net/mac80211/rx.c

   1 /*
   2  * Copyright 2002-2005, Instant802 Networks, Inc.
   3  * Copyright 2005-2006, Devicescape Software, Inc.
   4  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   5  * Copyright 2007-2010  Johannes Berg <johannes@sipsolutions.net>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/jiffies.h>
  13 #include <linux/slab.h>
  14 #include <linux/kernel.h>
  15 #include <linux/skbuff.h>
  16 #include <linux/netdevice.h>
  17 #include <linux/etherdevice.h>
  18 #include <linux/rcupdate.h>
  19 #include <net/mac80211.h>
  20 #include <net/ieee80211_radiotap.h>
  21
  22 #include "ieee80211_i.h"
  23 #include "driver-ops.h"
  24 #include "led.h"
  25 #include "mesh.h"
  26 #include "wep.h"
  27 #include "wpa.h"
  28 #include "tkip.h"
  29 #include "wme.h"
  30
  31 /*
  32  * monitor mode reception
  33  *
  34  * This function cleans up the SKB, i.e. it removes all the stuff
  35  * only useful for monitoring.
  36  */
  37 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
  38                                            struct sk_buff *skb)
  39 {
  40         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
  41                 if (likely(skb->len > FCS_LEN))
  42                         __pskb_trim(skb, skb->len - FCS_LEN);
  43                 else {
  44                         /* driver bug */
  45                         WARN_ON(1);
  46                         dev_kfree_skb(skb);
  47                         skb = NULL;
  48                 }
  49         }
  50
  51         return skb;
  52 }
  53
  54 static inline int should_drop_frame(struct sk_buff *skb,
  55                                     int present_fcs_len)
  56 {
  57         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  58         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  59
  60         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
  61                 return 1;
  62         if (unlikely(skb->len < 16 + present_fcs_len))
  63                 return 1;
  64         if (ieee80211_is_ctl(hdr->frame_control) &&
  65             !ieee80211_is_pspoll(hdr->frame_control) &&
  66             !ieee80211_is_back_req(hdr->frame_control))
  67                 return 1;
  68         return 0;
  69 }
  70
  71 static int
  72 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
  73                           struct ieee80211_rx_status *status)
  74 {
  75         int len;
  76
  77         /* always present fields */
  78         len = sizeof(struct ieee80211_radiotap_header) + 9;
  79
  80         if (status->flag & RX_FLAG_MACTIME_MPDU)
  81                 len += 8;
  82         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
  83                 len += 1;
  84
  85         if (len & 1) /* padding for RX_FLAGS if necessary */
  86                 len++;
  87
  88         if (status->flag & RX_FLAG_HT) /* HT info */
  89                 len += 3;
  90
  91         return len;
  92 }
  93
  94 /*
  95  * ieee80211_add_rx_radiotap_header - add radiotap header
  96  *
  97  * add a radiotap header containing all the fields which the hardware provided.
  98  */
  99 static void
 100 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
 101                                  struct sk_buff *skb,
 102                                  struct ieee80211_rate *rate,
 103                                  int rtap_len)
 104 {
 105         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 106         struct ieee80211_radiotap_header *rthdr;
 107         unsigned char *pos;
 108         u16 rx_flags = 0;
 109
 110         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
 111         memset(rthdr, 0, rtap_len);
 112
 113         /* radiotap header, set always present flags */
 114         rthdr->it_present =
 115                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 116                             (1 << IEEE80211_RADIOTAP_CHANNEL) |
 117                             (1 << IEEE80211_RADIOTAP_ANTENNA) |
 118                             (1 << IEEE80211_RADIOTAP_RX_FLAGS));
 119         rthdr->it_len = cpu_to_le16(rtap_len);
 120
 121         pos = (unsigned char *)(rthdr+1);
 122
 123         /* the order of the following fields is important */
 124
 125         /* IEEE80211_RADIOTAP_TSFT */
 126         if (status->flag & RX_FLAG_MACTIME_MPDU) {
 127                 put_unaligned_le64(status->mactime, pos);
 128                 rthdr->it_present |=
 129                         cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
 130                 pos += 8;
 131         }
 132
 133         /* IEEE80211_RADIOTAP_FLAGS */
 134         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 135                 *pos |= IEEE80211_RADIOTAP_F_FCS;
 136         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 137                 *pos |= IEEE80211_RADIOTAP_F_BADFCS;
 138         if (status->flag & RX_FLAG_SHORTPRE)
 139                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
 140         pos++;
 141
 142         /* IEEE80211_RADIOTAP_RATE */
 143         if (status->flag & RX_FLAG_HT) {
 144                 /*
 145                  * MCS information is a separate field in radiotap,
 146                  * added below. The byte here is needed as padding
 147                  * for the channel though, so initialise it to 0.
 148                  */
 149                 *pos = 0;
 150         } else {
 151                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
 152                 *pos = rate->bitrate / 5;
 153         }
 154         pos++;
 155
 156         /* IEEE80211_RADIOTAP_CHANNEL */
 157         put_unaligned_le16(status->freq, pos);
 158         pos += 2;
 159         if (status->band == IEEE80211_BAND_5GHZ)
 160                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ,
 161                                    pos);
 162         else if (status->flag & RX_FLAG_HT)
 163                 put_unaligned_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ,
 164                                    pos);
 165         else if (rate->flags & IEEE80211_RATE_ERP_G)
 166                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
 167                                    pos);
 168         else
 169                 put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
 170                                    pos);
 171         pos += 2;
 172
 173         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
 174         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
 175                 *pos = status->signal;
 176                 rthdr->it_present |=
 177                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
 178                 pos++;
 179         }
 180
 181         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
 182
 183         /* IEEE80211_RADIOTAP_ANTENNA */
 184         *pos = status->antenna;
 185         pos++;
 186
 187         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
 188
 189         /* IEEE80211_RADIOTAP_RX_FLAGS */
 190         /* ensure 2 byte alignment for the 2 byte field as required */
 191         if ((pos - (u8 *)rthdr) & 1)
 192                 pos++;
 193         if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
 194                 rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
 195         put_unaligned_le16(rx_flags, pos);
 196         pos += 2;
 197
 198         if (status->flag & RX_FLAG_HT) {
 199                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
 200                 *pos++ = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
 201                          IEEE80211_RADIOTAP_MCS_HAVE_GI |
 202                          IEEE80211_RADIOTAP_MCS_HAVE_BW;
 203                 *pos = 0;
 204                 if (status->flag & RX_FLAG_SHORT_GI)
 205                         *pos |= IEEE80211_RADIOTAP_MCS_SGI;
 206                 if (status->flag & RX_FLAG_40MHZ)
 207                         *pos |= IEEE80211_RADIOTAP_MCS_BW_40;
 208                 pos++;
 209                 *pos++ = status->rate_idx;
 210         }
 211 }
 212
 213 /*
 214  * This function copies a received frame to all monitor interfaces and
 215  * returns a cleaned-up SKB that no longer includes the FCS nor the
 216  * radiotap header the driver might have added.
 217  */
 218 static struct sk_buff *
 219 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
 220                      struct ieee80211_rate *rate)
 221 {
 222         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
 223         struct ieee80211_sub_if_data *sdata;
 224         int needed_headroom = 0;
 225         struct sk_buff *skb, *skb2;
 226         struct net_device *prev_dev = NULL;
 227         int present_fcs_len = 0;
 228
 229         /*
 230          * First, we may need to make a copy of the skb because
 231          *  (1) we need to modify it for radiotap (if not present), and
 232          *  (2) the other RX handlers will modify the skb we got.
 233          *
 234          * We don't need to, of course, if we aren't going to return
 235          * the SKB because it has a bad FCS/PLCP checksum.
 236          */
 237
 238         /* room for the radiotap header based on driver features */
 239         needed_headroom = ieee80211_rx_radiotap_len(local, status);
 240
 241         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 242                 present_fcs_len = FCS_LEN;
 243
 244         /* make sure hdr->frame_control is on the linear part */
 245         if (!pskb_may_pull(origskb, 2)) {
 246                 dev_kfree_skb(origskb);
 247                 return NULL;
 248         }
 249
 250         if (!local->monitors) {
 251                 if (should_drop_frame(origskb, present_fcs_len)) {
 252                         dev_kfree_skb(origskb);
 253                         return NULL;
 254                 }
 255
 256                 return remove_monitor_info(local, origskb);
 257         }
 258
 259         if (should_drop_frame(origskb, present_fcs_len)) {
 260                 /* only need to expand headroom if necessary */
 261                 skb = origskb;
 262                 origskb = NULL;
 263
 264                 /*
 265                  * This shouldn't trigger often because most devices have an
 266                  * RX header they pull before we get here, and that should
 267                  * be big enough for our radiotap information. We should
 268                  * probably export the length to drivers so that we can have
 269                  * them allocate enough headroom to start with.
 270                  */
 271                 if (skb_headroom(skb) < needed_headroom &&
 272                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
 273                         dev_kfree_skb(skb);
 274                         return NULL;
 275                 }
 276         } else {
 277                 /*
 278                  * Need to make a copy and possibly remove radiotap header
 279                  * and FCS from the original.
 280                  */
 281                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 282
 283                 origskb = remove_monitor_info(local, origskb);
 284
 285                 if (!skb)
 286                         return origskb;
 287         }
 288
 289         /* prepend radiotap information */
 290         ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom);
 291
 292         skb_reset_mac_header(skb);
 293         skb->ip_summed = CHECKSUM_UNNECESSARY;
 294         skb->pkt_type = PACKET_OTHERHOST;
 295         skb->protocol = htons(ETH_P_802_2);
 296
 297         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 298                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
 299                         continue;
 300
 301                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
 302                         continue;
 303
 304                 if (!ieee80211_sdata_running(sdata))
 305                         continue;
 306
 307                 if (prev_dev) {
 308                         skb2 = skb_clone(skb, GFP_ATOMIC);
 309                         if (skb2) {
 310                                 skb2->dev = prev_dev;
 311                                 netif_receive_skb(skb2);
 312                         }
 313                 }
 314
 315                 prev_dev = sdata->dev;
 316                 sdata->dev->stats.rx_packets++;
 317                 sdata->dev->stats.rx_bytes += skb->len;
 318         }
 319
 320         if (prev_dev) {
 321                 skb->dev = prev_dev;
 322                 netif_receive_skb(skb);
 323         } else
 324                 dev_kfree_skb(skb);
 325
 326         return origskb;
 327 }
 328
 329
 330 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
 331 {
 332         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 333         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 334         int tid;
 335
 336         /* does the frame have a qos control field? */
 337         if (ieee80211_is_data_qos(hdr->frame_control)) {
 338                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 339                 /* frame has qos control */
 340                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
 341                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
 342                         status->rx_flags |= IEEE80211_RX_AMSDU;
 343         } else {
 344                 /*
 345                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
 346                  *
 347                  *      Sequence numbers for management frames, QoS data
 348                  *      frames with a broadcast/multicast address in the
 349                  *      Address 1 field, and all non-QoS data frames sent
 350                  *      by QoS STAs are assigned using an additional single
 351                  *      modulo-4096 counter, [...]
 352                  *
 353                  * We also use that counter for non-QoS STAs.
 354                  */
 355                 tid = NUM_RX_DATA_QUEUES - 1;
 356         }
 357
 358         rx->queue = tid;
 359         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 360          * For now, set skb->priority to 0 for other cases. */
 361         rx->skb->priority = (tid > 7) ? 0 : tid;
 362 }
 363
 364 /**
 365  * DOC: Packet alignment
 366  *
 367  * Drivers always need to pass packets that are aligned to two-byte boundaries
 368  * to the stack.
 369  *
 370  * Additionally, should, if possible, align the payload data in a way that
 371  * guarantees that the contained IP header is aligned to a four-byte
 372  * boundary. In the case of regular frames, this simply means aligning the
 373  * payload to a four-byte boundary (because either the IP header is directly
 374  * contained, or IV/RFC1042 headers that have a length divisible by four are
 375  * in front of it).  If the payload data is not properly aligned and the
 376  * architecture doesn't support efficient unaligned operations, mac80211
 377  * will align the data.
 378  *
 379  * With A-MSDU frames, however, the payload data address must yield two modulo
 380  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
 381  * push the IP header further back to a multiple of four again. Thankfully, the
 382  * specs were sane enough this time around to require padding each A-MSDU
 383  * subframe to a length that is a multiple of four.
 384  *
 385  * Padding like Atheros hardware adds which is between the 802.11 header and
 386  * the payload is not supported, the driver is required to move the 802.11
 387  * header to be directly in front of the payload in that case.
 388  */
 389 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
 390 {
 391 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 392         WARN_ONCE((unsigned long)rx->skb->data & 1,
 393                   "unaligned packet at 0x%p\n", rx->skb->data);
 394 #endif
 395 }
 396
 397
 398 /* rx handlers */
 399
 400 static ieee80211_rx_result debug_noinline
 401 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 402 {
 403         struct ieee80211_local *local = rx->local;
 404         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 405         struct sk_buff *skb = rx->skb;
 406
 407         if (likely(!(status->rx_flags & IEEE80211_RX_IN_SCAN)))
 408                 return RX_CONTINUE;
 409
 410         if (test_bit(SCAN_HW_SCANNING, &local->scanning) ||
 411             test_bit(SCAN_SW_SCANNING, &local->scanning))
 412                 return ieee80211_scan_rx(rx->sdata, skb);
 413
 414         /* scanning finished during invoking of handlers */
 415         I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 416         return RX_DROP_UNUSABLE;
 417 }
 418
 419
 420 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
 421 {
 422         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 423
 424         if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
 425                 return 0;
 426
 427         return ieee80211_is_robust_mgmt_frame(hdr);
 428 }
 429
 430
 431 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
 432 {
 433         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 434
 435         if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
 436                 return 0;
 437
 438         return ieee80211_is_robust_mgmt_frame(hdr);
 439 }
 440
 441
 442 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
 443 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
 444 {
 445         struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
 446         struct ieee80211_mmie *mmie;
 447
 448         if (skb->len < 24 + sizeof(*mmie) ||
 449             !is_multicast_ether_addr(hdr->da))
 450                 return -1;
 451
 452         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
 453                 return -1; /* not a robust management frame */
 454
 455         mmie = (struct ieee80211_mmie *)
 456                 (skb->data + skb->len - sizeof(*mmie));
 457         if (mmie->element_id != WLAN_EID_MMIE ||
 458             mmie->length != sizeof(*mmie) - 2)
 459                 return -1;
 460
 461         return le16_to_cpu(mmie->key_id);
 462 }
 463
 464
 465 static ieee80211_rx_result
 466 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 467 {
 468         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 469         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 470         char *dev_addr = rx->sdata->vif.addr;
 471
 472         if (ieee80211_is_data(hdr->frame_control)) {
 473                 if (is_multicast_ether_addr(hdr->addr1)) {
 474                         if (ieee80211_has_tods(hdr->frame_control) ||
 475                                 !ieee80211_has_fromds(hdr->frame_control))
 476                                 return RX_DROP_MONITOR;
 477                         if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
 478                                 return RX_DROP_MONITOR;
 479                 } else {
 480                         if (!ieee80211_has_a4(hdr->frame_control))
 481                                 return RX_DROP_MONITOR;
 482                         if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
 483                                 return RX_DROP_MONITOR;
 484                 }
 485         }
 486
 487         /* If there is not an established peer link and this is not a peer link
 488          * establisment frame, beacon or probe, drop the frame.
 489          */
 490
 491         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
 492                 struct ieee80211_mgmt *mgmt;
 493
 494                 if (!ieee80211_is_mgmt(hdr->frame_control))
 495                         return RX_DROP_MONITOR;
 496
 497                 if (ieee80211_is_action(hdr->frame_control)) {
 498                         mgmt = (struct ieee80211_mgmt *)hdr;
 499                         if (mgmt->u.action.category != WLAN_CATEGORY_MESH_PLINK)
 500                                 return RX_DROP_MONITOR;
 501                         return RX_CONTINUE;
 502                 }
 503
 504                 if (ieee80211_is_probe_req(hdr->frame_control) ||
 505                     ieee80211_is_probe_resp(hdr->frame_control) ||
 506                     ieee80211_is_beacon(hdr->frame_control) ||
 507                     ieee80211_is_auth(hdr->frame_control))
 508                         return RX_CONTINUE;
 509
 510                 return RX_DROP_MONITOR;
 511
 512         }
 513
 514 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
 515
 516         if (ieee80211_is_data(hdr->frame_control) &&
 517             is_multicast_ether_addr(hdr->addr1) &&
 518             mesh_rmc_check(hdr->addr3, msh_h_get(hdr, hdrlen), rx->sdata))
 519                 return RX_DROP_MONITOR;
 520 #undef msh_h_get
 521
 522         return RX_CONTINUE;
 523 }
 524
 525 #define SEQ_MODULO 0x1000
 526 #define SEQ_MASK   0xfff
 527
 528 static inline int seq_less(u16 sq1, u16 sq2)
 529 {
 530         return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
 531 }
 532
 533 static inline u16 seq_inc(u16 sq)
 534 {
 535         return (sq + 1) & SEQ_MASK;
 536 }
 537
 538 static inline u16 seq_sub(u16 sq1, u16 sq2)
 539 {
 540         return (sq1 - sq2) & SEQ_MASK;
 541 }
 542
 543
 544 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
 545                                             struct tid_ampdu_rx *tid_agg_rx,
 546                                             int index)
 547 {
 548         struct ieee80211_local *local = hw_to_local(hw);
 549         struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
 550         struct ieee80211_rx_status *status;
 551
 552         lockdep_assert_held(&tid_agg_rx->reorder_lock);
 553
 554         if (!skb)
 555                 goto no_frame;
 556
 557         /* release the frame from the reorder ring buffer */
 558         tid_agg_rx->stored_mpdu_num--;
 559         tid_agg_rx->reorder_buf[index] = NULL;
 560         status = IEEE80211_SKB_RXCB(skb);
 561         status->rx_flags |= IEEE80211_RX_DEFERRED_RELEASE;
 562         skb_queue_tail(&local->rx_skb_queue, skb);
 563
 564 no_frame:
 565         tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
 566 }
 567
 568 static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
 569                                              struct tid_ampdu_rx *tid_agg_rx,
 570                                              u16 head_seq_num)
 571 {
 572         int index;
 573
 574         lockdep_assert_held(&tid_agg_rx->reorder_lock);
 575
 576         while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
 577                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 578                                                         tid_agg_rx->buf_size;
 579                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
 580         }
 581 }
 582
 583 /*
 584  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
 585  * the skb was added to the buffer longer than this time ago, the earlier
 586  * frames that have not yet been received are assumed to be lost and the skb
 587  * can be released for processing. This may also release other skb's from the
 588  * reorder buffer if there are no additional gaps between the frames.
 589  *
 590  * Callers must hold tid_agg_rx->reorder_lock.
 591  */
 592 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
 593
 594 static void ieee80211_sta_reorder_release(struct ieee80211_hw *hw,
 595                                           struct tid_ampdu_rx *tid_agg_rx)
 596 {
 597         int index, j;
 598
 599         lockdep_assert_held(&tid_agg_rx->reorder_lock);
 600
 601         /* release the buffer until next missing frame */
 602         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 603                                                 tid_agg_rx->buf_size;
 604         if (!tid_agg_rx->reorder_buf[index] &&
 605             tid_agg_rx->stored_mpdu_num > 1) {
 606                 /*
 607                  * No buffers ready to be released, but check whether any
 608                  * frames in the reorder buffer have timed out.
 609                  */
 610                 int skipped = 1;
 611                 for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
 612                      j = (j + 1) % tid_agg_rx->buf_size) {
 613                         if (!tid_agg_rx->reorder_buf[j]) {
 614                                 skipped++;
 615                                 continue;
 616                         }
 617                         if (skipped &&
 618                             !time_after(jiffies, tid_agg_rx->reorder_time[j] +
 619                                         HT_RX_REORDER_BUF_TIMEOUT))
 620                                 goto set_release_timer;
 621
 622 #ifdef CONFIG_MAC80211_HT_DEBUG
 623                         if (net_ratelimit())
 624                                 wiphy_debug(hw->wiphy,
 625                                             "release an RX reorder frame due to timeout on earlier frames\n");
 626 #endif
 627                         ieee80211_release_reorder_frame(hw, tid_agg_rx, j);
 628
 629                         /*
 630                          * Increment the head seq# also for the skipped slots.
 631                          */
 632                         tid_agg_rx->head_seq_num =
 633                                 (tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
 634                         skipped = 0;
 635                 }
 636         } else while (tid_agg_rx->reorder_buf[index]) {
 637                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
 638                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 639                                                         tid_agg_rx->buf_size;
 640         }
 641
 642         if (tid_agg_rx->stored_mpdu_num) {
 643                 j = index = seq_sub(tid_agg_rx->head_seq_num,
 644                                     tid_agg_rx->ssn) % tid_agg_rx->buf_size;
 645
 646                 for (; j != (index - 1) % tid_agg_rx->buf_size;
 647                      j = (j + 1) % tid_agg_rx->buf_size) {
 648                         if (tid_agg_rx->reorder_buf[j])
 649                                 break;
 650                 }
 651
 652  set_release_timer:
 653
 654                 mod_timer(&tid_agg_rx->reorder_timer,
 655                           tid_agg_rx->reorder_time[j] +
 656                           HT_RX_REORDER_BUF_TIMEOUT);
 657         } else {
 658                 del_timer(&tid_agg_rx->reorder_timer);
 659         }
 660 }
 661
 662 /*
 663  * As this function belongs to the RX path it must be under
 664  * rcu_read_lock protection. It returns false if the frame
 665  * can be processed immediately, true if it was consumed.
 666  */
 667 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
 668                                              struct tid_ampdu_rx *tid_agg_rx,
 669                                              struct sk_buff *skb)
 670 {
 671         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 672         u16 sc = le16_to_cpu(hdr->seq_ctrl);
 673         u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
 674         u16 head_seq_num, buf_size;
 675         int index;
 676         bool ret = true;
 677
 678         spin_lock(&tid_agg_rx->reorder_lock);
 679
 680         buf_size = tid_agg_rx->buf_size;
 681         head_seq_num = tid_agg_rx->head_seq_num;
 682
 683         /* frame with out of date sequence number */
 684         if (seq_less(mpdu_seq_num, head_seq_num)) {
 685                 dev_kfree_skb(skb);
 686                 goto out;
 687         }
 688
 689         /*
 690          * If frame the sequence number exceeds our buffering window
 691          * size release some previous frames to make room for this one.
 692          */
 693         if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
 694                 head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
 695                 /* release stored frames up to new head to stack */
 696                 ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num);
 697         }
 698
 699         /* Now the new frame is always in the range of the reordering buffer */
 700
 701         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size;
 702
 703         /* check if we already stored this frame */
 704         if (tid_agg_rx->reorder_buf[index]) {
 705                 dev_kfree_skb(skb);
 706                 goto out;
 707         }
 708
 709         /*
 710          * If the current MPDU is in the right order and nothing else
 711          * is stored we can process it directly, no need to buffer it.
 712          * If it is first but there's something stored, we may be able
 713          * to release frames after this one.
 714          */
 715         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
 716             tid_agg_rx->stored_mpdu_num == 0) {
 717                 tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
 718                 ret = false;
 719                 goto out;
 720         }
 721
 722         /* put the frame in the reordering buffer */
 723         tid_agg_rx->reorder_buf[index] = skb;
 724         tid_agg_rx->reorder_time[index] = jiffies;
 725         tid_agg_rx->stored_mpdu_num++;
 726         ieee80211_sta_reorder_release(hw, tid_agg_rx);
 727
 728  out:
 729         spin_unlock(&tid_agg_rx->reorder_lock);
 730         return ret;
 731 }
 732
 733 /*
 734  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
 735  * true if the MPDU was buffered, false if it should be processed.
 736  */
 737 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx)
 738 {
 739         struct sk_buff *skb = rx->skb;
 740         struct ieee80211_local *local = rx->local;
 741         struct ieee80211_hw *hw = &local->hw;
 742         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 743         struct sta_info *sta = rx->sta;
 744         struct tid_ampdu_rx *tid_agg_rx;
 745         u16 sc;
 746         int tid;
 747
 748         if (!ieee80211_is_data_qos(hdr->frame_control))
 749                 goto dont_reorder;
 750
 751         /*
 752          * filter the QoS data rx stream according to
 753          * STA/TID and check if this STA/TID is on aggregation
 754          */
 755
 756         if (!sta)
 757                 goto dont_reorder;
 758
 759         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
 760
 761         tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
 762         if (!tid_agg_rx)
 763                 goto dont_reorder;
 764
 765         /* qos null data frames are excluded */
 766         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
 767                 goto dont_reorder;
 768
 769         /* new, potentially un-ordered, ampdu frame - process it */
 770
 771         /* reset session timer */
 772         if (tid_agg_rx->timeout)
 773                 mod_timer(&tid_agg_rx->session_timer,
 774                           TU_TO_EXP_TIME(tid_agg_rx->timeout));
 775
 776         /* if this mpdu is fragmented - terminate rx aggregation session */
 777         sc = le16_to_cpu(hdr->seq_ctrl);
 778         if (sc & IEEE80211_SCTL_FRAG) {
 779                 skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
 780                 skb_queue_tail(&rx->sdata->skb_queue, skb);
 781                 ieee80211_queue_work(&local->hw, &rx->sdata->work);
 782                 return;
 783         }
 784
 785         /*
 786          * No locking needed -- we will only ever process one
 787          * RX packet at a time, and thus own tid_agg_rx. All
 788          * other code manipulating it needs to (and does) make
 789          * sure that we cannot get to it any more before doing
 790          * anything with it.
 791          */
 792         if (ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb))
 793                 return;
 794
 795  dont_reorder:
 796         skb_queue_tail(&local->rx_skb_queue, skb);
 797 }
 798
 799 static ieee80211_rx_result debug_noinline
 800 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
 801 {
 802         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 803         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 804
 805         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 806         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 807                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
 808                              rx->sta->last_seq_ctrl[rx->queue] ==
 809                              hdr->seq_ctrl)) {
 810                         if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
 811                                 rx->local->dot11FrameDuplicateCount++;
 812                                 rx->sta->num_duplicates++;
 813                         }
 814                         return RX_DROP_UNUSABLE;
 815                 } else
 816                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
 817         }
 818
 819         if (unlikely(rx->skb->len < 16)) {
 820                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 821                 return RX_DROP_MONITOR;
 822         }
 823
 824         /* Drop disallowed frame classes based on STA auth/assoc state;
 825          * IEEE 802.11, Chap 5.5.
 826          *
 827          * mac80211 filters only based on association state, i.e. it drops
 828          * Class 3 frames from not associated stations. hostapd sends
 829          * deauth/disassoc frames when needed. In addition, hostapd is
 830          * responsible for filtering on both auth and assoc states.
 831          */
 832
 833         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
 834                 return ieee80211_rx_mesh_check(rx);
 835
 836         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
 837                       ieee80211_is_pspoll(hdr->frame_control)) &&
 838                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
 839                      rx->sdata->vif.type != NL80211_IFTYPE_WDS &&
 840                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC))))
 841                 return RX_DROP_MONITOR;
 842
 843         return RX_CONTINUE;
 844 }
 845
 846
 847 static ieee80211_rx_result debug_noinline
 848 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 849 {
 850         struct sk_buff *skb = rx->skb;
 851         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 852         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 853         int keyidx;
 854         int hdrlen;
 855         ieee80211_rx_result result = RX_DROP_UNUSABLE;
 856         struct ieee80211_key *sta_ptk = NULL;
 857         int mmie_keyidx = -1;
 858         __le16 fc;
 859
 860         /*
 861          * Key selection 101
 862          *
 863          * There are four types of keys:
 864          *  - GTK (group keys)
 865          *  - IGTK (group keys for management frames)
 866          *  - PTK (pairwise keys)
 867          *  - STK (station-to-station pairwise keys)
 868          *
 869          * When selecting a key, we have to distinguish between multicast
 870          * (including broadcast) and unicast frames, the latter can only
 871          * use PTKs and STKs while the former always use GTKs and IGTKs.
 872          * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
 873          * unicast frames can also use key indices like GTKs. Hence, if we
 874          * don't have a PTK/STK we check the key index for a WEP key.
 875          *
 876          * Note that in a regular BSS, multicast frames are sent by the
 877          * AP only, associated stations unicast the frame to the AP first
 878          * which then multicasts it on their behalf.
 879          *
 880          * There is also a slight problem in IBSS mode: GTKs are negotiated
 881          * with each station, that is something we don't currently handle.
 882          * The spec seems to expect that one negotiates the same key with
 883          * every station but there's no such requirement; VLANs could be
 884          * possible.
 885          */
 886
 887         /*
 888          * No point in finding a key and decrypting if the frame is neither
 889          * addressed to us nor a multicast frame.
 890          */
 891         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
 892                 return RX_CONTINUE;
 893
 894         /* start without a key */
 895         rx->key = NULL;
 896
 897         if (rx->sta)
 898                 sta_ptk = rcu_dereference(rx->sta->ptk);
 899
 900         fc = hdr->frame_control;
 901
 902         if (!ieee80211_has_protected(fc))
 903                 mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
 904
 905         if (!is_multicast_ether_addr(hdr->addr1) && sta_ptk) {
 906                 rx->key = sta_ptk;
 907                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 908                     (status->flag & RX_FLAG_IV_STRIPPED))
 909                         return RX_CONTINUE;
 910                 /* Skip decryption if the frame is not protected. */
 911                 if (!ieee80211_has_protected(fc))
 912                         return RX_CONTINUE;
 913         } else if (mmie_keyidx >= 0) {
 914                 /* Broadcast/multicast robust management frame / BIP */
 915                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 916                     (status->flag & RX_FLAG_IV_STRIPPED))
 917                         return RX_CONTINUE;
 918
 919                 if (mmie_keyidx < NUM_DEFAULT_KEYS ||
 920                     mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 921                         return RX_DROP_MONITOR; /* unexpected BIP keyidx */
 922                 if (rx->sta)
 923                         rx->key = rcu_dereference(rx->sta->gtk[mmie_keyidx]);
 924                 if (!rx->key)
 925                         rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
 926         } else if (!ieee80211_has_protected(fc)) {
 927                 /*
 928                  * The frame was not protected, so skip decryption. However, we
 929                  * need to set rx->key if there is a key that could have been
 930                  * used so that the frame may be dropped if encryption would
 931                  * have been expected.
 932                  */
 933                 struct ieee80211_key *key = NULL;
 934                 struct ieee80211_sub_if_data *sdata = rx->sdata;
 935                 int i;
 936
 937                 if (ieee80211_is_mgmt(fc) &&
 938                     is_multicast_ether_addr(hdr->addr1) &&
 939                     (key = rcu_dereference(rx->sdata->default_mgmt_key)))
 940                         rx->key = key;
 941                 else {
 942                         if (rx->sta) {
 943                                 for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
 944                                         key = rcu_dereference(rx->sta->gtk[i]);
 945                                         if (key)
 946                                                 break;
 947                                 }
 948                         }
 949                         if (!key) {
 950                                 for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
 951                                         key = rcu_dereference(sdata->keys[i]);
 952                                         if (key)
 953                                                 break;
 954                                 }
 955                         }
 956                         if (key)
 957                                 rx->key = key;
 958                 }
 959                 return RX_CONTINUE;
 960         } else {
 961                 u8 keyid;
 962                 /*
 963                  * The device doesn't give us the IV so we won't be
 964                  * able to look up the key. That's ok though, we
 965                  * don't need to decrypt the frame, we just won't
 966                  * be able to keep statistics accurate.
 967                  * Except for key threshold notifications, should
 968                  * we somehow allow the driver to tell us which key
 969                  * the hardware used if this flag is set?
 970                  */
 971                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 972                     (status->flag & RX_FLAG_IV_STRIPPED))
 973                         return RX_CONTINUE;
 974
 975                 hdrlen = ieee80211_hdrlen(fc);
 976
 977                 if (rx->skb->len < 8 + hdrlen)
 978                         return RX_DROP_UNUSABLE; /* TODO: count this? */
 979
 980                 /*
 981                  * no need to call ieee80211_wep_get_keyidx,
 982                  * it verifies a bunch of things we've done already
 983                  */
 984                 skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
 985                 keyidx = keyid >> 6;
 986
 987                 /* check per-station GTK first, if multicast packet */
 988                 if (is_multicast_ether_addr(hdr->addr1) && rx->sta)
 989                         rx->key = rcu_dereference(rx->sta->gtk[keyidx]);
 990
 991                 /* if not found, try default key */
 992                 if (!rx->key) {
 993                         rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
 994
 995                         /*
 996                          * RSNA-protected unicast frames should always be
 997                          * sent with pairwise or station-to-station keys,
 998                          * but for WEP we allow using a key index as well.
 999                          */
1000                         if (rx->key &&
1001                             rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP40 &&
1002                             rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP104 &&
1003                             !is_multicast_ether_addr(hdr->addr1))
1004                                 rx->key = NULL;
1005                 }
1006         }
1007
1008         if (rx->key) {
1009                 rx->key->tx_rx_count++;
1010                 /* TODO: add threshold stuff again */
1011         } else {
1012                 return RX_DROP_MONITOR;
1013         }
1014
1015         if (skb_linearize(rx->skb))
1016                 return RX_DROP_UNUSABLE;
1017         /* the hdr variable is invalid now! */
1018
1019         switch (rx->key->conf.cipher) {
1020         case WLAN_CIPHER_SUITE_WEP40:
1021         case WLAN_CIPHER_SUITE_WEP104:
1022                 /* Check for weak IVs if possible */
1023                 if (rx->sta && ieee80211_is_data(fc) &&
1024                     (!(status->flag & RX_FLAG_IV_STRIPPED) ||
1025                      !(status->flag & RX_FLAG_DECRYPTED)) &&
1026                     ieee80211_wep_is_weak_iv(rx->skb, rx->key))
1027                         rx->sta->wep_weak_iv_count++;
1028
1029                 result = ieee80211_crypto_wep_decrypt(rx);
1030                 break;
1031         case WLAN_CIPHER_SUITE_TKIP:
1032                 result = ieee80211_crypto_tkip_decrypt(rx);
1033                 break;
1034         case WLAN_CIPHER_SUITE_CCMP:
1035                 result = ieee80211_crypto_ccmp_decrypt(rx);
1036                 break;
1037         case WLAN_CIPHER_SUITE_AES_CMAC:
1038                 result = ieee80211_crypto_aes_cmac_decrypt(rx);
1039                 break;
1040         default:
1041                 /*
1042                  * We can reach here only with HW-only algorithms
1043                  * but why didn't it decrypt the frame?!
1044                  */
1045                 return RX_DROP_UNUSABLE;
1046         }
1047
1048         /* either the frame has been decrypted or will be dropped */
1049         status->flag |= RX_FLAG_DECRYPTED;
1050
1051         return result;
1052 }
1053
1054 static ieee80211_rx_result debug_noinline
1055 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
1056 {
1057         struct ieee80211_local *local;
1058         struct ieee80211_hdr *hdr;
1059         struct sk_buff *skb;
1060
1061         local = rx->local;
1062         skb = rx->skb;
1063         hdr = (struct ieee80211_hdr *) skb->data;
1064
1065         if (!local->pspolling)
1066                 return RX_CONTINUE;
1067
1068         if (!ieee80211_has_fromds(hdr->frame_control))
1069                 /* this is not from AP */
1070                 return RX_CONTINUE;
1071
1072         if (!ieee80211_is_data(hdr->frame_control))
1073                 return RX_CONTINUE;
1074
1075         if (!ieee80211_has_moredata(hdr->frame_control)) {
1076                 /* AP has no more frames buffered for us */
1077                 local->pspolling = false;
1078                 return RX_CONTINUE;
1079         }
1080
1081         /* more data bit is set, let's request a new frame from the AP */
1082         ieee80211_send_pspoll(local, rx->sdata);
1083
1084         return RX_CONTINUE;
1085 }
1086
1087 static void ap_sta_ps_start(struct sta_info *sta)
1088 {
1089         struct ieee80211_sub_if_data *sdata = sta->sdata;
1090         struct ieee80211_local *local = sdata->local;
1091
1092         atomic_inc(&sdata->bss->num_sta_ps);
1093         set_sta_flags(sta, WLAN_STA_PS_STA);
1094         if (!(local->hw.flags & IEEE80211_HW_AP_LINK_PS))
1095                 drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
1096 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1097         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
1098                sdata->name, sta->sta.addr, sta->sta.aid);
1099 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1100 }
1101
1102 static void ap_sta_ps_end(struct sta_info *sta)
1103 {
1104         struct ieee80211_sub_if_data *sdata = sta->sdata;
1105
1106         atomic_dec(&sdata->bss->num_sta_ps);
1107
1108 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1109         printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
1110                sdata->name, sta->sta.addr, sta->sta.aid);
1111 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1112
1113         if (test_sta_flags(sta, WLAN_STA_PS_DRIVER)) {
1114 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1115                 printk(KERN_DEBUG "%s: STA %pM aid %d driver-ps-blocked\n",
1116                        sdata->name, sta->sta.addr, sta->sta.aid);
1117 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1118                 return;
1119         }
1120
1121         ieee80211_sta_ps_deliver_wakeup(sta);
1122 }
1123
1124 int ieee80211_sta_ps_transition(struct ieee80211_sta *sta, bool start)
1125 {
1126         struct sta_info *sta_inf = container_of(sta, struct sta_info, sta);
1127         bool in_ps;
1128
1129         WARN_ON(!(sta_inf->local->hw.flags & IEEE80211_HW_AP_LINK_PS));
1130
1131         /* Don't let the same PS state be set twice */
1132         in_ps = test_sta_flags(sta_inf, WLAN_STA_PS_STA);
1133         if ((start && in_ps) || (!start && !in_ps))
1134                 return -EINVAL;
1135
1136         if (start)
1137                 ap_sta_ps_start(sta_inf);
1138         else
1139                 ap_sta_ps_end(sta_inf);
1140
1141         return 0;
1142 }
1143 EXPORT_SYMBOL(ieee80211_sta_ps_transition);
1144
1145 static ieee80211_rx_result debug_noinline
1146 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1147 {
1148         struct sta_info *sta = rx->sta;
1149         struct sk_buff *skb = rx->skb;
1150         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1151         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1152
1153         if (!sta)
1154                 return RX_CONTINUE;
1155
1156         /*
1157          * Update last_rx only for IBSS packets which are for the current
1158          * BSSID to avoid keeping the current IBSS network alive in cases
1159          * where other STAs start using different BSSID.
1160          */
1161         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1162                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1163                                                 NL80211_IFTYPE_ADHOC);
1164                 if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0) {
1165                         sta->last_rx = jiffies;
1166                         if (ieee80211_is_data(hdr->frame_control)) {
1167                                 sta->last_rx_rate_idx = status->rate_idx;
1168                                 sta->last_rx_rate_flag = status->flag;
1169                         }
1170                 }
1171         } else if (!is_multicast_ether_addr(hdr->addr1)) {
1172                 /*
1173                  * Mesh beacons will update last_rx when if they are found to
1174                  * match the current local configuration when processed.
1175                  */
1176                 sta->last_rx = jiffies;
1177                 if (ieee80211_is_data(hdr->frame_control)) {
1178                         sta->last_rx_rate_idx = status->rate_idx;
1179                         sta->last_rx_rate_flag = status->flag;
1180                 }
1181         }
1182
1183         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1184                 return RX_CONTINUE;
1185
1186         if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1187                 ieee80211_sta_rx_notify(rx->sdata, hdr);
1188
1189         sta->rx_fragments++;
1190         sta->rx_bytes += rx->skb->len;
1191         sta->last_signal = status->signal;
1192         ewma_add(&sta->avg_signal, -status->signal);
1193
1194         /*
1195          * Change STA power saving mode only at the end of a frame
1196          * exchange sequence.
1197          */
1198         if (!(sta->local->hw.flags & IEEE80211_HW_AP_LINK_PS) &&
1199             !ieee80211_has_morefrags(hdr->frame_control) &&
1200             !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1201             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1202              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
1203                 if (test_sta_flags(sta, WLAN_STA_PS_STA)) {
1204                         /*
1205                          * Ignore doze->wake transitions that are
1206                          * indicated by non-data frames, the standard
1207                          * is unclear here, but for example going to
1208                          * PS mode and then scanning would cause a
1209                          * doze->wake transition for the probe request,
1210                          * and that is clearly undesirable.
1211                          */
1212                         if (ieee80211_is_data(hdr->frame_control) &&
1213                             !ieee80211_has_pm(hdr->frame_control))
1214                                 ap_sta_ps_end(sta);
1215                 } else {
1216                         if (ieee80211_has_pm(hdr->frame_control))
1217                                 ap_sta_ps_start(sta);
1218                 }
1219         }
1220
1221         /*
1222          * Drop (qos-)data::nullfunc frames silently, since they
1223          * are used only to control station power saving mode.
1224          */
1225         if (ieee80211_is_nullfunc(hdr->frame_control) ||
1226             ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1227                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
1228
1229                 /*
1230                  * If we receive a 4-addr nullfunc frame from a STA
1231                  * that was not moved to a 4-addr STA vlan yet, drop
1232                  * the frame to the monitor interface, to make sure
1233                  * that hostapd sees it
1234                  */
1235                 if (ieee80211_has_a4(hdr->frame_control) &&
1236                     (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1237                      (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1238                       !rx->sdata->u.vlan.sta)))
1239                         return RX_DROP_MONITOR;
1240                 /*
1241                  * Update counter and free packet here to avoid
1242                  * counting this as a dropped packed.
1243                  */
1244                 sta->rx_packets++;
1245                 dev_kfree_skb(rx->skb);
1246                 return RX_QUEUED;
1247         }
1248
1249         return RX_CONTINUE;
1250 } /* ieee80211_rx_h_sta_process */
1251
1252 static inline struct ieee80211_fragment_entry *
1253 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
1254                          unsigned int frag, unsigned int seq, int rx_queue,
1255                          struct sk_buff **skb)
1256 {
1257         struct ieee80211_fragment_entry *entry;
1258         int idx;
1259
1260         idx = sdata->fragment_next;
1261         entry = &sdata->fragments[sdata->fragment_next++];
1262         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
1263                 sdata->fragment_next = 0;
1264
1265         if (!skb_queue_empty(&entry->skb_list)) {
1266 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1267                 struct ieee80211_hdr *hdr =
1268                         (struct ieee80211_hdr *) entry->skb_list.next->data;
1269                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
1270                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
1271                        "addr1=%pM addr2=%pM\n",
1272                        sdata->name, idx,
1273                        jiffies - entry->first_frag_time, entry->seq,
1274                        entry->last_frag, hdr->addr1, hdr->addr2);
1275 #endif
1276                 __skb_queue_purge(&entry->skb_list);
1277         }
1278
1279         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
1280         *skb = NULL;
1281         entry->first_frag_time = jiffies;
1282         entry->seq = seq;
1283         entry->rx_queue = rx_queue;
1284         entry->last_frag = frag;
1285         entry->ccmp = 0;
1286         entry->extra_len = 0;
1287
1288         return entry;
1289 }
1290
1291 static inline struct ieee80211_fragment_entry *
1292 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
1293                           unsigned int frag, unsigned int seq,
1294                           int rx_queue, struct ieee80211_hdr *hdr)
1295 {
1296         struct ieee80211_fragment_entry *entry;
1297         int i, idx;
1298
1299         idx = sdata->fragment_next;
1300         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
1301                 struct ieee80211_hdr *f_hdr;
1302
1303                 idx--;
1304                 if (idx < 0)
1305                         idx = IEEE80211_FRAGMENT_MAX - 1;
1306
1307                 entry = &sdata->fragments[idx];
1308                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
1309                     entry->rx_queue != rx_queue ||
1310                     entry->last_frag + 1 != frag)
1311                         continue;
1312
1313                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
1314
1315                 /*
1316                  * Check ftype and addresses are equal, else check next fragment
1317                  */
1318                 if (((hdr->frame_control ^ f_hdr->frame_control) &
1319                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
1320                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
1321                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
1322                         continue;
1323
1324                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
1325                         __skb_queue_purge(&entry->skb_list);
1326                         continue;
1327                 }
1328                 return entry;
1329         }
1330
1331         return NULL;
1332 }
1333
1334 static ieee80211_rx_result debug_noinline
1335 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
1336 {
1337         struct ieee80211_hdr *hdr;
1338         u16 sc;
1339         __le16 fc;
1340         unsigned int frag, seq;
1341         struct ieee80211_fragment_entry *entry;
1342         struct sk_buff *skb;
1343         struct ieee80211_rx_status *status;
1344
1345         hdr = (struct ieee80211_hdr *)rx->skb->data;
1346         fc = hdr->frame_control;
1347         sc = le16_to_cpu(hdr->seq_ctrl);
1348         frag = sc & IEEE80211_SCTL_FRAG;
1349
1350         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1351                    (rx->skb)->len < 24 ||
1352                    is_multicast_ether_addr(hdr->addr1))) {
1353                 /* not fragmented */
1354                 goto out;
1355         }
1356         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1357
1358         if (skb_linearize(rx->skb))
1359                 return RX_DROP_UNUSABLE;
1360
1361         /*
1362          *  skb_linearize() might change the skb->data and
1363          *  previously cached variables (in this case, hdr) need to
1364          *  be refreshed with the new data.
1365          */
1366         hdr = (struct ieee80211_hdr *)rx->skb->data;
1367         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1368
1369         if (frag == 0) {
1370                 /* This is the first fragment of a new frame. */
1371                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1372                                                  rx->queue, &(rx->skb));
1373                 if (rx->key && rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP &&
1374                     ieee80211_has_protected(fc)) {
1375                         int queue = ieee80211_is_mgmt(fc) ?
1376                                 NUM_RX_DATA_QUEUES : rx->queue;
1377                         /* Store CCMP PN so that we can verify that the next
1378                          * fragment has a sequential PN value. */
1379                         entry->ccmp = 1;
1380                         memcpy(entry->last_pn,
1381                                rx->key->u.ccmp.rx_pn[queue],
1382                                CCMP_PN_LEN);
1383                 }
1384                 return RX_QUEUED;
1385         }
1386
1387         /* This is a fragment for a frame that should already be pending in
1388          * fragment cache. Add this fragment to the end of the pending entry.
1389          */
1390         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1391         if (!entry) {
1392                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1393                 return RX_DROP_MONITOR;
1394         }
1395
1396         /* Verify that MPDUs within one MSDU have sequential PN values.
1397          * (IEEE 802.11i, 8.3.3.4.5) */
1398         if (entry->ccmp) {
1399                 int i;
1400                 u8 pn[CCMP_PN_LEN], *rpn;
1401                 int queue;
1402                 if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP)
1403                         return RX_DROP_UNUSABLE;
1404                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1405                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1406                         pn[i]++;
1407                         if (pn[i])
1408                                 break;
1409                 }
1410                 queue = ieee80211_is_mgmt(fc) ?
1411                         NUM_RX_DATA_QUEUES : rx->queue;
1412                 rpn = rx->key->u.ccmp.rx_pn[queue];
1413                 if (memcmp(pn, rpn, CCMP_PN_LEN))
1414                         return RX_DROP_UNUSABLE;
1415                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1416         }
1417
1418         skb_pull(rx->skb, ieee80211_hdrlen(fc));
1419         __skb_queue_tail(&entry->skb_list, rx->skb);
1420         entry->last_frag = frag;
1421         entry->extra_len += rx->skb->len;
1422         if (ieee80211_has_morefrags(fc)) {
1423                 rx->skb = NULL;
1424                 return RX_QUEUED;
1425         }
1426
1427         rx->skb = __skb_dequeue(&entry->skb_list);
1428         if (skb_tailroom(rx->skb) < entry->extra_len) {
1429                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1430                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1431                                               GFP_ATOMIC))) {
1432                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1433                         __skb_queue_purge(&entry->skb_list);
1434                         return RX_DROP_UNUSABLE;
1435                 }
1436         }
1437         while ((skb = __skb_dequeue(&entry->skb_list))) {
1438                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1439                 dev_kfree_skb(skb);
1440         }
1441
1442         /* Complete frame has been reassembled - process it now */
1443         status = IEEE80211_SKB_RXCB(rx->skb);
1444         status->rx_flags |= IEEE80211_RX_FRAGMENTED;
1445
1446  out:
1447         if (rx->sta)
1448                 rx->sta->rx_packets++;
1449         if (is_multicast_ether_addr(hdr->addr1))
1450                 rx->local->dot11MulticastReceivedFrameCount++;
1451         else
1452                 ieee80211_led_rx(rx->local);
1453         return RX_CONTINUE;
1454 }
1455
1456 static ieee80211_rx_result debug_noinline
1457 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1458 {
1459         struct ieee80211_sub_if_data *sdata = rx->sdata;
1460         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1461         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1462
1463         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1464                    !(status->rx_flags & IEEE80211_RX_RA_MATCH)))
1465                 return RX_CONTINUE;
1466
1467         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1468             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1469                 return RX_DROP_UNUSABLE;
1470
1471         if (!test_sta_flags(rx->sta, WLAN_STA_PS_DRIVER))
1472                 ieee80211_sta_ps_deliver_poll_response(rx->sta);
1473         else
1474                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1475
1476         /* Free PS Poll skb here instead of returning RX_DROP that would
1477          * count as an dropped frame. */
1478         dev_kfree_skb(rx->skb);
1479
1480         return RX_QUEUED;
1481 }
1482
1483 static ieee80211_rx_result debug_noinline
1484 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1485 {
1486         u8 *data = rx->skb->data;
1487         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1488
1489         if (!ieee80211_is_data_qos(hdr->frame_control))
1490                 return RX_CONTINUE;
1491
1492         /* remove the qos control field, update frame type and meta-data */
1493         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1494                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1495         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1496         /* change frame type to non QOS */
1497         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1498
1499         return RX_CONTINUE;
1500 }
1501
1502 static int
1503 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1504 {
1505         if (unlikely(!rx->sta ||
1506             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1507                 return -EACCES;
1508
1509         return 0;
1510 }
1511
1512 static int
1513 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1514 {
1515         struct sk_buff *skb = rx->skb;
1516         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1517
1518         /*
1519          * Pass through unencrypted frames if the hardware has
1520          * decrypted them already.
1521          */
1522         if (status->flag & RX_FLAG_DECRYPTED)
1523                 return 0;
1524
1525         /* Drop unencrypted frames if key is set. */
1526         if (unlikely(!ieee80211_has_protected(fc) &&
1527                      !ieee80211_is_nullfunc(fc) &&
1528                      ieee80211_is_data(fc) &&
1529                      (rx->key || rx->sdata->drop_unencrypted)))
1530                 return -EACCES;
1531
1532         return 0;
1533 }
1534
1535 static int
1536 ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
1537 {
1538         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1539         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1540         __le16 fc = hdr->frame_control;
1541
1542         /*
1543          * Pass through unencrypted frames if the hardware has
1544          * decrypted them already.
1545          */
1546         if (status->flag & RX_FLAG_DECRYPTED)
1547                 return 0;
1548
1549         if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1550                 if (unlikely(!ieee80211_has_protected(fc) &&
1551                              ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1552                              rx->key)) {
1553                         if (ieee80211_is_deauth(fc))
1554                                 cfg80211_send_unprot_deauth(rx->sdata->dev,
1555                                                             rx->skb->data,
1556                                                             rx->skb->len);
1557                         else if (ieee80211_is_disassoc(fc))
1558                                 cfg80211_send_unprot_disassoc(rx->sdata->dev,
1559                                                               rx->skb->data,
1560                                                               rx->skb->len);
1561                         return -EACCES;
1562                 }
1563                 /* BIP does not use Protected field, so need to check MMIE */
1564                 if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1565                              ieee80211_get_mmie_keyidx(rx->skb) < 0)) {
1566                         if (ieee80211_is_deauth(fc))
1567                                 cfg80211_send_unprot_deauth(rx->sdata->dev,
1568                                                             rx->skb->data,
1569                                                             rx->skb->len);
1570                         else if (ieee80211_is_disassoc(fc))
1571                                 cfg80211_send_unprot_disassoc(rx->sdata->dev,
1572                                                               rx->skb->data,
1573                                                               rx->skb->len);
1574                         return -EACCES;
1575                 }
1576                 /*
1577                  * When using MFP, Action frames are not allowed prior to
1578                  * having configured keys.
1579                  */
1580                 if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1581                              ieee80211_is_robust_mgmt_frame(
1582                                      (struct ieee80211_hdr *) rx->skb->data)))
1583                         return -EACCES;
1584         }
1585
1586         return 0;
1587 }
1588
1589 static int
1590 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx, bool *port_control)
1591 {
1592         struct ieee80211_sub_if_data *sdata = rx->sdata;
1593         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1594         bool check_port_control = false;
1595         struct ethhdr *ehdr;
1596         int ret;
1597
1598         *port_control = false;
1599         if (ieee80211_has_a4(hdr->frame_control) &&
1600             sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1601                 return -1;
1602
1603         if (sdata->vif.type == NL80211_IFTYPE_STATION &&
1604             !!sdata->u.mgd.use_4addr != !!ieee80211_has_a4(hdr->frame_control)) {
1605
1606                 if (!sdata->u.mgd.use_4addr)
1607                         return -1;
1608                 else
1609                         check_port_control = true;
1610         }
1611
1612         if (is_multicast_ether_addr(hdr->addr1) &&
1613             sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta)
1614                 return -1;
1615
1616         ret = ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
1617         if (ret < 0)
1618                 return ret;
1619
1620         ehdr = (struct ethhdr *) rx->skb->data;
1621         if (ehdr->h_proto == rx->sdata->control_port_protocol)
1622                 *port_control = true;
1623         else if (check_port_control)
1624                 return -1;
1625
1626         return 0;
1627 }
1628
1629 /*
1630  * requires that rx->skb is a frame with ethernet header
1631  */
1632 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1633 {
1634         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1635                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1636         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1637
1638         /*
1639          * Allow EAPOL frames to us/the PAE group address regardless
1640          * of whether the frame was encrypted or not.
1641          */
1642         if (ehdr->h_proto == rx->sdata->control_port_protocol &&
1643             (compare_ether_addr(ehdr->h_dest, rx->sdata->vif.addr) == 0 ||
1644              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1645                 return true;
1646
1647         if (ieee80211_802_1x_port_control(rx) ||
1648             ieee80211_drop_unencrypted(rx, fc))
1649                 return false;
1650
1651         return true;
1652 }
1653
1654 /*
1655  * requires that rx->skb is a frame with ethernet header
1656  */
1657 static void
1658 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1659 {
1660         struct ieee80211_sub_if_data *sdata = rx->sdata;
1661         struct net_device *dev = sdata->dev;
1662         struct sk_buff *skb, *xmit_skb;
1663         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1664         struct sta_info *dsta;
1665         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1666
1667         skb = rx->skb;
1668         xmit_skb = NULL;
1669
1670         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1671              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1672             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1673             (status->rx_flags & IEEE80211_RX_RA_MATCH) &&
1674             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1675                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1676                         /*
1677                          * send multicast frames both to higher layers in
1678                          * local net stack and back to the wireless medium
1679                          */
1680                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1681                         if (!xmit_skb && net_ratelimit())
1682                                 printk(KERN_DEBUG "%s: failed to clone "
1683                                        "multicast frame\n", dev->name);
1684                 } else {
1685                         dsta = sta_info_get(sdata, skb->data);
1686                         if (dsta) {
1687                                 /*
1688                                  * The destination station is associated to
1689                                  * this AP (in this VLAN), so send the frame
1690                                  * directly to it and do not pass it to local
1691                                  * net stack.
1692                                  */
1693                                 xmit_skb = skb;
1694                                 skb = NULL;
1695                         }
1696                 }
1697         }
1698
1699         if (skb) {
1700                 int align __maybe_unused;
1701
1702 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1703                 /*
1704                  * 'align' will only take the values 0 or 2 here
1705                  * since all frames are required to be aligned
1706                  * to 2-byte boundaries when being passed to
1707                  * mac80211. That also explains the __skb_push()
1708                  * below.
1709                  */
1710                 align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1711                 if (align) {
1712                         if (WARN_ON(skb_headroom(skb) < 3)) {
1713                                 dev_kfree_skb(skb);
1714                                 skb = NULL;
1715                         } else {
1716                                 u8 *data = skb->data;
1717                                 size_t len = skb_headlen(skb);
1718                                 skb->data -= align;
1719                                 memmove(skb->data, data, len);
1720                                 skb_set_tail_pointer(skb, len);
1721                         }
1722                 }
1723 #endif
1724
1725                 if (skb) {
1726                         /* deliver to local stack */
1727                         skb->protocol = eth_type_trans(skb, dev);
1728                         memset(skb->cb, 0, sizeof(skb->cb));
1729                         netif_receive_skb(skb);
1730                 }
1731         }
1732
1733         if (xmit_skb) {
1734                 /* send to wireless media */
1735                 xmit_skb->protocol = htons(ETH_P_802_3);
1736                 skb_reset_network_header(xmit_skb);
1737                 skb_reset_mac_header(xmit_skb);
1738                 dev_queue_xmit(xmit_skb);
1739         }
1740 }
1741
1742 static ieee80211_rx_result debug_noinline
1743 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1744 {
1745         struct net_device *dev = rx->sdata->dev;
1746         struct sk_buff *skb = rx->skb;
1747         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1748         __le16 fc = hdr->frame_control;
1749         struct sk_buff_head frame_list;
1750         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1751
1752         if (unlikely(!ieee80211_is_data(fc)))
1753                 return RX_CONTINUE;
1754
1755         if (unlikely(!ieee80211_is_data_present(fc)))
1756                 return RX_DROP_MONITOR;
1757
1758         if (!(status->rx_flags & IEEE80211_RX_AMSDU))
1759                 return RX_CONTINUE;
1760
1761         if (ieee80211_has_a4(hdr->frame_control) &&
1762             rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1763             !rx->sdata->u.vlan.sta)
1764                 return RX_DROP_UNUSABLE;
1765
1766         if (is_multicast_ether_addr(hdr->addr1) &&
1767             ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1768               rx->sdata->u.vlan.sta) ||
1769              (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1770               rx->sdata->u.mgd.use_4addr)))
1771                 return RX_DROP_UNUSABLE;
1772
1773         skb->dev = dev;
1774         __skb_queue_head_init(&frame_list);
1775
1776         if (skb_linearize(skb))
1777                 return RX_DROP_UNUSABLE;
1778
1779         ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
1780                                  rx->sdata->vif.type,
1781                                  rx->local->hw.extra_tx_headroom);
1782
1783         while (!skb_queue_empty(&frame_list)) {
1784                 rx->skb = __skb_dequeue(&frame_list);
1785
1786                 if (!ieee80211_frame_allowed(rx, fc)) {
1787                         dev_kfree_skb(rx->skb);
1788                         continue;
1789                 }
1790                 dev->stats.rx_packets++;
1791                 dev->stats.rx_bytes += rx->skb->len;
1792
1793                 ieee80211_deliver_skb(rx);
1794         }
1795
1796         return RX_QUEUED;
1797 }
1798
1799 #ifdef CONFIG_MAC80211_MESH
1800 static ieee80211_rx_result
1801 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1802 {
1803         struct ieee80211_hdr *hdr;
1804         struct ieee80211s_hdr *mesh_hdr;
1805         unsigned int hdrlen;
1806         struct sk_buff *skb = rx->skb, *fwd_skb;
1807         struct ieee80211_local *local = rx->local;
1808         struct ieee80211_sub_if_data *sdata = rx->sdata;
1809         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1810
1811         hdr = (struct ieee80211_hdr *) skb->data;
1812         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1813         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1814
1815         if (!ieee80211_is_data(hdr->frame_control))
1816                 return RX_CONTINUE;
1817
1818         if (!mesh_hdr->ttl)
1819                 /* illegal frame */
1820                 return RX_DROP_MONITOR;
1821
1822         if (mesh_hdr->flags & MESH_FLAGS_AE) {
1823                 struct mesh_path *mppath;
1824                 char *proxied_addr;
1825                 char *mpp_addr;
1826
1827                 if (is_multicast_ether_addr(hdr->addr1)) {
1828                         mpp_addr = hdr->addr3;
1829                         proxied_addr = mesh_hdr->eaddr1;
1830                 } else {
1831                         mpp_addr = hdr->addr4;
1832                         proxied_addr = mesh_hdr->eaddr2;
1833                 }
1834
1835                 rcu_read_lock();
1836                 mppath = mpp_path_lookup(proxied_addr, sdata);
1837                 if (!mppath) {
1838                         mpp_path_add(proxied_addr, mpp_addr, sdata);
1839                 } else {
1840                         spin_lock_bh(&mppath->state_lock);
1841                         if (compare_ether_addr(mppath->mpp, mpp_addr) != 0)
1842                                 memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
1843                         spin_unlock_bh(&mppath->state_lock);
1844                 }
1845                 rcu_read_unlock();
1846         }
1847
1848         /* Frame has reached destination.  Don't forward */
1849         if (!is_multicast_ether_addr(hdr->addr1) &&
1850             compare_ether_addr(sdata->vif.addr, hdr->addr3) == 0)
1851                 return RX_CONTINUE;
1852
1853         mesh_hdr->ttl--;
1854
1855         if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
1856                 if (!mesh_hdr->ttl)
1857                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1858                                                      dropped_frames_ttl);
1859                 else {
1860                         struct ieee80211_hdr *fwd_hdr;
1861                         struct ieee80211_tx_info *info;
1862
1863                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1864
1865                         if (!fwd_skb && net_ratelimit())
1866                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1867                                                    sdata->name);
1868                         if (!fwd_skb)
1869                                 goto out;
1870
1871                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1872                         memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
1873                         info = IEEE80211_SKB_CB(fwd_skb);
1874                         memset(info, 0, sizeof(*info));
1875                         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1876                         info->control.vif = &rx->sdata->vif;
1877                         skb_set_queue_mapping(skb,
1878                                 ieee80211_select_queue(rx->sdata, fwd_skb));
1879                         ieee80211_set_qos_hdr(local, skb);
1880                         if (is_multicast_ether_addr(fwd_hdr->addr1))
1881                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1882                                                                 fwded_mcast);
1883                         else {
1884                                 int err;
1885                                 /*
1886                                  * Save TA to addr1 to send TA a path error if a
1887                                  * suitable next hop is not found
1888                                  */
1889                                 memcpy(fwd_hdr->addr1, fwd_hdr->addr2,
1890                                                 ETH_ALEN);
1891                                 err = mesh_nexthop_lookup(fwd_skb, sdata);
1892                                 /* Failed to immediately resolve next hop:
1893                                  * fwded frame was dropped or will be added
1894                                  * later to the pending skb queue.  */
1895                                 if (err)
1896                                         return RX_DROP_MONITOR;
1897
1898                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1899                                                                 fwded_unicast);
1900                         }
1901                         IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1902                                                      fwded_frames);
1903                         ieee80211_add_pending_skb(local, fwd_skb);
1904                 }
1905         }
1906
1907  out:
1908         if (is_multicast_ether_addr(hdr->addr1) ||
1909             sdata->dev->flags & IFF_PROMISC)
1910                 return RX_CONTINUE;
1911         else
1912                 return RX_DROP_MONITOR;
1913 }
1914 #endif
1915
1916 static ieee80211_rx_result debug_noinline
1917 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1918 {
1919         struct ieee80211_sub_if_data *sdata = rx->sdata;
1920         struct ieee80211_local *local = rx->local;
1921         struct net_device *dev = sdata->dev;
1922         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1923         __le16 fc = hdr->frame_control;
1924         bool port_control;
1925         int err;
1926
1927         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1928                 return RX_CONTINUE;
1929
1930         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1931                 return RX_DROP_MONITOR;
1932
1933         /*
1934          * Allow the cooked monitor interface of an AP to see 4-addr frames so
1935          * that a 4-addr station can be detected and moved into a separate VLAN
1936          */
1937         if (ieee80211_has_a4(hdr->frame_control) &&
1938             sdata->vif.type == NL80211_IFTYPE_AP)
1939                 return RX_DROP_MONITOR;
1940
1941         err = __ieee80211_data_to_8023(rx, &port_control);
1942         if (unlikely(err))
1943                 return RX_DROP_UNUSABLE;
1944
1945         if (!ieee80211_frame_allowed(rx, fc))
1946                 return RX_DROP_MONITOR;
1947
1948         if (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1949             unlikely(port_control) && sdata->bss) {
1950                 sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
1951                                      u.ap);
1952                 dev = sdata->dev;
1953                 rx->sdata = sdata;
1954         }
1955
1956         rx->skb->dev = dev;
1957
1958         dev->stats.rx_packets++;
1959         dev->stats.rx_bytes += rx->skb->len;
1960
1961         if (local->ps_sdata && local->hw.conf.dynamic_ps_timeout > 0 &&
1962             !is_multicast_ether_addr(
1963                     ((struct ethhdr *)rx->skb->data)->h_dest) &&
1964             (!local->scanning &&
1965              !test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state))) {
1966                         mod_timer(&local->dynamic_ps_timer, jiffies +
1967                          msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
1968         }
1969
1970         ieee80211_deliver_skb(rx);
1971
1972         return RX_QUEUED;
1973 }
1974
1975 static ieee80211_rx_result debug_noinline
1976 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1977 {
1978         struct ieee80211_local *local = rx->local;
1979         struct ieee80211_hw *hw = &local->hw;
1980         struct sk_buff *skb = rx->skb;
1981         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1982         struct tid_ampdu_rx *tid_agg_rx;
1983         u16 start_seq_num;
1984         u16 tid;
1985
1986         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1987                 return RX_CONTINUE;
1988
1989         if (ieee80211_is_back_req(bar->frame_control)) {
1990                 struct {
1991                         __le16 control, start_seq_num;
1992                 } __packed bar_data;
1993
1994                 if (!rx->sta)
1995                         return RX_DROP_MONITOR;
1996
1997                 if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
1998                                   &bar_data, sizeof(bar_data)))
1999                         return RX_DROP_MONITOR;
2000
2001                 tid = le16_to_cpu(bar_data.control) >> 12;
2002
2003                 tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
2004                 if (!tid_agg_rx)
2005                         return RX_DROP_MONITOR;
2006
2007                 start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
2008
2009                 /* reset session timer */
2010                 if (tid_agg_rx->timeout)
2011                         mod_timer(&tid_agg_rx->session_timer,
2012                                   TU_TO_EXP_TIME(tid_agg_rx->timeout));
2013
2014                 spin_lock(&tid_agg_rx->reorder_lock);
2015                 /* release stored frames up to start of BAR */
2016                 ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num);
2017                 spin_unlock(&tid_agg_rx->reorder_lock);
2018
2019                 kfree_skb(skb);
2020                 return RX_QUEUED;
2021         }
2022
2023         /*
2024          * After this point, we only want management frames,
2025          * so we can drop all remaining control frames to
2026          * cooked monitor interfaces.
2027          */
2028         return RX_DROP_MONITOR;
2029 }
2030
2031 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
2032                                            struct ieee80211_mgmt *mgmt,
2033                                            size_t len)
2034 {
2035         struct ieee80211_local *local = sdata->local;
2036         struct sk_buff *skb;
2037         struct ieee80211_mgmt *resp;
2038
2039         if (compare_ether_addr(mgmt->da, sdata->vif.addr) != 0) {
2040                 /* Not to own unicast address */
2041                 return;
2042         }
2043
2044         if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
2045             compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
2046                 /* Not from the current AP or not associated yet. */
2047                 return;
2048         }
2049
2050         if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
2051                 /* Too short SA Query request frame */
2052                 return;
2053         }
2054
2055         skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
2056         if (skb == NULL)
2057                 return;
2058
2059         skb_reserve(skb, local->hw.extra_tx_headroom);
2060         resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
2061         memset(resp, 0, 24);
2062         memcpy(resp->da, mgmt->sa, ETH_ALEN);
2063         memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
2064         memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
2065         resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2066                                           IEEE80211_STYPE_ACTION);
2067         skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
2068         resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
2069         resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
2070         memcpy(resp->u.action.u.sa_query.trans_id,
2071                mgmt->u.action.u.sa_query.trans_id,
2072                WLAN_SA_QUERY_TR_ID_LEN);
2073
2074         ieee80211_tx_skb(sdata, skb);
2075 }
2076
2077 static ieee80211_rx_result debug_noinline
2078 ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
2079 {
2080         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2081         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2082
2083         /*
2084          * From here on, look only at management frames.
2085          * Data and control frames are already handled,
2086          * and unknown (reserved) frames are useless.
2087          */
2088         if (rx->skb->len < 24)
2089                 return RX_DROP_MONITOR;
2090
2091         if (!ieee80211_is_mgmt(mgmt->frame_control))
2092                 return RX_DROP_MONITOR;
2093
2094         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2095                 return RX_DROP_MONITOR;
2096
2097         if (ieee80211_drop_unencrypted_mgmt(rx))
2098                 return RX_DROP_UNUSABLE;
2099
2100         return RX_CONTINUE;
2101 }
2102
2103 static ieee80211_rx_result debug_noinline
2104 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
2105 {
2106         struct ieee80211_local *local = rx->local;
2107         struct ieee80211_sub_if_data *sdata = rx->sdata;
2108         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2109         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2110         int len = rx->skb->len;
2111
2112         if (!ieee80211_is_action(mgmt->frame_control))
2113                 return RX_CONTINUE;
2114
2115         /* drop too small frames */
2116         if (len < IEEE80211_MIN_ACTION_SIZE)
2117                 return RX_DROP_UNUSABLE;
2118
2119         if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC)
2120                 return RX_DROP_UNUSABLE;
2121
2122         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2123                 return RX_DROP_UNUSABLE;
2124
2125         switch (mgmt->u.action.category) {
2126         case WLAN_CATEGORY_BACK:
2127                 /*
2128                  * The aggregation code is not prepared to handle
2129                  * anything but STA/AP due to the BSSID handling;
2130                  * IBSS could work in the code but isn't supported
2131                  * by drivers or the standard.
2132                  */
2133                 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2134                     sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2135                     sdata->vif.type != NL80211_IFTYPE_AP)
2136                         break;
2137
2138                 /* verify action_code is present */
2139                 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2140                         break;
2141
2142                 switch (mgmt->u.action.u.addba_req.action_code) {
2143                 case WLAN_ACTION_ADDBA_REQ:
2144                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2145                                    sizeof(mgmt->u.action.u.addba_req)))
2146                                 goto invalid;
2147                         break;
2148                 case WLAN_ACTION_ADDBA_RESP:
2149                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2150                                    sizeof(mgmt->u.action.u.addba_resp)))
2151                                 goto invalid;
2152                         break;
2153                 case WLAN_ACTION_DELBA:
2154                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2155                                    sizeof(mgmt->u.action.u.delba)))
2156                                 goto invalid;
2157                         break;
2158                 default:
2159                         goto invalid;
2160                 }
2161
2162                 goto queue;
2163         case WLAN_CATEGORY_SPECTRUM_MGMT:
2164                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
2165                         break;
2166
2167                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
2168                         break;
2169
2170                 /* verify action_code is present */
2171                 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2172                         break;
2173
2174                 switch (mgmt->u.action.u.measurement.action_code) {
2175                 case WLAN_ACTION_SPCT_MSR_REQ:
2176                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2177                                    sizeof(mgmt->u.action.u.measurement)))
2178                                 break;
2179                         ieee80211_process_measurement_req(sdata, mgmt, len);
2180                         goto handled;
2181                 case WLAN_ACTION_SPCT_CHL_SWITCH:
2182                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2183                                    sizeof(mgmt->u.action.u.chan_switch)))
2184                                 break;
2185
2186                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
2187                                 break;
2188
2189                         if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
2190                                 break;
2191
2192                         goto queue;
2193                 }
2194                 break;
2195         case WLAN_CATEGORY_SA_QUERY:
2196                 if (len < (IEEE80211_MIN_ACTION_SIZE +
2197                            sizeof(mgmt->u.action.u.sa_query)))
2198                         break;
2199
2200                 switch (mgmt->u.action.u.sa_query.action) {
2201                 case WLAN_ACTION_SA_QUERY_REQUEST:
2202                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
2203                                 break;
2204                         ieee80211_process_sa_query_req(sdata, mgmt, len);
2205                         goto handled;
2206                 }
2207                 break;
2208         case WLAN_CATEGORY_MESH_PLINK:
2209                 if (!ieee80211_vif_is_mesh(&sdata->vif))
2210                         break;
2211                 goto queue;
2212         case WLAN_CATEGORY_MESH_PATH_SEL:
2213                 if (!mesh_path_sel_is_hwmp(sdata))
2214                         break;
2215                 goto queue;
2216         }
2217
2218         return RX_CONTINUE;
2219
2220  invalid:
2221         status->rx_flags |= IEEE80211_RX_MALFORMED_ACTION_FRM;
2222         /* will return in the next handlers */
2223         return RX_CONTINUE;
2224
2225  handled:
2226         if (rx->sta)
2227                 rx->sta->rx_packets++;
2228         dev_kfree_skb(rx->skb);
2229         return RX_QUEUED;
2230
2231  queue:
2232         rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2233         skb_queue_tail(&sdata->skb_queue, rx->skb);
2234         ieee80211_queue_work(&local->hw, &sdata->work);
2235         if (rx->sta)
2236                 rx->sta->rx_packets++;
2237         return RX_QUEUED;
2238 }
2239
2240 static ieee80211_rx_result debug_noinline
2241 ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
2242 {
2243         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2244
2245         /* skip known-bad action frames and return them in the next handler */
2246         if (status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM)
2247                 return RX_CONTINUE;
2248
2249         /*
2250          * Getting here means the kernel doesn't know how to handle
2251          * it, but maybe userspace does ... include returned frames
2252          * so userspace can register for those to know whether ones
2253          * it transmitted were processed or returned.
2254          */
2255
2256         if (cfg80211_rx_mgmt(rx->sdata->dev, status->freq,
2257                              rx->skb->data, rx->skb->len,
2258                              GFP_ATOMIC)) {
2259                 if (rx->sta)
2260                         rx->sta->rx_packets++;
2261                 dev_kfree_skb(rx->skb);
2262                 return RX_QUEUED;
2263         }
2264
2265
2266         return RX_CONTINUE;
2267 }
2268
2269 static ieee80211_rx_result debug_noinline
2270 ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
2271 {
2272         struct ieee80211_local *local = rx->local;
2273         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2274         struct sk_buff *nskb;
2275         struct ieee80211_sub_if_data *sdata = rx->sdata;
2276         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2277
2278         if (!ieee80211_is_action(mgmt->frame_control))
2279                 return RX_CONTINUE;
2280
2281         /*
2282          * For AP mode, hostapd is responsible for handling any action
2283          * frames that we didn't handle, including returning unknown
2284          * ones. For all other modes we will return them to the sender,
2285          * setting the 0x80 bit in the action category, as required by
2286          * 802.11-2007 7.3.1.11.
2287          * Newer versions of hostapd shall also use the management frame
2288          * registration mechanisms, but older ones still use cooked
2289          * monitor interfaces so push all frames there.
2290          */
2291         if (!(status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM) &&
2292             (sdata->vif.type == NL80211_IFTYPE_AP ||
2293              sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
2294                 return RX_DROP_MONITOR;
2295
2296         /* do not return rejected action frames */
2297         if (mgmt->u.action.category & 0x80)
2298                 return RX_DROP_UNUSABLE;
2299
2300         nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
2301                                GFP_ATOMIC);
2302         if (nskb) {
2303                 struct ieee80211_mgmt *nmgmt = (void *)nskb->data;
2304
2305                 nmgmt->u.action.category |= 0x80;
2306                 memcpy(nmgmt->da, nmgmt->sa, ETH_ALEN);
2307                 memcpy(nmgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
2308
2309                 memset(nskb->cb, 0, sizeof(nskb->cb));
2310
2311                 ieee80211_tx_skb(rx->sdata, nskb);
2312         }
2313         dev_kfree_skb(rx->skb);
2314         return RX_QUEUED;
2315 }
2316
2317 static ieee80211_rx_result debug_noinline
2318 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
2319 {
2320         struct ieee80211_sub_if_data *sdata = rx->sdata;
2321         ieee80211_rx_result rxs;
2322         struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
2323         __le16 stype;
2324
2325         rxs = ieee80211_work_rx_mgmt(rx->sdata, rx->skb);
2326         if (rxs != RX_CONTINUE)
2327                 return rxs;
2328
2329         stype = mgmt->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE);
2330
2331         if (!ieee80211_vif_is_mesh(&sdata->vif) &&
2332             sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2333             sdata->vif.type != NL80211_IFTYPE_STATION)
2334                 return RX_DROP_MONITOR;
2335
2336         switch (stype) {
2337         case cpu_to_le16(IEEE80211_STYPE_BEACON):
2338         case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
2339                 /* process for all: mesh, mlme, ibss */
2340                 break;
2341         case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
2342         case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
2343                 if (is_multicast_ether_addr(mgmt->da) &&
2344                     !is_broadcast_ether_addr(mgmt->da))
2345                         return RX_DROP_MONITOR;
2346
2347                 /* process only for station */
2348                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
2349                         return RX_DROP_MONITOR;
2350                 break;
2351         case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
2352         case cpu_to_le16(IEEE80211_STYPE_AUTH):
2353                 /* process only for ibss */
2354                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
2355                         return RX_DROP_MONITOR;
2356                 break;
2357         default:
2358                 return RX_DROP_MONITOR;
2359         }
2360
2361         /* queue up frame and kick off work to process it */
2362         rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2363         skb_queue_tail(&sdata->skb_queue, rx->skb);
2364         ieee80211_queue_work(&rx->local->hw, &sdata->work);
2365         if (rx->sta)
2366                 rx->sta->rx_packets++;
2367
2368         return RX_QUEUED;
2369 }
2370
2371 static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
2372                                             struct ieee80211_rx_data *rx)
2373 {
2374         int keyidx;
2375         unsigned int hdrlen;
2376
2377         hdrlen = ieee80211_hdrlen(hdr->frame_control);
2378         if (rx->skb->len >= hdrlen + 4)
2379                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
2380         else
2381                 keyidx = -1;
2382
2383         if (!rx->sta) {
2384                 /*
2385                  * Some hardware seem to generate incorrect Michael MIC
2386                  * reports; ignore them to avoid triggering countermeasures.
2387                  */
2388                 return;
2389         }
2390
2391         if (!ieee80211_has_protected(hdr->frame_control))
2392                 return;
2393
2394         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
2395                 /*
2396                  * APs with pairwise keys should never receive Michael MIC
2397                  * errors for non-zero keyidx because these are reserved for
2398                  * group keys and only the AP is sending real multicast
2399                  * frames in the BSS.
2400                  */
2401                 return;
2402         }
2403
2404         if (!ieee80211_is_data(hdr->frame_control) &&
2405             !ieee80211_is_auth(hdr->frame_control))
2406                 return;
2407
2408         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
2409                                         GFP_ATOMIC);
2410 }
2411
2412 /* TODO: use IEEE80211_RX_FRAGMENTED */
2413 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
2414                                         struct ieee80211_rate *rate)
2415 {
2416         struct ieee80211_sub_if_data *sdata;
2417         struct ieee80211_local *local = rx->local;
2418         struct ieee80211_rtap_hdr {
2419                 struct ieee80211_radiotap_header hdr;
2420                 u8 flags;
2421                 u8 rate_or_pad;
2422                 __le16 chan_freq;
2423                 __le16 chan_flags;
2424         } __packed *rthdr;
2425         struct sk_buff *skb = rx->skb, *skb2;
2426         struct net_device *prev_dev = NULL;
2427         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2428
2429         /*
2430          * If cooked monitor has been processed already, then
2431          * don't do it again. If not, set the flag.
2432          */
2433         if (rx->flags & IEEE80211_RX_CMNTR)
2434                 goto out_free_skb;
2435         rx->flags |= IEEE80211_RX_CMNTR;
2436
2437         if (skb_headroom(skb) < sizeof(*rthdr) &&
2438             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
2439                 goto out_free_skb;
2440
2441         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
2442         memset(rthdr, 0, sizeof(*rthdr));
2443         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
2444         rthdr->hdr.it_present =
2445                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
2446                             (1 << IEEE80211_RADIOTAP_CHANNEL));
2447
2448         if (rate) {
2449                 rthdr->rate_or_pad = rate->bitrate / 5;
2450                 rthdr->hdr.it_present |=
2451                         cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
2452         }
2453         rthdr->chan_freq = cpu_to_le16(status->freq);
2454
2455         if (status->band == IEEE80211_BAND_5GHZ)
2456                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
2457                                                 IEEE80211_CHAN_5GHZ);
2458         else
2459                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
2460                                                 IEEE80211_CHAN_2GHZ);
2461
2462         skb_set_mac_header(skb, 0);
2463         skb->ip_summed = CHECKSUM_UNNECESSARY;
2464         skb->pkt_type = PACKET_OTHERHOST;
2465         skb->protocol = htons(ETH_P_802_2);
2466
2467         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2468                 if (!ieee80211_sdata_running(sdata))
2469                         continue;
2470
2471                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
2472                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
2473                         continue;
2474
2475                 if (prev_dev) {
2476                         skb2 = skb_clone(skb, GFP_ATOMIC);
2477                         if (skb2) {
2478                                 skb2->dev = prev_dev;
2479                                 netif_receive_skb(skb2);
2480                         }
2481                 }
2482
2483                 prev_dev = sdata->dev;
2484                 sdata->dev->stats.rx_packets++;
2485                 sdata->dev->stats.rx_bytes += skb->len;
2486         }
2487
2488         if (prev_dev) {
2489                 skb->dev = prev_dev;
2490                 netif_receive_skb(skb);
2491                 return;
2492         }
2493
2494  out_free_skb:
2495         dev_kfree_skb(skb);
2496 }
2497
2498 static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
2499                                          ieee80211_rx_result res)
2500 {
2501         switch (res) {
2502         case RX_DROP_MONITOR:
2503                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2504                 if (rx->sta)
2505                         rx->sta->rx_dropped++;
2506                 /* fall through */
2507         case RX_CONTINUE: {
2508                 struct ieee80211_rate *rate = NULL;
2509                 struct ieee80211_supported_band *sband;
2510                 struct ieee80211_rx_status *status;
2511
2512                 status = IEEE80211_SKB_RXCB((rx->skb));
2513
2514                 sband = rx->local->hw.wiphy->bands[status->band];
2515                 if (!(status->flag & RX_FLAG_HT))
2516                         rate = &sband->bitrates[status->rate_idx];
2517
2518                 ieee80211_rx_cooked_monitor(rx, rate);
2519                 break;
2520                 }
2521         case RX_DROP_UNUSABLE:
2522                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2523                 if (rx->sta)
2524                         rx->sta->rx_dropped++;
2525                 dev_kfree_skb(rx->skb);
2526                 break;
2527         case RX_QUEUED:
2528                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_queued);
2529                 break;
2530         }
2531 }
2532
2533 static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx)
2534 {
2535         ieee80211_rx_result res = RX_DROP_MONITOR;
2536         struct sk_buff *skb;
2537
2538 #define CALL_RXH(rxh)                   \
2539         do {                            \
2540                 res = rxh(rx);          \
2541                 if (res != RX_CONTINUE) \
2542                         goto rxh_next;  \
2543         } while (0);
2544
2545         spin_lock(&rx->local->rx_skb_queue.lock);
2546         if (rx->local->running_rx_handler)
2547                 goto unlock;
2548
2549         rx->local->running_rx_handler = true;
2550
2551         while ((skb = __skb_dequeue(&rx->local->rx_skb_queue))) {
2552                 spin_unlock(&rx->local->rx_skb_queue.lock);
2553
2554                 /*
2555                  * all the other fields are valid across frames
2556                  * that belong to an aMPDU since they are on the
2557                  * same TID from the same station
2558                  */
2559                 rx->skb = skb;
2560
2561                 CALL_RXH(ieee80211_rx_h_decrypt)
2562                 CALL_RXH(ieee80211_rx_h_check_more_data)
2563                 CALL_RXH(ieee80211_rx_h_sta_process)
2564                 CALL_RXH(ieee80211_rx_h_defragment)
2565                 CALL_RXH(ieee80211_rx_h_ps_poll)
2566                 CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2567                 /* must be after MMIC verify so header is counted in MPDU mic */
2568                 CALL_RXH(ieee80211_rx_h_remove_qos_control)
2569                 CALL_RXH(ieee80211_rx_h_amsdu)
2570 #ifdef CONFIG_MAC80211_MESH
2571                 if (ieee80211_vif_is_mesh(&rx->sdata->vif))
2572                         CALL_RXH(ieee80211_rx_h_mesh_fwding);
2573 #endif
2574                 CALL_RXH(ieee80211_rx_h_data)
2575                 CALL_RXH(ieee80211_rx_h_ctrl);
2576                 CALL_RXH(ieee80211_rx_h_mgmt_check)
2577                 CALL_RXH(ieee80211_rx_h_action)
2578                 CALL_RXH(ieee80211_rx_h_userspace_mgmt)
2579                 CALL_RXH(ieee80211_rx_h_action_return)
2580                 CALL_RXH(ieee80211_rx_h_mgmt)
2581
2582  rxh_next:
2583                 ieee80211_rx_handlers_result(rx, res);
2584                 spin_lock(&rx->local->rx_skb_queue.lock);
2585 #undef CALL_RXH
2586         }
2587
2588         rx->local->running_rx_handler = false;
2589
2590  unlock:
2591         spin_unlock(&rx->local->rx_skb_queue.lock);
2592 }
2593
2594 static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
2595 {
2596         ieee80211_rx_result res = RX_DROP_MONITOR;
2597
2598 #define CALL_RXH(rxh)                   \
2599         do {                            \
2600                 res = rxh(rx);          \
2601                 if (res != RX_CONTINUE) \
2602                         goto rxh_next;  \
2603         } while (0);
2604
2605         CALL_RXH(ieee80211_rx_h_passive_scan)
2606         CALL_RXH(ieee80211_rx_h_check)
2607
2608         ieee80211_rx_reorder_ampdu(rx);
2609
2610         ieee80211_rx_handlers(rx);
2611         return;
2612
2613  rxh_next:
2614         ieee80211_rx_handlers_result(rx, res);
2615
2616 #undef CALL_RXH
2617 }
2618
2619 /*
2620  * This function makes calls into the RX path, therefore
2621  * it has to be invoked under RCU read lock.
2622  */
2623 void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
2624 {
2625         struct ieee80211_rx_data rx = {
2626                 .sta = sta,
2627                 .sdata = sta->sdata,
2628                 .local = sta->local,
2629                 .queue = tid,
2630                 .flags = 0,
2631         };
2632         struct tid_ampdu_rx *tid_agg_rx;
2633
2634         tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
2635         if (!tid_agg_rx)
2636                 return;
2637
2638         spin_lock(&tid_agg_rx->reorder_lock);
2639         ieee80211_sta_reorder_release(&sta->local->hw, tid_agg_rx);
2640         spin_unlock(&tid_agg_rx->reorder_lock);
2641
2642         ieee80211_rx_handlers(&rx);
2643 }
2644
2645 /* main receive path */
2646
2647 static int prepare_for_handlers(struct ieee80211_rx_data *rx,
2648                                 struct ieee80211_hdr *hdr)
2649 {
2650         struct ieee80211_sub_if_data *sdata = rx->sdata;
2651         struct sk_buff *skb = rx->skb;
2652         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2653         u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
2654         int multicast = is_multicast_ether_addr(hdr->addr1);
2655
2656         switch (sdata->vif.type) {
2657         case NL80211_IFTYPE_STATION:
2658                 if (!bssid && !sdata->u.mgd.use_4addr)
2659                         return 0;
2660                 if (!multicast &&
2661                     compare_ether_addr(sdata->vif.addr, hdr->addr1) != 0) {
2662                         if (!(sdata->dev->flags & IFF_PROMISC) ||
2663                             sdata->u.mgd.use_4addr)
2664                                 return 0;
2665                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2666                 }
2667                 break;
2668         case NL80211_IFTYPE_ADHOC:
2669                 if (!bssid)
2670                         return 0;
2671                 if (ieee80211_is_beacon(hdr->frame_control)) {
2672                         return 1;
2673                 }
2674                 else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2675                         if (!(status->rx_flags & IEEE80211_RX_IN_SCAN))
2676                                 return 0;
2677                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2678                 } else if (!multicast &&
2679                            compare_ether_addr(sdata->vif.addr,
2680                                               hdr->addr1) != 0) {
2681                         if (!(sdata->dev->flags & IFF_PROMISC))
2682                                 return 0;
2683                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2684                 } else if (!rx->sta) {
2685                         int rate_idx;
2686                         if (status->flag & RX_FLAG_HT)
2687                                 rate_idx = 0; /* TODO: HT rates */
2688                         else
2689                                 rate_idx = status->rate_idx;
2690                         rx->sta = ieee80211_ibss_add_sta(sdata, bssid,
2691                                         hdr->addr2, BIT(rate_idx), GFP_ATOMIC);
2692                 }
2693                 break;
2694         case NL80211_IFTYPE_MESH_POINT:
2695                 if (!multicast &&
2696                     compare_ether_addr(sdata->vif.addr,
2697                                        hdr->addr1) != 0) {
2698                         if (!(sdata->dev->flags & IFF_PROMISC))
2699                                 return 0;
2700
2701                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2702                 }
2703                 break;
2704         case NL80211_IFTYPE_AP_VLAN:
2705         case NL80211_IFTYPE_AP:
2706                 if (!bssid) {
2707                         if (compare_ether_addr(sdata->vif.addr,
2708                                                hdr->addr1))
2709                                 return 0;
2710                 } else if (!ieee80211_bssid_match(bssid,
2711                                         sdata->vif.addr)) {
2712                         if (!(status->rx_flags & IEEE80211_RX_IN_SCAN) &&
2713                             !ieee80211_is_beacon(hdr->frame_control))
2714                                 return 0;
2715                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2716                 }
2717                 break;
2718         case NL80211_IFTYPE_WDS:
2719                 if (bssid || !ieee80211_is_data(hdr->frame_control))
2720                         return 0;
2721                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2722                         return 0;
2723                 break;
2724         default:
2725                 /* should never get here */
2726                 WARN_ON(1);
2727                 break;
2728         }
2729
2730         return 1;
2731 }
2732
2733 /*
2734  * This function returns whether or not the SKB
2735  * was destined for RX processing or not, which,
2736  * if consume is true, is equivalent to whether
2737  * or not the skb was consumed.
2738  */
2739 static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
2740                                             struct sk_buff *skb, bool consume)
2741 {
2742         struct ieee80211_local *local = rx->local;
2743         struct ieee80211_sub_if_data *sdata = rx->sdata;
2744         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2745         struct ieee80211_hdr *hdr = (void *)skb->data;
2746         int prepares;
2747
2748         rx->skb = skb;
2749         status->rx_flags |= IEEE80211_RX_RA_MATCH;
2750         prepares = prepare_for_handlers(rx, hdr);
2751
2752         if (!prepares)
2753                 return false;
2754
2755         if (status->flag & RX_FLAG_MMIC_ERROR) {
2756                 if (status->rx_flags & IEEE80211_RX_RA_MATCH)
2757                         ieee80211_rx_michael_mic_report(hdr, rx);
2758                 return false;
2759         }
2760
2761         if (!consume) {
2762                 skb = skb_copy(skb, GFP_ATOMIC);
2763                 if (!skb) {
2764                         if (net_ratelimit())
2765                                 wiphy_debug(local->hw.wiphy,
2766                                         "failed to copy skb for %s\n",
2767                                         sdata->name);
2768                         return true;
2769                 }
2770
2771                 rx->skb = skb;
2772         }
2773
2774         ieee80211_invoke_rx_handlers(rx);
2775         return true;
2776 }
2777
2778 /*
2779  * This is the actual Rx frames handler. as it blongs to Rx path it must
2780  * be called with rcu_read_lock protection.
2781  */
2782 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2783                                          struct sk_buff *skb)
2784 {
2785         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2786         struct ieee80211_local *local = hw_to_local(hw);
2787         struct ieee80211_sub_if_data *sdata;
2788         struct ieee80211_hdr *hdr;
2789         __le16 fc;
2790         struct ieee80211_rx_data rx;
2791         struct ieee80211_sub_if_data *prev;
2792         struct sta_info *sta, *tmp, *prev_sta;
2793         int err = 0;
2794
2795         fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
2796         memset(&rx, 0, sizeof(rx));
2797         rx.skb = skb;
2798         rx.local = local;
2799
2800         if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
2801                 local->dot11ReceivedFragmentCount++;
2802
2803         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
2804                      test_bit(SCAN_SW_SCANNING, &local->scanning)))
2805                 status->rx_flags |= IEEE80211_RX_IN_SCAN;
2806
2807         if (ieee80211_is_mgmt(fc))
2808                 err = skb_linearize(skb);
2809         else
2810                 err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
2811
2812         if (err) {
2813                 dev_kfree_skb(skb);
2814                 return;
2815         }
2816
2817         hdr = (struct ieee80211_hdr *)skb->data;
2818         ieee80211_parse_qos(&rx);
2819         ieee80211_verify_alignment(&rx);
2820
2821         if (ieee80211_is_data(fc)) {
2822                 prev_sta = NULL;
2823
2824                 for_each_sta_info(local, hdr->addr2, sta, tmp) {
2825                         if (!prev_sta) {
2826                                 prev_sta = sta;
2827                                 continue;
2828                         }
2829
2830                         rx.sta = prev_sta;
2831                         rx.sdata = prev_sta->sdata;
2832                         ieee80211_prepare_and_rx_handle(&rx, skb, false);
2833
2834                         prev_sta = sta;
2835                 }
2836
2837                 if (prev_sta) {
2838                         rx.sta = prev_sta;
2839                         rx.sdata = prev_sta->sdata;
2840
2841                         if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2842                                 return;
2843                         goto out;
2844                 }
2845         }
2846
2847         prev = NULL;
2848
2849         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2850                 if (!ieee80211_sdata_running(sdata))
2851                         continue;
2852
2853                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2854                     sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2855                         continue;
2856
2857                 /*
2858                  * frame is destined for this interface, but if it's
2859                  * not also for the previous one we handle that after
2860                  * the loop to avoid copying the SKB once too much
2861                  */
2862
2863                 if (!prev) {
2864                         prev = sdata;
2865                         continue;
2866                 }
2867
2868                 rx.sta = sta_info_get_bss(prev, hdr->addr2);
2869                 rx.sdata = prev;
2870                 ieee80211_prepare_and_rx_handle(&rx, skb, false);
2871
2872                 prev = sdata;
2873         }
2874
2875         if (prev) {
2876                 rx.sta = sta_info_get_bss(prev, hdr->addr2);
2877                 rx.sdata = prev;
2878
2879                 if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2880                         return;
2881         }
2882
2883  out:
2884         dev_kfree_skb(skb);
2885 }
2886
2887 /*
2888  * This is the receive path handler. It is called by a low level driver when an
2889  * 802.11 MPDU is received from the hardware.
2890  */
2891 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2892 {
2893         struct ieee80211_local *local = hw_to_local(hw);
2894         struct ieee80211_rate *rate = NULL;
2895         struct ieee80211_supported_band *sband;
2896         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2897
2898         WARN_ON_ONCE(softirq_count() == 0);
2899
2900         if (WARN_ON(status->band < 0 ||
2901                     status->band >= IEEE80211_NUM_BANDS))
2902                 goto drop;
2903
2904         sband = local->hw.wiphy->bands[status->band];
2905         if (WARN_ON(!sband))
2906                 goto drop;
2907
2908         /*
2909          * If we're suspending, it is possible although not too likely
2910          * that we'd be receiving frames after having already partially
2911          * quiesced the stack. We can't process such frames then since
2912          * that might, for example, cause stations to be added or other
2913          * driver callbacks be invoked.
2914          */
2915         if (unlikely(local->quiescing || local->suspended))
2916                 goto drop;
2917
2918         /*
2919          * The same happens when we're not even started,
2920          * but that's worth a warning.
2921          */
2922         if (WARN_ON(!local->started))
2923                 goto drop;
2924
2925         if (likely(!(status->flag & RX_FLAG_FAILED_PLCP_CRC))) {
2926                 /*
2927                  * Validate the rate, unless a PLCP error means that
2928                  * we probably can't have a valid rate here anyway.
2929                  */
2930
2931                 if (status->flag & RX_FLAG_HT) {
2932                         /*
2933                          * rate_idx is MCS index, which can be [0-76]
2934                          * as documented on:
2935                          *
2936                          * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
2937                          *
2938                          * Anything else would be some sort of driver or
2939                          * hardware error. The driver should catch hardware
2940                          * errors.
2941                          */
2942                         if (WARN((status->rate_idx < 0 ||
2943                                  status->rate_idx > 76),
2944                                  "Rate marked as an HT rate but passed "
2945                                  "status->rate_idx is not "
2946                                  "an MCS index [0-76]: %d (0x%02x)\n",
2947                                  status->rate_idx,
2948                                  status->rate_idx))
2949                                 goto drop;
2950                 } else {
2951                         if (WARN_ON(status->rate_idx < 0 ||
2952                                     status->rate_idx >= sband->n_bitrates))
2953                                 goto drop;
2954                         rate = &sband->bitrates[status->rate_idx];
2955                 }
2956         }
2957
2958         status->rx_flags = 0;
2959
2960         /*
2961          * key references and virtual interfaces are protected using RCU
2962          * and this requires that we are in a read-side RCU section during
2963          * receive processing
2964          */
2965         rcu_read_lock();
2966
2967         /*
2968          * Frames with failed FCS/PLCP checksum are not returned,
2969          * all other frames are returned without radiotap header
2970          * if it was previously present.
2971          * Also, frames with less than 16 bytes are dropped.
2972          */
2973         skb = ieee80211_rx_monitor(local, skb, rate);
2974         if (!skb) {
2975                 rcu_read_unlock();
2976                 return;
2977         }
2978
2979         ieee80211_tpt_led_trig_rx(local,
2980                         ((struct ieee80211_hdr *)skb->data)->frame_control,
2981                         skb->len);
2982         __ieee80211_rx_handle_packet(hw, skb);
2983
2984         rcu_read_unlock();
2985
2986         return;
2987  drop:
2988         kfree_skb(skb);
2989 }
2990 EXPORT_SYMBOL(ieee80211_rx);
2991
2992 /* This is a version of the rx handler that can be called from hard irq
2993  * context. Post the skb on the queue and schedule the tasklet */
2994 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
2995 {
2996         struct ieee80211_local *local = hw_to_local(hw);
2997
2998         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2999
3000         skb->pkt_type = IEEE80211_RX_MSG;
3001         skb_queue_tail(&local->skb_queue, skb);
3002         tasklet_schedule(&local->tasklet);
3003 }
3004 EXPORT_SYMBOL(ieee80211_rx_irqsafe);