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 2007-2010  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/jiffies.h>
  13 #include <linux/slab.h>
  14 #include <linux/kernel.h>
  15 #include <linux/skbuff.h>
  16 #include <linux/netdevice.h>
  17 #include <linux/etherdevice.h>
  18 #include <linux/rcupdate.h>
  19 #include <net/mac80211.h>
  20 #include <net/ieee80211_radiotap.h>
  21
  22 #include "ieee80211_i.h"
  23 #include "driver-ops.h"
  24 #include "led.h"
  25 #include "mesh.h"
  26 #include "wep.h"
  27 #include "wpa.h"
  28 #include "tkip.h"
  29 #include "wme.h"
  30
  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 {
  40         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
  41                 if (likely(skb->len > FCS_LEN))
  42                         __pskb_trim(skb, skb->len - FCS_LEN);
  43                 else {
  44                         /* driver bug */
  45                         WARN_ON(1);
  46                         dev_kfree_skb(skb);
  47                         skb = NULL;
  48                 }
  49         }
  50
  51         return skb;
  52 }
  53
  54 static inline int should_drop_frame(struct sk_buff *skb,
  55                                     int present_fcs_len)
  56 {
  57         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  58         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  59
  60         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
  61                 return 1;
  62         if (unlikely(skb->len < 16 + present_fcs_len))
  63                 return 1;
  64         if (ieee80211_is_ctl(hdr->frame_control) &&
  65             !ieee80211_is_pspoll(hdr->frame_control) &&
  66             !ieee80211_is_back_req(hdr->frame_control))
  67                 return 1;
  68         return 0;
  69 }
  70
  71 static int
  72 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
  73                           struct ieee80211_rx_status *status)
  74 {
  75         int len;
  76
  77         /* always present fields */
  78         len = sizeof(struct ieee80211_radiotap_header) + 9;
  79
  80         if (status->flag & RX_FLAG_MACTIME_MPDU)
  81                 len += 8;
  82         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
  83                 len += 1;
  84
  85         if (len & 1) /* padding for RX_FLAGS if necessary */
  86                 len++;
  87
  88         if (status->flag & RX_FLAG_HT) /* HT info */
  89                 len += 3;
  90
  91         return len;
  92 }
  93
  94 /*
  95  * ieee80211_add_rx_radiotap_header - add radiotap header
  96  *
  97  * add a radiotap header containing all the fields which the hardware provided.
  98  */
  99 static void
 100 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
 101                                  struct sk_buff *skb,
 102                                  struct ieee80211_rate *rate,
 103                                  int rtap_len)
 104 {
 105         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 106         struct ieee80211_radiotap_header *rthdr;
 107         unsigned char *pos;
 108         u16 rx_flags = 0;
 109
 110         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
 111         memset(rthdr, 0, rtap_len);
 112
 113         /* radiotap header, set always present flags */
 114         rthdr->it_present =
 115                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 116                             (1 << IEEE80211_RADIOTAP_CHANNEL) |
 117                             (1 << IEEE80211_RADIOTAP_ANTENNA) |
 118                             (1 << IEEE80211_RADIOTAP_RX_FLAGS));
 119         rthdr->it_len = cpu_to_le16(rtap_len);
 120
 121         pos = (unsigned char *)(rthdr+1);
 122
 123         /* the order of the following fields is important */
 124
 125         /* IEEE80211_RADIOTAP_TSFT */
 126         if (status->flag & RX_FLAG_MACTIME_MPDU) {
 127                 put_unaligned_le64(status->mactime, pos);
 128                 rthdr->it_present |=
 129                         cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
 130                 pos += 8;
 131         }
 132
 133         /* IEEE80211_RADIOTAP_FLAGS */
 134         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 135                 *pos |= IEEE80211_RADIOTAP_F_FCS;
 136         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 137                 *pos |= IEEE80211_RADIOTAP_F_BADFCS;
 138         if (status->flag & RX_FLAG_SHORTPRE)
 139                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
 140         pos++;
 141
 142         /* IEEE80211_RADIOTAP_RATE */
 143         if (status->flag & RX_FLAG_HT) {
 144                 /*
 145                  * MCS information is a separate field in radiotap,
 146                  * added below.
 147                  */
 148                 *pos = 0;
 149         } else {
 150                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
 151                 *pos = rate->bitrate / 5;
 152         }
 153         pos++;
 154
 155         /* IEEE80211_RADIOTAP_CHANNEL */
 156         put_unaligned_le16(status->freq, pos);
 157         pos += 2;
 158         if (status->band == IEEE80211_BAND_5GHZ)
 159                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ,
 160                                    pos);
 161         else if (status->flag & RX_FLAG_HT)
 162                 put_unaligned_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ,
 163                                    pos);
 164         else if (rate->flags & IEEE80211_RATE_ERP_G)
 165                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
 166                                    pos);
 167         else
 168                 put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
 169                                    pos);
 170         pos += 2;
 171
 172         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
 173         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
 174                 *pos = status->signal;
 175                 rthdr->it_present |=
 176                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
 177                 pos++;
 178         }
 179
 180         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
 181
 182         /* IEEE80211_RADIOTAP_ANTENNA */
 183         *pos = status->antenna;
 184         pos++;
 185
 186         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
 187
 188         /* IEEE80211_RADIOTAP_RX_FLAGS */
 189         /* ensure 2 byte alignment for the 2 byte field as required */
 190         if ((pos - (u8 *)rthdr) & 1)
 191                 pos++;
 192         if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
 193                 rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
 194         put_unaligned_le16(rx_flags, pos);
 195         pos += 2;
 196
 197         if (status->flag & RX_FLAG_HT) {
 198                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
 199                 *pos++ = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
 200                          IEEE80211_RADIOTAP_MCS_HAVE_GI |
 201                          IEEE80211_RADIOTAP_MCS_HAVE_BW;
 202                 *pos = 0;
 203                 if (status->flag & RX_FLAG_SHORT_GI)
 204                         *pos |= IEEE80211_RADIOTAP_MCS_SGI;
 205                 if (status->flag & RX_FLAG_40MHZ)
 206                         *pos |= IEEE80211_RADIOTAP_MCS_BW_40;
 207                 pos++;
 208                 *pos++ = status->rate_idx;
 209         }
 210 }
 211
 212 /*
 213  * This function copies a received frame to all monitor interfaces and
 214  * returns a cleaned-up SKB that no longer includes the FCS nor the
 215  * radiotap header the driver might have added.
 216  */
 217 static struct sk_buff *
 218 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
 219                      struct ieee80211_rate *rate)
 220 {
 221         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
 222         struct ieee80211_sub_if_data *sdata;
 223         int needed_headroom = 0;
 224         struct sk_buff *skb, *skb2;
 225         struct net_device *prev_dev = NULL;
 226         int present_fcs_len = 0;
 227
 228         /*
 229          * First, we may need to make a copy of the skb because
 230          *  (1) we need to modify it for radiotap (if not present), and
 231          *  (2) the other RX handlers will modify the skb we got.
 232          *
 233          * We don't need to, of course, if we aren't going to return
 234          * the SKB because it has a bad FCS/PLCP checksum.
 235          */
 236
 237         /* room for the radiotap header based on driver features */
 238         needed_headroom = ieee80211_rx_radiotap_len(local, status);
 239
 240         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 241                 present_fcs_len = FCS_LEN;
 242
 243         /* make sure hdr->frame_control is on the linear part */
 244         if (!pskb_may_pull(origskb, 2)) {
 245                 dev_kfree_skb(origskb);
 246                 return NULL;
 247         }
 248
 249         if (!local->monitors) {
 250                 if (should_drop_frame(origskb, present_fcs_len)) {
 251                         dev_kfree_skb(origskb);
 252                         return NULL;
 253                 }
 254
 255                 return remove_monitor_info(local, origskb);
 256         }
 257
 258         if (should_drop_frame(origskb, present_fcs_len)) {
 259                 /* only need to expand headroom if necessary */
 260                 skb = origskb;
 261                 origskb = NULL;
 262
 263                 /*
 264                  * This shouldn't trigger often because most devices have an
 265                  * RX header they pull before we get here, and that should
 266                  * be big enough for our radiotap information. We should
 267                  * probably export the length to drivers so that we can have
 268                  * them allocate enough headroom to start with.
 269                  */
 270                 if (skb_headroom(skb) < needed_headroom &&
 271                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
 272                         dev_kfree_skb(skb);
 273                         return NULL;
 274                 }
 275         } else {
 276                 /*
 277                  * Need to make a copy and possibly remove radiotap header
 278                  * and FCS from the original.
 279                  */
 280                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 281
 282                 origskb = remove_monitor_info(local, origskb);
 283
 284                 if (!skb)
 285                         return origskb;
 286         }
 287
 288         /* prepend radiotap information */
 289         ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom);
 290
 291         skb_reset_mac_header(skb);
 292         skb->ip_summed = CHECKSUM_UNNECESSARY;
 293         skb->pkt_type = PACKET_OTHERHOST;
 294         skb->protocol = htons(ETH_P_802_2);
 295
 296         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 297                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
 298                         continue;
 299
 300                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
 301                         continue;
 302
 303                 if (!ieee80211_sdata_running(sdata))
 304                         continue;
 305
 306                 if (prev_dev) {
 307                         skb2 = skb_clone(skb, GFP_ATOMIC);
 308                         if (skb2) {
 309                                 skb2->dev = prev_dev;
 310                                 netif_receive_skb(skb2);
 311                         }
 312                 }
 313
 314                 prev_dev = sdata->dev;
 315                 sdata->dev->stats.rx_packets++;
 316                 sdata->dev->stats.rx_bytes += skb->len;
 317         }
 318
 319         if (prev_dev) {
 320                 skb->dev = prev_dev;
 321                 netif_receive_skb(skb);
 322         } else
 323                 dev_kfree_skb(skb);
 324
 325         return origskb;
 326 }
 327
 328
 329 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
 330 {
 331         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 332         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 333         int tid;
 334
 335         /* does the frame have a qos control field? */
 336         if (ieee80211_is_data_qos(hdr->frame_control)) {
 337                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 338                 /* frame has qos control */
 339                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
 340                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
 341                         status->rx_flags |= IEEE80211_RX_AMSDU;
 342         } else {
 343                 /*
 344                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
 345                  *
 346                  *      Sequence numbers for management frames, QoS data
 347                  *      frames with a broadcast/multicast address in the
 348                  *      Address 1 field, and all non-QoS data frames sent
 349                  *      by QoS STAs are assigned using an additional single
 350                  *      modulo-4096 counter, [...]
 351                  *
 352                  * We also use that counter for non-QoS STAs.
 353                  */
 354                 tid = NUM_RX_DATA_QUEUES - 1;
 355         }
 356
 357         rx->queue = tid;
 358         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 359          * For now, set skb->priority to 0 for other cases. */
 360         rx->skb->priority = (tid > 7) ? 0 : tid;
 361 }
 362
 363 /**
 364  * DOC: Packet alignment
 365  *
 366  * Drivers always need to pass packets that are aligned to two-byte boundaries
 367  * to the stack.
 368  *
 369  * Additionally, should, if possible, align the payload data in a way that
 370  * guarantees that the contained IP header is aligned to a four-byte
 371  * boundary. In the case of regular frames, this simply means aligning the
 372  * payload to a four-byte boundary (because either the IP header is directly
 373  * contained, or IV/RFC1042 headers that have a length divisible by four are
 374  * in front of it).  If the payload data is not properly aligned and the
 375  * architecture doesn't support efficient unaligned operations, mac80211
 376  * will align the data.
 377  *
 378  * With A-MSDU frames, however, the payload data address must yield two modulo
 379  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
 380  * push the IP header further back to a multiple of four again. Thankfully, the
 381  * specs were sane enough this time around to require padding each A-MSDU
 382  * subframe to a length that is a multiple of four.
 383  *
 384  * Padding like Atheros hardware adds which is between the 802.11 header and
 385  * the payload is not supported, the driver is required to move the 802.11
 386  * header to be directly in front of the payload in that case.
 387  */
 388 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
 389 {
 390 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 391         WARN_ONCE((unsigned long)rx->skb->data & 1,
 392                   "unaligned packet at 0x%p\n", rx->skb->data);
 393 #endif
 394 }
 395
 396
 397 /* rx handlers */
 398
 399 static ieee80211_rx_result debug_noinline
 400 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 401 {
 402         struct ieee80211_local *local = rx->local;
 403         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 404         struct sk_buff *skb = rx->skb;
 405
 406         if (likely(!(status->rx_flags & IEEE80211_RX_IN_SCAN)))
 407                 return RX_CONTINUE;
 408
 409         if (test_bit(SCAN_HW_SCANNING, &local->scanning) ||
 410             test_bit(SCAN_SW_SCANNING, &local->scanning))
 411                 return ieee80211_scan_rx(rx->sdata, skb);
 412
 413         /* scanning finished during invoking of handlers */
 414         I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 415         return RX_DROP_UNUSABLE;
 416 }
 417
 418
 419 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
 420 {
 421         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 422
 423         if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
 424                 return 0;
 425
 426         return ieee80211_is_robust_mgmt_frame(hdr);
 427 }
 428
 429
 430 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
 431 {
 432         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 433
 434         if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
 435                 return 0;
 436
 437         return ieee80211_is_robust_mgmt_frame(hdr);
 438 }
 439
 440
 441 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
 442 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
 443 {
 444         struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
 445         struct ieee80211_mmie *mmie;
 446
 447         if (skb->len < 24 + sizeof(*mmie) ||
 448             !is_multicast_ether_addr(hdr->da))
 449                 return -1;
 450
 451         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
 452                 return -1; /* not a robust management frame */
 453
 454         mmie = (struct ieee80211_mmie *)
 455                 (skb->data + skb->len - sizeof(*mmie));
 456         if (mmie->element_id != WLAN_EID_MMIE ||
 457             mmie->length != sizeof(*mmie) - 2)
 458                 return -1;
 459
 460         return le16_to_cpu(mmie->key_id);
 461 }
 462
 463
 464 static ieee80211_rx_result
 465 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 466 {
 467         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 468         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 469         char *dev_addr = rx->sdata->vif.addr;
 470
 471         if (ieee80211_is_data(hdr->frame_control)) {
 472                 if (is_multicast_ether_addr(hdr->addr1)) {
 473                         if (ieee80211_has_tods(hdr->frame_control) ||
 474                                 !ieee80211_has_fromds(hdr->frame_control))
 475                                 return RX_DROP_MONITOR;
 476                         if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
 477                                 return RX_DROP_MONITOR;
 478                 } else {
 479                         if (!ieee80211_has_a4(hdr->frame_control))
 480                                 return RX_DROP_MONITOR;
 481                         if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
 482                                 return RX_DROP_MONITOR;
 483                 }
 484         }
 485
 486         /* If there is not an established peer link and this is not a peer link
 487          * establisment frame, beacon or probe, drop the frame.
 488          */
 489
 490         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
 491                 struct ieee80211_mgmt *mgmt;
 492
 493                 if (!ieee80211_is_mgmt(hdr->frame_control))
 494                         return RX_DROP_MONITOR;
 495
 496                 if (ieee80211_is_action(hdr->frame_control)) {
 497                         mgmt = (struct ieee80211_mgmt *)hdr;
 498                         if (mgmt->u.action.category != WLAN_CATEGORY_MESH_PLINK)
 499                                 return RX_DROP_MONITOR;
 500                         return RX_CONTINUE;
 501                 }
 502
 503                 if (ieee80211_is_probe_req(hdr->frame_control) ||
 504                     ieee80211_is_probe_resp(hdr->frame_control) ||
 505                     ieee80211_is_beacon(hdr->frame_control))
 506                         return RX_CONTINUE;
 507
 508                 return RX_DROP_MONITOR;
 509
 510         }
 511
 512 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
 513
 514         if (ieee80211_is_data(hdr->frame_control) &&
 515             is_multicast_ether_addr(hdr->addr1) &&
 516             mesh_rmc_check(hdr->addr3, msh_h_get(hdr, hdrlen), rx->sdata))
 517                 return RX_DROP_MONITOR;
 518 #undef msh_h_get
 519
 520         return RX_CONTINUE;
 521 }
 522
 523 #define SEQ_MODULO 0x1000
 524 #define SEQ_MASK   0xfff
 525
 526 static inline int seq_less(u16 sq1, u16 sq2)
 527 {
 528         return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
 529 }
 530
 531 static inline u16 seq_inc(u16 sq)
 532 {
 533         return (sq + 1) & SEQ_MASK;
 534 }
 535
 536 static inline u16 seq_sub(u16 sq1, u16 sq2)
 537 {
 538         return (sq1 - sq2) & SEQ_MASK;
 539 }
 540
 541
 542 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
 543                                             struct tid_ampdu_rx *tid_agg_rx,
 544                                             int index)
 545 {
 546         struct ieee80211_local *local = hw_to_local(hw);
 547         struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
 548         struct ieee80211_rx_status *status;
 549
 550         lockdep_assert_held(&tid_agg_rx->reorder_lock);
 551
 552         if (!skb)
 553                 goto no_frame;
 554
 555         /* release the frame from the reorder ring buffer */
 556         tid_agg_rx->stored_mpdu_num--;
 557         tid_agg_rx->reorder_buf[index] = NULL;
 558         status = IEEE80211_SKB_RXCB(skb);
 559         status->rx_flags |= IEEE80211_RX_DEFERRED_RELEASE;
 560         skb_queue_tail(&local->rx_skb_queue, skb);
 561
 562 no_frame:
 563         tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
 564 }
 565
 566 static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
 567                                              struct tid_ampdu_rx *tid_agg_rx,
 568                                              u16 head_seq_num)
 569 {
 570         int index;
 571
 572         lockdep_assert_held(&tid_agg_rx->reorder_lock);
 573
 574         while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
 575                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 576                                                         tid_agg_rx->buf_size;
 577                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
 578         }
 579 }
 580
 581 /*
 582  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
 583  * the skb was added to the buffer longer than this time ago, the earlier
 584  * frames that have not yet been received are assumed to be lost and the skb
 585  * can be released for processing. This may also release other skb's from the
 586  * reorder buffer if there are no additional gaps between the frames.
 587  *
 588  * Callers must hold tid_agg_rx->reorder_lock.
 589  */
 590 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
 591
 592 static void ieee80211_sta_reorder_release(struct ieee80211_hw *hw,
 593                                           struct tid_ampdu_rx *tid_agg_rx)
 594 {
 595         int index, j;
 596
 597         lockdep_assert_held(&tid_agg_rx->reorder_lock);
 598
 599         /* release the buffer until next missing frame */
 600         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 601                                                 tid_agg_rx->buf_size;
 602         if (!tid_agg_rx->reorder_buf[index] &&
 603             tid_agg_rx->stored_mpdu_num > 1) {
 604                 /*
 605                  * No buffers ready to be released, but check whether any
 606                  * frames in the reorder buffer have timed out.
 607                  */
 608                 int skipped = 1;
 609                 for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
 610                      j = (j + 1) % tid_agg_rx->buf_size) {
 611                         if (!tid_agg_rx->reorder_buf[j]) {
 612                                 skipped++;
 613                                 continue;
 614                         }
 615                         if (skipped &&
 616                             !time_after(jiffies, tid_agg_rx->reorder_time[j] +
 617                                         HT_RX_REORDER_BUF_TIMEOUT))
 618                                 goto set_release_timer;
 619
 620 #ifdef CONFIG_MAC80211_HT_DEBUG
 621                         if (net_ratelimit())
 622                                 wiphy_debug(hw->wiphy,
 623                                             "release an RX reorder frame due to timeout on earlier frames\n");
 624 #endif
 625                         ieee80211_release_reorder_frame(hw, tid_agg_rx, j);
 626
 627                         /*
 628                          * Increment the head seq# also for the skipped slots.
 629                          */
 630                         tid_agg_rx->head_seq_num =
 631                                 (tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
 632                         skipped = 0;
 633                 }
 634         } else while (tid_agg_rx->reorder_buf[index]) {
 635                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
 636                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 637                                                         tid_agg_rx->buf_size;
 638         }
 639
 640         if (tid_agg_rx->stored_mpdu_num) {
 641                 j = index = seq_sub(tid_agg_rx->head_seq_num,
 642                                     tid_agg_rx->ssn) % tid_agg_rx->buf_size;
 643
 644                 for (; j != (index - 1) % tid_agg_rx->buf_size;
 645                      j = (j + 1) % tid_agg_rx->buf_size) {
 646                         if (tid_agg_rx->reorder_buf[j])
 647                                 break;
 648                 }
 649
 650  set_release_timer:
 651
 652                 mod_timer(&tid_agg_rx->reorder_timer,
 653                           tid_agg_rx->reorder_time[j] +
 654                           HT_RX_REORDER_BUF_TIMEOUT);
 655         } else {
 656                 del_timer(&tid_agg_rx->reorder_timer);
 657         }
 658 }
 659
 660 /*
 661  * As this function belongs to the RX path it must be under
 662  * rcu_read_lock protection. It returns false if the frame
 663  * can be processed immediately, true if it was consumed.
 664  */
 665 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
 666                                              struct tid_ampdu_rx *tid_agg_rx,
 667                                              struct sk_buff *skb)
 668 {
 669         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 670         u16 sc = le16_to_cpu(hdr->seq_ctrl);
 671         u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
 672         u16 head_seq_num, buf_size;
 673         int index;
 674         bool ret = true;
 675
 676         spin_lock(&tid_agg_rx->reorder_lock);
 677
 678         buf_size = tid_agg_rx->buf_size;
 679         head_seq_num = tid_agg_rx->head_seq_num;
 680
 681         /* frame with out of date sequence number */
 682         if (seq_less(mpdu_seq_num, head_seq_num)) {
 683                 dev_kfree_skb(skb);
 684                 goto out;
 685         }
 686
 687         /*
 688          * If frame the sequence number exceeds our buffering window
 689          * size release some previous frames to make room for this one.
 690          */
 691         if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
 692                 head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
 693                 /* release stored frames up to new head to stack */
 694                 ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num);
 695         }
 696
 697         /* Now the new frame is always in the range of the reordering buffer */
 698
 699         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size;
 700
 701         /* check if we already stored this frame */
 702         if (tid_agg_rx->reorder_buf[index]) {
 703                 dev_kfree_skb(skb);
 704                 goto out;
 705         }
 706
 707         /*
 708          * If the current MPDU is in the right order and nothing else
 709          * is stored we can process it directly, no need to buffer it.
 710          */
 711         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
 712             tid_agg_rx->stored_mpdu_num == 0) {
 713                 tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
 714                 ret = false;
 715                 goto out;
 716         }
 717
 718         /* put the frame in the reordering buffer */
 719         tid_agg_rx->reorder_buf[index] = skb;
 720         tid_agg_rx->reorder_time[index] = jiffies;
 721         tid_agg_rx->stored_mpdu_num++;
 722         ieee80211_sta_reorder_release(hw, tid_agg_rx);
 723
 724  out:
 725         spin_unlock(&tid_agg_rx->reorder_lock);
 726         return ret;
 727 }
 728
 729 /*
 730  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
 731  * true if the MPDU was buffered, false if it should be processed.
 732  */
 733 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx)
 734 {
 735         struct sk_buff *skb = rx->skb;
 736         struct ieee80211_local *local = rx->local;
 737         struct ieee80211_hw *hw = &local->hw;
 738         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 739         struct sta_info *sta = rx->sta;
 740         struct tid_ampdu_rx *tid_agg_rx;
 741         u16 sc;
 742         int tid;
 743
 744         if (!ieee80211_is_data_qos(hdr->frame_control))
 745                 goto dont_reorder;
 746
 747         /*
 748          * filter the QoS data rx stream according to
 749          * STA/TID and check if this STA/TID is on aggregation
 750          */
 751
 752         if (!sta)
 753                 goto dont_reorder;
 754
 755         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
 756
 757         tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
 758         if (!tid_agg_rx)
 759                 goto dont_reorder;
 760
 761         /* qos null data frames are excluded */
 762         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
 763                 goto dont_reorder;
 764
 765         /* new, potentially un-ordered, ampdu frame - process it */
 766
 767         /* reset session timer */
 768         if (tid_agg_rx->timeout)
 769                 mod_timer(&tid_agg_rx->session_timer,
 770                           TU_TO_EXP_TIME(tid_agg_rx->timeout));
 771
 772         /* if this mpdu is fragmented - terminate rx aggregation session */
 773         sc = le16_to_cpu(hdr->seq_ctrl);
 774         if (sc & IEEE80211_SCTL_FRAG) {
 775                 skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
 776                 skb_queue_tail(&rx->sdata->skb_queue, skb);
 777                 ieee80211_queue_work(&local->hw, &rx->sdata->work);
 778                 return;
 779         }
 780
 781         /*
 782          * No locking needed -- we will only ever process one
 783          * RX packet at a time, and thus own tid_agg_rx. All
 784          * other code manipulating it needs to (and does) make
 785          * sure that we cannot get to it any more before doing
 786          * anything with it.
 787          */
 788         if (ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb))
 789                 return;
 790
 791  dont_reorder:
 792         skb_queue_tail(&local->rx_skb_queue, skb);
 793 }
 794
 795 static ieee80211_rx_result debug_noinline
 796 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
 797 {
 798         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 799         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 800
 801         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 802         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 803                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
 804                              rx->sta->last_seq_ctrl[rx->queue] ==
 805                              hdr->seq_ctrl)) {
 806                         if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
 807                                 rx->local->dot11FrameDuplicateCount++;
 808                                 rx->sta->num_duplicates++;
 809                         }
 810                         return RX_DROP_UNUSABLE;
 811                 } else
 812                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
 813         }
 814
 815         if (unlikely(rx->skb->len < 16)) {
 816                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 817                 return RX_DROP_MONITOR;
 818         }
 819
 820         /* Drop disallowed frame classes based on STA auth/assoc state;
 821          * IEEE 802.11, Chap 5.5.
 822          *
 823          * mac80211 filters only based on association state, i.e. it drops
 824          * Class 3 frames from not associated stations. hostapd sends
 825          * deauth/disassoc frames when needed. In addition, hostapd is
 826          * responsible for filtering on both auth and assoc states.
 827          */
 828
 829         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
 830                 return ieee80211_rx_mesh_check(rx);
 831
 832         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
 833                       ieee80211_is_pspoll(hdr->frame_control)) &&
 834                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
 835                      rx->sdata->vif.type != NL80211_IFTYPE_WDS &&
 836                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC))))
 837                 return RX_DROP_MONITOR;
 838
 839         return RX_CONTINUE;
 840 }
 841
 842
 843 static ieee80211_rx_result debug_noinline
 844 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 845 {
 846         struct sk_buff *skb = rx->skb;
 847         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 848         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 849         int keyidx;
 850         int hdrlen;
 851         ieee80211_rx_result result = RX_DROP_UNUSABLE;
 852         struct ieee80211_key *sta_ptk = NULL;
 853         int mmie_keyidx = -1;
 854         __le16 fc;
 855
 856         /*
 857          * Key selection 101
 858          *
 859          * There are four types of keys:
 860          *  - GTK (group keys)
 861          *  - IGTK (group keys for management frames)
 862          *  - PTK (pairwise keys)
 863          *  - STK (station-to-station pairwise keys)
 864          *
 865          * When selecting a key, we have to distinguish between multicast
 866          * (including broadcast) and unicast frames, the latter can only
 867          * use PTKs and STKs while the former always use GTKs and IGTKs.
 868          * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
 869          * unicast frames can also use key indices like GTKs. Hence, if we
 870          * don't have a PTK/STK we check the key index for a WEP key.
 871          *
 872          * Note that in a regular BSS, multicast frames are sent by the
 873          * AP only, associated stations unicast the frame to the AP first
 874          * which then multicasts it on their behalf.
 875          *
 876          * There is also a slight problem in IBSS mode: GTKs are negotiated
 877          * with each station, that is something we don't currently handle.
 878          * The spec seems to expect that one negotiates the same key with
 879          * every station but there's no such requirement; VLANs could be
 880          * possible.
 881          */
 882
 883         /*
 884          * No point in finding a key and decrypting if the frame is neither
 885          * addressed to us nor a multicast frame.
 886          */
 887         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
 888                 return RX_CONTINUE;
 889
 890         /* start without a key */
 891         rx->key = NULL;
 892
 893         if (rx->sta)
 894                 sta_ptk = rcu_dereference(rx->sta->ptk);
 895
 896         fc = hdr->frame_control;
 897
 898         if (!ieee80211_has_protected(fc))
 899                 mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
 900
 901         if (!is_multicast_ether_addr(hdr->addr1) && sta_ptk) {
 902                 rx->key = sta_ptk;
 903                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 904                     (status->flag & RX_FLAG_IV_STRIPPED))
 905                         return RX_CONTINUE;
 906                 /* Skip decryption if the frame is not protected. */
 907                 if (!ieee80211_has_protected(fc))
 908                         return RX_CONTINUE;
 909         } else if (mmie_keyidx >= 0) {
 910                 /* Broadcast/multicast robust management frame / BIP */
 911                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 912                     (status->flag & RX_FLAG_IV_STRIPPED))
 913                         return RX_CONTINUE;
 914
 915                 if (mmie_keyidx < NUM_DEFAULT_KEYS ||
 916                     mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 917                         return RX_DROP_MONITOR; /* unexpected BIP keyidx */
 918                 if (rx->sta)
 919                         rx->key = rcu_dereference(rx->sta->gtk[mmie_keyidx]);
 920                 if (!rx->key)
 921                         rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
 922         } else if (!ieee80211_has_protected(fc)) {
 923                 /*
 924                  * The frame was not protected, so skip decryption. However, we
 925                  * need to set rx->key if there is a key that could have been
 926                  * used so that the frame may be dropped if encryption would
 927                  * have been expected.
 928                  */
 929                 struct ieee80211_key *key = NULL;
 930                 struct ieee80211_sub_if_data *sdata = rx->sdata;
 931                 int i;
 932
 933                 if (ieee80211_is_mgmt(fc) &&
 934                     is_multicast_ether_addr(hdr->addr1) &&
 935                     (key = rcu_dereference(rx->sdata->default_mgmt_key)))
 936                         rx->key = key;
 937                 else {
 938                         if (rx->sta) {
 939                                 for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
 940                                         key = rcu_dereference(rx->sta->gtk[i]);
 941                                         if (key)
 942                                                 break;
 943                                 }
 944                         }
 945                         if (!key) {
 946                                 for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
 947                                         key = rcu_dereference(sdata->keys[i]);
 948                                         if (key)
 949                                                 break;
 950                                 }
 951                         }
 952                         if (key)
 953                                 rx->key = key;
 954                 }
 955                 return RX_CONTINUE;
 956         } else {
 957                 u8 keyid;
 958                 /*
 959                  * The device doesn't give us the IV so we won't be
 960                  * able to look up the key. That's ok though, we
 961                  * don't need to decrypt the frame, we just won't
 962                  * be able to keep statistics accurate.
 963                  * Except for key threshold notifications, should
 964                  * we somehow allow the driver to tell us which key
 965                  * the hardware used if this flag is set?
 966                  */
 967                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 968                     (status->flag & RX_FLAG_IV_STRIPPED))
 969                         return RX_CONTINUE;
 970
 971                 hdrlen = ieee80211_hdrlen(fc);
 972
 973                 if (rx->skb->len < 8 + hdrlen)
 974                         return RX_DROP_UNUSABLE; /* TODO: count this? */
 975
 976                 /*
 977                  * no need to call ieee80211_wep_get_keyidx,
 978                  * it verifies a bunch of things we've done already
 979                  */
 980                 skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
 981                 keyidx = keyid >> 6;
 982
 983                 /* check per-station GTK first, if multicast packet */
 984                 if (is_multicast_ether_addr(hdr->addr1) && rx->sta)
 985                         rx->key = rcu_dereference(rx->sta->gtk[keyidx]);
 986
 987                 /* if not found, try default key */
 988                 if (!rx->key) {
 989                         rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
 990
 991                         /*
 992                          * RSNA-protected unicast frames should always be
 993                          * sent with pairwise or station-to-station keys,
 994                          * but for WEP we allow using a key index as well.
 995                          */
 996                         if (rx->key &&
 997                             rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP40 &&
 998                             rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP104 &&
 999                             !is_multicast_ether_addr(hdr->addr1))
1000                                 rx->key = NULL;
1001                 }
1002         }
1003
1004         if (rx->key) {
1005                 rx->key->tx_rx_count++;
1006                 /* TODO: add threshold stuff again */
1007         } else {
1008                 return RX_DROP_MONITOR;
1009         }
1010
1011         if (skb_linearize(rx->skb))
1012                 return RX_DROP_UNUSABLE;
1013         /* the hdr variable is invalid now! */
1014
1015         switch (rx->key->conf.cipher) {
1016         case WLAN_CIPHER_SUITE_WEP40:
1017         case WLAN_CIPHER_SUITE_WEP104:
1018                 /* Check for weak IVs if possible */
1019                 if (rx->sta && ieee80211_is_data(fc) &&
1020                     (!(status->flag & RX_FLAG_IV_STRIPPED) ||
1021                      !(status->flag & RX_FLAG_DECRYPTED)) &&
1022                     ieee80211_wep_is_weak_iv(rx->skb, rx->key))
1023                         rx->sta->wep_weak_iv_count++;
1024
1025                 result = ieee80211_crypto_wep_decrypt(rx);
1026                 break;
1027         case WLAN_CIPHER_SUITE_TKIP:
1028                 result = ieee80211_crypto_tkip_decrypt(rx);
1029                 break;
1030         case WLAN_CIPHER_SUITE_CCMP:
1031                 result = ieee80211_crypto_ccmp_decrypt(rx);
1032                 break;
1033         case WLAN_CIPHER_SUITE_AES_CMAC:
1034                 result = ieee80211_crypto_aes_cmac_decrypt(rx);
1035                 break;
1036         default:
1037                 /*
1038                  * We can reach here only with HW-only algorithms
1039                  * but why didn't it decrypt the frame?!
1040                  */
1041                 return RX_DROP_UNUSABLE;
1042         }
1043
1044         /* either the frame has been decrypted or will be dropped */
1045         status->flag |= RX_FLAG_DECRYPTED;
1046
1047         return result;
1048 }
1049
1050 static ieee80211_rx_result debug_noinline
1051 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
1052 {
1053         struct ieee80211_local *local;
1054         struct ieee80211_hdr *hdr;
1055         struct sk_buff *skb;
1056
1057         local = rx->local;
1058         skb = rx->skb;
1059         hdr = (struct ieee80211_hdr *) skb->data;
1060
1061         if (!local->pspolling)
1062                 return RX_CONTINUE;
1063
1064         if (!ieee80211_has_fromds(hdr->frame_control))
1065                 /* this is not from AP */
1066                 return RX_CONTINUE;
1067
1068         if (!ieee80211_is_data(hdr->frame_control))
1069                 return RX_CONTINUE;
1070
1071         if (!ieee80211_has_moredata(hdr->frame_control)) {
1072                 /* AP has no more frames buffered for us */
1073                 local->pspolling = false;
1074                 return RX_CONTINUE;
1075         }
1076
1077         /* more data bit is set, let's request a new frame from the AP */
1078         ieee80211_send_pspoll(local, rx->sdata);
1079
1080         return RX_CONTINUE;
1081 }
1082
1083 static void ap_sta_ps_start(struct sta_info *sta)
1084 {
1085         struct ieee80211_sub_if_data *sdata = sta->sdata;
1086         struct ieee80211_local *local = sdata->local;
1087
1088         atomic_inc(&sdata->bss->num_sta_ps);
1089         set_sta_flags(sta, WLAN_STA_PS_STA);
1090         if (!(local->hw.flags & IEEE80211_HW_AP_LINK_PS))
1091                 drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
1092 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1093         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
1094                sdata->name, sta->sta.addr, sta->sta.aid);
1095 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1096 }
1097
1098 static void ap_sta_ps_end(struct sta_info *sta)
1099 {
1100         struct ieee80211_sub_if_data *sdata = sta->sdata;
1101
1102         atomic_dec(&sdata->bss->num_sta_ps);
1103
1104 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1105         printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
1106                sdata->name, sta->sta.addr, sta->sta.aid);
1107 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1108
1109         if (test_sta_flags(sta, WLAN_STA_PS_DRIVER)) {
1110 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1111                 printk(KERN_DEBUG "%s: STA %pM aid %d driver-ps-blocked\n",
1112                        sdata->name, sta->sta.addr, sta->sta.aid);
1113 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1114                 return;
1115         }
1116
1117         ieee80211_sta_ps_deliver_wakeup(sta);
1118 }
1119
1120 int ieee80211_sta_ps_transition(struct ieee80211_sta *sta, bool start)
1121 {
1122         struct sta_info *sta_inf = container_of(sta, struct sta_info, sta);
1123         bool in_ps;
1124
1125         WARN_ON(!(sta_inf->local->hw.flags & IEEE80211_HW_AP_LINK_PS));
1126
1127         /* Don't let the same PS state be set twice */
1128         in_ps = test_sta_flags(sta_inf, WLAN_STA_PS_STA);
1129         if ((start && in_ps) || (!start && !in_ps))
1130                 return -EINVAL;
1131
1132         if (start)
1133                 ap_sta_ps_start(sta_inf);
1134         else
1135                 ap_sta_ps_end(sta_inf);
1136
1137         return 0;
1138 }
1139 EXPORT_SYMBOL(ieee80211_sta_ps_transition);
1140
1141 static ieee80211_rx_result debug_noinline
1142 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1143 {
1144         struct sta_info *sta = rx->sta;
1145         struct sk_buff *skb = rx->skb;
1146         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1147         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1148
1149         if (!sta)
1150                 return RX_CONTINUE;
1151
1152         /*
1153          * Update last_rx only for IBSS packets which are for the current
1154          * BSSID to avoid keeping the current IBSS network alive in cases
1155          * where other STAs start using different BSSID.
1156          */
1157         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1158                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1159                                                 NL80211_IFTYPE_ADHOC);
1160                 if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0) {
1161                         sta->last_rx = jiffies;
1162                         if (ieee80211_is_data(hdr->frame_control)) {
1163                                 sta->last_rx_rate_idx = status->rate_idx;
1164                                 sta->last_rx_rate_flag = status->flag;
1165                         }
1166                 }
1167         } else if (!is_multicast_ether_addr(hdr->addr1)) {
1168                 /*
1169                  * Mesh beacons will update last_rx when if they are found to
1170                  * match the current local configuration when processed.
1171                  */
1172                 sta->last_rx = jiffies;
1173                 if (ieee80211_is_data(hdr->frame_control)) {
1174                         sta->last_rx_rate_idx = status->rate_idx;
1175                         sta->last_rx_rate_flag = status->flag;
1176                 }
1177         }
1178
1179         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1180                 return RX_CONTINUE;
1181
1182         if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1183                 ieee80211_sta_rx_notify(rx->sdata, hdr);
1184
1185         sta->rx_fragments++;
1186         sta->rx_bytes += rx->skb->len;
1187         sta->last_signal = status->signal;
1188         ewma_add(&sta->avg_signal, -status->signal);
1189
1190         /*
1191          * Change STA power saving mode only at the end of a frame
1192          * exchange sequence.
1193          */
1194         if (!(sta->local->hw.flags & IEEE80211_HW_AP_LINK_PS) &&
1195             !ieee80211_has_morefrags(hdr->frame_control) &&
1196             !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1197             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1198              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
1199                 if (test_sta_flags(sta, WLAN_STA_PS_STA)) {
1200                         /*
1201                          * Ignore doze->wake transitions that are
1202                          * indicated by non-data frames, the standard
1203                          * is unclear here, but for example going to
1204                          * PS mode and then scanning would cause a
1205                          * doze->wake transition for the probe request,
1206                          * and that is clearly undesirable.
1207                          */
1208                         if (ieee80211_is_data(hdr->frame_control) &&
1209                             !ieee80211_has_pm(hdr->frame_control))
1210                                 ap_sta_ps_end(sta);
1211                 } else {
1212                         if (ieee80211_has_pm(hdr->frame_control))
1213                                 ap_sta_ps_start(sta);
1214                 }
1215         }
1216
1217         /*
1218          * Drop (qos-)data::nullfunc frames silently, since they
1219          * are used only to control station power saving mode.
1220          */
1221         if (ieee80211_is_nullfunc(hdr->frame_control) ||
1222             ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1223                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
1224
1225                 /*
1226                  * If we receive a 4-addr nullfunc frame from a STA
1227                  * that was not moved to a 4-addr STA vlan yet, drop
1228                  * the frame to the monitor interface, to make sure
1229                  * that hostapd sees it
1230                  */
1231                 if (ieee80211_has_a4(hdr->frame_control) &&
1232                     (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1233                      (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1234                       !rx->sdata->u.vlan.sta)))
1235                         return RX_DROP_MONITOR;
1236                 /*
1237                  * Update counter and free packet here to avoid
1238                  * counting this as a dropped packed.
1239                  */
1240                 sta->rx_packets++;
1241                 dev_kfree_skb(rx->skb);
1242                 return RX_QUEUED;
1243         }
1244
1245         return RX_CONTINUE;
1246 } /* ieee80211_rx_h_sta_process */
1247
1248 static inline struct ieee80211_fragment_entry *
1249 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
1250                          unsigned int frag, unsigned int seq, int rx_queue,
1251                          struct sk_buff **skb)
1252 {
1253         struct ieee80211_fragment_entry *entry;
1254         int idx;
1255
1256         idx = sdata->fragment_next;
1257         entry = &sdata->fragments[sdata->fragment_next++];
1258         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
1259                 sdata->fragment_next = 0;
1260
1261         if (!skb_queue_empty(&entry->skb_list)) {
1262 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1263                 struct ieee80211_hdr *hdr =
1264                         (struct ieee80211_hdr *) entry->skb_list.next->data;
1265                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
1266                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
1267                        "addr1=%pM addr2=%pM\n",
1268                        sdata->name, idx,
1269                        jiffies - entry->first_frag_time, entry->seq,
1270                        entry->last_frag, hdr->addr1, hdr->addr2);
1271 #endif
1272                 __skb_queue_purge(&entry->skb_list);
1273         }
1274
1275         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
1276         *skb = NULL;
1277         entry->first_frag_time = jiffies;
1278         entry->seq = seq;
1279         entry->rx_queue = rx_queue;
1280         entry->last_frag = frag;
1281         entry->ccmp = 0;
1282         entry->extra_len = 0;
1283
1284         return entry;
1285 }
1286
1287 static inline struct ieee80211_fragment_entry *
1288 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
1289                           unsigned int frag, unsigned int seq,
1290                           int rx_queue, struct ieee80211_hdr *hdr)
1291 {
1292         struct ieee80211_fragment_entry *entry;
1293         int i, idx;
1294
1295         idx = sdata->fragment_next;
1296         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
1297                 struct ieee80211_hdr *f_hdr;
1298
1299                 idx--;
1300                 if (idx < 0)
1301                         idx = IEEE80211_FRAGMENT_MAX - 1;
1302
1303                 entry = &sdata->fragments[idx];
1304                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
1305                     entry->rx_queue != rx_queue ||
1306                     entry->last_frag + 1 != frag)
1307                         continue;
1308
1309                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
1310
1311                 /*
1312                  * Check ftype and addresses are equal, else check next fragment
1313                  */
1314                 if (((hdr->frame_control ^ f_hdr->frame_control) &
1315                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
1316                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
1317                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
1318                         continue;
1319
1320                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
1321                         __skb_queue_purge(&entry->skb_list);
1322                         continue;
1323                 }
1324                 return entry;
1325         }
1326
1327         return NULL;
1328 }
1329
1330 static ieee80211_rx_result debug_noinline
1331 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
1332 {
1333         struct ieee80211_hdr *hdr;
1334         u16 sc;
1335         __le16 fc;
1336         unsigned int frag, seq;
1337         struct ieee80211_fragment_entry *entry;
1338         struct sk_buff *skb;
1339         struct ieee80211_rx_status *status;
1340
1341         hdr = (struct ieee80211_hdr *)rx->skb->data;
1342         fc = hdr->frame_control;
1343         sc = le16_to_cpu(hdr->seq_ctrl);
1344         frag = sc & IEEE80211_SCTL_FRAG;
1345
1346         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1347                    (rx->skb)->len < 24 ||
1348                    is_multicast_ether_addr(hdr->addr1))) {
1349                 /* not fragmented */
1350                 goto out;
1351         }
1352         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1353
1354         if (skb_linearize(rx->skb))
1355                 return RX_DROP_UNUSABLE;
1356
1357         /*
1358          *  skb_linearize() might change the skb->data and
1359          *  previously cached variables (in this case, hdr) need to
1360          *  be refreshed with the new data.
1361          */
1362         hdr = (struct ieee80211_hdr *)rx->skb->data;
1363         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1364
1365         if (frag == 0) {
1366                 /* This is the first fragment of a new frame. */
1367                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1368                                                  rx->queue, &(rx->skb));
1369                 if (rx->key && rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP &&
1370                     ieee80211_has_protected(fc)) {
1371                         int queue = ieee80211_is_mgmt(fc) ?
1372                                 NUM_RX_DATA_QUEUES : rx->queue;
1373                         /* Store CCMP PN so that we can verify that the next
1374                          * fragment has a sequential PN value. */
1375                         entry->ccmp = 1;
1376                         memcpy(entry->last_pn,
1377                                rx->key->u.ccmp.rx_pn[queue],
1378                                CCMP_PN_LEN);
1379                 }
1380                 return RX_QUEUED;
1381         }
1382
1383         /* This is a fragment for a frame that should already be pending in
1384          * fragment cache. Add this fragment to the end of the pending entry.
1385          */
1386         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1387         if (!entry) {
1388                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1389                 return RX_DROP_MONITOR;
1390         }
1391
1392         /* Verify that MPDUs within one MSDU have sequential PN values.
1393          * (IEEE 802.11i, 8.3.3.4.5) */
1394         if (entry->ccmp) {
1395                 int i;
1396                 u8 pn[CCMP_PN_LEN], *rpn;
1397                 int queue;
1398                 if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP)
1399                         return RX_DROP_UNUSABLE;
1400                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1401                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1402                         pn[i]++;
1403                         if (pn[i])
1404                                 break;
1405                 }
1406                 queue = ieee80211_is_mgmt(fc) ?
1407                         NUM_RX_DATA_QUEUES : rx->queue;
1408                 rpn = rx->key->u.ccmp.rx_pn[queue];
1409                 if (memcmp(pn, rpn, CCMP_PN_LEN))
1410                         return RX_DROP_UNUSABLE;
1411                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1412         }
1413
1414         skb_pull(rx->skb, ieee80211_hdrlen(fc));
1415         __skb_queue_tail(&entry->skb_list, rx->skb);
1416         entry->last_frag = frag;
1417         entry->extra_len += rx->skb->len;
1418         if (ieee80211_has_morefrags(fc)) {
1419                 rx->skb = NULL;
1420                 return RX_QUEUED;
1421         }
1422
1423         rx->skb = __skb_dequeue(&entry->skb_list);
1424         if (skb_tailroom(rx->skb) < entry->extra_len) {
1425                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1426                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1427                                               GFP_ATOMIC))) {
1428                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1429                         __skb_queue_purge(&entry->skb_list);
1430                         return RX_DROP_UNUSABLE;
1431                 }
1432         }
1433         while ((skb = __skb_dequeue(&entry->skb_list))) {
1434                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1435                 dev_kfree_skb(skb);
1436         }
1437
1438         /* Complete frame has been reassembled - process it now */
1439         status = IEEE80211_SKB_RXCB(rx->skb);
1440         status->rx_flags |= IEEE80211_RX_FRAGMENTED;
1441
1442  out:
1443         if (rx->sta)
1444                 rx->sta->rx_packets++;
1445         if (is_multicast_ether_addr(hdr->addr1))
1446                 rx->local->dot11MulticastReceivedFrameCount++;
1447         else
1448                 ieee80211_led_rx(rx->local);
1449         return RX_CONTINUE;
1450 }
1451
1452 static ieee80211_rx_result debug_noinline
1453 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1454 {
1455         struct ieee80211_sub_if_data *sdata = rx->sdata;
1456         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1457         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1458
1459         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1460                    !(status->rx_flags & IEEE80211_RX_RA_MATCH)))
1461                 return RX_CONTINUE;
1462
1463         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1464             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1465                 return RX_DROP_UNUSABLE;
1466
1467         if (!test_sta_flags(rx->sta, WLAN_STA_PS_DRIVER))
1468                 ieee80211_sta_ps_deliver_poll_response(rx->sta);
1469         else
1470                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1471
1472         /* Free PS Poll skb here instead of returning RX_DROP that would
1473          * count as an dropped frame. */
1474         dev_kfree_skb(rx->skb);
1475
1476         return RX_QUEUED;
1477 }
1478
1479 static ieee80211_rx_result debug_noinline
1480 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1481 {
1482         u8 *data = rx->skb->data;
1483         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1484
1485         if (!ieee80211_is_data_qos(hdr->frame_control))
1486                 return RX_CONTINUE;
1487
1488         /* remove the qos control field, update frame type and meta-data */
1489         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1490                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1491         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1492         /* change frame type to non QOS */
1493         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1494
1495         return RX_CONTINUE;
1496 }
1497
1498 static int
1499 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1500 {
1501         if (unlikely(!rx->sta ||
1502             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1503                 return -EACCES;
1504
1505         return 0;
1506 }
1507
1508 static int
1509 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1510 {
1511         struct sk_buff *skb = rx->skb;
1512         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1513
1514         /*
1515          * Pass through unencrypted frames if the hardware has
1516          * decrypted them already.
1517          */
1518         if (status->flag & RX_FLAG_DECRYPTED)
1519                 return 0;
1520
1521         /* Drop unencrypted frames if key is set. */
1522         if (unlikely(!ieee80211_has_protected(fc) &&
1523                      !ieee80211_is_nullfunc(fc) &&
1524                      ieee80211_is_data(fc) &&
1525                      (rx->key || rx->sdata->drop_unencrypted)))
1526                 return -EACCES;
1527
1528         return 0;
1529 }
1530
1531 static int
1532 ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
1533 {
1534         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1535         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1536         __le16 fc = hdr->frame_control;
1537
1538         /*
1539          * Pass through unencrypted frames if the hardware has
1540          * decrypted them already.
1541          */
1542         if (status->flag & RX_FLAG_DECRYPTED)
1543                 return 0;
1544
1545         if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1546                 if (unlikely(!ieee80211_has_protected(fc) &&
1547                              ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1548                              rx->key)) {
1549                         if (ieee80211_is_deauth(fc))
1550                                 cfg80211_send_unprot_deauth(rx->sdata->dev,
1551                                                             rx->skb->data,
1552                                                             rx->skb->len);
1553                         else if (ieee80211_is_disassoc(fc))
1554                                 cfg80211_send_unprot_disassoc(rx->sdata->dev,
1555                                                               rx->skb->data,
1556                                                               rx->skb->len);
1557                         return -EACCES;
1558                 }
1559                 /* BIP does not use Protected field, so need to check MMIE */
1560                 if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1561                              ieee80211_get_mmie_keyidx(rx->skb) < 0)) {
1562                         if (ieee80211_is_deauth(fc))
1563                                 cfg80211_send_unprot_deauth(rx->sdata->dev,
1564                                                             rx->skb->data,
1565                                                             rx->skb->len);
1566                         else if (ieee80211_is_disassoc(fc))
1567                                 cfg80211_send_unprot_disassoc(rx->sdata->dev,
1568                                                               rx->skb->data,
1569                                                               rx->skb->len);
1570                         return -EACCES;
1571                 }
1572                 /*
1573                  * When using MFP, Action frames are not allowed prior to
1574                  * having configured keys.
1575                  */
1576                 if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1577                              ieee80211_is_robust_mgmt_frame(
1578                                      (struct ieee80211_hdr *) rx->skb->data)))
1579                         return -EACCES;
1580         }
1581
1582         return 0;
1583 }
1584
1585 static int
1586 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1587 {
1588         struct ieee80211_sub_if_data *sdata = rx->sdata;
1589         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1590         bool check_port_control = false;
1591         struct ethhdr *ehdr;
1592         int ret;
1593
1594         if (ieee80211_has_a4(hdr->frame_control) &&
1595             sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1596                 return -1;
1597
1598         if (sdata->vif.type == NL80211_IFTYPE_STATION &&
1599             !!sdata->u.mgd.use_4addr != !!ieee80211_has_a4(hdr->frame_control)) {
1600
1601                 if (!sdata->u.mgd.use_4addr)
1602                         return -1;
1603                 else
1604                         check_port_control = true;
1605         }
1606
1607         if (is_multicast_ether_addr(hdr->addr1) &&
1608             sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta)
1609                 return -1;
1610
1611         ret = ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
1612         if (ret < 0 || !check_port_control)
1613                 return ret;
1614
1615         ehdr = (struct ethhdr *) rx->skb->data;
1616         if (ehdr->h_proto != rx->sdata->control_port_protocol)
1617                 return -1;
1618
1619         return 0;
1620 }
1621
1622 /*
1623  * requires that rx->skb is a frame with ethernet header
1624  */
1625 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1626 {
1627         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1628                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1629         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1630
1631         /*
1632          * Allow EAPOL frames to us/the PAE group address regardless
1633          * of whether the frame was encrypted or not.
1634          */
1635         if (ehdr->h_proto == rx->sdata->control_port_protocol &&
1636             (compare_ether_addr(ehdr->h_dest, rx->sdata->vif.addr) == 0 ||
1637              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1638                 return true;
1639
1640         if (ieee80211_802_1x_port_control(rx) ||
1641             ieee80211_drop_unencrypted(rx, fc))
1642                 return false;
1643
1644         return true;
1645 }
1646
1647 /*
1648  * requires that rx->skb is a frame with ethernet header
1649  */
1650 static void
1651 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1652 {
1653         struct ieee80211_sub_if_data *sdata = rx->sdata;
1654         struct net_device *dev = sdata->dev;
1655         struct sk_buff *skb, *xmit_skb;
1656         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1657         struct sta_info *dsta;
1658         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1659
1660         skb = rx->skb;
1661         xmit_skb = NULL;
1662
1663         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1664              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1665             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1666             (status->rx_flags & IEEE80211_RX_RA_MATCH) &&
1667             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1668                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1669                         /*
1670                          * send multicast frames both to higher layers in
1671                          * local net stack and back to the wireless medium
1672                          */
1673                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1674                         if (!xmit_skb && net_ratelimit())
1675                                 printk(KERN_DEBUG "%s: failed to clone "
1676                                        "multicast frame\n", dev->name);
1677                 } else {
1678                         dsta = sta_info_get(sdata, skb->data);
1679                         if (dsta) {
1680                                 /*
1681                                  * The destination station is associated to
1682                                  * this AP (in this VLAN), so send the frame
1683                                  * directly to it and do not pass it to local
1684                                  * net stack.
1685                                  */
1686                                 xmit_skb = skb;
1687                                 skb = NULL;
1688                         }
1689                 }
1690         }
1691
1692         if (skb) {
1693                 int align __maybe_unused;
1694
1695 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1696                 /*
1697                  * 'align' will only take the values 0 or 2 here
1698                  * since all frames are required to be aligned
1699                  * to 2-byte boundaries when being passed to
1700                  * mac80211. That also explains the __skb_push()
1701                  * below.
1702                  */
1703                 align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1704                 if (align) {
1705                         if (WARN_ON(skb_headroom(skb) < 3)) {
1706                                 dev_kfree_skb(skb);
1707                                 skb = NULL;
1708                         } else {
1709                                 u8 *data = skb->data;
1710                                 size_t len = skb_headlen(skb);
1711                                 skb->data -= align;
1712                                 memmove(skb->data, data, len);
1713                                 skb_set_tail_pointer(skb, len);
1714                         }
1715                 }
1716 #endif
1717
1718                 if (skb) {
1719                         /* deliver to local stack */
1720                         skb->protocol = eth_type_trans(skb, dev);
1721                         memset(skb->cb, 0, sizeof(skb->cb));
1722                         netif_receive_skb(skb);
1723                 }
1724         }
1725
1726         if (xmit_skb) {
1727                 /* send to wireless media */
1728                 xmit_skb->protocol = htons(ETH_P_802_3);
1729                 skb_reset_network_header(xmit_skb);
1730                 skb_reset_mac_header(xmit_skb);
1731                 dev_queue_xmit(xmit_skb);
1732         }
1733 }
1734
1735 static ieee80211_rx_result debug_noinline
1736 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1737 {
1738         struct net_device *dev = rx->sdata->dev;
1739         struct sk_buff *skb = rx->skb;
1740         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1741         __le16 fc = hdr->frame_control;
1742         struct sk_buff_head frame_list;
1743         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1744
1745         if (unlikely(!ieee80211_is_data(fc)))
1746                 return RX_CONTINUE;
1747
1748         if (unlikely(!ieee80211_is_data_present(fc)))
1749                 return RX_DROP_MONITOR;
1750
1751         if (!(status->rx_flags & IEEE80211_RX_AMSDU))
1752                 return RX_CONTINUE;
1753
1754         if (ieee80211_has_a4(hdr->frame_control) &&
1755             rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1756             !rx->sdata->u.vlan.sta)
1757                 return RX_DROP_UNUSABLE;
1758
1759         if (is_multicast_ether_addr(hdr->addr1) &&
1760             ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1761               rx->sdata->u.vlan.sta) ||
1762              (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1763               rx->sdata->u.mgd.use_4addr)))
1764                 return RX_DROP_UNUSABLE;
1765
1766         skb->dev = dev;
1767         __skb_queue_head_init(&frame_list);
1768
1769         if (skb_linearize(skb))
1770                 return RX_DROP_UNUSABLE;
1771
1772         ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
1773                                  rx->sdata->vif.type,
1774                                  rx->local->hw.extra_tx_headroom);
1775
1776         while (!skb_queue_empty(&frame_list)) {
1777                 rx->skb = __skb_dequeue(&frame_list);
1778
1779                 if (!ieee80211_frame_allowed(rx, fc)) {
1780                         dev_kfree_skb(rx->skb);
1781                         continue;
1782                 }
1783                 dev->stats.rx_packets++;
1784                 dev->stats.rx_bytes += rx->skb->len;
1785
1786                 ieee80211_deliver_skb(rx);
1787         }
1788
1789         return RX_QUEUED;
1790 }
1791
1792 #ifdef CONFIG_MAC80211_MESH
1793 static ieee80211_rx_result
1794 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1795 {
1796         struct ieee80211_hdr *hdr;
1797         struct ieee80211s_hdr *mesh_hdr;
1798         unsigned int hdrlen;
1799         struct sk_buff *skb = rx->skb, *fwd_skb;
1800         struct ieee80211_local *local = rx->local;
1801         struct ieee80211_sub_if_data *sdata = rx->sdata;
1802         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1803
1804         hdr = (struct ieee80211_hdr *) skb->data;
1805         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1806         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1807
1808         if (!ieee80211_is_data(hdr->frame_control))
1809                 return RX_CONTINUE;
1810
1811         if (!mesh_hdr->ttl)
1812                 /* illegal frame */
1813                 return RX_DROP_MONITOR;
1814
1815         if (mesh_hdr->flags & MESH_FLAGS_AE) {
1816                 struct mesh_path *mppath;
1817                 char *proxied_addr;
1818                 char *mpp_addr;
1819
1820                 if (is_multicast_ether_addr(hdr->addr1)) {
1821                         mpp_addr = hdr->addr3;
1822                         proxied_addr = mesh_hdr->eaddr1;
1823                 } else {
1824                         mpp_addr = hdr->addr4;
1825                         proxied_addr = mesh_hdr->eaddr2;
1826                 }
1827
1828                 rcu_read_lock();
1829                 mppath = mpp_path_lookup(proxied_addr, sdata);
1830                 if (!mppath) {
1831                         mpp_path_add(proxied_addr, mpp_addr, sdata);
1832                 } else {
1833                         spin_lock_bh(&mppath->state_lock);
1834                         if (compare_ether_addr(mppath->mpp, mpp_addr) != 0)
1835                                 memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
1836                         spin_unlock_bh(&mppath->state_lock);
1837                 }
1838                 rcu_read_unlock();
1839         }
1840
1841         /* Frame has reached destination.  Don't forward */
1842         if (!is_multicast_ether_addr(hdr->addr1) &&
1843             compare_ether_addr(sdata->vif.addr, hdr->addr3) == 0)
1844                 return RX_CONTINUE;
1845
1846         mesh_hdr->ttl--;
1847
1848         if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
1849                 if (!mesh_hdr->ttl)
1850                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1851                                                      dropped_frames_ttl);
1852                 else {
1853                         struct ieee80211_hdr *fwd_hdr;
1854                         struct ieee80211_tx_info *info;
1855
1856                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1857
1858                         if (!fwd_skb && net_ratelimit())
1859                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1860                                                    sdata->name);
1861                         if (!fwd_skb)
1862                                 goto out;
1863
1864                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1865                         memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
1866                         info = IEEE80211_SKB_CB(fwd_skb);
1867                         memset(info, 0, sizeof(*info));
1868                         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1869                         info->control.vif = &rx->sdata->vif;
1870                         skb_set_queue_mapping(skb,
1871                                 ieee80211_select_queue(rx->sdata, fwd_skb));
1872                         ieee80211_set_qos_hdr(local, skb);
1873                         if (is_multicast_ether_addr(fwd_hdr->addr1))
1874                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1875                                                                 fwded_mcast);
1876                         else {
1877                                 int err;
1878                                 /*
1879                                  * Save TA to addr1 to send TA a path error if a
1880                                  * suitable next hop is not found
1881                                  */
1882                                 memcpy(fwd_hdr->addr1, fwd_hdr->addr2,
1883                                                 ETH_ALEN);
1884                                 err = mesh_nexthop_lookup(fwd_skb, sdata);
1885                                 /* Failed to immediately resolve next hop:
1886                                  * fwded frame was dropped or will be added
1887                                  * later to the pending skb queue.  */
1888                                 if (err)
1889                                         return RX_DROP_MONITOR;
1890
1891                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1892                                                                 fwded_unicast);
1893                         }
1894                         IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1895                                                      fwded_frames);
1896                         ieee80211_add_pending_skb(local, fwd_skb);
1897                 }
1898         }
1899
1900  out:
1901         if (is_multicast_ether_addr(hdr->addr1) ||
1902             sdata->dev->flags & IFF_PROMISC)
1903                 return RX_CONTINUE;
1904         else
1905                 return RX_DROP_MONITOR;
1906 }
1907 #endif
1908
1909 static ieee80211_rx_result debug_noinline
1910 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1911 {
1912         struct ieee80211_sub_if_data *sdata = rx->sdata;
1913         struct ieee80211_local *local = rx->local;
1914         struct net_device *dev = sdata->dev;
1915         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1916         __le16 fc = hdr->frame_control;
1917         int err;
1918
1919         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1920                 return RX_CONTINUE;
1921
1922         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1923                 return RX_DROP_MONITOR;
1924
1925         /*
1926          * Allow the cooked monitor interface of an AP to see 4-addr frames so
1927          * that a 4-addr station can be detected and moved into a separate VLAN
1928          */
1929         if (ieee80211_has_a4(hdr->frame_control) &&
1930             sdata->vif.type == NL80211_IFTYPE_AP)
1931                 return RX_DROP_MONITOR;
1932
1933         err = __ieee80211_data_to_8023(rx);
1934         if (unlikely(err))
1935                 return RX_DROP_UNUSABLE;
1936
1937         if (!ieee80211_frame_allowed(rx, fc))
1938                 return RX_DROP_MONITOR;
1939
1940         rx->skb->dev = dev;
1941
1942         dev->stats.rx_packets++;
1943         dev->stats.rx_bytes += rx->skb->len;
1944
1945         if (local->ps_sdata && local->hw.conf.dynamic_ps_timeout > 0 &&
1946             !is_multicast_ether_addr(
1947                     ((struct ethhdr *)rx->skb->data)->h_dest) &&
1948             (!local->scanning &&
1949              !test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state))) {
1950                         mod_timer(&local->dynamic_ps_timer, jiffies +
1951                          msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
1952         }
1953
1954         ieee80211_deliver_skb(rx);
1955
1956         return RX_QUEUED;
1957 }
1958
1959 static ieee80211_rx_result debug_noinline
1960 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1961 {
1962         struct ieee80211_local *local = rx->local;
1963         struct ieee80211_hw *hw = &local->hw;
1964         struct sk_buff *skb = rx->skb;
1965         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1966         struct tid_ampdu_rx *tid_agg_rx;
1967         u16 start_seq_num;
1968         u16 tid;
1969
1970         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1971                 return RX_CONTINUE;
1972
1973         if (ieee80211_is_back_req(bar->frame_control)) {
1974                 struct {
1975                         __le16 control, start_seq_num;
1976                 } __packed bar_data;
1977
1978                 if (!rx->sta)
1979                         return RX_DROP_MONITOR;
1980
1981                 if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
1982                                   &bar_data, sizeof(bar_data)))
1983                         return RX_DROP_MONITOR;
1984
1985                 tid = le16_to_cpu(bar_data.control) >> 12;
1986
1987                 tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
1988                 if (!tid_agg_rx)
1989                         return RX_DROP_MONITOR;
1990
1991                 start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
1992
1993                 /* reset session timer */
1994                 if (tid_agg_rx->timeout)
1995                         mod_timer(&tid_agg_rx->session_timer,
1996                                   TU_TO_EXP_TIME(tid_agg_rx->timeout));
1997
1998                 spin_lock(&tid_agg_rx->reorder_lock);
1999                 /* release stored frames up to start of BAR */
2000                 ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num);
2001                 spin_unlock(&tid_agg_rx->reorder_lock);
2002
2003                 kfree_skb(skb);
2004                 return RX_QUEUED;
2005         }
2006
2007         /*
2008          * After this point, we only want management frames,
2009          * so we can drop all remaining control frames to
2010          * cooked monitor interfaces.
2011          */
2012         return RX_DROP_MONITOR;
2013 }
2014
2015 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
2016                                            struct ieee80211_mgmt *mgmt,
2017                                            size_t len)
2018 {
2019         struct ieee80211_local *local = sdata->local;
2020         struct sk_buff *skb;
2021         struct ieee80211_mgmt *resp;
2022
2023         if (compare_ether_addr(mgmt->da, sdata->vif.addr) != 0) {
2024                 /* Not to own unicast address */
2025                 return;
2026         }
2027
2028         if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
2029             compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
2030                 /* Not from the current AP or not associated yet. */
2031                 return;
2032         }
2033
2034         if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
2035                 /* Too short SA Query request frame */
2036                 return;
2037         }
2038
2039         skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
2040         if (skb == NULL)
2041                 return;
2042
2043         skb_reserve(skb, local->hw.extra_tx_headroom);
2044         resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
2045         memset(resp, 0, 24);
2046         memcpy(resp->da, mgmt->sa, ETH_ALEN);
2047         memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
2048         memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
2049         resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2050                                           IEEE80211_STYPE_ACTION);
2051         skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
2052         resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
2053         resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
2054         memcpy(resp->u.action.u.sa_query.trans_id,
2055                mgmt->u.action.u.sa_query.trans_id,
2056                WLAN_SA_QUERY_TR_ID_LEN);
2057
2058         ieee80211_tx_skb(sdata, skb);
2059 }
2060
2061 static ieee80211_rx_result debug_noinline
2062 ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
2063 {
2064         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2065         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2066
2067         /*
2068          * From here on, look only at management frames.
2069          * Data and control frames are already handled,
2070          * and unknown (reserved) frames are useless.
2071          */
2072         if (rx->skb->len < 24)
2073                 return RX_DROP_MONITOR;
2074
2075         if (!ieee80211_is_mgmt(mgmt->frame_control))
2076                 return RX_DROP_MONITOR;
2077
2078         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2079                 return RX_DROP_MONITOR;
2080
2081         if (ieee80211_drop_unencrypted_mgmt(rx))
2082                 return RX_DROP_UNUSABLE;
2083
2084         return RX_CONTINUE;
2085 }
2086
2087 static ieee80211_rx_result debug_noinline
2088 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
2089 {
2090         struct ieee80211_local *local = rx->local;
2091         struct ieee80211_sub_if_data *sdata = rx->sdata;
2092         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2093         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2094         int len = rx->skb->len;
2095
2096         if (!ieee80211_is_action(mgmt->frame_control))
2097                 return RX_CONTINUE;
2098
2099         /* drop too small frames */
2100         if (len < IEEE80211_MIN_ACTION_SIZE)
2101                 return RX_DROP_UNUSABLE;
2102
2103         if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC)
2104                 return RX_DROP_UNUSABLE;
2105
2106         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2107                 return RX_DROP_UNUSABLE;
2108
2109         switch (mgmt->u.action.category) {
2110         case WLAN_CATEGORY_BACK:
2111                 /*
2112                  * The aggregation code is not prepared to handle
2113                  * anything but STA/AP due to the BSSID handling;
2114                  * IBSS could work in the code but isn't supported
2115                  * by drivers or the standard.
2116                  */
2117                 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2118                     sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2119                     sdata->vif.type != NL80211_IFTYPE_AP)
2120                         break;
2121
2122                 /* verify action_code is present */
2123                 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2124                         break;
2125
2126                 switch (mgmt->u.action.u.addba_req.action_code) {
2127                 case WLAN_ACTION_ADDBA_REQ:
2128                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2129                                    sizeof(mgmt->u.action.u.addba_req)))
2130                                 goto invalid;
2131                         break;
2132                 case WLAN_ACTION_ADDBA_RESP:
2133                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2134                                    sizeof(mgmt->u.action.u.addba_resp)))
2135                                 goto invalid;
2136                         break;
2137                 case WLAN_ACTION_DELBA:
2138                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2139                                    sizeof(mgmt->u.action.u.delba)))
2140                                 goto invalid;
2141                         break;
2142                 default:
2143                         goto invalid;
2144                 }
2145
2146                 goto queue;
2147         case WLAN_CATEGORY_SPECTRUM_MGMT:
2148                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
2149                         break;
2150
2151                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
2152                         break;
2153
2154                 /* verify action_code is present */
2155                 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2156                         break;
2157
2158                 switch (mgmt->u.action.u.measurement.action_code) {
2159                 case WLAN_ACTION_SPCT_MSR_REQ:
2160                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2161                                    sizeof(mgmt->u.action.u.measurement)))
2162                                 break;
2163                         ieee80211_process_measurement_req(sdata, mgmt, len);
2164                         goto handled;
2165                 case WLAN_ACTION_SPCT_CHL_SWITCH:
2166                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2167                                    sizeof(mgmt->u.action.u.chan_switch)))
2168                                 break;
2169
2170                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
2171                                 break;
2172
2173                         if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
2174                                 break;
2175
2176                         goto queue;
2177                 }
2178                 break;
2179         case WLAN_CATEGORY_SA_QUERY:
2180                 if (len < (IEEE80211_MIN_ACTION_SIZE +
2181                            sizeof(mgmt->u.action.u.sa_query)))
2182                         break;
2183
2184                 switch (mgmt->u.action.u.sa_query.action) {
2185                 case WLAN_ACTION_SA_QUERY_REQUEST:
2186                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
2187                                 break;
2188                         ieee80211_process_sa_query_req(sdata, mgmt, len);
2189                         goto handled;
2190                 }
2191                 break;
2192         case WLAN_CATEGORY_MESH_PLINK:
2193                 if (!ieee80211_vif_is_mesh(&sdata->vif))
2194                         break;
2195                 goto queue;
2196         case WLAN_CATEGORY_MESH_PATH_SEL:
2197                 if (!mesh_path_sel_is_hwmp(sdata))
2198                         break;
2199                 goto queue;
2200         }
2201
2202         return RX_CONTINUE;
2203
2204  invalid:
2205         status->rx_flags |= IEEE80211_RX_MALFORMED_ACTION_FRM;
2206         /* will return in the next handlers */
2207         return RX_CONTINUE;
2208
2209  handled:
2210         if (rx->sta)
2211                 rx->sta->rx_packets++;
2212         dev_kfree_skb(rx->skb);
2213         return RX_QUEUED;
2214
2215  queue:
2216         rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2217         skb_queue_tail(&sdata->skb_queue, rx->skb);
2218         ieee80211_queue_work(&local->hw, &sdata->work);
2219         if (rx->sta)
2220                 rx->sta->rx_packets++;
2221         return RX_QUEUED;
2222 }
2223
2224 static ieee80211_rx_result debug_noinline
2225 ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
2226 {
2227         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2228
2229         /* skip known-bad action frames and return them in the next handler */
2230         if (status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM)
2231                 return RX_CONTINUE;
2232
2233         /*
2234          * Getting here means the kernel doesn't know how to handle
2235          * it, but maybe userspace does ... include returned frames
2236          * so userspace can register for those to know whether ones
2237          * it transmitted were processed or returned.
2238          */
2239
2240         if (cfg80211_rx_mgmt(rx->sdata->dev, status->freq,
2241                              rx->skb->data, rx->skb->len,
2242                              GFP_ATOMIC)) {
2243                 if (rx->sta)
2244                         rx->sta->rx_packets++;
2245                 dev_kfree_skb(rx->skb);
2246                 return RX_QUEUED;
2247         }
2248
2249
2250         return RX_CONTINUE;
2251 }
2252
2253 static ieee80211_rx_result debug_noinline
2254 ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
2255 {
2256         struct ieee80211_local *local = rx->local;
2257         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2258         struct sk_buff *nskb;
2259         struct ieee80211_sub_if_data *sdata = rx->sdata;
2260         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2261
2262         if (!ieee80211_is_action(mgmt->frame_control))
2263                 return RX_CONTINUE;
2264
2265         /*
2266          * For AP mode, hostapd is responsible for handling any action
2267          * frames that we didn't handle, including returning unknown
2268          * ones. For all other modes we will return them to the sender,
2269          * setting the 0x80 bit in the action category, as required by
2270          * 802.11-2007 7.3.1.11.
2271          * Newer versions of hostapd shall also use the management frame
2272          * registration mechanisms, but older ones still use cooked
2273          * monitor interfaces so push all frames there.
2274          */
2275         if (!(status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM) &&
2276             (sdata->vif.type == NL80211_IFTYPE_AP ||
2277              sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
2278                 return RX_DROP_MONITOR;
2279
2280         /* do not return rejected action frames */
2281         if (mgmt->u.action.category & 0x80)
2282                 return RX_DROP_UNUSABLE;
2283
2284         nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
2285                                GFP_ATOMIC);
2286         if (nskb) {
2287                 struct ieee80211_mgmt *nmgmt = (void *)nskb->data;
2288
2289                 nmgmt->u.action.category |= 0x80;
2290                 memcpy(nmgmt->da, nmgmt->sa, ETH_ALEN);
2291                 memcpy(nmgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
2292
2293                 memset(nskb->cb, 0, sizeof(nskb->cb));
2294
2295                 ieee80211_tx_skb(rx->sdata, nskb);
2296         }
2297         dev_kfree_skb(rx->skb);
2298         return RX_QUEUED;
2299 }
2300
2301 static ieee80211_rx_result debug_noinline
2302 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
2303 {
2304         struct ieee80211_sub_if_data *sdata = rx->sdata;
2305         ieee80211_rx_result rxs;
2306         struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
2307         __le16 stype;
2308
2309         rxs = ieee80211_work_rx_mgmt(rx->sdata, rx->skb);
2310         if (rxs != RX_CONTINUE)
2311                 return rxs;
2312
2313         stype = mgmt->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE);
2314
2315         if (!ieee80211_vif_is_mesh(&sdata->vif) &&
2316             sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2317             sdata->vif.type != NL80211_IFTYPE_STATION)
2318                 return RX_DROP_MONITOR;
2319
2320         switch (stype) {
2321         case cpu_to_le16(IEEE80211_STYPE_BEACON):
2322         case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
2323                 /* process for all: mesh, mlme, ibss */
2324                 break;
2325         case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
2326         case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
2327                 if (is_multicast_ether_addr(mgmt->da) &&
2328                     !is_broadcast_ether_addr(mgmt->da))
2329                         return RX_DROP_MONITOR;
2330
2331                 /* process only for station */
2332                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
2333                         return RX_DROP_MONITOR;
2334                 break;
2335         case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
2336         case cpu_to_le16(IEEE80211_STYPE_AUTH):
2337                 /* process only for ibss */
2338                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
2339                         return RX_DROP_MONITOR;
2340                 break;
2341         default:
2342                 return RX_DROP_MONITOR;
2343         }
2344
2345         /* queue up frame and kick off work to process it */
2346         rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2347         skb_queue_tail(&sdata->skb_queue, rx->skb);
2348         ieee80211_queue_work(&rx->local->hw, &sdata->work);
2349         if (rx->sta)
2350                 rx->sta->rx_packets++;
2351
2352         return RX_QUEUED;
2353 }
2354
2355 static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
2356                                             struct ieee80211_rx_data *rx)
2357 {
2358         int keyidx;
2359         unsigned int hdrlen;
2360
2361         hdrlen = ieee80211_hdrlen(hdr->frame_control);
2362         if (rx->skb->len >= hdrlen + 4)
2363                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
2364         else
2365                 keyidx = -1;
2366
2367         if (!rx->sta) {
2368                 /*
2369                  * Some hardware seem to generate incorrect Michael MIC
2370                  * reports; ignore them to avoid triggering countermeasures.
2371                  */
2372                 return;
2373         }
2374
2375         if (!ieee80211_has_protected(hdr->frame_control))
2376                 return;
2377
2378         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
2379                 /*
2380                  * APs with pairwise keys should never receive Michael MIC
2381                  * errors for non-zero keyidx because these are reserved for
2382                  * group keys and only the AP is sending real multicast
2383                  * frames in the BSS.
2384                  */
2385                 return;
2386         }
2387
2388         if (!ieee80211_is_data(hdr->frame_control) &&
2389             !ieee80211_is_auth(hdr->frame_control))
2390                 return;
2391
2392         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
2393                                         GFP_ATOMIC);
2394 }
2395
2396 /* TODO: use IEEE80211_RX_FRAGMENTED */
2397 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
2398                                         struct ieee80211_rate *rate)
2399 {
2400         struct ieee80211_sub_if_data *sdata;
2401         struct ieee80211_local *local = rx->local;
2402         struct ieee80211_rtap_hdr {
2403                 struct ieee80211_radiotap_header hdr;
2404                 u8 flags;
2405                 u8 rate_or_pad;
2406                 __le16 chan_freq;
2407                 __le16 chan_flags;
2408         } __packed *rthdr;
2409         struct sk_buff *skb = rx->skb, *skb2;
2410         struct net_device *prev_dev = NULL;
2411         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2412
2413         /*
2414          * If cooked monitor has been processed already, then
2415          * don't do it again. If not, set the flag.
2416          */
2417         if (rx->flags & IEEE80211_RX_CMNTR)
2418                 goto out_free_skb;
2419         rx->flags |= IEEE80211_RX_CMNTR;
2420
2421         if (skb_headroom(skb) < sizeof(*rthdr) &&
2422             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
2423                 goto out_free_skb;
2424
2425         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
2426         memset(rthdr, 0, sizeof(*rthdr));
2427         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
2428         rthdr->hdr.it_present =
2429                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
2430                             (1 << IEEE80211_RADIOTAP_CHANNEL));
2431
2432         if (rate) {
2433                 rthdr->rate_or_pad = rate->bitrate / 5;
2434                 rthdr->hdr.it_present |=
2435                         cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
2436         }
2437         rthdr->chan_freq = cpu_to_le16(status->freq);
2438
2439         if (status->band == IEEE80211_BAND_5GHZ)
2440                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
2441                                                 IEEE80211_CHAN_5GHZ);
2442         else
2443                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
2444                                                 IEEE80211_CHAN_2GHZ);
2445
2446         skb_set_mac_header(skb, 0);
2447         skb->ip_summed = CHECKSUM_UNNECESSARY;
2448         skb->pkt_type = PACKET_OTHERHOST;
2449         skb->protocol = htons(ETH_P_802_2);
2450
2451         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2452                 if (!ieee80211_sdata_running(sdata))
2453                         continue;
2454
2455                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
2456                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
2457                         continue;
2458
2459                 if (prev_dev) {
2460                         skb2 = skb_clone(skb, GFP_ATOMIC);
2461                         if (skb2) {
2462                                 skb2->dev = prev_dev;
2463                                 netif_receive_skb(skb2);
2464                         }
2465                 }
2466
2467                 prev_dev = sdata->dev;
2468                 sdata->dev->stats.rx_packets++;
2469                 sdata->dev->stats.rx_bytes += skb->len;
2470         }
2471
2472         if (prev_dev) {
2473                 skb->dev = prev_dev;
2474                 netif_receive_skb(skb);
2475                 return;
2476         }
2477
2478  out_free_skb:
2479         dev_kfree_skb(skb);
2480 }
2481
2482 static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
2483                                          ieee80211_rx_result res)
2484 {
2485         switch (res) {
2486         case RX_DROP_MONITOR:
2487                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2488                 if (rx->sta)
2489                         rx->sta->rx_dropped++;
2490                 /* fall through */
2491         case RX_CONTINUE: {
2492                 struct ieee80211_rate *rate = NULL;
2493                 struct ieee80211_supported_band *sband;
2494                 struct ieee80211_rx_status *status;
2495
2496                 status = IEEE80211_SKB_RXCB((rx->skb));
2497
2498                 sband = rx->local->hw.wiphy->bands[status->band];
2499                 if (!(status->flag & RX_FLAG_HT))
2500                         rate = &sband->bitrates[status->rate_idx];
2501
2502                 ieee80211_rx_cooked_monitor(rx, rate);
2503                 break;
2504                 }
2505         case RX_DROP_UNUSABLE:
2506                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2507                 if (rx->sta)
2508                         rx->sta->rx_dropped++;
2509                 dev_kfree_skb(rx->skb);
2510                 break;
2511         case RX_QUEUED:
2512                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_queued);
2513                 break;
2514         }
2515 }
2516
2517 static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx)
2518 {
2519         ieee80211_rx_result res = RX_DROP_MONITOR;
2520         struct sk_buff *skb;
2521
2522 #define CALL_RXH(rxh)                   \
2523         do {                            \
2524                 res = rxh(rx);          \
2525                 if (res != RX_CONTINUE) \
2526                         goto rxh_next;  \
2527         } while (0);
2528
2529         spin_lock(&rx->local->rx_skb_queue.lock);
2530         if (rx->local->running_rx_handler)
2531                 goto unlock;
2532
2533         rx->local->running_rx_handler = true;
2534
2535         while ((skb = __skb_dequeue(&rx->local->rx_skb_queue))) {
2536                 spin_unlock(&rx->local->rx_skb_queue.lock);
2537
2538                 /*
2539                  * all the other fields are valid across frames
2540                  * that belong to an aMPDU since they are on the
2541                  * same TID from the same station
2542                  */
2543                 rx->skb = skb;
2544
2545                 CALL_RXH(ieee80211_rx_h_decrypt)
2546                 CALL_RXH(ieee80211_rx_h_check_more_data)
2547                 CALL_RXH(ieee80211_rx_h_sta_process)
2548                 CALL_RXH(ieee80211_rx_h_defragment)
2549                 CALL_RXH(ieee80211_rx_h_ps_poll)
2550                 CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2551                 /* must be after MMIC verify so header is counted in MPDU mic */
2552                 CALL_RXH(ieee80211_rx_h_remove_qos_control)
2553                 CALL_RXH(ieee80211_rx_h_amsdu)
2554 #ifdef CONFIG_MAC80211_MESH
2555                 if (ieee80211_vif_is_mesh(&rx->sdata->vif))
2556                         CALL_RXH(ieee80211_rx_h_mesh_fwding);
2557 #endif
2558                 CALL_RXH(ieee80211_rx_h_data)
2559                 CALL_RXH(ieee80211_rx_h_ctrl);
2560                 CALL_RXH(ieee80211_rx_h_mgmt_check)
2561                 CALL_RXH(ieee80211_rx_h_action)
2562                 CALL_RXH(ieee80211_rx_h_userspace_mgmt)
2563                 CALL_RXH(ieee80211_rx_h_action_return)
2564                 CALL_RXH(ieee80211_rx_h_mgmt)
2565
2566  rxh_next:
2567                 ieee80211_rx_handlers_result(rx, res);
2568                 spin_lock(&rx->local->rx_skb_queue.lock);
2569 #undef CALL_RXH
2570         }
2571
2572         rx->local->running_rx_handler = false;
2573
2574  unlock:
2575         spin_unlock(&rx->local->rx_skb_queue.lock);
2576 }
2577
2578 static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
2579 {
2580         ieee80211_rx_result res = RX_DROP_MONITOR;
2581
2582 #define CALL_RXH(rxh)                   \
2583         do {                            \
2584                 res = rxh(rx);          \
2585                 if (res != RX_CONTINUE) \
2586                         goto rxh_next;  \
2587         } while (0);
2588
2589         CALL_RXH(ieee80211_rx_h_passive_scan)
2590         CALL_RXH(ieee80211_rx_h_check)
2591
2592         ieee80211_rx_reorder_ampdu(rx);
2593
2594         ieee80211_rx_handlers(rx);
2595         return;
2596
2597  rxh_next:
2598         ieee80211_rx_handlers_result(rx, res);
2599
2600 #undef CALL_RXH
2601 }
2602
2603 /*
2604  * This function makes calls into the RX path, therefore
2605  * it has to be invoked under RCU read lock.
2606  */
2607 void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
2608 {
2609         struct ieee80211_rx_data rx = {
2610                 .sta = sta,
2611                 .sdata = sta->sdata,
2612                 .local = sta->local,
2613                 .queue = tid,
2614                 .flags = 0,
2615         };
2616         struct tid_ampdu_rx *tid_agg_rx;
2617
2618         tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
2619         if (!tid_agg_rx)
2620                 return;
2621
2622         spin_lock(&tid_agg_rx->reorder_lock);
2623         ieee80211_sta_reorder_release(&sta->local->hw, tid_agg_rx);
2624         spin_unlock(&tid_agg_rx->reorder_lock);
2625
2626         ieee80211_rx_handlers(&rx);
2627 }
2628
2629 /* main receive path */
2630
2631 static int prepare_for_handlers(struct ieee80211_rx_data *rx,
2632                                 struct ieee80211_hdr *hdr)
2633 {
2634         struct ieee80211_sub_if_data *sdata = rx->sdata;
2635         struct sk_buff *skb = rx->skb;
2636         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2637         u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
2638         int multicast = is_multicast_ether_addr(hdr->addr1);
2639
2640         switch (sdata->vif.type) {
2641         case NL80211_IFTYPE_STATION:
2642                 if (!bssid && !sdata->u.mgd.use_4addr)
2643                         return 0;
2644                 if (!multicast &&
2645                     compare_ether_addr(sdata->vif.addr, hdr->addr1) != 0) {
2646                         if (!(sdata->dev->flags & IFF_PROMISC) ||
2647                             sdata->u.mgd.use_4addr)
2648                                 return 0;
2649                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2650                 }
2651                 break;
2652         case NL80211_IFTYPE_ADHOC:
2653                 if (!bssid)
2654                         return 0;
2655                 if (ieee80211_is_beacon(hdr->frame_control)) {
2656                         return 1;
2657                 }
2658                 else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2659                         if (!(status->rx_flags & IEEE80211_RX_IN_SCAN))
2660                                 return 0;
2661                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2662                 } else if (!multicast &&
2663                            compare_ether_addr(sdata->vif.addr,
2664                                               hdr->addr1) != 0) {
2665                         if (!(sdata->dev->flags & IFF_PROMISC))
2666                                 return 0;
2667                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2668                 } else if (!rx->sta) {
2669                         int rate_idx;
2670                         if (status->flag & RX_FLAG_HT)
2671                                 rate_idx = 0; /* TODO: HT rates */
2672                         else
2673                                 rate_idx = status->rate_idx;
2674                         rx->sta = ieee80211_ibss_add_sta(sdata, bssid,
2675                                         hdr->addr2, BIT(rate_idx), GFP_ATOMIC);
2676                 }
2677                 break;
2678         case NL80211_IFTYPE_MESH_POINT:
2679                 if (!multicast &&
2680                     compare_ether_addr(sdata->vif.addr,
2681                                        hdr->addr1) != 0) {
2682                         if (!(sdata->dev->flags & IFF_PROMISC))
2683                                 return 0;
2684
2685                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2686                 }
2687                 break;
2688         case NL80211_IFTYPE_AP_VLAN:
2689         case NL80211_IFTYPE_AP:
2690                 if (!bssid) {
2691                         if (compare_ether_addr(sdata->vif.addr,
2692                                                hdr->addr1))
2693                                 return 0;
2694                 } else if (!ieee80211_bssid_match(bssid,
2695                                         sdata->vif.addr)) {
2696                         if (!(status->rx_flags & IEEE80211_RX_IN_SCAN) &&
2697                             !ieee80211_is_beacon(hdr->frame_control))
2698                                 return 0;
2699                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2700                 }
2701                 break;
2702         case NL80211_IFTYPE_WDS:
2703                 if (bssid || !ieee80211_is_data(hdr->frame_control))
2704                         return 0;
2705                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2706                         return 0;
2707                 break;
2708         default:
2709                 /* should never get here */
2710                 WARN_ON(1);
2711                 break;
2712         }
2713
2714         return 1;
2715 }
2716
2717 /*
2718  * This function returns whether or not the SKB
2719  * was destined for RX processing or not, which,
2720  * if consume is true, is equivalent to whether
2721  * or not the skb was consumed.
2722  */
2723 static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
2724                                             struct sk_buff *skb, bool consume)
2725 {
2726         struct ieee80211_local *local = rx->local;
2727         struct ieee80211_sub_if_data *sdata = rx->sdata;
2728         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2729         struct ieee80211_hdr *hdr = (void *)skb->data;
2730         int prepares;
2731
2732         rx->skb = skb;
2733         status->rx_flags |= IEEE80211_RX_RA_MATCH;
2734         prepares = prepare_for_handlers(rx, hdr);
2735
2736         if (!prepares)
2737                 return false;
2738
2739         if (status->flag & RX_FLAG_MMIC_ERROR) {
2740                 if (status->rx_flags & IEEE80211_RX_RA_MATCH)
2741                         ieee80211_rx_michael_mic_report(hdr, rx);
2742                 return false;
2743         }
2744
2745         if (!consume) {
2746                 skb = skb_copy(skb, GFP_ATOMIC);
2747                 if (!skb) {
2748                         if (net_ratelimit())
2749                                 wiphy_debug(local->hw.wiphy,
2750                                         "failed to copy skb for %s\n",
2751                                         sdata->name);
2752                         return true;
2753                 }
2754
2755                 rx->skb = skb;
2756         }
2757
2758         ieee80211_invoke_rx_handlers(rx);
2759         return true;
2760 }
2761
2762 /*
2763  * This is the actual Rx frames handler. as it blongs to Rx path it must
2764  * be called with rcu_read_lock protection.
2765  */
2766 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2767                                          struct sk_buff *skb)
2768 {
2769         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2770         struct ieee80211_local *local = hw_to_local(hw);
2771         struct ieee80211_sub_if_data *sdata;
2772         struct ieee80211_hdr *hdr;
2773         __le16 fc;
2774         struct ieee80211_rx_data rx;
2775         struct ieee80211_sub_if_data *prev;
2776         struct sta_info *sta, *tmp, *prev_sta;
2777         int err = 0;
2778
2779         fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
2780         memset(&rx, 0, sizeof(rx));
2781         rx.skb = skb;
2782         rx.local = local;
2783
2784         if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
2785                 local->dot11ReceivedFragmentCount++;
2786
2787         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
2788                      test_bit(SCAN_SW_SCANNING, &local->scanning)))
2789                 status->rx_flags |= IEEE80211_RX_IN_SCAN;
2790
2791         if (ieee80211_is_mgmt(fc))
2792                 err = skb_linearize(skb);
2793         else
2794                 err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
2795
2796         if (err) {
2797                 dev_kfree_skb(skb);
2798                 return;
2799         }
2800
2801         hdr = (struct ieee80211_hdr *)skb->data;
2802         ieee80211_parse_qos(&rx);
2803         ieee80211_verify_alignment(&rx);
2804
2805         if (ieee80211_is_data(fc)) {
2806                 prev_sta = NULL;
2807
2808                 for_each_sta_info(local, hdr->addr2, sta, tmp) {
2809                         if (!prev_sta) {
2810                                 prev_sta = sta;
2811                                 continue;
2812                         }
2813
2814                         rx.sta = prev_sta;
2815                         rx.sdata = prev_sta->sdata;
2816                         ieee80211_prepare_and_rx_handle(&rx, skb, false);
2817
2818                         prev_sta = sta;
2819                 }
2820
2821                 if (prev_sta) {
2822                         rx.sta = prev_sta;
2823                         rx.sdata = prev_sta->sdata;
2824
2825                         if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2826                                 return;
2827                         goto out;
2828                 }
2829         }
2830
2831         prev = NULL;
2832
2833         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2834                 if (!ieee80211_sdata_running(sdata))
2835                         continue;
2836
2837                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2838                     sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2839                         continue;
2840
2841                 /*
2842                  * frame is destined for this interface, but if it's
2843                  * not also for the previous one we handle that after
2844                  * the loop to avoid copying the SKB once too much
2845                  */
2846
2847                 if (!prev) {
2848                         prev = sdata;
2849                         continue;
2850                 }
2851
2852                 rx.sta = sta_info_get_bss(prev, hdr->addr2);
2853                 rx.sdata = prev;
2854                 ieee80211_prepare_and_rx_handle(&rx, skb, false);
2855
2856                 prev = sdata;
2857         }
2858
2859         if (prev) {
2860                 rx.sta = sta_info_get_bss(prev, hdr->addr2);
2861                 rx.sdata = prev;
2862
2863                 if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2864                         return;
2865         }
2866
2867  out:
2868         dev_kfree_skb(skb);
2869 }
2870
2871 /*
2872  * This is the receive path handler. It is called by a low level driver when an
2873  * 802.11 MPDU is received from the hardware.
2874  */
2875 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2876 {
2877         struct ieee80211_local *local = hw_to_local(hw);
2878         struct ieee80211_rate *rate = NULL;
2879         struct ieee80211_supported_band *sband;
2880         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2881
2882         WARN_ON_ONCE(softirq_count() == 0);
2883
2884         if (WARN_ON(status->band < 0 ||
2885                     status->band >= IEEE80211_NUM_BANDS))
2886                 goto drop;
2887
2888         sband = local->hw.wiphy->bands[status->band];
2889         if (WARN_ON(!sband))
2890                 goto drop;
2891
2892         /*
2893          * If we're suspending, it is possible although not too likely
2894          * that we'd be receiving frames after having already partially
2895          * quiesced the stack. We can't process such frames then since
2896          * that might, for example, cause stations to be added or other
2897          * driver callbacks be invoked.
2898          */
2899         if (unlikely(local->quiescing || local->suspended))
2900                 goto drop;
2901
2902         /*
2903          * The same happens when we're not even started,
2904          * but that's worth a warning.
2905          */
2906         if (WARN_ON(!local->started))
2907                 goto drop;
2908
2909         if (likely(!(status->flag & RX_FLAG_FAILED_PLCP_CRC))) {
2910                 /*
2911                  * Validate the rate, unless a PLCP error means that
2912                  * we probably can't have a valid rate here anyway.
2913                  */
2914
2915                 if (status->flag & RX_FLAG_HT) {
2916                         /*
2917                          * rate_idx is MCS index, which can be [0-76]
2918                          * as documented on:
2919                          *
2920                          * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
2921                          *
2922                          * Anything else would be some sort of driver or
2923                          * hardware error. The driver should catch hardware
2924                          * errors.
2925                          */
2926                         if (WARN((status->rate_idx < 0 ||
2927                                  status->rate_idx > 76),
2928                                  "Rate marked as an HT rate but passed "
2929                                  "status->rate_idx is not "
2930                                  "an MCS index [0-76]: %d (0x%02x)\n",
2931                                  status->rate_idx,
2932                                  status->rate_idx))
2933                                 goto drop;
2934                 } else {
2935                         if (WARN_ON(status->rate_idx < 0 ||
2936                                     status->rate_idx >= sband->n_bitrates))
2937                                 goto drop;
2938                         rate = &sband->bitrates[status->rate_idx];
2939                 }
2940         }
2941
2942         status->rx_flags = 0;
2943
2944         /*
2945          * key references and virtual interfaces are protected using RCU
2946          * and this requires that we are in a read-side RCU section during
2947          * receive processing
2948          */
2949         rcu_read_lock();
2950
2951         /*
2952          * Frames with failed FCS/PLCP checksum are not returned,
2953          * all other frames are returned without radiotap header
2954          * if it was previously present.
2955          * Also, frames with less than 16 bytes are dropped.
2956          */
2957         skb = ieee80211_rx_monitor(local, skb, rate);
2958         if (!skb) {
2959                 rcu_read_unlock();
2960                 return;
2961         }
2962
2963         ieee80211_tpt_led_trig_rx(local,
2964                         ((struct ieee80211_hdr *)skb->data)->frame_control,
2965                         skb->len);
2966         __ieee80211_rx_handle_packet(hw, skb);
2967
2968         rcu_read_unlock();
2969
2970         return;
2971  drop:
2972         kfree_skb(skb);
2973 }
2974 EXPORT_SYMBOL(ieee80211_rx);
2975
2976 /* This is a version of the rx handler that can be called from hard irq
2977  * context. Post the skb on the queue and schedule the tasklet */
2978 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
2979 {
2980         struct ieee80211_local *local = hw_to_local(hw);
2981
2982         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2983
2984         skb->pkt_type = IEEE80211_RX_MSG;
2985         skb_queue_tail(&local->skb_queue, skb);
2986         tasklet_schedule(&local->tasklet);
2987 }
2988 EXPORT_SYMBOL(ieee80211_rx_irqsafe);