net/mac80211/rx.c

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