net/mac80211/rx.c

   1 /*
   2  * Copyright 2002-2005, Instant802 Networks, Inc.
   3  * Copyright 2005-2006, Devicescape Software, Inc.
   4  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   5  * Copyright 2007-2010  Johannes Berg <johannes@sipsolutions.net>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/jiffies.h>
  13 #include <linux/slab.h>
  14 #include <linux/kernel.h>
  15 #include <linux/skbuff.h>
  16 #include <linux/netdevice.h>
  17 #include <linux/etherdevice.h>
  18 #include <linux/rcupdate.h>
  19 #include <net/mac80211.h>
  20 #include <net/ieee80211_radiotap.h>
  21
  22 #include "ieee80211_i.h"
  23 #include "driver-ops.h"
  24 #include "led.h"
  25 #include "mesh.h"
  26 #include "wep.h"
  27 #include "wpa.h"
  28 #include "tkip.h"
  29 #include "wme.h"
  30
  31 /*
  32  * monitor mode reception
  33  *
  34  * This function cleans up the SKB, i.e. it removes all the stuff
  35  * only useful for monitoring.
  36  */
  37 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
  38                                            struct sk_buff *skb)
  39 {
  40         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
  41                 if (likely(skb->len > FCS_LEN))
  42                         __pskb_trim(skb, skb->len - FCS_LEN);
  43                 else {
  44                         /* driver bug */
  45                         WARN_ON(1);
  46                         dev_kfree_skb(skb);
  47                         skb = NULL;
  48                 }
  49         }
  50
  51         return skb;
  52 }
  53
  54 static inline int should_drop_frame(struct sk_buff *skb,
  55                                     int present_fcs_len)
  56 {
  57         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  58         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  59
  60         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
  61                 return 1;
  62         if (unlikely(skb->len < 16 + present_fcs_len))
  63                 return 1;
  64         if (ieee80211_is_ctl(hdr->frame_control) &&
  65             !ieee80211_is_pspoll(hdr->frame_control) &&
  66             !ieee80211_is_back_req(hdr->frame_control))
  67                 return 1;
  68         return 0;
  69 }
  70
  71 static int
  72 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
  73                           struct ieee80211_rx_status *status)
  74 {
  75         int len;
  76
  77         /* always present fields */
  78         len = sizeof(struct ieee80211_radiotap_header) + 9;
  79
  80         if (status->flag & RX_FLAG_TSFT)
  81                 len += 8;
  82         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
  83                 len += 1;
  84
  85         if (len & 1) /* padding for RX_FLAGS if necessary */
  86                 len++;
  87
  88         return len;
  89 }
  90
  91 /*
  92  * ieee80211_add_rx_radiotap_header - add radiotap header
  93  *
  94  * add a radiotap header containing all the fields which the hardware provided.
  95  */
  96 static void
  97 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
  98                                  struct sk_buff *skb,
  99                                  struct ieee80211_rate *rate,
 100                                  int rtap_len)
 101 {
 102         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 103         struct ieee80211_radiotap_header *rthdr;
 104         unsigned char *pos;
 105         u16 rx_flags = 0;
 106
 107         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
 108         memset(rthdr, 0, rtap_len);
 109
 110         /* radiotap header, set always present flags */
 111         rthdr->it_present =
 112                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 113                             (1 << IEEE80211_RADIOTAP_CHANNEL) |
 114                             (1 << IEEE80211_RADIOTAP_ANTENNA) |
 115                             (1 << IEEE80211_RADIOTAP_RX_FLAGS));
 116         rthdr->it_len = cpu_to_le16(rtap_len);
 117
 118         pos = (unsigned char *)(rthdr+1);
 119
 120         /* the order of the following fields is important */
 121
 122         /* IEEE80211_RADIOTAP_TSFT */
 123         if (status->flag & RX_FLAG_TSFT) {
 124                 put_unaligned_le64(status->mactime, pos);
 125                 rthdr->it_present |=
 126                         cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
 127                 pos += 8;
 128         }
 129
 130         /* IEEE80211_RADIOTAP_FLAGS */
 131         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 132                 *pos |= IEEE80211_RADIOTAP_F_FCS;
 133         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 134                 *pos |= IEEE80211_RADIOTAP_F_BADFCS;
 135         if (status->flag & RX_FLAG_SHORTPRE)
 136                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
 137         pos++;
 138
 139         /* IEEE80211_RADIOTAP_RATE */
 140         if (status->flag & RX_FLAG_HT) {
 141                 /*
 142                  * TODO: add following information into radiotap header once
 143                  * suitable fields are defined for it:
 144                  * - MCS index (status->rate_idx)
 145                  * - HT40 (status->flag & RX_FLAG_40MHZ)
 146                  * - short-GI (status->flag & RX_FLAG_SHORT_GI)
 147                  */
 148                 *pos = 0;
 149         } else {
 150                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
 151                 *pos = rate->bitrate / 5;
 152         }
 153         pos++;
 154
 155         /* IEEE80211_RADIOTAP_CHANNEL */
 156         put_unaligned_le16(status->freq, pos);
 157         pos += 2;
 158         if (status->band == IEEE80211_BAND_5GHZ)
 159                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ,
 160                                    pos);
 161         else if (status->flag & RX_FLAG_HT)
 162                 put_unaligned_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ,
 163                                    pos);
 164         else if (rate->flags & IEEE80211_RATE_ERP_G)
 165                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
 166                                    pos);
 167         else
 168                 put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
 169                                    pos);
 170         pos += 2;
 171
 172         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
 173         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
 174                 *pos = status->signal;
 175                 rthdr->it_present |=
 176                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
 177                 pos++;
 178         }
 179
 180         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
 181
 182         /* IEEE80211_RADIOTAP_ANTENNA */
 183         *pos = status->antenna;
 184         pos++;
 185
 186         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
 187
 188         /* IEEE80211_RADIOTAP_RX_FLAGS */
 189         /* ensure 2 byte alignment for the 2 byte field as required */
 190         if ((pos - (u8 *)rthdr) & 1)
 191                 pos++;
 192         if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
 193                 rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
 194         put_unaligned_le16(rx_flags, pos);
 195         pos += 2;
 196 }
 197
 198 /*
 199  * This function copies a received frame to all monitor interfaces and
 200  * returns a cleaned-up SKB that no longer includes the FCS nor the
 201  * radiotap header the driver might have added.
 202  */
 203 static struct sk_buff *
 204 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
 205                      struct ieee80211_rate *rate)
 206 {
 207         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
 208         struct ieee80211_sub_if_data *sdata;
 209         int needed_headroom = 0;
 210         struct sk_buff *skb, *skb2;
 211         struct net_device *prev_dev = NULL;
 212         int present_fcs_len = 0;
 213
 214         /*
 215          * First, we may need to make a copy of the skb because
 216          *  (1) we need to modify it for radiotap (if not present), and
 217          *  (2) the other RX handlers will modify the skb we got.
 218          *
 219          * We don't need to, of course, if we aren't going to return
 220          * the SKB because it has a bad FCS/PLCP checksum.
 221          */
 222
 223         /* room for the radiotap header based on driver features */
 224         needed_headroom = ieee80211_rx_radiotap_len(local, status);
 225
 226         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 227                 present_fcs_len = FCS_LEN;
 228
 229         /* make sure hdr->frame_control is on the linear part */
 230         if (!pskb_may_pull(origskb, 2)) {
 231                 dev_kfree_skb(origskb);
 232                 return NULL;
 233         }
 234
 235         if (!local->monitors) {
 236                 if (should_drop_frame(origskb, present_fcs_len)) {
 237                         dev_kfree_skb(origskb);
 238                         return NULL;
 239                 }
 240
 241                 return remove_monitor_info(local, origskb);
 242         }
 243
 244         if (should_drop_frame(origskb, present_fcs_len)) {
 245                 /* only need to expand headroom if necessary */
 246                 skb = origskb;
 247                 origskb = NULL;
 248
 249                 /*
 250                  * This shouldn't trigger often because most devices have an
 251                  * RX header they pull before we get here, and that should
 252                  * be big enough for our radiotap information. We should
 253                  * probably export the length to drivers so that we can have
 254                  * them allocate enough headroom to start with.
 255                  */
 256                 if (skb_headroom(skb) < needed_headroom &&
 257                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
 258                         dev_kfree_skb(skb);
 259                         return NULL;
 260                 }
 261         } else {
 262                 /*
 263                  * Need to make a copy and possibly remove radiotap header
 264                  * and FCS from the original.
 265                  */
 266                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 267
 268                 origskb = remove_monitor_info(local, origskb);
 269
 270                 if (!skb)
 271                         return origskb;
 272         }
 273
 274         /* prepend radiotap information */
 275         ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom);
 276
 277         skb_reset_mac_header(skb);
 278         skb->ip_summed = CHECKSUM_UNNECESSARY;
 279         skb->pkt_type = PACKET_OTHERHOST;
 280         skb->protocol = htons(ETH_P_802_2);
 281
 282         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 283                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
 284                         continue;
 285
 286                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
 287                         continue;
 288
 289                 if (!ieee80211_sdata_running(sdata))
 290                         continue;
 291
 292                 if (prev_dev) {
 293                         skb2 = skb_clone(skb, GFP_ATOMIC);
 294                         if (skb2) {
 295                                 skb2->dev = prev_dev;
 296                                 netif_receive_skb(skb2);
 297                         }
 298                 }
 299
 300                 prev_dev = sdata->dev;
 301                 sdata->dev->stats.rx_packets++;
 302                 sdata->dev->stats.rx_bytes += skb->len;
 303         }
 304
 305         if (prev_dev) {
 306                 skb->dev = prev_dev;
 307                 netif_receive_skb(skb);
 308         } else
 309                 dev_kfree_skb(skb);
 310
 311         return origskb;
 312 }
 313
 314
 315 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
 316 {
 317         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 318         int tid;
 319
 320         /* does the frame have a qos control field? */
 321         if (ieee80211_is_data_qos(hdr->frame_control)) {
 322                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 323                 /* frame has qos control */
 324                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
 325                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
 326                         rx->flags |= IEEE80211_RX_AMSDU;
 327                 else
 328                         rx->flags &= ~IEEE80211_RX_AMSDU;
 329         } else {
 330                 /*
 331                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
 332                  *
 333                  *      Sequence numbers for management frames, QoS data
 334                  *      frames with a broadcast/multicast address in the
 335                  *      Address 1 field, and all non-QoS data frames sent
 336                  *      by QoS STAs are assigned using an additional single
 337                  *      modulo-4096 counter, [...]
 338                  *
 339                  * We also use that counter for non-QoS STAs.
 340                  */
 341                 tid = NUM_RX_DATA_QUEUES - 1;
 342         }
 343
 344         rx->queue = tid;
 345         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 346          * For now, set skb->priority to 0 for other cases. */
 347         rx->skb->priority = (tid > 7) ? 0 : tid;
 348 }
 349
 350 /**
 351  * DOC: Packet alignment
 352  *
 353  * Drivers always need to pass packets that are aligned to two-byte boundaries
 354  * to the stack.
 355  *
 356  * Additionally, should, if possible, align the payload data in a way that
 357  * guarantees that the contained IP header is aligned to a four-byte
 358  * boundary. In the case of regular frames, this simply means aligning the
 359  * payload to a four-byte boundary (because either the IP header is directly
 360  * contained, or IV/RFC1042 headers that have a length divisible by four are
 361  * in front of it).  If the payload data is not properly aligned and the
 362  * architecture doesn't support efficient unaligned operations, mac80211
 363  * will align the data.
 364  *
 365  * With A-MSDU frames, however, the payload data address must yield two modulo
 366  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
 367  * push the IP header further back to a multiple of four again. Thankfully, the
 368  * specs were sane enough this time around to require padding each A-MSDU
 369  * subframe to a length that is a multiple of four.
 370  *
 371  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
 372  * the payload is not supported, the driver is required to move the 802.11
 373  * header to be directly in front of the payload in that case.
 374  */
 375 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
 376 {
 377 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 378         WARN_ONCE((unsigned long)rx->skb->data & 1,
 379                   "unaligned packet at 0x%p\n", rx->skb->data);
 380 #endif
 381 }
 382
 383
 384 /* rx handlers */
 385
 386 static ieee80211_rx_result debug_noinline
 387 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 388 {
 389         struct ieee80211_local *local = rx->local;
 390         struct sk_buff *skb = rx->skb;
 391
 392         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning)))
 393                 return ieee80211_scan_rx(rx->sdata, skb);
 394
 395         if (unlikely(test_bit(SCAN_SW_SCANNING, &local->scanning) &&
 396                      (rx->flags & IEEE80211_RX_IN_SCAN))) {
 397                 /* drop all the other packets during a software scan anyway */
 398                 if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
 399                         dev_kfree_skb(skb);
 400                 return RX_QUEUED;
 401         }
 402
 403         if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
 404                 /* scanning finished during invoking of handlers */
 405                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 406                 return RX_DROP_UNUSABLE;
 407         }
 408
 409         return RX_CONTINUE;
 410 }
 411
 412
 413 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
 414 {
 415         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 416
 417         if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
 418                 return 0;
 419
 420         return ieee80211_is_robust_mgmt_frame(hdr);
 421 }
 422
 423
 424 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
 425 {
 426         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 427
 428         if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
 429                 return 0;
 430
 431         return ieee80211_is_robust_mgmt_frame(hdr);
 432 }
 433
 434
 435 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
 436 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
 437 {
 438         struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
 439         struct ieee80211_mmie *mmie;
 440
 441         if (skb->len < 24 + sizeof(*mmie) ||
 442             !is_multicast_ether_addr(hdr->da))
 443                 return -1;
 444
 445         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
 446                 return -1; /* not a robust management frame */
 447
 448         mmie = (struct ieee80211_mmie *)
 449                 (skb->data + skb->len - sizeof(*mmie));
 450         if (mmie->element_id != WLAN_EID_MMIE ||
 451             mmie->length != sizeof(*mmie) - 2)
 452                 return -1;
 453
 454         return le16_to_cpu(mmie->key_id);
 455 }
 456
 457
 458 static ieee80211_rx_result
 459 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 460 {
 461         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 462         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 463         char *dev_addr = rx->sdata->vif.addr;
 464
 465         if (ieee80211_is_data(hdr->frame_control)) {
 466                 if (is_multicast_ether_addr(hdr->addr1)) {
 467                         if (ieee80211_has_tods(hdr->frame_control) ||
 468                                 !ieee80211_has_fromds(hdr->frame_control))
 469                                 return RX_DROP_MONITOR;
 470                         if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
 471                                 return RX_DROP_MONITOR;
 472                 } else {
 473                         if (!ieee80211_has_a4(hdr->frame_control))
 474                                 return RX_DROP_MONITOR;
 475                         if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
 476                                 return RX_DROP_MONITOR;
 477                 }
 478         }
 479
 480         /* If there is not an established peer link and this is not a peer link
 481          * establisment frame, beacon or probe, drop the frame.
 482          */
 483
 484         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
 485                 struct ieee80211_mgmt *mgmt;
 486
 487                 if (!ieee80211_is_mgmt(hdr->frame_control))
 488                         return RX_DROP_MONITOR;
 489
 490                 if (ieee80211_is_action(hdr->frame_control)) {
 491                         mgmt = (struct ieee80211_mgmt *)hdr;
 492                         if (mgmt->u.action.category != WLAN_CATEGORY_MESH_PLINK)
 493                                 return RX_DROP_MONITOR;
 494                         return RX_CONTINUE;
 495                 }
 496
 497                 if (ieee80211_is_probe_req(hdr->frame_control) ||
 498                     ieee80211_is_probe_resp(hdr->frame_control) ||
 499                     ieee80211_is_beacon(hdr->frame_control))
 500                         return RX_CONTINUE;
 501
 502                 return RX_DROP_MONITOR;
 503
 504         }
 505
 506 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
 507
 508         if (ieee80211_is_data(hdr->frame_control) &&
 509             is_multicast_ether_addr(hdr->addr1) &&
 510             mesh_rmc_check(hdr->addr3, msh_h_get(hdr, hdrlen), rx->sdata))
 511                 return RX_DROP_MONITOR;
 512 #undef msh_h_get
 513
 514         return RX_CONTINUE;
 515 }
 516
 517 #define SEQ_MODULO 0x1000
 518 #define SEQ_MASK   0xfff
 519
 520 static inline int seq_less(u16 sq1, u16 sq2)
 521 {
 522         return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
 523 }
 524
 525 static inline u16 seq_inc(u16 sq)
 526 {
 527         return (sq + 1) & SEQ_MASK;
 528 }
 529
 530 static inline u16 seq_sub(u16 sq1, u16 sq2)
 531 {
 532         return (sq1 - sq2) & SEQ_MASK;
 533 }
 534
 535
 536 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
 537                                             struct tid_ampdu_rx *tid_agg_rx,
 538                                             int index,
 539                                             struct sk_buff_head *frames)
 540 {
 541         struct ieee80211_supported_band *sband;
 542         struct ieee80211_rate *rate = NULL;
 543         struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
 544         struct ieee80211_rx_status *status;
 545
 546         if (!skb)
 547                 goto no_frame;
 548
 549         status = IEEE80211_SKB_RXCB(skb);
 550
 551         /* release the reordered frames to stack */
 552         sband = hw->wiphy->bands[status->band];
 553         if (!(status->flag & RX_FLAG_HT))
 554                 rate = &sband->bitrates[status->rate_idx];
 555         tid_agg_rx->stored_mpdu_num--;
 556         tid_agg_rx->reorder_buf[index] = NULL;
 557         __skb_queue_tail(frames, skb);
 558
 559 no_frame:
 560         tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
 561 }
 562
 563 static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
 564                                              struct tid_ampdu_rx *tid_agg_rx,
 565                                              u16 head_seq_num,
 566                                              struct sk_buff_head *frames)
 567 {
 568         int index;
 569
 570         while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
 571                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 572                                                         tid_agg_rx->buf_size;
 573                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index, frames);
 574         }
 575 }
 576
 577 /*
 578  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
 579  * the skb was added to the buffer longer than this time ago, the earlier
 580  * frames that have not yet been received are assumed to be lost and the skb
 581  * can be released for processing. This may also release other skb's from the
 582  * reorder buffer if there are no additional gaps between the frames.
 583  */
 584 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
 585
 586 /*
 587  * As this function belongs to the RX path it must be under
 588  * rcu_read_lock protection. It returns false if the frame
 589  * can be processed immediately, true if it was consumed.
 590  */
 591 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
 592                                              struct tid_ampdu_rx *tid_agg_rx,
 593                                              struct sk_buff *skb,
 594                                              struct sk_buff_head *frames)
 595 {
 596         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 597         u16 sc = le16_to_cpu(hdr->seq_ctrl);
 598         u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
 599         u16 head_seq_num, buf_size;
 600         int index;
 601
 602         buf_size = tid_agg_rx->buf_size;
 603         head_seq_num = tid_agg_rx->head_seq_num;
 604
 605         /* frame with out of date sequence number */
 606         if (seq_less(mpdu_seq_num, head_seq_num)) {
 607                 dev_kfree_skb(skb);
 608                 return true;
 609         }
 610
 611         /*
 612          * If frame the sequence number exceeds our buffering window
 613          * size release some previous frames to make room for this one.
 614          */
 615         if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
 616                 head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
 617                 /* release stored frames up to new head to stack */
 618                 ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num,
 619                                                  frames);
 620         }
 621
 622         /* Now the new frame is always in the range of the reordering buffer */
 623
 624         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size;
 625
 626         /* check if we already stored this frame */
 627         if (tid_agg_rx->reorder_buf[index]) {
 628                 dev_kfree_skb(skb);
 629                 return true;
 630         }
 631
 632         /*
 633          * If the current MPDU is in the right order and nothing else
 634          * is stored we can process it directly, no need to buffer it.
 635          */
 636         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
 637             tid_agg_rx->stored_mpdu_num == 0) {
 638                 tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
 639                 return false;
 640         }
 641
 642         /* put the frame in the reordering buffer */
 643         tid_agg_rx->reorder_buf[index] = skb;
 644         tid_agg_rx->reorder_time[index] = jiffies;
 645         tid_agg_rx->stored_mpdu_num++;
 646         /* release the buffer until next missing frame */
 647         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 648                                                 tid_agg_rx->buf_size;
 649         if (!tid_agg_rx->reorder_buf[index] &&
 650             tid_agg_rx->stored_mpdu_num > 1) {
 651                 /*
 652                  * No buffers ready to be released, but check whether any
 653                  * frames in the reorder buffer have timed out.
 654                  */
 655                 int j;
 656                 int skipped = 1;
 657                 for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
 658                      j = (j + 1) % tid_agg_rx->buf_size) {
 659                         if (!tid_agg_rx->reorder_buf[j]) {
 660                                 skipped++;
 661                                 continue;
 662                         }
 663                         if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
 664                                         HT_RX_REORDER_BUF_TIMEOUT))
 665                                 break;
 666
 667 #ifdef CONFIG_MAC80211_HT_DEBUG
 668                         if (net_ratelimit())
 669                                 printk(KERN_DEBUG "%s: release an RX reorder "
 670                                        "frame due to timeout on earlier "
 671                                        "frames\n",
 672                                        wiphy_name(hw->wiphy));
 673 #endif
 674                         ieee80211_release_reorder_frame(hw, tid_agg_rx,
 675                                                         j, frames);
 676
 677                         /*
 678                          * Increment the head seq# also for the skipped slots.
 679                          */
 680                         tid_agg_rx->head_seq_num =
 681                                 (tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
 682                         skipped = 0;
 683                 }
 684         } else while (tid_agg_rx->reorder_buf[index]) {
 685                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index, frames);
 686                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 687                                                         tid_agg_rx->buf_size;
 688         }
 689
 690         return true;
 691 }
 692
 693 /*
 694  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
 695  * true if the MPDU was buffered, false if it should be processed.
 696  */
 697 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx,
 698                                        struct sk_buff_head *frames)
 699 {
 700         struct sk_buff *skb = rx->skb;
 701         struct ieee80211_local *local = rx->local;
 702         struct ieee80211_hw *hw = &local->hw;
 703         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 704         struct sta_info *sta = rx->sta;
 705         struct tid_ampdu_rx *tid_agg_rx;
 706         u16 sc;
 707         int tid;
 708
 709         if (!ieee80211_is_data_qos(hdr->frame_control))
 710                 goto dont_reorder;
 711
 712         /*
 713          * filter the QoS data rx stream according to
 714          * STA/TID and check if this STA/TID is on aggregation
 715          */
 716
 717         if (!sta)
 718                 goto dont_reorder;
 719
 720         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
 721
 722         tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
 723         if (!tid_agg_rx)
 724                 goto dont_reorder;
 725
 726         /* qos null data frames are excluded */
 727         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
 728                 goto dont_reorder;
 729
 730         /* new, potentially un-ordered, ampdu frame - process it */
 731
 732         /* reset session timer */
 733         if (tid_agg_rx->timeout)
 734                 mod_timer(&tid_agg_rx->session_timer,
 735                           TU_TO_EXP_TIME(tid_agg_rx->timeout));
 736
 737         /* if this mpdu is fragmented - terminate rx aggregation session */
 738         sc = le16_to_cpu(hdr->seq_ctrl);
 739         if (sc & IEEE80211_SCTL_FRAG) {
 740                 skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
 741                 skb_queue_tail(&rx->sdata->skb_queue, skb);
 742                 ieee80211_queue_work(&local->hw, &rx->sdata->work);
 743                 return;
 744         }
 745
 746         /*
 747          * No locking needed -- we will only ever process one
 748          * RX packet at a time, and thus own tid_agg_rx. All
 749          * other code manipulating it needs to (and does) make
 750          * sure that we cannot get to it any more before doing
 751          * anything with it.
 752          */
 753         if (ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb, frames))
 754                 return;
 755
 756  dont_reorder:
 757         __skb_queue_tail(frames, skb);
 758 }
 759
 760 static ieee80211_rx_result debug_noinline
 761 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
 762 {
 763         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 764
 765         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 766         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 767                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
 768                              rx->sta->last_seq_ctrl[rx->queue] ==
 769                              hdr->seq_ctrl)) {
 770                         if (rx->flags & IEEE80211_RX_RA_MATCH) {
 771                                 rx->local->dot11FrameDuplicateCount++;
 772                                 rx->sta->num_duplicates++;
 773                         }
 774                         return RX_DROP_MONITOR;
 775                 } else
 776                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
 777         }
 778
 779         if (unlikely(rx->skb->len < 16)) {
 780                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 781                 return RX_DROP_MONITOR;
 782         }
 783
 784         /* Drop disallowed frame classes based on STA auth/assoc state;
 785          * IEEE 802.11, Chap 5.5.
 786          *
 787          * mac80211 filters only based on association state, i.e. it drops
 788          * Class 3 frames from not associated stations. hostapd sends
 789          * deauth/disassoc frames when needed. In addition, hostapd is
 790          * responsible for filtering on both auth and assoc states.
 791          */
 792
 793         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
 794                 return ieee80211_rx_mesh_check(rx);
 795
 796         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
 797                       ieee80211_is_pspoll(hdr->frame_control)) &&
 798                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
 799                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
 800                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
 801                      !ieee80211_has_tods(hdr->frame_control) &&
 802                      ieee80211_is_data(hdr->frame_control)) ||
 803                     !(rx->flags & IEEE80211_RX_RA_MATCH)) {
 804                         /* Drop IBSS frames and frames for other hosts
 805                          * silently. */
 806                         return RX_DROP_MONITOR;
 807                 }
 808
 809                 return RX_DROP_MONITOR;
 810         }
 811
 812         return RX_CONTINUE;
 813 }
 814
 815
 816 static ieee80211_rx_result debug_noinline
 817 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 818 {
 819         struct sk_buff *skb = rx->skb;
 820         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 821         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 822         int keyidx;
 823         int hdrlen;
 824         ieee80211_rx_result result = RX_DROP_UNUSABLE;
 825         struct ieee80211_key *stakey = NULL;
 826         int mmie_keyidx = -1;
 827         __le16 fc;
 828
 829         /*
 830          * Key selection 101
 831          *
 832          * There are four types of keys:
 833          *  - GTK (group keys)
 834          *  - IGTK (group keys for management frames)
 835          *  - PTK (pairwise keys)
 836          *  - STK (station-to-station pairwise keys)
 837          *
 838          * When selecting a key, we have to distinguish between multicast
 839          * (including broadcast) and unicast frames, the latter can only
 840          * use PTKs and STKs while the former always use GTKs and IGTKs.
 841          * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
 842          * unicast frames can also use key indices like GTKs. Hence, if we
 843          * don't have a PTK/STK we check the key index for a WEP key.
 844          *
 845          * Note that in a regular BSS, multicast frames are sent by the
 846          * AP only, associated stations unicast the frame to the AP first
 847          * which then multicasts it on their behalf.
 848          *
 849          * There is also a slight problem in IBSS mode: GTKs are negotiated
 850          * with each station, that is something we don't currently handle.
 851          * The spec seems to expect that one negotiates the same key with
 852          * every station but there's no such requirement; VLANs could be
 853          * possible.
 854          */
 855
 856         /*
 857          * No point in finding a key and decrypting if the frame is neither
 858          * addressed to us nor a multicast frame.
 859          */
 860         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 861                 return RX_CONTINUE;
 862
 863         /* start without a key */
 864         rx->key = NULL;
 865
 866         if (rx->sta)
 867                 stakey = rcu_dereference(rx->sta->key);
 868
 869         fc = hdr->frame_control;
 870
 871         if (!ieee80211_has_protected(fc))
 872                 mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
 873
 874         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
 875                 rx->key = stakey;
 876                 /* Skip decryption if the frame is not protected. */
 877                 if (!ieee80211_has_protected(fc))
 878                         return RX_CONTINUE;
 879         } else if (mmie_keyidx >= 0) {
 880                 /* Broadcast/multicast robust management frame / BIP */
 881                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 882                     (status->flag & RX_FLAG_IV_STRIPPED))
 883                         return RX_CONTINUE;
 884
 885                 if (mmie_keyidx < NUM_DEFAULT_KEYS ||
 886                     mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 887                         return RX_DROP_MONITOR; /* unexpected BIP keyidx */
 888                 rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
 889         } else if (!ieee80211_has_protected(fc)) {
 890                 /*
 891                  * The frame was not protected, so skip decryption. However, we
 892                  * need to set rx->key if there is a key that could have been
 893                  * used so that the frame may be dropped if encryption would
 894                  * have been expected.
 895                  */
 896                 struct ieee80211_key *key = NULL;
 897                 if (ieee80211_is_mgmt(fc) &&
 898                     is_multicast_ether_addr(hdr->addr1) &&
 899                     (key = rcu_dereference(rx->sdata->default_mgmt_key)))
 900                         rx->key = key;
 901                 else if ((key = rcu_dereference(rx->sdata->default_key)))
 902                         rx->key = key;
 903                 return RX_CONTINUE;
 904         } else {
 905                 u8 keyid;
 906                 /*
 907                  * The device doesn't give us the IV so we won't be
 908                  * able to look up the key. That's ok though, we
 909                  * don't need to decrypt the frame, we just won't
 910                  * be able to keep statistics accurate.
 911                  * Except for key threshold notifications, should
 912                  * we somehow allow the driver to tell us which key
 913                  * the hardware used if this flag is set?
 914                  */
 915                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 916                     (status->flag & RX_FLAG_IV_STRIPPED))
 917                         return RX_CONTINUE;
 918
 919                 hdrlen = ieee80211_hdrlen(fc);
 920
 921                 if (rx->skb->len < 8 + hdrlen)
 922                         return RX_DROP_UNUSABLE; /* TODO: count this? */
 923
 924                 /*
 925                  * no need to call ieee80211_wep_get_keyidx,
 926                  * it verifies a bunch of things we've done already
 927                  */
 928                 skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
 929                 keyidx = keyid >> 6;
 930
 931                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
 932
 933                 /*
 934                  * RSNA-protected unicast frames should always be sent with
 935                  * pairwise or station-to-station keys, but for WEP we allow
 936                  * using a key index as well.
 937                  */
 938                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
 939                     !is_multicast_ether_addr(hdr->addr1))
 940                         rx->key = NULL;
 941         }
 942
 943         if (rx->key) {
 944                 rx->key->tx_rx_count++;
 945                 /* TODO: add threshold stuff again */
 946         } else {
 947                 return RX_DROP_MONITOR;
 948         }
 949
 950         if (skb_linearize(rx->skb))
 951                 return RX_DROP_UNUSABLE;
 952         /* the hdr variable is invalid now! */
 953
 954         switch (rx->key->conf.alg) {
 955         case ALG_WEP:
 956                 /* Check for weak IVs if possible */
 957                 if (rx->sta && ieee80211_is_data(fc) &&
 958                     (!(status->flag & RX_FLAG_IV_STRIPPED) ||
 959                      !(status->flag & RX_FLAG_DECRYPTED)) &&
 960                     ieee80211_wep_is_weak_iv(rx->skb, rx->key))
 961                         rx->sta->wep_weak_iv_count++;
 962
 963                 result = ieee80211_crypto_wep_decrypt(rx);
 964                 break;
 965         case ALG_TKIP:
 966                 result = ieee80211_crypto_tkip_decrypt(rx);
 967                 break;
 968         case ALG_CCMP:
 969                 result = ieee80211_crypto_ccmp_decrypt(rx);
 970                 break;
 971         case ALG_AES_CMAC:
 972                 result = ieee80211_crypto_aes_cmac_decrypt(rx);
 973                 break;
 974         }
 975
 976         /* either the frame has been decrypted or will be dropped */
 977         status->flag |= RX_FLAG_DECRYPTED;
 978
 979         return result;
 980 }
 981
 982 static ieee80211_rx_result debug_noinline
 983 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
 984 {
 985         struct ieee80211_local *local;
 986         struct ieee80211_hdr *hdr;
 987         struct sk_buff *skb;
 988
 989         local = rx->local;
 990         skb = rx->skb;
 991         hdr = (struct ieee80211_hdr *) skb->data;
 992
 993         if (!local->pspolling)
 994                 return RX_CONTINUE;
 995
 996         if (!ieee80211_has_fromds(hdr->frame_control))
 997                 /* this is not from AP */
 998                 return RX_CONTINUE;
 999
1000         if (!ieee80211_is_data(hdr->frame_control))
1001                 return RX_CONTINUE;
1002
1003         if (!ieee80211_has_moredata(hdr->frame_control)) {
1004                 /* AP has no more frames buffered for us */
1005                 local->pspolling = false;
1006                 return RX_CONTINUE;
1007         }
1008
1009         /* more data bit is set, let's request a new frame from the AP */
1010         ieee80211_send_pspoll(local, rx->sdata);
1011
1012         return RX_CONTINUE;
1013 }
1014
1015 static void ap_sta_ps_start(struct sta_info *sta)
1016 {
1017         struct ieee80211_sub_if_data *sdata = sta->sdata;
1018         struct ieee80211_local *local = sdata->local;
1019
1020         atomic_inc(&sdata->bss->num_sta_ps);
1021         set_sta_flags(sta, WLAN_STA_PS_STA);
1022         drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
1023 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1024         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
1025                sdata->name, sta->sta.addr, sta->sta.aid);
1026 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1027 }
1028
1029 static void ap_sta_ps_end(struct sta_info *sta)
1030 {
1031         struct ieee80211_sub_if_data *sdata = sta->sdata;
1032
1033         atomic_dec(&sdata->bss->num_sta_ps);
1034
1035         clear_sta_flags(sta, WLAN_STA_PS_STA);
1036
1037 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1038         printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
1039                sdata->name, sta->sta.addr, sta->sta.aid);
1040 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1041
1042         if (test_sta_flags(sta, WLAN_STA_PS_DRIVER)) {
1043 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1044                 printk(KERN_DEBUG "%s: STA %pM aid %d driver-ps-blocked\n",
1045                        sdata->name, sta->sta.addr, sta->sta.aid);
1046 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1047                 return;
1048         }
1049
1050         ieee80211_sta_ps_deliver_wakeup(sta);
1051 }
1052
1053 static ieee80211_rx_result debug_noinline
1054 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1055 {
1056         struct sta_info *sta = rx->sta;
1057         struct sk_buff *skb = rx->skb;
1058         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1059         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1060
1061         if (!sta)
1062                 return RX_CONTINUE;
1063
1064         /*
1065          * Update last_rx only for IBSS packets which are for the current
1066          * BSSID to avoid keeping the current IBSS network alive in cases
1067          * where other STAs start using different BSSID.
1068          */
1069         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1070                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1071                                                 NL80211_IFTYPE_ADHOC);
1072                 if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
1073                         sta->last_rx = jiffies;
1074         } else if (!is_multicast_ether_addr(hdr->addr1)) {
1075                 /*
1076                  * Mesh beacons will update last_rx when if they are found to
1077                  * match the current local configuration when processed.
1078                  */
1079                 sta->last_rx = jiffies;
1080         }
1081
1082         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1083                 return RX_CONTINUE;
1084
1085         if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1086                 ieee80211_sta_rx_notify(rx->sdata, hdr);
1087
1088         sta->rx_fragments++;
1089         sta->rx_bytes += rx->skb->len;
1090         sta->last_signal = status->signal;
1091
1092         /*
1093          * Change STA power saving mode only at the end of a frame
1094          * exchange sequence.
1095          */
1096         if (!ieee80211_has_morefrags(hdr->frame_control) &&
1097             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1098              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
1099                 if (test_sta_flags(sta, WLAN_STA_PS_STA)) {
1100                         /*
1101                          * Ignore doze->wake transitions that are
1102                          * indicated by non-data frames, the standard
1103                          * is unclear here, but for example going to
1104                          * PS mode and then scanning would cause a
1105                          * doze->wake transition for the probe request,
1106                          * and that is clearly undesirable.
1107                          */
1108                         if (ieee80211_is_data(hdr->frame_control) &&
1109                             !ieee80211_has_pm(hdr->frame_control))
1110                                 ap_sta_ps_end(sta);
1111                 } else {
1112                         if (ieee80211_has_pm(hdr->frame_control))
1113                                 ap_sta_ps_start(sta);
1114                 }
1115         }
1116
1117         /*
1118          * Drop (qos-)data::nullfunc frames silently, since they
1119          * are used only to control station power saving mode.
1120          */
1121         if (ieee80211_is_nullfunc(hdr->frame_control) ||
1122             ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1123                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
1124
1125                 /*
1126                  * If we receive a 4-addr nullfunc frame from a STA
1127                  * that was not moved to a 4-addr STA vlan yet, drop
1128                  * the frame to the monitor interface, to make sure
1129                  * that hostapd sees it
1130                  */
1131                 if (ieee80211_has_a4(hdr->frame_control) &&
1132                     (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1133                      (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1134                       !rx->sdata->u.vlan.sta)))
1135                         return RX_DROP_MONITOR;
1136                 /*
1137                  * Update counter and free packet here to avoid
1138                  * counting this as a dropped packed.
1139                  */
1140                 sta->rx_packets++;
1141                 dev_kfree_skb(rx->skb);
1142                 return RX_QUEUED;
1143         }
1144
1145         return RX_CONTINUE;
1146 } /* ieee80211_rx_h_sta_process */
1147
1148 static inline struct ieee80211_fragment_entry *
1149 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
1150                          unsigned int frag, unsigned int seq, int rx_queue,
1151                          struct sk_buff **skb)
1152 {
1153         struct ieee80211_fragment_entry *entry;
1154         int idx;
1155
1156         idx = sdata->fragment_next;
1157         entry = &sdata->fragments[sdata->fragment_next++];
1158         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
1159                 sdata->fragment_next = 0;
1160
1161         if (!skb_queue_empty(&entry->skb_list)) {
1162 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1163                 struct ieee80211_hdr *hdr =
1164                         (struct ieee80211_hdr *) entry->skb_list.next->data;
1165                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
1166                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
1167                        "addr1=%pM addr2=%pM\n",
1168                        sdata->name, idx,
1169                        jiffies - entry->first_frag_time, entry->seq,
1170                        entry->last_frag, hdr->addr1, hdr->addr2);
1171 #endif
1172                 __skb_queue_purge(&entry->skb_list);
1173         }
1174
1175         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
1176         *skb = NULL;
1177         entry->first_frag_time = jiffies;
1178         entry->seq = seq;
1179         entry->rx_queue = rx_queue;
1180         entry->last_frag = frag;
1181         entry->ccmp = 0;
1182         entry->extra_len = 0;
1183
1184         return entry;
1185 }
1186
1187 static inline struct ieee80211_fragment_entry *
1188 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
1189                           unsigned int frag, unsigned int seq,
1190                           int rx_queue, struct ieee80211_hdr *hdr)
1191 {
1192         struct ieee80211_fragment_entry *entry;
1193         int i, idx;
1194
1195         idx = sdata->fragment_next;
1196         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
1197                 struct ieee80211_hdr *f_hdr;
1198
1199                 idx--;
1200                 if (idx < 0)
1201                         idx = IEEE80211_FRAGMENT_MAX - 1;
1202
1203                 entry = &sdata->fragments[idx];
1204                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
1205                     entry->rx_queue != rx_queue ||
1206                     entry->last_frag + 1 != frag)
1207                         continue;
1208
1209                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
1210
1211                 /*
1212                  * Check ftype and addresses are equal, else check next fragment
1213                  */
1214                 if (((hdr->frame_control ^ f_hdr->frame_control) &
1215                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
1216                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
1217                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
1218                         continue;
1219
1220                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
1221                         __skb_queue_purge(&entry->skb_list);
1222                         continue;
1223                 }
1224                 return entry;
1225         }
1226
1227         return NULL;
1228 }
1229
1230 static ieee80211_rx_result debug_noinline
1231 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
1232 {
1233         struct ieee80211_hdr *hdr;
1234         u16 sc;
1235         __le16 fc;
1236         unsigned int frag, seq;
1237         struct ieee80211_fragment_entry *entry;
1238         struct sk_buff *skb;
1239
1240         hdr = (struct ieee80211_hdr *)rx->skb->data;
1241         fc = hdr->frame_control;
1242         sc = le16_to_cpu(hdr->seq_ctrl);
1243         frag = sc & IEEE80211_SCTL_FRAG;
1244
1245         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1246                    (rx->skb)->len < 24 ||
1247                    is_multicast_ether_addr(hdr->addr1))) {
1248                 /* not fragmented */
1249                 goto out;
1250         }
1251         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1252
1253         if (skb_linearize(rx->skb))
1254                 return RX_DROP_UNUSABLE;
1255
1256         /*
1257          *  skb_linearize() might change the skb->data and
1258          *  previously cached variables (in this case, hdr) need to
1259          *  be refreshed with the new data.
1260          */
1261         hdr = (struct ieee80211_hdr *)rx->skb->data;
1262         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1263
1264         if (frag == 0) {
1265                 /* This is the first fragment of a new frame. */
1266                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1267                                                  rx->queue, &(rx->skb));
1268                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
1269                     ieee80211_has_protected(fc)) {
1270                         int queue = ieee80211_is_mgmt(fc) ?
1271                                 NUM_RX_DATA_QUEUES : rx->queue;
1272                         /* Store CCMP PN so that we can verify that the next
1273                          * fragment has a sequential PN value. */
1274                         entry->ccmp = 1;
1275                         memcpy(entry->last_pn,
1276                                rx->key->u.ccmp.rx_pn[queue],
1277                                CCMP_PN_LEN);
1278                 }
1279                 return RX_QUEUED;
1280         }
1281
1282         /* This is a fragment for a frame that should already be pending in
1283          * fragment cache. Add this fragment to the end of the pending entry.
1284          */
1285         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1286         if (!entry) {
1287                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1288                 return RX_DROP_MONITOR;
1289         }
1290
1291         /* Verify that MPDUs within one MSDU have sequential PN values.
1292          * (IEEE 802.11i, 8.3.3.4.5) */
1293         if (entry->ccmp) {
1294                 int i;
1295                 u8 pn[CCMP_PN_LEN], *rpn;
1296                 int queue;
1297                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
1298                         return RX_DROP_UNUSABLE;
1299                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1300                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1301                         pn[i]++;
1302                         if (pn[i])
1303                                 break;
1304                 }
1305                 queue = ieee80211_is_mgmt(fc) ?
1306                         NUM_RX_DATA_QUEUES : rx->queue;
1307                 rpn = rx->key->u.ccmp.rx_pn[queue];
1308                 if (memcmp(pn, rpn, CCMP_PN_LEN))
1309                         return RX_DROP_UNUSABLE;
1310                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1311         }
1312
1313         skb_pull(rx->skb, ieee80211_hdrlen(fc));
1314         __skb_queue_tail(&entry->skb_list, rx->skb);
1315         entry->last_frag = frag;
1316         entry->extra_len += rx->skb->len;
1317         if (ieee80211_has_morefrags(fc)) {
1318                 rx->skb = NULL;
1319                 return RX_QUEUED;
1320         }
1321
1322         rx->skb = __skb_dequeue(&entry->skb_list);
1323         if (skb_tailroom(rx->skb) < entry->extra_len) {
1324                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1325                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1326                                               GFP_ATOMIC))) {
1327                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1328                         __skb_queue_purge(&entry->skb_list);
1329                         return RX_DROP_UNUSABLE;
1330                 }
1331         }
1332         while ((skb = __skb_dequeue(&entry->skb_list))) {
1333                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1334                 dev_kfree_skb(skb);
1335         }
1336
1337         /* Complete frame has been reassembled - process it now */
1338         rx->flags |= IEEE80211_RX_FRAGMENTED;
1339
1340  out:
1341         if (rx->sta)
1342                 rx->sta->rx_packets++;
1343         if (is_multicast_ether_addr(hdr->addr1))
1344                 rx->local->dot11MulticastReceivedFrameCount++;
1345         else
1346                 ieee80211_led_rx(rx->local);
1347         return RX_CONTINUE;
1348 }
1349
1350 static ieee80211_rx_result debug_noinline
1351 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1352 {
1353         struct ieee80211_sub_if_data *sdata = rx->sdata;
1354         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1355
1356         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1357                    !(rx->flags & IEEE80211_RX_RA_MATCH)))
1358                 return RX_CONTINUE;
1359
1360         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1361             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1362                 return RX_DROP_UNUSABLE;
1363
1364         if (!test_sta_flags(rx->sta, WLAN_STA_PS_DRIVER))
1365                 ieee80211_sta_ps_deliver_poll_response(rx->sta);
1366         else
1367                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1368
1369         /* Free PS Poll skb here instead of returning RX_DROP that would
1370          * count as an dropped frame. */
1371         dev_kfree_skb(rx->skb);
1372
1373         return RX_QUEUED;
1374 }
1375
1376 static ieee80211_rx_result debug_noinline
1377 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1378 {
1379         u8 *data = rx->skb->data;
1380         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1381
1382         if (!ieee80211_is_data_qos(hdr->frame_control))
1383                 return RX_CONTINUE;
1384
1385         /* remove the qos control field, update frame type and meta-data */
1386         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1387                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1388         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1389         /* change frame type to non QOS */
1390         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1391
1392         return RX_CONTINUE;
1393 }
1394
1395 static int
1396 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1397 {
1398         if (unlikely(!rx->sta ||
1399             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1400                 return -EACCES;
1401
1402         return 0;
1403 }
1404
1405 static int
1406 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1407 {
1408         struct sk_buff *skb = rx->skb;
1409         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1410
1411         /*
1412          * Pass through unencrypted frames if the hardware has
1413          * decrypted them already.
1414          */
1415         if (status->flag & RX_FLAG_DECRYPTED)
1416                 return 0;
1417
1418         /* Drop unencrypted frames if key is set. */
1419         if (unlikely(!ieee80211_has_protected(fc) &&
1420                      !ieee80211_is_nullfunc(fc) &&
1421                      ieee80211_is_data(fc) &&
1422                      (rx->key || rx->sdata->drop_unencrypted)))
1423                 return -EACCES;
1424
1425         return 0;
1426 }
1427
1428 static int
1429 ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
1430 {
1431         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1432         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1433         __le16 fc = hdr->frame_control;
1434
1435         /*
1436          * Pass through unencrypted frames if the hardware has
1437          * decrypted them already.
1438          */
1439         if (status->flag & RX_FLAG_DECRYPTED)
1440                 return 0;
1441
1442         if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1443                 if (unlikely(!ieee80211_has_protected(fc) &&
1444                              ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1445                              rx->key))
1446                         return -EACCES;
1447                 /* BIP does not use Protected field, so need to check MMIE */
1448                 if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1449                              ieee80211_get_mmie_keyidx(rx->skb) < 0))
1450                         return -EACCES;
1451                 /*
1452                  * When using MFP, Action frames are not allowed prior to
1453                  * having configured keys.
1454                  */
1455                 if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1456                              ieee80211_is_robust_mgmt_frame(
1457                                      (struct ieee80211_hdr *) rx->skb->data)))
1458                         return -EACCES;
1459         }
1460
1461         return 0;
1462 }
1463
1464 static int
1465 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1466 {
1467         struct ieee80211_sub_if_data *sdata = rx->sdata;
1468         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1469
1470         if (ieee80211_has_a4(hdr->frame_control) &&
1471             sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1472                 return -1;
1473
1474         if (is_multicast_ether_addr(hdr->addr1) &&
1475             ((sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta) ||
1476              (sdata->vif.type == NL80211_IFTYPE_STATION && sdata->u.mgd.use_4addr)))
1477                 return -1;
1478
1479         return ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
1480 }
1481
1482 /*
1483  * requires that rx->skb is a frame with ethernet header
1484  */
1485 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1486 {
1487         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1488                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1489         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1490
1491         /*
1492          * Allow EAPOL frames to us/the PAE group address regardless
1493          * of whether the frame was encrypted or not.
1494          */
1495         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1496             (compare_ether_addr(ehdr->h_dest, rx->sdata->vif.addr) == 0 ||
1497              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1498                 return true;
1499
1500         if (ieee80211_802_1x_port_control(rx) ||
1501             ieee80211_drop_unencrypted(rx, fc))
1502                 return false;
1503
1504         return true;
1505 }
1506
1507 /*
1508  * requires that rx->skb is a frame with ethernet header
1509  */
1510 static void
1511 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1512 {
1513         struct ieee80211_sub_if_data *sdata = rx->sdata;
1514         struct net_device *dev = sdata->dev;
1515         struct sk_buff *skb, *xmit_skb;
1516         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1517         struct sta_info *dsta;
1518
1519         skb = rx->skb;
1520         xmit_skb = NULL;
1521
1522         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1523              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1524             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1525             (rx->flags & IEEE80211_RX_RA_MATCH) &&
1526             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1527                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1528                         /*
1529                          * send multicast frames both to higher layers in
1530                          * local net stack and back to the wireless medium
1531                          */
1532                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1533                         if (!xmit_skb && net_ratelimit())
1534                                 printk(KERN_DEBUG "%s: failed to clone "
1535                                        "multicast frame\n", dev->name);
1536                 } else {
1537                         dsta = sta_info_get(sdata, skb->data);
1538                         if (dsta) {
1539                                 /*
1540                                  * The destination station is associated to
1541                                  * this AP (in this VLAN), so send the frame
1542                                  * directly to it and do not pass it to local
1543                                  * net stack.
1544                                  */
1545                                 xmit_skb = skb;
1546                                 skb = NULL;
1547                         }
1548                 }
1549         }
1550
1551         if (skb) {
1552                 int align __maybe_unused;
1553
1554 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1555                 /*
1556                  * 'align' will only take the values 0 or 2 here
1557                  * since all frames are required to be aligned
1558                  * to 2-byte boundaries when being passed to
1559                  * mac80211. That also explains the __skb_push()
1560                  * below.
1561                  */
1562                 align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1563                 if (align) {
1564                         if (WARN_ON(skb_headroom(skb) < 3)) {
1565                                 dev_kfree_skb(skb);
1566                                 skb = NULL;
1567                         } else {
1568                                 u8 *data = skb->data;
1569                                 size_t len = skb_headlen(skb);
1570                                 skb->data -= align;
1571                                 memmove(skb->data, data, len);
1572                                 skb_set_tail_pointer(skb, len);
1573                         }
1574                 }
1575 #endif
1576
1577                 if (skb) {
1578                         /* deliver to local stack */
1579                         skb->protocol = eth_type_trans(skb, dev);
1580                         memset(skb->cb, 0, sizeof(skb->cb));
1581                         netif_receive_skb(skb);
1582                 }
1583         }
1584
1585         if (xmit_skb) {
1586                 /* send to wireless media */
1587                 xmit_skb->protocol = htons(ETH_P_802_3);
1588                 skb_reset_network_header(xmit_skb);
1589                 skb_reset_mac_header(xmit_skb);
1590                 dev_queue_xmit(xmit_skb);
1591         }
1592 }
1593
1594 static ieee80211_rx_result debug_noinline
1595 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1596 {
1597         struct net_device *dev = rx->sdata->dev;
1598         struct sk_buff *skb = rx->skb;
1599         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1600         __le16 fc = hdr->frame_control;
1601         struct sk_buff_head frame_list;
1602
1603         if (unlikely(!ieee80211_is_data(fc)))
1604                 return RX_CONTINUE;
1605
1606         if (unlikely(!ieee80211_is_data_present(fc)))
1607                 return RX_DROP_MONITOR;
1608
1609         if (!(rx->flags & IEEE80211_RX_AMSDU))
1610                 return RX_CONTINUE;
1611
1612         if (ieee80211_has_a4(hdr->frame_control) &&
1613             rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1614             !rx->sdata->u.vlan.sta)
1615                 return RX_DROP_UNUSABLE;
1616
1617         if (is_multicast_ether_addr(hdr->addr1) &&
1618             ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1619               rx->sdata->u.vlan.sta) ||
1620              (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1621               rx->sdata->u.mgd.use_4addr)))
1622                 return RX_DROP_UNUSABLE;
1623
1624         skb->dev = dev;
1625         __skb_queue_head_init(&frame_list);
1626
1627         if (skb_linearize(skb))
1628                 return RX_DROP_UNUSABLE;
1629
1630         ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
1631                                  rx->sdata->vif.type,
1632                                  rx->local->hw.extra_tx_headroom);
1633
1634         while (!skb_queue_empty(&frame_list)) {
1635                 rx->skb = __skb_dequeue(&frame_list);
1636
1637                 if (!ieee80211_frame_allowed(rx, fc)) {
1638                         dev_kfree_skb(rx->skb);
1639                         continue;
1640                 }
1641                 dev->stats.rx_packets++;
1642                 dev->stats.rx_bytes += rx->skb->len;
1643
1644                 ieee80211_deliver_skb(rx);
1645         }
1646
1647         return RX_QUEUED;
1648 }
1649
1650 #ifdef CONFIG_MAC80211_MESH
1651 static ieee80211_rx_result
1652 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1653 {
1654         struct ieee80211_hdr *hdr;
1655         struct ieee80211s_hdr *mesh_hdr;
1656         unsigned int hdrlen;
1657         struct sk_buff *skb = rx->skb, *fwd_skb;
1658         struct ieee80211_local *local = rx->local;
1659         struct ieee80211_sub_if_data *sdata = rx->sdata;
1660
1661         hdr = (struct ieee80211_hdr *) skb->data;
1662         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1663         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1664
1665         if (!ieee80211_is_data(hdr->frame_control))
1666                 return RX_CONTINUE;
1667
1668         if (!mesh_hdr->ttl)
1669                 /* illegal frame */
1670                 return RX_DROP_MONITOR;
1671
1672         if (mesh_hdr->flags & MESH_FLAGS_AE) {
1673                 struct mesh_path *mppath;
1674                 char *proxied_addr;
1675                 char *mpp_addr;
1676
1677                 if (is_multicast_ether_addr(hdr->addr1)) {
1678                         mpp_addr = hdr->addr3;
1679                         proxied_addr = mesh_hdr->eaddr1;
1680                 } else {
1681                         mpp_addr = hdr->addr4;
1682                         proxied_addr = mesh_hdr->eaddr2;
1683                 }
1684
1685                 rcu_read_lock();
1686                 mppath = mpp_path_lookup(proxied_addr, sdata);
1687                 if (!mppath) {
1688                         mpp_path_add(proxied_addr, mpp_addr, sdata);
1689                 } else {
1690                         spin_lock_bh(&mppath->state_lock);
1691                         if (compare_ether_addr(mppath->mpp, mpp_addr) != 0)
1692                                 memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
1693                         spin_unlock_bh(&mppath->state_lock);
1694                 }
1695                 rcu_read_unlock();
1696         }
1697
1698         /* Frame has reached destination.  Don't forward */
1699         if (!is_multicast_ether_addr(hdr->addr1) &&
1700             compare_ether_addr(sdata->vif.addr, hdr->addr3) == 0)
1701                 return RX_CONTINUE;
1702
1703         mesh_hdr->ttl--;
1704
1705         if (rx->flags & IEEE80211_RX_RA_MATCH) {
1706                 if (!mesh_hdr->ttl)
1707                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1708                                                      dropped_frames_ttl);
1709                 else {
1710                         struct ieee80211_hdr *fwd_hdr;
1711                         struct ieee80211_tx_info *info;
1712
1713                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1714
1715                         if (!fwd_skb && net_ratelimit())
1716                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1717                                                    sdata->name);
1718
1719                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1720                         memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
1721                         info = IEEE80211_SKB_CB(fwd_skb);
1722                         memset(info, 0, sizeof(*info));
1723                         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1724                         info->control.vif = &rx->sdata->vif;
1725                         skb_set_queue_mapping(skb,
1726                                 ieee80211_select_queue(rx->sdata, fwd_skb));
1727                         ieee80211_set_qos_hdr(local, skb);
1728                         if (is_multicast_ether_addr(fwd_hdr->addr1))
1729                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1730                                                                 fwded_mcast);
1731                         else {
1732                                 int err;
1733                                 /*
1734                                  * Save TA to addr1 to send TA a path error if a
1735                                  * suitable next hop is not found
1736                                  */
1737                                 memcpy(fwd_hdr->addr1, fwd_hdr->addr2,
1738                                                 ETH_ALEN);
1739                                 err = mesh_nexthop_lookup(fwd_skb, sdata);
1740                                 /* Failed to immediately resolve next hop:
1741                                  * fwded frame was dropped or will be added
1742                                  * later to the pending skb queue.  */
1743                                 if (err)
1744                                         return RX_DROP_MONITOR;
1745
1746                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1747                                                                 fwded_unicast);
1748                         }
1749                         IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1750                                                      fwded_frames);
1751                         ieee80211_add_pending_skb(local, fwd_skb);
1752                 }
1753         }
1754
1755         if (is_multicast_ether_addr(hdr->addr1) ||
1756             sdata->dev->flags & IFF_PROMISC)
1757                 return RX_CONTINUE;
1758         else
1759                 return RX_DROP_MONITOR;
1760 }
1761 #endif
1762
1763 static ieee80211_rx_result debug_noinline
1764 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1765 {
1766         struct ieee80211_sub_if_data *sdata = rx->sdata;
1767         struct ieee80211_local *local = rx->local;
1768         struct net_device *dev = sdata->dev;
1769         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1770         __le16 fc = hdr->frame_control;
1771         int err;
1772
1773         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1774                 return RX_CONTINUE;
1775
1776         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1777                 return RX_DROP_MONITOR;
1778
1779         /*
1780          * Allow the cooked monitor interface of an AP to see 4-addr frames so
1781          * that a 4-addr station can be detected and moved into a separate VLAN
1782          */
1783         if (ieee80211_has_a4(hdr->frame_control) &&
1784             sdata->vif.type == NL80211_IFTYPE_AP)
1785                 return RX_DROP_MONITOR;
1786
1787         err = __ieee80211_data_to_8023(rx);
1788         if (unlikely(err))
1789                 return RX_DROP_UNUSABLE;
1790
1791         if (!ieee80211_frame_allowed(rx, fc))
1792                 return RX_DROP_MONITOR;
1793
1794         rx->skb->dev = dev;
1795
1796         dev->stats.rx_packets++;
1797         dev->stats.rx_bytes += rx->skb->len;
1798
1799         if (ieee80211_is_data(hdr->frame_control) &&
1800             !is_multicast_ether_addr(hdr->addr1) &&
1801             local->hw.conf.dynamic_ps_timeout > 0 && local->ps_sdata) {
1802                         mod_timer(&local->dynamic_ps_timer, jiffies +
1803                          msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
1804         }
1805
1806         ieee80211_deliver_skb(rx);
1807
1808         return RX_QUEUED;
1809 }
1810
1811 static ieee80211_rx_result debug_noinline
1812 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames)
1813 {
1814         struct ieee80211_local *local = rx->local;
1815         struct ieee80211_hw *hw = &local->hw;
1816         struct sk_buff *skb = rx->skb;
1817         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1818         struct tid_ampdu_rx *tid_agg_rx;
1819         u16 start_seq_num;
1820         u16 tid;
1821
1822         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1823                 return RX_CONTINUE;
1824
1825         if (ieee80211_is_back_req(bar->frame_control)) {
1826                 struct {
1827                         __le16 control, start_seq_num;
1828                 } __packed bar_data;
1829
1830                 if (!rx->sta)
1831                         return RX_DROP_MONITOR;
1832
1833                 if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
1834                                   &bar_data, sizeof(bar_data)))
1835                         return RX_DROP_MONITOR;
1836
1837                 tid = le16_to_cpu(bar_data.control) >> 12;
1838
1839                 tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
1840                 if (!tid_agg_rx)
1841                         return RX_DROP_MONITOR;
1842
1843                 start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
1844
1845                 /* reset session timer */
1846                 if (tid_agg_rx->timeout)
1847                         mod_timer(&tid_agg_rx->session_timer,
1848                                   TU_TO_EXP_TIME(tid_agg_rx->timeout));
1849
1850                 /* release stored frames up to start of BAR */
1851                 ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num,
1852                                                  frames);
1853                 kfree_skb(skb);
1854                 return RX_QUEUED;
1855         }
1856
1857         /*
1858          * After this point, we only want management frames,
1859          * so we can drop all remaining control frames to
1860          * cooked monitor interfaces.
1861          */
1862         return RX_DROP_MONITOR;
1863 }
1864
1865 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
1866                                            struct ieee80211_mgmt *mgmt,
1867                                            size_t len)
1868 {
1869         struct ieee80211_local *local = sdata->local;
1870         struct sk_buff *skb;
1871         struct ieee80211_mgmt *resp;
1872
1873         if (compare_ether_addr(mgmt->da, sdata->vif.addr) != 0) {
1874                 /* Not to own unicast address */
1875                 return;
1876         }
1877
1878         if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
1879             compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
1880                 /* Not from the current AP or not associated yet. */
1881                 return;
1882         }
1883
1884         if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
1885                 /* Too short SA Query request frame */
1886                 return;
1887         }
1888
1889         skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
1890         if (skb == NULL)
1891                 return;
1892
1893         skb_reserve(skb, local->hw.extra_tx_headroom);
1894         resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
1895         memset(resp, 0, 24);
1896         memcpy(resp->da, mgmt->sa, ETH_ALEN);
1897         memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
1898         memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
1899         resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1900                                           IEEE80211_STYPE_ACTION);
1901         skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
1902         resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
1903         resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
1904         memcpy(resp->u.action.u.sa_query.trans_id,
1905                mgmt->u.action.u.sa_query.trans_id,
1906                WLAN_SA_QUERY_TR_ID_LEN);
1907
1908         ieee80211_tx_skb(sdata, skb);
1909 }
1910
1911 static ieee80211_rx_result debug_noinline
1912 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1913 {
1914         struct ieee80211_local *local = rx->local;
1915         struct ieee80211_sub_if_data *sdata = rx->sdata;
1916         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1917         struct sk_buff *nskb;
1918         struct ieee80211_rx_status *status;
1919         int len = rx->skb->len;
1920
1921         if (!ieee80211_is_action(mgmt->frame_control))
1922                 return RX_CONTINUE;
1923
1924         /* drop too small frames */
1925         if (len < IEEE80211_MIN_ACTION_SIZE)
1926                 return RX_DROP_UNUSABLE;
1927
1928         if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC)
1929                 return RX_DROP_UNUSABLE;
1930
1931         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1932                 return RX_DROP_UNUSABLE;
1933
1934         if (ieee80211_drop_unencrypted_mgmt(rx))
1935                 return RX_DROP_UNUSABLE;
1936
1937         switch (mgmt->u.action.category) {
1938         case WLAN_CATEGORY_BACK:
1939                 /*
1940                  * The aggregation code is not prepared to handle
1941                  * anything but STA/AP due to the BSSID handling;
1942                  * IBSS could work in the code but isn't supported
1943                  * by drivers or the standard.
1944                  */
1945                 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1946                     sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
1947                     sdata->vif.type != NL80211_IFTYPE_AP)
1948                         break;
1949
1950                 /* verify action_code is present */
1951                 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1952                         break;
1953
1954                 switch (mgmt->u.action.u.addba_req.action_code) {
1955                 case WLAN_ACTION_ADDBA_REQ:
1956                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1957                                    sizeof(mgmt->u.action.u.addba_req)))
1958                                 goto invalid;
1959                         break;
1960                 case WLAN_ACTION_ADDBA_RESP:
1961                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1962                                    sizeof(mgmt->u.action.u.addba_resp)))
1963                                 goto invalid;
1964                         break;
1965                 case WLAN_ACTION_DELBA:
1966                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1967                                    sizeof(mgmt->u.action.u.delba)))
1968                                 goto invalid;
1969                         break;
1970                 default:
1971                         goto invalid;
1972                 }
1973
1974                 goto queue;
1975         case WLAN_CATEGORY_SPECTRUM_MGMT:
1976                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
1977                         break;
1978
1979                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
1980                         break;
1981
1982                 /* verify action_code is present */
1983                 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1984                         break;
1985
1986                 switch (mgmt->u.action.u.measurement.action_code) {
1987                 case WLAN_ACTION_SPCT_MSR_REQ:
1988                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1989                                    sizeof(mgmt->u.action.u.measurement)))
1990                                 break;
1991                         ieee80211_process_measurement_req(sdata, mgmt, len);
1992                         goto handled;
1993                 case WLAN_ACTION_SPCT_CHL_SWITCH:
1994                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1995                                    sizeof(mgmt->u.action.u.chan_switch)))
1996                                 break;
1997
1998                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1999                                 break;
2000
2001                         if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
2002                                 break;
2003
2004                         goto queue;
2005                 }
2006                 break;
2007         case WLAN_CATEGORY_SA_QUERY:
2008                 if (len < (IEEE80211_MIN_ACTION_SIZE +
2009                            sizeof(mgmt->u.action.u.sa_query)))
2010                         break;
2011
2012                 switch (mgmt->u.action.u.sa_query.action) {
2013                 case WLAN_ACTION_SA_QUERY_REQUEST:
2014                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
2015                                 break;
2016                         ieee80211_process_sa_query_req(sdata, mgmt, len);
2017                         goto handled;
2018                 }
2019                 break;
2020         case WLAN_CATEGORY_MESH_PLINK:
2021         case WLAN_CATEGORY_MESH_PATH_SEL:
2022                 if (!ieee80211_vif_is_mesh(&sdata->vif))
2023                         break;
2024                 goto queue;
2025         }
2026
2027  invalid:
2028         /*
2029          * For AP mode, hostapd is responsible for handling any action
2030          * frames that we didn't handle, including returning unknown
2031          * ones. For all other modes we will return them to the sender,
2032          * setting the 0x80 bit in the action category, as required by
2033          * 802.11-2007 7.3.1.11.
2034          */
2035         if (sdata->vif.type == NL80211_IFTYPE_AP ||
2036             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2037                 return RX_DROP_MONITOR;
2038
2039         /*
2040          * Getting here means the kernel doesn't know how to handle
2041          * it, but maybe userspace does ... include returned frames
2042          * so userspace can register for those to know whether ones
2043          * it transmitted were processed or returned.
2044          */
2045         status = IEEE80211_SKB_RXCB(rx->skb);
2046
2047         if (cfg80211_rx_action(rx->sdata->dev, status->freq,
2048                                rx->skb->data, rx->skb->len,
2049                                GFP_ATOMIC))
2050                 goto handled;
2051
2052         /* do not return rejected action frames */
2053         if (mgmt->u.action.category & 0x80)
2054                 return RX_DROP_UNUSABLE;
2055
2056         nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
2057                                GFP_ATOMIC);
2058         if (nskb) {
2059                 struct ieee80211_mgmt *nmgmt = (void *)nskb->data;
2060
2061                 nmgmt->u.action.category |= 0x80;
2062                 memcpy(nmgmt->da, nmgmt->sa, ETH_ALEN);
2063                 memcpy(nmgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
2064
2065                 memset(nskb->cb, 0, sizeof(nskb->cb));
2066
2067                 ieee80211_tx_skb(rx->sdata, nskb);
2068         }
2069
2070  handled:
2071         if (rx->sta)
2072                 rx->sta->rx_packets++;
2073         dev_kfree_skb(rx->skb);
2074         return RX_QUEUED;
2075
2076  queue:
2077         rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2078         skb_queue_tail(&sdata->skb_queue, rx->skb);
2079         ieee80211_queue_work(&local->hw, &sdata->work);
2080         if (rx->sta)
2081                 rx->sta->rx_packets++;
2082         return RX_QUEUED;
2083 }
2084
2085 static ieee80211_rx_result debug_noinline
2086 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
2087 {
2088         struct ieee80211_sub_if_data *sdata = rx->sdata;
2089         ieee80211_rx_result rxs;
2090         struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
2091         __le16 stype;
2092
2093         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
2094                 return RX_DROP_MONITOR;
2095
2096         if (rx->skb->len < 24)
2097                 return RX_DROP_MONITOR;
2098
2099         if (ieee80211_drop_unencrypted_mgmt(rx))
2100                 return RX_DROP_UNUSABLE;
2101
2102         rxs = ieee80211_work_rx_mgmt(rx->sdata, rx->skb);
2103         if (rxs != RX_CONTINUE)
2104                 return rxs;
2105
2106         stype = mgmt->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE);
2107
2108         if (!ieee80211_vif_is_mesh(&sdata->vif) &&
2109             sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2110             sdata->vif.type != NL80211_IFTYPE_STATION)
2111                 return RX_DROP_MONITOR;
2112
2113         switch (stype) {
2114         case cpu_to_le16(IEEE80211_STYPE_BEACON):
2115         case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
2116                 /* process for all: mesh, mlme, ibss */
2117                 break;
2118         case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
2119         case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
2120                 /* process only for station */
2121                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
2122                         return RX_DROP_MONITOR;
2123                 break;
2124         case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
2125         case cpu_to_le16(IEEE80211_STYPE_AUTH):
2126                 /* process only for ibss */
2127                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
2128                         return RX_DROP_MONITOR;
2129                 break;
2130         default:
2131                 return RX_DROP_MONITOR;
2132         }
2133
2134         /* queue up frame and kick off work to process it */
2135         rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2136         skb_queue_tail(&sdata->skb_queue, rx->skb);
2137         ieee80211_queue_work(&rx->local->hw, &sdata->work);
2138         if (rx->sta)
2139                 rx->sta->rx_packets++;
2140
2141         return RX_QUEUED;
2142 }
2143
2144 static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
2145                                             struct ieee80211_rx_data *rx)
2146 {
2147         int keyidx;
2148         unsigned int hdrlen;
2149
2150         hdrlen = ieee80211_hdrlen(hdr->frame_control);
2151         if (rx->skb->len >= hdrlen + 4)
2152                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
2153         else
2154                 keyidx = -1;
2155
2156         if (!rx->sta) {
2157                 /*
2158                  * Some hardware seem to generate incorrect Michael MIC
2159                  * reports; ignore them to avoid triggering countermeasures.
2160                  */
2161                 return;
2162         }
2163
2164         if (!ieee80211_has_protected(hdr->frame_control))
2165                 return;
2166
2167         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
2168                 /*
2169                  * APs with pairwise keys should never receive Michael MIC
2170                  * errors for non-zero keyidx because these are reserved for
2171                  * group keys and only the AP is sending real multicast
2172                  * frames in the BSS.
2173                  */
2174                 return;
2175         }
2176
2177         if (!ieee80211_is_data(hdr->frame_control) &&
2178             !ieee80211_is_auth(hdr->frame_control))
2179                 return;
2180
2181         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
2182                                         GFP_ATOMIC);
2183 }
2184
2185 /* TODO: use IEEE80211_RX_FRAGMENTED */
2186 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
2187                                         struct ieee80211_rate *rate)
2188 {
2189         struct ieee80211_sub_if_data *sdata;
2190         struct ieee80211_local *local = rx->local;
2191         struct ieee80211_rtap_hdr {
2192                 struct ieee80211_radiotap_header hdr;
2193                 u8 flags;
2194                 u8 rate_or_pad;
2195                 __le16 chan_freq;
2196                 __le16 chan_flags;
2197         } __packed *rthdr;
2198         struct sk_buff *skb = rx->skb, *skb2;
2199         struct net_device *prev_dev = NULL;
2200         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2201
2202         if (skb_headroom(skb) < sizeof(*rthdr) &&
2203             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
2204                 goto out_free_skb;
2205
2206         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
2207         memset(rthdr, 0, sizeof(*rthdr));
2208         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
2209         rthdr->hdr.it_present =
2210                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
2211                             (1 << IEEE80211_RADIOTAP_CHANNEL));
2212
2213         if (rate) {
2214                 rthdr->rate_or_pad = rate->bitrate / 5;
2215                 rthdr->hdr.it_present |=
2216                         cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
2217         }
2218         rthdr->chan_freq = cpu_to_le16(status->freq);
2219
2220         if (status->band == IEEE80211_BAND_5GHZ)
2221                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
2222                                                 IEEE80211_CHAN_5GHZ);
2223         else
2224                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
2225                                                 IEEE80211_CHAN_2GHZ);
2226
2227         skb_set_mac_header(skb, 0);
2228         skb->ip_summed = CHECKSUM_UNNECESSARY;
2229         skb->pkt_type = PACKET_OTHERHOST;
2230         skb->protocol = htons(ETH_P_802_2);
2231
2232         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2233                 if (!ieee80211_sdata_running(sdata))
2234                         continue;
2235
2236                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
2237                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
2238                         continue;
2239
2240                 if (prev_dev) {
2241                         skb2 = skb_clone(skb, GFP_ATOMIC);
2242                         if (skb2) {
2243                                 skb2->dev = prev_dev;
2244                                 netif_receive_skb(skb2);
2245                         }
2246                 }
2247
2248                 prev_dev = sdata->dev;
2249                 sdata->dev->stats.rx_packets++;
2250                 sdata->dev->stats.rx_bytes += skb->len;
2251         }
2252
2253         if (prev_dev) {
2254                 skb->dev = prev_dev;
2255                 netif_receive_skb(skb);
2256                 skb = NULL;
2257         } else
2258                 goto out_free_skb;
2259
2260         return;
2261
2262  out_free_skb:
2263         dev_kfree_skb(skb);
2264 }
2265
2266
2267 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
2268                                          struct ieee80211_rx_data *rx,
2269                                          struct sk_buff *skb,
2270                                          struct ieee80211_rate *rate)
2271 {
2272         struct sk_buff_head reorder_release;
2273         ieee80211_rx_result res = RX_DROP_MONITOR;
2274
2275         __skb_queue_head_init(&reorder_release);
2276
2277         rx->skb = skb;
2278         rx->sdata = sdata;
2279
2280 #define CALL_RXH(rxh)                   \
2281         do {                            \
2282                 res = rxh(rx);          \
2283                 if (res != RX_CONTINUE) \
2284                         goto rxh_next;  \
2285         } while (0);
2286
2287         /*
2288          * NB: the rxh_next label works even if we jump
2289          *     to it from here because then the list will
2290          *     be empty, which is a trivial check
2291          */
2292         CALL_RXH(ieee80211_rx_h_passive_scan)
2293         CALL_RXH(ieee80211_rx_h_check)
2294
2295         ieee80211_rx_reorder_ampdu(rx, &reorder_release);
2296
2297         while ((skb = __skb_dequeue(&reorder_release))) {
2298                 /*
2299                  * all the other fields are valid across frames
2300                  * that belong to an aMPDU since they are on the
2301                  * same TID from the same station
2302                  */
2303                 rx->skb = skb;
2304
2305                 CALL_RXH(ieee80211_rx_h_decrypt)
2306                 CALL_RXH(ieee80211_rx_h_check_more_data)
2307                 CALL_RXH(ieee80211_rx_h_sta_process)
2308                 CALL_RXH(ieee80211_rx_h_defragment)
2309                 CALL_RXH(ieee80211_rx_h_ps_poll)
2310                 CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2311                 /* must be after MMIC verify so header is counted in MPDU mic */
2312                 CALL_RXH(ieee80211_rx_h_remove_qos_control)
2313                 CALL_RXH(ieee80211_rx_h_amsdu)
2314 #ifdef CONFIG_MAC80211_MESH
2315                 if (ieee80211_vif_is_mesh(&sdata->vif))
2316                         CALL_RXH(ieee80211_rx_h_mesh_fwding);
2317 #endif
2318                 CALL_RXH(ieee80211_rx_h_data)
2319
2320                 /* special treatment -- needs the queue */
2321                 res = ieee80211_rx_h_ctrl(rx, &reorder_release);
2322                 if (res != RX_CONTINUE)
2323                         goto rxh_next;
2324
2325                 CALL_RXH(ieee80211_rx_h_action)
2326                 CALL_RXH(ieee80211_rx_h_mgmt)
2327
2328 #undef CALL_RXH
2329
2330  rxh_next:
2331                 switch (res) {
2332                 case RX_DROP_MONITOR:
2333                         I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2334                         if (rx->sta)
2335                                 rx->sta->rx_dropped++;
2336                         /* fall through */
2337                 case RX_CONTINUE:
2338                         ieee80211_rx_cooked_monitor(rx, rate);
2339                         break;
2340                 case RX_DROP_UNUSABLE:
2341                         I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2342                         if (rx->sta)
2343                                 rx->sta->rx_dropped++;
2344                         dev_kfree_skb(rx->skb);
2345                         break;
2346                 case RX_QUEUED:
2347                         I802_DEBUG_INC(sdata->local->rx_handlers_queued);
2348                         break;
2349                 }
2350         }
2351 }
2352
2353 /* main receive path */
2354
2355 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
2356                                 struct ieee80211_rx_data *rx,
2357                                 struct ieee80211_hdr *hdr)
2358 {
2359         struct sk_buff *skb = rx->skb;
2360         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2361         u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
2362         int multicast = is_multicast_ether_addr(hdr->addr1);
2363
2364         switch (sdata->vif.type) {
2365         case NL80211_IFTYPE_STATION:
2366                 if (!bssid && !sdata->u.mgd.use_4addr)
2367                         return 0;
2368                 if (!multicast &&
2369                     compare_ether_addr(sdata->vif.addr, hdr->addr1) != 0) {
2370                         if (!(sdata->dev->flags & IFF_PROMISC))
2371                                 return 0;
2372                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2373                 }
2374                 break;
2375         case NL80211_IFTYPE_ADHOC:
2376                 if (!bssid)
2377                         return 0;
2378                 if (ieee80211_is_beacon(hdr->frame_control)) {
2379                         return 1;
2380                 }
2381                 else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2382                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2383                                 return 0;
2384                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2385                 } else if (!multicast &&
2386                            compare_ether_addr(sdata->vif.addr,
2387                                               hdr->addr1) != 0) {
2388                         if (!(sdata->dev->flags & IFF_PROMISC))
2389                                 return 0;
2390                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2391                 } else if (!rx->sta) {
2392                         int rate_idx;
2393                         if (status->flag & RX_FLAG_HT)
2394                                 rate_idx = 0; /* TODO: HT rates */
2395                         else
2396                                 rate_idx = status->rate_idx;
2397                         rx->sta = ieee80211_ibss_add_sta(sdata, bssid,
2398                                         hdr->addr2, BIT(rate_idx), GFP_ATOMIC);
2399                 }
2400                 break;
2401         case NL80211_IFTYPE_MESH_POINT:
2402                 if (!multicast &&
2403                     compare_ether_addr(sdata->vif.addr,
2404                                        hdr->addr1) != 0) {
2405                         if (!(sdata->dev->flags & IFF_PROMISC))
2406                                 return 0;
2407
2408                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2409                 }
2410                 break;
2411         case NL80211_IFTYPE_AP_VLAN:
2412         case NL80211_IFTYPE_AP:
2413                 if (!bssid) {
2414                         if (compare_ether_addr(sdata->vif.addr,
2415                                                hdr->addr1))
2416                                 return 0;
2417                 } else if (!ieee80211_bssid_match(bssid,
2418                                         sdata->vif.addr)) {
2419                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2420                                 return 0;
2421                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2422                 }
2423                 break;
2424         case NL80211_IFTYPE_WDS:
2425                 if (bssid || !ieee80211_is_data(hdr->frame_control))
2426                         return 0;
2427                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2428                         return 0;
2429                 break;
2430         case NL80211_IFTYPE_MONITOR:
2431         case NL80211_IFTYPE_UNSPECIFIED:
2432         case __NL80211_IFTYPE_AFTER_LAST:
2433                 /* should never get here */
2434                 WARN_ON(1);
2435                 break;
2436         }
2437
2438         return 1;
2439 }
2440
2441 /*
2442  * This is the actual Rx frames handler. as it blongs to Rx path it must
2443  * be called with rcu_read_lock protection.
2444  */
2445 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2446                                          struct sk_buff *skb,
2447                                          struct ieee80211_rate *rate)
2448 {
2449         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2450         struct ieee80211_local *local = hw_to_local(hw);
2451         struct ieee80211_sub_if_data *sdata;
2452         struct ieee80211_hdr *hdr;
2453         __le16 fc;
2454         struct ieee80211_rx_data rx;
2455         int prepares;
2456         struct ieee80211_sub_if_data *prev = NULL;
2457         struct sk_buff *skb_new;
2458         struct sta_info *sta, *tmp;
2459         bool found_sta = false;
2460         int err = 0;
2461
2462         fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
2463         memset(&rx, 0, sizeof(rx));
2464         rx.skb = skb;
2465         rx.local = local;
2466
2467         if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
2468                 local->dot11ReceivedFragmentCount++;
2469
2470         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
2471                      test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
2472                 rx.flags |= IEEE80211_RX_IN_SCAN;
2473
2474         if (ieee80211_is_mgmt(fc))
2475                 err = skb_linearize(skb);
2476         else
2477                 err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
2478
2479         if (err) {
2480                 dev_kfree_skb(skb);
2481                 return;
2482         }
2483
2484         hdr = (struct ieee80211_hdr *)skb->data;
2485         ieee80211_parse_qos(&rx);
2486         ieee80211_verify_alignment(&rx);
2487
2488         if (ieee80211_is_data(fc)) {
2489                 for_each_sta_info(local, hdr->addr2, sta, tmp) {
2490                         rx.sta = sta;
2491                         found_sta = true;
2492                         rx.sdata = sta->sdata;
2493
2494                         rx.flags |= IEEE80211_RX_RA_MATCH;
2495                         prepares = prepare_for_handlers(rx.sdata, &rx, hdr);
2496                         if (prepares) {
2497                                 if (status->flag & RX_FLAG_MMIC_ERROR) {
2498                                         if (rx.flags & IEEE80211_RX_RA_MATCH)
2499                                                 ieee80211_rx_michael_mic_report(hdr, &rx);
2500                                 } else
2501                                         prev = rx.sdata;
2502                         }
2503                 }
2504         }
2505         if (!found_sta) {
2506                 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2507                         if (!ieee80211_sdata_running(sdata))
2508                                 continue;
2509
2510                         if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2511                             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2512                                 continue;
2513
2514                         /*
2515                          * frame is destined for this interface, but if it's
2516                          * not also for the previous one we handle that after
2517                          * the loop to avoid copying the SKB once too much
2518                          */
2519
2520                         if (!prev) {
2521                                 prev = sdata;
2522                                 continue;
2523                         }
2524
2525                         rx.sta = sta_info_get_bss(prev, hdr->addr2);
2526
2527                         rx.flags |= IEEE80211_RX_RA_MATCH;
2528                         prepares = prepare_for_handlers(prev, &rx, hdr);
2529
2530                         if (!prepares)
2531                                 goto next;
2532
2533                         if (status->flag & RX_FLAG_MMIC_ERROR) {
2534                                 rx.sdata = prev;
2535                                 if (rx.flags & IEEE80211_RX_RA_MATCH)
2536                                         ieee80211_rx_michael_mic_report(hdr,
2537                                                                         &rx);
2538                                 goto next;
2539                         }
2540
2541                         /*
2542                          * frame was destined for the previous interface
2543                          * so invoke RX handlers for it
2544                          */
2545
2546                         skb_new = skb_copy(skb, GFP_ATOMIC);
2547                         if (!skb_new) {
2548                                 if (net_ratelimit())
2549                                         printk(KERN_DEBUG "%s: failed to copy "
2550                                                "multicast frame for %s\n",
2551                                                wiphy_name(local->hw.wiphy),
2552                                                prev->name);
2553                                 goto next;
2554                         }
2555                         ieee80211_invoke_rx_handlers(prev, &rx, skb_new, rate);
2556 next:
2557                         prev = sdata;
2558                 }
2559
2560                 if (prev) {
2561                         rx.sta = sta_info_get_bss(prev, hdr->addr2);
2562
2563                         rx.flags |= IEEE80211_RX_RA_MATCH;
2564                         prepares = prepare_for_handlers(prev, &rx, hdr);
2565
2566                         if (!prepares)
2567                                 prev = NULL;
2568                 }
2569         }
2570         if (prev)
2571                 ieee80211_invoke_rx_handlers(prev, &rx, skb, rate);
2572         else
2573                 dev_kfree_skb(skb);
2574 }
2575
2576 /*
2577  * This is the receive path handler. It is called by a low level driver when an
2578  * 802.11 MPDU is received from the hardware.
2579  */
2580 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2581 {
2582         struct ieee80211_local *local = hw_to_local(hw);
2583         struct ieee80211_rate *rate = NULL;
2584         struct ieee80211_supported_band *sband;
2585         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2586
2587         WARN_ON_ONCE(softirq_count() == 0);
2588
2589         if (WARN_ON(status->band < 0 ||
2590                     status->band >= IEEE80211_NUM_BANDS))
2591                 goto drop;
2592
2593         sband = local->hw.wiphy->bands[status->band];
2594         if (WARN_ON(!sband))
2595                 goto drop;
2596
2597         /*
2598          * If we're suspending, it is possible although not too likely
2599          * that we'd be receiving frames after having already partially
2600          * quiesced the stack. We can't process such frames then since
2601          * that might, for example, cause stations to be added or other
2602          * driver callbacks be invoked.
2603          */
2604         if (unlikely(local->quiescing || local->suspended))
2605                 goto drop;
2606
2607         /*
2608          * The same happens when we're not even started,
2609          * but that's worth a warning.
2610          */
2611         if (WARN_ON(!local->started))
2612                 goto drop;
2613
2614         if (status->flag & RX_FLAG_HT) {
2615                 /*
2616                  * rate_idx is MCS index, which can be [0-76] as documented on:
2617                  *
2618                  * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
2619                  *
2620                  * Anything else would be some sort of driver or hardware error.
2621                  * The driver should catch hardware errors.
2622                  */
2623                 if (WARN((status->rate_idx < 0 ||
2624                          status->rate_idx > 76),
2625                          "Rate marked as an HT rate but passed "
2626                          "status->rate_idx is not "
2627                          "an MCS index [0-76]: %d (0x%02x)\n",
2628                          status->rate_idx,
2629                          status->rate_idx))
2630                         goto drop;
2631         } else {
2632                 if (WARN_ON(status->rate_idx < 0 ||
2633                             status->rate_idx >= sband->n_bitrates))
2634                         goto drop;
2635                 rate = &sband->bitrates[status->rate_idx];
2636         }
2637
2638         /*
2639          * key references and virtual interfaces are protected using RCU
2640          * and this requires that we are in a read-side RCU section during
2641          * receive processing
2642          */
2643         rcu_read_lock();
2644
2645         /*
2646          * Frames with failed FCS/PLCP checksum are not returned,
2647          * all other frames are returned without radiotap header
2648          * if it was previously present.
2649          * Also, frames with less than 16 bytes are dropped.
2650          */
2651         skb = ieee80211_rx_monitor(local, skb, rate);
2652         if (!skb) {
2653                 rcu_read_unlock();
2654                 return;
2655         }
2656
2657         __ieee80211_rx_handle_packet(hw, skb, rate);
2658
2659         rcu_read_unlock();
2660
2661         return;
2662  drop:
2663         kfree_skb(skb);
2664 }
2665 EXPORT_SYMBOL(ieee80211_rx);
2666
2667 /* This is a version of the rx handler that can be called from hard irq
2668  * context. Post the skb on the queue and schedule the tasklet */
2669 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
2670 {
2671         struct ieee80211_local *local = hw_to_local(hw);
2672
2673         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2674
2675         skb->pkt_type = IEEE80211_RX_MSG;
2676         skb_queue_tail(&local->skb_queue, skb);
2677         tasklet_schedule(&local->tasklet);
2678 }
2679 EXPORT_SYMBOL(ieee80211_rx_irqsafe);