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 void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
  31                                              struct tid_ampdu_rx *tid_agg_rx,
  32                                              u16 head_seq_num);
  33
  34 /*
  35  * monitor mode reception
  36  *
  37  * This function cleans up the SKB, i.e. it removes all the stuff
  38  * only useful for monitoring.
  39  */
  40 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
  41                                            struct sk_buff *skb)
  42 {
  43         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
  44                 if (likely(skb->len > FCS_LEN))
  45                         skb_trim(skb, skb->len - FCS_LEN);
  46                 else {
  47                         /* driver bug */
  48                         WARN_ON(1);
  49                         dev_kfree_skb(skb);
  50                         skb = NULL;
  51                 }
  52         }
  53
  54         return skb;
  55 }
  56
  57 static inline int should_drop_frame(struct sk_buff *skb,
  58                                     int present_fcs_len)
  59 {
  60         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  61         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  62
  63         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
  64                 return 1;
  65         if (unlikely(skb->len < 16 + present_fcs_len))
  66                 return 1;
  67         if (ieee80211_is_ctl(hdr->frame_control) &&
  68             !ieee80211_is_pspoll(hdr->frame_control) &&
  69             !ieee80211_is_back_req(hdr->frame_control))
  70                 return 1;
  71         return 0;
  72 }
  73
  74 static int
  75 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
  76                           struct ieee80211_rx_status *status)
  77 {
  78         int len;
  79
  80         /* always present fields */
  81         len = sizeof(struct ieee80211_radiotap_header) + 9;
  82
  83         if (status->flag & RX_FLAG_TSFT)
  84                 len += 8;
  85         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
  86                 len += 1;
  87         if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
  88                 len += 1;
  89
  90         if (len & 1) /* padding for RX_FLAGS if necessary */
  91                 len++;
  92
  93         return len;
  94 }
  95
  96 /*
  97  * ieee80211_add_rx_radiotap_header - add radiotap header
  98  *
  99  * add a radiotap header containing all the fields which the hardware provided.
 100  */
 101 static void
 102 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
 103                                  struct sk_buff *skb,
 104                                  struct ieee80211_rate *rate,
 105                                  int rtap_len)
 106 {
 107         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 108         struct ieee80211_radiotap_header *rthdr;
 109         unsigned char *pos;
 110         u16 rx_flags = 0;
 111
 112         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
 113         memset(rthdr, 0, rtap_len);
 114
 115         /* radiotap header, set always present flags */
 116         rthdr->it_present =
 117                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 118                             (1 << IEEE80211_RADIOTAP_CHANNEL) |
 119                             (1 << IEEE80211_RADIOTAP_ANTENNA) |
 120                             (1 << IEEE80211_RADIOTAP_RX_FLAGS));
 121         rthdr->it_len = cpu_to_le16(rtap_len);
 122
 123         pos = (unsigned char *)(rthdr+1);
 124
 125         /* the order of the following fields is important */
 126
 127         /* IEEE80211_RADIOTAP_TSFT */
 128         if (status->flag & RX_FLAG_TSFT) {
 129                 put_unaligned_le64(status->mactime, pos);
 130                 rthdr->it_present |=
 131                         cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
 132                 pos += 8;
 133         }
 134
 135         /* IEEE80211_RADIOTAP_FLAGS */
 136         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 137                 *pos |= IEEE80211_RADIOTAP_F_FCS;
 138         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 139                 *pos |= IEEE80211_RADIOTAP_F_BADFCS;
 140         if (status->flag & RX_FLAG_SHORTPRE)
 141                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
 142         pos++;
 143
 144         /* IEEE80211_RADIOTAP_RATE */
 145         if (status->flag & RX_FLAG_HT) {
 146                 /*
 147                  * TODO: add following information into radiotap header once
 148                  * suitable fields are defined for it:
 149                  * - MCS index (status->rate_idx)
 150                  * - HT40 (status->flag & RX_FLAG_40MHZ)
 151                  * - short-GI (status->flag & RX_FLAG_SHORT_GI)
 152                  */
 153                 *pos = 0;
 154         } else {
 155                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
 156                 *pos = rate->bitrate / 5;
 157         }
 158         pos++;
 159
 160         /* IEEE80211_RADIOTAP_CHANNEL */
 161         put_unaligned_le16(status->freq, pos);
 162         pos += 2;
 163         if (status->band == IEEE80211_BAND_5GHZ)
 164                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ,
 165                                    pos);
 166         else if (rate->flags & IEEE80211_RATE_ERP_G)
 167                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
 168                                    pos);
 169         else
 170                 put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
 171                                    pos);
 172         pos += 2;
 173
 174         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
 175         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
 176                 *pos = status->signal;
 177                 rthdr->it_present |=
 178                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
 179                 pos++;
 180         }
 181
 182         /* IEEE80211_RADIOTAP_DBM_ANTNOISE */
 183         if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
 184                 *pos = status->noise;
 185                 rthdr->it_present |=
 186                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
 187                 pos++;
 188         }
 189
 190         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
 191
 192         /* IEEE80211_RADIOTAP_ANTENNA */
 193         *pos = status->antenna;
 194         pos++;
 195
 196         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
 197
 198         /* IEEE80211_RADIOTAP_RX_FLAGS */
 199         /* ensure 2 byte alignment for the 2 byte field as required */
 200         if ((pos - (u8 *)rthdr) & 1)
 201                 pos++;
 202         if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
 203                 rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
 204         put_unaligned_le16(rx_flags, pos);
 205         pos += 2;
 206 }
 207
 208 /*
 209  * This function copies a received frame to all monitor interfaces and
 210  * returns a cleaned-up SKB that no longer includes the FCS nor the
 211  * radiotap header the driver might have added.
 212  */
 213 static struct sk_buff *
 214 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
 215                      struct ieee80211_rate *rate)
 216 {
 217         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
 218         struct ieee80211_sub_if_data *sdata;
 219         int needed_headroom = 0;
 220         struct sk_buff *skb, *skb2;
 221         struct net_device *prev_dev = NULL;
 222         int present_fcs_len = 0;
 223
 224         /*
 225          * First, we may need to make a copy of the skb because
 226          *  (1) we need to modify it for radiotap (if not present), and
 227          *  (2) the other RX handlers will modify the skb we got.
 228          *
 229          * We don't need to, of course, if we aren't going to return
 230          * the SKB because it has a bad FCS/PLCP checksum.
 231          */
 232
 233         /* room for the radiotap header based on driver features */
 234         needed_headroom = ieee80211_rx_radiotap_len(local, status);
 235
 236         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 237                 present_fcs_len = FCS_LEN;
 238
 239         if (!local->monitors) {
 240                 if (should_drop_frame(origskb, present_fcs_len)) {
 241                         dev_kfree_skb(origskb);
 242                         return NULL;
 243                 }
 244
 245                 return remove_monitor_info(local, origskb);
 246         }
 247
 248         if (should_drop_frame(origskb, present_fcs_len)) {
 249                 /* only need to expand headroom if necessary */
 250                 skb = origskb;
 251                 origskb = NULL;
 252
 253                 /*
 254                  * This shouldn't trigger often because most devices have an
 255                  * RX header they pull before we get here, and that should
 256                  * be big enough for our radiotap information. We should
 257                  * probably export the length to drivers so that we can have
 258                  * them allocate enough headroom to start with.
 259                  */
 260                 if (skb_headroom(skb) < needed_headroom &&
 261                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
 262                         dev_kfree_skb(skb);
 263                         return NULL;
 264                 }
 265         } else {
 266                 /*
 267                  * Need to make a copy and possibly remove radiotap header
 268                  * and FCS from the original.
 269                  */
 270                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 271
 272                 origskb = remove_monitor_info(local, origskb);
 273
 274                 if (!skb)
 275                         return origskb;
 276         }
 277
 278         /* prepend radiotap information */
 279         ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom);
 280
 281         skb_reset_mac_header(skb);
 282         skb->ip_summed = CHECKSUM_UNNECESSARY;
 283         skb->pkt_type = PACKET_OTHERHOST;
 284         skb->protocol = htons(ETH_P_802_2);
 285
 286         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 287                 if (!netif_running(sdata->dev))
 288                         continue;
 289
 290                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
 291                         continue;
 292
 293                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
 294                         continue;
 295
 296                 if (prev_dev) {
 297                         skb2 = skb_clone(skb, GFP_ATOMIC);
 298                         if (skb2) {
 299                                 skb2->dev = prev_dev;
 300                                 netif_rx(skb2);
 301                         }
 302                 }
 303
 304                 prev_dev = sdata->dev;
 305                 sdata->dev->stats.rx_packets++;
 306                 sdata->dev->stats.rx_bytes += skb->len;
 307         }
 308
 309         if (prev_dev) {
 310                 skb->dev = prev_dev;
 311                 netif_rx(skb);
 312         } else
 313                 dev_kfree_skb(skb);
 314
 315         return origskb;
 316 }
 317
 318
 319 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
 320 {
 321         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 322         int tid;
 323
 324         /* does the frame have a qos control field? */
 325         if (ieee80211_is_data_qos(hdr->frame_control)) {
 326                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 327                 /* frame has qos control */
 328                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
 329                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
 330                         rx->flags |= IEEE80211_RX_AMSDU;
 331                 else
 332                         rx->flags &= ~IEEE80211_RX_AMSDU;
 333         } else {
 334                 /*
 335                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
 336                  *
 337                  *      Sequence numbers for management frames, QoS data
 338                  *      frames with a broadcast/multicast address in the
 339                  *      Address 1 field, and all non-QoS data frames sent
 340                  *      by QoS STAs are assigned using an additional single
 341                  *      modulo-4096 counter, [...]
 342                  *
 343                  * We also use that counter for non-QoS STAs.
 344                  */
 345                 tid = NUM_RX_DATA_QUEUES - 1;
 346         }
 347
 348         rx->queue = tid;
 349         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 350          * For now, set skb->priority to 0 for other cases. */
 351         rx->skb->priority = (tid > 7) ? 0 : tid;
 352 }
 353
 354 /**
 355  * DOC: Packet alignment
 356  *
 357  * Drivers always need to pass packets that are aligned to two-byte boundaries
 358  * to the stack.
 359  *
 360  * Additionally, should, if possible, align the payload data in a way that
 361  * guarantees that the contained IP header is aligned to a four-byte
 362  * boundary. In the case of regular frames, this simply means aligning the
 363  * payload to a four-byte boundary (because either the IP header is directly
 364  * contained, or IV/RFC1042 headers that have a length divisible by four are
 365  * in front of it).
 366  *
 367  * With A-MSDU frames, however, the payload data address must yield two modulo
 368  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
 369  * push the IP header further back to a multiple of four again. Thankfully, the
 370  * specs were sane enough this time around to require padding each A-MSDU
 371  * subframe to a length that is a multiple of four.
 372  *
 373  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
 374  * the payload is not supported, the driver is required to move the 802.11
 375  * header to be directly in front of the payload in that case.
 376  */
 377 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
 378 {
 379         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 380         int hdrlen;
 381
 382 #ifndef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
 383         return;
 384 #endif
 385
 386         if (WARN_ONCE((unsigned long)rx->skb->data & 1,
 387                       "unaligned packet at 0x%p\n", rx->skb->data))
 388                 return;
 389
 390         if (!ieee80211_is_data_present(hdr->frame_control))
 391                 return;
 392
 393         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 394         if (rx->flags & IEEE80211_RX_AMSDU)
 395                 hdrlen += ETH_HLEN;
 396         WARN_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3,
 397                   "unaligned IP payload at 0x%p\n", rx->skb->data + hdrlen);
 398 }
 399
 400
 401 /* rx handlers */
 402
 403 static ieee80211_rx_result debug_noinline
 404 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 405 {
 406         struct ieee80211_local *local = rx->local;
 407         struct sk_buff *skb = rx->skb;
 408
 409         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning)))
 410                 return ieee80211_scan_rx(rx->sdata, skb);
 411
 412         if (unlikely(test_bit(SCAN_SW_SCANNING, &local->scanning) &&
 413                      (rx->flags & IEEE80211_RX_IN_SCAN))) {
 414                 /* drop all the other packets during a software scan anyway */
 415                 if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
 416                         dev_kfree_skb(skb);
 417                 return RX_QUEUED;
 418         }
 419
 420         if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
 421                 /* scanning finished during invoking of handlers */
 422                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 423                 return RX_DROP_UNUSABLE;
 424         }
 425
 426         return RX_CONTINUE;
 427 }
 428
 429
 430 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
 431 {
 432         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 433
 434         if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
 435                 return 0;
 436
 437         return ieee80211_is_robust_mgmt_frame(hdr);
 438 }
 439
 440
 441 static int ieee80211_is_multicast_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 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
 453 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
 454 {
 455         struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
 456         struct ieee80211_mmie *mmie;
 457
 458         if (skb->len < 24 + sizeof(*mmie) ||
 459             !is_multicast_ether_addr(hdr->da))
 460                 return -1;
 461
 462         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
 463                 return -1; /* not a robust management frame */
 464
 465         mmie = (struct ieee80211_mmie *)
 466                 (skb->data + skb->len - sizeof(*mmie));
 467         if (mmie->element_id != WLAN_EID_MMIE ||
 468             mmie->length != sizeof(*mmie) - 2)
 469                 return -1;
 470
 471         return le16_to_cpu(mmie->key_id);
 472 }
 473
 474
 475 static ieee80211_rx_result
 476 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 477 {
 478         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 479         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 480         char *dev_addr = rx->dev->dev_addr;
 481
 482         if (ieee80211_is_data(hdr->frame_control)) {
 483                 if (is_multicast_ether_addr(hdr->addr1)) {
 484                         if (ieee80211_has_tods(hdr->frame_control) ||
 485                                 !ieee80211_has_fromds(hdr->frame_control))
 486                                 return RX_DROP_MONITOR;
 487                         if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
 488                                 return RX_DROP_MONITOR;
 489                 } else {
 490                         if (!ieee80211_has_a4(hdr->frame_control))
 491                                 return RX_DROP_MONITOR;
 492                         if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
 493                                 return RX_DROP_MONITOR;
 494                 }
 495         }
 496
 497         /* If there is not an established peer link and this is not a peer link
 498          * establisment frame, beacon or probe, drop the frame.
 499          */
 500
 501         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
 502                 struct ieee80211_mgmt *mgmt;
 503
 504                 if (!ieee80211_is_mgmt(hdr->frame_control))
 505                         return RX_DROP_MONITOR;
 506
 507                 if (ieee80211_is_action(hdr->frame_control)) {
 508                         mgmt = (struct ieee80211_mgmt *)hdr;
 509                         if (mgmt->u.action.category != MESH_PLINK_CATEGORY)
 510                                 return RX_DROP_MONITOR;
 511                         return RX_CONTINUE;
 512                 }
 513
 514                 if (ieee80211_is_probe_req(hdr->frame_control) ||
 515                     ieee80211_is_probe_resp(hdr->frame_control) ||
 516                     ieee80211_is_beacon(hdr->frame_control))
 517                         return RX_CONTINUE;
 518
 519                 return RX_DROP_MONITOR;
 520
 521         }
 522
 523 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
 524
 525         if (ieee80211_is_data(hdr->frame_control) &&
 526             is_multicast_ether_addr(hdr->addr1) &&
 527             mesh_rmc_check(hdr->addr3, msh_h_get(hdr, hdrlen), rx->sdata))
 528                 return RX_DROP_MONITOR;
 529 #undef msh_h_get
 530
 531         return RX_CONTINUE;
 532 }
 533
 534
 535 static ieee80211_rx_result debug_noinline
 536 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
 537 {
 538         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 539
 540         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 541         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 542                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
 543                              rx->sta->last_seq_ctrl[rx->queue] ==
 544                              hdr->seq_ctrl)) {
 545                         if (rx->flags & IEEE80211_RX_RA_MATCH) {
 546                                 rx->local->dot11FrameDuplicateCount++;
 547                                 rx->sta->num_duplicates++;
 548                         }
 549                         return RX_DROP_MONITOR;
 550                 } else
 551                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
 552         }
 553
 554         if (unlikely(rx->skb->len < 16)) {
 555                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 556                 return RX_DROP_MONITOR;
 557         }
 558
 559         /* Drop disallowed frame classes based on STA auth/assoc state;
 560          * IEEE 802.11, Chap 5.5.
 561          *
 562          * mac80211 filters only based on association state, i.e. it drops
 563          * Class 3 frames from not associated stations. hostapd sends
 564          * deauth/disassoc frames when needed. In addition, hostapd is
 565          * responsible for filtering on both auth and assoc states.
 566          */
 567
 568         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
 569                 return ieee80211_rx_mesh_check(rx);
 570
 571         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
 572                       ieee80211_is_pspoll(hdr->frame_control)) &&
 573                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
 574                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
 575                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
 576                      !ieee80211_has_tods(hdr->frame_control) &&
 577                      ieee80211_is_data(hdr->frame_control)) ||
 578                     !(rx->flags & IEEE80211_RX_RA_MATCH)) {
 579                         /* Drop IBSS frames and frames for other hosts
 580                          * silently. */
 581                         return RX_DROP_MONITOR;
 582                 }
 583
 584                 return RX_DROP_MONITOR;
 585         }
 586
 587         return RX_CONTINUE;
 588 }
 589
 590
 591 static ieee80211_rx_result debug_noinline
 592 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 593 {
 594         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 595         int keyidx;
 596         int hdrlen;
 597         ieee80211_rx_result result = RX_DROP_UNUSABLE;
 598         struct ieee80211_key *stakey = NULL;
 599         int mmie_keyidx = -1;
 600
 601         /*
 602          * Key selection 101
 603          *
 604          * There are four types of keys:
 605          *  - GTK (group keys)
 606          *  - IGTK (group keys for management frames)
 607          *  - PTK (pairwise keys)
 608          *  - STK (station-to-station pairwise keys)
 609          *
 610          * When selecting a key, we have to distinguish between multicast
 611          * (including broadcast) and unicast frames, the latter can only
 612          * use PTKs and STKs while the former always use GTKs and IGTKs.
 613          * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
 614          * unicast frames can also use key indices like GTKs. Hence, if we
 615          * don't have a PTK/STK we check the key index for a WEP key.
 616          *
 617          * Note that in a regular BSS, multicast frames are sent by the
 618          * AP only, associated stations unicast the frame to the AP first
 619          * which then multicasts it on their behalf.
 620          *
 621          * There is also a slight problem in IBSS mode: GTKs are negotiated
 622          * with each station, that is something we don't currently handle.
 623          * The spec seems to expect that one negotiates the same key with
 624          * every station but there's no such requirement; VLANs could be
 625          * possible.
 626          */
 627
 628         /*
 629          * No point in finding a key and decrypting if the frame is neither
 630          * addressed to us nor a multicast frame.
 631          */
 632         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 633                 return RX_CONTINUE;
 634
 635         if (rx->sta)
 636                 stakey = rcu_dereference(rx->sta->key);
 637
 638         if (!ieee80211_has_protected(hdr->frame_control))
 639                 mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
 640
 641         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
 642                 rx->key = stakey;
 643                 /* Skip decryption if the frame is not protected. */
 644                 if (!ieee80211_has_protected(hdr->frame_control))
 645                         return RX_CONTINUE;
 646         } else if (mmie_keyidx >= 0) {
 647                 /* Broadcast/multicast robust management frame / BIP */
 648                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
 649                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
 650                         return RX_CONTINUE;
 651
 652                 if (mmie_keyidx < NUM_DEFAULT_KEYS ||
 653                     mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 654                         return RX_DROP_MONITOR; /* unexpected BIP keyidx */
 655                 rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
 656         } else if (!ieee80211_has_protected(hdr->frame_control)) {
 657                 /*
 658                  * The frame was not protected, so skip decryption. However, we
 659                  * need to set rx->key if there is a key that could have been
 660                  * used so that the frame may be dropped if encryption would
 661                  * have been expected.
 662                  */
 663                 struct ieee80211_key *key = NULL;
 664                 if (ieee80211_is_mgmt(hdr->frame_control) &&
 665                     is_multicast_ether_addr(hdr->addr1) &&
 666                     (key = rcu_dereference(rx->sdata->default_mgmt_key)))
 667                         rx->key = key;
 668                 else if ((key = rcu_dereference(rx->sdata->default_key)))
 669                         rx->key = key;
 670                 return RX_CONTINUE;
 671         } else {
 672                 /*
 673                  * The device doesn't give us the IV so we won't be
 674                  * able to look up the key. That's ok though, we
 675                  * don't need to decrypt the frame, we just won't
 676                  * be able to keep statistics accurate.
 677                  * Except for key threshold notifications, should
 678                  * we somehow allow the driver to tell us which key
 679                  * the hardware used if this flag is set?
 680                  */
 681                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
 682                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
 683                         return RX_CONTINUE;
 684
 685                 hdrlen = ieee80211_hdrlen(hdr->frame_control);
 686
 687                 if (rx->skb->len < 8 + hdrlen)
 688                         return RX_DROP_UNUSABLE; /* TODO: count this? */
 689
 690                 /*
 691                  * no need to call ieee80211_wep_get_keyidx,
 692                  * it verifies a bunch of things we've done already
 693                  */
 694                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
 695
 696                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
 697
 698                 /*
 699                  * RSNA-protected unicast frames should always be sent with
 700                  * pairwise or station-to-station keys, but for WEP we allow
 701                  * using a key index as well.
 702                  */
 703                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
 704                     !is_multicast_ether_addr(hdr->addr1))
 705                         rx->key = NULL;
 706         }
 707
 708         if (rx->key) {
 709                 rx->key->tx_rx_count++;
 710                 /* TODO: add threshold stuff again */
 711         } else {
 712                 return RX_DROP_MONITOR;
 713         }
 714
 715         /* Check for weak IVs if possible */
 716         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
 717             ieee80211_is_data(hdr->frame_control) &&
 718             (!(rx->status->flag & RX_FLAG_IV_STRIPPED) ||
 719              !(rx->status->flag & RX_FLAG_DECRYPTED)) &&
 720             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
 721                 rx->sta->wep_weak_iv_count++;
 722
 723         switch (rx->key->conf.alg) {
 724         case ALG_WEP:
 725                 result = ieee80211_crypto_wep_decrypt(rx);
 726                 break;
 727         case ALG_TKIP:
 728                 result = ieee80211_crypto_tkip_decrypt(rx);
 729                 break;
 730         case ALG_CCMP:
 731                 result = ieee80211_crypto_ccmp_decrypt(rx);
 732                 break;
 733         case ALG_AES_CMAC:
 734                 result = ieee80211_crypto_aes_cmac_decrypt(rx);
 735                 break;
 736         }
 737
 738         /* either the frame has been decrypted or will be dropped */
 739         rx->status->flag |= RX_FLAG_DECRYPTED;
 740
 741         return result;
 742 }
 743
 744 static ieee80211_rx_result debug_noinline
 745 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
 746 {
 747         struct ieee80211_local *local;
 748         struct ieee80211_hdr *hdr;
 749         struct sk_buff *skb;
 750
 751         local = rx->local;
 752         skb = rx->skb;
 753         hdr = (struct ieee80211_hdr *) skb->data;
 754
 755         if (!local->pspolling)
 756                 return RX_CONTINUE;
 757
 758         if (!ieee80211_has_fromds(hdr->frame_control))
 759                 /* this is not from AP */
 760                 return RX_CONTINUE;
 761
 762         if (!ieee80211_is_data(hdr->frame_control))
 763                 return RX_CONTINUE;
 764
 765         if (!ieee80211_has_moredata(hdr->frame_control)) {
 766                 /* AP has no more frames buffered for us */
 767                 local->pspolling = false;
 768                 return RX_CONTINUE;
 769         }
 770
 771         /* more data bit is set, let's request a new frame from the AP */
 772         ieee80211_send_pspoll(local, rx->sdata);
 773
 774         return RX_CONTINUE;
 775 }
 776
 777 static void ap_sta_ps_start(struct sta_info *sta)
 778 {
 779         struct ieee80211_sub_if_data *sdata = sta->sdata;
 780         struct ieee80211_local *local = sdata->local;
 781
 782         atomic_inc(&sdata->bss->num_sta_ps);
 783         set_sta_flags(sta, WLAN_STA_PS_STA);
 784         drv_sta_notify(local, &sdata->vif, STA_NOTIFY_SLEEP, &sta->sta);
 785 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 786         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
 787                sdata->dev->name, sta->sta.addr, sta->sta.aid);
 788 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 789 }
 790
 791 static void ap_sta_ps_end(struct sta_info *sta)
 792 {
 793         struct ieee80211_sub_if_data *sdata = sta->sdata;
 794
 795         atomic_dec(&sdata->bss->num_sta_ps);
 796
 797         clear_sta_flags(sta, WLAN_STA_PS_STA);
 798
 799 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 800         printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
 801                sdata->dev->name, sta->sta.addr, sta->sta.aid);
 802 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 803
 804         if (test_sta_flags(sta, WLAN_STA_PS_DRIVER)) {
 805 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 806                 printk(KERN_DEBUG "%s: STA %pM aid %d driver-ps-blocked\n",
 807                        sdata->dev->name, sta->sta.addr, sta->sta.aid);
 808 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 809                 return;
 810         }
 811
 812         ieee80211_sta_ps_deliver_wakeup(sta);
 813 }
 814
 815 static ieee80211_rx_result debug_noinline
 816 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
 817 {
 818         struct sta_info *sta = rx->sta;
 819         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 820
 821         if (!sta)
 822                 return RX_CONTINUE;
 823
 824         /*
 825          * Update last_rx only for IBSS packets which are for the current
 826          * BSSID to avoid keeping the current IBSS network alive in cases
 827          * where other STAs start using different BSSID.
 828          */
 829         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
 830                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
 831                                                 NL80211_IFTYPE_ADHOC);
 832                 if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
 833                         sta->last_rx = jiffies;
 834         } else if (!is_multicast_ether_addr(hdr->addr1)) {
 835                 /*
 836                  * Mesh beacons will update last_rx when if they are found to
 837                  * match the current local configuration when processed.
 838                  */
 839                 sta->last_rx = jiffies;
 840         }
 841
 842         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 843                 return RX_CONTINUE;
 844
 845         if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
 846                 ieee80211_sta_rx_notify(rx->sdata, hdr);
 847
 848         sta->rx_fragments++;
 849         sta->rx_bytes += rx->skb->len;
 850         sta->last_signal = rx->status->signal;
 851         sta->last_noise = rx->status->noise;
 852
 853         /*
 854          * Change STA power saving mode only at the end of a frame
 855          * exchange sequence.
 856          */
 857         if (!ieee80211_has_morefrags(hdr->frame_control) &&
 858             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
 859              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
 860                 if (test_sta_flags(sta, WLAN_STA_PS_STA)) {
 861                         /*
 862                          * Ignore doze->wake transitions that are
 863                          * indicated by non-data frames, the standard
 864                          * is unclear here, but for example going to
 865                          * PS mode and then scanning would cause a
 866                          * doze->wake transition for the probe request,
 867                          * and that is clearly undesirable.
 868                          */
 869                         if (ieee80211_is_data(hdr->frame_control) &&
 870                             !ieee80211_has_pm(hdr->frame_control))
 871                                 ap_sta_ps_end(sta);
 872                 } else {
 873                         if (ieee80211_has_pm(hdr->frame_control))
 874                                 ap_sta_ps_start(sta);
 875                 }
 876         }
 877
 878         /*
 879          * Drop (qos-)data::nullfunc frames silently, since they
 880          * are used only to control station power saving mode.
 881          */
 882         if (ieee80211_is_nullfunc(hdr->frame_control) ||
 883             ieee80211_is_qos_nullfunc(hdr->frame_control)) {
 884                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
 885                 /*
 886                  * Update counter and free packet here to avoid
 887                  * counting this as a dropped packed.
 888                  */
 889                 sta->rx_packets++;
 890                 dev_kfree_skb(rx->skb);
 891                 return RX_QUEUED;
 892         }
 893
 894         return RX_CONTINUE;
 895 } /* ieee80211_rx_h_sta_process */
 896
 897 static inline struct ieee80211_fragment_entry *
 898 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
 899                          unsigned int frag, unsigned int seq, int rx_queue,
 900                          struct sk_buff **skb)
 901 {
 902         struct ieee80211_fragment_entry *entry;
 903         int idx;
 904
 905         idx = sdata->fragment_next;
 906         entry = &sdata->fragments[sdata->fragment_next++];
 907         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
 908                 sdata->fragment_next = 0;
 909
 910         if (!skb_queue_empty(&entry->skb_list)) {
 911 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 912                 struct ieee80211_hdr *hdr =
 913                         (struct ieee80211_hdr *) entry->skb_list.next->data;
 914                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
 915                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
 916                        "addr1=%pM addr2=%pM\n",
 917                        sdata->dev->name, idx,
 918                        jiffies - entry->first_frag_time, entry->seq,
 919                        entry->last_frag, hdr->addr1, hdr->addr2);
 920 #endif
 921                 __skb_queue_purge(&entry->skb_list);
 922         }
 923
 924         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
 925         *skb = NULL;
 926         entry->first_frag_time = jiffies;
 927         entry->seq = seq;
 928         entry->rx_queue = rx_queue;
 929         entry->last_frag = frag;
 930         entry->ccmp = 0;
 931         entry->extra_len = 0;
 932
 933         return entry;
 934 }
 935
 936 static inline struct ieee80211_fragment_entry *
 937 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
 938                           unsigned int frag, unsigned int seq,
 939                           int rx_queue, struct ieee80211_hdr *hdr)
 940 {
 941         struct ieee80211_fragment_entry *entry;
 942         int i, idx;
 943
 944         idx = sdata->fragment_next;
 945         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
 946                 struct ieee80211_hdr *f_hdr;
 947
 948                 idx--;
 949                 if (idx < 0)
 950                         idx = IEEE80211_FRAGMENT_MAX - 1;
 951
 952                 entry = &sdata->fragments[idx];
 953                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
 954                     entry->rx_queue != rx_queue ||
 955                     entry->last_frag + 1 != frag)
 956                         continue;
 957
 958                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
 959
 960                 /*
 961                  * Check ftype and addresses are equal, else check next fragment
 962                  */
 963                 if (((hdr->frame_control ^ f_hdr->frame_control) &
 964                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
 965                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
 966                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
 967                         continue;
 968
 969                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
 970                         __skb_queue_purge(&entry->skb_list);
 971                         continue;
 972                 }
 973                 return entry;
 974         }
 975
 976         return NULL;
 977 }
 978
 979 static ieee80211_rx_result debug_noinline
 980 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 981 {
 982         struct ieee80211_hdr *hdr;
 983         u16 sc;
 984         __le16 fc;
 985         unsigned int frag, seq;
 986         struct ieee80211_fragment_entry *entry;
 987         struct sk_buff *skb;
 988
 989         hdr = (struct ieee80211_hdr *)rx->skb->data;
 990         fc = hdr->frame_control;
 991         sc = le16_to_cpu(hdr->seq_ctrl);
 992         frag = sc & IEEE80211_SCTL_FRAG;
 993
 994         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
 995                    (rx->skb)->len < 24 ||
 996                    is_multicast_ether_addr(hdr->addr1))) {
 997                 /* not fragmented */
 998                 goto out;
 999         }
1000         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1001
1002         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1003
1004         if (frag == 0) {
1005                 /* This is the first fragment of a new frame. */
1006                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1007                                                  rx->queue, &(rx->skb));
1008                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
1009                     ieee80211_has_protected(fc)) {
1010                         /* Store CCMP PN so that we can verify that the next
1011                          * fragment has a sequential PN value. */
1012                         entry->ccmp = 1;
1013                         memcpy(entry->last_pn,
1014                                rx->key->u.ccmp.rx_pn[rx->queue],
1015                                CCMP_PN_LEN);
1016                 }
1017                 return RX_QUEUED;
1018         }
1019
1020         /* This is a fragment for a frame that should already be pending in
1021          * fragment cache. Add this fragment to the end of the pending entry.
1022          */
1023         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1024         if (!entry) {
1025                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1026                 return RX_DROP_MONITOR;
1027         }
1028
1029         /* Verify that MPDUs within one MSDU have sequential PN values.
1030          * (IEEE 802.11i, 8.3.3.4.5) */
1031         if (entry->ccmp) {
1032                 int i;
1033                 u8 pn[CCMP_PN_LEN], *rpn;
1034                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
1035                         return RX_DROP_UNUSABLE;
1036                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1037                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1038                         pn[i]++;
1039                         if (pn[i])
1040                                 break;
1041                 }
1042                 rpn = rx->key->u.ccmp.rx_pn[rx->queue];
1043                 if (memcmp(pn, rpn, CCMP_PN_LEN))
1044                         return RX_DROP_UNUSABLE;
1045                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1046         }
1047
1048         skb_pull(rx->skb, ieee80211_hdrlen(fc));
1049         __skb_queue_tail(&entry->skb_list, rx->skb);
1050         entry->last_frag = frag;
1051         entry->extra_len += rx->skb->len;
1052         if (ieee80211_has_morefrags(fc)) {
1053                 rx->skb = NULL;
1054                 return RX_QUEUED;
1055         }
1056
1057         rx->skb = __skb_dequeue(&entry->skb_list);
1058         if (skb_tailroom(rx->skb) < entry->extra_len) {
1059                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1060                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1061                                               GFP_ATOMIC))) {
1062                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1063                         __skb_queue_purge(&entry->skb_list);
1064                         return RX_DROP_UNUSABLE;
1065                 }
1066         }
1067         while ((skb = __skb_dequeue(&entry->skb_list))) {
1068                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1069                 dev_kfree_skb(skb);
1070         }
1071
1072         /* Complete frame has been reassembled - process it now */
1073         rx->flags |= IEEE80211_RX_FRAGMENTED;
1074
1075  out:
1076         if (rx->sta)
1077                 rx->sta->rx_packets++;
1078         if (is_multicast_ether_addr(hdr->addr1))
1079                 rx->local->dot11MulticastReceivedFrameCount++;
1080         else
1081                 ieee80211_led_rx(rx->local);
1082         return RX_CONTINUE;
1083 }
1084
1085 static ieee80211_rx_result debug_noinline
1086 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1087 {
1088         struct ieee80211_sub_if_data *sdata = rx->sdata;
1089         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1090
1091         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1092                    !(rx->flags & IEEE80211_RX_RA_MATCH)))
1093                 return RX_CONTINUE;
1094
1095         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1096             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1097                 return RX_DROP_UNUSABLE;
1098
1099         if (!test_sta_flags(rx->sta, WLAN_STA_PS_DRIVER))
1100                 ieee80211_sta_ps_deliver_poll_response(rx->sta);
1101         else
1102                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1103
1104         /* Free PS Poll skb here instead of returning RX_DROP that would
1105          * count as an dropped frame. */
1106         dev_kfree_skb(rx->skb);
1107
1108         return RX_QUEUED;
1109 }
1110
1111 static ieee80211_rx_result debug_noinline
1112 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1113 {
1114         u8 *data = rx->skb->data;
1115         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1116
1117         if (!ieee80211_is_data_qos(hdr->frame_control))
1118                 return RX_CONTINUE;
1119
1120         /* remove the qos control field, update frame type and meta-data */
1121         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1122                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1123         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1124         /* change frame type to non QOS */
1125         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1126
1127         return RX_CONTINUE;
1128 }
1129
1130 static int
1131 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1132 {
1133         if (unlikely(!rx->sta ||
1134             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1135                 return -EACCES;
1136
1137         return 0;
1138 }
1139
1140 static int
1141 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1142 {
1143         /*
1144          * Pass through unencrypted frames if the hardware has
1145          * decrypted them already.
1146          */
1147         if (rx->status->flag & RX_FLAG_DECRYPTED)
1148                 return 0;
1149
1150         /* Drop unencrypted frames if key is set. */
1151         if (unlikely(!ieee80211_has_protected(fc) &&
1152                      !ieee80211_is_nullfunc(fc) &&
1153                      ieee80211_is_data(fc) &&
1154                      (rx->key || rx->sdata->drop_unencrypted)))
1155                 return -EACCES;
1156         if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1157                 if (unlikely(ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1158                              rx->key))
1159                         return -EACCES;
1160                 /* BIP does not use Protected field, so need to check MMIE */
1161                 if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb)
1162                              && ieee80211_get_mmie_keyidx(rx->skb) < 0 &&
1163                              rx->key))
1164                         return -EACCES;
1165                 /*
1166                  * When using MFP, Action frames are not allowed prior to
1167                  * having configured keys.
1168                  */
1169                 if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1170                              ieee80211_is_robust_mgmt_frame(
1171                                      (struct ieee80211_hdr *) rx->skb->data)))
1172                         return -EACCES;
1173         }
1174
1175         return 0;
1176 }
1177
1178 static int
1179 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1180 {
1181         struct net_device *dev = rx->dev;
1182         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1183         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1184
1185         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->use_4addr &&
1186             ieee80211_has_a4(hdr->frame_control))
1187                 return -1;
1188         if (sdata->use_4addr && is_multicast_ether_addr(hdr->addr1))
1189                 return -1;
1190
1191         return ieee80211_data_to_8023(rx->skb, dev->dev_addr, sdata->vif.type);
1192 }
1193
1194 /*
1195  * requires that rx->skb is a frame with ethernet header
1196  */
1197 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1198 {
1199         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1200                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1201         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1202
1203         /*
1204          * Allow EAPOL frames to us/the PAE group address regardless
1205          * of whether the frame was encrypted or not.
1206          */
1207         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1208             (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1209              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1210                 return true;
1211
1212         if (ieee80211_802_1x_port_control(rx) ||
1213             ieee80211_drop_unencrypted(rx, fc))
1214                 return false;
1215
1216         return true;
1217 }
1218
1219 /*
1220  * requires that rx->skb is a frame with ethernet header
1221  */
1222 static void
1223 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1224 {
1225         struct net_device *dev = rx->dev;
1226         struct ieee80211_local *local = rx->local;
1227         struct sk_buff *skb, *xmit_skb;
1228         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1229         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1230         struct sta_info *dsta;
1231
1232         skb = rx->skb;
1233         xmit_skb = NULL;
1234
1235         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1236              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1237             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1238             (rx->flags & IEEE80211_RX_RA_MATCH) && !rx->sdata->use_4addr) {
1239                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1240                         /*
1241                          * send multicast frames both to higher layers in
1242                          * local net stack and back to the wireless medium
1243                          */
1244                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1245                         if (!xmit_skb && net_ratelimit())
1246                                 printk(KERN_DEBUG "%s: failed to clone "
1247                                        "multicast frame\n", dev->name);
1248                 } else {
1249                         dsta = sta_info_get(local, skb->data);
1250                         if (dsta && dsta->sdata->dev == dev) {
1251                                 /*
1252                                  * The destination station is associated to
1253                                  * this AP (in this VLAN), so send the frame
1254                                  * directly to it and do not pass it to local
1255                                  * net stack.
1256                                  */
1257                                 xmit_skb = skb;
1258                                 skb = NULL;
1259                         }
1260                 }
1261         }
1262
1263         if (skb) {
1264                 int align __maybe_unused;
1265
1266 #if defined(CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT) || !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
1267                 /*
1268                  * 'align' will only take the values 0 or 2 here
1269                  * since all frames are required to be aligned
1270                  * to 2-byte boundaries when being passed to
1271                  * mac80211. That also explains the __skb_push()
1272                  * below.
1273                  */
1274                 align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1275                 if (align) {
1276                         if (WARN_ON(skb_headroom(skb) < 3)) {
1277                                 dev_kfree_skb(skb);
1278                                 skb = NULL;
1279                         } else {
1280                                 u8 *data = skb->data;
1281                                 size_t len = skb_headlen(skb);
1282                                 skb->data -= align;
1283                                 memmove(skb->data, data, len);
1284                                 skb_set_tail_pointer(skb, len);
1285                         }
1286                 }
1287 #endif
1288
1289                 if (skb) {
1290                         /* deliver to local stack */
1291                         skb->protocol = eth_type_trans(skb, dev);
1292                         memset(skb->cb, 0, sizeof(skb->cb));
1293                         netif_rx(skb);
1294                 }
1295         }
1296
1297         if (xmit_skb) {
1298                 /* send to wireless media */
1299                 xmit_skb->protocol = htons(ETH_P_802_3);
1300                 skb_reset_network_header(xmit_skb);
1301                 skb_reset_mac_header(xmit_skb);
1302                 dev_queue_xmit(xmit_skb);
1303         }
1304 }
1305
1306 static ieee80211_rx_result debug_noinline
1307 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1308 {
1309         struct net_device *dev = rx->dev;
1310         struct ieee80211_local *local = rx->local;
1311         u16 ethertype;
1312         u8 *payload;
1313         struct sk_buff *skb = rx->skb, *frame = NULL;
1314         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1315         __le16 fc = hdr->frame_control;
1316         const struct ethhdr *eth;
1317         int remaining, err;
1318         u8 dst[ETH_ALEN];
1319         u8 src[ETH_ALEN];
1320
1321         if (unlikely(!ieee80211_is_data(fc)))
1322                 return RX_CONTINUE;
1323
1324         if (unlikely(!ieee80211_is_data_present(fc)))
1325                 return RX_DROP_MONITOR;
1326
1327         if (!(rx->flags & IEEE80211_RX_AMSDU))
1328                 return RX_CONTINUE;
1329
1330         err = __ieee80211_data_to_8023(rx);
1331         if (unlikely(err))
1332                 return RX_DROP_UNUSABLE;
1333
1334         skb->dev = dev;
1335
1336         dev->stats.rx_packets++;
1337         dev->stats.rx_bytes += skb->len;
1338
1339         /* skip the wrapping header */
1340         eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1341         if (!eth)
1342                 return RX_DROP_UNUSABLE;
1343
1344         while (skb != frame) {
1345                 u8 padding;
1346                 __be16 len = eth->h_proto;
1347                 unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1348
1349                 remaining = skb->len;
1350                 memcpy(dst, eth->h_dest, ETH_ALEN);
1351                 memcpy(src, eth->h_source, ETH_ALEN);
1352
1353                 padding = ((4 - subframe_len) & 0x3);
1354                 /* the last MSDU has no padding */
1355                 if (subframe_len > remaining)
1356                         return RX_DROP_UNUSABLE;
1357
1358                 skb_pull(skb, sizeof(struct ethhdr));
1359                 /* if last subframe reuse skb */
1360                 if (remaining <= subframe_len + padding)
1361                         frame = skb;
1362                 else {
1363                         /*
1364                          * Allocate and reserve two bytes more for payload
1365                          * alignment since sizeof(struct ethhdr) is 14.
1366                          */
1367                         frame = dev_alloc_skb(
1368                                 ALIGN(local->hw.extra_tx_headroom, 4) +
1369                                 subframe_len + 2);
1370
1371                         if (frame == NULL)
1372                                 return RX_DROP_UNUSABLE;
1373
1374                         skb_reserve(frame,
1375                                     ALIGN(local->hw.extra_tx_headroom, 4) +
1376                                     sizeof(struct ethhdr) + 2);
1377                         memcpy(skb_put(frame, ntohs(len)), skb->data,
1378                                 ntohs(len));
1379
1380                         eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1381                                                         padding);
1382                         if (!eth) {
1383                                 dev_kfree_skb(frame);
1384                                 return RX_DROP_UNUSABLE;
1385                         }
1386                 }
1387
1388                 skb_reset_network_header(frame);
1389                 frame->dev = dev;
1390                 frame->priority = skb->priority;
1391                 rx->skb = frame;
1392
1393                 payload = frame->data;
1394                 ethertype = (payload[6] << 8) | payload[7];
1395
1396                 if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1397                             ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1398                            compare_ether_addr(payload,
1399                                               bridge_tunnel_header) == 0)) {
1400                         /* remove RFC1042 or Bridge-Tunnel
1401                          * encapsulation and replace EtherType */
1402                         skb_pull(frame, 6);
1403                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1404                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1405                 } else {
1406                         memcpy(skb_push(frame, sizeof(__be16)),
1407                                &len, sizeof(__be16));
1408                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1409                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1410                 }
1411
1412                 if (!ieee80211_frame_allowed(rx, fc)) {
1413                         if (skb == frame) /* last frame */
1414                                 return RX_DROP_UNUSABLE;
1415                         dev_kfree_skb(frame);
1416                         continue;
1417                 }
1418
1419                 ieee80211_deliver_skb(rx);
1420         }
1421
1422         return RX_QUEUED;
1423 }
1424
1425 #ifdef CONFIG_MAC80211_MESH
1426 static ieee80211_rx_result
1427 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1428 {
1429         struct ieee80211_hdr *hdr;
1430         struct ieee80211s_hdr *mesh_hdr;
1431         unsigned int hdrlen;
1432         struct sk_buff *skb = rx->skb, *fwd_skb;
1433         struct ieee80211_local *local = rx->local;
1434         struct ieee80211_sub_if_data *sdata;
1435
1436         hdr = (struct ieee80211_hdr *) skb->data;
1437         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1438         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1439         sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1440
1441         if (!ieee80211_is_data(hdr->frame_control))
1442                 return RX_CONTINUE;
1443
1444         if (!mesh_hdr->ttl)
1445                 /* illegal frame */
1446                 return RX_DROP_MONITOR;
1447
1448         if (mesh_hdr->flags & MESH_FLAGS_AE) {
1449                 struct mesh_path *mppath;
1450                 char *proxied_addr;
1451                 char *mpp_addr;
1452
1453                 if (is_multicast_ether_addr(hdr->addr1)) {
1454                         mpp_addr = hdr->addr3;
1455                         proxied_addr = mesh_hdr->eaddr1;
1456                 } else {
1457                         mpp_addr = hdr->addr4;
1458                         proxied_addr = mesh_hdr->eaddr2;
1459                 }
1460
1461                 rcu_read_lock();
1462                 mppath = mpp_path_lookup(proxied_addr, sdata);
1463                 if (!mppath) {
1464                         mpp_path_add(proxied_addr, mpp_addr, sdata);
1465                 } else {
1466                         spin_lock_bh(&mppath->state_lock);
1467                         mppath->exp_time = jiffies;
1468                         if (compare_ether_addr(mppath->mpp, mpp_addr) != 0)
1469                                 memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
1470                         spin_unlock_bh(&mppath->state_lock);
1471                 }
1472                 rcu_read_unlock();
1473         }
1474
1475         /* Frame has reached destination.  Don't forward */
1476         if (!is_multicast_ether_addr(hdr->addr1) &&
1477                         compare_ether_addr(rx->dev->dev_addr, hdr->addr3) == 0)
1478                 return RX_CONTINUE;
1479
1480         mesh_hdr->ttl--;
1481
1482         if (rx->flags & IEEE80211_RX_RA_MATCH) {
1483                 if (!mesh_hdr->ttl)
1484                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1485                                                      dropped_frames_ttl);
1486                 else {
1487                         struct ieee80211_hdr *fwd_hdr;
1488                         struct ieee80211_tx_info *info;
1489
1490                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1491
1492                         if (!fwd_skb && net_ratelimit())
1493                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1494                                                    rx->dev->name);
1495
1496                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1497                         memcpy(fwd_hdr->addr2, rx->dev->dev_addr, ETH_ALEN);
1498                         info = IEEE80211_SKB_CB(fwd_skb);
1499                         memset(info, 0, sizeof(*info));
1500                         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1501                         info->control.vif = &rx->sdata->vif;
1502                         ieee80211_select_queue(local, fwd_skb);
1503                         if (is_multicast_ether_addr(fwd_hdr->addr1))
1504                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1505                                                                 fwded_mcast);
1506                         else {
1507                                 int err;
1508                                 /*
1509                                  * Save TA to addr1 to send TA a path error if a
1510                                  * suitable next hop is not found
1511                                  */
1512                                 memcpy(fwd_hdr->addr1, fwd_hdr->addr2,
1513                                                 ETH_ALEN);
1514                                 err = mesh_nexthop_lookup(fwd_skb, sdata);
1515                                 /* Failed to immediately resolve next hop:
1516                                  * fwded frame was dropped or will be added
1517                                  * later to the pending skb queue.  */
1518                                 if (err)
1519                                         return RX_DROP_MONITOR;
1520
1521                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1522                                                                 fwded_unicast);
1523                         }
1524                         IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1525                                                      fwded_frames);
1526                         ieee80211_add_pending_skb(local, fwd_skb);
1527                 }
1528         }
1529
1530         if (is_multicast_ether_addr(hdr->addr1) ||
1531             rx->dev->flags & IFF_PROMISC)
1532                 return RX_CONTINUE;
1533         else
1534                 return RX_DROP_MONITOR;
1535 }
1536 #endif
1537
1538 static ieee80211_rx_result debug_noinline
1539 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1540 {
1541         struct net_device *dev = rx->dev;
1542         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1543         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1544         __le16 fc = hdr->frame_control;
1545         int err;
1546
1547         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1548                 return RX_CONTINUE;
1549
1550         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1551                 return RX_DROP_MONITOR;
1552
1553         /*
1554          * Allow the cooked monitor interface of an AP to see 4-addr frames so
1555          * that a 4-addr station can be detected and moved into a separate VLAN
1556          */
1557         if (ieee80211_has_a4(hdr->frame_control) &&
1558             sdata->vif.type == NL80211_IFTYPE_AP)
1559                 return RX_DROP_MONITOR;
1560
1561         err = __ieee80211_data_to_8023(rx);
1562         if (unlikely(err))
1563                 return RX_DROP_UNUSABLE;
1564
1565         if (!ieee80211_frame_allowed(rx, fc))
1566                 return RX_DROP_MONITOR;
1567
1568         rx->skb->dev = dev;
1569
1570         dev->stats.rx_packets++;
1571         dev->stats.rx_bytes += rx->skb->len;
1572
1573         ieee80211_deliver_skb(rx);
1574
1575         return RX_QUEUED;
1576 }
1577
1578 static ieee80211_rx_result debug_noinline
1579 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1580 {
1581         struct ieee80211_local *local = rx->local;
1582         struct ieee80211_hw *hw = &local->hw;
1583         struct sk_buff *skb = rx->skb;
1584         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1585         struct tid_ampdu_rx *tid_agg_rx;
1586         u16 start_seq_num;
1587         u16 tid;
1588
1589         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1590                 return RX_CONTINUE;
1591
1592         if (ieee80211_is_back_req(bar->frame_control)) {
1593                 if (!rx->sta)
1594                         return RX_DROP_MONITOR;
1595                 tid = le16_to_cpu(bar->control) >> 12;
1596                 if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1597                                         != HT_AGG_STATE_OPERATIONAL)
1598                         return RX_DROP_MONITOR;
1599                 tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1600
1601                 start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1602
1603                 /* reset session timer */
1604                 if (tid_agg_rx->timeout)
1605                         mod_timer(&tid_agg_rx->session_timer,
1606                                   TU_TO_EXP_TIME(tid_agg_rx->timeout));
1607
1608                 /* release stored frames up to start of BAR */
1609                 ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num);
1610                 kfree_skb(skb);
1611                 return RX_QUEUED;
1612         }
1613
1614         return RX_CONTINUE;
1615 }
1616
1617 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
1618                                            struct ieee80211_mgmt *mgmt,
1619                                            size_t len)
1620 {
1621         struct ieee80211_local *local = sdata->local;
1622         struct sk_buff *skb;
1623         struct ieee80211_mgmt *resp;
1624
1625         if (compare_ether_addr(mgmt->da, sdata->dev->dev_addr) != 0) {
1626                 /* Not to own unicast address */
1627                 return;
1628         }
1629
1630         if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
1631             compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
1632                 /* Not from the current AP or not associated yet. */
1633                 return;
1634         }
1635
1636         if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
1637                 /* Too short SA Query request frame */
1638                 return;
1639         }
1640
1641         skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
1642         if (skb == NULL)
1643                 return;
1644
1645         skb_reserve(skb, local->hw.extra_tx_headroom);
1646         resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
1647         memset(resp, 0, 24);
1648         memcpy(resp->da, mgmt->sa, ETH_ALEN);
1649         memcpy(resp->sa, sdata->dev->dev_addr, ETH_ALEN);
1650         memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
1651         resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1652                                           IEEE80211_STYPE_ACTION);
1653         skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
1654         resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
1655         resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
1656         memcpy(resp->u.action.u.sa_query.trans_id,
1657                mgmt->u.action.u.sa_query.trans_id,
1658                WLAN_SA_QUERY_TR_ID_LEN);
1659
1660         ieee80211_tx_skb(sdata, skb, 1);
1661 }
1662
1663 static ieee80211_rx_result debug_noinline
1664 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1665 {
1666         struct ieee80211_local *local = rx->local;
1667         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1668         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1669         int len = rx->skb->len;
1670
1671         if (!ieee80211_is_action(mgmt->frame_control))
1672                 return RX_CONTINUE;
1673
1674         if (!rx->sta)
1675                 return RX_DROP_MONITOR;
1676
1677         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1678                 return RX_DROP_MONITOR;
1679
1680         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1681                 return RX_DROP_MONITOR;
1682
1683         /* all categories we currently handle have action_code */
1684         if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1685                 return RX_DROP_MONITOR;
1686
1687         switch (mgmt->u.action.category) {
1688         case WLAN_CATEGORY_BACK:
1689                 /*
1690                  * The aggregation code is not prepared to handle
1691                  * anything but STA/AP due to the BSSID handling;
1692                  * IBSS could work in the code but isn't supported
1693                  * by drivers or the standard.
1694                  */
1695                 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1696                     sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
1697                     sdata->vif.type != NL80211_IFTYPE_AP)
1698                         return RX_DROP_MONITOR;
1699
1700                 switch (mgmt->u.action.u.addba_req.action_code) {
1701                 case WLAN_ACTION_ADDBA_REQ:
1702                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1703                                    sizeof(mgmt->u.action.u.addba_req)))
1704                                 return RX_DROP_MONITOR;
1705                         ieee80211_process_addba_request(local, rx->sta, mgmt, len);
1706                         break;
1707                 case WLAN_ACTION_ADDBA_RESP:
1708                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1709                                    sizeof(mgmt->u.action.u.addba_resp)))
1710                                 return RX_DROP_MONITOR;
1711                         ieee80211_process_addba_resp(local, rx->sta, mgmt, len);
1712                         break;
1713                 case WLAN_ACTION_DELBA:
1714                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1715                                    sizeof(mgmt->u.action.u.delba)))
1716                                 return RX_DROP_MONITOR;
1717                         ieee80211_process_delba(sdata, rx->sta, mgmt, len);
1718                         break;
1719                 }
1720                 break;
1721         case WLAN_CATEGORY_SPECTRUM_MGMT:
1722                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
1723                         return RX_DROP_MONITOR;
1724
1725                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
1726                         return RX_DROP_MONITOR;
1727
1728                 switch (mgmt->u.action.u.measurement.action_code) {
1729                 case WLAN_ACTION_SPCT_MSR_REQ:
1730                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1731                                    sizeof(mgmt->u.action.u.measurement)))
1732                                 return RX_DROP_MONITOR;
1733                         ieee80211_process_measurement_req(sdata, mgmt, len);
1734                         break;
1735                 case WLAN_ACTION_SPCT_CHL_SWITCH:
1736                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1737                                    sizeof(mgmt->u.action.u.chan_switch)))
1738                                 return RX_DROP_MONITOR;
1739
1740                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1741                                 return RX_DROP_MONITOR;
1742
1743                         if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
1744                                 return RX_DROP_MONITOR;
1745
1746                         return ieee80211_sta_rx_mgmt(sdata, rx->skb);
1747                 }
1748                 break;
1749         case WLAN_CATEGORY_SA_QUERY:
1750                 if (len < (IEEE80211_MIN_ACTION_SIZE +
1751                            sizeof(mgmt->u.action.u.sa_query)))
1752                         return RX_DROP_MONITOR;
1753                 switch (mgmt->u.action.u.sa_query.action) {
1754                 case WLAN_ACTION_SA_QUERY_REQUEST:
1755                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1756                                 return RX_DROP_MONITOR;
1757                         ieee80211_process_sa_query_req(sdata, mgmt, len);
1758                         break;
1759                 case WLAN_ACTION_SA_QUERY_RESPONSE:
1760                         /*
1761                          * SA Query response is currently only used in AP mode
1762                          * and it is processed in user space.
1763                          */
1764                         return RX_CONTINUE;
1765                 }
1766                 break;
1767         default:
1768                 return RX_CONTINUE;
1769         }
1770
1771         rx->sta->rx_packets++;
1772         dev_kfree_skb(rx->skb);
1773         return RX_QUEUED;
1774 }
1775
1776 static ieee80211_rx_result debug_noinline
1777 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
1778 {
1779         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1780         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1781
1782         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1783                 return RX_DROP_MONITOR;
1784
1785         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1786                 return RX_DROP_MONITOR;
1787
1788         if (ieee80211_vif_is_mesh(&sdata->vif))
1789                 return ieee80211_mesh_rx_mgmt(sdata, rx->skb);
1790
1791         if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
1792                 return ieee80211_ibss_rx_mgmt(sdata, rx->skb);
1793
1794         if (sdata->vif.type == NL80211_IFTYPE_STATION)
1795                 return ieee80211_sta_rx_mgmt(sdata, rx->skb);
1796
1797         return RX_DROP_MONITOR;
1798 }
1799
1800 static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
1801                                             struct ieee80211_rx_data *rx)
1802 {
1803         int keyidx;
1804         unsigned int hdrlen;
1805
1806         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1807         if (rx->skb->len >= hdrlen + 4)
1808                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
1809         else
1810                 keyidx = -1;
1811
1812         if (!rx->sta) {
1813                 /*
1814                  * Some hardware seem to generate incorrect Michael MIC
1815                  * reports; ignore them to avoid triggering countermeasures.
1816                  */
1817                 return;
1818         }
1819
1820         if (!ieee80211_has_protected(hdr->frame_control))
1821                 return;
1822
1823         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
1824                 /*
1825                  * APs with pairwise keys should never receive Michael MIC
1826                  * errors for non-zero keyidx because these are reserved for
1827                  * group keys and only the AP is sending real multicast
1828                  * frames in the BSS.
1829                  */
1830                 return;
1831         }
1832
1833         if (!ieee80211_is_data(hdr->frame_control) &&
1834             !ieee80211_is_auth(hdr->frame_control))
1835                 return;
1836
1837         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
1838                                         GFP_ATOMIC);
1839 }
1840
1841 /* TODO: use IEEE80211_RX_FRAGMENTED */
1842 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
1843 {
1844         struct ieee80211_sub_if_data *sdata;
1845         struct ieee80211_local *local = rx->local;
1846         struct ieee80211_rtap_hdr {
1847                 struct ieee80211_radiotap_header hdr;
1848                 u8 flags;
1849                 u8 rate;
1850                 __le16 chan_freq;
1851                 __le16 chan_flags;
1852         } __attribute__ ((packed)) *rthdr;
1853         struct sk_buff *skb = rx->skb, *skb2;
1854         struct net_device *prev_dev = NULL;
1855         struct ieee80211_rx_status *status = rx->status;
1856
1857         if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
1858                 goto out_free_skb;
1859
1860         if (skb_headroom(skb) < sizeof(*rthdr) &&
1861             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
1862                 goto out_free_skb;
1863
1864         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
1865         memset(rthdr, 0, sizeof(*rthdr));
1866         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
1867         rthdr->hdr.it_present =
1868                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
1869                             (1 << IEEE80211_RADIOTAP_RATE) |
1870                             (1 << IEEE80211_RADIOTAP_CHANNEL));
1871
1872         rthdr->rate = rx->rate->bitrate / 5;
1873         rthdr->chan_freq = cpu_to_le16(status->freq);
1874
1875         if (status->band == IEEE80211_BAND_5GHZ)
1876                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
1877                                                 IEEE80211_CHAN_5GHZ);
1878         else
1879                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
1880                                                 IEEE80211_CHAN_2GHZ);
1881
1882         skb_set_mac_header(skb, 0);
1883         skb->ip_summed = CHECKSUM_UNNECESSARY;
1884         skb->pkt_type = PACKET_OTHERHOST;
1885         skb->protocol = htons(ETH_P_802_2);
1886
1887         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1888                 if (!netif_running(sdata->dev))
1889                         continue;
1890
1891                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
1892                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
1893                         continue;
1894
1895                 if (prev_dev) {
1896                         skb2 = skb_clone(skb, GFP_ATOMIC);
1897                         if (skb2) {
1898                                 skb2->dev = prev_dev;
1899                                 netif_rx(skb2);
1900                         }
1901                 }
1902
1903                 prev_dev = sdata->dev;
1904                 sdata->dev->stats.rx_packets++;
1905                 sdata->dev->stats.rx_bytes += skb->len;
1906         }
1907
1908         if (prev_dev) {
1909                 skb->dev = prev_dev;
1910                 netif_rx(skb);
1911                 skb = NULL;
1912         } else
1913                 goto out_free_skb;
1914
1915         rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
1916         return;
1917
1918  out_free_skb:
1919         dev_kfree_skb(skb);
1920 }
1921
1922
1923 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
1924                                          struct ieee80211_rx_data *rx,
1925                                          struct sk_buff *skb)
1926 {
1927         ieee80211_rx_result res = RX_DROP_MONITOR;
1928
1929         rx->skb = skb;
1930         rx->sdata = sdata;
1931         rx->dev = sdata->dev;
1932
1933 #define CALL_RXH(rxh)                   \
1934         do {                            \
1935                 res = rxh(rx);          \
1936                 if (res != RX_CONTINUE) \
1937                         goto rxh_done;  \
1938         } while (0);
1939
1940         CALL_RXH(ieee80211_rx_h_passive_scan)
1941         CALL_RXH(ieee80211_rx_h_check)
1942         CALL_RXH(ieee80211_rx_h_decrypt)
1943         CALL_RXH(ieee80211_rx_h_check_more_data)
1944         CALL_RXH(ieee80211_rx_h_sta_process)
1945         CALL_RXH(ieee80211_rx_h_defragment)
1946         CALL_RXH(ieee80211_rx_h_ps_poll)
1947         CALL_RXH(ieee80211_rx_h_michael_mic_verify)
1948         /* must be after MMIC verify so header is counted in MPDU mic */
1949         CALL_RXH(ieee80211_rx_h_remove_qos_control)
1950         CALL_RXH(ieee80211_rx_h_amsdu)
1951 #ifdef CONFIG_MAC80211_MESH
1952         if (ieee80211_vif_is_mesh(&sdata->vif))
1953                 CALL_RXH(ieee80211_rx_h_mesh_fwding);
1954 #endif
1955         CALL_RXH(ieee80211_rx_h_data)
1956         CALL_RXH(ieee80211_rx_h_ctrl)
1957         CALL_RXH(ieee80211_rx_h_action)
1958         CALL_RXH(ieee80211_rx_h_mgmt)
1959
1960 #undef CALL_RXH
1961
1962  rxh_done:
1963         switch (res) {
1964         case RX_DROP_MONITOR:
1965                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1966                 if (rx->sta)
1967                         rx->sta->rx_dropped++;
1968                 /* fall through */
1969         case RX_CONTINUE:
1970                 ieee80211_rx_cooked_monitor(rx);
1971                 break;
1972         case RX_DROP_UNUSABLE:
1973                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1974                 if (rx->sta)
1975                         rx->sta->rx_dropped++;
1976                 dev_kfree_skb(rx->skb);
1977                 break;
1978         case RX_QUEUED:
1979                 I802_DEBUG_INC(sdata->local->rx_handlers_queued);
1980                 break;
1981         }
1982 }
1983
1984 /* main receive path */
1985
1986 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
1987                                 struct ieee80211_rx_data *rx,
1988                                 struct ieee80211_hdr *hdr)
1989 {
1990         u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len, sdata->vif.type);
1991         int multicast = is_multicast_ether_addr(hdr->addr1);
1992
1993         switch (sdata->vif.type) {
1994         case NL80211_IFTYPE_STATION:
1995                 if (!bssid && !sdata->use_4addr)
1996                         return 0;
1997                 if (!multicast &&
1998                     compare_ether_addr(sdata->dev->dev_addr, hdr->addr1) != 0) {
1999                         if (!(sdata->dev->flags & IFF_PROMISC))
2000                                 return 0;
2001                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2002                 }
2003                 break;
2004         case NL80211_IFTYPE_ADHOC:
2005                 if (!bssid)
2006                         return 0;
2007                 if (ieee80211_is_beacon(hdr->frame_control)) {
2008                         return 1;
2009                 }
2010                 else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2011                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2012                                 return 0;
2013                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2014                 } else if (!multicast &&
2015                            compare_ether_addr(sdata->dev->dev_addr,
2016                                               hdr->addr1) != 0) {
2017                         if (!(sdata->dev->flags & IFF_PROMISC))
2018                                 return 0;
2019                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2020                 } else if (!rx->sta) {
2021                         int rate_idx;
2022                         if (rx->status->flag & RX_FLAG_HT)
2023                                 rate_idx = 0; /* TODO: HT rates */
2024                         else
2025                                 rate_idx = rx->status->rate_idx;
2026                         rx->sta = ieee80211_ibss_add_sta(sdata, bssid, hdr->addr2,
2027                                 BIT(rate_idx));
2028                 }
2029                 break;
2030         case NL80211_IFTYPE_MESH_POINT:
2031                 if (!multicast &&
2032                     compare_ether_addr(sdata->dev->dev_addr,
2033                                        hdr->addr1) != 0) {
2034                         if (!(sdata->dev->flags & IFF_PROMISC))
2035                                 return 0;
2036
2037                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2038                 }
2039                 break;
2040         case NL80211_IFTYPE_AP_VLAN:
2041         case NL80211_IFTYPE_AP:
2042                 if (!bssid) {
2043                         if (compare_ether_addr(sdata->dev->dev_addr,
2044                                                hdr->addr1))
2045                                 return 0;
2046                 } else if (!ieee80211_bssid_match(bssid,
2047                                         sdata->dev->dev_addr)) {
2048                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2049                                 return 0;
2050                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2051                 }
2052                 break;
2053         case NL80211_IFTYPE_WDS:
2054                 if (bssid || !ieee80211_is_data(hdr->frame_control))
2055                         return 0;
2056                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2057                         return 0;
2058                 break;
2059         case NL80211_IFTYPE_MONITOR:
2060         case NL80211_IFTYPE_UNSPECIFIED:
2061         case __NL80211_IFTYPE_AFTER_LAST:
2062                 /* should never get here */
2063                 WARN_ON(1);
2064                 break;
2065         }
2066
2067         return 1;
2068 }
2069
2070 /*
2071  * This is the actual Rx frames handler. as it blongs to Rx path it must
2072  * be called with rcu_read_lock protection.
2073  */
2074 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2075                                          struct sk_buff *skb,
2076                                          struct ieee80211_rate *rate)
2077 {
2078         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2079         struct ieee80211_local *local = hw_to_local(hw);
2080         struct ieee80211_sub_if_data *sdata;
2081         struct ieee80211_hdr *hdr;
2082         struct ieee80211_rx_data rx;
2083         int prepares;
2084         struct ieee80211_sub_if_data *prev = NULL;
2085         struct sk_buff *skb_new;
2086
2087         hdr = (struct ieee80211_hdr *)skb->data;
2088         memset(&rx, 0, sizeof(rx));
2089         rx.skb = skb;
2090         rx.local = local;
2091         rx.status = status;
2092         rx.rate = rate;
2093
2094         if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
2095                 local->dot11ReceivedFragmentCount++;
2096
2097         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
2098                      test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
2099                 rx.flags |= IEEE80211_RX_IN_SCAN;
2100
2101         ieee80211_parse_qos(&rx);
2102         ieee80211_verify_alignment(&rx);
2103
2104         rx.sta = sta_info_get(local, hdr->addr2);
2105         if (rx.sta) {
2106                 rx.sdata = rx.sta->sdata;
2107                 rx.dev = rx.sta->sdata->dev;
2108         }
2109
2110         if (rx.sdata && ieee80211_is_data(hdr->frame_control)) {
2111                 rx.flags |= IEEE80211_RX_RA_MATCH;
2112                 prepares = prepare_for_handlers(rx.sdata, &rx, hdr);
2113                 if (prepares) {
2114                         if (status->flag & RX_FLAG_MMIC_ERROR) {
2115                                 if (rx.flags & IEEE80211_RX_RA_MATCH)
2116                                         ieee80211_rx_michael_mic_report(hdr, &rx);
2117                         } else
2118                                 prev = rx.sdata;
2119                 }
2120         } else list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2121                 if (!netif_running(sdata->dev))
2122                         continue;
2123
2124                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2125                     sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2126                         continue;
2127
2128                 rx.flags |= IEEE80211_RX_RA_MATCH;
2129                 prepares = prepare_for_handlers(sdata, &rx, hdr);
2130
2131                 if (!prepares)
2132                         continue;
2133
2134                 if (status->flag & RX_FLAG_MMIC_ERROR) {
2135                         rx.sdata = sdata;
2136                         if (rx.flags & IEEE80211_RX_RA_MATCH)
2137                                 ieee80211_rx_michael_mic_report(hdr, &rx);
2138                         continue;
2139                 }
2140
2141                 /*
2142                  * frame is destined for this interface, but if it's not
2143                  * also for the previous one we handle that after the
2144                  * loop to avoid copying the SKB once too much
2145                  */
2146
2147                 if (!prev) {
2148                         prev = sdata;
2149                         continue;
2150                 }
2151
2152                 /*
2153                  * frame was destined for the previous interface
2154                  * so invoke RX handlers for it
2155                  */
2156
2157                 skb_new = skb_copy(skb, GFP_ATOMIC);
2158                 if (!skb_new) {
2159                         if (net_ratelimit())
2160                                 printk(KERN_DEBUG "%s: failed to copy "
2161                                        "multicast frame for %s\n",
2162                                        wiphy_name(local->hw.wiphy),
2163                                        prev->dev->name);
2164                         continue;
2165                 }
2166                 ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
2167                 prev = sdata;
2168         }
2169         if (prev)
2170                 ieee80211_invoke_rx_handlers(prev, &rx, skb);
2171         else
2172                 dev_kfree_skb(skb);
2173 }
2174
2175 #define SEQ_MODULO 0x1000
2176 #define SEQ_MASK   0xfff
2177
2178 static inline int seq_less(u16 sq1, u16 sq2)
2179 {
2180         return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
2181 }
2182
2183 static inline u16 seq_inc(u16 sq)
2184 {
2185         return (sq + 1) & SEQ_MASK;
2186 }
2187
2188 static inline u16 seq_sub(u16 sq1, u16 sq2)
2189 {
2190         return (sq1 - sq2) & SEQ_MASK;
2191 }
2192
2193
2194 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
2195                                             struct tid_ampdu_rx *tid_agg_rx,
2196                                             int index)
2197 {
2198         struct ieee80211_supported_band *sband;
2199         struct ieee80211_rate *rate;
2200         struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
2201         struct ieee80211_rx_status *status;
2202
2203         if (!skb)
2204                 goto no_frame;
2205
2206         status = IEEE80211_SKB_RXCB(skb);
2207
2208         /* release the reordered frames to stack */
2209         sband = hw->wiphy->bands[status->band];
2210         if (status->flag & RX_FLAG_HT)
2211                 rate = sband->bitrates; /* TODO: HT rates */
2212         else
2213                 rate = &sband->bitrates[status->rate_idx];
2214         __ieee80211_rx_handle_packet(hw, skb, rate);
2215         tid_agg_rx->stored_mpdu_num--;
2216         tid_agg_rx->reorder_buf[index] = NULL;
2217
2218 no_frame:
2219         tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2220 }
2221
2222 static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
2223                                              struct tid_ampdu_rx *tid_agg_rx,
2224                                              u16 head_seq_num)
2225 {
2226         int index;
2227
2228         while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
2229                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
2230                                                         tid_agg_rx->buf_size;
2231                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
2232         }
2233 }
2234
2235 /*
2236  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
2237  * the skb was added to the buffer longer than this time ago, the earlier
2238  * frames that have not yet been received are assumed to be lost and the skb
2239  * can be released for processing. This may also release other skb's from the
2240  * reorder buffer if there are no additional gaps between the frames.
2241  */
2242 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
2243
2244 /*
2245  * As this function belongs to the RX path it must be under
2246  * rcu_read_lock protection. It returns false if the frame
2247  * can be processed immediately, true if it was consumed.
2248  */
2249 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
2250                                              struct tid_ampdu_rx *tid_agg_rx,
2251                                              struct sk_buff *skb)
2252 {
2253         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2254         u16 sc = le16_to_cpu(hdr->seq_ctrl);
2255         u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2256         u16 head_seq_num, buf_size;
2257         int index;
2258
2259         buf_size = tid_agg_rx->buf_size;
2260         head_seq_num = tid_agg_rx->head_seq_num;
2261
2262         /* frame with out of date sequence number */
2263         if (seq_less(mpdu_seq_num, head_seq_num)) {
2264                 dev_kfree_skb(skb);
2265                 return true;
2266         }
2267
2268         /*
2269          * If frame the sequence number exceeds our buffering window
2270          * size release some previous frames to make room for this one.
2271          */
2272         if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
2273                 head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
2274                 /* release stored frames up to new head to stack */
2275                 ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num);
2276         }
2277
2278         /* Now the new frame is always in the range of the reordering buffer */
2279
2280         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size;
2281
2282         /* check if we already stored this frame */
2283         if (tid_agg_rx->reorder_buf[index]) {
2284                 dev_kfree_skb(skb);
2285                 return true;
2286         }
2287
2288         /*
2289          * If the current MPDU is in the right order and nothing else
2290          * is stored we can process it directly, no need to buffer it.
2291          */
2292         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
2293             tid_agg_rx->stored_mpdu_num == 0) {
2294                 tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2295                 return false;
2296         }
2297
2298         /* put the frame in the reordering buffer */
2299         tid_agg_rx->reorder_buf[index] = skb;
2300         tid_agg_rx->reorder_time[index] = jiffies;
2301         tid_agg_rx->stored_mpdu_num++;
2302         /* release the buffer until next missing frame */
2303         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
2304                                                 tid_agg_rx->buf_size;
2305         if (!tid_agg_rx->reorder_buf[index] &&
2306             tid_agg_rx->stored_mpdu_num > 1) {
2307                 /*
2308                  * No buffers ready to be released, but check whether any
2309                  * frames in the reorder buffer have timed out.
2310                  */
2311                 int j;
2312                 int skipped = 1;
2313                 for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
2314                      j = (j + 1) % tid_agg_rx->buf_size) {
2315                         if (!tid_agg_rx->reorder_buf[j]) {
2316                                 skipped++;
2317                                 continue;
2318                         }
2319                         if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
2320                                         HT_RX_REORDER_BUF_TIMEOUT))
2321                                 break;
2322
2323 #ifdef CONFIG_MAC80211_HT_DEBUG
2324                         if (net_ratelimit())
2325                                 printk(KERN_DEBUG "%s: release an RX reorder "
2326                                        "frame due to timeout on earlier "
2327                                        "frames\n",
2328                                        wiphy_name(hw->wiphy));
2329 #endif
2330                         ieee80211_release_reorder_frame(hw, tid_agg_rx, j);
2331
2332                         /*
2333                          * Increment the head seq# also for the skipped slots.
2334                          */
2335                         tid_agg_rx->head_seq_num =
2336                                 (tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
2337                         skipped = 0;
2338                 }
2339         } else while (tid_agg_rx->reorder_buf[index]) {
2340                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
2341                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
2342                                                         tid_agg_rx->buf_size;
2343         }
2344
2345         return true;
2346 }
2347
2348 /*
2349  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
2350  * true if the MPDU was buffered, false if it should be processed.
2351  */
2352 static bool ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
2353                                        struct sk_buff *skb)
2354 {
2355         struct ieee80211_hw *hw = &local->hw;
2356         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2357         struct sta_info *sta;
2358         struct tid_ampdu_rx *tid_agg_rx;
2359         u16 sc;
2360         int tid;
2361
2362         if (!ieee80211_is_data_qos(hdr->frame_control))
2363                 return false;
2364
2365         /*
2366          * filter the QoS data rx stream according to
2367          * STA/TID and check if this STA/TID is on aggregation
2368          */
2369
2370         sta = sta_info_get(local, hdr->addr2);
2371         if (!sta)
2372                 return false;
2373
2374         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
2375
2376         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
2377                 return false;
2378
2379         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
2380
2381         /* qos null data frames are excluded */
2382         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
2383                 return false;
2384
2385         /* new, potentially un-ordered, ampdu frame - process it */
2386
2387         /* reset session timer */
2388         if (tid_agg_rx->timeout)
2389                 mod_timer(&tid_agg_rx->session_timer,
2390                           TU_TO_EXP_TIME(tid_agg_rx->timeout));
2391
2392         /* if this mpdu is fragmented - terminate rx aggregation session */
2393         sc = le16_to_cpu(hdr->seq_ctrl);
2394         if (sc & IEEE80211_SCTL_FRAG) {
2395                 ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
2396                         tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
2397                 dev_kfree_skb(skb);
2398                 return true;
2399         }
2400
2401         return ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb);
2402 }
2403
2404 /*
2405  * This is the receive path handler. It is called by a low level driver when an
2406  * 802.11 MPDU is received from the hardware.
2407  */
2408 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2409 {
2410         struct ieee80211_local *local = hw_to_local(hw);
2411         struct ieee80211_rate *rate = NULL;
2412         struct ieee80211_supported_band *sband;
2413         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2414
2415         WARN_ON_ONCE(softirq_count() == 0);
2416
2417         if (WARN_ON(status->band < 0 ||
2418                     status->band >= IEEE80211_NUM_BANDS))
2419                 goto drop;
2420
2421         sband = local->hw.wiphy->bands[status->band];
2422         if (WARN_ON(!sband))
2423                 goto drop;
2424
2425         /*
2426          * If we're suspending, it is possible although not too likely
2427          * that we'd be receiving frames after having already partially
2428          * quiesced the stack. We can't process such frames then since
2429          * that might, for example, cause stations to be added or other
2430          * driver callbacks be invoked.
2431          */
2432         if (unlikely(local->quiescing || local->suspended))
2433                 goto drop;
2434
2435         /*
2436          * The same happens when we're not even started,
2437          * but that's worth a warning.
2438          */
2439         if (WARN_ON(!local->started))
2440                 goto drop;
2441
2442         if (status->flag & RX_FLAG_HT) {
2443                 /*
2444                  * rate_idx is MCS index, which can be [0-76] as documented on:
2445                  *
2446                  * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
2447                  *
2448                  * Anything else would be some sort of driver or hardware error.
2449                  * The driver should catch hardware errors.
2450                  */
2451                 if (WARN((status->rate_idx < 0 ||
2452                          status->rate_idx > 76),
2453                          "Rate marked as an HT rate but passed "
2454                          "status->rate_idx is not "
2455                          "an MCS index [0-76]: %d (0x%02x)\n",
2456                          status->rate_idx,
2457                          status->rate_idx))
2458                         goto drop;
2459                 /* HT rates are not in the table - use the highest legacy rate
2460                  * for now since other parts of mac80211 may not yet be fully
2461                  * MCS aware. */
2462                 rate = &sband->bitrates[sband->n_bitrates - 1];
2463         } else {
2464                 if (WARN_ON(status->rate_idx < 0 ||
2465                             status->rate_idx >= sband->n_bitrates))
2466                         goto drop;
2467                 rate = &sband->bitrates[status->rate_idx];
2468         }
2469
2470         /*
2471          * key references and virtual interfaces are protected using RCU
2472          * and this requires that we are in a read-side RCU section during
2473          * receive processing
2474          */
2475         rcu_read_lock();
2476
2477         /*
2478          * Frames with failed FCS/PLCP checksum are not returned,
2479          * all other frames are returned without radiotap header
2480          * if it was previously present.
2481          * Also, frames with less than 16 bytes are dropped.
2482          */
2483         skb = ieee80211_rx_monitor(local, skb, rate);
2484         if (!skb) {
2485                 rcu_read_unlock();
2486                 return;
2487         }
2488
2489         /*
2490          * In theory, the block ack reordering should happen after duplicate
2491          * removal (ieee80211_rx_h_check(), which is an RX handler). As such,
2492          * the call to ieee80211_rx_reorder_ampdu() should really be moved to
2493          * happen as a new RX handler between ieee80211_rx_h_check and
2494          * ieee80211_rx_h_decrypt. This cleanup may eventually happen, but for
2495          * the time being, the call can be here since RX reorder buf processing
2496          * will implicitly skip duplicates. We could, in theory at least,
2497          * process frames that ieee80211_rx_h_passive_scan would drop (e.g.,
2498          * frames from other than operational channel), but that should not
2499          * happen in normal networks.
2500          */
2501         if (!ieee80211_rx_reorder_ampdu(local, skb))
2502                 __ieee80211_rx_handle_packet(hw, skb, rate);
2503
2504         rcu_read_unlock();
2505
2506         return;
2507  drop:
2508         kfree_skb(skb);
2509 }
2510 EXPORT_SYMBOL(ieee80211_rx);
2511
2512 /* This is a version of the rx handler that can be called from hard irq
2513  * context. Post the skb on the queue and schedule the tasklet */
2514 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
2515 {
2516         struct ieee80211_local *local = hw_to_local(hw);
2517
2518         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2519
2520         skb->pkt_type = IEEE80211_RX_MSG;
2521         skb_queue_tail(&local->skb_queue, skb);
2522         tasklet_schedule(&local->tasklet);
2523 }
2524 EXPORT_SYMBOL(ieee80211_rx_irqsafe);