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