb(skb);
1912                 return 1;
1913         }
1914
1915         /* if arrived mpdu is in the right order and nothing else stored */
1916         /* release it immediately */
1917         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
1918                         tid_agg_rx->stored_mpdu_num == 0) {
1919                 tid_agg_rx->head_seq_num =
1920                         seq_inc(tid_agg_rx->head_seq_num);
1921                 return 0;
1922         }
1923
1924         /* put the frame in the reordering buffer */
1925         tid_agg_rx->reorder_buf[index] = skb;
1926         tid_agg_rx->stored_mpdu_num++;
1927         /* release the buffer until next missing frame */
1928         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
1929                                                 % tid_agg_rx->buf_size;
1930         while (tid_agg_rx->reorder_buf[index]) {
1931                 /* release the reordered frame back to stack */
1932                 memcpy(&status, tid_agg_rx->reorder_buf[index]->cb,
1933                         sizeof(status));
1934                 pkt_load = ieee80211_rx_load_stats(local,
1935                                         tid_agg_rx->reorder_buf[index],
1936                                         &status);
1937                 __ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index],
1938                                                 &status, pkt_load);
1939                 tid_agg_rx->stored_mpdu_num--;
1940                 tid_agg_rx->reorder_buf[index] = NULL;
1941                 tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
1942                 index = seq_sub(tid_agg_rx->head_seq_num,
1943                         tid_agg_rx->ssn) % tid_agg_rx->buf_size;
1944         }
1945         return 1;
1946 }
1947
1948 static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
1949                                      struct sk_buff *skb)
1950 {
1951         struct ieee80211_hw *hw = &local->hw;
1952         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1953         struct sta_info *sta;
1954         struct tid_ampdu_rx *tid_agg_rx;
1955         u16 fc, sc;
1956         u16 mpdu_seq_num;
1957         u8 ret = 0, *qc;
1958         int tid;
1959
1960         sta = sta_info_get(local, hdr->addr2);
1961         if (!sta)
1962                 return ret;
1963
1964         fc = le16_to_cpu(hdr->frame_control);
1965
1966         /* filter the QoS data rx stream according to
1967          * STA/TID and check if this STA/TID is on aggregation */
1968         if (!WLAN_FC_IS_QOS_DATA(fc))
1969                 goto end_reorder;
1970
1971         qc = skb->data + ieee80211_get_hdrlen(fc) - QOS_CONTROL_LEN;
1972         tid = qc[0] & QOS_CONTROL_TID_MASK;
1973         tid_agg_rx = &(sta->ampdu_mlme.tid_rx[tid]);
1974
1975         if (tid_agg_rx->state != HT_AGG_STATE_OPERATIONAL)
1976                 goto end_reorder;
1977
1978         /* null data frames are excluded */
1979         if (unlikely(fc & IEEE80211_STYPE_NULLFUNC))
1980                 goto end_reorder;
1981
1982         /* new un-ordered ampdu frame - process it */
1983
1984         /* reset session timer */
1985         if (tid_agg_rx->timeout) {
1986                 unsigned long expires =
1987                         jiffies + (tid_agg_rx->timeout / 1000) * HZ;
1988                 mod_timer(&tid_agg_rx->session_timer, expires);
1989         }
1990
1991         /* if this mpdu is fragmented - terminate rx aggregation session */
1992         sc = le16_to_cpu(hdr->seq_ctrl);
1993         if (sc & IEEE80211_SCTL_FRAG) {
1994                 ieee80211_sta_stop_rx_ba_session(sta->dev, sta->addr,
1995                         tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
1996                 ret = 1;
1997                 goto end_reorder;
1998         }
1999
2000         /* according to mpdu sequence number deal with reordering buffer */
2001         mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2002         ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb,
2003                                                 mpdu_seq_num, 0);
2004 end_reorder:
2005         if (sta)
2006                 sta_info_put(sta);
2007         return ret;
2008 }
2009
2010 /*
2011  * This is the receive path handler. It is called by a low level driver when an
2012  * 802.11 MPDU is received from the hardware.
2013  */
2014 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
2015                     struct ieee80211_rx_status *status)
2016 {
2017         struct ieee80211_local *local = hw_to_local(hw);
2018         u32 pkt_load;
2019
2020         /*
2021          * key references and virtual interfaces are protected using RCU
2022          * and this requires that we are in a read-side RCU section during
2023          * receive processing
2024          */
2025         rcu_read_lock();
2026
2027         /*
2028          * Frames with failed FCS/PLCP checksum are not returned,
2029          * all other frames are returned without radiotap header
2030          * if it was previously present.
2031          * Also, frames with less than 16 bytes are dropped.
2032          */
2033         skb = ieee80211_rx_monitor(local, skb, status);
2034         if (!skb) {
2035                 rcu_read_unlock();
2036                 return;
2037         }
2038
2039         pkt_load = ieee80211_rx_load_stats(local, skb, status);
2040         local->channel_use_raw += pkt_load;
2041
2042         if (!ieee80211_rx_reorder_ampdu(local, skb))
2043                 __ieee80211_rx_handle_packet(hw, skb, status, pkt_load);
2044
2045         rcu_read_unlock();
2046 }
2047 EXPORT_SYMBOL(__ieee80211_rx);
2048
2049 /* This is a version of the rx handler that can be called from hard irq
2050  * context. Post the skb on the queue and schedule the tasklet */
2051 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb,
2052                           struct ieee80211_rx_status *status)
2053 {
2054         struct ieee80211_local *local = hw_to_local(hw);
2055
2056         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2057
2058         skb->dev = local->mdev;
2059         /* copy status into skb->cb for use by tasklet */
2060         memcpy(skb->cb, status, sizeof(*status));
2061         skb->pkt_type = IEEE80211_RX_MSG;
2062         skb_queue_tail(&local->skb_queue, skb);
2063         tasklet_schedule(&local->tasklet);
2064 }
2065 EXPORT_SYMBOL(ieee80211_rx_irqsafe);