net/mac80211/rx.c

   1 /*
   2  * Copyright 2002-2005, Instant802 Networks, Inc.
   3  * Copyright 2005-2006, Devicescape Software, Inc.
   4  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   5  * Copyright 2007-2010  Johannes Berg <johannes@sipsolutions.net>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/jiffies.h>
  13 #include <linux/slab.h>
  14 #include <linux/kernel.h>
  15 #include <linux/skbuff.h>
  16 #include <linux/netdevice.h>
  17 #include <linux/etherdevice.h>
  18 #include <linux/rcupdate.h>
  19 #include <net/mac80211.h>
  20 #include <net/ieee80211_radiotap.h>
  21
  22 #include "ieee80211_i.h"
  23 #include "driver-ops.h"
  24 #include "led.h"
  25 #include "mesh.h"
  26 #include "wep.h"
  27 #include "wpa.h"
  28 #include "tkip.h"
  29 #include "wme.h"
  30
  31 /*
  32  * monitor mode reception
  33  *
  34  * This function cleans up the SKB, i.e. it removes all the stuff
  35  * only useful for monitoring.
  36  */
  37 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
  38                                            struct sk_buff *skb)
  39 {
  40         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
  41                 if (likely(skb->len > FCS_LEN))
  42                         __pskb_trim(skb, skb->len - FCS_LEN);
  43                 else {
  44                         /* driver bug */
  45                         WARN_ON(1);
  46                         dev_kfree_skb(skb);
  47                         skb = NULL;
  48                 }
  49         }
  50
  51         return skb;
  52 }
  53
  54 static inline int should_drop_frame(struct sk_buff *skb,
  55                                     int present_fcs_len)
  56 {
  57         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  58         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  59
  60         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
  61                 return 1;
  62         if (unlikely(skb->len < 16 + present_fcs_len))
  63                 return 1;
  64         if (ieee80211_is_ctl(hdr->frame_control) &&
  65             !ieee80211_is_pspoll(hdr->frame_control) &&
  66             !ieee80211_is_back_req(hdr->frame_control))
  67                 return 1;
  68         return 0;
  69 }
  70
  71 static int
  72 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
  73                           struct ieee80211_rx_status *status)
  74 {
  75         int len;
  76
  77         /* always present fields */
  78         len = sizeof(struct ieee80211_radiotap_header) + 9;
  79
  80         if (status->flag & RX_FLAG_TSFT)
  81                 len += 8;
  82         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
  83                 len += 1;
  84
  85         if (len & 1) /* padding for RX_FLAGS if necessary */
  86                 len++;
  87
  88         if (status->flag & RX_FLAG_HT) /* HT info */
  89                 len += 3;
  90
  91         return len;
  92 }
  93
  94 /*
  95  * ieee80211_add_rx_radiotap_header - add radiotap header
  96  *
  97  * add a radiotap header containing all the fields which the hardware provided.
  98  */
  99 static void
 100 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
 101                                  struct sk_buff *skb,
 102                                  struct ieee80211_rate *rate,
 103                                  int rtap_len)
 104 {
 105         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 106         struct ieee80211_radiotap_header *rthdr;
 107         unsigned char *pos;
 108         u16 rx_flags = 0;
 109
 110         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
 111         memset(rthdr, 0, rtap_len);
 112
 113         /* radiotap header, set always present flags */
 114         rthdr->it_present =
 115                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 116                             (1 << IEEE80211_RADIOTAP_CHANNEL) |
 117                             (1 << IEEE80211_RADIOTAP_ANTENNA) |
 118                             (1 << IEEE80211_RADIOTAP_RX_FLAGS));
 119         rthdr->it_len = cpu_to_le16(rtap_len);
 120
 121         pos = (unsigned char *)(rthdr+1);
 122
 123         /* the order of the following fields is important */
 124
 125         /* IEEE80211_RADIOTAP_TSFT */
 126         if (status->flag & RX_FLAG_TSFT) {
 127                 put_unaligned_le64(status->mactime, pos);
 128                 rthdr->it_present |=
 129                         cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
 130                 pos += 8;
 131         }
 132
 133         /* IEEE80211_RADIOTAP_FLAGS */
 134         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 135                 *pos |= IEEE80211_RADIOTAP_F_FCS;
 136         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 137                 *pos |= IEEE80211_RADIOTAP_F_BADFCS;
 138         if (status->flag & RX_FLAG_SHORTPRE)
 139                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
 140         pos++;
 141
 142         /* IEEE80211_RADIOTAP_RATE */
 143         if (status->flag & RX_FLAG_HT) {
 144                 /*
 145                  * TODO: add following information into radiotap header once
 146                  * suitable fields are defined for it:
 147                  * - MCS index (status->rate_idx)
 148                  * - HT40 (status->flag & RX_FLAG_40MHZ)
 149                  * - short-GI (status->flag & RX_FLAG_SHORT_GI)
 150                  */
 151                 *pos = 0;
 152         } else {
 153                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
 154                 *pos = rate->bitrate / 5;
 155         }
 156         pos++;
 157
 158         /* IEEE80211_RADIOTAP_CHANNEL */
 159         put_unaligned_le16(status->freq, pos);
 160         pos += 2;
 161         if (status->band == IEEE80211_BAND_5GHZ)
 162                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ,
 163                                    pos);
 164         else if (status->flag & RX_FLAG_HT)
 165                 put_unaligned_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ,
 166                                    pos);
 167         else if (rate->flags & IEEE80211_RATE_ERP_G)
 168                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
 169                                    pos);
 170         else
 171                 put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
 172                                    pos);
 173         pos += 2;
 174
 175         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
 176         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
 177                 *pos = status->signal;
 178                 rthdr->it_present |=
 179                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
 180                 pos++;
 181         }
 182
 183         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
 184
 185         /* IEEE80211_RADIOTAP_ANTENNA */
 186         *pos = status->antenna;
 187         pos++;
 188
 189         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
 190
 191         /* IEEE80211_RADIOTAP_RX_FLAGS */
 192         /* ensure 2 byte alignment for the 2 byte field as required */
 193         if ((pos - (u8 *)rthdr) & 1)
 194                 pos++;
 195         if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
 196                 rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
 197         put_unaligned_le16(rx_flags, pos);
 198         pos += 2;
 199
 200         if (status->flag & RX_FLAG_HT) {
 201                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
 202                 *pos++ = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
 203                          IEEE80211_RADIOTAP_MCS_HAVE_GI |
 204                          IEEE80211_RADIOTAP_MCS_HAVE_BW;
 205                 *pos = 0;
 206                 if (status->flag & RX_FLAG_SHORT_GI)
 207                         *pos |= IEEE80211_RADIOTAP_MCS_SGI;
 208                 if (status->flag & RX_FLAG_40MHZ)
 209                         *pos |= IEEE80211_RADIOTAP_MCS_BW_40;
 210                 pos++;
 211                 *pos++ = status->rate_idx;
 212         }
 213 }
 214
 215 /*
 216  * This function copies a received frame to all monitor interfaces and
 217  * returns a cleaned-up SKB that no longer includes the FCS nor the
 218  * radiotap header the driver might have added.
 219  */
 220 static struct sk_buff *
 221 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
 222                      struct ieee80211_rate *rate)
 223 {
 224         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
 225         struct ieee80211_sub_if_data *sdata;
 226         int needed_headroom = 0;
 227         struct sk_buff *skb, *skb2;
 228         struct net_device *prev_dev = NULL;
 229         int present_fcs_len = 0;
 230
 231         /*
 232          * First, we may need to make a copy of the skb because
 233          *  (1) we need to modify it for radiotap (if not present), and
 234          *  (2) the other RX handlers will modify the skb we got.
 235          *
 236          * We don't need to, of course, if we aren't going to return
 237          * the SKB because it has a bad FCS/PLCP checksum.
 238          */
 239
 240         /* room for the radiotap header based on driver features */
 241         needed_headroom = ieee80211_rx_radiotap_len(local, status);
 242
 243         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 244                 present_fcs_len = FCS_LEN;
 245
 246         /* make sure hdr->frame_control is on the linear part */
 247         if (!pskb_may_pull(origskb, 2)) {
 248                 dev_kfree_skb(origskb);
 249                 return NULL;
 250         }
 251
 252         if (!local->monitors) {
 253                 if (should_drop_frame(origskb, present_fcs_len)) {
 254                         dev_kfree_skb(origskb);
 255                         return NULL;
 256                 }
 257
 258                 return remove_monitor_info(local, origskb);
 259         }
 260
 261         if (should_drop_frame(origskb, present_fcs_len)) {
 262                 /* only need to expand headroom if necessary */
 263                 skb = origskb;
 264                 origskb = NULL;
 265
 266                 /*
 267                  * This shouldn't trigger often because most devices have an
 268                  * RX header they pull before we get here, and that should
 269                  * be big enough for our radiotap information. We should
 270                  * probably export the length to drivers so that we can have
 271                  * them allocate enough headroom to start with.
 272                  */
 273                 if (skb_headroom(skb) < needed_headroom &&
 274                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
 275                         dev_kfree_skb(skb);
 276                         return NULL;
 277                 }
 278         } else {
 279                 /*
 280                  * Need to make a copy and possibly remove radiotap header
 281                  * and FCS from the original.
 282                  */
 283                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 284
 285                 origskb = remove_monitor_info(local, origskb);
 286
 287                 if (!skb)
 288                         return origskb;
 289         }
 290
 291         /* prepend radiotap information */
 292         ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom);
 293
 294         skb_reset_mac_header(skb);
 295         skb->ip_summed = CHECKSUM_UNNECESSARY;
 296         skb->pkt_type = PACKET_OTHERHOST;
 297         skb->protocol = htons(ETH_P_802_2);
 298
 299         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 300                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
 301                         continue;
 302
 303                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
 304                         continue;
 305
 306                 if (!ieee80211_sdata_running(sdata))
 307                         continue;
 308
 309                 if (prev_dev) {
 310                         skb2 = skb_clone(skb, GFP_ATOMIC);
 311                         if (skb2) {
 312                                 skb2->dev = prev_dev;
 313                                 netif_receive_skb(skb2);
 314                         }
 315                 }
 316
 317                 prev_dev = sdata->dev;
 318                 sdata->dev->stats.rx_packets++;
 319                 sdata->dev->stats.rx_bytes += skb->len;
 320         }
 321
 322         if (prev_dev) {
 323                 skb->dev = prev_dev;
 324                 netif_receive_skb(skb);
 325         } else
 326                 dev_kfree_skb(skb);
 327
 328         return origskb;
 329 }
 330
 331
 332 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
 333 {
 334         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 335         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 336         int tid;
 337
 338         /* does the frame have a qos control field? */
 339         if (ieee80211_is_data_qos(hdr->frame_control)) {
 340                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 341                 /* frame has qos control */
 342                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
 343                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
 344                         status->rx_flags |= IEEE80211_RX_AMSDU;
 345         } else {
 346                 /*
 347                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
 348                  *
 349                  *      Sequence numbers for management frames, QoS data
 350                  *      frames with a broadcast/multicast address in the
 351                  *      Address 1 field, and all non-QoS data frames sent
 352                  *      by QoS STAs are assigned using an additional single
 353                  *      modulo-4096 counter, [...]
 354                  *
 355                  * We also use that counter for non-QoS STAs.
 356                  */
 357                 tid = NUM_RX_DATA_QUEUES - 1;
 358         }
 359
 360         rx->queue = tid;
 361         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 362          * For now, set skb->priority to 0 for other cases. */
 363         rx->skb->priority = (tid > 7) ? 0 : tid;
 364 }
 365
 366 /**
 367  * DOC: Packet alignment
 368  *
 369  * Drivers always need to pass packets that are aligned to two-byte boundaries
 370  * to the stack.
 371  *
 372  * Additionally, should, if possible, align the payload data in a way that
 373  * guarantees that the contained IP header is aligned to a four-byte
 374  * boundary. In the case of regular frames, this simply means aligning the
 375  * payload to a four-byte boundary (because either the IP header is directly
 376  * contained, or IV/RFC1042 headers that have a length divisible by four are
 377  * in front of it).  If the payload data is not properly aligned and the
 378  * architecture doesn't support efficient unaligned operations, mac80211
 379  * will align the data.
 380  *
 381  * With A-MSDU frames, however, the payload data address must yield two modulo
 382  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
 383  * push the IP header further back to a multiple of four again. Thankfully, the
 384  * specs were sane enough this time around to require padding each A-MSDU
 385  * subframe to a length that is a multiple of four.
 386  *
 387  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
 388  * the payload is not supported, the driver is required to move the 802.11
 389  * header to be directly in front of the payload in that case.
 390  */
 391 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
 392 {
 393 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 394         WARN_ONCE((unsigned long)rx->skb->data & 1,
 395                   "unaligned packet at 0x%p\n", rx->skb->data);
 396 #endif
 397 }
 398
 399
 400 /* rx handlers */
 401
 402 static ieee80211_rx_result debug_noinline
 403 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 404 {
 405         struct ieee80211_local *local = rx->local;
 406         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 407         struct sk_buff *skb = rx->skb;
 408
 409         if (likely(!(status->rx_flags & IEEE80211_RX_IN_SCAN)))
 410                 return RX_CONTINUE;
 411
 412         if (test_bit(SCAN_HW_SCANNING, &local->scanning))
 413                 return ieee80211_scan_rx(rx->sdata, skb);
 414
 415         if (test_bit(SCAN_SW_SCANNING, &local->scanning)) {
 416                 /* drop all the other packets during a software scan anyway */
 417                 if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
 418                         dev_kfree_skb(skb);
 419                 return RX_QUEUED;
 420         }
 421
 422         /* scanning finished during invoking of handlers */
 423         I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 424         return RX_DROP_UNUSABLE;
 425 }
 426
 427
 428 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
 429 {
 430         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 431
 432         if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
 433                 return 0;
 434
 435         return ieee80211_is_robust_mgmt_frame(hdr);
 436 }
 437
 438
 439 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
 440 {
 441         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 442
 443         if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
 444                 return 0;
 445
 446         return ieee80211_is_robust_mgmt_frame(hdr);
 447 }
 448
 449
 450 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
 451 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
 452 {
 453         struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
 454         struct ieee80211_mmie *mmie;
 455
 456         if (skb->len < 24 + sizeof(*mmie) ||
 457             !is_multicast_ether_addr(hdr->da))
 458                 return -1;
 459
 460         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
 461                 return -1; /* not a robust management frame */
 462
 463         mmie = (struct ieee80211_mmie *)
 464                 (skb->data + skb->len - sizeof(*mmie));
 465         if (mmie->element_id != WLAN_EID_MMIE ||
 466             mmie->length != sizeof(*mmie) - 2)
 467                 return -1;
 468
 469         return le16_to_cpu(mmie->key_id);
 470 }
 471
 472
 473 static ieee80211_rx_result
 474 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 475 {
 476         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 477         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 478         char *dev_addr = rx->sdata->vif.addr;
 479
 480         if (ieee80211_is_data(hdr->frame_control)) {
 481                 if (is_multicast_ether_addr(hdr->addr1)) {
 482                         if (ieee80211_has_tods(hdr->frame_control) ||
 483                                 !ieee80211_has_fromds(hdr->frame_control))
 484                                 return RX_DROP_MONITOR;
 485                         if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
 486                                 return RX_DROP_MONITOR;
 487                 } else {
 488                         if (!ieee80211_has_a4(hdr->frame_control))
 489                                 return RX_DROP_MONITOR;
 490                         if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
 491                                 return RX_DROP_MONITOR;
 492                 }
 493         }
 494
 495         /* If there is not an established peer link and this is not a peer link
 496          * establisment frame, beacon or probe, drop the frame.
 497          */
 498
 499         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
 500                 struct ieee80211_mgmt *mgmt;
 501
 502                 if (!ieee80211_is_mgmt(hdr->frame_control))
 503                         return RX_DROP_MONITOR;
 504
 505                 if (ieee80211_is_action(hdr->frame_control)) {
 506                         mgmt = (struct ieee80211_mgmt *)hdr;
 507                         if (mgmt->u.action.category != WLAN_CATEGORY_MESH_PLINK)
 508                                 return RX_DROP_MONITOR;
 509                         return RX_CONTINUE;
 510                 }
 511
 512                 if (ieee80211_is_probe_req(hdr->frame_control) ||
 513                     ieee80211_is_probe_resp(hdr->frame_control) ||
 514                     ieee80211_is_beacon(hdr->frame_control))
 515                         return RX_CONTINUE;
 516
 517                 return RX_DROP_MONITOR;
 518
 519         }
 520
 521 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
 522
 523         if (ieee80211_is_data(hdr->frame_control) &&
 524             is_multicast_ether_addr(hdr->addr1) &&
 525             mesh_rmc_check(hdr->addr3, msh_h_get(hdr, hdrlen), rx->sdata))
 526                 return RX_DROP_MONITOR;
 527 #undef msh_h_get
 528
 529         return RX_CONTINUE;
 530 }
 531
 532 #define SEQ_MODULO 0x1000
 533 #define SEQ_MASK   0xfff
 534
 535 static inline int seq_less(u16 sq1, u16 sq2)
 536 {
 537         return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
 538 }
 539
 540 static inline u16 seq_inc(u16 sq)
 541 {
 542         return (sq + 1) & SEQ_MASK;
 543 }
 544
 545 static inline u16 seq_sub(u16 sq1, u16 sq2)
 546 {
 547         return (sq1 - sq2) & SEQ_MASK;
 548 }
 549
 550
 551 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
 552                                             struct tid_ampdu_rx *tid_agg_rx,
 553                                             int index)
 554 {
 555         struct ieee80211_local *local = hw_to_local(hw);
 556         struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
 557         struct ieee80211_rx_status *status;
 558
 559         lockdep_assert_held(&tid_agg_rx->reorder_lock);
 560
 561         if (!skb)
 562                 goto no_frame;
 563
 564         /* release the frame from the reorder ring buffer */
 565         tid_agg_rx->stored_mpdu_num--;
 566         tid_agg_rx->reorder_buf[index] = NULL;
 567         status = IEEE80211_SKB_RXCB(skb);
 568         status->rx_flags |= IEEE80211_RX_DEFERRED_RELEASE;
 569         skb_queue_tail(&local->rx_skb_queue, skb);
 570
 571 no_frame:
 572         tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
 573 }
 574
 575 static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
 576                                              struct tid_ampdu_rx *tid_agg_rx,
 577                                              u16 head_seq_num)
 578 {
 579         int index;
 580
 581         lockdep_assert_held(&tid_agg_rx->reorder_lock);
 582
 583         while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
 584                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 585                                                         tid_agg_rx->buf_size;
 586                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
 587         }
 588 }
 589
 590 /*
 591  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
 592  * the skb was added to the buffer longer than this time ago, the earlier
 593  * frames that have not yet been received are assumed to be lost and the skb
 594  * can be released for processing. This may also release other skb's from the
 595  * reorder buffer if there are no additional gaps between the frames.
 596  *
 597  * Callers must hold tid_agg_rx->reorder_lock.
 598  */
 599 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
 600
 601 static void ieee80211_sta_reorder_release(struct ieee80211_hw *hw,
 602                                           struct tid_ampdu_rx *tid_agg_rx)
 603 {
 604         int index, j;
 605
 606         lockdep_assert_held(&tid_agg_rx->reorder_lock);
 607
 608         /* release the buffer until next missing frame */
 609         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 610                                                 tid_agg_rx->buf_size;
 611         if (!tid_agg_rx->reorder_buf[index] &&
 612             tid_agg_rx->stored_mpdu_num > 1) {
 613                 /*
 614                  * No buffers ready to be released, but check whether any
 615                  * frames in the reorder buffer have timed out.
 616                  */
 617                 int skipped = 1;
 618                 for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
 619                      j = (j + 1) % tid_agg_rx->buf_size) {
 620                         if (!tid_agg_rx->reorder_buf[j]) {
 621                                 skipped++;
 622                                 continue;
 623                         }
 624                         if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
 625                                         HT_RX_REORDER_BUF_TIMEOUT))
 626                                 goto set_release_timer;
 627
 628 #ifdef CONFIG_MAC80211_HT_DEBUG
 629                         if (net_ratelimit())
 630                                 wiphy_debug(hw->wiphy,
 631                                             "release an RX reorder frame due to timeout on earlier frames\n");
 632 #endif
 633                         ieee80211_release_reorder_frame(hw, tid_agg_rx, j);
 634
 635                         /*
 636                          * Increment the head seq# also for the skipped slots.
 637                          */
 638                         tid_agg_rx->head_seq_num =
 639                                 (tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
 640                         skipped = 0;
 641                 }
 642         } else while (tid_agg_rx->reorder_buf[index]) {
 643                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
 644                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 645                                                         tid_agg_rx->buf_size;
 646         }
 647
 648         if (tid_agg_rx->stored_mpdu_num) {
 649                 j = index = seq_sub(tid_agg_rx->head_seq_num,
 650                                     tid_agg_rx->ssn) % tid_agg_rx->buf_size;
 651
 652                 for (; j != (index - 1) % tid_agg_rx->buf_size;
 653                      j = (j + 1) % tid_agg_rx->buf_size) {
 654                         if (tid_agg_rx->reorder_buf[j])
 655                                 break;
 656                 }
 657
 658  set_release_timer:
 659
 660                 mod_timer(&tid_agg_rx->reorder_timer,
 661                           tid_agg_rx->reorder_time[j] +
 662                           HT_RX_REORDER_BUF_TIMEOUT);
 663         } else {
 664                 del_timer(&tid_agg_rx->reorder_timer);
 665         }
 666 }
 667
 668 /*
 669  * As this function belongs to the RX path it must be under
 670  * rcu_read_lock protection. It returns false if the frame
 671  * can be processed immediately, true if it was consumed.
 672  */
 673 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
 674                                              struct tid_ampdu_rx *tid_agg_rx,
 675                                              struct sk_buff *skb)
 676 {
 677         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 678         u16 sc = le16_to_cpu(hdr->seq_ctrl);
 679         u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
 680         u16 head_seq_num, buf_size;
 681         int index;
 682         bool ret = true;
 683
 684         spin_lock(&tid_agg_rx->reorder_lock);
 685
 686         buf_size = tid_agg_rx->buf_size;
 687         head_seq_num = tid_agg_rx->head_seq_num;
 688
 689         /* frame with out of date sequence number */
 690         if (seq_less(mpdu_seq_num, head_seq_num)) {
 691                 dev_kfree_skb(skb);
 692                 goto out;
 693         }
 694
 695         /*
 696          * If frame the sequence number exceeds our buffering window
 697          * size release some previous frames to make room for this one.
 698          */
 699         if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
 700                 head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
 701                 /* release stored frames up to new head to stack */
 702                 ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num);
 703         }
 704
 705         /* Now the new frame is always in the range of the reordering buffer */
 706
 707         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size;
 708
 709         /* check if we already stored this frame */
 710         if (tid_agg_rx->reorder_buf[index]) {
 711                 dev_kfree_skb(skb);
 712                 goto out;
 713         }
 714
 715         /*
 716          * If the current MPDU is in the right order and nothing else
 717          * is stored we can process it directly, no need to buffer it.
 718          */
 719         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
 720             tid_agg_rx->stored_mpdu_num == 0) {
 721                 tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
 722                 ret = false;
 723                 goto out;
 724         }
 725
 726         /* put the frame in the reordering buffer */
 727         tid_agg_rx->reorder_buf[index] = skb;
 728         tid_agg_rx->reorder_time[index] = jiffies;
 729         tid_agg_rx->stored_mpdu_num++;
 730         ieee80211_sta_reorder_release(hw, tid_agg_rx);
 731
 732  out:
 733         spin_unlock(&tid_agg_rx->reorder_lock);
 734         return ret;
 735 }
 736
 737 /*
 738  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
 739  * true if the MPDU was buffered, false if it should be processed.
 740  */
 741 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx)
 742 {
 743         struct sk_buff *skb = rx->skb;
 744         struct ieee80211_local *local = rx->local;
 745         struct ieee80211_hw *hw = &local->hw;
 746         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 747         struct sta_info *sta = rx->sta;
 748         struct tid_ampdu_rx *tid_agg_rx;
 749         u16 sc;
 750         int tid;
 751
 752         if (!ieee80211_is_data_qos(hdr->frame_control))
 753                 goto dont_reorder;
 754
 755         /*
 756          * filter the QoS data rx stream according to
 757          * STA/TID and check if this STA/TID is on aggregation
 758          */
 759
 760         if (!sta)
 761                 goto dont_reorder;
 762
 763         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
 764
 765         tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
 766         if (!tid_agg_rx)
 767                 goto dont_reorder;
 768
 769         /* qos null data frames are excluded */
 770         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
 771                 goto dont_reorder;
 772
 773         /* new, potentially un-ordered, ampdu frame - process it */
 774
 775         /* reset session timer */
 776         if (tid_agg_rx->timeout)
 777                 mod_timer(&tid_agg_rx->session_timer,
 778                           TU_TO_EXP_TIME(tid_agg_rx->timeout));
 779
 780         /* if this mpdu is fragmented - terminate rx aggregation session */
 781         sc = le16_to_cpu(hdr->seq_ctrl);
 782         if (sc & IEEE80211_SCTL_FRAG) {
 783                 skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
 784                 skb_queue_tail(&rx->sdata->skb_queue, skb);
 785                 ieee80211_queue_work(&local->hw, &rx->sdata->work);
 786                 return;
 787         }
 788
 789         /*
 790          * No locking needed -- we will only ever process one
 791          * RX packet at a time, and thus own tid_agg_rx. All
 792          * other code manipulating it needs to (and does) make
 793          * sure that we cannot get to it any more before doing
 794          * anything with it.
 795          */
 796         if (ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb))
 797                 return;
 798
 799  dont_reorder:
 800         skb_queue_tail(&local->rx_skb_queue, skb);
 801 }
 802
 803 static ieee80211_rx_result debug_noinline
 804 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
 805 {
 806         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 807         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 808
 809         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 810         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 811                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
 812                              rx->sta->last_seq_ctrl[rx->queue] ==
 813                              hdr->seq_ctrl)) {
 814                         if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
 815                                 rx->local->dot11FrameDuplicateCount++;
 816                                 rx->sta->num_duplicates++;
 817                         }
 818                         return RX_DROP_MONITOR;
 819                 } else
 820                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
 821         }
 822
 823         if (unlikely(rx->skb->len < 16)) {
 824                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 825                 return RX_DROP_MONITOR;
 826         }
 827
 828         /* Drop disallowed frame classes based on STA auth/assoc state;
 829          * IEEE 802.11, Chap 5.5.
 830          *
 831          * mac80211 filters only based on association state, i.e. it drops
 832          * Class 3 frames from not associated stations. hostapd sends
 833          * deauth/disassoc frames when needed. In addition, hostapd is
 834          * responsible for filtering on both auth and assoc states.
 835          */
 836
 837         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
 838                 return ieee80211_rx_mesh_check(rx);
 839
 840         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
 841                       ieee80211_is_pspoll(hdr->frame_control)) &&
 842                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
 843                      rx->sdata->vif.type != NL80211_IFTYPE_WDS &&
 844                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
 845                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
 846                      !ieee80211_has_tods(hdr->frame_control) &&
 847                      ieee80211_is_data(hdr->frame_control)) ||
 848                     !(status->rx_flags & IEEE80211_RX_RA_MATCH)) {
 849                         /* Drop IBSS frames and frames for other hosts
 850                          * silently. */
 851                         return RX_DROP_MONITOR;
 852                 }
 853
 854                 return RX_DROP_MONITOR;
 855         }
 856
 857         return RX_CONTINUE;
 858 }
 859
 860
 861 static ieee80211_rx_result debug_noinline
 862 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 863 {
 864         struct sk_buff *skb = rx->skb;
 865         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 866         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 867         int keyidx;
 868         int hdrlen;
 869         ieee80211_rx_result result = RX_DROP_UNUSABLE;
 870         struct ieee80211_key *sta_ptk = NULL;
 871         int mmie_keyidx = -1;
 872         __le16 fc;
 873
 874         /*
 875          * Key selection 101
 876          *
 877          * There are four types of keys:
 878          *  - GTK (group keys)
 879          *  - IGTK (group keys for management frames)
 880          *  - PTK (pairwise keys)
 881          *  - STK (station-to-station pairwise keys)
 882          *
 883          * When selecting a key, we have to distinguish between multicast
 884          * (including broadcast) and unicast frames, the latter can only
 885          * use PTKs and STKs while the former always use GTKs and IGTKs.
 886          * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
 887          * unicast frames can also use key indices like GTKs. Hence, if we
 888          * don't have a PTK/STK we check the key index for a WEP key.
 889          *
 890          * Note that in a regular BSS, multicast frames are sent by the
 891          * AP only, associated stations unicast the frame to the AP first
 892          * which then multicasts it on their behalf.
 893          *
 894          * There is also a slight problem in IBSS mode: GTKs are negotiated
 895          * with each station, that is something we don't currently handle.
 896          * The spec seems to expect that one negotiates the same key with
 897          * every station but there's no such requirement; VLANs could be
 898          * possible.
 899          */
 900
 901         /*
 902          * No point in finding a key and decrypting if the frame is neither
 903          * addressed to us nor a multicast frame.
 904          */
 905         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
 906                 return RX_CONTINUE;
 907
 908         /* start without a key */
 909         rx->key = NULL;
 910
 911         if (rx->sta)
 912                 sta_ptk = rcu_dereference(rx->sta->ptk);
 913
 914         fc = hdr->frame_control;
 915
 916         if (!ieee80211_has_protected(fc))
 917                 mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
 918
 919         if (!is_multicast_ether_addr(hdr->addr1) && sta_ptk) {
 920                 rx->key = sta_ptk;
 921                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 922                     (status->flag & RX_FLAG_IV_STRIPPED))
 923                         return RX_CONTINUE;
 924                 /* Skip decryption if the frame is not protected. */
 925                 if (!ieee80211_has_protected(fc))
 926                         return RX_CONTINUE;
 927         } else if (mmie_keyidx >= 0) {
 928                 /* Broadcast/multicast robust management frame / BIP */
 929                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 930                     (status->flag & RX_FLAG_IV_STRIPPED))
 931                         return RX_CONTINUE;
 932
 933                 if (mmie_keyidx < NUM_DEFAULT_KEYS ||
 934                     mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 935                         return RX_DROP_MONITOR; /* unexpected BIP keyidx */
 936                 if (rx->sta)
 937                         rx->key = rcu_dereference(rx->sta->gtk[mmie_keyidx]);
 938                 if (!rx->key)
 939                         rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
 940         } else if (!ieee80211_has_protected(fc)) {
 941                 /*
 942                  * The frame was not protected, so skip decryption. However, we
 943                  * need to set rx->key if there is a key that could have been
 944                  * used so that the frame may be dropped if encryption would
 945                  * have been expected.
 946                  */
 947                 struct ieee80211_key *key = NULL;
 948                 struct ieee80211_sub_if_data *sdata = rx->sdata;
 949                 int i;
 950
 951                 if (ieee80211_is_mgmt(fc) &&
 952                     is_multicast_ether_addr(hdr->addr1) &&
 953                     (key = rcu_dereference(rx->sdata->default_mgmt_key)))
 954                         rx->key = key;
 955                 else {
 956                         if (rx->sta) {
 957                                 for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
 958                                         key = rcu_dereference(rx->sta->gtk[i]);
 959                                         if (key)
 960                                                 break;
 961                                 }
 962                         }
 963                         if (!key) {
 964                                 for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
 965                                         key = rcu_dereference(sdata->keys[i]);
 966                                         if (key)
 967                                                 break;
 968                                 }
 969                         }
 970                         if (key)
 971                                 rx->key = key;
 972                 }
 973                 return RX_CONTINUE;
 974         } else {
 975                 u8 keyid;
 976                 /*
 977                  * The device doesn't give us the IV so we won't be
 978                  * able to look up the key. That's ok though, we
 979                  * don't need to decrypt the frame, we just won't
 980                  * be able to keep statistics accurate.
 981                  * Except for key threshold notifications, should
 982                  * we somehow allow the driver to tell us which key
 983                  * the hardware used if this flag is set?
 984                  */
 985                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 986                     (status->flag & RX_FLAG_IV_STRIPPED))
 987                         return RX_CONTINUE;
 988
 989                 hdrlen = ieee80211_hdrlen(fc);
 990
 991                 if (rx->skb->len < 8 + hdrlen)
 992                         return RX_DROP_UNUSABLE; /* TODO: count this? */
 993
 994                 /*
 995                  * no need to call ieee80211_wep_get_keyidx,
 996                  * it verifies a bunch of things we've done already
 997                  */
 998                 skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
 999                 keyidx = keyid >> 6;
1000
1001                 /* check per-station GTK first, if multicast packet */
1002                 if (is_multicast_ether_addr(hdr->addr1) && rx->sta)
1003                         rx->key = rcu_dereference(rx->sta->gtk[keyidx]);
1004
1005                 /* if not found, try default key */
1006                 if (!rx->key) {
1007                         rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
1008
1009                         /*
1010                          * RSNA-protected unicast frames should always be
1011                          * sent with pairwise or station-to-station keys,
1012                          * but for WEP we allow using a key index as well.
1013                          */
1014                         if (rx->key &&
1015                             rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP40 &&
1016                             rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP104 &&
1017                             !is_multicast_ether_addr(hdr->addr1))
1018                                 rx->key = NULL;
1019                 }
1020         }
1021
1022         if (rx->key) {
1023                 rx->key->tx_rx_count++;
1024                 /* TODO: add threshold stuff again */
1025         } else {
1026                 return RX_DROP_MONITOR;
1027         }
1028
1029         if (skb_linearize(rx->skb))
1030                 return RX_DROP_UNUSABLE;
1031         /* the hdr variable is invalid now! */
1032
1033         switch (rx->key->conf.cipher) {
1034         case WLAN_CIPHER_SUITE_WEP40:
1035         case WLAN_CIPHER_SUITE_WEP104:
1036                 /* Check for weak IVs if possible */
1037                 if (rx->sta && ieee80211_is_data(fc) &&
1038                     (!(status->flag & RX_FLAG_IV_STRIPPED) ||
1039                      !(status->flag & RX_FLAG_DECRYPTED)) &&
1040                     ieee80211_wep_is_weak_iv(rx->skb, rx->key))
1041                         rx->sta->wep_weak_iv_count++;
1042
1043                 result = ieee80211_crypto_wep_decrypt(rx);
1044                 break;
1045         case WLAN_CIPHER_SUITE_TKIP:
1046                 result = ieee80211_crypto_tkip_decrypt(rx);
1047                 break;
1048         case WLAN_CIPHER_SUITE_CCMP:
1049                 result = ieee80211_crypto_ccmp_decrypt(rx);
1050                 break;
1051         case WLAN_CIPHER_SUITE_AES_CMAC:
1052                 result = ieee80211_crypto_aes_cmac_decrypt(rx);
1053                 break;
1054         default:
1055                 /*
1056                  * We can reach here only with HW-only algorithms
1057                  * but why didn't it decrypt the frame?!
1058                  */
1059                 return RX_DROP_UNUSABLE;
1060         }
1061
1062         /* either the frame has been decrypted or will be dropped */
1063         status->flag |= RX_FLAG_DECRYPTED;
1064
1065         return result;
1066 }
1067
1068 static ieee80211_rx_result debug_noinline
1069 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
1070 {
1071         struct ieee80211_local *local;
1072         struct ieee80211_hdr *hdr;
1073         struct sk_buff *skb;
1074
1075         local = rx->local;
1076         skb = rx->skb;
1077         hdr = (struct ieee80211_hdr *) skb->data;
1078
1079         if (!local->pspolling)
1080                 return RX_CONTINUE;
1081
1082         if (!ieee80211_has_fromds(hdr->frame_control))
1083                 /* this is not from AP */
1084                 return RX_CONTINUE;
1085
1086         if (!ieee80211_is_data(hdr->frame_control))
1087                 return RX_CONTINUE;
1088
1089         if (!ieee80211_has_moredata(hdr->frame_control)) {
1090                 /* AP has no more frames buffered for us */
1091                 local->pspolling = false;
1092                 return RX_CONTINUE;
1093         }
1094
1095         /* more data bit is set, let's request a new frame from the AP */
1096         ieee80211_send_pspoll(local, rx->sdata);
1097
1098         return RX_CONTINUE;
1099 }
1100
1101 static void ap_sta_ps_start(struct sta_info *sta)
1102 {
1103         struct ieee80211_sub_if_data *sdata = sta->sdata;
1104         struct ieee80211_local *local = sdata->local;
1105
1106         atomic_inc(&sdata->bss->num_sta_ps);
1107         set_sta_flags(sta, WLAN_STA_PS_STA);
1108         if (!(local->hw.flags & IEEE80211_HW_AP_LINK_PS))
1109                 drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
1110 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1111         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
1112                sdata->name, sta->sta.addr, sta->sta.aid);
1113 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1114 }
1115
1116 static void ap_sta_ps_end(struct sta_info *sta)
1117 {
1118         struct ieee80211_sub_if_data *sdata = sta->sdata;
1119
1120         atomic_dec(&sdata->bss->num_sta_ps);
1121
1122 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1123         printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
1124                sdata->name, sta->sta.addr, sta->sta.aid);
1125 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1126
1127         if (test_sta_flags(sta, WLAN_STA_PS_DRIVER)) {
1128 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1129                 printk(KERN_DEBUG "%s: STA %pM aid %d driver-ps-blocked\n",
1130                        sdata->name, sta->sta.addr, sta->sta.aid);
1131 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1132                 return;
1133         }
1134
1135         ieee80211_sta_ps_deliver_wakeup(sta);
1136 }
1137
1138 int ieee80211_sta_ps_transition(struct ieee80211_sta *sta, bool start)
1139 {
1140         struct sta_info *sta_inf = container_of(sta, struct sta_info, sta);
1141         bool in_ps;
1142
1143         WARN_ON(!(sta_inf->local->hw.flags & IEEE80211_HW_AP_LINK_PS));
1144
1145         /* Don't let the same PS state be set twice */
1146         in_ps = test_sta_flags(sta_inf, WLAN_STA_PS_STA);
1147         if ((start && in_ps) || (!start && !in_ps))
1148                 return -EINVAL;
1149
1150         if (start)
1151                 ap_sta_ps_start(sta_inf);
1152         else
1153                 ap_sta_ps_end(sta_inf);
1154
1155         return 0;
1156 }
1157 EXPORT_SYMBOL(ieee80211_sta_ps_transition);
1158
1159 static ieee80211_rx_result debug_noinline
1160 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1161 {
1162         struct sta_info *sta = rx->sta;
1163         struct sk_buff *skb = rx->skb;
1164         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1165         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1166
1167         if (!sta)
1168                 return RX_CONTINUE;
1169
1170         /*
1171          * Update last_rx only for IBSS packets which are for the current
1172          * BSSID to avoid keeping the current IBSS network alive in cases
1173          * where other STAs start using different BSSID.
1174          */
1175         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1176                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1177                                                 NL80211_IFTYPE_ADHOC);
1178                 if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
1179                         sta->last_rx = jiffies;
1180         } else if (!is_multicast_ether_addr(hdr->addr1)) {
1181                 /*
1182                  * Mesh beacons will update last_rx when if they are found to
1183                  * match the current local configuration when processed.
1184                  */
1185                 sta->last_rx = jiffies;
1186         }
1187
1188         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1189                 return RX_CONTINUE;
1190
1191         if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1192                 ieee80211_sta_rx_notify(rx->sdata, hdr);
1193
1194         sta->rx_fragments++;
1195         sta->rx_bytes += rx->skb->len;
1196         sta->last_signal = status->signal;
1197         ewma_add(&sta->avg_signal, -status->signal);
1198
1199         /*
1200          * Change STA power saving mode only at the end of a frame
1201          * exchange sequence.
1202          */
1203         if (!(sta->local->hw.flags & IEEE80211_HW_AP_LINK_PS) &&
1204             !ieee80211_has_morefrags(hdr->frame_control) &&
1205             !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1206             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1207              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
1208                 if (test_sta_flags(sta, WLAN_STA_PS_STA)) {
1209                         /*
1210                          * Ignore doze->wake transitions that are
1211                          * indicated by non-data frames, the standard
1212                          * is unclear here, but for example going to
1213                          * PS mode and then scanning would cause a
1214                          * doze->wake transition for the probe request,
1215                          * and that is clearly undesirable.
1216                          */
1217                         if (ieee80211_is_data(hdr->frame_control) &&
1218                             !ieee80211_has_pm(hdr->frame_control))
1219                                 ap_sta_ps_end(sta);
1220                 } else {
1221                         if (ieee80211_has_pm(hdr->frame_control))
1222                                 ap_sta_ps_start(sta);
1223                 }
1224         }
1225
1226         /*
1227          * Drop (qos-)data::nullfunc frames silently, since they
1228          * are used only to control station power saving mode.
1229          */
1230         if (ieee80211_is_nullfunc(hdr->frame_control) ||
1231             ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1232                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
1233
1234                 /*
1235                  * If we receive a 4-addr nullfunc frame from a STA
1236                  * that was not moved to a 4-addr STA vlan yet, drop
1237                  * the frame to the monitor interface, to make sure
1238                  * that hostapd sees it
1239                  */
1240                 if (ieee80211_has_a4(hdr->frame_control) &&
1241                     (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1242                      (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1243                       !rx->sdata->u.vlan.sta)))
1244                         return RX_DROP_MONITOR;
1245                 /*
1246                  * Update counter and free packet here to avoid
1247                  * counting this as a dropped packed.
1248                  */
1249                 sta->rx_packets++;
1250                 dev_kfree_skb(rx->skb);
1251                 return RX_QUEUED;
1252         }
1253
1254         return RX_CONTINUE;
1255 } /* ieee80211_rx_h_sta_process */
1256
1257 static inline struct ieee80211_fragment_entry *
1258 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
1259                          unsigned int frag, unsigned int seq, int rx_queue,
1260                          struct sk_buff **skb)
1261 {
1262         struct ieee80211_fragment_entry *entry;
1263         int idx;
1264
1265         idx = sdata->fragment_next;
1266         entry = &sdata->fragments[sdata->fragment_next++];
1267         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
1268                 sdata->fragment_next = 0;
1269
1270         if (!skb_queue_empty(&entry->skb_list)) {
1271 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1272                 struct ieee80211_hdr *hdr =
1273                         (struct ieee80211_hdr *) entry->skb_list.next->data;
1274                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
1275                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
1276                        "addr1=%pM addr2=%pM\n",
1277                        sdata->name, idx,
1278                        jiffies - entry->first_frag_time, entry->seq,
1279                        entry->last_frag, hdr->addr1, hdr->addr2);
1280 #endif
1281                 __skb_queue_purge(&entry->skb_list);
1282         }
1283
1284         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
1285         *skb = NULL;
1286         entry->first_frag_time = jiffies;
1287         entry->seq = seq;
1288         entry->rx_queue = rx_queue;
1289         entry->last_frag = frag;
1290         entry->ccmp = 0;
1291         entry->extra_len = 0;
1292
1293         return entry;
1294 }
1295
1296 static inline struct ieee80211_fragment_entry *
1297 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
1298                           unsigned int frag, unsigned int seq,
1299                           int rx_queue, struct ieee80211_hdr *hdr)
1300 {
1301         struct ieee80211_fragment_entry *entry;
1302         int i, idx;
1303
1304         idx = sdata->fragment_next;
1305         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
1306                 struct ieee80211_hdr *f_hdr;
1307
1308                 idx--;
1309                 if (idx < 0)
1310                         idx = IEEE80211_FRAGMENT_MAX - 1;
1311
1312                 entry = &sdata->fragments[idx];
1313                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
1314                     entry->rx_queue != rx_queue ||
1315                     entry->last_frag + 1 != frag)
1316                         continue;
1317
1318                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
1319
1320                 /*
1321                  * Check ftype and addresses are equal, else check next fragment
1322                  */
1323                 if (((hdr->frame_control ^ f_hdr->frame_control) &
1324                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
1325                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
1326                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
1327                         continue;
1328
1329                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
1330                         __skb_queue_purge(&entry->skb_list);
1331                         continue;
1332                 }
1333                 return entry;
1334         }
1335
1336         return NULL;
1337 }
1338
1339 static ieee80211_rx_result debug_noinline
1340 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
1341 {
1342         struct ieee80211_hdr *hdr;
1343         u16 sc;
1344         __le16 fc;
1345         unsigned int frag, seq;
1346         struct ieee80211_fragment_entry *entry;
1347         struct sk_buff *skb;
1348         struct ieee80211_rx_status *status;
1349
1350         hdr = (struct ieee80211_hdr *)rx->skb->data;
1351         fc = hdr->frame_control;
1352         sc = le16_to_cpu(hdr->seq_ctrl);
1353         frag = sc & IEEE80211_SCTL_FRAG;
1354
1355         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1356                    (rx->skb)->len < 24 ||
1357                    is_multicast_ether_addr(hdr->addr1))) {
1358                 /* not fragmented */
1359                 goto out;
1360         }
1361         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1362
1363         if (skb_linearize(rx->skb))
1364                 return RX_DROP_UNUSABLE;
1365
1366         /*
1367          *  skb_linearize() might change the skb->data and
1368          *  previously cached variables (in this case, hdr) need to
1369          *  be refreshed with the new data.
1370          */
1371         hdr = (struct ieee80211_hdr *)rx->skb->data;
1372         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1373
1374         if (frag == 0) {
1375                 /* This is the first fragment of a new frame. */
1376                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1377                                                  rx->queue, &(rx->skb));
1378                 if (rx->key && rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP &&
1379                     ieee80211_has_protected(fc)) {
1380                         int queue = ieee80211_is_mgmt(fc) ?
1381                                 NUM_RX_DATA_QUEUES : rx->queue;
1382                         /* Store CCMP PN so that we can verify that the next
1383                          * fragment has a sequential PN value. */
1384                         entry->ccmp = 1;
1385                         memcpy(entry->last_pn,
1386                                rx->key->u.ccmp.rx_pn[queue],
1387                                CCMP_PN_LEN);
1388                 }
1389                 return RX_QUEUED;
1390         }
1391
1392         /* This is a fragment for a frame that should already be pending in
1393          * fragment cache. Add this fragment to the end of the pending entry.
1394          */
1395         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1396         if (!entry) {
1397                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1398                 return RX_DROP_MONITOR;
1399         }
1400
1401         /* Verify that MPDUs within one MSDU have sequential PN values.
1402          * (IEEE 802.11i, 8.3.3.4.5) */
1403         if (entry->ccmp) {
1404                 int i;
1405                 u8 pn[CCMP_PN_LEN], *rpn;
1406                 int queue;
1407                 if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP)
1408                         return RX_DROP_UNUSABLE;
1409                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1410                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1411                         pn[i]++;
1412                         if (pn[i])
1413                                 break;
1414                 }
1415                 queue = ieee80211_is_mgmt(fc) ?
1416                         NUM_RX_DATA_QUEUES : rx->queue;
1417                 rpn = rx->key->u.ccmp.rx_pn[queue];
1418                 if (memcmp(pn, rpn, CCMP_PN_LEN))
1419                         return RX_DROP_UNUSABLE;
1420                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1421         }
1422
1423         skb_pull(rx->skb, ieee80211_hdrlen(fc));
1424         __skb_queue_tail(&entry->skb_list, rx->skb);
1425         entry->last_frag = frag;
1426         entry->extra_len += rx->skb->len;
1427         if (ieee80211_has_morefrags(fc)) {
1428                 rx->skb = NULL;
1429                 return RX_QUEUED;
1430         }
1431
1432         rx->skb = __skb_dequeue(&entry->skb_list);
1433         if (skb_tailroom(rx->skb) < entry->extra_len) {
1434                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1435                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1436                                               GFP_ATOMIC))) {
1437                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1438                         __skb_queue_purge(&entry->skb_list);
1439                         return RX_DROP_UNUSABLE;
1440                 }
1441         }
1442         while ((skb = __skb_dequeue(&entry->skb_list))) {
1443                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1444                 dev_kfree_skb(skb);
1445         }
1446
1447         /* Complete frame has been reassembled - process it now */
1448         status = IEEE80211_SKB_RXCB(rx->skb);
1449         status->rx_flags |= IEEE80211_RX_FRAGMENTED;
1450
1451  out:
1452         if (rx->sta)
1453                 rx->sta->rx_packets++;
1454         if (is_multicast_ether_addr(hdr->addr1))
1455                 rx->local->dot11MulticastReceivedFrameCount++;
1456         else
1457                 ieee80211_led_rx(rx->local);
1458         return RX_CONTINUE;
1459 }
1460
1461 static ieee80211_rx_result debug_noinline
1462 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1463 {
1464         struct ieee80211_sub_if_data *sdata = rx->sdata;
1465         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1466         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1467
1468         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1469                    !(status->rx_flags & IEEE80211_RX_RA_MATCH)))
1470                 return RX_CONTINUE;
1471
1472         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1473             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1474                 return RX_DROP_UNUSABLE;
1475
1476         if (!test_sta_flags(rx->sta, WLAN_STA_PS_DRIVER))
1477                 ieee80211_sta_ps_deliver_poll_response(rx->sta);
1478         else
1479                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1480
1481         /* Free PS Poll skb here instead of returning RX_DROP that would
1482          * count as an dropped frame. */
1483         dev_kfree_skb(rx->skb);
1484
1485         return RX_QUEUED;
1486 }
1487
1488 static ieee80211_rx_result debug_noinline
1489 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1490 {
1491         u8 *data = rx->skb->data;
1492         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1493
1494         if (!ieee80211_is_data_qos(hdr->frame_control))
1495                 return RX_CONTINUE;
1496
1497         /* remove the qos control field, update frame type and meta-data */
1498         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1499                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1500         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1501         /* change frame type to non QOS */
1502         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1503
1504         return RX_CONTINUE;
1505 }
1506
1507 static int
1508 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1509 {
1510         if (unlikely(!rx->sta ||
1511             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1512                 return -EACCES;
1513
1514         return 0;
1515 }
1516
1517 static int
1518 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1519 {
1520         struct sk_buff *skb = rx->skb;
1521         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1522
1523         /*
1524          * Pass through unencrypted frames if the hardware has
1525          * decrypted them already.
1526          */
1527         if (status->flag & RX_FLAG_DECRYPTED)
1528                 return 0;
1529
1530         /* Drop unencrypted frames if key is set. */
1531         if (unlikely(!ieee80211_has_protected(fc) &&
1532                      !ieee80211_is_nullfunc(fc) &&
1533                      ieee80211_is_data(fc) &&
1534                      (rx->key || rx->sdata->drop_unencrypted)))
1535                 return -EACCES;
1536
1537         return 0;
1538 }
1539
1540 static int
1541 ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
1542 {
1543         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1544         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1545         __le16 fc = hdr->frame_control;
1546
1547         /*
1548          * Pass through unencrypted frames if the hardware has
1549          * decrypted them already.
1550          */
1551         if (status->flag & RX_FLAG_DECRYPTED)
1552                 return 0;
1553
1554         if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1555                 if (unlikely(!ieee80211_has_protected(fc) &&
1556                              ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1557                              rx->key)) {
1558                         if (ieee80211_is_deauth(fc))
1559                                 cfg80211_send_unprot_deauth(rx->sdata->dev,
1560                                                             rx->skb->data,
1561                                                             rx->skb->len);
1562                         else if (ieee80211_is_disassoc(fc))
1563                                 cfg80211_send_unprot_disassoc(rx->sdata->dev,
1564                                                               rx->skb->data,
1565                                                               rx->skb->len);
1566                         return -EACCES;
1567                 }
1568                 /* BIP does not use Protected field, so need to check MMIE */
1569                 if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1570                              ieee80211_get_mmie_keyidx(rx->skb) < 0)) {
1571                         if (ieee80211_is_deauth(fc))
1572                                 cfg80211_send_unprot_deauth(rx->sdata->dev,
1573                                                             rx->skb->data,
1574                                                             rx->skb->len);
1575                         else if (ieee80211_is_disassoc(fc))
1576                                 cfg80211_send_unprot_disassoc(rx->sdata->dev,
1577                                                               rx->skb->data,
1578                                                               rx->skb->len);
1579                         return -EACCES;
1580                 }
1581                 /*
1582                  * When using MFP, Action frames are not allowed prior to
1583                  * having configured keys.
1584                  */
1585                 if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1586                              ieee80211_is_robust_mgmt_frame(
1587                                      (struct ieee80211_hdr *) rx->skb->data)))
1588                         return -EACCES;
1589         }
1590
1591         return 0;
1592 }
1593
1594 static int
1595 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1596 {
1597         struct ieee80211_sub_if_data *sdata = rx->sdata;
1598         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1599         bool check_port_control = false;
1600         struct ethhdr *ehdr;
1601         int ret;
1602
1603         if (ieee80211_has_a4(hdr->frame_control) &&
1604             sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1605                 return -1;
1606
1607         if (sdata->vif.type == NL80211_IFTYPE_STATION &&
1608             !!sdata->u.mgd.use_4addr != !!ieee80211_has_a4(hdr->frame_control)) {
1609
1610                 if (!sdata->u.mgd.use_4addr)
1611                         return -1;
1612                 else
1613                         check_port_control = true;
1614         }
1615
1616         if (is_multicast_ether_addr(hdr->addr1) &&
1617             sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta)
1618                 return -1;
1619
1620         ret = ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
1621         if (ret < 0 || !check_port_control)
1622                 return ret;
1623
1624         ehdr = (struct ethhdr *) rx->skb->data;
1625         if (ehdr->h_proto != rx->sdata->control_port_protocol)
1626                 return -1;
1627
1628         return 0;
1629 }
1630
1631 /*
1632  * requires that rx->skb is a frame with ethernet header
1633  */
1634 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1635 {
1636         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1637                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1638         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1639
1640         /*
1641          * Allow EAPOL frames to us/the PAE group address regardless
1642          * of whether the frame was encrypted or not.
1643          */
1644         if (ehdr->h_proto == rx->sdata->control_port_protocol &&
1645             (compare_ether_addr(ehdr->h_dest, rx->sdata->vif.addr) == 0 ||
1646              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1647                 return true;
1648
1649         if (ieee80211_802_1x_port_control(rx) ||
1650             ieee80211_drop_unencrypted(rx, fc))
1651                 return false;
1652
1653         return true;
1654 }
1655
1656 /*
1657  * requires that rx->skb is a frame with ethernet header
1658  */
1659 static void
1660 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1661 {
1662         struct ieee80211_sub_if_data *sdata = rx->sdata;
1663         struct net_device *dev = sdata->dev;
1664         struct sk_buff *skb, *xmit_skb;
1665         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1666         struct sta_info *dsta;
1667         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1668
1669         skb = rx->skb;
1670         xmit_skb = NULL;
1671
1672         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1673              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1674             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1675             (status->rx_flags & IEEE80211_RX_RA_MATCH) &&
1676             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1677                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1678                         /*
1679                          * send multicast frames both to higher layers in
1680                          * local net stack and back to the wireless medium
1681                          */
1682                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1683                         if (!xmit_skb && net_ratelimit())
1684                                 printk(KERN_DEBUG "%s: failed to clone "
1685                                        "multicast frame\n", dev->name);
1686                 } else {
1687                         dsta = sta_info_get(sdata, skb->data);
1688                         if (dsta) {
1689                                 /*
1690                                  * The destination station is associated to
1691                                  * this AP (in this VLAN), so send the frame
1692                                  * directly to it and do not pass it to local
1693                                  * net stack.
1694                                  */
1695                                 xmit_skb = skb;
1696                                 skb = NULL;
1697                         }
1698                 }
1699         }
1700
1701         if (skb) {
1702                 int align __maybe_unused;
1703
1704 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1705                 /*
1706                  * 'align' will only take the values 0 or 2 here
1707                  * since all frames are required to be aligned
1708                  * to 2-byte boundaries when being passed to
1709                  * mac80211. That also explains the __skb_push()
1710                  * below.
1711                  */
1712                 align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1713                 if (align) {
1714                         if (WARN_ON(skb_headroom(skb) < 3)) {
1715                                 dev_kfree_skb(skb);
1716                                 skb = NULL;
1717                         } else {
1718                                 u8 *data = skb->data;
1719                                 size_t len = skb_headlen(skb);
1720                                 skb->data -= align;
1721                                 memmove(skb->data, data, len);
1722                                 skb_set_tail_pointer(skb, len);
1723                         }
1724                 }
1725 #endif
1726
1727                 if (skb) {
1728                         /* deliver to local stack */
1729                         skb->protocol = eth_type_trans(skb, dev);
1730                         memset(skb->cb, 0, sizeof(skb->cb));
1731                         netif_receive_skb(skb);
1732                 }
1733         }
1734
1735         if (xmit_skb) {
1736                 /* send to wireless media */
1737                 xmit_skb->protocol = htons(ETH_P_802_3);
1738                 skb_reset_network_header(xmit_skb);
1739                 skb_reset_mac_header(xmit_skb);
1740                 dev_queue_xmit(xmit_skb);
1741         }
1742 }
1743
1744 static ieee80211_rx_result debug_noinline
1745 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1746 {
1747         struct net_device *dev = rx->sdata->dev;
1748         struct sk_buff *skb = rx->skb;
1749         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1750         __le16 fc = hdr->frame_control;
1751         struct sk_buff_head frame_list;
1752         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1753
1754         if (unlikely(!ieee80211_is_data(fc)))
1755                 return RX_CONTINUE;
1756
1757         if (unlikely(!ieee80211_is_data_present(fc)))
1758                 return RX_DROP_MONITOR;
1759
1760         if (!(status->rx_flags & IEEE80211_RX_AMSDU))
1761                 return RX_CONTINUE;
1762
1763         if (ieee80211_has_a4(hdr->frame_control) &&
1764             rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1765             !rx->sdata->u.vlan.sta)
1766                 return RX_DROP_UNUSABLE;
1767
1768         if (is_multicast_ether_addr(hdr->addr1) &&
1769             ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1770               rx->sdata->u.vlan.sta) ||
1771              (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1772               rx->sdata->u.mgd.use_4addr)))
1773                 return RX_DROP_UNUSABLE;
1774
1775         skb->dev = dev;
1776         __skb_queue_head_init(&frame_list);
1777
1778         if (skb_linearize(skb))
1779                 return RX_DROP_UNUSABLE;
1780
1781         ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
1782                                  rx->sdata->vif.type,
1783                                  rx->local->hw.extra_tx_headroom);
1784
1785         while (!skb_queue_empty(&frame_list)) {
1786                 rx->skb = __skb_dequeue(&frame_list);
1787
1788                 if (!ieee80211_frame_allowed(rx, fc)) {
1789                         dev_kfree_skb(rx->skb);
1790                         continue;
1791                 }
1792                 dev->stats.rx_packets++;
1793                 dev->stats.rx_bytes += rx->skb->len;
1794
1795                 ieee80211_deliver_skb(rx);
1796         }
1797
1798         return RX_QUEUED;
1799 }
1800
1801 #ifdef CONFIG_MAC80211_MESH
1802 static ieee80211_rx_result
1803 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1804 {
1805         struct ieee80211_hdr *hdr;
1806         struct ieee80211s_hdr *mesh_hdr;
1807         unsigned int hdrlen;
1808         struct sk_buff *skb = rx->skb, *fwd_skb;
1809         struct ieee80211_local *local = rx->local;
1810         struct ieee80211_sub_if_data *sdata = rx->sdata;
1811         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1812
1813         hdr = (struct ieee80211_hdr *) skb->data;
1814         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1815         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1816
1817         if (!ieee80211_is_data(hdr->frame_control))
1818                 return RX_CONTINUE;
1819
1820         if (!mesh_hdr->ttl)
1821                 /* illegal frame */
1822                 return RX_DROP_MONITOR;
1823
1824         if (mesh_hdr->flags & MESH_FLAGS_AE) {
1825                 struct mesh_path *mppath;
1826                 char *proxied_addr;
1827                 char *mpp_addr;
1828
1829                 if (is_multicast_ether_addr(hdr->addr1)) {
1830                         mpp_addr = hdr->addr3;
1831                         proxied_addr = mesh_hdr->eaddr1;
1832                 } else {
1833                         mpp_addr = hdr->addr4;
1834                         proxied_addr = mesh_hdr->eaddr2;
1835                 }
1836
1837                 rcu_read_lock();
1838                 mppath = mpp_path_lookup(proxied_addr, sdata);
1839                 if (!mppath) {
1840                         mpp_path_add(proxied_addr, mpp_addr, sdata);
1841                 } else {
1842                         spin_lock_bh(&mppath->state_lock);
1843                         if (compare_ether_addr(mppath->mpp, mpp_addr) != 0)
1844                                 memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
1845                         spin_unlock_bh(&mppath->state_lock);
1846                 }
1847                 rcu_read_unlock();
1848         }
1849
1850         /* Frame has reached destination.  Don't forward */
1851         if (!is_multicast_ether_addr(hdr->addr1) &&
1852             compare_ether_addr(sdata->vif.addr, hdr->addr3) == 0)
1853                 return RX_CONTINUE;
1854
1855         mesh_hdr->ttl--;
1856
1857         if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
1858                 if (!mesh_hdr->ttl)
1859                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1860                                                      dropped_frames_ttl);
1861                 else {
1862                         struct ieee80211_hdr *fwd_hdr;
1863                         struct ieee80211_tx_info *info;
1864
1865                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1866
1867                         if (!fwd_skb && net_ratelimit())
1868                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1869                                                    sdata->name);
1870                         if (!fwd_skb)
1871                                 goto out;
1872
1873                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1874                         memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
1875                         info = IEEE80211_SKB_CB(fwd_skb);
1876                         memset(info, 0, sizeof(*info));
1877                         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1878                         info->control.vif = &rx->sdata->vif;
1879                         skb_set_queue_mapping(skb,
1880                                 ieee80211_select_queue(rx->sdata, fwd_skb));
1881                         ieee80211_set_qos_hdr(local, skb);
1882                         if (is_multicast_ether_addr(fwd_hdr->addr1))
1883                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1884                                                                 fwded_mcast);
1885                         else {
1886                                 int err;
1887                                 /*
1888                                  * Save TA to addr1 to send TA a path error if a
1889                                  * suitable next hop is not found
1890                                  */
1891                                 memcpy(fwd_hdr->addr1, fwd_hdr->addr2,
1892                                                 ETH_ALEN);
1893                                 err = mesh_nexthop_lookup(fwd_skb, sdata);
1894                                 /* Failed to immediately resolve next hop:
1895                                  * fwded frame was dropped or will be added
1896                                  * later to the pending skb queue.  */
1897                                 if (err)
1898                                         return RX_DROP_MONITOR;
1899
1900                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1901                                                                 fwded_unicast);
1902                         }
1903                         IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1904                                                      fwded_frames);
1905                         ieee80211_add_pending_skb(local, fwd_skb);
1906                 }
1907         }
1908
1909  out:
1910         if (is_multicast_ether_addr(hdr->addr1) ||
1911             sdata->dev->flags & IFF_PROMISC)
1912                 return RX_CONTINUE;
1913         else
1914                 return RX_DROP_MONITOR;
1915 }
1916 #endif
1917
1918 static ieee80211_rx_result debug_noinline
1919 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1920 {
1921         struct ieee80211_sub_if_data *sdata = rx->sdata;
1922         struct ieee80211_local *local = rx->local;
1923         struct net_device *dev = sdata->dev;
1924         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1925         __le16 fc = hdr->frame_control;
1926         int err;
1927
1928         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1929                 return RX_CONTINUE;
1930
1931         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1932                 return RX_DROP_MONITOR;
1933
1934         /*
1935          * Allow the cooked monitor interface of an AP to see 4-addr frames so
1936          * that a 4-addr station can be detected and moved into a separate VLAN
1937          */
1938         if (ieee80211_has_a4(hdr->frame_control) &&
1939             sdata->vif.type == NL80211_IFTYPE_AP)
1940                 return RX_DROP_MONITOR;
1941
1942         err = __ieee80211_data_to_8023(rx);
1943         if (unlikely(err))
1944                 return RX_DROP_UNUSABLE;
1945
1946         if (!ieee80211_frame_allowed(rx, fc))
1947                 return RX_DROP_MONITOR;
1948
1949         rx->skb->dev = dev;
1950
1951         dev->stats.rx_packets++;
1952         dev->stats.rx_bytes += rx->skb->len;
1953
1954         if (local->ps_sdata && local->hw.conf.dynamic_ps_timeout > 0 &&
1955             !is_multicast_ether_addr(((struct ethhdr *)rx->skb->data)->h_dest)) {
1956                         mod_timer(&local->dynamic_ps_timer, jiffies +
1957                          msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
1958         }
1959
1960         ieee80211_deliver_skb(rx);
1961
1962         return RX_QUEUED;
1963 }
1964
1965 static ieee80211_rx_result debug_noinline
1966 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1967 {
1968         struct ieee80211_local *local = rx->local;
1969         struct ieee80211_hw *hw = &local->hw;
1970         struct sk_buff *skb = rx->skb;
1971         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1972         struct tid_ampdu_rx *tid_agg_rx;
1973         u16 start_seq_num;
1974         u16 tid;
1975
1976         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1977                 return RX_CONTINUE;
1978
1979         if (ieee80211_is_back_req(bar->frame_control)) {
1980                 struct {
1981                         __le16 control, start_seq_num;
1982                 } __packed bar_data;
1983
1984                 if (!rx->sta)
1985                         return RX_DROP_MONITOR;
1986
1987                 if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
1988                                   &bar_data, sizeof(bar_data)))
1989                         return RX_DROP_MONITOR;
1990
1991                 tid = le16_to_cpu(bar_data.control) >> 12;
1992
1993                 tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
1994                 if (!tid_agg_rx)
1995                         return RX_DROP_MONITOR;
1996
1997                 start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
1998
1999                 /* reset session timer */
2000                 if (tid_agg_rx->timeout)
2001                         mod_timer(&tid_agg_rx->session_timer,
2002                                   TU_TO_EXP_TIME(tid_agg_rx->timeout));
2003
2004                 spin_lock(&tid_agg_rx->reorder_lock);
2005                 /* release stored frames up to start of BAR */
2006                 ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num);
2007                 spin_unlock(&tid_agg_rx->reorder_lock);
2008
2009                 kfree_skb(skb);
2010                 return RX_QUEUED;
2011         }
2012
2013         /*
2014          * After this point, we only want management frames,
2015          * so we can drop all remaining control frames to
2016          * cooked monitor interfaces.
2017          */
2018         return RX_DROP_MONITOR;
2019 }
2020
2021 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
2022                                            struct ieee80211_mgmt *mgmt,
2023                                            size_t len)
2024 {
2025         struct ieee80211_local *local = sdata->local;
2026         struct sk_buff *skb;
2027         struct ieee80211_mgmt *resp;
2028
2029         if (compare_ether_addr(mgmt->da, sdata->vif.addr) != 0) {
2030                 /* Not to own unicast address */
2031                 return;
2032         }
2033
2034         if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
2035             compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
2036                 /* Not from the current AP or not associated yet. */
2037                 return;
2038         }
2039
2040         if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
2041                 /* Too short SA Query request frame */
2042                 return;
2043         }
2044
2045         skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
2046         if (skb == NULL)
2047                 return;
2048
2049         skb_reserve(skb, local->hw.extra_tx_headroom);
2050         resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
2051         memset(resp, 0, 24);
2052         memcpy(resp->da, mgmt->sa, ETH_ALEN);
2053         memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
2054         memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
2055         resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2056                                           IEEE80211_STYPE_ACTION);
2057         skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
2058         resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
2059         resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
2060         memcpy(resp->u.action.u.sa_query.trans_id,
2061                mgmt->u.action.u.sa_query.trans_id,
2062                WLAN_SA_QUERY_TR_ID_LEN);
2063
2064         ieee80211_tx_skb(sdata, skb);
2065 }
2066
2067 static ieee80211_rx_result debug_noinline
2068 ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
2069 {
2070         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2071         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2072
2073         /*
2074          * From here on, look only at management frames.
2075          * Data and control frames are already handled,
2076          * and unknown (reserved) frames are useless.
2077          */
2078         if (rx->skb->len < 24)
2079                 return RX_DROP_MONITOR;
2080
2081         if (!ieee80211_is_mgmt(mgmt->frame_control))
2082                 return RX_DROP_MONITOR;
2083
2084         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2085                 return RX_DROP_MONITOR;
2086
2087         if (ieee80211_drop_unencrypted_mgmt(rx))
2088                 return RX_DROP_UNUSABLE;
2089
2090         return RX_CONTINUE;
2091 }
2092
2093 static ieee80211_rx_result debug_noinline
2094 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
2095 {
2096         struct ieee80211_local *local = rx->local;
2097         struct ieee80211_sub_if_data *sdata = rx->sdata;
2098         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2099         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2100         int len = rx->skb->len;
2101
2102         if (!ieee80211_is_action(mgmt->frame_control))
2103                 return RX_CONTINUE;
2104
2105         /* drop too small frames */
2106         if (len < IEEE80211_MIN_ACTION_SIZE)
2107                 return RX_DROP_UNUSABLE;
2108
2109         if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC)
2110                 return RX_DROP_UNUSABLE;
2111
2112         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2113                 return RX_DROP_UNUSABLE;
2114
2115         switch (mgmt->u.action.category) {
2116         case WLAN_CATEGORY_BACK:
2117                 /*
2118                  * The aggregation code is not prepared to handle
2119                  * anything but STA/AP due to the BSSID handling;
2120                  * IBSS could work in the code but isn't supported
2121                  * by drivers or the standard.
2122                  */
2123                 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2124                     sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2125                     sdata->vif.type != NL80211_IFTYPE_AP)
2126                         break;
2127
2128                 /* verify action_code is present */
2129                 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2130                         break;
2131
2132                 switch (mgmt->u.action.u.addba_req.action_code) {
2133                 case WLAN_ACTION_ADDBA_REQ:
2134                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2135                                    sizeof(mgmt->u.action.u.addba_req)))
2136                                 goto invalid;
2137                         break;
2138                 case WLAN_ACTION_ADDBA_RESP:
2139                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2140                                    sizeof(mgmt->u.action.u.addba_resp)))
2141                                 goto invalid;
2142                         break;
2143                 case WLAN_ACTION_DELBA:
2144                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2145                                    sizeof(mgmt->u.action.u.delba)))
2146                                 goto invalid;
2147                         break;
2148                 default:
2149                         goto invalid;
2150                 }
2151
2152                 goto queue;
2153         case WLAN_CATEGORY_SPECTRUM_MGMT:
2154                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
2155                         break;
2156
2157                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
2158                         break;
2159
2160                 /* verify action_code is present */
2161                 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2162                         break;
2163
2164                 switch (mgmt->u.action.u.measurement.action_code) {
2165                 case WLAN_ACTION_SPCT_MSR_REQ:
2166                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2167                                    sizeof(mgmt->u.action.u.measurement)))
2168                                 break;
2169                         ieee80211_process_measurement_req(sdata, mgmt, len);
2170                         goto handled;
2171                 case WLAN_ACTION_SPCT_CHL_SWITCH:
2172                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2173                                    sizeof(mgmt->u.action.u.chan_switch)))
2174                                 break;
2175
2176                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
2177                                 break;
2178
2179                         if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
2180                                 break;
2181
2182                         goto queue;
2183                 }
2184                 break;
2185         case WLAN_CATEGORY_SA_QUERY:
2186                 if (len < (IEEE80211_MIN_ACTION_SIZE +
2187                            sizeof(mgmt->u.action.u.sa_query)))
2188                         break;
2189
2190                 switch (mgmt->u.action.u.sa_query.action) {
2191                 case WLAN_ACTION_SA_QUERY_REQUEST:
2192                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
2193                                 break;
2194                         ieee80211_process_sa_query_req(sdata, mgmt, len);
2195                         goto handled;
2196                 }
2197                 break;
2198         case WLAN_CATEGORY_MESH_PLINK:
2199                 if (!ieee80211_vif_is_mesh(&sdata->vif))
2200                         break;
2201                 goto queue;
2202         case WLAN_CATEGORY_MESH_PATH_SEL:
2203                 if (!mesh_path_sel_is_hwmp(sdata))
2204                         break;
2205                 goto queue;
2206         }
2207
2208         return RX_CONTINUE;
2209
2210  invalid:
2211         status->rx_flags |= IEEE80211_RX_MALFORMED_ACTION_FRM;
2212         /* will return in the next handlers */
2213         return RX_CONTINUE;
2214
2215  handled:
2216         if (rx->sta)
2217                 rx->sta->rx_packets++;
2218         dev_kfree_skb(rx->skb);
2219         return RX_QUEUED;
2220
2221  queue:
2222         rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2223         skb_queue_tail(&sdata->skb_queue, rx->skb);
2224         ieee80211_queue_work(&local->hw, &sdata->work);
2225         if (rx->sta)
2226                 rx->sta->rx_packets++;
2227         return RX_QUEUED;
2228 }
2229
2230 static ieee80211_rx_result debug_noinline
2231 ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
2232 {
2233         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2234
2235         /* skip known-bad action frames and return them in the next handler */
2236         if (status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM)
2237                 return RX_CONTINUE;
2238
2239         /*
2240          * Getting here means the kernel doesn't know how to handle
2241          * it, but maybe userspace does ... include returned frames
2242          * so userspace can register for those to know whether ones
2243          * it transmitted were processed or returned.
2244          */
2245
2246         if (cfg80211_rx_mgmt(rx->sdata->dev, status->freq,
2247                              rx->skb->data, rx->skb->len,
2248                              GFP_ATOMIC)) {
2249                 if (rx->sta)
2250                         rx->sta->rx_packets++;
2251                 dev_kfree_skb(rx->skb);
2252                 return RX_QUEUED;
2253         }
2254
2255
2256         return RX_CONTINUE;
2257 }
2258
2259 static ieee80211_rx_result debug_noinline
2260 ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
2261 {
2262         struct ieee80211_local *local = rx->local;
2263         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2264         struct sk_buff *nskb;
2265         struct ieee80211_sub_if_data *sdata = rx->sdata;
2266         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2267
2268         if (!ieee80211_is_action(mgmt->frame_control))
2269                 return RX_CONTINUE;
2270
2271         /*
2272          * For AP mode, hostapd is responsible for handling any action
2273          * frames that we didn't handle, including returning unknown
2274          * ones. For all other modes we will return them to the sender,
2275          * setting the 0x80 bit in the action category, as required by
2276          * 802.11-2007 7.3.1.11.
2277          * Newer versions of hostapd shall also use the management frame
2278          * registration mechanisms, but older ones still use cooked
2279          * monitor interfaces so push all frames there.
2280          */
2281         if (!(status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM) &&
2282             (sdata->vif.type == NL80211_IFTYPE_AP ||
2283              sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
2284                 return RX_DROP_MONITOR;
2285
2286         /* do not return rejected action frames */
2287         if (mgmt->u.action.category & 0x80)
2288                 return RX_DROP_UNUSABLE;
2289
2290         nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
2291                                GFP_ATOMIC);
2292         if (nskb) {
2293                 struct ieee80211_mgmt *nmgmt = (void *)nskb->data;
2294
2295                 nmgmt->u.action.category |= 0x80;
2296                 memcpy(nmgmt->da, nmgmt->sa, ETH_ALEN);
2297                 memcpy(nmgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
2298
2299                 memset(nskb->cb, 0, sizeof(nskb->cb));
2300
2301                 ieee80211_tx_skb(rx->sdata, nskb);
2302         }
2303         dev_kfree_skb(rx->skb);
2304         return RX_QUEUED;
2305 }
2306
2307 static ieee80211_rx_result debug_noinline
2308 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
2309 {
2310         struct ieee80211_sub_if_data *sdata = rx->sdata;
2311         ieee80211_rx_result rxs;
2312         struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
2313         __le16 stype;
2314
2315         rxs = ieee80211_work_rx_mgmt(rx->sdata, rx->skb);
2316         if (rxs != RX_CONTINUE)
2317                 return rxs;
2318
2319         stype = mgmt->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE);
2320
2321         if (!ieee80211_vif_is_mesh(&sdata->vif) &&
2322             sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2323             sdata->vif.type != NL80211_IFTYPE_STATION)
2324                 return RX_DROP_MONITOR;
2325
2326         switch (stype) {
2327         case cpu_to_le16(IEEE80211_STYPE_BEACON):
2328         case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
2329                 /* process for all: mesh, mlme, ibss */
2330                 break;
2331         case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
2332         case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
2333                 if (is_multicast_ether_addr(mgmt->da) &&
2334                     !is_broadcast_ether_addr(mgmt->da))
2335                         return RX_DROP_MONITOR;
2336
2337                 /* process only for station */
2338                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
2339                         return RX_DROP_MONITOR;
2340                 break;
2341         case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
2342         case cpu_to_le16(IEEE80211_STYPE_AUTH):
2343                 /* process only for ibss */
2344                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
2345                         return RX_DROP_MONITOR;
2346                 break;
2347         default:
2348                 return RX_DROP_MONITOR;
2349         }
2350
2351         /* queue up frame and kick off work to process it */
2352         rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2353         skb_queue_tail(&sdata->skb_queue, rx->skb);
2354         ieee80211_queue_work(&rx->local->hw, &sdata->work);
2355         if (rx->sta)
2356                 rx->sta->rx_packets++;
2357
2358         return RX_QUEUED;
2359 }
2360
2361 static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
2362                                             struct ieee80211_rx_data *rx)
2363 {
2364         int keyidx;
2365         unsigned int hdrlen;
2366
2367         hdrlen = ieee80211_hdrlen(hdr->frame_control);
2368         if (rx->skb->len >= hdrlen + 4)
2369                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
2370         else
2371                 keyidx = -1;
2372
2373         if (!rx->sta) {
2374                 /*
2375                  * Some hardware seem to generate incorrect Michael MIC
2376                  * reports; ignore them to avoid triggering countermeasures.
2377                  */
2378                 return;
2379         }
2380
2381         if (!ieee80211_has_protected(hdr->frame_control))
2382                 return;
2383
2384         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
2385                 /*
2386                  * APs with pairwise keys should never receive Michael MIC
2387                  * errors for non-zero keyidx because these are reserved for
2388                  * group keys and only the AP is sending real multicast
2389                  * frames in the BSS.
2390                  */
2391                 return;
2392         }
2393
2394         if (!ieee80211_is_data(hdr->frame_control) &&
2395             !ieee80211_is_auth(hdr->frame_control))
2396                 return;
2397
2398         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
2399                                         GFP_ATOMIC);
2400 }
2401
2402 /* TODO: use IEEE80211_RX_FRAGMENTED */
2403 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
2404                                         struct ieee80211_rate *rate)
2405 {
2406         struct ieee80211_sub_if_data *sdata;
2407         struct ieee80211_local *local = rx->local;
2408         struct ieee80211_rtap_hdr {
2409                 struct ieee80211_radiotap_header hdr;
2410                 u8 flags;
2411                 u8 rate_or_pad;
2412                 __le16 chan_freq;
2413                 __le16 chan_flags;
2414         } __packed *rthdr;
2415         struct sk_buff *skb = rx->skb, *skb2;
2416         struct net_device *prev_dev = NULL;
2417         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2418
2419         /*
2420          * If cooked monitor has been processed already, then
2421          * don't do it again. If not, set the flag.
2422          */
2423         if (rx->flags & IEEE80211_RX_CMNTR)
2424                 goto out_free_skb;
2425         rx->flags |= IEEE80211_RX_CMNTR;
2426
2427         if (skb_headroom(skb) < sizeof(*rthdr) &&
2428             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
2429                 goto out_free_skb;
2430
2431         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
2432         memset(rthdr, 0, sizeof(*rthdr));
2433         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
2434         rthdr->hdr.it_present =
2435                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
2436                             (1 << IEEE80211_RADIOTAP_CHANNEL));
2437
2438         if (rate) {
2439                 rthdr->rate_or_pad = rate->bitrate / 5;
2440                 rthdr->hdr.it_present |=
2441                         cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
2442         }
2443         rthdr->chan_freq = cpu_to_le16(status->freq);
2444
2445         if (status->band == IEEE80211_BAND_5GHZ)
2446                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
2447                                                 IEEE80211_CHAN_5GHZ);
2448         else
2449                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
2450                                                 IEEE80211_CHAN_2GHZ);
2451
2452         skb_set_mac_header(skb, 0);
2453         skb->ip_summed = CHECKSUM_UNNECESSARY;
2454         skb->pkt_type = PACKET_OTHERHOST;
2455         skb->protocol = htons(ETH_P_802_2);
2456
2457         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2458                 if (!ieee80211_sdata_running(sdata))
2459                         continue;
2460
2461                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
2462                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
2463                         continue;
2464
2465                 if (prev_dev) {
2466                         skb2 = skb_clone(skb, GFP_ATOMIC);
2467                         if (skb2) {
2468                                 skb2->dev = prev_dev;
2469                                 netif_receive_skb(skb2);
2470                         }
2471                 }
2472
2473                 prev_dev = sdata->dev;
2474                 sdata->dev->stats.rx_packets++;
2475                 sdata->dev->stats.rx_bytes += skb->len;
2476         }
2477
2478         if (prev_dev) {
2479                 skb->dev = prev_dev;
2480                 netif_receive_skb(skb);
2481                 return;
2482         }
2483
2484  out_free_skb:
2485         dev_kfree_skb(skb);
2486 }
2487
2488 static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
2489                                          ieee80211_rx_result res)
2490 {
2491         switch (res) {
2492         case RX_DROP_MONITOR:
2493                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2494                 if (rx->sta)
2495                         rx->sta->rx_dropped++;
2496                 /* fall through */
2497         case RX_CONTINUE: {
2498                 struct ieee80211_rate *rate = NULL;
2499                 struct ieee80211_supported_band *sband;
2500                 struct ieee80211_rx_status *status;
2501
2502                 status = IEEE80211_SKB_RXCB((rx->skb));
2503
2504                 sband = rx->local->hw.wiphy->bands[status->band];
2505                 if (!(status->flag & RX_FLAG_HT))
2506                         rate = &sband->bitrates[status->rate_idx];
2507
2508                 ieee80211_rx_cooked_monitor(rx, rate);
2509                 break;
2510                 }
2511         case RX_DROP_UNUSABLE:
2512                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2513                 if (rx->sta)
2514                         rx->sta->rx_dropped++;
2515                 dev_kfree_skb(rx->skb);
2516                 break;
2517         case RX_QUEUED:
2518                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_queued);
2519                 break;
2520         }
2521 }
2522
2523 static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx)
2524 {
2525         ieee80211_rx_result res = RX_DROP_MONITOR;
2526         struct sk_buff *skb;
2527
2528 #define CALL_RXH(rxh)                   \
2529         do {                            \
2530                 res = rxh(rx);          \
2531                 if (res != RX_CONTINUE) \
2532                         goto rxh_next;  \
2533         } while (0);
2534
2535         spin_lock(&rx->local->rx_skb_queue.lock);
2536         if (rx->local->running_rx_handler)
2537                 goto unlock;
2538
2539         rx->local->running_rx_handler = true;
2540
2541         while ((skb = __skb_dequeue(&rx->local->rx_skb_queue))) {
2542                 spin_unlock(&rx->local->rx_skb_queue.lock);
2543
2544                 /*
2545                  * all the other fields are valid across frames
2546                  * that belong to an aMPDU since they are on the
2547                  * same TID from the same station
2548                  */
2549                 rx->skb = skb;
2550                 rx->flags = 0;
2551
2552                 CALL_RXH(ieee80211_rx_h_decrypt)
2553                 CALL_RXH(ieee80211_rx_h_check_more_data)
2554                 CALL_RXH(ieee80211_rx_h_sta_process)
2555                 CALL_RXH(ieee80211_rx_h_defragment)
2556                 CALL_RXH(ieee80211_rx_h_ps_poll)
2557                 CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2558                 /* must be after MMIC verify so header is counted in MPDU mic */
2559                 CALL_RXH(ieee80211_rx_h_remove_qos_control)
2560                 CALL_RXH(ieee80211_rx_h_amsdu)
2561 #ifdef CONFIG_MAC80211_MESH
2562                 if (ieee80211_vif_is_mesh(&rx->sdata->vif))
2563                         CALL_RXH(ieee80211_rx_h_mesh_fwding);
2564 #endif
2565                 CALL_RXH(ieee80211_rx_h_data)
2566                 CALL_RXH(ieee80211_rx_h_ctrl);
2567                 CALL_RXH(ieee80211_rx_h_mgmt_check)
2568                 CALL_RXH(ieee80211_rx_h_action)
2569                 CALL_RXH(ieee80211_rx_h_userspace_mgmt)
2570                 CALL_RXH(ieee80211_rx_h_action_return)
2571                 CALL_RXH(ieee80211_rx_h_mgmt)
2572
2573  rxh_next:
2574                 ieee80211_rx_handlers_result(rx, res);
2575                 spin_lock(&rx->local->rx_skb_queue.lock);
2576 #undef CALL_RXH
2577         }
2578
2579         rx->local->running_rx_handler = false;
2580
2581  unlock:
2582         spin_unlock(&rx->local->rx_skb_queue.lock);
2583 }
2584
2585 static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
2586 {
2587         ieee80211_rx_result res = RX_DROP_MONITOR;
2588
2589 #define CALL_RXH(rxh)                   \
2590         do {                            \
2591                 res = rxh(rx);          \
2592                 if (res != RX_CONTINUE) \
2593                         goto rxh_next;  \
2594         } while (0);
2595
2596         CALL_RXH(ieee80211_rx_h_passive_scan)
2597         CALL_RXH(ieee80211_rx_h_check)
2598
2599         ieee80211_rx_reorder_ampdu(rx);
2600
2601         ieee80211_rx_handlers(rx);
2602         return;
2603
2604  rxh_next:
2605         ieee80211_rx_handlers_result(rx, res);
2606
2607 #undef CALL_RXH
2608 }
2609
2610 /*
2611  * This function makes calls into the RX path, therefore
2612  * it has to be invoked under RCU read lock.
2613  */
2614 void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
2615 {
2616         struct ieee80211_rx_data rx = {
2617                 .sta = sta,
2618                 .sdata = sta->sdata,
2619                 .local = sta->local,
2620                 .queue = tid,
2621         };
2622         struct tid_ampdu_rx *tid_agg_rx;
2623
2624         tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
2625         if (!tid_agg_rx)
2626                 return;
2627
2628         spin_lock(&tid_agg_rx->reorder_lock);
2629         ieee80211_sta_reorder_release(&sta->local->hw, tid_agg_rx);
2630         spin_unlock(&tid_agg_rx->reorder_lock);
2631
2632         ieee80211_rx_handlers(&rx);
2633 }
2634
2635 /* main receive path */
2636
2637 static int prepare_for_handlers(struct ieee80211_rx_data *rx,
2638                                 struct ieee80211_hdr *hdr)
2639 {
2640         struct ieee80211_sub_if_data *sdata = rx->sdata;
2641         struct sk_buff *skb = rx->skb;
2642         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2643         u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
2644         int multicast = is_multicast_ether_addr(hdr->addr1);
2645
2646         switch (sdata->vif.type) {
2647         case NL80211_IFTYPE_STATION:
2648                 if (!bssid && !sdata->u.mgd.use_4addr)
2649                         return 0;
2650                 if (!multicast &&
2651                     compare_ether_addr(sdata->vif.addr, hdr->addr1) != 0) {
2652                         if (!(sdata->dev->flags & IFF_PROMISC))
2653                                 return 0;
2654                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2655                 }
2656                 break;
2657         case NL80211_IFTYPE_ADHOC:
2658                 if (!bssid)
2659                         return 0;
2660                 if (ieee80211_is_beacon(hdr->frame_control)) {
2661                         return 1;
2662                 }
2663                 else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2664                         if (!(status->rx_flags & IEEE80211_RX_IN_SCAN))
2665                                 return 0;
2666                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2667                 } else if (!multicast &&
2668                            compare_ether_addr(sdata->vif.addr,
2669                                               hdr->addr1) != 0) {
2670                         if (!(sdata->dev->flags & IFF_PROMISC))
2671                                 return 0;
2672                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2673                 } else if (!rx->sta) {
2674                         int rate_idx;
2675                         if (status->flag & RX_FLAG_HT)
2676                                 rate_idx = 0; /* TODO: HT rates */
2677                         else
2678                                 rate_idx = status->rate_idx;
2679                         rx->sta = ieee80211_ibss_add_sta(sdata, bssid,
2680                                         hdr->addr2, BIT(rate_idx), GFP_ATOMIC);
2681                 }
2682                 break;
2683         case NL80211_IFTYPE_MESH_POINT:
2684                 if (!multicast &&
2685                     compare_ether_addr(sdata->vif.addr,
2686                                        hdr->addr1) != 0) {
2687                         if (!(sdata->dev->flags & IFF_PROMISC))
2688                                 return 0;
2689
2690                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2691                 }
2692                 break;
2693         case NL80211_IFTYPE_AP_VLAN:
2694         case NL80211_IFTYPE_AP:
2695                 if (!bssid) {
2696                         if (compare_ether_addr(sdata->vif.addr,
2697                                                hdr->addr1))
2698                                 return 0;
2699                 } else if (!ieee80211_bssid_match(bssid,
2700                                         sdata->vif.addr)) {
2701                         if (!(status->rx_flags & IEEE80211_RX_IN_SCAN))
2702                                 return 0;
2703                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2704                 }
2705                 break;
2706         case NL80211_IFTYPE_WDS:
2707                 if (bssid || !ieee80211_is_data(hdr->frame_control))
2708                         return 0;
2709                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2710                         return 0;
2711                 break;
2712         default:
2713                 /* should never get here */
2714                 WARN_ON(1);
2715                 break;
2716         }
2717
2718         return 1;
2719 }
2720
2721 /*
2722  * This function returns whether or not the SKB
2723  * was destined for RX processing or not, which,
2724  * if consume is true, is equivalent to whether
2725  * or not the skb was consumed.
2726  */
2727 static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
2728                                             struct sk_buff *skb, bool consume)
2729 {
2730         struct ieee80211_local *local = rx->local;
2731         struct ieee80211_sub_if_data *sdata = rx->sdata;
2732         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2733         struct ieee80211_hdr *hdr = (void *)skb->data;
2734         int prepares;
2735
2736         rx->skb = skb;
2737         status->rx_flags |= IEEE80211_RX_RA_MATCH;
2738         prepares = prepare_for_handlers(rx, hdr);
2739
2740         if (!prepares)
2741                 return false;
2742
2743         if (status->flag & RX_FLAG_MMIC_ERROR) {
2744                 if (status->rx_flags & IEEE80211_RX_RA_MATCH)
2745                         ieee80211_rx_michael_mic_report(hdr, rx);
2746                 return false;
2747         }
2748
2749         if (!consume) {
2750                 skb = skb_copy(skb, GFP_ATOMIC);
2751                 if (!skb) {
2752                         if (net_ratelimit())
2753                                 wiphy_debug(local->hw.wiphy,
2754                                         "failed to copy skb for %s\n",
2755                                         sdata->name);
2756                         return true;
2757                 }
2758
2759                 rx->skb = skb;
2760         }
2761
2762         ieee80211_invoke_rx_handlers(rx);
2763         return true;
2764 }
2765
2766 /*
2767  * This is the actual Rx frames handler. as it blongs to Rx path it must
2768  * be called with rcu_read_lock protection.
2769  */
2770 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2771                                          struct sk_buff *skb)
2772 {
2773         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2774         struct ieee80211_local *local = hw_to_local(hw);
2775         struct ieee80211_sub_if_data *sdata;
2776         struct ieee80211_hdr *hdr;
2777         __le16 fc;
2778         struct ieee80211_rx_data rx;
2779         struct ieee80211_sub_if_data *prev;
2780         struct sta_info *sta, *tmp, *prev_sta;
2781         int err = 0;
2782
2783         fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
2784         memset(&rx, 0, sizeof(rx));
2785         rx.skb = skb;
2786         rx.local = local;
2787
2788         if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
2789                 local->dot11ReceivedFragmentCount++;
2790
2791         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
2792                      test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
2793                 status->rx_flags |= IEEE80211_RX_IN_SCAN;
2794
2795         if (ieee80211_is_mgmt(fc))
2796                 err = skb_linearize(skb);
2797         else
2798                 err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
2799
2800         if (err) {
2801                 dev_kfree_skb(skb);
2802                 return;
2803         }
2804
2805         hdr = (struct ieee80211_hdr *)skb->data;
2806         ieee80211_parse_qos(&rx);
2807         ieee80211_verify_alignment(&rx);
2808
2809         if (ieee80211_is_data(fc)) {
2810                 prev_sta = NULL;
2811
2812                 for_each_sta_info(local, hdr->addr2, sta, tmp) {
2813                         if (!prev_sta) {
2814                                 prev_sta = sta;
2815                                 continue;
2816                         }
2817
2818                         rx.sta = prev_sta;
2819                         rx.sdata = prev_sta->sdata;
2820                         ieee80211_prepare_and_rx_handle(&rx, skb, false);
2821
2822                         prev_sta = sta;
2823                 }
2824
2825                 if (prev_sta) {
2826                         rx.sta = prev_sta;
2827                         rx.sdata = prev_sta->sdata;
2828
2829                         if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2830                                 return;
2831                         goto out;
2832                 }
2833         }
2834
2835         prev = NULL;
2836
2837         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2838                 if (!ieee80211_sdata_running(sdata))
2839                         continue;
2840
2841                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2842                     sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2843                         continue;
2844
2845                 /*
2846                  * frame is destined for this interface, but if it's
2847                  * not also for the previous one we handle that after
2848                  * the loop to avoid copying the SKB once too much
2849                  */
2850
2851                 if (!prev) {
2852                         prev = sdata;
2853                         continue;
2854                 }
2855
2856                 rx.sta = sta_info_get_bss(prev, hdr->addr2);
2857                 rx.sdata = prev;
2858                 ieee80211_prepare_and_rx_handle(&rx, skb, false);
2859
2860                 prev = sdata;
2861         }
2862
2863         if (prev) {
2864                 rx.sta = sta_info_get_bss(prev, hdr->addr2);
2865                 rx.sdata = prev;
2866
2867                 if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2868                         return;
2869         }
2870
2871  out:
2872         dev_kfree_skb(skb);
2873 }
2874
2875 /*
2876  * This is the receive path handler. It is called by a low level driver when an
2877  * 802.11 MPDU is received from the hardware.
2878  */
2879 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2880 {
2881         struct ieee80211_local *local = hw_to_local(hw);
2882         struct ieee80211_rate *rate = NULL;
2883         struct ieee80211_supported_band *sband;
2884         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2885
2886         WARN_ON_ONCE(softirq_count() == 0);
2887
2888         if (WARN_ON(status->band < 0 ||
2889                     status->band >= IEEE80211_NUM_BANDS))
2890                 goto drop;
2891
2892         sband = local->hw.wiphy->bands[status->band];
2893         if (WARN_ON(!sband))
2894                 goto drop;
2895
2896         /*
2897          * If we're suspending, it is possible although not too likely
2898          * that we'd be receiving frames after having already partially
2899          * quiesced the stack. We can't process such frames then since
2900          * that might, for example, cause stations to be added or other
2901          * driver callbacks be invoked.
2902          */
2903         if (unlikely(local->quiescing || local->suspended))
2904                 goto drop;
2905
2906         /*
2907          * The same happens when we're not even started,
2908          * but that's worth a warning.
2909          */
2910         if (WARN_ON(!local->started))
2911                 goto drop;
2912
2913         if (likely(!(status->flag & RX_FLAG_FAILED_PLCP_CRC))) {
2914                 /*
2915                  * Validate the rate, unless a PLCP error means that
2916                  * we probably can't have a valid rate here anyway.
2917                  */
2918
2919                 if (status->flag & RX_FLAG_HT) {
2920                         /*
2921                          * rate_idx is MCS index, which can be [0-76]
2922                          * as documented on:
2923                          *
2924                          * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
2925                          *
2926                          * Anything else would be some sort of driver or
2927                          * hardware error. The driver should catch hardware
2928                          * errors.
2929                          */
2930                         if (WARN((status->rate_idx < 0 ||
2931                                  status->rate_idx > 76),
2932                                  "Rate marked as an HT rate but passed "
2933                                  "status->rate_idx is not "
2934                                  "an MCS index [0-76]: %d (0x%02x)\n",
2935                                  status->rate_idx,
2936                                  status->rate_idx))
2937                                 goto drop;
2938                 } else {
2939                         if (WARN_ON(status->rate_idx < 0 ||
2940                                     status->rate_idx >= sband->n_bitrates))
2941                                 goto drop;
2942                         rate = &sband->bitrates[status->rate_idx];
2943                 }
2944         }
2945
2946         status->rx_flags = 0;
2947
2948         /*
2949          * key references and virtual interfaces are protected using RCU
2950          * and this requires that we are in a read-side RCU section during
2951          * receive processing
2952          */
2953         rcu_read_lock();
2954
2955         /*
2956          * Frames with failed FCS/PLCP checksum are not returned,
2957          * all other frames are returned without radiotap header
2958          * if it was previously present.
2959          * Also, frames with less than 16 bytes are dropped.
2960          */
2961         skb = ieee80211_rx_monitor(local, skb, rate);
2962         if (!skb) {
2963                 rcu_read_unlock();
2964                 return;
2965         }
2966
2967         ieee80211_tpt_led_trig_rx(local,
2968                         ((struct ieee80211_hdr *)skb->data)->frame_control,
2969                         skb->len);
2970         __ieee80211_rx_handle_packet(hw, skb);
2971
2972         rcu_read_unlock();
2973
2974         return;
2975  drop:
2976         kfree_skb(skb);
2977 }
2978 EXPORT_SYMBOL(ieee80211_rx);
2979
2980 /* This is a version of the rx handler that can be called from hard irq
2981  * context. Post the skb on the queue and schedule the tasklet */
2982 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
2983 {
2984         struct ieee80211_local *local = hw_to_local(hw);
2985
2986         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2987
2988         skb->pkt_type = IEEE80211_RX_MSG;
2989         skb_queue_tail(&local->skb_queue, skb);
2990         tasklet_schedule(&local->tasklet);
2991 }
2992 EXPORT_SYMBOL(ieee80211_rx_irqsafe);