net/mac80211/rx.c

   1 /*
   2  * Copyright 2002-2005, Instant802 Networks, Inc.
   3  * Copyright 2005-2006, Devicescape Software, Inc.
   4  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   5  * Copyright 2007-2010  Johannes Berg <johannes@sipsolutions.net>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/jiffies.h>
  13 #include <linux/slab.h>
  14 #include <linux/kernel.h>
  15 #include <linux/skbuff.h>
  16 #include <linux/netdevice.h>
  17 #include <linux/etherdevice.h>
  18 #include <linux/rcupdate.h>
  19 #include <net/mac80211.h>
  20 #include <net/ieee80211_radiotap.h>
  21
  22 #include "ieee80211_i.h"
  23 #include "driver-ops.h"
  24 #include "led.h"
  25 #include "mesh.h"
  26 #include "wep.h"
  27 #include "wpa.h"
  28 #include "tkip.h"
  29 #include "wme.h"
  30
  31 /*
  32  * monitor mode reception
  33  *
  34  * This function cleans up the SKB, i.e. it removes all the stuff
  35  * only useful for monitoring.
  36  */
  37 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
  38                                            struct sk_buff *skb)
  39 {
  40         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
  41                 if (likely(skb->len > FCS_LEN))
  42                         __pskb_trim(skb, skb->len - FCS_LEN);
  43                 else {
  44                         /* driver bug */
  45                         WARN_ON(1);
  46                         dev_kfree_skb(skb);
  47                         skb = NULL;
  48                 }
  49         }
  50
  51         return skb;
  52 }
  53
  54 static inline int should_drop_frame(struct sk_buff *skb,
  55                                     int present_fcs_len)
  56 {
  57         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  58         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  59
  60         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
  61                 return 1;
  62         if (unlikely(skb->len < 16 + present_fcs_len))
  63                 return 1;
  64         if (ieee80211_is_ctl(hdr->frame_control) &&
  65             !ieee80211_is_pspoll(hdr->frame_control) &&
  66             !ieee80211_is_back_req(hdr->frame_control))
  67                 return 1;
  68         return 0;
  69 }
  70
  71 static int
  72 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
  73                           struct ieee80211_rx_status *status)
  74 {
  75         int len;
  76
  77         /* always present fields */
  78         len = sizeof(struct ieee80211_radiotap_header) + 9;
  79
  80         if (status->flag & RX_FLAG_MACTIME_MPDU)
  81                 len += 8;
  82         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
  83                 len += 1;
  84
  85         if (len & 1) /* padding for RX_FLAGS if necessary */
  86                 len++;
  87
  88         if (status->flag & RX_FLAG_HT) /* HT info */
  89                 len += 3;
  90
  91         return len;
  92 }
  93
  94 /*
  95  * ieee80211_add_rx_radiotap_header - add radiotap header
  96  *
  97  * add a radiotap header containing all the fields which the hardware provided.
  98  */
  99 static void
 100 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
 101                                  struct sk_buff *skb,
 102                                  struct ieee80211_rate *rate,
 103                                  int rtap_len)
 104 {
 105         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 106         struct ieee80211_radiotap_header *rthdr;
 107         unsigned char *pos;
 108         u16 rx_flags = 0;
 109
 110         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
 111         memset(rthdr, 0, rtap_len);
 112
 113         /* radiotap header, set always present flags */
 114         rthdr->it_present =
 115                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 116                             (1 << IEEE80211_RADIOTAP_CHANNEL) |
 117                             (1 << IEEE80211_RADIOTAP_ANTENNA) |
 118                             (1 << IEEE80211_RADIOTAP_RX_FLAGS));
 119         rthdr->it_len = cpu_to_le16(rtap_len);
 120
 121         pos = (unsigned char *)(rthdr+1);
 122
 123         /* the order of the following fields is important */
 124
 125         /* IEEE80211_RADIOTAP_TSFT */
 126         if (status->flag & RX_FLAG_MACTIME_MPDU) {
 127                 put_unaligned_le64(status->mactime, pos);
 128                 rthdr->it_present |=
 129                         cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
 130                 pos += 8;
 131         }
 132
 133         /* IEEE80211_RADIOTAP_FLAGS */
 134         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 135                 *pos |= IEEE80211_RADIOTAP_F_FCS;
 136         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 137                 *pos |= IEEE80211_RADIOTAP_F_BADFCS;
 138         if (status->flag & RX_FLAG_SHORTPRE)
 139                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
 140         pos++;
 141
 142         /* IEEE80211_RADIOTAP_RATE */
 143         if (status->flag & RX_FLAG_HT) {
 144                 /*
 145                  * MCS information is a separate field in radiotap,
 146                  * added below.
 147                  */
 148                 *pos = 0;
 149         } else {
 150                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
 151                 *pos = rate->bitrate / 5;
 152         }
 153         pos++;
 154
 155         /* IEEE80211_RADIOTAP_CHANNEL */
 156         put_unaligned_le16(status->freq, pos);
 157         pos += 2;
 158         if (status->band == IEEE80211_BAND_5GHZ)
 159                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ,
 160                                    pos);
 161         else if (status->flag & RX_FLAG_HT)
 162                 put_unaligned_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ,
 163                                    pos);
 164         else if (rate->flags & IEEE80211_RATE_ERP_G)
 165                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
 166                                    pos);
 167         else
 168                 put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
 169                                    pos);
 170         pos += 2;
 171
 172         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
 173         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
 174                 *pos = status->signal;
 175                 rthdr->it_present |=
 176                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
 177                 pos++;
 178         }
 179
 180         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
 181
 182         /* IEEE80211_RADIOTAP_ANTENNA */
 183         *pos = status->antenna;
 184         pos++;
 185
 186         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
 187
 188         /* IEEE80211_RADIOTAP_RX_FLAGS */
 189         /* ensure 2 byte alignment for the 2 byte field as required */
 190         if ((pos - (u8 *)rthdr) & 1)
 191                 pos++;
 192         if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
 193                 rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
 194         put_unaligned_le16(rx_flags, pos);
 195         pos += 2;
 196
 197         if (status->flag & RX_FLAG_HT) {
 198                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
 199                 *pos++ = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
 200                          IEEE80211_RADIOTAP_MCS_HAVE_GI |
 201                          IEEE80211_RADIOTAP_MCS_HAVE_BW;
 202                 *pos = 0;
 203                 if (status->flag & RX_FLAG_SHORT_GI)
 204                         *pos |= IEEE80211_RADIOTAP_MCS_SGI;
 205                 if (status->flag & RX_FLAG_40MHZ)
 206                         *pos |= IEEE80211_RADIOTAP_MCS_BW_40;
 207                 pos++;
 208                 *pos++ = status->rate_idx;
 209         }
 210 }
 211
 212 /*
 213  * This function copies a received frame to all monitor interfaces and
 214  * returns a cleaned-up SKB that no longer includes the FCS nor the
 215  * radiotap header the driver might have added.
 216  */
 217 static struct sk_buff *
 218 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
 219                      struct ieee80211_rate *rate)
 220 {
 221         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
 222         struct ieee80211_sub_if_data *sdata;
 223         int needed_headroom = 0;
 224         struct sk_buff *skb, *skb2;
 225         struct net_device *prev_dev = NULL;
 226         int present_fcs_len = 0;
 227
 228         /*
 229          * First, we may need to make a copy of the skb because
 230          *  (1) we need to modify it for radiotap (if not present), and
 231          *  (2) the other RX handlers will modify the skb we got.
 232          *
 233          * We don't need to, of course, if we aren't going to return
 234          * the SKB because it has a bad FCS/PLCP checksum.
 235          */
 236
 237         /* room for the radiotap header based on driver features */
 238         needed_headroom = ieee80211_rx_radiotap_len(local, status);
 239
 240         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 241                 present_fcs_len = FCS_LEN;
 242
 243         /* make sure hdr->frame_control is on the linear part */
 244         if (!pskb_may_pull(origskb, 2)) {
 245                 dev_kfree_skb(origskb);
 246                 return NULL;
 247         }
 248
 249         if (!local->monitors) {
 250                 if (should_drop_frame(origskb, present_fcs_len)) {
 251                         dev_kfree_skb(origskb);
 252                         return NULL;
 253                 }
 254
 255                 return remove_monitor_info(local, origskb);
 256         }
 257
 258         if (should_drop_frame(origskb, present_fcs_len)) {
 259                 /* only need to expand headroom if necessary */
 260                 skb = origskb;
 261                 origskb = NULL;
 262
 263                 /*
 264                  * This shouldn't trigger often because most devices have an
 265                  * RX header they pull before we get here, and that should
 266                  * be big enough for our radiotap information. We should
 267                  * probably export the length to drivers so that we can have
 268                  * them allocate enough headroom to start with.
 269                  */
 270                 if (skb_headroom(skb) < needed_headroom &&
 271                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
 272                         dev_kfree_skb(skb);
 273                         return NULL;
 274                 }
 275         } else {
 276                 /*
 277                  * Need to make a copy and possibly remove radiotap header
 278                  * and FCS from the original.
 279                  */
 280                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 281
 282                 origskb = remove_monitor_info(local, origskb);
 283
 284                 if (!skb)
 285                         return origskb;
 286         }
 287
 288         /* prepend radiotap information */
 289         ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom);
 290
 291         skb_reset_mac_header(skb);
 292         skb->ip_summed = CHECKSUM_UNNECESSARY;
 293         skb->pkt_type = PACKET_OTHERHOST;
 294         skb->protocol = htons(ETH_P_802_2);
 295
 296         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 297                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
 298                         continue;
 299
 300                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
 301                         continue;
 302
 303                 if (!ieee80211_sdata_running(sdata))
 304                         continue;
 305
 306                 if (prev_dev) {
 307                         skb2 = skb_clone(skb, GFP_ATOMIC);
 308                         if (skb2) {
 309                                 skb2->dev = prev_dev;
 310                                 netif_receive_skb(skb2);
 311                         }
 312                 }
 313
 314                 prev_dev = sdata->dev;
 315                 sdata->dev->stats.rx_packets++;
 316                 sdata->dev->stats.rx_bytes += skb->len;
 317         }
 318
 319         if (prev_dev) {
 320                 skb->dev = prev_dev;
 321                 netif_receive_skb(skb);
 322         } else
 323                 dev_kfree_skb(skb);
 324
 325         return origskb;
 326 }
 327
 328
 329 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
 330 {
 331         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 332         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 333         int tid;
 334
 335         /* does the frame have a qos control field? */
 336         if (ieee80211_is_data_qos(hdr->frame_control)) {
 337                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 338                 /* frame has qos control */
 339                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
 340                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
 341                         status->rx_flags |= IEEE80211_RX_AMSDU;
 342         } else {
 343                 /*
 344                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
 345                  *
 346                  *      Sequence numbers for management frames, QoS data
 347                  *      frames with a broadcast/multicast address in the
 348                  *      Address 1 field, and all non-QoS data frames sent
 349                  *      by QoS STAs are assigned using an additional single
 350                  *      modulo-4096 counter, [...]
 351                  *
 352                  * We also use that counter for non-QoS STAs.
 353                  */
 354                 tid = NUM_RX_DATA_QUEUES - 1;
 355         }
 356
 357         rx->queue = tid;
 358         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 359          * For now, set skb->priority to 0 for other cases. */
 360         rx->skb->priority = (tid > 7) ? 0 : tid;
 361 }
 362
 363 /**
 364  * DOC: Packet alignment
 365  *
 366  * Drivers always need to pass packets that are aligned to two-byte boundaries
 367  * to the stack.
 368  *
 369  * Additionally, should, if possible, align the payload data in a way that
 370  * guarantees that the contained IP header is aligned to a four-byte
 371  * boundary. In the case of regular frames, this simply means aligning the
 372  * payload to a four-byte boundary (because either the IP header is directly
 373  * contained, or IV/RFC1042 headers that have a length divisible by four are
 374  * in front of it).  If the payload data is not properly aligned and the
 375  * architecture doesn't support efficient unaligned operations, mac80211
 376  * will align the data.
 377  *
 378  * With A-MSDU frames, however, the payload data address must yield two modulo
 379  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
 380  * push the IP header further back to a multiple of four again. Thankfully, the
 381  * specs were sane enough this time around to require padding each A-MSDU
 382  * subframe to a length that is a multiple of four.
 383  *
 384  * Padding like Atheros hardware adds which is between the 802.11 header and
 385  * the payload is not supported, the driver is required to move the 802.11
 386  * header to be directly in front of the payload in that case.
 387  */
 388 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
 389 {
 390 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 391         WARN_ONCE((unsigned long)rx->skb->data & 1,
 392                   "unaligned packet at 0x%p\n", rx->skb->data);
 393 #endif
 394 }
 395
 396
 397 /* rx handlers */
 398
 399 static ieee80211_rx_result debug_noinline
 400 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 401 {
 402         struct ieee80211_local *local = rx->local;
 403         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 404         struct sk_buff *skb = rx->skb;
 405
 406         if (likely(!(status->rx_flags & IEEE80211_RX_IN_SCAN)))
 407                 return RX_CONTINUE;
 408
 409         if (test_bit(SCAN_HW_SCANNING, &local->scanning) ||
 410             test_bit(SCAN_SW_SCANNING, &local->scanning))
 411                 return ieee80211_scan_rx(rx->sdata, skb);
 412
 413         /* scanning finished during invoking of handlers */
 414         I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 415         return RX_DROP_UNUSABLE;
 416 }
 417
 418
 419 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
 420 {
 421         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 422
 423         if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
 424                 return 0;
 425
 426         return ieee80211_is_robust_mgmt_frame(hdr);
 427 }
 428
 429
 430 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
 431 {
 432         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 433
 434         if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
 435                 return 0;
 436
 437         return ieee80211_is_robust_mgmt_frame(hdr);
 438 }
 439
 440
 441 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
 442 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
 443 {
 444         struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
 445         struct ieee80211_mmie *mmie;
 446
 447         if (skb->len < 24 + sizeof(*mmie) ||
 448             !is_multicast_ether_addr(hdr->da))
 449                 return -1;
 450
 451         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
 452                 return -1; /* not a robust management frame */
 453
 454         mmie = (struct ieee80211_mmie *)
 455                 (skb->data + skb->len - sizeof(*mmie));
 456         if (mmie->element_id != WLAN_EID_MMIE ||
 457             mmie->length != sizeof(*mmie) - 2)
 458                 return -1;
 459
 460         return le16_to_cpu(mmie->key_id);
 461 }
 462
 463
 464 static ieee80211_rx_result
 465 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 466 {
 467         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 468         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 469         char *dev_addr = rx->sdata->vif.addr;
 470
 471         if (ieee80211_is_data(hdr->frame_control)) {
 472                 if (is_multicast_ether_addr(hdr->addr1)) {
 473                         if (ieee80211_has_tods(hdr->frame_control) ||
 474                                 !ieee80211_has_fromds(hdr->frame_control))
 475                                 return RX_DROP_MONITOR;
 476                         if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
 477                                 return RX_DROP_MONITOR;
 478                 } else {
 479                         if (!ieee80211_has_a4(hdr->frame_control))
 480                                 return RX_DROP_MONITOR;
 481                         if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
 482                                 return RX_DROP_MONITOR;
 483                 }
 484         }
 485
 486         /* If there is not an established peer link and this is not a peer link
 487          * establisment frame, beacon or probe, drop the frame.
 488          */
 489
 490         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
 491                 struct ieee80211_mgmt *mgmt;
 492
 493                 if (!ieee80211_is_mgmt(hdr->frame_control))
 494                         return RX_DROP_MONITOR;
 495
 496                 if (ieee80211_is_action(hdr->frame_control)) {
 497                         mgmt = (struct ieee80211_mgmt *)hdr;
 498                         if (mgmt->u.action.category != WLAN_CATEGORY_MESH_PLINK)
 499                                 return RX_DROP_MONITOR;
 500                         return RX_CONTINUE;
 501                 }
 502
 503                 if (ieee80211_is_probe_req(hdr->frame_control) ||
 504                     ieee80211_is_probe_resp(hdr->frame_control) ||
 505                     ieee80211_is_beacon(hdr->frame_control))
 506                         return RX_CONTINUE;
 507
 508                 return RX_DROP_MONITOR;
 509
 510         }
 511
 512 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
 513
 514         if (ieee80211_is_data(hdr->frame_control) &&
 515             is_multicast_ether_addr(hdr->addr1) &&
 516             mesh_rmc_check(hdr->addr3, msh_h_get(hdr, hdrlen), rx->sdata))
 517                 return RX_DROP_MONITOR;
 518 #undef msh_h_get
 519
 520         return RX_CONTINUE;
 521 }
 522
 523 #define SEQ_MODULO 0x1000
 524 #define SEQ_MASK   0xfff
 525
 526 static inline int seq_less(u16 sq1, u16 sq2)
 527 {
 528         return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
 529 }
 530
 531 static inline u16 seq_inc(u16 sq)
 532 {
 533         return (sq + 1) & SEQ_MASK;
 534 }
 535
 536 static inline u16 seq_sub(u16 sq1, u16 sq2)
 537 {
 538         return (sq1 - sq2) & SEQ_MASK;
 539 }
 540
 541
 542 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
 543                                             struct tid_ampdu_rx *tid_agg_rx,
 544                                             int index)
 545 {
 546         struct ieee80211_local *local = hw_to_local(hw);
 547         struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
 548         struct ieee80211_rx_status *status;
 549
 550         lockdep_assert_held(&tid_agg_rx->reorder_lock);
 551
 552         if (!skb)
 553                 goto no_frame;
 554
 555         /* release the frame from the reorder ring buffer */
 556         tid_agg_rx->stored_mpdu_num--;
 557         tid_agg_rx->reorder_buf[index] = NULL;
 558         status = IEEE80211_SKB_RXCB(skb);
 559         status->rx_flags |= IEEE80211_RX_DEFERRED_RELEASE;
 560         skb_queue_tail(&local->rx_skb_queue, skb);
 561
 562 no_frame:
 563         tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
 564 }
 565
 566 static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
 567                                              struct tid_ampdu_rx *tid_agg_rx,
 568                                              u16 head_seq_num)
 569 {
 570         int index;
 571
 572         lockdep_assert_held(&tid_agg_rx->reorder_lock);
 573
 574         while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
 575                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 576                                                         tid_agg_rx->buf_size;
 577                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
 578         }
 579 }
 580
 581 /*
 582  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
 583  * the skb was added to the buffer longer than this time ago, the earlier
 584  * frames that have not yet been received are assumed to be lost and the skb
 585  * can be released for processing. This may also release other skb's from the
 586  * reorder buffer if there are no additional gaps between the frames.
 587  *
 588  * Callers must hold tid_agg_rx->reorder_lock.
 589  */
 590 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
 591
 592 static void ieee80211_sta_reorder_release(struct ieee80211_hw *hw,
 593                                           struct tid_ampdu_rx *tid_agg_rx)
 594 {
 595         int index, j;
 596
 597         lockdep_assert_held(&tid_agg_rx->reorder_lock);
 598
 599         /* release the buffer until next missing frame */
 600         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 601                                                 tid_agg_rx->buf_size;
 602         if (!tid_agg_rx->reorder_buf[index] &&
 603             tid_agg_rx->stored_mpdu_num > 1) {
 604                 /*
 605                  * No buffers ready to be released, but check whether any
 606                  * frames in the reorder buffer have timed out.
 607                  */
 608                 int skipped = 1;
 609                 for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
 610                      j = (j + 1) % tid_agg_rx->buf_size) {
 611                         if (!tid_agg_rx->reorder_buf[j]) {
 612                                 skipped++;
 613                                 continue;
 614                         }
 615                         if (skipped &&
 616                             !time_after(jiffies, tid_agg_rx->reorder_time[j] +
 617                                         HT_RX_REORDER_BUF_TIMEOUT))
 618                                 goto set_release_timer;
 619
 620 #ifdef CONFIG_MAC80211_HT_DEBUG
 621                         if (net_ratelimit())
 622                                 wiphy_debug(hw->wiphy,
 623                                             "release an RX reorder frame due to timeout on earlier frames\n");
 624 #endif
 625                         ieee80211_release_reorder_frame(hw, tid_agg_rx, j);
 626
 627                         /*
 628                          * Increment the head seq# also for the skipped slots.
 629                          */
 630                         tid_agg_rx->head_seq_num =
 631                                 (tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
 632                         skipped = 0;
 633                 }
 634         } else while (tid_agg_rx->reorder_buf[index]) {
 635                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
 636                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 637                                                         tid_agg_rx->buf_size;
 638         }
 639
 640         if (tid_agg_rx->stored_mpdu_num) {
 641                 j = index = seq_sub(tid_agg_rx->head_seq_num,
 642                                     tid_agg_rx->ssn) % tid_agg_rx->buf_size;
 643
 644                 for (; j != (index - 1) % tid_agg_rx->buf_size;
 645                      j = (j + 1) % tid_agg_rx->buf_size) {
 646                         if (tid_agg_rx->reorder_buf[j])
 647                                 break;
 648                 }
 649
 650  set_release_timer:
 651
 652                 mod_timer(&tid_agg_rx->reorder_timer,
 653                           tid_agg_rx->reorder_time[j] +
 654                           HT_RX_REORDER_BUF_TIMEOUT);
 655         } else {
 656                 del_timer(&tid_agg_rx->reorder_timer);
 657         }
 658 }
 659
 660 /*
 661  * As this function belongs to the RX path it must be under
 662  * rcu_read_lock protection. It returns false if the frame
 663  * can be processed immediately, true if it was consumed.
 664  */
 665 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
 666                                              struct tid_ampdu_rx *tid_agg_rx,
 667                                              struct sk_buff *skb)
 668 {
 669         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 670         u16 sc = le16_to_cpu(hdr->seq_ctrl);
 671         u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
 672         u16 head_seq_num, buf_size;
 673         int index;
 674         bool ret = true;
 675
 676         spin_lock(&tid_agg_rx->reorder_lock);
 677
 678         buf_size = tid_agg_rx->buf_size;
 679         head_seq_num = tid_agg_rx->head_seq_num;
 680
 681         /* frame with out of date sequence number */
 682         if (seq_less(mpdu_seq_num, head_seq_num)) {
 683                 dev_kfree_skb(skb);
 684                 goto out;
 685         }
 686
 687         /*
 688          * If frame the sequence number exceeds our buffering window
 689          * size release some previous frames to make room for this one.
 690          */
 691         if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
 692                 head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
 693                 /* release stored frames up to new head to stack */
 694                 ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num);
 695         }
 696
 697         /* Now the new frame is always in the range of the reordering buffer */
 698
 699         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size;
 700
 701         /* check if we already stored this frame */
 702         if (tid_agg_rx->reorder_buf[index]) {
 703                 dev_kfree_skb(skb);
 704                 goto out;
 705         }
 706
 707         /*
 708          * If the current MPDU is in the right order and nothing else
 709          * is stored we can process it directly, no need to buffer it.
 710          * If it is first but there's something stored, we may be able
 711          * to release frames after this one.
 712          */
 713         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
 714             tid_agg_rx->stored_mpdu_num == 0) {
 715                 tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
 716                 ret = false;
 717                 goto out;
 718         }
 719
 720         /* put the frame in the reordering buffer */
 721         tid_agg_rx->reorder_buf[index] = skb;
 722         tid_agg_rx->reorder_time[index] = jiffies;
 723         tid_agg_rx->stored_mpdu_num++;
 724         ieee80211_sta_reorder_release(hw, tid_agg_rx);
 725
 726  out:
 727         spin_unlock(&tid_agg_rx->reorder_lock);
 728         return ret;
 729 }
 730
 731 /*
 732  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
 733  * true if the MPDU was buffered, false if it should be processed.
 734  */
 735 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx)
 736 {
 737         struct sk_buff *skb = rx->skb;
 738         struct ieee80211_local *local = rx->local;
 739         struct ieee80211_hw *hw = &local->hw;
 740         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 741         struct sta_info *sta = rx->sta;
 742         struct tid_ampdu_rx *tid_agg_rx;
 743         u16 sc;
 744         int tid;
 745
 746         if (!ieee80211_is_data_qos(hdr->frame_control))
 747                 goto dont_reorder;
 748
 749         /*
 750          * filter the QoS data rx stream according to
 751          * STA/TID and check if this STA/TID is on aggregation
 752          */
 753
 754         if (!sta)
 755                 goto dont_reorder;
 756
 757         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
 758
 759         tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
 760         if (!tid_agg_rx)
 761                 goto dont_reorder;
 762
 763         /* qos null data frames are excluded */
 764         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
 765                 goto dont_reorder;
 766
 767         /* new, potentially un-ordered, ampdu frame - process it */
 768
 769         /* reset session timer */
 770         if (tid_agg_rx->timeout)
 771                 mod_timer(&tid_agg_rx->session_timer,
 772                           TU_TO_EXP_TIME(tid_agg_rx->timeout));
 773
 774         /* if this mpdu is fragmented - terminate rx aggregation session */
 775         sc = le16_to_cpu(hdr->seq_ctrl);
 776         if (sc & IEEE80211_SCTL_FRAG) {
 777                 skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
 778                 skb_queue_tail(&rx->sdata->skb_queue, skb);
 779                 ieee80211_queue_work(&local->hw, &rx->sdata->work);
 780                 return;
 781         }
 782
 783         /*
 784          * No locking needed -- we will only ever process one
 785          * RX packet at a time, and thus own tid_agg_rx. All
 786          * other code manipulating it needs to (and does) make
 787          * sure that we cannot get to it any more before doing
 788          * anything with it.
 789          */
 790         if (ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb))
 791                 return;
 792
 793  dont_reorder:
 794         skb_queue_tail(&local->rx_skb_queue, skb);
 795 }
 796
 797 static ieee80211_rx_result debug_noinline
 798 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
 799 {
 800         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 801         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 802
 803         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 804         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 805                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
 806                              rx->sta->last_seq_ctrl[rx->queue] ==
 807                              hdr->seq_ctrl)) {
 808                         if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
 809                                 rx->local->dot11FrameDuplicateCount++;
 810                                 rx->sta->num_duplicates++;
 811                         }
 812                         return RX_DROP_UNUSABLE;
 813                 } else
 814                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
 815         }
 816
 817         if (unlikely(rx->skb->len < 16)) {
 818                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 819                 return RX_DROP_MONITOR;
 820         }
 821
 822         /* Drop disallowed frame classes based on STA auth/assoc state;
 823          * IEEE 802.11, Chap 5.5.
 824          *
 825          * mac80211 filters only based on association state, i.e. it drops
 826          * Class 3 frames from not associated stations. hostapd sends
 827          * deauth/disassoc frames when needed. In addition, hostapd is
 828          * responsible for filtering on both auth and assoc states.
 829          */
 830
 831         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
 832                 return ieee80211_rx_mesh_check(rx);
 833
 834         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
 835                       ieee80211_is_pspoll(hdr->frame_control)) &&
 836                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
 837                      rx->sdata->vif.type != NL80211_IFTYPE_WDS &&
 838                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC))))
 839                 return RX_DROP_MONITOR;
 840
 841         return RX_CONTINUE;
 842 }
 843
 844
 845 static ieee80211_rx_result debug_noinline
 846 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 847 {
 848         struct sk_buff *skb = rx->skb;
 849         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 850         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 851         int keyidx;
 852         int hdrlen;
 853         ieee80211_rx_result result = RX_DROP_UNUSABLE;
 854         struct ieee80211_key *sta_ptk = NULL;
 855         int mmie_keyidx = -1;
 856         __le16 fc;
 857
 858         /*
 859          * Key selection 101
 860          *
 861          * There are four types of keys:
 862          *  - GTK (group keys)
 863          *  - IGTK (group keys for management frames)
 864          *  - PTK (pairwise keys)
 865          *  - STK (station-to-station pairwise keys)
 866          *
 867          * When selecting a key, we have to distinguish between multicast
 868          * (including broadcast) and unicast frames, the latter can only
 869          * use PTKs and STKs while the former always use GTKs and IGTKs.
 870          * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
 871          * unicast frames can also use key indices like GTKs. Hence, if we
 872          * don't have a PTK/STK we check the key index for a WEP key.
 873          *
 874          * Note that in a regular BSS, multicast frames are sent by the
 875          * AP only, associated stations unicast the frame to the AP first
 876          * which then multicasts it on their behalf.
 877          *
 878          * There is also a slight problem in IBSS mode: GTKs are negotiated
 879          * with each station, that is something we don't currently handle.
 880          * The spec seems to expect that one negotiates the same key with
 881          * every station but there's no such requirement; VLANs could be
 882          * possible.
 883          */
 884
 885         /*
 886          * No point in finding a key and decrypting if the frame is neither
 887          * addressed to us nor a multicast frame.
 888          */
 889         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
 890                 return RX_CONTINUE;
 891
 892         /* start without a key */
 893         rx->key = NULL;
 894
 895         if (rx->sta)
 896                 sta_ptk = rcu_dereference(rx->sta->ptk);
 897
 898         fc = hdr->frame_control;
 899
 900         if (!ieee80211_has_protected(fc))
 901                 mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
 902
 903         if (!is_multicast_ether_addr(hdr->addr1) && sta_ptk) {
 904                 rx->key = sta_ptk;
 905                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 906                     (status->flag & RX_FLAG_IV_STRIPPED))
 907                         return RX_CONTINUE;
 908                 /* Skip decryption if the frame is not protected. */
 909                 if (!ieee80211_has_protected(fc))
 910                         return RX_CONTINUE;
 911         } else if (mmie_keyidx >= 0) {
 912                 /* Broadcast/multicast robust management frame / BIP */
 913                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 914                     (status->flag & RX_FLAG_IV_STRIPPED))
 915                         return RX_CONTINUE;
 916
 917                 if (mmie_keyidx < NUM_DEFAULT_KEYS ||
 918                     mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 919                         return RX_DROP_MONITOR; /* unexpected BIP keyidx */
 920                 if (rx->sta)
 921                         rx->key = rcu_dereference(rx->sta->gtk[mmie_keyidx]);
 922                 if (!rx->key)
 923                         rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
 924         } else if (!ieee80211_has_protected(fc)) {
 925                 /*
 926                  * The frame was not protected, so skip decryption. However, we
 927                  * need to set rx->key if there is a key that could have been
 928                  * used so that the frame may be dropped if encryption would
 929                  * have been expected.
 930                  */
 931                 struct ieee80211_key *key = NULL;
 932                 struct ieee80211_sub_if_data *sdata = rx->sdata;
 933                 int i;
 934
 935                 if (ieee80211_is_mgmt(fc) &&
 936                     is_multicast_ether_addr(hdr->addr1) &&
 937                     (key = rcu_dereference(rx->sdata->default_mgmt_key)))
 938                         rx->key = key;
 939                 else {
 940                         if (rx->sta) {
 941                                 for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
 942                                         key = rcu_dereference(rx->sta->gtk[i]);
 943                                         if (key)
 944                                                 break;
 945                                 }
 946                         }
 947                         if (!key) {
 948                                 for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
 949                                         key = rcu_dereference(sdata->keys[i]);
 950                                         if (key)
 951                                                 break;
 952                                 }
 953                         }
 954                         if (key)
 955                                 rx->key = key;
 956                 }
 957                 return RX_CONTINUE;
 958         } else {
 959                 u8 keyid;
 960                 /*
 961                  * The device doesn't give us the IV so we won't be
 962                  * able to look up the key. That's ok though, we
 963                  * don't need to decrypt the frame, we just won't
 964                  * be able to keep statistics accurate.
 965                  * Except for key threshold notifications, should
 966                  * we somehow allow the driver to tell us which key
 967                  * the hardware used if this flag is set?
 968                  */
 969                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 970                     (status->flag & RX_FLAG_IV_STRIPPED))
 971                         return RX_CONTINUE;
 972
 973                 hdrlen = ieee80211_hdrlen(fc);
 974
 975                 if (rx->skb->len < 8 + hdrlen)
 976                         return RX_DROP_UNUSABLE; /* TODO: count this? */
 977
 978                 /*
 979                  * no need to call ieee80211_wep_get_keyidx,
 980                  * it verifies a bunch of things we've done already
 981                  */
 982                 skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
 983                 keyidx = keyid >> 6;
 984
 985                 /* check per-station GTK first, if multicast packet */
 986                 if (is_multicast_ether_addr(hdr->addr1) && rx->sta)
 987                         rx->key = rcu_dereference(rx->sta->gtk[keyidx]);
 988
 989                 /* if not found, try default key */
 990                 if (!rx->key) {
 991                         rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
 992
 993                         /*
 994                          * RSNA-protected unicast frames should always be
 995                          * sent with pairwise or station-to-station keys,
 996                          * but for WEP we allow using a key index as well.
 997                          */
 998                         if (rx->key &&
 999                             rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP40 &&
1000                             rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP104 &&
1001                             !is_multicast_ether_addr(hdr->addr1))
1002                                 rx->key = NULL;
1003                 }
1004         }
1005
1006         if (rx->key) {
1007                 rx->key->tx_rx_count++;
1008                 /* TODO: add threshold stuff again */
1009         } else {
1010                 return RX_DROP_MONITOR;
1011         }
1012
1013         if (skb_linearize(rx->skb))
1014                 return RX_DROP_UNUSABLE;
1015         /* the hdr variable is invalid now! */
1016
1017         switch (rx->key->conf.cipher) {
1018         case WLAN_CIPHER_SUITE_WEP40:
1019         case WLAN_CIPHER_SUITE_WEP104:
1020                 /* Check for weak IVs if possible */
1021                 if (rx->sta && ieee80211_is_data(fc) &&
1022                     (!(status->flag & RX_FLAG_IV_STRIPPED) ||
1023                      !(status->flag & RX_FLAG_DECRYPTED)) &&
1024                     ieee80211_wep_is_weak_iv(rx->skb, rx->key))
1025                         rx->sta->wep_weak_iv_count++;
1026
1027                 result = ieee80211_crypto_wep_decrypt(rx);
1028                 break;
1029         case WLAN_CIPHER_SUITE_TKIP:
1030                 result = ieee80211_crypto_tkip_decrypt(rx);
1031                 break;
1032         case WLAN_CIPHER_SUITE_CCMP:
1033                 result = ieee80211_crypto_ccmp_decrypt(rx);
1034                 break;
1035         case WLAN_CIPHER_SUITE_AES_CMAC:
1036                 result = ieee80211_crypto_aes_cmac_decrypt(rx);
1037                 break;
1038         default:
1039                 /*
1040                  * We can reach here only with HW-only algorithms
1041                  * but why didn't it decrypt the frame?!
1042                  */
1043                 return RX_DROP_UNUSABLE;
1044         }
1045
1046         /* either the frame has been decrypted or will be dropped */
1047         status->flag |= RX_FLAG_DECRYPTED;
1048
1049         return result;
1050 }
1051
1052 static ieee80211_rx_result debug_noinline
1053 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
1054 {
1055         struct ieee80211_local *local;
1056         struct ieee80211_hdr *hdr;
1057         struct sk_buff *skb;
1058
1059         local = rx->local;
1060         skb = rx->skb;
1061         hdr = (struct ieee80211_hdr *) skb->data;
1062
1063         if (!local->pspolling)
1064                 return RX_CONTINUE;
1065
1066         if (!ieee80211_has_fromds(hdr->frame_control))
1067                 /* this is not from AP */
1068                 return RX_CONTINUE;
1069
1070         if (!ieee80211_is_data(hdr->frame_control))
1071                 return RX_CONTINUE;
1072
1073         if (!ieee80211_has_moredata(hdr->frame_control)) {
1074                 /* AP has no more frames buffered for us */
1075                 local->pspolling = false;
1076                 return RX_CONTINUE;
1077         }
1078
1079         /* more data bit is set, let's request a new frame from the AP */
1080         ieee80211_send_pspoll(local, rx->sdata);
1081
1082         return RX_CONTINUE;
1083 }
1084
1085 static void ap_sta_ps_start(struct sta_info *sta)
1086 {
1087         struct ieee80211_sub_if_data *sdata = sta->sdata;
1088         struct ieee80211_local *local = sdata->local;
1089
1090         atomic_inc(&sdata->bss->num_sta_ps);
1091         set_sta_flags(sta, WLAN_STA_PS_STA);
1092         if (!(local->hw.flags & IEEE80211_HW_AP_LINK_PS))
1093                 drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
1094 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1095         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
1096                sdata->name, sta->sta.addr, sta->sta.aid);
1097 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1098 }
1099
1100 static void ap_sta_ps_end(struct sta_info *sta)
1101 {
1102         struct ieee80211_sub_if_data *sdata = sta->sdata;
1103
1104         atomic_dec(&sdata->bss->num_sta_ps);
1105
1106 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1107         printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
1108                sdata->name, sta->sta.addr, sta->sta.aid);
1109 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1110
1111         if (test_sta_flags(sta, WLAN_STA_PS_DRIVER)) {
1112 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1113                 printk(KERN_DEBUG "%s: STA %pM aid %d driver-ps-blocked\n",
1114                        sdata->name, sta->sta.addr, sta->sta.aid);
1115 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1116                 return;
1117         }
1118
1119         ieee80211_sta_ps_deliver_wakeup(sta);
1120 }
1121
1122 int ieee80211_sta_ps_transition(struct ieee80211_sta *sta, bool start)
1123 {
1124         struct sta_info *sta_inf = container_of(sta, struct sta_info, sta);
1125         bool in_ps;
1126
1127         WARN_ON(!(sta_inf->local->hw.flags & IEEE80211_HW_AP_LINK_PS));
1128
1129         /* Don't let the same PS state be set twice */
1130         in_ps = test_sta_flags(sta_inf, WLAN_STA_PS_STA);
1131         if ((start && in_ps) || (!start && !in_ps))
1132                 return -EINVAL;
1133
1134         if (start)
1135                 ap_sta_ps_start(sta_inf);
1136         else
1137                 ap_sta_ps_end(sta_inf);
1138
1139         return 0;
1140 }
1141 EXPORT_SYMBOL(ieee80211_sta_ps_transition);
1142
1143 static ieee80211_rx_result debug_noinline
1144 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1145 {
1146         struct sta_info *sta = rx->sta;
1147         struct sk_buff *skb = rx->skb;
1148         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1149         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1150
1151         if (!sta)
1152                 return RX_CONTINUE;
1153
1154         /*
1155          * Update last_rx only for IBSS packets which are for the current
1156          * BSSID to avoid keeping the current IBSS network alive in cases
1157          * where other STAs start using different BSSID.
1158          */
1159         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1160                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1161                                                 NL80211_IFTYPE_ADHOC);
1162                 if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0) {
1163                         sta->last_rx = jiffies;
1164                         if (ieee80211_is_data(hdr->frame_control)) {
1165                                 sta->last_rx_rate_idx = status->rate_idx;
1166                                 sta->last_rx_rate_flag = status->flag;
1167                         }
1168                 }
1169         } else if (!is_multicast_ether_addr(hdr->addr1)) {
1170                 /*
1171                  * Mesh beacons will update last_rx when if they are found to
1172                  * match the current local configuration when processed.
1173                  */
1174                 sta->last_rx = jiffies;
1175                 if (ieee80211_is_data(hdr->frame_control)) {
1176                         sta->last_rx_rate_idx = status->rate_idx;
1177                         sta->last_rx_rate_flag = status->flag;
1178                 }
1179         }
1180
1181         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1182                 return RX_CONTINUE;
1183
1184         if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1185                 ieee80211_sta_rx_notify(rx->sdata, hdr);
1186
1187         sta->rx_fragments++;
1188         sta->rx_bytes += rx->skb->len;
1189         sta->last_signal = status->signal;
1190         ewma_add(&sta->avg_signal, -status->signal);
1191
1192         /*
1193          * Change STA power saving mode only at the end of a frame
1194          * exchange sequence.
1195          */
1196         if (!(sta->local->hw.flags & IEEE80211_HW_AP_LINK_PS) &&
1197             !ieee80211_has_morefrags(hdr->frame_control) &&
1198             !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1199             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1200              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
1201                 if (test_sta_flags(sta, WLAN_STA_PS_STA)) {
1202                         /*
1203                          * Ignore doze->wake transitions that are
1204                          * indicated by non-data frames, the standard
1205                          * is unclear here, but for example going to
1206                          * PS mode and then scanning would cause a
1207                          * doze->wake transition for the probe request,
1208                          * and that is clearly undesirable.
1209                          */
1210                         if (ieee80211_is_data(hdr->frame_control) &&
1211                             !ieee80211_has_pm(hdr->frame_control))
1212                                 ap_sta_ps_end(sta);
1213                 } else {
1214                         if (ieee80211_has_pm(hdr->frame_control))
1215                                 ap_sta_ps_start(sta);
1216                 }
1217         }
1218
1219         /*
1220          * Drop (qos-)data::nullfunc frames silently, since they
1221          * are used only to control station power saving mode.
1222          */
1223         if (ieee80211_is_nullfunc(hdr->frame_control) ||
1224             ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1225                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
1226
1227                 /*
1228                  * If we receive a 4-addr nullfunc frame from a STA
1229                  * that was not moved to a 4-addr STA vlan yet, drop
1230                  * the frame to the monitor interface, to make sure
1231                  * that hostapd sees it
1232                  */
1233                 if (ieee80211_has_a4(hdr->frame_control) &&
1234                     (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1235                      (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1236                       !rx->sdata->u.vlan.sta)))
1237                         return RX_DROP_MONITOR;
1238                 /*
1239                  * Update counter and free packet here to avoid
1240                  * counting this as a dropped packed.
1241                  */
1242                 sta->rx_packets++;
1243                 dev_kfree_skb(rx->skb);
1244                 return RX_QUEUED;
1245         }
1246
1247         return RX_CONTINUE;
1248 } /* ieee80211_rx_h_sta_process */
1249
1250 static inline struct ieee80211_fragment_entry *
1251 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
1252                          unsigned int frag, unsigned int seq, int rx_queue,
1253                          struct sk_buff **skb)
1254 {
1255         struct ieee80211_fragment_entry *entry;
1256         int idx;
1257
1258         idx = sdata->fragment_next;
1259         entry = &sdata->fragments[sdata->fragment_next++];
1260         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
1261                 sdata->fragment_next = 0;
1262
1263         if (!skb_queue_empty(&entry->skb_list)) {
1264 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1265                 struct ieee80211_hdr *hdr =
1266                         (struct ieee80211_hdr *) entry->skb_list.next->data;
1267                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
1268                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
1269                        "addr1=%pM addr2=%pM\n",
1270                        sdata->name, idx,
1271                        jiffies - entry->first_frag_time, entry->seq,
1272                        entry->last_frag, hdr->addr1, hdr->addr2);
1273 #endif
1274                 __skb_queue_purge(&entry->skb_list);
1275         }
1276
1277         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
1278         *skb = NULL;
1279         entry->first_frag_time = jiffies;
1280         entry->seq = seq;
1281         entry->rx_queue = rx_queue;
1282         entry->last_frag = frag;
1283         entry->ccmp = 0;
1284         entry->extra_len = 0;
1285
1286         return entry;
1287 }
1288
1289 static inline struct ieee80211_fragment_entry *
1290 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
1291                           unsigned int frag, unsigned int seq,
1292                           int rx_queue, struct ieee80211_hdr *hdr)
1293 {
1294         struct ieee80211_fragment_entry *entry;
1295         int i, idx;
1296
1297         idx = sdata->fragment_next;
1298         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
1299                 struct ieee80211_hdr *f_hdr;
1300
1301                 idx--;
1302                 if (idx < 0)
1303                         idx = IEEE80211_FRAGMENT_MAX - 1;
1304
1305                 entry = &sdata->fragments[idx];
1306                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
1307                     entry->rx_queue != rx_queue ||
1308                     entry->last_frag + 1 != frag)
1309                         continue;
1310
1311                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
1312
1313                 /*
1314                  * Check ftype and addresses are equal, else check next fragment
1315                  */
1316                 if (((hdr->frame_control ^ f_hdr->frame_control) &
1317                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
1318                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
1319                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
1320                         continue;
1321
1322                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
1323                         __skb_queue_purge(&entry->skb_list);
1324                         continue;
1325                 }
1326                 return entry;
1327         }
1328
1329         return NULL;
1330 }
1331
1332 static ieee80211_rx_result debug_noinline
1333 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
1334 {
1335         struct ieee80211_hdr *hdr;
1336         u16 sc;
1337         __le16 fc;
1338         unsigned int frag, seq;
1339         struct ieee80211_fragment_entry *entry;
1340         struct sk_buff *skb;
1341         struct ieee80211_rx_status *status;
1342
1343         hdr = (struct ieee80211_hdr *)rx->skb->data;
1344         fc = hdr->frame_control;
1345         sc = le16_to_cpu(hdr->seq_ctrl);
1346         frag = sc & IEEE80211_SCTL_FRAG;
1347
1348         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1349                    (rx->skb)->len < 24 ||
1350                    is_multicast_ether_addr(hdr->addr1))) {
1351                 /* not fragmented */
1352                 goto out;
1353         }
1354         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1355
1356         if (skb_linearize(rx->skb))
1357                 return RX_DROP_UNUSABLE;
1358
1359         /*
1360          *  skb_linearize() might change the skb->data and
1361          *  previously cached variables (in this case, hdr) need to
1362          *  be refreshed with the new data.
1363          */
1364         hdr = (struct ieee80211_hdr *)rx->skb->data;
1365         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1366
1367         if (frag == 0) {
1368                 /* This is the first fragment of a new frame. */
1369                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1370                                                  rx->queue, &(rx->skb));
1371                 if (rx->key && rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP &&
1372                     ieee80211_has_protected(fc)) {
1373                         int queue = ieee80211_is_mgmt(fc) ?
1374                                 NUM_RX_DATA_QUEUES : rx->queue;
1375                         /* Store CCMP PN so that we can verify that the next
1376                          * fragment has a sequential PN value. */
1377                         entry->ccmp = 1;
1378                         memcpy(entry->last_pn,
1379                                rx->key->u.ccmp.rx_pn[queue],
1380                                CCMP_PN_LEN);
1381                 }
1382                 return RX_QUEUED;
1383         }
1384
1385         /* This is a fragment for a frame that should already be pending in
1386          * fragment cache. Add this fragment to the end of the pending entry.
1387          */
1388         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1389         if (!entry) {
1390                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1391                 return RX_DROP_MONITOR;
1392         }
1393
1394         /* Verify that MPDUs within one MSDU have sequential PN values.
1395          * (IEEE 802.11i, 8.3.3.4.5) */
1396         if (entry->ccmp) {
1397                 int i;
1398                 u8 pn[CCMP_PN_LEN], *rpn;
1399                 int queue;
1400                 if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP)
1401                         return RX_DROP_UNUSABLE;
1402                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1403                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1404                         pn[i]++;
1405                         if (pn[i])
1406                                 break;
1407                 }
1408                 queue = ieee80211_is_mgmt(fc) ?
1409                         NUM_RX_DATA_QUEUES : rx->queue;
1410                 rpn = rx->key->u.ccmp.rx_pn[queue];
1411                 if (memcmp(pn, rpn, CCMP_PN_LEN))
1412                         return RX_DROP_UNUSABLE;
1413                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1414         }
1415
1416         skb_pull(rx->skb, ieee80211_hdrlen(fc));
1417         __skb_queue_tail(&entry->skb_list, rx->skb);
1418         entry->last_frag = frag;
1419         entry->extra_len += rx->skb->len;
1420         if (ieee80211_has_morefrags(fc)) {
1421                 rx->skb = NULL;
1422                 return RX_QUEUED;
1423         }
1424
1425         rx->skb = __skb_dequeue(&entry->skb_list);
1426         if (skb_tailroom(rx->skb) < entry->extra_len) {
1427                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1428                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1429                                               GFP_ATOMIC))) {
1430                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1431                         __skb_queue_purge(&entry->skb_list);
1432                         return RX_DROP_UNUSABLE;
1433                 }
1434         }
1435         while ((skb = __skb_dequeue(&entry->skb_list))) {
1436                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1437                 dev_kfree_skb(skb);
1438         }
1439
1440         /* Complete frame has been reassembled - process it now */
1441         status = IEEE80211_SKB_RXCB(rx->skb);
1442         status->rx_flags |= IEEE80211_RX_FRAGMENTED;
1443
1444  out:
1445         if (rx->sta)
1446                 rx->sta->rx_packets++;
1447         if (is_multicast_ether_addr(hdr->addr1))
1448                 rx->local->dot11MulticastReceivedFrameCount++;
1449         else
1450                 ieee80211_led_rx(rx->local);
1451         return RX_CONTINUE;
1452 }
1453
1454 static ieee80211_rx_result debug_noinline
1455 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1456 {
1457         struct ieee80211_sub_if_data *sdata = rx->sdata;
1458         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1459         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1460
1461         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1462                    !(status->rx_flags & IEEE80211_RX_RA_MATCH)))
1463                 return RX_CONTINUE;
1464
1465         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1466             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1467                 return RX_DROP_UNUSABLE;
1468
1469         if (!test_sta_flags(rx->sta, WLAN_STA_PS_DRIVER))
1470                 ieee80211_sta_ps_deliver_poll_response(rx->sta);
1471         else
1472                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1473
1474         /* Free PS Poll skb here instead of returning RX_DROP that would
1475          * count as an dropped frame. */
1476         dev_kfree_skb(rx->skb);
1477
1478         return RX_QUEUED;
1479 }
1480
1481 static ieee80211_rx_result debug_noinline
1482 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1483 {
1484         u8 *data = rx->skb->data;
1485         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1486
1487         if (!ieee80211_is_data_qos(hdr->frame_control))
1488                 return RX_CONTINUE;
1489
1490         /* remove the qos control field, update frame type and meta-data */
1491         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1492                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1493         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1494         /* change frame type to non QOS */
1495         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1496
1497         return RX_CONTINUE;
1498 }
1499
1500 static int
1501 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1502 {
1503         if (unlikely(!rx->sta ||
1504             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1505                 return -EACCES;
1506
1507         return 0;
1508 }
1509
1510 static int
1511 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1512 {
1513         struct sk_buff *skb = rx->skb;
1514         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1515
1516         /*
1517          * Pass through unencrypted frames if the hardware has
1518          * decrypted them already.
1519          */
1520         if (status->flag & RX_FLAG_DECRYPTED)
1521                 return 0;
1522
1523         /* Drop unencrypted frames if key is set. */
1524         if (unlikely(!ieee80211_has_protected(fc) &&
1525                      !ieee80211_is_nullfunc(fc) &&
1526                      ieee80211_is_data(fc) &&
1527                      (rx->key || rx->sdata->drop_unencrypted)))
1528                 return -EACCES;
1529
1530         return 0;
1531 }
1532
1533 static int
1534 ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
1535 {
1536         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1537         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1538         __le16 fc = hdr->frame_control;
1539
1540         /*
1541          * Pass through unencrypted frames if the hardware has
1542          * decrypted them already.
1543          */
1544         if (status->flag & RX_FLAG_DECRYPTED)
1545                 return 0;
1546
1547         if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1548                 if (unlikely(!ieee80211_has_protected(fc) &&
1549                              ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1550                              rx->key)) {
1551                         if (ieee80211_is_deauth(fc))
1552                                 cfg80211_send_unprot_deauth(rx->sdata->dev,
1553                                                             rx->skb->data,
1554                                                             rx->skb->len);
1555                         else if (ieee80211_is_disassoc(fc))
1556                                 cfg80211_send_unprot_disassoc(rx->sdata->dev,
1557                                                               rx->skb->data,
1558                                                               rx->skb->len);
1559                         return -EACCES;
1560                 }
1561                 /* BIP does not use Protected field, so need to check MMIE */
1562                 if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1563                              ieee80211_get_mmie_keyidx(rx->skb) < 0)) {
1564                         if (ieee80211_is_deauth(fc))
1565                                 cfg80211_send_unprot_deauth(rx->sdata->dev,
1566                                                             rx->skb->data,
1567                                                             rx->skb->len);
1568                         else if (ieee80211_is_disassoc(fc))
1569                                 cfg80211_send_unprot_disassoc(rx->sdata->dev,
1570                                                               rx->skb->data,
1571                                                               rx->skb->len);
1572                         return -EACCES;
1573                 }
1574                 /*
1575                  * When using MFP, Action frames are not allowed prior to
1576                  * having configured keys.
1577                  */
1578                 if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1579                              ieee80211_is_robust_mgmt_frame(
1580                                      (struct ieee80211_hdr *) rx->skb->data)))
1581                         return -EACCES;
1582         }
1583
1584         return 0;
1585 }
1586
1587 static int
1588 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1589 {
1590         struct ieee80211_sub_if_data *sdata = rx->sdata;
1591         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1592         bool check_port_control = false;
1593         struct ethhdr *ehdr;
1594         int ret;
1595
1596         if (ieee80211_has_a4(hdr->frame_control) &&
1597             sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1598                 return -1;
1599
1600         if (sdata->vif.type == NL80211_IFTYPE_STATION &&
1601             !!sdata->u.mgd.use_4addr != !!ieee80211_has_a4(hdr->frame_control)) {
1602
1603                 if (!sdata->u.mgd.use_4addr)
1604                         return -1;
1605                 else
1606                         check_port_control = true;
1607         }
1608
1609         if (is_multicast_ether_addr(hdr->addr1) &&
1610             sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta)
1611                 return -1;
1612
1613         ret = ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
1614         if (ret < 0 || !check_port_control)
1615                 return ret;
1616
1617         ehdr = (struct ethhdr *) rx->skb->data;
1618         if (ehdr->h_proto != rx->sdata->control_port_protocol)
1619                 return -1;
1620
1621         return 0;
1622 }
1623
1624 /*
1625  * requires that rx->skb is a frame with ethernet header
1626  */
1627 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1628 {
1629         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1630                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1631         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1632
1633         /*
1634          * Allow EAPOL frames to us/the PAE group address regardless
1635          * of whether the frame was encrypted or not.
1636          */
1637         if (ehdr->h_proto == rx->sdata->control_port_protocol &&
1638             (compare_ether_addr(ehdr->h_dest, rx->sdata->vif.addr) == 0 ||
1639              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1640                 return true;
1641
1642         if (ieee80211_802_1x_port_control(rx) ||
1643             ieee80211_drop_unencrypted(rx, fc))
1644                 return false;
1645
1646         return true;
1647 }
1648
1649 /*
1650  * requires that rx->skb is a frame with ethernet header
1651  */
1652 static void
1653 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1654 {
1655         struct ieee80211_sub_if_data *sdata = rx->sdata;
1656         struct net_device *dev = sdata->dev;
1657         struct sk_buff *skb, *xmit_skb;
1658         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1659         struct sta_info *dsta;
1660         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1661
1662         skb = rx->skb;
1663         xmit_skb = NULL;
1664
1665         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1666              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1667             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1668             (status->rx_flags & IEEE80211_RX_RA_MATCH) &&
1669             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1670                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1671                         /*
1672                          * send multicast frames both to higher layers in
1673                          * local net stack and back to the wireless medium
1674                          */
1675                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1676                         if (!xmit_skb && net_ratelimit())
1677                                 printk(KERN_DEBUG "%s: failed to clone "
1678                                        "multicast frame\n", dev->name);
1679                 } else {
1680                         dsta = sta_info_get(sdata, skb->data);
1681                         if (dsta) {
1682                                 /*
1683                                  * The destination station is associated to
1684                                  * this AP (in this VLAN), so send the frame
1685                                  * directly to it and do not pass it to local
1686                                  * net stack.
1687                                  */
1688                                 xmit_skb = skb;
1689                                 skb = NULL;
1690                         }
1691                 }
1692         }
1693
1694         if (skb) {
1695                 int align __maybe_unused;
1696
1697 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1698                 /*
1699                  * 'align' will only take the values 0 or 2 here
1700                  * since all frames are required to be aligned
1701                  * to 2-byte boundaries when being passed to
1702                  * mac80211. That also explains the __skb_push()
1703                  * below.
1704                  */
1705                 align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1706                 if (align) {
1707                         if (WARN_ON(skb_headroom(skb) < 3)) {
1708                                 dev_kfree_skb(skb);
1709                                 skb = NULL;
1710                         } else {
1711                                 u8 *data = skb->data;
1712                                 size_t len = skb_headlen(skb);
1713                                 skb->data -= align;
1714                                 memmove(skb->data, data, len);
1715                                 skb_set_tail_pointer(skb, len);
1716                         }
1717                 }
1718 #endif
1719
1720                 if (skb) {
1721                         /* deliver to local stack */
1722                         skb->protocol = eth_type_trans(skb, dev);
1723                         memset(skb->cb, 0, sizeof(skb->cb));
1724                         netif_receive_skb(skb);
1725                 }
1726         }
1727
1728         if (xmit_skb) {
1729                 /* send to wireless media */
1730                 xmit_skb->protocol = htons(ETH_P_802_3);
1731                 skb_reset_network_header(xmit_skb);
1732                 skb_reset_mac_header(xmit_skb);
1733                 dev_queue_xmit(xmit_skb);
1734         }
1735 }
1736
1737 static ieee80211_rx_result debug_noinline
1738 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1739 {
1740         struct net_device *dev = rx->sdata->dev;
1741         struct sk_buff *skb = rx->skb;
1742         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1743         __le16 fc = hdr->frame_control;
1744         struct sk_buff_head frame_list;
1745         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1746
1747         if (unlikely(!ieee80211_is_data(fc)))
1748                 return RX_CONTINUE;
1749
1750         if (unlikely(!ieee80211_is_data_present(fc)))
1751                 return RX_DROP_MONITOR;
1752
1753         if (!(status->rx_flags & IEEE80211_RX_AMSDU))
1754                 return RX_CONTINUE;
1755
1756         if (ieee80211_has_a4(hdr->frame_control) &&
1757             rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1758             !rx->sdata->u.vlan.sta)
1759                 return RX_DROP_UNUSABLE;
1760
1761         if (is_multicast_ether_addr(hdr->addr1) &&
1762             ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1763               rx->sdata->u.vlan.sta) ||
1764              (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1765               rx->sdata->u.mgd.use_4addr)))
1766                 return RX_DROP_UNUSABLE;
1767
1768         skb->dev = dev;
1769         __skb_queue_head_init(&frame_list);
1770
1771         if (skb_linearize(skb))
1772                 return RX_DROP_UNUSABLE;
1773
1774         ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
1775                                  rx->sdata->vif.type,
1776                                  rx->local->hw.extra_tx_headroom);
1777
1778         while (!skb_queue_empty(&frame_list)) {
1779                 rx->skb = __skb_dequeue(&frame_list);
1780
1781                 if (!ieee80211_frame_allowed(rx, fc)) {
1782                         dev_kfree_skb(rx->skb);
1783                         continue;
1784                 }
1785                 dev->stats.rx_packets++;
1786                 dev->stats.rx_bytes += rx->skb->len;
1787
1788                 ieee80211_deliver_skb(rx);
1789         }
1790
1791         return RX_QUEUED;
1792 }
1793
1794 #ifdef CONFIG_MAC80211_MESH
1795 static ieee80211_rx_result
1796 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1797 {
1798         struct ieee80211_hdr *hdr;
1799         struct ieee80211s_hdr *mesh_hdr;
1800         unsigned int hdrlen;
1801         struct sk_buff *skb = rx->skb, *fwd_skb;
1802         struct ieee80211_local *local = rx->local;
1803         struct ieee80211_sub_if_data *sdata = rx->sdata;
1804         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1805
1806         hdr = (struct ieee80211_hdr *) skb->data;
1807         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1808         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1809
1810         if (!ieee80211_is_data(hdr->frame_control))
1811                 return RX_CONTINUE;
1812
1813         if (!mesh_hdr->ttl)
1814                 /* illegal frame */
1815                 return RX_DROP_MONITOR;
1816
1817         if (mesh_hdr->flags & MESH_FLAGS_AE) {
1818                 struct mesh_path *mppath;
1819                 char *proxied_addr;
1820                 char *mpp_addr;
1821
1822                 if (is_multicast_ether_addr(hdr->addr1)) {
1823                         mpp_addr = hdr->addr3;
1824                         proxied_addr = mesh_hdr->eaddr1;
1825                 } else {
1826                         mpp_addr = hdr->addr4;
1827                         proxied_addr = mesh_hdr->eaddr2;
1828                 }
1829
1830                 rcu_read_lock();
1831                 mppath = mpp_path_lookup(proxied_addr, sdata);
1832                 if (!mppath) {
1833                         mpp_path_add(proxied_addr, mpp_addr, sdata);
1834                 } else {
1835                         spin_lock_bh(&mppath->state_lock);
1836                         if (compare_ether_addr(mppath->mpp, mpp_addr) != 0)
1837                                 memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
1838                         spin_unlock_bh(&mppath->state_lock);
1839                 }
1840                 rcu_read_unlock();
1841         }
1842
1843         /* Frame has reached destination.  Don't forward */
1844         if (!is_multicast_ether_addr(hdr->addr1) &&
1845             compare_ether_addr(sdata->vif.addr, hdr->addr3) == 0)
1846                 return RX_CONTINUE;
1847
1848         mesh_hdr->ttl--;
1849
1850         if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
1851                 if (!mesh_hdr->ttl)
1852                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1853                                                      dropped_frames_ttl);
1854                 else {
1855                         struct ieee80211_hdr *fwd_hdr;
1856                         struct ieee80211_tx_info *info;
1857
1858                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1859
1860                         if (!fwd_skb && net_ratelimit())
1861                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1862                                                    sdata->name);
1863                         if (!fwd_skb)
1864                                 goto out;
1865
1866                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1867                         memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
1868                         info = IEEE80211_SKB_CB(fwd_skb);
1869                         memset(info, 0, sizeof(*info));
1870                         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1871                         info->control.vif = &rx->sdata->vif;
1872                         skb_set_queue_mapping(skb,
1873                                 ieee80211_select_queue(rx->sdata, fwd_skb));
1874                         ieee80211_set_qos_hdr(local, skb);
1875                         if (is_multicast_ether_addr(fwd_hdr->addr1))
1876                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1877                                                                 fwded_mcast);
1878                         else {
1879                                 int err;
1880                                 /*
1881                                  * Save TA to addr1 to send TA a path error if a
1882                                  * suitable next hop is not found
1883                                  */
1884                                 memcpy(fwd_hdr->addr1, fwd_hdr->addr2,
1885                                                 ETH_ALEN);
1886                                 err = mesh_nexthop_lookup(fwd_skb, sdata);
1887                                 /* Failed to immediately resolve next hop:
1888                                  * fwded frame was dropped or will be added
1889                                  * later to the pending skb queue.  */
1890                                 if (err)
1891                                         return RX_DROP_MONITOR;
1892
1893                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1894                                                                 fwded_unicast);
1895                         }
1896                         IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1897                                                      fwded_frames);
1898                         ieee80211_add_pending_skb(local, fwd_skb);
1899                 }
1900         }
1901
1902  out:
1903         if (is_multicast_ether_addr(hdr->addr1) ||
1904             sdata->dev->flags & IFF_PROMISC)
1905                 return RX_CONTINUE;
1906         else
1907                 return RX_DROP_MONITOR;
1908 }
1909 #endif
1910
1911 static ieee80211_rx_result debug_noinline
1912 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1913 {
1914         struct ieee80211_sub_if_data *sdata = rx->sdata;
1915         struct ieee80211_local *local = rx->local;
1916         struct net_device *dev = sdata->dev;
1917         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1918         __le16 fc = hdr->frame_control;
1919         int err;
1920
1921         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1922                 return RX_CONTINUE;
1923
1924         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1925                 return RX_DROP_MONITOR;
1926
1927         /*
1928          * Allow the cooked monitor interface of an AP to see 4-addr frames so
1929          * that a 4-addr station can be detected and moved into a separate VLAN
1930          */
1931         if (ieee80211_has_a4(hdr->frame_control) &&
1932             sdata->vif.type == NL80211_IFTYPE_AP)
1933                 return RX_DROP_MONITOR;
1934
1935         err = __ieee80211_data_to_8023(rx);
1936         if (unlikely(err))
1937                 return RX_DROP_UNUSABLE;
1938
1939         if (!ieee80211_frame_allowed(rx, fc))
1940                 return RX_DROP_MONITOR;
1941
1942         rx->skb->dev = dev;
1943
1944         dev->stats.rx_packets++;
1945         dev->stats.rx_bytes += rx->skb->len;
1946
1947         if (local->ps_sdata && local->hw.conf.dynamic_ps_timeout > 0 &&
1948             !is_multicast_ether_addr(
1949                     ((struct ethhdr *)rx->skb->data)->h_dest) &&
1950             (!local->scanning &&
1951              !test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state))) {
1952                         mod_timer(&local->dynamic_ps_timer, jiffies +
1953                          msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
1954         }
1955
1956         ieee80211_deliver_skb(rx);
1957
1958         return RX_QUEUED;
1959 }
1960
1961 static ieee80211_rx_result debug_noinline
1962 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1963 {
1964         struct ieee80211_local *local = rx->local;
1965         struct ieee80211_hw *hw = &local->hw;
1966         struct sk_buff *skb = rx->skb;
1967         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1968         struct tid_ampdu_rx *tid_agg_rx;
1969         u16 start_seq_num;
1970         u16 tid;
1971
1972         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1973                 return RX_CONTINUE;
1974
1975         if (ieee80211_is_back_req(bar->frame_control)) {
1976                 struct {
1977                         __le16 control, start_seq_num;
1978                 } __packed bar_data;
1979
1980                 if (!rx->sta)
1981                         return RX_DROP_MONITOR;
1982
1983                 if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
1984                                   &bar_data, sizeof(bar_data)))
1985                         return RX_DROP_MONITOR;
1986
1987                 tid = le16_to_cpu(bar_data.control) >> 12;
1988
1989                 tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
1990                 if (!tid_agg_rx)
1991                         return RX_DROP_MONITOR;
1992
1993                 start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
1994
1995                 /* reset session timer */
1996                 if (tid_agg_rx->timeout)
1997                         mod_timer(&tid_agg_rx->session_timer,
1998                                   TU_TO_EXP_TIME(tid_agg_rx->timeout));
1999
2000                 spin_lock(&tid_agg_rx->reorder_lock);
2001                 /* release stored frames up to start of BAR */
2002                 ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num);
2003                 spin_unlock(&tid_agg_rx->reorder_lock);
2004
2005                 kfree_skb(skb);
2006                 return RX_QUEUED;
2007         }
2008
2009         /*
2010          * After this point, we only want management frames,
2011          * so we can drop all remaining control frames to
2012          * cooked monitor interfaces.
2013          */
2014         return RX_DROP_MONITOR;
2015 }
2016
2017 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
2018                                            struct ieee80211_mgmt *mgmt,
2019                                            size_t len)
2020 {
2021         struct ieee80211_local *local = sdata->local;
2022         struct sk_buff *skb;
2023         struct ieee80211_mgmt *resp;
2024
2025         if (compare_ether_addr(mgmt->da, sdata->vif.addr) != 0) {
2026                 /* Not to own unicast address */
2027                 return;
2028         }
2029
2030         if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
2031             compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
2032                 /* Not from the current AP or not associated yet. */
2033                 return;
2034         }
2035
2036         if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
2037                 /* Too short SA Query request frame */
2038                 return;
2039         }
2040
2041         skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
2042         if (skb == NULL)
2043                 return;
2044
2045         skb_reserve(skb, local->hw.extra_tx_headroom);
2046         resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
2047         memset(resp, 0, 24);
2048         memcpy(resp->da, mgmt->sa, ETH_ALEN);
2049         memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
2050         memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
2051         resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2052                                           IEEE80211_STYPE_ACTION);
2053         skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
2054         resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
2055         resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
2056         memcpy(resp->u.action.u.sa_query.trans_id,
2057                mgmt->u.action.u.sa_query.trans_id,
2058                WLAN_SA_QUERY_TR_ID_LEN);
2059
2060         ieee80211_tx_skb(sdata, skb);
2061 }
2062
2063 static ieee80211_rx_result debug_noinline
2064 ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
2065 {
2066         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2067         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2068
2069         /*
2070          * From here on, look only at management frames.
2071          * Data and control frames are already handled,
2072          * and unknown (reserved) frames are useless.
2073          */
2074         if (rx->skb->len < 24)
2075                 return RX_DROP_MONITOR;
2076
2077         if (!ieee80211_is_mgmt(mgmt->frame_control))
2078                 return RX_DROP_MONITOR;
2079
2080         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2081                 return RX_DROP_MONITOR;
2082
2083         if (ieee80211_drop_unencrypted_mgmt(rx))
2084                 return RX_DROP_UNUSABLE;
2085
2086         return RX_CONTINUE;
2087 }
2088
2089 static ieee80211_rx_result debug_noinline
2090 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
2091 {
2092         struct ieee80211_local *local = rx->local;
2093         struct ieee80211_sub_if_data *sdata = rx->sdata;
2094         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2095         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2096         int len = rx->skb->len;
2097
2098         if (!ieee80211_is_action(mgmt->frame_control))
2099                 return RX_CONTINUE;
2100
2101         /* drop too small frames */
2102         if (len < IEEE80211_MIN_ACTION_SIZE)
2103                 return RX_DROP_UNUSABLE;
2104
2105         if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC)
2106                 return RX_DROP_UNUSABLE;
2107
2108         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2109                 return RX_DROP_UNUSABLE;
2110
2111         switch (mgmt->u.action.category) {
2112         case WLAN_CATEGORY_BACK:
2113                 /*
2114                  * The aggregation code is not prepared to handle
2115                  * anything but STA/AP due to the BSSID handling;
2116                  * IBSS could work in the code but isn't supported
2117                  * by drivers or the standard.
2118                  */
2119                 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2120                     sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2121                     sdata->vif.type != NL80211_IFTYPE_AP)
2122                         break;
2123
2124                 /* verify action_code is present */
2125                 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2126                         break;
2127
2128                 switch (mgmt->u.action.u.addba_req.action_code) {
2129                 case WLAN_ACTION_ADDBA_REQ:
2130                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2131                                    sizeof(mgmt->u.action.u.addba_req)))
2132                                 goto invalid;
2133                         break;
2134                 case WLAN_ACTION_ADDBA_RESP:
2135                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2136                                    sizeof(mgmt->u.action.u.addba_resp)))
2137                                 goto invalid;
2138                         break;
2139                 case WLAN_ACTION_DELBA:
2140                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2141                                    sizeof(mgmt->u.action.u.delba)))
2142                                 goto invalid;
2143                         break;
2144                 default:
2145                         goto invalid;
2146                 }
2147
2148                 goto queue;
2149         case WLAN_CATEGORY_SPECTRUM_MGMT:
2150                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
2151                         break;
2152
2153                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
2154                         break;
2155
2156                 /* verify action_code is present */
2157                 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2158                         break;
2159
2160                 switch (mgmt->u.action.u.measurement.action_code) {
2161                 case WLAN_ACTION_SPCT_MSR_REQ:
2162                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2163                                    sizeof(mgmt->u.action.u.measurement)))
2164                                 break;
2165                         ieee80211_process_measurement_req(sdata, mgmt, len);
2166                         goto handled;
2167                 case WLAN_ACTION_SPCT_CHL_SWITCH:
2168                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2169                                    sizeof(mgmt->u.action.u.chan_switch)))
2170                                 break;
2171
2172                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
2173                                 break;
2174
2175                         if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
2176                                 break;
2177
2178                         goto queue;
2179                 }
2180                 break;
2181         case WLAN_CATEGORY_SA_QUERY:
2182                 if (len < (IEEE80211_MIN_ACTION_SIZE +
2183                            sizeof(mgmt->u.action.u.sa_query)))
2184                         break;
2185
2186                 switch (mgmt->u.action.u.sa_query.action) {
2187                 case WLAN_ACTION_SA_QUERY_REQUEST:
2188                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
2189                                 break;
2190                         ieee80211_process_sa_query_req(sdata, mgmt, len);
2191                         goto handled;
2192                 }
2193                 break;
2194         case WLAN_CATEGORY_MESH_PLINK:
2195                 if (!ieee80211_vif_is_mesh(&sdata->vif))
2196                         break;
2197                 goto queue;
2198         case WLAN_CATEGORY_MESH_PATH_SEL:
2199                 if (!mesh_path_sel_is_hwmp(sdata))
2200                         break;
2201                 goto queue;
2202         }
2203
2204         return RX_CONTINUE;
2205
2206  invalid:
2207         status->rx_flags |= IEEE80211_RX_MALFORMED_ACTION_FRM;
2208         /* will return in the next handlers */
2209         return RX_CONTINUE;
2210
2211  handled:
2212         if (rx->sta)
2213                 rx->sta->rx_packets++;
2214         dev_kfree_skb(rx->skb);
2215         return RX_QUEUED;
2216
2217  queue:
2218         rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2219         skb_queue_tail(&sdata->skb_queue, rx->skb);
2220         ieee80211_queue_work(&local->hw, &sdata->work);
2221         if (rx->sta)
2222                 rx->sta->rx_packets++;
2223         return RX_QUEUED;
2224 }
2225
2226 static ieee80211_rx_result debug_noinline
2227 ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
2228 {
2229         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2230
2231         /* skip known-bad action frames and return them in the next handler */
2232         if (status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM)
2233                 return RX_CONTINUE;
2234
2235         /*
2236          * Getting here means the kernel doesn't know how to handle
2237          * it, but maybe userspace does ... include returned frames
2238          * so userspace can register for those to know whether ones
2239          * it transmitted were processed or returned.
2240          */
2241
2242         if (cfg80211_rx_mgmt(rx->sdata->dev, status->freq,
2243                              rx->skb->data, rx->skb->len,
2244                              GFP_ATOMIC)) {
2245                 if (rx->sta)
2246                         rx->sta->rx_packets++;
2247                 dev_kfree_skb(rx->skb);
2248                 return RX_QUEUED;
2249         }
2250
2251
2252         return RX_CONTINUE;
2253 }
2254
2255 static ieee80211_rx_result debug_noinline
2256 ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
2257 {
2258         struct ieee80211_local *local = rx->local;
2259         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2260         struct sk_buff *nskb;
2261         struct ieee80211_sub_if_data *sdata = rx->sdata;
2262         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2263
2264         if (!ieee80211_is_action(mgmt->frame_control))
2265                 return RX_CONTINUE;
2266
2267         /*
2268          * For AP mode, hostapd is responsible for handling any action
2269          * frames that we didn't handle, including returning unknown
2270          * ones. For all other modes we will return them to the sender,
2271          * setting the 0x80 bit in the action category, as required by
2272          * 802.11-2007 7.3.1.11.
2273          * Newer versions of hostapd shall also use the management frame
2274          * registration mechanisms, but older ones still use cooked
2275          * monitor interfaces so push all frames there.
2276          */
2277         if (!(status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM) &&
2278             (sdata->vif.type == NL80211_IFTYPE_AP ||
2279              sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
2280                 return RX_DROP_MONITOR;
2281
2282         /* do not return rejected action frames */
2283         if (mgmt->u.action.category & 0x80)
2284                 return RX_DROP_UNUSABLE;
2285
2286         nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
2287                                GFP_ATOMIC);
2288         if (nskb) {
2289                 struct ieee80211_mgmt *nmgmt = (void *)nskb->data;
2290
2291                 nmgmt->u.action.category |= 0x80;
2292                 memcpy(nmgmt->da, nmgmt->sa, ETH_ALEN);
2293                 memcpy(nmgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
2294
2295                 memset(nskb->cb, 0, sizeof(nskb->cb));
2296
2297                 ieee80211_tx_skb(rx->sdata, nskb);
2298         }
2299         dev_kfree_skb(rx->skb);
2300         return RX_QUEUED;
2301 }
2302
2303 static ieee80211_rx_result debug_noinline
2304 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
2305 {
2306         struct ieee80211_sub_if_data *sdata = rx->sdata;
2307         ieee80211_rx_result rxs;
2308         struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
2309         __le16 stype;
2310
2311         rxs = ieee80211_work_rx_mgmt(rx->sdata, rx->skb);
2312         if (rxs != RX_CONTINUE)
2313                 return rxs;
2314
2315         stype = mgmt->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE);
2316
2317         if (!ieee80211_vif_is_mesh(&sdata->vif) &&
2318             sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2319             sdata->vif.type != NL80211_IFTYPE_STATION)
2320                 return RX_DROP_MONITOR;
2321
2322         switch (stype) {
2323         case cpu_to_le16(IEEE80211_STYPE_BEACON):
2324         case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
2325                 /* process for all: mesh, mlme, ibss */
2326                 break;
2327         case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
2328         case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
2329                 if (is_multicast_ether_addr(mgmt->da) &&
2330                     !is_broadcast_ether_addr(mgmt->da))
2331                         return RX_DROP_MONITOR;
2332
2333                 /* process only for station */
2334                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
2335                         return RX_DROP_MONITOR;
2336                 break;
2337         case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
2338         case cpu_to_le16(IEEE80211_STYPE_AUTH):
2339                 /* process only for ibss */
2340                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
2341                         return RX_DROP_MONITOR;
2342                 break;
2343         default:
2344                 return RX_DROP_MONITOR;
2345         }
2346
2347         /* queue up frame and kick off work to process it */
2348         rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2349         skb_queue_tail(&sdata->skb_queue, rx->skb);
2350         ieee80211_queue_work(&rx->local->hw, &sdata->work);
2351         if (rx->sta)
2352                 rx->sta->rx_packets++;
2353
2354         return RX_QUEUED;
2355 }
2356
2357 static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
2358                                             struct ieee80211_rx_data *rx)
2359 {
2360         int keyidx;
2361         unsigned int hdrlen;
2362
2363         hdrlen = ieee80211_hdrlen(hdr->frame_control);
2364         if (rx->skb->len >= hdrlen + 4)
2365                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
2366         else
2367                 keyidx = -1;
2368
2369         if (!rx->sta) {
2370                 /*
2371                  * Some hardware seem to generate incorrect Michael MIC
2372                  * reports; ignore them to avoid triggering countermeasures.
2373                  */
2374                 return;
2375         }
2376
2377         if (!ieee80211_has_protected(hdr->frame_control))
2378                 return;
2379
2380         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
2381                 /*
2382                  * APs with pairwise keys should never receive Michael MIC
2383                  * errors for non-zero keyidx because these are reserved for
2384                  * group keys and only the AP is sending real multicast
2385                  * frames in the BSS.
2386                  */
2387                 return;
2388         }
2389
2390         if (!ieee80211_is_data(hdr->frame_control) &&
2391             !ieee80211_is_auth(hdr->frame_control))
2392                 return;
2393
2394         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
2395                                         GFP_ATOMIC);
2396 }
2397
2398 /* TODO: use IEEE80211_RX_FRAGMENTED */
2399 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
2400                                         struct ieee80211_rate *rate)
2401 {
2402         struct ieee80211_sub_if_data *sdata;
2403         struct ieee80211_local *local = rx->local;
2404         struct ieee80211_rtap_hdr {
2405                 struct ieee80211_radiotap_header hdr;
2406                 u8 flags;
2407                 u8 rate_or_pad;
2408                 __le16 chan_freq;
2409                 __le16 chan_flags;
2410         } __packed *rthdr;
2411         struct sk_buff *skb = rx->skb, *skb2;
2412         struct net_device *prev_dev = NULL;
2413         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2414
2415         /*
2416          * If cooked monitor has been processed already, then
2417          * don't do it again. If not, set the flag.
2418          */
2419         if (rx->flags & IEEE80211_RX_CMNTR)
2420                 goto out_free_skb;
2421         rx->flags |= IEEE80211_RX_CMNTR;
2422
2423         if (skb_headroom(skb) < sizeof(*rthdr) &&
2424             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
2425                 goto out_free_skb;
2426
2427         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
2428         memset(rthdr, 0, sizeof(*rthdr));
2429         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
2430         rthdr->hdr.it_present =
2431                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
2432                             (1 << IEEE80211_RADIOTAP_CHANNEL));
2433
2434         if (rate) {
2435                 rthdr->rate_or_pad = rate->bitrate / 5;
2436                 rthdr->hdr.it_present |=
2437                         cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
2438         }
2439         rthdr->chan_freq = cpu_to_le16(status->freq);
2440
2441         if (status->band == IEEE80211_BAND_5GHZ)
2442                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
2443                                                 IEEE80211_CHAN_5GHZ);
2444         else
2445                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
2446                                                 IEEE80211_CHAN_2GHZ);
2447
2448         skb_set_mac_header(skb, 0);
2449         skb->ip_summed = CHECKSUM_UNNECESSARY;
2450         skb->pkt_type = PACKET_OTHERHOST;
2451         skb->protocol = htons(ETH_P_802_2);
2452
2453         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2454                 if (!ieee80211_sdata_running(sdata))
2455                         continue;
2456
2457                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
2458                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
2459                         continue;
2460
2461                 if (prev_dev) {
2462                         skb2 = skb_clone(skb, GFP_ATOMIC);
2463                         if (skb2) {
2464                                 skb2->dev = prev_dev;
2465                                 netif_receive_skb(skb2);
2466                         }
2467                 }
2468
2469                 prev_dev = sdata->dev;
2470                 sdata->dev->stats.rx_packets++;
2471                 sdata->dev->stats.rx_bytes += skb->len;
2472         }
2473
2474         if (prev_dev) {
2475                 skb->dev = prev_dev;
2476                 netif_receive_skb(skb);
2477                 return;
2478         }
2479
2480  out_free_skb:
2481         dev_kfree_skb(skb);
2482 }
2483
2484 static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
2485                                          ieee80211_rx_result res)
2486 {
2487         switch (res) {
2488         case RX_DROP_MONITOR:
2489                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2490                 if (rx->sta)
2491                         rx->sta->rx_dropped++;
2492                 /* fall through */
2493         case RX_CONTINUE: {
2494                 struct ieee80211_rate *rate = NULL;
2495                 struct ieee80211_supported_band *sband;
2496                 struct ieee80211_rx_status *status;
2497
2498                 status = IEEE80211_SKB_RXCB((rx->skb));
2499
2500                 sband = rx->local->hw.wiphy->bands[status->band];
2501                 if (!(status->flag & RX_FLAG_HT))
2502                         rate = &sband->bitrates[status->rate_idx];
2503
2504                 ieee80211_rx_cooked_monitor(rx, rate);
2505                 break;
2506                 }
2507         case RX_DROP_UNUSABLE:
2508                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2509                 if (rx->sta)
2510                         rx->sta->rx_dropped++;
2511                 dev_kfree_skb(rx->skb);
2512                 break;
2513         case RX_QUEUED:
2514                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_queued);
2515                 break;
2516         }
2517 }
2518
2519 static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx)
2520 {
2521         ieee80211_rx_result res = RX_DROP_MONITOR;
2522         struct sk_buff *skb;
2523
2524 #define CALL_RXH(rxh)                   \
2525         do {                            \
2526                 res = rxh(rx);          \
2527                 if (res != RX_CONTINUE) \
2528                         goto rxh_next;  \
2529         } while (0);
2530
2531         spin_lock(&rx->local->rx_skb_queue.lock);
2532         if (rx->local->running_rx_handler)
2533                 goto unlock;
2534
2535         rx->local->running_rx_handler = true;
2536
2537         while ((skb = __skb_dequeue(&rx->local->rx_skb_queue))) {
2538                 spin_unlock(&rx->local->rx_skb_queue.lock);
2539
2540                 /*
2541                  * all the other fields are valid across frames
2542                  * that belong to an aMPDU since they are on the
2543                  * same TID from the same station
2544                  */
2545                 rx->skb = skb;
2546
2547                 CALL_RXH(ieee80211_rx_h_decrypt)
2548                 CALL_RXH(ieee80211_rx_h_check_more_data)
2549                 CALL_RXH(ieee80211_rx_h_sta_process)
2550                 CALL_RXH(ieee80211_rx_h_defragment)
2551                 CALL_RXH(ieee80211_rx_h_ps_poll)
2552                 CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2553                 /* must be after MMIC verify so header is counted in MPDU mic */
2554                 CALL_RXH(ieee80211_rx_h_remove_qos_control)
2555                 CALL_RXH(ieee80211_rx_h_amsdu)
2556 #ifdef CONFIG_MAC80211_MESH
2557                 if (ieee80211_vif_is_mesh(&rx->sdata->vif))
2558                         CALL_RXH(ieee80211_rx_h_mesh_fwding);
2559 #endif
2560                 CALL_RXH(ieee80211_rx_h_data)
2561                 CALL_RXH(ieee80211_rx_h_ctrl);
2562                 CALL_RXH(ieee80211_rx_h_mgmt_check)
2563                 CALL_RXH(ieee80211_rx_h_action)
2564                 CALL_RXH(ieee80211_rx_h_userspace_mgmt)
2565                 CALL_RXH(ieee80211_rx_h_action_return)
2566                 CALL_RXH(ieee80211_rx_h_mgmt)
2567
2568  rxh_next:
2569                 ieee80211_rx_handlers_result(rx, res);
2570                 spin_lock(&rx->local->rx_skb_queue.lock);
2571 #undef CALL_RXH
2572         }
2573
2574         rx->local->running_rx_handler = false;
2575
2576  unlock:
2577         spin_unlock(&rx->local->rx_skb_queue.lock);
2578 }
2579
2580 static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
2581 {
2582         ieee80211_rx_result res = RX_DROP_MONITOR;
2583
2584 #define CALL_RXH(rxh)                   \
2585         do {                            \
2586                 res = rxh(rx);          \
2587                 if (res != RX_CONTINUE) \
2588                         goto rxh_next;  \
2589         } while (0);
2590
2591         CALL_RXH(ieee80211_rx_h_passive_scan)
2592         CALL_RXH(ieee80211_rx_h_check)
2593
2594         ieee80211_rx_reorder_ampdu(rx);
2595
2596         ieee80211_rx_handlers(rx);
2597         return;
2598
2599  rxh_next:
2600         ieee80211_rx_handlers_result(rx, res);
2601
2602 #undef CALL_RXH
2603 }
2604
2605 /*
2606  * This function makes calls into the RX path, therefore
2607  * it has to be invoked under RCU read lock.
2608  */
2609 void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
2610 {
2611         struct ieee80211_rx_data rx = {
2612                 .sta = sta,
2613                 .sdata = sta->sdata,
2614                 .local = sta->local,
2615                 .queue = tid,
2616                 .flags = 0,
2617         };
2618         struct tid_ampdu_rx *tid_agg_rx;
2619
2620         tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
2621         if (!tid_agg_rx)
2622                 return;
2623
2624         spin_lock(&tid_agg_rx->reorder_lock);
2625         ieee80211_sta_reorder_release(&sta->local->hw, tid_agg_rx);
2626         spin_unlock(&tid_agg_rx->reorder_lock);
2627
2628         ieee80211_rx_handlers(&rx);
2629 }
2630
2631 /* main receive path */
2632
2633 static int prepare_for_handlers(struct ieee80211_rx_data *rx,
2634                                 struct ieee80211_hdr *hdr)
2635 {
2636         struct ieee80211_sub_if_data *sdata = rx->sdata;
2637         struct sk_buff *skb = rx->skb;
2638         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2639         u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
2640         int multicast = is_multicast_ether_addr(hdr->addr1);
2641
2642         switch (sdata->vif.type) {
2643         case NL80211_IFTYPE_STATION:
2644                 if (!bssid && !sdata->u.mgd.use_4addr)
2645                         return 0;
2646                 if (!multicast &&
2647                     compare_ether_addr(sdata->vif.addr, hdr->addr1) != 0) {
2648                         if (!(sdata->dev->flags & IFF_PROMISC) ||
2649                             sdata->u.mgd.use_4addr)
2650                                 return 0;
2651                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2652                 }
2653                 break;
2654         case NL80211_IFTYPE_ADHOC:
2655                 if (!bssid)
2656                         return 0;
2657                 if (ieee80211_is_beacon(hdr->frame_control)) {
2658                         return 1;
2659                 }
2660                 else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2661                         if (!(status->rx_flags & IEEE80211_RX_IN_SCAN))
2662                                 return 0;
2663                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2664                 } else if (!multicast &&
2665                            compare_ether_addr(sdata->vif.addr,
2666                                               hdr->addr1) != 0) {
2667                         if (!(sdata->dev->flags & IFF_PROMISC))
2668                                 return 0;
2669                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2670                 } else if (!rx->sta) {
2671                         int rate_idx;
2672                         if (status->flag & RX_FLAG_HT)
2673                                 rate_idx = 0; /* TODO: HT rates */
2674                         else
2675                                 rate_idx = status->rate_idx;
2676                         rx->sta = ieee80211_ibss_add_sta(sdata, bssid,
2677                                         hdr->addr2, BIT(rate_idx), GFP_ATOMIC);
2678                 }
2679                 break;
2680         case NL80211_IFTYPE_MESH_POINT:
2681                 if (!multicast &&
2682                     compare_ether_addr(sdata->vif.addr,
2683                                        hdr->addr1) != 0) {
2684                         if (!(sdata->dev->flags & IFF_PROMISC))
2685                                 return 0;
2686
2687                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2688                 }
2689                 break;
2690         case NL80211_IFTYPE_AP_VLAN:
2691         case NL80211_IFTYPE_AP:
2692                 if (!bssid) {
2693                         if (compare_ether_addr(sdata->vif.addr,
2694                                                hdr->addr1))
2695                                 return 0;
2696                 } else if (!ieee80211_bssid_match(bssid,
2697                                         sdata->vif.addr)) {
2698                         if (!(status->rx_flags & IEEE80211_RX_IN_SCAN) &&
2699                             !ieee80211_is_beacon(hdr->frame_control))
2700                                 return 0;
2701                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2702                 }
2703                 break;
2704         case NL80211_IFTYPE_WDS:
2705                 if (bssid || !ieee80211_is_data(hdr->frame_control))
2706                         return 0;
2707                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2708                         return 0;
2709                 break;
2710         default:
2711                 /* should never get here */
2712                 WARN_ON(1);
2713                 break;
2714         }
2715
2716         return 1;
2717 }
2718
2719 /*
2720  * This function returns whether or not the SKB
2721  * was destined for RX processing or not, which,
2722  * if consume is true, is equivalent to whether
2723  * or not the skb was consumed.
2724  */
2725 static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
2726                                             struct sk_buff *skb, bool consume)
2727 {
2728         struct ieee80211_local *local = rx->local;
2729         struct ieee80211_sub_if_data *sdata = rx->sdata;
2730         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2731         struct ieee80211_hdr *hdr = (void *)skb->data;
2732         int prepares;
2733
2734         rx->skb = skb;
2735         status->rx_flags |= IEEE80211_RX_RA_MATCH;
2736         prepares = prepare_for_handlers(rx, hdr);
2737
2738         if (!prepares)
2739                 return false;
2740
2741         if (status->flag & RX_FLAG_MMIC_ERROR) {
2742                 if (status->rx_flags & IEEE80211_RX_RA_MATCH)
2743                         ieee80211_rx_michael_mic_report(hdr, rx);
2744                 return false;
2745         }
2746
2747         if (!consume) {
2748                 skb = skb_copy(skb, GFP_ATOMIC);
2749                 if (!skb) {
2750                         if (net_ratelimit())
2751                                 wiphy_debug(local->hw.wiphy,
2752                                         "failed to copy skb for %s\n",
2753                                         sdata->name);
2754                         return true;
2755                 }
2756
2757                 rx->skb = skb;
2758         }
2759
2760         ieee80211_invoke_rx_handlers(rx);
2761         return true;
2762 }
2763
2764 /*
2765  * This is the actual Rx frames handler. as it blongs to Rx path it must
2766  * be called with rcu_read_lock protection.
2767  */
2768 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2769                                          struct sk_buff *skb)
2770 {
2771         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2772         struct ieee80211_local *local = hw_to_local(hw);
2773         struct ieee80211_sub_if_data *sdata;
2774         struct ieee80211_hdr *hdr;
2775         __le16 fc;
2776         struct ieee80211_rx_data rx;
2777         struct ieee80211_sub_if_data *prev;
2778         struct sta_info *sta, *tmp, *prev_sta;
2779         int err = 0;
2780
2781         fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
2782         memset(&rx, 0, sizeof(rx));
2783         rx.skb = skb;
2784         rx.local = local;
2785
2786         if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
2787                 local->dot11ReceivedFragmentCount++;
2788
2789         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
2790                      test_bit(SCAN_SW_SCANNING, &local->scanning)))
2791                 status->rx_flags |= IEEE80211_RX_IN_SCAN;
2792
2793         if (ieee80211_is_mgmt(fc))
2794                 err = skb_linearize(skb);
2795         else
2796                 err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
2797
2798         if (err) {
2799                 dev_kfree_skb(skb);
2800                 return;
2801         }
2802
2803         hdr = (struct ieee80211_hdr *)skb->data;
2804         ieee80211_parse_qos(&rx);
2805         ieee80211_verify_alignment(&rx);
2806
2807         if (ieee80211_is_data(fc)) {
2808                 prev_sta = NULL;
2809
2810                 for_each_sta_info(local, hdr->addr2, sta, tmp) {
2811                         if (!prev_sta) {
2812                                 prev_sta = sta;
2813                                 continue;
2814                         }
2815
2816                         rx.sta = prev_sta;
2817                         rx.sdata = prev_sta->sdata;
2818                         ieee80211_prepare_and_rx_handle(&rx, skb, false);
2819
2820                         prev_sta = sta;
2821                 }
2822
2823                 if (prev_sta) {
2824                         rx.sta = prev_sta;
2825                         rx.sdata = prev_sta->sdata;
2826
2827                         if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2828                                 return;
2829                         goto out;
2830                 }
2831         }
2832
2833         prev = NULL;
2834
2835         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2836                 if (!ieee80211_sdata_running(sdata))
2837                         continue;
2838
2839                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2840                     sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2841                         continue;
2842
2843                 /*
2844                  * frame is destined for this interface, but if it's
2845                  * not also for the previous one we handle that after
2846                  * the loop to avoid copying the SKB once too much
2847                  */
2848
2849                 if (!prev) {
2850                         prev = sdata;
2851                         continue;
2852                 }
2853
2854                 rx.sta = sta_info_get_bss(prev, hdr->addr2);
2855                 rx.sdata = prev;
2856                 ieee80211_prepare_and_rx_handle(&rx, skb, false);
2857
2858                 prev = sdata;
2859         }
2860
2861         if (prev) {
2862                 rx.sta = sta_info_get_bss(prev, hdr->addr2);
2863                 rx.sdata = prev;
2864
2865                 if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2866                         return;
2867         }
2868
2869  out:
2870         dev_kfree_skb(skb);
2871 }
2872
2873 /*
2874  * This is the receive path handler. It is called by a low level driver when an
2875  * 802.11 MPDU is received from the hardware.
2876  */
2877 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2878 {
2879         struct ieee80211_local *local = hw_to_local(hw);
2880         struct ieee80211_rate *rate = NULL;
2881         struct ieee80211_supported_band *sband;
2882         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2883
2884         WARN_ON_ONCE(softirq_count() == 0);
2885
2886         if (WARN_ON(status->band < 0 ||
2887                     status->band >= IEEE80211_NUM_BANDS))
2888                 goto drop;
2889
2890         sband = local->hw.wiphy->bands[status->band];
2891         if (WARN_ON(!sband))
2892                 goto drop;
2893
2894         /*
2895          * If we're suspending, it is possible although not too likely
2896          * that we'd be receiving frames after having already partially
2897          * quiesced the stack. We can't process such frames then since
2898          * that might, for example, cause stations to be added or other
2899          * driver callbacks be invoked.
2900          */
2901         if (unlikely(local->quiescing || local->suspended))
2902                 goto drop;
2903
2904         /*
2905          * The same happens when we're not even started,
2906          * but that's worth a warning.
2907          */
2908         if (WARN_ON(!local->started))
2909                 goto drop;
2910
2911         if (likely(!(status->flag & RX_FLAG_FAILED_PLCP_CRC))) {
2912                 /*
2913                  * Validate the rate, unless a PLCP error means that
2914                  * we probably can't have a valid rate here anyway.
2915                  */
2916
2917                 if (status->flag & RX_FLAG_HT) {
2918                         /*
2919                          * rate_idx is MCS index, which can be [0-76]
2920                          * as documented on:
2921                          *
2922                          * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
2923                          *
2924                          * Anything else would be some sort of driver or
2925                          * hardware error. The driver should catch hardware
2926                          * errors.
2927                          */
2928                         if (WARN((status->rate_idx < 0 ||
2929                                  status->rate_idx > 76),
2930                                  "Rate marked as an HT rate but passed "
2931                                  "status->rate_idx is not "
2932                                  "an MCS index [0-76]: %d (0x%02x)\n",
2933                                  status->rate_idx,
2934                                  status->rate_idx))
2935                                 goto drop;
2936                 } else {
2937                         if (WARN_ON(status->rate_idx < 0 ||
2938                                     status->rate_idx >= sband->n_bitrates))
2939                                 goto drop;
2940                         rate = &sband->bitrates[status->rate_idx];
2941                 }
2942         }
2943
2944         status->rx_flags = 0;
2945
2946         /*
2947          * key references and virtual interfaces are protected using RCU
2948          * and this requires that we are in a read-side RCU section during
2949          * receive processing
2950          */
2951         rcu_read_lock();
2952
2953         /*
2954          * Frames with failed FCS/PLCP checksum are not returned,
2955          * all other frames are returned without radiotap header
2956          * if it was previously present.
2957          * Also, frames with less than 16 bytes are dropped.
2958          */
2959         skb = ieee80211_rx_monitor(local, skb, rate);
2960         if (!skb) {
2961                 rcu_read_unlock();
2962                 return;
2963         }
2964
2965         ieee80211_tpt_led_trig_rx(local,
2966                         ((struct ieee80211_hdr *)skb->data)->frame_control,
2967                         skb->len);
2968         __ieee80211_rx_handle_packet(hw, skb);
2969
2970         rcu_read_unlock();
2971
2972         return;
2973  drop:
2974         kfree_skb(skb);
2975 }
2976 EXPORT_SYMBOL(ieee80211_rx);
2977
2978 /* This is a version of the rx handler that can be called from hard irq
2979  * context. Post the skb on the queue and schedule the tasklet */
2980 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
2981 {
2982         struct ieee80211_local *local = hw_to_local(hw);
2983
2984         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2985
2986         skb->pkt_type = IEEE80211_RX_MSG;
2987         skb_queue_tail(&local->skb_queue, skb);
2988         tasklet_schedule(&local->tasklet);
2989 }
2990 EXPORT_SYMBOL(ieee80211_rx_irqsafe);