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       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/kernel.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/etherdevice.h>
  17 #include <linux/rcupdate.h>
  18 #include <net/mac80211.h>
  19 #include <net/ieee80211_radiotap.h>
  20
  21 #include "ieee80211_i.h"
  22 #include "driver-ops.h"
  23 #include "led.h"
  24 #include "mesh.h"
  25 #include "wep.h"
  26 #include "wpa.h"
  27 #include "tkip.h"
  28 #include "wme.h"
  29
  30 static u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
  31                                            struct tid_ampdu_rx *tid_agg_rx,
  32                                            struct sk_buff *skb,
  33                                            u16 mpdu_seq_num,
  34                                            int bar_req);
  35 /*
  36  * monitor mode reception
  37  *
  38  * This function cleans up the SKB, i.e. it removes all the stuff
  39  * only useful for monitoring.
  40  */
  41 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
  42                                            struct sk_buff *skb,
  43                                            int rtap_len)
  44 {
  45         skb_pull(skb, rtap_len);
  46
  47         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
  48                 if (likely(skb->len > FCS_LEN))
  49                         skb_trim(skb, skb->len - FCS_LEN);
  50                 else {
  51                         /* driver bug */
  52                         WARN_ON(1);
  53                         dev_kfree_skb(skb);
  54                         skb = NULL;
  55                 }
  56         }
  57
  58         return skb;
  59 }
  60
  61 static inline int should_drop_frame(struct sk_buff *skb,
  62                                     int present_fcs_len,
  63                                     int radiotap_len)
  64 {
  65         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  66         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  67
  68         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
  69                 return 1;
  70         if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
  71                 return 1;
  72         if (ieee80211_is_ctl(hdr->frame_control) &&
  73             !ieee80211_is_pspoll(hdr->frame_control) &&
  74             !ieee80211_is_back_req(hdr->frame_control))
  75                 return 1;
  76         return 0;
  77 }
  78
  79 static int
  80 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
  81                           struct ieee80211_rx_status *status)
  82 {
  83         int len;
  84
  85         /* always present fields */
  86         len = sizeof(struct ieee80211_radiotap_header) + 9;
  87
  88         if (status->flag & RX_FLAG_TSFT)
  89                 len += 8;
  90         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
  91                 len += 1;
  92         if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
  93                 len += 1;
  94
  95         if (len & 1) /* padding for RX_FLAGS if necessary */
  96                 len++;
  97
  98         /* make sure radiotap starts at a naturally aligned address */
  99         if (len % 8)
 100                 len = roundup(len, 8);
 101
 102         return len;
 103 }
 104
 105 /*
 106  * ieee80211_add_rx_radiotap_header - add radiotap header
 107  *
 108  * add a radiotap header containing all the fields which the hardware provided.
 109  */
 110 static void
 111 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
 112                                  struct sk_buff *skb,
 113                                  struct ieee80211_rate *rate,
 114                                  int rtap_len)
 115 {
 116         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 117         struct ieee80211_radiotap_header *rthdr;
 118         unsigned char *pos;
 119
 120         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
 121         memset(rthdr, 0, rtap_len);
 122
 123         /* radiotap header, set always present flags */
 124         rthdr->it_present =
 125                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 126                             (1 << IEEE80211_RADIOTAP_CHANNEL) |
 127                             (1 << IEEE80211_RADIOTAP_ANTENNA) |
 128                             (1 << IEEE80211_RADIOTAP_RX_FLAGS));
 129         rthdr->it_len = cpu_to_le16(rtap_len);
 130
 131         pos = (unsigned char *)(rthdr+1);
 132
 133         /* the order of the following fields is important */
 134
 135         /* IEEE80211_RADIOTAP_TSFT */
 136         if (status->flag & RX_FLAG_TSFT) {
 137                 *(__le64 *)pos = cpu_to_le64(status->mactime);
 138                 rthdr->it_present |=
 139                         cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
 140                 pos += 8;
 141         }
 142
 143         /* IEEE80211_RADIOTAP_FLAGS */
 144         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 145                 *pos |= IEEE80211_RADIOTAP_F_FCS;
 146         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 147                 *pos |= IEEE80211_RADIOTAP_F_BADFCS;
 148         if (status->flag & RX_FLAG_SHORTPRE)
 149                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
 150         pos++;
 151
 152         /* IEEE80211_RADIOTAP_RATE */
 153         if (status->flag & RX_FLAG_HT) {
 154                 /*
 155                  * TODO: add following information into radiotap header once
 156                  * suitable fields are defined for it:
 157                  * - MCS index (status->rate_idx)
 158                  * - HT40 (status->flag & RX_FLAG_40MHZ)
 159                  * - short-GI (status->flag & RX_FLAG_SHORT_GI)
 160                  */
 161                 *pos = 0;
 162         } else {
 163                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
 164                 *pos = rate->bitrate / 5;
 165         }
 166         pos++;
 167
 168         /* IEEE80211_RADIOTAP_CHANNEL */
 169         *(__le16 *)pos = cpu_to_le16(status->freq);
 170         pos += 2;
 171         if (status->band == IEEE80211_BAND_5GHZ)
 172                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
 173                                              IEEE80211_CHAN_5GHZ);
 174         else if (rate->flags & IEEE80211_RATE_ERP_G)
 175                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
 176                                              IEEE80211_CHAN_2GHZ);
 177         else
 178                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_CCK |
 179                                              IEEE80211_CHAN_2GHZ);
 180         pos += 2;
 181
 182         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
 183         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
 184                 *pos = status->signal;
 185                 rthdr->it_present |=
 186                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
 187                 pos++;
 188         }
 189
 190         /* IEEE80211_RADIOTAP_DBM_ANTNOISE */
 191         if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
 192                 *pos = status->noise;
 193                 rthdr->it_present |=
 194                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
 195                 pos++;
 196         }
 197
 198         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
 199
 200         /* IEEE80211_RADIOTAP_ANTENNA */
 201         *pos = status->antenna;
 202         pos++;
 203
 204         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
 205
 206         /* IEEE80211_RADIOTAP_RX_FLAGS */
 207         /* ensure 2 byte alignment for the 2 byte field as required */
 208         if ((pos - (unsigned char *)rthdr) & 1)
 209                 pos++;
 210         if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
 211                 *(__le16 *)pos |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADPLCP);
 212         pos += 2;
 213 }
 214
 215 /*
 216  * This function copies a received frame to all monitor interfaces and
 217  * returns a cleaned-up SKB that no longer includes the FCS nor the
 218  * radiotap header the driver might have added.
 219  */
 220 static struct sk_buff *
 221 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
 222                      struct ieee80211_rate *rate)
 223 {
 224         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
 225         struct ieee80211_sub_if_data *sdata;
 226         int needed_headroom = 0;
 227         struct sk_buff *skb, *skb2;
 228         struct net_device *prev_dev = NULL;
 229         int present_fcs_len = 0;
 230         int rtap_len = 0;
 231
 232         /*
 233          * First, we may need to make a copy of the skb because
 234          *  (1) we need to modify it for radiotap (if not present), and
 235          *  (2) the other RX handlers will modify the skb we got.
 236          *
 237          * We don't need to, of course, if we aren't going to return
 238          * the SKB because it has a bad FCS/PLCP checksum.
 239          */
 240         if (status->flag & RX_FLAG_RADIOTAP)
 241                 rtap_len = ieee80211_get_radiotap_len(origskb->data);
 242         else
 243                 /* room for the radiotap header based on driver features */
 244                 needed_headroom = ieee80211_rx_radiotap_len(local, status);
 245
 246         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 247                 present_fcs_len = FCS_LEN;
 248
 249         if (!local->monitors) {
 250                 if (should_drop_frame(origskb, present_fcs_len, rtap_len)) {
 251                         dev_kfree_skb(origskb);
 252                         return NULL;
 253                 }
 254
 255                 return remove_monitor_info(local, origskb, rtap_len);
 256         }
 257
 258         if (should_drop_frame(origskb, present_fcs_len, rtap_len)) {
 259                 /* only need to expand headroom if necessary */
 260                 skb = origskb;
 261                 origskb = NULL;
 262
 263                 /*
 264                  * This shouldn't trigger often because most devices have an
 265                  * RX header they pull before we get here, and that should
 266                  * be big enough for our radiotap information. We should
 267                  * probably export the length to drivers so that we can have
 268                  * them allocate enough headroom to start with.
 269                  */
 270                 if (skb_headroom(skb) < needed_headroom &&
 271                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
 272                         dev_kfree_skb(skb);
 273                         return NULL;
 274                 }
 275         } else {
 276                 /*
 277                  * Need to make a copy and possibly remove radiotap header
 278                  * and FCS from the original.
 279                  */
 280                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 281
 282                 origskb = remove_monitor_info(local, origskb, rtap_len);
 283
 284                 if (!skb)
 285                         return origskb;
 286         }
 287
 288         /* if necessary, prepend radiotap information */
 289         if (!(status->flag & RX_FLAG_RADIOTAP))
 290                 ieee80211_add_rx_radiotap_header(local, skb, rate,
 291                                                  needed_headroom);
 292
 293         skb_reset_mac_header(skb);
 294         skb->ip_summed = CHECKSUM_UNNECESSARY;
 295         skb->pkt_type = PACKET_OTHERHOST;
 296         skb->protocol = htons(ETH_P_802_2);
 297
 298         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 299                 if (!netif_running(sdata->dev))
 300                         continue;
 301
 302                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
 303                         continue;
 304
 305                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
 306                         continue;
 307
 308                 if (prev_dev) {
 309                         skb2 = skb_clone(skb, GFP_ATOMIC);
 310                         if (skb2) {
 311                                 skb2->dev = prev_dev;
 312                                 netif_rx(skb2);
 313                         }
 314                 }
 315
 316                 prev_dev = sdata->dev;
 317                 sdata->dev->stats.rx_packets++;
 318                 sdata->dev->stats.rx_bytes += skb->len;
 319         }
 320
 321         if (prev_dev) {
 322                 skb->dev = prev_dev;
 323                 netif_rx(skb);
 324         } else
 325                 dev_kfree_skb(skb);
 326
 327         return origskb;
 328 }
 329
 330
 331 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
 332 {
 333         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 334         int tid;
 335
 336         /* does the frame have a qos control field? */
 337         if (ieee80211_is_data_qos(hdr->frame_control)) {
 338                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 339                 /* frame has qos control */
 340                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
 341                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
 342                         rx->flags |= IEEE80211_RX_AMSDU;
 343                 else
 344                         rx->flags &= ~IEEE80211_RX_AMSDU;
 345         } else {
 346                 /*
 347                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
 348                  *
 349                  *      Sequence numbers for management frames, QoS data
 350                  *      frames with a broadcast/multicast address in the
 351                  *      Address 1 field, and all non-QoS data frames sent
 352                  *      by QoS STAs are assigned using an additional single
 353                  *      modulo-4096 counter, [...]
 354                  *
 355                  * We also use that counter for non-QoS STAs.
 356                  */
 357                 tid = NUM_RX_DATA_QUEUES - 1;
 358         }
 359
 360         rx->queue = tid;
 361         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 362          * For now, set skb->priority to 0 for other cases. */
 363         rx->skb->priority = (tid > 7) ? 0 : tid;
 364 }
 365
 366 /**
 367  * DOC: Packet alignment
 368  *
 369  * Drivers always need to pass packets that are aligned to two-byte boundaries
 370  * to the stack.
 371  *
 372  * Additionally, should, if possible, align the payload data in a way that
 373  * guarantees that the contained IP header is aligned to a four-byte
 374  * boundary. In the case of regular frames, this simply means aligning the
 375  * payload to a four-byte boundary (because either the IP header is directly
 376  * contained, or IV/RFC1042 headers that have a length divisible by four are
 377  * in front of it).
 378  *
 379  * With A-MSDU frames, however, the payload data address must yield two modulo
 380  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
 381  * push the IP header further back to a multiple of four again. Thankfully, the
 382  * specs were sane enough this time around to require padding each A-MSDU
 383  * subframe to a length that is a multiple of four.
 384  *
 385  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
 386  * the payload is not supported, the driver is required to move the 802.11
 387  * header to be directly in front of the payload in that case.
 388  */
 389 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
 390 {
 391         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 392         int hdrlen;
 393
 394 #ifndef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
 395         return;
 396 #endif
 397
 398         if (WARN_ONCE((unsigned long)rx->skb->data & 1,
 399                       "unaligned packet at 0x%p\n", rx->skb->data))
 400                 return;
 401
 402         if (!ieee80211_is_data_present(hdr->frame_control))
 403                 return;
 404
 405         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 406         if (rx->flags & IEEE80211_RX_AMSDU)
 407                 hdrlen += ETH_HLEN;
 408         WARN_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3,
 409                   "unaligned IP payload at 0x%p\n", rx->skb->data + hdrlen);
 410 }
 411
 412
 413 /* rx handlers */
 414
 415 static ieee80211_rx_result debug_noinline
 416 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 417 {
 418         struct ieee80211_local *local = rx->local;
 419         struct sk_buff *skb = rx->skb;
 420
 421         if (unlikely(local->hw_scanning))
 422                 return ieee80211_scan_rx(rx->sdata, skb);
 423
 424         if (unlikely(local->sw_scanning)) {
 425                 /* drop all the other packets during a software scan anyway */
 426                 if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
 427                         dev_kfree_skb(skb);
 428                 return RX_QUEUED;
 429         }
 430
 431         if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
 432                 /* scanning finished during invoking of handlers */
 433                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 434                 return RX_DROP_UNUSABLE;
 435         }
 436
 437         return RX_CONTINUE;
 438 }
 439
 440
 441 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
 442 {
 443         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 444
 445         if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
 446                 return 0;
 447
 448         return ieee80211_is_robust_mgmt_frame(hdr);
 449 }
 450
 451
 452 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
 453 {
 454         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 455
 456         if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
 457                 return 0;
 458
 459         return ieee80211_is_robust_mgmt_frame(hdr);
 460 }
 461
 462
 463 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
 464 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
 465 {
 466         struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
 467         struct ieee80211_mmie *mmie;
 468
 469         if (skb->len < 24 + sizeof(*mmie) ||
 470             !is_multicast_ether_addr(hdr->da))
 471                 return -1;
 472
 473         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
 474                 return -1; /* not a robust management frame */
 475
 476         mmie = (struct ieee80211_mmie *)
 477                 (skb->data + skb->len - sizeof(*mmie));
 478         if (mmie->element_id != WLAN_EID_MMIE ||
 479             mmie->length != sizeof(*mmie) - 2)
 480                 return -1;
 481
 482         return le16_to_cpu(mmie->key_id);
 483 }
 484
 485
 486 static ieee80211_rx_result
 487 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 488 {
 489         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 490         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 491
 492         if (ieee80211_is_data(hdr->frame_control)) {
 493                 if (!ieee80211_has_a4(hdr->frame_control))
 494                         return RX_DROP_MONITOR;
 495                 if (memcmp(hdr->addr4, rx->dev->dev_addr, ETH_ALEN) == 0)
 496                         return RX_DROP_MONITOR;
 497         }
 498
 499         /* If there is not an established peer link and this is not a peer link
 500          * establisment frame, beacon or probe, drop the frame.
 501          */
 502
 503         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
 504                 struct ieee80211_mgmt *mgmt;
 505
 506                 if (!ieee80211_is_mgmt(hdr->frame_control))
 507                         return RX_DROP_MONITOR;
 508
 509                 if (ieee80211_is_action(hdr->frame_control)) {
 510                         mgmt = (struct ieee80211_mgmt *)hdr;
 511                         if (mgmt->u.action.category != PLINK_CATEGORY)
 512                                 return RX_DROP_MONITOR;
 513                         return RX_CONTINUE;
 514                 }
 515
 516                 if (ieee80211_is_probe_req(hdr->frame_control) ||
 517                     ieee80211_is_probe_resp(hdr->frame_control) ||
 518                     ieee80211_is_beacon(hdr->frame_control))
 519                         return RX_CONTINUE;
 520
 521                 return RX_DROP_MONITOR;
 522
 523         }
 524
 525 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
 526
 527         if (ieee80211_is_data(hdr->frame_control) &&
 528             is_multicast_ether_addr(hdr->addr1) &&
 529             mesh_rmc_check(hdr->addr4, msh_h_get(hdr, hdrlen), rx->sdata))
 530                 return RX_DROP_MONITOR;
 531 #undef msh_h_get
 532
 533         return RX_CONTINUE;
 534 }
 535
 536
 537 static ieee80211_rx_result debug_noinline
 538 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
 539 {
 540         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 541
 542         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 543         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 544                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
 545                              rx->sta->last_seq_ctrl[rx->queue] ==
 546                              hdr->seq_ctrl)) {
 547                         if (rx->flags & IEEE80211_RX_RA_MATCH) {
 548                                 rx->local->dot11FrameDuplicateCount++;
 549                                 rx->sta->num_duplicates++;
 550                         }
 551                         return RX_DROP_MONITOR;
 552                 } else
 553                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
 554         }
 555
 556         if (unlikely(rx->skb->len < 16)) {
 557                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 558                 return RX_DROP_MONITOR;
 559         }
 560
 561         /* Drop disallowed frame classes based on STA auth/assoc state;
 562          * IEEE 802.11, Chap 5.5.
 563          *
 564          * mac80211 filters only based on association state, i.e. it drops
 565          * Class 3 frames from not associated stations. hostapd sends
 566          * deauth/disassoc frames when needed. In addition, hostapd is
 567          * responsible for filtering on both auth and assoc states.
 568          */
 569
 570         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
 571                 return ieee80211_rx_mesh_check(rx);
 572
 573         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
 574                       ieee80211_is_pspoll(hdr->frame_control)) &&
 575                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
 576                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
 577                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
 578                      !ieee80211_has_tods(hdr->frame_control) &&
 579                      ieee80211_is_data(hdr->frame_control)) ||
 580                     !(rx->flags & IEEE80211_RX_RA_MATCH)) {
 581                         /* Drop IBSS frames and frames for other hosts
 582                          * silently. */
 583                         return RX_DROP_MONITOR;
 584                 }
 585
 586                 return RX_DROP_MONITOR;
 587         }
 588
 589         return RX_CONTINUE;
 590 }
 591
 592
 593 static ieee80211_rx_result debug_noinline
 594 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 595 {
 596         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 597         int keyidx;
 598         int hdrlen;
 599         ieee80211_rx_result result = RX_DROP_UNUSABLE;
 600         struct ieee80211_key *stakey = NULL;
 601         int mmie_keyidx = -1;
 602
 603         /*
 604          * Key selection 101
 605          *
 606          * There are four types of keys:
 607          *  - GTK (group keys)
 608          *  - IGTK (group keys for management frames)
 609          *  - PTK (pairwise keys)
 610          *  - STK (station-to-station pairwise keys)
 611          *
 612          * When selecting a key, we have to distinguish between multicast
 613          * (including broadcast) and unicast frames, the latter can only
 614          * use PTKs and STKs while the former always use GTKs and IGTKs.
 615          * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
 616          * unicast frames can also use key indices like GTKs. Hence, if we
 617          * don't have a PTK/STK we check the key index for a WEP key.
 618          *
 619          * Note that in a regular BSS, multicast frames are sent by the
 620          * AP only, associated stations unicast the frame to the AP first
 621          * which then multicasts it on their behalf.
 622          *
 623          * There is also a slight problem in IBSS mode: GTKs are negotiated
 624          * with each station, that is something we don't currently handle.
 625          * The spec seems to expect that one negotiates the same key with
 626          * every station but there's no such requirement; VLANs could be
 627          * possible.
 628          */
 629
 630         /*
 631          * No point in finding a key and decrypting if the frame is neither
 632          * addressed to us nor a multicast frame.
 633          */
 634         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 635                 return RX_CONTINUE;
 636
 637         if (rx->sta)
 638                 stakey = rcu_dereference(rx->sta->key);
 639
 640         if (!ieee80211_has_protected(hdr->frame_control))
 641                 mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
 642
 643         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
 644                 rx->key = stakey;
 645                 /* Skip decryption if the frame is not protected. */
 646                 if (!ieee80211_has_protected(hdr->frame_control))
 647                         return RX_CONTINUE;
 648         } else if (mmie_keyidx >= 0) {
 649                 /* Broadcast/multicast robust management frame / BIP */
 650                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
 651                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
 652                         return RX_CONTINUE;
 653
 654                 if (mmie_keyidx < NUM_DEFAULT_KEYS ||
 655                     mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 656                         return RX_DROP_MONITOR; /* unexpected BIP keyidx */
 657                 rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
 658         } else if (!ieee80211_has_protected(hdr->frame_control)) {
 659                 /*
 660                  * The frame was not protected, so skip decryption. However, we
 661                  * need to set rx->key if there is a key that could have been
 662                  * used so that the frame may be dropped if encryption would
 663                  * have been expected.
 664                  */
 665                 struct ieee80211_key *key = NULL;
 666                 if (ieee80211_is_mgmt(hdr->frame_control) &&
 667                     is_multicast_ether_addr(hdr->addr1) &&
 668                     (key = rcu_dereference(rx->sdata->default_mgmt_key)))
 669                         rx->key = key;
 670                 else if ((key = rcu_dereference(rx->sdata->default_key)))
 671                         rx->key = key;
 672                 return RX_CONTINUE;
 673         } else {
 674                 /*
 675                  * The device doesn't give us the IV so we won't be
 676                  * able to look up the key. That's ok though, we
 677                  * don't need to decrypt the frame, we just won't
 678                  * be able to keep statistics accurate.
 679                  * Except for key threshold notifications, should
 680                  * we somehow allow the driver to tell us which key
 681                  * the hardware used if this flag is set?
 682                  */
 683                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
 684                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
 685                         return RX_CONTINUE;
 686
 687                 hdrlen = ieee80211_hdrlen(hdr->frame_control);
 688
 689                 if (rx->skb->len < 8 + hdrlen)
 690                         return RX_DROP_UNUSABLE; /* TODO: count this? */
 691
 692                 /*
 693                  * no need to call ieee80211_wep_get_keyidx,
 694                  * it verifies a bunch of things we've done already
 695                  */
 696                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
 697
 698                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
 699
 700                 /*
 701                  * RSNA-protected unicast frames should always be sent with
 702                  * pairwise or station-to-station keys, but for WEP we allow
 703                  * using a key index as well.
 704                  */
 705                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
 706                     !is_multicast_ether_addr(hdr->addr1))
 707                         rx->key = NULL;
 708         }
 709
 710         if (rx->key) {
 711                 rx->key->tx_rx_count++;
 712                 /* TODO: add threshold stuff again */
 713         } else {
 714                 return RX_DROP_MONITOR;
 715         }
 716
 717         /* Check for weak IVs if possible */
 718         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
 719             ieee80211_is_data(hdr->frame_control) &&
 720             (!(rx->status->flag & RX_FLAG_IV_STRIPPED) ||
 721              !(rx->status->flag & RX_FLAG_DECRYPTED)) &&
 722             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
 723                 rx->sta->wep_weak_iv_count++;
 724
 725         switch (rx->key->conf.alg) {
 726         case ALG_WEP:
 727                 result = ieee80211_crypto_wep_decrypt(rx);
 728                 break;
 729         case ALG_TKIP:
 730                 result = ieee80211_crypto_tkip_decrypt(rx);
 731                 break;
 732         case ALG_CCMP:
 733                 result = ieee80211_crypto_ccmp_decrypt(rx);
 734                 break;
 735         case ALG_AES_CMAC:
 736                 result = ieee80211_crypto_aes_cmac_decrypt(rx);
 737                 break;
 738         }
 739
 740         /* either the frame has been decrypted or will be dropped */
 741         rx->status->flag |= RX_FLAG_DECRYPTED;
 742
 743         return result;
 744 }
 745
 746 static ieee80211_rx_result debug_noinline
 747 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
 748 {
 749         struct ieee80211_local *local;
 750         struct ieee80211_hdr *hdr;
 751         struct sk_buff *skb;
 752
 753         local = rx->local;
 754         skb = rx->skb;
 755         hdr = (struct ieee80211_hdr *) skb->data;
 756
 757         if (!local->pspolling)
 758                 return RX_CONTINUE;
 759
 760         if (!ieee80211_has_fromds(hdr->frame_control))
 761                 /* this is not from AP */
 762                 return RX_CONTINUE;
 763
 764         if (!ieee80211_is_data(hdr->frame_control))
 765                 return RX_CONTINUE;
 766
 767         if (!ieee80211_has_moredata(hdr->frame_control)) {
 768                 /* AP has no more frames buffered for us */
 769                 local->pspolling = false;
 770                 return RX_CONTINUE;
 771         }
 772
 773         /* more data bit is set, let's request a new frame from the AP */
 774         ieee80211_send_pspoll(local, rx->sdata);
 775
 776         return RX_CONTINUE;
 777 }
 778
 779 static void ap_sta_ps_start(struct sta_info *sta)
 780 {
 781         struct ieee80211_sub_if_data *sdata = sta->sdata;
 782         struct ieee80211_local *local = sdata->local;
 783
 784         atomic_inc(&sdata->bss->num_sta_ps);
 785         set_and_clear_sta_flags(sta, WLAN_STA_PS, WLAN_STA_PSPOLL);
 786         drv_sta_notify(local, &sdata->vif, STA_NOTIFY_SLEEP, &sta->sta);
 787 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 788         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
 789                sdata->dev->name, sta->sta.addr, sta->sta.aid);
 790 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 791 }
 792
 793 static int ap_sta_ps_end(struct sta_info *sta)
 794 {
 795         struct ieee80211_sub_if_data *sdata = sta->sdata;
 796         struct ieee80211_local *local = sdata->local;
 797         int sent, buffered;
 798
 799         atomic_dec(&sdata->bss->num_sta_ps);
 800
 801         clear_sta_flags(sta, WLAN_STA_PS | WLAN_STA_PSPOLL);
 802         drv_sta_notify(local, &sdata->vif, STA_NOTIFY_AWAKE, &sta->sta);
 803
 804         if (!skb_queue_empty(&sta->ps_tx_buf))
 805                 sta_info_clear_tim_bit(sta);
 806
 807 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 808         printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
 809                sdata->dev->name, sta->sta.addr, sta->sta.aid);
 810 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 811
 812         /* Send all buffered frames to the station */
 813         sent = ieee80211_add_pending_skbs(local, &sta->tx_filtered);
 814         buffered = ieee80211_add_pending_skbs(local, &sta->ps_tx_buf);
 815         sent += buffered;
 816         local->total_ps_buffered -= buffered;
 817
 818 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 819         printk(KERN_DEBUG "%s: STA %pM aid %d sending %d filtered/%d PS frames "
 820                "since STA not sleeping anymore\n", sdata->dev->name,
 821                sta->sta.addr, sta->sta.aid, sent - buffered, buffered);
 822 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 823
 824         return sent;
 825 }
 826
 827 static ieee80211_rx_result debug_noinline
 828 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
 829 {
 830         struct sta_info *sta = rx->sta;
 831         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 832
 833         if (!sta)
 834                 return RX_CONTINUE;
 835
 836         /* Update last_rx only for IBSS packets which are for the current
 837          * BSSID to avoid keeping the current IBSS network alive in cases where
 838          * other STAs are using different BSSID. */
 839         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
 840                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
 841                                                 NL80211_IFTYPE_ADHOC);
 842                 if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
 843                         sta->last_rx = jiffies;
 844         } else
 845         if (!is_multicast_ether_addr(hdr->addr1) ||
 846             rx->sdata->vif.type == NL80211_IFTYPE_STATION) {
 847                 /* Update last_rx only for unicast frames in order to prevent
 848                  * the Probe Request frames (the only broadcast frames from a
 849                  * STA in infrastructure mode) from keeping a connection alive.
 850                  * Mesh beacons will update last_rx when if they are found to
 851                  * match the current local configuration when processed.
 852                  */
 853                 if (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
 854                     ieee80211_is_beacon(hdr->frame_control)) {
 855                         rx->sdata->u.mgd.last_beacon = jiffies;
 856                 } else
 857                         sta->last_rx = jiffies;
 858         }
 859
 860         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 861                 return RX_CONTINUE;
 862
 863         if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
 864                 ieee80211_sta_rx_notify(rx->sdata, hdr);
 865
 866         sta->rx_fragments++;
 867         sta->rx_bytes += rx->skb->len;
 868         sta->last_signal = rx->status->signal;
 869         sta->last_qual = rx->status->qual;
 870         sta->last_noise = rx->status->noise;
 871
 872         /*
 873          * Change STA power saving mode only at the end of a frame
 874          * exchange sequence.
 875          */
 876         if (!ieee80211_has_morefrags(hdr->frame_control) &&
 877             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
 878              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
 879                 if (test_sta_flags(sta, WLAN_STA_PS)) {
 880                         /*
 881                          * Ignore doze->wake transitions that are
 882                          * indicated by non-data frames, the standard
 883                          * is unclear here, but for example going to
 884                          * PS mode and then scanning would cause a
 885                          * doze->wake transition for the probe request,
 886                          * and that is clearly undesirable.
 887                          */
 888                         if (ieee80211_is_data(hdr->frame_control) &&
 889                             !ieee80211_has_pm(hdr->frame_control))
 890                                 rx->sent_ps_buffered += ap_sta_ps_end(sta);
 891                 } else {
 892                         if (ieee80211_has_pm(hdr->frame_control))
 893                                 ap_sta_ps_start(sta);
 894                 }
 895         }
 896
 897         /* Drop data::nullfunc frames silently, since they are used only to
 898          * control station power saving mode. */
 899         if (ieee80211_is_nullfunc(hdr->frame_control)) {
 900                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
 901                 /* Update counter and free packet here to avoid counting this
 902                  * as a dropped packed. */
 903                 sta->rx_packets++;
 904                 dev_kfree_skb(rx->skb);
 905                 return RX_QUEUED;
 906         }
 907
 908         return RX_CONTINUE;
 909 } /* ieee80211_rx_h_sta_process */
 910
 911 static inline struct ieee80211_fragment_entry *
 912 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
 913                          unsigned int frag, unsigned int seq, int rx_queue,
 914                          struct sk_buff **skb)
 915 {
 916         struct ieee80211_fragment_entry *entry;
 917         int idx;
 918
 919         idx = sdata->fragment_next;
 920         entry = &sdata->fragments[sdata->fragment_next++];
 921         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
 922                 sdata->fragment_next = 0;
 923
 924         if (!skb_queue_empty(&entry->skb_list)) {
 925 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 926                 struct ieee80211_hdr *hdr =
 927                         (struct ieee80211_hdr *) entry->skb_list.next->data;
 928                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
 929                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
 930                        "addr1=%pM addr2=%pM\n",
 931                        sdata->dev->name, idx,
 932                        jiffies - entry->first_frag_time, entry->seq,
 933                        entry->last_frag, hdr->addr1, hdr->addr2);
 934 #endif
 935                 __skb_queue_purge(&entry->skb_list);
 936         }
 937
 938         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
 939         *skb = NULL;
 940         entry->first_frag_time = jiffies;
 941         entry->seq = seq;
 942         entry->rx_queue = rx_queue;
 943         entry->last_frag = frag;
 944         entry->ccmp = 0;
 945         entry->extra_len = 0;
 946
 947         return entry;
 948 }
 949
 950 static inline struct ieee80211_fragment_entry *
 951 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
 952                           unsigned int frag, unsigned int seq,
 953                           int rx_queue, struct ieee80211_hdr *hdr)
 954 {
 955         struct ieee80211_fragment_entry *entry;
 956         int i, idx;
 957
 958         idx = sdata->fragment_next;
 959         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
 960                 struct ieee80211_hdr *f_hdr;
 961
 962                 idx--;
 963                 if (idx < 0)
 964                         idx = IEEE80211_FRAGMENT_MAX - 1;
 965
 966                 entry = &sdata->fragments[idx];
 967                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
 968                     entry->rx_queue != rx_queue ||
 969                     entry->last_frag + 1 != frag)
 970                         continue;
 971
 972                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
 973
 974                 /*
 975                  * Check ftype and addresses are equal, else check next fragment
 976                  */
 977                 if (((hdr->frame_control ^ f_hdr->frame_control) &
 978                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
 979                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
 980                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
 981                         continue;
 982
 983                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
 984                         __skb_queue_purge(&entry->skb_list);
 985                         continue;
 986                 }
 987                 return entry;
 988         }
 989
 990         return NULL;
 991 }
 992
 993 static ieee80211_rx_result debug_noinline
 994 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 995 {
 996         struct ieee80211_hdr *hdr;
 997         u16 sc;
 998         __le16 fc;
 999         unsigned int frag, seq;
1000         struct ieee80211_fragment_entry *entry;
1001         struct sk_buff *skb;
1002
1003         hdr = (struct ieee80211_hdr *)rx->skb->data;
1004         fc = hdr->frame_control;
1005         sc = le16_to_cpu(hdr->seq_ctrl);
1006         frag = sc & IEEE80211_SCTL_FRAG;
1007
1008         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1009                    (rx->skb)->len < 24 ||
1010                    is_multicast_ether_addr(hdr->addr1))) {
1011                 /* not fragmented */
1012                 goto out;
1013         }
1014         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1015
1016         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1017
1018         if (frag == 0) {
1019                 /* This is the first fragment of a new frame. */
1020                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1021                                                  rx->queue, &(rx->skb));
1022                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
1023                     ieee80211_has_protected(fc)) {
1024                         /* Store CCMP PN so that we can verify that the next
1025                          * fragment has a sequential PN value. */
1026                         entry->ccmp = 1;
1027                         memcpy(entry->last_pn,
1028                                rx->key->u.ccmp.rx_pn[rx->queue],
1029                                CCMP_PN_LEN);
1030                 }
1031                 return RX_QUEUED;
1032         }
1033
1034         /* This is a fragment for a frame that should already be pending in
1035          * fragment cache. Add this fragment to the end of the pending entry.
1036          */
1037         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1038         if (!entry) {
1039                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1040                 return RX_DROP_MONITOR;
1041         }
1042
1043         /* Verify that MPDUs within one MSDU have sequential PN values.
1044          * (IEEE 802.11i, 8.3.3.4.5) */
1045         if (entry->ccmp) {
1046                 int i;
1047                 u8 pn[CCMP_PN_LEN], *rpn;
1048                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
1049                         return RX_DROP_UNUSABLE;
1050                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1051                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1052                         pn[i]++;
1053                         if (pn[i])
1054                                 break;
1055                 }
1056                 rpn = rx->key->u.ccmp.rx_pn[rx->queue];
1057                 if (memcmp(pn, rpn, CCMP_PN_LEN))
1058                         return RX_DROP_UNUSABLE;
1059                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1060         }
1061
1062         skb_pull(rx->skb, ieee80211_hdrlen(fc));
1063         __skb_queue_tail(&entry->skb_list, rx->skb);
1064         entry->last_frag = frag;
1065         entry->extra_len += rx->skb->len;
1066         if (ieee80211_has_morefrags(fc)) {
1067                 rx->skb = NULL;
1068                 return RX_QUEUED;
1069         }
1070
1071         rx->skb = __skb_dequeue(&entry->skb_list);
1072         if (skb_tailroom(rx->skb) < entry->extra_len) {
1073                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1074                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1075                                               GFP_ATOMIC))) {
1076                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1077                         __skb_queue_purge(&entry->skb_list);
1078                         return RX_DROP_UNUSABLE;
1079                 }
1080         }
1081         while ((skb = __skb_dequeue(&entry->skb_list))) {
1082                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1083                 dev_kfree_skb(skb);
1084         }
1085
1086         /* Complete frame has been reassembled - process it now */
1087         rx->flags |= IEEE80211_RX_FRAGMENTED;
1088
1089  out:
1090         if (rx->sta)
1091                 rx->sta->rx_packets++;
1092         if (is_multicast_ether_addr(hdr->addr1))
1093                 rx->local->dot11MulticastReceivedFrameCount++;
1094         else
1095                 ieee80211_led_rx(rx->local);
1096         return RX_CONTINUE;
1097 }
1098
1099 static ieee80211_rx_result debug_noinline
1100 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1101 {
1102         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1103         struct sk_buff *skb;
1104         int no_pending_pkts;
1105         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1106
1107         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1108                    !(rx->flags & IEEE80211_RX_RA_MATCH)))
1109                 return RX_CONTINUE;
1110
1111         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1112             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1113                 return RX_DROP_UNUSABLE;
1114
1115         skb = skb_dequeue(&rx->sta->tx_filtered);
1116         if (!skb) {
1117                 skb = skb_dequeue(&rx->sta->ps_tx_buf);
1118                 if (skb)
1119                         rx->local->total_ps_buffered--;
1120         }
1121         no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
1122                 skb_queue_empty(&rx->sta->ps_tx_buf);
1123
1124         if (skb) {
1125                 struct ieee80211_hdr *hdr =
1126                         (struct ieee80211_hdr *) skb->data;
1127
1128                 /*
1129                  * Tell TX path to send one frame even though the STA may
1130                  * still remain is PS mode after this frame exchange.
1131                  */
1132                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1133
1134 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1135                 printk(KERN_DEBUG "STA %pM aid %d: PS Poll (entries after %d)\n",
1136                        rx->sta->sta.addr, rx->sta->sta.aid,
1137                        skb_queue_len(&rx->sta->ps_tx_buf));
1138 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1139
1140                 /* Use MoreData flag to indicate whether there are more
1141                  * buffered frames for this STA */
1142                 if (no_pending_pkts)
1143                         hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
1144                 else
1145                         hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1146
1147                 dev_queue_xmit(skb);
1148
1149                 if (no_pending_pkts)
1150                         sta_info_clear_tim_bit(rx->sta);
1151 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1152         } else if (!rx->sent_ps_buffered) {
1153                 /*
1154                  * FIXME: This can be the result of a race condition between
1155                  *        us expiring a frame and the station polling for it.
1156                  *        Should we send it a null-func frame indicating we
1157                  *        have nothing buffered for it?
1158                  */
1159                 printk(KERN_DEBUG "%s: STA %pM sent PS Poll even "
1160                        "though there are no buffered frames for it\n",
1161                        rx->dev->name, rx->sta->sta.addr);
1162 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1163         }
1164
1165         /* Free PS Poll skb here instead of returning RX_DROP that would
1166          * count as an dropped frame. */
1167         dev_kfree_skb(rx->skb);
1168
1169         return RX_QUEUED;
1170 }
1171
1172 static ieee80211_rx_result debug_noinline
1173 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1174 {
1175         u8 *data = rx->skb->data;
1176         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1177
1178         if (!ieee80211_is_data_qos(hdr->frame_control))
1179                 return RX_CONTINUE;
1180
1181         /* remove the qos control field, update frame type and meta-data */
1182         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1183                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1184         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1185         /* change frame type to non QOS */
1186         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1187
1188         return RX_CONTINUE;
1189 }
1190
1191 static int
1192 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1193 {
1194         if (unlikely(!rx->sta ||
1195             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1196                 return -EACCES;
1197
1198         return 0;
1199 }
1200
1201 static int
1202 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1203 {
1204         /*
1205          * Pass through unencrypted frames if the hardware has
1206          * decrypted them already.
1207          */
1208         if (rx->status->flag & RX_FLAG_DECRYPTED)
1209                 return 0;
1210
1211         /* Drop unencrypted frames if key is set. */
1212         if (unlikely(!ieee80211_has_protected(fc) &&
1213                      !ieee80211_is_nullfunc(fc) &&
1214                      ieee80211_is_data(fc) &&
1215                      (rx->key || rx->sdata->drop_unencrypted)))
1216                 return -EACCES;
1217         if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1218                 if (unlikely(ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1219                              rx->key))
1220                         return -EACCES;
1221                 /* BIP does not use Protected field, so need to check MMIE */
1222                 if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb)
1223                              && ieee80211_get_mmie_keyidx(rx->skb) < 0 &&
1224                              rx->key))
1225                         return -EACCES;
1226                 /*
1227                  * When using MFP, Action frames are not allowed prior to
1228                  * having configured keys.
1229                  */
1230                 if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1231                              ieee80211_is_robust_mgmt_frame(
1232                                      (struct ieee80211_hdr *) rx->skb->data)))
1233                         return -EACCES;
1234         }
1235
1236         return 0;
1237 }
1238
1239 static int
1240 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1241 {
1242         struct net_device *dev = rx->dev;
1243         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1244
1245         return ieee80211_data_to_8023(rx->skb, dev->dev_addr, sdata->vif.type);
1246 }
1247
1248 /*
1249  * requires that rx->skb is a frame with ethernet header
1250  */
1251 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1252 {
1253         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1254                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1255         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1256
1257         /*
1258          * Allow EAPOL frames to us/the PAE group address regardless
1259          * of whether the frame was encrypted or not.
1260          */
1261         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1262             (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1263              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1264                 return true;
1265
1266         if (ieee80211_802_1x_port_control(rx) ||
1267             ieee80211_drop_unencrypted(rx, fc))
1268                 return false;
1269
1270         return true;
1271 }
1272
1273 /*
1274  * requires that rx->skb is a frame with ethernet header
1275  */
1276 static void
1277 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1278 {
1279         struct net_device *dev = rx->dev;
1280         struct ieee80211_local *local = rx->local;
1281         struct sk_buff *skb, *xmit_skb;
1282         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1283         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1284         struct sta_info *dsta;
1285
1286         skb = rx->skb;
1287         xmit_skb = NULL;
1288
1289         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1290              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1291             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1292             (rx->flags & IEEE80211_RX_RA_MATCH)) {
1293                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1294                         /*
1295                          * send multicast frames both to higher layers in
1296                          * local net stack and back to the wireless medium
1297                          */
1298                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1299                         if (!xmit_skb && net_ratelimit())
1300                                 printk(KERN_DEBUG "%s: failed to clone "
1301                                        "multicast frame\n", dev->name);
1302                 } else {
1303                         dsta = sta_info_get(local, skb->data);
1304                         if (dsta && dsta->sdata->dev == dev) {
1305                                 /*
1306                                  * The destination station is associated to
1307                                  * this AP (in this VLAN), so send the frame
1308                                  * directly to it and do not pass it to local
1309                                  * net stack.
1310                                  */
1311                                 xmit_skb = skb;
1312                                 skb = NULL;
1313                         }
1314                 }
1315         }
1316
1317         if (skb) {
1318                 int align __maybe_unused;
1319
1320 #if defined(CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT) || !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
1321                 /*
1322                  * 'align' will only take the values 0 or 2 here
1323                  * since all frames are required to be aligned
1324                  * to 2-byte boundaries when being passed to
1325                  * mac80211. That also explains the __skb_push()
1326                  * below.
1327                  */
1328                 align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1329                 if (align) {
1330                         if (WARN_ON(skb_headroom(skb) < 3)) {
1331                                 dev_kfree_skb(skb);
1332                                 skb = NULL;
1333                         } else {
1334                                 u8 *data = skb->data;
1335                                 size_t len = skb->len;
1336                                 u8 *new = __skb_push(skb, align);
1337                                 memmove(new, data, len);
1338                                 __skb_trim(skb, len);
1339                         }
1340                 }
1341 #endif
1342
1343                 if (skb) {
1344                         /* deliver to local stack */
1345                         skb->protocol = eth_type_trans(skb, dev);
1346                         memset(skb->cb, 0, sizeof(skb->cb));
1347                         netif_rx(skb);
1348                 }
1349         }
1350
1351         if (xmit_skb) {
1352                 /* send to wireless media */
1353                 xmit_skb->protocol = htons(ETH_P_802_3);
1354                 skb_reset_network_header(xmit_skb);
1355                 skb_reset_mac_header(xmit_skb);
1356                 dev_queue_xmit(xmit_skb);
1357         }
1358 }
1359
1360 static ieee80211_rx_result debug_noinline
1361 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1362 {
1363         struct net_device *dev = rx->dev;
1364         struct ieee80211_local *local = rx->local;
1365         u16 ethertype;
1366         u8 *payload;
1367         struct sk_buff *skb = rx->skb, *frame = NULL;
1368         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1369         __le16 fc = hdr->frame_control;
1370         const struct ethhdr *eth;
1371         int remaining, err;
1372         u8 dst[ETH_ALEN];
1373         u8 src[ETH_ALEN];
1374
1375         if (unlikely(!ieee80211_is_data(fc)))
1376                 return RX_CONTINUE;
1377
1378         if (unlikely(!ieee80211_is_data_present(fc)))
1379                 return RX_DROP_MONITOR;
1380
1381         if (!(rx->flags & IEEE80211_RX_AMSDU))
1382                 return RX_CONTINUE;
1383
1384         err = __ieee80211_data_to_8023(rx);
1385         if (unlikely(err))
1386                 return RX_DROP_UNUSABLE;
1387
1388         skb->dev = dev;
1389
1390         dev->stats.rx_packets++;
1391         dev->stats.rx_bytes += skb->len;
1392
1393         /* skip the wrapping header */
1394         eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1395         if (!eth)
1396                 return RX_DROP_UNUSABLE;
1397
1398         while (skb != frame) {
1399                 u8 padding;
1400                 __be16 len = eth->h_proto;
1401                 unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1402
1403                 remaining = skb->len;
1404                 memcpy(dst, eth->h_dest, ETH_ALEN);
1405                 memcpy(src, eth->h_source, ETH_ALEN);
1406
1407                 padding = ((4 - subframe_len) & 0x3);
1408                 /* the last MSDU has no padding */
1409                 if (subframe_len > remaining)
1410                         return RX_DROP_UNUSABLE;
1411
1412                 skb_pull(skb, sizeof(struct ethhdr));
1413                 /* if last subframe reuse skb */
1414                 if (remaining <= subframe_len + padding)
1415                         frame = skb;
1416                 else {
1417                         /*
1418                          * Allocate and reserve two bytes more for payload
1419                          * alignment since sizeof(struct ethhdr) is 14.
1420                          */
1421                         frame = dev_alloc_skb(
1422                                 ALIGN(local->hw.extra_tx_headroom, 4) +
1423                                 subframe_len + 2);
1424
1425                         if (frame == NULL)
1426                                 return RX_DROP_UNUSABLE;
1427
1428                         skb_reserve(frame,
1429                                     ALIGN(local->hw.extra_tx_headroom, 4) +
1430                                     sizeof(struct ethhdr) + 2);
1431                         memcpy(skb_put(frame, ntohs(len)), skb->data,
1432                                 ntohs(len));
1433
1434                         eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1435                                                         padding);
1436                         if (!eth) {
1437                                 dev_kfree_skb(frame);
1438                                 return RX_DROP_UNUSABLE;
1439                         }
1440                 }
1441
1442                 skb_reset_network_header(frame);
1443                 frame->dev = dev;
1444                 frame->priority = skb->priority;
1445                 rx->skb = frame;
1446
1447                 payload = frame->data;
1448                 ethertype = (payload[6] << 8) | payload[7];
1449
1450                 if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1451                             ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1452                            compare_ether_addr(payload,
1453                                               bridge_tunnel_header) == 0)) {
1454                         /* remove RFC1042 or Bridge-Tunnel
1455                          * encapsulation and replace EtherType */
1456                         skb_pull(frame, 6);
1457                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1458                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1459                 } else {
1460                         memcpy(skb_push(frame, sizeof(__be16)),
1461                                &len, sizeof(__be16));
1462                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1463                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1464                 }
1465
1466                 if (!ieee80211_frame_allowed(rx, fc)) {
1467                         if (skb == frame) /* last frame */
1468                                 return RX_DROP_UNUSABLE;
1469                         dev_kfree_skb(frame);
1470                         continue;
1471                 }
1472
1473                 ieee80211_deliver_skb(rx);
1474         }
1475
1476         return RX_QUEUED;
1477 }
1478
1479 #ifdef CONFIG_MAC80211_MESH
1480 static ieee80211_rx_result
1481 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1482 {
1483         struct ieee80211_hdr *hdr;
1484         struct ieee80211s_hdr *mesh_hdr;
1485         unsigned int hdrlen;
1486         struct sk_buff *skb = rx->skb, *fwd_skb;
1487
1488         hdr = (struct ieee80211_hdr *) skb->data;
1489         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1490         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1491
1492         if (!ieee80211_is_data(hdr->frame_control))
1493                 return RX_CONTINUE;
1494
1495         if (!mesh_hdr->ttl)
1496                 /* illegal frame */
1497                 return RX_DROP_MONITOR;
1498
1499         if (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6){
1500                 struct ieee80211_sub_if_data *sdata;
1501                 struct mesh_path *mppath;
1502
1503                 sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1504                 rcu_read_lock();
1505                 mppath = mpp_path_lookup(mesh_hdr->eaddr2, sdata);
1506                 if (!mppath) {
1507                         mpp_path_add(mesh_hdr->eaddr2, hdr->addr4, sdata);
1508                 } else {
1509                         spin_lock_bh(&mppath->state_lock);
1510                         mppath->exp_time = jiffies;
1511                         if (compare_ether_addr(mppath->mpp, hdr->addr4) != 0)
1512                                 memcpy(mppath->mpp, hdr->addr4, ETH_ALEN);
1513                         spin_unlock_bh(&mppath->state_lock);
1514                 }
1515                 rcu_read_unlock();
1516         }
1517
1518         if (compare_ether_addr(rx->dev->dev_addr, hdr->addr3) == 0)
1519                 return RX_CONTINUE;
1520
1521         mesh_hdr->ttl--;
1522
1523         if (rx->flags & IEEE80211_RX_RA_MATCH) {
1524                 if (!mesh_hdr->ttl)
1525                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1526                                                      dropped_frames_ttl);
1527                 else {
1528                         struct ieee80211_hdr *fwd_hdr;
1529                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1530
1531                         if (!fwd_skb && net_ratelimit())
1532                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1533                                                    rx->dev->name);
1534
1535                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1536                         /*
1537                          * Save TA to addr1 to send TA a path error if a
1538                          * suitable next hop is not found
1539                          */
1540                         memcpy(fwd_hdr->addr1, fwd_hdr->addr2, ETH_ALEN);
1541                         memcpy(fwd_hdr->addr2, rx->dev->dev_addr, ETH_ALEN);
1542                         fwd_skb->dev = rx->local->mdev;
1543                         fwd_skb->iif = rx->dev->ifindex;
1544                         dev_queue_xmit(fwd_skb);
1545                 }
1546         }
1547
1548         if (is_multicast_ether_addr(hdr->addr3) ||
1549             rx->dev->flags & IFF_PROMISC)
1550                 return RX_CONTINUE;
1551         else
1552                 return RX_DROP_MONITOR;
1553 }
1554 #endif
1555
1556 static ieee80211_rx_result debug_noinline
1557 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1558 {
1559         struct net_device *dev = rx->dev;
1560         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1561         __le16 fc = hdr->frame_control;
1562         int err;
1563
1564         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1565                 return RX_CONTINUE;
1566
1567         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1568                 return RX_DROP_MONITOR;
1569
1570         err = __ieee80211_data_to_8023(rx);
1571         if (unlikely(err))
1572                 return RX_DROP_UNUSABLE;
1573
1574         if (!ieee80211_frame_allowed(rx, fc))
1575                 return RX_DROP_MONITOR;
1576
1577         rx->skb->dev = dev;
1578
1579         dev->stats.rx_packets++;
1580         dev->stats.rx_bytes += rx->skb->len;
1581
1582         ieee80211_deliver_skb(rx);
1583
1584         return RX_QUEUED;
1585 }
1586
1587 static ieee80211_rx_result debug_noinline
1588 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1589 {
1590         struct ieee80211_local *local = rx->local;
1591         struct ieee80211_hw *hw = &local->hw;
1592         struct sk_buff *skb = rx->skb;
1593         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1594         struct tid_ampdu_rx *tid_agg_rx;
1595         u16 start_seq_num;
1596         u16 tid;
1597
1598         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1599                 return RX_CONTINUE;
1600
1601         if (ieee80211_is_back_req(bar->frame_control)) {
1602                 if (!rx->sta)
1603                         return RX_CONTINUE;
1604                 tid = le16_to_cpu(bar->control) >> 12;
1605                 if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1606                                         != HT_AGG_STATE_OPERATIONAL)
1607                         return RX_CONTINUE;
1608                 tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1609
1610                 start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1611
1612                 /* reset session timer */
1613                 if (tid_agg_rx->timeout)
1614                         mod_timer(&tid_agg_rx->session_timer,
1615                                   TU_TO_EXP_TIME(tid_agg_rx->timeout));
1616
1617                 /* manage reordering buffer according to requested */
1618                 /* sequence number */
1619                 rcu_read_lock();
1620                 ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL,
1621                                                  start_seq_num, 1);
1622                 rcu_read_unlock();
1623                 return RX_DROP_UNUSABLE;
1624         }
1625
1626         return RX_CONTINUE;
1627 }
1628
1629 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
1630                                            struct ieee80211_mgmt *mgmt,
1631                                            size_t len)
1632 {
1633         struct ieee80211_local *local = sdata->local;
1634         struct sk_buff *skb;
1635         struct ieee80211_mgmt *resp;
1636
1637         if (compare_ether_addr(mgmt->da, sdata->dev->dev_addr) != 0) {
1638                 /* Not to own unicast address */
1639                 return;
1640         }
1641
1642         if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
1643             compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
1644                 /* Not from the current AP. */
1645                 return;
1646         }
1647
1648         if (sdata->u.mgd.state == IEEE80211_STA_MLME_ASSOCIATE) {
1649                 /* Association in progress; ignore SA Query */
1650                 return;
1651         }
1652
1653         if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
1654                 /* Too short SA Query request frame */
1655                 return;
1656         }
1657
1658         skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
1659         if (skb == NULL)
1660                 return;
1661
1662         skb_reserve(skb, local->hw.extra_tx_headroom);
1663         resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
1664         memset(resp, 0, 24);
1665         memcpy(resp->da, mgmt->sa, ETH_ALEN);
1666         memcpy(resp->sa, sdata->dev->dev_addr, ETH_ALEN);
1667         memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
1668         resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1669                                           IEEE80211_STYPE_ACTION);
1670         skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
1671         resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
1672         resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
1673         memcpy(resp->u.action.u.sa_query.trans_id,
1674                mgmt->u.action.u.sa_query.trans_id,
1675                WLAN_SA_QUERY_TR_ID_LEN);
1676
1677         ieee80211_tx_skb(sdata, skb, 1);
1678 }
1679
1680 static ieee80211_rx_result debug_noinline
1681 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1682 {
1683         struct ieee80211_local *local = rx->local;
1684         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1685         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1686         struct ieee80211_bss *bss;
1687         int len = rx->skb->len;
1688
1689         if (!ieee80211_is_action(mgmt->frame_control))
1690                 return RX_CONTINUE;
1691
1692         if (!rx->sta)
1693                 return RX_DROP_MONITOR;
1694
1695         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1696                 return RX_DROP_MONITOR;
1697
1698         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1699                 return RX_DROP_MONITOR;
1700
1701         /* all categories we currently handle have action_code */
1702         if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1703                 return RX_DROP_MONITOR;
1704
1705         switch (mgmt->u.action.category) {
1706         case WLAN_CATEGORY_BACK:
1707                 /*
1708                  * The aggregation code is not prepared to handle
1709                  * anything but STA/AP due to the BSSID handling;
1710                  * IBSS could work in the code but isn't supported
1711                  * by drivers or the standard.
1712                  */
1713                 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1714                     sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
1715                     sdata->vif.type != NL80211_IFTYPE_AP)
1716                         return RX_DROP_MONITOR;
1717
1718                 switch (mgmt->u.action.u.addba_req.action_code) {
1719                 case WLAN_ACTION_ADDBA_REQ:
1720                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1721                                    sizeof(mgmt->u.action.u.addba_req)))
1722                                 return RX_DROP_MONITOR;
1723                         ieee80211_process_addba_request(local, rx->sta, mgmt, len);
1724                         break;
1725                 case WLAN_ACTION_ADDBA_RESP:
1726                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1727                                    sizeof(mgmt->u.action.u.addba_resp)))
1728                                 return RX_DROP_MONITOR;
1729                         ieee80211_process_addba_resp(local, rx->sta, mgmt, len);
1730                         break;
1731                 case WLAN_ACTION_DELBA:
1732                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1733                                    sizeof(mgmt->u.action.u.delba)))
1734                                 return RX_DROP_MONITOR;
1735                         ieee80211_process_delba(sdata, rx->sta, mgmt, len);
1736                         break;
1737                 }
1738                 break;
1739         case WLAN_CATEGORY_SPECTRUM_MGMT:
1740                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
1741                         return RX_DROP_MONITOR;
1742
1743                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
1744                         return RX_DROP_MONITOR;
1745
1746                 switch (mgmt->u.action.u.measurement.action_code) {
1747                 case WLAN_ACTION_SPCT_MSR_REQ:
1748                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1749                                    sizeof(mgmt->u.action.u.measurement)))
1750                                 return RX_DROP_MONITOR;
1751                         ieee80211_process_measurement_req(sdata, mgmt, len);
1752                         break;
1753                 case WLAN_ACTION_SPCT_CHL_SWITCH:
1754                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1755                                    sizeof(mgmt->u.action.u.chan_switch)))
1756                                 return RX_DROP_MONITOR;
1757
1758                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1759                                 return RX_DROP_MONITOR;
1760
1761                         if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
1762                                 return RX_DROP_MONITOR;
1763
1764                         bss = ieee80211_rx_bss_get(local, sdata->u.mgd.bssid,
1765                                            local->hw.conf.channel->center_freq,
1766                                            sdata->u.mgd.ssid,
1767                                            sdata->u.mgd.ssid_len);
1768                         if (!bss)
1769                                 return RX_DROP_MONITOR;
1770
1771                         ieee80211_sta_process_chanswitch(sdata,
1772                                      &mgmt->u.action.u.chan_switch.sw_elem, bss);
1773                         ieee80211_rx_bss_put(local, bss);
1774                         break;
1775                 }
1776                 break;
1777         case WLAN_CATEGORY_SA_QUERY:
1778                 if (len < (IEEE80211_MIN_ACTION_SIZE +
1779                            sizeof(mgmt->u.action.u.sa_query)))
1780                         return RX_DROP_MONITOR;
1781                 switch (mgmt->u.action.u.sa_query.action) {
1782                 case WLAN_ACTION_SA_QUERY_REQUEST:
1783                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1784                                 return RX_DROP_MONITOR;
1785                         ieee80211_process_sa_query_req(sdata, mgmt, len);
1786                         break;
1787                 case WLAN_ACTION_SA_QUERY_RESPONSE:
1788                         /*
1789                          * SA Query response is currently only used in AP mode
1790                          * and it is processed in user space.
1791                          */
1792                         return RX_CONTINUE;
1793                 }
1794                 break;
1795         default:
1796                 return RX_CONTINUE;
1797         }
1798
1799         rx->sta->rx_packets++;
1800         dev_kfree_skb(rx->skb);
1801         return RX_QUEUED;
1802 }
1803
1804 static ieee80211_rx_result debug_noinline
1805 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
1806 {
1807         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1808         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1809
1810         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1811                 return RX_DROP_MONITOR;
1812
1813         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1814                 return RX_DROP_MONITOR;
1815
1816         if (ieee80211_vif_is_mesh(&sdata->vif))
1817                 return ieee80211_mesh_rx_mgmt(sdata, rx->skb);
1818
1819         if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
1820                 return ieee80211_ibss_rx_mgmt(sdata, rx->skb);
1821
1822         if (sdata->vif.type == NL80211_IFTYPE_STATION)
1823                 return ieee80211_sta_rx_mgmt(sdata, rx->skb);
1824
1825         return RX_DROP_MONITOR;
1826 }
1827
1828 static void ieee80211_rx_michael_mic_report(struct net_device *dev,
1829                                             struct ieee80211_hdr *hdr,
1830                                             struct ieee80211_rx_data *rx)
1831 {
1832         int keyidx;
1833         unsigned int hdrlen;
1834
1835         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1836         if (rx->skb->len >= hdrlen + 4)
1837                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
1838         else
1839                 keyidx = -1;
1840
1841         if (!rx->sta) {
1842                 /*
1843                  * Some hardware seem to generate incorrect Michael MIC
1844                  * reports; ignore them to avoid triggering countermeasures.
1845                  */
1846                 goto ignore;
1847         }
1848
1849         if (!ieee80211_has_protected(hdr->frame_control))
1850                 goto ignore;
1851
1852         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
1853                 /*
1854                  * APs with pairwise keys should never receive Michael MIC
1855                  * errors for non-zero keyidx because these are reserved for
1856                  * group keys and only the AP is sending real multicast
1857                  * frames in the BSS.
1858                  */
1859                 goto ignore;
1860         }
1861
1862         if (!ieee80211_is_data(hdr->frame_control) &&
1863             !ieee80211_is_auth(hdr->frame_control))
1864                 goto ignore;
1865
1866         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
1867                                         GFP_ATOMIC);
1868  ignore:
1869         dev_kfree_skb(rx->skb);
1870         rx->skb = NULL;
1871 }
1872
1873 /* TODO: use IEEE80211_RX_FRAGMENTED */
1874 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
1875 {
1876         struct ieee80211_sub_if_data *sdata;
1877         struct ieee80211_local *local = rx->local;
1878         struct ieee80211_rtap_hdr {
1879                 struct ieee80211_radiotap_header hdr;
1880                 u8 flags;
1881                 u8 rate;
1882                 __le16 chan_freq;
1883                 __le16 chan_flags;
1884         } __attribute__ ((packed)) *rthdr;
1885         struct sk_buff *skb = rx->skb, *skb2;
1886         struct net_device *prev_dev = NULL;
1887         struct ieee80211_rx_status *status = rx->status;
1888
1889         if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
1890                 goto out_free_skb;
1891
1892         if (skb_headroom(skb) < sizeof(*rthdr) &&
1893             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
1894                 goto out_free_skb;
1895
1896         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
1897         memset(rthdr, 0, sizeof(*rthdr));
1898         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
1899         rthdr->hdr.it_present =
1900                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
1901                             (1 << IEEE80211_RADIOTAP_RATE) |
1902                             (1 << IEEE80211_RADIOTAP_CHANNEL));
1903
1904         rthdr->rate = rx->rate->bitrate / 5;
1905         rthdr->chan_freq = cpu_to_le16(status->freq);
1906
1907         if (status->band == IEEE80211_BAND_5GHZ)
1908                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
1909                                                 IEEE80211_CHAN_5GHZ);
1910         else
1911                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
1912                                                 IEEE80211_CHAN_2GHZ);
1913
1914         skb_set_mac_header(skb, 0);
1915         skb->ip_summed = CHECKSUM_UNNECESSARY;
1916         skb->pkt_type = PACKET_OTHERHOST;
1917         skb->protocol = htons(ETH_P_802_2);
1918
1919         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1920                 if (!netif_running(sdata->dev))
1921                         continue;
1922
1923                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
1924                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
1925                         continue;
1926
1927                 if (prev_dev) {
1928                         skb2 = skb_clone(skb, GFP_ATOMIC);
1929                         if (skb2) {
1930                                 skb2->dev = prev_dev;
1931                                 netif_rx(skb2);
1932                         }
1933                 }
1934
1935                 prev_dev = sdata->dev;
1936                 sdata->dev->stats.rx_packets++;
1937                 sdata->dev->stats.rx_bytes += skb->len;
1938         }
1939
1940         if (prev_dev) {
1941                 skb->dev = prev_dev;
1942                 netif_rx(skb);
1943                 skb = NULL;
1944         } else
1945                 goto out_free_skb;
1946
1947         rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
1948         return;
1949
1950  out_free_skb:
1951         dev_kfree_skb(skb);
1952 }
1953
1954
1955 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
1956                                          struct ieee80211_rx_data *rx,
1957                                          struct sk_buff *skb)
1958 {
1959         ieee80211_rx_result res = RX_DROP_MONITOR;
1960
1961         rx->skb = skb;
1962         rx->sdata = sdata;
1963         rx->dev = sdata->dev;
1964
1965 #define CALL_RXH(rxh)                   \
1966         do {                            \
1967                 res = rxh(rx);          \
1968                 if (res != RX_CONTINUE) \
1969                         goto rxh_done;  \
1970         } while (0);
1971
1972         CALL_RXH(ieee80211_rx_h_passive_scan)
1973         CALL_RXH(ieee80211_rx_h_check)
1974         CALL_RXH(ieee80211_rx_h_decrypt)
1975         CALL_RXH(ieee80211_rx_h_check_more_data)
1976         CALL_RXH(ieee80211_rx_h_sta_process)
1977         CALL_RXH(ieee80211_rx_h_defragment)
1978         CALL_RXH(ieee80211_rx_h_ps_poll)
1979         CALL_RXH(ieee80211_rx_h_michael_mic_verify)
1980         /* must be after MMIC verify so header is counted in MPDU mic */
1981         CALL_RXH(ieee80211_rx_h_remove_qos_control)
1982         CALL_RXH(ieee80211_rx_h_amsdu)
1983 #ifdef CONFIG_MAC80211_MESH
1984         if (ieee80211_vif_is_mesh(&sdata->vif))
1985                 CALL_RXH(ieee80211_rx_h_mesh_fwding);
1986 #endif
1987         CALL_RXH(ieee80211_rx_h_data)
1988         CALL_RXH(ieee80211_rx_h_ctrl)
1989         CALL_RXH(ieee80211_rx_h_action)
1990         CALL_RXH(ieee80211_rx_h_mgmt)
1991
1992 #undef CALL_RXH
1993
1994  rxh_done:
1995         switch (res) {
1996         case RX_DROP_MONITOR:
1997                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1998                 if (rx->sta)
1999                         rx->sta->rx_dropped++;
2000                 /* fall through */
2001         case RX_CONTINUE:
2002                 ieee80211_rx_cooked_monitor(rx);
2003                 break;
2004         case RX_DROP_UNUSABLE:
2005                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2006                 if (rx->sta)
2007                         rx->sta->rx_dropped++;
2008                 dev_kfree_skb(rx->skb);
2009                 break;
2010         case RX_QUEUED:
2011                 I802_DEBUG_INC(sdata->local->rx_handlers_queued);
2012                 break;
2013         }
2014 }
2015
2016 /* main receive path */
2017
2018 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
2019                                 struct ieee80211_rx_data *rx,
2020                                 struct ieee80211_hdr *hdr)
2021 {
2022         u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len, sdata->vif.type);
2023         int multicast = is_multicast_ether_addr(hdr->addr1);
2024
2025         switch (sdata->vif.type) {
2026         case NL80211_IFTYPE_STATION:
2027                 if (!bssid)
2028                         return 0;
2029                 if (!ieee80211_bssid_match(bssid, sdata->u.mgd.bssid)) {
2030                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2031                                 return 0;
2032                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2033                 } else if (!multicast &&
2034                            compare_ether_addr(sdata->dev->dev_addr,
2035                                               hdr->addr1) != 0) {
2036                         if (!(sdata->dev->flags & IFF_PROMISC))
2037                                 return 0;
2038                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2039                 }
2040                 break;
2041         case NL80211_IFTYPE_ADHOC:
2042                 if (!bssid)
2043                         return 0;
2044                 if (ieee80211_is_beacon(hdr->frame_control)) {
2045                         return 1;
2046                 }
2047                 else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2048                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2049                                 return 0;
2050                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2051                 } else if (!multicast &&
2052                            compare_ether_addr(sdata->dev->dev_addr,
2053                                               hdr->addr1) != 0) {
2054                         if (!(sdata->dev->flags & IFF_PROMISC))
2055                                 return 0;
2056                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2057                 } else if (!rx->sta) {
2058                         int rate_idx;
2059                         if (rx->status->flag & RX_FLAG_HT)
2060                                 rate_idx = 0; /* TODO: HT rates */
2061                         else
2062                                 rate_idx = rx->status->rate_idx;
2063                         rx->sta = ieee80211_ibss_add_sta(sdata, bssid, hdr->addr2,
2064                                 BIT(rate_idx));
2065                 }
2066                 break;
2067         case NL80211_IFTYPE_MESH_POINT:
2068                 if (!multicast &&
2069                     compare_ether_addr(sdata->dev->dev_addr,
2070                                        hdr->addr1) != 0) {
2071                         if (!(sdata->dev->flags & IFF_PROMISC))
2072                                 return 0;
2073
2074                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2075                 }
2076                 break;
2077         case NL80211_IFTYPE_AP_VLAN:
2078         case NL80211_IFTYPE_AP:
2079                 if (!bssid) {
2080                         if (compare_ether_addr(sdata->dev->dev_addr,
2081                                                hdr->addr1))
2082                                 return 0;
2083                 } else if (!ieee80211_bssid_match(bssid,
2084                                         sdata->dev->dev_addr)) {
2085                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2086                                 return 0;
2087                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2088                 }
2089                 break;
2090         case NL80211_IFTYPE_WDS:
2091                 if (bssid || !ieee80211_is_data(hdr->frame_control))
2092                         return 0;
2093                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2094                         return 0;
2095                 break;
2096         case NL80211_IFTYPE_MONITOR:
2097                 /* take everything */
2098                 break;
2099         case NL80211_IFTYPE_UNSPECIFIED:
2100         case __NL80211_IFTYPE_AFTER_LAST:
2101                 /* should never get here */
2102                 WARN_ON(1);
2103                 break;
2104         }
2105
2106         return 1;
2107 }
2108
2109 /*
2110  * This is the actual Rx frames handler. as it blongs to Rx path it must
2111  * be called with rcu_read_lock protection.
2112  */
2113 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2114                                          struct sk_buff *skb,
2115                                          struct ieee80211_rate *rate)
2116 {
2117         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2118         struct ieee80211_local *local = hw_to_local(hw);
2119         struct ieee80211_sub_if_data *sdata;
2120         struct ieee80211_hdr *hdr;
2121         struct ieee80211_rx_data rx;
2122         int prepares;
2123         struct ieee80211_sub_if_data *prev = NULL;
2124         struct sk_buff *skb_new;
2125
2126         hdr = (struct ieee80211_hdr *)skb->data;
2127         memset(&rx, 0, sizeof(rx));
2128         rx.skb = skb;
2129         rx.local = local;
2130
2131         rx.status = status;
2132         rx.rate = rate;
2133
2134         if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
2135                 local->dot11ReceivedFragmentCount++;
2136
2137         rx.sta = sta_info_get(local, hdr->addr2);
2138         if (rx.sta) {
2139                 rx.sdata = rx.sta->sdata;
2140                 rx.dev = rx.sta->sdata->dev;
2141         }
2142
2143         if ((status->flag & RX_FLAG_MMIC_ERROR)) {
2144                 ieee80211_rx_michael_mic_report(local->mdev, hdr, &rx);
2145                 return;
2146         }
2147
2148         if (unlikely(local->sw_scanning || local->hw_scanning))
2149                 rx.flags |= IEEE80211_RX_IN_SCAN;
2150
2151         ieee80211_parse_qos(&rx);
2152         ieee80211_verify_alignment(&rx);
2153
2154         skb = rx.skb;
2155
2156         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2157                 if (!netif_running(sdata->dev))
2158                         continue;
2159
2160                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR)
2161                         continue;
2162
2163                 rx.flags |= IEEE80211_RX_RA_MATCH;
2164                 prepares = prepare_for_handlers(sdata, &rx, hdr);
2165
2166                 if (!prepares)
2167                         continue;
2168
2169                 /*
2170                  * frame is destined for this interface, but if it's not
2171                  * also for the previous one we handle that after the
2172                  * loop to avoid copying the SKB once too much
2173                  */
2174
2175                 if (!prev) {
2176                         prev = sdata;
2177                         continue;
2178                 }
2179
2180                 /*
2181                  * frame was destined for the previous interface
2182                  * so invoke RX handlers for it
2183                  */
2184
2185                 skb_new = skb_copy(skb, GFP_ATOMIC);
2186                 if (!skb_new) {
2187                         if (net_ratelimit())
2188                                 printk(KERN_DEBUG "%s: failed to copy "
2189                                        "multicast frame for %s\n",
2190                                        wiphy_name(local->hw.wiphy),
2191                                        prev->dev->name);
2192                         continue;
2193                 }
2194                 ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
2195                 prev = sdata;
2196         }
2197         if (prev)
2198                 ieee80211_invoke_rx_handlers(prev, &rx, skb);
2199         else
2200                 dev_kfree_skb(skb);
2201 }
2202
2203 #define SEQ_MODULO 0x1000
2204 #define SEQ_MASK   0xfff
2205
2206 static inline int seq_less(u16 sq1, u16 sq2)
2207 {
2208         return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
2209 }
2210
2211 static inline u16 seq_inc(u16 sq)
2212 {
2213         return (sq + 1) & SEQ_MASK;
2214 }
2215
2216 static inline u16 seq_sub(u16 sq1, u16 sq2)
2217 {
2218         return (sq1 - sq2) & SEQ_MASK;
2219 }
2220
2221
2222 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
2223                                             struct tid_ampdu_rx *tid_agg_rx,
2224                                             int index)
2225 {
2226         struct ieee80211_supported_band *sband;
2227         struct ieee80211_rate *rate;
2228         struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
2229         struct ieee80211_rx_status *status;
2230
2231         if (!skb)
2232                 goto no_frame;
2233
2234         status = IEEE80211_SKB_RXCB(skb);
2235
2236         /* release the reordered frames to stack */
2237         sband = hw->wiphy->bands[status->band];
2238         if (status->flag & RX_FLAG_HT)
2239                 rate = sband->bitrates; /* TODO: HT rates */
2240         else
2241                 rate = &sband->bitrates[status->rate_idx];
2242         __ieee80211_rx_handle_packet(hw, skb, rate);
2243         tid_agg_rx->stored_mpdu_num--;
2244         tid_agg_rx->reorder_buf[index] = NULL;
2245
2246 no_frame:
2247         tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2248 }
2249
2250
2251 /*
2252  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
2253  * the skb was added to the buffer longer than this time ago, the earlier
2254  * frames that have not yet been received are assumed to be lost and the skb
2255  * can be released for processing. This may also release other skb's from the
2256  * reorder buffer if there are no additional gaps between the frames.
2257  */
2258 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
2259
2260 /*
2261  * As it function blongs to Rx path it must be called with
2262  * the proper rcu_read_lock protection for its flow.
2263  */
2264 static u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
2265                                            struct tid_ampdu_rx *tid_agg_rx,
2266                                            struct sk_buff *skb,
2267                                            u16 mpdu_seq_num,
2268                                            int bar_req)
2269 {
2270         u16 head_seq_num, buf_size;
2271         int index;
2272
2273         buf_size = tid_agg_rx->buf_size;
2274         head_seq_num = tid_agg_rx->head_seq_num;
2275
2276         /* frame with out of date sequence number */
2277         if (seq_less(mpdu_seq_num, head_seq_num)) {
2278                 dev_kfree_skb(skb);
2279                 return 1;
2280         }
2281
2282         /* if frame sequence number exceeds our buffering window size or
2283          * block Ack Request arrived - release stored frames */
2284         if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
2285                 /* new head to the ordering buffer */
2286                 if (bar_req)
2287                         head_seq_num = mpdu_seq_num;
2288                 else
2289                         head_seq_num =
2290                                 seq_inc(seq_sub(mpdu_seq_num, buf_size));
2291                 /* release stored frames up to new head to stack */
2292                 while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
2293                         index = seq_sub(tid_agg_rx->head_seq_num,
2294                                 tid_agg_rx->ssn)
2295                                 % tid_agg_rx->buf_size;
2296                         ieee80211_release_reorder_frame(hw, tid_agg_rx,
2297                                                         index);
2298                 }
2299                 if (bar_req)
2300                         return 1;
2301         }
2302
2303         /* now the new frame is always in the range of the reordering */
2304         /* buffer window */
2305         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
2306                                 % tid_agg_rx->buf_size;
2307         /* check if we already stored this frame */
2308         if (tid_agg_rx->reorder_buf[index]) {
2309                 dev_kfree_skb(skb);
2310                 return 1;
2311         }
2312
2313         /* if arrived mpdu is in the right order and nothing else stored */
2314         /* release it immediately */
2315         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
2316                         tid_agg_rx->stored_mpdu_num == 0) {
2317                 tid_agg_rx->head_seq_num =
2318                         seq_inc(tid_agg_rx->head_seq_num);
2319                 return 0;
2320         }
2321
2322         /* put the frame in the reordering buffer */
2323         tid_agg_rx->reorder_buf[index] = skb;
2324         tid_agg_rx->reorder_time[index] = jiffies;
2325         tid_agg_rx->stored_mpdu_num++;
2326         /* release the buffer until next missing frame */
2327         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
2328                                                 % tid_agg_rx->buf_size;
2329         if (!tid_agg_rx->reorder_buf[index] &&
2330             tid_agg_rx->stored_mpdu_num > 1) {
2331                 /*
2332                  * No buffers ready to be released, but check whether any
2333                  * frames in the reorder buffer have timed out.
2334                  */
2335                 int j;
2336                 int skipped = 1;
2337                 for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
2338                      j = (j + 1) % tid_agg_rx->buf_size) {
2339                         if (tid_agg_rx->reorder_buf[j] == NULL) {
2340                                 skipped++;
2341                                 continue;
2342                         }
2343                         if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
2344                                         HZ / 10))
2345                                 break;
2346
2347 #ifdef CONFIG_MAC80211_HT_DEBUG
2348                         if (net_ratelimit())
2349                                 printk(KERN_DEBUG "%s: release an RX reorder "
2350                                        "frame due to timeout on earlier "
2351                                        "frames\n",
2352                                        wiphy_name(hw->wiphy));
2353 #endif
2354                         ieee80211_release_reorder_frame(hw, tid_agg_rx, j);
2355
2356                         /*
2357                          * Increment the head seq# also for the skipped slots.
2358                          */
2359                         tid_agg_rx->head_seq_num =
2360                                 (tid_agg_rx->head_seq_num + skipped) &
2361                                 SEQ_MASK;
2362                         skipped = 0;
2363                 }
2364         } else while (tid_agg_rx->reorder_buf[index]) {
2365                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
2366                 index = seq_sub(tid_agg_rx->head_seq_num,
2367                         tid_agg_rx->ssn) % tid_agg_rx->buf_size;
2368         }
2369         return 1;
2370 }
2371
2372 static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
2373                                      struct sk_buff *skb)
2374 {
2375         struct ieee80211_hw *hw = &local->hw;
2376         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2377         struct sta_info *sta;
2378         struct tid_ampdu_rx *tid_agg_rx;
2379         u16 sc;
2380         u16 mpdu_seq_num;
2381         u8 ret = 0;
2382         int tid;
2383
2384         sta = sta_info_get(local, hdr->addr2);
2385         if (!sta)
2386                 return ret;
2387
2388         /* filter the QoS data rx stream according to
2389          * STA/TID and check if this STA/TID is on aggregation */
2390         if (!ieee80211_is_data_qos(hdr->frame_control))
2391                 goto end_reorder;
2392
2393         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
2394
2395         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
2396                 goto end_reorder;
2397
2398         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
2399
2400         /* qos null data frames are excluded */
2401         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
2402                 goto end_reorder;
2403
2404         /* new un-ordered ampdu frame - process it */
2405
2406         /* reset session timer */
2407         if (tid_agg_rx->timeout)
2408                 mod_timer(&tid_agg_rx->session_timer,
2409                           TU_TO_EXP_TIME(tid_agg_rx->timeout));
2410
2411         /* if this mpdu is fragmented - terminate rx aggregation session */
2412         sc = le16_to_cpu(hdr->seq_ctrl);
2413         if (sc & IEEE80211_SCTL_FRAG) {
2414                 ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
2415                         tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
2416                 ret = 1;
2417                 goto end_reorder;
2418         }
2419
2420         /* according to mpdu sequence number deal with reordering buffer */
2421         mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2422         ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb,
2423                                                 mpdu_seq_num, 0);
2424  end_reorder:
2425         return ret;
2426 }
2427
2428 /*
2429  * This is the receive path handler. It is called by a low level driver when an
2430  * 802.11 MPDU is received from the hardware.
2431  */
2432 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2433 {
2434         struct ieee80211_local *local = hw_to_local(hw);
2435         struct ieee80211_rate *rate = NULL;
2436         struct ieee80211_supported_band *sband;
2437         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2438
2439         if (status->band < 0 ||
2440             status->band >= IEEE80211_NUM_BANDS) {
2441                 WARN_ON(1);
2442                 return;
2443         }
2444
2445         sband = local->hw.wiphy->bands[status->band];
2446         if (!sband) {
2447                 WARN_ON(1);
2448                 return;
2449         }
2450
2451         if (status->flag & RX_FLAG_HT) {
2452                 /* rate_idx is MCS index */
2453                 if (WARN_ON(status->rate_idx < 0 ||
2454                             status->rate_idx >= 76))
2455                         return;
2456                 /* HT rates are not in the table - use the highest legacy rate
2457                  * for now since other parts of mac80211 may not yet be fully
2458                  * MCS aware. */
2459                 rate = &sband->bitrates[sband->n_bitrates - 1];
2460         } else {
2461                 if (WARN_ON(status->rate_idx < 0 ||
2462                             status->rate_idx >= sband->n_bitrates))
2463                         return;
2464                 rate = &sband->bitrates[status->rate_idx];
2465         }
2466
2467         /*
2468          * key references and virtual interfaces are protected using RCU
2469          * and this requires that we are in a read-side RCU section during
2470          * receive processing
2471          */
2472         rcu_read_lock();
2473
2474         /*
2475          * Frames with failed FCS/PLCP checksum are not returned,
2476          * all other frames are returned without radiotap header
2477          * if it was previously present.
2478          * Also, frames with less than 16 bytes are dropped.
2479          */
2480         skb = ieee80211_rx_monitor(local, skb, rate);
2481         if (!skb) {
2482                 rcu_read_unlock();
2483                 return;
2484         }
2485
2486         /*
2487          * In theory, the block ack reordering should happen after duplicate
2488          * removal (ieee80211_rx_h_check(), which is an RX handler). As such,
2489          * the call to ieee80211_rx_reorder_ampdu() should really be moved to
2490          * happen as a new RX handler between ieee80211_rx_h_check and
2491          * ieee80211_rx_h_decrypt. This cleanup may eventually happen, but for
2492          * the time being, the call can be here since RX reorder buf processing
2493          * will implicitly skip duplicates. We could, in theory at least,
2494          * process frames that ieee80211_rx_h_passive_scan would drop (e.g.,
2495          * frames from other than operational channel), but that should not
2496          * happen in normal networks.
2497          */
2498         if (!ieee80211_rx_reorder_ampdu(local, skb))
2499                 __ieee80211_rx_handle_packet(hw, skb, rate);
2500
2501         rcu_read_unlock();
2502 }
2503 EXPORT_SYMBOL(__ieee80211_rx);
2504
2505 /* This is a version of the rx handler that can be called from hard irq
2506  * context. Post the skb on the queue and schedule the tasklet */
2507 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
2508 {
2509         struct ieee80211_local *local = hw_to_local(hw);
2510
2511         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2512
2513         skb->dev = local->mdev;
2514         skb->pkt_type = IEEE80211_RX_MSG;
2515         skb_queue_tail(&local->skb_queue, skb);
2516         tasklet_schedule(&local->tasklet);
2517 }
2518 EXPORT_SYMBOL(ieee80211_rx_irqsafe);