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_TSFT)
  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         return len;
  89 }
  90
  91 /*
  92  * ieee80211_add_rx_radiotap_header - add radiotap header
  93  *
  94  * add a radiotap header containing all the fields which the hardware provided.
  95  */
  96 static void
  97 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
  98                                  struct sk_buff *skb,
  99                                  struct ieee80211_rate *rate,
 100                                  int rtap_len)
 101 {
 102         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 103         struct ieee80211_radiotap_header *rthdr;
 104         unsigned char *pos;
 105         u16 rx_flags = 0;
 106
 107         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
 108         memset(rthdr, 0, rtap_len);
 109
 110         /* radiotap header, set always present flags */
 111         rthdr->it_present =
 112                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 113                             (1 << IEEE80211_RADIOTAP_CHANNEL) |
 114                             (1 << IEEE80211_RADIOTAP_ANTENNA) |
 115                             (1 << IEEE80211_RADIOTAP_RX_FLAGS));
 116         rthdr->it_len = cpu_to_le16(rtap_len);
 117
 118         pos = (unsigned char *)(rthdr+1);
 119
 120         /* the order of the following fields is important */
 121
 122         /* IEEE80211_RADIOTAP_TSFT */
 123         if (status->flag & RX_FLAG_TSFT) {
 124                 put_unaligned_le64(status->mactime, pos);
 125                 rthdr->it_present |=
 126                         cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
 127                 pos += 8;
 128         }
 129
 130         /* IEEE80211_RADIOTAP_FLAGS */
 131         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 132                 *pos |= IEEE80211_RADIOTAP_F_FCS;
 133         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 134                 *pos |= IEEE80211_RADIOTAP_F_BADFCS;
 135         if (status->flag & RX_FLAG_SHORTPRE)
 136                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
 137         pos++;
 138
 139         /* IEEE80211_RADIOTAP_RATE */
 140         if (status->flag & RX_FLAG_HT) {
 141                 /*
 142                  * TODO: add following information into radiotap header once
 143                  * suitable fields are defined for it:
 144                  * - MCS index (status->rate_idx)
 145                  * - HT40 (status->flag & RX_FLAG_40MHZ)
 146                  * - short-GI (status->flag & RX_FLAG_SHORT_GI)
 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
 198 /*
 199  * This function copies a received frame to all monitor interfaces and
 200  * returns a cleaned-up SKB that no longer includes the FCS nor the
 201  * radiotap header the driver might have added.
 202  */
 203 static struct sk_buff *
 204 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
 205                      struct ieee80211_rate *rate)
 206 {
 207         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
 208         struct ieee80211_sub_if_data *sdata;
 209         int needed_headroom = 0;
 210         struct sk_buff *skb, *skb2;
 211         struct net_device *prev_dev = NULL;
 212         int present_fcs_len = 0;
 213
 214         /*
 215          * First, we may need to make a copy of the skb because
 216          *  (1) we need to modify it for radiotap (if not present), and
 217          *  (2) the other RX handlers will modify the skb we got.
 218          *
 219          * We don't need to, of course, if we aren't going to return
 220          * the SKB because it has a bad FCS/PLCP checksum.
 221          */
 222
 223         /* room for the radiotap header based on driver features */
 224         needed_headroom = ieee80211_rx_radiotap_len(local, status);
 225
 226         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 227                 present_fcs_len = FCS_LEN;
 228
 229         /* make sure hdr->frame_control is on the linear part */
 230         if (!pskb_may_pull(origskb, 2)) {
 231                 dev_kfree_skb(origskb);
 232                 return NULL;
 233         }
 234
 235         if (!local->monitors) {
 236                 if (should_drop_frame(origskb, present_fcs_len)) {
 237                         dev_kfree_skb(origskb);
 238                         return NULL;
 239                 }
 240
 241                 return remove_monitor_info(local, origskb);
 242         }
 243
 244         if (should_drop_frame(origskb, present_fcs_len)) {
 245                 /* only need to expand headroom if necessary */
 246                 skb = origskb;
 247                 origskb = NULL;
 248
 249                 /*
 250                  * This shouldn't trigger often because most devices have an
 251                  * RX header they pull before we get here, and that should
 252                  * be big enough for our radiotap information. We should
 253                  * probably export the length to drivers so that we can have
 254                  * them allocate enough headroom to start with.
 255                  */
 256                 if (skb_headroom(skb) < needed_headroom &&
 257                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
 258                         dev_kfree_skb(skb);
 259                         return NULL;
 260                 }
 261         } else {
 262                 /*
 263                  * Need to make a copy and possibly remove radiotap header
 264                  * and FCS from the original.
 265                  */
 266                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 267
 268                 origskb = remove_monitor_info(local, origskb);
 269
 270                 if (!skb)
 271                         return origskb;
 272         }
 273
 274         /* prepend radiotap information */
 275         ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom);
 276
 277         skb_reset_mac_header(skb);
 278         skb->ip_summed = CHECKSUM_UNNECESSARY;
 279         skb->pkt_type = PACKET_OTHERHOST;
 280         skb->protocol = htons(ETH_P_802_2);
 281
 282         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 283                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
 284                         continue;
 285
 286                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
 287                         continue;
 288
 289                 if (!ieee80211_sdata_running(sdata))
 290                         continue;
 291
 292                 if (prev_dev) {
 293                         skb2 = skb_clone(skb, GFP_ATOMIC);
 294                         if (skb2) {
 295                                 skb2->dev = prev_dev;
 296                                 netif_receive_skb(skb2);
 297                         }
 298                 }
 299
 300                 prev_dev = sdata->dev;
 301                 sdata->dev->stats.rx_packets++;
 302                 sdata->dev->stats.rx_bytes += skb->len;
 303         }
 304
 305         if (prev_dev) {
 306                 skb->dev = prev_dev;
 307                 netif_receive_skb(skb);
 308         } else
 309                 dev_kfree_skb(skb);
 310
 311         return origskb;
 312 }
 313
 314
 315 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
 316 {
 317         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 318         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 319         int tid;
 320
 321         /* does the frame have a qos control field? */
 322         if (ieee80211_is_data_qos(hdr->frame_control)) {
 323                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 324                 /* frame has qos control */
 325                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
 326                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
 327                         status->rx_flags |= IEEE80211_RX_AMSDU;
 328         } else {
 329                 /*
 330                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
 331                  *
 332                  *      Sequence numbers for management frames, QoS data
 333                  *      frames with a broadcast/multicast address in the
 334                  *      Address 1 field, and all non-QoS data frames sent
 335                  *      by QoS STAs are assigned using an additional single
 336                  *      modulo-4096 counter, [...]
 337                  *
 338                  * We also use that counter for non-QoS STAs.
 339                  */
 340                 tid = NUM_RX_DATA_QUEUES - 1;
 341         }
 342
 343         rx->queue = tid;
 344         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 345          * For now, set skb->priority to 0 for other cases. */
 346         rx->skb->priority = (tid > 7) ? 0 : tid;
 347 }
 348
 349 /**
 350  * DOC: Packet alignment
 351  *
 352  * Drivers always need to pass packets that are aligned to two-byte boundaries
 353  * to the stack.
 354  *
 355  * Additionally, should, if possible, align the payload data in a way that
 356  * guarantees that the contained IP header is aligned to a four-byte
 357  * boundary. In the case of regular frames, this simply means aligning the
 358  * payload to a four-byte boundary (because either the IP header is directly
 359  * contained, or IV/RFC1042 headers that have a length divisible by four are
 360  * in front of it).  If the payload data is not properly aligned and the
 361  * architecture doesn't support efficient unaligned operations, mac80211
 362  * will align the data.
 363  *
 364  * With A-MSDU frames, however, the payload data address must yield two modulo
 365  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
 366  * push the IP header further back to a multiple of four again. Thankfully, the
 367  * specs were sane enough this time around to require padding each A-MSDU
 368  * subframe to a length that is a multiple of four.
 369  *
 370  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
 371  * the payload is not supported, the driver is required to move the 802.11
 372  * header to be directly in front of the payload in that case.
 373  */
 374 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
 375 {
 376 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 377         WARN_ONCE((unsigned long)rx->skb->data & 1,
 378                   "unaligned packet at 0x%p\n", rx->skb->data);
 379 #endif
 380 }
 381
 382
 383 /* rx handlers */
 384
 385 static ieee80211_rx_result debug_noinline
 386 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 387 {
 388         struct ieee80211_local *local = rx->local;
 389         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 390         struct sk_buff *skb = rx->skb;
 391
 392         if (likely(!(status->rx_flags & IEEE80211_RX_IN_SCAN)))
 393                 return RX_CONTINUE;
 394
 395         if (test_bit(SCAN_HW_SCANNING, &local->scanning))
 396                 return ieee80211_scan_rx(rx->sdata, skb);
 397
 398         if (test_bit(SCAN_SW_SCANNING, &local->scanning)) {
 399                 /* drop all the other packets during a software scan anyway */
 400                 if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
 401                         dev_kfree_skb(skb);
 402                 return RX_QUEUED;
 403         }
 404
 405         /* scanning finished during invoking of handlers */
 406         I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 407         return RX_DROP_UNUSABLE;
 408 }
 409
 410
 411 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
 412 {
 413         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 414
 415         if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
 416                 return 0;
 417
 418         return ieee80211_is_robust_mgmt_frame(hdr);
 419 }
 420
 421
 422 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
 423 {
 424         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 425
 426         if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
 427                 return 0;
 428
 429         return ieee80211_is_robust_mgmt_frame(hdr);
 430 }
 431
 432
 433 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
 434 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
 435 {
 436         struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
 437         struct ieee80211_mmie *mmie;
 438
 439         if (skb->len < 24 + sizeof(*mmie) ||
 440             !is_multicast_ether_addr(hdr->da))
 441                 return -1;
 442
 443         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
 444                 return -1; /* not a robust management frame */
 445
 446         mmie = (struct ieee80211_mmie *)
 447                 (skb->data + skb->len - sizeof(*mmie));
 448         if (mmie->element_id != WLAN_EID_MMIE ||
 449             mmie->length != sizeof(*mmie) - 2)
 450                 return -1;
 451
 452         return le16_to_cpu(mmie->key_id);
 453 }
 454
 455
 456 static ieee80211_rx_result
 457 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 458 {
 459         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 460         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 461         char *dev_addr = rx->sdata->vif.addr;
 462
 463         if (ieee80211_is_data(hdr->frame_control)) {
 464                 if (is_multicast_ether_addr(hdr->addr1)) {
 465                         if (ieee80211_has_tods(hdr->frame_control) ||
 466                                 !ieee80211_has_fromds(hdr->frame_control))
 467                                 return RX_DROP_MONITOR;
 468                         if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
 469                                 return RX_DROP_MONITOR;
 470                 } else {
 471                         if (!ieee80211_has_a4(hdr->frame_control))
 472                                 return RX_DROP_MONITOR;
 473                         if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
 474                                 return RX_DROP_MONITOR;
 475                 }
 476         }
 477
 478         /* If there is not an established peer link and this is not a peer link
 479          * establisment frame, beacon or probe, drop the frame.
 480          */
 481
 482         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
 483                 struct ieee80211_mgmt *mgmt;
 484
 485                 if (!ieee80211_is_mgmt(hdr->frame_control))
 486                         return RX_DROP_MONITOR;
 487
 488                 if (ieee80211_is_action(hdr->frame_control)) {
 489                         mgmt = (struct ieee80211_mgmt *)hdr;
 490                         if (mgmt->u.action.category != WLAN_CATEGORY_MESH_PLINK)
 491                                 return RX_DROP_MONITOR;
 492                         return RX_CONTINUE;
 493                 }
 494
 495                 if (ieee80211_is_probe_req(hdr->frame_control) ||
 496                     ieee80211_is_probe_resp(hdr->frame_control) ||
 497                     ieee80211_is_beacon(hdr->frame_control))
 498                         return RX_CONTINUE;
 499
 500                 return RX_DROP_MONITOR;
 501
 502         }
 503
 504 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
 505
 506         if (ieee80211_is_data(hdr->frame_control) &&
 507             is_multicast_ether_addr(hdr->addr1) &&
 508             mesh_rmc_check(hdr->addr3, msh_h_get(hdr, hdrlen), rx->sdata))
 509                 return RX_DROP_MONITOR;
 510 #undef msh_h_get
 511
 512         return RX_CONTINUE;
 513 }
 514
 515 #define SEQ_MODULO 0x1000
 516 #define SEQ_MASK   0xfff
 517
 518 static inline int seq_less(u16 sq1, u16 sq2)
 519 {
 520         return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
 521 }
 522
 523 static inline u16 seq_inc(u16 sq)
 524 {
 525         return (sq + 1) & SEQ_MASK;
 526 }
 527
 528 static inline u16 seq_sub(u16 sq1, u16 sq2)
 529 {
 530         return (sq1 - sq2) & SEQ_MASK;
 531 }
 532
 533
 534 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
 535                                             struct tid_ampdu_rx *tid_agg_rx,
 536                                             int index,
 537                                             struct sk_buff_head *frames)
 538 {
 539         struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
 540
 541         lockdep_assert_held(&tid_agg_rx->reorder_lock);
 542
 543         if (!skb)
 544                 goto no_frame;
 545
 546         /* release the frame from the reorder ring buffer */
 547         tid_agg_rx->stored_mpdu_num--;
 548         tid_agg_rx->reorder_buf[index] = NULL;
 549         __skb_queue_tail(frames, skb);
 550
 551 no_frame:
 552         tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
 553 }
 554
 555 static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
 556                                              struct tid_ampdu_rx *tid_agg_rx,
 557                                              u16 head_seq_num,
 558                                              struct sk_buff_head *frames)
 559 {
 560         int index;
 561
 562         lockdep_assert_held(&tid_agg_rx->reorder_lock);
 563
 564         while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
 565                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 566                                                         tid_agg_rx->buf_size;
 567                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index, frames);
 568         }
 569 }
 570
 571 /*
 572  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
 573  * the skb was added to the buffer longer than this time ago, the earlier
 574  * frames that have not yet been received are assumed to be lost and the skb
 575  * can be released for processing. This may also release other skb's from the
 576  * reorder buffer if there are no additional gaps between the frames.
 577  *
 578  * Callers must hold tid_agg_rx->reorder_lock.
 579  */
 580 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
 581
 582 static void ieee80211_sta_reorder_release(struct ieee80211_hw *hw,
 583                                           struct tid_ampdu_rx *tid_agg_rx,
 584                                           struct sk_buff_head *frames)
 585 {
 586         int index, j;
 587
 588         lockdep_assert_held(&tid_agg_rx->reorder_lock);
 589
 590         /* release the buffer until next missing frame */
 591         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 592                                                 tid_agg_rx->buf_size;
 593         if (!tid_agg_rx->reorder_buf[index] &&
 594             tid_agg_rx->stored_mpdu_num > 1) {
 595                 /*
 596                  * No buffers ready to be released, but check whether any
 597                  * frames in the reorder buffer have timed out.
 598                  */
 599                 int skipped = 1;
 600                 for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
 601                      j = (j + 1) % tid_agg_rx->buf_size) {
 602                         if (!tid_agg_rx->reorder_buf[j]) {
 603                                 skipped++;
 604                                 continue;
 605                         }
 606                         if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
 607                                         HT_RX_REORDER_BUF_TIMEOUT))
 608                                 goto set_release_timer;
 609
 610 #ifdef CONFIG_MAC80211_HT_DEBUG
 611                         if (net_ratelimit())
 612                                 wiphy_debug(hw->wiphy,
 613                                             "release an RX reorder frame due to timeout on earlier frames\n");
 614 #endif
 615                         ieee80211_release_reorder_frame(hw, tid_agg_rx,
 616                                                         j, frames);
 617
 618                         /*
 619                          * Increment the head seq# also for the skipped slots.
 620                          */
 621                         tid_agg_rx->head_seq_num =
 622                                 (tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
 623                         skipped = 0;
 624                 }
 625         } else while (tid_agg_rx->reorder_buf[index]) {
 626                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index, frames);
 627                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 628                                                         tid_agg_rx->buf_size;
 629         }
 630
 631         /*
 632          * Disable the reorder release timer for now.
 633          *
 634          * The current implementation lacks a proper locking scheme
 635          * which would protect vital statistic and debug counters
 636          * from being updated by two different but concurrent BHs.
 637          *
 638          * More information about the topic is available from:
 639          * - thread: http://marc.info/?t=128635927000001
 640          *
 641          * What was wrong:
 642          * =>  http://marc.info/?l=linux-wireless&m=128636170811964
 643          * "Basically the thing is that until your patch, the data
 644          *  in the struct didn't actually need locking because it
 645          *  was accessed by the RX path only which is not concurrent."
 646          *
 647          * List of what needs to be fixed:
 648          * => http://marc.info/?l=linux-wireless&m=128656352920957
 649          *
 650
 651         if (tid_agg_rx->stored_mpdu_num) {
 652                 j = index = seq_sub(tid_agg_rx->head_seq_num,
 653                                     tid_agg_rx->ssn) % tid_agg_rx->buf_size;
 654
 655                 for (; j != (index - 1) % tid_agg_rx->buf_size;
 656                      j = (j + 1) % tid_agg_rx->buf_size) {
 657                         if (tid_agg_rx->reorder_buf[j])
 658                                 break;
 659                 }
 660
 661  set_release_timer:
 662
 663                 mod_timer(&tid_agg_rx->reorder_timer,
 664                           tid_agg_rx->reorder_time[j] +
 665                           HT_RX_REORDER_BUF_TIMEOUT);
 666         } else {
 667                 del_timer(&tid_agg_rx->reorder_timer);
 668         }
 669         */
 670
 671 set_release_timer:
 672         return;
 673 }
 674
 675 /*
 676  * As this function belongs to the RX path it must be under
 677  * rcu_read_lock protection. It returns false if the frame
 678  * can be processed immediately, true if it was consumed.
 679  */
 680 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
 681                                              struct tid_ampdu_rx *tid_agg_rx,
 682                                              struct sk_buff *skb,
 683                                              struct sk_buff_head *frames)
 684 {
 685         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 686         u16 sc = le16_to_cpu(hdr->seq_ctrl);
 687         u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
 688         u16 head_seq_num, buf_size;
 689         int index;
 690         bool ret = true;
 691
 692         spin_lock(&tid_agg_rx->reorder_lock);
 693
 694         buf_size = tid_agg_rx->buf_size;
 695         head_seq_num = tid_agg_rx->head_seq_num;
 696
 697         /* frame with out of date sequence number */
 698         if (seq_less(mpdu_seq_num, head_seq_num)) {
 699                 dev_kfree_skb(skb);
 700                 goto out;
 701         }
 702
 703         /*
 704          * If frame the sequence number exceeds our buffering window
 705          * size release some previous frames to make room for this one.
 706          */
 707         if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
 708                 head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
 709                 /* release stored frames up to new head to stack */
 710                 ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num,
 711                                                  frames);
 712         }
 713
 714         /* Now the new frame is always in the range of the reordering buffer */
 715
 716         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size;
 717
 718         /* check if we already stored this frame */
 719         if (tid_agg_rx->reorder_buf[index]) {
 720                 dev_kfree_skb(skb);
 721                 goto out;
 722         }
 723
 724         /*
 725          * If the current MPDU is in the right order and nothing else
 726          * is stored we can process it directly, no need to buffer it.
 727          */
 728         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
 729             tid_agg_rx->stored_mpdu_num == 0) {
 730                 tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
 731                 ret = false;
 732                 goto out;
 733         }
 734
 735         /* put the frame in the reordering buffer */
 736         tid_agg_rx->reorder_buf[index] = skb;
 737         tid_agg_rx->reorder_time[index] = jiffies;
 738         tid_agg_rx->stored_mpdu_num++;
 739         ieee80211_sta_reorder_release(hw, tid_agg_rx, frames);
 740
 741  out:
 742         spin_unlock(&tid_agg_rx->reorder_lock);
 743         return ret;
 744 }
 745
 746 /*
 747  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
 748  * true if the MPDU was buffered, false if it should be processed.
 749  */
 750 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx,
 751                                        struct sk_buff_head *frames)
 752 {
 753         struct sk_buff *skb = rx->skb;
 754         struct ieee80211_local *local = rx->local;
 755         struct ieee80211_hw *hw = &local->hw;
 756         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 757         struct sta_info *sta = rx->sta;
 758         struct tid_ampdu_rx *tid_agg_rx;
 759         u16 sc;
 760         int tid;
 761
 762         if (!ieee80211_is_data_qos(hdr->frame_control))
 763                 goto dont_reorder;
 764
 765         /*
 766          * filter the QoS data rx stream according to
 767          * STA/TID and check if this STA/TID is on aggregation
 768          */
 769
 770         if (!sta)
 771                 goto dont_reorder;
 772
 773         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
 774
 775         tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
 776         if (!tid_agg_rx)
 777                 goto dont_reorder;
 778
 779         /* qos null data frames are excluded */
 780         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
 781                 goto dont_reorder;
 782
 783         /* new, potentially un-ordered, ampdu frame - process it */
 784
 785         /* reset session timer */
 786         if (tid_agg_rx->timeout)
 787                 mod_timer(&tid_agg_rx->session_timer,
 788                           TU_TO_EXP_TIME(tid_agg_rx->timeout));
 789
 790         /* if this mpdu is fragmented - terminate rx aggregation session */
 791         sc = le16_to_cpu(hdr->seq_ctrl);
 792         if (sc & IEEE80211_SCTL_FRAG) {
 793                 skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
 794                 skb_queue_tail(&rx->sdata->skb_queue, skb);
 795                 ieee80211_queue_work(&local->hw, &rx->sdata->work);
 796                 return;
 797         }
 798
 799         /*
 800          * No locking needed -- we will only ever process one
 801          * RX packet at a time, and thus own tid_agg_rx. All
 802          * other code manipulating it needs to (and does) make
 803          * sure that we cannot get to it any more before doing
 804          * anything with it.
 805          */
 806         if (ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb, frames))
 807                 return;
 808
 809  dont_reorder:
 810         __skb_queue_tail(frames, skb);
 811 }
 812
 813 static ieee80211_rx_result debug_noinline
 814 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
 815 {
 816         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 817         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 818
 819         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 820         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 821                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
 822                              rx->sta->last_seq_ctrl[rx->queue] ==
 823                              hdr->seq_ctrl)) {
 824                         if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
 825                                 rx->local->dot11FrameDuplicateCount++;
 826                                 rx->sta->num_duplicates++;
 827                         }
 828                         return RX_DROP_MONITOR;
 829                 } else
 830                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
 831         }
 832
 833         if (unlikely(rx->skb->len < 16)) {
 834                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 835                 return RX_DROP_MONITOR;
 836         }
 837
 838         /* Drop disallowed frame classes based on STA auth/assoc state;
 839          * IEEE 802.11, Chap 5.5.
 840          *
 841          * mac80211 filters only based on association state, i.e. it drops
 842          * Class 3 frames from not associated stations. hostapd sends
 843          * deauth/disassoc frames when needed. In addition, hostapd is
 844          * responsible for filtering on both auth and assoc states.
 845          */
 846
 847         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
 848                 return ieee80211_rx_mesh_check(rx);
 849
 850         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
 851                       ieee80211_is_pspoll(hdr->frame_control)) &&
 852                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
 853                      rx->sdata->vif.type != NL80211_IFTYPE_WDS &&
 854                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
 855                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
 856                      !ieee80211_has_tods(hdr->frame_control) &&
 857                      ieee80211_is_data(hdr->frame_control)) ||
 858                     !(status->rx_flags & IEEE80211_RX_RA_MATCH)) {
 859                         /* Drop IBSS frames and frames for other hosts
 860                          * silently. */
 861                         return RX_DROP_MONITOR;
 862                 }
 863
 864                 return RX_DROP_MONITOR;
 865         }
 866
 867         return RX_CONTINUE;
 868 }
 869
 870
 871 static ieee80211_rx_result debug_noinline
 872 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 873 {
 874         struct sk_buff *skb = rx->skb;
 875         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 876         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 877         int keyidx;
 878         int hdrlen;
 879         ieee80211_rx_result result = RX_DROP_UNUSABLE;
 880         struct ieee80211_key *sta_ptk = NULL;
 881         int mmie_keyidx = -1;
 882         __le16 fc;
 883
 884         /*
 885          * Key selection 101
 886          *
 887          * There are four types of keys:
 888          *  - GTK (group keys)
 889          *  - IGTK (group keys for management frames)
 890          *  - PTK (pairwise keys)
 891          *  - STK (station-to-station pairwise keys)
 892          *
 893          * When selecting a key, we have to distinguish between multicast
 894          * (including broadcast) and unicast frames, the latter can only
 895          * use PTKs and STKs while the former always use GTKs and IGTKs.
 896          * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
 897          * unicast frames can also use key indices like GTKs. Hence, if we
 898          * don't have a PTK/STK we check the key index for a WEP key.
 899          *
 900          * Note that in a regular BSS, multicast frames are sent by the
 901          * AP only, associated stations unicast the frame to the AP first
 902          * which then multicasts it on their behalf.
 903          *
 904          * There is also a slight problem in IBSS mode: GTKs are negotiated
 905          * with each station, that is something we don't currently handle.
 906          * The spec seems to expect that one negotiates the same key with
 907          * every station but there's no such requirement; VLANs could be
 908          * possible.
 909          */
 910
 911         /*
 912          * No point in finding a key and decrypting if the frame is neither
 913          * addressed to us nor a multicast frame.
 914          */
 915         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
 916                 return RX_CONTINUE;
 917
 918         /* start without a key */
 919         rx->key = NULL;
 920
 921         if (rx->sta)
 922                 sta_ptk = rcu_dereference(rx->sta->ptk);
 923
 924         fc = hdr->frame_control;
 925
 926         if (!ieee80211_has_protected(fc))
 927                 mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
 928
 929         if (!is_multicast_ether_addr(hdr->addr1) && sta_ptk) {
 930                 rx->key = sta_ptk;
 931                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 932                     (status->flag & RX_FLAG_IV_STRIPPED))
 933                         return RX_CONTINUE;
 934                 /* Skip decryption if the frame is not protected. */
 935                 if (!ieee80211_has_protected(fc))
 936                         return RX_CONTINUE;
 937         } else if (mmie_keyidx >= 0) {
 938                 /* Broadcast/multicast robust management frame / BIP */
 939                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 940                     (status->flag & RX_FLAG_IV_STRIPPED))
 941                         return RX_CONTINUE;
 942
 943                 if (mmie_keyidx < NUM_DEFAULT_KEYS ||
 944                     mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 945                         return RX_DROP_MONITOR; /* unexpected BIP keyidx */
 946                 if (rx->sta)
 947                         rx->key = rcu_dereference(rx->sta->gtk[mmie_keyidx]);
 948                 if (!rx->key)
 949                         rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
 950         } else if (!ieee80211_has_protected(fc)) {
 951                 /*
 952                  * The frame was not protected, so skip decryption. However, we
 953                  * need to set rx->key if there is a key that could have been
 954                  * used so that the frame may be dropped if encryption would
 955                  * have been expected.
 956                  */
 957                 struct ieee80211_key *key = NULL;
 958                 struct ieee80211_sub_if_data *sdata = rx->sdata;
 959                 int i;
 960
 961                 if (ieee80211_is_mgmt(fc) &&
 962                     is_multicast_ether_addr(hdr->addr1) &&
 963                     (key = rcu_dereference(rx->sdata->default_mgmt_key)))
 964                         rx->key = key;
 965                 else {
 966                         if (rx->sta) {
 967                                 for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
 968                                         key = rcu_dereference(rx->sta->gtk[i]);
 969                                         if (key)
 970                                                 break;
 971                                 }
 972                         }
 973                         if (!key) {
 974                                 for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
 975                                         key = rcu_dereference(sdata->keys[i]);
 976                                         if (key)
 977                                                 break;
 978                                 }
 979                         }
 980                         if (key)
 981                                 rx->key = key;
 982                 }
 983                 return RX_CONTINUE;
 984         } else {
 985                 u8 keyid;
 986                 /*
 987                  * The device doesn't give us the IV so we won't be
 988                  * able to look up the key. That's ok though, we
 989                  * don't need to decrypt the frame, we just won't
 990                  * be able to keep statistics accurate.
 991                  * Except for key threshold notifications, should
 992                  * we somehow allow the driver to tell us which key
 993                  * the hardware used if this flag is set?
 994                  */
 995                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 996                     (status->flag & RX_FLAG_IV_STRIPPED))
 997                         return RX_CONTINUE;
 998
 999                 hdrlen = ieee80211_hdrlen(fc);
1000
1001                 if (rx->skb->len < 8 + hdrlen)
1002                         return RX_DROP_UNUSABLE; /* TODO: count this? */
1003
1004                 /*
1005                  * no need to call ieee80211_wep_get_keyidx,
1006                  * it verifies a bunch of things we've done already
1007                  */
1008                 skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
1009                 keyidx = keyid >> 6;
1010
1011                 /* check per-station GTK first, if multicast packet */
1012                 if (is_multicast_ether_addr(hdr->addr1) && rx->sta)
1013                         rx->key = rcu_dereference(rx->sta->gtk[keyidx]);
1014
1015                 /* if not found, try default key */
1016                 if (!rx->key) {
1017                         rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
1018
1019                         /*
1020                          * RSNA-protected unicast frames should always be
1021                          * sent with pairwise or station-to-station keys,
1022                          * but for WEP we allow using a key index as well.
1023                          */
1024                         if (rx->key &&
1025                             rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP40 &&
1026                             rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP104 &&
1027                             !is_multicast_ether_addr(hdr->addr1))
1028                                 rx->key = NULL;
1029                 }
1030         }
1031
1032         if (rx->key) {
1033                 rx->key->tx_rx_count++;
1034                 /* TODO: add threshold stuff again */
1035         } else {
1036                 return RX_DROP_MONITOR;
1037         }
1038
1039         if (skb_linearize(rx->skb))
1040                 return RX_DROP_UNUSABLE;
1041         /* the hdr variable is invalid now! */
1042
1043         switch (rx->key->conf.cipher) {
1044         case WLAN_CIPHER_SUITE_WEP40:
1045         case WLAN_CIPHER_SUITE_WEP104:
1046                 /* Check for weak IVs if possible */
1047                 if (rx->sta && ieee80211_is_data(fc) &&
1048                     (!(status->flag & RX_FLAG_IV_STRIPPED) ||
1049                      !(status->flag & RX_FLAG_DECRYPTED)) &&
1050                     ieee80211_wep_is_weak_iv(rx->skb, rx->key))
1051                         rx->sta->wep_weak_iv_count++;
1052
1053                 result = ieee80211_crypto_wep_decrypt(rx);
1054                 break;
1055         case WLAN_CIPHER_SUITE_TKIP:
1056                 result = ieee80211_crypto_tkip_decrypt(rx);
1057                 break;
1058         case WLAN_CIPHER_SUITE_CCMP:
1059                 result = ieee80211_crypto_ccmp_decrypt(rx);
1060                 break;
1061         case WLAN_CIPHER_SUITE_AES_CMAC:
1062                 result = ieee80211_crypto_aes_cmac_decrypt(rx);
1063                 break;
1064         default:
1065                 /*
1066                  * We can reach here only with HW-only algorithms
1067                  * but why didn't it decrypt the frame?!
1068                  */
1069                 return RX_DROP_UNUSABLE;
1070         }
1071
1072         /* either the frame has been decrypted or will be dropped */
1073         status->flag |= RX_FLAG_DECRYPTED;
1074
1075         return result;
1076 }
1077
1078 static ieee80211_rx_result debug_noinline
1079 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
1080 {
1081         struct ieee80211_local *local;
1082         struct ieee80211_hdr *hdr;
1083         struct sk_buff *skb;
1084
1085         local = rx->local;
1086         skb = rx->skb;
1087         hdr = (struct ieee80211_hdr *) skb->data;
1088
1089         if (!local->pspolling)
1090                 return RX_CONTINUE;
1091
1092         if (!ieee80211_has_fromds(hdr->frame_control))
1093                 /* this is not from AP */
1094                 return RX_CONTINUE;
1095
1096         if (!ieee80211_is_data(hdr->frame_control))
1097                 return RX_CONTINUE;
1098
1099         if (!ieee80211_has_moredata(hdr->frame_control)) {
1100                 /* AP has no more frames buffered for us */
1101                 local->pspolling = false;
1102                 return RX_CONTINUE;
1103         }
1104
1105         /* more data bit is set, let's request a new frame from the AP */
1106         ieee80211_send_pspoll(local, rx->sdata);
1107
1108         return RX_CONTINUE;
1109 }
1110
1111 static void ap_sta_ps_start(struct sta_info *sta)
1112 {
1113         struct ieee80211_sub_if_data *sdata = sta->sdata;
1114         struct ieee80211_local *local = sdata->local;
1115
1116         atomic_inc(&sdata->bss->num_sta_ps);
1117         set_sta_flags(sta, WLAN_STA_PS_STA);
1118         drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
1119 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1120         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
1121                sdata->name, sta->sta.addr, sta->sta.aid);
1122 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1123 }
1124
1125 static void ap_sta_ps_end(struct sta_info *sta)
1126 {
1127         struct ieee80211_sub_if_data *sdata = sta->sdata;
1128
1129         atomic_dec(&sdata->bss->num_sta_ps);
1130
1131 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1132         printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
1133                sdata->name, sta->sta.addr, sta->sta.aid);
1134 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1135
1136         if (test_sta_flags(sta, WLAN_STA_PS_DRIVER)) {
1137 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1138                 printk(KERN_DEBUG "%s: STA %pM aid %d driver-ps-blocked\n",
1139                        sdata->name, sta->sta.addr, sta->sta.aid);
1140 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1141                 return;
1142         }
1143
1144         ieee80211_sta_ps_deliver_wakeup(sta);
1145 }
1146
1147 static ieee80211_rx_result debug_noinline
1148 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1149 {
1150         struct sta_info *sta = rx->sta;
1151         struct sk_buff *skb = rx->skb;
1152         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1153         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1154
1155         if (!sta)
1156                 return RX_CONTINUE;
1157
1158         /*
1159          * Update last_rx only for IBSS packets which are for the current
1160          * BSSID to avoid keeping the current IBSS network alive in cases
1161          * where other STAs start using different BSSID.
1162          */
1163         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1164                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1165                                                 NL80211_IFTYPE_ADHOC);
1166                 if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
1167                         sta->last_rx = jiffies;
1168         } else if (!is_multicast_ether_addr(hdr->addr1)) {
1169                 /*
1170                  * Mesh beacons will update last_rx when if they are found to
1171                  * match the current local configuration when processed.
1172                  */
1173                 sta->last_rx = jiffies;
1174         }
1175
1176         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1177                 return RX_CONTINUE;
1178
1179         if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1180                 ieee80211_sta_rx_notify(rx->sdata, hdr);
1181
1182         sta->rx_fragments++;
1183         sta->rx_bytes += rx->skb->len;
1184         sta->last_signal = status->signal;
1185         ewma_add(&sta->avg_signal, -status->signal);
1186
1187         /*
1188          * Change STA power saving mode only at the end of a frame
1189          * exchange sequence.
1190          */
1191         if (!ieee80211_has_morefrags(hdr->frame_control) &&
1192             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1193              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
1194                 if (test_sta_flags(sta, WLAN_STA_PS_STA)) {
1195                         /*
1196                          * Ignore doze->wake transitions that are
1197                          * indicated by non-data frames, the standard
1198                          * is unclear here, but for example going to
1199                          * PS mode and then scanning would cause a
1200                          * doze->wake transition for the probe request,
1201                          * and that is clearly undesirable.
1202                          */
1203                         if (ieee80211_is_data(hdr->frame_control) &&
1204                             !ieee80211_has_pm(hdr->frame_control))
1205                                 ap_sta_ps_end(sta);
1206                 } else {
1207                         if (ieee80211_has_pm(hdr->frame_control))
1208                                 ap_sta_ps_start(sta);
1209                 }
1210         }
1211
1212         /*
1213          * Drop (qos-)data::nullfunc frames silently, since they
1214          * are used only to control station power saving mode.
1215          */
1216         if (ieee80211_is_nullfunc(hdr->frame_control) ||
1217             ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1218                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
1219
1220                 /*
1221                  * If we receive a 4-addr nullfunc frame from a STA
1222                  * that was not moved to a 4-addr STA vlan yet, drop
1223                  * the frame to the monitor interface, to make sure
1224                  * that hostapd sees it
1225                  */
1226                 if (ieee80211_has_a4(hdr->frame_control) &&
1227                     (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1228                      (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1229                       !rx->sdata->u.vlan.sta)))
1230                         return RX_DROP_MONITOR;
1231                 /*
1232                  * Update counter and free packet here to avoid
1233                  * counting this as a dropped packed.
1234                  */
1235                 sta->rx_packets++;
1236                 dev_kfree_skb(rx->skb);
1237                 return RX_QUEUED;
1238         }
1239
1240         return RX_CONTINUE;
1241 } /* ieee80211_rx_h_sta_process */
1242
1243 static inline struct ieee80211_fragment_entry *
1244 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
1245                          unsigned int frag, unsigned int seq, int rx_queue,
1246                          struct sk_buff **skb)
1247 {
1248         struct ieee80211_fragment_entry *entry;
1249         int idx;
1250
1251         idx = sdata->fragment_next;
1252         entry = &sdata->fragments[sdata->fragment_next++];
1253         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
1254                 sdata->fragment_next = 0;
1255
1256         if (!skb_queue_empty(&entry->skb_list)) {
1257 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1258                 struct ieee80211_hdr *hdr =
1259                         (struct ieee80211_hdr *) entry->skb_list.next->data;
1260                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
1261                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
1262                        "addr1=%pM addr2=%pM\n",
1263                        sdata->name, idx,
1264                        jiffies - entry->first_frag_time, entry->seq,
1265                        entry->last_frag, hdr->addr1, hdr->addr2);
1266 #endif
1267                 __skb_queue_purge(&entry->skb_list);
1268         }
1269
1270         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
1271         *skb = NULL;
1272         entry->first_frag_time = jiffies;
1273         entry->seq = seq;
1274         entry->rx_queue = rx_queue;
1275         entry->last_frag = frag;
1276         entry->ccmp = 0;
1277         entry->extra_len = 0;
1278
1279         return entry;
1280 }
1281
1282 static inline struct ieee80211_fragment_entry *
1283 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
1284                           unsigned int frag, unsigned int seq,
1285                           int rx_queue, struct ieee80211_hdr *hdr)
1286 {
1287         struct ieee80211_fragment_entry *entry;
1288         int i, idx;
1289
1290         idx = sdata->fragment_next;
1291         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
1292                 struct ieee80211_hdr *f_hdr;
1293
1294                 idx--;
1295                 if (idx < 0)
1296                         idx = IEEE80211_FRAGMENT_MAX - 1;
1297
1298                 entry = &sdata->fragments[idx];
1299                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
1300                     entry->rx_queue != rx_queue ||
1301                     entry->last_frag + 1 != frag)
1302                         continue;
1303
1304                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
1305
1306                 /*
1307                  * Check ftype and addresses are equal, else check next fragment
1308                  */
1309                 if (((hdr->frame_control ^ f_hdr->frame_control) &
1310                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
1311                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
1312                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
1313                         continue;
1314
1315                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
1316                         __skb_queue_purge(&entry->skb_list);
1317                         continue;
1318                 }
1319                 return entry;
1320         }
1321
1322         return NULL;
1323 }
1324
1325 static ieee80211_rx_result debug_noinline
1326 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
1327 {
1328         struct ieee80211_hdr *hdr;
1329         u16 sc;
1330         __le16 fc;
1331         unsigned int frag, seq;
1332         struct ieee80211_fragment_entry *entry;
1333         struct sk_buff *skb;
1334         struct ieee80211_rx_status *status;
1335
1336         hdr = (struct ieee80211_hdr *)rx->skb->data;
1337         fc = hdr->frame_control;
1338         sc = le16_to_cpu(hdr->seq_ctrl);
1339         frag = sc & IEEE80211_SCTL_FRAG;
1340
1341         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1342                    (rx->skb)->len < 24 ||
1343                    is_multicast_ether_addr(hdr->addr1))) {
1344                 /* not fragmented */
1345                 goto out;
1346         }
1347         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1348
1349         if (skb_linearize(rx->skb))
1350                 return RX_DROP_UNUSABLE;
1351
1352         /*
1353          *  skb_linearize() might change the skb->data and
1354          *  previously cached variables (in this case, hdr) need to
1355          *  be refreshed with the new data.
1356          */
1357         hdr = (struct ieee80211_hdr *)rx->skb->data;
1358         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1359
1360         if (frag == 0) {
1361                 /* This is the first fragment of a new frame. */
1362                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1363                                                  rx->queue, &(rx->skb));
1364                 if (rx->key && rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP &&
1365                     ieee80211_has_protected(fc)) {
1366                         int queue = ieee80211_is_mgmt(fc) ?
1367                                 NUM_RX_DATA_QUEUES : rx->queue;
1368                         /* Store CCMP PN so that we can verify that the next
1369                          * fragment has a sequential PN value. */
1370                         entry->ccmp = 1;
1371                         memcpy(entry->last_pn,
1372                                rx->key->u.ccmp.rx_pn[queue],
1373                                CCMP_PN_LEN);
1374                 }
1375                 return RX_QUEUED;
1376         }
1377
1378         /* This is a fragment for a frame that should already be pending in
1379          * fragment cache. Add this fragment to the end of the pending entry.
1380          */
1381         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1382         if (!entry) {
1383                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1384                 return RX_DROP_MONITOR;
1385         }
1386
1387         /* Verify that MPDUs within one MSDU have sequential PN values.
1388          * (IEEE 802.11i, 8.3.3.4.5) */
1389         if (entry->ccmp) {
1390                 int i;
1391                 u8 pn[CCMP_PN_LEN], *rpn;
1392                 int queue;
1393                 if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP)
1394                         return RX_DROP_UNUSABLE;
1395                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1396                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1397                         pn[i]++;
1398                         if (pn[i])
1399                                 break;
1400                 }
1401                 queue = ieee80211_is_mgmt(fc) ?
1402                         NUM_RX_DATA_QUEUES : rx->queue;
1403                 rpn = rx->key->u.ccmp.rx_pn[queue];
1404                 if (memcmp(pn, rpn, CCMP_PN_LEN))
1405                         return RX_DROP_UNUSABLE;
1406                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1407         }
1408
1409         skb_pull(rx->skb, ieee80211_hdrlen(fc));
1410         __skb_queue_tail(&entry->skb_list, rx->skb);
1411         entry->last_frag = frag;
1412         entry->extra_len += rx->skb->len;
1413         if (ieee80211_has_morefrags(fc)) {
1414                 rx->skb = NULL;
1415                 return RX_QUEUED;
1416         }
1417
1418         rx->skb = __skb_dequeue(&entry->skb_list);
1419         if (skb_tailroom(rx->skb) < entry->extra_len) {
1420                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1421                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1422                                               GFP_ATOMIC))) {
1423                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1424                         __skb_queue_purge(&entry->skb_list);
1425                         return RX_DROP_UNUSABLE;
1426                 }
1427         }
1428         while ((skb = __skb_dequeue(&entry->skb_list))) {
1429                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1430                 dev_kfree_skb(skb);
1431         }
1432
1433         /* Complete frame has been reassembled - process it now */
1434         status = IEEE80211_SKB_RXCB(rx->skb);
1435         status->rx_flags |= IEEE80211_RX_FRAGMENTED;
1436
1437  out:
1438         if (rx->sta)
1439                 rx->sta->rx_packets++;
1440         if (is_multicast_ether_addr(hdr->addr1))
1441                 rx->local->dot11MulticastReceivedFrameCount++;
1442         else
1443                 ieee80211_led_rx(rx->local);
1444         return RX_CONTINUE;
1445 }
1446
1447 static ieee80211_rx_result debug_noinline
1448 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1449 {
1450         struct ieee80211_sub_if_data *sdata = rx->sdata;
1451         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1452         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1453
1454         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1455                    !(status->rx_flags & IEEE80211_RX_RA_MATCH)))
1456                 return RX_CONTINUE;
1457
1458         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1459             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1460                 return RX_DROP_UNUSABLE;
1461
1462         if (!test_sta_flags(rx->sta, WLAN_STA_PS_DRIVER))
1463                 ieee80211_sta_ps_deliver_poll_response(rx->sta);
1464         else
1465                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1466
1467         /* Free PS Poll skb here instead of returning RX_DROP that would
1468          * count as an dropped frame. */
1469         dev_kfree_skb(rx->skb);
1470
1471         return RX_QUEUED;
1472 }
1473
1474 static ieee80211_rx_result debug_noinline
1475 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1476 {
1477         u8 *data = rx->skb->data;
1478         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1479
1480         if (!ieee80211_is_data_qos(hdr->frame_control))
1481                 return RX_CONTINUE;
1482
1483         /* remove the qos control field, update frame type and meta-data */
1484         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1485                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1486         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1487         /* change frame type to non QOS */
1488         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1489
1490         return RX_CONTINUE;
1491 }
1492
1493 static int
1494 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1495 {
1496         if (unlikely(!rx->sta ||
1497             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1498                 return -EACCES;
1499
1500         return 0;
1501 }
1502
1503 static int
1504 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1505 {
1506         struct sk_buff *skb = rx->skb;
1507         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1508
1509         /*
1510          * Pass through unencrypted frames if the hardware has
1511          * decrypted them already.
1512          */
1513         if (status->flag & RX_FLAG_DECRYPTED)
1514                 return 0;
1515
1516         /* Drop unencrypted frames if key is set. */
1517         if (unlikely(!ieee80211_has_protected(fc) &&
1518                      !ieee80211_is_nullfunc(fc) &&
1519                      ieee80211_is_data(fc) &&
1520                      (rx->key || rx->sdata->drop_unencrypted)))
1521                 return -EACCES;
1522
1523         return 0;
1524 }
1525
1526 static int
1527 ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
1528 {
1529         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1530         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1531         __le16 fc = hdr->frame_control;
1532
1533         /*
1534          * Pass through unencrypted frames if the hardware has
1535          * decrypted them already.
1536          */
1537         if (status->flag & RX_FLAG_DECRYPTED)
1538                 return 0;
1539
1540         if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1541                 if (unlikely(!ieee80211_has_protected(fc) &&
1542                              ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1543                              rx->key)) {
1544                         if (ieee80211_is_deauth(fc))
1545                                 cfg80211_send_unprot_deauth(rx->sdata->dev,
1546                                                             rx->skb->data,
1547                                                             rx->skb->len);
1548                         else if (ieee80211_is_disassoc(fc))
1549                                 cfg80211_send_unprot_disassoc(rx->sdata->dev,
1550                                                               rx->skb->data,
1551                                                               rx->skb->len);
1552                         return -EACCES;
1553                 }
1554                 /* BIP does not use Protected field, so need to check MMIE */
1555                 if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1556                              ieee80211_get_mmie_keyidx(rx->skb) < 0)) {
1557                         if (ieee80211_is_deauth(fc))
1558                                 cfg80211_send_unprot_deauth(rx->sdata->dev,
1559                                                             rx->skb->data,
1560                                                             rx->skb->len);
1561                         else if (ieee80211_is_disassoc(fc))
1562                                 cfg80211_send_unprot_disassoc(rx->sdata->dev,
1563                                                               rx->skb->data,
1564                                                               rx->skb->len);
1565                         return -EACCES;
1566                 }
1567                 /*
1568                  * When using MFP, Action frames are not allowed prior to
1569                  * having configured keys.
1570                  */
1571                 if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1572                              ieee80211_is_robust_mgmt_frame(
1573                                      (struct ieee80211_hdr *) rx->skb->data)))
1574                         return -EACCES;
1575         }
1576
1577         return 0;
1578 }
1579
1580 static int
1581 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1582 {
1583         struct ieee80211_sub_if_data *sdata = rx->sdata;
1584         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1585
1586         if (ieee80211_has_a4(hdr->frame_control) &&
1587             sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1588                 return -1;
1589
1590         if (is_multicast_ether_addr(hdr->addr1) &&
1591             ((sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta) ||
1592              (sdata->vif.type == NL80211_IFTYPE_STATION && sdata->u.mgd.use_4addr)))
1593                 return -1;
1594
1595         return ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
1596 }
1597
1598 /*
1599  * requires that rx->skb is a frame with ethernet header
1600  */
1601 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1602 {
1603         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1604                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1605         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1606
1607         /*
1608          * Allow EAPOL frames to us/the PAE group address regardless
1609          * of whether the frame was encrypted or not.
1610          */
1611         if (ehdr->h_proto == rx->sdata->control_port_protocol &&
1612             (compare_ether_addr(ehdr->h_dest, rx->sdata->vif.addr) == 0 ||
1613              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1614                 return true;
1615
1616         if (ieee80211_802_1x_port_control(rx) ||
1617             ieee80211_drop_unencrypted(rx, fc))
1618                 return false;
1619
1620         return true;
1621 }
1622
1623 /*
1624  * requires that rx->skb is a frame with ethernet header
1625  */
1626 static void
1627 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1628 {
1629         struct ieee80211_sub_if_data *sdata = rx->sdata;
1630         struct net_device *dev = sdata->dev;
1631         struct sk_buff *skb, *xmit_skb;
1632         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1633         struct sta_info *dsta;
1634         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1635
1636         skb = rx->skb;
1637         xmit_skb = NULL;
1638
1639         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1640              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1641             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1642             (status->rx_flags & IEEE80211_RX_RA_MATCH) &&
1643             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1644                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1645                         /*
1646                          * send multicast frames both to higher layers in
1647                          * local net stack and back to the wireless medium
1648                          */
1649                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1650                         if (!xmit_skb && net_ratelimit())
1651                                 printk(KERN_DEBUG "%s: failed to clone "
1652                                        "multicast frame\n", dev->name);
1653                 } else {
1654                         dsta = sta_info_get(sdata, skb->data);
1655                         if (dsta) {
1656                                 /*
1657                                  * The destination station is associated to
1658                                  * this AP (in this VLAN), so send the frame
1659                                  * directly to it and do not pass it to local
1660                                  * net stack.
1661                                  */
1662                                 xmit_skb = skb;
1663                                 skb = NULL;
1664                         }
1665                 }
1666         }
1667
1668         if (skb) {
1669                 int align __maybe_unused;
1670
1671 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1672                 /*
1673                  * 'align' will only take the values 0 or 2 here
1674                  * since all frames are required to be aligned
1675                  * to 2-byte boundaries when being passed to
1676                  * mac80211. That also explains the __skb_push()
1677                  * below.
1678                  */
1679                 align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1680                 if (align) {
1681                         if (WARN_ON(skb_headroom(skb) < 3)) {
1682                                 dev_kfree_skb(skb);
1683                                 skb = NULL;
1684                         } else {
1685                                 u8 *data = skb->data;
1686                                 size_t len = skb_headlen(skb);
1687                                 skb->data -= align;
1688                                 memmove(skb->data, data, len);
1689                                 skb_set_tail_pointer(skb, len);
1690                         }
1691                 }
1692 #endif
1693
1694                 if (skb) {
1695                         /* deliver to local stack */
1696                         skb->protocol = eth_type_trans(skb, dev);
1697                         memset(skb->cb, 0, sizeof(skb->cb));
1698                         netif_receive_skb(skb);
1699                 }
1700         }
1701
1702         if (xmit_skb) {
1703                 /* send to wireless media */
1704                 xmit_skb->protocol = htons(ETH_P_802_3);
1705                 skb_reset_network_header(xmit_skb);
1706                 skb_reset_mac_header(xmit_skb);
1707                 dev_queue_xmit(xmit_skb);
1708         }
1709 }
1710
1711 static ieee80211_rx_result debug_noinline
1712 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1713 {
1714         struct net_device *dev = rx->sdata->dev;
1715         struct sk_buff *skb = rx->skb;
1716         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1717         __le16 fc = hdr->frame_control;
1718         struct sk_buff_head frame_list;
1719         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1720
1721         if (unlikely(!ieee80211_is_data(fc)))
1722                 return RX_CONTINUE;
1723
1724         if (unlikely(!ieee80211_is_data_present(fc)))
1725                 return RX_DROP_MONITOR;
1726
1727         if (!(status->rx_flags & IEEE80211_RX_AMSDU))
1728                 return RX_CONTINUE;
1729
1730         if (ieee80211_has_a4(hdr->frame_control) &&
1731             rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1732             !rx->sdata->u.vlan.sta)
1733                 return RX_DROP_UNUSABLE;
1734
1735         if (is_multicast_ether_addr(hdr->addr1) &&
1736             ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1737               rx->sdata->u.vlan.sta) ||
1738              (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1739               rx->sdata->u.mgd.use_4addr)))
1740                 return RX_DROP_UNUSABLE;
1741
1742         skb->dev = dev;
1743         __skb_queue_head_init(&frame_list);
1744
1745         if (skb_linearize(skb))
1746                 return RX_DROP_UNUSABLE;
1747
1748         ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
1749                                  rx->sdata->vif.type,
1750                                  rx->local->hw.extra_tx_headroom);
1751
1752         while (!skb_queue_empty(&frame_list)) {
1753                 rx->skb = __skb_dequeue(&frame_list);
1754
1755                 if (!ieee80211_frame_allowed(rx, fc)) {
1756                         dev_kfree_skb(rx->skb);
1757                         continue;
1758                 }
1759                 dev->stats.rx_packets++;
1760                 dev->stats.rx_bytes += rx->skb->len;
1761
1762                 ieee80211_deliver_skb(rx);
1763         }
1764
1765         return RX_QUEUED;
1766 }
1767
1768 #ifdef CONFIG_MAC80211_MESH
1769 static ieee80211_rx_result
1770 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1771 {
1772         struct ieee80211_hdr *hdr;
1773         struct ieee80211s_hdr *mesh_hdr;
1774         unsigned int hdrlen;
1775         struct sk_buff *skb = rx->skb, *fwd_skb;
1776         struct ieee80211_local *local = rx->local;
1777         struct ieee80211_sub_if_data *sdata = rx->sdata;
1778         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1779
1780         hdr = (struct ieee80211_hdr *) skb->data;
1781         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1782         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1783
1784         if (!ieee80211_is_data(hdr->frame_control))
1785                 return RX_CONTINUE;
1786
1787         if (!mesh_hdr->ttl)
1788                 /* illegal frame */
1789                 return RX_DROP_MONITOR;
1790
1791         if (mesh_hdr->flags & MESH_FLAGS_AE) {
1792                 struct mesh_path *mppath;
1793                 char *proxied_addr;
1794                 char *mpp_addr;
1795
1796                 if (is_multicast_ether_addr(hdr->addr1)) {
1797                         mpp_addr = hdr->addr3;
1798                         proxied_addr = mesh_hdr->eaddr1;
1799                 } else {
1800                         mpp_addr = hdr->addr4;
1801                         proxied_addr = mesh_hdr->eaddr2;
1802                 }
1803
1804                 rcu_read_lock();
1805                 mppath = mpp_path_lookup(proxied_addr, sdata);
1806                 if (!mppath) {
1807                         mpp_path_add(proxied_addr, mpp_addr, sdata);
1808                 } else {
1809                         spin_lock_bh(&mppath->state_lock);
1810                         if (compare_ether_addr(mppath->mpp, mpp_addr) != 0)
1811                                 memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
1812                         spin_unlock_bh(&mppath->state_lock);
1813                 }
1814                 rcu_read_unlock();
1815         }
1816
1817         /* Frame has reached destination.  Don't forward */
1818         if (!is_multicast_ether_addr(hdr->addr1) &&
1819             compare_ether_addr(sdata->vif.addr, hdr->addr3) == 0)
1820                 return RX_CONTINUE;
1821
1822         mesh_hdr->ttl--;
1823
1824         if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
1825                 if (!mesh_hdr->ttl)
1826                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1827                                                      dropped_frames_ttl);
1828                 else {
1829                         struct ieee80211_hdr *fwd_hdr;
1830                         struct ieee80211_tx_info *info;
1831
1832                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1833
1834                         if (!fwd_skb && net_ratelimit()) {
1835                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1836                                                    sdata->name);
1837                                 goto out;
1838                         }
1839
1840                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1841                         memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
1842                         info = IEEE80211_SKB_CB(fwd_skb);
1843                         memset(info, 0, sizeof(*info));
1844                         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1845                         info->control.vif = &rx->sdata->vif;
1846                         skb_set_queue_mapping(skb,
1847                                 ieee80211_select_queue(rx->sdata, fwd_skb));
1848                         ieee80211_set_qos_hdr(local, skb);
1849                         if (is_multicast_ether_addr(fwd_hdr->addr1))
1850                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1851                                                                 fwded_mcast);
1852                         else {
1853                                 int err;
1854                                 /*
1855                                  * Save TA to addr1 to send TA a path error if a
1856                                  * suitable next hop is not found
1857                                  */
1858                                 memcpy(fwd_hdr->addr1, fwd_hdr->addr2,
1859                                                 ETH_ALEN);
1860                                 err = mesh_nexthop_lookup(fwd_skb, sdata);
1861                                 /* Failed to immediately resolve next hop:
1862                                  * fwded frame was dropped or will be added
1863                                  * later to the pending skb queue.  */
1864                                 if (err)
1865                                         return RX_DROP_MONITOR;
1866
1867                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1868                                                                 fwded_unicast);
1869                         }
1870                         IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1871                                                      fwded_frames);
1872                         ieee80211_add_pending_skb(local, fwd_skb);
1873                 }
1874         }
1875
1876  out:
1877         if (is_multicast_ether_addr(hdr->addr1) ||
1878             sdata->dev->flags & IFF_PROMISC)
1879                 return RX_CONTINUE;
1880         else
1881                 return RX_DROP_MONITOR;
1882 }
1883 #endif
1884
1885 static ieee80211_rx_result debug_noinline
1886 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1887 {
1888         struct ieee80211_sub_if_data *sdata = rx->sdata;
1889         struct ieee80211_local *local = rx->local;
1890         struct net_device *dev = sdata->dev;
1891         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1892         __le16 fc = hdr->frame_control;
1893         int err;
1894
1895         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1896                 return RX_CONTINUE;
1897
1898         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1899                 return RX_DROP_MONITOR;
1900
1901         /*
1902          * Allow the cooked monitor interface of an AP to see 4-addr frames so
1903          * that a 4-addr station can be detected and moved into a separate VLAN
1904          */
1905         if (ieee80211_has_a4(hdr->frame_control) &&
1906             sdata->vif.type == NL80211_IFTYPE_AP)
1907                 return RX_DROP_MONITOR;
1908
1909         err = __ieee80211_data_to_8023(rx);
1910         if (unlikely(err))
1911                 return RX_DROP_UNUSABLE;
1912
1913         if (!ieee80211_frame_allowed(rx, fc))
1914                 return RX_DROP_MONITOR;
1915
1916         rx->skb->dev = dev;
1917
1918         dev->stats.rx_packets++;
1919         dev->stats.rx_bytes += rx->skb->len;
1920
1921         if (local->ps_sdata && local->hw.conf.dynamic_ps_timeout > 0 &&
1922             !is_multicast_ether_addr(((struct ethhdr *)rx->skb->data)->h_dest)) {
1923                         mod_timer(&local->dynamic_ps_timer, jiffies +
1924                          msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
1925         }
1926
1927         ieee80211_deliver_skb(rx);
1928
1929         return RX_QUEUED;
1930 }
1931
1932 static ieee80211_rx_result debug_noinline
1933 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames)
1934 {
1935         struct ieee80211_local *local = rx->local;
1936         struct ieee80211_hw *hw = &local->hw;
1937         struct sk_buff *skb = rx->skb;
1938         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1939         struct tid_ampdu_rx *tid_agg_rx;
1940         u16 start_seq_num;
1941         u16 tid;
1942
1943         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1944                 return RX_CONTINUE;
1945
1946         if (ieee80211_is_back_req(bar->frame_control)) {
1947                 struct {
1948                         __le16 control, start_seq_num;
1949                 } __packed bar_data;
1950
1951                 if (!rx->sta)
1952                         return RX_DROP_MONITOR;
1953
1954                 if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
1955                                   &bar_data, sizeof(bar_data)))
1956                         return RX_DROP_MONITOR;
1957
1958                 tid = le16_to_cpu(bar_data.control) >> 12;
1959
1960                 tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
1961                 if (!tid_agg_rx)
1962                         return RX_DROP_MONITOR;
1963
1964                 start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
1965
1966                 /* reset session timer */
1967                 if (tid_agg_rx->timeout)
1968                         mod_timer(&tid_agg_rx->session_timer,
1969                                   TU_TO_EXP_TIME(tid_agg_rx->timeout));
1970
1971                 spin_lock(&tid_agg_rx->reorder_lock);
1972                 /* release stored frames up to start of BAR */
1973                 ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num,
1974                                                  frames);
1975                 spin_unlock(&tid_agg_rx->reorder_lock);
1976
1977                 kfree_skb(skb);
1978                 return RX_QUEUED;
1979         }
1980
1981         /*
1982          * After this point, we only want management frames,
1983          * so we can drop all remaining control frames to
1984          * cooked monitor interfaces.
1985          */
1986         return RX_DROP_MONITOR;
1987 }
1988
1989 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
1990                                            struct ieee80211_mgmt *mgmt,
1991                                            size_t len)
1992 {
1993         struct ieee80211_local *local = sdata->local;
1994         struct sk_buff *skb;
1995         struct ieee80211_mgmt *resp;
1996
1997         if (compare_ether_addr(mgmt->da, sdata->vif.addr) != 0) {
1998                 /* Not to own unicast address */
1999                 return;
2000         }
2001
2002         if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
2003             compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
2004                 /* Not from the current AP or not associated yet. */
2005                 return;
2006         }
2007
2008         if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
2009                 /* Too short SA Query request frame */
2010                 return;
2011         }
2012
2013         skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
2014         if (skb == NULL)
2015                 return;
2016
2017         skb_reserve(skb, local->hw.extra_tx_headroom);
2018         resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
2019         memset(resp, 0, 24);
2020         memcpy(resp->da, mgmt->sa, ETH_ALEN);
2021         memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
2022         memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
2023         resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2024                                           IEEE80211_STYPE_ACTION);
2025         skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
2026         resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
2027         resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
2028         memcpy(resp->u.action.u.sa_query.trans_id,
2029                mgmt->u.action.u.sa_query.trans_id,
2030                WLAN_SA_QUERY_TR_ID_LEN);
2031
2032         ieee80211_tx_skb(sdata, skb);
2033 }
2034
2035 static ieee80211_rx_result debug_noinline
2036 ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
2037 {
2038         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2039         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2040
2041         /*
2042          * From here on, look only at management frames.
2043          * Data and control frames are already handled,
2044          * and unknown (reserved) frames are useless.
2045          */
2046         if (rx->skb->len < 24)
2047                 return RX_DROP_MONITOR;
2048
2049         if (!ieee80211_is_mgmt(mgmt->frame_control))
2050                 return RX_DROP_MONITOR;
2051
2052         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2053                 return RX_DROP_MONITOR;
2054
2055         if (ieee80211_drop_unencrypted_mgmt(rx))
2056                 return RX_DROP_UNUSABLE;
2057
2058         return RX_CONTINUE;
2059 }
2060
2061 static ieee80211_rx_result debug_noinline
2062 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
2063 {
2064         struct ieee80211_local *local = rx->local;
2065         struct ieee80211_sub_if_data *sdata = rx->sdata;
2066         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2067         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2068         int len = rx->skb->len;
2069
2070         if (!ieee80211_is_action(mgmt->frame_control))
2071                 return RX_CONTINUE;
2072
2073         /* drop too small frames */
2074         if (len < IEEE80211_MIN_ACTION_SIZE)
2075                 return RX_DROP_UNUSABLE;
2076
2077         if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC)
2078                 return RX_DROP_UNUSABLE;
2079
2080         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2081                 return RX_DROP_UNUSABLE;
2082
2083         switch (mgmt->u.action.category) {
2084         case WLAN_CATEGORY_BACK:
2085                 /*
2086                  * The aggregation code is not prepared to handle
2087                  * anything but STA/AP due to the BSSID handling;
2088                  * IBSS could work in the code but isn't supported
2089                  * by drivers or the standard.
2090                  */
2091                 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2092                     sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2093                     sdata->vif.type != NL80211_IFTYPE_AP)
2094                         break;
2095
2096                 /* verify action_code is present */
2097                 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2098                         break;
2099
2100                 switch (mgmt->u.action.u.addba_req.action_code) {
2101                 case WLAN_ACTION_ADDBA_REQ:
2102                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2103                                    sizeof(mgmt->u.action.u.addba_req)))
2104                                 goto invalid;
2105                         break;
2106                 case WLAN_ACTION_ADDBA_RESP:
2107                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2108                                    sizeof(mgmt->u.action.u.addba_resp)))
2109                                 goto invalid;
2110                         break;
2111                 case WLAN_ACTION_DELBA:
2112                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2113                                    sizeof(mgmt->u.action.u.delba)))
2114                                 goto invalid;
2115                         break;
2116                 default:
2117                         goto invalid;
2118                 }
2119
2120                 goto queue;
2121         case WLAN_CATEGORY_SPECTRUM_MGMT:
2122                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
2123                         break;
2124
2125                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
2126                         break;
2127
2128                 /* verify action_code is present */
2129                 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2130                         break;
2131
2132                 switch (mgmt->u.action.u.measurement.action_code) {
2133                 case WLAN_ACTION_SPCT_MSR_REQ:
2134                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2135                                    sizeof(mgmt->u.action.u.measurement)))
2136                                 break;
2137                         ieee80211_process_measurement_req(sdata, mgmt, len);
2138                         goto handled;
2139                 case WLAN_ACTION_SPCT_CHL_SWITCH:
2140                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2141                                    sizeof(mgmt->u.action.u.chan_switch)))
2142                                 break;
2143
2144                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
2145                                 break;
2146
2147                         if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
2148                                 break;
2149
2150                         goto queue;
2151                 }
2152                 break;
2153         case WLAN_CATEGORY_SA_QUERY:
2154                 if (len < (IEEE80211_MIN_ACTION_SIZE +
2155                            sizeof(mgmt->u.action.u.sa_query)))
2156                         break;
2157
2158                 switch (mgmt->u.action.u.sa_query.action) {
2159                 case WLAN_ACTION_SA_QUERY_REQUEST:
2160                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
2161                                 break;
2162                         ieee80211_process_sa_query_req(sdata, mgmt, len);
2163                         goto handled;
2164                 }
2165                 break;
2166         case WLAN_CATEGORY_MESH_PLINK:
2167                 if (!ieee80211_vif_is_mesh(&sdata->vif))
2168                         break;
2169                 goto queue;
2170         case WLAN_CATEGORY_MESH_PATH_SEL:
2171                 if (!mesh_path_sel_is_hwmp(sdata))
2172                         break;
2173                 goto queue;
2174         }
2175
2176         return RX_CONTINUE;
2177
2178  invalid:
2179         status->rx_flags |= IEEE80211_RX_MALFORMED_ACTION_FRM;
2180         /* will return in the next handlers */
2181         return RX_CONTINUE;
2182
2183  handled:
2184         if (rx->sta)
2185                 rx->sta->rx_packets++;
2186         dev_kfree_skb(rx->skb);
2187         return RX_QUEUED;
2188
2189  queue:
2190         rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2191         skb_queue_tail(&sdata->skb_queue, rx->skb);
2192         ieee80211_queue_work(&local->hw, &sdata->work);
2193         if (rx->sta)
2194                 rx->sta->rx_packets++;
2195         return RX_QUEUED;
2196 }
2197
2198 static ieee80211_rx_result debug_noinline
2199 ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
2200 {
2201         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2202
2203         /* skip known-bad action frames and return them in the next handler */
2204         if (status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM)
2205                 return RX_CONTINUE;
2206
2207         /*
2208          * Getting here means the kernel doesn't know how to handle
2209          * it, but maybe userspace does ... include returned frames
2210          * so userspace can register for those to know whether ones
2211          * it transmitted were processed or returned.
2212          */
2213
2214         if (cfg80211_rx_mgmt(rx->sdata->dev, status->freq,
2215                              rx->skb->data, rx->skb->len,
2216                              GFP_ATOMIC)) {
2217                 if (rx->sta)
2218                         rx->sta->rx_packets++;
2219                 dev_kfree_skb(rx->skb);
2220                 return RX_QUEUED;
2221         }
2222
2223
2224         return RX_CONTINUE;
2225 }
2226
2227 static ieee80211_rx_result debug_noinline
2228 ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
2229 {
2230         struct ieee80211_local *local = rx->local;
2231         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2232         struct sk_buff *nskb;
2233         struct ieee80211_sub_if_data *sdata = rx->sdata;
2234         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2235
2236         if (!ieee80211_is_action(mgmt->frame_control))
2237                 return RX_CONTINUE;
2238
2239         /*
2240          * For AP mode, hostapd is responsible for handling any action
2241          * frames that we didn't handle, including returning unknown
2242          * ones. For all other modes we will return them to the sender,
2243          * setting the 0x80 bit in the action category, as required by
2244          * 802.11-2007 7.3.1.11.
2245          * Newer versions of hostapd shall also use the management frame
2246          * registration mechanisms, but older ones still use cooked
2247          * monitor interfaces so push all frames there.
2248          */
2249         if (!(status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM) &&
2250             (sdata->vif.type == NL80211_IFTYPE_AP ||
2251              sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
2252                 return RX_DROP_MONITOR;
2253
2254         /* do not return rejected action frames */
2255         if (mgmt->u.action.category & 0x80)
2256                 return RX_DROP_UNUSABLE;
2257
2258         nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
2259                                GFP_ATOMIC);
2260         if (nskb) {
2261                 struct ieee80211_mgmt *nmgmt = (void *)nskb->data;
2262
2263                 nmgmt->u.action.category |= 0x80;
2264                 memcpy(nmgmt->da, nmgmt->sa, ETH_ALEN);
2265                 memcpy(nmgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
2266
2267                 memset(nskb->cb, 0, sizeof(nskb->cb));
2268
2269                 ieee80211_tx_skb(rx->sdata, nskb);
2270         }
2271         dev_kfree_skb(rx->skb);
2272         return RX_QUEUED;
2273 }
2274
2275 static ieee80211_rx_result debug_noinline
2276 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
2277 {
2278         struct ieee80211_sub_if_data *sdata = rx->sdata;
2279         ieee80211_rx_result rxs;
2280         struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
2281         __le16 stype;
2282
2283         rxs = ieee80211_work_rx_mgmt(rx->sdata, rx->skb);
2284         if (rxs != RX_CONTINUE)
2285                 return rxs;
2286
2287         stype = mgmt->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE);
2288
2289         if (!ieee80211_vif_is_mesh(&sdata->vif) &&
2290             sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2291             sdata->vif.type != NL80211_IFTYPE_STATION)
2292                 return RX_DROP_MONITOR;
2293
2294         switch (stype) {
2295         case cpu_to_le16(IEEE80211_STYPE_BEACON):
2296         case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
2297                 /* process for all: mesh, mlme, ibss */
2298                 break;
2299         case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
2300         case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
2301                 if (is_multicast_ether_addr(mgmt->da) &&
2302                     !is_broadcast_ether_addr(mgmt->da))
2303                         return RX_DROP_MONITOR;
2304
2305                 /* process only for station */
2306                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
2307                         return RX_DROP_MONITOR;
2308                 break;
2309         case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
2310         case cpu_to_le16(IEEE80211_STYPE_AUTH):
2311                 /* process only for ibss */
2312                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
2313                         return RX_DROP_MONITOR;
2314                 break;
2315         default:
2316                 return RX_DROP_MONITOR;
2317         }
2318
2319         /* queue up frame and kick off work to process it */
2320         rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2321         skb_queue_tail(&sdata->skb_queue, rx->skb);
2322         ieee80211_queue_work(&rx->local->hw, &sdata->work);
2323         if (rx->sta)
2324                 rx->sta->rx_packets++;
2325
2326         return RX_QUEUED;
2327 }
2328
2329 static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
2330                                             struct ieee80211_rx_data *rx)
2331 {
2332         int keyidx;
2333         unsigned int hdrlen;
2334
2335         hdrlen = ieee80211_hdrlen(hdr->frame_control);
2336         if (rx->skb->len >= hdrlen + 4)
2337                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
2338         else
2339                 keyidx = -1;
2340
2341         if (!rx->sta) {
2342                 /*
2343                  * Some hardware seem to generate incorrect Michael MIC
2344                  * reports; ignore them to avoid triggering countermeasures.
2345                  */
2346                 return;
2347         }
2348
2349         if (!ieee80211_has_protected(hdr->frame_control))
2350                 return;
2351
2352         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
2353                 /*
2354                  * APs with pairwise keys should never receive Michael MIC
2355                  * errors for non-zero keyidx because these are reserved for
2356                  * group keys and only the AP is sending real multicast
2357                  * frames in the BSS.
2358                  */
2359                 return;
2360         }
2361
2362         if (!ieee80211_is_data(hdr->frame_control) &&
2363             !ieee80211_is_auth(hdr->frame_control))
2364                 return;
2365
2366         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
2367                                         GFP_ATOMIC);
2368 }
2369
2370 /* TODO: use IEEE80211_RX_FRAGMENTED */
2371 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
2372                                         struct ieee80211_rate *rate)
2373 {
2374         struct ieee80211_sub_if_data *sdata;
2375         struct ieee80211_local *local = rx->local;
2376         struct ieee80211_rtap_hdr {
2377                 struct ieee80211_radiotap_header hdr;
2378                 u8 flags;
2379                 u8 rate_or_pad;
2380                 __le16 chan_freq;
2381                 __le16 chan_flags;
2382         } __packed *rthdr;
2383         struct sk_buff *skb = rx->skb, *skb2;
2384         struct net_device *prev_dev = NULL;
2385         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2386
2387         /*
2388          * If cooked monitor has been processed already, then
2389          * don't do it again. If not, set the flag.
2390          */
2391         if (rx->flags & IEEE80211_RX_CMNTR)
2392                 goto out_free_skb;
2393         rx->flags |= IEEE80211_RX_CMNTR;
2394
2395         if (skb_headroom(skb) < sizeof(*rthdr) &&
2396             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
2397                 goto out_free_skb;
2398
2399         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
2400         memset(rthdr, 0, sizeof(*rthdr));
2401         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
2402         rthdr->hdr.it_present =
2403                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
2404                             (1 << IEEE80211_RADIOTAP_CHANNEL));
2405
2406         if (rate) {
2407                 rthdr->rate_or_pad = rate->bitrate / 5;
2408                 rthdr->hdr.it_present |=
2409                         cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
2410         }
2411         rthdr->chan_freq = cpu_to_le16(status->freq);
2412
2413         if (status->band == IEEE80211_BAND_5GHZ)
2414                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
2415                                                 IEEE80211_CHAN_5GHZ);
2416         else
2417                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
2418                                                 IEEE80211_CHAN_2GHZ);
2419
2420         skb_set_mac_header(skb, 0);
2421         skb->ip_summed = CHECKSUM_UNNECESSARY;
2422         skb->pkt_type = PACKET_OTHERHOST;
2423         skb->protocol = htons(ETH_P_802_2);
2424
2425         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2426                 if (!ieee80211_sdata_running(sdata))
2427                         continue;
2428
2429                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
2430                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
2431                         continue;
2432
2433                 if (prev_dev) {
2434                         skb2 = skb_clone(skb, GFP_ATOMIC);
2435                         if (skb2) {
2436                                 skb2->dev = prev_dev;
2437                                 netif_receive_skb(skb2);
2438                         }
2439                 }
2440
2441                 prev_dev = sdata->dev;
2442                 sdata->dev->stats.rx_packets++;
2443                 sdata->dev->stats.rx_bytes += skb->len;
2444         }
2445
2446         if (prev_dev) {
2447                 skb->dev = prev_dev;
2448                 netif_receive_skb(skb);
2449                 return;
2450         }
2451
2452  out_free_skb:
2453         dev_kfree_skb(skb);
2454 }
2455
2456 static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
2457                                          ieee80211_rx_result res)
2458 {
2459         switch (res) {
2460         case RX_DROP_MONITOR:
2461                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2462                 if (rx->sta)
2463                         rx->sta->rx_dropped++;
2464                 /* fall through */
2465         case RX_CONTINUE: {
2466                 struct ieee80211_rate *rate = NULL;
2467                 struct ieee80211_supported_band *sband;
2468                 struct ieee80211_rx_status *status;
2469
2470                 status = IEEE80211_SKB_RXCB((rx->skb));
2471
2472                 sband = rx->local->hw.wiphy->bands[status->band];
2473                 if (!(status->flag & RX_FLAG_HT))
2474                         rate = &sband->bitrates[status->rate_idx];
2475
2476                 ieee80211_rx_cooked_monitor(rx, rate);
2477                 break;
2478                 }
2479         case RX_DROP_UNUSABLE:
2480                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2481                 if (rx->sta)
2482                         rx->sta->rx_dropped++;
2483                 dev_kfree_skb(rx->skb);
2484                 break;
2485         case RX_QUEUED:
2486                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_queued);
2487                 break;
2488         }
2489 }
2490
2491 static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx,
2492                                   struct sk_buff_head *frames)
2493 {
2494         ieee80211_rx_result res = RX_DROP_MONITOR;
2495         struct sk_buff *skb;
2496
2497 #define CALL_RXH(rxh)                   \
2498         do {                            \
2499                 res = rxh(rx);          \
2500                 if (res != RX_CONTINUE) \
2501                         goto rxh_next;  \
2502         } while (0);
2503
2504         while ((skb = __skb_dequeue(frames))) {
2505                 /*
2506                  * all the other fields are valid across frames
2507                  * that belong to an aMPDU since they are on the
2508                  * same TID from the same station
2509                  */
2510                 rx->skb = skb;
2511                 rx->flags = 0;
2512
2513                 CALL_RXH(ieee80211_rx_h_decrypt)
2514                 CALL_RXH(ieee80211_rx_h_check_more_data)
2515                 CALL_RXH(ieee80211_rx_h_sta_process)
2516                 CALL_RXH(ieee80211_rx_h_defragment)
2517                 CALL_RXH(ieee80211_rx_h_ps_poll)
2518                 CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2519                 /* must be after MMIC verify so header is counted in MPDU mic */
2520                 CALL_RXH(ieee80211_rx_h_remove_qos_control)
2521                 CALL_RXH(ieee80211_rx_h_amsdu)
2522 #ifdef CONFIG_MAC80211_MESH
2523                 if (ieee80211_vif_is_mesh(&rx->sdata->vif))
2524                         CALL_RXH(ieee80211_rx_h_mesh_fwding);
2525 #endif
2526                 CALL_RXH(ieee80211_rx_h_data)
2527
2528                 /* special treatment -- needs the queue */
2529                 res = ieee80211_rx_h_ctrl(rx, frames);
2530                 if (res != RX_CONTINUE)
2531                         goto rxh_next;
2532
2533                 CALL_RXH(ieee80211_rx_h_mgmt_check)
2534                 CALL_RXH(ieee80211_rx_h_action)
2535                 CALL_RXH(ieee80211_rx_h_userspace_mgmt)
2536                 CALL_RXH(ieee80211_rx_h_action_return)
2537                 CALL_RXH(ieee80211_rx_h_mgmt)
2538
2539  rxh_next:
2540                 ieee80211_rx_handlers_result(rx, res);
2541
2542 #undef CALL_RXH
2543         }
2544 }
2545
2546 static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
2547 {
2548         struct sk_buff_head reorder_release;
2549         ieee80211_rx_result res = RX_DROP_MONITOR;
2550
2551         __skb_queue_head_init(&reorder_release);
2552
2553 #define CALL_RXH(rxh)                   \
2554         do {                            \
2555                 res = rxh(rx);          \
2556                 if (res != RX_CONTINUE) \
2557                         goto rxh_next;  \
2558         } while (0);
2559
2560         CALL_RXH(ieee80211_rx_h_passive_scan)
2561         CALL_RXH(ieee80211_rx_h_check)
2562
2563         ieee80211_rx_reorder_ampdu(rx, &reorder_release);
2564
2565         ieee80211_rx_handlers(rx, &reorder_release);
2566         return;
2567
2568  rxh_next:
2569         ieee80211_rx_handlers_result(rx, res);
2570
2571 #undef CALL_RXH
2572 }
2573
2574 /*
2575  * This function makes calls into the RX path, therefore
2576  * it has to be invoked under RCU read lock.
2577  */
2578 void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
2579 {
2580         struct sk_buff_head frames;
2581         struct ieee80211_rx_data rx = {
2582                 .sta = sta,
2583                 .sdata = sta->sdata,
2584                 .local = sta->local,
2585                 .queue = tid,
2586         };
2587         struct tid_ampdu_rx *tid_agg_rx;
2588
2589         tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
2590         if (!tid_agg_rx)
2591                 return;
2592
2593         __skb_queue_head_init(&frames);
2594
2595         spin_lock(&tid_agg_rx->reorder_lock);
2596         ieee80211_sta_reorder_release(&sta->local->hw, tid_agg_rx, &frames);
2597         spin_unlock(&tid_agg_rx->reorder_lock);
2598
2599         ieee80211_rx_handlers(&rx, &frames);
2600 }
2601
2602 /* main receive path */
2603
2604 static int prepare_for_handlers(struct ieee80211_rx_data *rx,
2605                                 struct ieee80211_hdr *hdr)
2606 {
2607         struct ieee80211_sub_if_data *sdata = rx->sdata;
2608         struct sk_buff *skb = rx->skb;
2609         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2610         u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
2611         int multicast = is_multicast_ether_addr(hdr->addr1);
2612
2613         switch (sdata->vif.type) {
2614         case NL80211_IFTYPE_STATION:
2615                 if (!bssid && !sdata->u.mgd.use_4addr)
2616                         return 0;
2617                 if (!multicast &&
2618                     compare_ether_addr(sdata->vif.addr, hdr->addr1) != 0) {
2619                         if (!(sdata->dev->flags & IFF_PROMISC))
2620                                 return 0;
2621                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2622                 }
2623                 break;
2624         case NL80211_IFTYPE_ADHOC:
2625                 if (!bssid)
2626                         return 0;
2627                 if (ieee80211_is_beacon(hdr->frame_control)) {
2628                         return 1;
2629                 }
2630                 else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2631                         if (!(status->rx_flags & IEEE80211_RX_IN_SCAN))
2632                                 return 0;
2633                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2634                 } else if (!multicast &&
2635                            compare_ether_addr(sdata->vif.addr,
2636                                               hdr->addr1) != 0) {
2637                         if (!(sdata->dev->flags & IFF_PROMISC))
2638                                 return 0;
2639                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2640                 } else if (!rx->sta) {
2641                         int rate_idx;
2642                         if (status->flag & RX_FLAG_HT)
2643                                 rate_idx = 0; /* TODO: HT rates */
2644                         else
2645                                 rate_idx = status->rate_idx;
2646                         rx->sta = ieee80211_ibss_add_sta(sdata, bssid,
2647                                         hdr->addr2, BIT(rate_idx), GFP_ATOMIC);
2648                 }
2649                 break;
2650         case NL80211_IFTYPE_MESH_POINT:
2651                 if (!multicast &&
2652                     compare_ether_addr(sdata->vif.addr,
2653                                        hdr->addr1) != 0) {
2654                         if (!(sdata->dev->flags & IFF_PROMISC))
2655                                 return 0;
2656
2657                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2658                 }
2659                 break;
2660         case NL80211_IFTYPE_AP_VLAN:
2661         case NL80211_IFTYPE_AP:
2662                 if (!bssid) {
2663                         if (compare_ether_addr(sdata->vif.addr,
2664                                                hdr->addr1))
2665                                 return 0;
2666                 } else if (!ieee80211_bssid_match(bssid,
2667                                         sdata->vif.addr)) {
2668                         if (!(status->rx_flags & IEEE80211_RX_IN_SCAN))
2669                                 return 0;
2670                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2671                 }
2672                 break;
2673         case NL80211_IFTYPE_WDS:
2674                 if (bssid || !ieee80211_is_data(hdr->frame_control))
2675                         return 0;
2676                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2677                         return 0;
2678                 break;
2679         default:
2680                 /* should never get here */
2681                 WARN_ON(1);
2682                 break;
2683         }
2684
2685         return 1;
2686 }
2687
2688 /*
2689  * This function returns whether or not the SKB
2690  * was destined for RX processing or not, which,
2691  * if consume is true, is equivalent to whether
2692  * or not the skb was consumed.
2693  */
2694 static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
2695                                             struct sk_buff *skb, bool consume)
2696 {
2697         struct ieee80211_local *local = rx->local;
2698         struct ieee80211_sub_if_data *sdata = rx->sdata;
2699         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2700         struct ieee80211_hdr *hdr = (void *)skb->data;
2701         int prepares;
2702
2703         rx->skb = skb;
2704         status->rx_flags |= IEEE80211_RX_RA_MATCH;
2705         prepares = prepare_for_handlers(rx, hdr);
2706
2707         if (!prepares)
2708                 return false;
2709
2710         if (status->flag & RX_FLAG_MMIC_ERROR) {
2711                 if (status->rx_flags & IEEE80211_RX_RA_MATCH)
2712                         ieee80211_rx_michael_mic_report(hdr, rx);
2713                 return false;
2714         }
2715
2716         if (!consume) {
2717                 skb = skb_copy(skb, GFP_ATOMIC);
2718                 if (!skb) {
2719                         if (net_ratelimit())
2720                                 wiphy_debug(local->hw.wiphy,
2721                                         "failed to copy multicast frame for %s\n",
2722                                         sdata->name);
2723                         return true;
2724                 }
2725
2726                 rx->skb = skb;
2727         }
2728
2729         ieee80211_invoke_rx_handlers(rx);
2730         return true;
2731 }
2732
2733 /*
2734  * This is the actual Rx frames handler. as it blongs to Rx path it must
2735  * be called with rcu_read_lock protection.
2736  */
2737 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2738                                          struct sk_buff *skb)
2739 {
2740         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2741         struct ieee80211_local *local = hw_to_local(hw);
2742         struct ieee80211_sub_if_data *sdata;
2743         struct ieee80211_hdr *hdr;
2744         __le16 fc;
2745         struct ieee80211_rx_data rx;
2746         struct ieee80211_sub_if_data *prev;
2747         struct sta_info *sta, *tmp, *prev_sta;
2748         int err = 0;
2749
2750         fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
2751         memset(&rx, 0, sizeof(rx));
2752         rx.skb = skb;
2753         rx.local = local;
2754
2755         if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
2756                 local->dot11ReceivedFragmentCount++;
2757
2758         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
2759                      test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
2760                 status->rx_flags |= IEEE80211_RX_IN_SCAN;
2761
2762         if (ieee80211_is_mgmt(fc))
2763                 err = skb_linearize(skb);
2764         else
2765                 err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
2766
2767         if (err) {
2768                 dev_kfree_skb(skb);
2769                 return;
2770         }
2771
2772         hdr = (struct ieee80211_hdr *)skb->data;
2773         ieee80211_parse_qos(&rx);
2774         ieee80211_verify_alignment(&rx);
2775
2776         if (ieee80211_is_data(fc)) {
2777                 prev_sta = NULL;
2778
2779                 for_each_sta_info(local, hdr->addr2, sta, tmp) {
2780                         if (!prev_sta) {
2781                                 prev_sta = sta;
2782                                 continue;
2783                         }
2784
2785                         rx.sta = prev_sta;
2786                         rx.sdata = prev_sta->sdata;
2787                         ieee80211_prepare_and_rx_handle(&rx, skb, false);
2788
2789                         prev_sta = sta;
2790                 }
2791
2792                 if (prev_sta) {
2793                         rx.sta = prev_sta;
2794                         rx.sdata = prev_sta->sdata;
2795
2796                         if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2797                                 return;
2798                         goto out;
2799                 }
2800         }
2801
2802         prev = NULL;
2803
2804         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2805                 if (!ieee80211_sdata_running(sdata))
2806                         continue;
2807
2808                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2809                     sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2810                         continue;
2811
2812                 /*
2813                  * frame is destined for this interface, but if it's
2814                  * not also for the previous one we handle that after
2815                  * the loop to avoid copying the SKB once too much
2816                  */
2817
2818                 if (!prev) {
2819                         prev = sdata;
2820                         continue;
2821                 }
2822
2823                 rx.sta = sta_info_get_bss(prev, hdr->addr2);
2824                 rx.sdata = prev;
2825                 ieee80211_prepare_and_rx_handle(&rx, skb, false);
2826
2827                 prev = sdata;
2828         }
2829
2830         if (prev) {
2831                 rx.sta = sta_info_get_bss(prev, hdr->addr2);
2832                 rx.sdata = prev;
2833
2834                 if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2835                         return;
2836         }
2837
2838  out:
2839         dev_kfree_skb(skb);
2840 }
2841
2842 /*
2843  * This is the receive path handler. It is called by a low level driver when an
2844  * 802.11 MPDU is received from the hardware.
2845  */
2846 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2847 {
2848         struct ieee80211_local *local = hw_to_local(hw);
2849         struct ieee80211_rate *rate = NULL;
2850         struct ieee80211_supported_band *sband;
2851         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2852
2853         WARN_ON_ONCE(softirq_count() == 0);
2854
2855         if (WARN_ON(status->band < 0 ||
2856                     status->band >= IEEE80211_NUM_BANDS))
2857                 goto drop;
2858
2859         sband = local->hw.wiphy->bands[status->band];
2860         if (WARN_ON(!sband))
2861                 goto drop;
2862
2863         /*
2864          * If we're suspending, it is possible although not too likely
2865          * that we'd be receiving frames after having already partially
2866          * quiesced the stack. We can't process such frames then since
2867          * that might, for example, cause stations to be added or other
2868          * driver callbacks be invoked.
2869          */
2870         if (unlikely(local->quiescing || local->suspended))
2871                 goto drop;
2872
2873         /*
2874          * The same happens when we're not even started,
2875          * but that's worth a warning.
2876          */
2877         if (WARN_ON(!local->started))
2878                 goto drop;
2879
2880         if (likely(!(status->flag & RX_FLAG_FAILED_PLCP_CRC))) {
2881                 /*
2882                  * Validate the rate, unless a PLCP error means that
2883                  * we probably can't have a valid rate here anyway.
2884                  */
2885
2886                 if (status->flag & RX_FLAG_HT) {
2887                         /*
2888                          * rate_idx is MCS index, which can be [0-76]
2889                          * as documented on:
2890                          *
2891                          * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
2892                          *
2893                          * Anything else would be some sort of driver or
2894                          * hardware error. The driver should catch hardware
2895                          * errors.
2896                          */
2897                         if (WARN((status->rate_idx < 0 ||
2898                                  status->rate_idx > 76),
2899                                  "Rate marked as an HT rate but passed "
2900                                  "status->rate_idx is not "
2901                                  "an MCS index [0-76]: %d (0x%02x)\n",
2902                                  status->rate_idx,
2903                                  status->rate_idx))
2904                                 goto drop;
2905                 } else {
2906                         if (WARN_ON(status->rate_idx < 0 ||
2907                                     status->rate_idx >= sband->n_bitrates))
2908                                 goto drop;
2909                         rate = &sband->bitrates[status->rate_idx];
2910                 }
2911         }
2912
2913         status->rx_flags = 0;
2914
2915         /*
2916          * key references and virtual interfaces are protected using RCU
2917          * and this requires that we are in a read-side RCU section during
2918          * receive processing
2919          */
2920         rcu_read_lock();
2921
2922         /*
2923          * Frames with failed FCS/PLCP checksum are not returned,
2924          * all other frames are returned without radiotap header
2925          * if it was previously present.
2926          * Also, frames with less than 16 bytes are dropped.
2927          */
2928         skb = ieee80211_rx_monitor(local, skb, rate);
2929         if (!skb) {
2930                 rcu_read_unlock();
2931                 return;
2932         }
2933
2934         ieee80211_tpt_led_trig_rx(local,
2935                         ((struct ieee80211_hdr *)skb->data)->frame_control,
2936                         skb->len);
2937         __ieee80211_rx_handle_packet(hw, skb);
2938
2939         rcu_read_unlock();
2940
2941         return;
2942  drop:
2943         kfree_skb(skb);
2944 }
2945 EXPORT_SYMBOL(ieee80211_rx);
2946
2947 /* This is a version of the rx handler that can be called from hard irq
2948  * context. Post the skb on the queue and schedule the tasklet */
2949 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
2950 {
2951         struct ieee80211_local *local = hw_to_local(hw);
2952
2953         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2954
2955         skb->pkt_type = IEEE80211_RX_MSG;
2956         skb_queue_tail(&local->skb_queue, skb);
2957         tasklet_schedule(&local->tasklet);
2958 }
2959 EXPORT_SYMBOL(ieee80211_rx_irqsafe);